1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions for handling an incoming SMTP call. */
15 /* Initialize for TCP wrappers if so configured. It appears that the macro
16 HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
17 including that header, and restore its value afterwards. */
19 #ifdef USE_TCP_WRAPPERS
22 #define EXIM_HAVE_IPV6
28 #define HAVE_IPV6 TRUE
31 int allow_severity
= LOG_INFO
;
32 int deny_severity
= LOG_NOTICE
;
33 uschar
*tcp_wrappers_name
;
37 /* Size of buffer for reading SMTP commands. We used to use 512, as defined
38 by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
39 commands that accept arguments, and this in particular applies to AUTH, where
40 the data can be quite long. More recently this value was 2048 in Exim;
41 however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
42 such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
43 The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
44 we need room to handle large base64-encoded AUTHs for GSSAPI.
47 #define SMTP_CMD_BUFFER_SIZE 16384
49 /* Size of buffer for reading SMTP incoming packets */
51 #define IN_BUFFER_SIZE 8192
53 /* Structure for SMTP command list */
60 short int is_mail_cmd
;
63 /* Codes for identifying commands. We order them so that those that come first
64 are those for which synchronization is always required. Checking this can help
68 /* These commands are required to be synchronized, i.e. to be the last in a
69 block of commands when pipelining. */
71 HELO_CMD
, EHLO_CMD
, DATA_CMD
, /* These are listed in the pipelining */
72 VRFY_CMD
, EXPN_CMD
, NOOP_CMD
, /* RFC as requiring synchronization */
73 ETRN_CMD
, /* This by analogy with TURN from the RFC */
74 STARTTLS_CMD
, /* Required by the STARTTLS RFC */
75 TLS_AUTH_CMD
, /* auto-command at start of SSL */
77 /* This is a dummy to identify the non-sync commands when pipelining */
79 NON_SYNC_CMD_PIPELINING
,
81 /* These commands need not be synchronized when pipelining */
83 MAIL_CMD
, RCPT_CMD
, RSET_CMD
,
85 /* This is a dummy to identify the non-sync commands when not pipelining */
87 NON_SYNC_CMD_NON_PIPELINING
,
89 /* RFC3030 section 2: "After all MAIL and RCPT responses are collected and
90 processed the message is sent using a series of BDAT commands"
91 implies that BDAT should be synchronized. However, we see Google, at least,
92 sending MAIL,RCPT,BDAT-LAST in a single packet, clearly not waiting for
93 processing of the RCPT response(s). We shall do the same, and not require
94 synch for BDAT. Worse, as the chunk may (very likely will) follow the
95 command-header in the same packet we cannot do the usual "is there any
96 follow-on data after the command line" even for non-pipeline mode.
97 So we'll need an explicit check after reading the expected chunk amount
98 when non-pipe, before sending the ACK. */
102 /* I have been unable to find a statement about the use of pipelining
103 with AUTH, so to be on the safe side it is here, though I kind of feel
104 it should be up there with the synchronized commands. */
108 /* I'm not sure about these, but I don't think they matter. */
113 PROXY_FAIL_IGNORE_CMD
,
116 /* These are specials that don't correspond to actual commands */
118 EOF_CMD
, OTHER_CMD
, BADARG_CMD
, BADCHAR_CMD
, BADSYN_CMD
,
119 TOO_MANY_NONMAIL_CMD
};
122 /* This is a convenience macro for adding the identity of an SMTP command
123 to the circular buffer that holds a list of the last n received. */
126 smtp_connection_had[smtp_ch_index++] = n; \
127 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
130 /*************************************************
131 * Local static variables *
132 *************************************************/
135 BOOL auth_advertised
:1;
137 BOOL tls_advertised
:1;
139 BOOL dsn_advertised
:1;
141 BOOL helo_required
:1;
144 BOOL helo_accept_junk
:1;
145 #ifndef DISABLE_PIPE_CONNECT
146 BOOL pipe_connect_acceptable
:1;
148 BOOL rcpt_smtp_response_same
:1;
149 BOOL rcpt_in_progress
:1;
150 BOOL smtp_exit_function_called
:1;
152 BOOL smtputf8_advertised
:1;
155 .helo_required
= FALSE
,
156 .helo_verify
= FALSE
,
157 .smtp_exit_function_called
= FALSE
,
160 static auth_instance
*authenticated_by
;
161 static int count_nonmail
;
162 static int nonmail_command_count
;
163 static int synprot_error_count
;
164 static int unknown_command_count
;
165 static int sync_cmd_limit
;
166 static int smtp_write_error
= 0;
168 static uschar
*rcpt_smtp_response
;
169 static uschar
*smtp_data_buffer
;
170 static uschar
*smtp_cmd_data
;
172 /* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
173 final fields of all except AUTH are forced TRUE at the start of a new message
174 setup, to allow one of each between messages that is not counted as a nonmail
175 command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
176 allow a new EHLO after starting up TLS.
178 AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
179 counted. However, the flag is changed when AUTH is received, so that multiple
180 failing AUTHs will eventually hit the limit. After a successful AUTH, another
181 AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
182 forced TRUE, to allow for the re-authentication that can happen at that point.
184 QUIT is also "falsely" labelled as a mail command so that it doesn't up the
185 count of non-mail commands and possibly provoke an error.
187 tls_auth is a pseudo-command, never expected in input. It is activated
188 on TLS startup and looks for a tls authenticator. */
190 static smtp_cmd_list cmd_list
[] = {
191 /* name len cmd has_arg is_mail_cmd */
193 { "rset", sizeof("rset")-1, RSET_CMD
, FALSE
, FALSE
}, /* First */
194 { "helo", sizeof("helo")-1, HELO_CMD
, TRUE
, FALSE
},
195 { "ehlo", sizeof("ehlo")-1, EHLO_CMD
, TRUE
, FALSE
},
196 { "auth", sizeof("auth")-1, AUTH_CMD
, TRUE
, TRUE
},
198 { "starttls", sizeof("starttls")-1, STARTTLS_CMD
, FALSE
, FALSE
},
199 { "tls_auth", 0, TLS_AUTH_CMD
, FALSE
, FALSE
},
202 /* If you change anything above here, also fix the definitions below. */
204 { "mail from:", sizeof("mail from:")-1, MAIL_CMD
, TRUE
, TRUE
},
205 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD
, TRUE
, TRUE
},
206 { "data", sizeof("data")-1, DATA_CMD
, FALSE
, TRUE
},
207 { "bdat", sizeof("bdat")-1, BDAT_CMD
, TRUE
, TRUE
},
208 { "quit", sizeof("quit")-1, QUIT_CMD
, FALSE
, TRUE
},
209 { "noop", sizeof("noop")-1, NOOP_CMD
, TRUE
, FALSE
},
210 { "etrn", sizeof("etrn")-1, ETRN_CMD
, TRUE
, FALSE
},
211 { "vrfy", sizeof("vrfy")-1, VRFY_CMD
, TRUE
, FALSE
},
212 { "expn", sizeof("expn")-1, EXPN_CMD
, TRUE
, FALSE
},
213 { "help", sizeof("help")-1, HELP_CMD
, TRUE
, FALSE
}
216 static smtp_cmd_list
*cmd_list_end
=
217 cmd_list
+ sizeof(cmd_list
)/sizeof(smtp_cmd_list
);
219 #define CMD_LIST_RSET 0
220 #define CMD_LIST_HELO 1
221 #define CMD_LIST_EHLO 2
222 #define CMD_LIST_AUTH 3
223 #define CMD_LIST_STARTTLS 4
224 #define CMD_LIST_TLS_AUTH 5
226 /* This list of names is used for performing the smtp_no_mail logging action.
227 It must be kept in step with the SCH_xxx enumerations. */
229 static uschar
*smtp_names
[] =
231 US
"NONE", US
"AUTH", US
"DATA", US
"BDAT", US
"EHLO", US
"ETRN", US
"EXPN",
232 US
"HELO", US
"HELP", US
"MAIL", US
"NOOP", US
"QUIT", US
"RCPT", US
"RSET",
233 US
"STARTTLS", US
"VRFY" };
235 static uschar
*protocols_local
[] = {
236 US
"local-smtp", /* HELO */
237 US
"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
238 US
"local-esmtp", /* EHLO */
239 US
"local-esmtps", /* EHLO->STARTTLS->EHLO */
240 US
"local-esmtpa", /* EHLO->AUTH */
241 US
"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
243 static uschar
*protocols
[] = {
245 US
"smtps", /* The rare case EHLO->STARTTLS->HELO */
246 US
"esmtp", /* EHLO */
247 US
"esmtps", /* EHLO->STARTTLS->EHLO */
248 US
"esmtpa", /* EHLO->AUTH */
249 US
"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
254 #define pcrpted 1 /* added to pextend or pnormal */
255 #define pauthed 2 /* added to pextend */
257 /* Sanity check and validate optional args to MAIL FROM: envelope */
260 ENV_MAIL_OPT_SIZE
, ENV_MAIL_OPT_BODY
, ENV_MAIL_OPT_AUTH
,
264 ENV_MAIL_OPT_RET
, ENV_MAIL_OPT_ENVID
,
270 uschar
* name
; /* option requested during MAIL cmd */
271 int value
; /* enum type */
272 BOOL need_value
; /* TRUE requires value (name=value pair format)
273 FALSE is a singleton */
275 static env_mail_type_t env_mail_type_list
[] = {
276 { US
"SIZE", ENV_MAIL_OPT_SIZE
, TRUE
},
277 { US
"BODY", ENV_MAIL_OPT_BODY
, TRUE
},
278 { US
"AUTH", ENV_MAIL_OPT_AUTH
, TRUE
},
280 { US
"PRDR", ENV_MAIL_OPT_PRDR
, FALSE
},
282 { US
"RET", ENV_MAIL_OPT_RET
, TRUE
},
283 { US
"ENVID", ENV_MAIL_OPT_ENVID
, TRUE
},
285 { US
"SMTPUTF8",ENV_MAIL_OPT_UTF8
, FALSE
}, /* rfc6531 */
287 /* keep this the last entry */
288 { US
"NULL", ENV_MAIL_OPT_NULL
, FALSE
},
291 /* When reading SMTP from a remote host, we have to use our own versions of the
292 C input-reading functions, in order to be able to flush the SMTP output only
293 when about to read more data from the socket. This is the only way to get
294 optimal performance when the client is using pipelining. Flushing for every
295 command causes a separate packet and reply packet each time; saving all the
296 responses up (when pipelining) combines them into one packet and one response.
298 For simplicity, these functions are used for *all* SMTP input, not only when
299 receiving over a socket. However, after setting up a secure socket (SSL), input
300 is read via the OpenSSL library, and another set of functions is used instead
303 These functions are set in the receive_getc etc. variables and called with the
304 same interface as the C functions. However, since there can only ever be
305 one incoming SMTP call, we just use a single buffer and flags. There is no need
306 to implement a complicated private FILE-like structure.*/
308 static uschar
*smtp_inbuffer
;
309 static uschar
*smtp_inptr
;
310 static uschar
*smtp_inend
;
311 static int smtp_had_eof
;
312 static int smtp_had_error
;
315 /* forward declarations */
316 static int smtp_read_command(BOOL check_sync
, unsigned buffer_lim
);
317 static int synprot_error(int type
, int code
, uschar
*data
, uschar
*errmess
);
318 static void smtp_quit_handler(uschar
**, uschar
**);
319 static void smtp_rset_handler(void);
321 /*************************************************
322 * Recheck synchronization *
323 *************************************************/
325 /* Synchronization checks can never be perfect because a packet may be on its
326 way but not arrived when the check is done. Normally, the checks happen when
327 commands are read: Exim ensures that there is no more input in the input buffer.
328 In normal cases, the response to the command will be fast, and there is no
331 However, for some commands an ACL is run, and that can include delays. In those
332 cases, it is useful to do another check on the input just before sending the
333 response. This also applies at the start of a connection. This function does
334 that check by means of the select() function, as long as the facility is not
335 disabled or inappropriate. A failure of select() is ignored.
337 When there is unwanted input, we read it so that it appears in the log of the
341 Returns: TRUE if all is well; FALSE if there is input pending
345 wouldblock_reading(void)
349 struct timeval tzero
;
352 if (tls_in
.active
.sock
>= 0)
353 return !tls_could_read();
356 if (smtp_inptr
< smtp_inend
)
359 fd
= fileno(smtp_in
);
364 rc
= select(fd
+ 1, (SELECT_ARG2_TYPE
*)&fds
, NULL
, NULL
, &tzero
);
366 if (rc
<= 0) return TRUE
; /* Not ready to read */
367 rc
= smtp_getc(GETC_BUFFER_UNLIMITED
);
368 if (rc
< 0) return TRUE
; /* End of file or error */
377 if (!smtp_enforce_sync
|| !sender_host_address
|| f
.sender_host_notsocket
)
380 return wouldblock_reading();
384 /* If there's input waiting (and we're doing pipelineing) then we can pipeline
385 a reponse with the one following. */
388 pipeline_response(void)
390 if ( !smtp_enforce_sync
|| !sender_host_address
391 || f
.sender_host_notsocket
|| !f
.smtp_in_pipelining_advertised
)
394 if (wouldblock_reading()) return FALSE
;
395 f
.smtp_in_pipelining_used
= TRUE
;
400 #ifndef DISABLE_PIPE_CONNECT
402 pipeline_connect_sends(void)
404 if (!sender_host_address
|| f
.sender_host_notsocket
|| !fl
.pipe_connect_acceptable
)
407 if (wouldblock_reading()) return FALSE
;
408 f
.smtp_in_early_pipe_used
= TRUE
;
413 /*************************************************
414 * Log incomplete transactions *
415 *************************************************/
417 /* This function is called after a transaction has been aborted by RSET, QUIT,
418 connection drops or other errors. It logs the envelope information received
419 so far in order to preserve address verification attempts.
421 Argument: string to indicate what aborted the transaction
426 incomplete_transaction_log(uschar
*what
)
428 if (!sender_address
/* No transaction in progress */
429 || !LOGGING(smtp_incomplete_transaction
))
432 /* Build list of recipients for logging */
434 if (recipients_count
> 0)
436 raw_recipients
= store_get(recipients_count
* sizeof(uschar
*), FALSE
);
437 for (int i
= 0; i
< recipients_count
; i
++)
438 raw_recipients
[i
] = recipients_list
[i
].address
;
439 raw_recipients_count
= recipients_count
;
442 log_write(L_smtp_incomplete_transaction
, LOG_MAIN
|LOG_SENDER
|LOG_RECIPIENTS
,
443 "%s incomplete transaction (%s)", host_and_ident(TRUE
), what
);
450 smtp_command_timeout_exit(void)
452 log_write(L_lost_incoming_connection
,
453 LOG_MAIN
, "SMTP command timeout on%s connection from %s",
454 tls_in
.active
.sock
>= 0 ? " TLS" : "", host_and_ident(FALSE
));
455 if (smtp_batched_input
)
456 moan_smtp_batch(NULL
, "421 SMTP command timeout"); /* Does not return */
457 smtp_notquit_exit(US
"command-timeout", US
"421",
458 US
"%s: SMTP command timeout - closing connection",
459 smtp_active_hostname
);
460 exim_exit(EXIT_FAILURE
, US
"receiving");
464 smtp_command_sigterm_exit(void)
466 log_write(0, LOG_MAIN
, "%s closed after SIGTERM", smtp_get_connection_info());
467 if (smtp_batched_input
)
468 moan_smtp_batch(NULL
, "421 SIGTERM received"); /* Does not return */
469 smtp_notquit_exit(US
"signal-exit", US
"421",
470 US
"%s: Service not available - closing connection", smtp_active_hostname
);
471 exim_exit(EXIT_FAILURE
, US
"receiving");
475 smtp_data_timeout_exit(void)
477 log_write(L_lost_incoming_connection
,
478 LOG_MAIN
, "SMTP data timeout (message abandoned) on connection from %s F=<%s>",
479 sender_fullhost
? sender_fullhost
: US
"local process", sender_address
);
480 receive_bomb_out(US
"data-timeout", US
"SMTP incoming data timeout");
481 /* Does not return */
485 smtp_data_sigint_exit(void)
487 log_write(0, LOG_MAIN
, "%s closed after %s",
488 smtp_get_connection_info(), had_data_sigint
== SIGTERM
? "SIGTERM":"SIGINT");
489 receive_bomb_out(US
"signal-exit",
490 US
"Service not available - SIGTERM or SIGINT received");
491 /* Does not return */
496 /* Refill the buffer, and notify DKIM verification code.
497 Return false for error or EOF.
501 smtp_refill(unsigned lim
)
504 if (!smtp_out
) return FALSE
;
506 if (smtp_receive_timeout
> 0) ALARM(smtp_receive_timeout
);
508 /* Limit amount read, so non-message data is not fed to DKIM.
509 Take care to not touch the safety NUL at the end of the buffer. */
511 rc
= read(fileno(smtp_in
), smtp_inbuffer
, MIN(IN_BUFFER_SIZE
-1, lim
));
513 if (smtp_receive_timeout
> 0) ALARM_CLR(0);
516 /* Must put the error text in fixed store, because this might be during
517 header reading, where it releases unused store above the header. */
520 if (had_command_timeout
) /* set by signal handler */
521 smtp_command_timeout_exit(); /* does not return */
522 if (had_command_sigterm
)
523 smtp_command_sigterm_exit();
524 if (had_data_timeout
)
525 smtp_data_timeout_exit();
527 smtp_data_sigint_exit();
529 smtp_had_error
= save_errno
;
530 smtp_read_error
= string_copy_perm(
531 string_sprintf(" (error: %s)", strerror(save_errno
)), FALSE
);
538 dkim_exim_verify_feed(smtp_inbuffer
, rc
);
540 smtp_inend
= smtp_inbuffer
+ rc
;
541 smtp_inptr
= smtp_inbuffer
;
545 /*************************************************
546 * SMTP version of getc() *
547 *************************************************/
549 /* This gets the next byte from the SMTP input buffer. If the buffer is empty,
550 it flushes the output, and refills the buffer, with a timeout. The signal
551 handler is set appropriately by the calling function. This function is not used
552 after a connection has negotiated itself into an TLS/SSL state.
554 Arguments: lim Maximum amount to read/buffer
555 Returns: the next character or EOF
559 smtp_getc(unsigned lim
)
561 if (smtp_inptr
>= smtp_inend
)
562 if (!smtp_refill(lim
))
564 return *smtp_inptr
++;
568 smtp_getbuf(unsigned * len
)
573 if (smtp_inptr
>= smtp_inend
)
574 if (!smtp_refill(*len
))
575 { *len
= 0; return NULL
; }
577 if ((size
= smtp_inend
- smtp_inptr
) > *len
) size
= *len
;
588 int n
= smtp_inend
- smtp_inptr
;
590 dkim_exim_verify_feed(smtp_inptr
, n
);
595 /* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
596 previous BDAT chunk and getting new ones when we run out. Uses the
597 underlying smtp_getc or tls_getc both for that and for getting the
598 (buffered) data byte. EOD signals (an expected) no further data.
599 ERR signals a protocol error, and EOF a closed input stream.
601 Called from read_bdat_smtp() in receive.c for the message body, but also
602 by the headers read loop in receive_msg(); manipulates chunking_state
603 to handle the BDAT command/response.
604 Placed here due to the correlation with the above smtp_getc(), which it wraps,
605 and also by the need to do smtp command/response handling.
607 Arguments: lim (ignored)
608 Returns: the next character or ERR, EOD or EOF
612 bdat_getc(unsigned lim
)
614 uschar
* user_msg
= NULL
;
623 if (chunking_data_left
> 0)
624 return lwr_receive_getc(chunking_data_left
--);
626 receive_getc
= lwr_receive_getc
;
627 receive_getbuf
= lwr_receive_getbuf
;
628 receive_ungetc
= lwr_receive_ungetc
;
630 dkim_save
= dkim_collect_input
;
631 dkim_collect_input
= 0;
634 /* Unless PIPELINING was offered, there should be no next command
635 until after we ack that chunk */
637 if (!f
.smtp_in_pipelining_advertised
&& !check_sync())
639 unsigned n
= smtp_inend
- smtp_inptr
;
642 incomplete_transaction_log(US
"sync failure");
643 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP protocol synchronization error "
644 "(next input sent too soon: pipelining was not advertised): "
645 "rejected \"%s\" %s next input=\"%s\"%s",
646 smtp_cmd_buffer
, host_and_ident(TRUE
),
647 string_printing(string_copyn(smtp_inptr
, n
)),
648 smtp_inend
- smtp_inptr
> n
? "..." : "");
649 (void) synprot_error(L_smtp_protocol_error
, 554, NULL
,
650 US
"SMTP synchronization error");
651 goto repeat_until_rset
;
654 /* If not the last, ack the received chunk. The last response is delayed
655 until after the data ACL decides on it */
657 if (chunking_state
== CHUNKING_LAST
)
660 dkim_exim_verify_feed(NULL
, 0); /* notify EOD */
665 smtp_printf("250 %u byte chunk received\r\n", FALSE
, chunking_datasize
);
666 chunking_state
= CHUNKING_OFFERED
;
667 DEBUG(D_receive
) debug_printf("chunking state %d\n", (int)chunking_state
);
669 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
670 QUIT, RSET or NOOP but handling them seems obvious */
673 switch(smtp_read_command(TRUE
, 1))
676 (void) synprot_error(L_smtp_protocol_error
, 503, NULL
,
677 US
"only BDAT permissible after non-LAST BDAT");
680 switch(smtp_read_command(TRUE
, 1))
682 case QUIT_CMD
: smtp_quit_handler(&user_msg
, &log_msg
); /*FALLTHROUGH */
683 case EOF_CMD
: return EOF
;
684 case RSET_CMD
: smtp_rset_handler(); return ERR
;
685 default: if (synprot_error(L_smtp_protocol_error
, 503, NULL
,
686 US
"only RSET accepted now") > 0)
688 goto repeat_until_rset
;
692 smtp_quit_handler(&user_msg
, &log_msg
);
703 smtp_printf("250 OK\r\n", FALSE
);
710 if (sscanf(CS smtp_cmd_data
, "%u %n", &chunking_datasize
, &n
) < 1)
712 (void) synprot_error(L_smtp_protocol_error
, 501, NULL
,
713 US
"missing size for BDAT command");
716 chunking_state
= strcmpic(smtp_cmd_data
+n
, US
"LAST") == 0
717 ? CHUNKING_LAST
: CHUNKING_ACTIVE
;
718 chunking_data_left
= chunking_datasize
;
719 DEBUG(D_receive
) debug_printf("chunking state %d, %d bytes\n",
720 (int)chunking_state
, chunking_data_left
);
722 if (chunking_datasize
== 0)
723 if (chunking_state
== CHUNKING_LAST
)
727 (void) synprot_error(L_smtp_protocol_error
, 504, NULL
,
728 US
"zero size for BDAT command");
729 goto repeat_until_rset
;
732 receive_getc
= bdat_getc
;
733 receive_getbuf
= bdat_getbuf
; /* r~getbuf is never actually used */
734 receive_ungetc
= bdat_ungetc
;
736 dkim_collect_input
= dkim_save
;
738 break; /* to top of main loop */
745 bdat_getbuf(unsigned * len
)
749 if (chunking_data_left
<= 0)
750 { *len
= 0; return NULL
; }
752 if (*len
> chunking_data_left
) *len
= chunking_data_left
;
753 buf
= lwr_receive_getbuf(len
); /* Either smtp_getbuf or tls_getbuf */
754 chunking_data_left
-= *len
;
759 bdat_flush_data(void)
761 while (chunking_data_left
)
763 unsigned n
= chunking_data_left
;
764 if (!bdat_getbuf(&n
)) break;
767 receive_getc
= lwr_receive_getc
;
768 receive_getbuf
= lwr_receive_getbuf
;
769 receive_ungetc
= lwr_receive_ungetc
;
771 if (chunking_state
!= CHUNKING_LAST
)
773 chunking_state
= CHUNKING_OFFERED
;
774 DEBUG(D_receive
) debug_printf("chunking state %d\n", (int)chunking_state
);
781 /*************************************************
782 * SMTP version of ungetc() *
783 *************************************************/
785 /* Puts a character back in the input buffer. Only ever
791 Returns: the character
805 chunking_data_left
++;
806 return lwr_receive_ungetc(ch
);
811 /*************************************************
812 * SMTP version of feof() *
813 *************************************************/
815 /* Tests for a previous EOF
818 Returns: non-zero if the eof flag is set
830 /*************************************************
831 * SMTP version of ferror() *
832 *************************************************/
834 /* Tests for a previous read error, and returns with errno
835 restored to what it was when the error was detected.
838 Returns: non-zero if the error flag is set
844 errno
= smtp_had_error
;
845 return smtp_had_error
;
850 /*************************************************
851 * Test for characters in the SMTP buffer *
852 *************************************************/
854 /* Used at the end of a message
863 return smtp_inptr
< smtp_inend
;
868 /*************************************************
869 * Write formatted string to SMTP channel *
870 *************************************************/
872 /* This is a separate function so that we don't have to repeat everything for
873 TLS support or debugging. It is global so that the daemon and the
874 authentication functions can use it. It does not return any error indication,
875 because major problems such as dropped connections won't show up till an output
876 flush for non-TLS connections. The smtp_fflush() function is available for
877 checking that: for convenience, TLS output errors are remembered here so that
878 they are also picked up later by smtp_fflush().
882 more further data expected
883 ... optional arguments
889 smtp_printf(const char *format
, BOOL more
, ...)
894 smtp_vprintf(format
, more
, ap
);
898 /* This is split off so that verify.c:respond_printf() can, in effect, call
899 smtp_printf(), bearing in mind that in C a vararg function can't directly
900 call another vararg function, only a function which accepts a va_list. */
901 /*XXX consider passing caller-info in, for string_vformat-onward */
904 smtp_vprintf(const char *format
, BOOL more
, va_list ap
)
906 gstring gs
= { .size
= big_buffer_size
, .ptr
= 0, .s
= big_buffer
};
909 /* Use taint-unchecked routines for writing into big_buffer, trusting
910 that we'll never expand it. */
912 yield
= !! string_vformat(&gs
, SVFMT_TAINT_NOCHK
, format
, ap
);
913 string_from_gstring(&gs
);
917 uschar
*msg_copy
, *cr
, *end
;
918 msg_copy
= string_copy(gs
.s
);
919 end
= msg_copy
+ gs
.ptr
;
920 while ((cr
= Ustrchr(msg_copy
, '\r')) != NULL
) /* lose CRs */
921 memmove(cr
, cr
+ 1, (end
--) - cr
);
922 debug_printf("SMTP>> %s", msg_copy
);
927 log_write(0, LOG_MAIN
|LOG_PANIC
, "string too large in smtp_printf()");
928 smtp_closedown(US
"Unexpected error");
929 exim_exit(EXIT_FAILURE
, NULL
);
932 /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
933 have had the same. Note: this code is also present in smtp_respond(). It would
934 be tidier to have it only in one place, but when it was added, it was easier to
935 do it that way, so as not to have to mess with the code for the RCPT command,
936 which sometimes uses smtp_printf() and sometimes smtp_respond(). */
938 if (fl
.rcpt_in_progress
)
940 if (rcpt_smtp_response
== NULL
)
941 rcpt_smtp_response
= string_copy(big_buffer
);
942 else if (fl
.rcpt_smtp_response_same
&&
943 Ustrcmp(rcpt_smtp_response
, big_buffer
) != 0)
944 fl
.rcpt_smtp_response_same
= FALSE
;
945 fl
.rcpt_in_progress
= FALSE
;
948 /* Now write the string */
952 tls_in
.active
.sock
>= 0 ? (tls_write(NULL
, gs
.s
, gs
.ptr
, more
) < 0) :
954 (fwrite(gs
.s
, gs
.ptr
, 1, smtp_out
) == 0)
956 smtp_write_error
= -1;
961 /*************************************************
962 * Flush SMTP out and check for error *
963 *************************************************/
965 /* This function isn't currently used within Exim (it detects errors when it
966 tries to read the next SMTP input), but is available for use in local_scan().
967 It flushes the output and checks for errors.
970 Returns: 0 for no error; -1 after an error
976 if (tls_in
.active
.sock
< 0 && fflush(smtp_out
) != 0) smtp_write_error
= -1;
980 tls_in
.active
.sock
>= 0 ? (tls_write(NULL
, NULL
, 0, FALSE
) < 0) :
982 (fflush(smtp_out
) != 0)
984 smtp_write_error
= -1;
986 return smtp_write_error
;
991 /*************************************************
992 * SMTP command read timeout *
993 *************************************************/
995 /* Signal handler for timing out incoming SMTP commands. This attempts to
998 Argument: signal number (SIGALRM)
1003 command_timeout_handler(int sig
)
1005 had_command_timeout
= sig
;
1010 /*************************************************
1011 * SIGTERM received *
1012 *************************************************/
1014 /* Signal handler for handling SIGTERM. Again, try to finish tidily.
1016 Argument: signal number (SIGTERM)
1021 command_sigterm_handler(int sig
)
1023 had_command_sigterm
= sig
;
1029 #ifdef SUPPORT_PROXY
1030 /*************************************************
1031 * Restore socket timeout to previous value *
1032 *************************************************/
1033 /* If the previous value was successfully retrieved, restore
1034 it before returning control to the non-proxy routines
1036 Arguments: fd - File descriptor for input
1037 get_ok - Successfully retrieved previous values
1038 tvtmp - Time struct with previous values
1039 vslen - Length of time struct
1043 restore_socket_timeout(int fd
, int get_ok
, struct timeval
* tvtmp
, socklen_t vslen
)
1046 (void) setsockopt(fd
, SOL_SOCKET
, SO_RCVTIMEO
, CS tvtmp
, vslen
);
1049 /*************************************************
1050 * Check if host is required proxy host *
1051 *************************************************/
1052 /* The function determines if inbound host will be a regular smtp host
1053 or if it is configured that it must use Proxy Protocol. A local
1061 check_proxy_protocol_host()
1065 if ( sender_host_address
1066 && (rc
= verify_check_this_host(CUSS
&hosts_proxy
, NULL
, NULL
,
1067 sender_host_address
, NULL
)) == OK
)
1070 debug_printf("Detected proxy protocol configured host\n");
1071 proxy_session
= TRUE
;
1073 return proxy_session
;
1077 /*************************************************
1078 * Read data until newline or end of buffer *
1079 *************************************************/
1080 /* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1081 read an entire buffer and assume there will be nothing past a proxy protocol
1082 header. Our approach normally is to use stdio, but again that relies upon
1083 "STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1084 reading _nothing_ before client TLS handshake. So we don't want to use the
1085 usual buffering reads which may read enough to block TLS starting.
1087 So unfortunately we're down to "read one byte at a time, with a syscall each,
1088 and expect a little overhead", for all proxy-opened connections which are v1,
1089 just to handle the TLS-on-connect case. Since SSL functions wrap the
1090 underlying fd, we can't assume that we can feed them any already-read content.
1092 We need to know where to read to, the max capacity, and we'll read until we
1093 get a CR and one more character. Let the caller scream if it's CR+!LF.
1095 Return the amount read.
1099 swallow_until_crlf(int fd
, uschar
*base
, int already
, int capacity
)
1101 uschar
*to
= base
+ already
;
1107 /* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1108 up through the \r; for the _normal_ case, we haven't yet seen the \r. */
1110 cr
= memchr(base
, '\r', already
);
1113 if ((cr
- base
) < already
- 1)
1115 /* \r and presumed \n already within what we have; probably not
1116 actually proxy protocol, but abort cleanly. */
1119 /* \r is last character read, just need one more. */
1123 while (capacity
> 0)
1125 do { ret
= recv(fd
, to
, 1, 0); } while (ret
== -1 && errno
== EINTR
);
1137 /* reached end without having room for a final newline, abort */
1142 /*************************************************
1143 * Setup host for proxy protocol *
1144 *************************************************/
1145 /* The function configures the connection based on a header from the
1146 inbound host to use Proxy Protocol. The specification is very exact
1147 so exit with an error if do not find the exact required pieces. This
1148 includes an incorrect number of spaces separating args.
1151 Returns: Boolean success
1155 setup_proxy_protocol_host()
1167 struct { /* TCP/UDP over IPv4, len = 12 */
1173 struct { /* TCP/UDP over IPv6, len = 36 */
1174 uint8_t src_addr
[16];
1175 uint8_t dst_addr
[16];
1179 struct { /* AF_UNIX sockets, len = 216 */
1180 uschar src_addr
[108];
1181 uschar dst_addr
[108];
1187 /* Temp variables used in PPv2 address:port parsing */
1189 char tmpip
[INET_ADDRSTRLEN
];
1190 struct sockaddr_in tmpaddr
;
1191 char tmpip6
[INET6_ADDRSTRLEN
];
1192 struct sockaddr_in6 tmpaddr6
;
1194 /* We can't read "all data until end" because while SMTP is
1195 server-speaks-first, the TLS handshake is client-speaks-first, so for
1196 TLS-on-connect ports the proxy protocol header will usually be immediately
1197 followed by a TLS handshake, and with N TLS libraries, we can't reliably
1198 reinject data for reading by those. So instead we first read "enough to be
1199 safely read within the header, and figure out how much more to read".
1200 For v1 we will later read to the end-of-line, for v2 we will read based upon
1203 The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1204 data is needed total. For v1, where the line looks like:
1205 PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1207 However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1208 We seem to support that. So, if we read 14 octets then we can tell if we're
1209 v2 or v1. If we're v1, we can continue reading as normal.
1211 If we're v2, we can't slurp up the entire header. We need the length in the
1212 15th & 16th octets, then to read everything after that.
1214 So to safely handle v1 and v2, with client-sent-first supported correctly,
1215 we have to do a minimum of 3 read calls, not 1. Eww.
1218 #define PROXY_INITIAL_READ 14
1219 #define PROXY_V2_HEADER_SIZE 16
1220 #if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1221 # error Code bug in sizes of data to read for proxy usage
1226 int fd
= fileno(smtp_in
);
1227 const char v2sig
[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
1228 uschar
* iptype
; /* To display debug info */
1230 struct timeval tvtmp
;
1231 socklen_t vslen
= sizeof(struct timeval
);
1234 /* Save current socket timeout values */
1235 get_ok
= getsockopt(fd
, SOL_SOCKET
, SO_RCVTIMEO
, CS
&tvtmp
, &vslen
);
1237 /* Proxy Protocol host must send header within a short time
1238 (default 3 seconds) or it's considered invalid */
1239 tv
.tv_sec
= PROXY_NEGOTIATION_TIMEOUT_SEC
;
1240 tv
.tv_usec
= PROXY_NEGOTIATION_TIMEOUT_USEC
;
1241 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVTIMEO
, CS
&tv
, sizeof(tv
)) < 0)
1246 /* The inbound host was declared to be a Proxy Protocol host, so
1247 don't do a PEEK into the data, actually slurp up enough to be
1248 "safe". Can't take it all because TLS-on-connect clients follow
1249 immediately with TLS handshake. */
1250 ret
= recv(fd
, &hdr
, PROXY_INITIAL_READ
, 0);
1252 while (ret
== -1 && errno
== EINTR
);
1257 /* For v2, handle reading the length, and then the rest. */
1258 if ((ret
== PROXY_INITIAL_READ
) && (memcmp(&hdr
.v2
, v2sig
, sizeof(v2sig
)) == 0))
1263 /* First get the length fields. */
1266 retmore
= recv(fd
, (uschar
*)&hdr
+ ret
, PROXY_V2_HEADER_SIZE
- PROXY_INITIAL_READ
, 0);
1267 } while (retmore
== -1 && errno
== EINTR
);
1272 ver
= (hdr
.v2
.ver_cmd
& 0xf0) >> 4;
1274 /* May 2014: haproxy combined the version and command into one byte to
1275 allow two full bytes for the length field in order to proxy SSL
1276 connections. SSL Proxy is not supported in this version of Exim, but
1277 must still separate values here. */
1281 DEBUG(D_receive
) debug_printf("Invalid Proxy Protocol version: %d\n", ver
);
1285 /* The v2 header will always be 16 bytes per the spec. */
1286 size
= 16 + ntohs(hdr
.v2
.len
);
1287 DEBUG(D_receive
) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1288 size
, (int)sizeof(hdr
));
1290 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1291 amount that we need. Double-check that the size is not unreasonable, then
1293 if (size
> sizeof(hdr
))
1295 DEBUG(D_receive
) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
1303 retmore
= recv(fd
, (uschar
*)&hdr
+ ret
, size
-ret
, 0);
1304 } while (retmore
== -1 && errno
== EINTR
);
1308 DEBUG(D_receive
) debug_printf("PROXYv2: have %d/%d required octets\n", ret
, size
);
1309 } while (ret
< size
);
1311 } /* end scope for getting rest of data for v2 */
1313 /* At this point: if PROXYv2, we've read the exact size required for all data;
1314 if PROXYv1 then we've read "less than required for any valid line" and should
1317 if (ret
>= 16 && memcmp(&hdr
.v2
, v2sig
, 12) == 0)
1319 uint8_t cmd
= (hdr
.v2
.ver_cmd
& 0x0f);
1323 case 0x01: /* PROXY command */
1326 case 0x11: /* TCPv4 address type */
1328 tmpaddr
.sin_addr
.s_addr
= hdr
.v2
.addr
.ip4
.src_addr
;
1329 inet_ntop(AF_INET
, &tmpaddr
.sin_addr
, CS
&tmpip
, sizeof(tmpip
));
1330 if (!string_is_ip_address(US tmpip
, NULL
))
1332 DEBUG(D_receive
) debug_printf("Invalid %s source IP\n", iptype
);
1335 proxy_local_address
= sender_host_address
;
1336 sender_host_address
= string_copy(US tmpip
);
1337 tmpport
= ntohs(hdr
.v2
.addr
.ip4
.src_port
);
1338 proxy_local_port
= sender_host_port
;
1339 sender_host_port
= tmpport
;
1340 /* Save dest ip/port */
1341 tmpaddr
.sin_addr
.s_addr
= hdr
.v2
.addr
.ip4
.dst_addr
;
1342 inet_ntop(AF_INET
, &tmpaddr
.sin_addr
, CS
&tmpip
, sizeof(tmpip
));
1343 if (!string_is_ip_address(US tmpip
, NULL
))
1345 DEBUG(D_receive
) debug_printf("Invalid %s dest port\n", iptype
);
1348 proxy_external_address
= string_copy(US tmpip
);
1349 tmpport
= ntohs(hdr
.v2
.addr
.ip4
.dst_port
);
1350 proxy_external_port
= tmpport
;
1352 case 0x21: /* TCPv6 address type */
1354 memmove(tmpaddr6
.sin6_addr
.s6_addr
, hdr
.v2
.addr
.ip6
.src_addr
, 16);
1355 inet_ntop(AF_INET6
, &tmpaddr6
.sin6_addr
, CS
&tmpip6
, sizeof(tmpip6
));
1356 if (!string_is_ip_address(US tmpip6
, NULL
))
1358 DEBUG(D_receive
) debug_printf("Invalid %s source IP\n", iptype
);
1361 proxy_local_address
= sender_host_address
;
1362 sender_host_address
= string_copy(US tmpip6
);
1363 tmpport
= ntohs(hdr
.v2
.addr
.ip6
.src_port
);
1364 proxy_local_port
= sender_host_port
;
1365 sender_host_port
= tmpport
;
1366 /* Save dest ip/port */
1367 memmove(tmpaddr6
.sin6_addr
.s6_addr
, hdr
.v2
.addr
.ip6
.dst_addr
, 16);
1368 inet_ntop(AF_INET6
, &tmpaddr6
.sin6_addr
, CS
&tmpip6
, sizeof(tmpip6
));
1369 if (!string_is_ip_address(US tmpip6
, NULL
))
1371 DEBUG(D_receive
) debug_printf("Invalid %s dest port\n", iptype
);
1374 proxy_external_address
= string_copy(US tmpip6
);
1375 tmpport
= ntohs(hdr
.v2
.addr
.ip6
.dst_port
);
1376 proxy_external_port
= tmpport
;
1380 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1384 /* Unsupported protocol, keep local connection address */
1386 case 0x00: /* LOCAL command */
1387 /* Keep local connection address for LOCAL */
1392 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd
);
1396 else if (ret
>= 8 && memcmp(hdr
.v1
.line
, "PROXY", 5) == 0)
1400 uschar
*sp
; /* Utility variables follow */
1405 /* get the rest of the line */
1406 r2
= swallow_until_crlf(fd
, (uschar
*)&hdr
, ret
, sizeof(hdr
)-ret
);
1411 p
= string_copy(hdr
.v1
.line
);
1412 end
= memchr(p
, '\r', ret
- 1);
1414 if (!end
|| (end
== (uschar
*)&hdr
+ ret
) || end
[1] != '\n')
1416 DEBUG(D_receive
) debug_printf("Partial or invalid PROXY header\n");
1419 *end
= '\0'; /* Terminate the string */
1420 size
= end
+ 2 - p
; /* Skip header + CRLF */
1421 DEBUG(D_receive
) debug_printf("Detected PROXYv1 header\n");
1422 DEBUG(D_receive
) debug_printf("Bytes read not within PROXY header: %d\n", ret
- size
);
1423 /* Step through the string looking for the required fields. Ensure
1424 strict adherence to required formatting, exit for any error. */
1426 if (!isspace(*(p
++)))
1428 DEBUG(D_receive
) debug_printf("Missing space after PROXY command\n");
1431 if (!Ustrncmp(p
, CCS
"TCP4", 4))
1433 else if (!Ustrncmp(p
,CCS
"TCP6", 4))
1435 else if (!Ustrncmp(p
,CCS
"UNKNOWN", 7))
1437 iptype
= US
"Unknown";
1442 DEBUG(D_receive
) debug_printf("Invalid TCP type\n");
1446 p
+= Ustrlen(iptype
);
1447 if (!isspace(*(p
++)))
1449 DEBUG(D_receive
) debug_printf("Missing space after TCP4/6 command\n");
1452 /* Find the end of the arg */
1453 if ((sp
= Ustrchr(p
, ' ')) == NULL
)
1456 debug_printf("Did not find proxied src %s\n", iptype
);
1460 if(!string_is_ip_address(p
, NULL
))
1463 debug_printf("Proxied src arg is not an %s address\n", iptype
);
1466 proxy_local_address
= sender_host_address
;
1467 sender_host_address
= p
;
1469 if ((sp
= Ustrchr(p
, ' ')) == NULL
)
1472 debug_printf("Did not find proxy dest %s\n", iptype
);
1476 if(!string_is_ip_address(p
, NULL
))
1479 debug_printf("Proxy dest arg is not an %s address\n", iptype
);
1482 proxy_external_address
= p
;
1484 if ((sp
= Ustrchr(p
, ' ')) == NULL
)
1486 DEBUG(D_receive
) debug_printf("Did not find proxied src port\n");
1490 tmp_port
= strtol(CCS p
, &endc
, 10);
1491 if (*endc
|| tmp_port
== 0)
1494 debug_printf("Proxied src port '%s' not an integer\n", p
);
1497 proxy_local_port
= sender_host_port
;
1498 sender_host_port
= tmp_port
;
1500 if ((sp
= Ustrchr(p
, '\0')) == NULL
)
1502 DEBUG(D_receive
) debug_printf("Did not find proxy dest port\n");
1505 tmp_port
= strtol(CCS p
, &endc
, 10);
1506 if (*endc
|| tmp_port
== 0)
1509 debug_printf("Proxy dest port '%s' not an integer\n", p
);
1512 proxy_external_port
= tmp_port
;
1513 /* Already checked for /r /n above. Good V1 header received. */
1517 /* Wrong protocol */
1518 DEBUG(D_receive
) debug_printf("Invalid proxy protocol version negotiation\n");
1519 (void) swallow_until_crlf(fd
, (uschar
*)&hdr
, ret
, sizeof(hdr
)-ret
);
1525 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype
);
1526 yield
= proxy_session
;
1528 /* Don't flush any potential buffer contents. Any input on proxyfail
1529 should cause a synchronization failure */
1532 restore_socket_timeout(fd
, get_ok
, &tvtmp
, vslen
);
1537 sender_host_name
= NULL
;
1538 (void) host_name_lookup();
1539 host_build_sender_fullhost();
1543 f
.proxy_session_failed
= TRUE
;
1545 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1552 /*************************************************
1553 * Read one command line *
1554 *************************************************/
1556 /* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1557 There are sites that don't do this, and in any case internal SMTP probably
1558 should check only for LF. Consequently, we check here for LF only. The line
1559 ends up with [CR]LF removed from its end. If we get an overlong line, treat as
1560 an unknown command. The command is read into the global smtp_cmd_buffer so that
1561 it is available via $smtp_command.
1563 The character reading routine sets up a timeout for each block actually read
1564 from the input (which may contain more than one command). We set up a special
1565 signal handler that closes down the session on a timeout. Control does not
1566 return when it runs.
1569 check_sync if TRUE, check synchronization rules if global option is TRUE
1570 buffer_lim maximum to buffer in lower layer
1572 Returns: a code identifying the command (enumerated above)
1576 smtp_read_command(BOOL check_sync
, unsigned buffer_lim
)
1580 BOOL hadnull
= FALSE
;
1582 had_command_timeout
= 0;
1583 os_non_restarting_signal(SIGALRM
, command_timeout_handler
);
1585 while ((c
= (receive_getc
)(buffer_lim
)) != '\n' && c
!= EOF
)
1587 if (ptr
>= SMTP_CMD_BUFFER_SIZE
)
1589 os_non_restarting_signal(SIGALRM
, sigalrm_handler
);
1597 smtp_cmd_buffer
[ptr
++] = c
;
1600 receive_linecount
++; /* For BSMTP errors */
1601 os_non_restarting_signal(SIGALRM
, sigalrm_handler
);
1603 /* If hit end of file, return pseudo EOF command. Whether we have a
1604 part-line already read doesn't matter, since this is an error state. */
1606 if (c
== EOF
) return EOF_CMD
;
1608 /* Remove any CR and white space at the end of the line, and terminate the
1611 while (ptr
> 0 && isspace(smtp_cmd_buffer
[ptr
-1])) ptr
--;
1612 smtp_cmd_buffer
[ptr
] = 0;
1614 DEBUG(D_receive
) debug_printf("SMTP<< %s\n", smtp_cmd_buffer
);
1616 /* NULLs are not allowed in SMTP commands */
1618 if (hadnull
) return BADCHAR_CMD
;
1620 /* Scan command list and return identity, having set the data pointer
1621 to the start of the actual data characters. Check for SMTP synchronization
1624 for (smtp_cmd_list
* p
= cmd_list
; p
< cmd_list_end
; p
++)
1626 #ifdef SUPPORT_PROXY
1627 /* Only allow QUIT command if Proxy Protocol parsing failed */
1628 if (proxy_session
&& f
.proxy_session_failed
&& p
->cmd
!= QUIT_CMD
)
1632 && strncmpic(smtp_cmd_buffer
, US p
->name
, p
->len
) == 0
1633 && ( smtp_cmd_buffer
[p
->len
-1] == ':' /* "mail from:" or "rcpt to:" */
1634 || smtp_cmd_buffer
[p
->len
] == 0
1635 || smtp_cmd_buffer
[p
->len
] == ' '
1638 if (smtp_inptr
< smtp_inend
&& /* Outstanding input */
1639 p
->cmd
< sync_cmd_limit
&& /* Command should sync */
1640 check_sync
&& /* Local flag set */
1641 smtp_enforce_sync
&& /* Global flag set */
1642 sender_host_address
!= NULL
&& /* Not local input */
1643 !f
.sender_host_notsocket
) /* Really is a socket */
1646 /* The variables $smtp_command and $smtp_command_argument point into the
1647 unmodified input buffer. A copy of the latter is taken for actual
1648 processing, so that it can be chopped up into separate parts if necessary,
1649 for example, when processing a MAIL command options such as SIZE that can
1650 follow the sender address. */
1652 smtp_cmd_argument
= smtp_cmd_buffer
+ p
->len
;
1653 while (isspace(*smtp_cmd_argument
)) smtp_cmd_argument
++;
1654 Ustrcpy(smtp_data_buffer
, smtp_cmd_argument
);
1655 smtp_cmd_data
= smtp_data_buffer
;
1657 /* Count non-mail commands from those hosts that are controlled in this
1658 way. The default is all hosts. We don't waste effort checking the list
1659 until we get a non-mail command, but then cache the result to save checking
1660 again. If there's a DEFER while checking the host, assume it's in the list.
1662 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1663 start of each incoming message by fiddling with the value in the table. */
1665 if (!p
->is_mail_cmd
)
1667 if (count_nonmail
== TRUE_UNSET
) count_nonmail
=
1668 verify_check_host(&smtp_accept_max_nonmail_hosts
) != FAIL
;
1669 if (count_nonmail
&& ++nonmail_command_count
> smtp_accept_max_nonmail
)
1670 return TOO_MANY_NONMAIL_CMD
;
1673 /* If there is data for a command that does not expect it, generate the
1676 return (p
->has_arg
|| *smtp_cmd_data
== 0)? p
->cmd
: BADARG_CMD
;
1680 #ifdef SUPPORT_PROXY
1681 /* Only allow QUIT command if Proxy Protocol parsing failed */
1682 if (proxy_session
&& f
.proxy_session_failed
)
1683 return PROXY_FAIL_IGNORE_CMD
;
1686 /* Enforce synchronization for unknown commands */
1688 if ( smtp_inptr
< smtp_inend
/* Outstanding input */
1689 && check_sync
/* Local flag set */
1690 && smtp_enforce_sync
/* Global flag set */
1691 && sender_host_address
/* Not local input */
1692 && !f
.sender_host_notsocket
) /* Really is a socket */
1700 /*************************************************
1701 * Forced closedown of call *
1702 *************************************************/
1704 /* This function is called from log.c when Exim is dying because of a serious
1705 disaster, and also from some other places. If an incoming non-batched SMTP
1706 channel is open, it swallows the rest of the incoming message if in the DATA
1707 phase, sends the reply string, and gives an error to all subsequent commands
1708 except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1712 message SMTP reply string to send, excluding the code
1718 smtp_closedown(uschar
*message
)
1720 if (!smtp_in
|| smtp_batched_input
) return;
1721 receive_swallow_smtp();
1722 smtp_printf("421 %s\r\n", FALSE
, message
);
1724 for (;;) switch(smtp_read_command(FALSE
, GETC_BUFFER_UNLIMITED
))
1730 smtp_printf("221 %s closing connection\r\n", FALSE
, smtp_active_hostname
);
1735 smtp_printf("250 Reset OK\r\n", FALSE
);
1739 smtp_printf("421 %s\r\n", FALSE
, message
);
1747 /*************************************************
1748 * Set up connection info for logging *
1749 *************************************************/
1751 /* This function is called when logging information about an SMTP connection.
1752 It sets up appropriate source information, depending on the type of connection.
1753 If sender_fullhost is NULL, we are at a very early stage of the connection;
1754 just use the IP address.
1757 Returns: a string describing the connection
1761 smtp_get_connection_info(void)
1763 const uschar
* hostname
= sender_fullhost
1764 ? sender_fullhost
: sender_host_address
;
1767 return string_sprintf("SMTP connection from %s", hostname
);
1769 if (f
.sender_host_unknown
|| f
.sender_host_notsocket
)
1770 return string_sprintf("SMTP connection from %s", sender_ident
);
1773 return string_sprintf("SMTP connection from %s (via inetd)", hostname
);
1775 if (LOGGING(incoming_interface
) && interface_address
)
1776 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname
,
1777 interface_address
, interface_port
);
1779 return string_sprintf("SMTP connection from %s", hostname
);
1785 /* Append TLS-related information to a log line
1788 g String under construction: allocated string to extend, or NULL
1790 Returns: Allocated string or NULL
1793 s_tlslog(gstring
* g
)
1795 if (LOGGING(tls_cipher
) && tls_in
.cipher
)
1797 g
= string_append(g
, 2, US
" X=", tls_in
.cipher
);
1798 #ifdef EXPERIMENTAL_TLS_RESUME
1799 if (LOGGING(tls_resumption
) && tls_in
.resumption
& RESUME_USED
)
1800 g
= string_catn(g
, US
"*", 1);
1803 if (LOGGING(tls_certificate_verified
) && tls_in
.cipher
)
1804 g
= string_append(g
, 2, US
" CV=", tls_in
.certificate_verified
? "yes":"no");
1805 if (LOGGING(tls_peerdn
) && tls_in
.peerdn
)
1806 g
= string_append(g
, 3, US
" DN=\"", string_printing(tls_in
.peerdn
), US
"\"");
1807 if (LOGGING(tls_sni
) && tls_in
.sni
)
1808 g
= string_append(g
, 3, US
" SNI=\"", string_printing(tls_in
.sni
), US
"\"");
1813 /*************************************************
1814 * Log lack of MAIL if so configured *
1815 *************************************************/
1817 /* This function is called when an SMTP session ends. If the log selector
1818 smtp_no_mail is set, write a log line giving some details of what has happened
1819 in the SMTP session.
1826 smtp_log_no_mail(void)
1831 if (smtp_mailcmd_count
> 0 || !LOGGING(smtp_no_mail
))
1834 if (sender_host_authenticated
)
1836 g
= string_append(g
, 2, US
" A=", sender_host_authenticated
);
1837 if (authenticated_id
) g
= string_append(g
, 2, US
":", authenticated_id
);
1844 sep
= smtp_connection_had
[SMTP_HBUFF_SIZE
-1] != SCH_NONE
? US
" C=..." : US
" C=";
1846 for (int i
= smtp_ch_index
; i
< SMTP_HBUFF_SIZE
; i
++)
1847 if (smtp_connection_had
[i
] != SCH_NONE
)
1849 g
= string_append(g
, 2, sep
, smtp_names
[smtp_connection_had
[i
]]);
1853 for (int i
= 0; i
< smtp_ch_index
; i
++)
1855 g
= string_append(g
, 2, sep
, smtp_names
[smtp_connection_had
[i
]]);
1859 if (!(s
= string_from_gstring(g
))) s
= US
"";
1861 log_write(0, LOG_MAIN
, "no MAIL in %sSMTP connection from %s D=%s%s",
1862 f
.tcp_in_fastopen
? f
.tcp_in_fastopen_data
? US
"TFO* " : US
"TFO " : US
"",
1863 host_and_ident(FALSE
), string_timesince(&smtp_connection_start
), s
);
1867 /* Return list of recent smtp commands */
1872 gstring
* list
= NULL
;
1875 for (int i
= smtp_ch_index
; i
< SMTP_HBUFF_SIZE
; i
++)
1876 if (smtp_connection_had
[i
] != SCH_NONE
)
1877 list
= string_append_listele(list
, ',', smtp_names
[smtp_connection_had
[i
]]);
1879 for (int i
= 0; i
< smtp_ch_index
; i
++)
1880 list
= string_append_listele(list
, ',', smtp_names
[smtp_connection_had
[i
]]);
1882 s
= string_from_gstring(list
);
1883 return s
? s
: US
"";
1889 /*************************************************
1890 * Check HELO line and set sender_helo_name *
1891 *************************************************/
1893 /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1894 the domain name of the sending host, or an ip literal in square brackets. The
1895 argument is placed in sender_helo_name, which is in malloc store, because it
1896 must persist over multiple incoming messages. If helo_accept_junk is set, this
1897 host is permitted to send any old junk (needed for some broken hosts).
1898 Otherwise, helo_allow_chars can be used for rogue characters in general
1899 (typically people want to let in underscores).
1902 s the data portion of the line (already past any white space)
1904 Returns: TRUE or FALSE
1908 check_helo(uschar
*s
)
1911 uschar
*end
= s
+ Ustrlen(s
);
1912 BOOL yield
= fl
.helo_accept_junk
;
1914 /* Discard any previous helo name */
1916 sender_helo_name
= NULL
;
1918 /* Skip tests if junk is permitted. */
1922 /* Allow the new standard form for IPv6 address literals, namely,
1923 [IPv6:....], and because someone is bound to use it, allow an equivalent
1924 IPv4 form. Allow plain addresses as well. */
1931 if (strncmpic(s
, US
"[IPv6:", 6) == 0)
1932 yield
= (string_is_ip_address(s
+6, NULL
) == 6);
1933 else if (strncmpic(s
, US
"[IPv4:", 6) == 0)
1934 yield
= (string_is_ip_address(s
+6, NULL
) == 4);
1936 yield
= (string_is_ip_address(s
+1, NULL
) != 0);
1941 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1942 that have been configured (usually underscore - sigh). */
1945 for (yield
= TRUE
; *s
; s
++)
1946 if (!isalnum(*s
) && *s
!= '.' && *s
!= '-' &&
1947 Ustrchr(helo_allow_chars
, *s
) == NULL
)
1953 /* Save argument if OK */
1955 if (yield
) sender_helo_name
= string_copy_perm(start
, TRUE
);
1963 /*************************************************
1964 * Extract SMTP command option *
1965 *************************************************/
1967 /* This function picks the next option setting off the end of smtp_cmd_data. It
1968 is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1969 things that can appear there.
1972 name point this at the name
1973 value point this at the data string
1975 Returns: TRUE if found an option
1979 extract_option(uschar
**name
, uschar
**value
)
1982 uschar
*v
= smtp_cmd_data
+ Ustrlen(smtp_cmd_data
) - 1;
1983 while (isspace(*v
)) v
--;
1985 while (v
> smtp_cmd_data
&& *v
!= '=' && !isspace(*v
))
1987 /* Take care to not stop at a space embedded in a quoted local-part */
1989 if (*v
== '"') do v
--; while (*v
!= '"' && v
> smtp_cmd_data
+1);
1996 while(isalpha(n
[-1])) n
--;
1997 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1998 if (!isspace(n
[-1])) return FALSE
;
2004 if (v
== smtp_cmd_data
) return FALSE
;
2016 /*************************************************
2017 * Reset for new message *
2018 *************************************************/
2020 /* This function is called whenever the SMTP session is reset from
2021 within either of the setup functions; also from the daemon loop.
2023 Argument: the stacking pool storage reset point
2028 smtp_reset(void *reset_point
)
2030 recipients_list
= NULL
;
2031 rcpt_count
= rcpt_defer_count
= rcpt_fail_count
=
2032 raw_recipients_count
= recipients_count
= recipients_list_max
= 0;
2033 message_linecount
= 0;
2035 acl_added_headers
= NULL
;
2036 acl_removed_headers
= NULL
;
2037 f
.queue_only_policy
= FALSE
;
2038 rcpt_smtp_response
= NULL
;
2039 fl
.rcpt_smtp_response_same
= TRUE
;
2040 fl
.rcpt_in_progress
= FALSE
;
2041 f
.deliver_freeze
= FALSE
; /* Can be set by ACL */
2042 freeze_tell
= freeze_tell_config
; /* Can be set by ACL */
2043 fake_response
= OK
; /* Can be set by ACL */
2044 #ifdef WITH_CONTENT_SCAN
2045 f
.no_mbox_unspool
= FALSE
; /* Can be set by ACL */
2047 f
.submission_mode
= FALSE
; /* Can be set by ACL */
2048 f
.suppress_local_fixups
= f
.suppress_local_fixups_default
; /* Can be set by ACL */
2049 f
.active_local_from_check
= local_from_check
; /* Can be set by ACL */
2050 f
.active_local_sender_retain
= local_sender_retain
; /* Can be set by ACL */
2051 sending_ip_address
= NULL
;
2052 return_path
= sender_address
= NULL
;
2053 sender_data
= NULL
; /* Can be set by ACL */
2054 deliver_localpart_parent
= deliver_localpart_orig
= NULL
;
2055 deliver_domain_parent
= deliver_domain_orig
= NULL
;
2056 callout_address
= NULL
;
2057 submission_name
= NULL
; /* Can be set by ACL */
2058 raw_sender
= NULL
; /* After SMTP rewrite, before qualifying */
2059 sender_address_unrewritten
= NULL
; /* Set only after verify rewrite */
2060 sender_verified_list
= NULL
; /* No senders verified */
2061 memset(sender_address_cache
, 0, sizeof(sender_address_cache
));
2062 memset(sender_domain_cache
, 0, sizeof(sender_domain_cache
));
2064 authenticated_sender
= NULL
;
2065 #ifdef EXPERIMENTAL_BRIGHTMAIL
2067 bmi_verdicts
= NULL
;
2069 dnslist_domain
= dnslist_matched
= NULL
;
2071 spf_header_comment
= spf_received
= spf_result
= spf_smtp_comment
= NULL
;
2072 spf_result_guessed
= FALSE
;
2074 #ifndef DISABLE_DKIM
2075 dkim_cur_signer
= dkim_signers
=
2076 dkim_signing_domain
= dkim_signing_selector
= dkim_signatures
= NULL
;
2077 dkim_cur_signer
= dkim_signers
= dkim_signing_domain
= dkim_signing_selector
= NULL
;
2078 f
.dkim_disable_verify
= FALSE
;
2079 dkim_collect_input
= 0;
2080 dkim_verify_overall
= dkim_verify_status
= dkim_verify_reason
= NULL
;
2081 dkim_key_length
= 0;
2083 #ifdef SUPPORT_DMARC
2084 f
.dmarc_has_been_checked
= f
.dmarc_disable_verify
= f
.dmarc_enable_forensic
= FALSE
;
2085 dmarc_domain_policy
= dmarc_status
= dmarc_status_text
=
2086 dmarc_used_domain
= NULL
;
2088 #ifdef EXPERIMENTAL_ARC
2089 arc_state
= arc_state_reason
= NULL
;
2093 deliver_host
= deliver_host_address
= NULL
; /* Can be set by ACL */
2094 #ifndef DISABLE_PRDR
2095 prdr_requested
= FALSE
;
2098 message_smtputf8
= FALSE
;
2100 body_linecount
= body_zerocount
= 0;
2102 sender_rate
= sender_rate_limit
= sender_rate_period
= NULL
;
2103 ratelimiters_mail
= NULL
; /* Updated by ratelimit ACL condition */
2104 /* Note that ratelimiters_conn persists across resets. */
2106 /* Reset message ACL variables */
2110 /* The message body variables use malloc store. They may be set if this is
2111 not the first message in an SMTP session and the previous message caused them
2112 to be referenced in an ACL. */
2116 store_free(message_body
);
2117 message_body
= NULL
;
2120 if (message_body_end
)
2122 store_free(message_body_end
);
2123 message_body_end
= NULL
;
2126 /* Warning log messages are also saved in malloc store. They are saved to avoid
2127 repetition in the same message, but it seems right to repeat them for different
2130 while (acl_warn_logged
)
2132 string_item
*this = acl_warn_logged
;
2133 acl_warn_logged
= acl_warn_logged
->next
;
2136 store_reset(reset_point
);
2137 return store_mark();
2144 /*************************************************
2145 * Initialize for incoming batched SMTP message *
2146 *************************************************/
2148 /* This function is called from smtp_setup_msg() in the case when
2149 smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2150 of messages in one file with SMTP commands between them. All errors must be
2151 reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2152 relevant. After an error on a sender, or an invalid recipient, the remainder
2153 of the message is skipped. The value of received_protocol is already set.
2156 Returns: > 0 message successfully started (reached DATA)
2157 = 0 QUIT read or end of file reached
2158 < 0 should not occur
2162 smtp_setup_batch_msg(void)
2165 rmark reset_point
= store_mark();
2167 /* Save the line count at the start of each transaction - single commands
2168 like HELO and RSET count as whole transactions. */
2170 bsmtp_transaction_linecount
= receive_linecount
;
2172 if ((receive_feof
)()) return 0; /* Treat EOF as QUIT */
2174 cancel_cutthrough_connection(TRUE
, US
"smtp_setup_batch_msg");
2175 reset_point
= smtp_reset(reset_point
); /* Reset for start of message */
2177 /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2178 value. The values are 2 larger than the required yield of the function. */
2183 uschar
*recipient
= NULL
;
2184 int start
, end
, sender_domain
, recipient_domain
;
2186 switch(smtp_read_command(FALSE
, GETC_BUFFER_UNLIMITED
))
2188 /* The HELO/EHLO commands set sender_address_helo if they have
2189 valid data; otherwise they are ignored, except that they do
2190 a reset of the state. */
2195 check_helo(smtp_cmd_data
);
2199 cancel_cutthrough_connection(TRUE
, US
"RSET received");
2200 reset_point
= smtp_reset(reset_point
);
2201 bsmtp_transaction_linecount
= receive_linecount
;
2205 /* The MAIL FROM command requires an address as an operand. All we
2206 do here is to parse it for syntactic correctness. The form "<>" is
2207 a special case which converts into an empty string. The start/end
2208 pointers in the original are not used further for this address, as
2209 it is the canonical extracted address which is all that is kept. */
2212 smtp_mailcmd_count
++; /* Count for no-mail log */
2213 if (sender_address
!= NULL
)
2214 /* The function moan_smtp_batch() does not return. */
2215 moan_smtp_batch(smtp_cmd_buffer
, "503 Sender already given");
2217 if (smtp_cmd_data
[0] == 0)
2218 /* The function moan_smtp_batch() does not return. */
2219 moan_smtp_batch(smtp_cmd_buffer
, "501 MAIL FROM must have an address operand");
2221 /* Reset to start of message */
2223 cancel_cutthrough_connection(TRUE
, US
"MAIL received");
2224 reset_point
= smtp_reset(reset_point
);
2226 /* Apply SMTP rewrite */
2228 raw_sender
= ((rewrite_existflags
& rewrite_smtp
) != 0)?
2229 rewrite_one(smtp_cmd_data
, rewrite_smtp
|rewrite_smtp_sender
, NULL
, FALSE
,
2230 US
"", global_rewrite_rules
) : smtp_cmd_data
;
2232 /* Extract the address; the TRUE flag allows <> as valid */
2235 parse_extract_address(raw_sender
, &errmess
, &start
, &end
, &sender_domain
,
2239 /* The function moan_smtp_batch() does not return. */
2240 moan_smtp_batch(smtp_cmd_buffer
, "501 %s", errmess
);
2242 sender_address
= string_copy(raw_sender
);
2244 /* Qualify unqualified sender addresses if permitted to do so. */
2247 && sender_address
[0] != 0 && sender_address
[0] != '@')
2248 if (f
.allow_unqualified_sender
)
2250 sender_address
= rewrite_address_qualify(sender_address
, FALSE
);
2251 DEBUG(D_receive
) debug_printf("unqualified address %s accepted "
2252 "and rewritten\n", raw_sender
);
2254 /* The function moan_smtp_batch() does not return. */
2256 moan_smtp_batch(smtp_cmd_buffer
, "501 sender address must contain "
2261 /* The RCPT TO command requires an address as an operand. All we do
2262 here is to parse it for syntactic correctness. There may be any number
2263 of RCPT TO commands, specifying multiple senders. We build them all into
2264 a data structure that is in argc/argv format. The start/end values
2265 given by parse_extract_address are not used, as we keep only the
2266 extracted address. */
2269 if (!sender_address
)
2270 /* The function moan_smtp_batch() does not return. */
2271 moan_smtp_batch(smtp_cmd_buffer
, "503 No sender yet given");
2273 if (smtp_cmd_data
[0] == 0)
2274 /* The function moan_smtp_batch() does not return. */
2275 moan_smtp_batch(smtp_cmd_buffer
,
2276 "501 RCPT TO must have an address operand");
2278 /* Check maximum number allowed */
2280 if (recipients_max
> 0 && recipients_count
+ 1 > recipients_max
)
2281 /* The function moan_smtp_batch() does not return. */
2282 moan_smtp_batch(smtp_cmd_buffer
, "%s too many recipients",
2283 recipients_max_reject
? "552": "452");
2285 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2286 recipient address */
2288 recipient
= rewrite_existflags
& rewrite_smtp
2289 ? rewrite_one(smtp_cmd_data
, rewrite_smtp
, NULL
, FALSE
, US
"",
2290 global_rewrite_rules
)
2293 recipient
= parse_extract_address(recipient
, &errmess
, &start
, &end
,
2294 &recipient_domain
, FALSE
);
2297 /* The function moan_smtp_batch() does not return. */
2298 moan_smtp_batch(smtp_cmd_buffer
, "501 %s", errmess
);
2300 /* If the recipient address is unqualified, qualify it if permitted. Then
2301 add it to the list of recipients. */
2303 if (!recipient_domain
)
2304 if (f
.allow_unqualified_recipient
)
2306 DEBUG(D_receive
) debug_printf("unqualified address %s accepted\n",
2308 recipient
= rewrite_address_qualify(recipient
, TRUE
);
2310 /* The function moan_smtp_batch() does not return. */
2312 moan_smtp_batch(smtp_cmd_buffer
,
2313 "501 recipient address must contain a domain");
2315 receive_add_recipient(recipient
, -1);
2319 /* The DATA command is legal only if it follows successful MAIL FROM
2320 and RCPT TO commands. This function is complete when a valid DATA
2321 command is encountered. */
2324 if (!sender_address
|| recipients_count
<= 0)
2325 /* The function moan_smtp_batch() does not return. */
2326 if (!sender_address
)
2327 moan_smtp_batch(smtp_cmd_buffer
,
2328 "503 MAIL FROM:<sender> command must precede DATA");
2330 moan_smtp_batch(smtp_cmd_buffer
,
2331 "503 RCPT TO:<recipient> must precede DATA");
2334 done
= 3; /* DATA successfully achieved */
2335 message_ended
= END_NOTENDED
; /* Indicate in middle of message */
2340 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2347 bsmtp_transaction_linecount
= receive_linecount
;
2358 /* The function moan_smtp_batch() does not return. */
2359 moan_smtp_batch(smtp_cmd_buffer
, "501 Unexpected argument data");
2364 /* The function moan_smtp_batch() does not return. */
2365 moan_smtp_batch(smtp_cmd_buffer
, "501 Unexpected NULL in SMTP command");
2370 /* The function moan_smtp_batch() does not return. */
2371 moan_smtp_batch(smtp_cmd_buffer
, "500 Command unrecognized");
2376 return done
- 2; /* Convert yield values */
2384 smtp_log_tls_fail(uschar
* errstr
)
2386 uschar
* conn_info
= smtp_get_connection_info();
2388 if (Ustrncmp(conn_info
, US
"SMTP ", 5) == 0) conn_info
+= 5;
2389 /* I'd like to get separated H= here, but too hard for now */
2391 log_write(0, LOG_MAIN
, "TLS error on %s %s", conn_info
, errstr
);
2405 socklen_t len
= sizeof(is_fastopen
);
2407 /* The tinfo TCPOPT_FAST_OPEN bit seems unreliable, and we don't see state
2408 TCP_SYN_RCV (as of 12.1) so no idea about data-use. */
2410 if (getsockopt(fileno(smtp_out
), IPPROTO_TCP
, TCP_FASTOPEN
, &is_fastopen
, &len
) == 0)
2415 debug_printf("TFO mode connection (TCP_FASTOPEN getsockopt)\n");
2416 f
.tcp_in_fastopen
= TRUE
;
2419 else DEBUG(D_receive
)
2420 debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno
));
2422 # elif defined(TCP_INFO)
2423 struct tcp_info tinfo
;
2424 socklen_t len
= sizeof(tinfo
);
2426 if (getsockopt(fileno(smtp_out
), IPPROTO_TCP
, TCP_INFO
, &tinfo
, &len
) == 0)
2427 # ifdef TCPI_OPT_SYN_DATA /* FreeBSD 11,12 do not seem to have this yet */
2428 if (tinfo
.tcpi_options
& TCPI_OPT_SYN_DATA
)
2431 debug_printf("TFO mode connection (ACKd data-on-SYN)\n");
2432 f
.tcp_in_fastopen_data
= f
.tcp_in_fastopen
= TRUE
;
2436 if (tinfo
.tcpi_state
== TCP_SYN_RECV
) /* Not seen on FreeBSD 12.1 */
2439 debug_printf("TFO mode connection (state TCP_SYN_RECV)\n");
2440 f
.tcp_in_fastopen
= TRUE
;
2442 else DEBUG(D_receive
)
2443 debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno
));
2449 /*************************************************
2450 * Start an SMTP session *
2451 *************************************************/
2453 /* This function is called at the start of an SMTP session. Thereafter,
2454 smtp_setup_msg() is called to initiate each separate message. This
2455 function does host-specific testing, and outputs the banner line.
2458 Returns: FALSE if the session can not continue; something has
2459 gone wrong, or the connection to the host is blocked
2463 smtp_start_session(void)
2466 uschar
*user_msg
, *log_msg
;
2471 gettimeofday(&smtp_connection_start
, NULL
);
2472 for (smtp_ch_index
= 0; smtp_ch_index
< SMTP_HBUFF_SIZE
; smtp_ch_index
++)
2473 smtp_connection_had
[smtp_ch_index
] = SCH_NONE
;
2476 /* Default values for certain variables */
2478 fl
.helo_seen
= fl
.esmtp
= fl
.helo_accept_junk
= FALSE
;
2479 smtp_mailcmd_count
= 0;
2480 count_nonmail
= TRUE_UNSET
;
2481 synprot_error_count
= unknown_command_count
= nonmail_command_count
= 0;
2482 smtp_delay_mail
= smtp_rlm_base
;
2483 fl
.auth_advertised
= FALSE
;
2484 f
.smtp_in_pipelining_advertised
= f
.smtp_in_pipelining_used
= FALSE
;
2485 f
.pipelining_enable
= TRUE
;
2486 sync_cmd_limit
= NON_SYNC_CMD_NON_PIPELINING
;
2487 fl
.smtp_exit_function_called
= FALSE
; /* For avoiding loop in not-quit exit */
2489 /* If receiving by -bs from a trusted user, or testing with -bh, we allow
2490 authentication settings from -oMaa to remain in force. */
2492 if (!host_checking
&& !f
.sender_host_notsocket
)
2493 sender_host_auth_pubname
= sender_host_authenticated
= NULL
;
2494 authenticated_by
= NULL
;
2497 tls_in
.ver
= tls_in
.cipher
= tls_in
.peerdn
= NULL
;
2498 tls_in
.ourcert
= tls_in
.peercert
= NULL
;
2500 tls_in
.ocsp
= OCSP_NOT_REQ
;
2501 fl
.tls_advertised
= FALSE
;
2503 fl
.dsn_advertised
= FALSE
;
2505 fl
.smtputf8_advertised
= FALSE
;
2508 /* Reset ACL connection variables */
2512 /* Allow for trailing 0 in the command and data buffers. Tainted. */
2514 smtp_cmd_buffer
= store_get_perm(2*SMTP_CMD_BUFFER_SIZE
+ 2, TRUE
);
2516 smtp_cmd_buffer
[0] = 0;
2517 smtp_data_buffer
= smtp_cmd_buffer
+ SMTP_CMD_BUFFER_SIZE
+ 1;
2519 /* For batched input, the protocol setting can be overridden from the
2520 command line by a trusted caller. */
2522 if (smtp_batched_input
)
2524 if (!received_protocol
) received_protocol
= US
"local-bsmtp";
2527 /* For non-batched SMTP input, the protocol setting is forced here. It will be
2528 reset later if any of EHLO/AUTH/STARTTLS are received. */
2532 (sender_host_address
? protocols
: protocols_local
) [pnormal
];
2534 /* Set up the buffer for inputting using direct read() calls, and arrange to
2535 call the local functions instead of the standard C ones. Place a NUL at the
2536 end of the buffer to safety-stop C-string reads from it. */
2538 if (!(smtp_inbuffer
= US
malloc(IN_BUFFER_SIZE
)))
2539 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "malloc() failed for SMTP input buffer");
2540 smtp_inbuffer
[IN_BUFFER_SIZE
-1] = '\0';
2542 receive_getc
= smtp_getc
;
2543 receive_getbuf
= smtp_getbuf
;
2544 receive_get_cache
= smtp_get_cache
;
2545 receive_ungetc
= smtp_ungetc
;
2546 receive_feof
= smtp_feof
;
2547 receive_ferror
= smtp_ferror
;
2548 receive_smtp_buffered
= smtp_buffered
;
2549 smtp_inptr
= smtp_inend
= smtp_inbuffer
;
2550 smtp_had_eof
= smtp_had_error
= 0;
2552 /* Set up the message size limit; this may be host-specific */
2554 thismessage_size_limit
= expand_string_integer(message_size_limit
, TRUE
);
2555 if (expand_string_message
)
2557 if (thismessage_size_limit
== -1)
2558 log_write(0, LOG_MAIN
|LOG_PANIC
, "unable to expand message_size_limit: "
2559 "%s", expand_string_message
);
2561 log_write(0, LOG_MAIN
|LOG_PANIC
, "invalid message_size_limit: "
2562 "%s", expand_string_message
);
2563 smtp_closedown(US
"Temporary local problem - please try later");
2567 /* When a message is input locally via the -bs or -bS options, sender_host_
2568 unknown is set unless -oMa was used to force an IP address, in which case it
2569 is checked like a real remote connection. When -bs is used from inetd, this
2570 flag is not set, causing the sending host to be checked. The code that deals
2571 with IP source routing (if configured) is never required for -bs or -bS and
2572 the flag sender_host_notsocket is used to suppress it.
2574 If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2575 reserve for certain hosts and/or networks. */
2577 if (!f
.sender_host_unknown
)
2580 BOOL reserved_host
= FALSE
;
2582 /* Look up IP options (source routing info) on the socket if this is not an
2583 -oMa "host", and if any are found, log them and drop the connection.
2585 Linux (and others now, see below) is different to everyone else, so there
2586 has to be some conditional compilation here. Versions of Linux before 2.1.15
2587 used a structure whose name was "options". Somebody finally realized that
2588 this name was silly, and it got changed to "ip_options". I use the
2589 newer name here, but there is a fudge in the script that sets up os.h
2590 to define a macro in older Linux systems.
2592 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2593 glibc 2, which has chosen ip_opts for the structure name. This is now
2594 really a glibc thing rather than a Linux thing, so the condition name
2595 has been changed to reflect this. It is relevant also to GNU/Hurd.
2597 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2598 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2599 a special macro defined in the os.h file.
2601 Some DGUX versions on older hardware appear not to support IP options at
2602 all, so there is now a general macro which can be set to cut out this
2605 How to do this properly in IPv6 is not yet known. */
2607 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
2609 #ifdef GLIBC_IP_OPTIONS
2610 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2615 #elif defined DARWIN_IP_OPTIONS
2621 if (!host_checking
&& !f
.sender_host_notsocket
)
2624 EXIM_SOCKLEN_T optlen
= sizeof(struct ip_options
) + MAX_IPOPTLEN
;
2625 struct ip_options
*ipopt
= store_get(optlen
, FALSE
);
2627 struct ip_opts ipoptblock
;
2628 struct ip_opts
*ipopt
= &ipoptblock
;
2629 EXIM_SOCKLEN_T optlen
= sizeof(ipoptblock
);
2631 struct ipoption ipoptblock
;
2632 struct ipoption
*ipopt
= &ipoptblock
;
2633 EXIM_SOCKLEN_T optlen
= sizeof(ipoptblock
);
2636 /* Occasional genuine failures of getsockopt() have been seen - for
2637 example, "reset by peer". Therefore, just log and give up on this
2638 call, unless the error is ENOPROTOOPT. This error is given by systems
2639 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2640 of writing. So for that error, carry on - we just can't do an IP options
2643 DEBUG(D_receive
) debug_printf("checking for IP options\n");
2645 if (getsockopt(fileno(smtp_out
), IPPROTO_IP
, IP_OPTIONS
, US (ipopt
),
2648 if (errno
!= ENOPROTOOPT
)
2650 log_write(0, LOG_MAIN
, "getsockopt() failed from %s: %s",
2651 host_and_ident(FALSE
), strerror(errno
));
2652 smtp_printf("451 SMTP service not available\r\n", FALSE
);
2657 /* Deal with any IP options that are set. On the systems I have looked at,
2658 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2659 more logging data than will fit in big_buffer. Nevertheless, after somebody
2660 questioned this code, I've added in some paranoid checking. */
2662 else if (optlen
> 0)
2664 uschar
*p
= big_buffer
;
2665 uschar
*pend
= big_buffer
+ big_buffer_size
;
2668 struct in_addr addr
;
2671 uschar
*optstart
= US (ipopt
->__data
);
2673 uschar
*optstart
= US (ipopt
->ip_opts
);
2675 uschar
*optstart
= US (ipopt
->ipopt_list
);
2678 DEBUG(D_receive
) debug_printf("IP options exist\n");
2680 Ustrcpy(p
, "IP options on incoming call:");
2683 for (uschar
* opt
= optstart
; opt
&& opt
< US (ipopt
) + optlen
; )
2696 if (!string_format(p
, pend
-p
, " %s [@%s",
2697 (*opt
== IPOPT_SSRR
)? "SSRR" : "LSRR",
2699 inet_ntoa(*((struct in_addr
*)(&(ipopt
->faddr
))))))
2701 inet_ntoa(ipopt
->ip_dst
)))
2703 inet_ntoa(ipopt
->ipopt_dst
)))
2711 optcount
= (opt
[1] - 3) / sizeof(struct in_addr
);
2713 while (optcount
-- > 0)
2715 memcpy(&addr
, adptr
, sizeof(addr
));
2716 if (!string_format(p
, pend
- p
- 1, "%s%s",
2717 (optcount
== 0)? ":" : "@", inet_ntoa(addr
)))
2723 adptr
+= sizeof(struct in_addr
);
2731 if (pend
- p
< 4 + 3*opt
[1]) { opt
= NULL
; break; }
2734 for (int i
= 0; i
< opt
[1]; i
++)
2735 p
+= sprintf(CS p
, "%2.2x ", opt
[i
]);
2743 log_write(0, LOG_MAIN
, "%s", big_buffer
);
2745 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2747 log_write(0, LOG_MAIN
|LOG_REJECT
,
2748 "connection from %s refused (IP options)", host_and_ident(FALSE
));
2750 smtp_printf("554 SMTP service not available\r\n", FALSE
);
2754 /* Length of options = 0 => there are no options */
2756 else DEBUG(D_receive
) debug_printf("no IP options found\n");
2758 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2760 /* Set keep-alive in socket options. The option is on by default. This
2761 setting is an attempt to get rid of some hanging connections that stick in
2762 read() when the remote end (usually a dialup) goes away. */
2764 if (smtp_accept_keepalive
&& !f
.sender_host_notsocket
)
2765 ip_keepalive(fileno(smtp_out
), sender_host_address
, FALSE
);
2767 /* If the current host matches host_lookup, set the name by doing a
2768 reverse lookup. On failure, sender_host_name will be NULL and
2769 host_lookup_failed will be TRUE. This may or may not be serious - optional
2772 if (verify_check_host(&host_lookup
) == OK
)
2774 (void)host_name_lookup();
2775 host_build_sender_fullhost();
2778 /* Delay this until we have the full name, if it is looked up. */
2780 set_process_info("handling incoming connection from %s",
2781 host_and_ident(FALSE
));
2783 /* Expand smtp_receive_timeout, if needed */
2785 if (smtp_receive_timeout_s
)
2788 if ( !(exp
= expand_string(smtp_receive_timeout_s
))
2790 || (smtp_receive_timeout
= readconf_readtime(exp
, 0, FALSE
)) < 0
2792 log_write(0, LOG_MAIN
|LOG_PANIC
,
2793 "bad value for smtp_receive_timeout: '%s'", exp
? exp
: US
"");
2796 /* Test for explicit connection rejection */
2798 if (verify_check_host(&host_reject_connection
) == OK
)
2800 log_write(L_connection_reject
, LOG_MAIN
|LOG_REJECT
, "refused connection "
2801 "from %s (host_reject_connection)", host_and_ident(FALSE
));
2802 smtp_printf("554 SMTP service not available\r\n", FALSE
);
2806 /* Test with TCP Wrappers if so configured. There is a problem in that
2807 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2808 such as disks dying. In these cases, it is desirable to reject with a 4xx
2809 error instead of a 5xx error. There isn't a "right" way to detect such
2810 problems. The following kludge is used: errno is zeroed before calling
2811 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2812 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2815 #ifdef USE_TCP_WRAPPERS
2817 if (!(tcp_wrappers_name
= expand_string(tcp_wrappers_daemon_name
)))
2818 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "Expansion of \"%s\" "
2819 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name
),
2820 expand_string_message
);
2822 if (!hosts_ctl(tcp_wrappers_name
,
2823 sender_host_name
? CS sender_host_name
: STRING_UNKNOWN
,
2824 sender_host_address
? CS sender_host_address
: STRING_UNKNOWN
,
2825 sender_ident
? CS sender_ident
: STRING_UNKNOWN
))
2827 if (errno
== 0 || errno
== ENOENT
)
2829 HDEBUG(D_receive
) debug_printf("tcp wrappers rejection\n");
2830 log_write(L_connection_reject
,
2831 LOG_MAIN
|LOG_REJECT
, "refused connection from %s "
2832 "(tcp wrappers)", host_and_ident(FALSE
));
2833 smtp_printf("554 SMTP service not available\r\n", FALSE
);
2837 int save_errno
= errno
;
2838 HDEBUG(D_receive
) debug_printf("tcp wrappers rejected with unexpected "
2839 "errno value %d\n", save_errno
);
2840 log_write(L_connection_reject
,
2841 LOG_MAIN
|LOG_REJECT
, "temporarily refused connection from %s "
2842 "(tcp wrappers errno=%d)", host_and_ident(FALSE
), save_errno
);
2843 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE
);
2849 /* Check for reserved slots. The value of smtp_accept_count has already been
2850 incremented to include this process. */
2852 if (smtp_accept_max
> 0 &&
2853 smtp_accept_count
> smtp_accept_max
- smtp_accept_reserve
)
2855 if ((rc
= verify_check_host(&smtp_reserve_hosts
)) != OK
)
2857 log_write(L_connection_reject
,
2858 LOG_MAIN
, "temporarily refused connection from %s: not in "
2859 "reserve list: connected=%d max=%d reserve=%d%s",
2860 host_and_ident(FALSE
), smtp_accept_count
- 1, smtp_accept_max
,
2861 smtp_accept_reserve
, (rc
== DEFER
)? " (lookup deferred)" : "");
2862 smtp_printf("421 %s: Too many concurrent SMTP connections; "
2863 "please try again later\r\n", FALSE
, smtp_active_hostname
);
2866 reserved_host
= TRUE
;
2869 /* If a load level above which only messages from reserved hosts are
2870 accepted is set, check the load. For incoming calls via the daemon, the
2871 check is done in the superior process if there are no reserved hosts, to
2872 save a fork. In all cases, the load average will already be available
2873 in a global variable at this point. */
2875 if (smtp_load_reserve
>= 0 &&
2876 load_average
> smtp_load_reserve
&&
2878 verify_check_host(&smtp_reserve_hosts
) != OK
)
2880 log_write(L_connection_reject
,
2881 LOG_MAIN
, "temporarily refused connection from %s: not in "
2882 "reserve list and load average = %.2f", host_and_ident(FALSE
),
2883 (double)load_average
/1000.0);
2884 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE
,
2885 smtp_active_hostname
);
2889 /* Determine whether unqualified senders or recipients are permitted
2890 for this host. Unfortunately, we have to do this every time, in order to
2891 set the flags so that they can be inspected when considering qualifying
2892 addresses in the headers. For a site that permits no qualification, this
2893 won't take long, however. */
2895 f
.allow_unqualified_sender
=
2896 verify_check_host(&sender_unqualified_hosts
) == OK
;
2898 f
.allow_unqualified_recipient
=
2899 verify_check_host(&recipient_unqualified_hosts
) == OK
;
2901 /* Determine whether HELO/EHLO is required for this host. The requirement
2902 can be hard or soft. */
2904 fl
.helo_required
= verify_check_host(&helo_verify_hosts
) == OK
;
2905 if (!fl
.helo_required
)
2906 fl
.helo_verify
= verify_check_host(&helo_try_verify_hosts
) == OK
;
2908 /* Determine whether this hosts is permitted to send syntactic junk
2909 after a HELO or EHLO command. */
2911 fl
.helo_accept_junk
= verify_check_host(&helo_accept_junk_hosts
) == OK
;
2914 /* For batch SMTP input we are now done. */
2916 if (smtp_batched_input
) return TRUE
;
2918 /* If valid Proxy Protocol source is connecting, set up session.
2919 * Failure will not allow any SMTP function other than QUIT. */
2921 #ifdef SUPPORT_PROXY
2922 proxy_session
= FALSE
;
2923 f
.proxy_session_failed
= FALSE
;
2924 if (check_proxy_protocol_host())
2925 setup_proxy_protocol_host();
2928 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2929 smtps port for use with older style SSL MTAs. */
2932 if (tls_in
.on_connect
)
2934 if (tls_server_start(tls_require_ciphers
, &user_msg
) != OK
)
2935 return smtp_log_tls_fail(user_msg
);
2936 cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
= TRUE
;
2940 /* Run the connect ACL if it exists */
2943 if (acl_smtp_connect
)
2946 if ((rc
= acl_check(ACL_WHERE_CONNECT
, NULL
, acl_smtp_connect
, &user_msg
,
2949 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT
, rc
, user_msg
, log_msg
);
2954 /* Output the initial message for a two-way SMTP connection. It may contain
2955 newlines, which then cause a multi-line response to be given. */
2957 code
= US
"220"; /* Default status code */
2958 esc
= US
""; /* Default extended status code */
2959 esclen
= 0; /* Length of esc */
2963 if (!(s
= expand_string(smtp_banner
)))
2964 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "Expansion of \"%s\" (smtp_banner) "
2965 "failed: %s", smtp_banner
, expand_string_message
);
2971 smtp_message_code(&code
, &codelen
, &s
, NULL
, TRUE
);
2975 esclen
= codelen
- 4;
2979 /* Remove any terminating newlines; might as well remove trailing space too */
2982 while (p
> s
&& isspace(p
[-1])) p
--;
2985 /* It seems that CC:Mail is braindead, and assumes that the greeting message
2986 is all contained in a single IP packet. The original code wrote out the
2987 greeting using several calls to fprint/fputc, and on busy servers this could
2988 cause it to be split over more than one packet - which caused CC:Mail to fall
2989 over when it got the second part of the greeting after sending its first
2990 command. Sigh. To try to avoid this, build the complete greeting message
2991 first, and output it in one fell swoop. This gives a better chance of it
2992 ending up as a single packet. */
2994 ss
= string_get(256);
2997 do /* At least once, in case we have an empty string */
3000 uschar
*linebreak
= Ustrchr(p
, '\n');
3001 ss
= string_catn(ss
, code
, 3);
3005 ss
= string_catn(ss
, US
" ", 1);
3009 len
= linebreak
- p
;
3010 ss
= string_catn(ss
, US
"-", 1);
3012 ss
= string_catn(ss
, esc
, esclen
);
3013 ss
= string_catn(ss
, p
, len
);
3014 ss
= string_catn(ss
, US
"\r\n", 2);
3020 /* Before we write the banner, check that there is no input pending, unless
3021 this synchronisation check is disabled. */
3023 #ifndef DISABLE_PIPE_CONNECT
3024 fl
.pipe_connect_acceptable
=
3025 sender_host_address
&& verify_check_host(&pipe_connect_advertise_hosts
) == OK
;
3028 if (fl
.pipe_connect_acceptable
)
3029 f
.smtp_in_early_pipe_used
= TRUE
;
3035 unsigned n
= smtp_inend
- smtp_inptr
;
3038 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP protocol "
3039 "synchronization error (input sent without waiting for greeting): "
3040 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE
),
3041 string_printing(string_copyn(smtp_inptr
, n
)));
3042 smtp_printf("554 SMTP synchronization error\r\n", FALSE
);
3046 /* Now output the banner */
3047 /*XXX the ehlo-resp code does its own tls/nontls bit. Maybe subroutine that? */
3050 #ifndef DISABLE_PIPE_CONNECT
3051 fl
.pipe_connect_acceptable
&& pipeline_connect_sends(),
3055 string_from_gstring(ss
));
3057 /* Attempt to see if we sent the banner before the last ACK of the 3-way
3058 handshake arrived. If so we must have managed a TFO. */
3061 if (sender_host_address
&& !f
.sender_host_notsocket
) tfo_in_check();
3071 /*************************************************
3072 * Handle SMTP syntax and protocol errors *
3073 *************************************************/
3075 /* Write to the log for SMTP syntax errors in incoming commands, if configured
3076 to do so. Then transmit the error response. The return value depends on the
3077 number of syntax and protocol errors in this SMTP session.
3080 type error type, given as a log flag bit
3081 code response code; <= 0 means don't send a response
3082 data data to reflect in the response (can be NULL)
3083 errmess the error message
3085 Returns: -1 limit of syntax/protocol errors NOT exceeded
3086 +1 limit of syntax/protocol errors IS exceeded
3088 These values fit in with the values of the "done" variable in the main
3089 processing loop in smtp_setup_msg(). */
3092 synprot_error(int type
, int code
, uschar
*data
, uschar
*errmess
)
3096 log_write(type
, LOG_MAIN
, "SMTP %s error in \"%s\" %s %s",
3097 (type
== L_smtp_syntax_error
)? "syntax" : "protocol",
3098 string_printing(smtp_cmd_buffer
), host_and_ident(TRUE
), errmess
);
3100 if (++synprot_error_count
> smtp_max_synprot_errors
)
3103 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
3104 "syntax or protocol errors (last command was \"%s\")",
3105 host_and_ident(FALSE
), string_printing(smtp_cmd_buffer
));
3110 smtp_printf("%d%c%s%s%s\r\n", FALSE
, code
, yield
== 1 ? '-' : ' ',
3111 data
? data
: US
"", data
? US
": " : US
"", errmess
);
3113 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE
, code
);
3122 /*************************************************
3123 * Send SMTP response, possibly multiline *
3124 *************************************************/
3126 /* There are, it seems, broken clients out there that cannot handle multiline
3127 responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3128 output nothing for non-final calls, and only the first line for anything else.
3131 code SMTP code, may involve extended status codes
3132 codelen length of smtp code; if > 4 there's an ESC
3133 final FALSE if the last line isn't the final line
3134 msg message text, possibly containing newlines
3140 smtp_respond(uschar
* code
, int codelen
, BOOL final
, uschar
*msg
)
3145 if (!final
&& f
.no_multiline_responses
) return;
3150 esclen
= codelen
- 4;
3153 /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3154 have had the same. Note: this code is also present in smtp_printf(). It would
3155 be tidier to have it only in one place, but when it was added, it was easier to
3156 do it that way, so as not to have to mess with the code for the RCPT command,
3157 which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3159 if (fl
.rcpt_in_progress
)
3161 if (rcpt_smtp_response
== NULL
)
3162 rcpt_smtp_response
= string_copy(msg
);
3163 else if (fl
.rcpt_smtp_response_same
&&
3164 Ustrcmp(rcpt_smtp_response
, msg
) != 0)
3165 fl
.rcpt_smtp_response_same
= FALSE
;
3166 fl
.rcpt_in_progress
= FALSE
;
3169 /* Now output the message, splitting it up into multiple lines if necessary.
3170 We only handle pipelining these responses as far as nonfinal/final groups,
3171 not the whole MAIL/RCPT/DATA response set. */
3175 uschar
*nl
= Ustrchr(msg
, '\n');
3178 smtp_printf("%.3s%c%.*s%s\r\n", !final
, code
, final
? ' ':'-', esclen
, esc
, msg
);
3181 else if (nl
[1] == 0 || f
.no_multiline_responses
)
3183 smtp_printf("%.3s%c%.*s%.*s\r\n", !final
, code
, final
? ' ':'-', esclen
, esc
,
3184 (int)(nl
- msg
), msg
);
3189 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE
, code
, esclen
, esc
, (int)(nl
- msg
), msg
);
3191 while (isspace(*msg
)) msg
++;
3199 /*************************************************
3200 * Parse user SMTP message *
3201 *************************************************/
3203 /* This function allows for user messages overriding the response code details
3204 by providing a suitable response code string at the start of the message
3205 user_msg. Check the message for starting with a response code and optionally an
3206 extended status code. If found, check that the first digit is valid, and if so,
3207 change the code pointer and length to use the replacement. An invalid code
3208 causes a panic log; in this case, if the log messages is the same as the user
3209 message, we must also adjust the value of the log message to show the code that
3210 is actually going to be used (the original one).
3212 This function is global because it is called from receive.c as well as within
3215 Note that the code length returned includes the terminating whitespace
3216 character, which is always included in the regex match.
3219 code SMTP code, may involve extended status codes
3220 codelen length of smtp code; if > 4 there's an ESC
3222 log_msg optional log message, to be adjusted with the new SMTP code
3223 check_valid if true, verify the response code
3229 smtp_message_code(uschar
**code
, int *codelen
, uschar
**msg
, uschar
**log_msg
,
3235 if (!msg
|| !*msg
) return;
3237 if ((n
= pcre_exec(regex_smtp_code
, NULL
, CS
*msg
, Ustrlen(*msg
), 0,
3238 PCRE_EOPT
, ovector
, sizeof(ovector
)/sizeof(int))) < 0) return;
3240 if (check_valid
&& (*msg
)[0] != (*code
)[0])
3242 log_write(0, LOG_MAIN
|LOG_PANIC
, "configured error code starts with "
3243 "incorrect digit (expected %c) in \"%s\"", (*code
)[0], *msg
);
3244 if (log_msg
!= NULL
&& *log_msg
== *msg
)
3245 *log_msg
= string_sprintf("%s %s", *code
, *log_msg
+ ovector
[1]);
3250 *codelen
= ovector
[1]; /* Includes final space */
3252 *msg
+= ovector
[1]; /* Chop the code off the message */
3259 /*************************************************
3260 * Handle an ACL failure *
3261 *************************************************/
3263 /* This function is called when acl_check() fails. As well as calls from within
3264 this module, it is called from receive.c for an ACL after DATA. It sorts out
3265 logging the incident, and sends the error response. A message containing
3266 newlines is turned into a multiline SMTP response, but for logging, only the
3269 There's a table of default permanent failure response codes to use in
3270 globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3271 defaults disabled in Exim. However, discussion in connection with RFC 821bis
3272 (aka RFC 2821) has concluded that the response should be 252 in the disabled
3273 state, because there are broken clients that try VRFY before RCPT. A 5xx
3274 response should be given only when the address is positively known to be
3275 undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3276 no explicit code, but if there is one we let it know best.
3277 Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
3279 From Exim 4.63, it is possible to override the response code details by
3280 providing a suitable response code string at the start of the message provided
3281 in user_msg. The code's first digit is checked for validity.
3284 where where the ACL was called from
3286 user_msg a message that can be included in an SMTP response
3287 log_msg a message for logging
3289 Returns: 0 in most cases
3290 2 if the failure code was FAIL_DROP, in which case the
3291 SMTP connection should be dropped (this value fits with the
3292 "done" variable in smtp_setup_msg() below)
3296 smtp_handle_acl_fail(int where
, int rc
, uschar
*user_msg
, uschar
*log_msg
)
3298 BOOL drop
= rc
== FAIL_DROP
;
3302 uschar
*sender_info
= US
"";
3304 #ifdef WITH_CONTENT_SCAN
3305 where
== ACL_WHERE_MIME
? US
"during MIME ACL checks" :
3307 where
== ACL_WHERE_PREDATA
? US
"DATA" :
3308 where
== ACL_WHERE_DATA
? US
"after DATA" :
3309 #ifndef DISABLE_PRDR
3310 where
== ACL_WHERE_PRDR
? US
"after DATA PRDR" :
3313 string_sprintf("%s %s", acl_wherenames
[where
], smtp_cmd_data
) :
3314 string_sprintf("%s in \"connect\" ACL", acl_wherenames
[where
]);
3316 if (drop
) rc
= FAIL
;
3318 /* Set the default SMTP code, and allow a user message to change it. */
3320 smtp_code
= rc
== FAIL
? acl_wherecodes
[where
] : US
"451";
3321 smtp_message_code(&smtp_code
, &codelen
, &user_msg
, &log_msg
,
3322 where
!= ACL_WHERE_VRFY
);
3324 /* We used to have sender_address here; however, there was a bug that was not
3325 updating sender_address after a rewrite during a verify. When this bug was
3326 fixed, sender_address at this point became the rewritten address. I'm not sure
3327 this is what should be logged, so I've changed to logging the unrewritten
3328 address to retain backward compatibility. */
3330 #ifndef WITH_CONTENT_SCAN
3331 if (where
== ACL_WHERE_RCPT
|| where
== ACL_WHERE_DATA
)
3333 if (where
== ACL_WHERE_RCPT
|| where
== ACL_WHERE_DATA
|| where
== ACL_WHERE_MIME
)
3336 sender_info
= string_sprintf("F=<%s>%s%s%s%s ",
3337 sender_address_unrewritten
? sender_address_unrewritten
: sender_address
,
3338 sender_host_authenticated
? US
" A=" : US
"",
3339 sender_host_authenticated
? sender_host_authenticated
: US
"",
3340 sender_host_authenticated
&& authenticated_id
? US
":" : US
"",
3341 sender_host_authenticated
&& authenticated_id
? authenticated_id
: US
""
3345 /* If there's been a sender verification failure with a specific message, and
3346 we have not sent a response about it yet, do so now, as a preliminary line for
3347 failures, but not defers. However, always log it for defer, and log it for fail
3348 unless the sender_verify_fail log selector has been turned off. */
3350 if (sender_verified_failed
&&
3351 !testflag(sender_verified_failed
, af_sverify_told
))
3353 BOOL save_rcpt_in_progress
= fl
.rcpt_in_progress
;
3354 fl
.rcpt_in_progress
= FALSE
; /* So as not to treat these as the error */
3356 setflag(sender_verified_failed
, af_sverify_told
);
3358 if (rc
!= FAIL
|| LOGGING(sender_verify_fail
))
3359 log_write(0, LOG_MAIN
|LOG_REJECT
, "%s sender verify %s for <%s>%s",
3360 host_and_ident(TRUE
),
3361 ((sender_verified_failed
->special_action
& 255) == DEFER
)? "defer":"fail",
3362 sender_verified_failed
->address
,
3363 (sender_verified_failed
->message
== NULL
)? US
"" :
3364 string_sprintf(": %s", sender_verified_failed
->message
));
3366 if (rc
== FAIL
&& sender_verified_failed
->user_message
)
3367 smtp_respond(smtp_code
, codelen
, FALSE
, string_sprintf(
3368 testflag(sender_verified_failed
, af_verify_pmfail
)?
3369 "Postmaster verification failed while checking <%s>\n%s\n"
3370 "Several RFCs state that you are required to have a postmaster\n"
3371 "mailbox for each mail domain. This host does not accept mail\n"
3372 "from domains whose servers reject the postmaster address."
3374 testflag(sender_verified_failed
, af_verify_nsfail
)?
3375 "Callback setup failed while verifying <%s>\n%s\n"
3376 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3377 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3378 "RFC requirements, and stops you from receiving standard bounce\n"
3379 "messages. This host does not accept mail from domains whose servers\n"
3382 "Verification failed for <%s>\n%s",
3383 sender_verified_failed
->address
,
3384 sender_verified_failed
->user_message
));
3386 fl
.rcpt_in_progress
= save_rcpt_in_progress
;
3389 /* Sort out text for logging */
3391 log_msg
= log_msg
? string_sprintf(": %s", log_msg
) : US
"";
3392 if ((lognl
= Ustrchr(log_msg
, '\n'))) *lognl
= 0;
3394 /* Send permanent failure response to the command, but the code used isn't
3395 always a 5xx one - see comments at the start of this function. If the original
3396 rc was FAIL_DROP we drop the connection and yield 2. */
3399 smtp_respond(smtp_code
, codelen
, TRUE
,
3400 user_msg
? user_msg
: US
"Administrative prohibition");
3402 /* Send temporary failure response to the command. Don't give any details,
3403 unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3404 verb, and for a header verify when smtp_return_error_details is set.
3406 This conditional logic is all somewhat of a mess because of the odd
3407 interactions between temp_details and return_error_details. One day it should
3408 be re-implemented in a tidier fashion. */
3411 if (f
.acl_temp_details
&& user_msg
)
3413 if ( smtp_return_error_details
3414 && sender_verified_failed
3415 && sender_verified_failed
->message
3417 smtp_respond(smtp_code
, codelen
, FALSE
, sender_verified_failed
->message
);
3419 smtp_respond(smtp_code
, codelen
, TRUE
, user_msg
);
3422 smtp_respond(smtp_code
, codelen
, TRUE
,
3423 US
"Temporary local problem - please try later");
3425 /* Log the incident to the logs that are specified by log_reject_target
3426 (default main, reject). This can be empty to suppress logging of rejections. If
3427 the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3428 is closing if required and return 2. */
3430 if (log_reject_target
!= 0)
3433 gstring
* g
= s_tlslog(NULL
);
3434 uschar
* tls
= string_from_gstring(g
);
3435 if (!tls
) tls
= US
"";
3437 uschar
* tls
= US
"";
3439 log_write(where
== ACL_WHERE_CONNECT
? L_connection_reject
: 0,
3440 log_reject_target
, "%s%s%s %s%srejected %s%s",
3441 LOGGING(dnssec
) && sender_host_dnssec
? US
" DS" : US
"",
3442 host_and_ident(TRUE
),
3445 rc
== FAIL
? US
"" : US
"temporarily ",
3449 if (!drop
) return 0;
3451 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by DROP in ACL",
3452 smtp_get_connection_info());
3454 /* Run the not-quit ACL, but without any custom messages. This should not be a
3455 problem, because we get here only if some other ACL has issued "drop", and
3456 in that case, *its* custom messages will have been used above. */
3458 smtp_notquit_exit(US
"acl-drop", NULL
, NULL
);
3465 /*************************************************
3466 * Handle SMTP exit when QUIT is not given *
3467 *************************************************/
3469 /* This function provides a logging/statistics hook for when an SMTP connection
3470 is dropped on the floor or the other end goes away. It's a global function
3471 because it's called from receive.c as well as this module. As well as running
3472 the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3473 response, either with a custom message from the ACL, or using a default. There
3474 is one case, however, when no message is output - after "drop". In that case,
3475 the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3476 passed to this function.
3478 In case things go wrong while processing this function, causing an error that
3479 may re-enter this function, there is a recursion check.
3482 reason What $smtp_notquit_reason will be set to in the ACL;
3483 if NULL, the ACL is not run
3484 code The error code to return as part of the response
3485 defaultrespond The default message if there's no user_msg
3491 smtp_notquit_exit(uschar
*reason
, uschar
*code
, uschar
*defaultrespond
, ...)
3494 uschar
*user_msg
= NULL
;
3495 uschar
*log_msg
= NULL
;
3497 /* Check for recursive call */
3499 if (fl
.smtp_exit_function_called
)
3501 log_write(0, LOG_PANIC
, "smtp_notquit_exit() called more than once (%s)",
3505 fl
.smtp_exit_function_called
= TRUE
;
3507 /* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3509 if (acl_smtp_notquit
&& reason
)
3511 smtp_notquit_reason
= reason
;
3512 if ((rc
= acl_check(ACL_WHERE_NOTQUIT
, NULL
, acl_smtp_notquit
, &user_msg
,
3513 &log_msg
)) == ERROR
)
3514 log_write(0, LOG_MAIN
|LOG_PANIC
, "ACL for not-QUIT returned ERROR: %s",
3518 /* If the connection was dropped, we certainly are no longer talking TLS */
3519 tls_in
.active
.sock
= -1;
3521 /* Write an SMTP response if we are expected to give one. As the default
3522 responses are all internal, they should be reasonable size. */
3524 if (code
&& defaultrespond
)
3527 smtp_respond(code
, 3, TRUE
, user_msg
);
3533 va_start(ap
, defaultrespond
);
3534 g
= string_vformat(NULL
, SVFMT_EXTEND
|SVFMT_REBUFFER
, CS defaultrespond
, ap
);
3536 smtp_printf("%s %s\r\n", FALSE
, code
, string_from_gstring(g
));
3545 /*************************************************
3546 * Verify HELO argument *
3547 *************************************************/
3549 /* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3550 matched. It is also called from ACL processing if verify = helo is used and
3551 verification was not previously tried (i.e. helo_try_verify_hosts was not
3552 matched). The result of its processing is to set helo_verified and
3553 helo_verify_failed. These variables should both be FALSE for this function to
3556 Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3557 for IPv6 ::ffff: literals.
3560 Returns: TRUE if testing was completed;
3561 FALSE on a temporary failure
3565 smtp_verify_helo(void)
3569 HDEBUG(D_receive
) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3572 if (sender_helo_name
== NULL
)
3574 HDEBUG(D_receive
) debug_printf("no EHLO/HELO command was issued\n");
3577 /* Deal with the case of -bs without an IP address */
3579 else if (sender_host_address
== NULL
)
3581 HDEBUG(D_receive
) debug_printf("no client IP address: assume success\n");
3582 f
.helo_verified
= TRUE
;
3585 /* Deal with the more common case when there is a sending IP address */
3587 else if (sender_helo_name
[0] == '[')
3589 f
.helo_verified
= Ustrncmp(sender_helo_name
+1, sender_host_address
,
3590 Ustrlen(sender_host_address
)) == 0;
3593 if (!f
.helo_verified
)
3595 if (strncmpic(sender_host_address
, US
"::ffff:", 7) == 0)
3596 f
.helo_verified
= Ustrncmp(sender_helo_name
+ 1,
3597 sender_host_address
+ 7, Ustrlen(sender_host_address
) - 7) == 0;
3602 { if (f
.helo_verified
) debug_printf("matched host address\n"); }
3605 /* Do a reverse lookup if one hasn't already given a positive or negative
3606 response. If that fails, or the name doesn't match, try checking with a forward
3611 if (sender_host_name
== NULL
&& !host_lookup_failed
)
3612 yield
= host_name_lookup() != DEFER
;
3614 /* If a host name is known, check it and all its aliases. */
3616 if (sender_host_name
)
3617 if ((f
.helo_verified
= strcmpic(sender_host_name
, sender_helo_name
) == 0))
3619 sender_helo_dnssec
= sender_host_dnssec
;
3620 HDEBUG(D_receive
) debug_printf("matched host name\n");
3624 uschar
**aliases
= sender_host_aliases
;
3626 if ((f
.helo_verified
= strcmpic(*aliases
++, sender_helo_name
) == 0))
3628 sender_helo_dnssec
= sender_host_dnssec
;
3632 HDEBUG(D_receive
) if (f
.helo_verified
)
3633 debug_printf("matched alias %s\n", *(--aliases
));
3636 /* Final attempt: try a forward lookup of the helo name */
3638 if (!f
.helo_verified
)
3642 {.name
= sender_helo_name
, .address
= NULL
, .mx
= MX_NONE
, .next
= NULL
};
3644 {.request
= US
"*", .require
= US
""};
3646 HDEBUG(D_receive
) debug_printf("getting IP address for %s\n",
3648 rc
= host_find_bydns(&h
, NULL
, HOST_FIND_BY_A
| HOST_FIND_BY_AAAA
,
3649 NULL
, NULL
, NULL
, &d
, NULL
, NULL
);
3650 if (rc
== HOST_FOUND
|| rc
== HOST_FOUND_LOCAL
)
3651 for (host_item
* hh
= &h
; hh
; hh
= hh
->next
)
3652 if (Ustrcmp(hh
->address
, sender_host_address
) == 0)
3654 f
.helo_verified
= TRUE
;
3655 if (h
.dnssec
== DS_YES
) sender_helo_dnssec
= TRUE
;
3657 debug_printf("IP address for %s matches calling address\n"
3658 "Forward DNS security status: %sverified\n",
3659 sender_helo_name
, sender_helo_dnssec
? "" : "un");
3665 if (!f
.helo_verified
) f
.helo_verify_failed
= TRUE
; /* We've tried ... */
3672 /*************************************************
3673 * Send user response message *
3674 *************************************************/
3676 /* This function is passed a default response code and a user message. It calls
3677 smtp_message_code() to check and possibly modify the response code, and then
3678 calls smtp_respond() to transmit the response. I put this into a function
3679 just to avoid a lot of repetition.
3682 code the response code
3683 user_msg the user message
3689 smtp_user_msg(uschar
*code
, uschar
*user_msg
)
3692 smtp_message_code(&code
, &len
, &user_msg
, NULL
, TRUE
);
3693 smtp_respond(code
, len
, TRUE
, user_msg
);
3699 smtp_in_auth(auth_instance
*au
, uschar
** s
, uschar
** ss
)
3701 const uschar
*set_id
= NULL
;
3704 /* Run the checking code, passing the remainder of the command line as
3705 data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
3706 it as the only set numerical variable. The authenticator may set $auth<n>
3707 and also set other numeric variables. The $auth<n> variables are preferred
3708 nowadays; the numerical variables remain for backwards compatibility.
3710 Afterwards, have a go at expanding the set_id string, even if
3711 authentication failed - for bad passwords it can be useful to log the
3712 userid. On success, require set_id to expand and exist, and put it in
3713 authenticated_id. Save this in permanent store, as the working store gets
3714 reset at HELO, RSET, etc. */
3716 for (int i
= 0; i
< AUTH_VARS
; i
++) auth_vars
[i
] = NULL
;
3718 expand_nlength
[0] = 0; /* $0 contains nothing */
3720 rc
= (au
->info
->servercode
)(au
, smtp_cmd_data
);
3721 if (au
->set_id
) set_id
= expand_string(au
->set_id
);
3722 expand_nmax
= -1; /* Reset numeric variables */
3723 for (int i
= 0; i
< AUTH_VARS
; i
++) auth_vars
[i
] = NULL
; /* Reset $auth<n> */
3725 /* The value of authenticated_id is stored in the spool file and printed in
3726 log lines. It must not contain binary zeros or newline characters. In
3727 normal use, it never will, but when playing around or testing, this error
3728 can (did) happen. To guard against this, ensure that the id contains only
3729 printing characters. */
3731 if (set_id
) set_id
= string_printing(set_id
);
3733 /* For the non-OK cases, set up additional logging data if set_id
3737 set_id
= set_id
&& *set_id
3738 ? string_sprintf(" (set_id=%s)", set_id
) : US
"";
3740 /* Switch on the result */
3745 if (!au
->set_id
|| set_id
) /* Complete success */
3747 if (set_id
) authenticated_id
= string_copy_perm(set_id
, TRUE
);
3748 sender_host_authenticated
= au
->name
;
3749 sender_host_auth_pubname
= au
->public_name
;
3750 authentication_failed
= FALSE
;
3751 authenticated_fail_id
= NULL
; /* Impossible to already be set? */
3754 (sender_host_address
? protocols
: protocols_local
)
3755 [pextend
+ pauthed
+ (tls_in
.active
.sock
>= 0 ? pcrpted
:0)];
3756 *s
= *ss
= US
"235 Authentication succeeded";
3757 authenticated_by
= au
;
3761 /* Authentication succeeded, but we failed to expand the set_id string.
3762 Treat this as a temporary error. */
3764 auth_defer_msg
= expand_string_message
;
3768 if (set_id
) authenticated_fail_id
= string_copy_perm(set_id
, TRUE
);
3769 *s
= string_sprintf("435 Unable to authenticate at present%s",
3770 auth_defer_user_msg
);
3771 *ss
= string_sprintf("435 Unable to authenticate at present%s: %s",
3772 set_id
, auth_defer_msg
);
3776 *s
= *ss
= US
"501 Invalid base64 data";
3780 *s
= *ss
= US
"501 Authentication cancelled";
3784 *s
= *ss
= US
"553 Initial data not expected";
3788 if (set_id
) authenticated_fail_id
= string_copy_perm(set_id
, TRUE
);
3789 *s
= US
"535 Incorrect authentication data";
3790 *ss
= string_sprintf("535 Incorrect authentication data%s", set_id
);
3794 if (set_id
) authenticated_fail_id
= string_copy_perm(set_id
, TRUE
);
3795 *s
= US
"435 Internal error";
3796 *ss
= string_sprintf("435 Internal error%s: return %d from authentication "
3797 "check", set_id
, rc
);
3809 qualify_recipient(uschar
** recipient
, uschar
* smtp_cmd_data
, uschar
* tag
)
3812 if (f
.allow_unqualified_recipient
|| strcmpic(*recipient
, US
"postmaster") == 0)
3814 DEBUG(D_receive
) debug_printf("unqualified address %s accepted\n",
3816 rd
= Ustrlen(recipient
) + 1;
3817 *recipient
= rewrite_address_qualify(*recipient
, TRUE
);
3820 smtp_printf("501 %s: recipient address must contain a domain\r\n", FALSE
,
3822 log_write(L_smtp_syntax_error
,
3823 LOG_MAIN
|LOG_REJECT
, "unqualified %s rejected: <%s> %s%s",
3824 tag
, *recipient
, host_and_ident(TRUE
), host_lookup_msg
);
3832 smtp_quit_handler(uschar
** user_msgp
, uschar
** log_msgp
)
3835 incomplete_transaction_log(US
"QUIT");
3838 int rc
= acl_check(ACL_WHERE_QUIT
, NULL
, acl_smtp_quit
, user_msgp
, log_msgp
);
3840 log_write(0, LOG_MAIN
|LOG_PANIC
, "ACL for QUIT returned ERROR: %s",
3845 (void) setsockopt(fileno(smtp_out
), IPPROTO_TCP
, TCP_CORK
, US
&on
, sizeof(on
));
3849 smtp_respond(US
"221", 3, TRUE
, *user_msgp
);
3851 smtp_printf("221 %s closing connection\r\n", FALSE
, smtp_active_hostname
);
3854 tls_close(NULL
, TLS_SHUTDOWN_NOWAIT
);
3857 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by QUIT",
3858 smtp_get_connection_info());
3863 smtp_rset_handler(void)
3866 incomplete_transaction_log(US
"RSET");
3867 smtp_printf("250 Reset OK\r\n", FALSE
);
3868 cmd_list
[CMD_LIST_RSET
].is_mail_cmd
= FALSE
;
3873 /*************************************************
3874 * Initialize for SMTP incoming message *
3875 *************************************************/
3877 /* This function conducts the initial dialogue at the start of an incoming SMTP
3878 message, and builds a list of recipients. However, if the incoming message
3879 is part of a batch (-bS option) a separate function is called since it would
3880 be messy having tests splattered about all over this function. This function
3881 therefore handles the case where interaction is occurring. The input and output
3882 files are set up in smtp_in and smtp_out.
3884 The global recipients_list is set to point to a vector of recipient_item
3885 blocks, whose number is given by recipients_count. This is extended by the
3886 receive_add_recipient() function. The global variable sender_address is set to
3887 the sender's address. The yield is +1 if a message has been successfully
3888 started, 0 if a QUIT command was encountered or the connection was refused from
3889 the particular host, or -1 if the connection was lost.
3893 Returns: > 0 message successfully started (reached DATA)
3894 = 0 QUIT read or end of file reached or call refused
3899 smtp_setup_msg(void)
3902 BOOL toomany
= FALSE
;
3903 BOOL discarded
= FALSE
;
3904 BOOL last_was_rej_mail
= FALSE
;
3905 BOOL last_was_rcpt
= FALSE
;
3906 rmark reset_point
= store_mark();
3908 DEBUG(D_receive
) debug_printf("smtp_setup_msg entered\n");
3910 /* Reset for start of new message. We allow one RSET not to be counted as a
3911 nonmail command, for those MTAs that insist on sending it between every
3912 message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
3913 TLS between messages (an Exim client may do this if it has messages queued up
3914 for the host). Note: we do NOT reset AUTH at this point. */
3916 reset_point
= smtp_reset(reset_point
);
3917 message_ended
= END_NOTSTARTED
;
3919 chunking_state
= f
.chunking_offered
? CHUNKING_OFFERED
: CHUNKING_NOT_OFFERED
;
3921 cmd_list
[CMD_LIST_RSET
].is_mail_cmd
= TRUE
;
3922 cmd_list
[CMD_LIST_HELO
].is_mail_cmd
= TRUE
;
3923 cmd_list
[CMD_LIST_EHLO
].is_mail_cmd
= TRUE
;
3925 cmd_list
[CMD_LIST_STARTTLS
].is_mail_cmd
= TRUE
;
3928 /* Set the local signal handler for SIGTERM - it tries to end off tidily */
3930 had_command_sigterm
= 0;
3931 os_non_restarting_signal(SIGTERM
, command_sigterm_handler
);
3933 /* Batched SMTP is handled in a different function. */
3935 if (smtp_batched_input
) return smtp_setup_batch_msg();
3937 /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
3938 value. The values are 2 larger than the required yield of the function. */
3942 const uschar
**argv
;
3943 uschar
*etrn_command
;
3944 uschar
*etrn_serialize_key
;
3946 uschar
*log_msg
, *smtp_code
;
3947 uschar
*user_msg
= NULL
;
3948 uschar
*recipient
= NULL
;
3949 uschar
*hello
= NULL
;
3951 BOOL was_rej_mail
= FALSE
;
3952 BOOL was_rcpt
= FALSE
;
3953 void (*oldsignal
)(int);
3955 int start
, end
, sender_domain
, recipient_domain
;
3958 uschar
*orcpt
= NULL
;
3963 /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
3964 if ( tls_in
.active
.sock
>= 0
3966 && tls_in
.certificate_verified
3967 && cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
3970 cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
= FALSE
;
3972 for (auth_instance
* au
= auths
; au
; au
= au
->next
)
3973 if (strcmpic(US
"tls", au
->driver_name
) == 0)
3976 && (rc
= acl_check(ACL_WHERE_AUTH
, NULL
, acl_smtp_auth
,
3977 &user_msg
, &log_msg
)) != OK
3979 done
= smtp_handle_acl_fail(ACL_WHERE_AUTH
, rc
, user_msg
, log_msg
);
3982 smtp_cmd_data
= NULL
;
3984 if (smtp_in_auth(au
, &s
, &ss
) == OK
)
3985 { DEBUG(D_auth
) debug_printf("tls auth succeeded\n"); }
3987 { DEBUG(D_auth
) debug_printf("tls auth not succeeded\n"); }
3995 if (smtp_in
) /* Avoid pure-ACKs while in cmd pingpong phase */
3996 (void) setsockopt(fileno(smtp_in
), IPPROTO_TCP
, TCP_QUICKACK
,
3997 US
&off
, sizeof(off
));
4000 switch(smtp_read_command(
4001 #ifndef DISABLE_PIPE_CONNECT
4002 !fl
.pipe_connect_acceptable
,
4006 GETC_BUFFER_UNLIMITED
))
4008 /* The AUTH command is not permitted to occur inside a transaction, and may
4009 occur successfully only once per connection. Actually, that isn't quite
4010 true. When TLS is started, all previous information about a connection must
4011 be discarded, so a new AUTH is permitted at that time.
4013 AUTH may only be used when it has been advertised. However, it seems that
4014 there are clients that send AUTH when it hasn't been advertised, some of
4015 them even doing this after HELO. And there are MTAs that accept this. Sigh.
4016 So there's a get-out that allows this to happen.
4018 AUTH is initially labelled as a "nonmail command" so that one occurrence
4019 doesn't get counted. We change the label here so that multiple failing
4020 AUTHS will eventually hit the nonmail threshold. */
4024 authentication_failed
= TRUE
;
4025 cmd_list
[CMD_LIST_AUTH
].is_mail_cmd
= FALSE
;
4027 if (!fl
.auth_advertised
&& !f
.allow_auth_unadvertised
)
4029 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4030 US
"AUTH command used when not advertised");
4033 if (sender_host_authenticated
)
4035 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4036 US
"already authenticated");
4041 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4042 US
"not permitted in mail transaction");
4049 && (rc
= acl_check(ACL_WHERE_AUTH
, NULL
, acl_smtp_auth
,
4050 &user_msg
, &log_msg
)) != OK
4053 done
= smtp_handle_acl_fail(ACL_WHERE_AUTH
, rc
, user_msg
, log_msg
);
4057 /* Find the name of the requested authentication mechanism. */
4060 while ((c
= *smtp_cmd_data
) != 0 && !isspace(c
))
4062 if (!isalnum(c
) && c
!= '-' && c
!= '_')
4064 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4065 US
"invalid character in authentication mechanism name");
4071 /* If not at the end of the line, we must be at white space. Terminate the
4072 name and move the pointer on to any data that may be present. */
4074 if (*smtp_cmd_data
!= 0)
4076 *smtp_cmd_data
++ = 0;
4077 while (isspace(*smtp_cmd_data
)) smtp_cmd_data
++;
4080 /* Search for an authentication mechanism which is configured for use
4081 as a server and which has been advertised (unless, sigh, allow_auth_
4082 unadvertised is set). */
4086 for (au
= auths
; au
; au
= au
->next
)
4087 if (strcmpic(s
, au
->public_name
) == 0 && au
->server
&&
4088 (au
->advertised
|| f
.allow_auth_unadvertised
))
4093 c
= smtp_in_auth(au
, &s
, &ss
);
4095 smtp_printf("%s\r\n", FALSE
, s
);
4097 log_write(0, LOG_MAIN
|LOG_REJECT
, "%s authenticator failed for %s: %s",
4098 au
->name
, host_and_ident(FALSE
), ss
);
4101 done
= synprot_error(L_smtp_protocol_error
, 504, NULL
,
4102 string_sprintf("%s authentication mechanism not supported", s
));
4105 break; /* AUTH_CMD */
4107 /* The HELO/EHLO commands are permitted to appear in the middle of a
4108 session as well as at the beginning. They have the effect of a reset in
4109 addition to their other functions. Their absence at the start cannot be
4110 taken to be an error.
4114 If the EHLO command is not acceptable to the SMTP server, 501, 500,
4115 or 502 failure replies MUST be returned as appropriate. The SMTP
4116 server MUST stay in the same state after transmitting these replies
4117 that it was in before the EHLO was received.
4119 Therefore, we do not do the reset until after checking the command for
4120 acceptability. This change was made for Exim release 4.11. Previously
4121 it did the reset first. */
4134 HELO_EHLO
: /* Common code for HELO and EHLO */
4135 cmd_list
[CMD_LIST_HELO
].is_mail_cmd
= FALSE
;
4136 cmd_list
[CMD_LIST_EHLO
].is_mail_cmd
= FALSE
;
4138 /* Reject the HELO if its argument was invalid or non-existent. A
4139 successful check causes the argument to be saved in malloc store. */
4141 if (!check_helo(smtp_cmd_data
))
4143 smtp_printf("501 Syntactically invalid %s argument(s)\r\n", FALSE
, hello
);
4145 log_write(0, LOG_MAIN
|LOG_REJECT
, "rejected %s from %s: syntactically "
4146 "invalid argument(s): %s", hello
, host_and_ident(FALSE
),
4147 *smtp_cmd_argument
== 0 ? US
"(no argument given)" :
4148 string_printing(smtp_cmd_argument
));
4150 if (++synprot_error_count
> smtp_max_synprot_errors
)
4152 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
4153 "syntax or protocol errors (last command was \"%s\")",
4154 host_and_ident(FALSE
), string_printing(smtp_cmd_buffer
));
4161 /* If sender_host_unknown is true, we have got here via the -bs interface,
4162 not called from inetd. Otherwise, we are running an IP connection and the
4163 host address will be set. If the helo name is the primary name of this
4164 host and we haven't done a reverse lookup, force one now. If helo_required
4165 is set, ensure that the HELO name matches the actual host. If helo_verify
4166 is set, do the same check, but softly. */
4168 if (!f
.sender_host_unknown
)
4170 BOOL old_helo_verified
= f
.helo_verified
;
4171 uschar
*p
= smtp_cmd_data
;
4173 while (*p
!= 0 && !isspace(*p
)) { *p
= tolower(*p
); p
++; }
4176 /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
4177 because otherwise the log can be confusing. */
4179 if ( !sender_host_name
4180 && match_isinlist(sender_helo_name
, CUSS
&helo_lookup_domains
, 0,
4181 &domainlist_anchor
, NULL
, MCL_DOMAIN
, TRUE
, NULL
) == OK
)
4182 (void)host_name_lookup();
4184 /* Rebuild the fullhost info to include the HELO name (and the real name
4185 if it was looked up.) */
4187 host_build_sender_fullhost(); /* Rebuild */
4188 set_process_info("handling%s incoming connection from %s",
4189 tls_in
.active
.sock
>= 0 ? " TLS" : "", host_and_ident(FALSE
));
4191 /* Verify if configured. This doesn't give much security, but it does
4192 make some people happy to be able to do it. If helo_required is set,
4193 (host matches helo_verify_hosts) failure forces rejection. If helo_verify
4194 is set (host matches helo_try_verify_hosts), it does not. This is perhaps
4195 now obsolescent, since the verification can now be requested selectively
4198 f
.helo_verified
= f
.helo_verify_failed
= sender_helo_dnssec
= FALSE
;
4199 if (fl
.helo_required
|| fl
.helo_verify
)
4201 BOOL tempfail
= !smtp_verify_helo();
4202 if (!f
.helo_verified
)
4204 if (fl
.helo_required
)
4206 smtp_printf("%d %s argument does not match calling host\r\n", FALSE
,
4207 tempfail
? 451 : 550, hello
);
4208 log_write(0, LOG_MAIN
|LOG_REJECT
, "%srejected \"%s %s\" from %s",
4209 tempfail
? "temporarily " : "",
4210 hello
, sender_helo_name
, host_and_ident(FALSE
));
4211 f
.helo_verified
= old_helo_verified
;
4212 break; /* End of HELO/EHLO processing */
4214 HDEBUG(D_all
) debug_printf("%s verification failed but host is in "
4215 "helo_try_verify_hosts\n", hello
);
4221 /* set up SPF context */
4222 spf_conn_init(sender_helo_name
, sender_host_address
);
4225 /* Apply an ACL check if one is defined; afterwards, recheck
4226 synchronization in case the client started sending in a delay. */
4229 if ((rc
= acl_check(ACL_WHERE_HELO
, NULL
, acl_smtp_helo
,
4230 &user_msg
, &log_msg
)) != OK
)
4232 done
= smtp_handle_acl_fail(ACL_WHERE_HELO
, rc
, user_msg
, log_msg
);
4233 sender_helo_name
= NULL
;
4234 host_build_sender_fullhost(); /* Rebuild */
4237 #ifndef DISABLE_PIPE_CONNECT
4238 else if (!fl
.pipe_connect_acceptable
&& !check_sync())
4240 else if (!check_sync())
4244 /* Generate an OK reply. The default string includes the ident if present,
4245 and also the IP address if present. Reflecting back the ident is intended
4246 as a deterrent to mail forgers. For maximum efficiency, and also because
4247 some broken systems expect each response to be in a single packet, arrange
4248 that the entire reply is sent in one write(). */
4250 fl
.auth_advertised
= FALSE
;
4251 f
.smtp_in_pipelining_advertised
= FALSE
;
4253 fl
.tls_advertised
= FALSE
;
4255 fl
.dsn_advertised
= FALSE
;
4257 fl
.smtputf8_advertised
= FALSE
;
4260 smtp_code
= US
"250 "; /* Default response code plus space*/
4263 /* sender_host_name below will be tainted, so save on copy when we hit it */
4264 g
= string_get_tainted(24, TRUE
);
4265 g
= string_fmt_append(g
, "%.3s %s Hello %s%s%s",
4267 smtp_active_hostname
,
4268 sender_ident
? sender_ident
: US
"",
4269 sender_ident
? US
" at " : US
"",
4270 sender_host_name
? sender_host_name
: sender_helo_name
);
4272 if (sender_host_address
)
4273 g
= string_fmt_append(g
, " [%s]", sender_host_address
);
4276 /* A user-supplied EHLO greeting may not contain more than one line. Note
4277 that the code returned by smtp_message_code() includes the terminating
4278 whitespace character. */
4284 smtp_message_code(&smtp_code
, &codelen
, &user_msg
, NULL
, TRUE
);
4285 s
= string_sprintf("%.*s%s", codelen
, smtp_code
, user_msg
);
4286 if ((ss
= strpbrk(CS s
, "\r\n")) != NULL
)
4288 log_write(0, LOG_MAIN
|LOG_PANIC
, "EHLO/HELO response must not contain "
4289 "newlines: message truncated: %s", string_printing(s
));
4292 g
= string_cat(NULL
, s
);
4295 g
= string_catn(g
, US
"\r\n", 2);
4297 /* If we received EHLO, we must create a multiline response which includes
4298 the functions supported. */
4304 /* I'm not entirely happy with this, as an MTA is supposed to check
4305 that it has enough room to accept a message of maximum size before
4306 it sends this. However, there seems little point in not sending it.
4307 The actual size check happens later at MAIL FROM time. By postponing it
4308 till then, VRFY and EXPN can be used after EHLO when space is short. */
4310 if (thismessage_size_limit
> 0)
4311 g
= string_fmt_append(g
, "%.3s-SIZE %d\r\n", smtp_code
,
4312 thismessage_size_limit
);
4315 g
= string_catn(g
, smtp_code
, 3);
4316 g
= string_catn(g
, US
"-SIZE\r\n", 7);
4319 /* Exim does not do protocol conversion or data conversion. It is 8-bit
4320 clean; if it has an 8-bit character in its hand, it just sends it. It
4321 cannot therefore specify 8BITMIME and remain consistent with the RFCs.
4322 However, some users want this option simply in order to stop MUAs
4323 mangling messages that contain top-bit-set characters. It is therefore
4324 provided as an option. */
4326 if (accept_8bitmime
)
4328 g
= string_catn(g
, smtp_code
, 3);
4329 g
= string_catn(g
, US
"-8BITMIME\r\n", 11);
4332 /* Advertise DSN support if configured to do so. */
4333 if (verify_check_host(&dsn_advertise_hosts
) != FAIL
)
4335 g
= string_catn(g
, smtp_code
, 3);
4336 g
= string_catn(g
, US
"-DSN\r\n", 6);
4337 fl
.dsn_advertised
= TRUE
;
4340 /* Advertise ETRN/VRFY/EXPN if there's are ACL checking whether a host is
4341 permitted to issue them; a check is made when any host actually tries. */
4345 g
= string_catn(g
, smtp_code
, 3);
4346 g
= string_catn(g
, US
"-ETRN\r\n", 7);
4350 g
= string_catn(g
, smtp_code
, 3);
4351 g
= string_catn(g
, US
"-VRFY\r\n", 7);
4355 g
= string_catn(g
, smtp_code
, 3);
4356 g
= string_catn(g
, US
"-EXPN\r\n", 7);
4359 /* Exim is quite happy with pipelining, so let the other end know that
4360 it is safe to use it, unless advertising is disabled. */
4362 if ( f
.pipelining_enable
4363 && verify_check_host(&pipelining_advertise_hosts
) == OK
)
4365 g
= string_catn(g
, smtp_code
, 3);
4366 g
= string_catn(g
, US
"-PIPELINING\r\n", 13);
4367 sync_cmd_limit
= NON_SYNC_CMD_PIPELINING
;
4368 f
.smtp_in_pipelining_advertised
= TRUE
;
4370 #ifndef DISABLE_PIPE_CONNECT
4371 if (fl
.pipe_connect_acceptable
)
4373 f
.smtp_in_early_pipe_advertised
= TRUE
;
4374 g
= string_catn(g
, smtp_code
, 3);
4375 g
= string_catn(g
, US
"-" EARLY_PIPE_FEATURE_NAME
"\r\n", EARLY_PIPE_FEATURE_LEN
+3);
4381 /* If any server authentication mechanisms are configured, advertise
4382 them if the current host is in auth_advertise_hosts. The problem with
4383 advertising always is that some clients then require users to
4384 authenticate (and aren't configurable otherwise) even though it may not
4385 be necessary (e.g. if the host is in host_accept_relay).
4387 RFC 2222 states that SASL mechanism names contain only upper case
4388 letters, so output the names in upper case, though we actually recognize
4389 them in either case in the AUTH command. */
4393 && !sender_host_authenticated
4395 && verify_check_host(&auth_advertise_hosts
) == OK
4399 for (auth_instance
* au
= auths
; au
; au
= au
->next
)
4401 au
->advertised
= FALSE
;
4404 DEBUG(D_auth
+D_expand
) debug_printf_indent(
4405 "Evaluating advertise_condition for %s athenticator\n",
4407 if ( !au
->advertise_condition
4408 || expand_check_condition(au
->advertise_condition
, au
->name
,
4415 g
= string_catn(g
, smtp_code
, 3);
4416 g
= string_catn(g
, US
"-AUTH", 5);
4418 fl
.auth_advertised
= TRUE
;
4421 g
= string_catn(g
, US
" ", 1);
4422 g
= string_cat (g
, au
->public_name
);
4423 while (++saveptr
< g
->ptr
) g
->s
[saveptr
] = toupper(g
->s
[saveptr
]);
4424 au
->advertised
= TRUE
;
4429 if (!first
) g
= string_catn(g
, US
"\r\n", 2);
4432 /* RFC 3030 CHUNKING */
4434 if (verify_check_host(&chunking_advertise_hosts
) != FAIL
)
4436 g
= string_catn(g
, smtp_code
, 3);
4437 g
= string_catn(g
, US
"-CHUNKING\r\n", 11);
4438 f
.chunking_offered
= TRUE
;
4439 chunking_state
= CHUNKING_OFFERED
;
4442 /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
4443 if it has been included in the binary, and the host matches
4444 tls_advertise_hosts. We must *not* advertise if we are already in a
4445 secure connection. */
4448 if (tls_in
.active
.sock
< 0 &&
4449 verify_check_host(&tls_advertise_hosts
) != FAIL
)
4451 g
= string_catn(g
, smtp_code
, 3);
4452 g
= string_catn(g
, US
"-STARTTLS\r\n", 11);
4453 fl
.tls_advertised
= TRUE
;
4457 #ifndef DISABLE_PRDR
4458 /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */
4461 g
= string_catn(g
, smtp_code
, 3);
4462 g
= string_catn(g
, US
"-PRDR\r\n", 7);
4467 if ( accept_8bitmime
4468 && verify_check_host(&smtputf8_advertise_hosts
) != FAIL
)
4470 g
= string_catn(g
, smtp_code
, 3);
4471 g
= string_catn(g
, US
"-SMTPUTF8\r\n", 11);
4472 fl
.smtputf8_advertised
= TRUE
;
4476 /* Finish off the multiline reply with one that is always available. */
4478 g
= string_catn(g
, smtp_code
, 3);
4479 g
= string_catn(g
, US
" HELP\r\n", 7);
4482 /* Terminate the string (for debug), write it, and note that HELO/EHLO
4486 if (tls_in
.active
.sock
>= 0)
4487 (void)tls_write(NULL
, g
->s
, g
->ptr
,
4488 # ifndef DISABLE_PIPE_CONNECT
4489 fl
.pipe_connect_acceptable
&& pipeline_connect_sends());
4497 int i
= fwrite(g
->s
, 1, g
->ptr
, smtp_out
); i
= i
; /* compiler quietening */
4503 (void) string_from_gstring(g
);
4504 while ((cr
= Ustrchr(g
->s
, '\r')) != NULL
) /* lose CRs */
4505 memmove(cr
, cr
+ 1, (g
->ptr
--) - (cr
- g
->s
));
4506 debug_printf("SMTP>> %s", g
->s
);
4508 fl
.helo_seen
= TRUE
;
4510 /* Reset the protocol and the state, abandoning any previous message. */
4512 (sender_host_address
? protocols
: protocols_local
)
4514 ? pextend
+ (sender_host_authenticated
? pauthed
: 0)
4516 + (tls_in
.active
.sock
>= 0 ? pcrpted
: 0)
4518 cancel_cutthrough_connection(TRUE
, US
"sent EHLO response");
4519 reset_point
= smtp_reset(reset_point
);
4521 break; /* HELO/EHLO */
4524 /* The MAIL command requires an address as an operand. All we do
4525 here is to parse it for syntactic correctness. The form "<>" is
4526 a special case which converts into an empty string. The start/end
4527 pointers in the original are not used further for this address, as
4528 it is the canonical extracted address which is all that is kept. */
4532 smtp_mailcmd_count
++; /* Count for limit and ratelimit */
4533 was_rej_mail
= TRUE
; /* Reset if accepted */
4534 env_mail_type_t
* mail_args
; /* Sanity check & validate args */
4536 if (fl
.helo_required
&& !fl
.helo_seen
)
4538 smtp_printf("503 HELO or EHLO required\r\n", FALSE
);
4539 log_write(0, LOG_MAIN
|LOG_REJECT
, "rejected MAIL from %s: no "
4540 "HELO/EHLO given", host_and_ident(FALSE
));
4546 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4547 US
"sender already given");
4551 if (!*smtp_cmd_data
)
4553 done
= synprot_error(L_smtp_protocol_error
, 501, NULL
,
4554 US
"MAIL must have an address operand");
4558 /* Check to see if the limit for messages per connection would be
4559 exceeded by accepting further messages. */
4561 if (smtp_accept_max_per_connection
> 0 &&
4562 smtp_mailcmd_count
> smtp_accept_max_per_connection
)
4564 smtp_printf("421 too many messages in this connection\r\n", FALSE
);
4565 log_write(0, LOG_MAIN
|LOG_REJECT
, "rejected MAIL command %s: too many "
4566 "messages in one connection", host_and_ident(TRUE
));
4570 /* Reset for start of message - even if this is going to fail, we
4571 obviously need to throw away any previous data. */
4573 cancel_cutthrough_connection(TRUE
, US
"MAIL received");
4574 reset_point
= smtp_reset(reset_point
);
4576 sender_data
= recipient_data
= NULL
;
4578 /* Loop, checking for ESMTP additions to the MAIL FROM command. */
4580 if (fl
.esmtp
) for(;;)
4582 uschar
*name
, *value
, *end
;
4583 unsigned long int size
;
4584 BOOL arg_error
= FALSE
;
4586 if (!extract_option(&name
, &value
)) break;
4588 for (mail_args
= env_mail_type_list
;
4589 mail_args
->value
!= ENV_MAIL_OPT_NULL
;
4592 if (strcmpic(name
, mail_args
->name
) == 0)
4594 if (mail_args
->need_value
&& strcmpic(value
, US
"") == 0)
4597 switch(mail_args
->value
)
4599 /* Handle SIZE= by reading the value. We don't do the check till later,
4600 in order to be able to log the sender address on failure. */
4601 case ENV_MAIL_OPT_SIZE
:
4602 if (((size
= Ustrtoul(value
, &end
, 10)), *end
== 0))
4604 if ((size
== ULONG_MAX
&& errno
== ERANGE
) || size
> INT_MAX
)
4606 message_size
= (int)size
;
4612 /* If this session was initiated with EHLO and accept_8bitmime is set,
4613 Exim will have indicated that it supports the BODY=8BITMIME option. In
4614 fact, it does not support this according to the RFCs, in that it does not
4615 take any special action for forwarding messages containing 8-bit
4616 characters. That is why accept_8bitmime is not the default setting, but
4617 some sites want the action that is provided. We recognize both "8BITMIME"
4618 and "7BIT" as body types, but take no action. */
4619 case ENV_MAIL_OPT_BODY
:
4620 if (accept_8bitmime
) {
4621 if (strcmpic(value
, US
"8BITMIME") == 0)
4623 else if (strcmpic(value
, US
"7BIT") == 0)
4628 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4629 US
"invalid data for BODY");
4632 DEBUG(D_receive
) debug_printf("8BITMIME: %d\n", body_8bitmime
);
4638 /* Handle the two DSN options, but only if configured to do so (which
4639 will have caused "DSN" to be given in the EHLO response). The code itself
4640 is included only if configured in at build time. */
4642 case ENV_MAIL_OPT_RET
:
4643 if (fl
.dsn_advertised
)
4645 /* Check if RET has already been set */
4648 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4649 US
"RET can be specified once only");
4652 dsn_ret
= strcmpic(value
, US
"HDRS") == 0
4654 : strcmpic(value
, US
"FULL") == 0
4657 DEBUG(D_receive
) debug_printf("DSN_RET: %d\n", dsn_ret
);
4658 /* Check for invalid invalid value, and exit with error */
4661 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4662 US
"Value for RET is invalid");
4667 case ENV_MAIL_OPT_ENVID
:
4668 if (fl
.dsn_advertised
)
4670 /* Check if the dsn envid has been already set */
4673 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4674 US
"ENVID can be specified once only");
4677 dsn_envid
= string_copy(value
);
4678 DEBUG(D_receive
) debug_printf("DSN_ENVID: %s\n", dsn_envid
);
4682 /* Handle the AUTH extension. If the value given is not "<>" and either
4683 the ACL says "yes" or there is no ACL but the sending host is
4684 authenticated, we set it up as the authenticated sender. However, if the
4685 authenticator set a condition to be tested, we ignore AUTH on MAIL unless
4686 the condition is met. The value of AUTH is an xtext, which means that +,
4687 = and cntrl chars are coded in hex; however "<>" is unaffected by this
4689 case ENV_MAIL_OPT_AUTH
:
4690 if (Ustrcmp(value
, "<>") != 0)
4695 if (auth_xtextdecode(value
, &authenticated_sender
) < 0)
4697 /* Put back terminator overrides for error message */
4700 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4701 US
"invalid data for AUTH");
4704 if (!acl_smtp_mailauth
)
4706 ignore_msg
= US
"client not authenticated";
4707 rc
= sender_host_authenticated
? OK
: FAIL
;
4711 ignore_msg
= US
"rejected by ACL";
4712 rc
= acl_check(ACL_WHERE_MAILAUTH
, NULL
, acl_smtp_mailauth
,
4713 &user_msg
, &log_msg
);
4719 if (authenticated_by
== NULL
||
4720 authenticated_by
->mail_auth_condition
== NULL
||
4721 expand_check_condition(authenticated_by
->mail_auth_condition
,
4722 authenticated_by
->name
, US
"authenticator"))
4723 break; /* Accept the AUTH */
4725 ignore_msg
= US
"server_mail_auth_condition failed";
4726 if (authenticated_id
!= NULL
)
4727 ignore_msg
= string_sprintf("%s: authenticated ID=\"%s\"",
4728 ignore_msg
, authenticated_id
);
4733 authenticated_sender
= NULL
;
4734 log_write(0, LOG_MAIN
, "ignoring AUTH=%s from %s (%s)",
4735 value
, host_and_ident(TRUE
), ignore_msg
);
4738 /* Should only get DEFER or ERROR here. Put back terminator
4739 overrides for error message */
4744 (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH
, rc
, user_msg
,
4751 #ifndef DISABLE_PRDR
4752 case ENV_MAIL_OPT_PRDR
:
4754 prdr_requested
= TRUE
;
4759 case ENV_MAIL_OPT_UTF8
:
4760 if (!fl
.smtputf8_advertised
)
4762 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4763 US
"SMTPUTF8 used when not advertised");
4767 DEBUG(D_receive
) debug_printf("smtputf8 requested\n");
4768 message_smtputf8
= allow_utf8_domains
= TRUE
;
4769 if (Ustrncmp(received_protocol
, US
"utf8", 4) != 0)
4771 int old_pool
= store_pool
;
4772 store_pool
= POOL_PERM
;
4773 received_protocol
= string_sprintf("utf8%s", received_protocol
);
4774 store_pool
= old_pool
;
4779 /* No valid option. Stick back the terminator characters and break
4780 the loop. Do the name-terminator second as extract_option sets
4781 value==name when it found no equal-sign.
4782 An error for a malformed address will occur. */
4783 case ENV_MAIL_OPT_NULL
:
4791 /* Break out of for loop if switch() had bad argument or
4792 when start of the email address is reached */
4793 if (arg_error
) break;
4796 /* If we have passed the threshold for rate limiting, apply the current
4797 delay, and update it for next time, provided this is a limited host. */
4799 if (smtp_mailcmd_count
> smtp_rlm_threshold
&&
4800 verify_check_host(&smtp_ratelimit_hosts
) == OK
)
4802 DEBUG(D_receive
) debug_printf("rate limit MAIL: delay %.3g sec\n",
4803 smtp_delay_mail
/1000.0);
4804 millisleep((int)smtp_delay_mail
);
4805 smtp_delay_mail
*= smtp_rlm_factor
;
4806 if (smtp_delay_mail
> (double)smtp_rlm_limit
)
4807 smtp_delay_mail
= (double)smtp_rlm_limit
;
4810 /* Now extract the address, first applying any SMTP-time rewriting. The
4811 TRUE flag allows "<>" as a sender address. */
4813 raw_sender
= rewrite_existflags
& rewrite_smtp
4814 ? rewrite_one(smtp_cmd_data
, rewrite_smtp
, NULL
, FALSE
, US
"",
4815 global_rewrite_rules
)
4819 parse_extract_address(raw_sender
, &errmess
, &start
, &end
, &sender_domain
,
4824 done
= synprot_error(L_smtp_syntax_error
, 501, smtp_cmd_data
, errmess
);
4828 sender_address
= raw_sender
;
4830 /* If there is a configured size limit for mail, check that this message
4831 doesn't exceed it. The check is postponed to this point so that the sender
4834 if (thismessage_size_limit
> 0 && message_size
> thismessage_size_limit
)
4836 smtp_printf("552 Message size exceeds maximum permitted\r\n", FALSE
);
4837 log_write(L_size_reject
,
4838 LOG_MAIN
|LOG_REJECT
, "rejected MAIL FROM:<%s> %s: "
4839 "message too big: size%s=%d max=%d",
4841 host_and_ident(TRUE
),
4842 (message_size
== INT_MAX
)? ">" : "",
4844 thismessage_size_limit
);
4845 sender_address
= NULL
;
4849 /* Check there is enough space on the disk unless configured not to.
4850 When smtp_check_spool_space is set, the check is for thismessage_size_limit
4851 plus the current message - i.e. we accept the message only if it won't
4852 reduce the space below the threshold. Add 5000 to the size to allow for
4853 overheads such as the Received: line and storing of recipients, etc.
4854 By putting the check here, even when SIZE is not given, it allow VRFY
4855 and EXPN etc. to be used when space is short. */
4857 if (!receive_check_fs(
4858 (smtp_check_spool_space
&& message_size
>= 0)?
4859 message_size
+ 5000 : 0))
4861 smtp_printf("452 Space shortage, please try later\r\n", FALSE
);
4862 sender_address
= NULL
;
4866 /* If sender_address is unqualified, reject it, unless this is a locally
4867 generated message, or the sending host or net is permitted to send
4868 unqualified addresses - typically local machines behaving as MUAs -
4869 in which case just qualify the address. The flag is set above at the start
4870 of the SMTP connection. */
4872 if (!sender_domain
&& *sender_address
)
4873 if (f
.allow_unqualified_sender
)
4875 sender_domain
= Ustrlen(sender_address
) + 1;
4876 sender_address
= rewrite_address_qualify(sender_address
, FALSE
);
4877 DEBUG(D_receive
) debug_printf("unqualified address %s accepted\n",
4882 smtp_printf("501 %s: sender address must contain a domain\r\n", FALSE
,
4884 log_write(L_smtp_syntax_error
,
4885 LOG_MAIN
|LOG_REJECT
,
4886 "unqualified sender rejected: <%s> %s%s",
4888 host_and_ident(TRUE
),
4890 sender_address
= NULL
;
4894 /* Apply an ACL check if one is defined, before responding. Afterwards,
4895 when pipelining is not advertised, do another sync check in case the ACL
4896 delayed and the client started sending in the meantime. */
4900 rc
= acl_check(ACL_WHERE_MAIL
, NULL
, acl_smtp_mail
, &user_msg
, &log_msg
);
4901 if (rc
== OK
&& !f
.smtp_in_pipelining_advertised
&& !check_sync())
4907 if (rc
== OK
|| rc
== DISCARD
)
4909 BOOL more
= pipeline_response();
4912 smtp_printf("%s%s%s", more
, US
"250 OK",
4913 #ifndef DISABLE_PRDR
4914 prdr_requested
? US
", PRDR Requested" : US
"",
4921 #ifndef DISABLE_PRDR
4923 user_msg
= string_sprintf("%s%s", user_msg
, US
", PRDR Requested");
4925 smtp_user_msg(US
"250", user_msg
);
4927 smtp_delay_rcpt
= smtp_rlr_base
;
4928 f
.recipients_discarded
= (rc
== DISCARD
);
4929 was_rej_mail
= FALSE
;
4933 done
= smtp_handle_acl_fail(ACL_WHERE_MAIL
, rc
, user_msg
, log_msg
);
4934 sender_address
= NULL
;
4939 /* The RCPT command requires an address as an operand. There may be any
4940 number of RCPT commands, specifying multiple recipients. We build them all
4941 into a data structure. The start/end values given by parse_extract_address
4942 are not used, as we keep only the extracted address. */
4947 was_rcpt
= fl
.rcpt_in_progress
= TRUE
;
4949 /* There must be a sender address; if the sender was rejected and
4950 pipelining was advertised, we assume the client was pipelining, and do not
4951 count this as a protocol error. Reset was_rej_mail so that further RCPTs
4952 get the same treatment. */
4954 if (sender_address
== NULL
)
4956 if (f
.smtp_in_pipelining_advertised
&& last_was_rej_mail
)
4958 smtp_printf("503 sender not yet given\r\n", FALSE
);
4959 was_rej_mail
= TRUE
;
4963 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4964 US
"sender not yet given");
4965 was_rcpt
= FALSE
; /* Not a valid RCPT */
4971 /* Check for an operand */
4973 if (smtp_cmd_data
[0] == 0)
4975 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4976 US
"RCPT must have an address operand");
4981 /* Set the DSN flags orcpt and dsn_flags from the session*/
4985 if (fl
.esmtp
) for(;;)
4987 uschar
*name
, *value
;
4989 if (!extract_option(&name
, &value
))
4992 if (fl
.dsn_advertised
&& strcmpic(name
, US
"ORCPT") == 0)
4994 /* Check whether orcpt has been already set */
4997 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4998 US
"ORCPT can be specified once only");
5001 orcpt
= string_copy(value
);
5002 DEBUG(D_receive
) debug_printf("DSN orcpt: %s\n", orcpt
);
5005 else if (fl
.dsn_advertised
&& strcmpic(name
, US
"NOTIFY") == 0)
5007 /* Check if the notify flags have been already set */
5010 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
5011 US
"NOTIFY can be specified once only");
5014 if (strcmpic(value
, US
"NEVER") == 0)
5015 dsn_flags
|= rf_notify_never
;
5022 while (*pp
!= 0 && *pp
!= ',') pp
++;
5023 if (*pp
== ',') *pp
++ = 0;
5024 if (strcmpic(p
, US
"SUCCESS") == 0)
5026 DEBUG(D_receive
) debug_printf("DSN: Setting notify success\n");
5027 dsn_flags
|= rf_notify_success
;
5029 else if (strcmpic(p
, US
"FAILURE") == 0)
5031 DEBUG(D_receive
) debug_printf("DSN: Setting notify failure\n");
5032 dsn_flags
|= rf_notify_failure
;
5034 else if (strcmpic(p
, US
"DELAY") == 0)
5036 DEBUG(D_receive
) debug_printf("DSN: Setting notify delay\n");
5037 dsn_flags
|= rf_notify_delay
;
5041 /* Catch any strange values */
5042 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
5043 US
"Invalid value for NOTIFY parameter");
5048 DEBUG(D_receive
) debug_printf("DSN Flags: %x\n", dsn_flags
);
5052 /* Unknown option. Stick back the terminator characters and break
5053 the loop. An error for a malformed address will occur. */
5057 DEBUG(D_receive
) debug_printf("Invalid RCPT option: %s : %s\n", name
, value
);
5064 /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
5065 as a recipient address */
5067 recipient
= rewrite_existflags
& rewrite_smtp
5068 ? rewrite_one(smtp_cmd_data
, rewrite_smtp
, NULL
, FALSE
, US
"",
5069 global_rewrite_rules
)
5072 if (!(recipient
= parse_extract_address(recipient
, &errmess
, &start
, &end
,
5073 &recipient_domain
, FALSE
)))
5075 done
= synprot_error(L_smtp_syntax_error
, 501, smtp_cmd_data
, errmess
);
5080 /* If the recipient address is unqualified, reject it, unless this is a
5081 locally generated message. However, unqualified addresses are permitted
5082 from a configured list of hosts and nets - typically when behaving as
5083 MUAs rather than MTAs. Sad that SMTP is used for both types of traffic,
5084 really. The flag is set at the start of the SMTP connection.
5086 RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always
5087 assumed this meant "reserved local part", but the revision of RFC 821 and
5088 friends now makes it absolutely clear that it means *mailbox*. Consequently
5089 we must always qualify this address, regardless. */
5091 if (!recipient_domain
)
5092 if (!(recipient_domain
= qualify_recipient(&recipient
, smtp_cmd_data
,
5099 /* Check maximum allowed */
5101 if (rcpt_count
> recipients_max
&& recipients_max
> 0)
5103 if (recipients_max_reject
)
5106 smtp_printf("552 too many recipients\r\n", FALSE
);
5108 log_write(0, LOG_MAIN
|LOG_REJECT
, "too many recipients: message "
5109 "rejected: sender=<%s> %s", sender_address
, host_and_ident(TRUE
));
5114 smtp_printf("452 too many recipients\r\n", FALSE
);
5116 log_write(0, LOG_MAIN
|LOG_REJECT
, "too many recipients: excess "
5117 "temporarily rejected: sender=<%s> %s", sender_address
,
5118 host_and_ident(TRUE
));
5125 /* If we have passed the threshold for rate limiting, apply the current
5126 delay, and update it for next time, provided this is a limited host. */
5128 if (rcpt_count
> smtp_rlr_threshold
&&
5129 verify_check_host(&smtp_ratelimit_hosts
) == OK
)
5131 DEBUG(D_receive
) debug_printf("rate limit RCPT: delay %.3g sec\n",
5132 smtp_delay_rcpt
/1000.0);
5133 millisleep((int)smtp_delay_rcpt
);
5134 smtp_delay_rcpt
*= smtp_rlr_factor
;
5135 if (smtp_delay_rcpt
> (double)smtp_rlr_limit
)
5136 smtp_delay_rcpt
= (double)smtp_rlr_limit
;
5139 /* If the MAIL ACL discarded all the recipients, we bypass ACL checking
5140 for them. Otherwise, check the access control list for this recipient. As
5141 there may be a delay in this, re-check for a synchronization error
5142 afterwards, unless pipelining was advertised. */
5144 if (f
.recipients_discarded
)
5147 if ( (rc
= acl_check(ACL_WHERE_RCPT
, recipient
, acl_smtp_rcpt
, &user_msg
,
5149 && !f
.smtp_in_pipelining_advertised
&& !check_sync())
5152 /* The ACL was happy */
5156 BOOL more
= pipeline_response();
5159 smtp_user_msg(US
"250", user_msg
);
5161 smtp_printf("250 Accepted\r\n", more
);
5162 receive_add_recipient(recipient
, -1);
5164 /* Set the dsn flags in the recipients_list */
5165 recipients_list
[recipients_count
-1].orcpt
= orcpt
;
5166 recipients_list
[recipients_count
-1].dsn_flags
= dsn_flags
;
5168 DEBUG(D_receive
) debug_printf("DSN: orcpt: %s flags: %d\n",
5169 recipients_list
[recipients_count
-1].orcpt
,
5170 recipients_list
[recipients_count
-1].dsn_flags
);
5173 /* The recipient was discarded */
5175 else if (rc
== DISCARD
)
5178 smtp_user_msg(US
"250", user_msg
);
5180 smtp_printf("250 Accepted\r\n", FALSE
);
5183 log_write(0, LOG_MAIN
|LOG_REJECT
, "%s F=<%s> RCPT %s: "
5184 "discarded by %s ACL%s%s", host_and_ident(TRUE
),
5185 sender_address_unrewritten
? sender_address_unrewritten
: sender_address
,
5186 smtp_cmd_argument
, f
.recipients_discarded
? "MAIL" : "RCPT",
5187 log_msg
? US
": " : US
"", log_msg
? log_msg
: US
"");
5190 /* Either the ACL failed the address, or it was deferred. */
5194 if (rc
== FAIL
) rcpt_fail_count
++; else rcpt_defer_count
++;
5195 done
= smtp_handle_acl_fail(ACL_WHERE_RCPT
, rc
, user_msg
, log_msg
);
5200 /* The DATA command is legal only if it follows successful MAIL FROM
5201 and RCPT TO commands. However, if pipelining is advertised, a bad DATA is
5202 not counted as a protocol error if it follows RCPT (which must have been
5203 rejected if there are no recipients.) This function is complete when a
5204 valid DATA command is encountered.
5206 Note concerning the code used: RFC 2821 says this:
5208 - If there was no MAIL, or no RCPT, command, or all such commands
5209 were rejected, the server MAY return a "command out of sequence"
5210 (503) or "no valid recipients" (554) reply in response to the
5213 The example in the pipelining RFC 2920 uses 554, but I use 503 here
5214 because it is the same whether pipelining is in use or not.
5216 If all the RCPT commands that precede DATA provoked the same error message
5217 (often indicating some kind of system error), it is helpful to include it
5218 with the DATA rejection (an idea suggested by Tony Finch). */
5225 if (chunking_state
!= CHUNKING_OFFERED
)
5227 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5228 US
"BDAT command used when CHUNKING not advertised");
5232 /* grab size, endmarker */
5234 if (sscanf(CS smtp_cmd_data
, "%u %n", &chunking_datasize
, &n
) < 1)
5236 done
= synprot_error(L_smtp_protocol_error
, 501, NULL
,
5237 US
"missing size for BDAT command");
5240 chunking_state
= strcmpic(smtp_cmd_data
+n
, US
"LAST") == 0
5241 ? CHUNKING_LAST
: CHUNKING_ACTIVE
;
5242 chunking_data_left
= chunking_datasize
;
5243 DEBUG(D_receive
) debug_printf("chunking state %d, %d bytes\n",
5244 (int)chunking_state
, chunking_data_left
);
5246 /* push the current receive_* function on the "stack", and
5247 replace them by bdat_getc(), which in turn will use the lwr_receive_*
5248 functions to do the dirty work. */
5249 lwr_receive_getc
= receive_getc
;
5250 lwr_receive_getbuf
= receive_getbuf
;
5251 lwr_receive_ungetc
= receive_ungetc
;
5253 receive_getc
= bdat_getc
;
5254 receive_ungetc
= bdat_ungetc
;
5265 DATA_BDAT
: /* Common code for DATA and BDAT */
5266 #ifndef DISABLE_PIPE_CONNECT
5267 fl
.pipe_connect_acceptable
= FALSE
;
5269 if (!discarded
&& recipients_count
<= 0)
5271 if (fl
.rcpt_smtp_response_same
&& rcpt_smtp_response
!= NULL
)
5273 uschar
*code
= US
"503";
5274 int len
= Ustrlen(rcpt_smtp_response
);
5275 smtp_respond(code
, 3, FALSE
, US
"All RCPT commands were rejected with "
5277 /* Responses from smtp_printf() will have \r\n on the end */
5278 if (len
> 2 && rcpt_smtp_response
[len
-2] == '\r')
5279 rcpt_smtp_response
[len
-2] = 0;
5280 smtp_respond(code
, 3, FALSE
, rcpt_smtp_response
);
5282 if (f
.smtp_in_pipelining_advertised
&& last_was_rcpt
)
5283 smtp_printf("503 Valid RCPT command must precede %s\r\n", FALSE
,
5284 smtp_names
[smtp_connection_had
[smtp_ch_index
-1]]);
5286 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5287 smtp_connection_had
[smtp_ch_index
-1] == SCH_DATA
5288 ? US
"valid RCPT command must precede DATA"
5289 : US
"valid RCPT command must precede BDAT");
5291 if (chunking_state
> CHUNKING_OFFERED
)
5296 if (toomany
&& recipients_max_reject
)
5298 sender_address
= NULL
; /* This will allow a new MAIL without RSET */
5299 sender_address_unrewritten
= NULL
;
5300 smtp_printf("554 Too many recipients\r\n", FALSE
);
5304 if (chunking_state
> CHUNKING_OFFERED
)
5305 rc
= OK
; /* No predata ACL or go-ahead output for BDAT */
5308 /* If there is an ACL, re-check the synchronization afterwards, since the
5309 ACL may have delayed. To handle cutthrough delivery enforce a dummy call
5310 to get the DATA command sent. */
5312 if (acl_smtp_predata
== NULL
&& cutthrough
.cctx
.sock
< 0)
5316 uschar
* acl
= acl_smtp_predata
? acl_smtp_predata
: US
"accept";
5317 f
.enable_dollar_recipients
= TRUE
;
5318 rc
= acl_check(ACL_WHERE_PREDATA
, NULL
, acl
, &user_msg
,
5320 f
.enable_dollar_recipients
= FALSE
;
5321 if (rc
== OK
&& !check_sync())
5325 { /* Either the ACL failed the address, or it was deferred. */
5326 done
= smtp_handle_acl_fail(ACL_WHERE_PREDATA
, rc
, user_msg
, log_msg
);
5332 smtp_user_msg(US
"354", user_msg
);
5335 "354 Enter message, ending with \".\" on a line by itself\r\n", FALSE
);
5339 if (smtp_in
) /* all ACKs needed to ramp window up for bulk data */
5340 (void) setsockopt(fileno(smtp_in
), IPPROTO_TCP
, TCP_QUICKACK
,
5341 US
&on
, sizeof(on
));
5344 message_ended
= END_NOTENDED
; /* Indicate in middle of data */
5355 if (!(address
= parse_extract_address(smtp_cmd_data
, &errmess
,
5356 &start
, &end
, &recipient_domain
, FALSE
)))
5358 smtp_printf("501 %s\r\n", FALSE
, errmess
);
5362 if (!recipient_domain
)
5363 if (!(recipient_domain
= qualify_recipient(&address
, smtp_cmd_data
,
5367 if ((rc
= acl_check(ACL_WHERE_VRFY
, address
, acl_smtp_vrfy
,
5368 &user_msg
, &log_msg
)) != OK
)
5369 done
= smtp_handle_acl_fail(ACL_WHERE_VRFY
, rc
, user_msg
, log_msg
);
5373 address_item
* addr
= deliver_make_addr(address
, FALSE
);
5375 switch(verify_address(addr
, NULL
, vopt_is_recipient
| vopt_qualify
, -1,
5376 -1, -1, NULL
, NULL
, NULL
))
5379 s
= string_sprintf("250 <%s> is deliverable", address
);
5383 s
= (addr
->user_message
!= NULL
)?
5384 string_sprintf("451 <%s> %s", address
, addr
->user_message
) :
5385 string_sprintf("451 Cannot resolve <%s> at this time", address
);
5389 s
= (addr
->user_message
!= NULL
)?
5390 string_sprintf("550 <%s> %s", address
, addr
->user_message
) :
5391 string_sprintf("550 <%s> is not deliverable", address
);
5392 log_write(0, LOG_MAIN
, "VRFY failed for %s %s",
5393 smtp_cmd_argument
, host_and_ident(TRUE
));
5397 smtp_printf("%s\r\n", FALSE
, s
);
5405 rc
= acl_check(ACL_WHERE_EXPN
, NULL
, acl_smtp_expn
, &user_msg
, &log_msg
);
5407 done
= smtp_handle_acl_fail(ACL_WHERE_EXPN
, rc
, user_msg
, log_msg
);
5410 BOOL save_log_testing_mode
= f
.log_testing_mode
;
5411 f
.address_test_mode
= f
.log_testing_mode
= TRUE
;
5412 (void) verify_address(deliver_make_addr(smtp_cmd_data
, FALSE
),
5413 smtp_out
, vopt_is_recipient
| vopt_qualify
| vopt_expn
, -1, -1, -1,
5415 f
.address_test_mode
= FALSE
;
5416 f
.log_testing_mode
= save_log_testing_mode
; /* true for -bh */
5425 if (!fl
.tls_advertised
)
5427 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5428 US
"STARTTLS command used when not advertised");
5432 /* Apply an ACL check if one is defined */
5434 if ( acl_smtp_starttls
5435 && (rc
= acl_check(ACL_WHERE_STARTTLS
, NULL
, acl_smtp_starttls
,
5436 &user_msg
, &log_msg
)) != OK
5439 done
= smtp_handle_acl_fail(ACL_WHERE_STARTTLS
, rc
, user_msg
, log_msg
);
5443 /* RFC 2487 is not clear on when this command may be sent, though it
5444 does state that all information previously obtained from the client
5445 must be discarded if a TLS session is started. It seems reasonable to
5446 do an implied RSET when STARTTLS is received. */
5448 incomplete_transaction_log(US
"STARTTLS");
5449 cancel_cutthrough_connection(TRUE
, US
"STARTTLS received");
5450 reset_point
= smtp_reset(reset_point
);
5452 cmd_list
[CMD_LIST_STARTTLS
].is_mail_cmd
= FALSE
;
5454 /* There's an attack where more data is read in past the STARTTLS command
5455 before TLS is negotiated, then assumed to be part of the secure session
5456 when used afterwards; we use segregated input buffers, so are not
5457 vulnerable, but we want to note when it happens and, for sheer paranoia,
5458 ensure that the buffer is "wiped".
5459 Pipelining sync checks will normally have protected us too, unless disabled
5460 by configuration. */
5462 if (receive_smtp_buffered())
5465 debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n");
5466 if (tls_in
.active
.sock
< 0)
5467 smtp_inend
= smtp_inptr
= smtp_inbuffer
;
5468 /* and if TLS is already active, tls_server_start() should fail */
5471 /* There is nothing we value in the input buffer and if TLS is successfully
5472 negotiated, we won't use this buffer again; if TLS fails, we'll just read
5473 fresh content into it. The buffer contains arbitrary content from an
5474 untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n
5475 It seems safest to just wipe away the content rather than leave it as a
5476 target to jump to. */
5478 memset(smtp_inbuffer
, 0, IN_BUFFER_SIZE
);
5480 /* Attempt to start up a TLS session, and if successful, discard all
5481 knowledge that was obtained previously. At least, that's what the RFC says,
5482 and that's what happens by default. However, in order to work round YAEB,
5483 there is an option to remember the esmtp state. Sigh.
5485 We must allow for an extra EHLO command and an extra AUTH command after
5486 STARTTLS that don't add to the nonmail command count. */
5489 if ((rc
= tls_server_start(tls_require_ciphers
, &s
)) == OK
)
5491 if (!tls_remember_esmtp
)
5492 fl
.helo_seen
= fl
.esmtp
= fl
.auth_advertised
= f
.smtp_in_pipelining_advertised
= FALSE
;
5493 cmd_list
[CMD_LIST_EHLO
].is_mail_cmd
= TRUE
;
5494 cmd_list
[CMD_LIST_AUTH
].is_mail_cmd
= TRUE
;
5495 cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
= TRUE
;
5496 if (sender_helo_name
)
5498 sender_helo_name
= NULL
;
5499 host_build_sender_fullhost(); /* Rebuild */
5500 set_process_info("handling incoming TLS connection from %s",
5501 host_and_ident(FALSE
));
5504 (sender_host_address
? protocols
: protocols_local
)
5506 ? pextend
+ (sender_host_authenticated
? pauthed
: 0)
5508 + (tls_in
.active
.sock
>= 0 ? pcrpted
: 0)
5511 sender_host_auth_pubname
= sender_host_authenticated
= NULL
;
5512 authenticated_id
= NULL
;
5513 sync_cmd_limit
= NON_SYNC_CMD_NON_PIPELINING
;
5514 DEBUG(D_tls
) debug_printf("TLS active\n");
5515 break; /* Successful STARTTLS */
5518 (void) smtp_log_tls_fail(s
);
5520 /* Some local configuration problem was discovered before actually trying
5521 to do a TLS handshake; give a temporary error. */
5525 smtp_printf("454 TLS currently unavailable\r\n", FALSE
);
5529 /* Hard failure. Reject everything except QUIT or closed connection. One
5530 cause for failure is a nested STARTTLS, in which case tls_in.active remains
5531 set, but we must still reject all incoming commands. Another is a handshake
5532 failure - and there may some encrypted data still in the pipe to us, which we
5533 see as garbage commands. */
5535 DEBUG(D_tls
) debug_printf("TLS failed to start\n");
5536 while (done
<= 0) switch(smtp_read_command(FALSE
, GETC_BUFFER_UNLIMITED
))
5539 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by EOF",
5540 smtp_get_connection_info());
5541 smtp_notquit_exit(US
"tls-failed", NULL
, NULL
);
5545 /* It is perhaps arguable as to which exit ACL should be called here,
5546 but as it is probably a situation that almost never arises, it
5547 probably doesn't matter. We choose to call the real QUIT ACL, which in
5548 some sense is perhaps "right". */
5553 && ((rc
= acl_check(ACL_WHERE_QUIT
, NULL
, acl_smtp_quit
, &user_msg
,
5554 &log_msg
)) == ERROR
))
5555 log_write(0, LOG_MAIN
|LOG_PANIC
, "ACL for QUIT returned ERROR: %s",
5558 smtp_respond(US
"221", 3, TRUE
, user_msg
);
5560 smtp_printf("221 %s closing connection\r\n", FALSE
, smtp_active_hostname
);
5561 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by QUIT",
5562 smtp_get_connection_info());
5567 smtp_printf("554 Security failure\r\n", FALSE
);
5570 tls_close(NULL
, TLS_SHUTDOWN_NOWAIT
);
5575 /* The ACL for QUIT is provided for gathering statistical information or
5576 similar; it does not affect the response code, but it can supply a custom
5580 smtp_quit_handler(&user_msg
, &log_msg
);
5586 smtp_rset_handler();
5587 cancel_cutthrough_connection(TRUE
, US
"RSET received");
5588 reset_point
= smtp_reset(reset_point
);
5595 smtp_printf("250 OK\r\n", FALSE
);
5599 /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually
5600 used, a check will be done for permitted hosts. Show STARTTLS only if not
5601 already in a TLS session and if it would be advertised in the EHLO
5606 smtp_printf("214-Commands supported:\r\n", TRUE
);
5610 Ustrcat(buffer
, US
" AUTH");
5612 if (tls_in
.active
.sock
< 0 &&
5613 verify_check_host(&tls_advertise_hosts
) != FAIL
)
5614 Ustrcat(buffer
, US
" STARTTLS");
5616 Ustrcat(buffer
, US
" HELO EHLO MAIL RCPT DATA BDAT");
5617 Ustrcat(buffer
, US
" NOOP QUIT RSET HELP");
5618 if (acl_smtp_etrn
) Ustrcat(buffer
, US
" ETRN");
5619 if (acl_smtp_expn
) Ustrcat(buffer
, US
" EXPN");
5620 if (acl_smtp_vrfy
) Ustrcat(buffer
, US
" VRFY");
5621 smtp_printf("214%s\r\n", FALSE
, buffer
);
5627 incomplete_transaction_log(US
"connection lost");
5628 smtp_notquit_exit(US
"connection-lost", US
"421",
5629 US
"%s lost input connection", smtp_active_hostname
);
5631 /* Don't log by default unless in the middle of a message, as some mailers
5632 just drop the call rather than sending QUIT, and it clutters up the logs.
5635 if (sender_address
|| recipients_count
> 0)
5636 log_write(L_lost_incoming_connection
, LOG_MAIN
,
5637 "unexpected %s while reading SMTP command from %s%s%s D=%s",
5638 f
.sender_host_unknown
? "EOF" : "disconnection",
5639 f
.tcp_in_fastopen_logged
5642 ? f
.tcp_in_fastopen_data
? US
"TFO* " : US
"TFO "
5644 host_and_ident(FALSE
), smtp_read_error
,
5645 string_timesince(&smtp_connection_start
)
5649 log_write(L_smtp_connection
, LOG_MAIN
, "%s %slost%s D=%s",
5650 smtp_get_connection_info(),
5651 f
.tcp_in_fastopen
&& !f
.tcp_in_fastopen_logged
? US
"TFO " : US
"",
5653 string_timesince(&smtp_connection_start
)
5664 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5665 US
"ETRN is not permitted inside a transaction");
5669 log_write(L_etrn
, LOG_MAIN
, "ETRN %s received from %s", smtp_cmd_argument
,
5670 host_and_ident(FALSE
));
5672 if ((rc
= acl_check(ACL_WHERE_ETRN
, NULL
, acl_smtp_etrn
,
5673 &user_msg
, &log_msg
)) != OK
)
5675 done
= smtp_handle_acl_fail(ACL_WHERE_ETRN
, rc
, user_msg
, log_msg
);
5679 /* Compute the serialization key for this command. */
5681 etrn_serialize_key
= string_sprintf("etrn-%s\n", smtp_cmd_data
);
5683 /* If a command has been specified for running as a result of ETRN, we
5684 permit any argument to ETRN. If not, only the # standard form is permitted,
5685 since that is strictly the only kind of ETRN that can be implemented
5686 according to the RFC. */
5688 if (smtp_etrn_command
)
5692 etrn_command
= smtp_etrn_command
;
5693 deliver_domain
= smtp_cmd_data
;
5694 rc
= transport_set_up_command(&argv
, smtp_etrn_command
, TRUE
, 0, NULL
,
5695 US
"ETRN processing", &error
);
5696 deliver_domain
= NULL
;
5699 log_write(0, LOG_MAIN
|LOG_PANIC
, "failed to set up ETRN command: %s",
5701 smtp_printf("458 Internal failure\r\n", FALSE
);
5706 /* Else set up to call Exim with the -R option. */
5710 if (*smtp_cmd_data
++ != '#')
5712 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
5713 US
"argument must begin with #");
5716 etrn_command
= US
"exim -R";
5717 argv
= CUSS
child_exec_exim(CEE_RETURN_ARGV
, TRUE
, NULL
, TRUE
,
5718 *queue_name
? 4 : 2,
5719 US
"-R", smtp_cmd_data
,
5720 US
"-MCG", queue_name
);
5723 /* If we are host-testing, don't actually do anything. */
5729 debug_printf("ETRN command is: %s\n", etrn_command
);
5730 debug_printf("ETRN command execution skipped\n");
5732 if (user_msg
== NULL
) smtp_printf("250 OK\r\n", FALSE
);
5733 else smtp_user_msg(US
"250", user_msg
);
5738 /* If ETRN queue runs are to be serialized, check the database to
5739 ensure one isn't already running. */
5741 if (smtp_etrn_serialize
&& !enq_start(etrn_serialize_key
, 1))
5743 smtp_printf("458 Already processing %s\r\n", FALSE
, smtp_cmd_data
);
5747 /* Fork a child process and run the command. We don't want to have to
5748 wait for the process at any point, so set SIGCHLD to SIG_IGN before
5749 forking. It should be set that way anyway for external incoming SMTP,
5750 but we save and restore to be tidy. If serialization is required, we
5751 actually run the command in yet another process, so we can wait for it
5752 to complete and then remove the serialization lock. */
5754 oldsignal
= signal(SIGCHLD
, SIG_IGN
);
5756 if ((pid
= fork()) == 0)
5758 smtp_input
= FALSE
; /* This process is not associated with the */
5759 (void)fclose(smtp_in
); /* SMTP call any more. */
5760 (void)fclose(smtp_out
);
5762 signal(SIGCHLD
, SIG_DFL
); /* Want to catch child */
5764 /* If not serializing, do the exec right away. Otherwise, fork down
5765 into another process. */
5767 if (!smtp_etrn_serialize
|| (pid
= fork()) == 0)
5769 DEBUG(D_exec
) debug_print_argv(argv
);
5770 exim_nullstd(); /* Ensure std{in,out,err} exist */
5771 execv(CS argv
[0], (char *const *)argv
);
5772 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "exec of \"%s\" (ETRN) failed: %s",
5773 etrn_command
, strerror(errno
));
5774 _exit(EXIT_FAILURE
); /* paranoia */
5777 /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That
5778 is, we are in the first subprocess, after forking again. All we can do
5779 for a failing fork is to log it. Otherwise, wait for the 2nd process to
5780 complete, before removing the serialization. */
5783 log_write(0, LOG_MAIN
|LOG_PANIC
, "2nd fork for serialized ETRN "
5784 "failed: %s", strerror(errno
));
5788 DEBUG(D_any
) debug_printf("waiting for serialized ETRN process %d\n",
5790 (void)wait(&status
);
5791 DEBUG(D_any
) debug_printf("serialized ETRN process %d ended\n",
5795 enq_end(etrn_serialize_key
);
5796 exim_underbar_exit(EXIT_SUCCESS
);
5799 /* Back in the top level SMTP process. Check that we started a subprocess
5800 and restore the signal state. */
5804 log_write(0, LOG_MAIN
|LOG_PANIC
, "fork of process for ETRN failed: %s",
5806 smtp_printf("458 Unable to fork process\r\n", FALSE
);
5807 if (smtp_etrn_serialize
) enq_end(etrn_serialize_key
);
5811 smtp_printf("250 OK\r\n", FALSE
);
5813 smtp_user_msg(US
"250", user_msg
);
5815 signal(SIGCHLD
, oldsignal
);
5820 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
5821 US
"unexpected argument data");
5825 /* This currently happens only for NULLs, but could be extended. */
5828 done
= synprot_error(L_smtp_syntax_error
, 0, NULL
, /* Just logs */
5829 US
"NUL character(s) present (shown as '?')");
5830 smtp_printf("501 NUL characters are not allowed in SMTP commands\r\n",
5837 if (smtp_inend
>= smtp_inbuffer
+ IN_BUFFER_SIZE
)
5838 smtp_inend
= smtp_inbuffer
+ IN_BUFFER_SIZE
- 1;
5839 c
= smtp_inend
- smtp_inptr
;
5840 if (c
> 150) c
= 150; /* limit logged amount */
5842 incomplete_transaction_log(US
"sync failure");
5843 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP protocol synchronization error "
5844 "(next input sent too soon: pipelining was%s advertised): "
5845 "rejected \"%s\" %s next input=\"%s\"",
5846 f
.smtp_in_pipelining_advertised
? "" : " not",
5847 smtp_cmd_buffer
, host_and_ident(TRUE
),
5848 string_printing(smtp_inptr
));
5849 smtp_notquit_exit(US
"synchronization-error", US
"554",
5850 US
"SMTP synchronization error");
5851 done
= 1; /* Pretend eof - drops connection */
5855 case TOO_MANY_NONMAIL_CMD
:
5856 s
= smtp_cmd_buffer
;
5857 while (*s
!= 0 && !isspace(*s
)) s
++;
5858 incomplete_transaction_log(US
"too many non-mail commands");
5859 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
5860 "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE
),
5861 (int)(s
- smtp_cmd_buffer
), smtp_cmd_buffer
);
5862 smtp_notquit_exit(US
"bad-commands", US
"554", US
"Too many nonmail commands");
5863 done
= 1; /* Pretend eof - drops connection */
5866 #ifdef SUPPORT_PROXY
5867 case PROXY_FAIL_IGNORE_CMD
:
5868 smtp_printf("503 Command refused, required Proxy negotiation failed\r\n", FALSE
);
5873 if (unknown_command_count
++ >= smtp_max_unknown_commands
)
5875 log_write(L_smtp_syntax_error
, LOG_MAIN
,
5876 "SMTP syntax error in \"%s\" %s %s",
5877 string_printing(smtp_cmd_buffer
), host_and_ident(TRUE
),
5878 US
"unrecognized command");
5879 incomplete_transaction_log(US
"unrecognized command");
5880 smtp_notquit_exit(US
"bad-commands", US
"500",
5881 US
"Too many unrecognized commands");
5883 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
5884 "unrecognized commands (last was \"%s\")", host_and_ident(FALSE
),
5885 string_printing(smtp_cmd_buffer
));
5888 done
= synprot_error(L_smtp_syntax_error
, 500, NULL
,
5889 US
"unrecognized command");
5893 /* This label is used by goto's inside loops that want to break out to
5894 the end of the command-processing loop. */
5897 last_was_rej_mail
= was_rej_mail
; /* Remember some last commands for */
5898 last_was_rcpt
= was_rcpt
; /* protocol error handling */
5902 return done
- 2; /* Convert yield values */
5908 authres_smtpauth(gstring
* g
)
5910 if (!sender_host_authenticated
)
5913 g
= string_append(g
, 2, US
";\n\tauth=pass (", sender_host_auth_pubname
);
5915 if (Ustrcmp(sender_host_auth_pubname
, "tls") != 0)
5916 g
= string_append(g
, 2, US
") smtp.auth=", authenticated_id
);
5917 else if (authenticated_id
)
5918 g
= string_append(g
, 2, US
") x509.auth=", authenticated_id
);
5920 g
= string_catn(g
, US
") reason=x509.auth", 17);
5922 if (authenticated_sender
)
5923 g
= string_append(g
, 2, US
" smtp.mailfrom=", authenticated_sender
);
5931 /* End of smtp_in.c */