1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2017 */
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 *************************************************/
134 static auth_instance
*authenticated_by
;
135 static BOOL auth_advertised
;
137 static BOOL tls_advertised
;
139 static BOOL dsn_advertised
;
141 static BOOL helo_required
= FALSE
;
142 static BOOL helo_verify
= FALSE
;
143 static BOOL helo_seen
;
144 static BOOL helo_accept_junk
;
145 static BOOL count_nonmail
;
146 static BOOL pipelining_advertised
;
147 static BOOL rcpt_smtp_response_same
;
148 static BOOL rcpt_in_progress
;
149 static int nonmail_command_count
;
150 static BOOL smtp_exit_function_called
= 0;
152 static BOOL smtputf8_advertised
;
154 static int synprot_error_count
;
155 static int unknown_command_count
;
156 static int sync_cmd_limit
;
157 static int smtp_write_error
= 0;
159 static uschar
*rcpt_smtp_response
;
160 static uschar
*smtp_data_buffer
;
161 static uschar
*smtp_cmd_data
;
163 /* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
164 final fields of all except AUTH are forced TRUE at the start of a new message
165 setup, to allow one of each between messages that is not counted as a nonmail
166 command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
167 allow a new EHLO after starting up TLS.
169 AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
170 counted. However, the flag is changed when AUTH is received, so that multiple
171 failing AUTHs will eventually hit the limit. After a successful AUTH, another
172 AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
173 forced TRUE, to allow for the re-authentication that can happen at that point.
175 QUIT is also "falsely" labelled as a mail command so that it doesn't up the
176 count of non-mail commands and possibly provoke an error.
178 tls_auth is a pseudo-command, never expected in input. It is activated
179 on TLS startup and looks for a tls authenticator. */
181 static smtp_cmd_list cmd_list
[] = {
182 /* name len cmd has_arg is_mail_cmd */
184 { "rset", sizeof("rset")-1, RSET_CMD
, FALSE
, FALSE
}, /* First */
185 { "helo", sizeof("helo")-1, HELO_CMD
, TRUE
, FALSE
},
186 { "ehlo", sizeof("ehlo")-1, EHLO_CMD
, TRUE
, FALSE
},
187 { "auth", sizeof("auth")-1, AUTH_CMD
, TRUE
, TRUE
},
189 { "starttls", sizeof("starttls")-1, STARTTLS_CMD
, FALSE
, FALSE
},
190 { "tls_auth", 0, TLS_AUTH_CMD
, FALSE
, TRUE
},
193 /* If you change anything above here, also fix the definitions below. */
195 { "mail from:", sizeof("mail from:")-1, MAIL_CMD
, TRUE
, TRUE
},
196 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD
, TRUE
, TRUE
},
197 { "data", sizeof("data")-1, DATA_CMD
, FALSE
, TRUE
},
198 { "bdat", sizeof("bdat")-1, BDAT_CMD
, TRUE
, TRUE
},
199 { "quit", sizeof("quit")-1, QUIT_CMD
, FALSE
, TRUE
},
200 { "noop", sizeof("noop")-1, NOOP_CMD
, TRUE
, FALSE
},
201 { "etrn", sizeof("etrn")-1, ETRN_CMD
, TRUE
, FALSE
},
202 { "vrfy", sizeof("vrfy")-1, VRFY_CMD
, TRUE
, FALSE
},
203 { "expn", sizeof("expn")-1, EXPN_CMD
, TRUE
, FALSE
},
204 { "help", sizeof("help")-1, HELP_CMD
, TRUE
, FALSE
}
207 static smtp_cmd_list
*cmd_list_end
=
208 cmd_list
+ sizeof(cmd_list
)/sizeof(smtp_cmd_list
);
210 #define CMD_LIST_RSET 0
211 #define CMD_LIST_HELO 1
212 #define CMD_LIST_EHLO 2
213 #define CMD_LIST_AUTH 3
214 #define CMD_LIST_STARTTLS 4
215 #define CMD_LIST_TLS_AUTH 5
217 /* This list of names is used for performing the smtp_no_mail logging action.
218 It must be kept in step with the SCH_xxx enumerations. */
220 static uschar
*smtp_names
[] =
222 US
"NONE", US
"AUTH", US
"DATA", US
"BDAT", US
"EHLO", US
"ETRN", US
"EXPN",
223 US
"HELO", US
"HELP", US
"MAIL", US
"NOOP", US
"QUIT", US
"RCPT", US
"RSET",
224 US
"STARTTLS", US
"VRFY" };
226 static uschar
*protocols_local
[] = {
227 US
"local-smtp", /* HELO */
228 US
"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
229 US
"local-esmtp", /* EHLO */
230 US
"local-esmtps", /* EHLO->STARTTLS->EHLO */
231 US
"local-esmtpa", /* EHLO->AUTH */
232 US
"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
234 static uschar
*protocols
[] = {
236 US
"smtps", /* The rare case EHLO->STARTTLS->HELO */
237 US
"esmtp", /* EHLO */
238 US
"esmtps", /* EHLO->STARTTLS->EHLO */
239 US
"esmtpa", /* EHLO->AUTH */
240 US
"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
245 #define pcrpted 1 /* added to pextend or pnormal */
246 #define pauthed 2 /* added to pextend */
248 /* Sanity check and validate optional args to MAIL FROM: envelope */
251 ENV_MAIL_OPT_SIZE
, ENV_MAIL_OPT_BODY
, ENV_MAIL_OPT_AUTH
,
255 ENV_MAIL_OPT_RET
, ENV_MAIL_OPT_ENVID
,
261 uschar
* name
; /* option requested during MAIL cmd */
262 int value
; /* enum type */
263 BOOL need_value
; /* TRUE requires value (name=value pair format)
264 FALSE is a singleton */
266 static env_mail_type_t env_mail_type_list
[] = {
267 { US
"SIZE", ENV_MAIL_OPT_SIZE
, TRUE
},
268 { US
"BODY", ENV_MAIL_OPT_BODY
, TRUE
},
269 { US
"AUTH", ENV_MAIL_OPT_AUTH
, TRUE
},
271 { US
"PRDR", ENV_MAIL_OPT_PRDR
, FALSE
},
273 { US
"RET", ENV_MAIL_OPT_RET
, TRUE
},
274 { US
"ENVID", ENV_MAIL_OPT_ENVID
, TRUE
},
276 { US
"SMTPUTF8",ENV_MAIL_OPT_UTF8
, FALSE
}, /* rfc6531 */
278 /* keep this the last entry */
279 { US
"NULL", ENV_MAIL_OPT_NULL
, FALSE
},
282 /* When reading SMTP from a remote host, we have to use our own versions of the
283 C input-reading functions, in order to be able to flush the SMTP output only
284 when about to read more data from the socket. This is the only way to get
285 optimal performance when the client is using pipelining. Flushing for every
286 command causes a separate packet and reply packet each time; saving all the
287 responses up (when pipelining) combines them into one packet and one response.
289 For simplicity, these functions are used for *all* SMTP input, not only when
290 receiving over a socket. However, after setting up a secure socket (SSL), input
291 is read via the OpenSSL library, and another set of functions is used instead
294 These functions are set in the receive_getc etc. variables and called with the
295 same interface as the C functions. However, since there can only ever be
296 one incoming SMTP call, we just use a single buffer and flags. There is no need
297 to implement a complicated private FILE-like structure.*/
299 static uschar
*smtp_inbuffer
;
300 static uschar
*smtp_inptr
;
301 static uschar
*smtp_inend
;
302 static int smtp_had_eof
;
303 static int smtp_had_error
;
306 /* forward declarations */
307 static int smtp_read_command(BOOL check_sync
, unsigned buffer_lim
);
308 static int synprot_error(int type
, int code
, uschar
*data
, uschar
*errmess
);
309 static void smtp_quit_handler(uschar
**, uschar
**);
310 static void smtp_rset_handler(void);
312 /*************************************************
313 * Recheck synchronization *
314 *************************************************/
316 /* Synchronization checks can never be perfect because a packet may be on its
317 way but not arrived when the check is done. Normally, the checks happen when
318 commands are read: Exim ensures that there is no more input in the input buffer.
319 In normal cases, the response to the command will be fast, and there is no
322 However, for some commands an ACL is run, and that can include delays. In those
323 cases, it is useful to do another check on the input just before sending the
324 response. This also applies at the start of a connection. This function does
325 that check by means of the select() function, as long as the facility is not
326 disabled or inappropriate. A failure of select() is ignored.
328 When there is unwanted input, we read it so that it appears in the log of the
332 Returns: TRUE if all is well; FALSE if there is input pending
336 wouldblock_reading(void)
340 struct timeval tzero
;
343 if (tls_in
.active
>= 0)
344 return !tls_could_read();
347 if (smtp_inptr
< smtp_inend
)
350 fd
= fileno(smtp_in
);
355 rc
= select(fd
+ 1, (SELECT_ARG2_TYPE
*)&fds
, NULL
, NULL
, &tzero
);
357 if (rc
<= 0) return TRUE
; /* Not ready to read */
358 rc
= smtp_getc(GETC_BUFFER_UNLIMITED
);
359 if (rc
< 0) return TRUE
; /* End of file or error */
362 rc
= smtp_inend
- smtp_inptr
;
363 if (rc
> 150) rc
= 150;
371 if (!smtp_enforce_sync
|| sender_host_address
== NULL
|| sender_host_notsocket
)
374 return wouldblock_reading();
378 /* If there's input waiting (and we're doing pipelineing) then we can pipeline
379 a reponse with the one following. */
382 pipeline_response(void)
384 if ( !smtp_enforce_sync
|| !sender_host_address
385 || sender_host_notsocket
|| !pipelining_advertised
)
388 return !wouldblock_reading();
393 /*************************************************
394 * Log incomplete transactions *
395 *************************************************/
397 /* This function is called after a transaction has been aborted by RSET, QUIT,
398 connection drops or other errors. It logs the envelope information received
399 so far in order to preserve address verification attempts.
401 Argument: string to indicate what aborted the transaction
406 incomplete_transaction_log(uschar
*what
)
408 if (sender_address
== NULL
|| /* No transaction in progress */
409 !LOGGING(smtp_incomplete_transaction
))
412 /* Build list of recipients for logging */
414 if (recipients_count
> 0)
417 raw_recipients
= store_get(recipients_count
* sizeof(uschar
*));
418 for (i
= 0; i
< recipients_count
; i
++)
419 raw_recipients
[i
] = recipients_list
[i
].address
;
420 raw_recipients_count
= recipients_count
;
423 log_write(L_smtp_incomplete_transaction
, LOG_MAIN
|LOG_SENDER
|LOG_RECIPIENTS
,
424 "%s incomplete transaction (%s)", host_and_ident(TRUE
), what
);
430 /* Refill the buffer, and notify DKIM verification code.
431 Return false for error or EOF.
435 smtp_refill(unsigned lim
)
438 if (!smtp_out
) return FALSE
;
440 if (smtp_receive_timeout
> 0) alarm(smtp_receive_timeout
);
442 /* Limit amount read, so non-message data is not fed to DKIM */
444 rc
= read(fileno(smtp_in
), smtp_inbuffer
, MIN(IN_BUFFER_SIZE
, lim
));
449 /* Must put the error text in fixed store, because this might be during
450 header reading, where it releases unused store above the header. */
453 smtp_had_error
= save_errno
;
454 smtp_read_error
= string_copy_malloc(
455 string_sprintf(" (error: %s)", strerror(save_errno
)));
457 else smtp_had_eof
= 1;
461 dkim_exim_verify_feed(smtp_inbuffer
, rc
);
463 smtp_inend
= smtp_inbuffer
+ rc
;
464 smtp_inptr
= smtp_inbuffer
;
468 /*************************************************
469 * SMTP version of getc() *
470 *************************************************/
472 /* This gets the next byte from the SMTP input buffer. If the buffer is empty,
473 it flushes the output, and refills the buffer, with a timeout. The signal
474 handler is set appropriately by the calling function. This function is not used
475 after a connection has negotiated itself into an TLS/SSL state.
477 Arguments: lim Maximum amount to read/buffer
478 Returns: the next character or EOF
482 smtp_getc(unsigned lim
)
484 if (smtp_inptr
>= smtp_inend
)
485 if (!smtp_refill(lim
))
487 return *smtp_inptr
++;
491 smtp_getbuf(unsigned * len
)
496 if (smtp_inptr
>= smtp_inend
)
497 if (!smtp_refill(*len
))
498 { *len
= 0; return NULL
; }
500 if ((size
= smtp_inend
- smtp_inptr
) > *len
) size
= *len
;
511 int n
= smtp_inend
- smtp_inptr
;
513 dkim_exim_verify_feed(smtp_inptr
, n
);
518 /* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
519 previous BDAT chunk and getting new ones when we run out. Uses the
520 underlying smtp_getc or tls_getc both for that and for getting the
521 (buffered) data byte. EOD signals (an expected) no further data.
522 ERR signals a protocol error, and EOF a closed input stream.
524 Called from read_bdat_smtp() in receive.c for the message body, but also
525 by the headers read loop in receive_msg(); manipulates chunking_state
526 to handle the BDAT command/response.
527 Placed here due to the correlation with the above smtp_getc(), which it wraps,
528 and also by the need to do smtp command/response handling.
530 Arguments: lim (ignored)
531 Returns: the next character or ERR, EOD or EOF
535 bdat_getc(unsigned lim
)
537 uschar
* user_msg
= NULL
;
546 if (chunking_data_left
> 0)
547 return lwr_receive_getc(chunking_data_left
--);
549 receive_getc
= lwr_receive_getc
;
550 receive_getbuf
= lwr_receive_getbuf
;
551 receive_ungetc
= lwr_receive_ungetc
;
553 dkim_save
= dkim_collect_input
;
554 dkim_collect_input
= FALSE
;
557 /* Unless PIPELINING was offered, there should be no next command
558 until after we ack that chunk */
560 if (!pipelining_advertised
&& !check_sync())
562 unsigned n
= smtp_inend
- smtp_inptr
;
565 incomplete_transaction_log(US
"sync failure");
566 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP protocol synchronization error "
567 "(next input sent too soon: pipelining was not advertised): "
568 "rejected \"%s\" %s next input=\"%s\"%s",
569 smtp_cmd_buffer
, host_and_ident(TRUE
),
570 string_printing(string_copyn(smtp_inptr
, n
)),
571 smtp_inend
- smtp_inptr
> n
? "..." : "");
572 (void) synprot_error(L_smtp_protocol_error
, 554, NULL
,
573 US
"SMTP synchronization error");
574 goto repeat_until_rset
;
577 /* If not the last, ack the received chunk. The last response is delayed
578 until after the data ACL decides on it */
580 if (chunking_state
== CHUNKING_LAST
)
583 dkim_exim_verify_feed(NULL
, 0); /* notify EOD */
588 smtp_printf("250 %u byte chunk received\r\n", FALSE
, chunking_datasize
);
589 chunking_state
= CHUNKING_OFFERED
;
590 DEBUG(D_receive
) debug_printf("chunking state %d\n", (int)chunking_state
);
592 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
593 QUIT, RSET or NOOP but handling them seems obvious */
596 switch(smtp_read_command(TRUE
, 1))
599 (void) synprot_error(L_smtp_protocol_error
, 503, NULL
,
600 US
"only BDAT permissible after non-LAST BDAT");
603 switch(smtp_read_command(TRUE
, 1))
605 case QUIT_CMD
: smtp_quit_handler(&user_msg
, &log_msg
); /*FALLTHROUGH */
606 case EOF_CMD
: return EOF
;
607 case RSET_CMD
: smtp_rset_handler(); return ERR
;
608 default: if (synprot_error(L_smtp_protocol_error
, 503, NULL
,
609 US
"only RSET accepted now") > 0)
611 goto repeat_until_rset
;
615 smtp_quit_handler(&user_msg
, &log_msg
);
626 smtp_printf("250 OK\r\n", FALSE
);
633 if (sscanf(CS smtp_cmd_data
, "%u %n", &chunking_datasize
, &n
) < 1)
635 (void) synprot_error(L_smtp_protocol_error
, 501, NULL
,
636 US
"missing size for BDAT command");
639 chunking_state
= strcmpic(smtp_cmd_data
+n
, US
"LAST") == 0
640 ? CHUNKING_LAST
: CHUNKING_ACTIVE
;
641 chunking_data_left
= chunking_datasize
;
642 DEBUG(D_receive
) debug_printf("chunking state %d, %d bytes\n",
643 (int)chunking_state
, chunking_data_left
);
645 if (chunking_datasize
== 0)
646 if (chunking_state
== CHUNKING_LAST
)
650 (void) synprot_error(L_smtp_protocol_error
, 504, NULL
,
651 US
"zero size for BDAT command");
652 goto repeat_until_rset
;
655 receive_getc
= bdat_getc
;
656 receive_getbuf
= bdat_getbuf
;
657 receive_ungetc
= bdat_ungetc
;
659 dkim_collect_input
= dkim_save
;
661 break; /* to top of main loop */
668 bdat_getbuf(unsigned * len
)
672 if (chunking_data_left
<= 0)
673 { *len
= 0; return NULL
; }
675 if (*len
> chunking_data_left
) *len
= chunking_data_left
;
676 buf
= lwr_receive_getbuf(len
); /* Either smtp_getbuf or tls_getbuf */
677 chunking_data_left
-= *len
;
682 bdat_flush_data(void)
684 unsigned n
= chunking_data_left
;
685 (void) bdat_getbuf(&n
);
687 receive_getc
= lwr_receive_getc
;
688 receive_getbuf
= lwr_receive_getbuf
;
689 receive_ungetc
= lwr_receive_ungetc
;
691 if (chunking_state
!= CHUNKING_LAST
)
693 chunking_state
= CHUNKING_OFFERED
;
694 DEBUG(D_receive
) debug_printf("chunking state %d\n", (int)chunking_state
);
701 /*************************************************
702 * SMTP version of ungetc() *
703 *************************************************/
705 /* Puts a character back in the input buffer. Only ever
711 Returns: the character
725 chunking_data_left
++;
726 return lwr_receive_ungetc(ch
);
731 /*************************************************
732 * SMTP version of feof() *
733 *************************************************/
735 /* Tests for a previous EOF
738 Returns: non-zero if the eof flag is set
750 /*************************************************
751 * SMTP version of ferror() *
752 *************************************************/
754 /* Tests for a previous read error, and returns with errno
755 restored to what it was when the error was detected.
758 Returns: non-zero if the error flag is set
764 errno
= smtp_had_error
;
765 return smtp_had_error
;
770 /*************************************************
771 * Test for characters in the SMTP buffer *
772 *************************************************/
774 /* Used at the end of a message
783 return smtp_inptr
< smtp_inend
;
788 /*************************************************
789 * Write formatted string to SMTP channel *
790 *************************************************/
792 /* This is a separate function so that we don't have to repeat everything for
793 TLS support or debugging. It is global so that the daemon and the
794 authentication functions can use it. It does not return any error indication,
795 because major problems such as dropped connections won't show up till an output
796 flush for non-TLS connections. The smtp_fflush() function is available for
797 checking that: for convenience, TLS output errors are remembered here so that
798 they are also picked up later by smtp_fflush().
802 more further data expected
803 ... optional arguments
809 smtp_printf(const char *format
, BOOL more
, ...)
814 smtp_vprintf(format
, more
, ap
);
818 /* This is split off so that verify.c:respond_printf() can, in effect, call
819 smtp_printf(), bearing in mind that in C a vararg function can't directly
820 call another vararg function, only a function which accepts a va_list. */
823 smtp_vprintf(const char *format
, BOOL more
, va_list ap
)
827 yield
= string_vformat(big_buffer
, big_buffer_size
, format
, ap
);
831 void *reset_point
= store_get(0);
832 uschar
*msg_copy
, *cr
, *end
;
833 msg_copy
= string_copy(big_buffer
);
834 end
= msg_copy
+ Ustrlen(msg_copy
);
835 while ((cr
= Ustrchr(msg_copy
, '\r')) != NULL
) /* lose CRs */
836 memmove(cr
, cr
+ 1, (end
--) - cr
);
837 debug_printf("SMTP>> %s", msg_copy
);
838 store_reset(reset_point
);
843 log_write(0, LOG_MAIN
|LOG_PANIC
, "string too large in smtp_printf()");
844 smtp_closedown(US
"Unexpected error");
845 exim_exit(EXIT_FAILURE
);
848 /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
849 have had the same. Note: this code is also present in smtp_respond(). It would
850 be tidier to have it only in one place, but when it was added, it was easier to
851 do it that way, so as not to have to mess with the code for the RCPT command,
852 which sometimes uses smtp_printf() and sometimes smtp_respond(). */
854 if (rcpt_in_progress
)
856 if (rcpt_smtp_response
== NULL
)
857 rcpt_smtp_response
= string_copy(big_buffer
);
858 else if (rcpt_smtp_response_same
&&
859 Ustrcmp(rcpt_smtp_response
, big_buffer
) != 0)
860 rcpt_smtp_response_same
= FALSE
;
861 rcpt_in_progress
= FALSE
;
864 /* Now write the string */
867 if (tls_in
.active
>= 0)
869 if (tls_write(TRUE
, big_buffer
, Ustrlen(big_buffer
), more
) < 0)
870 smtp_write_error
= -1;
875 if (fprintf(smtp_out
, "%s", big_buffer
) < 0) smtp_write_error
= -1;
880 /*************************************************
881 * Flush SMTP out and check for error *
882 *************************************************/
884 /* This function isn't currently used within Exim (it detects errors when it
885 tries to read the next SMTP input), but is available for use in local_scan().
886 For non-TLS connections, it flushes the output and checks for errors. For
887 TLS-connections, it checks for a previously-detected TLS write error.
890 Returns: 0 for no error; -1 after an error
896 if (tls_in
.active
< 0 && fflush(smtp_out
) != 0) smtp_write_error
= -1;
897 return smtp_write_error
;
902 /*************************************************
903 * SMTP command read timeout *
904 *************************************************/
906 /* Signal handler for timing out incoming SMTP commands. This attempts to
909 Argument: signal number (SIGALRM)
914 command_timeout_handler(int sig
)
916 sig
= sig
; /* Keep picky compilers happy */
917 log_write(L_lost_incoming_connection
,
918 LOG_MAIN
, "SMTP command timeout on%s connection from %s",
919 (tls_in
.active
>= 0)? " TLS" : "",
920 host_and_ident(FALSE
));
921 if (smtp_batched_input
)
922 moan_smtp_batch(NULL
, "421 SMTP command timeout"); /* Does not return */
923 smtp_notquit_exit(US
"command-timeout", US
"421",
924 US
"%s: SMTP command timeout - closing connection", smtp_active_hostname
);
925 exim_exit(EXIT_FAILURE
);
930 /*************************************************
932 *************************************************/
934 /* Signal handler for handling SIGTERM. Again, try to finish tidily.
936 Argument: signal number (SIGTERM)
941 command_sigterm_handler(int sig
)
943 sig
= sig
; /* Keep picky compilers happy */
944 log_write(0, LOG_MAIN
, "%s closed after SIGTERM", smtp_get_connection_info());
945 if (smtp_batched_input
)
946 moan_smtp_batch(NULL
, "421 SIGTERM received"); /* Does not return */
947 smtp_notquit_exit(US
"signal-exit", US
"421",
948 US
"%s: Service not available - closing connection", smtp_active_hostname
);
949 exim_exit(EXIT_FAILURE
);
956 /*************************************************
957 * Restore socket timeout to previous value *
958 *************************************************/
959 /* If the previous value was successfully retrieved, restore
960 it before returning control to the non-proxy routines
962 Arguments: fd - File descriptor for input
963 get_ok - Successfully retrieved previous values
964 tvtmp - Time struct with previous values
965 vslen - Length of time struct
969 restore_socket_timeout(int fd
, int get_ok
, struct timeval
* tvtmp
, socklen_t vslen
)
972 (void) setsockopt(fd
, SOL_SOCKET
, SO_RCVTIMEO
, CS tvtmp
, vslen
);
975 /*************************************************
976 * Check if host is required proxy host *
977 *************************************************/
978 /* The function determines if inbound host will be a regular smtp host
979 or if it is configured that it must use Proxy Protocol. A local
987 check_proxy_protocol_host()
991 if ( sender_host_address
992 && (rc
= verify_check_this_host(CUSS
&hosts_proxy
, NULL
, NULL
,
993 sender_host_address
, NULL
)) == OK
)
996 debug_printf("Detected proxy protocol configured host\n");
997 proxy_session
= TRUE
;
999 return proxy_session
;
1003 /*************************************************
1004 * Read data until newline or end of buffer *
1005 *************************************************/
1006 /* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1007 read an entire buffer and assume there will be nothing past a proxy protocol
1008 header. Our approach normally is to use stdio, but again that relies upon
1009 "STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1010 reading _nothing_ before client TLS handshake. So we don't want to use the
1011 usual buffering reads which may read enough to block TLS starting.
1013 So unfortunately we're down to "read one byte at a time, with a syscall each,
1014 and expect a little overhead", for all proxy-opened connections which are v1,
1015 just to handle the TLS-on-connect case. Since SSL functions wrap the
1016 underlying fd, we can't assume that we can feed them any already-read content.
1018 We need to know where to read to, the max capacity, and we'll read until we
1019 get a CR and one more character. Let the caller scream if it's CR+!LF.
1021 Return the amount read.
1025 swallow_until_crlf(int fd
, uschar
*base
, int already
, int capacity
)
1027 uschar
*to
= base
+ already
;
1033 /* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1034 up through the \r; for the _normal_ case, we haven't yet seen the \r. */
1036 cr
= memchr(base
, '\r', already
);
1039 if ((cr
- base
) < already
- 1)
1041 /* \r and presumed \n already within what we have; probably not
1042 actually proxy protocol, but abort cleanly. */
1045 /* \r is last character read, just need one more. */
1049 while (capacity
> 0)
1051 do { ret
= recv(fd
, to
, 1, 0); } while (ret
== -1 && errno
== EINTR
);
1063 /* reached end without having room for a final newline, abort */
1068 /*************************************************
1069 * Setup host for proxy protocol *
1070 *************************************************/
1071 /* The function configures the connection based on a header from the
1072 inbound host to use Proxy Protocol. The specification is very exact
1073 so exit with an error if do not find the exact required pieces. This
1074 includes an incorrect number of spaces separating args.
1077 Returns: Boolean success
1081 setup_proxy_protocol_host()
1093 struct { /* TCP/UDP over IPv4, len = 12 */
1099 struct { /* TCP/UDP over IPv6, len = 36 */
1100 uint8_t src_addr
[16];
1101 uint8_t dst_addr
[16];
1105 struct { /* AF_UNIX sockets, len = 216 */
1106 uschar src_addr
[108];
1107 uschar dst_addr
[108];
1113 /* Temp variables used in PPv2 address:port parsing */
1115 char tmpip
[INET_ADDRSTRLEN
];
1116 struct sockaddr_in tmpaddr
;
1117 char tmpip6
[INET6_ADDRSTRLEN
];
1118 struct sockaddr_in6 tmpaddr6
;
1120 /* We can't read "all data until end" because while SMTP is
1121 server-speaks-first, the TLS handshake is client-speaks-first, so for
1122 TLS-on-connect ports the proxy protocol header will usually be immediately
1123 followed by a TLS handshake, and with N TLS libraries, we can't reliably
1124 reinject data for reading by those. So instead we first read "enough to be
1125 safely read within the header, and figure out how much more to read".
1126 For v1 we will later read to the end-of-line, for v2 we will read based upon
1129 The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1130 data is needed total. For v1, where the line looks like:
1131 PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1133 However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1134 We seem to support that. So, if we read 14 octets then we can tell if we're
1135 v2 or v1. If we're v1, we can continue reading as normal.
1137 If we're v2, we can't slurp up the entire header. We need the length in the
1138 15th & 16th octets, then to read everything after that.
1140 So to safely handle v1 and v2, with client-sent-first supported correctly,
1141 we have to do a minimum of 3 read calls, not 1. Eww.
1144 #define PROXY_INITIAL_READ 14
1145 #define PROXY_V2_HEADER_SIZE 16
1146 #if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1147 # error Code bug in sizes of data to read for proxy usage
1152 int fd
= fileno(smtp_in
);
1153 const char v2sig
[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
1154 uschar
* iptype
; /* To display debug info */
1156 struct timeval tvtmp
;
1157 socklen_t vslen
= sizeof(struct timeval
);
1160 /* Save current socket timeout values */
1161 get_ok
= getsockopt(fd
, SOL_SOCKET
, SO_RCVTIMEO
, CS
&tvtmp
, &vslen
);
1163 /* Proxy Protocol host must send header within a short time
1164 (default 3 seconds) or it's considered invalid */
1165 tv
.tv_sec
= PROXY_NEGOTIATION_TIMEOUT_SEC
;
1166 tv
.tv_usec
= PROXY_NEGOTIATION_TIMEOUT_USEC
;
1167 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVTIMEO
, CS
&tv
, sizeof(tv
)) < 0)
1172 /* The inbound host was declared to be a Proxy Protocol host, so
1173 don't do a PEEK into the data, actually slurp up enough to be
1174 "safe". Can't take it all because TLS-on-connect clients follow
1175 immediately with TLS handshake. */
1176 ret
= recv(fd
, &hdr
, PROXY_INITIAL_READ
, 0);
1178 while (ret
== -1 && errno
== EINTR
);
1183 /* For v2, handle reading the length, and then the rest. */
1184 if ((ret
== PROXY_INITIAL_READ
) && (memcmp(&hdr
.v2
, v2sig
, sizeof(v2sig
)) == 0))
1189 /* First get the length fields. */
1192 retmore
= recv(fd
, (uschar
*)&hdr
+ ret
, PROXY_V2_HEADER_SIZE
- PROXY_INITIAL_READ
, 0);
1193 } while (retmore
== -1 && errno
== EINTR
);
1198 ver
= (hdr
.v2
.ver_cmd
& 0xf0) >> 4;
1200 /* May 2014: haproxy combined the version and command into one byte to
1201 allow two full bytes for the length field in order to proxy SSL
1202 connections. SSL Proxy is not supported in this version of Exim, but
1203 must still separate values here. */
1207 DEBUG(D_receive
) debug_printf("Invalid Proxy Protocol version: %d\n", ver
);
1211 /* The v2 header will always be 16 bytes per the spec. */
1212 size
= 16 + ntohs(hdr
.v2
.len
);
1213 DEBUG(D_receive
) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1214 size
, (int)sizeof(hdr
));
1216 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1217 amount that we need. Double-check that the size is not unreasonable, then
1219 if (size
> sizeof(hdr
))
1221 DEBUG(D_receive
) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
1229 retmore
= recv(fd
, (uschar
*)&hdr
+ ret
, size
-ret
, 0);
1230 } while (retmore
== -1 && errno
== EINTR
);
1234 DEBUG(D_receive
) debug_printf("PROXYv2: have %d/%d required octets\n", ret
, size
);
1235 } while (ret
< size
);
1237 } /* end scope for getting rest of data for v2 */
1239 /* At this point: if PROXYv2, we've read the exact size required for all data;
1240 if PROXYv1 then we've read "less than required for any valid line" and should
1243 if (ret
>= 16 && memcmp(&hdr
.v2
, v2sig
, 12) == 0)
1245 uint8_t cmd
= (hdr
.v2
.ver_cmd
& 0x0f);
1249 case 0x01: /* PROXY command */
1252 case 0x11: /* TCPv4 address type */
1254 tmpaddr
.sin_addr
.s_addr
= hdr
.v2
.addr
.ip4
.src_addr
;
1255 inet_ntop(AF_INET
, &tmpaddr
.sin_addr
, CS
&tmpip
, sizeof(tmpip
));
1256 if (!string_is_ip_address(US tmpip
, NULL
))
1258 DEBUG(D_receive
) debug_printf("Invalid %s source IP\n", iptype
);
1261 proxy_local_address
= sender_host_address
;
1262 sender_host_address
= string_copy(US tmpip
);
1263 tmpport
= ntohs(hdr
.v2
.addr
.ip4
.src_port
);
1264 proxy_local_port
= sender_host_port
;
1265 sender_host_port
= tmpport
;
1266 /* Save dest ip/port */
1267 tmpaddr
.sin_addr
.s_addr
= hdr
.v2
.addr
.ip4
.dst_addr
;
1268 inet_ntop(AF_INET
, &tmpaddr
.sin_addr
, CS
&tmpip
, sizeof(tmpip
));
1269 if (!string_is_ip_address(US tmpip
, NULL
))
1271 DEBUG(D_receive
) debug_printf("Invalid %s dest port\n", iptype
);
1274 proxy_external_address
= string_copy(US tmpip
);
1275 tmpport
= ntohs(hdr
.v2
.addr
.ip4
.dst_port
);
1276 proxy_external_port
= tmpport
;
1278 case 0x21: /* TCPv6 address type */
1280 memmove(tmpaddr6
.sin6_addr
.s6_addr
, hdr
.v2
.addr
.ip6
.src_addr
, 16);
1281 inet_ntop(AF_INET6
, &tmpaddr6
.sin6_addr
, CS
&tmpip6
, sizeof(tmpip6
));
1282 if (!string_is_ip_address(US tmpip6
, NULL
))
1284 DEBUG(D_receive
) debug_printf("Invalid %s source IP\n", iptype
);
1287 proxy_local_address
= sender_host_address
;
1288 sender_host_address
= string_copy(US tmpip6
);
1289 tmpport
= ntohs(hdr
.v2
.addr
.ip6
.src_port
);
1290 proxy_local_port
= sender_host_port
;
1291 sender_host_port
= tmpport
;
1292 /* Save dest ip/port */
1293 memmove(tmpaddr6
.sin6_addr
.s6_addr
, hdr
.v2
.addr
.ip6
.dst_addr
, 16);
1294 inet_ntop(AF_INET6
, &tmpaddr6
.sin6_addr
, CS
&tmpip6
, sizeof(tmpip6
));
1295 if (!string_is_ip_address(US tmpip6
, NULL
))
1297 DEBUG(D_receive
) debug_printf("Invalid %s dest port\n", iptype
);
1300 proxy_external_address
= string_copy(US tmpip6
);
1301 tmpport
= ntohs(hdr
.v2
.addr
.ip6
.dst_port
);
1302 proxy_external_port
= tmpport
;
1306 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1310 /* Unsupported protocol, keep local connection address */
1312 case 0x00: /* LOCAL command */
1313 /* Keep local connection address for LOCAL */
1318 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd
);
1322 else if (ret
>= 8 && memcmp(hdr
.v1
.line
, "PROXY", 5) == 0)
1326 uschar
*sp
; /* Utility variables follow */
1331 /* get the rest of the line */
1332 r2
= swallow_until_crlf(fd
, (uschar
*)&hdr
, ret
, sizeof(hdr
)-ret
);
1337 p
= string_copy(hdr
.v1
.line
);
1338 end
= memchr(p
, '\r', ret
- 1);
1340 if (!end
|| (end
== (uschar
*)&hdr
+ ret
) || end
[1] != '\n')
1342 DEBUG(D_receive
) debug_printf("Partial or invalid PROXY header\n");
1345 *end
= '\0'; /* Terminate the string */
1346 size
= end
+ 2 - p
; /* Skip header + CRLF */
1347 DEBUG(D_receive
) debug_printf("Detected PROXYv1 header\n");
1348 DEBUG(D_receive
) debug_printf("Bytes read not within PROXY header: %d\n", ret
- size
);
1349 /* Step through the string looking for the required fields. Ensure
1350 strict adherence to required formatting, exit for any error. */
1352 if (!isspace(*(p
++)))
1354 DEBUG(D_receive
) debug_printf("Missing space after PROXY command\n");
1357 if (!Ustrncmp(p
, CCS
"TCP4", 4))
1359 else if (!Ustrncmp(p
,CCS
"TCP6", 4))
1361 else if (!Ustrncmp(p
,CCS
"UNKNOWN", 7))
1363 iptype
= US
"Unknown";
1368 DEBUG(D_receive
) debug_printf("Invalid TCP type\n");
1372 p
+= Ustrlen(iptype
);
1373 if (!isspace(*(p
++)))
1375 DEBUG(D_receive
) debug_printf("Missing space after TCP4/6 command\n");
1378 /* Find the end of the arg */
1379 if ((sp
= Ustrchr(p
, ' ')) == NULL
)
1382 debug_printf("Did not find proxied src %s\n", iptype
);
1386 if(!string_is_ip_address(p
, NULL
))
1389 debug_printf("Proxied src arg is not an %s address\n", iptype
);
1392 proxy_local_address
= sender_host_address
;
1393 sender_host_address
= p
;
1395 if ((sp
= Ustrchr(p
, ' ')) == NULL
)
1398 debug_printf("Did not find proxy dest %s\n", iptype
);
1402 if(!string_is_ip_address(p
, NULL
))
1405 debug_printf("Proxy dest arg is not an %s address\n", iptype
);
1408 proxy_external_address
= p
;
1410 if ((sp
= Ustrchr(p
, ' ')) == NULL
)
1412 DEBUG(D_receive
) debug_printf("Did not find proxied src port\n");
1416 tmp_port
= strtol(CCS p
, &endc
, 10);
1417 if (*endc
|| tmp_port
== 0)
1420 debug_printf("Proxied src port '%s' not an integer\n", p
);
1423 proxy_local_port
= sender_host_port
;
1424 sender_host_port
= tmp_port
;
1426 if ((sp
= Ustrchr(p
, '\0')) == NULL
)
1428 DEBUG(D_receive
) debug_printf("Did not find proxy dest port\n");
1431 tmp_port
= strtol(CCS p
, &endc
, 10);
1432 if (*endc
|| tmp_port
== 0)
1435 debug_printf("Proxy dest port '%s' not an integer\n", p
);
1438 proxy_external_port
= tmp_port
;
1439 /* Already checked for /r /n above. Good V1 header received. */
1443 /* Wrong protocol */
1444 DEBUG(D_receive
) debug_printf("Invalid proxy protocol version negotiation\n");
1445 (void) swallow_until_crlf(fd
, (uschar
*)&hdr
, ret
, sizeof(hdr
)-ret
);
1451 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype
);
1452 yield
= proxy_session
;
1454 /* Don't flush any potential buffer contents. Any input on proxyfail
1455 should cause a synchronization failure */
1458 restore_socket_timeout(fd
, get_ok
, &tvtmp
, vslen
);
1463 sender_host_name
= NULL
;
1464 (void) host_name_lookup();
1465 host_build_sender_fullhost();
1469 proxy_session_failed
= TRUE
;
1471 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1478 /*************************************************
1479 * Read one command line *
1480 *************************************************/
1482 /* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1483 There are sites that don't do this, and in any case internal SMTP probably
1484 should check only for LF. Consequently, we check here for LF only. The line
1485 ends up with [CR]LF removed from its end. If we get an overlong line, treat as
1486 an unknown command. The command is read into the global smtp_cmd_buffer so that
1487 it is available via $smtp_command.
1489 The character reading routine sets up a timeout for each block actually read
1490 from the input (which may contain more than one command). We set up a special
1491 signal handler that closes down the session on a timeout. Control does not
1492 return when it runs.
1495 check_sync if TRUE, check synchronization rules if global option is TRUE
1496 buffer_lim maximum to buffer in lower layer
1498 Returns: a code identifying the command (enumerated above)
1502 smtp_read_command(BOOL check_sync
, unsigned buffer_lim
)
1507 BOOL hadnull
= FALSE
;
1509 os_non_restarting_signal(SIGALRM
, command_timeout_handler
);
1511 while ((c
= (receive_getc
)(buffer_lim
)) != '\n' && c
!= EOF
)
1513 if (ptr
>= SMTP_CMD_BUFFER_SIZE
)
1515 os_non_restarting_signal(SIGALRM
, sigalrm_handler
);
1523 smtp_cmd_buffer
[ptr
++] = c
;
1526 receive_linecount
++; /* For BSMTP errors */
1527 os_non_restarting_signal(SIGALRM
, sigalrm_handler
);
1529 /* If hit end of file, return pseudo EOF command. Whether we have a
1530 part-line already read doesn't matter, since this is an error state. */
1532 if (c
== EOF
) return EOF_CMD
;
1534 /* Remove any CR and white space at the end of the line, and terminate the
1537 while (ptr
> 0 && isspace(smtp_cmd_buffer
[ptr
-1])) ptr
--;
1538 smtp_cmd_buffer
[ptr
] = 0;
1540 DEBUG(D_receive
) debug_printf("SMTP<< %s\n", smtp_cmd_buffer
);
1542 /* NULLs are not allowed in SMTP commands */
1544 if (hadnull
) return BADCHAR_CMD
;
1546 /* Scan command list and return identity, having set the data pointer
1547 to the start of the actual data characters. Check for SMTP synchronization
1550 for (p
= cmd_list
; p
< cmd_list_end
; p
++)
1552 #ifdef SUPPORT_PROXY
1553 /* Only allow QUIT command if Proxy Protocol parsing failed */
1554 if (proxy_session
&& proxy_session_failed
&& p
->cmd
!= QUIT_CMD
)
1558 && strncmpic(smtp_cmd_buffer
, US p
->name
, p
->len
) == 0
1559 && ( smtp_cmd_buffer
[p
->len
-1] == ':' /* "mail from:" or "rcpt to:" */
1560 || smtp_cmd_buffer
[p
->len
] == 0
1561 || smtp_cmd_buffer
[p
->len
] == ' '
1564 if (smtp_inptr
< smtp_inend
&& /* Outstanding input */
1565 p
->cmd
< sync_cmd_limit
&& /* Command should sync */
1566 check_sync
&& /* Local flag set */
1567 smtp_enforce_sync
&& /* Global flag set */
1568 sender_host_address
!= NULL
&& /* Not local input */
1569 !sender_host_notsocket
) /* Really is a socket */
1572 /* The variables $smtp_command and $smtp_command_argument point into the
1573 unmodified input buffer. A copy of the latter is taken for actual
1574 processing, so that it can be chopped up into separate parts if necessary,
1575 for example, when processing a MAIL command options such as SIZE that can
1576 follow the sender address. */
1578 smtp_cmd_argument
= smtp_cmd_buffer
+ p
->len
;
1579 while (isspace(*smtp_cmd_argument
)) smtp_cmd_argument
++;
1580 Ustrcpy(smtp_data_buffer
, smtp_cmd_argument
);
1581 smtp_cmd_data
= smtp_data_buffer
;
1583 /* Count non-mail commands from those hosts that are controlled in this
1584 way. The default is all hosts. We don't waste effort checking the list
1585 until we get a non-mail command, but then cache the result to save checking
1586 again. If there's a DEFER while checking the host, assume it's in the list.
1588 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1589 start of each incoming message by fiddling with the value in the table. */
1591 if (!p
->is_mail_cmd
)
1593 if (count_nonmail
== TRUE_UNSET
) count_nonmail
=
1594 verify_check_host(&smtp_accept_max_nonmail_hosts
) != FAIL
;
1595 if (count_nonmail
&& ++nonmail_command_count
> smtp_accept_max_nonmail
)
1596 return TOO_MANY_NONMAIL_CMD
;
1599 /* If there is data for a command that does not expect it, generate the
1602 return (p
->has_arg
|| *smtp_cmd_data
== 0)? p
->cmd
: BADARG_CMD
;
1606 #ifdef SUPPORT_PROXY
1607 /* Only allow QUIT command if Proxy Protocol parsing failed */
1608 if (proxy_session
&& proxy_session_failed
)
1609 return PROXY_FAIL_IGNORE_CMD
;
1612 /* Enforce synchronization for unknown commands */
1614 if (smtp_inptr
< smtp_inend
&& /* Outstanding input */
1615 check_sync
&& /* Local flag set */
1616 smtp_enforce_sync
&& /* Global flag set */
1617 sender_host_address
!= NULL
&& /* Not local input */
1618 !sender_host_notsocket
) /* Really is a socket */
1626 /*************************************************
1627 * Forced closedown of call *
1628 *************************************************/
1630 /* This function is called from log.c when Exim is dying because of a serious
1631 disaster, and also from some other places. If an incoming non-batched SMTP
1632 channel is open, it swallows the rest of the incoming message if in the DATA
1633 phase, sends the reply string, and gives an error to all subsequent commands
1634 except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1638 message SMTP reply string to send, excluding the code
1644 smtp_closedown(uschar
*message
)
1646 if (smtp_in
== NULL
|| smtp_batched_input
) return;
1647 receive_swallow_smtp();
1648 smtp_printf("421 %s\r\n", FALSE
, message
);
1650 for (;;) switch(smtp_read_command(FALSE
, GETC_BUFFER_UNLIMITED
))
1656 smtp_printf("221 %s closing connection\r\n", FALSE
, smtp_active_hostname
);
1661 smtp_printf("250 Reset OK\r\n", FALSE
);
1665 smtp_printf("421 %s\r\n", FALSE
, message
);
1673 /*************************************************
1674 * Set up connection info for logging *
1675 *************************************************/
1677 /* This function is called when logging information about an SMTP connection.
1678 It sets up appropriate source information, depending on the type of connection.
1679 If sender_fullhost is NULL, we are at a very early stage of the connection;
1680 just use the IP address.
1683 Returns: a string describing the connection
1687 smtp_get_connection_info(void)
1689 const uschar
* hostname
= sender_fullhost
1690 ? sender_fullhost
: sender_host_address
;
1693 return string_sprintf("SMTP connection from %s", hostname
);
1695 if (sender_host_unknown
|| sender_host_notsocket
)
1696 return string_sprintf("SMTP connection from %s", sender_ident
);
1699 return string_sprintf("SMTP connection from %s (via inetd)", hostname
);
1701 if (LOGGING(incoming_interface
) && interface_address
!= NULL
)
1702 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname
,
1703 interface_address
, interface_port
);
1705 return string_sprintf("SMTP connection from %s", hostname
);
1711 /* Append TLS-related information to a log line
1714 s String under construction: allocated string to extend, or NULL
1715 sizep Pointer to current allocation size (update on return), or NULL
1716 ptrp Pointer to index for new entries in string (update on return), or NULL
1718 Returns: Allocated string or NULL
1721 s_tlslog(uschar
* s
, int * sizep
, int * ptrp
)
1723 int size
= sizep
? *sizep
: 0;
1724 int ptr
= ptrp
? *ptrp
: 0;
1726 if (LOGGING(tls_cipher
) && tls_in
.cipher
!= NULL
)
1727 s
= string_append(s
, &size
, &ptr
, 2, US
" X=", tls_in
.cipher
);
1728 if (LOGGING(tls_certificate_verified
) && tls_in
.cipher
!= NULL
)
1729 s
= string_append(s
, &size
, &ptr
, 2, US
" CV=",
1730 tls_in
.certificate_verified
? "yes":"no");
1731 if (LOGGING(tls_peerdn
) && tls_in
.peerdn
!= NULL
)
1732 s
= string_append(s
, &size
, &ptr
, 3, US
" DN=\"",
1733 string_printing(tls_in
.peerdn
), US
"\"");
1734 if (LOGGING(tls_sni
) && tls_in
.sni
!= NULL
)
1735 s
= string_append(s
, &size
, &ptr
, 3, US
" SNI=\"",
1736 string_printing(tls_in
.sni
), US
"\"");
1741 if (sizep
) *sizep
= size
;
1742 if (ptrp
) *ptrp
= ptr
;
1748 /*************************************************
1749 * Log lack of MAIL if so configured *
1750 *************************************************/
1752 /* This function is called when an SMTP session ends. If the log selector
1753 smtp_no_mail is set, write a log line giving some details of what has happened
1754 in the SMTP session.
1761 smtp_log_no_mail(void)
1766 if (smtp_mailcmd_count
> 0 || !LOGGING(smtp_no_mail
))
1772 if (sender_host_authenticated
!= NULL
)
1774 s
= string_append(s
, &size
, &ptr
, 2, US
" A=", sender_host_authenticated
);
1775 if (authenticated_id
!= NULL
)
1776 s
= string_append(s
, &size
, &ptr
, 2, US
":", authenticated_id
);
1780 s
= s_tlslog(s
, &size
, &ptr
);
1783 sep
= (smtp_connection_had
[SMTP_HBUFF_SIZE
-1] != SCH_NONE
)?
1784 US
" C=..." : US
" C=";
1785 for (i
= smtp_ch_index
; i
< SMTP_HBUFF_SIZE
; i
++)
1787 if (smtp_connection_had
[i
] != SCH_NONE
)
1789 s
= string_append(s
, &size
, &ptr
, 2, sep
,
1790 smtp_names
[smtp_connection_had
[i
]]);
1795 for (i
= 0; i
< smtp_ch_index
; i
++)
1797 s
= string_append(s
, &size
, &ptr
, 2, sep
, smtp_names
[smtp_connection_had
[i
]]);
1801 if (s
) s
[ptr
] = 0; else s
= US
"";
1802 log_write(0, LOG_MAIN
, "no MAIL in %sSMTP connection from %s D=%s%s",
1803 tcp_in_fastopen
? US
"TFO " : US
"",
1804 host_and_ident(FALSE
), string_timesince(&smtp_connection_start
), s
);
1808 /* Return list of recent smtp commands */
1813 uschar
* list
= NULL
;
1814 int size
= 0, len
= 0, i
;
1816 for (i
= smtp_ch_index
; i
< SMTP_HBUFF_SIZE
; i
++)
1817 if (smtp_connection_had
[i
] != SCH_NONE
)
1818 list
= string_append_listele(list
, &size
, &len
, ',',
1819 smtp_names
[smtp_connection_had
[i
]]);
1820 for (i
= 0; i
< smtp_ch_index
; i
++)
1821 list
= string_append_listele(list
, &size
, &len
, ',',
1822 smtp_names
[smtp_connection_had
[i
]]);
1823 return list
? list
: US
"";
1829 /*************************************************
1830 * Check HELO line and set sender_helo_name *
1831 *************************************************/
1833 /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1834 the domain name of the sending host, or an ip literal in square brackets. The
1835 argument is placed in sender_helo_name, which is in malloc store, because it
1836 must persist over multiple incoming messages. If helo_accept_junk is set, this
1837 host is permitted to send any old junk (needed for some broken hosts).
1838 Otherwise, helo_allow_chars can be used for rogue characters in general
1839 (typically people want to let in underscores).
1842 s the data portion of the line (already past any white space)
1844 Returns: TRUE or FALSE
1848 check_helo(uschar
*s
)
1851 uschar
*end
= s
+ Ustrlen(s
);
1852 BOOL yield
= helo_accept_junk
;
1854 /* Discard any previous helo name */
1856 if (sender_helo_name
!= NULL
)
1858 store_free(sender_helo_name
);
1859 sender_helo_name
= NULL
;
1862 /* Skip tests if junk is permitted. */
1866 /* Allow the new standard form for IPv6 address literals, namely,
1867 [IPv6:....], and because someone is bound to use it, allow an equivalent
1868 IPv4 form. Allow plain addresses as well. */
1875 if (strncmpic(s
, US
"[IPv6:", 6) == 0)
1876 yield
= (string_is_ip_address(s
+6, NULL
) == 6);
1877 else if (strncmpic(s
, US
"[IPv4:", 6) == 0)
1878 yield
= (string_is_ip_address(s
+6, NULL
) == 4);
1880 yield
= (string_is_ip_address(s
+1, NULL
) != 0);
1885 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1886 that have been configured (usually underscore - sigh). */
1893 if (!isalnum(*s
) && *s
!= '.' && *s
!= '-' &&
1894 Ustrchr(helo_allow_chars
, *s
) == NULL
)
1904 /* Save argument if OK */
1906 if (yield
) sender_helo_name
= string_copy_malloc(start
);
1914 /*************************************************
1915 * Extract SMTP command option *
1916 *************************************************/
1918 /* This function picks the next option setting off the end of smtp_cmd_data. It
1919 is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1920 things that can appear there.
1923 name point this at the name
1924 value point this at the data string
1926 Returns: TRUE if found an option
1930 extract_option(uschar
**name
, uschar
**value
)
1933 uschar
*v
= smtp_cmd_data
+ Ustrlen(smtp_cmd_data
) - 1;
1934 while (isspace(*v
)) v
--;
1936 while (v
> smtp_cmd_data
&& *v
!= '=' && !isspace(*v
))
1938 /* Take care to not stop at a space embedded in a quoted local-part */
1940 if (*v
== '"') do v
--; while (*v
!= '"' && v
> smtp_cmd_data
+1);
1947 while(isalpha(n
[-1])) n
--;
1948 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1949 if (!isspace(n
[-1])) return FALSE
;
1955 if (v
== smtp_cmd_data
) return FALSE
;
1967 /*************************************************
1968 * Reset for new message *
1969 *************************************************/
1971 /* This function is called whenever the SMTP session is reset from
1972 within either of the setup functions.
1974 Argument: the stacking pool storage reset point
1979 smtp_reset(void *reset_point
)
1981 recipients_list
= NULL
;
1982 rcpt_count
= rcpt_defer_count
= rcpt_fail_count
=
1983 raw_recipients_count
= recipients_count
= recipients_list_max
= 0;
1984 message_linecount
= 0;
1986 acl_added_headers
= NULL
;
1987 acl_removed_headers
= NULL
;
1988 queue_only_policy
= FALSE
;
1989 rcpt_smtp_response
= NULL
;
1990 rcpt_smtp_response_same
= TRUE
;
1991 rcpt_in_progress
= FALSE
;
1992 deliver_freeze
= FALSE
; /* Can be set by ACL */
1993 freeze_tell
= freeze_tell_config
; /* Can be set by ACL */
1994 fake_response
= OK
; /* Can be set by ACL */
1995 #ifdef WITH_CONTENT_SCAN
1996 no_mbox_unspool
= FALSE
; /* Can be set by ACL */
1998 submission_mode
= FALSE
; /* Can be set by ACL */
1999 suppress_local_fixups
= suppress_local_fixups_default
; /* Can be set by ACL */
2000 active_local_from_check
= local_from_check
; /* Can be set by ACL */
2001 active_local_sender_retain
= local_sender_retain
; /* Can be set by ACL */
2002 sending_ip_address
= NULL
;
2003 return_path
= sender_address
= NULL
;
2004 sender_data
= NULL
; /* Can be set by ACL */
2005 deliver_localpart_orig
= NULL
;
2006 deliver_domain_orig
= NULL
;
2007 callout_address
= NULL
;
2008 submission_name
= NULL
; /* Can be set by ACL */
2009 raw_sender
= NULL
; /* After SMTP rewrite, before qualifying */
2010 sender_address_unrewritten
= NULL
; /* Set only after verify rewrite */
2011 sender_verified_list
= NULL
; /* No senders verified */
2012 memset(sender_address_cache
, 0, sizeof(sender_address_cache
));
2013 memset(sender_domain_cache
, 0, sizeof(sender_domain_cache
));
2015 authenticated_sender
= NULL
;
2016 #ifdef EXPERIMENTAL_BRIGHTMAIL
2018 bmi_verdicts
= NULL
;
2020 dnslist_domain
= dnslist_matched
= NULL
;
2021 #ifndef DISABLE_DKIM
2022 dkim_signers
= NULL
;
2023 dkim_disable_verify
= FALSE
;
2024 dkim_collect_input
= FALSE
;
2028 deliver_host
= deliver_host_address
= NULL
; /* Can be set by ACL */
2029 #ifndef DISABLE_PRDR
2030 prdr_requested
= FALSE
;
2032 #ifdef EXPERIMENTAL_SPF
2033 spf_header_comment
= NULL
;
2034 spf_received
= NULL
;
2036 spf_smtp_comment
= NULL
;
2039 message_smtputf8
= FALSE
;
2041 body_linecount
= body_zerocount
= 0;
2043 sender_rate
= sender_rate_limit
= sender_rate_period
= NULL
;
2044 ratelimiters_mail
= NULL
; /* Updated by ratelimit ACL condition */
2045 /* Note that ratelimiters_conn persists across resets. */
2047 /* Reset message ACL variables */
2051 /* The message body variables use malloc store. They may be set if this is
2052 not the first message in an SMTP session and the previous message caused them
2053 to be referenced in an ACL. */
2057 store_free(message_body
);
2058 message_body
= NULL
;
2061 if (message_body_end
)
2063 store_free(message_body_end
);
2064 message_body_end
= NULL
;
2067 /* Warning log messages are also saved in malloc store. They are saved to avoid
2068 repetition in the same message, but it seems right to repeat them for different
2071 while (acl_warn_logged
)
2073 string_item
*this = acl_warn_logged
;
2074 acl_warn_logged
= acl_warn_logged
->next
;
2077 store_reset(reset_point
);
2084 /*************************************************
2085 * Initialize for incoming batched SMTP message *
2086 *************************************************/
2088 /* This function is called from smtp_setup_msg() in the case when
2089 smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2090 of messages in one file with SMTP commands between them. All errors must be
2091 reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2092 relevant. After an error on a sender, or an invalid recipient, the remainder
2093 of the message is skipped. The value of received_protocol is already set.
2096 Returns: > 0 message successfully started (reached DATA)
2097 = 0 QUIT read or end of file reached
2098 < 0 should not occur
2102 smtp_setup_batch_msg(void)
2105 void *reset_point
= store_get(0);
2107 /* Save the line count at the start of each transaction - single commands
2108 like HELO and RSET count as whole transactions. */
2110 bsmtp_transaction_linecount
= receive_linecount
;
2112 if ((receive_feof
)()) return 0; /* Treat EOF as QUIT */
2114 cancel_cutthrough_connection(TRUE
, US
"smtp_setup_batch_msg");
2115 smtp_reset(reset_point
); /* Reset for start of message */
2117 /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2118 value. The values are 2 larger than the required yield of the function. */
2123 uschar
*recipient
= NULL
;
2124 int start
, end
, sender_domain
, recipient_domain
;
2126 switch(smtp_read_command(FALSE
, GETC_BUFFER_UNLIMITED
))
2128 /* The HELO/EHLO commands set sender_address_helo if they have
2129 valid data; otherwise they are ignored, except that they do
2130 a reset of the state. */
2135 check_helo(smtp_cmd_data
);
2139 cancel_cutthrough_connection(TRUE
, US
"RSET received");
2140 smtp_reset(reset_point
);
2141 bsmtp_transaction_linecount
= receive_linecount
;
2145 /* The MAIL FROM command requires an address as an operand. All we
2146 do here is to parse it for syntactic correctness. The form "<>" is
2147 a special case which converts into an empty string. The start/end
2148 pointers in the original are not used further for this address, as
2149 it is the canonical extracted address which is all that is kept. */
2152 smtp_mailcmd_count
++; /* Count for no-mail log */
2153 if (sender_address
!= NULL
)
2154 /* The function moan_smtp_batch() does not return. */
2155 moan_smtp_batch(smtp_cmd_buffer
, "503 Sender already given");
2157 if (smtp_cmd_data
[0] == 0)
2158 /* The function moan_smtp_batch() does not return. */
2159 moan_smtp_batch(smtp_cmd_buffer
, "501 MAIL FROM must have an address operand");
2161 /* Reset to start of message */
2163 cancel_cutthrough_connection(TRUE
, US
"MAIL received");
2164 smtp_reset(reset_point
);
2166 /* Apply SMTP rewrite */
2168 raw_sender
= ((rewrite_existflags
& rewrite_smtp
) != 0)?
2169 rewrite_one(smtp_cmd_data
, rewrite_smtp
|rewrite_smtp_sender
, NULL
, FALSE
,
2170 US
"", global_rewrite_rules
) : smtp_cmd_data
;
2172 /* Extract the address; the TRUE flag allows <> as valid */
2175 parse_extract_address(raw_sender
, &errmess
, &start
, &end
, &sender_domain
,
2178 if (raw_sender
== NULL
)
2179 /* The function moan_smtp_batch() does not return. */
2180 moan_smtp_batch(smtp_cmd_buffer
, "501 %s", errmess
);
2182 sender_address
= string_copy(raw_sender
);
2184 /* Qualify unqualified sender addresses if permitted to do so. */
2186 if (sender_domain
== 0 && sender_address
[0] != 0 && sender_address
[0] != '@')
2188 if (allow_unqualified_sender
)
2190 sender_address
= rewrite_address_qualify(sender_address
, FALSE
);
2191 DEBUG(D_receive
) debug_printf("unqualified address %s accepted "
2192 "and rewritten\n", raw_sender
);
2194 /* The function moan_smtp_batch() does not return. */
2195 else moan_smtp_batch(smtp_cmd_buffer
, "501 sender address must contain "
2201 /* The RCPT TO command requires an address as an operand. All we do
2202 here is to parse it for syntactic correctness. There may be any number
2203 of RCPT TO commands, specifying multiple senders. We build them all into
2204 a data structure that is in argc/argv format. The start/end values
2205 given by parse_extract_address are not used, as we keep only the
2206 extracted address. */
2209 if (sender_address
== NULL
)
2210 /* The function moan_smtp_batch() does not return. */
2211 moan_smtp_batch(smtp_cmd_buffer
, "503 No sender yet given");
2213 if (smtp_cmd_data
[0] == 0)
2214 /* The function moan_smtp_batch() does not return. */
2215 moan_smtp_batch(smtp_cmd_buffer
, "501 RCPT TO must have an address operand");
2217 /* Check maximum number allowed */
2219 if (recipients_max
> 0 && recipients_count
+ 1 > recipients_max
)
2220 /* The function moan_smtp_batch() does not return. */
2221 moan_smtp_batch(smtp_cmd_buffer
, "%s too many recipients",
2222 recipients_max_reject
? "552": "452");
2224 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2225 recipient address */
2227 recipient
= rewrite_existflags
& rewrite_smtp
2228 ? rewrite_one(smtp_cmd_data
, rewrite_smtp
, NULL
, FALSE
, US
"",
2229 global_rewrite_rules
)
2232 recipient
= parse_extract_address(recipient
, &errmess
, &start
, &end
,
2233 &recipient_domain
, FALSE
);
2236 /* The function moan_smtp_batch() does not return. */
2237 moan_smtp_batch(smtp_cmd_buffer
, "501 %s", errmess
);
2239 /* If the recipient address is unqualified, qualify it if permitted. Then
2240 add it to the list of recipients. */
2242 if (recipient_domain
== 0)
2244 if (allow_unqualified_recipient
)
2246 DEBUG(D_receive
) debug_printf("unqualified address %s accepted\n",
2248 recipient
= rewrite_address_qualify(recipient
, TRUE
);
2250 /* The function moan_smtp_batch() does not return. */
2251 else moan_smtp_batch(smtp_cmd_buffer
, "501 recipient address must contain "
2254 receive_add_recipient(recipient
, -1);
2258 /* The DATA command is legal only if it follows successful MAIL FROM
2259 and RCPT TO commands. This function is complete when a valid DATA
2260 command is encountered. */
2263 if (sender_address
== NULL
|| recipients_count
<= 0)
2265 /* The function moan_smtp_batch() does not return. */
2266 if (sender_address
== NULL
)
2267 moan_smtp_batch(smtp_cmd_buffer
,
2268 "503 MAIL FROM:<sender> command must precede DATA");
2270 moan_smtp_batch(smtp_cmd_buffer
,
2271 "503 RCPT TO:<recipient> must precede DATA");
2275 done
= 3; /* DATA successfully achieved */
2276 message_ended
= END_NOTENDED
; /* Indicate in middle of message */
2281 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2288 bsmtp_transaction_linecount
= receive_linecount
;
2299 /* The function moan_smtp_batch() does not return. */
2300 moan_smtp_batch(smtp_cmd_buffer
, "501 Unexpected argument data");
2305 /* The function moan_smtp_batch() does not return. */
2306 moan_smtp_batch(smtp_cmd_buffer
, "501 Unexpected NULL in SMTP command");
2311 /* The function moan_smtp_batch() does not return. */
2312 moan_smtp_batch(smtp_cmd_buffer
, "500 Command unrecognized");
2317 return done
- 2; /* Convert yield values */
2324 smtp_log_tls_fail(uschar
* errstr
)
2326 uschar
* conn_info
= smtp_get_connection_info();
2328 if (Ustrncmp(conn_info
, US
"SMTP ", 5) == 0) conn_info
+= 5;
2329 /* I'd like to get separated H= here, but too hard for now */
2331 log_write(0, LOG_MAIN
, "TLS error on %s %s", conn_info
, errstr
);
2343 struct tcp_info tinfo
;
2344 socklen_t len
= sizeof(tinfo
);
2346 if ( getsockopt(fileno(smtp_out
), IPPROTO_TCP
, TCP_INFO
, &tinfo
, &len
) == 0
2347 && tinfo
.tcpi_state
== TCP_SYN_RECV
2350 DEBUG(D_receive
) debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
2351 tcp_in_fastopen
= TRUE
;
2358 /*************************************************
2359 * Start an SMTP session *
2360 *************************************************/
2362 /* This function is called at the start of an SMTP session. Thereafter,
2363 smtp_setup_msg() is called to initiate each separate message. This
2364 function does host-specific testing, and outputs the banner line.
2367 Returns: FALSE if the session can not continue; something has
2368 gone wrong, or the connection to the host is blocked
2372 smtp_start_session(void)
2376 uschar
*user_msg
, *log_msg
;
2380 gettimeofday(&smtp_connection_start
, NULL
);
2381 for (smtp_ch_index
= 0; smtp_ch_index
< SMTP_HBUFF_SIZE
; smtp_ch_index
++)
2382 smtp_connection_had
[smtp_ch_index
] = SCH_NONE
;
2385 /* Default values for certain variables */
2387 helo_seen
= esmtp
= helo_accept_junk
= FALSE
;
2388 smtp_mailcmd_count
= 0;
2389 count_nonmail
= TRUE_UNSET
;
2390 synprot_error_count
= unknown_command_count
= nonmail_command_count
= 0;
2391 smtp_delay_mail
= smtp_rlm_base
;
2392 auth_advertised
= FALSE
;
2393 pipelining_advertised
= FALSE
;
2394 pipelining_enable
= TRUE
;
2395 sync_cmd_limit
= NON_SYNC_CMD_NON_PIPELINING
;
2396 smtp_exit_function_called
= FALSE
; /* For avoiding loop in not-quit exit */
2398 /* If receiving by -bs from a trusted user, or testing with -bh, we allow
2399 authentication settings from -oMaa to remain in force. */
2401 if (!host_checking
&& !sender_host_notsocket
) sender_host_authenticated
= NULL
;
2402 authenticated_by
= NULL
;
2405 tls_in
.cipher
= tls_in
.peerdn
= NULL
;
2406 tls_in
.ourcert
= tls_in
.peercert
= NULL
;
2408 tls_in
.ocsp
= OCSP_NOT_REQ
;
2409 tls_advertised
= FALSE
;
2411 dsn_advertised
= FALSE
;
2413 smtputf8_advertised
= FALSE
;
2416 /* Reset ACL connection variables */
2420 /* Allow for trailing 0 in the command and data buffers. */
2422 if (!(smtp_cmd_buffer
= US
malloc(2*SMTP_CMD_BUFFER_SIZE
+ 2)))
2423 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
,
2424 "malloc() failed for SMTP command buffer");
2426 smtp_cmd_buffer
[0] = 0;
2427 smtp_data_buffer
= smtp_cmd_buffer
+ SMTP_CMD_BUFFER_SIZE
+ 1;
2429 /* For batched input, the protocol setting can be overridden from the
2430 command line by a trusted caller. */
2432 if (smtp_batched_input
)
2434 if (!received_protocol
) received_protocol
= US
"local-bsmtp";
2437 /* For non-batched SMTP input, the protocol setting is forced here. It will be
2438 reset later if any of EHLO/AUTH/STARTTLS are received. */
2442 (sender_host_address
? protocols
: protocols_local
) [pnormal
];
2444 /* Set up the buffer for inputting using direct read() calls, and arrange to
2445 call the local functions instead of the standard C ones. */
2447 if (!(smtp_inbuffer
= US
malloc(IN_BUFFER_SIZE
)))
2448 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "malloc() failed for SMTP input buffer");
2450 receive_getc
= smtp_getc
;
2451 receive_getbuf
= smtp_getbuf
;
2452 receive_get_cache
= smtp_get_cache
;
2453 receive_ungetc
= smtp_ungetc
;
2454 receive_feof
= smtp_feof
;
2455 receive_ferror
= smtp_ferror
;
2456 receive_smtp_buffered
= smtp_buffered
;
2457 smtp_inptr
= smtp_inend
= smtp_inbuffer
;
2458 smtp_had_eof
= smtp_had_error
= 0;
2460 /* Set up the message size limit; this may be host-specific */
2462 thismessage_size_limit
= expand_string_integer(message_size_limit
, TRUE
);
2463 if (expand_string_message
!= NULL
)
2465 if (thismessage_size_limit
== -1)
2466 log_write(0, LOG_MAIN
|LOG_PANIC
, "unable to expand message_size_limit: "
2467 "%s", expand_string_message
);
2469 log_write(0, LOG_MAIN
|LOG_PANIC
, "invalid message_size_limit: "
2470 "%s", expand_string_message
);
2471 smtp_closedown(US
"Temporary local problem - please try later");
2475 /* When a message is input locally via the -bs or -bS options, sender_host_
2476 unknown is set unless -oMa was used to force an IP address, in which case it
2477 is checked like a real remote connection. When -bs is used from inetd, this
2478 flag is not set, causing the sending host to be checked. The code that deals
2479 with IP source routing (if configured) is never required for -bs or -bS and
2480 the flag sender_host_notsocket is used to suppress it.
2482 If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2483 reserve for certain hosts and/or networks. */
2485 if (!sender_host_unknown
)
2488 BOOL reserved_host
= FALSE
;
2490 /* Look up IP options (source routing info) on the socket if this is not an
2491 -oMa "host", and if any are found, log them and drop the connection.
2493 Linux (and others now, see below) is different to everyone else, so there
2494 has to be some conditional compilation here. Versions of Linux before 2.1.15
2495 used a structure whose name was "options". Somebody finally realized that
2496 this name was silly, and it got changed to "ip_options". I use the
2497 newer name here, but there is a fudge in the script that sets up os.h
2498 to define a macro in older Linux systems.
2500 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2501 glibc 2, which has chosen ip_opts for the structure name. This is now
2502 really a glibc thing rather than a Linux thing, so the condition name
2503 has been changed to reflect this. It is relevant also to GNU/Hurd.
2505 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2506 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2507 a special macro defined in the os.h file.
2509 Some DGUX versions on older hardware appear not to support IP options at
2510 all, so there is now a general macro which can be set to cut out this
2513 How to do this properly in IPv6 is not yet known. */
2515 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
2517 #ifdef GLIBC_IP_OPTIONS
2518 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2523 #elif defined DARWIN_IP_OPTIONS
2529 if (!host_checking
&& !sender_host_notsocket
)
2532 EXIM_SOCKLEN_T optlen
= sizeof(struct ip_options
) + MAX_IPOPTLEN
;
2533 struct ip_options
*ipopt
= store_get(optlen
);
2535 struct ip_opts ipoptblock
;
2536 struct ip_opts
*ipopt
= &ipoptblock
;
2537 EXIM_SOCKLEN_T optlen
= sizeof(ipoptblock
);
2539 struct ipoption ipoptblock
;
2540 struct ipoption
*ipopt
= &ipoptblock
;
2541 EXIM_SOCKLEN_T optlen
= sizeof(ipoptblock
);
2544 /* Occasional genuine failures of getsockopt() have been seen - for
2545 example, "reset by peer". Therefore, just log and give up on this
2546 call, unless the error is ENOPROTOOPT. This error is given by systems
2547 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2548 of writing. So for that error, carry on - we just can't do an IP options
2551 DEBUG(D_receive
) debug_printf("checking for IP options\n");
2553 if (getsockopt(fileno(smtp_out
), IPPROTO_IP
, IP_OPTIONS
, US (ipopt
),
2556 if (errno
!= ENOPROTOOPT
)
2558 log_write(0, LOG_MAIN
, "getsockopt() failed from %s: %s",
2559 host_and_ident(FALSE
), strerror(errno
));
2560 smtp_printf("451 SMTP service not available\r\n", FALSE
);
2565 /* Deal with any IP options that are set. On the systems I have looked at,
2566 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2567 more logging data than will fit in big_buffer. Nevertheless, after somebody
2568 questioned this code, I've added in some paranoid checking. */
2570 else if (optlen
> 0)
2572 uschar
*p
= big_buffer
;
2573 uschar
*pend
= big_buffer
+ big_buffer_size
;
2574 uschar
*opt
, *adptr
;
2576 struct in_addr addr
;
2579 uschar
*optstart
= US (ipopt
->__data
);
2581 uschar
*optstart
= US (ipopt
->ip_opts
);
2583 uschar
*optstart
= US (ipopt
->ipopt_list
);
2586 DEBUG(D_receive
) debug_printf("IP options exist\n");
2588 Ustrcpy(p
, "IP options on incoming call:");
2591 for (opt
= optstart
; opt
!= NULL
&&
2592 opt
< US (ipopt
) + optlen
;)
2606 if (!string_format(p
, pend
-p
, " %s [@%s",
2607 (*opt
== IPOPT_SSRR
)? "SSRR" : "LSRR",
2609 inet_ntoa(*((struct in_addr
*)(&(ipopt
->faddr
))))))
2611 inet_ntoa(ipopt
->ip_dst
)))
2613 inet_ntoa(ipopt
->ipopt_dst
)))
2621 optcount
= (opt
[1] - 3) / sizeof(struct in_addr
);
2623 while (optcount
-- > 0)
2625 memcpy(&addr
, adptr
, sizeof(addr
));
2626 if (!string_format(p
, pend
- p
- 1, "%s%s",
2627 (optcount
== 0)? ":" : "@", inet_ntoa(addr
)))
2633 adptr
+= sizeof(struct in_addr
);
2642 if (pend
- p
< 4 + 3*opt
[1]) { opt
= NULL
; break; }
2645 for (i
= 0; i
< opt
[1]; i
++)
2646 p
+= sprintf(CS p
, "%2.2x ", opt
[i
]);
2655 log_write(0, LOG_MAIN
, "%s", big_buffer
);
2657 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2659 log_write(0, LOG_MAIN
|LOG_REJECT
,
2660 "connection from %s refused (IP options)", host_and_ident(FALSE
));
2662 smtp_printf("554 SMTP service not available\r\n", FALSE
);
2666 /* Length of options = 0 => there are no options */
2668 else DEBUG(D_receive
) debug_printf("no IP options found\n");
2670 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2672 /* Set keep-alive in socket options. The option is on by default. This
2673 setting is an attempt to get rid of some hanging connections that stick in
2674 read() when the remote end (usually a dialup) goes away. */
2676 if (smtp_accept_keepalive
&& !sender_host_notsocket
)
2677 ip_keepalive(fileno(smtp_out
), sender_host_address
, FALSE
);
2679 /* If the current host matches host_lookup, set the name by doing a
2680 reverse lookup. On failure, sender_host_name will be NULL and
2681 host_lookup_failed will be TRUE. This may or may not be serious - optional
2684 if (verify_check_host(&host_lookup
) == OK
)
2686 (void)host_name_lookup();
2687 host_build_sender_fullhost();
2690 /* Delay this until we have the full name, if it is looked up. */
2692 set_process_info("handling incoming connection from %s",
2693 host_and_ident(FALSE
));
2695 /* Expand smtp_receive_timeout, if needed */
2697 if (smtp_receive_timeout_s
)
2700 if ( !(exp
= expand_string(smtp_receive_timeout_s
))
2702 || (smtp_receive_timeout
= readconf_readtime(exp
, 0, FALSE
)) < 0
2704 log_write(0, LOG_MAIN
|LOG_PANIC
,
2705 "bad value for smtp_receive_timeout: '%s'", exp
? exp
: US
"");
2708 /* Test for explicit connection rejection */
2710 if (verify_check_host(&host_reject_connection
) == OK
)
2712 log_write(L_connection_reject
, LOG_MAIN
|LOG_REJECT
, "refused connection "
2713 "from %s (host_reject_connection)", host_and_ident(FALSE
));
2714 smtp_printf("554 SMTP service not available\r\n", FALSE
);
2718 /* Test with TCP Wrappers if so configured. There is a problem in that
2719 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2720 such as disks dying. In these cases, it is desirable to reject with a 4xx
2721 error instead of a 5xx error. There isn't a "right" way to detect such
2722 problems. The following kludge is used: errno is zeroed before calling
2723 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2724 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2727 #ifdef USE_TCP_WRAPPERS
2729 if (!(tcp_wrappers_name
= expand_string(tcp_wrappers_daemon_name
)))
2730 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "Expansion of \"%s\" "
2731 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name
),
2732 expand_string_message
);
2734 if (!hosts_ctl(tcp_wrappers_name
,
2735 sender_host_name
? CS sender_host_name
: STRING_UNKNOWN
,
2736 sender_host_address
? CS sender_host_address
: STRING_UNKNOWN
,
2737 sender_ident
? CS sender_ident
: STRING_UNKNOWN
))
2739 if (errno
== 0 || errno
== ENOENT
)
2741 HDEBUG(D_receive
) debug_printf("tcp wrappers rejection\n");
2742 log_write(L_connection_reject
,
2743 LOG_MAIN
|LOG_REJECT
, "refused connection from %s "
2744 "(tcp wrappers)", host_and_ident(FALSE
));
2745 smtp_printf("554 SMTP service not available\r\n", FALSE
);
2749 int save_errno
= errno
;
2750 HDEBUG(D_receive
) debug_printf("tcp wrappers rejected with unexpected "
2751 "errno value %d\n", save_errno
);
2752 log_write(L_connection_reject
,
2753 LOG_MAIN
|LOG_REJECT
, "temporarily refused connection from %s "
2754 "(tcp wrappers errno=%d)", host_and_ident(FALSE
), save_errno
);
2755 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE
);
2761 /* Check for reserved slots. The value of smtp_accept_count has already been
2762 incremented to include this process. */
2764 if (smtp_accept_max
> 0 &&
2765 smtp_accept_count
> smtp_accept_max
- smtp_accept_reserve
)
2767 if ((rc
= verify_check_host(&smtp_reserve_hosts
)) != OK
)
2769 log_write(L_connection_reject
,
2770 LOG_MAIN
, "temporarily refused connection from %s: not in "
2771 "reserve list: connected=%d max=%d reserve=%d%s",
2772 host_and_ident(FALSE
), smtp_accept_count
- 1, smtp_accept_max
,
2773 smtp_accept_reserve
, (rc
== DEFER
)? " (lookup deferred)" : "");
2774 smtp_printf("421 %s: Too many concurrent SMTP connections; "
2775 "please try again later\r\n", FALSE
, smtp_active_hostname
);
2778 reserved_host
= TRUE
;
2781 /* If a load level above which only messages from reserved hosts are
2782 accepted is set, check the load. For incoming calls via the daemon, the
2783 check is done in the superior process if there are no reserved hosts, to
2784 save a fork. In all cases, the load average will already be available
2785 in a global variable at this point. */
2787 if (smtp_load_reserve
>= 0 &&
2788 load_average
> smtp_load_reserve
&&
2790 verify_check_host(&smtp_reserve_hosts
) != OK
)
2792 log_write(L_connection_reject
,
2793 LOG_MAIN
, "temporarily refused connection from %s: not in "
2794 "reserve list and load average = %.2f", host_and_ident(FALSE
),
2795 (double)load_average
/1000.0);
2796 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE
,
2797 smtp_active_hostname
);
2801 /* Determine whether unqualified senders or recipients are permitted
2802 for this host. Unfortunately, we have to do this every time, in order to
2803 set the flags so that they can be inspected when considering qualifying
2804 addresses in the headers. For a site that permits no qualification, this
2805 won't take long, however. */
2807 allow_unqualified_sender
=
2808 verify_check_host(&sender_unqualified_hosts
) == OK
;
2810 allow_unqualified_recipient
=
2811 verify_check_host(&recipient_unqualified_hosts
) == OK
;
2813 /* Determine whether HELO/EHLO is required for this host. The requirement
2814 can be hard or soft. */
2816 helo_required
= verify_check_host(&helo_verify_hosts
) == OK
;
2818 helo_verify
= verify_check_host(&helo_try_verify_hosts
) == OK
;
2820 /* Determine whether this hosts is permitted to send syntactic junk
2821 after a HELO or EHLO command. */
2823 helo_accept_junk
= verify_check_host(&helo_accept_junk_hosts
) == OK
;
2826 /* For batch SMTP input we are now done. */
2828 if (smtp_batched_input
) return TRUE
;
2830 /* If valid Proxy Protocol source is connecting, set up session.
2831 * Failure will not allow any SMTP function other than QUIT. */
2833 #ifdef SUPPORT_PROXY
2834 proxy_session
= FALSE
;
2835 proxy_session_failed
= FALSE
;
2836 if (check_proxy_protocol_host())
2837 setup_proxy_protocol_host();
2840 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2841 smtps port for use with older style SSL MTAs. */
2844 if (tls_in
.on_connect
&& tls_server_start(tls_require_ciphers
, &user_msg
) != OK
)
2845 return smtp_log_tls_fail(user_msg
);
2848 /* Run the connect ACL if it exists */
2851 if (acl_smtp_connect
)
2854 if ((rc
= acl_check(ACL_WHERE_CONNECT
, NULL
, acl_smtp_connect
, &user_msg
,
2857 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT
, rc
, user_msg
, log_msg
);
2862 /* Output the initial message for a two-way SMTP connection. It may contain
2863 newlines, which then cause a multi-line response to be given. */
2865 code
= US
"220"; /* Default status code */
2866 esc
= US
""; /* Default extended status code */
2867 esclen
= 0; /* Length of esc */
2871 if (!(s
= expand_string(smtp_banner
)))
2872 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "Expansion of \"%s\" (smtp_banner) "
2873 "failed: %s", smtp_banner
, expand_string_message
);
2879 smtp_message_code(&code
, &codelen
, &s
, NULL
, TRUE
);
2883 esclen
= codelen
- 4;
2887 /* Remove any terminating newlines; might as well remove trailing space too */
2890 while (p
> s
&& isspace(p
[-1])) p
--;
2893 /* It seems that CC:Mail is braindead, and assumes that the greeting message
2894 is all contained in a single IP packet. The original code wrote out the
2895 greeting using several calls to fprint/fputc, and on busy servers this could
2896 cause it to be split over more than one packet - which caused CC:Mail to fall
2897 over when it got the second part of the greeting after sending its first
2898 command. Sigh. To try to avoid this, build the complete greeting message
2899 first, and output it in one fell swoop. This gives a better chance of it
2900 ending up as a single packet. */
2902 ss
= store_get(size
);
2906 do /* At least once, in case we have an empty string */
2909 uschar
*linebreak
= Ustrchr(p
, '\n');
2910 ss
= string_catn(ss
, &size
, &ptr
, code
, 3);
2911 if (linebreak
== NULL
)
2914 ss
= string_catn(ss
, &size
, &ptr
, US
" ", 1);
2918 len
= linebreak
- p
;
2919 ss
= string_catn(ss
, &size
, &ptr
, US
"-", 1);
2921 ss
= string_catn(ss
, &size
, &ptr
, esc
, esclen
);
2922 ss
= string_catn(ss
, &size
, &ptr
, p
, len
);
2923 ss
= string_catn(ss
, &size
, &ptr
, US
"\r\n", 2);
2925 if (linebreak
!= NULL
) p
++;
2929 ss
[ptr
] = 0; /* string_cat leaves room for this */
2931 /* Before we write the banner, check that there is no input pending, unless
2932 this synchronisation check is disabled. */
2936 unsigned n
= smtp_inend
- smtp_inptr
;
2939 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP protocol "
2940 "synchronization error (input sent without waiting for greeting): "
2941 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE
),
2942 string_printing(string_copyn(smtp_inptr
, n
)));
2943 smtp_printf("554 SMTP synchronization error\r\n", FALSE
);
2947 /* Now output the banner */
2949 smtp_printf("%s", FALSE
, ss
);
2951 /* Attempt to see if we sent the banner before the last ACK of the 3-way
2952 handshake arrived. If so we must have managed a TFO. */
2965 /*************************************************
2966 * Handle SMTP syntax and protocol errors *
2967 *************************************************/
2969 /* Write to the log for SMTP syntax errors in incoming commands, if configured
2970 to do so. Then transmit the error response. The return value depends on the
2971 number of syntax and protocol errors in this SMTP session.
2974 type error type, given as a log flag bit
2975 code response code; <= 0 means don't send a response
2976 data data to reflect in the response (can be NULL)
2977 errmess the error message
2979 Returns: -1 limit of syntax/protocol errors NOT exceeded
2980 +1 limit of syntax/protocol errors IS exceeded
2982 These values fit in with the values of the "done" variable in the main
2983 processing loop in smtp_setup_msg(). */
2986 synprot_error(int type
, int code
, uschar
*data
, uschar
*errmess
)
2990 log_write(type
, LOG_MAIN
, "SMTP %s error in \"%s\" %s %s",
2991 (type
== L_smtp_syntax_error
)? "syntax" : "protocol",
2992 string_printing(smtp_cmd_buffer
), host_and_ident(TRUE
), errmess
);
2994 if (++synprot_error_count
> smtp_max_synprot_errors
)
2997 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
2998 "syntax or protocol errors (last command was \"%s\")",
2999 host_and_ident(FALSE
), string_printing(smtp_cmd_buffer
));
3004 smtp_printf("%d%c%s%s%s\r\n", FALSE
, code
, yield
== 1 ? '-' : ' ',
3005 data
? data
: US
"", data
? US
": " : US
"", errmess
);
3007 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE
, code
);
3016 /*************************************************
3017 * Send SMTP response, possibly multiline *
3018 *************************************************/
3020 /* There are, it seems, broken clients out there that cannot handle multiline
3021 responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3022 output nothing for non-final calls, and only the first line for anything else.
3025 code SMTP code, may involve extended status codes
3026 codelen length of smtp code; if > 4 there's an ESC
3027 final FALSE if the last line isn't the final line
3028 msg message text, possibly containing newlines
3034 smtp_respond(uschar
* code
, int codelen
, BOOL final
, uschar
*msg
)
3039 if (!final
&& no_multiline_responses
) return;
3044 esclen
= codelen
- 4;
3047 /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3048 have had the same. Note: this code is also present in smtp_printf(). It would
3049 be tidier to have it only in one place, but when it was added, it was easier to
3050 do it that way, so as not to have to mess with the code for the RCPT command,
3051 which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3053 if (rcpt_in_progress
)
3055 if (rcpt_smtp_response
== NULL
)
3056 rcpt_smtp_response
= string_copy(msg
);
3057 else if (rcpt_smtp_response_same
&&
3058 Ustrcmp(rcpt_smtp_response
, msg
) != 0)
3059 rcpt_smtp_response_same
= FALSE
;
3060 rcpt_in_progress
= FALSE
;
3063 /* Now output the message, splitting it up into multiple lines if necessary.
3064 We only handle pipelining these responses as far as nonfinal/final groups,
3065 not the whole MAIL/RCPT/DATA response set. */
3069 uschar
*nl
= Ustrchr(msg
, '\n');
3072 smtp_printf("%.3s%c%.*s%s\r\n", !final
, code
, final
? ' ':'-', esclen
, esc
, msg
);
3075 else if (nl
[1] == 0 || no_multiline_responses
)
3077 smtp_printf("%.3s%c%.*s%.*s\r\n", !final
, code
, final
? ' ':'-', esclen
, esc
,
3078 (int)(nl
- msg
), msg
);
3083 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE
, code
, esclen
, esc
, (int)(nl
- msg
), msg
);
3085 while (isspace(*msg
)) msg
++;
3093 /*************************************************
3094 * Parse user SMTP message *
3095 *************************************************/
3097 /* This function allows for user messages overriding the response code details
3098 by providing a suitable response code string at the start of the message
3099 user_msg. Check the message for starting with a response code and optionally an
3100 extended status code. If found, check that the first digit is valid, and if so,
3101 change the code pointer and length to use the replacement. An invalid code
3102 causes a panic log; in this case, if the log messages is the same as the user
3103 message, we must also adjust the value of the log message to show the code that
3104 is actually going to be used (the original one).
3106 This function is global because it is called from receive.c as well as within
3109 Note that the code length returned includes the terminating whitespace
3110 character, which is always included in the regex match.
3113 code SMTP code, may involve extended status codes
3114 codelen length of smtp code; if > 4 there's an ESC
3116 log_msg optional log message, to be adjusted with the new SMTP code
3117 check_valid if true, verify the response code
3123 smtp_message_code(uschar
**code
, int *codelen
, uschar
**msg
, uschar
**log_msg
,
3129 if (!msg
|| !*msg
) return;
3131 if ((n
= pcre_exec(regex_smtp_code
, NULL
, CS
*msg
, Ustrlen(*msg
), 0,
3132 PCRE_EOPT
, ovector
, sizeof(ovector
)/sizeof(int))) < 0) return;
3134 if (check_valid
&& (*msg
)[0] != (*code
)[0])
3136 log_write(0, LOG_MAIN
|LOG_PANIC
, "configured error code starts with "
3137 "incorrect digit (expected %c) in \"%s\"", (*code
)[0], *msg
);
3138 if (log_msg
!= NULL
&& *log_msg
== *msg
)
3139 *log_msg
= string_sprintf("%s %s", *code
, *log_msg
+ ovector
[1]);
3144 *codelen
= ovector
[1]; /* Includes final space */
3146 *msg
+= ovector
[1]; /* Chop the code off the message */
3153 /*************************************************
3154 * Handle an ACL failure *
3155 *************************************************/
3157 /* This function is called when acl_check() fails. As well as calls from within
3158 this module, it is called from receive.c for an ACL after DATA. It sorts out
3159 logging the incident, and sets up the error response. A message containing
3160 newlines is turned into a multiline SMTP response, but for logging, only the
3163 There's a table of default permanent failure response codes to use in
3164 globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3165 defaults disabled in Exim. However, discussion in connection with RFC 821bis
3166 (aka RFC 2821) has concluded that the response should be 252 in the disabled
3167 state, because there are broken clients that try VRFY before RCPT. A 5xx
3168 response should be given only when the address is positively known to be
3169 undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3170 no explicit code, but if there is one we let it know best.
3171 Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
3173 From Exim 4.63, it is possible to override the response code details by
3174 providing a suitable response code string at the start of the message provided
3175 in user_msg. The code's first digit is checked for validity.
3178 where where the ACL was called from
3180 user_msg a message that can be included in an SMTP response
3181 log_msg a message for logging
3183 Returns: 0 in most cases
3184 2 if the failure code was FAIL_DROP, in which case the
3185 SMTP connection should be dropped (this value fits with the
3186 "done" variable in smtp_setup_msg() below)
3190 smtp_handle_acl_fail(int where
, int rc
, uschar
*user_msg
, uschar
*log_msg
)
3192 BOOL drop
= rc
== FAIL_DROP
;
3196 uschar
*sender_info
= US
"";
3198 #ifdef WITH_CONTENT_SCAN
3199 where
== ACL_WHERE_MIME
? US
"during MIME ACL checks" :
3201 where
== ACL_WHERE_PREDATA
? US
"DATA" :
3202 where
== ACL_WHERE_DATA
? US
"after DATA" :
3203 #ifndef DISABLE_PRDR
3204 where
== ACL_WHERE_PRDR
? US
"after DATA PRDR" :
3207 string_sprintf("%s %s", acl_wherenames
[where
], smtp_cmd_data
) :
3208 string_sprintf("%s in \"connect\" ACL", acl_wherenames
[where
]);
3210 if (drop
) rc
= FAIL
;
3212 /* Set the default SMTP code, and allow a user message to change it. */
3214 smtp_code
= rc
== FAIL
? acl_wherecodes
[where
] : US
"451";
3215 smtp_message_code(&smtp_code
, &codelen
, &user_msg
, &log_msg
,
3216 where
!= ACL_WHERE_VRFY
);
3218 /* We used to have sender_address here; however, there was a bug that was not
3219 updating sender_address after a rewrite during a verify. When this bug was
3220 fixed, sender_address at this point became the rewritten address. I'm not sure
3221 this is what should be logged, so I've changed to logging the unrewritten
3222 address to retain backward compatibility. */
3224 #ifndef WITH_CONTENT_SCAN
3225 if (where
== ACL_WHERE_RCPT
|| where
== ACL_WHERE_DATA
)
3227 if (where
== ACL_WHERE_RCPT
|| where
== ACL_WHERE_DATA
|| where
== ACL_WHERE_MIME
)
3230 sender_info
= string_sprintf("F=<%s>%s%s%s%s ",
3231 sender_address_unrewritten
? sender_address_unrewritten
: sender_address
,
3232 sender_host_authenticated
? US
" A=" : US
"",
3233 sender_host_authenticated
? sender_host_authenticated
: US
"",
3234 sender_host_authenticated
&& authenticated_id
? US
":" : US
"",
3235 sender_host_authenticated
&& authenticated_id
? authenticated_id
: US
""
3239 /* If there's been a sender verification failure with a specific message, and
3240 we have not sent a response about it yet, do so now, as a preliminary line for
3241 failures, but not defers. However, always log it for defer, and log it for fail
3242 unless the sender_verify_fail log selector has been turned off. */
3244 if (sender_verified_failed
&&
3245 !testflag(sender_verified_failed
, af_sverify_told
))
3247 BOOL save_rcpt_in_progress
= rcpt_in_progress
;
3248 rcpt_in_progress
= FALSE
; /* So as not to treat these as the error */
3250 setflag(sender_verified_failed
, af_sverify_told
);
3252 if (rc
!= FAIL
|| LOGGING(sender_verify_fail
))
3253 log_write(0, LOG_MAIN
|LOG_REJECT
, "%s sender verify %s for <%s>%s",
3254 host_and_ident(TRUE
),
3255 ((sender_verified_failed
->special_action
& 255) == DEFER
)? "defer":"fail",
3256 sender_verified_failed
->address
,
3257 (sender_verified_failed
->message
== NULL
)? US
"" :
3258 string_sprintf(": %s", sender_verified_failed
->message
));
3260 if (rc
== FAIL
&& sender_verified_failed
->user_message
)
3261 smtp_respond(smtp_code
, codelen
, FALSE
, string_sprintf(
3262 testflag(sender_verified_failed
, af_verify_pmfail
)?
3263 "Postmaster verification failed while checking <%s>\n%s\n"
3264 "Several RFCs state that you are required to have a postmaster\n"
3265 "mailbox for each mail domain. This host does not accept mail\n"
3266 "from domains whose servers reject the postmaster address."
3268 testflag(sender_verified_failed
, af_verify_nsfail
)?
3269 "Callback setup failed while verifying <%s>\n%s\n"
3270 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3271 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3272 "RFC requirements, and stops you from receiving standard bounce\n"
3273 "messages. This host does not accept mail from domains whose servers\n"
3276 "Verification failed for <%s>\n%s",
3277 sender_verified_failed
->address
,
3278 sender_verified_failed
->user_message
));
3280 rcpt_in_progress
= save_rcpt_in_progress
;
3283 /* Sort out text for logging */
3285 log_msg
= log_msg
? string_sprintf(": %s", log_msg
) : US
"";
3286 if ((lognl
= Ustrchr(log_msg
, '\n'))) *lognl
= 0;
3288 /* Send permanent failure response to the command, but the code used isn't
3289 always a 5xx one - see comments at the start of this function. If the original
3290 rc was FAIL_DROP we drop the connection and yield 2. */
3293 smtp_respond(smtp_code
, codelen
, TRUE
,
3294 user_msg
? user_msg
: US
"Administrative prohibition");
3296 /* Send temporary failure response to the command. Don't give any details,
3297 unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3298 verb, and for a header verify when smtp_return_error_details is set.
3300 This conditional logic is all somewhat of a mess because of the odd
3301 interactions between temp_details and return_error_details. One day it should
3302 be re-implemented in a tidier fashion. */
3305 if (acl_temp_details
&& user_msg
)
3307 if ( smtp_return_error_details
3308 && sender_verified_failed
3309 && sender_verified_failed
->message
3311 smtp_respond(smtp_code
, codelen
, FALSE
, sender_verified_failed
->message
);
3313 smtp_respond(smtp_code
, codelen
, TRUE
, user_msg
);
3316 smtp_respond(smtp_code
, codelen
, TRUE
,
3317 US
"Temporary local problem - please try later");
3319 /* Log the incident to the logs that are specified by log_reject_target
3320 (default main, reject). This can be empty to suppress logging of rejections. If
3321 the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3322 is closing if required and return 2. */
3324 if (log_reject_target
!= 0)
3327 uschar
* tls
= s_tlslog(NULL
, NULL
, NULL
);
3328 if (!tls
) tls
= US
"";
3330 uschar
* tls
= US
"";
3332 log_write(where
== ACL_WHERE_CONNECT
? L_connection_reject
: 0,
3333 log_reject_target
, "%s%s%s %s%srejected %s%s",
3334 LOGGING(dnssec
) && sender_host_dnssec
? US
" DS" : US
"",
3335 host_and_ident(TRUE
),
3338 rc
== FAIL
? US
"" : US
"temporarily ",
3342 if (!drop
) return 0;
3344 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by DROP in ACL",
3345 smtp_get_connection_info());
3347 /* Run the not-quit ACL, but without any custom messages. This should not be a
3348 problem, because we get here only if some other ACL has issued "drop", and
3349 in that case, *its* custom messages will have been used above. */
3351 smtp_notquit_exit(US
"acl-drop", NULL
, NULL
);
3358 /*************************************************
3359 * Handle SMTP exit when QUIT is not given *
3360 *************************************************/
3362 /* This function provides a logging/statistics hook for when an SMTP connection
3363 is dropped on the floor or the other end goes away. It's a global function
3364 because it's called from receive.c as well as this module. As well as running
3365 the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3366 response, either with a custom message from the ACL, or using a default. There
3367 is one case, however, when no message is output - after "drop". In that case,
3368 the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3369 passed to this function.
3371 In case things go wrong while processing this function, causing an error that
3372 may re-enter this function, there is a recursion check.
3375 reason What $smtp_notquit_reason will be set to in the ACL;
3376 if NULL, the ACL is not run
3377 code The error code to return as part of the response
3378 defaultrespond The default message if there's no user_msg
3384 smtp_notquit_exit(uschar
*reason
, uschar
*code
, uschar
*defaultrespond
, ...)
3387 uschar
*user_msg
= NULL
;
3388 uschar
*log_msg
= NULL
;
3390 /* Check for recursive acll */
3392 if (smtp_exit_function_called
)
3394 log_write(0, LOG_PANIC
, "smtp_notquit_exit() called more than once (%s)",
3398 smtp_exit_function_called
= TRUE
;
3400 /* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3402 if (acl_smtp_notquit
&& reason
)
3404 smtp_notquit_reason
= reason
;
3405 if ((rc
= acl_check(ACL_WHERE_NOTQUIT
, NULL
, acl_smtp_notquit
, &user_msg
,
3406 &log_msg
)) == ERROR
)
3407 log_write(0, LOG_MAIN
|LOG_PANIC
, "ACL for not-QUIT returned ERROR: %s",
3411 /* Write an SMTP response if we are expected to give one. As the default
3412 responses are all internal, they should always fit in the buffer, but code a
3413 warning, just in case. Note that string_vformat() still leaves a complete
3414 string, even if it is incomplete. */
3416 if (code
&& defaultrespond
)
3419 smtp_respond(code
, 3, TRUE
, user_msg
);
3424 va_start(ap
, defaultrespond
);
3425 if (!string_vformat(buffer
, sizeof(buffer
), CS defaultrespond
, ap
))
3426 log_write(0, LOG_MAIN
|LOG_PANIC
, "string too large in smtp_notquit_exit()");
3427 smtp_printf("%s %s\r\n", FALSE
, code
, buffer
);
3437 /*************************************************
3438 * Verify HELO argument *
3439 *************************************************/
3441 /* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3442 matched. It is also called from ACL processing if verify = helo is used and
3443 verification was not previously tried (i.e. helo_try_verify_hosts was not
3444 matched). The result of its processing is to set helo_verified and
3445 helo_verify_failed. These variables should both be FALSE for this function to
3448 Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3449 for IPv6 ::ffff: literals.
3452 Returns: TRUE if testing was completed;
3453 FALSE on a temporary failure
3457 smtp_verify_helo(void)
3461 HDEBUG(D_receive
) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3464 if (sender_helo_name
== NULL
)
3466 HDEBUG(D_receive
) debug_printf("no EHLO/HELO command was issued\n");
3469 /* Deal with the case of -bs without an IP address */
3471 else if (sender_host_address
== NULL
)
3473 HDEBUG(D_receive
) debug_printf("no client IP address: assume success\n");
3474 helo_verified
= TRUE
;
3477 /* Deal with the more common case when there is a sending IP address */
3479 else if (sender_helo_name
[0] == '[')
3481 helo_verified
= Ustrncmp(sender_helo_name
+1, sender_host_address
,
3482 Ustrlen(sender_host_address
)) == 0;
3487 if (strncmpic(sender_host_address
, US
"::ffff:", 7) == 0)
3488 helo_verified
= Ustrncmp(sender_helo_name
+ 1,
3489 sender_host_address
+ 7, Ustrlen(sender_host_address
) - 7) == 0;
3494 { if (helo_verified
) debug_printf("matched host address\n"); }
3497 /* Do a reverse lookup if one hasn't already given a positive or negative
3498 response. If that fails, or the name doesn't match, try checking with a forward
3503 if (sender_host_name
== NULL
&& !host_lookup_failed
)
3504 yield
= host_name_lookup() != DEFER
;
3506 /* If a host name is known, check it and all its aliases. */
3508 if (sender_host_name
)
3509 if ((helo_verified
= strcmpic(sender_host_name
, sender_helo_name
) == 0))
3511 sender_helo_dnssec
= sender_host_dnssec
;
3512 HDEBUG(D_receive
) debug_printf("matched host name\n");
3516 uschar
**aliases
= sender_host_aliases
;
3518 if ((helo_verified
= strcmpic(*aliases
++, sender_helo_name
) == 0))
3520 sender_helo_dnssec
= sender_host_dnssec
;
3524 HDEBUG(D_receive
) if (helo_verified
)
3525 debug_printf("matched alias %s\n", *(--aliases
));
3528 /* Final attempt: try a forward lookup of the helo name */
3537 h
.name
= sender_helo_name
;
3544 HDEBUG(D_receive
) debug_printf("getting IP address for %s\n",
3546 rc
= host_find_bydns(&h
, NULL
, HOST_FIND_BY_A
,
3547 NULL
, NULL
, NULL
, &d
, NULL
, NULL
);
3548 if (rc
== HOST_FOUND
|| rc
== HOST_FOUND_LOCAL
)
3549 for (hh
= &h
; hh
; hh
= hh
->next
)
3550 if (Ustrcmp(hh
->address
, sender_host_address
) == 0)
3552 helo_verified
= TRUE
;
3553 if (h
.dnssec
== DS_YES
) sender_helo_dnssec
= TRUE
;
3556 debug_printf("IP address for %s matches calling address\n"
3557 "Forward DNS security status: %sverified\n",
3558 sender_helo_name
, sender_helo_dnssec
? "" : "un");
3565 if (!helo_verified
) helo_verify_failed
= TRUE
; /* We've tried ... */
3572 /*************************************************
3573 * Send user response message *
3574 *************************************************/
3576 /* This function is passed a default response code and a user message. It calls
3577 smtp_message_code() to check and possibly modify the response code, and then
3578 calls smtp_respond() to transmit the response. I put this into a function
3579 just to avoid a lot of repetition.
3582 code the response code
3583 user_msg the user message
3589 smtp_user_msg(uschar
*code
, uschar
*user_msg
)
3592 smtp_message_code(&code
, &len
, &user_msg
, NULL
, TRUE
);
3593 smtp_respond(code
, len
, TRUE
, user_msg
);
3599 smtp_in_auth(auth_instance
*au
, uschar
** s
, uschar
** ss
)
3601 const uschar
*set_id
= NULL
;
3604 /* Run the checking code, passing the remainder of the command line as
3605 data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
3606 it as the only set numerical variable. The authenticator may set $auth<n>
3607 and also set other numeric variables. The $auth<n> variables are preferred
3608 nowadays; the numerical variables remain for backwards compatibility.
3610 Afterwards, have a go at expanding the set_id string, even if
3611 authentication failed - for bad passwords it can be useful to log the
3612 userid. On success, require set_id to expand and exist, and put it in
3613 authenticated_id. Save this in permanent store, as the working store gets
3614 reset at HELO, RSET, etc. */
3616 for (i
= 0; i
< AUTH_VARS
; i
++) auth_vars
[i
] = NULL
;
3618 expand_nlength
[0] = 0; /* $0 contains nothing */
3620 rc
= (au
->info
->servercode
)(au
, smtp_cmd_data
);
3621 if (au
->set_id
) set_id
= expand_string(au
->set_id
);
3622 expand_nmax
= -1; /* Reset numeric variables */
3623 for (i
= 0; i
< AUTH_VARS
; i
++) auth_vars
[i
] = NULL
; /* Reset $auth<n> */
3625 /* The value of authenticated_id is stored in the spool file and printed in
3626 log lines. It must not contain binary zeros or newline characters. In
3627 normal use, it never will, but when playing around or testing, this error
3628 can (did) happen. To guard against this, ensure that the id contains only
3629 printing characters. */
3631 if (set_id
) set_id
= string_printing(set_id
);
3633 /* For the non-OK cases, set up additional logging data if set_id
3637 set_id
= set_id
&& *set_id
3638 ? string_sprintf(" (set_id=%s)", set_id
) : US
"";
3640 /* Switch on the result */
3645 if (!au
->set_id
|| set_id
) /* Complete success */
3647 if (set_id
) authenticated_id
= string_copy_malloc(set_id
);
3648 sender_host_authenticated
= au
->name
;
3649 authentication_failed
= FALSE
;
3650 authenticated_fail_id
= NULL
; /* Impossible to already be set? */
3653 (sender_host_address
? protocols
: protocols_local
)
3654 [pextend
+ pauthed
+ (tls_in
.active
>= 0 ? pcrpted
:0)];
3655 *s
= *ss
= US
"235 Authentication succeeded";
3656 authenticated_by
= au
;
3660 /* Authentication succeeded, but we failed to expand the set_id string.
3661 Treat this as a temporary error. */
3663 auth_defer_msg
= expand_string_message
;
3667 if (set_id
) authenticated_fail_id
= string_copy_malloc(set_id
);
3668 *s
= string_sprintf("435 Unable to authenticate at present%s",
3669 auth_defer_user_msg
);
3670 *ss
= string_sprintf("435 Unable to authenticate at present%s: %s",
3671 set_id
, auth_defer_msg
);
3675 *s
= *ss
= US
"501 Invalid base64 data";
3679 *s
= *ss
= US
"501 Authentication cancelled";
3683 *s
= *ss
= US
"553 Initial data not expected";
3687 if (set_id
) authenticated_fail_id
= string_copy_malloc(set_id
);
3688 *s
= US
"535 Incorrect authentication data";
3689 *ss
= string_sprintf("535 Incorrect authentication data%s", set_id
);
3693 if (set_id
) authenticated_fail_id
= string_copy_malloc(set_id
);
3694 *s
= US
"435 Internal error";
3695 *ss
= string_sprintf("435 Internal error%s: return %d from authentication "
3696 "check", set_id
, rc
);
3708 qualify_recipient(uschar
** recipient
, uschar
* smtp_cmd_data
, uschar
* tag
)
3711 if (allow_unqualified_recipient
|| strcmpic(*recipient
, US
"postmaster") == 0)
3713 DEBUG(D_receive
) debug_printf("unqualified address %s accepted\n",
3715 rd
= Ustrlen(recipient
) + 1;
3716 *recipient
= rewrite_address_qualify(*recipient
, TRUE
);
3719 smtp_printf("501 %s: recipient address must contain a domain\r\n", FALSE
,
3721 log_write(L_smtp_syntax_error
,
3722 LOG_MAIN
|LOG_REJECT
, "unqualified %s rejected: <%s> %s%s",
3723 tag
, *recipient
, host_and_ident(TRUE
), host_lookup_msg
);
3731 smtp_quit_handler(uschar
** user_msgp
, uschar
** log_msgp
)
3734 incomplete_transaction_log(US
"QUIT");
3737 int rc
= acl_check(ACL_WHERE_QUIT
, NULL
, acl_smtp_quit
, user_msgp
, log_msgp
);
3739 log_write(0, LOG_MAIN
|LOG_PANIC
, "ACL for QUIT returned ERROR: %s",
3743 smtp_respond(US
"221", 3, TRUE
, *user_msgp
);
3745 smtp_printf("221 %s closing connection\r\n", FALSE
, smtp_active_hostname
);
3748 tls_close(TRUE
, TRUE
);
3751 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by QUIT",
3752 smtp_get_connection_info());
3757 smtp_rset_handler(void)
3760 incomplete_transaction_log(US
"RSET");
3761 smtp_printf("250 Reset OK\r\n", FALSE
);
3762 cmd_list
[CMD_LIST_RSET
].is_mail_cmd
= FALSE
;
3767 /*************************************************
3768 * Initialize for SMTP incoming message *
3769 *************************************************/
3771 /* This function conducts the initial dialogue at the start of an incoming SMTP
3772 message, and builds a list of recipients. However, if the incoming message
3773 is part of a batch (-bS option) a separate function is called since it would
3774 be messy having tests splattered about all over this function. This function
3775 therefore handles the case where interaction is occurring. The input and output
3776 files are set up in smtp_in and smtp_out.
3778 The global recipients_list is set to point to a vector of recipient_item
3779 blocks, whose number is given by recipients_count. This is extended by the
3780 receive_add_recipient() function. The global variable sender_address is set to
3781 the sender's address. The yield is +1 if a message has been successfully
3782 started, 0 if a QUIT command was encountered or the connection was refused from
3783 the particular host, or -1 if the connection was lost.
3787 Returns: > 0 message successfully started (reached DATA)
3788 = 0 QUIT read or end of file reached or call refused
3793 smtp_setup_msg(void)
3796 BOOL toomany
= FALSE
;
3797 BOOL discarded
= FALSE
;
3798 BOOL last_was_rej_mail
= FALSE
;
3799 BOOL last_was_rcpt
= FALSE
;
3800 void *reset_point
= store_get(0);
3802 DEBUG(D_receive
) debug_printf("smtp_setup_msg entered\n");
3804 /* Reset for start of new message. We allow one RSET not to be counted as a
3805 nonmail command, for those MTAs that insist on sending it between every
3806 message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
3807 TLS between messages (an Exim client may do this if it has messages queued up
3808 for the host). Note: we do NOT reset AUTH at this point. */
3810 smtp_reset(reset_point
);
3811 message_ended
= END_NOTSTARTED
;
3813 chunking_state
= chunking_offered
? CHUNKING_OFFERED
: CHUNKING_NOT_OFFERED
;
3815 cmd_list
[CMD_LIST_RSET
].is_mail_cmd
= TRUE
;
3816 cmd_list
[CMD_LIST_HELO
].is_mail_cmd
= TRUE
;
3817 cmd_list
[CMD_LIST_EHLO
].is_mail_cmd
= TRUE
;
3819 cmd_list
[CMD_LIST_STARTTLS
].is_mail_cmd
= TRUE
;
3820 cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
= TRUE
;
3823 /* Set the local signal handler for SIGTERM - it tries to end off tidily */
3825 os_non_restarting_signal(SIGTERM
, command_sigterm_handler
);
3827 /* Batched SMTP is handled in a different function. */
3829 if (smtp_batched_input
) return smtp_setup_batch_msg();
3831 /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
3832 value. The values are 2 larger than the required yield of the function. */
3836 const uschar
**argv
;
3837 uschar
*etrn_command
;
3838 uschar
*etrn_serialize_key
;
3840 uschar
*log_msg
, *smtp_code
;
3841 uschar
*user_msg
= NULL
;
3842 uschar
*recipient
= NULL
;
3843 uschar
*hello
= NULL
;
3845 BOOL was_rej_mail
= FALSE
;
3846 BOOL was_rcpt
= FALSE
;
3847 void (*oldsignal
)(int);
3849 int start
, end
, sender_domain
, recipient_domain
;
3853 uschar
*orcpt
= NULL
;
3857 /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
3858 if ( tls_in
.active
>= 0
3860 && tls_in
.certificate_verified
3861 && cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
3864 cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
= FALSE
;
3866 && (rc
= acl_check(ACL_WHERE_AUTH
, NULL
, acl_smtp_auth
,
3867 &user_msg
, &log_msg
)) != OK
3870 done
= smtp_handle_acl_fail(ACL_WHERE_AUTH
, rc
, user_msg
, log_msg
);
3874 for (au
= auths
; au
; au
= au
->next
)
3875 if (strcmpic(US
"tls", au
->driver_name
) == 0)
3877 smtp_cmd_data
= NULL
;
3879 if (smtp_in_auth(au
, &s
, &ss
) == OK
)
3880 { DEBUG(D_auth
) debug_printf("tls auth succeeded\n"); }
3882 { DEBUG(D_auth
) debug_printf("tls auth not succeeded\n"); }
3889 if (smtp_in
) /* Avoid pure-ACKs while in cmd pingpong phase */
3890 (void) setsockopt(fileno(smtp_in
), IPPROTO_TCP
, TCP_QUICKACK
,
3891 US
&off
, sizeof(off
));
3894 switch(smtp_read_command(TRUE
, GETC_BUFFER_UNLIMITED
))
3896 /* The AUTH command is not permitted to occur inside a transaction, and may
3897 occur successfully only once per connection. Actually, that isn't quite
3898 true. When TLS is started, all previous information about a connection must
3899 be discarded, so a new AUTH is permitted at that time.
3901 AUTH may only be used when it has been advertised. However, it seems that
3902 there are clients that send AUTH when it hasn't been advertised, some of
3903 them even doing this after HELO. And there are MTAs that accept this. Sigh.
3904 So there's a get-out that allows this to happen.
3906 AUTH is initially labelled as a "nonmail command" so that one occurrence
3907 doesn't get counted. We change the label here so that multiple failing
3908 AUTHS will eventually hit the nonmail threshold. */
3912 authentication_failed
= TRUE
;
3913 cmd_list
[CMD_LIST_AUTH
].is_mail_cmd
= FALSE
;
3915 if (!auth_advertised
&& !allow_auth_unadvertised
)
3917 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
3918 US
"AUTH command used when not advertised");
3921 if (sender_host_authenticated
)
3923 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
3924 US
"already authenticated");
3929 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
3930 US
"not permitted in mail transaction");
3937 && (rc
= acl_check(ACL_WHERE_AUTH
, NULL
, acl_smtp_auth
,
3938 &user_msg
, &log_msg
)) != OK
3941 done
= smtp_handle_acl_fail(ACL_WHERE_AUTH
, rc
, user_msg
, log_msg
);
3945 /* Find the name of the requested authentication mechanism. */
3948 while ((c
= *smtp_cmd_data
) != 0 && !isspace(c
))
3950 if (!isalnum(c
) && c
!= '-' && c
!= '_')
3952 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
3953 US
"invalid character in authentication mechanism name");
3959 /* If not at the end of the line, we must be at white space. Terminate the
3960 name and move the pointer on to any data that may be present. */
3962 if (*smtp_cmd_data
!= 0)
3964 *smtp_cmd_data
++ = 0;
3965 while (isspace(*smtp_cmd_data
)) smtp_cmd_data
++;
3968 /* Search for an authentication mechanism which is configured for use
3969 as a server and which has been advertised (unless, sigh, allow_auth_
3970 unadvertised is set). */
3972 for (au
= auths
; au
; au
= au
->next
)
3973 if (strcmpic(s
, au
->public_name
) == 0 && au
->server
&&
3974 (au
->advertised
|| allow_auth_unadvertised
))
3979 c
= smtp_in_auth(au
, &s
, &ss
);
3981 smtp_printf("%s\r\n", FALSE
, s
);
3983 log_write(0, LOG_MAIN
|LOG_REJECT
, "%s authenticator failed for %s: %s",
3984 au
->name
, host_and_ident(FALSE
), ss
);
3987 done
= synprot_error(L_smtp_protocol_error
, 504, NULL
,
3988 string_sprintf("%s authentication mechanism not supported", s
));
3990 break; /* AUTH_CMD */
3992 /* The HELO/EHLO commands are permitted to appear in the middle of a
3993 session as well as at the beginning. They have the effect of a reset in
3994 addition to their other functions. Their absence at the start cannot be
3995 taken to be an error.
3999 If the EHLO command is not acceptable to the SMTP server, 501, 500,
4000 or 502 failure replies MUST be returned as appropriate. The SMTP
4001 server MUST stay in the same state after transmitting these replies
4002 that it was in before the EHLO was received.
4004 Therefore, we do not do the reset until after checking the command for
4005 acceptability. This change was made for Exim release 4.11. Previously
4006 it did the reset first. */
4019 HELO_EHLO
: /* Common code for HELO and EHLO */
4020 cmd_list
[CMD_LIST_HELO
].is_mail_cmd
= FALSE
;
4021 cmd_list
[CMD_LIST_EHLO
].is_mail_cmd
= FALSE
;
4023 /* Reject the HELO if its argument was invalid or non-existent. A
4024 successful check causes the argument to be saved in malloc store. */
4026 if (!check_helo(smtp_cmd_data
))
4028 smtp_printf("501 Syntactically invalid %s argument(s)\r\n", FALSE
, hello
);
4030 log_write(0, LOG_MAIN
|LOG_REJECT
, "rejected %s from %s: syntactically "
4031 "invalid argument(s): %s", hello
, host_and_ident(FALSE
),
4032 (*smtp_cmd_argument
== 0)? US
"(no argument given)" :
4033 string_printing(smtp_cmd_argument
));
4035 if (++synprot_error_count
> smtp_max_synprot_errors
)
4037 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
4038 "syntax or protocol errors (last command was \"%s\")",
4039 host_and_ident(FALSE
), string_printing(smtp_cmd_buffer
));
4046 /* If sender_host_unknown is true, we have got here via the -bs interface,
4047 not called from inetd. Otherwise, we are running an IP connection and the
4048 host address will be set. If the helo name is the primary name of this
4049 host and we haven't done a reverse lookup, force one now. If helo_required
4050 is set, ensure that the HELO name matches the actual host. If helo_verify
4051 is set, do the same check, but softly. */
4053 if (!sender_host_unknown
)
4055 BOOL old_helo_verified
= helo_verified
;
4056 uschar
*p
= smtp_cmd_data
;
4058 while (*p
!= 0 && !isspace(*p
)) { *p
= tolower(*p
); p
++; }
4061 /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
4062 because otherwise the log can be confusing. */
4064 if (sender_host_name
== NULL
&&
4065 (deliver_domain
= sender_helo_name
, /* set $domain */
4066 match_isinlist(sender_helo_name
, CUSS
&helo_lookup_domains
, 0,
4067 &domainlist_anchor
, NULL
, MCL_DOMAIN
, TRUE
, NULL
)) == OK
)
4068 (void)host_name_lookup();
4070 /* Rebuild the fullhost info to include the HELO name (and the real name
4071 if it was looked up.) */
4073 host_build_sender_fullhost(); /* Rebuild */
4074 set_process_info("handling%s incoming connection from %s",
4075 (tls_in
.active
>= 0)? " TLS" : "", host_and_ident(FALSE
));
4077 /* Verify if configured. This doesn't give much security, but it does
4078 make some people happy to be able to do it. If helo_required is set,
4079 (host matches helo_verify_hosts) failure forces rejection. If helo_verify
4080 is set (host matches helo_try_verify_hosts), it does not. This is perhaps
4081 now obsolescent, since the verification can now be requested selectively
4084 helo_verified
= helo_verify_failed
= sender_helo_dnssec
= FALSE
;
4085 if (helo_required
|| helo_verify
)
4087 BOOL tempfail
= !smtp_verify_helo();
4092 smtp_printf("%d %s argument does not match calling host\r\n", FALSE
,
4093 tempfail
? 451 : 550, hello
);
4094 log_write(0, LOG_MAIN
|LOG_REJECT
, "%srejected \"%s %s\" from %s",
4095 tempfail
? "temporarily " : "",
4096 hello
, sender_helo_name
, host_and_ident(FALSE
));
4097 helo_verified
= old_helo_verified
;
4098 break; /* End of HELO/EHLO processing */
4100 HDEBUG(D_all
) debug_printf("%s verification failed but host is in "
4101 "helo_try_verify_hosts\n", hello
);
4106 #ifdef EXPERIMENTAL_SPF
4107 /* set up SPF context */
4108 spf_init(sender_helo_name
, sender_host_address
);
4111 /* Apply an ACL check if one is defined; afterwards, recheck
4112 synchronization in case the client started sending in a delay. */
4115 if ((rc
= acl_check(ACL_WHERE_HELO
, NULL
, acl_smtp_helo
,
4116 &user_msg
, &log_msg
)) != OK
)
4118 done
= smtp_handle_acl_fail(ACL_WHERE_HELO
, rc
, user_msg
, log_msg
);
4119 sender_helo_name
= NULL
;
4120 host_build_sender_fullhost(); /* Rebuild */
4123 else if (!check_sync()) goto SYNC_FAILURE
;
4125 /* Generate an OK reply. The default string includes the ident if present,
4126 and also the IP address if present. Reflecting back the ident is intended
4127 as a deterrent to mail forgers. For maximum efficiency, and also because
4128 some broken systems expect each response to be in a single packet, arrange
4129 that the entire reply is sent in one write(). */
4131 auth_advertised
= FALSE
;
4132 pipelining_advertised
= FALSE
;
4134 tls_advertised
= FALSE
;
4136 dsn_advertised
= FALSE
;
4138 smtputf8_advertised
= FALSE
;
4141 smtp_code
= US
"250 "; /* Default response code plus space*/
4144 s
= string_sprintf("%.3s %s Hello %s%s%s",
4146 smtp_active_hostname
,
4147 sender_ident
? sender_ident
: US
"",
4148 sender_ident
? US
" at " : US
"",
4149 sender_host_name
? sender_host_name
: sender_helo_name
);
4154 if (sender_host_address
)
4156 s
= string_catn(s
, &size
, &ptr
, US
" [", 2);
4157 s
= string_cat (s
, &size
, &ptr
, sender_host_address
);
4158 s
= string_catn(s
, &size
, &ptr
, US
"]", 1);
4162 /* A user-supplied EHLO greeting may not contain more than one line. Note
4163 that the code returned by smtp_message_code() includes the terminating
4164 whitespace character. */
4170 smtp_message_code(&smtp_code
, &codelen
, &user_msg
, NULL
, TRUE
);
4171 s
= string_sprintf("%.*s%s", codelen
, smtp_code
, user_msg
);
4172 if ((ss
= strpbrk(CS s
, "\r\n")) != NULL
)
4174 log_write(0, LOG_MAIN
|LOG_PANIC
, "EHLO/HELO response must not contain "
4175 "newlines: message truncated: %s", string_printing(s
));
4182 s
= string_catn(s
, &size
, &ptr
, US
"\r\n", 2);
4184 /* If we received EHLO, we must create a multiline response which includes
4185 the functions supported. */
4191 /* I'm not entirely happy with this, as an MTA is supposed to check
4192 that it has enough room to accept a message of maximum size before
4193 it sends this. However, there seems little point in not sending it.
4194 The actual size check happens later at MAIL FROM time. By postponing it
4195 till then, VRFY and EXPN can be used after EHLO when space is short. */
4197 if (thismessage_size_limit
> 0)
4199 sprintf(CS big_buffer
, "%.3s-SIZE %d\r\n", smtp_code
,
4200 thismessage_size_limit
);
4201 s
= string_cat(s
, &size
, &ptr
, big_buffer
);
4205 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4206 s
= string_catn(s
, &size
, &ptr
, US
"-SIZE\r\n", 7);
4209 /* Exim does not do protocol conversion or data conversion. It is 8-bit
4210 clean; if it has an 8-bit character in its hand, it just sends it. It
4211 cannot therefore specify 8BITMIME and remain consistent with the RFCs.
4212 However, some users want this option simply in order to stop MUAs
4213 mangling messages that contain top-bit-set characters. It is therefore
4214 provided as an option. */
4216 if (accept_8bitmime
)
4218 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4219 s
= string_catn(s
, &size
, &ptr
, US
"-8BITMIME\r\n", 11);
4222 /* Advertise DSN support if configured to do so. */
4223 if (verify_check_host(&dsn_advertise_hosts
) != FAIL
)
4225 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4226 s
= string_catn(s
, &size
, &ptr
, US
"-DSN\r\n", 6);
4227 dsn_advertised
= TRUE
;
4230 /* Advertise ETRN/VRFY/EXPN if there's are ACL checking whether a host is
4231 permitted to issue them; a check is made when any host actually tries. */
4235 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4236 s
= string_catn(s
, &size
, &ptr
, US
"-ETRN\r\n", 7);
4240 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4241 s
= string_catn(s
, &size
, &ptr
, US
"-VRFY\r\n", 7);
4245 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4246 s
= string_catn(s
, &size
, &ptr
, US
"-EXPN\r\n", 7);
4249 /* Exim is quite happy with pipelining, so let the other end know that
4250 it is safe to use it, unless advertising is disabled. */
4252 if (pipelining_enable
&&
4253 verify_check_host(&pipelining_advertise_hosts
) == OK
)
4255 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4256 s
= string_catn(s
, &size
, &ptr
, US
"-PIPELINING\r\n", 13);
4257 sync_cmd_limit
= NON_SYNC_CMD_PIPELINING
;
4258 pipelining_advertised
= TRUE
;
4262 /* If any server authentication mechanisms are configured, advertise
4263 them if the current host is in auth_advertise_hosts. The problem with
4264 advertising always is that some clients then require users to
4265 authenticate (and aren't configurable otherwise) even though it may not
4266 be necessary (e.g. if the host is in host_accept_relay).
4268 RFC 2222 states that SASL mechanism names contain only upper case
4269 letters, so output the names in upper case, though we actually recognize
4270 them in either case in the AUTH command. */
4274 && !sender_host_authenticated
4276 && verify_check_host(&auth_advertise_hosts
) == OK
4281 for (au
= auths
; au
; au
= au
->next
)
4283 au
->advertised
= FALSE
;
4286 DEBUG(D_auth
+D_expand
) debug_printf_indent(
4287 "Evaluating advertise_condition for %s athenticator\n",
4289 if ( !au
->advertise_condition
4290 || expand_check_condition(au
->advertise_condition
, au
->name
,
4297 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4298 s
= string_catn(s
, &size
, &ptr
, US
"-AUTH", 5);
4300 auth_advertised
= TRUE
;
4303 s
= string_catn(s
, &size
, &ptr
, US
" ", 1);
4304 s
= string_cat (s
, &size
, &ptr
, au
->public_name
);
4305 while (++saveptr
< ptr
) s
[saveptr
] = toupper(s
[saveptr
]);
4306 au
->advertised
= TRUE
;
4311 if (!first
) s
= string_catn(s
, &size
, &ptr
, US
"\r\n", 2);
4314 /* RFC 3030 CHUNKING */
4316 if (verify_check_host(&chunking_advertise_hosts
) != FAIL
)
4318 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4319 s
= string_catn(s
, &size
, &ptr
, US
"-CHUNKING\r\n", 11);
4320 chunking_offered
= TRUE
;
4321 chunking_state
= CHUNKING_OFFERED
;
4324 /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
4325 if it has been included in the binary, and the host matches
4326 tls_advertise_hosts. We must *not* advertise if we are already in a
4327 secure connection. */
4330 if (tls_in
.active
< 0 &&
4331 verify_check_host(&tls_advertise_hosts
) != FAIL
)
4333 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4334 s
= string_catn(s
, &size
, &ptr
, US
"-STARTTLS\r\n", 11);
4335 tls_advertised
= TRUE
;
4339 #ifndef DISABLE_PRDR
4340 /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */
4343 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4344 s
= string_catn(s
, &size
, &ptr
, US
"-PRDR\r\n", 7);
4349 if ( accept_8bitmime
4350 && verify_check_host(&smtputf8_advertise_hosts
) != FAIL
)
4352 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4353 s
= string_catn(s
, &size
, &ptr
, US
"-SMTPUTF8\r\n", 11);
4354 smtputf8_advertised
= TRUE
;
4358 /* Finish off the multiline reply with one that is always available. */
4360 s
= string_catn(s
, &size
, &ptr
, smtp_code
, 3);
4361 s
= string_catn(s
, &size
, &ptr
, US
" HELP\r\n", 7);
4364 /* Terminate the string (for debug), write it, and note that HELO/EHLO
4370 if (tls_in
.active
>= 0) (void)tls_write(TRUE
, s
, ptr
, FALSE
); else
4374 int i
= fwrite(s
, 1, ptr
, smtp_out
); i
= i
; /* compiler quietening */
4379 while ((cr
= Ustrchr(s
, '\r')) != NULL
) /* lose CRs */
4380 memmove(cr
, cr
+ 1, (ptr
--) - (cr
- s
));
4381 debug_printf("SMTP>> %s", s
);
4385 /* Reset the protocol and the state, abandoning any previous message. */
4387 (sender_host_address
? protocols
: protocols_local
)
4389 ? pextend
+ (sender_host_authenticated
? pauthed
: 0)
4391 + (tls_in
.active
>= 0 ? pcrpted
: 0)
4393 cancel_cutthrough_connection(TRUE
, US
"sent EHLO response");
4394 smtp_reset(reset_point
);
4396 break; /* HELO/EHLO */
4399 /* The MAIL command requires an address as an operand. All we do
4400 here is to parse it for syntactic correctness. The form "<>" is
4401 a special case which converts into an empty string. The start/end
4402 pointers in the original are not used further for this address, as
4403 it is the canonical extracted address which is all that is kept. */
4407 smtp_mailcmd_count
++; /* Count for limit and ratelimit */
4408 was_rej_mail
= TRUE
; /* Reset if accepted */
4409 env_mail_type_t
* mail_args
; /* Sanity check & validate args */
4411 if (helo_required
&& !helo_seen
)
4413 smtp_printf("503 HELO or EHLO required\r\n", FALSE
);
4414 log_write(0, LOG_MAIN
|LOG_REJECT
, "rejected MAIL from %s: no "
4415 "HELO/EHLO given", host_and_ident(FALSE
));
4419 if (sender_address
!= NULL
)
4421 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4422 US
"sender already given");
4426 if (smtp_cmd_data
[0] == 0)
4428 done
= synprot_error(L_smtp_protocol_error
, 501, NULL
,
4429 US
"MAIL must have an address operand");
4433 /* Check to see if the limit for messages per connection would be
4434 exceeded by accepting further messages. */
4436 if (smtp_accept_max_per_connection
> 0 &&
4437 smtp_mailcmd_count
> smtp_accept_max_per_connection
)
4439 smtp_printf("421 too many messages in this connection\r\n", FALSE
);
4440 log_write(0, LOG_MAIN
|LOG_REJECT
, "rejected MAIL command %s: too many "
4441 "messages in one connection", host_and_ident(TRUE
));
4445 /* Reset for start of message - even if this is going to fail, we
4446 obviously need to throw away any previous data. */
4448 cancel_cutthrough_connection(TRUE
, US
"MAIL received");
4449 smtp_reset(reset_point
);
4451 sender_data
= recipient_data
= NULL
;
4453 /* Loop, checking for ESMTP additions to the MAIL FROM command. */
4457 uschar
*name
, *value
, *end
;
4458 unsigned long int size
;
4459 BOOL arg_error
= FALSE
;
4461 if (!extract_option(&name
, &value
)) break;
4463 for (mail_args
= env_mail_type_list
;
4464 mail_args
->value
!= ENV_MAIL_OPT_NULL
;
4467 if (strcmpic(name
, mail_args
->name
) == 0)
4469 if (mail_args
->need_value
&& strcmpic(value
, US
"") == 0)
4472 switch(mail_args
->value
)
4474 /* Handle SIZE= by reading the value. We don't do the check till later,
4475 in order to be able to log the sender address on failure. */
4476 case ENV_MAIL_OPT_SIZE
:
4477 if (((size
= Ustrtoul(value
, &end
, 10)), *end
== 0))
4479 if ((size
== ULONG_MAX
&& errno
== ERANGE
) || size
> INT_MAX
)
4481 message_size
= (int)size
;
4487 /* If this session was initiated with EHLO and accept_8bitmime is set,
4488 Exim will have indicated that it supports the BODY=8BITMIME option. In
4489 fact, it does not support this according to the RFCs, in that it does not
4490 take any special action for forwarding messages containing 8-bit
4491 characters. That is why accept_8bitmime is not the default setting, but
4492 some sites want the action that is provided. We recognize both "8BITMIME"
4493 and "7BIT" as body types, but take no action. */
4494 case ENV_MAIL_OPT_BODY
:
4495 if (accept_8bitmime
) {
4496 if (strcmpic(value
, US
"8BITMIME") == 0)
4498 else if (strcmpic(value
, US
"7BIT") == 0)
4503 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4504 US
"invalid data for BODY");
4507 DEBUG(D_receive
) debug_printf("8BITMIME: %d\n", body_8bitmime
);
4513 /* Handle the two DSN options, but only if configured to do so (which
4514 will have caused "DSN" to be given in the EHLO response). The code itself
4515 is included only if configured in at build time. */
4517 case ENV_MAIL_OPT_RET
:
4520 /* Check if RET has already been set */
4523 synprot_error(L_smtp_syntax_error
, 501, NULL
,
4524 US
"RET can be specified once only");
4527 dsn_ret
= strcmpic(value
, US
"HDRS") == 0
4529 : strcmpic(value
, US
"FULL") == 0
4532 DEBUG(D_receive
) debug_printf("DSN_RET: %d\n", dsn_ret
);
4533 /* Check for invalid invalid value, and exit with error */
4536 synprot_error(L_smtp_syntax_error
, 501, NULL
,
4537 US
"Value for RET is invalid");
4542 case ENV_MAIL_OPT_ENVID
:
4545 /* Check if the dsn envid has been already set */
4546 if (dsn_envid
!= NULL
)
4548 synprot_error(L_smtp_syntax_error
, 501, NULL
,
4549 US
"ENVID can be specified once only");
4552 dsn_envid
= string_copy(value
);
4553 DEBUG(D_receive
) debug_printf("DSN_ENVID: %s\n", dsn_envid
);
4557 /* Handle the AUTH extension. If the value given is not "<>" and either
4558 the ACL says "yes" or there is no ACL but the sending host is
4559 authenticated, we set it up as the authenticated sender. However, if the
4560 authenticator set a condition to be tested, we ignore AUTH on MAIL unless
4561 the condition is met. The value of AUTH is an xtext, which means that +,
4562 = and cntrl chars are coded in hex; however "<>" is unaffected by this
4564 case ENV_MAIL_OPT_AUTH
:
4565 if (Ustrcmp(value
, "<>") != 0)
4570 if (auth_xtextdecode(value
, &authenticated_sender
) < 0)
4572 /* Put back terminator overrides for error message */
4575 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4576 US
"invalid data for AUTH");
4579 if (acl_smtp_mailauth
== NULL
)
4581 ignore_msg
= US
"client not authenticated";
4582 rc
= (sender_host_authenticated
!= NULL
)? OK
: FAIL
;
4586 ignore_msg
= US
"rejected by ACL";
4587 rc
= acl_check(ACL_WHERE_MAILAUTH
, NULL
, acl_smtp_mailauth
,
4588 &user_msg
, &log_msg
);
4594 if (authenticated_by
== NULL
||
4595 authenticated_by
->mail_auth_condition
== NULL
||
4596 expand_check_condition(authenticated_by
->mail_auth_condition
,
4597 authenticated_by
->name
, US
"authenticator"))
4598 break; /* Accept the AUTH */
4600 ignore_msg
= US
"server_mail_auth_condition failed";
4601 if (authenticated_id
!= NULL
)
4602 ignore_msg
= string_sprintf("%s: authenticated ID=\"%s\"",
4603 ignore_msg
, authenticated_id
);
4608 authenticated_sender
= NULL
;
4609 log_write(0, LOG_MAIN
, "ignoring AUTH=%s from %s (%s)",
4610 value
, host_and_ident(TRUE
), ignore_msg
);
4613 /* Should only get DEFER or ERROR here. Put back terminator
4614 overrides for error message */
4619 (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH
, rc
, user_msg
,
4626 #ifndef DISABLE_PRDR
4627 case ENV_MAIL_OPT_PRDR
:
4629 prdr_requested
= TRUE
;
4634 case ENV_MAIL_OPT_UTF8
:
4635 if (smtputf8_advertised
)
4637 int old_pool
= store_pool
;
4639 DEBUG(D_receive
) debug_printf("smtputf8 requested\n");
4640 message_smtputf8
= allow_utf8_domains
= TRUE
;
4641 store_pool
= POOL_PERM
;
4642 received_protocol
= string_sprintf("utf8%s", received_protocol
);
4643 store_pool
= old_pool
;
4647 /* No valid option. Stick back the terminator characters and break
4648 the loop. Do the name-terminator second as extract_option sets
4649 value==name when it found no equal-sign.
4650 An error for a malformed address will occur. */
4651 case ENV_MAIL_OPT_NULL
:
4659 /* Break out of for loop if switch() had bad argument or
4660 when start of the email address is reached */
4661 if (arg_error
) break;
4664 /* If we have passed the threshold for rate limiting, apply the current
4665 delay, and update it for next time, provided this is a limited host. */
4667 if (smtp_mailcmd_count
> smtp_rlm_threshold
&&
4668 verify_check_host(&smtp_ratelimit_hosts
) == OK
)
4670 DEBUG(D_receive
) debug_printf("rate limit MAIL: delay %.3g sec\n",
4671 smtp_delay_mail
/1000.0);
4672 millisleep((int)smtp_delay_mail
);
4673 smtp_delay_mail
*= smtp_rlm_factor
;
4674 if (smtp_delay_mail
> (double)smtp_rlm_limit
)
4675 smtp_delay_mail
= (double)smtp_rlm_limit
;
4678 /* Now extract the address, first applying any SMTP-time rewriting. The
4679 TRUE flag allows "<>" as a sender address. */
4681 raw_sender
= rewrite_existflags
& rewrite_smtp
4682 ? rewrite_one(smtp_cmd_data
, rewrite_smtp
, NULL
, FALSE
, US
"",
4683 global_rewrite_rules
)
4687 parse_extract_address(raw_sender
, &errmess
, &start
, &end
, &sender_domain
,
4692 done
= synprot_error(L_smtp_syntax_error
, 501, smtp_cmd_data
, errmess
);
4696 sender_address
= raw_sender
;
4698 /* If there is a configured size limit for mail, check that this message
4699 doesn't exceed it. The check is postponed to this point so that the sender
4702 if (thismessage_size_limit
> 0 && message_size
> thismessage_size_limit
)
4704 smtp_printf("552 Message size exceeds maximum permitted\r\n", FALSE
);
4705 log_write(L_size_reject
,
4706 LOG_MAIN
|LOG_REJECT
, "rejected MAIL FROM:<%s> %s: "
4707 "message too big: size%s=%d max=%d",
4709 host_and_ident(TRUE
),
4710 (message_size
== INT_MAX
)? ">" : "",
4712 thismessage_size_limit
);
4713 sender_address
= NULL
;
4717 /* Check there is enough space on the disk unless configured not to.
4718 When smtp_check_spool_space is set, the check is for thismessage_size_limit
4719 plus the current message - i.e. we accept the message only if it won't
4720 reduce the space below the threshold. Add 5000 to the size to allow for
4721 overheads such as the Received: line and storing of recipients, etc.
4722 By putting the check here, even when SIZE is not given, it allow VRFY
4723 and EXPN etc. to be used when space is short. */
4725 if (!receive_check_fs(
4726 (smtp_check_spool_space
&& message_size
>= 0)?
4727 message_size
+ 5000 : 0))
4729 smtp_printf("452 Space shortage, please try later\r\n", FALSE
);
4730 sender_address
= NULL
;
4734 /* If sender_address is unqualified, reject it, unless this is a locally
4735 generated message, or the sending host or net is permitted to send
4736 unqualified addresses - typically local machines behaving as MUAs -
4737 in which case just qualify the address. The flag is set above at the start
4738 of the SMTP connection. */
4740 if (sender_domain
== 0 && sender_address
[0] != 0)
4742 if (allow_unqualified_sender
)
4744 sender_domain
= Ustrlen(sender_address
) + 1;
4745 sender_address
= rewrite_address_qualify(sender_address
, FALSE
);
4746 DEBUG(D_receive
) debug_printf("unqualified address %s accepted\n",
4751 smtp_printf("501 %s: sender address must contain a domain\r\n", FALSE
,
4753 log_write(L_smtp_syntax_error
,
4754 LOG_MAIN
|LOG_REJECT
,
4755 "unqualified sender rejected: <%s> %s%s",
4757 host_and_ident(TRUE
),
4759 sender_address
= NULL
;
4764 /* Apply an ACL check if one is defined, before responding. Afterwards,
4765 when pipelining is not advertised, do another sync check in case the ACL
4766 delayed and the client started sending in the meantime. */
4770 rc
= acl_check(ACL_WHERE_MAIL
, NULL
, acl_smtp_mail
, &user_msg
, &log_msg
);
4771 if (rc
== OK
&& !pipelining_advertised
&& !check_sync())
4777 if (rc
== OK
|| rc
== DISCARD
)
4779 BOOL more
= pipeline_response();
4782 smtp_printf("%s%s%s", more
, US
"250 OK",
4783 #ifndef DISABLE_PRDR
4784 prdr_requested
? US
", PRDR Requested" : US
"",
4791 #ifndef DISABLE_PRDR
4793 user_msg
= string_sprintf("%s%s", user_msg
, US
", PRDR Requested");
4795 smtp_user_msg(US
"250", user_msg
);
4797 smtp_delay_rcpt
= smtp_rlr_base
;
4798 recipients_discarded
= (rc
== DISCARD
);
4799 was_rej_mail
= FALSE
;
4803 done
= smtp_handle_acl_fail(ACL_WHERE_MAIL
, rc
, user_msg
, log_msg
);
4804 sender_address
= NULL
;
4809 /* The RCPT command requires an address as an operand. There may be any
4810 number of RCPT commands, specifying multiple recipients. We build them all
4811 into a data structure. The start/end values given by parse_extract_address
4812 are not used, as we keep only the extracted address. */
4817 was_rcpt
= rcpt_in_progress
= TRUE
;
4819 /* There must be a sender address; if the sender was rejected and
4820 pipelining was advertised, we assume the client was pipelining, and do not
4821 count this as a protocol error. Reset was_rej_mail so that further RCPTs
4822 get the same treatment. */
4824 if (sender_address
== NULL
)
4826 if (pipelining_advertised
&& last_was_rej_mail
)
4828 smtp_printf("503 sender not yet given\r\n", FALSE
);
4829 was_rej_mail
= TRUE
;
4833 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
4834 US
"sender not yet given");
4835 was_rcpt
= FALSE
; /* Not a valid RCPT */
4841 /* Check for an operand */
4843 if (smtp_cmd_data
[0] == 0)
4845 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
4846 US
"RCPT must have an address operand");
4851 /* Set the DSN flags orcpt and dsn_flags from the session*/
4857 uschar
*name
, *value
;
4859 if (!extract_option(&name
, &value
))
4862 if (dsn_advertised
&& strcmpic(name
, US
"ORCPT") == 0)
4864 /* Check whether orcpt has been already set */
4867 synprot_error(L_smtp_syntax_error
, 501, NULL
,
4868 US
"ORCPT can be specified once only");
4871 orcpt
= string_copy(value
);
4872 DEBUG(D_receive
) debug_printf("DSN orcpt: %s\n", orcpt
);
4875 else if (dsn_advertised
&& strcmpic(name
, US
"NOTIFY") == 0)
4877 /* Check if the notify flags have been already set */
4880 synprot_error(L_smtp_syntax_error
, 501, NULL
,
4881 US
"NOTIFY can be specified once only");
4884 if (strcmpic(value
, US
"NEVER") == 0)
4885 flags
|= rf_notify_never
;
4892 while (*pp
!= 0 && *pp
!= ',') pp
++;
4893 if (*pp
== ',') *pp
++ = 0;
4894 if (strcmpic(p
, US
"SUCCESS") == 0)
4896 DEBUG(D_receive
) debug_printf("DSN: Setting notify success\n");
4897 flags
|= rf_notify_success
;
4899 else if (strcmpic(p
, US
"FAILURE") == 0)
4901 DEBUG(D_receive
) debug_printf("DSN: Setting notify failure\n");
4902 flags
|= rf_notify_failure
;
4904 else if (strcmpic(p
, US
"DELAY") == 0)
4906 DEBUG(D_receive
) debug_printf("DSN: Setting notify delay\n");
4907 flags
|= rf_notify_delay
;
4911 /* Catch any strange values */
4912 synprot_error(L_smtp_syntax_error
, 501, NULL
,
4913 US
"Invalid value for NOTIFY parameter");
4918 DEBUG(D_receive
) debug_printf("DSN Flags: %x\n", flags
);
4922 /* Unknown option. Stick back the terminator characters and break
4923 the loop. An error for a malformed address will occur. */
4927 DEBUG(D_receive
) debug_printf("Invalid RCPT option: %s : %s\n", name
, value
);
4934 /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
4935 as a recipient address */
4937 recipient
= rewrite_existflags
& rewrite_smtp
4938 ? rewrite_one(smtp_cmd_data
, rewrite_smtp
, NULL
, FALSE
, US
"",
4939 global_rewrite_rules
)
4942 if (!(recipient
= parse_extract_address(recipient
, &errmess
, &start
, &end
,
4943 &recipient_domain
, FALSE
)))
4945 done
= synprot_error(L_smtp_syntax_error
, 501, smtp_cmd_data
, errmess
);
4950 /* If the recipient address is unqualified, reject it, unless this is a
4951 locally generated message. However, unqualified addresses are permitted
4952 from a configured list of hosts and nets - typically when behaving as
4953 MUAs rather than MTAs. Sad that SMTP is used for both types of traffic,
4954 really. The flag is set at the start of the SMTP connection.
4956 RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always
4957 assumed this meant "reserved local part", but the revision of RFC 821 and
4958 friends now makes it absolutely clear that it means *mailbox*. Consequently
4959 we must always qualify this address, regardless. */
4961 if (!recipient_domain
)
4962 if (!(recipient_domain
= qualify_recipient(&recipient
, smtp_cmd_data
,
4969 /* Check maximum allowed */
4971 if (rcpt_count
> recipients_max
&& recipients_max
> 0)
4973 if (recipients_max_reject
)
4976 smtp_printf("552 too many recipients\r\n", FALSE
);
4978 log_write(0, LOG_MAIN
|LOG_REJECT
, "too many recipients: message "
4979 "rejected: sender=<%s> %s", sender_address
, host_and_ident(TRUE
));
4984 smtp_printf("452 too many recipients\r\n", FALSE
);
4986 log_write(0, LOG_MAIN
|LOG_REJECT
, "too many recipients: excess "
4987 "temporarily rejected: sender=<%s> %s", sender_address
,
4988 host_and_ident(TRUE
));
4995 /* If we have passed the threshold for rate limiting, apply the current
4996 delay, and update it for next time, provided this is a limited host. */
4998 if (rcpt_count
> smtp_rlr_threshold
&&
4999 verify_check_host(&smtp_ratelimit_hosts
) == OK
)
5001 DEBUG(D_receive
) debug_printf("rate limit RCPT: delay %.3g sec\n",
5002 smtp_delay_rcpt
/1000.0);
5003 millisleep((int)smtp_delay_rcpt
);
5004 smtp_delay_rcpt
*= smtp_rlr_factor
;
5005 if (smtp_delay_rcpt
> (double)smtp_rlr_limit
)
5006 smtp_delay_rcpt
= (double)smtp_rlr_limit
;
5009 /* If the MAIL ACL discarded all the recipients, we bypass ACL checking
5010 for them. Otherwise, check the access control list for this recipient. As
5011 there may be a delay in this, re-check for a synchronization error
5012 afterwards, unless pipelining was advertised. */
5014 if (recipients_discarded
)
5017 if ( (rc
= acl_check(ACL_WHERE_RCPT
, recipient
, acl_smtp_rcpt
, &user_msg
,
5019 && !pipelining_advertised
&& !check_sync())
5022 /* The ACL was happy */
5026 BOOL more
= pipeline_response();
5029 smtp_user_msg(US
"250", user_msg
);
5031 smtp_printf("250 Accepted\r\n", more
);
5032 receive_add_recipient(recipient
, -1);
5034 /* Set the dsn flags in the recipients_list */
5035 recipients_list
[recipients_count
-1].orcpt
= orcpt
;
5036 recipients_list
[recipients_count
-1].dsn_flags
= flags
;
5038 DEBUG(D_receive
) debug_printf("DSN: orcpt: %s flags: %d\n",
5039 recipients_list
[recipients_count
-1].orcpt
,
5040 recipients_list
[recipients_count
-1].dsn_flags
);
5043 /* The recipient was discarded */
5045 else if (rc
== DISCARD
)
5048 smtp_user_msg(US
"250", user_msg
);
5050 smtp_printf("250 Accepted\r\n", FALSE
);
5053 log_write(0, LOG_MAIN
|LOG_REJECT
, "%s F=<%s> RCPT %s: "
5054 "discarded by %s ACL%s%s", host_and_ident(TRUE
),
5055 sender_address_unrewritten
? sender_address_unrewritten
: sender_address
,
5056 smtp_cmd_argument
, recipients_discarded
? "MAIL" : "RCPT",
5057 log_msg
? US
": " : US
"", log_msg
? log_msg
: US
"");
5060 /* Either the ACL failed the address, or it was deferred. */
5064 if (rc
== FAIL
) rcpt_fail_count
++; else rcpt_defer_count
++;
5065 done
= smtp_handle_acl_fail(ACL_WHERE_RCPT
, rc
, user_msg
, log_msg
);
5070 /* The DATA command is legal only if it follows successful MAIL FROM
5071 and RCPT TO commands. However, if pipelining is advertised, a bad DATA is
5072 not counted as a protocol error if it follows RCPT (which must have been
5073 rejected if there are no recipients.) This function is complete when a
5074 valid DATA command is encountered.
5076 Note concerning the code used: RFC 2821 says this:
5078 - If there was no MAIL, or no RCPT, command, or all such commands
5079 were rejected, the server MAY return a "command out of sequence"
5080 (503) or "no valid recipients" (554) reply in response to the
5083 The example in the pipelining RFC 2920 uses 554, but I use 503 here
5084 because it is the same whether pipelining is in use or not.
5086 If all the RCPT commands that precede DATA provoked the same error message
5087 (often indicating some kind of system error), it is helpful to include it
5088 with the DATA rejection (an idea suggested by Tony Finch). */
5095 if (chunking_state
!= CHUNKING_OFFERED
)
5097 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5098 US
"BDAT command used when CHUNKING not advertised");
5102 /* grab size, endmarker */
5104 if (sscanf(CS smtp_cmd_data
, "%u %n", &chunking_datasize
, &n
) < 1)
5106 done
= synprot_error(L_smtp_protocol_error
, 501, NULL
,
5107 US
"missing size for BDAT command");
5110 chunking_state
= strcmpic(smtp_cmd_data
+n
, US
"LAST") == 0
5111 ? CHUNKING_LAST
: CHUNKING_ACTIVE
;
5112 chunking_data_left
= chunking_datasize
;
5113 DEBUG(D_receive
) debug_printf("chunking state %d, %d bytes\n",
5114 (int)chunking_state
, chunking_data_left
);
5116 lwr_receive_getc
= receive_getc
;
5117 lwr_receive_getbuf
= receive_getbuf
;
5118 lwr_receive_ungetc
= receive_ungetc
;
5119 receive_getc
= bdat_getc
;
5120 receive_ungetc
= bdat_ungetc
;
5128 DATA_BDAT
: /* Common code for DATA and BDAT */
5129 if (!discarded
&& recipients_count
<= 0)
5131 if (rcpt_smtp_response_same
&& rcpt_smtp_response
!= NULL
)
5133 uschar
*code
= US
"503";
5134 int len
= Ustrlen(rcpt_smtp_response
);
5135 smtp_respond(code
, 3, FALSE
, US
"All RCPT commands were rejected with "
5137 /* Responses from smtp_printf() will have \r\n on the end */
5138 if (len
> 2 && rcpt_smtp_response
[len
-2] == '\r')
5139 rcpt_smtp_response
[len
-2] = 0;
5140 smtp_respond(code
, 3, FALSE
, rcpt_smtp_response
);
5142 if (pipelining_advertised
&& last_was_rcpt
)
5143 smtp_printf("503 Valid RCPT command must precede %s\r\n", FALSE
,
5144 smtp_names
[smtp_connection_had
[smtp_ch_index
-1]]);
5146 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5147 smtp_connection_had
[smtp_ch_index
-1] == SCH_DATA
5148 ? US
"valid RCPT command must precede DATA"
5149 : US
"valid RCPT command must precede BDAT");
5151 if (chunking_state
> CHUNKING_OFFERED
)
5156 if (toomany
&& recipients_max_reject
)
5158 sender_address
= NULL
; /* This will allow a new MAIL without RSET */
5159 sender_address_unrewritten
= NULL
;
5160 smtp_printf("554 Too many recipients\r\n", FALSE
);
5164 if (chunking_state
> CHUNKING_OFFERED
)
5165 rc
= OK
; /* No predata ACL or go-ahead output for BDAT */
5168 /* If there is an ACL, re-check the synchronization afterwards, since the
5169 ACL may have delayed. To handle cutthrough delivery enforce a dummy call
5170 to get the DATA command sent. */
5172 if (acl_smtp_predata
== NULL
&& cutthrough
.fd
< 0)
5176 uschar
* acl
= acl_smtp_predata
? acl_smtp_predata
: US
"accept";
5177 enable_dollar_recipients
= TRUE
;
5178 rc
= acl_check(ACL_WHERE_PREDATA
, NULL
, acl
, &user_msg
,
5180 enable_dollar_recipients
= FALSE
;
5181 if (rc
== OK
&& !check_sync())
5185 { /* Either the ACL failed the address, or it was deferred. */
5186 done
= smtp_handle_acl_fail(ACL_WHERE_PREDATA
, rc
, user_msg
, log_msg
);
5192 smtp_user_msg(US
"354", user_msg
);
5195 "354 Enter message, ending with \".\" on a line by itself\r\n", FALSE
);
5199 if (smtp_in
) /* all ACKs needed to ramp window up for bulk data */
5200 (void) setsockopt(fileno(smtp_in
), IPPROTO_TCP
, TCP_QUICKACK
,
5201 US
&on
, sizeof(on
));
5204 message_ended
= END_NOTENDED
; /* Indicate in middle of data */
5215 if (!(address
= parse_extract_address(smtp_cmd_data
, &errmess
,
5216 &start
, &end
, &recipient_domain
, FALSE
)))
5218 smtp_printf("501 %s\r\n", FALSE
, errmess
);
5222 if (!recipient_domain
)
5223 if (!(recipient_domain
= qualify_recipient(&address
, smtp_cmd_data
,
5227 if ((rc
= acl_check(ACL_WHERE_VRFY
, address
, acl_smtp_vrfy
,
5228 &user_msg
, &log_msg
)) != OK
)
5229 done
= smtp_handle_acl_fail(ACL_WHERE_VRFY
, rc
, user_msg
, log_msg
);
5233 address_item
* addr
= deliver_make_addr(address
, FALSE
);
5235 switch(verify_address(addr
, NULL
, vopt_is_recipient
| vopt_qualify
, -1,
5236 -1, -1, NULL
, NULL
, NULL
))
5239 s
= string_sprintf("250 <%s> is deliverable", address
);
5243 s
= (addr
->user_message
!= NULL
)?
5244 string_sprintf("451 <%s> %s", address
, addr
->user_message
) :
5245 string_sprintf("451 Cannot resolve <%s> at this time", address
);
5249 s
= (addr
->user_message
!= NULL
)?
5250 string_sprintf("550 <%s> %s", address
, addr
->user_message
) :
5251 string_sprintf("550 <%s> is not deliverable", address
);
5252 log_write(0, LOG_MAIN
, "VRFY failed for %s %s",
5253 smtp_cmd_argument
, host_and_ident(TRUE
));
5257 smtp_printf("%s\r\n", FALSE
, s
);
5265 rc
= acl_check(ACL_WHERE_EXPN
, NULL
, acl_smtp_expn
, &user_msg
, &log_msg
);
5267 done
= smtp_handle_acl_fail(ACL_WHERE_EXPN
, rc
, user_msg
, log_msg
);
5270 BOOL save_log_testing_mode
= log_testing_mode
;
5271 address_test_mode
= log_testing_mode
= TRUE
;
5272 (void) verify_address(deliver_make_addr(smtp_cmd_data
, FALSE
),
5273 smtp_out
, vopt_is_recipient
| vopt_qualify
| vopt_expn
, -1, -1, -1,
5275 address_test_mode
= FALSE
;
5276 log_testing_mode
= save_log_testing_mode
; /* true for -bh */
5285 if (!tls_advertised
)
5287 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5288 US
"STARTTLS command used when not advertised");
5292 /* Apply an ACL check if one is defined */
5294 if ( acl_smtp_starttls
5295 && (rc
= acl_check(ACL_WHERE_STARTTLS
, NULL
, acl_smtp_starttls
,
5296 &user_msg
, &log_msg
)) != OK
5299 done
= smtp_handle_acl_fail(ACL_WHERE_STARTTLS
, rc
, user_msg
, log_msg
);
5303 /* RFC 2487 is not clear on when this command may be sent, though it
5304 does state that all information previously obtained from the client
5305 must be discarded if a TLS session is started. It seems reasonable to
5306 do an implied RSET when STARTTLS is received. */
5308 incomplete_transaction_log(US
"STARTTLS");
5309 cancel_cutthrough_connection(TRUE
, US
"STARTTLS received");
5310 smtp_reset(reset_point
);
5312 cmd_list
[CMD_LIST_STARTTLS
].is_mail_cmd
= FALSE
;
5314 /* There's an attack where more data is read in past the STARTTLS command
5315 before TLS is negotiated, then assumed to be part of the secure session
5316 when used afterwards; we use segregated input buffers, so are not
5317 vulnerable, but we want to note when it happens and, for sheer paranoia,
5318 ensure that the buffer is "wiped".
5319 Pipelining sync checks will normally have protected us too, unless disabled
5320 by configuration. */
5322 if (receive_smtp_buffered())
5325 debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n");
5326 if (tls_in
.active
< 0)
5327 smtp_inend
= smtp_inptr
= smtp_inbuffer
;
5328 /* and if TLS is already active, tls_server_start() should fail */
5331 /* There is nothing we value in the input buffer and if TLS is successfully
5332 negotiated, we won't use this buffer again; if TLS fails, we'll just read
5333 fresh content into it. The buffer contains arbitrary content from an
5334 untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n
5335 It seems safest to just wipe away the content rather than leave it as a
5336 target to jump to. */
5338 memset(smtp_inbuffer
, 0, IN_BUFFER_SIZE
);
5340 /* Attempt to start up a TLS session, and if successful, discard all
5341 knowledge that was obtained previously. At least, that's what the RFC says,
5342 and that's what happens by default. However, in order to work round YAEB,
5343 there is an option to remember the esmtp state. Sigh.
5345 We must allow for an extra EHLO command and an extra AUTH command after
5346 STARTTLS that don't add to the nonmail command count. */
5349 if ((rc
= tls_server_start(tls_require_ciphers
, &s
)) == OK
)
5351 if (!tls_remember_esmtp
)
5352 helo_seen
= esmtp
= auth_advertised
= pipelining_advertised
= FALSE
;
5353 cmd_list
[CMD_LIST_EHLO
].is_mail_cmd
= TRUE
;
5354 cmd_list
[CMD_LIST_AUTH
].is_mail_cmd
= TRUE
;
5355 cmd_list
[CMD_LIST_TLS_AUTH
].is_mail_cmd
= TRUE
;
5356 if (sender_helo_name
!= NULL
)
5358 store_free(sender_helo_name
);
5359 sender_helo_name
= NULL
;
5360 host_build_sender_fullhost(); /* Rebuild */
5361 set_process_info("handling incoming TLS connection from %s",
5362 host_and_ident(FALSE
));
5365 (sender_host_address
? protocols
: protocols_local
)
5367 ? pextend
+ (sender_host_authenticated
? pauthed
: 0)
5369 + (tls_in
.active
>= 0 ? pcrpted
: 0)
5372 sender_host_authenticated
= NULL
;
5373 authenticated_id
= NULL
;
5374 sync_cmd_limit
= NON_SYNC_CMD_NON_PIPELINING
;
5375 DEBUG(D_tls
) debug_printf("TLS active\n");
5376 break; /* Successful STARTTLS */
5379 (void) smtp_log_tls_fail(s
);
5381 /* Some local configuration problem was discovered before actually trying
5382 to do a TLS handshake; give a temporary error. */
5386 smtp_printf("454 TLS currently unavailable\r\n", FALSE
);
5390 /* Hard failure. Reject everything except QUIT or closed connection. One
5391 cause for failure is a nested STARTTLS, in which case tls_in.active remains
5392 set, but we must still reject all incoming commands. */
5394 DEBUG(D_tls
) debug_printf("TLS failed to start\n");
5395 while (done
<= 0) switch(smtp_read_command(FALSE
, GETC_BUFFER_UNLIMITED
))
5398 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by EOF",
5399 smtp_get_connection_info());
5400 smtp_notquit_exit(US
"tls-failed", NULL
, NULL
);
5404 /* It is perhaps arguable as to which exit ACL should be called here,
5405 but as it is probably a situation that almost never arises, it
5406 probably doesn't matter. We choose to call the real QUIT ACL, which in
5407 some sense is perhaps "right". */
5412 && ((rc
= acl_check(ACL_WHERE_QUIT
, NULL
, acl_smtp_quit
, &user_msg
,
5413 &log_msg
)) == ERROR
))
5414 log_write(0, LOG_MAIN
|LOG_PANIC
, "ACL for QUIT returned ERROR: %s",
5417 smtp_respond(US
"221", 3, TRUE
, user_msg
);
5419 smtp_printf("221 %s closing connection\r\n", FALSE
, smtp_active_hostname
);
5420 log_write(L_smtp_connection
, LOG_MAIN
, "%s closed by QUIT",
5421 smtp_get_connection_info());
5426 smtp_printf("554 Security failure\r\n", FALSE
);
5429 tls_close(TRUE
, TRUE
);
5434 /* The ACL for QUIT is provided for gathering statistical information or
5435 similar; it does not affect the response code, but it can supply a custom
5439 smtp_quit_handler(&user_msg
, &log_msg
);
5445 smtp_rset_handler();
5446 cancel_cutthrough_connection(TRUE
, US
"RSET received");
5447 smtp_reset(reset_point
);
5454 smtp_printf("250 OK\r\n", FALSE
);
5458 /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually
5459 used, a check will be done for permitted hosts. Show STARTTLS only if not
5460 already in a TLS session and if it would be advertised in the EHLO
5465 smtp_printf("214-Commands supported:\r\n", TRUE
);
5469 Ustrcat(buffer
, " AUTH");
5471 if (tls_in
.active
< 0 &&
5472 verify_check_host(&tls_advertise_hosts
) != FAIL
)
5473 Ustrcat(buffer
, " STARTTLS");
5475 Ustrcat(buffer
, " HELO EHLO MAIL RCPT DATA BDAT");
5476 Ustrcat(buffer
, " NOOP QUIT RSET HELP");
5477 if (acl_smtp_etrn
!= NULL
) Ustrcat(buffer
, " ETRN");
5478 if (acl_smtp_expn
!= NULL
) Ustrcat(buffer
, " EXPN");
5479 if (acl_smtp_vrfy
!= NULL
) Ustrcat(buffer
, " VRFY");
5480 smtp_printf("214%s\r\n", FALSE
, buffer
);
5486 incomplete_transaction_log(US
"connection lost");
5487 smtp_notquit_exit(US
"connection-lost", US
"421",
5488 US
"%s lost input connection", smtp_active_hostname
);
5490 /* Don't log by default unless in the middle of a message, as some mailers
5491 just drop the call rather than sending QUIT, and it clutters up the logs.
5494 if (sender_address
|| recipients_count
> 0)
5495 log_write(L_lost_incoming_connection
, LOG_MAIN
,
5496 "unexpected %s while reading SMTP command from %s%s%s D=%s",
5497 sender_host_unknown
? "EOF" : "disconnection",
5498 tcp_in_fastopen
&& !tcp_in_fastopen_logged
? US
"TFO " : US
"",
5499 host_and_ident(FALSE
), smtp_read_error
,
5500 string_timesince(&smtp_connection_start
)
5504 log_write(L_smtp_connection
, LOG_MAIN
, "%s %slost%s D=%s",
5505 smtp_get_connection_info(),
5506 tcp_in_fastopen
&& !tcp_in_fastopen_logged
? US
"TFO " : US
"",
5508 string_timesince(&smtp_connection_start
)
5517 if (sender_address
!= NULL
)
5519 done
= synprot_error(L_smtp_protocol_error
, 503, NULL
,
5520 US
"ETRN is not permitted inside a transaction");
5524 log_write(L_etrn
, LOG_MAIN
, "ETRN %s received from %s", smtp_cmd_argument
,
5525 host_and_ident(FALSE
));
5527 if ((rc
= acl_check(ACL_WHERE_ETRN
, NULL
, acl_smtp_etrn
,
5528 &user_msg
, &log_msg
)) != OK
)
5530 done
= smtp_handle_acl_fail(ACL_WHERE_ETRN
, rc
, user_msg
, log_msg
);
5534 /* Compute the serialization key for this command. */
5536 etrn_serialize_key
= string_sprintf("etrn-%s\n", smtp_cmd_data
);
5538 /* If a command has been specified for running as a result of ETRN, we
5539 permit any argument to ETRN. If not, only the # standard form is permitted,
5540 since that is strictly the only kind of ETRN that can be implemented
5541 according to the RFC. */
5543 if (smtp_etrn_command
!= NULL
)
5547 etrn_command
= smtp_etrn_command
;
5548 deliver_domain
= smtp_cmd_data
;
5549 rc
= transport_set_up_command(&argv
, smtp_etrn_command
, TRUE
, 0, NULL
,
5550 US
"ETRN processing", &error
);
5551 deliver_domain
= NULL
;
5554 log_write(0, LOG_MAIN
|LOG_PANIC
, "failed to set up ETRN command: %s",
5556 smtp_printf("458 Internal failure\r\n", FALSE
);
5561 /* Else set up to call Exim with the -R option. */
5565 if (*smtp_cmd_data
++ != '#')
5567 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
5568 US
"argument must begin with #");
5571 etrn_command
= US
"exim -R";
5572 argv
= CUSS
child_exec_exim(CEE_RETURN_ARGV
, TRUE
, NULL
, TRUE
,
5573 *queue_name
? 4 : 2,
5574 US
"-R", smtp_cmd_data
,
5575 US
"-MCG", queue_name
);
5578 /* If we are host-testing, don't actually do anything. */
5584 debug_printf("ETRN command is: %s\n", etrn_command
);
5585 debug_printf("ETRN command execution skipped\n");
5587 if (user_msg
== NULL
) smtp_printf("250 OK\r\n", FALSE
);
5588 else smtp_user_msg(US
"250", user_msg
);
5593 /* If ETRN queue runs are to be serialized, check the database to
5594 ensure one isn't already running. */
5596 if (smtp_etrn_serialize
&& !enq_start(etrn_serialize_key
, 1))
5598 smtp_printf("458 Already processing %s\r\n", FALSE
, smtp_cmd_data
);
5602 /* Fork a child process and run the command. We don't want to have to
5603 wait for the process at any point, so set SIGCHLD to SIG_IGN before
5604 forking. It should be set that way anyway for external incoming SMTP,
5605 but we save and restore to be tidy. If serialization is required, we
5606 actually run the command in yet another process, so we can wait for it
5607 to complete and then remove the serialization lock. */
5609 oldsignal
= signal(SIGCHLD
, SIG_IGN
);
5611 if ((pid
= fork()) == 0)
5613 smtp_input
= FALSE
; /* This process is not associated with the */
5614 (void)fclose(smtp_in
); /* SMTP call any more. */
5615 (void)fclose(smtp_out
);
5617 signal(SIGCHLD
, SIG_DFL
); /* Want to catch child */
5619 /* If not serializing, do the exec right away. Otherwise, fork down
5620 into another process. */
5622 if (!smtp_etrn_serialize
|| (pid
= fork()) == 0)
5624 DEBUG(D_exec
) debug_print_argv(argv
);
5625 exim_nullstd(); /* Ensure std{in,out,err} exist */
5626 execv(CS argv
[0], (char *const *)argv
);
5627 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "exec of \"%s\" (ETRN) failed: %s",
5628 etrn_command
, strerror(errno
));
5629 _exit(EXIT_FAILURE
); /* paranoia */
5632 /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That
5633 is, we are in the first subprocess, after forking again. All we can do
5634 for a failing fork is to log it. Otherwise, wait for the 2nd process to
5635 complete, before removing the serialization. */
5638 log_write(0, LOG_MAIN
|LOG_PANIC
, "2nd fork for serialized ETRN "
5639 "failed: %s", strerror(errno
));
5643 DEBUG(D_any
) debug_printf("waiting for serialized ETRN process %d\n",
5645 (void)wait(&status
);
5646 DEBUG(D_any
) debug_printf("serialized ETRN process %d ended\n",
5650 enq_end(etrn_serialize_key
);
5651 _exit(EXIT_SUCCESS
);
5654 /* Back in the top level SMTP process. Check that we started a subprocess
5655 and restore the signal state. */
5659 log_write(0, LOG_MAIN
|LOG_PANIC
, "fork of process for ETRN failed: %s",
5661 smtp_printf("458 Unable to fork process\r\n", FALSE
);
5662 if (smtp_etrn_serialize
) enq_end(etrn_serialize_key
);
5666 if (user_msg
== NULL
) smtp_printf("250 OK\r\n", FALSE
);
5667 else smtp_user_msg(US
"250", user_msg
);
5670 signal(SIGCHLD
, oldsignal
);
5675 done
= synprot_error(L_smtp_syntax_error
, 501, NULL
,
5676 US
"unexpected argument data");
5680 /* This currently happens only for NULLs, but could be extended. */
5683 done
= synprot_error(L_smtp_syntax_error
, 0, NULL
, /* Just logs */
5684 US
"NULL character(s) present (shown as '?')");
5685 smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n", FALSE
);
5691 if (smtp_inend
>= smtp_inbuffer
+ IN_BUFFER_SIZE
)
5692 smtp_inend
= smtp_inbuffer
+ IN_BUFFER_SIZE
- 1;
5693 c
= smtp_inend
- smtp_inptr
;
5694 if (c
> 150) c
= 150;
5696 incomplete_transaction_log(US
"sync failure");
5697 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP protocol synchronization error "
5698 "(next input sent too soon: pipelining was%s advertised): "
5699 "rejected \"%s\" %s next input=\"%s\"",
5700 pipelining_advertised
? "" : " not",
5701 smtp_cmd_buffer
, host_and_ident(TRUE
),
5702 string_printing(smtp_inptr
));
5703 smtp_notquit_exit(US
"synchronization-error", US
"554",
5704 US
"SMTP synchronization error");
5705 done
= 1; /* Pretend eof - drops connection */
5709 case TOO_MANY_NONMAIL_CMD
:
5710 s
= smtp_cmd_buffer
;
5711 while (*s
!= 0 && !isspace(*s
)) s
++;
5712 incomplete_transaction_log(US
"too many non-mail commands");
5713 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
5714 "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE
),
5715 (int)(s
- smtp_cmd_buffer
), smtp_cmd_buffer
);
5716 smtp_notquit_exit(US
"bad-commands", US
"554", US
"Too many nonmail commands");
5717 done
= 1; /* Pretend eof - drops connection */
5720 #ifdef SUPPORT_PROXY
5721 case PROXY_FAIL_IGNORE_CMD
:
5722 smtp_printf("503 Command refused, required Proxy negotiation failed\r\n", FALSE
);
5727 if (unknown_command_count
++ >= smtp_max_unknown_commands
)
5729 log_write(L_smtp_syntax_error
, LOG_MAIN
,
5730 "SMTP syntax error in \"%s\" %s %s",
5731 string_printing(smtp_cmd_buffer
), host_and_ident(TRUE
),
5732 US
"unrecognized command");
5733 incomplete_transaction_log(US
"unrecognized command");
5734 smtp_notquit_exit(US
"bad-commands", US
"500",
5735 US
"Too many unrecognized commands");
5737 log_write(0, LOG_MAIN
|LOG_REJECT
, "SMTP call from %s dropped: too many "
5738 "unrecognized commands (last was \"%s\")", host_and_ident(FALSE
),
5739 string_printing(smtp_cmd_buffer
));
5742 done
= synprot_error(L_smtp_syntax_error
, 500, NULL
,
5743 US
"unrecognized command");
5747 /* This label is used by goto's inside loops that want to break out to
5748 the end of the command-processing loop. */
5751 last_was_rej_mail
= was_rej_mail
; /* Remember some last commands for */
5752 last_was_rcpt
= was_rcpt
; /* protocol error handling */
5756 return done
- 2; /* Convert yield values */
5761 /* End of smtp_in.c */