DANE: fix build under LibreSSL. Bug 2020
[exim.git] / src / src / smtp_in.c
CommitLineData
059ec3d9
PH
1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
80fea873 5/* Copyright (c) University of Cambridge 1995 - 2016 */
059ec3d9
PH
6/* See the file NOTICE for conditions of use and distribution. */
7
8/* Functions for handling an incoming SMTP call. */
9
10
11#include "exim.h"
2ef7ed08 12#include <assert.h>
059ec3d9
PH
13
14
15/* Initialize for TCP wrappers if so configured. It appears that the macro
16HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
17including that header, and restore its value afterwards. */
18
19#ifdef USE_TCP_WRAPPERS
20
21 #if HAVE_IPV6
22 #define EXIM_HAVE_IPV6
23 #endif
24 #undef HAVE_IPV6
25 #include <tcpd.h>
26 #undef HAVE_IPV6
27 #ifdef EXIM_HAVE_IPV6
28 #define HAVE_IPV6 TRUE
29 #endif
30
31int allow_severity = LOG_INFO;
32int deny_severity = LOG_NOTICE;
5dc43717 33uschar *tcp_wrappers_name;
059ec3d9
PH
34#endif
35
36
8d67ada3
PH
37/* Size of buffer for reading SMTP commands. We used to use 512, as defined
38by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
39commands that accept arguments, and this in particular applies to AUTH, where
94431adb 40the data can be quite long. More recently this value was 2048 in Exim;
e2ca7082 41however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
94431adb
HSHR
42such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
43The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
e2ca7082
PP
44we need room to handle large base64-encoded AUTHs for GSSAPI.
45*/
46
bd8fbe36 47#define SMTP_CMD_BUFFER_SIZE 16384
059ec3d9
PH
48
49/* Size of buffer for reading SMTP incoming packets */
50
bd8fbe36 51#define IN_BUFFER_SIZE 8192
059ec3d9
PH
52
53/* Structure for SMTP command list */
54
55typedef struct {
1ba28e2b 56 const char *name;
059ec3d9
PH
57 int len;
58 short int cmd;
59 short int has_arg;
60 short int is_mail_cmd;
61} smtp_cmd_list;
62
63/* Codes for identifying commands. We order them so that those that come first
64are those for which synchronization is always required. Checking this can help
65block some spam. */
66
67enum {
68 /* These commands are required to be synchronized, i.e. to be the last in a
69 block of commands when pipelining. */
70
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 */
b3ef41c9 75 TLS_AUTH_CMD, /* auto-command at start of SSL */
059ec3d9
PH
76
77 /* This is a dummy to identify the non-sync commands when pipelining */
78
79 NON_SYNC_CMD_PIPELINING,
80
81 /* These commands need not be synchronized when pipelining */
82
83 MAIL_CMD, RCPT_CMD, RSET_CMD,
84
f4630439
JH
85 /* This is a dummy to identify the non-sync commands when not pipelining */
86
87 NON_SYNC_CMD_NON_PIPELINING,
88
6d5c916c
JH
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
f4630439
JH
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
4c04137d 96 follow-on data after the command line" even for non-pipeline mode.
f4630439 97 So we'll need an explicit check after reading the expected chunk amount
4c04137d 98 when non-pipe, before sending the ACK. */
6d5c916c
JH
99
100 BDAT_CMD,
101
059ec3d9
PH
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. */
105
106 AUTH_CMD,
107
108 /* I'm not sure about these, but I don't think they matter. */
109
110 QUIT_CMD, HELP_CMD,
111
cee5f132 112#ifdef SUPPORT_PROXY
a3c86431
TL
113 PROXY_FAIL_IGNORE_CMD,
114#endif
115
059ec3d9
PH
116 /* These are specials that don't correspond to actual commands */
117
118 EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
119 TOO_MANY_NONMAIL_CMD };
120
121
b4ed4da0
PH
122/* This is a convenience macro for adding the identity of an SMTP command
123to the circular buffer that holds a list of the last n received. */
124
125#define HAD(n) \
126 smtp_connection_had[smtp_ch_index++] = n; \
127 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
128
059ec3d9
PH
129
130/*************************************************
131* Local static variables *
132*************************************************/
133
134static auth_instance *authenticated_by;
135static BOOL auth_advertised;
136#ifdef SUPPORT_TLS
137static BOOL tls_advertised;
138#endif
6c1c3d1d 139static BOOL dsn_advertised;
059ec3d9
PH
140static BOOL esmtp;
141static BOOL helo_required = FALSE;
142static BOOL helo_verify = FALSE;
143static BOOL helo_seen;
144static BOOL helo_accept_junk;
145static BOOL count_nonmail;
146static BOOL pipelining_advertised;
2679d413
PH
147static BOOL rcpt_smtp_response_same;
148static BOOL rcpt_in_progress;
059ec3d9 149static int nonmail_command_count;
8f128379 150static BOOL smtp_exit_function_called = 0;
8c5d388a 151#ifdef SUPPORT_I18N
d1a13eea
JH
152static BOOL smtputf8_advertised;
153#endif
059ec3d9
PH
154static int synprot_error_count;
155static int unknown_command_count;
156static int sync_cmd_limit;
157static int smtp_write_error = 0;
158
2679d413 159static uschar *rcpt_smtp_response;
ca86f471
PH
160static uschar *smtp_data_buffer;
161static uschar *smtp_cmd_data;
162
059ec3d9
PH
163/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
164final fields of all except AUTH are forced TRUE at the start of a new message
165setup, to allow one of each between messages that is not counted as a nonmail
166command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
167allow a new EHLO after starting up TLS.
168
169AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
170counted. However, the flag is changed when AUTH is received, so that multiple
171failing AUTHs will eventually hit the limit. After a successful AUTH, another
172AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
173forced TRUE, to allow for the re-authentication that can happen at that point.
174
175QUIT is also "falsely" labelled as a mail command so that it doesn't up the
2f460950
JH
176count of non-mail commands and possibly provoke an error.
177
178tls_auth is a pseudo-command, never expected in input. It is activated
179on TLS startup and looks for a tls authenticator. */
059ec3d9
PH
180
181static smtp_cmd_list cmd_list[] = {
d1a13eea
JH
182 /* name len cmd has_arg is_mail_cmd */
183
059ec3d9
PH
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 },
188 #ifdef SUPPORT_TLS
189 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
b3ef41c9 190 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, TRUE },
059ec3d9
PH
191 #endif
192
193/* If you change anything above here, also fix the definitions below. */
194
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 },
18481de3 198 { "bdat", sizeof("bdat")-1, BDAT_CMD, TRUE, TRUE },
059ec3d9
PH
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 }
205};
206
207static smtp_cmd_list *cmd_list_end =
208 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
209
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
b3ef41c9 215#define CMD_LIST_TLS_AUTH 5
059ec3d9 216
b4ed4da0
PH
217/* This list of names is used for performing the smtp_no_mail logging action.
218It must be kept in step with the SCH_xxx enumerations. */
219
220static uschar *smtp_names[] =
221 {
18481de3
JH
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" };
b4ed4da0 225
e524074d 226static uschar *protocols_local[] = {
981756db
PH
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 */
059ec3d9 233 };
e524074d
JH
234static uschar *protocols[] = {
235 US"smtp", /* HELO */
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 */
241 };
059ec3d9
PH
242
243#define pnormal 0
981756db
PH
244#define pextend 2
245#define pcrpted 1 /* added to pextend or pnormal */
246#define pauthed 2 /* added to pextend */
059ec3d9 247
d27f98fe
TL
248/* Sanity check and validate optional args to MAIL FROM: envelope */
249enum {
2ef7ed08 250 ENV_MAIL_OPT_NULL,
d27f98fe 251 ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
8ccd00b1 252#ifndef DISABLE_PRDR
fd98a5c6
JH
253 ENV_MAIL_OPT_PRDR,
254#endif
6c1c3d1d 255 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
8c5d388a 256#ifdef SUPPORT_I18N
d1a13eea
JH
257 ENV_MAIL_OPT_UTF8,
258#endif
d27f98fe
TL
259 };
260typedef struct {
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 */
265 } env_mail_type_t;
266static 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 },
8ccd00b1 270#ifndef DISABLE_PRDR
fd98a5c6
JH
271 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
272#endif
6c1c3d1d
WB
273 { US"RET", ENV_MAIL_OPT_RET, TRUE },
274 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
8c5d388a 275#ifdef SUPPORT_I18N
d1a13eea
JH
276 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
277#endif
2ef7ed08
HSHR
278 /* keep this the last entry */
279 { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
d27f98fe
TL
280 };
281
059ec3d9
PH
282/* When reading SMTP from a remote host, we have to use our own versions of the
283C input-reading functions, in order to be able to flush the SMTP output only
284when about to read more data from the socket. This is the only way to get
285optimal performance when the client is using pipelining. Flushing for every
286command causes a separate packet and reply packet each time; saving all the
287responses up (when pipelining) combines them into one packet and one response.
288
289For simplicity, these functions are used for *all* SMTP input, not only when
290receiving over a socket. However, after setting up a secure socket (SSL), input
291is read via the OpenSSL library, and another set of functions is used instead
292(see tls.c).
293
294These functions are set in the receive_getc etc. variables and called with the
295same interface as the C functions. However, since there can only ever be
296one incoming SMTP call, we just use a single buffer and flags. There is no need
297to implement a complicated private FILE-like structure.*/
298
299static uschar *smtp_inbuffer;
300static uschar *smtp_inptr;
301static uschar *smtp_inend;
302static int smtp_had_eof;
303static int smtp_had_error;
304
305
7e3ce68e
JH
306/* forward declarations */
307int bdat_ungetc(int ch);
bd8fbe36 308static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
7e3ce68e
JH
309static int synprot_error(int type, int code, uschar *data, uschar *errmess);
310static void smtp_quit_handler(uschar **, uschar **);
311static void smtp_rset_handler(void);
312
059ec3d9 313/*************************************************
f4630439
JH
314* Recheck synchronization *
315*************************************************/
316
317/* Synchronization checks can never be perfect because a packet may be on its
318way but not arrived when the check is done. Such checks can in any case only be
319done when TLS is not in use. Normally, the checks happen when commands are
320read: Exim ensures that there is no more input in the input buffer. In normal
321cases, the response to the command will be fast, and there is no further check.
322
323However, for some commands an ACL is run, and that can include delays. In those
324cases, it is useful to do another check on the input just before sending the
325response. This also applies at the start of a connection. This function does
326that check by means of the select() function, as long as the facility is not
327disabled or inappropriate. A failure of select() is ignored.
328
329When there is unwanted input, we read it so that it appears in the log of the
330error.
331
332Arguments: none
333Returns: TRUE if all is well; FALSE if there is input pending
334*/
335
336static BOOL
337check_sync(void)
338{
339int fd, rc;
340fd_set fds;
341struct timeval tzero;
342
343if (!smtp_enforce_sync || sender_host_address == NULL ||
344 sender_host_notsocket || tls_in.active >= 0)
345 return TRUE;
346
347fd = fileno(smtp_in);
348FD_ZERO(&fds);
349FD_SET(fd, &fds);
350tzero.tv_sec = 0;
351tzero.tv_usec = 0;
352rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
353
354if (rc <= 0) return TRUE; /* Not ready to read */
bd8fbe36 355rc = smtp_getc(GETC_BUFFER_UNLIMITED);
f4630439
JH
356if (rc < 0) return TRUE; /* End of file or error */
357
358smtp_ungetc(rc);
359rc = smtp_inend - smtp_inptr;
360if (rc > 150) rc = 150;
361smtp_inptr[rc] = 0;
362return FALSE;
363}
364
365
366
367/*************************************************
368* Log incomplete transactions *
369*************************************************/
370
371/* This function is called after a transaction has been aborted by RSET, QUIT,
372connection drops or other errors. It logs the envelope information received
373so far in order to preserve address verification attempts.
374
375Argument: string to indicate what aborted the transaction
376Returns: nothing
377*/
378
379static void
380incomplete_transaction_log(uschar *what)
381{
382if (sender_address == NULL || /* No transaction in progress */
383 !LOGGING(smtp_incomplete_transaction))
384 return;
385
386/* Build list of recipients for logging */
387
388if (recipients_count > 0)
389 {
390 int i;
391 raw_recipients = store_get(recipients_count * sizeof(uschar *));
392 for (i = 0; i < recipients_count; i++)
393 raw_recipients[i] = recipients_list[i].address;
394 raw_recipients_count = recipients_count;
395 }
396
397log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
398 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
399}
400
401
402
403
404/*************************************************
059ec3d9
PH
405* SMTP version of getc() *
406*************************************************/
407
408/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
409it flushes the output, and refills the buffer, with a timeout. The signal
410handler is set appropriately by the calling function. This function is not used
4c04137d 411after a connection has negotiated itself into an TLS/SSL state.
059ec3d9 412
bd8fbe36 413Arguments: lim Maximum amount to read/buffer
059ec3d9
PH
414Returns: the next character or EOF
415*/
416
417int
bd8fbe36 418smtp_getc(unsigned lim)
059ec3d9
PH
419{
420if (smtp_inptr >= smtp_inend)
421 {
422 int rc, save_errno;
60d10ce7 423 if (!smtp_out) return EOF;
059ec3d9
PH
424 fflush(smtp_out);
425 if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
bd8fbe36
JH
426
427 /* Limit amount read, so non-message data is not fed to DKIM */
428
429 rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE, lim));
059ec3d9
PH
430 save_errno = errno;
431 alarm(0);
432 if (rc <= 0)
433 {
434 /* Must put the error text in fixed store, because this might be during
435 header reading, where it releases unused store above the header. */
436 if (rc < 0)
437 {
438 smtp_had_error = save_errno;
439 smtp_read_error = string_copy_malloc(
440 string_sprintf(" (error: %s)", strerror(save_errno)));
441 }
442 else smtp_had_eof = 1;
443 return EOF;
444 }
80a47a2c
TK
445#ifndef DISABLE_DKIM
446 dkim_exim_verify_feed(smtp_inbuffer, rc);
447#endif
059ec3d9
PH
448 smtp_inend = smtp_inbuffer + rc;
449 smtp_inptr = smtp_inbuffer;
450 }
451return *smtp_inptr++;
452}
453
584e96c6
JH
454void
455smtp_get_cache(void)
456{
9960d1e5 457#ifndef DISABLE_DKIM
584e96c6
JH
458int n = smtp_inend - smtp_inptr;
459if (n > 0)
460 dkim_exim_verify_feed(smtp_inptr, n);
584e96c6 461#endif
9960d1e5 462}
059ec3d9
PH
463
464
7e3ce68e
JH
465/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
466previous BDAT chunk and getting new ones when we run out. Uses the
467underlying smtp_getc or tls_getc both for that and for getting the
468(buffered) data byte. EOD signals (an expected) no further data.
469ERR signals a protocol error, and EOF a closed input stream.
470
471Called from read_bdat_smtp() in receive.c for the message body, but also
472by the headers read loop in receive_msg(); manipulates chunking_state
473to handle the BDAT command/response.
474Placed here due to the correlation with the above smtp_getc(), which it wraps,
475and also by the need to do smtp command/response handling.
476
bd8fbe36 477Arguments: lim (ignored)
7e3ce68e
JH
478Returns: the next character or ERR, EOD or EOF
479*/
480
481int
bd8fbe36 482bdat_getc(unsigned lim)
7e3ce68e
JH
483{
484uschar * user_msg = NULL;
485uschar * log_msg;
486
487for(;;)
488 {
bd8fbe36
JH
489 if (chunking_data_left > 0)
490 return lwr_receive_getc(chunking_data_left--);
7e3ce68e
JH
491
492 receive_getc = lwr_receive_getc;
493 receive_ungetc = lwr_receive_ungetc;
bd8fbe36
JH
494#ifndef DISABLE_DKIM
495 dkim_collect_input = FALSE;
496#endif
7e3ce68e 497
f4630439
JH
498 /* Unless PIPELINING was offered, there should be no next command
499 until after we ack that chunk */
500
501 if (!pipelining_advertised && !check_sync())
502 {
503 incomplete_transaction_log(US"sync failure");
504 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
505 "(next input sent too soon: pipelining was not advertised): "
506 "rejected \"%s\" %s next input=\"%s\"",
507 smtp_cmd_buffer, host_and_ident(TRUE),
508 string_printing(smtp_inptr));
509 (void) synprot_error(L_smtp_protocol_error, 554, NULL,
510 US"SMTP synchronization error");
511 goto repeat_until_rset;
512 }
513
7e3ce68e
JH
514 /* If not the last, ack the received chunk. The last response is delayed
515 until after the data ACL decides on it */
7e3ce68e
JH
516
517 if (chunking_state == CHUNKING_LAST)
584e96c6
JH
518 {
519#ifndef DISABLE_DKIM
e983e85a 520 dkim_exim_verify_feed(NULL, 0); /* notify EOD */
584e96c6 521#endif
7e3ce68e 522 return EOD;
584e96c6 523 }
7e3ce68e 524
7e3ce68e 525 smtp_printf("250 %u byte chunk received\r\n", chunking_datasize);
bd8fbe36
JH
526 chunking_state = CHUNKING_OFFERED;
527 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
7e3ce68e
JH
528
529 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
530 QUIT, RSET or NOOP but handling them seems obvious */
531
532next_cmd:
bd8fbe36 533 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
534 {
535 default:
536 (void) synprot_error(L_smtp_protocol_error, 503, NULL,
537 US"only BDAT permissible after non-LAST BDAT");
538
539 repeat_until_rset:
bd8fbe36 540 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
541 {
542 case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
543 case EOF_CMD: return EOF;
544 case RSET_CMD: smtp_rset_handler(); return ERR;
545 default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
546 US"only RSET accepted now") > 0)
547 return EOF;
548 goto repeat_until_rset;
549 }
550
551 case QUIT_CMD:
552 smtp_quit_handler(&user_msg, &log_msg);
553 /*FALLTHROUGH*/
554 case EOF_CMD:
555 return EOF;
556
557 case RSET_CMD:
558 smtp_rset_handler();
559 return ERR;
560
561 case NOOP_CMD:
562 HAD(SCH_NOOP);
563 smtp_printf("250 OK\r\n");
564 goto next_cmd;
565
566 case BDAT_CMD:
567 {
568 int n;
569
570 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
571 {
572 (void) synprot_error(L_smtp_protocol_error, 501, NULL,
573 US"missing size for BDAT command");
574 return ERR;
575 }
576 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
577 ? CHUNKING_LAST : CHUNKING_ACTIVE;
578 chunking_data_left = chunking_datasize;
bd8fbe36
JH
579 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
580 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
581
582 if (chunking_datasize == 0)
583 if (chunking_state == CHUNKING_LAST)
584 return EOD;
585 else
586 {
587 (void) synprot_error(L_smtp_protocol_error, 504, NULL,
588 US"zero size for BDAT command");
589 goto repeat_until_rset;
590 }
591
592 receive_getc = bdat_getc;
593 receive_ungetc = bdat_ungetc;
bd8fbe36
JH
594#ifndef DISABLE_DKIM
595 dkim_collect_input = TRUE;
596#endif
7e3ce68e
JH
597 break; /* to top of main loop */
598 }
599 }
600 }
601}
602
45bd315d
JH
603static void
604bdat_flush_data(void)
605{
bd8fbe36
JH
606while (chunking_data_left > 0)
607 if (lwr_receive_getc(chunking_data_left--) < 0)
45bd315d
JH
608 break;
609
610receive_getc = lwr_receive_getc;
611receive_ungetc = lwr_receive_ungetc;
612
613if (chunking_state != CHUNKING_LAST)
bd8fbe36 614 {
45bd315d 615 chunking_state = CHUNKING_OFFERED;
bd8fbe36
JH
616 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
617 }
45bd315d
JH
618}
619
7e3ce68e
JH
620
621
622
059ec3d9
PH
623/*************************************************
624* SMTP version of ungetc() *
625*************************************************/
626
627/* Puts a character back in the input buffer. Only ever
628called once.
629
630Arguments:
631 ch the character
632
633Returns: the character
634*/
635
636int
637smtp_ungetc(int ch)
638{
7e3ce68e 639*--smtp_inptr = ch;
059ec3d9
PH
640return ch;
641}
642
643
7e3ce68e
JH
644int
645bdat_ungetc(int ch)
646{
647chunking_data_left++;
648return lwr_receive_ungetc(ch);
649}
650
059ec3d9
PH
651
652
653/*************************************************
654* SMTP version of feof() *
655*************************************************/
656
657/* Tests for a previous EOF
658
659Arguments: none
660Returns: non-zero if the eof flag is set
661*/
662
663int
664smtp_feof(void)
665{
666return smtp_had_eof;
667}
668
669
670
671
672/*************************************************
673* SMTP version of ferror() *
674*************************************************/
675
676/* Tests for a previous read error, and returns with errno
677restored to what it was when the error was detected.
678
679Arguments: none
680Returns: non-zero if the error flag is set
681*/
682
683int
684smtp_ferror(void)
685{
686errno = smtp_had_error;
687return smtp_had_error;
688}
689
690
691
58eb016e
PH
692/*************************************************
693* Test for characters in the SMTP buffer *
694*************************************************/
695
696/* Used at the end of a message
697
698Arguments: none
699Returns: TRUE/FALSE
700*/
701
702BOOL
703smtp_buffered(void)
704{
705return smtp_inptr < smtp_inend;
706}
707
708
059ec3d9
PH
709
710/*************************************************
711* Write formatted string to SMTP channel *
712*************************************************/
713
714/* This is a separate function so that we don't have to repeat everything for
715TLS support or debugging. It is global so that the daemon and the
716authentication functions can use it. It does not return any error indication,
717because major problems such as dropped connections won't show up till an output
718flush for non-TLS connections. The smtp_fflush() function is available for
719checking that: for convenience, TLS output errors are remembered here so that
720they are also picked up later by smtp_fflush().
721
722Arguments:
723 format format string
724 ... optional arguments
725
726Returns: nothing
727*/
728
729void
1ba28e2b 730smtp_printf(const char *format, ...)
059ec3d9
PH
731{
732va_list ap;
733
ce552449
NM
734va_start(ap, format);
735smtp_vprintf(format, ap);
736va_end(ap);
737}
738
739/* This is split off so that verify.c:respond_printf() can, in effect, call
740smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 741call another vararg function, only a function which accepts a va_list. */
ce552449
NM
742
743void
1ba28e2b 744smtp_vprintf(const char *format, va_list ap)
ce552449 745{
fb08281f
DW
746BOOL yield;
747
748yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 749
059ec3d9
PH
750DEBUG(D_receive)
751 {
fb08281f
DW
752 void *reset_point = store_get(0);
753 uschar *msg_copy, *cr, *end;
754 msg_copy = string_copy(big_buffer);
755 end = msg_copy + Ustrlen(msg_copy);
756 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
757 memmove(cr, cr + 1, (end--) - cr);
758 debug_printf("SMTP>> %s", msg_copy);
759 store_reset(reset_point);
059ec3d9
PH
760 }
761
fb08281f 762if (!yield)
2679d413
PH
763 {
764 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
765 smtp_closedown(US"Unexpected error");
766 exim_exit(EXIT_FAILURE);
767 }
2679d413
PH
768
769/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
770have had the same. Note: this code is also present in smtp_respond(). It would
771be tidier to have it only in one place, but when it was added, it was easier to
772do it that way, so as not to have to mess with the code for the RCPT command,
773which sometimes uses smtp_printf() and sometimes smtp_respond(). */
774
775if (rcpt_in_progress)
776 {
777 if (rcpt_smtp_response == NULL)
778 rcpt_smtp_response = string_copy(big_buffer);
779 else if (rcpt_smtp_response_same &&
780 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
781 rcpt_smtp_response_same = FALSE;
782 rcpt_in_progress = FALSE;
783 }
059ec3d9 784
2679d413 785/* Now write the string */
059ec3d9
PH
786
787#ifdef SUPPORT_TLS
817d9f57 788if (tls_in.active >= 0)
059ec3d9 789 {
817d9f57
JH
790 if (tls_write(TRUE, big_buffer, Ustrlen(big_buffer)) < 0)
791 smtp_write_error = -1;
059ec3d9
PH
792 }
793else
794#endif
795
2679d413 796if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
059ec3d9
PH
797}
798
799
800
801/*************************************************
802* Flush SMTP out and check for error *
803*************************************************/
804
805/* This function isn't currently used within Exim (it detects errors when it
806tries to read the next SMTP input), but is available for use in local_scan().
807For non-TLS connections, it flushes the output and checks for errors. For
808TLS-connections, it checks for a previously-detected TLS write error.
809
810Arguments: none
811Returns: 0 for no error; -1 after an error
812*/
813
814int
815smtp_fflush(void)
816{
817d9f57 817if (tls_in.active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
059ec3d9
PH
818return smtp_write_error;
819}
820
821
822
823/*************************************************
824* SMTP command read timeout *
825*************************************************/
826
827/* Signal handler for timing out incoming SMTP commands. This attempts to
828finish off tidily.
829
830Argument: signal number (SIGALRM)
831Returns: nothing
832*/
833
834static void
835command_timeout_handler(int sig)
836{
837sig = sig; /* Keep picky compilers happy */
838log_write(L_lost_incoming_connection,
839 LOG_MAIN, "SMTP command timeout on%s connection from %s",
817d9f57 840 (tls_in.active >= 0)? " TLS" : "",
059ec3d9
PH
841 host_and_ident(FALSE));
842if (smtp_batched_input)
843 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
8f128379
PH
844smtp_notquit_exit(US"command-timeout", US"421",
845 US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
059ec3d9
PH
846exim_exit(EXIT_FAILURE);
847}
848
849
850
851/*************************************************
852* SIGTERM received *
853*************************************************/
854
855/* Signal handler for handling SIGTERM. Again, try to finish tidily.
856
857Argument: signal number (SIGTERM)
858Returns: nothing
859*/
860
861static void
862command_sigterm_handler(int sig)
863{
864sig = sig; /* Keep picky compilers happy */
865log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
866if (smtp_batched_input)
867 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
8f128379
PH
868smtp_notquit_exit(US"signal-exit", US"421",
869 US"%s: Service not available - closing connection", smtp_active_hostname);
059ec3d9
PH
870exim_exit(EXIT_FAILURE);
871}
872
873
874
a14e5636 875
cee5f132 876#ifdef SUPPORT_PROXY
a3c86431 877/*************************************************
a3bddaa8
TL
878* Restore socket timeout to previous value *
879*************************************************/
880/* If the previous value was successfully retrieved, restore
881it before returning control to the non-proxy routines
882
883Arguments: fd - File descriptor for input
884 get_ok - Successfully retrieved previous values
885 tvtmp - Time struct with previous values
886 vslen - Length of time struct
887Returns: none
888*/
889static void
f267271d 890restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen)
a3bddaa8
TL
891{
892if (get_ok == 0)
f267271d 893 (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen);
a3bddaa8
TL
894}
895
896/*************************************************
a3c86431
TL
897* Check if host is required proxy host *
898*************************************************/
899/* The function determines if inbound host will be a regular smtp host
900or if it is configured that it must use Proxy Protocol.
901
902Arguments: none
903Returns: bool
904*/
905
906static BOOL
907check_proxy_protocol_host()
908{
909int rc;
910/* Cannot configure local connection as a proxy inbound */
911if (sender_host_address == NULL) return proxy_session;
912
7a2fa0bc 913rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
a3c86431
TL
914 sender_host_address, NULL);
915if (rc == OK)
916 {
917 DEBUG(D_receive)
918 debug_printf("Detected proxy protocol configured host\n");
919 proxy_session = TRUE;
920 }
921return proxy_session;
922}
923
924
925/*************************************************
a3c86431
TL
926* Setup host for proxy protocol *
927*************************************************/
928/* The function configures the connection based on a header from the
929inbound host to use Proxy Protocol. The specification is very exact
930so exit with an error if do not find the exact required pieces. This
931includes an incorrect number of spaces separating args.
932
933Arguments: none
f267271d 934Returns: Boolean success
a3c86431
TL
935*/
936
937static BOOL
938setup_proxy_protocol_host()
939{
940union {
941 struct {
942 uschar line[108];
943 } v1;
944 struct {
945 uschar sig[12];
36719342
TL
946 uint8_t ver_cmd;
947 uint8_t fam;
948 uint16_t len;
a3c86431
TL
949 union {
950 struct { /* TCP/UDP over IPv4, len = 12 */
951 uint32_t src_addr;
952 uint32_t dst_addr;
953 uint16_t src_port;
954 uint16_t dst_port;
955 } ip4;
956 struct { /* TCP/UDP over IPv6, len = 36 */
957 uint8_t src_addr[16];
958 uint8_t dst_addr[16];
959 uint16_t src_port;
960 uint16_t dst_port;
961 } ip6;
962 struct { /* AF_UNIX sockets, len = 216 */
963 uschar src_addr[108];
964 uschar dst_addr[108];
965 } unx;
966 } addr;
967 } v2;
968} hdr;
969
eb57651e
TL
970/* Temp variables used in PPv2 address:port parsing */
971uint16_t tmpport;
972char tmpip[INET_ADDRSTRLEN];
973struct sockaddr_in tmpaddr;
974char tmpip6[INET6_ADDRSTRLEN];
975struct sockaddr_in6 tmpaddr6;
976
977int get_ok = 0;
f267271d
JH
978int size, ret;
979int fd = fileno(smtp_in);
36719342 980const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
a3c86431
TL
981uschar *iptype; /* To display debug info */
982struct timeval tv;
a3bddaa8 983struct timeval tvtmp;
f267271d 984socklen_t vslen = sizeof(struct timeval);
a3c86431 985
a3bddaa8 986/* Save current socket timeout values */
f267271d 987get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
a3bddaa8 988
a3c86431
TL
989/* Proxy Protocol host must send header within a short time
990(default 3 seconds) or it's considered invalid */
991tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
992tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
f267271d
JH
993if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
994 return FALSE;
a3bddaa8 995
a3c86431
TL
996do
997 {
eb57651e
TL
998 /* The inbound host was declared to be a Proxy Protocol host, so
999 don't do a PEEK into the data, actually slurp it up. */
1000 ret = recv(fd, &hdr, sizeof(hdr), 0);
a3c86431
TL
1001 }
1002 while (ret == -1 && errno == EINTR);
1003
1004if (ret == -1)
f267271d 1005 goto proxyfail;
a3c86431 1006
5d036699 1007if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
a3c86431 1008 {
5d036699
JH
1009 uint8_t ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
1010 uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
36719342
TL
1011
1012 /* May 2014: haproxy combined the version and command into one byte to
1013 allow two full bytes for the length field in order to proxy SSL
1014 connections. SSL Proxy is not supported in this version of Exim, but
4c04137d 1015 must still separate values here. */
36719342
TL
1016
1017 if (ver != 0x02)
1018 {
1019 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
1020 goto proxyfail;
1021 }
a3c86431 1022 DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n");
36719342 1023 /* The v2 header will always be 16 bytes per the spec. */
5d036699 1024 size = 16 + ntohs(hdr.v2.len);
a3c86431
TL
1025 if (ret < size)
1026 {
36719342
TL
1027 DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header (%d/%d)\n",
1028 ret, size);
a3c86431
TL
1029 goto proxyfail;
1030 }
36719342 1031 switch (cmd)
a3c86431
TL
1032 {
1033 case 0x01: /* PROXY command */
1034 switch (hdr.v2.fam)
1035 {
eb57651e
TL
1036 case 0x11: /* TCPv4 address type */
1037 iptype = US"IPv4";
1038 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
5d036699
JH
1039 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1040 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1041 {
1042 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1043 goto proxyfail;
eb57651e 1044 }
e6d2a989 1045 proxy_local_address = sender_host_address;
eb57651e
TL
1046 sender_host_address = string_copy(US tmpip);
1047 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
e6d2a989 1048 proxy_local_port = sender_host_port;
eb57651e
TL
1049 sender_host_port = tmpport;
1050 /* Save dest ip/port */
1051 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
5d036699
JH
1052 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1053 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1054 {
1055 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1056 goto proxyfail;
eb57651e 1057 }
7a2fa0bc 1058 proxy_external_address = string_copy(US tmpip);
eb57651e 1059 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
7a2fa0bc 1060 proxy_external_port = tmpport;
a3c86431 1061 goto done;
eb57651e
TL
1062 case 0x21: /* TCPv6 address type */
1063 iptype = US"IPv6";
1064 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
5d036699
JH
1065 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1066 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1067 {
1068 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1069 goto proxyfail;
eb57651e 1070 }
e6d2a989 1071 proxy_local_address = sender_host_address;
eb57651e
TL
1072 sender_host_address = string_copy(US tmpip6);
1073 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
e6d2a989 1074 proxy_local_port = sender_host_port;
eb57651e
TL
1075 sender_host_port = tmpport;
1076 /* Save dest ip/port */
1077 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
5d036699
JH
1078 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1079 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1080 {
1081 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1082 goto proxyfail;
eb57651e 1083 }
7a2fa0bc 1084 proxy_external_address = string_copy(US tmpip6);
eb57651e 1085 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
7a2fa0bc 1086 proxy_external_port = tmpport;
a3c86431 1087 goto done;
eb57651e
TL
1088 default:
1089 DEBUG(D_receive)
1090 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1091 hdr.v2.fam);
1092 goto proxyfail;
a3c86431
TL
1093 }
1094 /* Unsupported protocol, keep local connection address */
1095 break;
1096 case 0x00: /* LOCAL command */
1097 /* Keep local connection address for LOCAL */
1098 break;
1099 default:
eb57651e 1100 DEBUG(D_receive)
36719342 1101 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
1102 goto proxyfail;
1103 }
1104 }
5d036699 1105else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
a3c86431
TL
1106 {
1107 uschar *p = string_copy(hdr.v1.line);
1108 uschar *end = memchr(p, '\r', ret - 1);
1109 uschar *sp; /* Utility variables follow */
1110 int tmp_port;
1111 char *endc;
1112
1113 if (!end || end[1] != '\n')
1114 {
1115 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
1116 goto proxyfail;
1117 }
1118 *end = '\0'; /* Terminate the string */
1119 size = end + 2 - hdr.v1.line; /* Skip header + CRLF */
1120 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
1121 /* Step through the string looking for the required fields. Ensure
4c04137d 1122 strict adherence to required formatting, exit for any error. */
a3c86431
TL
1123 p += 5;
1124 if (!isspace(*(p++)))
1125 {
1126 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
1127 goto proxyfail;
1128 }
1129 if (!Ustrncmp(p, CCS"TCP4", 4))
1130 iptype = US"IPv4";
1131 else if (!Ustrncmp(p,CCS"TCP6", 4))
1132 iptype = US"IPv6";
1133 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
1134 {
1135 iptype = US"Unknown";
1136 goto done;
1137 }
1138 else
1139 {
1140 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
1141 goto proxyfail;
1142 }
1143
1144 p += Ustrlen(iptype);
1145 if (!isspace(*(p++)))
1146 {
1147 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
1148 goto proxyfail;
1149 }
1150 /* Find the end of the arg */
1151 if ((sp = Ustrchr(p, ' ')) == NULL)
1152 {
1153 DEBUG(D_receive)
1154 debug_printf("Did not find proxied src %s\n", iptype);
1155 goto proxyfail;
1156 }
1157 *sp = '\0';
5d036699 1158 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1159 {
1160 DEBUG(D_receive)
1161 debug_printf("Proxied src arg is not an %s address\n", iptype);
1162 goto proxyfail;
1163 }
e6d2a989 1164 proxy_local_address = sender_host_address;
a3c86431
TL
1165 sender_host_address = p;
1166 p = sp + 1;
1167 if ((sp = Ustrchr(p, ' ')) == NULL)
1168 {
1169 DEBUG(D_receive)
1170 debug_printf("Did not find proxy dest %s\n", iptype);
1171 goto proxyfail;
1172 }
1173 *sp = '\0';
5d036699 1174 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1175 {
1176 DEBUG(D_receive)
1177 debug_printf("Proxy dest arg is not an %s address\n", iptype);
1178 goto proxyfail;
1179 }
7a2fa0bc 1180 proxy_external_address = p;
a3c86431
TL
1181 p = sp + 1;
1182 if ((sp = Ustrchr(p, ' ')) == NULL)
1183 {
1184 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
1185 goto proxyfail;
1186 }
1187 *sp = '\0';
5d036699 1188 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1189 if (*endc || tmp_port == 0)
1190 {
1191 DEBUG(D_receive)
1192 debug_printf("Proxied src port '%s' not an integer\n", p);
1193 goto proxyfail;
1194 }
e6d2a989 1195 proxy_local_port = sender_host_port;
a3c86431
TL
1196 sender_host_port = tmp_port;
1197 p = sp + 1;
1198 if ((sp = Ustrchr(p, '\0')) == NULL)
1199 {
1200 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
1201 goto proxyfail;
1202 }
5d036699 1203 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1204 if (*endc || tmp_port == 0)
1205 {
1206 DEBUG(D_receive)
1207 debug_printf("Proxy dest port '%s' not an integer\n", p);
1208 goto proxyfail;
1209 }
7a2fa0bc 1210 proxy_external_port = tmp_port;
a3c86431
TL
1211 /* Already checked for /r /n above. Good V1 header received. */
1212 goto done;
1213 }
1214else
1215 {
1216 /* Wrong protocol */
eb57651e 1217 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
a3c86431
TL
1218 goto proxyfail;
1219 }
1220
1221proxyfail:
f267271d 1222restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1223/* Don't flush any potential buffer contents. Any input should cause a
eb57651e 1224 synchronization failure */
a3c86431
TL
1225return FALSE;
1226
1227done:
f267271d 1228restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1229DEBUG(D_receive)
eb57651e 1230 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
a3c86431
TL
1231return proxy_session;
1232}
1233#endif
1234
059ec3d9
PH
1235/*************************************************
1236* Read one command line *
1237*************************************************/
1238
1239/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1240There are sites that don't do this, and in any case internal SMTP probably
1241should check only for LF. Consequently, we check here for LF only. The line
1242ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
1243an unknown command. The command is read into the global smtp_cmd_buffer so that
1244it is available via $smtp_command.
059ec3d9
PH
1245
1246The character reading routine sets up a timeout for each block actually read
1247from the input (which may contain more than one command). We set up a special
1248signal handler that closes down the session on a timeout. Control does not
1249return when it runs.
1250
1251Arguments:
bd8fbe36
JH
1252 check_sync if TRUE, check synchronization rules if global option is TRUE
1253 buffer_lim maximum to buffer in lower layer
059ec3d9
PH
1254
1255Returns: a code identifying the command (enumerated above)
1256*/
1257
1258static int
bd8fbe36 1259smtp_read_command(BOOL check_sync, unsigned buffer_lim)
059ec3d9
PH
1260{
1261int c;
1262int ptr = 0;
1263smtp_cmd_list *p;
1264BOOL hadnull = FALSE;
1265
1266os_non_restarting_signal(SIGALRM, command_timeout_handler);
1267
bd8fbe36 1268while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
059ec3d9 1269 {
bd8fbe36 1270 if (ptr >= SMTP_CMD_BUFFER_SIZE)
059ec3d9
PH
1271 {
1272 os_non_restarting_signal(SIGALRM, sigalrm_handler);
1273 return OTHER_CMD;
1274 }
1275 if (c == 0)
1276 {
1277 hadnull = TRUE;
1278 c = '?';
1279 }
3ee512ff 1280 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1281 }
1282
1283receive_linecount++; /* For BSMTP errors */
1284os_non_restarting_signal(SIGALRM, sigalrm_handler);
1285
1286/* If hit end of file, return pseudo EOF command. Whether we have a
1287part-line already read doesn't matter, since this is an error state. */
1288
1289if (c == EOF) return EOF_CMD;
1290
1291/* Remove any CR and white space at the end of the line, and terminate the
1292string. */
1293
3ee512ff
PH
1294while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1295smtp_cmd_buffer[ptr] = 0;
059ec3d9 1296
3ee512ff 1297DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1298
1299/* NULLs are not allowed in SMTP commands */
1300
1301if (hadnull) return BADCHAR_CMD;
1302
1303/* Scan command list and return identity, having set the data pointer
1304to the start of the actual data characters. Check for SMTP synchronization
1305if required. */
1306
1307for (p = cmd_list; p < cmd_list_end; p++)
1308 {
cee5f132 1309 #ifdef SUPPORT_PROXY
a3c86431
TL
1310 /* Only allow QUIT command if Proxy Protocol parsing failed */
1311 if (proxy_session && proxy_session_failed)
1312 {
1313 if (p->cmd != QUIT_CMD)
1314 continue;
1315 }
1316 #endif
2f460950
JH
1317 if ( p->len
1318 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1319 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1320 || smtp_cmd_buffer[p->len] == 0
1321 || smtp_cmd_buffer[p->len] == ' '
1322 ) )
059ec3d9
PH
1323 {
1324 if (smtp_inptr < smtp_inend && /* Outstanding input */
1325 p->cmd < sync_cmd_limit && /* Command should sync */
1326 check_sync && /* Local flag set */
1327 smtp_enforce_sync && /* Global flag set */
1328 sender_host_address != NULL && /* Not local input */
1329 !sender_host_notsocket) /* Really is a socket */
1330 return BADSYN_CMD;
1331
ca86f471
PH
1332 /* The variables $smtp_command and $smtp_command_argument point into the
1333 unmodified input buffer. A copy of the latter is taken for actual
1334 processing, so that it can be chopped up into separate parts if necessary,
1335 for example, when processing a MAIL command options such as SIZE that can
1336 follow the sender address. */
059ec3d9 1337
3ee512ff 1338 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1339 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1340 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1341 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1342
1343 /* Count non-mail commands from those hosts that are controlled in this
1344 way. The default is all hosts. We don't waste effort checking the list
1345 until we get a non-mail command, but then cache the result to save checking
1346 again. If there's a DEFER while checking the host, assume it's in the list.
1347
1348 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1349 start of each incoming message by fiddling with the value in the table. */
1350
1351 if (!p->is_mail_cmd)
1352 {
1353 if (count_nonmail == TRUE_UNSET) count_nonmail =
1354 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1355 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1356 return TOO_MANY_NONMAIL_CMD;
1357 }
1358
ca86f471
PH
1359 /* If there is data for a command that does not expect it, generate the
1360 error here. */
059ec3d9 1361
ca86f471 1362 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1363 }
1364 }
1365
cee5f132 1366#ifdef SUPPORT_PROXY
a3c86431
TL
1367/* Only allow QUIT command if Proxy Protocol parsing failed */
1368if (proxy_session && proxy_session_failed)
1369 return PROXY_FAIL_IGNORE_CMD;
1370#endif
1371
059ec3d9
PH
1372/* Enforce synchronization for unknown commands */
1373
1374if (smtp_inptr < smtp_inend && /* Outstanding input */
1375 check_sync && /* Local flag set */
1376 smtp_enforce_sync && /* Global flag set */
1377 sender_host_address != NULL && /* Not local input */
1378 !sender_host_notsocket) /* Really is a socket */
1379 return BADSYN_CMD;
1380
1381return OTHER_CMD;
1382}
1383
1384
1385
1386/*************************************************
1387* Forced closedown of call *
1388*************************************************/
1389
1390/* This function is called from log.c when Exim is dying because of a serious
1391disaster, and also from some other places. If an incoming non-batched SMTP
1392channel is open, it swallows the rest of the incoming message if in the DATA
1393phase, sends the reply string, and gives an error to all subsequent commands
1394except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1395smtp_in.
1396
8f128379
PH
1397Arguments:
1398 message SMTP reply string to send, excluding the code
1399
059ec3d9
PH
1400Returns: nothing
1401*/
1402
1403void
1404smtp_closedown(uschar *message)
1405{
1406if (smtp_in == NULL || smtp_batched_input) return;
1407receive_swallow_smtp();
1408smtp_printf("421 %s\r\n", message);
1409
bd8fbe36 1410for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 1411 {
60d10ce7
JH
1412 case EOF_CMD:
1413 return;
059ec3d9 1414
60d10ce7
JH
1415 case QUIT_CMD:
1416 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
1417 mac_smtp_fflush();
1418 return;
059ec3d9 1419
60d10ce7
JH
1420 case RSET_CMD:
1421 smtp_printf("250 Reset OK\r\n");
1422 break;
059ec3d9 1423
60d10ce7
JH
1424 default:
1425 smtp_printf("421 %s\r\n", message);
1426 break;
059ec3d9
PH
1427 }
1428}
1429
1430
1431
1432
1433/*************************************************
1434* Set up connection info for logging *
1435*************************************************/
1436
1437/* This function is called when logging information about an SMTP connection.
1438It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1439If sender_fullhost is NULL, we are at a very early stage of the connection;
1440just use the IP address.
059ec3d9
PH
1441
1442Argument: none
1443Returns: a string describing the connection
1444*/
1445
1446uschar *
1447smtp_get_connection_info(void)
1448{
f5d25c2b
JH
1449const uschar * hostname = sender_fullhost
1450 ? sender_fullhost : sender_host_address;
dac79d3e 1451
059ec3d9 1452if (host_checking)
dac79d3e 1453 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1454
1455if (sender_host_unknown || sender_host_notsocket)
1456 return string_sprintf("SMTP connection from %s", sender_ident);
1457
1458if (is_inetd)
dac79d3e 1459 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1460
6c6d6e48 1461if (LOGGING(incoming_interface) && interface_address != NULL)
dac79d3e 1462 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1463 interface_address, interface_port);
1464
dac79d3e 1465return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1466}
1467
1468
1469
e45a1c37 1470#ifdef SUPPORT_TLS
887291d2
JH
1471/* Append TLS-related information to a log line
1472
1473Arguments:
1474 s String under construction: allocated string to extend, or NULL
1475 sizep Pointer to current allocation size (update on return), or NULL
1476 ptrp Pointer to index for new entries in string (update on return), or NULL
1477
1478Returns: Allocated string or NULL
1479*/
e45a1c37
JH
1480static uschar *
1481s_tlslog(uschar * s, int * sizep, int * ptrp)
1482{
1483 int size = sizep ? *sizep : 0;
1484 int ptr = ptrp ? *ptrp : 0;
1485
6c6d6e48 1486 if (LOGGING(tls_cipher) && tls_in.cipher != NULL)
e45a1c37 1487 s = string_append(s, &size, &ptr, 2, US" X=", tls_in.cipher);
6c6d6e48 1488 if (LOGGING(tls_certificate_verified) && tls_in.cipher != NULL)
e45a1c37
JH
1489 s = string_append(s, &size, &ptr, 2, US" CV=",
1490 tls_in.certificate_verified? "yes":"no");
6c6d6e48 1491 if (LOGGING(tls_peerdn) && tls_in.peerdn != NULL)
e45a1c37
JH
1492 s = string_append(s, &size, &ptr, 3, US" DN=\"",
1493 string_printing(tls_in.peerdn), US"\"");
6c6d6e48 1494 if (LOGGING(tls_sni) && tls_in.sni != NULL)
e45a1c37
JH
1495 s = string_append(s, &size, &ptr, 3, US" SNI=\"",
1496 string_printing(tls_in.sni), US"\"");
1497
67d81c10
JH
1498 if (s)
1499 {
1500 s[ptr] = '\0';
1501 if (sizep) *sizep = size;
1502 if (ptrp) *ptrp = ptr;
1503 }
e45a1c37
JH
1504 return s;
1505}
1506#endif
1507
059ec3d9 1508/*************************************************
b4ed4da0
PH
1509* Log lack of MAIL if so configured *
1510*************************************************/
1511
1512/* This function is called when an SMTP session ends. If the log selector
1513smtp_no_mail is set, write a log line giving some details of what has happened
1514in the SMTP session.
1515
1516Arguments: none
1517Returns: nothing
1518*/
1519
1520void
1521smtp_log_no_mail(void)
1522{
1523int size, ptr, i;
1524uschar *s, *sep;
1525
6c6d6e48 1526if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
1527 return;
1528
1529s = NULL;
1530size = ptr = 0;
1531
1532if (sender_host_authenticated != NULL)
1533 {
1534 s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated);
1535 if (authenticated_id != NULL)
1536 s = string_append(s, &size, &ptr, 2, US":", authenticated_id);
1537 }
1538
1539#ifdef SUPPORT_TLS
e45a1c37 1540s = s_tlslog(s, &size, &ptr);
3f0945ff 1541#endif
b4ed4da0
PH
1542
1543sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)?
1544 US" C=..." : US" C=";
1545for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1546 {
1547 if (smtp_connection_had[i] != SCH_NONE)
1548 {
1549 s = string_append(s, &size, &ptr, 2, sep,
1550 smtp_names[smtp_connection_had[i]]);
1551 sep = US",";
1552 }
1553 }
1554
1555for (i = 0; i < smtp_ch_index; i++)
1556 {
1557 s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]);
1558 sep = US",";
1559 }
1560
1561if (s != NULL) s[ptr] = 0; else s = US"";
1562log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s",
1563 host_and_ident(FALSE),
19050083
JH
1564 readconf_printtime( (int) ((long)time(NULL) - (long)smtp_connection_start)),
1565 s);
b4ed4da0
PH
1566}
1567
1568
1569
1570/*************************************************
059ec3d9
PH
1571* Check HELO line and set sender_helo_name *
1572*************************************************/
1573
1574/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1575the domain name of the sending host, or an ip literal in square brackets. The
4c04137d 1576argument is placed in sender_helo_name, which is in malloc store, because it
059ec3d9
PH
1577must persist over multiple incoming messages. If helo_accept_junk is set, this
1578host is permitted to send any old junk (needed for some broken hosts).
1579Otherwise, helo_allow_chars can be used for rogue characters in general
1580(typically people want to let in underscores).
1581
1582Argument:
1583 s the data portion of the line (already past any white space)
1584
1585Returns: TRUE or FALSE
1586*/
1587
1588static BOOL
1589check_helo(uschar *s)
1590{
1591uschar *start = s;
1592uschar *end = s + Ustrlen(s);
1593BOOL yield = helo_accept_junk;
1594
1595/* Discard any previous helo name */
1596
1597if (sender_helo_name != NULL)
1598 {
1599 store_free(sender_helo_name);
1600 sender_helo_name = NULL;
1601 }
1602
1603/* Skip tests if junk is permitted. */
1604
1605if (!yield)
1606 {
1607 /* Allow the new standard form for IPv6 address literals, namely,
1608 [IPv6:....], and because someone is bound to use it, allow an equivalent
1609 IPv4 form. Allow plain addresses as well. */
1610
1611 if (*s == '[')
1612 {
1613 if (end[-1] == ']')
1614 {
1615 end[-1] = 0;
1616 if (strncmpic(s, US"[IPv6:", 6) == 0)
1617 yield = (string_is_ip_address(s+6, NULL) == 6);
1618 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1619 yield = (string_is_ip_address(s+6, NULL) == 4);
1620 else
1621 yield = (string_is_ip_address(s+1, NULL) != 0);
1622 end[-1] = ']';
1623 }
1624 }
1625
1626 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1627 that have been configured (usually underscore - sigh). */
1628
1629 else if (*s != 0)
1630 {
1631 yield = TRUE;
1632 while (*s != 0)
1633 {
1634 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1635 Ustrchr(helo_allow_chars, *s) == NULL)
1636 {
1637 yield = FALSE;
1638 break;
1639 }
1640 s++;
1641 }
1642 }
1643 }
1644
1645/* Save argument if OK */
1646
1647if (yield) sender_helo_name = string_copy_malloc(start);
1648return yield;
1649}
1650
1651
1652
1653
1654
1655/*************************************************
1656* Extract SMTP command option *
1657*************************************************/
1658
ca86f471 1659/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1660is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1661things that can appear there.
1662
1663Arguments:
1664 name point this at the name
1665 value point this at the data string
1666
1667Returns: TRUE if found an option
1668*/
1669
1670static BOOL
1671extract_option(uschar **name, uschar **value)
1672{
1673uschar *n;
ca86f471 1674uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1675while (isspace(*v)) v--;
1676v[1] = 0;
d7a2c833
JH
1677while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
1678 {
1679 /* Take care to not stop at a space embedded in a quoted local-part */
1680
1681 if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
1682 v--;
1683 }
059ec3d9
PH
1684
1685n = v;
fd98a5c6
JH
1686if (*v == '=')
1687{
1688 while(isalpha(n[-1])) n--;
1689 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1690 if (!isspace(n[-1])) return FALSE;
1691 n[-1] = 0;
1692}
1693else
1694{
1695 n++;
1696 if (v == smtp_cmd_data) return FALSE;
1697}
059ec3d9 1698*v++ = 0;
fd98a5c6 1699*name = n;
059ec3d9
PH
1700*value = v;
1701return TRUE;
1702}
1703
1704
1705
1706
1707
059ec3d9
PH
1708/*************************************************
1709* Reset for new message *
1710*************************************************/
1711
1712/* This function is called whenever the SMTP session is reset from
1713within either of the setup functions.
1714
1715Argument: the stacking pool storage reset point
1716Returns: nothing
1717*/
1718
1719static void
1720smtp_reset(void *reset_point)
1721{
059ec3d9
PH
1722store_reset(reset_point);
1723recipients_list = NULL;
1724rcpt_count = rcpt_defer_count = rcpt_fail_count =
1725 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e5b33cd 1726cancel_cutthrough_connection("smtp reset");
2e0c1448 1727message_linecount = 0;
059ec3d9 1728message_size = -1;
71fafd95 1729acl_added_headers = NULL;
e7568d51 1730acl_removed_headers = NULL;
059ec3d9 1731queue_only_policy = FALSE;
2679d413
PH
1732rcpt_smtp_response = NULL;
1733rcpt_smtp_response_same = TRUE;
1734rcpt_in_progress = FALSE;
69358f02 1735deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 1736freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 1737fake_response = OK; /* Can be set by ACL */
6951ac6c 1738#ifdef WITH_CONTENT_SCAN
8523533c
TK
1739no_mbox_unspool = FALSE; /* Can be set by ACL */
1740#endif
69358f02 1741submission_mode = FALSE; /* Can be set by ACL */
f4ee74ac 1742suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
69358f02
PH
1743active_local_from_check = local_from_check; /* Can be set by ACL */
1744active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
059ec3d9 1745sender_address = NULL;
2fe1a124 1746submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
1747raw_sender = NULL; /* After SMTP rewrite, before qualifying */
1748sender_address_unrewritten = NULL; /* Set only after verify rewrite */
1749sender_verified_list = NULL; /* No senders verified */
1750memset(sender_address_cache, 0, sizeof(sender_address_cache));
1751memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 1752
059ec3d9 1753authenticated_sender = NULL;
8523533c
TK
1754#ifdef EXPERIMENTAL_BRIGHTMAIL
1755bmi_run = 0;
1756bmi_verdicts = NULL;
1757#endif
80a47a2c 1758#ifndef DISABLE_DKIM
9e5d6b55 1759dkim_signers = NULL;
80a47a2c
TK
1760dkim_disable_verify = FALSE;
1761dkim_collect_input = FALSE;
f7572e5a 1762#endif
aa368db3
JH
1763dsn_ret = 0;
1764dsn_envid = NULL;
1765#ifndef DISABLE_PRDR
1766prdr_requested = FALSE;
1767#endif
8523533c
TK
1768#ifdef EXPERIMENTAL_SPF
1769spf_header_comment = NULL;
1770spf_received = NULL;
8e669ac1 1771spf_result = NULL;
8523533c
TK
1772spf_smtp_comment = NULL;
1773#endif
8c5d388a 1774#ifdef SUPPORT_I18N
d1a13eea
JH
1775message_smtputf8 = FALSE;
1776#endif
059ec3d9
PH
1777body_linecount = body_zerocount = 0;
1778
870f6ba8
TF
1779sender_rate = sender_rate_limit = sender_rate_period = NULL;
1780ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
1781 /* Note that ratelimiters_conn persists across resets. */
1782
38a0a95f 1783/* Reset message ACL variables */
47ca6d6c 1784
38a0a95f 1785acl_var_m = NULL;
059ec3d9
PH
1786
1787/* The message body variables use malloc store. They may be set if this is
1788not the first message in an SMTP session and the previous message caused them
1789to be referenced in an ACL. */
1790
1791if (message_body != NULL)
1792 {
1793 store_free(message_body);
1794 message_body = NULL;
1795 }
1796
1797if (message_body_end != NULL)
1798 {
1799 store_free(message_body_end);
1800 message_body_end = NULL;
1801 }
1802
1803/* Warning log messages are also saved in malloc store. They are saved to avoid
1804repetition in the same message, but it seems right to repeat them for different
4e88a19f 1805messages. */
059ec3d9
PH
1806
1807while (acl_warn_logged != NULL)
1808 {
1809 string_item *this = acl_warn_logged;
1810 acl_warn_logged = acl_warn_logged->next;
1811 store_free(this);
1812 }
1813}
1814
1815
1816
1817
1818
1819/*************************************************
1820* Initialize for incoming batched SMTP message *
1821*************************************************/
1822
1823/* This function is called from smtp_setup_msg() in the case when
1824smtp_batched_input is true. This happens when -bS is used to pass a whole batch
1825of messages in one file with SMTP commands between them. All errors must be
1826reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
1827relevant. After an error on a sender, or an invalid recipient, the remainder
1828of the message is skipped. The value of received_protocol is already set.
1829
1830Argument: none
1831Returns: > 0 message successfully started (reached DATA)
1832 = 0 QUIT read or end of file reached
1833 < 0 should not occur
1834*/
1835
1836static int
1837smtp_setup_batch_msg(void)
1838{
1839int done = 0;
1840void *reset_point = store_get(0);
1841
1842/* Save the line count at the start of each transaction - single commands
1843like HELO and RSET count as whole transactions. */
1844
1845bsmtp_transaction_linecount = receive_linecount;
1846
1847if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
1848
1849smtp_reset(reset_point); /* Reset for start of message */
1850
1851/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
1852value. The values are 2 larger than the required yield of the function. */
1853
1854while (done <= 0)
1855 {
1856 uschar *errmess;
1857 uschar *recipient = NULL;
1858 int start, end, sender_domain, recipient_domain;
1859
bd8fbe36 1860 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
1861 {
1862 /* The HELO/EHLO commands set sender_address_helo if they have
1863 valid data; otherwise they are ignored, except that they do
1864 a reset of the state. */
1865
1866 case HELO_CMD:
1867 case EHLO_CMD:
1868
ca86f471 1869 check_helo(smtp_cmd_data);
059ec3d9
PH
1870 /* Fall through */
1871
1872 case RSET_CMD:
1873 smtp_reset(reset_point);
1874 bsmtp_transaction_linecount = receive_linecount;
1875 break;
1876
1877
1878 /* The MAIL FROM command requires an address as an operand. All we
1879 do here is to parse it for syntactic correctness. The form "<>" is
1880 a special case which converts into an empty string. The start/end
1881 pointers in the original are not used further for this address, as
1882 it is the canonical extracted address which is all that is kept. */
1883
1884 case MAIL_CMD:
474f71bf 1885 smtp_mailcmd_count++; /* Count for no-mail log */
059ec3d9
PH
1886 if (sender_address != NULL)
1887 /* The function moan_smtp_batch() does not return. */
3ee512ff 1888 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 1889
ca86f471 1890 if (smtp_cmd_data[0] == 0)
059ec3d9 1891 /* The function moan_smtp_batch() does not return. */
3ee512ff 1892 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9
PH
1893
1894 /* Reset to start of message */
1895
1896 smtp_reset(reset_point);
1897
1898 /* Apply SMTP rewrite */
1899
1900 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
ca86f471
PH
1901 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
1902 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9
PH
1903
1904 /* Extract the address; the TRUE flag allows <> as valid */
1905
1906 raw_sender =
1907 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
1908 TRUE);
1909
1910 if (raw_sender == NULL)
1911 /* The function moan_smtp_batch() does not return. */
3ee512ff 1912 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9
PH
1913
1914 sender_address = string_copy(raw_sender);
1915
1916 /* Qualify unqualified sender addresses if permitted to do so. */
1917
1918 if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@')
1919 {
1920 if (allow_unqualified_sender)
1921 {
1922 sender_address = rewrite_address_qualify(sender_address, FALSE);
1923 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
1924 "and rewritten\n", raw_sender);
1925 }
1926 /* The function moan_smtp_batch() does not return. */
3ee512ff 1927 else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
059ec3d9
PH
1928 "a domain");
1929 }
1930 break;
1931
1932
1933 /* The RCPT TO command requires an address as an operand. All we do
1934 here is to parse it for syntactic correctness. There may be any number
1935 of RCPT TO commands, specifying multiple senders. We build them all into
1936 a data structure that is in argc/argv format. The start/end values
1937 given by parse_extract_address are not used, as we keep only the
1938 extracted address. */
1939
1940 case RCPT_CMD:
1941 if (sender_address == NULL)
1942 /* The function moan_smtp_batch() does not return. */
3ee512ff 1943 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 1944
ca86f471 1945 if (smtp_cmd_data[0] == 0)
059ec3d9 1946 /* The function moan_smtp_batch() does not return. */
3ee512ff 1947 moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand");
059ec3d9
PH
1948
1949 /* Check maximum number allowed */
1950
1951 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
1952 /* The function moan_smtp_batch() does not return. */
3ee512ff 1953 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
059ec3d9
PH
1954 recipients_max_reject? "552": "452");
1955
1956 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
1957 recipient address */
1958
2685d6e0
JH
1959 recipient = rewrite_existflags & rewrite_smtp
1960 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
1961 global_rewrite_rules)
1962 : smtp_cmd_data;
059ec3d9 1963
059ec3d9
PH
1964 recipient = parse_extract_address(recipient, &errmess, &start, &end,
1965 &recipient_domain, FALSE);
059ec3d9 1966
2685d6e0 1967 if (!recipient)
059ec3d9 1968 /* The function moan_smtp_batch() does not return. */
3ee512ff 1969 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9
PH
1970
1971 /* If the recipient address is unqualified, qualify it if permitted. Then
1972 add it to the list of recipients. */
1973
1974 if (recipient_domain == 0)
1975 {
1976 if (allow_unqualified_recipient)
1977 {
1978 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
1979 recipient);
1980 recipient = rewrite_address_qualify(recipient, TRUE);
1981 }
1982 /* The function moan_smtp_batch() does not return. */
3ee512ff 1983 else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain "
059ec3d9
PH
1984 "a domain");
1985 }
1986 receive_add_recipient(recipient, -1);
1987 break;
1988
1989
1990 /* The DATA command is legal only if it follows successful MAIL FROM
1991 and RCPT TO commands. This function is complete when a valid DATA
1992 command is encountered. */
1993
1994 case DATA_CMD:
1995 if (sender_address == NULL || recipients_count <= 0)
1996 {
1997 /* The function moan_smtp_batch() does not return. */
1998 if (sender_address == NULL)
3ee512ff 1999 moan_smtp_batch(smtp_cmd_buffer,
059ec3d9
PH
2000 "503 MAIL FROM:<sender> command must precede DATA");
2001 else
3ee512ff 2002 moan_smtp_batch(smtp_cmd_buffer,
059ec3d9
PH
2003 "503 RCPT TO:<recipient> must precede DATA");
2004 }
2005 else
2006 {
2007 done = 3; /* DATA successfully achieved */
2008 message_ended = END_NOTENDED; /* Indicate in middle of message */
2009 }
2010 break;
2011
2012
2013 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2014
2015 case VRFY_CMD:
2016 case EXPN_CMD:
2017 case HELP_CMD:
2018 case NOOP_CMD:
2019 case ETRN_CMD:
2020 bsmtp_transaction_linecount = receive_linecount;
2021 break;
2022
2023
2024 case EOF_CMD:
2025 case QUIT_CMD:
2026 done = 2;
2027 break;
2028
2029
2030 case BADARG_CMD:
2031 /* The function moan_smtp_batch() does not return. */
3ee512ff 2032 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
059ec3d9
PH
2033 break;
2034
2035
2036 case BADCHAR_CMD:
2037 /* The function moan_smtp_batch() does not return. */
3ee512ff 2038 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
059ec3d9
PH
2039 break;
2040
2041
2042 default:
2043 /* The function moan_smtp_batch() does not return. */
3ee512ff 2044 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
059ec3d9
PH
2045 break;
2046 }
2047 }
2048
2049return done - 2; /* Convert yield values */
2050}
2051
2052
2053
2054
2055/*************************************************
2056* Start an SMTP session *
2057*************************************************/
2058
2059/* This function is called at the start of an SMTP session. Thereafter,
2060smtp_setup_msg() is called to initiate each separate message. This
2061function does host-specific testing, and outputs the banner line.
2062
2063Arguments: none
2064Returns: FALSE if the session can not continue; something has
2065 gone wrong, or the connection to the host is blocked
2066*/
2067
2068BOOL
2069smtp_start_session(void)
2070{
2071int size = 256;
4e88a19f
PH
2072int ptr, esclen;
2073uschar *user_msg, *log_msg;
2074uschar *code, *esc;
059ec3d9
PH
2075uschar *p, *s, *ss;
2076
b4ed4da0
PH
2077smtp_connection_start = time(NULL);
2078for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2079 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2080smtp_ch_index = 0;
2081
00f00ca5
PH
2082/* Default values for certain variables */
2083
059ec3d9 2084helo_seen = esmtp = helo_accept_junk = FALSE;
b4ed4da0 2085smtp_mailcmd_count = 0;
059ec3d9
PH
2086count_nonmail = TRUE_UNSET;
2087synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2088smtp_delay_mail = smtp_rlm_base;
2089auth_advertised = FALSE;
2090pipelining_advertised = FALSE;
cf8b11a5 2091pipelining_enable = TRUE;
059ec3d9 2092sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
8f128379 2093smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2094
33d73e3b
PH
2095/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2096authentication settings from -oMaa to remain in force. */
2097
2098if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL;
059ec3d9
PH
2099authenticated_by = NULL;
2100
2101#ifdef SUPPORT_TLS
817d9f57 2102tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2103tls_in.ourcert = tls_in.peercert = NULL;
2104tls_in.sni = NULL;
44662487 2105tls_in.ocsp = OCSP_NOT_REQ;
059ec3d9
PH
2106tls_advertised = FALSE;
2107#endif
6c1c3d1d 2108dsn_advertised = FALSE;
8c5d388a 2109#ifdef SUPPORT_I18N
d1a13eea
JH
2110smtputf8_advertised = FALSE;
2111#endif
059ec3d9
PH
2112
2113/* Reset ACL connection variables */
2114
38a0a95f 2115acl_var_c = NULL;
059ec3d9 2116
ca86f471 2117/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 2118
bd8fbe36 2119if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
059ec3d9
PH
2120 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2121 "malloc() failed for SMTP command buffer");
40c90bca 2122
2416c261 2123smtp_cmd_buffer[0] = 0;
bd8fbe36 2124smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2125
2126/* For batched input, the protocol setting can be overridden from the
2127command line by a trusted caller. */
2128
2129if (smtp_batched_input)
2130 {
40c90bca 2131 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2132 }
2133
2134/* For non-batched SMTP input, the protocol setting is forced here. It will be
2135reset later if any of EHLO/AUTH/STARTTLS are received. */
2136
2137else
2138 received_protocol =
e524074d 2139 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2140
2141/* Set up the buffer for inputting using direct read() calls, and arrange to
2142call the local functions instead of the standard C ones. */
2143
bd8fbe36 2144if (!(smtp_inbuffer = (uschar *)malloc(IN_BUFFER_SIZE)))
059ec3d9 2145 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
40c90bca 2146
059ec3d9 2147receive_getc = smtp_getc;
584e96c6 2148receive_get_cache = smtp_get_cache;
059ec3d9
PH
2149receive_ungetc = smtp_ungetc;
2150receive_feof = smtp_feof;
2151receive_ferror = smtp_ferror;
58eb016e 2152receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2153smtp_inptr = smtp_inend = smtp_inbuffer;
2154smtp_had_eof = smtp_had_error = 0;
2155
2156/* Set up the message size limit; this may be host-specific */
2157
d45b1de8
PH
2158thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
2159if (expand_string_message != NULL)
059ec3d9
PH
2160 {
2161 if (thismessage_size_limit == -1)
2162 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2163 "%s", expand_string_message);
2164 else
2165 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2166 "%s", expand_string_message);
2167 smtp_closedown(US"Temporary local problem - please try later");
2168 return FALSE;
2169 }
2170
2171/* When a message is input locally via the -bs or -bS options, sender_host_
2172unknown is set unless -oMa was used to force an IP address, in which case it
2173is checked like a real remote connection. When -bs is used from inetd, this
2174flag is not set, causing the sending host to be checked. The code that deals
2175with IP source routing (if configured) is never required for -bs or -bS and
2176the flag sender_host_notsocket is used to suppress it.
2177
2178If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2179reserve for certain hosts and/or networks. */
2180
2181if (!sender_host_unknown)
2182 {
2183 int rc;
2184 BOOL reserved_host = FALSE;
2185
2186 /* Look up IP options (source routing info) on the socket if this is not an
2187 -oMa "host", and if any are found, log them and drop the connection.
2188
2189 Linux (and others now, see below) is different to everyone else, so there
2190 has to be some conditional compilation here. Versions of Linux before 2.1.15
2191 used a structure whose name was "options". Somebody finally realized that
2192 this name was silly, and it got changed to "ip_options". I use the
2193 newer name here, but there is a fudge in the script that sets up os.h
2194 to define a macro in older Linux systems.
2195
2196 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2197 glibc 2, which has chosen ip_opts for the structure name. This is now
2198 really a glibc thing rather than a Linux thing, so the condition name
2199 has been changed to reflect this. It is relevant also to GNU/Hurd.
2200
2201 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2202 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2203 a special macro defined in the os.h file.
2204
2205 Some DGUX versions on older hardware appear not to support IP options at
2206 all, so there is now a general macro which can be set to cut out this
2207 support altogether.
2208
2209 How to do this properly in IPv6 is not yet known. */
2210
2211 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
2212
2213 #ifdef GLIBC_IP_OPTIONS
2214 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2215 #define OPTSTYLE 1
2216 #else
2217 #define OPTSTYLE 2
2218 #endif
2219 #elif defined DARWIN_IP_OPTIONS
2220 #define OPTSTYLE 2
2221 #else
2222 #define OPTSTYLE 3
2223 #endif
2224
2225 if (!host_checking && !sender_host_notsocket)
2226 {
2227 #if OPTSTYLE == 1
36a3b041 2228 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2229 struct ip_options *ipopt = store_get(optlen);
2230 #elif OPTSTYLE == 2
2231 struct ip_opts ipoptblock;
2232 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2233 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2234 #else
2235 struct ipoption ipoptblock;
2236 struct ipoption *ipopt = &ipoptblock;
36a3b041 2237 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2238 #endif
2239
2240 /* Occasional genuine failures of getsockopt() have been seen - for
2241 example, "reset by peer". Therefore, just log and give up on this
2242 call, unless the error is ENOPROTOOPT. This error is given by systems
2243 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2244 of writing. So for that error, carry on - we just can't do an IP options
2245 check. */
2246
2247 DEBUG(D_receive) debug_printf("checking for IP options\n");
2248
2249 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt),
2250 &optlen) < 0)
2251 {
2252 if (errno != ENOPROTOOPT)
2253 {
2254 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2255 host_and_ident(FALSE), strerror(errno));
2256 smtp_printf("451 SMTP service not available\r\n");
2257 return FALSE;
2258 }
2259 }
2260
2261 /* Deal with any IP options that are set. On the systems I have looked at,
2262 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2263 more logging data than will fit in big_buffer. Nevertheless, after somebody
2264 questioned this code, I've added in some paranoid checking. */
2265
2266 else if (optlen > 0)
2267 {
2268 uschar *p = big_buffer;
2269 uschar *pend = big_buffer + big_buffer_size;
2270 uschar *opt, *adptr;
2271 int optcount;
2272 struct in_addr addr;
2273
2274 #if OPTSTYLE == 1
2275 uschar *optstart = (uschar *)(ipopt->__data);
2276 #elif OPTSTYLE == 2
2277 uschar *optstart = (uschar *)(ipopt->ip_opts);
2278 #else
2279 uschar *optstart = (uschar *)(ipopt->ipopt_list);
2280 #endif
2281
2282 DEBUG(D_receive) debug_printf("IP options exist\n");
2283
2284 Ustrcpy(p, "IP options on incoming call:");
2285 p += Ustrlen(p);
2286
2287 for (opt = optstart; opt != NULL &&
2288 opt < (uschar *)(ipopt) + optlen;)
2289 {
2290 switch (*opt)
2291 {
2292 case IPOPT_EOL:
2293 opt = NULL;
2294 break;
2295
2296 case IPOPT_NOP:
2297 opt++;
2298 break;
2299
2300 case IPOPT_SSRR:
2301 case IPOPT_LSRR:
2302 if (!string_format(p, pend-p, " %s [@%s",
2303 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2304 #if OPTSTYLE == 1
2305 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2306 #elif OPTSTYLE == 2
2307 inet_ntoa(ipopt->ip_dst)))
2308 #else
2309 inet_ntoa(ipopt->ipopt_dst)))
2310 #endif
2311 {
2312 opt = NULL;
2313 break;
2314 }
2315
2316 p += Ustrlen(p);
2317 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2318 adptr = opt + 3;
2319 while (optcount-- > 0)
2320 {
2321 memcpy(&addr, adptr, sizeof(addr));
2322 if (!string_format(p, pend - p - 1, "%s%s",
2323 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2324 {
2325 opt = NULL;
2326 break;
2327 }
2328 p += Ustrlen(p);
2329 adptr += sizeof(struct in_addr);
2330 }
2331 *p++ = ']';
2332 opt += opt[1];
2333 break;
2334
2335 default:
2336 {
2337 int i;
2338 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2339 Ustrcat(p, "[ ");
2340 p += 2;
2341 for (i = 0; i < opt[1]; i++)
2342 {
2343 sprintf(CS p, "%2.2x ", opt[i]);
2344 p += 3;
2345 }
2346 *p++ = ']';
2347 }
2348 opt += opt[1];
2349 break;
2350 }
2351 }
2352
2353 *p = 0;
2354 log_write(0, LOG_MAIN, "%s", big_buffer);
2355
2356 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2357
2358 log_write(0, LOG_MAIN|LOG_REJECT,
2359 "connection from %s refused (IP options)", host_and_ident(FALSE));
2360
2361 smtp_printf("554 SMTP service not available\r\n");
2362 return FALSE;
2363 }
2364
2365 /* Length of options = 0 => there are no options */
2366
2367 else DEBUG(D_receive) debug_printf("no IP options found\n");
2368 }
2369 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2370
2371 /* Set keep-alive in socket options. The option is on by default. This
2372 setting is an attempt to get rid of some hanging connections that stick in
2373 read() when the remote end (usually a dialup) goes away. */
2374
2375 if (smtp_accept_keepalive && !sender_host_notsocket)
2376 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2377
2378 /* If the current host matches host_lookup, set the name by doing a
2379 reverse lookup. On failure, sender_host_name will be NULL and
2380 host_lookup_failed will be TRUE. This may or may not be serious - optional
2381 checks later. */
2382
2383 if (verify_check_host(&host_lookup) == OK)
2384 {
2385 (void)host_name_lookup();
2386 host_build_sender_fullhost();
2387 }
2388
2389 /* Delay this until we have the full name, if it is looked up. */
2390
2391 set_process_info("handling incoming connection from %s",
2392 host_and_ident(FALSE));
2393
1ad6489e
JH
2394 /* Expand smtp_receive_timeout, if needed */
2395
2396 if (smtp_receive_timeout_s)
2397 {
2398 uschar * exp;
2399 if ( !(exp = expand_string(smtp_receive_timeout_s))
2400 || !(*exp)
2401 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2402 )
2403 log_write(0, LOG_MAIN|LOG_PANIC,
2404 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2405 }
2406
059ec3d9
PH
2407 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2408 smtps port for use with older style SSL MTAs. */
2409
2410 #ifdef SUPPORT_TLS
817d9f57 2411 if (tls_in.on_connect && tls_server_start(tls_require_ciphers) != OK)
059ec3d9
PH
2412 return FALSE;
2413 #endif
2414
2415 /* Test for explicit connection rejection */
2416
2417 if (verify_check_host(&host_reject_connection) == OK)
2418 {
2419 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2420 "from %s (host_reject_connection)", host_and_ident(FALSE));
2421 smtp_printf("554 SMTP service not available\r\n");
2422 return FALSE;
2423 }
2424
afb3eaaf
PH
2425 /* Test with TCP Wrappers if so configured. There is a problem in that
2426 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2427 such as disks dying. In these cases, it is desirable to reject with a 4xx
2428 error instead of a 5xx error. There isn't a "right" way to detect such
2429 problems. The following kludge is used: errno is zeroed before calling
2430 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2431 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2432 not exist). */
059ec3d9
PH
2433
2434 #ifdef USE_TCP_WRAPPERS
afb3eaaf 2435 errno = 0;
5dc43717
JJ
2436 tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name);
2437 if (tcp_wrappers_name == NULL)
2438 {
2439 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2440 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2441 expand_string_message);
2442 }
2443 if (!hosts_ctl(tcp_wrappers_name,
059ec3d9
PH
2444 (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name,
2445 (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address,
2446 (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident))
2447 {
afb3eaaf
PH
2448 if (errno == 0 || errno == ENOENT)
2449 {
2450 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2451 log_write(L_connection_reject,
2452 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2453 "(tcp wrappers)", host_and_ident(FALSE));
2454 smtp_printf("554 SMTP service not available\r\n");
2455 }
2456 else
2457 {
2458 int save_errno = errno;
2459 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2460 "errno value %d\n", save_errno);
2461 log_write(L_connection_reject,
2462 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2463 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
2464 smtp_printf("451 Temporary local problem - please try later\r\n");
2465 }
059ec3d9
PH
2466 return FALSE;
2467 }
2468 #endif
2469
b01dd148
PH
2470 /* Check for reserved slots. The value of smtp_accept_count has already been
2471 incremented to include this process. */
059ec3d9
PH
2472
2473 if (smtp_accept_max > 0 &&
b01dd148 2474 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2475 {
2476 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2477 {
2478 log_write(L_connection_reject,
2479 LOG_MAIN, "temporarily refused connection from %s: not in "
2480 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2481 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2482 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2483 smtp_printf("421 %s: Too many concurrent SMTP connections; "
2484 "please try again later\r\n", smtp_active_hostname);
2485 return FALSE;
2486 }
2487 reserved_host = TRUE;
2488 }
2489
2490 /* If a load level above which only messages from reserved hosts are
2491 accepted is set, check the load. For incoming calls via the daemon, the
2492 check is done in the superior process if there are no reserved hosts, to
2493 save a fork. In all cases, the load average will already be available
2494 in a global variable at this point. */
2495
2496 if (smtp_load_reserve >= 0 &&
2497 load_average > smtp_load_reserve &&
2498 !reserved_host &&
2499 verify_check_host(&smtp_reserve_hosts) != OK)
2500 {
2501 log_write(L_connection_reject,
2502 LOG_MAIN, "temporarily refused connection from %s: not in "
2503 "reserve list and load average = %.2f", host_and_ident(FALSE),
2504 (double)load_average/1000.0);
2505 smtp_printf("421 %s: Too much load; please try again later\r\n",
2506 smtp_active_hostname);
2507 return FALSE;
2508 }
2509
2510 /* Determine whether unqualified senders or recipients are permitted
2511 for this host. Unfortunately, we have to do this every time, in order to
2512 set the flags so that they can be inspected when considering qualifying
2513 addresses in the headers. For a site that permits no qualification, this
2514 won't take long, however. */
2515
2516 allow_unqualified_sender =
2517 verify_check_host(&sender_unqualified_hosts) == OK;
2518
2519 allow_unqualified_recipient =
2520 verify_check_host(&recipient_unqualified_hosts) == OK;
2521
2522 /* Determine whether HELO/EHLO is required for this host. The requirement
2523 can be hard or soft. */
2524
2525 helo_required = verify_check_host(&helo_verify_hosts) == OK;
2526 if (!helo_required)
2527 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
2528
2529 /* Determine whether this hosts is permitted to send syntactic junk
2530 after a HELO or EHLO command. */
2531
2532 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
2533 }
2534
2535/* For batch SMTP input we are now done. */
2536
2537if (smtp_batched_input) return TRUE;
2538
cee5f132 2539#ifdef SUPPORT_PROXY
a3c86431
TL
2540/* If valid Proxy Protocol source is connecting, set up session.
2541 * Failure will not allow any SMTP function other than QUIT. */
2542proxy_session = FALSE;
2543proxy_session_failed = FALSE;
2544if (check_proxy_protocol_host())
f267271d 2545 if (!setup_proxy_protocol_host())
a3c86431
TL
2546 {
2547 proxy_session_failed = TRUE;
2548 DEBUG(D_receive)
2549 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
2550 }
2551 else
2552 {
2553 sender_host_name = NULL;
2554 (void)host_name_lookup();
2555 host_build_sender_fullhost();
2556 }
a3c86431
TL
2557#endif
2558
059ec3d9
PH
2559/* Run the ACL if it exists */
2560
4e88a19f 2561user_msg = NULL;
3cc3f762 2562if (acl_smtp_connect)
059ec3d9
PH
2563 {
2564 int rc;
3cc3f762
JH
2565 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2566 &log_msg)) != OK)
059ec3d9 2567 {
3cc3f762 2568 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2569 return FALSE;
2570 }
2571 }
2572
2573/* Output the initial message for a two-way SMTP connection. It may contain
2574newlines, which then cause a multi-line response to be given. */
2575
4e88a19f
PH
2576code = US"220"; /* Default status code */
2577esc = US""; /* Default extended status code */
2578esclen = 0; /* Length of esc */
2579
d4ff61d1 2580if (!user_msg)
4e88a19f 2581 {
d4ff61d1 2582 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2583 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2584 "failed: %s", smtp_banner, expand_string_message);
2585 }
2586else
2587 {
2588 int codelen = 3;
2589 s = user_msg;
4f6ae5c3 2590 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2591 if (codelen > 4)
4e88a19f
PH
2592 {
2593 esc = code + 4;
2594 esclen = codelen - 4;
2595 }
2596 }
059ec3d9
PH
2597
2598/* Remove any terminating newlines; might as well remove trailing space too */
2599
2600p = s + Ustrlen(s);
2601while (p > s && isspace(p[-1])) p--;
2602*p = 0;
2603
2604/* It seems that CC:Mail is braindead, and assumes that the greeting message
2605is all contained in a single IP packet. The original code wrote out the
2606greeting using several calls to fprint/fputc, and on busy servers this could
2607cause it to be split over more than one packet - which caused CC:Mail to fall
2608over when it got the second part of the greeting after sending its first
2609command. Sigh. To try to avoid this, build the complete greeting message
2610first, and output it in one fell swoop. This gives a better chance of it
2611ending up as a single packet. */
2612
2613ss = store_get(size);
2614ptr = 0;
2615
2616p = s;
2617do /* At least once, in case we have an empty string */
2618 {
2619 int len;
2620 uschar *linebreak = Ustrchr(p, '\n');
c2f669a4 2621 ss = string_catn(ss, &size, &ptr, code, 3);
059ec3d9
PH
2622 if (linebreak == NULL)
2623 {
2624 len = Ustrlen(p);
c2f669a4 2625 ss = string_catn(ss, &size, &ptr, US" ", 1);
059ec3d9
PH
2626 }
2627 else
2628 {
2629 len = linebreak - p;
c2f669a4 2630 ss = string_catn(ss, &size, &ptr, US"-", 1);
059ec3d9 2631 }
c2f669a4
JH
2632 ss = string_catn(ss, &size, &ptr, esc, esclen);
2633 ss = string_catn(ss, &size, &ptr, p, len);
2634 ss = string_catn(ss, &size, &ptr, US"\r\n", 2);
059ec3d9
PH
2635 p += len;
2636 if (linebreak != NULL) p++;
2637 }
2638while (*p != 0);
2639
2640ss[ptr] = 0; /* string_cat leaves room for this */
2641
2642/* Before we write the banner, check that there is no input pending, unless
2643this synchronisation check is disabled. */
2644
a14e5636 2645if (!check_sync())
059ec3d9 2646 {
a14e5636
PH
2647 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2648 "synchronization error (input sent without waiting for greeting): "
2649 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
2650 string_printing(smtp_inptr));
2651 smtp_printf("554 SMTP synchronization error\r\n");
2652 return FALSE;
059ec3d9
PH
2653 }
2654
2655/* Now output the banner */
2656
2657smtp_printf("%s", ss);
2658return TRUE;
2659}
2660
2661
2662
2663
2664
2665/*************************************************
2666* Handle SMTP syntax and protocol errors *
2667*************************************************/
2668
2669/* Write to the log for SMTP syntax errors in incoming commands, if configured
2670to do so. Then transmit the error response. The return value depends on the
2671number of syntax and protocol errors in this SMTP session.
2672
2673Arguments:
2674 type error type, given as a log flag bit
2675 code response code; <= 0 means don't send a response
2676 data data to reflect in the response (can be NULL)
2677 errmess the error message
2678
2679Returns: -1 limit of syntax/protocol errors NOT exceeded
2680 +1 limit of syntax/protocol errors IS exceeded
2681
2682These values fit in with the values of the "done" variable in the main
2683processing loop in smtp_setup_msg(). */
2684
2685static int
2686synprot_error(int type, int code, uschar *data, uschar *errmess)
2687{
2688int yield = -1;
2689
2690log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
2691 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 2692 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
2693
2694if (++synprot_error_count > smtp_max_synprot_errors)
2695 {
2696 yield = 1;
2697 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
2698 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 2699 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
2700 }
2701
2702if (code > 0)
2703 {
2704 smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ',
2705 (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess);
2706 if (yield == 1)
2707 smtp_printf("%d Too many syntax or protocol errors\r\n", code);
2708 }
2709
2710return yield;
2711}
2712
2713
2714
2715
2716/*************************************************
059ec3d9
PH
2717* Send SMTP response, possibly multiline *
2718*************************************************/
2719
2720/* There are, it seems, broken clients out there that cannot handle multiline
2721responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
2722output nothing for non-final calls, and only the first line for anything else.
2723
2724Arguments:
a5bd321b 2725 code SMTP code, may involve extended status codes
d6a96edc 2726 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
2727 final FALSE if the last line isn't the final line
2728 msg message text, possibly containing newlines
2729
2730Returns: nothing
2731*/
2732
2733void
a5bd321b 2734smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 2735{
a5bd321b
PH
2736int esclen = 0;
2737uschar *esc = US"";
2738
059ec3d9
PH
2739if (!final && no_multiline_responses) return;
2740
d6a96edc 2741if (codelen > 4)
a5bd321b
PH
2742 {
2743 esc = code + 4;
2744 esclen = codelen - 4;
2745 }
2746
2679d413
PH
2747/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
2748have had the same. Note: this code is also present in smtp_printf(). It would
2749be tidier to have it only in one place, but when it was added, it was easier to
2750do it that way, so as not to have to mess with the code for the RCPT command,
2751which sometimes uses smtp_printf() and sometimes smtp_respond(). */
2752
2753if (rcpt_in_progress)
2754 {
2755 if (rcpt_smtp_response == NULL)
2756 rcpt_smtp_response = string_copy(msg);
2757 else if (rcpt_smtp_response_same &&
2758 Ustrcmp(rcpt_smtp_response, msg) != 0)
2759 rcpt_smtp_response_same = FALSE;
2760 rcpt_in_progress = FALSE;
2761 }
2762
2763/* Not output the message, splitting it up into multiple lines if necessary. */
2764
059ec3d9
PH
2765for (;;)
2766 {
2767 uschar *nl = Ustrchr(msg, '\n');
2768 if (nl == NULL)
2769 {
a5bd321b 2770 smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg);
059ec3d9
PH
2771 return;
2772 }
2773 else if (nl[1] == 0 || no_multiline_responses)
2774 {
a5bd321b
PH
2775 smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc,
2776 (int)(nl - msg), msg);
059ec3d9
PH
2777 return;
2778 }
2779 else
2780 {
a5bd321b 2781 smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
2782 msg = nl + 1;
2783 while (isspace(*msg)) msg++;
2784 }
2785 }
2786}
2787
2788
2789
2790
2791/*************************************************
4e88a19f
PH
2792* Parse user SMTP message *
2793*************************************************/
2794
2795/* This function allows for user messages overriding the response code details
2796by providing a suitable response code string at the start of the message
2797user_msg. Check the message for starting with a response code and optionally an
2798extended status code. If found, check that the first digit is valid, and if so,
2799change the code pointer and length to use the replacement. An invalid code
2800causes a panic log; in this case, if the log messages is the same as the user
2801message, we must also adjust the value of the log message to show the code that
2802is actually going to be used (the original one).
2803
2804This function is global because it is called from receive.c as well as within
2805this module.
2806
d6a96edc
PH
2807Note that the code length returned includes the terminating whitespace
2808character, which is always included in the regex match.
2809
4e88a19f
PH
2810Arguments:
2811 code SMTP code, may involve extended status codes
d6a96edc 2812 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
2813 msg message text
2814 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 2815 check_valid if true, verify the response code
4e88a19f
PH
2816
2817Returns: nothing
2818*/
2819
2820void
4f6ae5c3
JH
2821smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
2822 BOOL check_valid)
4e88a19f
PH
2823{
2824int n;
2825int ovector[3];
2826
4f6ae5c3 2827if (!msg || !*msg) return;
4e88a19f 2828
4f6ae5c3
JH
2829if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
2830 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 2831
4f6ae5c3 2832if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
2833 {
2834 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
2835 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
2836 if (log_msg != NULL && *log_msg == *msg)
2837 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
2838 }
2839else
2840 {
2841 *code = *msg;
2842 *codelen = ovector[1]; /* Includes final space */
2843 }
2844*msg += ovector[1]; /* Chop the code off the message */
2845return;
2846}
2847
2848
2849
2850
2851/*************************************************
059ec3d9
PH
2852* Handle an ACL failure *
2853*************************************************/
2854
2855/* This function is called when acl_check() fails. As well as calls from within
2856this module, it is called from receive.c for an ACL after DATA. It sorts out
2857logging the incident, and sets up the error response. A message containing
2858newlines is turned into a multiline SMTP response, but for logging, only the
2859first line is used.
2860
a5bd321b
PH
2861There's a table of default permanent failure response codes to use in
2862globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
2863defaults disabled in Exim. However, discussion in connection with RFC 821bis
2864(aka RFC 2821) has concluded that the response should be 252 in the disabled
2865state, because there are broken clients that try VRFY before RCPT. A 5xx
2866response should be given only when the address is positively known to be
4f6ae5c3
JH
2867undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
2868no explicit code, but if there is one we let it know best.
2869Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
2870
2871From Exim 4.63, it is possible to override the response code details by
2872providing a suitable response code string at the start of the message provided
2873in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
2874
2875Arguments:
4f6ae5c3
JH
2876 where where the ACL was called from
2877 rc the failure code
2878 user_msg a message that can be included in an SMTP response
2879 log_msg a message for logging
059ec3d9
PH
2880
2881Returns: 0 in most cases
2882 2 if the failure code was FAIL_DROP, in which case the
2883 SMTP connection should be dropped (this value fits with the
2884 "done" variable in smtp_setup_msg() below)
2885*/
2886
2887int
2888smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
2889{
059ec3d9 2890BOOL drop = rc == FAIL_DROP;
a5bd321b 2891int codelen = 3;
a5bd321b 2892uschar *smtp_code;
059ec3d9
PH
2893uschar *lognl;
2894uschar *sender_info = US"";
64ffc24f 2895uschar *what =
8523533c 2896#ifdef WITH_CONTENT_SCAN
3cc3f762 2897 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 2898#endif
3cc3f762
JH
2899 where == ACL_WHERE_PREDATA ? US"DATA" :
2900 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 2901#ifndef DISABLE_PRDR
3cc3f762 2902 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 2903#endif
3cc3f762
JH
2904 smtp_cmd_data ?
2905 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
2906 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
2907
2908if (drop) rc = FAIL;
2909
4e88a19f 2910/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 2911
4f6ae5c3
JH
2912smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
2913smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
2914 where != ACL_WHERE_VRFY);
a5bd321b 2915
059ec3d9
PH
2916/* We used to have sender_address here; however, there was a bug that was not
2917updating sender_address after a rewrite during a verify. When this bug was
2918fixed, sender_address at this point became the rewritten address. I'm not sure
2919this is what should be logged, so I've changed to logging the unrewritten
2920address to retain backward compatibility. */
2921
8523533c 2922#ifndef WITH_CONTENT_SCAN
059ec3d9 2923if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
2924#else
2925if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
2926#endif
059ec3d9 2927 {
b98bb9ac
PP
2928 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
2929 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
2930 sender_host_authenticated ? US" A=" : US"",
2931 sender_host_authenticated ? sender_host_authenticated : US"",
2932 sender_host_authenticated && authenticated_id ? US":" : US"",
2933 sender_host_authenticated && authenticated_id ? authenticated_id : US""
2934 );
059ec3d9
PH
2935 }
2936
2937/* If there's been a sender verification failure with a specific message, and
2938we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
2939failures, but not defers. However, always log it for defer, and log it for fail
2940unless the sender_verify_fail log selector has been turned off. */
059ec3d9 2941
02b41d71 2942if (sender_verified_failed &&
059ec3d9
PH
2943 !testflag(sender_verified_failed, af_sverify_told))
2944 {
2679d413
PH
2945 BOOL save_rcpt_in_progress = rcpt_in_progress;
2946 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
2947
059ec3d9
PH
2948 setflag(sender_verified_failed, af_sverify_told);
2949
6c6d6e48 2950 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
2951 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
2952 host_and_ident(TRUE),
2953 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
2954 sender_verified_failed->address,
2955 (sender_verified_failed->message == NULL)? US"" :
2956 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 2957
02b41d71 2958 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 2959 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
2960 testflag(sender_verified_failed, af_verify_pmfail)?
2961 "Postmaster verification failed while checking <%s>\n%s\n"
2962 "Several RFCs state that you are required to have a postmaster\n"
2963 "mailbox for each mail domain. This host does not accept mail\n"
2964 "from domains whose servers reject the postmaster address."
2965 :
2966 testflag(sender_verified_failed, af_verify_nsfail)?
2967 "Callback setup failed while verifying <%s>\n%s\n"
2968 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
2969 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
2970 "RFC requirements, and stops you from receiving standard bounce\n"
2971 "messages. This host does not accept mail from domains whose servers\n"
2972 "refuse bounces."
2973 :
2974 "Verification failed for <%s>\n%s",
2975 sender_verified_failed->address,
2976 sender_verified_failed->user_message));
2679d413
PH
2977
2978 rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
2979 }
2980
2981/* Sort out text for logging */
2982
3cc3f762
JH
2983log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
2984if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
2985
2986/* Send permanent failure response to the command, but the code used isn't
2987always a 5xx one - see comments at the start of this function. If the original
2988rc was FAIL_DROP we drop the connection and yield 2. */
2989
ff5929e3
JH
2990if (rc == FAIL)
2991 smtp_respond(smtp_code, codelen, TRUE,
2992 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
2993
2994/* Send temporary failure response to the command. Don't give any details,
2995unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
2996verb, and for a header verify when smtp_return_error_details is set.
2997
2998This conditional logic is all somewhat of a mess because of the odd
2999interactions between temp_details and return_error_details. One day it should
3000be re-implemented in a tidier fashion. */
3001
3002else
ff5929e3 3003 if (acl_temp_details && user_msg)
059ec3d9 3004 {
ff5929e3
JH
3005 if ( smtp_return_error_details
3006 && sender_verified_failed
3007 && sender_verified_failed->message
3008 )
a5bd321b 3009 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3010
a5bd321b 3011 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3012 }
3013 else
a5bd321b
PH
3014 smtp_respond(smtp_code, codelen, TRUE,
3015 US"Temporary local problem - please try later");
059ec3d9 3016
6ea85e9a
PH
3017/* Log the incident to the logs that are specified by log_reject_target
3018(default main, reject). This can be empty to suppress logging of rejections. If
3019the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3020is closing if required and return 2. */
059ec3d9 3021
6ea85e9a 3022if (log_reject_target != 0)
887291d2 3023 {
e45a1c37 3024#ifdef SUPPORT_TLS
fc16abb4
JH
3025 uschar * tls = s_tlslog(NULL, NULL, NULL);
3026 if (!tls) tls = US"";
e45a1c37 3027#else
fc16abb4 3028 uschar * tls = US"";
e45a1c37 3029#endif
3cc3f762
JH
3030 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3031 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3032 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3033 host_and_ident(TRUE),
3034 tls,
3035 sender_info,
3036 rc == FAIL ? US"" : US"temporarily ",
3037 what, log_msg);
887291d2 3038 }
059ec3d9
PH
3039
3040if (!drop) return 0;
3041
3042log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3043 smtp_get_connection_info());
8f128379
PH
3044
3045/* Run the not-quit ACL, but without any custom messages. This should not be a
3046problem, because we get here only if some other ACL has issued "drop", and
3047in that case, *its* custom messages will have been used above. */
3048
3049smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3050return 2;
3051}
3052
3053
3054
3055
3056/*************************************************
8f128379
PH
3057* Handle SMTP exit when QUIT is not given *
3058*************************************************/
3059
3060/* This function provides a logging/statistics hook for when an SMTP connection
3061is dropped on the floor or the other end goes away. It's a global function
3062because it's called from receive.c as well as this module. As well as running
3063the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3064response, either with a custom message from the ACL, or using a default. There
3065is one case, however, when no message is output - after "drop". In that case,
3066the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3067passed to this function.
3068
3069In case things go wrong while processing this function, causing an error that
4c04137d 3070may re-enter this function, there is a recursion check.
8f128379
PH
3071
3072Arguments:
3073 reason What $smtp_notquit_reason will be set to in the ACL;
3074 if NULL, the ACL is not run
3075 code The error code to return as part of the response
3076 defaultrespond The default message if there's no user_msg
3077
3078Returns: Nothing
3079*/
3080
3081void
3082smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
3083{
3084int rc;
3085uschar *user_msg = NULL;
3086uschar *log_msg = NULL;
3087
3088/* Check for recursive acll */
3089
3090if (smtp_exit_function_called)
3091 {
3092 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
3093 reason);
3094 return;
3095 }
3096smtp_exit_function_called = TRUE;
3097
3098/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3099
eea0defe 3100if (acl_smtp_notquit && reason)
8f128379
PH
3101 {
3102 smtp_notquit_reason = reason;
eea0defe
JB
3103 if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
3104 &log_msg)) == ERROR)
8f128379
PH
3105 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
3106 log_msg);
3107 }
3108
3109/* Write an SMTP response if we are expected to give one. As the default
3110responses are all internal, they should always fit in the buffer, but code a
3111warning, just in case. Note that string_vformat() still leaves a complete
3112string, even if it is incomplete. */
3113
eea0defe 3114if (code && defaultrespond)
8f128379 3115 {
eea0defe
JB
3116 if (user_msg)
3117 smtp_respond(code, 3, TRUE, user_msg);
3118 else
8f128379
PH
3119 {
3120 uschar buffer[128];
3121 va_list ap;
3122 va_start(ap, defaultrespond);
3123 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
3124 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
3125 smtp_printf("%s %s\r\n", code, buffer);
3126 va_end(ap);
3127 }
8f128379
PH
3128 mac_smtp_fflush();
3129 }
3130}
3131
3132
3133
3134
3135/*************************************************
d7b47fd0
PH
3136* Verify HELO argument *
3137*************************************************/
3138
3139/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3140matched. It is also called from ACL processing if verify = helo is used and
3141verification was not previously tried (i.e. helo_try_verify_hosts was not
3142matched). The result of its processing is to set helo_verified and
3143helo_verify_failed. These variables should both be FALSE for this function to
3144be called.
3145
3146Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3147for IPv6 ::ffff: literals.
3148
3149Argument: none
3150Returns: TRUE if testing was completed;
3151 FALSE on a temporary failure
3152*/
3153
3154BOOL
3155smtp_verify_helo(void)
3156{
3157BOOL yield = TRUE;
3158
3159HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3160 sender_helo_name);
3161
3162if (sender_helo_name == NULL)
3163 {
3164 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
3165 }
3166
d1d5595c
PH
3167/* Deal with the case of -bs without an IP address */
3168
3169else if (sender_host_address == NULL)
3170 {
3171 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
3172 helo_verified = TRUE;
3173 }
3174
3175/* Deal with the more common case when there is a sending IP address */
3176
d7b47fd0
PH
3177else if (sender_helo_name[0] == '[')
3178 {
3179 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
3180 Ustrlen(sender_host_address)) == 0;
3181
3182 #if HAVE_IPV6
3183 if (!helo_verified)
3184 {
3185 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
3186 helo_verified = Ustrncmp(sender_helo_name + 1,
3187 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
3188 }
3189 #endif
3190
3191 HDEBUG(D_receive)
3192 { if (helo_verified) debug_printf("matched host address\n"); }
3193 }
3194
3195/* Do a reverse lookup if one hasn't already given a positive or negative
3196response. If that fails, or the name doesn't match, try checking with a forward
3197lookup. */
3198
3199else
3200 {
3201 if (sender_host_name == NULL && !host_lookup_failed)
3202 yield = host_name_lookup() != DEFER;
3203
3204 /* If a host name is known, check it and all its aliases. */
3205
1705dd20
JH
3206 if (sender_host_name)
3207 if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
d7b47fd0 3208 {
1705dd20 3209 sender_helo_dnssec = sender_host_dnssec;
d7b47fd0
PH
3210 HDEBUG(D_receive) debug_printf("matched host name\n");
3211 }
3212 else
3213 {
3214 uschar **aliases = sender_host_aliases;
1705dd20
JH
3215 while (*aliases)
3216 if ((helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
3217 {
3218 sender_helo_dnssec = sender_host_dnssec;
3219 break;
3220 }
3221
3222 HDEBUG(D_receive) if (helo_verified)
d7b47fd0 3223 debug_printf("matched alias %s\n", *(--aliases));
d7b47fd0 3224 }
d7b47fd0
PH
3225
3226 /* Final attempt: try a forward lookup of the helo name */
3227
3228 if (!helo_verified)
3229 {
3230 int rc;
3231 host_item h;
1705dd20
JH
3232 dnssec_domains d;
3233 host_item *hh;
3234
d7b47fd0
PH
3235 h.name = sender_helo_name;
3236 h.address = NULL;
3237 h.mx = MX_NONE;
3238 h.next = NULL;
1705dd20
JH
3239 d.request = US"*";
3240 d.require = US"";
3241
d7b47fd0
PH
3242 HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
3243 sender_helo_name);
1705dd20
JH
3244 rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A,
3245 NULL, NULL, NULL, &d, NULL, NULL);
d7b47fd0 3246 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1705dd20 3247 for (hh = &h; hh; hh = hh->next)
d7b47fd0
PH
3248 if (Ustrcmp(hh->address, sender_host_address) == 0)
3249 {
3250 helo_verified = TRUE;
1705dd20 3251 if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
d7b47fd0 3252 HDEBUG(D_receive)
1705dd20
JH
3253 {
3254 debug_printf("IP address for %s matches calling address\n"
3255 "Forward DNS security status: %sverified\n",
3256 sender_helo_name, sender_helo_dnssec ? "" : "un");
3257 }
d7b47fd0
PH
3258 break;
3259 }
d7b47fd0
PH
3260 }
3261 }
3262
d1d5595c 3263if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
d7b47fd0
PH
3264return yield;
3265}
3266
3267
3268
3269
3270/*************************************************
4e88a19f
PH
3271* Send user response message *
3272*************************************************/
3273
3274/* This function is passed a default response code and a user message. It calls
3275smtp_message_code() to check and possibly modify the response code, and then
3276calls smtp_respond() to transmit the response. I put this into a function
3277just to avoid a lot of repetition.
3278
3279Arguments:
3280 code the response code
3281 user_msg the user message
3282
3283Returns: nothing
3284*/
3285
3286static void
3287smtp_user_msg(uschar *code, uschar *user_msg)
3288{
3289int len = 3;
4f6ae5c3 3290smtp_message_code(&code, &len, &user_msg, NULL, TRUE);
4e88a19f
PH
3291smtp_respond(code, len, TRUE, user_msg);
3292}
3293
3294
3295
b3ef41c9
JH
3296static int
3297smtp_in_auth(auth_instance *au, uschar ** s, uschar ** ss)
3298{
3299const uschar *set_id = NULL;
3300int rc, i;
3301
3302/* Run the checking code, passing the remainder of the command line as
3303data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
3304it as the only set numerical variable. The authenticator may set $auth<n>
3305and also set other numeric variables. The $auth<n> variables are preferred
3306nowadays; the numerical variables remain for backwards compatibility.
3307
3308Afterwards, have a go at expanding the set_id string, even if
3309authentication failed - for bad passwords it can be useful to log the
3310userid. On success, require set_id to expand and exist, and put it in
3311authenticated_id. Save this in permanent store, as the working store gets
3312reset at HELO, RSET, etc. */
3313
3314for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
3315expand_nmax = 0;
3316expand_nlength[0] = 0; /* $0 contains nothing */
3317
3318rc = (au->info->servercode)(au, smtp_cmd_data);
3319if (au->set_id) set_id = expand_string(au->set_id);
3320expand_nmax = -1; /* Reset numeric variables */
3321for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
3322
3323/* The value of authenticated_id is stored in the spool file and printed in
3324log lines. It must not contain binary zeros or newline characters. In
3325normal use, it never will, but when playing around or testing, this error
3326can (did) happen. To guard against this, ensure that the id contains only
3327printing characters. */
3328
3329if (set_id) set_id = string_printing(set_id);
3330
3331/* For the non-OK cases, set up additional logging data if set_id
3332is not empty. */
3333
3334if (rc != OK)
3335 set_id = set_id && *set_id
3336 ? string_sprintf(" (set_id=%s)", set_id) : US"";
3337
3338/* Switch on the result */
3339
3340switch(rc)
3341 {
3342 case OK:
3343 if (!au->set_id || set_id) /* Complete success */
3344 {
3345 if (set_id) authenticated_id = string_copy_malloc(set_id);
3346 sender_host_authenticated = au->name;
3347 authentication_failed = FALSE;
3348 authenticated_fail_id = NULL; /* Impossible to already be set? */
3349
3350 received_protocol =
3351 (sender_host_address ? protocols : protocols_local)
3352 [pextend + pauthed + (tls_in.active >= 0 ? pcrpted:0)];
3353 *s = *ss = US"235 Authentication succeeded";
3354 authenticated_by = au;
3355 break;
3356 }
3357
3358 /* Authentication succeeded, but we failed to expand the set_id string.
3359 Treat this as a temporary error. */
3360
3361 auth_defer_msg = expand_string_message;
3362 /* Fall through */
3363
3364 case DEFER:
3365 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3366 *s = string_sprintf("435 Unable to authenticate at present%s",
3367 auth_defer_user_msg);
3368 *ss = string_sprintf("435 Unable to authenticate at present%s: %s",
3369 set_id, auth_defer_msg);
3370 break;
3371
3372 case BAD64:
3373 *s = *ss = US"501 Invalid base64 data";
3374 break;
3375
3376 case CANCELLED:
3377 *s = *ss = US"501 Authentication cancelled";
3378 break;
3379
3380 case UNEXPECTED:
3381 *s = *ss = US"553 Initial data not expected";
3382 break;
3383
3384 case FAIL:
3385 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3386 *s = US"535 Incorrect authentication data";
3387 *ss = string_sprintf("535 Incorrect authentication data%s", set_id);
3388 break;
3389
3390 default:
3391 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3392 *s = US"435 Internal error";
3393 *ss = string_sprintf("435 Internal error%s: return %d from authentication "
3394 "check", set_id, rc);
3395 break;
3396 }
3397
3398return rc;
3399}
3400
3401
3402
2685d6e0
JH
3403
3404
3405static int
3406qualify_recipient(uschar ** recipient, uschar * smtp_cmd_data, uschar * tag)
3407{
3408int rd;
3409if (allow_unqualified_recipient || strcmpic(*recipient, US"postmaster") == 0)
3410 {
3411 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
3412 *recipient);
3413 rd = Ustrlen(recipient) + 1;
3414 *recipient = rewrite_address_qualify(*recipient, TRUE);
3415 return rd;
3416 }
3417smtp_printf("501 %s: recipient address must contain a domain\r\n",
3418 smtp_cmd_data);
3419log_write(L_smtp_syntax_error,
3420 LOG_MAIN|LOG_REJECT, "unqualified %s rejected: <%s> %s%s",
3421 tag, *recipient, host_and_ident(TRUE), host_lookup_msg);
3422return 0;
3423}
3424
3425
3426
3427
7e3ce68e
JH
3428static void
3429smtp_quit_handler(uschar ** user_msgp, uschar ** log_msgp)
3430{
3431HAD(SCH_QUIT);
3432incomplete_transaction_log(US"QUIT");
60d10ce7 3433if (acl_smtp_quit)
7e3ce68e
JH
3434 {
3435 int rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, user_msgp, log_msgp);
3436 if (rc == ERROR)
3437 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
3438 *log_msgp);
3439 }
3440if (*user_msgp)
3441 smtp_respond(US"221", 3, TRUE, *user_msgp);
3442else
3443 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
3444
3445#ifdef SUPPORT_TLS
3446tls_close(TRUE, TRUE);
3447#endif
3448
3449log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
3450 smtp_get_connection_info());
3451}
3452
3453
3454static void
3455smtp_rset_handler(void)
3456{
3457HAD(SCH_RSET);
3458incomplete_transaction_log(US"RSET");
3459smtp_printf("250 Reset OK\r\n");
3460cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
3461}
3462
3463
3464
4e88a19f 3465/*************************************************
059ec3d9
PH
3466* Initialize for SMTP incoming message *
3467*************************************************/
3468
3469/* This function conducts the initial dialogue at the start of an incoming SMTP
3470message, and builds a list of recipients. However, if the incoming message
3471is part of a batch (-bS option) a separate function is called since it would
3472be messy having tests splattered about all over this function. This function
3473therefore handles the case where interaction is occurring. The input and output
3474files are set up in smtp_in and smtp_out.
3475
3476The global recipients_list is set to point to a vector of recipient_item
3477blocks, whose number is given by recipients_count. This is extended by the
3478receive_add_recipient() function. The global variable sender_address is set to
3479the sender's address. The yield is +1 if a message has been successfully
3480started, 0 if a QUIT command was encountered or the connection was refused from
3481the particular host, or -1 if the connection was lost.
3482
3483Argument: none
3484
3485Returns: > 0 message successfully started (reached DATA)
3486 = 0 QUIT read or end of file reached or call refused
3487 < 0 lost connection
3488*/
3489
3490int
3491smtp_setup_msg(void)
3492{
3493int done = 0;
3494BOOL toomany = FALSE;
3495BOOL discarded = FALSE;
3496BOOL last_was_rej_mail = FALSE;
3497BOOL last_was_rcpt = FALSE;
3498void *reset_point = store_get(0);
3499
3500DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n");
3501
3502/* Reset for start of new message. We allow one RSET not to be counted as a
3503nonmail command, for those MTAs that insist on sending it between every
3504message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
3505TLS between messages (an Exim client may do this if it has messages queued up
3506for the host). Note: we do NOT reset AUTH at this point. */
3507
3508smtp_reset(reset_point);
3509message_ended = END_NOTSTARTED;
3510
7e3ce68e
JH
3511chunking_state = chunking_offered ? CHUNKING_OFFERED : CHUNKING_NOT_OFFERED;
3512
059ec3d9
PH
3513cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
3514cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
3515cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
3516#ifdef SUPPORT_TLS
3517cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
b3ef41c9 3518cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
059ec3d9
PH
3519#endif
3520
3521/* Set the local signal handler for SIGTERM - it tries to end off tidily */
3522
3523os_non_restarting_signal(SIGTERM, command_sigterm_handler);
3524
3525/* Batched SMTP is handled in a different function. */
3526
3527if (smtp_batched_input) return smtp_setup_batch_msg();
3528
3529/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
3530value. The values are 2 larger than the required yield of the function. */
3531
3532while (done <= 0)
3533 {
55414b25 3534 const uschar **argv;
059ec3d9
PH
3535 uschar *etrn_command;
3536 uschar *etrn_serialize_key;
3537 uschar *errmess;
4e88a19f
PH
3538 uschar *log_msg, *smtp_code;
3539 uschar *user_msg = NULL;
059ec3d9
PH
3540 uschar *recipient = NULL;
3541 uschar *hello = NULL;
059ec3d9
PH
3542 uschar *s, *ss;
3543 BOOL was_rej_mail = FALSE;
3544 BOOL was_rcpt = FALSE;
3545 void (*oldsignal)(int);
3546 pid_t pid;
3547 int start, end, sender_domain, recipient_domain;
3548 int ptr, size, rc;
aa7751be 3549 int c;
059ec3d9 3550 auth_instance *au;
6c1c3d1d
WB
3551 uschar *orcpt = NULL;
3552 int flags;
059ec3d9 3553
16be7f11 3554#ifdef AUTH_TLS
b3ef41c9
JH
3555 /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
3556 if ( tls_in.active >= 0
3557 && tls_in.peercert
3558 && tls_in.certificate_verified
3559 && cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd
3560 )
3561 {
3562 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = FALSE;
4f6ae5c3
JH
3563 if ( acl_smtp_auth
3564 && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth,
3565 &user_msg, &log_msg)) != OK
3566 )
b3ef41c9 3567 {
4f6ae5c3
JH
3568 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3569 continue;
b3ef41c9
JH
3570 }
3571
3572 for (au = auths; au; au = au->next)
3573 if (strcmpic(US"tls", au->driver_name) == 0)
3574 {
3575 smtp_cmd_data = NULL;
3576
805bb5c3 3577 if (smtp_in_auth(au, &s, &ss) == OK)
cb570b5e 3578 { DEBUG(D_auth) debug_printf("tls auth succeeded\n"); }
805bb5c3 3579 else
cb570b5e 3580 { DEBUG(D_auth) debug_printf("tls auth not succeeded\n"); }
b3ef41c9
JH
3581 break;
3582 }
3583 }
3584#endif
3585
8d330698
JH
3586#ifdef TCP_QUICKACK
3587 if (smtp_in) /* Avoid pure-ACKs while in cmd pingpong phase */
3588 (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK,
3589 US &off, sizeof(off));
3590#endif
3591
bd8fbe36 3592 switch(smtp_read_command(TRUE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
3593 {
3594 /* The AUTH command is not permitted to occur inside a transaction, and may
c46782ef
PH
3595 occur successfully only once per connection. Actually, that isn't quite
3596 true. When TLS is started, all previous information about a connection must
3597 be discarded, so a new AUTH is permitted at that time.
3598
3599 AUTH may only be used when it has been advertised. However, it seems that
3600 there are clients that send AUTH when it hasn't been advertised, some of
3601 them even doing this after HELO. And there are MTAs that accept this. Sigh.
3602 So there's a get-out that allows this to happen.
059ec3d9
PH
3603
3604 AUTH is initially labelled as a "nonmail command" so that one occurrence
3605 doesn't get counted. We change the label here so that multiple failing
3606 AUTHS will eventually hit the nonmail threshold. */
3607
3608 case AUTH_CMD:
b4ed4da0 3609 HAD(SCH_AUTH);
059ec3d9
PH
3610 authentication_failed = TRUE;
3611 cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
3612
c46782ef 3613 if (!auth_advertised && !allow_auth_unadvertised)
059ec3d9
PH
3614 {
3615 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3616 US"AUTH command used when not advertised");
3617 break;
3618 }
b3ef41c9 3619 if (sender_host_authenticated)
059ec3d9
PH
3620 {
3621 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3622 US"already authenticated");
3623 break;
3624 }
b3ef41c9 3625 if (sender_address)
059ec3d9
PH
3626 {
3627 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3628 US"not permitted in mail transaction");
3629 break;
3630 }
3631
3632 /* Check the ACL */
3633
4f6ae5c3
JH
3634 if ( acl_smtp_auth
3635 && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth,
3636 &user_msg, &log_msg)) != OK
3637 )
059ec3d9 3638 {
4f6ae5c3
JH
3639 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3640 break;
059ec3d9
PH
3641 }
3642
3643 /* Find the name of the requested authentication mechanism. */
3644
ca86f471
PH
3645 s = smtp_cmd_data;
3646 while ((c = *smtp_cmd_data) != 0 && !isspace(c))
059ec3d9
PH
3647 {
3648 if (!isalnum(c) && c != '-' && c != '_')
3649 {
3650 done = synprot_error(L_smtp_syntax_error, 501, NULL,
3651 US"invalid character in authentication mechanism name");
3652 goto COMMAND_LOOP;
3653 }
ca86f471 3654 smtp_cmd_data++;
059ec3d9
PH
3655 }
3656
3657 /* If not at the end of the line, we must be at white space. Terminate the
3658 name and move the pointer on to any data that may be present. */
3659
ca86f471 3660 if (*smtp_cmd_data != 0)
059ec3d9 3661 {
ca86f471
PH
3662 *smtp_cmd_data++ = 0;
3663 while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
059ec3d9
PH
3664 }
3665
3666 /* Search for an authentication mechanism which is configured for use
c46782ef
PH
3667 as a server and which has been advertised (unless, sigh, allow_auth_
3668 unadvertised is set). */
059ec3d9 3669
b3ef41c9 3670 for (au = auths; au; au = au->next)
059ec3d9 3671 if (strcmpic(s, au->public_name) == 0 && au->server &&
b3ef41c9
JH
3672 (au->advertised || allow_auth_unadvertised))
3673 break;
059ec3d9 3674
b3ef41c9 3675 if (au)
059ec3d9 3676 {
b3ef41c9 3677 c = smtp_in_auth(au, &s, &ss);
059ec3d9 3678
b3ef41c9
JH
3679 smtp_printf("%s\r\n", s);
3680 if (c != OK)
3681 log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
3682 au->name, host_and_ident(FALSE), ss);
059ec3d9 3683 }
b3ef41c9
JH
3684 else
3685 done = synprot_error(L_smtp_protocol_error, 504, NULL,
3686 string_sprintf("%s authentication mechanism not supported", s));
059ec3d9
PH
3687
3688 break; /* AUTH_CMD */
3689
3690 /* The HELO/EHLO commands are permitted to appear in the middle of a
3691 session as well as at the beginning. They have the effect of a reset in</