Tidying: indentation
[exim.git] / src / src / smtp_in.c
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
f9ba5e22 5/* Copyright (c) University of Cambridge 1995 - 2018 */
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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>
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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;
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34#endif
35
36
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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
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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
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44we need room to handle large base64-encoded AUTHs for GSSAPI.
45*/
46
bd8fbe36 47#define SMTP_CMD_BUFFER_SIZE 16384
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48
49/* Size of buffer for reading SMTP incoming packets */
50
bd8fbe36 51#define IN_BUFFER_SIZE 8192
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52
53/* Structure for SMTP command list */
54
55typedef struct {
1ba28e2b 56 const char *name;
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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 */
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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
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85 /* This is a dummy to identify the non-sync commands when not pipelining */
86
87 NON_SYNC_CMD_NON_PIPELINING,
88
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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
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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. */
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99
100 BDAT_CMD,
101
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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
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113 PROXY_FAIL_IGNORE_CMD,
114#endif
115
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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
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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
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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;
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138# ifdef EXPERIMENTAL_REQUIRETLS
139static BOOL requiretls_advertised;
140# endif
059ec3d9 141#endif
6c1c3d1d 142static BOOL dsn_advertised;
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143static BOOL esmtp;
144static BOOL helo_required = FALSE;
145static BOOL helo_verify = FALSE;
146static BOOL helo_seen;
147static BOOL helo_accept_junk;
148static BOOL count_nonmail;
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149static BOOL rcpt_smtp_response_same;
150static BOOL rcpt_in_progress;
059ec3d9 151static int nonmail_command_count;
8f128379 152static BOOL smtp_exit_function_called = 0;
8c5d388a 153#ifdef SUPPORT_I18N
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154static BOOL smtputf8_advertised;
155#endif
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156static int synprot_error_count;
157static int unknown_command_count;
158static int sync_cmd_limit;
159static int smtp_write_error = 0;
160
2679d413 161static uschar *rcpt_smtp_response;
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162static uschar *smtp_data_buffer;
163static uschar *smtp_cmd_data;
164
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165/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
166final fields of all except AUTH are forced TRUE at the start of a new message
167setup, to allow one of each between messages that is not counted as a nonmail
168command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
169allow a new EHLO after starting up TLS.
170
171AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
172counted. However, the flag is changed when AUTH is received, so that multiple
173failing AUTHs will eventually hit the limit. After a successful AUTH, another
174AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
175forced TRUE, to allow for the re-authentication that can happen at that point.
176
177QUIT is also "falsely" labelled as a mail command so that it doesn't up the
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178count of non-mail commands and possibly provoke an error.
179
180tls_auth is a pseudo-command, never expected in input. It is activated
181on TLS startup and looks for a tls authenticator. */
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182
183static smtp_cmd_list cmd_list[] = {
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184 /* name len cmd has_arg is_mail_cmd */
185
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186 { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
187 { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
188 { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
189 { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
e0574cb5 190#ifdef SUPPORT_TLS
059ec3d9 191 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
69d8eed7 192 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, FALSE },
e0574cb5 193#endif
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194
195/* If you change anything above here, also fix the definitions below. */
196
197 { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
198 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
199 { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
18481de3 200 { "bdat", sizeof("bdat")-1, BDAT_CMD, TRUE, TRUE },
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201 { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
202 { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
203 { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
204 { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE },
205 { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE },
206 { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE }
207};
208
209static smtp_cmd_list *cmd_list_end =
210 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
211
212#define CMD_LIST_RSET 0
213#define CMD_LIST_HELO 1
214#define CMD_LIST_EHLO 2
215#define CMD_LIST_AUTH 3
216#define CMD_LIST_STARTTLS 4
b3ef41c9 217#define CMD_LIST_TLS_AUTH 5
059ec3d9 218
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219/* This list of names is used for performing the smtp_no_mail logging action.
220It must be kept in step with the SCH_xxx enumerations. */
221
222static uschar *smtp_names[] =
223 {
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224 US"NONE", US"AUTH", US"DATA", US"BDAT", US"EHLO", US"ETRN", US"EXPN",
225 US"HELO", US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET",
226 US"STARTTLS", US"VRFY" };
b4ed4da0 227
e524074d 228static uschar *protocols_local[] = {
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229 US"local-smtp", /* HELO */
230 US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
231 US"local-esmtp", /* EHLO */
232 US"local-esmtps", /* EHLO->STARTTLS->EHLO */
233 US"local-esmtpa", /* EHLO->AUTH */
234 US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
059ec3d9 235 };
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236static uschar *protocols[] = {
237 US"smtp", /* HELO */
238 US"smtps", /* The rare case EHLO->STARTTLS->HELO */
239 US"esmtp", /* EHLO */
240 US"esmtps", /* EHLO->STARTTLS->EHLO */
241 US"esmtpa", /* EHLO->AUTH */
242 US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
243 };
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244
245#define pnormal 0
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246#define pextend 2
247#define pcrpted 1 /* added to pextend or pnormal */
248#define pauthed 2 /* added to pextend */
059ec3d9 249
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250/* Sanity check and validate optional args to MAIL FROM: envelope */
251enum {
2ef7ed08 252 ENV_MAIL_OPT_NULL,
d27f98fe 253 ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
8ccd00b1 254#ifndef DISABLE_PRDR
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255 ENV_MAIL_OPT_PRDR,
256#endif
6c1c3d1d 257 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
8c5d388a 258#ifdef SUPPORT_I18N
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259 ENV_MAIL_OPT_UTF8,
260#endif
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261#ifdef EXPERIMENTAL_REQUIRETLS
262 ENV_MAIL_OPT_REQTLS,
263#endif
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264 };
265typedef struct {
266 uschar * name; /* option requested during MAIL cmd */
267 int value; /* enum type */
268 BOOL need_value; /* TRUE requires value (name=value pair format)
269 FALSE is a singleton */
270 } env_mail_type_t;
271static env_mail_type_t env_mail_type_list[] = {
272 { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
273 { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
274 { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
8ccd00b1 275#ifndef DISABLE_PRDR
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276 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
277#endif
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278 { US"RET", ENV_MAIL_OPT_RET, TRUE },
279 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
8c5d388a 280#ifdef SUPPORT_I18N
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281 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
282#endif
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283#ifdef EXPERIMENTAL_REQUIRETLS
284 /* https://tools.ietf.org/html/draft-ietf-uta-smtp-require-tls-03 */
285 { US"REQUIRETLS",ENV_MAIL_OPT_REQTLS, FALSE },
286#endif
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287 /* keep this the last entry */
288 { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
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289 };
290
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291/* When reading SMTP from a remote host, we have to use our own versions of the
292C input-reading functions, in order to be able to flush the SMTP output only
293when about to read more data from the socket. This is the only way to get
294optimal performance when the client is using pipelining. Flushing for every
295command causes a separate packet and reply packet each time; saving all the
296responses up (when pipelining) combines them into one packet and one response.
297
298For simplicity, these functions are used for *all* SMTP input, not only when
299receiving over a socket. However, after setting up a secure socket (SSL), input
300is read via the OpenSSL library, and another set of functions is used instead
301(see tls.c).
302
303These functions are set in the receive_getc etc. variables and called with the
304same interface as the C functions. However, since there can only ever be
305one incoming SMTP call, we just use a single buffer and flags. There is no need
306to implement a complicated private FILE-like structure.*/
307
308static uschar *smtp_inbuffer;
309static uschar *smtp_inptr;
310static uschar *smtp_inend;
311static int smtp_had_eof;
312static int smtp_had_error;
313
314
7e3ce68e 315/* forward declarations */
bd8fbe36 316static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
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317static int synprot_error(int type, int code, uschar *data, uschar *errmess);
318static void smtp_quit_handler(uschar **, uschar **);
319static void smtp_rset_handler(void);
320
059ec3d9 321/*************************************************
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322* Recheck synchronization *
323*************************************************/
324
325/* Synchronization checks can never be perfect because a packet may be on its
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326way but not arrived when the check is done. Normally, the checks happen when
327commands are read: Exim ensures that there is no more input in the input buffer.
328In normal cases, the response to the command will be fast, and there is no
329further check.
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330
331However, for some commands an ACL is run, and that can include delays. In those
332cases, it is useful to do another check on the input just before sending the
333response. This also applies at the start of a connection. This function does
334that check by means of the select() function, as long as the facility is not
335disabled or inappropriate. A failure of select() is ignored.
336
337When there is unwanted input, we read it so that it appears in the log of the
338error.
339
340Arguments: none
341Returns: TRUE if all is well; FALSE if there is input pending
342*/
343
344static BOOL
925ac8e4 345wouldblock_reading(void)
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346{
347int fd, rc;
348fd_set fds;
349struct timeval tzero;
350
9067f574 351#ifdef SUPPORT_TLS
74f1a423 352if (tls_in.active.sock >= 0)
e5de01f0 353 return !tls_could_read();
9067f574 354#endif
f4630439 355
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356if (smtp_inptr < smtp_inend)
357 return FALSE;
358
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359fd = fileno(smtp_in);
360FD_ZERO(&fds);
361FD_SET(fd, &fds);
362tzero.tv_sec = 0;
363tzero.tv_usec = 0;
364rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
365
366if (rc <= 0) return TRUE; /* Not ready to read */
bd8fbe36 367rc = smtp_getc(GETC_BUFFER_UNLIMITED);
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368if (rc < 0) return TRUE; /* End of file or error */
369
370smtp_ungetc(rc);
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371return FALSE;
372}
373
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374static BOOL
375check_sync(void)
376{
ecce6d9a 377if (!smtp_enforce_sync || !sender_host_address || sender_host_notsocket)
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378 return TRUE;
379
380return wouldblock_reading();
381}
382
383
384/* If there's input waiting (and we're doing pipelineing) then we can pipeline
385a reponse with the one following. */
386
387static BOOL
388pipeline_response(void)
389{
390if ( !smtp_enforce_sync || !sender_host_address
7c576fca 391 || sender_host_notsocket || !smtp_in_pipelining_advertised)
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392 return FALSE;
393
394return !wouldblock_reading();
395}
396
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397
398
399/*************************************************
400* Log incomplete transactions *
401*************************************************/
402
403/* This function is called after a transaction has been aborted by RSET, QUIT,
404connection drops or other errors. It logs the envelope information received
405so far in order to preserve address verification attempts.
406
407Argument: string to indicate what aborted the transaction
408Returns: nothing
409*/
410
411static void
412incomplete_transaction_log(uschar *what)
413{
414if (sender_address == NULL || /* No transaction in progress */
415 !LOGGING(smtp_incomplete_transaction))
416 return;
417
418/* Build list of recipients for logging */
419
420if (recipients_count > 0)
421 {
422 int i;
423 raw_recipients = store_get(recipients_count * sizeof(uschar *));
424 for (i = 0; i < recipients_count; i++)
425 raw_recipients[i] = recipients_list[i].address;
426 raw_recipients_count = recipients_count;
427 }
428
429log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
430 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
431}
432
433
434
435
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436void
437smtp_command_timeout_exit(void)
438{
439log_write(L_lost_incoming_connection,
440 LOG_MAIN, "SMTP command timeout on%s connection from %s",
74f1a423 441 tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE));
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442if (smtp_batched_input)
443 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
444smtp_notquit_exit(US"command-timeout", US"421",
445 US"%s: SMTP command timeout - closing connection",
446 smtp_active_hostname);
447exim_exit(EXIT_FAILURE, US"receiving");
448}
449
450void
451smtp_command_sigterm_exit(void)
452{
453log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
454if (smtp_batched_input)
455 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
456smtp_notquit_exit(US"signal-exit", US"421",
457 US"%s: Service not available - closing connection", smtp_active_hostname);
458exim_exit(EXIT_FAILURE, US"receiving");
459}
460
461void
462smtp_data_timeout_exit(void)
463{
464log_write(L_lost_incoming_connection,
465 LOG_MAIN, "SMTP data timeout (message abandoned) on connection from %s F=<%s>",
466 sender_fullhost ? sender_fullhost : US"local process", sender_address);
467receive_bomb_out(US"data-timeout", US"SMTP incoming data timeout");
468/* Does not return */
469}
470
471void
472smtp_data_sigint_exit(void)
473{
474log_write(0, LOG_MAIN, "%s closed after %s",
475 smtp_get_connection_info(), had_data_sigint == SIGTERM ? "SIGTERM":"SIGINT");
476receive_bomb_out(US"signal-exit",
477 US"Service not available - SIGTERM or SIGINT received");
478/* Does not return */
479}
480
481
482
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483/* Refill the buffer, and notify DKIM verification code.
484Return false for error or EOF.
485*/
486
487static BOOL
488smtp_refill(unsigned lim)
489{
490int rc, save_errno;
491if (!smtp_out) return FALSE;
492fflush(smtp_out);
493if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
494
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495/* Limit amount read, so non-message data is not fed to DKIM.
496Take care to not touch the safety NUL at the end of the buffer. */
0d81dabc 497
ecce6d9a 498rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE-1, lim));
0d81dabc 499save_errno = errno;
9723f966 500if (smtp_receive_timeout > 0) alarm(0);
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501if (rc <= 0)
502 {
503 /* Must put the error text in fixed store, because this might be during
504 header reading, where it releases unused store above the header. */
505 if (rc < 0)
506 {
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507 if (had_command_timeout) /* set by signal handler */
508 smtp_command_timeout_exit(); /* does not return */
509 if (had_command_sigterm)
510 smtp_command_sigterm_exit();
511 if (had_data_timeout)
512 smtp_data_timeout_exit();
513 if (had_data_sigint)
514 smtp_data_sigint_exit();
515
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516 smtp_had_error = save_errno;
517 smtp_read_error = string_copy_malloc(
518 string_sprintf(" (error: %s)", strerror(save_errno)));
519 }
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520 else
521 smtp_had_eof = 1;
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522 return FALSE;
523 }
524#ifndef DISABLE_DKIM
525dkim_exim_verify_feed(smtp_inbuffer, rc);
526#endif
527smtp_inend = smtp_inbuffer + rc;
528smtp_inptr = smtp_inbuffer;
529return TRUE;
530}
531
f4630439 532/*************************************************
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533* SMTP version of getc() *
534*************************************************/
535
536/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
537it flushes the output, and refills the buffer, with a timeout. The signal
538handler is set appropriately by the calling function. This function is not used
4c04137d 539after a connection has negotiated itself into an TLS/SSL state.
059ec3d9 540
bd8fbe36 541Arguments: lim Maximum amount to read/buffer
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542Returns: the next character or EOF
543*/
544
545int
bd8fbe36 546smtp_getc(unsigned lim)
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547{
548if (smtp_inptr >= smtp_inend)
0d81dabc 549 if (!smtp_refill(lim))
059ec3d9 550 return EOF;
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551return *smtp_inptr++;
552}
553
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554uschar *
555smtp_getbuf(unsigned * len)
556{
557unsigned size;
558uschar * buf;
559
560if (smtp_inptr >= smtp_inend)
561 if (!smtp_refill(*len))
562 { *len = 0; return NULL; }
563
564if ((size = smtp_inend - smtp_inptr) > *len) size = *len;
565buf = smtp_inptr;
566smtp_inptr += size;
567*len = size;
568return buf;
569}
570
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571void
572smtp_get_cache(void)
573{
9960d1e5 574#ifndef DISABLE_DKIM
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575int n = smtp_inend - smtp_inptr;
576if (n > 0)
577 dkim_exim_verify_feed(smtp_inptr, n);
584e96c6 578#endif
9960d1e5 579}
059ec3d9
PH
580
581
7e3ce68e
JH
582/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
583previous BDAT chunk and getting new ones when we run out. Uses the
584underlying smtp_getc or tls_getc both for that and for getting the
585(buffered) data byte. EOD signals (an expected) no further data.
586ERR signals a protocol error, and EOF a closed input stream.
587
588Called from read_bdat_smtp() in receive.c for the message body, but also
589by the headers read loop in receive_msg(); manipulates chunking_state
590to handle the BDAT command/response.
591Placed here due to the correlation with the above smtp_getc(), which it wraps,
592and also by the need to do smtp command/response handling.
593
bd8fbe36 594Arguments: lim (ignored)
7e3ce68e
JH
595Returns: the next character or ERR, EOD or EOF
596*/
597
598int
bd8fbe36 599bdat_getc(unsigned lim)
7e3ce68e
JH
600{
601uschar * user_msg = NULL;
602uschar * log_msg;
603
604for(;;)
605 {
79de4f37 606#ifndef DISABLE_DKIM
64b67b65 607 unsigned dkim_save;
79de4f37
JH
608#endif
609
bd8fbe36
JH
610 if (chunking_data_left > 0)
611 return lwr_receive_getc(chunking_data_left--);
7e3ce68e
JH
612
613 receive_getc = lwr_receive_getc;
0d81dabc 614 receive_getbuf = lwr_receive_getbuf;
7e3ce68e 615 receive_ungetc = lwr_receive_ungetc;
bd8fbe36 616#ifndef DISABLE_DKIM
79de4f37 617 dkim_save = dkim_collect_input;
64b67b65 618 dkim_collect_input = 0;
bd8fbe36 619#endif
7e3ce68e 620
f4630439
JH
621 /* Unless PIPELINING was offered, there should be no next command
622 until after we ack that chunk */
623
7c576fca 624 if (!smtp_in_pipelining_advertised && !check_sync())
f4630439 625 {
40525d07
JH
626 unsigned n = smtp_inend - smtp_inptr;
627 if (n > 32) n = 32;
628
f4630439
JH
629 incomplete_transaction_log(US"sync failure");
630 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
631 "(next input sent too soon: pipelining was not advertised): "
9e0ed81f 632 "rejected \"%s\" %s next input=\"%s\"%s",
f4630439 633 smtp_cmd_buffer, host_and_ident(TRUE),
9e0ed81f
JH
634 string_printing(string_copyn(smtp_inptr, n)),
635 smtp_inend - smtp_inptr > n ? "..." : "");
636 (void) synprot_error(L_smtp_protocol_error, 554, NULL,
637 US"SMTP synchronization error");
f4630439
JH
638 goto repeat_until_rset;
639 }
640
7e3ce68e
JH
641 /* If not the last, ack the received chunk. The last response is delayed
642 until after the data ACL decides on it */
7e3ce68e
JH
643
644 if (chunking_state == CHUNKING_LAST)
584e96c6
JH
645 {
646#ifndef DISABLE_DKIM
e983e85a 647 dkim_exim_verify_feed(NULL, 0); /* notify EOD */
584e96c6 648#endif
7e3ce68e 649 return EOD;
584e96c6 650 }
7e3ce68e 651
925ac8e4 652 smtp_printf("250 %u byte chunk received\r\n", FALSE, chunking_datasize);
bd8fbe36
JH
653 chunking_state = CHUNKING_OFFERED;
654 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
7e3ce68e
JH
655
656 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
657 QUIT, RSET or NOOP but handling them seems obvious */
658
659next_cmd:
bd8fbe36 660 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
661 {
662 default:
663 (void) synprot_error(L_smtp_protocol_error, 503, NULL,
664 US"only BDAT permissible after non-LAST BDAT");
665
666 repeat_until_rset:
bd8fbe36 667 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
668 {
669 case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
670 case EOF_CMD: return EOF;
671 case RSET_CMD: smtp_rset_handler(); return ERR;
672 default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
673 US"only RSET accepted now") > 0)
674 return EOF;
675 goto repeat_until_rset;
676 }
677
678 case QUIT_CMD:
679 smtp_quit_handler(&user_msg, &log_msg);
680 /*FALLTHROUGH*/
681 case EOF_CMD:
682 return EOF;
683
684 case RSET_CMD:
685 smtp_rset_handler();
686 return ERR;
687
688 case NOOP_CMD:
689 HAD(SCH_NOOP);
925ac8e4 690 smtp_printf("250 OK\r\n", FALSE);
7e3ce68e
JH
691 goto next_cmd;
692
693 case BDAT_CMD:
694 {
695 int n;
696
697 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
698 {
699 (void) synprot_error(L_smtp_protocol_error, 501, NULL,
700 US"missing size for BDAT command");
701 return ERR;
702 }
703 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
704 ? CHUNKING_LAST : CHUNKING_ACTIVE;
705 chunking_data_left = chunking_datasize;
bd8fbe36
JH
706 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
707 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
708
709 if (chunking_datasize == 0)
710 if (chunking_state == CHUNKING_LAST)
711 return EOD;
712 else
713 {
714 (void) synprot_error(L_smtp_protocol_error, 504, NULL,
715 US"zero size for BDAT command");
716 goto repeat_until_rset;
717 }
718
719 receive_getc = bdat_getc;
8b77d27a 720 receive_getbuf = bdat_getbuf; /* r~getbuf is never actually used */
7e3ce68e 721 receive_ungetc = bdat_ungetc;
bd8fbe36 722#ifndef DISABLE_DKIM
79de4f37 723 dkim_collect_input = dkim_save;
bd8fbe36 724#endif
7e3ce68e
JH
725 break; /* to top of main loop */
726 }
727 }
728 }
729}
730
0d81dabc
JH
731uschar *
732bdat_getbuf(unsigned * len)
733{
734uschar * buf;
735
736if (chunking_data_left <= 0)
737 { *len = 0; return NULL; }
738
739if (*len > chunking_data_left) *len = chunking_data_left;
740buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */
741chunking_data_left -= *len;
742return buf;
743}
744
1ebe15c3 745void
45bd315d
JH
746bdat_flush_data(void)
747{
e99a3a6c 748while (chunking_data_left)
db57e575 749 {
e99a3a6c 750 unsigned n = chunking_data_left;
8b77d27a 751 if (!bdat_getbuf(&n)) break;
db57e575 752 }
45bd315d
JH
753
754receive_getc = lwr_receive_getc;
0d81dabc 755receive_getbuf = lwr_receive_getbuf;
45bd315d
JH
756receive_ungetc = lwr_receive_ungetc;
757
758if (chunking_state != CHUNKING_LAST)
bd8fbe36 759 {
45bd315d 760 chunking_state = CHUNKING_OFFERED;
bd8fbe36
JH
761 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
762 }
45bd315d
JH
763}
764
7e3ce68e
JH
765
766
767
059ec3d9
PH
768/*************************************************
769* SMTP version of ungetc() *
770*************************************************/
771
772/* Puts a character back in the input buffer. Only ever
773called once.
774
775Arguments:
776 ch the character
777
778Returns: the character
779*/
780
781int
782smtp_ungetc(int ch)
783{
7e3ce68e 784*--smtp_inptr = ch;
059ec3d9
PH
785return ch;
786}
787
788
7e3ce68e
JH
789int
790bdat_ungetc(int ch)
791{
792chunking_data_left++;
793return lwr_receive_ungetc(ch);
794}
795
059ec3d9
PH
796
797
798/*************************************************
799* SMTP version of feof() *
800*************************************************/
801
802/* Tests for a previous EOF
803
804Arguments: none
805Returns: non-zero if the eof flag is set
806*/
807
808int
809smtp_feof(void)
810{
811return smtp_had_eof;
812}
813
814
815
816
817/*************************************************
818* SMTP version of ferror() *
819*************************************************/
820
821/* Tests for a previous read error, and returns with errno
822restored to what it was when the error was detected.
823
824Arguments: none
825Returns: non-zero if the error flag is set
826*/
827
828int
829smtp_ferror(void)
830{
831errno = smtp_had_error;
832return smtp_had_error;
833}
834
835
836
58eb016e
PH
837/*************************************************
838* Test for characters in the SMTP buffer *
839*************************************************/
840
841/* Used at the end of a message
842
843Arguments: none
844Returns: TRUE/FALSE
845*/
846
847BOOL
848smtp_buffered(void)
849{
850return smtp_inptr < smtp_inend;
851}
852
853
059ec3d9
PH
854
855/*************************************************
856* Write formatted string to SMTP channel *
857*************************************************/
858
859/* This is a separate function so that we don't have to repeat everything for
860TLS support or debugging. It is global so that the daemon and the
861authentication functions can use it. It does not return any error indication,
862because major problems such as dropped connections won't show up till an output
863flush for non-TLS connections. The smtp_fflush() function is available for
864checking that: for convenience, TLS output errors are remembered here so that
865they are also picked up later by smtp_fflush().
866
867Arguments:
868 format format string
925ac8e4 869 more further data expected
059ec3d9
PH
870 ... optional arguments
871
872Returns: nothing
873*/
874
875void
925ac8e4 876smtp_printf(const char *format, BOOL more, ...)
059ec3d9
PH
877{
878va_list ap;
879
925ac8e4
JH
880va_start(ap, more);
881smtp_vprintf(format, more, ap);
ce552449
NM
882va_end(ap);
883}
884
885/* This is split off so that verify.c:respond_printf() can, in effect, call
886smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 887call another vararg function, only a function which accepts a va_list. */
ce552449
NM
888
889void
925ac8e4 890smtp_vprintf(const char *format, BOOL more, va_list ap)
ce552449 891{
fb08281f
DW
892BOOL yield;
893
894yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 895
059ec3d9
PH
896DEBUG(D_receive)
897 {
fb08281f
DW
898 void *reset_point = store_get(0);
899 uschar *msg_copy, *cr, *end;
900 msg_copy = string_copy(big_buffer);
901 end = msg_copy + Ustrlen(msg_copy);
902 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
903 memmove(cr, cr + 1, (end--) - cr);
904 debug_printf("SMTP>> %s", msg_copy);
905 store_reset(reset_point);
059ec3d9
PH
906 }
907
fb08281f 908if (!yield)
2679d413
PH
909 {
910 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
911 smtp_closedown(US"Unexpected error");
9bfb7e1b 912 exim_exit(EXIT_FAILURE, NULL);
2679d413 913 }
2679d413
PH
914
915/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
916have had the same. Note: this code is also present in smtp_respond(). It would
917be tidier to have it only in one place, but when it was added, it was easier to
918do it that way, so as not to have to mess with the code for the RCPT command,
919which sometimes uses smtp_printf() and sometimes smtp_respond(). */
920
921if (rcpt_in_progress)
922 {
923 if (rcpt_smtp_response == NULL)
924 rcpt_smtp_response = string_copy(big_buffer);
925 else if (rcpt_smtp_response_same &&
926 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
927 rcpt_smtp_response_same = FALSE;
928 rcpt_in_progress = FALSE;
929 }
059ec3d9 930
2679d413 931/* Now write the string */
059ec3d9
PH
932
933#ifdef SUPPORT_TLS
74f1a423 934if (tls_in.active.sock >= 0)
059ec3d9 935 {
74f1a423 936 if (tls_write(NULL, big_buffer, Ustrlen(big_buffer), more) < 0)
817d9f57 937 smtp_write_error = -1;
059ec3d9
PH
938 }
939else
940#endif
941
2679d413 942if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
059ec3d9
PH
943}
944
945
946
947/*************************************************
948* Flush SMTP out and check for error *
949*************************************************/
950
951/* This function isn't currently used within Exim (it detects errors when it
952tries to read the next SMTP input), but is available for use in local_scan().
953For non-TLS connections, it flushes the output and checks for errors. For
954TLS-connections, it checks for a previously-detected TLS write error.
955
956Arguments: none
957Returns: 0 for no error; -1 after an error
958*/
959
960int
961smtp_fflush(void)
962{
74f1a423 963if (tls_in.active.sock < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
059ec3d9
PH
964return smtp_write_error;
965}
966
967
968
969/*************************************************
970* SMTP command read timeout *
971*************************************************/
972
973/* Signal handler for timing out incoming SMTP commands. This attempts to
974finish off tidily.
975
976Argument: signal number (SIGALRM)
977Returns: nothing
978*/
979
980static void
981command_timeout_handler(int sig)
982{
9723f966 983had_command_timeout = sig;
059ec3d9
PH
984}
985
986
987
988/*************************************************
989* SIGTERM received *
990*************************************************/
991
992/* Signal handler for handling SIGTERM. Again, try to finish tidily.
993
994Argument: signal number (SIGTERM)
995Returns: nothing
996*/
997
998static void
999command_sigterm_handler(int sig)
1000{
9723f966 1001had_command_sigterm = sig;
059ec3d9
PH
1002}
1003
1004
1005
a14e5636 1006
cee5f132 1007#ifdef SUPPORT_PROXY
a3c86431 1008/*************************************************
a3bddaa8
TL
1009* Restore socket timeout to previous value *
1010*************************************************/
1011/* If the previous value was successfully retrieved, restore
1012it before returning control to the non-proxy routines
1013
1014Arguments: fd - File descriptor for input
1015 get_ok - Successfully retrieved previous values
1016 tvtmp - Time struct with previous values
1017 vslen - Length of time struct
1018Returns: none
1019*/
1020static void
f267271d 1021restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen)
a3bddaa8
TL
1022{
1023if (get_ok == 0)
f267271d 1024 (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen);
a3bddaa8
TL
1025}
1026
1027/*************************************************
a3c86431
TL
1028* Check if host is required proxy host *
1029*************************************************/
1030/* The function determines if inbound host will be a regular smtp host
1811cb4c
JH
1031or if it is configured that it must use Proxy Protocol. A local
1032connection cannot.
a3c86431
TL
1033
1034Arguments: none
1035Returns: bool
1036*/
1037
1038static BOOL
1039check_proxy_protocol_host()
1040{
1041int rc;
a3c86431 1042
1811cb4c
JH
1043if ( sender_host_address
1044 && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
1045 sender_host_address, NULL)) == OK)
a3c86431
TL
1046 {
1047 DEBUG(D_receive)
1048 debug_printf("Detected proxy protocol configured host\n");
1049 proxy_session = TRUE;
1050 }
1051return proxy_session;
1052}
1053
1054
1055/*************************************************
3f251b3c
PP
1056* Read data until newline or end of buffer *
1057*************************************************/
1058/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1059read an entire buffer and assume there will be nothing past a proxy protocol
1060header. Our approach normally is to use stdio, but again that relies upon
1061"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1062reading _nothing_ before client TLS handshake. So we don't want to use the
1063usual buffering reads which may read enough to block TLS starting.
1064
1065So unfortunately we're down to "read one byte at a time, with a syscall each,
1066and expect a little overhead", for all proxy-opened connections which are v1,
1067just to handle the TLS-on-connect case. Since SSL functions wrap the
1068underlying fd, we can't assume that we can feed them any already-read content.
1069
1070We need to know where to read to, the max capacity, and we'll read until we
1071get a CR and one more character. Let the caller scream if it's CR+!LF.
1072
1073Return the amount read.
1074*/
1075
1076static int
da88acae 1077swallow_until_crlf(int fd, uschar *base, int already, int capacity)
3f251b3c 1078{
2c0f3ea1
JH
1079uschar *to = base + already;
1080uschar *cr;
1081int have = 0;
1082int ret;
1083int last = 0;
1084
1085/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1086up through the \r; for the _normal_ case, we haven't yet seen the \r. */
da88acae 1087
2c0f3ea1
JH
1088cr = memchr(base, '\r', already);
1089if (cr != NULL)
1090 {
1091 if ((cr - base) < already - 1)
da88acae 1092 {
2c0f3ea1
JH
1093 /* \r and presumed \n already within what we have; probably not
1094 actually proxy protocol, but abort cleanly. */
1095 return 0;
da88acae 1096 }
2c0f3ea1
JH
1097 /* \r is last character read, just need one more. */
1098 last = 1;
1099 }
1100
1101while (capacity > 0)
1102 {
1103 do { ret = recv(fd, to, 1, 0); } while (ret == -1 && errno == EINTR);
1104 if (ret == -1)
1105 return -1;
1106 have++;
1107 if (last)
1108 return have;
1109 if (*to == '\r')
1110 last = 1;
1111 capacity--;
1112 to++;
1113 }
1114
1115/* reached end without having room for a final newline, abort */
1116errno = EOVERFLOW;
1117return -1;
3f251b3c
PP
1118}
1119
1120/*************************************************
a3c86431
TL
1121* Setup host for proxy protocol *
1122*************************************************/
1123/* The function configures the connection based on a header from the
1124inbound host to use Proxy Protocol. The specification is very exact
1125so exit with an error if do not find the exact required pieces. This
1126includes an incorrect number of spaces separating args.
1127
1128Arguments: none
f267271d 1129Returns: Boolean success
a3c86431
TL
1130*/
1131
1811cb4c 1132static void
a3c86431
TL
1133setup_proxy_protocol_host()
1134{
1135union {
1136 struct {
1137 uschar line[108];
1138 } v1;
1139 struct {
1140 uschar sig[12];
36719342
TL
1141 uint8_t ver_cmd;
1142 uint8_t fam;
1143 uint16_t len;
a3c86431
TL
1144 union {
1145 struct { /* TCP/UDP over IPv4, len = 12 */
1146 uint32_t src_addr;
1147 uint32_t dst_addr;
1148 uint16_t src_port;
1149 uint16_t dst_port;
1150 } ip4;
1151 struct { /* TCP/UDP over IPv6, len = 36 */
1152 uint8_t src_addr[16];
1153 uint8_t dst_addr[16];
1154 uint16_t src_port;
1155 uint16_t dst_port;
1156 } ip6;
1157 struct { /* AF_UNIX sockets, len = 216 */
1158 uschar src_addr[108];
1159 uschar dst_addr[108];
1160 } unx;
1161 } addr;
1162 } v2;
1163} hdr;
1164
eb57651e
TL
1165/* Temp variables used in PPv2 address:port parsing */
1166uint16_t tmpport;
1167char tmpip[INET_ADDRSTRLEN];
1168struct sockaddr_in tmpaddr;
1169char tmpip6[INET6_ADDRSTRLEN];
1170struct sockaddr_in6 tmpaddr6;
1171
da88acae
PP
1172/* We can't read "all data until end" because while SMTP is
1173server-speaks-first, the TLS handshake is client-speaks-first, so for
1174TLS-on-connect ports the proxy protocol header will usually be immediately
1175followed by a TLS handshake, and with N TLS libraries, we can't reliably
1176reinject data for reading by those. So instead we first read "enough to be
1177safely read within the header, and figure out how much more to read".
1178For v1 we will later read to the end-of-line, for v2 we will read based upon
1179the stated length.
1180
1181The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1182data is needed total. For v1, where the line looks like:
1183PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1184
1185However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1186We seem to support that. So, if we read 14 octets then we can tell if we're
1187v2 or v1. If we're v1, we can continue reading as normal.
1188
1189If we're v2, we can't slurp up the entire header. We need the length in the
119015th & 16th octets, then to read everything after that.
1191
1192So to safely handle v1 and v2, with client-sent-first supported correctly,
1193we have to do a minimum of 3 read calls, not 1. Eww.
1194*/
1195
1196#define PROXY_INITIAL_READ 14
1197#define PROXY_V2_HEADER_SIZE 16
1198#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1199# error Code bug in sizes of data to read for proxy usage
1200#endif
1201
eb57651e 1202int get_ok = 0;
f267271d
JH
1203int size, ret;
1204int fd = fileno(smtp_in);
36719342 1205const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
9e7e0f6a 1206uschar * iptype; /* To display debug info */
a3c86431 1207struct timeval tv;
a3bddaa8 1208struct timeval tvtmp;
f267271d 1209socklen_t vslen = sizeof(struct timeval);
1811cb4c 1210BOOL yield = FALSE;
a3c86431 1211
a3bddaa8 1212/* Save current socket timeout values */
f267271d 1213get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
a3bddaa8 1214
a3c86431
TL
1215/* Proxy Protocol host must send header within a short time
1216(default 3 seconds) or it's considered invalid */
1217tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
1218tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
f267271d 1219if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
1811cb4c 1220 goto bad;
a3bddaa8 1221
a3c86431
TL
1222do
1223 {
eb57651e 1224 /* The inbound host was declared to be a Proxy Protocol host, so
2c0f3ea1
JH
1225 don't do a PEEK into the data, actually slurp up enough to be
1226 "safe". Can't take it all because TLS-on-connect clients follow
1227 immediately with TLS handshake. */
3f251b3c 1228 ret = recv(fd, &hdr, PROXY_INITIAL_READ, 0);
a3c86431
TL
1229 }
1230 while (ret == -1 && errno == EINTR);
1231
1232if (ret == -1)
f267271d 1233 goto proxyfail;
a3c86431 1234
da88acae
PP
1235/* For v2, handle reading the length, and then the rest. */
1236if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
a3c86431 1237 {
da88acae
PP
1238 int retmore;
1239 uint8_t ver;
1240
1241 /* First get the length fields. */
1242 do
1243 {
1244 retmore = recv(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ, 0);
1245 } while (retmore == -1 && errno == EINTR);
1246 if (retmore == -1)
3f251b3c 1247 goto proxyfail;
da88acae 1248 ret += retmore;
3f251b3c
PP
1249
1250 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
36719342
TL
1251
1252 /* May 2014: haproxy combined the version and command into one byte to
2c0f3ea1
JH
1253 allow two full bytes for the length field in order to proxy SSL
1254 connections. SSL Proxy is not supported in this version of Exim, but
1255 must still separate values here. */
36719342
TL
1256
1257 if (ver != 0x02)
1258 {
1259 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
1260 goto proxyfail;
1261 }
da88acae 1262
36719342 1263 /* The v2 header will always be 16 bytes per the spec. */
5d036699 1264 size = 16 + ntohs(hdr.v2.len);
da88acae
PP
1265 DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1266 size, (int)sizeof(hdr));
1267
1268 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1269 amount that we need. Double-check that the size is not unreasonable, then
1270 get the rest. */
1271 if (size > sizeof(hdr))
a3c86431 1272 {
da88acae 1273 DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
a3c86431
TL
1274 goto proxyfail;
1275 }
da88acae
PP
1276
1277 do
1278 {
1279 do
1280 {
1281 retmore = recv(fd, (uschar*)&hdr + ret, size-ret, 0);
1282 } while (retmore == -1 && errno == EINTR);
1283 if (retmore == -1)
1284 goto proxyfail;
1285 ret += retmore;
1286 DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
1287 } while (ret < size);
1288
1289 } /* end scope for getting rest of data for v2 */
1290
1291/* At this point: if PROXYv2, we've read the exact size required for all data;
1292if PROXYv1 then we've read "less than required for any valid line" and should
1293read the rest". */
1294
1295if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
1296 {
1297 uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
1298
36719342 1299 switch (cmd)
a3c86431
TL
1300 {
1301 case 0x01: /* PROXY command */
1302 switch (hdr.v2.fam)
1303 {
eb57651e
TL
1304 case 0x11: /* TCPv4 address type */
1305 iptype = US"IPv4";
1306 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
5d036699
JH
1307 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1308 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1309 {
1310 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1311 goto proxyfail;
eb57651e 1312 }
e6d2a989 1313 proxy_local_address = sender_host_address;
eb57651e
TL
1314 sender_host_address = string_copy(US tmpip);
1315 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
e6d2a989 1316 proxy_local_port = sender_host_port;
eb57651e
TL
1317 sender_host_port = tmpport;
1318 /* Save dest ip/port */
1319 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
5d036699
JH
1320 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1321 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1322 {
1323 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1324 goto proxyfail;
eb57651e 1325 }
7a2fa0bc 1326 proxy_external_address = string_copy(US tmpip);
eb57651e 1327 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
7a2fa0bc 1328 proxy_external_port = tmpport;
a3c86431 1329 goto done;
eb57651e
TL
1330 case 0x21: /* TCPv6 address type */
1331 iptype = US"IPv6";
1332 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
5d036699
JH
1333 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1334 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1335 {
1336 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1337 goto proxyfail;
eb57651e 1338 }
e6d2a989 1339 proxy_local_address = sender_host_address;
eb57651e
TL
1340 sender_host_address = string_copy(US tmpip6);
1341 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
e6d2a989 1342 proxy_local_port = sender_host_port;
eb57651e
TL
1343 sender_host_port = tmpport;
1344 /* Save dest ip/port */
1345 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
5d036699
JH
1346 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1347 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1348 {
1349 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1350 goto proxyfail;
eb57651e 1351 }
7a2fa0bc 1352 proxy_external_address = string_copy(US tmpip6);
eb57651e 1353 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
7a2fa0bc 1354 proxy_external_port = tmpport;
a3c86431 1355 goto done;
eb57651e
TL
1356 default:
1357 DEBUG(D_receive)
1358 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1359 hdr.v2.fam);
1360 goto proxyfail;
a3c86431
TL
1361 }
1362 /* Unsupported protocol, keep local connection address */
1363 break;
1364 case 0x00: /* LOCAL command */
1365 /* Keep local connection address for LOCAL */
9e7e0f6a 1366 iptype = US"local";
a3c86431
TL
1367 break;
1368 default:
eb57651e 1369 DEBUG(D_receive)
36719342 1370 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
1371 goto proxyfail;
1372 }
1373 }
5d036699 1374else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
a3c86431 1375 {
3f251b3c
PP
1376 uschar *p;
1377 uschar *end;
a3c86431
TL
1378 uschar *sp; /* Utility variables follow */
1379 int tmp_port;
3f251b3c 1380 int r2;
a3c86431
TL
1381 char *endc;
1382
3f251b3c 1383 /* get the rest of the line */
da88acae 1384 r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
3f251b3c
PP
1385 if (r2 == -1)
1386 goto proxyfail;
1387 ret += r2;
1388
1389 p = string_copy(hdr.v1.line);
1390 end = memchr(p, '\r', ret - 1);
1391
da88acae 1392 if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
a3c86431
TL
1393 {
1394 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
1395 goto proxyfail;
1396 }
1397 *end = '\0'; /* Terminate the string */
a5d4db40 1398 size = end + 2 - p; /* Skip header + CRLF */
a3c86431 1399 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
3f251b3c 1400 DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
a3c86431 1401 /* Step through the string looking for the required fields. Ensure
2c0f3ea1 1402 strict adherence to required formatting, exit for any error. */
a3c86431
TL
1403 p += 5;
1404 if (!isspace(*(p++)))
1405 {
1406 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
1407 goto proxyfail;
1408 }
1409 if (!Ustrncmp(p, CCS"TCP4", 4))
1410 iptype = US"IPv4";
1411 else if (!Ustrncmp(p,CCS"TCP6", 4))
1412 iptype = US"IPv6";
1413 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
1414 {
1415 iptype = US"Unknown";
1416 goto done;
1417 }
1418 else
1419 {
1420 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
1421 goto proxyfail;
1422 }
1423
1424 p += Ustrlen(iptype);
1425 if (!isspace(*(p++)))
1426 {
1427 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
1428 goto proxyfail;
1429 }
1430 /* Find the end of the arg */
1431 if ((sp = Ustrchr(p, ' ')) == NULL)
1432 {
1433 DEBUG(D_receive)
1434 debug_printf("Did not find proxied src %s\n", iptype);
1435 goto proxyfail;
1436 }
1437 *sp = '\0';
5d036699 1438 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1439 {
1440 DEBUG(D_receive)
1441 debug_printf("Proxied src arg is not an %s address\n", iptype);
1442 goto proxyfail;
1443 }
e6d2a989 1444 proxy_local_address = sender_host_address;
a3c86431
TL
1445 sender_host_address = p;
1446 p = sp + 1;
1447 if ((sp = Ustrchr(p, ' ')) == NULL)
1448 {
1449 DEBUG(D_receive)
1450 debug_printf("Did not find proxy dest %s\n", iptype);
1451 goto proxyfail;
1452 }
1453 *sp = '\0';
5d036699 1454 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1455 {
1456 DEBUG(D_receive)
1457 debug_printf("Proxy dest arg is not an %s address\n", iptype);
1458 goto proxyfail;
1459 }
7a2fa0bc 1460 proxy_external_address = p;
a3c86431
TL
1461 p = sp + 1;
1462 if ((sp = Ustrchr(p, ' ')) == NULL)
1463 {
1464 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
1465 goto proxyfail;
1466 }
1467 *sp = '\0';
5d036699 1468 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1469 if (*endc || tmp_port == 0)
1470 {
1471 DEBUG(D_receive)
1472 debug_printf("Proxied src port '%s' not an integer\n", p);
1473 goto proxyfail;
1474 }
e6d2a989 1475 proxy_local_port = sender_host_port;
a3c86431
TL
1476 sender_host_port = tmp_port;
1477 p = sp + 1;
1478 if ((sp = Ustrchr(p, '\0')) == NULL)
1479 {
1480 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
1481 goto proxyfail;
1482 }
5d036699 1483 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1484 if (*endc || tmp_port == 0)
1485 {
1486 DEBUG(D_receive)
1487 debug_printf("Proxy dest port '%s' not an integer\n", p);
1488 goto proxyfail;
1489 }
7a2fa0bc 1490 proxy_external_port = tmp_port;
a3c86431 1491 /* Already checked for /r /n above. Good V1 header received. */
a3c86431
TL
1492 }
1493else
1494 {
1495 /* Wrong protocol */
eb57651e 1496 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
da88acae 1497 (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
a3c86431
TL
1498 goto proxyfail;
1499 }
1500
1811cb4c
JH
1501done:
1502 DEBUG(D_receive)
1503 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
1504 yield = proxy_session;
1505
1506/* Don't flush any potential buffer contents. Any input on proxyfail
1507should cause a synchronization failure */
1508
a3c86431 1509proxyfail:
1811cb4c 1510 restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1511
1811cb4c
JH
1512bad:
1513 if (yield)
1514 {
1515 sender_host_name = NULL;
1516 (void) host_name_lookup();
1517 host_build_sender_fullhost();
1518 }
1519 else
1520 {
1521 proxy_session_failed = TRUE;
1522 DEBUG(D_receive)
1523 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1524 }
1525
1526return;
a3c86431
TL
1527}
1528#endif
1529
059ec3d9
PH
1530/*************************************************
1531* Read one command line *
1532*************************************************/
1533
1534/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1535There are sites that don't do this, and in any case internal SMTP probably
1536should check only for LF. Consequently, we check here for LF only. The line
1537ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
1538an unknown command. The command is read into the global smtp_cmd_buffer so that
1539it is available via $smtp_command.
059ec3d9
PH
1540
1541The character reading routine sets up a timeout for each block actually read
1542from the input (which may contain more than one command). We set up a special
1543signal handler that closes down the session on a timeout. Control does not
1544return when it runs.
1545
1546Arguments:
bd8fbe36
JH
1547 check_sync if TRUE, check synchronization rules if global option is TRUE
1548 buffer_lim maximum to buffer in lower layer
059ec3d9
PH
1549
1550Returns: a code identifying the command (enumerated above)
1551*/
1552
1553static int
bd8fbe36 1554smtp_read_command(BOOL check_sync, unsigned buffer_lim)
059ec3d9
PH
1555{
1556int c;
1557int ptr = 0;
1558smtp_cmd_list *p;
1559BOOL hadnull = FALSE;
1560
9723f966 1561had_command_timeout = 0;
059ec3d9
PH
1562os_non_restarting_signal(SIGALRM, command_timeout_handler);
1563
bd8fbe36 1564while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
059ec3d9 1565 {
bd8fbe36 1566 if (ptr >= SMTP_CMD_BUFFER_SIZE)
059ec3d9
PH
1567 {
1568 os_non_restarting_signal(SIGALRM, sigalrm_handler);
1569 return OTHER_CMD;
1570 }
1571 if (c == 0)
1572 {
1573 hadnull = TRUE;
1574 c = '?';
1575 }
3ee512ff 1576 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1577 }
1578
1579receive_linecount++; /* For BSMTP errors */
1580os_non_restarting_signal(SIGALRM, sigalrm_handler);
1581
1582/* If hit end of file, return pseudo EOF command. Whether we have a
1583part-line already read doesn't matter, since this is an error state. */
1584
1585if (c == EOF) return EOF_CMD;
1586
1587/* Remove any CR and white space at the end of the line, and terminate the
1588string. */
1589
3ee512ff
PH
1590while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1591smtp_cmd_buffer[ptr] = 0;
059ec3d9 1592
3ee512ff 1593DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1594
1595/* NULLs are not allowed in SMTP commands */
1596
1597if (hadnull) return BADCHAR_CMD;
1598
1599/* Scan command list and return identity, having set the data pointer
1600to the start of the actual data characters. Check for SMTP synchronization
1601if required. */
1602
1603for (p = cmd_list; p < cmd_list_end; p++)
1604 {
1811cb4c 1605#ifdef SUPPORT_PROXY
a3c86431 1606 /* Only allow QUIT command if Proxy Protocol parsing failed */
1811cb4c
JH
1607 if (proxy_session && proxy_session_failed && p->cmd != QUIT_CMD)
1608 continue;
1609#endif
2f460950
JH
1610 if ( p->len
1611 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1612 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1613 || smtp_cmd_buffer[p->len] == 0
1614 || smtp_cmd_buffer[p->len] == ' '
1615 ) )
059ec3d9
PH
1616 {
1617 if (smtp_inptr < smtp_inend && /* Outstanding input */
1618 p->cmd < sync_cmd_limit && /* Command should sync */
1619 check_sync && /* Local flag set */
1620 smtp_enforce_sync && /* Global flag set */
1621 sender_host_address != NULL && /* Not local input */
1622 !sender_host_notsocket) /* Really is a socket */
1623 return BADSYN_CMD;
1624
ca86f471
PH
1625 /* The variables $smtp_command and $smtp_command_argument point into the
1626 unmodified input buffer. A copy of the latter is taken for actual
1627 processing, so that it can be chopped up into separate parts if necessary,
1628 for example, when processing a MAIL command options such as SIZE that can
1629 follow the sender address. */
059ec3d9 1630
3ee512ff 1631 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1632 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1633 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1634 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1635
1636 /* Count non-mail commands from those hosts that are controlled in this
1637 way. The default is all hosts. We don't waste effort checking the list
1638 until we get a non-mail command, but then cache the result to save checking
1639 again. If there's a DEFER while checking the host, assume it's in the list.
1640
1641 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1642 start of each incoming message by fiddling with the value in the table. */
1643
1644 if (!p->is_mail_cmd)
1645 {
1646 if (count_nonmail == TRUE_UNSET) count_nonmail =
1647 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1648 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1649 return TOO_MANY_NONMAIL_CMD;
1650 }
1651
ca86f471
PH
1652 /* If there is data for a command that does not expect it, generate the
1653 error here. */
059ec3d9 1654
ca86f471 1655 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1656 }
1657 }
1658
cee5f132 1659#ifdef SUPPORT_PROXY
a3c86431
TL
1660/* Only allow QUIT command if Proxy Protocol parsing failed */
1661if (proxy_session && proxy_session_failed)
1662 return PROXY_FAIL_IGNORE_CMD;
1663#endif
1664
059ec3d9
PH
1665/* Enforce synchronization for unknown commands */
1666
ecce6d9a
JH
1667if ( smtp_inptr < smtp_inend /* Outstanding input */
1668 && check_sync /* Local flag set */
1669 && smtp_enforce_sync /* Global flag set */
1670 && sender_host_address /* Not local input */
1671 && !sender_host_notsocket) /* Really is a socket */
059ec3d9
PH
1672 return BADSYN_CMD;
1673
1674return OTHER_CMD;
1675}
1676
1677
1678
1679/*************************************************
1680* Forced closedown of call *
1681*************************************************/
1682
1683/* This function is called from log.c when Exim is dying because of a serious
1684disaster, and also from some other places. If an incoming non-batched SMTP
1685channel is open, it swallows the rest of the incoming message if in the DATA
1686phase, sends the reply string, and gives an error to all subsequent commands
1687except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1688smtp_in.
1689
8f128379
PH
1690Arguments:
1691 message SMTP reply string to send, excluding the code
1692
059ec3d9
PH
1693Returns: nothing
1694*/
1695
1696void
1697smtp_closedown(uschar *message)
1698{
db57e575 1699if (!smtp_in || smtp_batched_input) return;
059ec3d9 1700receive_swallow_smtp();
925ac8e4 1701smtp_printf("421 %s\r\n", FALSE, message);
059ec3d9 1702
bd8fbe36 1703for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 1704 {
60d10ce7 1705 case EOF_CMD:
db57e575 1706 return;
059ec3d9 1707
60d10ce7 1708 case QUIT_CMD:
db57e575
JH
1709 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
1710 mac_smtp_fflush();
1711 return;
059ec3d9 1712
60d10ce7 1713 case RSET_CMD:
db57e575
JH
1714 smtp_printf("250 Reset OK\r\n", FALSE);
1715 break;
059ec3d9 1716
60d10ce7 1717 default:
db57e575
JH
1718 smtp_printf("421 %s\r\n", FALSE, message);
1719 break;
059ec3d9
PH
1720 }
1721}
1722
1723
1724
1725
1726/*************************************************
1727* Set up connection info for logging *
1728*************************************************/
1729
1730/* This function is called when logging information about an SMTP connection.
1731It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1732If sender_fullhost is NULL, we are at a very early stage of the connection;
1733just use the IP address.
059ec3d9
PH
1734
1735Argument: none
1736Returns: a string describing the connection
1737*/
1738
1739uschar *
1740smtp_get_connection_info(void)
1741{
f5d25c2b
JH
1742const uschar * hostname = sender_fullhost
1743 ? sender_fullhost : sender_host_address;
dac79d3e 1744
059ec3d9 1745if (host_checking)
dac79d3e 1746 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1747
1748if (sender_host_unknown || sender_host_notsocket)
1749 return string_sprintf("SMTP connection from %s", sender_ident);
1750
1751if (is_inetd)
dac79d3e 1752 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1753
6c6d6e48 1754if (LOGGING(incoming_interface) && interface_address != NULL)
dac79d3e 1755 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1756 interface_address, interface_port);
1757
dac79d3e 1758return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1759}
1760
1761
1762
e45a1c37 1763#ifdef SUPPORT_TLS
887291d2
JH
1764/* Append TLS-related information to a log line
1765
1766Arguments:
acec9514 1767 g String under construction: allocated string to extend, or NULL
887291d2
JH
1768
1769Returns: Allocated string or NULL
1770*/
acec9514
JH
1771static gstring *
1772s_tlslog(gstring * g)
e45a1c37 1773{
acec9514
JH
1774if (LOGGING(tls_cipher) && tls_in.cipher)
1775 g = string_append(g, 2, US" X=", tls_in.cipher);
1776if (LOGGING(tls_certificate_verified) && tls_in.cipher)
1777 g = string_append(g, 2, US" CV=", tls_in.certificate_verified? "yes":"no");
1778if (LOGGING(tls_peerdn) && tls_in.peerdn)
1779 g = string_append(g, 3, US" DN=\"", string_printing(tls_in.peerdn), US"\"");
1780if (LOGGING(tls_sni) && tls_in.sni)
1781 g = string_append(g, 3, US" SNI=\"", string_printing(tls_in.sni), US"\"");
1782return g;
e45a1c37
JH
1783}
1784#endif
1785
059ec3d9 1786/*************************************************
b4ed4da0
PH
1787* Log lack of MAIL if so configured *
1788*************************************************/
1789
1790/* This function is called when an SMTP session ends. If the log selector
1791smtp_no_mail is set, write a log line giving some details of what has happened
1792in the SMTP session.
1793
1794Arguments: none
1795Returns: nothing
1796*/
1797
1798void
1799smtp_log_no_mail(void)
1800{
acec9514
JH
1801int i;
1802uschar * sep, * s;
1803gstring * g = NULL;
b4ed4da0 1804
6c6d6e48 1805if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
1806 return;
1807
db57e575 1808if (sender_host_authenticated)
b4ed4da0 1809 {
acec9514
JH
1810 g = string_append(g, 2, US" A=", sender_host_authenticated);
1811 if (authenticated_id) g = string_append(g, 2, US":", authenticated_id);
b4ed4da0
PH
1812 }
1813
1814#ifdef SUPPORT_TLS
acec9514 1815g = s_tlslog(g);
3f0945ff 1816#endif
b4ed4da0 1817
acec9514
JH
1818sep = smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE ? US" C=..." : US" C=";
1819
b4ed4da0 1820for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
b4ed4da0
PH
1821 if (smtp_connection_had[i] != SCH_NONE)
1822 {
acec9514 1823 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1824 sep = US",";
1825 }
b4ed4da0
PH
1826
1827for (i = 0; i < smtp_ch_index; i++)
1828 {
acec9514 1829 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1830 sep = US",";
1831 }
1832
acec9514
JH
1833if (!(s = string_from_gstring(g))) s = US"";
1834
a2673768
JH
1835log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s",
1836 tcp_in_fastopen ? US"TFO " : US"",
0f1a8658 1837 host_and_ident(FALSE), string_timesince(&smtp_connection_start), s);
b4ed4da0
PH
1838}
1839
1840
a09f2942
JH
1841/* Return list of recent smtp commands */
1842
1843uschar *
1844smtp_cmd_hist(void)
1845{
acec9514
JH
1846int i;
1847gstring * list = NULL;
1848uschar * s;
a09f2942
JH
1849
1850for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1851 if (smtp_connection_had[i] != SCH_NONE)
acec9514
JH
1852 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1853
a09f2942 1854for (i = 0; i < smtp_ch_index; i++)
acec9514
JH
1855 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1856
1857s = string_from_gstring(list);
1858return s ? s : US"";
a09f2942
JH
1859}
1860
1861
1862
b4ed4da0
PH
1863
1864/*************************************************
059ec3d9
PH
1865* Check HELO line and set sender_helo_name *
1866*************************************************/
1867
1868/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1869the domain name of the sending host, or an ip literal in square brackets. The
4c04137d 1870argument is placed in sender_helo_name, which is in malloc store, because it
059ec3d9
PH
1871must persist over multiple incoming messages. If helo_accept_junk is set, this
1872host is permitted to send any old junk (needed for some broken hosts).
1873Otherwise, helo_allow_chars can be used for rogue characters in general
1874(typically people want to let in underscores).
1875
1876Argument:
1877 s the data portion of the line (already past any white space)
1878
1879Returns: TRUE or FALSE
1880*/
1881
1882static BOOL
1883check_helo(uschar *s)
1884{
1885uschar *start = s;
1886uschar *end = s + Ustrlen(s);
1887BOOL yield = helo_accept_junk;
1888
1889/* Discard any previous helo name */
1890
2d0dc929 1891if (sender_helo_name)
059ec3d9
PH
1892 {
1893 store_free(sender_helo_name);
1894 sender_helo_name = NULL;
1895 }
1896
1897/* Skip tests if junk is permitted. */
1898
1899if (!yield)
db57e575 1900
059ec3d9
PH
1901 /* Allow the new standard form for IPv6 address literals, namely,
1902 [IPv6:....], and because someone is bound to use it, allow an equivalent
1903 IPv4 form. Allow plain addresses as well. */
1904
1905 if (*s == '[')
1906 {
1907 if (end[-1] == ']')
1908 {
1909 end[-1] = 0;
1910 if (strncmpic(s, US"[IPv6:", 6) == 0)
1911 yield = (string_is_ip_address(s+6, NULL) == 6);
1912 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1913 yield = (string_is_ip_address(s+6, NULL) == 4);
1914 else
1915 yield = (string_is_ip_address(s+1, NULL) != 0);
1916 end[-1] = ']';
1917 }
1918 }
1919
1920 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1921 that have been configured (usually underscore - sigh). */
1922
db57e575
JH
1923 else if (*s)
1924 for (yield = TRUE; *s; s++)
059ec3d9
PH
1925 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1926 Ustrchr(helo_allow_chars, *s) == NULL)
1927 {
1928 yield = FALSE;
1929 break;
1930 }
059ec3d9
PH
1931
1932/* Save argument if OK */
1933
1934if (yield) sender_helo_name = string_copy_malloc(start);
1935return yield;
1936}
1937
1938
1939
1940
1941
1942/*************************************************
1943* Extract SMTP command option *
1944*************************************************/
1945
ca86f471 1946/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1947is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1948things that can appear there.
1949
1950Arguments:
1951 name point this at the name
1952 value point this at the data string
1953
1954Returns: TRUE if found an option
1955*/
1956
1957static BOOL
1958extract_option(uschar **name, uschar **value)
1959{
1960uschar *n;
ca86f471 1961uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1962while (isspace(*v)) v--;
1963v[1] = 0;
d7a2c833
JH
1964while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
1965 {
1966 /* Take care to not stop at a space embedded in a quoted local-part */
1967
1968 if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
1969 v--;
1970 }
059ec3d9
PH
1971
1972n = v;
fd98a5c6 1973if (*v == '=')
a2673768 1974 {
fd98a5c6
JH
1975 while(isalpha(n[-1])) n--;
1976 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1977 if (!isspace(n[-1])) return FALSE;
1978 n[-1] = 0;
a2673768 1979 }
fd98a5c6 1980else
a2673768 1981 {
fd98a5c6
JH
1982 n++;
1983 if (v == smtp_cmd_data) return FALSE;
a2673768 1984 }
059ec3d9 1985*v++ = 0;
fd98a5c6 1986*name = n;
059ec3d9
PH
1987*value = v;
1988return TRUE;
1989}
1990
1991
1992
1993
1994
059ec3d9
PH
1995/*************************************************
1996* Reset for new message *
1997*************************************************/
1998
1999/* This function is called whenever the SMTP session is reset from
e04bfa34 2000within either of the setup functions; also from the daemon loop.
059ec3d9
PH
2001
2002Argument: the stacking pool storage reset point
2003Returns: nothing
2004*/
2005
e04bfa34 2006void
059ec3d9
PH
2007smtp_reset(void *reset_point)
2008{
059ec3d9
PH
2009recipients_list = NULL;
2010rcpt_count = rcpt_defer_count = rcpt_fail_count =
2011 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e0c1448 2012message_linecount = 0;
059ec3d9 2013message_size = -1;
71fafd95 2014acl_added_headers = NULL;
e7568d51 2015acl_removed_headers = NULL;
059ec3d9 2016queue_only_policy = FALSE;
2679d413
PH
2017rcpt_smtp_response = NULL;
2018rcpt_smtp_response_same = TRUE;
2019rcpt_in_progress = FALSE;
69358f02 2020deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 2021freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 2022fake_response = OK; /* Can be set by ACL */
6951ac6c 2023#ifdef WITH_CONTENT_SCAN
8523533c
TK
2024no_mbox_unspool = FALSE; /* Can be set by ACL */
2025#endif
69358f02 2026submission_mode = FALSE; /* Can be set by ACL */
f4ee74ac 2027suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
69358f02
PH
2028active_local_from_check = local_from_check; /* Can be set by ACL */
2029active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
90341c71
JH
2030sending_ip_address = NULL;
2031return_path = sender_address = NULL;
2032sender_data = NULL; /* Can be set by ACL */
c679ee08
JH
2033deliver_localpart_parent = deliver_localpart_orig = NULL;
2034deliver_domain_parent = deliver_domain_orig = NULL;
90341c71 2035callout_address = NULL;
2fe1a124 2036submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
2037raw_sender = NULL; /* After SMTP rewrite, before qualifying */
2038sender_address_unrewritten = NULL; /* Set only after verify rewrite */
2039sender_verified_list = NULL; /* No senders verified */
2040memset(sender_address_cache, 0, sizeof(sender_address_cache));
2041memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 2042
059ec3d9 2043authenticated_sender = NULL;
8523533c
TK
2044#ifdef EXPERIMENTAL_BRIGHTMAIL
2045bmi_run = 0;
2046bmi_verdicts = NULL;
2047#endif
90341c71 2048dnslist_domain = dnslist_matched = NULL;
01067968
JH
2049#ifdef SUPPORT_SPF
2050spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL;
2051spf_result_guessed = FALSE;
2052#endif
80a47a2c 2053#ifndef DISABLE_DKIM
d342446f 2054dkim_cur_signer = dkim_signers =
b4757e36 2055dkim_signing_domain = dkim_signing_selector = dkim_signatures = NULL;
d342446f 2056dkim_cur_signer = dkim_signers = dkim_signing_domain = dkim_signing_selector = NULL;
64b67b65
JH
2057dkim_disable_verify = FALSE;
2058dkim_collect_input = 0;
d342446f
JH
2059dkim_verify_overall = dkim_verify_status = dkim_verify_reason = NULL;
2060dkim_key_length = 0;
2061dkim_verify_signers = US"$dkim_signers";
f7572e5a 2062#endif
b4757e36
JH
2063#ifdef EXPERIMENTAL_DMARC
2064dmarc_has_been_checked = dmarc_disable_verify = dmarc_enable_forensic = FALSE;
8aeef98a 2065dmarc_domain_policy = dmarc_status = dmarc_status_text =
6372d4c9 2066dmarc_used_domain = NULL;
f7572e5a 2067#endif
01067968
JH
2068#ifdef EXPERIMENTAL_ARC
2069arc_state = arc_state_reason = NULL;
b4757e36 2070#endif
aa368db3
JH
2071dsn_ret = 0;
2072dsn_envid = NULL;
90341c71 2073deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
aa368db3
JH
2074#ifndef DISABLE_PRDR
2075prdr_requested = FALSE;
2076#endif
8c5d388a 2077#ifdef SUPPORT_I18N
d1a13eea
JH
2078message_smtputf8 = FALSE;
2079#endif
059ec3d9
PH
2080body_linecount = body_zerocount = 0;
2081
870f6ba8
TF
2082sender_rate = sender_rate_limit = sender_rate_period = NULL;
2083ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
2084 /* Note that ratelimiters_conn persists across resets. */
2085
38a0a95f 2086/* Reset message ACL variables */
47ca6d6c 2087
38a0a95f 2088acl_var_m = NULL;
059ec3d9
PH
2089
2090/* The message body variables use malloc store. They may be set if this is
2091not the first message in an SMTP session and the previous message caused them
2092to be referenced in an ACL. */
2093
90341c71 2094if (message_body)
059ec3d9
PH
2095 {
2096 store_free(message_body);
2097 message_body = NULL;
2098 }
2099
90341c71 2100if (message_body_end)
059ec3d9
PH
2101 {
2102 store_free(message_body_end);
2103 message_body_end = NULL;
2104 }
2105
2106/* Warning log messages are also saved in malloc store. They are saved to avoid
2107repetition in the same message, but it seems right to repeat them for different
4e88a19f 2108messages. */
059ec3d9 2109
90341c71 2110while (acl_warn_logged)
059ec3d9
PH
2111 {
2112 string_item *this = acl_warn_logged;
2113 acl_warn_logged = acl_warn_logged->next;
2114 store_free(this);
2115 }
90341c71 2116store_reset(reset_point);
059ec3d9
PH
2117}
2118
2119
2120
2121
2122
2123/*************************************************
2124* Initialize for incoming batched SMTP message *
2125*************************************************/
2126
2127/* This function is called from smtp_setup_msg() in the case when
2128smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2129of messages in one file with SMTP commands between them. All errors must be
2130reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2131relevant. After an error on a sender, or an invalid recipient, the remainder
2132of the message is skipped. The value of received_protocol is already set.
2133
2134Argument: none
2135Returns: > 0 message successfully started (reached DATA)
2136 = 0 QUIT read or end of file reached
2137 < 0 should not occur
2138*/
2139
2140static int
2141smtp_setup_batch_msg(void)
2142{
2143int done = 0;
2144void *reset_point = store_get(0);
2145
2146/* Save the line count at the start of each transaction - single commands
2147like HELO and RSET count as whole transactions. */
2148
2149bsmtp_transaction_linecount = receive_linecount;
2150
2151if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
2152
57cc2785 2153cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
059ec3d9
PH
2154smtp_reset(reset_point); /* Reset for start of message */
2155
2156/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2157value. The values are 2 larger than the required yield of the function. */
2158
2159while (done <= 0)
2160 {
2161 uschar *errmess;
2162 uschar *recipient = NULL;
2163 int start, end, sender_domain, recipient_domain;
2164
bd8fbe36 2165 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
2166 {
2167 /* The HELO/EHLO commands set sender_address_helo if they have
2168 valid data; otherwise they are ignored, except that they do
2169 a reset of the state. */
2170
2171 case HELO_CMD:
2172 case EHLO_CMD:
2173
db57e575
JH
2174 check_helo(smtp_cmd_data);
2175 /* Fall through */
059ec3d9
PH
2176
2177 case RSET_CMD:
db57e575
JH
2178 cancel_cutthrough_connection(TRUE, US"RSET received");
2179 smtp_reset(reset_point);
2180 bsmtp_transaction_linecount = receive_linecount;
2181 break;
059ec3d9
PH
2182
2183
2184 /* The MAIL FROM command requires an address as an operand. All we
2185 do here is to parse it for syntactic correctness. The form "<>" is
2186 a special case which converts into an empty string. The start/end
2187 pointers in the original are not used further for this address, as
2188 it is the canonical extracted address which is all that is kept. */
2189
2190 case MAIL_CMD:
db57e575
JH
2191 smtp_mailcmd_count++; /* Count for no-mail log */
2192 if (sender_address != NULL)
2193 /* The function moan_smtp_batch() does not return. */
2194 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 2195
db57e575
JH
2196 if (smtp_cmd_data[0] == 0)
2197 /* The function moan_smtp_batch() does not return. */
2198 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9 2199
db57e575 2200 /* Reset to start of message */
059ec3d9 2201
db57e575
JH
2202 cancel_cutthrough_connection(TRUE, US"MAIL received");
2203 smtp_reset(reset_point);
059ec3d9 2204
db57e575 2205 /* Apply SMTP rewrite */
059ec3d9 2206
db57e575
JH
2207 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
2208 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
2209 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9 2210
db57e575 2211 /* Extract the address; the TRUE flag allows <> as valid */
059ec3d9 2212
db57e575
JH
2213 raw_sender =
2214 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
2215 TRUE);
059ec3d9 2216
db57e575
JH
2217 if (!raw_sender)
2218 /* The function moan_smtp_batch() does not return. */
2219 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2220
db57e575 2221 sender_address = string_copy(raw_sender);
059ec3d9 2222
db57e575 2223 /* Qualify unqualified sender addresses if permitted to do so. */
059ec3d9 2224
db57e575
JH
2225 if ( !sender_domain
2226 && sender_address[0] != 0 && sender_address[0] != '@')
2227 if (allow_unqualified_sender)
2228 {
2229 sender_address = rewrite_address_qualify(sender_address, FALSE);
2230 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
2231 "and rewritten\n", raw_sender);
2232 }
2233 /* The function moan_smtp_batch() does not return. */
2234 else
2235 moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
2236 "a domain");
2237 break;
059ec3d9
PH
2238
2239
2240 /* The RCPT TO command requires an address as an operand. All we do
2241 here is to parse it for syntactic correctness. There may be any number
2242 of RCPT TO commands, specifying multiple senders. We build them all into
2243 a data structure that is in argc/argv format. The start/end values
2244 given by parse_extract_address are not used, as we keep only the
2245 extracted address. */
2246
2247 case RCPT_CMD:
db57e575
JH
2248 if (!sender_address)
2249 /* The function moan_smtp_batch() does not return. */
2250 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 2251
db57e575
JH
2252 if (smtp_cmd_data[0] == 0)
2253 /* The function moan_smtp_batch() does not return. */
2254 moan_smtp_batch(smtp_cmd_buffer,
2255 "501 RCPT TO must have an address operand");
059ec3d9 2256
db57e575 2257 /* Check maximum number allowed */
059ec3d9 2258
db57e575
JH
2259 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
2260 /* The function moan_smtp_batch() does not return. */
2261 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
2262 recipients_max_reject? "552": "452");
059ec3d9 2263
db57e575
JH
2264 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2265 recipient address */
059ec3d9 2266
db57e575
JH
2267 recipient = rewrite_existflags & rewrite_smtp
2268 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
2269 global_rewrite_rules)
2270 : smtp_cmd_data;
059ec3d9 2271
db57e575
JH
2272 recipient = parse_extract_address(recipient, &errmess, &start, &end,
2273 &recipient_domain, FALSE);
059ec3d9 2274
db57e575
JH
2275 if (!recipient)
2276 /* The function moan_smtp_batch() does not return. */
2277 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2278
db57e575
JH
2279 /* If the recipient address is unqualified, qualify it if permitted. Then
2280 add it to the list of recipients. */
059ec3d9 2281
db57e575
JH
2282 if (!recipient_domain)
2283 if (allow_unqualified_recipient)
2284 {
2285 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
2286 recipient);
2287 recipient = rewrite_address_qualify(recipient, TRUE);
2288 }
2289 /* The function moan_smtp_batch() does not return. */
2290 else
2291 moan_smtp_batch(smtp_cmd_buffer,
2292 "501 recipient address must contain a domain");
2293
2294 receive_add_recipient(recipient, -1);
2295 break;
059ec3d9
PH
2296
2297
2298 /* The DATA command is legal only if it follows successful MAIL FROM
2299 and RCPT TO commands. This function is complete when a valid DATA
2300 command is encountered. */
2301
2302 case DATA_CMD:
db57e575
JH
2303 if (!sender_address || recipients_count <= 0)
2304 /* The function moan_smtp_batch() does not return. */
2305 if (!sender_address)
2306 moan_smtp_batch(smtp_cmd_buffer,
2307 "503 MAIL FROM:<sender> command must precede DATA");
2308 else
2309 moan_smtp_batch(smtp_cmd_buffer,
2310 "503 RCPT TO:<recipient> must precede DATA");
059ec3d9 2311 else
db57e575
JH
2312 {
2313 done = 3; /* DATA successfully achieved */
2314 message_ended = END_NOTENDED; /* Indicate in middle of message */
2315 }
2316 break;
059ec3d9
PH
2317
2318
2319 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2320
2321 case VRFY_CMD:
2322 case EXPN_CMD:
2323 case HELP_CMD:
2324 case NOOP_CMD:
2325 case ETRN_CMD:
db57e575
JH
2326 bsmtp_transaction_linecount = receive_linecount;
2327 break;
059ec3d9
PH
2328
2329
2330 case EOF_CMD:
2331 case QUIT_CMD:
db57e575
JH
2332 done = 2;
2333 break;
059ec3d9
PH
2334
2335
2336 case BADARG_CMD:
db57e575
JH
2337 /* The function moan_smtp_batch() does not return. */
2338 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
2339 break;
059ec3d9
PH
2340
2341
2342 case BADCHAR_CMD:
db57e575
JH
2343 /* The function moan_smtp_batch() does not return. */
2344 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
2345 break;
059ec3d9
PH
2346
2347
2348 default:
db57e575
JH
2349 /* The function moan_smtp_batch() does not return. */
2350 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
2351 break;
059ec3d9
PH
2352 }
2353 }
2354
2355return done - 2; /* Convert yield values */
2356}
2357
2358
2359
2360
cf0c6164
JH
2361static BOOL
2362smtp_log_tls_fail(uschar * errstr)
2363{
2364uschar * conn_info = smtp_get_connection_info();
2365
2366if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
2367/* I'd like to get separated H= here, but too hard for now */
2368
2369log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
2370return FALSE;
2371}
2372
2373
a2673768
JH
2374
2375
2376#ifdef TCP_FASTOPEN
2377static void
2378tfo_in_check(void)
2379{
2380# ifdef TCP_INFO
2381struct tcp_info tinfo;
2382socklen_t len = sizeof(tinfo);
2383
2384if ( getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
2385 && tinfo.tcpi_state == TCP_SYN_RECV
2386 )
2387 {
1ccd5f67 2388 DEBUG(D_receive) debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
a2673768
JH
2389 tcp_in_fastopen = TRUE;
2390 }
2391# endif
2392}
2393#endif
2394
2395
059ec3d9
PH
2396/*************************************************
2397* Start an SMTP session *
2398*************************************************/
2399
2400/* This function is called at the start of an SMTP session. Thereafter,
2401smtp_setup_msg() is called to initiate each separate message. This
2402function does host-specific testing, and outputs the banner line.
2403
2404Arguments: none
2405Returns: FALSE if the session can not continue; something has
2406 gone wrong, or the connection to the host is blocked
2407*/
2408
2409BOOL
2410smtp_start_session(void)
2411{
acec9514 2412int esclen;
4e88a19f
PH
2413uschar *user_msg, *log_msg;
2414uschar *code, *esc;
acec9514
JH
2415uschar *p, *s;
2416gstring * ss;
059ec3d9 2417
0f1a8658 2418gettimeofday(&smtp_connection_start, NULL);
b4ed4da0
PH
2419for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2420 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2421smtp_ch_index = 0;
2422
00f00ca5
PH
2423/* Default values for certain variables */
2424
059ec3d9 2425helo_seen = esmtp = helo_accept_junk = FALSE;
b4ed4da0 2426smtp_mailcmd_count = 0;
059ec3d9
PH
2427count_nonmail = TRUE_UNSET;
2428synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2429smtp_delay_mail = smtp_rlm_base;
2430auth_advertised = FALSE;
7c576fca 2431smtp_in_pipelining_advertised = FALSE;
cf8b11a5 2432pipelining_enable = TRUE;
059ec3d9 2433sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
8f128379 2434smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2435
33d73e3b
PH
2436/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2437authentication settings from -oMaa to remain in force. */
2438
c44ff8be
JH
2439if (!host_checking && !sender_host_notsocket)
2440 sender_host_auth_pubname = sender_host_authenticated = NULL;
059ec3d9
PH
2441authenticated_by = NULL;
2442
2443#ifdef SUPPORT_TLS
817d9f57 2444tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2445tls_in.ourcert = tls_in.peercert = NULL;
2446tls_in.sni = NULL;
44662487 2447tls_in.ocsp = OCSP_NOT_REQ;
059ec3d9 2448tls_advertised = FALSE;
8ac90765
JH
2449# ifdef EXPERIMENTAL_REQUIRETLS
2450requiretls_advertised = FALSE;
2451# endif
059ec3d9 2452#endif
6c1c3d1d 2453dsn_advertised = FALSE;
8c5d388a 2454#ifdef SUPPORT_I18N
d1a13eea
JH
2455smtputf8_advertised = FALSE;
2456#endif
059ec3d9
PH
2457
2458/* Reset ACL connection variables */
2459
38a0a95f 2460acl_var_c = NULL;
059ec3d9 2461
ca86f471 2462/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 2463
bd8fbe36 2464if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
059ec3d9
PH
2465 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2466 "malloc() failed for SMTP command buffer");
40c90bca 2467
2416c261 2468smtp_cmd_buffer[0] = 0;
bd8fbe36 2469smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2470
2471/* For batched input, the protocol setting can be overridden from the
2472command line by a trusted caller. */
2473
2474if (smtp_batched_input)
2475 {
40c90bca 2476 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2477 }
2478
2479/* For non-batched SMTP input, the protocol setting is forced here. It will be
2480reset later if any of EHLO/AUTH/STARTTLS are received. */
2481
2482else
2483 received_protocol =
e524074d 2484 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2485
2486/* Set up the buffer for inputting using direct read() calls, and arrange to
ecce6d9a
JH
2487call the local functions instead of the standard C ones. Place a NUL at the
2488end of the buffer to safety-stop C-string reads from it. */
059ec3d9 2489
5903c6ff 2490if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
059ec3d9 2491 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
ecce6d9a 2492smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0';
40c90bca 2493
059ec3d9 2494receive_getc = smtp_getc;
0d81dabc 2495receive_getbuf = smtp_getbuf;
584e96c6 2496receive_get_cache = smtp_get_cache;
059ec3d9
PH
2497receive_ungetc = smtp_ungetc;
2498receive_feof = smtp_feof;
2499receive_ferror = smtp_ferror;
58eb016e 2500receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2501smtp_inptr = smtp_inend = smtp_inbuffer;
2502smtp_had_eof = smtp_had_error = 0;
2503
2504/* Set up the message size limit; this may be host-specific */
2505
d45b1de8 2506thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
db57e575 2507if (expand_string_message)
059ec3d9
PH
2508 {
2509 if (thismessage_size_limit == -1)
2510 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2511 "%s", expand_string_message);
2512 else
2513 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2514 "%s", expand_string_message);
2515 smtp_closedown(US"Temporary local problem - please try later");
2516 return FALSE;
2517 }
2518
2519/* When a message is input locally via the -bs or -bS options, sender_host_
2520unknown is set unless -oMa was used to force an IP address, in which case it
2521is checked like a real remote connection. When -bs is used from inetd, this
2522flag is not set, causing the sending host to be checked. The code that deals
2523with IP source routing (if configured) is never required for -bs or -bS and
2524the flag sender_host_notsocket is used to suppress it.
2525
2526If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2527reserve for certain hosts and/or networks. */
2528
2529if (!sender_host_unknown)
2530 {
2531 int rc;
2532 BOOL reserved_host = FALSE;
2533
2534 /* Look up IP options (source routing info) on the socket if this is not an
2535 -oMa "host", and if any are found, log them and drop the connection.
2536
2537 Linux (and others now, see below) is different to everyone else, so there
2538 has to be some conditional compilation here. Versions of Linux before 2.1.15
2539 used a structure whose name was "options". Somebody finally realized that
2540 this name was silly, and it got changed to "ip_options". I use the
2541 newer name here, but there is a fudge in the script that sets up os.h
2542 to define a macro in older Linux systems.
2543
2544 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2545 glibc 2, which has chosen ip_opts for the structure name. This is now
2546 really a glibc thing rather than a Linux thing, so the condition name
2547 has been changed to reflect this. It is relevant also to GNU/Hurd.
2548
2549 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2550 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2551 a special macro defined in the os.h file.
2552
2553 Some DGUX versions on older hardware appear not to support IP options at
2554 all, so there is now a general macro which can be set to cut out this
2555 support altogether.
2556
2557 How to do this properly in IPv6 is not yet known. */
2558
e0574cb5 2559#if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
059ec3d9
PH
2560
2561 #ifdef GLIBC_IP_OPTIONS
2562 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2563 #define OPTSTYLE 1
2564 #else
2565 #define OPTSTYLE 2
2566 #endif
2567 #elif defined DARWIN_IP_OPTIONS
2568 #define OPTSTYLE 2
2569 #else
2570 #define OPTSTYLE 3
2571 #endif
2572
2573 if (!host_checking && !sender_host_notsocket)
2574 {
2575 #if OPTSTYLE == 1
36a3b041 2576 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2577 struct ip_options *ipopt = store_get(optlen);
2578 #elif OPTSTYLE == 2
2579 struct ip_opts ipoptblock;
2580 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2581 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2582 #else
2583 struct ipoption ipoptblock;
2584 struct ipoption *ipopt = &ipoptblock;
36a3b041 2585 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2586 #endif
2587
2588 /* Occasional genuine failures of getsockopt() have been seen - for
2589 example, "reset by peer". Therefore, just log and give up on this
2590 call, unless the error is ENOPROTOOPT. This error is given by systems
2591 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2592 of writing. So for that error, carry on - we just can't do an IP options
2593 check. */
2594
2595 DEBUG(D_receive) debug_printf("checking for IP options\n");
2596
5903c6ff 2597 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
059ec3d9
PH
2598 &optlen) < 0)
2599 {
2600 if (errno != ENOPROTOOPT)
2601 {
2602 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2603 host_and_ident(FALSE), strerror(errno));
925ac8e4 2604 smtp_printf("451 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2605 return FALSE;
2606 }
2607 }
2608
2609 /* Deal with any IP options that are set. On the systems I have looked at,
2610 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2611 more logging data than will fit in big_buffer. Nevertheless, after somebody
2612 questioned this code, I've added in some paranoid checking. */
2613
2614 else if (optlen > 0)
2615 {
2616 uschar *p = big_buffer;
2617 uschar *pend = big_buffer + big_buffer_size;
2618 uschar *opt, *adptr;
2619 int optcount;
2620 struct in_addr addr;
2621
2622 #if OPTSTYLE == 1
5903c6ff 2623 uschar *optstart = US (ipopt->__data);
059ec3d9 2624 #elif OPTSTYLE == 2
5903c6ff 2625 uschar *optstart = US (ipopt->ip_opts);
059ec3d9 2626 #else
5903c6ff 2627 uschar *optstart = US (ipopt->ipopt_list);
059ec3d9
PH
2628 #endif
2629
2630 DEBUG(D_receive) debug_printf("IP options exist\n");
2631
2632 Ustrcpy(p, "IP options on incoming call:");
2633 p += Ustrlen(p);
2634
2635 for (opt = optstart; opt != NULL &&
5903c6ff 2636 opt < US (ipopt) + optlen;)
059ec3d9
PH
2637 {
2638 switch (*opt)
2639 {
2640 case IPOPT_EOL:
2641 opt = NULL;
2642 break;
2643
2644 case IPOPT_NOP:
2645 opt++;
2646 break;
2647
2648 case IPOPT_SSRR:
2649 case IPOPT_LSRR:
2650 if (!string_format(p, pend-p, " %s [@%s",
2651 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2652 #if OPTSTYLE == 1
2653 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2654 #elif OPTSTYLE == 2
2655 inet_ntoa(ipopt->ip_dst)))
2656 #else
2657 inet_ntoa(ipopt->ipopt_dst)))
2658 #endif
2659 {
2660 opt = NULL;
2661 break;
2662 }
2663
2664 p += Ustrlen(p);
2665 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2666 adptr = opt + 3;
2667 while (optcount-- > 0)
2668 {
2669 memcpy(&addr, adptr, sizeof(addr));
2670 if (!string_format(p, pend - p - 1, "%s%s",
2671 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2672 {
2673 opt = NULL;
2674 break;
2675 }
2676 p += Ustrlen(p);
2677 adptr += sizeof(struct in_addr);
2678 }
2679 *p++ = ']';
2680 opt += opt[1];
2681 break;
2682
2683 default:
2684 {
2685 int i;
2686 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2687 Ustrcat(p, "[ ");
2688 p += 2;
2689 for (i = 0; i < opt[1]; i++)
5976eb99 2690 p += sprintf(CS p, "%2.2x ", opt[i]);
059ec3d9
PH
2691 *p++ = ']';
2692 }
2693 opt += opt[1];
2694 break;
2695 }
2696 }
2697
2698 *p = 0;
2699 log_write(0, LOG_MAIN, "%s", big_buffer);
2700
2701 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2702
2703 log_write(0, LOG_MAIN|LOG_REJECT,
2704 "connection from %s refused (IP options)", host_and_ident(FALSE));
2705
925ac8e4 2706 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2707 return FALSE;
2708 }
2709
2710 /* Length of options = 0 => there are no options */
2711
2712 else DEBUG(D_receive) debug_printf("no IP options found\n");
2713 }
e0574cb5 2714#endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
059ec3d9
PH
2715
2716 /* Set keep-alive in socket options. The option is on by default. This
2717 setting is an attempt to get rid of some hanging connections that stick in
2718 read() when the remote end (usually a dialup) goes away. */
2719
2720 if (smtp_accept_keepalive && !sender_host_notsocket)
2721 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2722
2723 /* If the current host matches host_lookup, set the name by doing a
2724 reverse lookup. On failure, sender_host_name will be NULL and
2725 host_lookup_failed will be TRUE. This may or may not be serious - optional
2726 checks later. */
2727
2728 if (verify_check_host(&host_lookup) == OK)
2729 {
2730 (void)host_name_lookup();
2731 host_build_sender_fullhost();
2732 }
2733
2734 /* Delay this until we have the full name, if it is looked up. */
2735
2736 set_process_info("handling incoming connection from %s",
2737 host_and_ident(FALSE));
2738
1ad6489e
JH
2739 /* Expand smtp_receive_timeout, if needed */
2740
2741 if (smtp_receive_timeout_s)
2742 {
2743 uschar * exp;
2744 if ( !(exp = expand_string(smtp_receive_timeout_s))
2745 || !(*exp)
2746 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2747 )
2748 log_write(0, LOG_MAIN|LOG_PANIC,
2749 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2750 }
2751
059ec3d9
PH
2752 /* Test for explicit connection rejection */
2753
2754 if (verify_check_host(&host_reject_connection) == OK)
2755 {
2756 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2757 "from %s (host_reject_connection)", host_and_ident(FALSE));
925ac8e4 2758 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2759 return FALSE;
2760 }
2761
afb3eaaf
PH
2762 /* Test with TCP Wrappers if so configured. There is a problem in that
2763 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2764 such as disks dying. In these cases, it is desirable to reject with a 4xx
2765 error instead of a 5xx error. There isn't a "right" way to detect such
2766 problems. The following kludge is used: errno is zeroed before calling
2767 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2768 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2769 not exist). */
059ec3d9 2770
1811cb4c 2771#ifdef USE_TCP_WRAPPERS
afb3eaaf 2772 errno = 0;
1811cb4c 2773 if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
5dc43717
JJ
2774 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2775 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2776 expand_string_message);
1811cb4c 2777
5dc43717 2778 if (!hosts_ctl(tcp_wrappers_name,
1811cb4c
JH
2779 sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
2780 sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
2781 sender_ident ? CS sender_ident : STRING_UNKNOWN))
059ec3d9 2782 {
afb3eaaf
PH
2783 if (errno == 0 || errno == ENOENT)
2784 {
2785 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2786 log_write(L_connection_reject,
2787 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2788 "(tcp wrappers)", host_and_ident(FALSE));
925ac8e4 2789 smtp_printf("554 SMTP service not available\r\n", FALSE);
afb3eaaf
PH
2790 }
2791 else
2792 {
2793 int save_errno = errno;
2794 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2795 "errno value %d\n", save_errno);
2796 log_write(L_connection_reject,
2797 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2798 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
925ac8e4 2799 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
afb3eaaf 2800 }
059ec3d9
PH
2801 return FALSE;
2802 }
1811cb4c 2803#endif
059ec3d9 2804
b01dd148
PH
2805 /* Check for reserved slots. The value of smtp_accept_count has already been
2806 incremented to include this process. */
059ec3d9
PH
2807
2808 if (smtp_accept_max > 0 &&
b01dd148 2809 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2810 {
2811 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2812 {
2813 log_write(L_connection_reject,
2814 LOG_MAIN, "temporarily refused connection from %s: not in "
2815 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2816 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2817 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2818 smtp_printf("421 %s: Too many concurrent SMTP connections; "
925ac8e4 2819 "please try again later\r\n", FALSE, smtp_active_hostname);
059ec3d9
PH
2820 return FALSE;
2821 }
2822 reserved_host = TRUE;
2823 }
2824
2825 /* If a load level above which only messages from reserved hosts are
2826 accepted is set, check the load. For incoming calls via the daemon, the
2827 check is done in the superior process if there are no reserved hosts, to
2828 save a fork. In all cases, the load average will already be available
2829 in a global variable at this point. */
2830
2831 if (smtp_load_reserve >= 0 &&
2832 load_average > smtp_load_reserve &&
2833 !reserved_host &&
2834 verify_check_host(&smtp_reserve_hosts) != OK)
2835 {
2836 log_write(L_connection_reject,
2837 LOG_MAIN, "temporarily refused connection from %s: not in "
2838 "reserve list and load average = %.2f", host_and_ident(FALSE),
2839 (double)load_average/1000.0);
925ac8e4 2840 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
059ec3d9
PH
2841 smtp_active_hostname);
2842 return FALSE;
2843 }
2844
2845 /* Determine whether unqualified senders or recipients are permitted
2846 for this host. Unfortunately, we have to do this every time, in order to
2847 set the flags so that they can be inspected when considering qualifying
2848 addresses in the headers. For a site that permits no qualification, this
2849 won't take long, however. */
2850
2851 allow_unqualified_sender =
2852 verify_check_host(&sender_unqualified_hosts) == OK;
2853
2854 allow_unqualified_recipient =
2855 verify_check_host(&recipient_unqualified_hosts) == OK;
2856
2857 /* Determine whether HELO/EHLO is required for this host. The requirement
2858 can be hard or soft. */
2859
2860 helo_required = verify_check_host(&helo_verify_hosts) == OK;
2861 if (!helo_required)
2862 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
2863
2864 /* Determine whether this hosts is permitted to send syntactic junk
2865 after a HELO or EHLO command. */
2866
2867 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
2868 }
2869
2870/* For batch SMTP input we are now done. */
2871
2872if (smtp_batched_input) return TRUE;
2873
a3c86431
TL
2874/* If valid Proxy Protocol source is connecting, set up session.
2875 * Failure will not allow any SMTP function other than QUIT. */
1811cb4c
JH
2876
2877#ifdef SUPPORT_PROXY
a3c86431
TL
2878proxy_session = FALSE;
2879proxy_session_failed = FALSE;
2880if (check_proxy_protocol_host())
1811cb4c
JH
2881 setup_proxy_protocol_host();
2882#endif
2883
2884 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2885 smtps port for use with older style SSL MTAs. */
2886
2887#ifdef SUPPORT_TLS
69d8eed7
JH
2888 if (tls_in.on_connect)
2889 {
2890 if (tls_server_start(tls_require_ciphers, &user_msg) != OK)
2891 return smtp_log_tls_fail(user_msg);
2892 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
2893 }
a3c86431
TL
2894#endif
2895
1811cb4c 2896/* Run the connect ACL if it exists */
059ec3d9 2897
4e88a19f 2898user_msg = NULL;
3cc3f762 2899if (acl_smtp_connect)
059ec3d9
PH
2900 {
2901 int rc;
3cc3f762
JH
2902 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2903 &log_msg)) != OK)
059ec3d9 2904 {
3cc3f762 2905 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2906 return FALSE;
2907 }
2908 }
2909
2910/* Output the initial message for a two-way SMTP connection. It may contain
2911newlines, which then cause a multi-line response to be given. */
2912
4e88a19f
PH
2913code = US"220"; /* Default status code */
2914esc = US""; /* Default extended status code */
2915esclen = 0; /* Length of esc */
2916
d4ff61d1 2917if (!user_msg)
4e88a19f 2918 {
d4ff61d1 2919 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2920 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2921 "failed: %s", smtp_banner, expand_string_message);
2922 }
2923else
2924 {
2925 int codelen = 3;
2926 s = user_msg;
4f6ae5c3 2927 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2928 if (codelen > 4)
4e88a19f
PH
2929 {
2930 esc = code + 4;
2931 esclen = codelen - 4;
2932 }
2933 }
059ec3d9
PH
2934
2935/* Remove any terminating newlines; might as well remove trailing space too */
2936
2937p = s + Ustrlen(s);
2938while (p > s && isspace(p[-1])) p--;
2939*p = 0;
2940
2941/* It seems that CC:Mail is braindead, and assumes that the greeting message
2942is all contained in a single IP packet. The original code wrote out the
2943greeting using several calls to fprint/fputc, and on busy servers this could
2944cause it to be split over more than one packet - which caused CC:Mail to fall
2945over when it got the second part of the greeting after sending its first
2946command. Sigh. To try to avoid this, build the complete greeting message
2947first, and output it in one fell swoop. This gives a better chance of it
2948ending up as a single packet. */
2949
acec9514 2950ss = string_get(256);
059ec3d9
PH
2951
2952p = s;
2953do /* At least once, in case we have an empty string */
2954 {
2955 int len;
2956 uschar *linebreak = Ustrchr(p, '\n');
acec9514 2957 ss = string_catn(ss, code, 3);
db57e575 2958 if (!linebreak)
059ec3d9
PH
2959 {
2960 len = Ustrlen(p);
acec9514 2961 ss = string_catn(ss, US" ", 1);
059ec3d9
PH
2962 }
2963 else
2964 {
2965 len = linebreak - p;
acec9514 2966 ss = string_catn(ss, US"-", 1);
059ec3d9 2967 }
acec9514
JH
2968 ss = string_catn(ss, esc, esclen);
2969 ss = string_catn(ss, p, len);
2970 ss = string_catn(ss, US"\r\n", 2);
059ec3d9 2971 p += len;
db57e575 2972 if (linebreak) p++;
059ec3d9 2973 }
db57e575 2974while (*p);
059ec3d9 2975
059ec3d9
PH
2976/* Before we write the banner, check that there is no input pending, unless
2977this synchronisation check is disabled. */
2978
a14e5636 2979if (!check_sync())
059ec3d9 2980 {
40525d07
JH
2981 unsigned n = smtp_inend - smtp_inptr;
2982 if (n > 32) n = 32;
2983
a14e5636
PH
2984 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2985 "synchronization error (input sent without waiting for greeting): "
2986 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
40525d07 2987 string_printing(string_copyn(smtp_inptr, n)));
925ac8e4 2988 smtp_printf("554 SMTP synchronization error\r\n", FALSE);
a14e5636 2989 return FALSE;
059ec3d9
PH
2990 }
2991
2992/* Now output the banner */
2993
acec9514 2994smtp_printf("%s", FALSE, string_from_gstring(ss));
a2673768
JH
2995
2996/* Attempt to see if we sent the banner before the last ACK of the 3-way
2997handshake arrived. If so we must have managed a TFO. */
2998
2999#ifdef TCP_FASTOPEN
3000tfo_in_check();
3001#endif
3002
059ec3d9
PH
3003return TRUE;
3004}
3005
3006
3007
3008
3009
3010/*************************************************
3011* Handle SMTP syntax and protocol errors *
3012*************************************************/
3013
3014/* Write to the log for SMTP syntax errors in incoming commands, if configured
3015to do so. Then transmit the error response. The return value depends on the
3016number of syntax and protocol errors in this SMTP session.
3017
3018Arguments:
3019 type error type, given as a log flag bit
3020 code response code; <= 0 means don't send a response
3021 data data to reflect in the response (can be NULL)
3022 errmess the error message
3023
3024Returns: -1 limit of syntax/protocol errors NOT exceeded
3025 +1 limit of syntax/protocol errors IS exceeded
3026
3027These values fit in with the values of the "done" variable in the main
3028processing loop in smtp_setup_msg(). */
3029
3030static int
3031synprot_error(int type, int code, uschar *data, uschar *errmess)
3032{
3033int yield = -1;
3034
3035log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
3036 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 3037 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
3038
3039if (++synprot_error_count > smtp_max_synprot_errors)
3040 {
3041 yield = 1;
3042 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
3043 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 3044 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
3045 }
3046
3047if (code > 0)
3048 {
925ac8e4
JH
3049 smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
3050 data ? data : US"", data ? US": " : US"", errmess);
059ec3d9 3051 if (yield == 1)
925ac8e4 3052 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
059ec3d9
PH
3053 }
3054
3055return yield;
3056}
3057
3058
3059
3060
3061/*************************************************
059ec3d9
PH
3062* Send SMTP response, possibly multiline *
3063*************************************************/
3064
3065/* There are, it seems, broken clients out there that cannot handle multiline
3066responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3067output nothing for non-final calls, and only the first line for anything else.
3068
3069Arguments:
a5bd321b 3070 code SMTP code, may involve extended status codes
d6a96edc 3071 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
3072 final FALSE if the last line isn't the final line
3073 msg message text, possibly containing newlines
3074
3075Returns: nothing
3076*/
3077
3078void
a5bd321b 3079smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 3080{
a5bd321b
PH
3081int esclen = 0;
3082uschar *esc = US"";
3083
059ec3d9
PH
3084if (!final && no_multiline_responses) return;
3085
d6a96edc 3086if (codelen > 4)
a5bd321b
PH
3087 {
3088 esc = code + 4;
3089 esclen = codelen - 4;
3090 }
3091
2679d413
PH
3092/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3093have had the same. Note: this code is also present in smtp_printf(). It would
3094be tidier to have it only in one place, but when it was added, it was easier to
3095do it that way, so as not to have to mess with the code for the RCPT command,
3096which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3097
3098if (rcpt_in_progress)
3099 {
3100 if (rcpt_smtp_response == NULL)
3101 rcpt_smtp_response = string_copy(msg);
3102 else if (rcpt_smtp_response_same &&
3103 Ustrcmp(rcpt_smtp_response, msg) != 0)
3104 rcpt_smtp_response_same = FALSE;
3105 rcpt_in_progress = FALSE;
3106 }
3107
e5de01f0 3108/* Now output the message, splitting it up into multiple lines if necessary.
925ac8e4
JH
3109We only handle pipelining these responses as far as nonfinal/final groups,
3110not the whole MAIL/RCPT/DATA response set. */
2679d413 3111
059ec3d9
PH
3112for (;;)
3113 {
3114 uschar *nl = Ustrchr(msg, '\n');
3115 if (nl == NULL)
3116 {
925ac8e4 3117 smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
059ec3d9
PH
3118 return;
3119 }
3120 else if (nl[1] == 0 || no_multiline_responses)
3121 {
925ac8e4 3122 smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
a5bd321b 3123 (int)(nl - msg), msg);
059ec3d9
PH
3124 return;
3125 }
3126 else
3127 {
925ac8e4 3128 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
3129 msg = nl + 1;
3130 while (isspace(*msg)) msg++;
3131 }
3132 }
3133}
3134
3135
3136
3137
3138/*************************************************
4e88a19f
PH
3139* Parse user SMTP message *
3140*************************************************/
3141
3142/* This function allows for user messages overriding the response code details
3143by providing a suitable response code string at the start of the message
3144user_msg. Check the message for starting with a response code and optionally an
3145extended status code. If found, check that the first digit is valid, and if so,
3146change the code pointer and length to use the replacement. An invalid code
3147causes a panic log; in this case, if the log messages is the same as the user
3148message, we must also adjust the value of the log message to show the code that
3149is actually going to be used (the original one).
3150
3151This function is global because it is called from receive.c as well as within
3152this module.
3153
d6a96edc
PH
3154Note that the code length returned includes the terminating whitespace
3155character, which is always included in the regex match.
3156
4e88a19f
PH
3157Arguments:
3158 code SMTP code, may involve extended status codes
d6a96edc 3159 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
3160 msg message text
3161 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 3162 check_valid if true, verify the response code
4e88a19f
PH
3163
3164Returns: nothing
3165*/
3166
3167void
4f6ae5c3
JH
3168smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
3169 BOOL check_valid)
4e88a19f
PH
3170{
3171int n;
3172int ovector[3];
3173
4f6ae5c3 3174if (!msg || !*msg) return;
4e88a19f 3175
4f6ae5c3
JH
3176if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
3177 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 3178
4f6ae5c3 3179if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
3180 {
3181 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
3182 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
3183 if (log_msg != NULL && *log_msg == *msg)
3184 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
3185 }
3186else
3187 {
3188 *code = *msg;
3189 *codelen = ovector[1]; /* Includes final space */
3190 }
3191*msg += ovector[1]; /* Chop the code off the message */
3192return;
3193}
3194
3195
3196
3197
3198/*************************************************
059ec3d9
PH
3199* Handle an ACL failure *
3200*************************************************/
3201
3202/* This function is called when acl_check() fails. As well as calls from within
3203this module, it is called from receive.c for an ACL after DATA. It sorts out
5b6f7658 3204logging the incident, and sends the error response. A message containing
059ec3d9
PH
3205newlines is turned into a multiline SMTP response, but for logging, only the
3206first line is used.
3207
a5bd321b
PH
3208There's a table of default permanent failure response codes to use in
3209globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3210defaults disabled in Exim. However, discussion in connection with RFC 821bis
3211(aka RFC 2821) has concluded that the response should be 252 in the disabled
3212state, because there are broken clients that try VRFY before RCPT. A 5xx
3213response should be given only when the address is positively known to be
4f6ae5c3
JH
3214undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3215no explicit code, but if there is one we let it know best.
3216Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
3217
3218From Exim 4.63, it is possible to override the response code details by
3219providing a suitable response code string at the start of the message provided
3220in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
3221
3222Arguments:
4f6ae5c3
JH
3223 where where the ACL was called from
3224 rc the failure code
3225 user_msg a message that can be included in an SMTP response
3226 log_msg a message for logging
059ec3d9
PH
3227
3228Returns: 0 in most cases
3229 2 if the failure code was FAIL_DROP, in which case the
3230 SMTP connection should be dropped (this value fits with the
3231 "done" variable in smtp_setup_msg() below)
3232*/
3233
3234int
3235smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
3236{
059ec3d9 3237BOOL drop = rc == FAIL_DROP;
a5bd321b 3238int codelen = 3;
a5bd321b 3239uschar *smtp_code;
059ec3d9
PH
3240uschar *lognl;
3241uschar *sender_info = US"";
64ffc24f 3242uschar *what =
8523533c 3243#ifdef WITH_CONTENT_SCAN
3cc3f762 3244 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 3245#endif
3cc3f762
JH
3246 where == ACL_WHERE_PREDATA ? US"DATA" :
3247 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 3248#ifndef DISABLE_PRDR
3cc3f762 3249 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 3250#endif
3cc3f762
JH
3251 smtp_cmd_data ?
3252 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
3253 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
3254
3255if (drop) rc = FAIL;
3256
4e88a19f 3257/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 3258
4f6ae5c3
JH
3259smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
3260smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
3261 where != ACL_WHERE_VRFY);
a5bd321b 3262
059ec3d9
PH
3263/* We used to have sender_address here; however, there was a bug that was not
3264updating sender_address after a rewrite during a verify. When this bug was
3265fixed, sender_address at this point became the rewritten address. I'm not sure
3266this is what should be logged, so I've changed to logging the unrewritten
3267address to retain backward compatibility. */
3268
8523533c 3269#ifndef WITH_CONTENT_SCAN
059ec3d9 3270if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
3271#else
3272if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
3273#endif
059ec3d9 3274 {
b98bb9ac
PP
3275 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
3276 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
3277 sender_host_authenticated ? US" A=" : US"",
3278 sender_host_authenticated ? sender_host_authenticated : US"",
3279 sender_host_authenticated && authenticated_id ? US":" : US"",
3280 sender_host_authenticated && authenticated_id ? authenticated_id : US""
3281 );
059ec3d9
PH
3282 }
3283
3284/* If there's been a sender verification failure with a specific message, and
3285we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
3286failures, but not defers. However, always log it for defer, and log it for fail
3287unless the sender_verify_fail log selector has been turned off. */
059ec3d9 3288
02b41d71 3289if (sender_verified_failed &&
059ec3d9
PH
3290 !testflag(sender_verified_failed, af_sverify_told))
3291 {
2679d413
PH
3292 BOOL save_rcpt_in_progress = rcpt_in_progress;
3293 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
3294
059ec3d9
PH
3295 setflag(sender_verified_failed, af_sverify_told);
3296
6c6d6e48 3297 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
3298 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
3299 host_and_ident(TRUE),
3300 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
3301 sender_verified_failed->address,
3302 (sender_verified_failed->message == NULL)? US"" :
3303 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 3304
02b41d71 3305 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 3306 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
3307 testflag(sender_verified_failed, af_verify_pmfail)?
3308 "Postmaster verification failed while checking <%s>\n%s\n"
3309 "Several RFCs state that you are required to have a postmaster\n"
3310 "mailbox for each mail domain. This host does not accept mail\n"
3311 "from domains whose servers reject the postmaster address."
3312 :
3313 testflag(sender_verified_failed, af_verify_nsfail)?
3314 "Callback setup failed while verifying <%s>\n%s\n"
3315 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3316 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3317 "RFC requirements, and stops you from receiving standard bounce\n"
3318 "messages. This host does not accept mail from domains whose servers\n"
3319 "refuse bounces."
3320 :
3321 "Verification failed for <%s>\n%s",
3322 sender_verified_failed->address,
3323 sender_verified_failed->user_message));
2679d413
PH
3324
3325 rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
3326 }
3327
3328/* Sort out text for logging */
3329
3cc3f762
JH
3330log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
3331if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
3332
3333/* Send permanent failure response to the command, but the code used isn't
3334always a 5xx one - see comments at the start of this function. If the original
3335rc was FAIL_DROP we drop the connection and yield 2. */
3336
ff5929e3
JH
3337if (rc == FAIL)
3338 smtp_respond(smtp_code, codelen, TRUE,
3339 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
3340
3341/* Send temporary failure response to the command. Don't give any details,
3342unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3343verb, and for a header verify when smtp_return_error_details is set.
3344
3345This conditional logic is all somewhat of a mess because of the odd
3346interactions between temp_details and return_error_details. One day it should
3347be re-implemented in a tidier fashion. */
3348
3349else
ff5929e3 3350 if (acl_temp_details && user_msg)
059ec3d9 3351 {
ff5929e3
JH
3352 if ( smtp_return_error_details
3353 && sender_verified_failed
3354 && sender_verified_failed->message
3355 )
a5bd321b 3356 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3357
a5bd321b 3358 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3359 }
3360 else
a5bd321b
PH
3361 smtp_respond(smtp_code, codelen, TRUE,
3362 US"Temporary local problem - please try later");
059ec3d9 3363
6ea85e9a
PH
3364/* Log the incident to the logs that are specified by log_reject_target
3365(default main, reject). This can be empty to suppress logging of rejections. If
3366the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3367is closing if required and return 2. */
059ec3d9 3368
6ea85e9a 3369if (log_reject_target != 0)
887291d2 3370 {
e45a1c37 3371#ifdef SUPPORT_TLS
acec9514
JH
3372 gstring * g = s_tlslog(NULL);
3373 uschar * tls = string_from_gstring(g);
fc16abb4 3374 if (!tls) tls = US"";
e45a1c37 3375#else
fc16abb4 3376 uschar * tls = US"";
e45a1c37 3377#endif
3cc3f762
JH
3378 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3379 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3380 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3381 host_and_ident(TRUE),
3382 tls,
3383 sender_info,
3384 rc == FAIL ? US"" : US"temporarily ",
3385 what, log_msg);
887291d2 3386 }
059ec3d9
PH
3387
3388if (!drop) return 0;
3389
3390log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3391 smtp_get_connection_info());
8f128379
PH
3392
3393/* Run the not-quit ACL, but without any custom messages. This should not be a
3394problem, because we get here only if some other ACL has issued "drop", and
3395in that case, *its* custom messages will have been used above. */
3396
3397smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3398return 2;
3399}
3400
3401
3402
3403
3404/*************************************************
8f128379
PH
3405* Handle SMTP exit when QUIT is not given *
3406*************************************************/
3407
3408/* This function provides a logging/statistics hook for when an SMTP connection
3409is dropped on the floor or the other end goes away. It's a global function
3410because it's called from receive.c as well as this module. As well as running
3411the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3412response, either with a custom message from the ACL, or using a default. There
3413is one case, however, when no message is output - after "drop". In that case,
3414the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3415passed to this function.
3416
3417In case things go wrong while processing this function, causing an error that
4c04137d 3418may re-enter this function, there is a recursion check.
8f128379
PH
3419
3420Arguments:
3421 reason What $smtp_notquit_reason will be set to in the ACL;
3422 if NULL, the ACL is not run
3423 code The error code to return as part of the response
3424 defaultrespond The default message if there's no user_msg
3425
3426Returns: Nothing
3427*/
3428
3429void
3430smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
3431{
3432int rc;
3433uschar *user_msg = NULL;
3434uschar *log_msg = NULL;
3435
3436/* Check for recursive acll */
3437
3438if (smtp_exit_function_called)
3439 {
3440 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
3441 reason);
3442 return;
3443 }
3444smtp_exit_function_called = TRUE;
3445
3446/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3447
eea0defe 3448if (acl_smtp_notquit && reason)
8f128379
PH
3449 {
3450 smtp_notquit_reason = reason;
eea0defe
JB
3451 if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
3452 &log_msg)) == ERROR)
8f128379
PH
3453 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
3454 log_msg);
3455 }
3456
3457/* Write an SMTP response if we are expected to give one. As the default
3458responses are all internal, they should always fit in the buffer, but code a
3459warning, just in case. Note that string_vformat() still leaves a complete
3460string, even if it is incomplete. */
3461
eea0defe 3462if (code && defaultrespond)
8f128379 3463 {
eea0defe
JB
3464 if (user_msg)
3465 smtp_respond(code, 3, TRUE, user_msg);
3466 else
8f128379
PH
3467 {
3468 uschar buffer[128];
3469 va_list ap;
3470 va_start(ap, defaultrespond);
3471 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
3472 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
925ac8e4 3473 smtp_printf("%s %s\r\n", FALSE, code, buffer);
8f128379
PH
3474 va_end(ap);
3475 }
8f128379
PH
3476 mac_smtp_fflush();
3477 }
3478}
3479
3480
3481
3482
3483/*************************************************
d7b47fd0
PH
3484* Verify HELO argument *
3485*************************************************/
3486
3487/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3488matched. It is also called from ACL processing if verify = helo is used and
3489verification was not previously tried (i.e. helo_try_verify_hosts was not
3490matched). The result of its processing is to set helo_verified and
3491helo_verify_failed. These variables should both be FALSE for this function to
3492be called.
3493
3494Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3495for IPv6 ::ffff: literals.
3496
3497Argument: none
3498Returns: TRUE if testing was completed;
3499 FALSE on a temporary failure
3500*/
3501
3502BOOL
3503smtp_verify_helo(void)
3504{
3505BOOL yield = TRUE;
3506
3507HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3508 sender_helo_name);
3509
3510if (sender_helo_name == NULL)
3511 {
3512 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
3513 }
3514
d1d5595c
PH
3515/* Deal with the case of -bs without an IP address */
3516
3517else if (sender_host_address == NULL)
3518 {
3519 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
3520 helo_verified = TRUE;
3521 }
3522
3523/* Deal with the more common case when there is a sending IP address */
3524
d7b47fd0
PH
3525else if (sender_helo_name[0] == '[')
3526 {
3527 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
3528 Ustrlen(sender_host_address)) == 0;
3529
e0574cb5 3530#if HAVE_IPV6
d7b47fd0
PH
3531 if (!helo_verified)
3532 {
3533 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
3534 helo_verified = Ustrncmp(sender_helo_name + 1,
3535 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
3536 }
e0574cb5 3537#endif
d7b47fd0
PH
3538
3539 HDEBUG(D_receive)
3540 { if (helo_verified) debug_printf("matched host address\n"); }
3541 }
3542
3543/* Do a reverse lookup if one hasn't already given a positive or negative
3544response. If that fails, or the name doesn't match, try checking with a forward
3545lookup. */
3546
3547else
3548 {
3549 if (sender_host_name == NULL && !host_lookup_failed)
3550 yield = host_name_lookup() != DEFER;
3551
3552 /* If a host name is known, check it and all its aliases. */
3553
1705dd20
JH
3554 if (sender_host_name)
3555 if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
d7b47fd0 3556 {
1705dd20 3557 sender_helo_dnssec = sender_host_dnssec;
d7b47fd0
PH
3558 HDEBUG(D_receive) debug_printf("matched host name\n");