1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) The Exim Maintainers 2020 - 2022 */
6 /* Copyright (c) University of Cambridge 1995 - 2018 */
7 /* See the file NOTICE for conditions of use and distribution. */
9 /* General functions concerned with transportation, and generic options for all
15 /* Generic options for transports, all of which live inside transport_instance
16 data blocks and which therefore have the opt_public flag set. Note that there
17 are other options living inside this structure which can be set only from
18 certain transports. */
19 #define LOFF(field) OPT_OFF(transport_instance, field)
21 optionlist optionlist_transports[] = {
23 { "*expand_group", opt_stringptr|opt_hidden|opt_public,
25 { "*expand_user", opt_stringptr|opt_hidden|opt_public,
27 { "*headers_rewrite_flags", opt_int|opt_public|opt_hidden,
28 LOFF(rewrite_existflags) },
29 { "*headers_rewrite_rules", opt_void|opt_public|opt_hidden,
30 LOFF(rewrite_rules) },
31 { "*set_group", opt_bool|opt_hidden|opt_public,
33 { "*set_user", opt_bool|opt_hidden|opt_public,
35 { "body_only", opt_bool|opt_public,
37 { "current_directory", opt_stringptr|opt_public,
39 { "debug_print", opt_stringptr | opt_public,
41 { "delivery_date_add", opt_bool|opt_public,
42 LOFF(delivery_date_add) },
43 { "disable_logging", opt_bool|opt_public,
44 LOFF(disable_logging) },
45 { "driver", opt_stringptr|opt_public,
47 { "envelope_to_add", opt_bool|opt_public,
48 LOFF(envelope_to_add) },
50 { "event_action", opt_stringptr | opt_public,
53 { "group", opt_expand_gid|opt_public,
55 { "headers_add", opt_stringptr|opt_public|opt_rep_str,
57 { "headers_only", opt_bool|opt_public,
59 { "headers_remove", opt_stringptr|opt_public|opt_rep_str,
60 LOFF(remove_headers) },
61 { "headers_rewrite", opt_rewrite|opt_public,
62 LOFF(headers_rewrite) },
63 { "home_directory", opt_stringptr|opt_public,
65 { "initgroups", opt_bool|opt_public,
67 { "max_parallel", opt_stringptr|opt_public,
69 { "message_size_limit", opt_stringptr|opt_public,
70 LOFF(message_size_limit) },
71 { "rcpt_include_affixes", opt_bool|opt_public,
72 LOFF(rcpt_include_affixes) },
73 { "retry_use_local_part", opt_bool|opt_public,
74 LOFF(retry_use_local_part) },
75 { "return_path", opt_stringptr|opt_public,
77 { "return_path_add", opt_bool|opt_public,
78 LOFF(return_path_add) },
79 { "shadow_condition", opt_stringptr|opt_public,
80 LOFF(shadow_condition) },
81 { "shadow_transport", opt_stringptr|opt_public,
83 { "transport_filter", opt_stringptr|opt_public,
84 LOFF(filter_command) },
85 { "transport_filter_timeout", opt_time|opt_public,
86 LOFF(filter_timeout) },
87 { "user", opt_expand_uid|opt_public,
91 int optionlist_transports_size = nelem(optionlist_transports);
95 # include "macro_predef.h"
98 options_transports(void)
102 options_from_list(optionlist_transports, nelem(optionlist_transports), US"TRANSPORTS", NULL);
104 for (transport_info * ti = transports_available; ti->driver_name[0]; ti++)
106 spf(buf, sizeof(buf), US"_DRIVER_TRANSPORT_%T", ti->driver_name);
107 builtin_macro_create(buf);
108 options_from_list(ti->options, (unsigned)*ti->options_count, US"TRANSPORT", ti->driver_name);
112 #else /*!MACRO_PREDEF*/
114 /* Structure for keeping list of addresses that have been added to
115 Envelope-To:, in order to avoid duplication. */
123 /* Static data for write_chunk() */
125 static uschar *chunk_ptr; /* chunk pointer */
126 static uschar *nl_check; /* string to look for at line start */
127 static int nl_check_length; /* length of same */
128 static uschar *nl_escape; /* string to insert */
129 static int nl_escape_length; /* length of same */
130 static int nl_partial_match; /* length matched at chunk end */
133 /*************************************************
134 * Initialize transport list *
135 *************************************************/
137 /* Read the transports section of the configuration file, and set up a chain of
138 transport instances according to its contents. Each transport has generic
139 options and may also have its own private options. This function is only ever
140 called when transports == NULL. We use generic code in readconf to do most of
146 readconf_driver_init(US"transport",
147 (driver_instance **)(&transports), /* chain anchor */
148 (driver_info *)transports_available, /* available drivers */
149 sizeof(transport_info), /* size of info block */
150 &transport_defaults, /* default values for generic options */
151 sizeof(transport_instance), /* size of instance block */
152 optionlist_transports, /* generic options */
153 optionlist_transports_size);
155 /* Now scan the configured transports and check inconsistencies. A shadow
156 transport is permitted only for local transports. */
158 for (transport_instance * t = transports; t; t = t->next)
160 if (!t->info->local && t->shadow)
161 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
162 "shadow transport not allowed on non-local transport %s", t->name);
164 if (t->body_only && t->headers_only)
165 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
166 "%s transport: body_only and headers_only are mutually exclusive",
173 /*************************************************
174 * Write block of data *
175 *************************************************/
178 tpt_write(int fd, uschar * block, int len, BOOL more, int options)
182 tls_out.active.sock == fd
183 ? tls_write(tls_out.active.tls_ctx, block, len, more) :
186 more && !(options & topt_not_socket) ? send(fd, block, len, MSG_MORE) :
188 write(fd, block, len);
191 /* Subroutine called by write_chunk() and at the end of the message actually
192 to write a data block. Also called directly by some transports to write
193 additional data to the file descriptor (e.g. prefix, suffix).
195 If a transport wants data transfers to be timed, it sets a non-zero value in
196 transport_write_timeout. A non-zero transport_write_timeout causes a timer to
197 be set for each block of data written from here. If time runs out, then write()
198 fails and provokes an error return. The caller can then inspect sigalrm_seen to
201 On some systems, if a quota is exceeded during the write, the yield is the
202 number of bytes written rather than an immediate error code. This also happens
203 on some systems in other cases, for example a pipe that goes away because the
204 other end's process terminates (Linux). On other systems, (e.g. Solaris 2) you
205 get the error codes the first time.
207 The write() function is also interruptible; the Solaris 2.6 man page says:
209 If write() is interrupted by a signal before it writes any
210 data, it will return -1 with errno set to EINTR.
212 If write() is interrupted by a signal after it successfully
213 writes some data, it will return the number of bytes written.
215 To handle these cases, we want to restart the write() to output the remainder
216 of the data after a non-negative return from write(), except after a timeout.
217 In the error cases (EDQUOT, EPIPE) no bytes get written the second time, and a
218 proper error then occurs. In principle, after an interruption, the second
219 write() could suffer the same fate, but we do not want to continue for
220 evermore, so stick a maximum repetition count on the loop to act as a
224 tctx transport context: file descriptor or string to write to
225 block block of bytes to write
226 len number of bytes to write
227 more further data expected soon
229 Returns: TRUE on success, FALSE on failure (with errno preserved);
230 transport_count is incremented by the number of bytes written
234 transport_write_block_fd(transport_ctx * tctx, uschar * block, int len, BOOL more)
237 int local_timeout = transport_write_timeout;
241 /* This loop is for handling incomplete writes and other retries. In most
242 normal cases, it is only ever executed once. */
244 for (int i = 0; i < 100; i++)
247 debug_printf("writing data block fd=%d size=%d timeout=%d%s\n",
248 fd, len, local_timeout, more ? " (more expected)" : "");
250 /* When doing TCP Fast Open we may get this far before the 3-way handshake
251 is complete, and write returns ENOTCONN. Detect that, wait for the socket
252 to become writable, and retry once only. */
256 /* This code makes use of alarm() in order to implement the timeout. This
257 isn't a very tidy way of doing things. Using non-blocking I/O with select()
258 provides a neater approach. However, I don't know how to do this when TLS is
261 if (transport_write_timeout <= 0) /* No timeout wanted */
263 rc = tpt_write(fd, block, len, more, tctx->options);
266 else /* Timeout wanted. */
268 sigalrm_seen = FALSE;
269 ALARM(local_timeout);
270 rc = tpt_write(fd, block, len, more, tctx->options);
272 local_timeout = ALARM_CLR(0);
280 if (rc >= 0 || errno != ENOTCONN || connretry <= 0)
283 poll_one_fd(fd, POLLOUT, -1); /* could set timeout? retval check? */
287 /* Hopefully, the most common case is success, so test that first. */
289 if (rc == len) { transport_count += len; return TRUE; }
291 /* A non-negative return code is an incomplete write. Try again for the rest
292 of the block. If we have exactly hit the timeout, give up. */
298 transport_count += rc;
299 DEBUG(D_transport) debug_printf("write incomplete (%d)\n", rc);
300 goto CHECK_TIMEOUT; /* A few lines below */
303 /* A negative return code with an EINTR error is another form of
304 incomplete write, zero bytes having been written */
306 if (save_errno == EINTR)
309 debug_printf("write interrupted before anything written\n");
310 goto CHECK_TIMEOUT; /* A few lines below */
313 /* A response of EAGAIN from write() is likely only in the case of writing
314 to a FIFO that is not swallowing the data as fast as Exim is writing it. */
316 if (save_errno == EAGAIN)
319 debug_printf("write temporarily locked out, waiting 1 sec\n");
322 /* Before continuing to try another write, check that we haven't run out of
326 if (transport_write_timeout > 0 && local_timeout <= 0)
334 /* Otherwise there's been an error */
336 DEBUG(D_transport) debug_printf("writing error %d: %s\n", save_errno,
337 strerror(save_errno));
342 /* We've tried and tried and tried but still failed */
344 errno = ERRNO_WRITEINCOMPLETE;
350 transport_write_block(transport_ctx * tctx, uschar *block, int len, BOOL more)
352 if (!(tctx->options & topt_output_string))
353 return transport_write_block_fd(tctx, block, len, more);
355 /* Write to expanding-string. NOTE: not NUL-terminated */
358 tctx->u.msg = string_get(1024);
360 tctx->u.msg = string_catn(tctx->u.msg, block, len);
367 /*************************************************
368 * Write formatted string *
369 *************************************************/
371 /* This is called by various transports. It is a convenience function.
376 ... arguments for format
378 Returns: the yield of transport_write_block()
382 transport_write_string(int fd, const char *format, ...)
384 transport_ctx tctx = {{0}};
385 gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer };
388 /* Use taint-unchecked routines for writing into big_buffer, trusting
389 that the result will never be expanded. */
391 va_start(ap, format);
392 if (!string_vformat(&gs, SVFMT_TAINT_NOCHK, format, ap))
393 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong formatted string in transport");
396 return transport_write_block(&tctx, gs.s, gs.ptr, FALSE);
403 transport_write_reset(int options)
405 if (!(options & topt_continuation)) chunk_ptr = deliver_out_buffer;
406 nl_partial_match = -1;
407 nl_check_length = nl_escape_length = 0;
412 /*************************************************
413 * Write character chunk *
414 *************************************************/
416 /* Subroutine used by transport_write_message() to scan character chunks for
417 newlines and act appropriately. The object is to minimise the number of writes.
418 The output byte stream is buffered up in deliver_out_buffer, which is written
419 only when it gets full, thus minimizing write operations and TCP packets.
421 Static data is used to handle the case when the last character of the previous
422 chunk was NL, or matched part of the data that has to be escaped.
425 tctx transport context - processing to be done during output,
426 and file descriptor to write to
427 chunk pointer to data to write
428 len length of data to write
430 In addition, the static nl_xxx variables must be set as required.
432 Returns: TRUE on success, FALSE on failure (with errno preserved)
436 write_chunk(transport_ctx * tctx, uschar *chunk, int len)
438 uschar *start = chunk;
439 uschar *end = chunk + len;
440 int mlen = DELIVER_OUT_BUFFER_SIZE - nl_escape_length - 2;
442 /* The assumption is made that the check string will never stretch over move
443 than one chunk since the only time there are partial matches is when copying
444 the body in large buffers. There is always enough room in the buffer for an
445 escape string, since the loop below ensures this for each character it
446 processes, and it won't have stuck in the escape string if it left a partial
449 if (nl_partial_match >= 0)
451 if (nl_check_length > 0 && len >= nl_check_length &&
452 Ustrncmp(start, nl_check + nl_partial_match,
453 nl_check_length - nl_partial_match) == 0)
455 Ustrncpy(chunk_ptr, nl_escape, nl_escape_length);
456 chunk_ptr += nl_escape_length;
457 start += nl_check_length - nl_partial_match;
460 /* The partial match was a false one. Insert the characters carried over
461 from the previous chunk. */
463 else if (nl_partial_match > 0)
465 Ustrncpy(chunk_ptr, nl_check, nl_partial_match);
466 chunk_ptr += nl_partial_match;
469 nl_partial_match = -1;
472 /* Now process the characters in the chunk. Whenever we hit a newline we check
473 for possible escaping. The code for the non-NL route should be as fast as
476 for (uschar * ptr = start; ptr < end; ptr++)
480 /* Flush the buffer if it has reached the threshold - we want to leave enough
481 room for the next uschar, plus a possible extra CR for an LF, plus the escape
484 if ((len = chunk_ptr - deliver_out_buffer) > mlen)
486 DEBUG(D_transport) debug_printf("flushing headers buffer\n");
488 /* If CHUNKING, prefix with BDAT (size) NON-LAST. Also, reap responses
489 from previous SMTP commands. */
491 if (tctx->options & topt_use_bdat && tctx->chunk_cb)
493 if ( tctx->chunk_cb(tctx, (unsigned)len, 0) != OK
494 || !transport_write_block(tctx, deliver_out_buffer, len, FALSE)
495 || tctx->chunk_cb(tctx, 0, tc_reap_prev) != OK
500 if (!transport_write_block(tctx, deliver_out_buffer, len, FALSE))
502 chunk_ptr = deliver_out_buffer;
505 /* Remove CR before NL if required */
507 if ( *ptr == '\r' && ptr[1] == '\n'
508 && !(tctx->options & topt_use_crlf)
509 && f.spool_file_wireformat
513 if ((ch = *ptr) == '\n')
515 int left = end - ptr - 1; /* count of chars left after NL */
517 /* Insert CR before NL if required */
519 if (tctx->options & topt_use_crlf && !f.spool_file_wireformat)
522 transport_newlines++;
524 /* The check_string test (formerly "from hack") replaces the specific
525 string at the start of a line with an escape string (e.g. "From " becomes
526 ">From " or "." becomes "..". It is a case-sensitive test. The length
527 check above ensures there is always enough room to insert this string. */
529 if (nl_check_length > 0)
531 if (left >= nl_check_length &&
532 Ustrncmp(ptr+1, nl_check, nl_check_length) == 0)
534 Ustrncpy(chunk_ptr, nl_escape, nl_escape_length);
535 chunk_ptr += nl_escape_length;
536 ptr += nl_check_length;
539 /* Handle the case when there isn't enough left to match the whole
540 check string, but there may be a partial match. We remember how many
541 characters matched, and finish processing this chunk. */
543 else if (left <= 0) nl_partial_match = 0;
545 else if (Ustrncmp(ptr+1, nl_check, left) == 0)
547 nl_partial_match = left;
553 /* Not a NL character */
555 else *chunk_ptr++ = ch;
564 /*************************************************
565 * Generate address for RCPT TO *
566 *************************************************/
568 /* This function puts together an address for RCPT to, using the caseful
569 version of the local part and the caseful version of the domain. If there is no
570 prefix or suffix, or if affixes are to be retained, we can just use the
571 original address. Otherwise, if there is a prefix but no suffix we can use a
572 pointer into the original address. If there is a suffix, however, we have to
576 addr the address item
577 include_affixes TRUE if affixes are to be included
583 transport_rcpt_address(address_item *addr, BOOL include_affixes)
590 setflag(addr, af_include_affixes); /* Affects logged => line */
591 return addr->address;
596 if (!addr->prefix) return addr->address;
597 return addr->address + Ustrlen(addr->prefix);
600 at = Ustrrchr(addr->address, '@');
601 plen = addr->prefix ? Ustrlen(addr->prefix) : 0;
602 slen = Ustrlen(addr->suffix);
604 return string_sprintf("%.*s@%s", (int)(at - addr->address - plen - slen),
605 addr->address + plen, at + 1);
609 /*************************************************
610 * Output Envelope-To: address & scan duplicates *
611 *************************************************/
613 /* This function is called from internal_transport_write_message() below, when
614 generating an Envelope-To: header line. It checks for duplicates of the given
615 address and its ancestors. When one is found, this function calls itself
616 recursively, to output the envelope address of the duplicate.
618 We want to avoid duplication in the list, which can arise for example when
619 A->B,C and then both B and C alias to D. This can also happen when there are
620 unseen drivers in use. So a list of addresses that have been output is kept in
623 It is also possible to have loops in the address ancestry/duplication graph,
624 for example if there are two top level addresses A and B and we have A->B,C and
625 B->A. To break the loop, we use a list of processed addresses in the dlist
628 After handling duplication, this function outputs the progenitor of the given
632 p the address we are interested in
633 pplist address of anchor of the list of addresses not to output
634 pdlist address of anchor of the list of processed addresses
635 first TRUE if this is the first address; set it FALSE afterwards
636 tctx transport context - processing to be done during output
637 and the file descriptor to write to
639 Returns: FALSE if writing failed
643 write_env_to(address_item *p, struct aci **pplist, struct aci **pdlist,
644 BOOL *first, transport_ctx * tctx)
649 /* Do nothing if we have already handled this address. If not, remember it
650 so that we don't handle it again. */
652 for (ppp = *pdlist; ppp; ppp = ppp->next) if (p == ppp->ptr) return TRUE;
654 ppp = store_get(sizeof(struct aci), GET_UNTAINTED);
659 /* Now scan up the ancestry, checking for duplicates at each generation. */
661 for (pp = p;; pp = pp->parent)
664 for (dup = addr_duplicate; dup; dup = dup->next)
665 if (dup->dupof == pp) /* a dup of our address */
666 if (!write_env_to(dup, pplist, pdlist, first, tctx))
668 if (!pp->parent) break;
671 /* Check to see if we have already output the progenitor. */
673 for (ppp = *pplist; ppp; ppp = ppp->next) if (pp == ppp->ptr) break;
674 if (ppp) return TRUE;
676 /* Remember what we have output, and output it. */
678 ppp = store_get(sizeof(struct aci), GET_UNTAINTED);
683 if (!*first && !write_chunk(tctx, US",\n ", 3)) return FALSE;
685 return write_chunk(tctx, pp->address, Ustrlen(pp->address));
691 /* Add/remove/rewrite headers, and send them plus the empty-line separator.
697 addr (chain of) addresses (for extra headers), or NULL;
698 only the first address is used
699 tctx transport context
700 sendfn function for output (transport or verify)
702 Returns: TRUE on success; FALSE on failure.
705 transport_headers_send(transport_ctx * tctx,
706 BOOL (*sendfn)(transport_ctx * tctx, uschar * s, int len))
709 transport_instance * tblock = tctx ? tctx->tblock : NULL;
710 address_item * addr = tctx ? tctx->addr : NULL;
712 /* Then the message's headers. Don't write any that are flagged as "old";
713 that means they were rewritten, or are a record of envelope rewriting, or
714 were removed (e.g. Bcc). If remove_headers is not null, skip any headers that
715 match any entries therein. It is a colon-sep list; expand the items
716 separately and squash any empty ones.
717 Then check addr->prop.remove_headers too, provided that addr is not NULL. */
719 for (header_line * h = header_list; h; h = h->next) if (h->type != htype_old)
721 BOOL include_header = TRUE;
723 list = tblock ? tblock->remove_headers : NULL;
724 for (int i = 0; i < 2; i++) /* For remove_headers && addr->prop.remove_headers */
728 int sep = ':'; /* This is specified as a colon-separated list */
730 while ((s = string_nextinlist(&list, &sep, NULL, 0)))
735 if (!(s = expand_string(s)) && !f.expand_string_forcedfail)
737 errno = ERRNO_CHHEADER_FAIL;
740 len = s ? Ustrlen(s) : 0;
741 if (len && s[len-1] == '*') /* trailing glob */
743 if (strncmpic(h->text, s, len-1) == 0) break;
747 if (strncmpic(h->text, s, len) != 0) continue;
749 while (*ss == ' ' || *ss == '\t') ss++;
750 if (*ss == ':') break;
753 if (s) { include_header = FALSE; break; }
755 if (addr) list = addr->prop.remove_headers;
758 /* If this header is to be output, try to rewrite it if there are rewriting
763 if (tblock && tblock->rewrite_rules)
765 rmark reset_point = store_mark();
768 if ((hh = rewrite_header(h, NULL, NULL, tblock->rewrite_rules,
769 tblock->rewrite_existflags, FALSE)))
771 if (!sendfn(tctx, hh->text, hh->slen)) return FALSE;
772 store_reset(reset_point);
773 continue; /* With the next header line */
777 /* Either no rewriting rules, or it didn't get rewritten */
779 if (!sendfn(tctx, h->text, h->slen)) return FALSE;
785 DEBUG(D_transport) debug_printf("removed header line:\n %s---\n", h->text);
788 /* Add on any address-specific headers. If there are multiple addresses,
789 they will all have the same headers in order to be batched. The headers
790 are chained in reverse order of adding (so several addresses from the
791 same alias might share some of them) but we want to output them in the
792 opposite order. This is a bit tedious, but there shouldn't be very many
793 of them. We just walk the list twice, reversing the pointers each time,
794 but on the second time, write out the items.
796 Headers added to an address by a router are guaranteed to end with a newline.
801 header_line * hprev = addr->prop.extra_headers, * hnext, * h;
803 for (int i = 0; i < 2; i++)
804 for (h = hprev, hprev = NULL; h; h = hnext)
811 if (!sendfn(tctx, h->text, h->slen)) return FALSE;
813 debug_printf("added header line(s):\n %s---\n", h->text);
818 /* If a string containing additional headers exists it is a newline-sep
819 list. Expand each item and write out the result. This is done last so that
820 if it (deliberately or accidentally) isn't in header format, it won't mess
821 up any other headers. An empty string or a forced expansion failure are
822 noops. An added header string from a transport may not end with a newline;
823 add one if it does not. */
825 if (tblock && (list = CUS tblock->add_headers))
830 while ((s = string_nextinlist(&list, &sep, NULL, 0)))
831 if ((s = expand_string(s)))
833 int len = Ustrlen(s);
836 if (!sendfn(tctx, s, len)) return FALSE;
837 if (s[len-1] != '\n' && !sendfn(tctx, US"\n", 1))
841 debug_printf("added header line:\n %s", s);
842 if (s[len-1] != '\n') debug_printf("\n");
843 debug_printf("---\n");
847 else if (!f.expand_string_forcedfail)
848 { errno = ERRNO_CHHEADER_FAIL; return FALSE; }
851 /* Separate headers from body with a blank line */
853 return sendfn(tctx, US"\n", 1);
857 /*************************************************
858 * Write the message *
859 *************************************************/
861 /* This function writes the message to the given file descriptor. The headers
862 are in the in-store data structure, and the rest of the message is in the open
863 file descriptor deliver_datafile. Make sure we start it at the beginning.
865 . If add_return_path is TRUE, a "return-path:" header is added to the message,
866 containing the envelope sender's address.
868 . If add_envelope_to is TRUE, a "envelope-to:" header is added to the message,
869 giving the top-level envelope address that caused this delivery to happen.
871 . If add_delivery_date is TRUE, a "delivery-date:" header is added to the
872 message. It gives the time and date that delivery took place.
874 . If check_string is not null, the start of each line is checked for that
875 string. If it is found, it is replaced by escape_string. This used to be
876 the "from hack" for files, and "smtp_dots" for escaping SMTP dots.
878 . If use_crlf is true, newlines are turned into CRLF (SMTP output).
880 The yield is TRUE if all went well, and FALSE if not. Exit *immediately* after
881 any writing or reading error, leaving the code in errno intact. Error exits
882 can include timeouts for certain transports, which are requested by setting
883 transport_write_timeout non-zero.
887 (fd, msg) Either an fd, to write the message to,
888 or a string: if null write message to allocated space
889 otherwire take content as headers.
890 addr (chain of) addresses (for extra headers), or NULL;
891 only the first address is used
892 tblock optional transport instance block (NULL signifies NULL/0):
893 add_headers a string containing one or more headers to add; it is
894 expanded, and must be in correct RFC 822 format as
895 it is transmitted verbatim; NULL => no additions,
896 and so does empty string or forced expansion fail
897 remove_headers a colon-separated list of headers to remove, or NULL
898 rewrite_rules chain of header rewriting rules
899 rewrite_existflags flags for the rewriting rules
900 options bit-wise options:
901 add_return_path if TRUE, add a "return-path" header
902 add_envelope_to if TRUE, add a "envelope-to" header
903 add_delivery_date if TRUE, add a "delivery-date" header
904 use_crlf if TRUE, turn NL into CR LF
905 end_dot if TRUE, send a terminating "." line at the end
906 no_flush if TRUE, do not flush at end
907 no_headers if TRUE, omit the headers
908 no_body if TRUE, omit the body
909 check_string a string to check for at the start of lines, or NULL
910 escape_string a string to insert in front of any check string
911 size_limit if > 0, this is a limit to the size of message written;
912 it is used when returning messages to their senders,
913 and is approximate rather than exact, owing to chunk
916 Returns: TRUE on success; FALSE (with errno) on failure.
917 In addition, the global variable transport_count
918 is incremented by the number of bytes written.
922 internal_transport_write_message(transport_ctx * tctx, int size_limit)
926 /* Initialize pointer in output buffer. */
928 transport_write_reset(tctx->options);
930 /* Set up the data for start-of-line data checking and escaping */
932 if (tctx->check_string && tctx->escape_string)
934 nl_check = tctx->check_string;
935 nl_check_length = Ustrlen(nl_check);
936 nl_escape = tctx->escape_string;
937 nl_escape_length = Ustrlen(nl_escape);
940 /* Whether the escaping mechanism is applied to headers or not is controlled by
941 an option (set for SMTP, not otherwise). Negate the length if not wanted till
942 after the headers. */
944 if (!(tctx->options & topt_escape_headers))
945 nl_check_length = -nl_check_length;
947 /* Write the headers if required, including any that have to be added. If there
948 are header rewriting rules, apply them. The datasource is not the -D spoolfile
949 so temporarily hide the global that adjusts for its format. */
951 if (!(tctx->options & topt_no_headers))
953 BOOL save_wireformat = f.spool_file_wireformat;
954 f.spool_file_wireformat = FALSE;
956 /* Add return-path: if requested. */
958 if (tctx->options & topt_add_return_path)
961 uschar * s = string_sprintf("Return-path: <%.*s>\n%n",
962 EXIM_EMAILADDR_MAX, return_path, &n);
963 if (!write_chunk(tctx, s, n)) goto bad;
966 /* Add envelope-to: if requested */
968 if (tctx->options & topt_add_envelope_to)
971 struct aci *plist = NULL;
972 struct aci *dlist = NULL;
973 rmark reset_point = store_mark();
975 if (!write_chunk(tctx, US"Envelope-to: ", 13)) goto bad;
977 /* Pick up from all the addresses. The plist and dlist variables are
978 anchors for lists of addresses already handled; they have to be defined at
979 this level because write_env_to() calls itself recursively. */
981 for (address_item * p = tctx->addr; p; p = p->next)
982 if (!write_env_to(p, &plist, &dlist, &first, tctx))
985 /* Add a final newline and reset the store used for tracking duplicates */
987 if (!write_chunk(tctx, US"\n", 1)) goto bad;
988 store_reset(reset_point);
991 /* Add delivery-date: if requested. */
993 if (tctx->options & topt_add_delivery_date)
995 uschar * s = tod_stamp(tod_full);
997 if ( !write_chunk(tctx, US"Delivery-date: ", 15)
998 || !write_chunk(tctx, s, Ustrlen(s))
999 || !write_chunk(tctx, US"\n", 1)) goto bad;
1002 /* Then the message's headers. Don't write any that are flagged as "old";
1003 that means they were rewritten, or are a record of envelope rewriting, or
1004 were removed (e.g. Bcc). If remove_headers is not null, skip any headers that
1005 match any entries therein. Then check addr->prop.remove_headers too, provided that
1006 addr is not NULL. */
1008 if (!transport_headers_send(tctx, &write_chunk))
1011 f.spool_file_wireformat = save_wireformat;
1015 f.spool_file_wireformat = save_wireformat;
1018 /* When doing RFC3030 CHUNKING output, work out how much data would be in a
1019 last-BDAT, consisting of the current write_chunk() output buffer fill
1020 (optimally, all of the headers - but it does not matter if we already had to
1021 flush that buffer with non-last BDAT prependix) plus the amount of body data
1022 (as expanded for CRLF lines). Then create and write BDAT(s), and ensure
1023 that further use of write_chunk() will not prepend BDATs.
1024 The first BDAT written will also first flush any outstanding MAIL and RCPT
1025 commands which were buffered thans to PIPELINING.
1026 Commands go out (using a send()) from a different buffer to data (using a
1027 write()). They might not end up in the same TCP segment, which is
1030 if (tctx->options & topt_use_bdat)
1035 if ((hsize = chunk_ptr - deliver_out_buffer) < 0)
1037 if (!(tctx->options & topt_no_body))
1039 if ((fsize = lseek(deliver_datafile, 0, SEEK_END)) < 0) return FALSE;
1040 fsize -= SPOOL_DATA_START_OFFSET;
1041 if (size_limit > 0 && fsize > size_limit)
1043 size = hsize + fsize;
1044 if (tctx->options & topt_use_crlf && !f.spool_file_wireformat)
1045 size += body_linecount; /* account for CRLF-expansion */
1047 /* With topt_use_bdat we never do dot-stuffing; no need to
1048 account for any expansion due to that. */
1051 /* If the message is large, emit first a non-LAST chunk with just the
1052 headers, and reap the command responses. This lets us error out early
1053 on RCPT rejects rather than sending megabytes of data. Include headers
1054 on the assumption they are cheap enough and some clever implementations
1055 might errorcheck them too, on-the-fly, and reject that chunk. */
1057 if (size > DELIVER_OUT_BUFFER_SIZE && hsize > 0)
1060 debug_printf("sending small initial BDAT; hsize=%d\n", hsize);
1061 if ( tctx->chunk_cb(tctx, hsize, 0) != OK
1062 || !transport_write_block(tctx, deliver_out_buffer, hsize, FALSE)
1063 || tctx->chunk_cb(tctx, 0, tc_reap_prev) != OK
1066 chunk_ptr = deliver_out_buffer;
1070 /* Emit a LAST datachunk command, and unmark the context for further
1073 if (tctx->chunk_cb(tctx, size, tc_chunk_last) != OK)
1075 tctx->options &= ~topt_use_bdat;
1078 /* If the body is required, ensure that the data for check strings (formerly
1079 the "from hack") is enabled by negating the length if necessary. (It will be
1080 negative in cases where it isn't to apply to the headers). Then ensure the body
1081 is positioned at the start of its file (following the message id), then write
1082 it, applying the size limit if required. */
1084 /* If we have a wireformat -D file (CRNL lines, non-dotstuffed, no ending dot)
1085 and we want to send a body without dotstuffing or ending-dot, in-clear,
1086 then we can just dump it using sendfile.
1087 This should get used for CHUNKING output and also for writing the -K file for
1088 dkim signing, when we had CHUNKING input. */
1091 if ( f.spool_file_wireformat
1092 && !(tctx->options & (topt_no_body | topt_end_dot))
1094 && tls_out.active.sock != tctx->u.fd
1098 off_t offset = SPOOL_DATA_START_OFFSET;
1100 /* Write out any header data in the buffer */
1102 if ((len = chunk_ptr - deliver_out_buffer) > 0)
1104 if (!transport_write_block(tctx, deliver_out_buffer, len, TRUE))
1109 DEBUG(D_transport) debug_printf("using sendfile for body\n");
1113 if ((copied = os_sendfile(tctx->u.fd, deliver_datafile, &offset, size)) <= 0) break;
1119 DEBUG(D_transport) debug_printf("cannot use sendfile for body: no support\n");
1123 if (!(tctx->options & topt_no_body))
1124 debug_printf("cannot use sendfile for body: %s\n",
1125 !f.spool_file_wireformat ? "spoolfile not wireformat"
1126 : tctx->options & topt_end_dot ? "terminating dot wanted"
1127 : nl_check_length ? "dot- or From-stuffing wanted"
1128 : "TLS output wanted");
1130 if (!(tctx->options & topt_no_body))
1132 unsigned long size = size_limit > 0 ? size_limit : ULONG_MAX;
1134 nl_check_length = abs(nl_check_length);
1135 nl_partial_match = 0;
1136 if (lseek(deliver_datafile, SPOOL_DATA_START_OFFSET, SEEK_SET) < 0)
1138 while ( (len = MIN(DELIVER_IN_BUFFER_SIZE, size)) > 0
1139 && (len = read(deliver_datafile, deliver_in_buffer, len)) > 0)
1141 if (!write_chunk(tctx, deliver_in_buffer, len))
1146 /* A read error on the body will have left len == -1 and errno set. */
1148 if (len != 0) return FALSE;
1151 /* Finished with the check string, and spool-format consideration */
1153 nl_check_length = nl_escape_length = 0;
1154 f.spool_file_wireformat = FALSE;
1156 /* If requested, add a terminating "." line (SMTP output). */
1158 if (tctx->options & topt_end_dot)
1160 smtp_debug_cmd(US".", 0);
1161 if (!write_chunk(tctx, US".\n", 2))
1165 /* Write out any remaining data in the buffer before returning. */
1167 return (len = chunk_ptr - deliver_out_buffer) <= 0
1168 || transport_write_block(tctx, deliver_out_buffer, len,
1169 !!(tctx->options & topt_no_flush));
1175 /*************************************************
1176 * External interface to write the message *
1177 *************************************************/
1179 /* If there is no filtering required, call the internal function above to do
1180 the real work, passing over all the arguments from this function. Otherwise,
1181 set up a filtering process, fork another process to call the internal function
1182 to write to the filter, and in this process just suck from the filter and write
1183 down the fd in the transport context. At the end, tidy up the pipes and the
1186 Arguments: as for internal_transport_write_message() above
1188 Returns: TRUE on success; FALSE (with errno) for any failure
1189 transport_count is incremented by the number of bytes written
1193 transport_write_message(transport_ctx * tctx, int size_limit)
1195 BOOL last_filter_was_NL = TRUE;
1196 BOOL save_spool_file_wireformat = f.spool_file_wireformat;
1198 int rc, len, fd_read, fd_write, save_errno;
1199 int pfd[2] = {-1, -1};
1200 pid_t filter_pid, write_pid;
1202 f.transport_filter_timed_out = FALSE;
1204 /* If there is no filter command set up, call the internal function that does
1205 the actual work, passing it the incoming fd, and return its result. */
1207 if ( !transport_filter_argv
1208 || !*transport_filter_argv
1209 || !**transport_filter_argv
1211 return internal_transport_write_message(tctx, size_limit);
1213 /* Otherwise the message must be written to a filter process and read back
1214 before being written to the incoming fd. First set up the special processing to
1215 be done during the copying. */
1217 nl_partial_match = -1;
1219 if (tctx->check_string && tctx->escape_string)
1221 nl_check = tctx->check_string;
1222 nl_check_length = Ustrlen(nl_check);
1223 nl_escape = tctx->escape_string;
1224 nl_escape_length = Ustrlen(nl_escape);
1226 else nl_check_length = nl_escape_length = 0;
1228 /* Start up a subprocess to run the command. Ensure that our main fd will
1229 be closed when the subprocess execs, but remove the flag afterwards.
1230 (Otherwise, if this is a TCP/IP socket, it can't get passed on to another
1231 process to deliver another message.) We get back stdin/stdout file descriptors.
1232 If the process creation failed, give an error return. */
1238 write_pid = (pid_t)(-1);
1241 int bits = fcntl(tctx->u.fd, F_GETFD);
1242 (void) fcntl(tctx->u.fd, F_SETFD, bits | FD_CLOEXEC);
1243 filter_pid = child_open(USS transport_filter_argv, NULL, 077,
1244 &fd_write, &fd_read, FALSE, US"transport-filter");
1245 (void) fcntl(tctx->u.fd, F_SETFD, bits & ~FD_CLOEXEC);
1247 if (filter_pid < 0) goto TIDY_UP; /* errno set */
1250 debug_printf("process %d running as transport filter: fd_write=%d fd_read=%d\n",
1251 (int)filter_pid, fd_write, fd_read);
1253 /* Fork subprocess to write the message to the filter, and return the result
1254 via a(nother) pipe. While writing to the filter, we do not do the CRLF,
1255 smtp dots, or check string processing. */
1257 if (pipe(pfd) != 0) goto TIDY_UP; /* errno set */
1258 if ((write_pid = exim_fork(US"tpt-filter-writer")) == 0)
1261 (void)close(fd_read);
1262 (void)close(pfd[pipe_read]);
1263 nl_check_length = nl_escape_length = 0;
1265 tctx->u.fd = fd_write;
1266 tctx->check_string = tctx->escape_string = NULL;
1267 tctx->options &= ~(topt_use_crlf | topt_end_dot | topt_use_bdat | topt_no_flush);
1269 rc = internal_transport_write_message(tctx, size_limit);
1272 if ( write(pfd[pipe_write], (void *)&rc, sizeof(BOOL))
1274 || write(pfd[pipe_write], (void *)&save_errno, sizeof(int))
1276 || write(pfd[pipe_write], (void *)&tctx->addr->more_errno, sizeof(int))
1278 || write(pfd[pipe_write], (void *)&tctx->addr->delivery_time, sizeof(struct timeval))
1279 != sizeof(struct timeval)
1281 rc = FALSE; /* compiler quietening */
1282 exim_underbar_exit(EXIT_SUCCESS);
1286 /* Parent process: close our copy of the writing subprocess' pipes. */
1288 (void)close(pfd[pipe_write]);
1289 (void)close(fd_write);
1292 /* Writing process creation failed */
1296 errno = save_errno; /* restore */
1300 /* When testing, let the subprocess get going */
1302 testharness_pause_ms(250);
1305 debug_printf("process %d writing to transport filter\n", (int)write_pid);
1307 /* Copy the message from the filter to the output fd. A read error leaves len
1308 == -1 and errno set. We need to apply a timeout to the read, to cope with
1309 the case when the filter gets stuck, but it can be quite a long one. The
1310 default is 5m, but this is now configurable. */
1312 DEBUG(D_transport) debug_printf("copying from the filter\n");
1314 /* Copy the output of the filter, remembering if the last character was NL. If
1315 no data is returned, that counts as "ended with NL" (default setting of the
1316 variable is TRUE). The output should always be unix-format as we converted
1317 any wireformat source on writing input to the filter. */
1319 f.spool_file_wireformat = FALSE;
1320 chunk_ptr = deliver_out_buffer;
1324 sigalrm_seen = FALSE;
1325 ALARM(transport_filter_timeout);
1326 len = read(fd_read, deliver_in_buffer, DELIVER_IN_BUFFER_SIZE);
1330 DEBUG(D_transport) debug_printf("timed out reading from filter\n");
1332 f.transport_filter_timed_out = TRUE;
1336 /* If the read was successful, write the block down the original fd,
1337 remembering whether it ends in \n or not. */
1341 if (!write_chunk(tctx, deliver_in_buffer, len)) goto TIDY_UP;
1342 last_filter_was_NL = (deliver_in_buffer[len-1] == '\n');
1345 /* Otherwise, break the loop. If we have hit EOF, set yield = TRUE. */
1349 if (len == 0) yield = TRUE;
1354 /* Tidying up code. If yield = FALSE there has been an error and errno is set
1355 to something. Ensure the pipes are all closed and the processes are removed. If
1356 there has been an error, kill the processes before waiting for them, just to be
1357 sure. Also apply a paranoia timeout. */
1360 f.spool_file_wireformat = save_spool_file_wireformat;
1363 (void)close(fd_read);
1364 if (fd_write > 0) (void)close(fd_write);
1368 if (filter_pid > 0) kill(filter_pid, SIGKILL);
1369 if (write_pid > 0) kill(write_pid, SIGKILL);
1372 /* Wait for the filter process to complete. */
1374 DEBUG(D_transport) debug_printf("waiting for filter process\n");
1375 if (filter_pid > 0 && (rc = child_close(filter_pid, 30)) != 0 && yield)
1378 save_errno = ERRNO_FILTER_FAIL;
1379 tctx->addr->more_errno = rc;
1380 DEBUG(D_transport) debug_printf("filter process returned %d\n", rc);
1383 /* Wait for the writing process to complete. If it ends successfully,
1384 read the results from its pipe, provided we haven't already had a filter
1387 DEBUG(D_transport) debug_printf("waiting for writing process\n");
1390 rc = child_close(write_pid, 30);
1395 if (read(pfd[pipe_read], (void *)&ok, sizeof(BOOL)) != sizeof(BOOL))
1398 debug_printf("pipe read from writing process: %s\n", strerror(errno));
1399 save_errno = ERRNO_FILTER_FAIL;
1403 { /* Try to drain the pipe; read fails are don't care */
1404 int dummy = read(pfd[pipe_read], (void *)&save_errno, sizeof(int));
1405 dummy = read(pfd[pipe_read], (void *)&tctx->addr->more_errno, sizeof(int));
1406 dummy = read(pfd[pipe_read], (void *)&tctx->addr->delivery_time, sizeof(struct timeval));
1413 save_errno = ERRNO_FILTER_FAIL;
1414 tctx->addr->more_errno = rc;
1415 DEBUG(D_transport) debug_printf("writing process returned %d\n", rc);
1418 (void)close(pfd[pipe_read]);
1420 /* If there have been no problems we can now add the terminating "." if this is
1421 SMTP output, turning off escaping beforehand. If the last character from the
1422 filter was not NL, insert a NL to make the SMTP protocol work. */
1426 nl_check_length = nl_escape_length = 0;
1427 f.spool_file_wireformat = FALSE;
1428 if ( tctx->options & topt_end_dot
1429 && ( last_filter_was_NL
1430 ? !write_chunk(tctx, US".\n", 2)
1431 : !write_chunk(tctx, US"\n.\n", 3)
1433 { smtp_debug_cmd(US".", 0); yield = FALSE; }
1435 /* Write out any remaining data in the buffer. */
1438 yield = (len = chunk_ptr - deliver_out_buffer) <= 0
1439 || transport_write_block(tctx, deliver_out_buffer, len, FALSE);
1442 errno = save_errno; /* From some earlier error */
1446 debug_printf("end of filtering transport writing: yield=%d\n", yield);
1448 debug_printf(" errno=%d more_errno=%d\n", errno, tctx->addr->more_errno);
1458 /*************************************************
1459 * Update waiting database *
1460 *************************************************/
1462 /* This is called when an address is deferred by remote transports that are
1463 capable of sending more than one message over one connection. A database is
1464 maintained for each transport, keeping track of which messages are waiting for
1465 which hosts. The transport can then consult this when eventually a successful
1466 delivery happens, and if it finds that another message is waiting for the same
1467 host, it can fire up a new process to deal with it using the same connection.
1469 The database records are keyed by host name. They can get full if there are
1470 lots of messages waiting, and so there is a continuation mechanism for them.
1472 Each record contains a list of message ids, packed end to end without any
1473 zeros. Each one is MESSAGE_ID_LENGTH bytes long. The count field says how many
1474 in this record, and the sequence field says if there are any other records for
1475 this host. If the sequence field is 0, there are none. If it is 1, then another
1476 record with the name <hostname>:0 exists; if it is 2, then two other records
1477 with sequence numbers 0 and 1 exist, and so on.
1479 Currently, an exhaustive search of all continuation records has to be done to
1480 determine whether to add a message id to a given record. This shouldn't be
1481 too bad except in extreme cases. I can't figure out a *simple* way of doing
1484 Old records should eventually get swept up by the exim_tidydb utility.
1487 hostlist list of hosts that this message could be sent to
1488 tpname name of the transport
1494 transport_update_waiting(host_item *hostlist, uschar *tpname)
1496 const uschar *prevname = US"";
1500 DEBUG(D_transport) debug_printf("updating wait-%s database\n", tpname);
1502 /* Open the database for this transport */
1504 if (!(dbm_file = dbfn_open(string_sprintf("wait-%.200s", tpname),
1505 O_RDWR, &dbblock, TRUE, TRUE)))
1508 /* Scan the list of hosts for which this message is waiting, and ensure
1509 that the message id is in each host record. */
1511 for (host_item * host = hostlist; host; host = host->next)
1513 BOOL already = FALSE;
1514 dbdata_wait *host_record;
1518 /* Skip if this is the same host as we just processed; otherwise remember
1519 the name for next time. */
1521 if (Ustrcmp(prevname, host->name) == 0) continue;
1522 prevname = host->name;
1524 /* Look up the host record; if there isn't one, make an empty one. */
1526 if (!(host_record = dbfn_read(dbm_file, host->name)))
1528 host_record = store_get(sizeof(dbdata_wait) + MESSAGE_ID_LENGTH, GET_UNTAINTED);
1529 host_record->count = host_record->sequence = 0;
1532 /* Compute the current length */
1534 host_length = host_record->count * MESSAGE_ID_LENGTH;
1536 /* Search the record to see if the current message is already in it. */
1538 for (uschar * s = host_record->text; s < host_record->text + host_length;
1539 s += MESSAGE_ID_LENGTH)
1540 if (Ustrncmp(s, message_id, MESSAGE_ID_LENGTH) == 0)
1541 { already = TRUE; break; }
1543 /* If we haven't found this message in the main record, search any
1544 continuation records that exist. */
1546 for (int i = host_record->sequence - 1; i >= 0 && !already; i--)
1549 sprintf(CS buffer, "%.200s:%d", host->name, i);
1550 if ((cont = dbfn_read(dbm_file, buffer)))
1552 int clen = cont->count * MESSAGE_ID_LENGTH;
1553 for (uschar * s = cont->text; s < cont->text + clen; s += MESSAGE_ID_LENGTH)
1554 if (Ustrncmp(s, message_id, MESSAGE_ID_LENGTH) == 0)
1555 { already = TRUE; break; }
1559 /* If this message is already in a record, no need to update. */
1563 DEBUG(D_transport) debug_printf("already listed for %s\n", host->name);
1568 /* If this record is full, write it out with a new name constructed
1569 from the sequence number, increase the sequence number, and empty
1570 the record. If we're doing a two-phase queue run initial phase, ping the
1571 daemon to consider running a delivery on this host. */
1573 if (host_record->count >= WAIT_NAME_MAX)
1575 sprintf(CS buffer, "%.200s:%d", host->name, host_record->sequence);
1576 dbfn_write(dbm_file, buffer, host_record, sizeof(dbdata_wait) + host_length);
1577 #ifndef DISABLE_QUEUE_RAMP
1578 if (f.queue_2stage && queue_fast_ramp && !queue_run_in_order)
1579 queue_notify_daemon(message_id);
1581 host_record->sequence++;
1582 host_record->count = 0;
1586 /* If this record is not full, increase the size of the record to
1587 allow for one new message id. */
1592 store_get(sizeof(dbdata_wait) + host_length + MESSAGE_ID_LENGTH, GET_UNTAINTED);
1593 memcpy(newr, host_record, sizeof(dbdata_wait) + host_length);
1597 /* Now add the new name on the end */
1599 memcpy(host_record->text + host_length, message_id, MESSAGE_ID_LENGTH);
1600 host_record->count++;
1601 host_length += MESSAGE_ID_LENGTH;
1603 /* Update the database */
1605 dbfn_write(dbm_file, host->name, host_record, sizeof(dbdata_wait) + host_length);
1606 DEBUG(D_transport) debug_printf("added %.*s to queue for %s\n",
1607 MESSAGE_ID_LENGTH, message_id, host->name);
1612 dbfn_close(dbm_file);
1618 /*************************************************
1619 * Test for waiting messages *
1620 *************************************************/
1622 /* This function is called by a remote transport which uses the previous
1623 function to remember which messages are waiting for which remote hosts. It's
1624 called after a successful delivery and its job is to check whether there is
1625 another message waiting for the same host. However, it doesn't do this if the
1626 current continue sequence is greater than the maximum supplied as an argument,
1627 or greater than the global connection_max_messages, which, if set, overrides.
1630 transport_name name of the transport
1631 hostname name of the host
1632 local_message_max maximum number of messages down one connection
1633 as set by the caller transport
1634 new_message_id set to the message id of a waiting message
1635 oicf_func function to call to validate if it is ok to send
1636 to this message_id from the current instance.
1637 oicf_data opaque data for oicf_func
1639 Returns: TRUE if new_message_id set; FALSE otherwise
1642 typedef struct msgq_s
1644 uschar message_id [MESSAGE_ID_LENGTH + 1];
1649 transport_check_waiting(const uschar *transport_name, const uschar *hostname,
1650 int local_message_max, uschar *new_message_id, oicf oicf_func, void *oicf_data)
1652 dbdata_wait *host_record;
1658 struct stat statbuf;
1662 debug_printf("transport_check_waiting entered\n");
1663 debug_printf(" sequence=%d local_max=%d global_max=%d\n",
1664 continue_sequence, local_message_max, connection_max_messages);
1668 /* Do nothing if we have hit the maximum number that can be send down one
1671 if (connection_max_messages >= 0) local_message_max = connection_max_messages;
1672 if (local_message_max > 0 && continue_sequence >= local_message_max)
1675 debug_printf_indent("max messages for one connection reached: returning\n");
1679 /* Open the waiting information database. */
1681 if (!(dbm_file = dbfn_open(string_sprintf("wait-%.200s", transport_name),
1682 O_RDWR, &dbblock, TRUE, TRUE)))
1685 /* See if there is a record for this host; if not, there's nothing to do. */
1687 if (!(host_record = dbfn_read(dbm_file, hostname)))
1689 dbfn_close(dbm_file);
1690 DEBUG(D_transport) debug_printf_indent("no messages waiting for %s\n", hostname);
1694 /* If the data in the record looks corrupt, just log something and
1695 don't try to use it. */
1697 if (host_record->count > WAIT_NAME_MAX)
1699 dbfn_close(dbm_file);
1700 log_write(0, LOG_MAIN|LOG_PANIC, "smtp-wait database entry for %s has bad "
1701 "count=%d (max=%d)", hostname, host_record->count, WAIT_NAME_MAX);
1705 /* Scan the message ids in the record from the end towards the beginning,
1706 until one is found for which a spool file actually exists. If the record gets
1707 emptied, delete it and continue with any continuation records that may exist.
1710 /* For Bug 1141, I refactored this major portion of the routine, it is risky
1711 but the 1 off will remain without it. This code now allows me to SKIP over
1712 a message I do not want to send out on this run. */
1714 host_length = host_record->count * MESSAGE_ID_LENGTH;
1720 int msgq_actual = 0;
1721 BOOL bFound = FALSE;
1722 BOOL bContinuation = FALSE;
1724 /* create an array to read entire message queue into memory for processing */
1726 msgq = store_get(sizeof(msgq_t) * host_record->count, GET_UNTAINTED);
1727 msgq_count = host_record->count;
1728 msgq_actual = msgq_count;
1730 for (i = 0; i < host_record->count; ++i)
1732 msgq[i].bKeep = TRUE;
1734 Ustrncpy_nt(msgq[i].message_id, host_record->text + (i * MESSAGE_ID_LENGTH),
1736 msgq[i].message_id[MESSAGE_ID_LENGTH] = 0;
1739 /* first thing remove current message id if it exists */
1740 /*XXX but what if it has un-sent addrs? */
1742 for (i = 0; i < msgq_count; ++i)
1743 if (Ustrcmp(msgq[i].message_id, message_id) == 0)
1745 msgq[i].bKeep = FALSE;
1749 /* now find the next acceptable message_id */
1751 for (i = msgq_count - 1; i >= 0; --i) if (msgq[i].bKeep)
1754 uschar * mid = msgq[i].message_id;
1756 set_subdir_str(subdir, mid, 0);
1757 if (Ustat(spool_fname(US"input", subdir, mid, US"-D"), &statbuf) != 0)
1758 msgq[i].bKeep = FALSE;
1759 else if (!oicf_func || oicf_func(mid, oicf_data))
1761 Ustrcpy_nt(new_message_id, mid);
1762 msgq[i].bKeep = FALSE;
1769 for (msgq_actual = 0, i = 0; i < msgq_count; ++i)
1773 /* reassemble the host record, based on removed message ids, from in
1776 if (msgq_actual <= 0)
1779 host_record->count = 0;
1783 host_length = msgq_actual * MESSAGE_ID_LENGTH;
1784 host_record->count = msgq_actual;
1786 if (msgq_actual < msgq_count)
1789 for (new_count = 0, i = 0; i < msgq_count; ++i)
1791 Ustrncpy(&host_record->text[new_count++ * MESSAGE_ID_LENGTH],
1792 msgq[i].message_id, MESSAGE_ID_LENGTH);
1794 host_record->text[new_count * MESSAGE_ID_LENGTH] = 0;
1798 /* Check for a continuation record. */
1800 while (host_length <= 0)
1802 dbdata_wait * newr = NULL;
1805 /* Search for a continuation */
1807 for (int i = host_record->sequence - 1; i >= 0 && !newr; i--)
1809 sprintf(CS buffer, "%.200s:%d", hostname, i);
1810 newr = dbfn_read(dbm_file, buffer);
1813 /* If no continuation, delete the current and break the loop */
1817 dbfn_delete(dbm_file, hostname);
1821 /* Else replace the current with the continuation */
1823 dbfn_delete(dbm_file, buffer);
1825 host_length = host_record->count * MESSAGE_ID_LENGTH;
1827 bContinuation = TRUE;
1830 if (bFound) /* Usual exit from main loop */
1833 /* If host_length <= 0 we have emptied a record and not found a good message,
1834 and there are no continuation records. Otherwise there is a continuation
1835 record to process. */
1837 if (host_length <= 0)
1839 dbfn_close(dbm_file);
1840 DEBUG(D_transport) debug_printf_indent("waiting messages already delivered\n");
1844 /* we were not able to find an acceptable message, nor was there a
1845 * continuation record. So bug out, outer logic will clean this up.
1850 Ustrcpy(new_message_id, message_id);
1851 dbfn_close(dbm_file);
1854 } /* we need to process a continuation record */
1856 /* Control gets here when an existing message has been encountered; its
1857 id is in new_message_id, and host_length is the revised length of the
1858 host record. If it is zero, the record has been removed. Update the
1859 record if required, close the database, and return TRUE. */
1861 if (host_length > 0)
1863 host_record->count = host_length/MESSAGE_ID_LENGTH;
1864 dbfn_write(dbm_file, hostname, host_record, (int)sizeof(dbdata_wait) + host_length);
1867 dbfn_close(dbm_file);
1868 DEBUG(D_transport) {acl_level--; debug_printf("transport_check_waiting: TRUE\n"); }
1872 DEBUG(D_transport) {acl_level--; debug_printf("transport_check_waiting: FALSE\n"); }
1876 /*************************************************
1877 * Deliver waiting message down same socket *
1878 *************************************************/
1880 /* Just the regain-root-privilege exec portion */
1882 transport_do_pass_socket(const uschar *transport_name, const uschar *hostname,
1883 const uschar *hostaddress, uschar *id, int socket_fd)
1886 const uschar **argv;
1889 if (smtp_peer_options & OPTION_TLS) i += 6;
1891 #ifdef EXPERIMENTAL_ESMTP_LIMITS
1892 if (continue_limit_mail || continue_limit_rcpt || continue_limit_rcptdom)
1895 if (queue_run_pid != (pid_t)0) i += 3;
1896 #ifdef SUPPORT_SOCKS
1897 if (proxy_session) i += 5;
1900 /* Set up the calling arguments; use the standard function for the basics,
1901 but we have a number of extras that may be added. */
1903 argv = CUSS child_exec_exim(CEE_RETURN_ARGV, TRUE, &i, FALSE, 0);
1905 if (f.smtp_authenticated) argv[i++] = US"-MCA";
1906 if (smtp_peer_options & OPTION_CHUNKING) argv[i++] = US"-MCK";
1907 if (smtp_peer_options & OPTION_DSN) argv[i++] = US"-MCD";
1908 if (smtp_peer_options & OPTION_PIPE) argv[i++] = US"-MCP";
1909 if (smtp_peer_options & OPTION_SIZE) argv[i++] = US"-MCS";
1911 if (smtp_peer_options & OPTION_TLS)
1912 if (tls_out.active.sock >= 0 || continue_proxy_cipher)
1914 argv[i++] = US"-MCt";
1915 argv[i++] = sending_ip_address;
1916 argv[i++] = string_sprintf("%d", sending_port);
1917 argv[i++] = tls_out.active.sock >= 0 ? tls_out.cipher : continue_proxy_cipher;
1923 tls_out.dane_verified ? US"-MCr" :
1926 argv[i++] = tls_out.sni;
1930 argv[i++] = US"-MCT";
1933 #ifdef EXPERIMENTAL_ESMTP_LIMITS
1934 if (continue_limit_rcpt || continue_limit_rcptdom)
1936 argv[i++] = US"-MCL";
1937 argv[i++] = string_sprintf("%u", continue_limit_mail);
1938 argv[i++] = string_sprintf("%u", continue_limit_rcpt);
1939 argv[i++] = string_sprintf("%u", continue_limit_rcptdom);
1943 if (queue_run_pid != (pid_t)0)
1945 argv[i++] = US"-MCQ";
1946 argv[i++] = string_sprintf("%d", queue_run_pid);
1947 argv[i++] = string_sprintf("%d", queue_run_pipe);
1950 #ifdef SUPPORT_SOCKS
1953 argv[i++] = US"-MCp";
1954 argv[i++] = proxy_local_address;
1955 argv[i++] = string_sprintf("%d", proxy_local_port);
1956 argv[i++] = proxy_external_address;
1957 argv[i++] = string_sprintf("%d", proxy_external_port);
1961 argv[i++] = US"-MC";
1962 argv[i++] = US transport_name;
1963 argv[i++] = US hostname;
1964 argv[i++] = US hostaddress;
1965 argv[i++] = string_sprintf("%d", continue_sequence + 1);
1969 /* Arrange for the channel to be on stdin. */
1973 (void)dup2(socket_fd, 0);
1974 (void)close(socket_fd);
1977 DEBUG(D_exec) debug_print_argv(argv);
1978 exim_nullstd(); /* Ensure std{out,err} exist */
1979 /* argv[0] should be untainted, from child_exec_exim() */
1980 execv(CS argv[0], (char *const *)argv);
1982 DEBUG(D_any) debug_printf("execv failed: %s\n", strerror(errno));
1983 _exit(errno); /* Note: must be _exit(), NOT exit() */
1988 /* Fork a new exim process to deliver the message, and do a re-exec, both to
1989 get a clean delivery process, and to regain root privilege in cases where it
1990 has been given away.
1993 transport_name to pass to the new process
1996 id the new message to process
1997 socket_fd the connected socket
1999 Returns: FALSE if fork fails; TRUE otherwise
2003 transport_pass_socket(const uschar *transport_name, const uschar *hostname,
2004 const uschar *hostaddress, uschar *id, int socket_fd
2005 #ifdef EXPERIMENTAL_ESMTP_LIMITS
2006 , unsigned peer_limit_mail, unsigned peer_limit_rcpt, unsigned peer_limit_rcptdom
2013 DEBUG(D_transport) debug_printf("transport_pass_socket entered\n");
2015 #ifdef EXPERIMENTAL_ESMTP_LIMITS
2016 continue_limit_mail = peer_limit_mail;
2017 continue_limit_rcpt = peer_limit_rcpt;
2018 continue_limit_rcptdom = peer_limit_rcptdom;
2021 if ((pid = exim_fork(US"continued-transport-interproc")) == 0)
2023 /* Disconnect entirely from the parent process. If we are running in the
2024 test harness, wait for a bit to allow the previous process time to finish,
2025 write the log, etc., so that the output is always in the same order for
2026 automatic comparison. */
2028 if ((pid = exim_fork(US"continued-transport")) != 0)
2029 _exit(EXIT_SUCCESS);
2030 testharness_pause_ms(1000);
2032 transport_do_pass_socket(transport_name, hostname, hostaddress,
2036 /* If the process creation succeeded, wait for the first-level child, which
2037 immediately exits, leaving the second level process entirely disconnected from
2043 while ((rc = wait(&status)) != pid && (rc >= 0 || errno != ECHILD));
2048 DEBUG(D_transport) debug_printf("transport_pass_socket failed to fork: %s\n",
2056 /* Enforce all args untainted, for consistency with a router-sourced pipe
2057 command, where (because the whole line is passed as one to the tpt) a
2058 tainted arg taints the executable name. It's unclear also that letting an
2059 attacker supply command arguments is wise. */
2062 arg_is_tainted(const uschar * s, int argn, address_item * addr,
2063 const uschar * etext, uschar ** errptr)
2067 uschar * msg = string_sprintf("Tainted arg %d for %s command: '%s'",
2071 addr->transport_return = FAIL;
2072 addr->message = msg;
2081 /*************************************************
2082 * Set up direct (non-shell) command *
2083 *************************************************/
2085 /* This function is called when a command line is to be parsed and executed
2086 directly, without the use of /bin/sh. It is called by the pipe transport,
2087 the queryprogram router, and also from the main delivery code when setting up a
2088 transport filter process. The code for ETRN also makes use of this; in that
2089 case, no addresses are passed.
2092 argvptr pointer to anchor for argv vector
2093 cmd points to the command string (modified IN PLACE)
2094 expand_arguments true if expansion is to occur
2095 expand_failed error value to set if expansion fails; not relevant if
2097 addr chain of addresses, or NULL
2098 allow_tainted_args as it says; used for ${run}
2099 etext text for use in error messages
2100 errptr where to put error message if addr is NULL;
2101 otherwise it is put in the first address
2103 Returns: TRUE if all went well; otherwise an error will be
2104 set in the first address and FALSE returned
2108 transport_set_up_command(const uschar *** argvptr, const uschar * cmd,
2109 BOOL expand_arguments, int expand_failed, address_item * addr,
2110 BOOL allow_tainted_args, const uschar * etext, uschar ** errptr)
2112 const uschar ** argv, * s;
2113 int address_count = 0, argcount = 0, max_args;
2115 /* Get store in which to build an argument list. Count the number of addresses
2116 supplied, and allow for that many arguments, plus an additional 60, which
2117 should be enough for anybody. Multiple addresses happen only when the local
2118 delivery batch option is set. */
2120 for (address_item * ad = addr; ad; ad = ad->next) address_count++;
2121 max_args = address_count + 60;
2122 *argvptr = argv = store_get((max_args+1)*sizeof(uschar *), GET_UNTAINTED);
2124 /* Split the command up into arguments terminated by white space. Lose
2125 trailing space at the start and end. Double-quoted arguments can contain \\ and
2126 \" escapes and so can be handled by the standard function; single-quoted
2127 arguments are verbatim. Copy each argument into a new string. */
2130 Uskip_whitespace(&s);
2132 for (; *s && argcount < max_args; argcount++)
2136 int n = Ustrcspn(++s, "'");
2137 argv[argcount] = string_copyn(s, n);
2138 if (*(s += n) == '\'') s++;
2141 argv[argcount] = string_dequote(CUSS &s);
2142 Uskip_whitespace(&s);
2145 argv[argcount] = NULL;
2147 /* If *s != 0 we have run out of argument slots. */
2151 uschar *msg = string_sprintf("Too many arguments in command \"%s\" in "
2155 addr->transport_return = FAIL;
2156 addr->message = msg;
2162 /* Expand each individual argument if required. Expansion happens for pipes set
2163 up in filter files and with directly-supplied commands. It does not happen if
2164 the pipe comes from a traditional .forward file. A failing expansion is a big
2165 disaster if the command came from Exim's configuration; if it came from a user
2166 it is just a normal failure. The expand_failed value is used as the error value
2167 to cater for these two cases.
2169 An argument consisting just of the text "$pipe_addresses" is treated specially.
2170 It is not passed to the general expansion function. Instead, it is replaced by
2171 a number of arguments, one for each address. This avoids problems with shell
2172 metacharacters and spaces in addresses.
2174 If the parent of the top address has an original part of "system-filter", this
2175 pipe was set up by the system filter, and we can permit the expansion of
2180 debug_printf("direct command:\n");
2181 for (int i = 0; argv[i]; i++)
2182 debug_printf(" argv[%d] = '%s'\n", i, string_printing(argv[i]));
2185 if (expand_arguments)
2187 BOOL allow_dollar_recipients = addr && addr->parent
2188 && Ustrcmp(addr->parent->address, "system-filter") == 0;
2190 for (int i = 0; argv[i]; i++)
2192 /* Handle special fudge for passing an address list */
2195 (Ustrcmp(argv[i], "$pipe_addresses") == 0 ||
2196 Ustrcmp(argv[i], "${pipe_addresses}") == 0))
2200 if (argcount + address_count - 1 > max_args)
2202 addr->transport_return = FAIL;
2203 addr->message = string_sprintf("Too many arguments to command \"%s\" "
2204 "in %s", cmd, etext);
2208 additional = address_count - 1;
2210 memmove(argv + i + 1 + additional, argv + i + 1,
2211 (argcount - i)*sizeof(uschar *));
2213 for (address_item * ad = addr; ad; ad = ad->next)
2215 /* $pipe_addresses is spefically not checked for taint, because there is
2216 a testcase (321) depending on it. It's unclear if the exact thing being
2217 done really needs to be legitimate, though I suspect it reflects an
2218 actual use-case that showed up a bug.
2219 This is a hole in the taint-pretection, mitigated only in that
2220 shell-syntax metachars cannot be injected via this route. */
2222 DEBUG(D_transport) if (is_tainted(ad->address))
2223 debug_printf("tainted element '%s' from $pipe_addresses\n", ad->address);
2225 argv[i++] = ad->address;
2229 /* Subtract one since we replace $pipe_addresses */
2234 /* Handle special case of $address_pipe when af_force_command is set */
2236 else if (addr && testflag(addr,af_force_command) &&
2237 (Ustrcmp(argv[i], "$address_pipe") == 0 ||
2238 Ustrcmp(argv[i], "${address_pipe}") == 0))
2240 int address_pipe_argcount = 0;
2241 int address_pipe_max_args;
2242 uschar **address_pipe_argv;
2244 /* We can never have more then the argv we will be loading into */
2245 address_pipe_max_args = max_args - argcount + 1;
2248 debug_printf("address_pipe_max_args=%d\n", address_pipe_max_args);
2250 /* We allocate an additional for (uschar *)0 */
2251 address_pipe_argv = store_get((address_pipe_max_args+1)*sizeof(uschar *), GET_UNTAINTED);
2253 /* +1 because addr->local_part[0] == '|' since af_force_command is set */
2254 s = expand_string(addr->local_part + 1);
2258 addr->transport_return = FAIL;
2259 addr->message = string_sprintf("Expansion of \"%s\" "
2260 "from command \"%s\" in %s failed: %s",
2261 (addr->local_part + 1), cmd, etext, expand_string_message);
2265 Uskip_whitespace(&s); /* strip leading space */
2267 while (*s && address_pipe_argcount < address_pipe_max_args)
2271 int n = Ustrcspn(++s, "'");
2272 argv[argcount] = string_copyn(s, n);
2273 if (*(s += n) == '\'') s++;
2276 address_pipe_argv[address_pipe_argcount++] = string_dequote(CUSS &s);
2277 Uskip_whitespace(&s); /* strip space after arg */
2280 address_pipe_argv[address_pipe_argcount] = NULL;
2282 /* If *s != 0 we have run out of argument slots. */
2285 uschar *msg = string_sprintf("Too many arguments in $address_pipe "
2286 "\"%s\" in %s", addr->local_part + 1, etext);
2289 addr->transport_return = FAIL;
2290 addr->message = msg;
2296 /* address_pipe_argcount - 1
2297 because we are replacing $address_pipe in the argument list
2298 with the first thing it expands to */
2300 if (argcount + address_pipe_argcount - 1 > max_args)
2302 addr->transport_return = FAIL;
2303 addr->message = string_sprintf("Too many arguments to command "
2304 "\"%s\" after expanding $address_pipe in %s", cmd, etext);
2308 /* If we are not just able to replace the slot that contained
2309 $address_pipe (address_pipe_argcount == 1)
2310 We have to move the existing argv by address_pipe_argcount - 1
2311 Visually if address_pipe_argcount == 2:
2312 [argv 0][argv 1][argv 2($address_pipe)][argv 3][0]
2313 [argv 0][argv 1][ap_arg0][ap_arg1][old argv 3][0] */
2315 if (address_pipe_argcount > 1)
2317 /* current position + additional args */
2318 argv + i + address_pipe_argcount,
2319 /* current position + 1 (for the (uschar *)0 at the end) */
2321 /* -1 for the (uschar *)0 at the end)*/
2322 (argcount - i)*sizeof(uschar *)
2325 /* Now we fill in the slots we just moved argv out of
2326 [argv 0][argv 1][argv 2=pipeargv[0]][argv 3=pipeargv[1]][old argv 3][0] */
2328 for (int address_pipe_i = 0;
2329 address_pipe_argv[address_pipe_i];
2330 address_pipe_i++, argcount++)
2332 uschar * s = address_pipe_argv[address_pipe_i];
2333 if (arg_is_tainted(s, i, addr, etext, errptr)) return FALSE;
2337 /* Subtract one since we replace $address_pipe */
2342 /* Handle normal expansion string */
2346 const uschar *expanded_arg;
2347 f.enable_dollar_recipients = allow_dollar_recipients;
2348 expanded_arg = expand_cstring(argv[i]);
2349 f.enable_dollar_recipients = FALSE;
2353 uschar *msg = string_sprintf("Expansion of \"%s\" "
2354 "from command \"%s\" in %s failed: %s",
2355 argv[i], cmd, etext, expand_string_message);
2358 addr->transport_return = expand_failed;
2359 addr->message = msg;
2365 if ( f.running_in_test_harness && is_tainted(expanded_arg)
2366 && Ustrcmp(etext, "queryprogram router") == 0)
2367 { /* hack, would be good to not need it */
2369 debug_printf("SPECIFIC TESTSUITE EXEMPTION: tainted arg '%s'\n",
2372 else if ( !allow_tainted_args
2373 && arg_is_tainted(expanded_arg, i, addr, etext, errptr))
2375 argv[i] = expanded_arg;
2381 debug_printf("direct command after expansion:\n");
2382 for (int i = 0; argv[i]; i++)
2384 debug_printf(" argv[%d] = '%s'\n", i, string_printing(argv[i]));
2385 debug_print_taint(argv[i]);
2395 /* For error messages, a string describing the config location associated
2396 with current processing. NULL if we are not in a transport. */
2397 /* Name only, for now */
2400 transport_current_name(void)
2402 if (!transport_name) return NULL;
2403 return string_sprintf(" (transport %s, %s %d)", transport_name, driver_srcfile, driver_srcline);
2406 #endif /*!MACRO_PREDEF*/
2409 /* End of transport.c */