1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* General functions concerned with transportation, and generic options for all
14 #ifdef HAVE_LINUX_SENDFILE
15 #include <sys/sendfile.h>
18 /* Structure for keeping list of addresses that have been added to
19 Envelope-To:, in order to avoid duplication. */
27 /* Static data for write_chunk() */
29 static uschar *chunk_ptr; /* chunk pointer */
30 static uschar *nl_check; /* string to look for at line start */
31 static int nl_check_length; /* length of same */
32 static uschar *nl_escape; /* string to insert */
33 static int nl_escape_length; /* length of same */
34 static int nl_partial_match; /* length matched at chunk end */
37 /* Generic options for transports, all of which live inside transport_instance
38 data blocks and which therefore have the opt_public flag set. Note that there
39 are other options living inside this structure which can be set only from
40 certain transports. */
42 optionlist optionlist_transports[] = {
43 { "*expand_group", opt_stringptr|opt_hidden|opt_public,
44 (void *)offsetof(transport_instance, expand_gid) },
45 { "*expand_user", opt_stringptr|opt_hidden|opt_public,
46 (void *)offsetof(transport_instance, expand_uid) },
47 { "*headers_rewrite_flags", opt_int|opt_public|opt_hidden,
48 (void *)offsetof(transport_instance, rewrite_existflags) },
49 { "*headers_rewrite_rules", opt_void|opt_public|opt_hidden,
50 (void *)offsetof(transport_instance, rewrite_rules) },
51 { "*set_group", opt_bool|opt_hidden|opt_public,
52 (void *)offsetof(transport_instance, gid_set) },
53 { "*set_user", opt_bool|opt_hidden|opt_public,
54 (void *)offsetof(transport_instance, uid_set) },
55 { "body_only", opt_bool|opt_public,
56 (void *)offsetof(transport_instance, body_only) },
57 { "current_directory", opt_stringptr|opt_public,
58 (void *)offsetof(transport_instance, current_dir) },
59 { "debug_print", opt_stringptr | opt_public,
60 (void *)offsetof(transport_instance, debug_string) },
61 { "delivery_date_add", opt_bool|opt_public,
62 (void *)(offsetof(transport_instance, delivery_date_add)) },
63 { "disable_logging", opt_bool|opt_public,
64 (void *)(offsetof(transport_instance, disable_logging)) },
65 { "driver", opt_stringptr|opt_public,
66 (void *)offsetof(transport_instance, driver_name) },
67 { "envelope_to_add", opt_bool|opt_public,
68 (void *)(offsetof(transport_instance, envelope_to_add)) },
70 { "event_action", opt_stringptr | opt_public,
71 (void *)offsetof(transport_instance, event_action) },
73 { "group", opt_expand_gid|opt_public,
74 (void *)offsetof(transport_instance, gid) },
75 { "headers_add", opt_stringptr|opt_public|opt_rep_str,
76 (void *)offsetof(transport_instance, add_headers) },
77 { "headers_only", opt_bool|opt_public,
78 (void *)offsetof(transport_instance, headers_only) },
79 { "headers_remove", opt_stringptr|opt_public|opt_rep_str,
80 (void *)offsetof(transport_instance, remove_headers) },
81 { "headers_rewrite", opt_rewrite|opt_public,
82 (void *)offsetof(transport_instance, headers_rewrite) },
83 { "home_directory", opt_stringptr|opt_public,
84 (void *)offsetof(transport_instance, home_dir) },
85 { "initgroups", opt_bool|opt_public,
86 (void *)offsetof(transport_instance, initgroups) },
87 { "max_parallel", opt_stringptr|opt_public,
88 (void *)offsetof(transport_instance, max_parallel) },
89 { "message_size_limit", opt_stringptr|opt_public,
90 (void *)offsetof(transport_instance, message_size_limit) },
91 { "rcpt_include_affixes", opt_bool|opt_public,
92 (void *)offsetof(transport_instance, rcpt_include_affixes) },
93 { "retry_use_local_part", opt_bool|opt_public,
94 (void *)offsetof(transport_instance, retry_use_local_part) },
95 { "return_path", opt_stringptr|opt_public,
96 (void *)(offsetof(transport_instance, return_path)) },
97 { "return_path_add", opt_bool|opt_public,
98 (void *)(offsetof(transport_instance, return_path_add)) },
99 { "shadow_condition", opt_stringptr|opt_public,
100 (void *)offsetof(transport_instance, shadow_condition) },
101 { "shadow_transport", opt_stringptr|opt_public,
102 (void *)offsetof(transport_instance, shadow) },
103 { "transport_filter", opt_stringptr|opt_public,
104 (void *)offsetof(transport_instance, filter_command) },
105 { "transport_filter_timeout", opt_time|opt_public,
106 (void *)offsetof(transport_instance, filter_timeout) },
107 { "user", opt_expand_uid|opt_public,
108 (void *)offsetof(transport_instance, uid) }
111 int optionlist_transports_size =
112 sizeof(optionlist_transports)/sizeof(optionlist);
115 /*************************************************
116 * Initialize transport list *
117 *************************************************/
119 /* Read the transports section of the configuration file, and set up a chain of
120 transport instances according to its contents. Each transport has generic
121 options and may also have its own private options. This function is only ever
122 called when transports == NULL. We use generic code in readconf to do most of
128 transport_instance *t;
130 readconf_driver_init(US"transport",
131 (driver_instance **)(&transports), /* chain anchor */
132 (driver_info *)transports_available, /* available drivers */
133 sizeof(transport_info), /* size of info block */
134 &transport_defaults, /* default values for generic options */
135 sizeof(transport_instance), /* size of instance block */
136 optionlist_transports, /* generic options */
137 optionlist_transports_size);
139 /* Now scan the configured transports and check inconsistencies. A shadow
140 transport is permitted only for local transports. */
142 for (t = transports; t; t = t->next)
144 if (!t->info->local && t->shadow)
145 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
146 "shadow transport not allowed on non-local transport %s", t->name);
148 if (t->body_only && t->headers_only)
149 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
150 "%s transport: body_only and headers_only are mutually exclusive",
157 /*************************************************
158 * Write block of data *
159 *************************************************/
161 /* Subroutine called by write_chunk() and at the end of the message actually
162 to write a data block. Also called directly by some transports to write
163 additional data to the file descriptor (e.g. prefix, suffix).
165 If a transport wants data transfers to be timed, it sets a non-zero value in
166 transport_write_timeout. A non-zero transport_write_timeout causes a timer to
167 be set for each block of data written from here. If time runs out, then write()
168 fails and provokes an error return. The caller can then inspect sigalrm_seen to
171 On some systems, if a quota is exceeded during the write, the yield is the
172 number of bytes written rather than an immediate error code. This also happens
173 on some systems in other cases, for example a pipe that goes away because the
174 other end's process terminates (Linux). On other systems, (e.g. Solaris 2) you
175 get the error codes the first time.
177 The write() function is also interruptible; the Solaris 2.6 man page says:
179 If write() is interrupted by a signal before it writes any
180 data, it will return -1 with errno set to EINTR.
182 If write() is interrupted by a signal after it successfully
183 writes some data, it will return the number of bytes written.
185 To handle these cases, we want to restart the write() to output the remainder
186 of the data after a non-negative return from write(), except after a timeout.
187 In the error cases (EDQUOT, EPIPE) no bytes get written the second time, and a
188 proper error then occurs. In principle, after an interruption, the second
189 write() could suffer the same fate, but we do not want to continue for
190 evermore, so stick a maximum repetition count on the loop to act as a
194 fd file descriptor to write to
195 block block of bytes to write
196 len number of bytes to write
198 Returns: TRUE on success, FALSE on failure (with errno preserved);
199 transport_count is incremented by the number of bytes written
203 transport_write_block(int fd, uschar *block, int len)
205 int i, rc, save_errno;
206 int local_timeout = transport_write_timeout;
208 /* This loop is for handling incomplete writes and other retries. In most
209 normal cases, it is only ever executed once. */
211 for (i = 0; i < 100; i++)
214 debug_printf("writing data block fd=%d size=%d timeout=%d\n",
215 fd, len, local_timeout);
217 /* This code makes use of alarm() in order to implement the timeout. This
218 isn't a very tidy way of doing things. Using non-blocking I/O with select()
219 provides a neater approach. However, I don't know how to do this when TLS is
222 if (transport_write_timeout <= 0) /* No timeout wanted */
225 if (tls_out.active == fd) rc = tls_write(FALSE, block, len); else
227 rc = write(fd, block, len);
231 /* Timeout wanted. */
235 alarm(local_timeout);
237 if (tls_out.active == fd)
238 rc = tls_write(FALSE, block, len);
241 rc = write(fd, block, len);
243 local_timeout = alarm(0);
251 /* Hopefully, the most common case is success, so test that first. */
253 if (rc == len) { transport_count += len; return TRUE; }
255 /* A non-negative return code is an incomplete write. Try again for the rest
256 of the block. If we have exactly hit the timeout, give up. */
262 transport_count += rc;
263 DEBUG(D_transport) debug_printf("write incomplete (%d)\n", rc);
264 goto CHECK_TIMEOUT; /* A few lines below */
267 /* A negative return code with an EINTR error is another form of
268 incomplete write, zero bytes having been written */
270 if (save_errno == EINTR)
273 debug_printf("write interrupted before anything written\n");
274 goto CHECK_TIMEOUT; /* A few lines below */
277 /* A response of EAGAIN from write() is likely only in the case of writing
278 to a FIFO that is not swallowing the data as fast as Exim is writing it. */
280 if (save_errno == EAGAIN)
283 debug_printf("write temporarily locked out, waiting 1 sec\n");
286 /* Before continuing to try another write, check that we haven't run out of
290 if (transport_write_timeout > 0 && local_timeout <= 0)
298 /* Otherwise there's been an error */
300 DEBUG(D_transport) debug_printf("writing error %d: %s\n", save_errno,
301 strerror(save_errno));
306 /* We've tried and tried and tried but still failed */
308 errno = ERRNO_WRITEINCOMPLETE;
315 /*************************************************
316 * Write formatted string *
317 *************************************************/
319 /* This is called by various transports. It is a convenience function.
324 ... arguments for format
326 Returns: the yield of transport_write_block()
330 transport_write_string(int fd, const char *format, ...)
333 va_start(ap, format);
334 if (!string_vformat(big_buffer, big_buffer_size, format, ap))
335 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong formatted string in transport");
337 return transport_write_block(fd, big_buffer, Ustrlen(big_buffer));
343 /*************************************************
344 * Write character chunk *
345 *************************************************/
347 /* Subroutine used by transport_write_message() to scan character chunks for
348 newlines and act appropriately. The object is to minimise the number of writes.
349 The output byte stream is buffered up in deliver_out_buffer, which is written
350 only when it gets full, thus minimizing write operations and TCP packets.
352 Static data is used to handle the case when the last character of the previous
353 chunk was NL, or matched part of the data that has to be escaped.
356 fd file descript to write to
357 chunk pointer to data to write
358 len length of data to write
359 tctx transport context - processing to be done during output
361 In addition, the static nl_xxx variables must be set as required.
363 Returns: TRUE on success, FALSE on failure (with errno preserved)
367 write_chunk(int fd, transport_ctx * tctx, uschar *chunk, int len)
369 uschar *start = chunk;
370 uschar *end = chunk + len;
372 int mlen = DELIVER_OUT_BUFFER_SIZE - nl_escape_length - 2;
374 /* The assumption is made that the check string will never stretch over move
375 than one chunk since the only time there are partial matches is when copying
376 the body in large buffers. There is always enough room in the buffer for an
377 escape string, since the loop below ensures this for each character it
378 processes, and it won't have stuck in the escape string if it left a partial
381 if (nl_partial_match >= 0)
383 if (nl_check_length > 0 && len >= nl_check_length &&
384 Ustrncmp(start, nl_check + nl_partial_match,
385 nl_check_length - nl_partial_match) == 0)
387 Ustrncpy(chunk_ptr, nl_escape, nl_escape_length);
388 chunk_ptr += nl_escape_length;
389 start += nl_check_length - nl_partial_match;
392 /* The partial match was a false one. Insert the characters carried over
393 from the previous chunk. */
395 else if (nl_partial_match > 0)
397 Ustrncpy(chunk_ptr, nl_check, nl_partial_match);
398 chunk_ptr += nl_partial_match;
401 nl_partial_match = -1;
404 /* Now process the characters in the chunk. Whenever we hit a newline we check
405 for possible escaping. The code for the non-NL route should be as fast as
408 for (ptr = start; ptr < end; ptr++)
412 /* Flush the buffer if it has reached the threshold - we want to leave enough
413 room for the next uschar, plus a possible extra CR for an LF, plus the escape
416 if ((len = chunk_ptr - deliver_out_buffer) > mlen)
418 DEBUG(D_transport) debug_printf("flushing headers buffer\n");
420 /* If CHUNKING, prefix with BDAT (size) NON-LAST. Also, reap responses
421 from previous SMTP commands. */
423 if (tctx && tctx->options & topt_use_bdat && tctx->chunk_cb)
425 if ( tctx->chunk_cb(fd, tctx, (unsigned)len, 0) != OK
426 || !transport_write_block(fd, deliver_out_buffer, len)
427 || tctx->chunk_cb(fd, tctx, 0, tc_reap_prev) != OK
432 if (!transport_write_block(fd, deliver_out_buffer, len))
434 chunk_ptr = deliver_out_buffer;
437 if ((ch = *ptr) == '\n')
439 int left = end - ptr - 1; /* count of chars left after NL */
441 /* Insert CR before NL if required */
443 if (tctx && tctx->options & topt_use_crlf) *chunk_ptr++ = '\r';
445 transport_newlines++;
447 /* The check_string test (formerly "from hack") replaces the specific
448 string at the start of a line with an escape string (e.g. "From " becomes
449 ">From " or "." becomes "..". It is a case-sensitive test. The length
450 check above ensures there is always enough room to insert this string. */
452 if (nl_check_length > 0)
454 if (left >= nl_check_length &&
455 Ustrncmp(ptr+1, nl_check, nl_check_length) == 0)
457 Ustrncpy(chunk_ptr, nl_escape, nl_escape_length);
458 chunk_ptr += nl_escape_length;
459 ptr += nl_check_length;
462 /* Handle the case when there isn't enough left to match the whole
463 check string, but there may be a partial match. We remember how many
464 characters matched, and finish processing this chunk. */
466 else if (left <= 0) nl_partial_match = 0;
468 else if (Ustrncmp(ptr+1, nl_check, left) == 0)
470 nl_partial_match = left;
476 /* Not a NL character */
478 else *chunk_ptr++ = ch;
487 /*************************************************
488 * Generate address for RCPT TO *
489 *************************************************/
491 /* This function puts together an address for RCPT to, using the caseful
492 version of the local part and the caseful version of the domain. If there is no
493 prefix or suffix, or if affixes are to be retained, we can just use the
494 original address. Otherwise, if there is a prefix but no suffix we can use a
495 pointer into the original address. If there is a suffix, however, we have to
499 addr the address item
500 include_affixes TRUE if affixes are to be included
506 transport_rcpt_address(address_item *addr, BOOL include_affixes)
513 setflag(addr, af_include_affixes); /* Affects logged => line */
514 return addr->address;
517 if (addr->suffix == NULL)
519 if (addr->prefix == NULL) return addr->address;
520 return addr->address + Ustrlen(addr->prefix);
523 at = Ustrrchr(addr->address, '@');
524 plen = (addr->prefix == NULL)? 0 : Ustrlen(addr->prefix);
525 slen = Ustrlen(addr->suffix);
527 return string_sprintf("%.*s@%s", (at - addr->address - plen - slen),
528 addr->address + plen, at + 1);
532 /*************************************************
533 * Output Envelope-To: address & scan duplicates *
534 *************************************************/
536 /* This function is called from internal_transport_write_message() below, when
537 generating an Envelope-To: header line. It checks for duplicates of the given
538 address and its ancestors. When one is found, this function calls itself
539 recursively, to output the envelope address of the duplicate.
541 We want to avoid duplication in the list, which can arise for example when
542 A->B,C and then both B and C alias to D. This can also happen when there are
543 unseen drivers in use. So a list of addresses that have been output is kept in
546 It is also possible to have loops in the address ancestry/duplication graph,
547 for example if there are two top level addresses A and B and we have A->B,C and
548 B->A. To break the loop, we use a list of processed addresses in the dlist
551 After handling duplication, this function outputs the progenitor of the given
555 p the address we are interested in
556 pplist address of anchor of the list of addresses not to output
557 pdlist address of anchor of the list of processed addresses
558 first TRUE if this is the first address; set it FALSE afterwards
559 fd the file descriptor to write to
560 tctx transport context - processing to be done during output
562 Returns: FALSE if writing failed
566 write_env_to(address_item *p, struct aci **pplist, struct aci **pdlist,
567 BOOL *first, int fd, transport_ctx * tctx)
572 /* Do nothing if we have already handled this address. If not, remember it
573 so that we don't handle it again. */
575 for (ppp = *pdlist; ppp; ppp = ppp->next) if (p == ppp->ptr) return TRUE;
577 ppp = store_get(sizeof(struct aci));
582 /* Now scan up the ancestry, checking for duplicates at each generation. */
584 for (pp = p;; pp = pp->parent)
587 for (dup = addr_duplicate; dup; dup = dup->next)
588 if (dup->dupof == pp) /* a dup of our address */
589 if (!write_env_to(dup, pplist, pdlist, first, fd, tctx))
591 if (!pp->parent) break;
594 /* Check to see if we have already output the progenitor. */
596 for (ppp = *pplist; ppp; ppp = ppp->next) if (pp == ppp->ptr) break;
597 if (ppp) return TRUE;
599 /* Remember what we have output, and output it. */
601 ppp = store_get(sizeof(struct aci));
606 if (!*first && !write_chunk(fd, tctx, US",\n ", 3)) return FALSE;
608 return write_chunk(fd, tctx, pp->address, Ustrlen(pp->address));
614 /* Add/remove/rewwrite headers, and send them plus the empty-line sparator.
620 addr (chain of) addresses (for extra headers), or NULL;
621 only the first address is used
622 fd file descriptor to write the message to
623 tctx transport context
624 sendfn function for output (transport or verify)
626 Returns: TRUE on success; FALSE on failure.
629 transport_headers_send(int fd, transport_ctx * tctx,
630 BOOL (*sendfn)(int fd, transport_ctx * tctx, uschar * s, int len))
634 transport_instance * tblock = tctx ? tctx->tblock : NULL;
635 address_item * addr = tctx ? tctx->addr : NULL;
637 /* Then the message's headers. Don't write any that are flagged as "old";
638 that means they were rewritten, or are a record of envelope rewriting, or
639 were removed (e.g. Bcc). If remove_headers is not null, skip any headers that
640 match any entries therein. It is a colon-sep list; expand the items
641 separately and squash any empty ones.
642 Then check addr->prop.remove_headers too, provided that addr is not NULL. */
644 for (h = header_list; h; h = h->next) if (h->type != htype_old)
647 BOOL include_header = TRUE;
649 list = tblock ? tblock->remove_headers : NULL;
650 for (i = 0; i < 2; i++) /* For remove_headers && addr->prop.remove_headers */
654 int sep = ':'; /* This is specified as a colon-separated list */
656 while ((s = string_nextinlist(&list, &sep, NULL, 0)))
661 if (!(s = expand_string(s)) && !expand_string_forcedfail)
663 errno = ERRNO_CHHEADER_FAIL;
666 len = s ? Ustrlen(s) : 0;
667 if (strncmpic(h->text, s, len) != 0) continue;
669 while (*ss == ' ' || *ss == '\t') ss++;
670 if (*ss == ':') break;
672 if (s) { include_header = FALSE; break; }
674 if (addr) list = addr->prop.remove_headers;
677 /* If this header is to be output, try to rewrite it if there are rewriting
682 if (tblock && tblock->rewrite_rules)
684 void *reset_point = store_get(0);
687 if ((hh = rewrite_header(h, NULL, NULL, tblock->rewrite_rules,
688 tblock->rewrite_existflags, FALSE)))
690 if (!sendfn(fd, tctx, hh->text, hh->slen)) return FALSE;
691 store_reset(reset_point);
692 continue; /* With the next header line */
696 /* Either no rewriting rules, or it didn't get rewritten */
698 if (!sendfn(fd, tctx, h->text, h->slen)) return FALSE;
705 DEBUG(D_transport) debug_printf("removed header line:\n%s---\n", h->text);
709 /* Add on any address-specific headers. If there are multiple addresses,
710 they will all have the same headers in order to be batched. The headers
711 are chained in reverse order of adding (so several addresses from the
712 same alias might share some of them) but we want to output them in the
713 opposite order. This is a bit tedious, but there shouldn't be very many
714 of them. We just walk the list twice, reversing the pointers each time,
715 but on the second time, write out the items.
717 Headers added to an address by a router are guaranteed to end with a newline.
723 header_line *hprev = addr->prop.extra_headers;
725 for (i = 0; i < 2; i++)
726 for (h = hprev, hprev = NULL; h; h = hnext)
733 if (!sendfn(fd, tctx, h->text, h->slen)) return FALSE;
735 debug_printf("added header line(s):\n%s---\n", h->text);
740 /* If a string containing additional headers exists it is a newline-sep
741 list. Expand each item and write out the result. This is done last so that
742 if it (deliberately or accidentally) isn't in header format, it won't mess
743 up any other headers. An empty string or a forced expansion failure are
744 noops. An added header string from a transport may not end with a newline;
745 add one if it does not. */
747 if (tblock && (list = CUS tblock->add_headers))
752 while ((s = string_nextinlist(&list, &sep, NULL, 0)))
753 if ((s = expand_string(s)))
755 int len = Ustrlen(s);
758 if (!sendfn(fd, tctx, s, len)) return FALSE;
759 if (s[len-1] != '\n' && !sendfn(fd, tctx, US"\n", 1))
763 debug_printf("added header line:\n%s", s);
764 if (s[len-1] != '\n') debug_printf("\n");
765 debug_printf("---\n");
769 else if (!expand_string_forcedfail)
770 { errno = ERRNO_CHHEADER_FAIL; return FALSE; }
773 /* Separate headers from body with a blank line */
775 return sendfn(fd, tctx, US"\n", 1);
779 /*************************************************
780 * Write the message *
781 *************************************************/
783 /* This function writes the message to the given file descriptor. The headers
784 are in the in-store data structure, and the rest of the message is in the open
785 file descriptor deliver_datafile. Make sure we start it at the beginning.
787 . If add_return_path is TRUE, a "return-path:" header is added to the message,
788 containing the envelope sender's address.
790 . If add_envelope_to is TRUE, a "envelope-to:" header is added to the message,
791 giving the top-level envelope address that caused this delivery to happen.
793 . If add_delivery_date is TRUE, a "delivery-date:" header is added to the
794 message. It gives the time and date that delivery took place.
796 . If check_string is not null, the start of each line is checked for that
797 string. If it is found, it is replaced by escape_string. This used to be
798 the "from hack" for files, and "smtp_dots" for escaping SMTP dots.
800 . If use_crlf is true, newlines are turned into CRLF (SMTP output).
802 The yield is TRUE if all went well, and FALSE if not. Exit *immediately* after
803 any writing or reading error, leaving the code in errno intact. Error exits
804 can include timeouts for certain transports, which are requested by setting
805 transport_write_timeout non-zero.
808 fd file descriptor to write the message to
810 addr (chain of) addresses (for extra headers), or NULL;
811 only the first address is used
812 tblock optional transport instance block (NULL signifies NULL/0):
813 add_headers a string containing one or more headers to add; it is
814 expanded, and must be in correct RFC 822 format as
815 it is transmitted verbatim; NULL => no additions,
816 and so does empty string or forced expansion fail
817 remove_headers a colon-separated list of headers to remove, or NULL
818 rewrite_rules chain of header rewriting rules
819 rewrite_existflags flags for the rewriting rules
820 options bit-wise options:
821 add_return_path if TRUE, add a "return-path" header
822 add_envelope_to if TRUE, add a "envelope-to" header
823 add_delivery_date if TRUE, add a "delivery-date" header
824 use_crlf if TRUE, turn NL into CR LF
825 end_dot if TRUE, send a terminating "." line at the end
826 no_headers if TRUE, omit the headers
827 no_body if TRUE, omit the body
828 check_string a string to check for at the start of lines, or NULL
829 escape_string a string to insert in front of any check string
830 size_limit if > 0, this is a limit to the size of message written;
831 it is used when returning messages to their senders,
832 and is approximate rather than exact, owing to chunk
835 Returns: TRUE on success; FALSE (with errno) on failure.
836 In addition, the global variable transport_count
837 is incremented by the number of bytes written.
841 internal_transport_write_message(int fd, transport_ctx * tctx, int size_limit)
845 /* Initialize pointer in output buffer. */
847 chunk_ptr = deliver_out_buffer;
849 /* Set up the data for start-of-line data checking and escaping */
851 nl_partial_match = -1;
852 if (tctx->check_string && tctx->escape_string)
854 nl_check = tctx->check_string;
855 nl_check_length = Ustrlen(nl_check);
856 nl_escape = tctx->escape_string;
857 nl_escape_length = Ustrlen(nl_escape);
860 nl_check_length = nl_escape_length = 0;
862 /* Whether the escaping mechanism is applied to headers or not is controlled by
863 an option (set for SMTP, not otherwise). Negate the length if not wanted till
864 after the headers. */
866 if (!(tctx->options & topt_escape_headers))
867 nl_check_length = -nl_check_length;
869 /* Write the headers if required, including any that have to be added. If there
870 are header rewriting rules, apply them. */
872 if (!(tctx->options & topt_no_headers))
874 /* Add return-path: if requested. */
876 if (tctx->options & topt_add_return_path)
878 uschar buffer[ADDRESS_MAXLENGTH + 20];
879 int n = sprintf(CS buffer, "Return-path: <%.*s>\n", ADDRESS_MAXLENGTH,
881 if (!write_chunk(fd, tctx, buffer, n)) return FALSE;
884 /* Add envelope-to: if requested */
886 if (tctx->options & topt_add_envelope_to)
890 struct aci *plist = NULL;
891 struct aci *dlist = NULL;
892 void *reset_point = store_get(0);
894 if (!write_chunk(fd, tctx, US"Envelope-to: ", 13)) return FALSE;
896 /* Pick up from all the addresses. The plist and dlist variables are
897 anchors for lists of addresses already handled; they have to be defined at
898 this level becuase write_env_to() calls itself recursively. */
900 for (p = tctx->addr; p; p = p->next)
901 if (!write_env_to(p, &plist, &dlist, &first, fd, tctx))
904 /* Add a final newline and reset the store used for tracking duplicates */
906 if (!write_chunk(fd, tctx, US"\n", 1)) return FALSE;
907 store_reset(reset_point);
910 /* Add delivery-date: if requested. */
912 if (tctx->options & topt_add_delivery_date)
915 int n = sprintf(CS buffer, "Delivery-date: %s\n", tod_stamp(tod_full));
916 if (!write_chunk(fd, tctx, buffer, n)) return FALSE;
919 /* Then the message's headers. Don't write any that are flagged as "old";
920 that means they were rewritten, or are a record of envelope rewriting, or
921 were removed (e.g. Bcc). If remove_headers is not null, skip any headers that
922 match any entries therein. Then check addr->prop.remove_headers too, provided that
925 if (!transport_headers_send(fd, tctx, &write_chunk))
929 /* When doing RFC3030 CHUNKING output, work out how much data would be in a
930 last-BDAT, consisting of the current write_chunk() output buffer fill
931 (optimally, all of the headers - but it does not matter if we already had to
932 flush that buffer with non-last BDAT prependix) plus the amount of body data
933 (as expanded for CRLF lines). Then create and write BDAT(s), and ensure
934 that further use of write_chunk() will not prepend BDATs.
935 The first BDAT written will also first flush any outstanding MAIL and RCPT
936 commands which were buffered thans to PIPELINING.
937 Commands go out (using a send()) from a different buffer to data (using a
938 write()). They might not end up in the same TCP segment, which is
941 if (tctx->options & topt_use_bdat)
946 if ((hsize = chunk_ptr - deliver_out_buffer) < 0)
948 if (!(tctx->options & topt_no_body))
950 if ((fsize = lseek(deliver_datafile, 0, SEEK_END)) < 0) return FALSE;
951 fsize -= SPOOL_DATA_START_OFFSET;
952 if (size_limit > 0 && fsize > size_limit)
954 size = hsize + fsize;
955 if (tctx->options & topt_use_crlf)
956 size += body_linecount; /* account for CRLF-expansion */
959 /* If the message is large, emit first a non-LAST chunk with just the
960 headers, and reap the command responses. This lets us error out early
961 on RCPT rejects rather than sending megabytes of data. Include headers
962 on the assumption they are cheap enough and some clever implementations
963 might errorcheck them too, on-the-fly, and reject that chunk. */
965 if (size > DELIVER_OUT_BUFFER_SIZE && hsize > 0)
968 debug_printf("sending small initial BDAT; hssize=%d\n", hsize);
969 if ( tctx->chunk_cb(fd, tctx, hsize, 0) != OK
970 || !transport_write_block(fd, deliver_out_buffer, hsize)
971 || tctx->chunk_cb(fd, tctx, 0, tc_reap_prev) != OK
974 chunk_ptr = deliver_out_buffer;
978 /* Emit a LAST datachunk command. */
980 if (tctx->chunk_cb(fd, tctx, size, tc_chunk_last) != OK)
983 tctx->options &= ~topt_use_bdat;
986 /* If the body is required, ensure that the data for check strings (formerly
987 the "from hack") is enabled by negating the length if necessary. (It will be
988 negative in cases where it isn't to apply to the headers). Then ensure the body
989 is positioned at the start of its file (following the message id), then write
990 it, applying the size limit if required. */
992 if (!(tctx->options & topt_no_body))
994 int size = size_limit;
996 nl_check_length = abs(nl_check_length);
997 nl_partial_match = 0;
998 if (lseek(deliver_datafile, SPOOL_DATA_START_OFFSET, SEEK_SET) < 0)
1000 while ( (len = MAX(DELIVER_IN_BUFFER_SIZE, size)) > 0
1001 && (len = read(deliver_datafile, deliver_in_buffer, len)) > 0)
1003 if (!write_chunk(fd, tctx, deliver_in_buffer, len))
1008 /* A read error on the body will have left len == -1 and errno set. */
1010 if (len != 0) return FALSE;
1013 /* Finished with the check string */
1015 nl_check_length = nl_escape_length = 0;
1017 /* If requested, add a terminating "." line (SMTP output). */
1019 if (tctx->options & topt_end_dot && !write_chunk(fd, tctx, US".\n", 2))
1022 /* Write out any remaining data in the buffer before returning. */
1024 return (len = chunk_ptr - deliver_out_buffer) <= 0 ||
1025 transport_write_block(fd, deliver_out_buffer, len);
1029 #ifndef DISABLE_DKIM
1031 /***************************************************************************************************
1032 * External interface to write the message, while signing it with DKIM and/or Domainkeys *
1033 ***************************************************************************************************/
1035 /* This function is a wrapper around transport_write_message().
1036 It is only called from the smtp transport if DKIM or Domainkeys support
1037 is compiled in. The function sets up a replacement fd into a -K file,
1038 then calls the normal function. This way, the exact bits that exim would
1039 have put "on the wire" will end up in the file (except for TLS
1040 encapsulation, which is the very very last thing). When we are done
1041 signing the file, send the signed message down the original fd (or TLS fd).
1044 as for internal_transport_write_message() above, with additional arguments
1047 Returns: TRUE on success; FALSE (with errno) for any failure
1051 dkim_transport_write_message(int out_fd, transport_ctx * tctx,
1052 struct ob_dkim * dkim)
1057 uschar * dkim_spool_name;
1060 uschar *dkim_signature = NULL;
1065 /* If we can't sign, just call the original function. */
1067 if (!(dkim->dkim_private_key && dkim->dkim_domain && dkim->dkim_selector))
1068 return transport_write_message(out_fd, tctx, 0);
1070 dkim_spool_name = spool_fname(US"input", message_subdir, message_id,
1071 string_sprintf("-%d-K", (int)getpid()));
1073 if ((dkim_fd = Uopen(dkim_spool_name, O_RDWR|O_CREAT|O_TRUNC, SPOOL_MODE)) < 0)
1075 /* Can't create spool file. Ugh. */
1081 /* Call original function to write the -K file; does the CRLF expansion
1082 (but, in the CHUNKING case, not dot-stuffing and dot-termination). */
1084 options = tctx->options;
1085 tctx->options &= ~topt_use_bdat;
1086 rc = transport_write_message(dkim_fd, tctx, 0);
1087 tctx->options = options;
1089 /* Save error state. We must clean up before returning. */
1096 /* Rewind file and feed it to the goats^W DKIM lib */
1097 dkim->dot_stuffed = !!(options & topt_end_dot);
1098 lseek(dkim_fd, 0, SEEK_SET);
1099 if ((dkim_signature = dkim_exim_sign(dkim_fd, dkim)))
1100 siglen = Ustrlen(dkim_signature);
1101 else if (dkim->dkim_strict)
1103 uschar *dkim_strict_result = expand_string(dkim->dkim_strict);
1104 if (dkim_strict_result)
1105 if ( (strcmpic(dkim->dkim_strict,US"1") == 0) ||
1106 (strcmpic(dkim->dkim_strict,US"true") == 0) )
1108 /* Set errno to something halfway meaningful */
1109 save_errno = EACCES;
1110 log_write(0, LOG_MAIN, "DKIM: message could not be signed,"
1111 " and dkim_strict is set. Deferring message delivery.");
1117 #ifndef HAVE_LINUX_SENDFILE
1118 if (options & topt_use_bdat)
1120 k_file_size = lseek(dkim_fd, 0, SEEK_END); /* Fetch file size */
1122 if (options & topt_use_bdat)
1125 /* On big messages output a precursor chunk to get any pipelined
1126 MAIL & RCPT commands flushed, then reap the responses so we can
1127 error out on RCPT rejects before sending megabytes. */
1129 if (siglen + k_file_size > DELIVER_OUT_BUFFER_SIZE && siglen > 0)
1131 if ( tctx->chunk_cb(out_fd, tctx, siglen, 0) != OK
1132 || !transport_write_block(out_fd, dkim_signature, siglen)
1133 || tctx->chunk_cb(out_fd, tctx, 0, tc_reap_prev) != OK
1139 if (tctx->chunk_cb(out_fd, tctx, siglen + k_file_size, tc_chunk_last) != OK)
1143 if(siglen > 0 && !transport_write_block(out_fd, dkim_signature, siglen))
1146 #ifdef HAVE_LINUX_SENDFILE
1147 /* We can use sendfile() to shove the file contents
1148 to the socket. However only if we don't use TLS,
1149 as then there's another layer of indirection
1150 before the data finally hits the socket. */
1151 if (tls_out.active != out_fd)
1157 lseek(dkim_fd, 0, SEEK_SET);
1159 while(copied >= 0 && offset < k_file_size)
1160 copied = sendfile(out_fd, dkim_fd, &offset, k_file_size - offset);
1170 lseek(dkim_fd, 0, SEEK_SET);
1172 /* Send file down the original fd */
1173 while((sread = read(dkim_fd, deliver_out_buffer, DELIVER_OUT_BUFFER_SIZE)) >0)
1175 char *p = deliver_out_buffer;
1176 /* write the chunk */
1181 wwritten = tls_out.active == out_fd
1182 ? tls_write(FALSE, US p, sread)
1183 : write(out_fd, p, sread);
1185 wwritten = write(out_fd, p, sread);
1202 /* unlink -K file */
1203 (void)close(dkim_fd);
1204 Uunlink(dkim_spool_name);
1218 /*************************************************
1219 * External interface to write the message *
1220 *************************************************/
1222 /* If there is no filtering required, call the internal function above to do
1223 the real work, passing over all the arguments from this function. Otherwise,
1224 set up a filtering process, fork another process to call the internal function
1225 to write to the filter, and in this process just suck from the filter and write
1226 down the given fd. At the end, tidy up the pipes and the processes.
1229 Arguments: as for internal_transport_write_message() above
1231 Returns: TRUE on success; FALSE (with errno) for any failure
1232 transport_count is incremented by the number of bytes written
1236 transport_write_message(int fd, transport_ctx * tctx, int size_limit)
1239 BOOL last_filter_was_NL = TRUE;
1240 int rc, len, yield, fd_read, fd_write, save_errno;
1241 int pfd[2] = {-1, -1};
1242 pid_t filter_pid, write_pid;
1243 static transport_ctx dummy_tctx = {0};
1245 if (!tctx) tctx = &dummy_tctx;
1247 transport_filter_timed_out = FALSE;
1249 /* If there is no filter command set up, call the internal function that does
1250 the actual work, passing it the incoming fd, and return its result. */
1252 if ( !transport_filter_argv
1253 || !*transport_filter_argv
1254 || !**transport_filter_argv
1256 return internal_transport_write_message(fd, tctx, size_limit);
1258 /* Otherwise the message must be written to a filter process and read back
1259 before being written to the incoming fd. First set up the special processing to
1260 be done during the copying. */
1262 wck_flags = tctx->options & topt_use_crlf;
1263 nl_partial_match = -1;
1265 if (tctx->check_string && tctx->escape_string)
1267 nl_check = tctx->check_string;
1268 nl_check_length = Ustrlen(nl_check);
1269 nl_escape = tctx->escape_string;
1270 nl_escape_length = Ustrlen(nl_escape);
1272 else nl_check_length = nl_escape_length = 0;
1274 /* Start up a subprocess to run the command. Ensure that our main fd will
1275 be closed when the subprocess execs, but remove the flag afterwards.
1276 (Otherwise, if this is a TCP/IP socket, it can't get passed on to another
1277 process to deliver another message.) We get back stdin/stdout file descriptors.
1278 If the process creation failed, give an error return. */
1284 write_pid = (pid_t)(-1);
1286 (void)fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
1287 filter_pid = child_open(USS transport_filter_argv, NULL, 077,
1288 &fd_write, &fd_read, FALSE);
1289 (void)fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) & ~FD_CLOEXEC);
1290 if (filter_pid < 0) goto TIDY_UP; /* errno set */
1293 debug_printf("process %d running as transport filter: fd_write=%d fd_read=%d\n",
1294 (int)filter_pid, fd_write, fd_read);
1296 /* Fork subprocess to write the message to the filter, and return the result
1297 via a(nother) pipe. While writing to the filter, we do not do the CRLF,
1298 smtp dots, or check string processing. */
1300 if (pipe(pfd) != 0) goto TIDY_UP; /* errno set */
1301 if ((write_pid = fork()) == 0)
1304 (void)close(fd_read);
1305 (void)close(pfd[pipe_read]);
1306 nl_check_length = nl_escape_length = 0;
1308 tctx->check_string = tctx->escape_string = NULL;
1309 tctx->options &= ~(topt_use_crlf | topt_end_dot | topt_use_bdat);
1311 rc = internal_transport_write_message(fd_write, tctx, size_limit);
1314 if ( write(pfd[pipe_write], (void *)&rc, sizeof(BOOL))
1316 || write(pfd[pipe_write], (void *)&save_errno, sizeof(int))
1318 || write(pfd[pipe_write], (void *)&tctx->addr->more_errno, sizeof(int))
1321 rc = FALSE; /* compiler quietening */
1326 /* Parent process: close our copy of the writing subprocess' pipes. */
1328 (void)close(pfd[pipe_write]);
1329 (void)close(fd_write);
1332 /* Writing process creation failed */
1336 errno = save_errno; /* restore */
1340 /* When testing, let the subprocess get going */
1342 if (running_in_test_harness) millisleep(250);
1345 debug_printf("process %d writing to transport filter\n", (int)write_pid);
1347 /* Copy the message from the filter to the output fd. A read error leaves len
1348 == -1 and errno set. We need to apply a timeout to the read, to cope with
1349 the case when the filter gets stuck, but it can be quite a long one. The
1350 default is 5m, but this is now configurable. */
1352 DEBUG(D_transport) debug_printf("copying from the filter\n");
1354 /* Copy the output of the filter, remembering if the last character was NL. If
1355 no data is returned, that counts as "ended with NL" (default setting of the
1356 variable is TRUE). */
1358 chunk_ptr = deliver_out_buffer;
1362 sigalrm_seen = FALSE;
1363 alarm(transport_filter_timeout);
1364 len = read(fd_read, deliver_in_buffer, DELIVER_IN_BUFFER_SIZE);
1369 transport_filter_timed_out = TRUE;
1373 /* If the read was successful, write the block down the original fd,
1374 remembering whether it ends in \n or not. */
1378 if (!write_chunk(fd, tctx, deliver_in_buffer, len)) goto TIDY_UP;
1379 last_filter_was_NL = (deliver_in_buffer[len-1] == '\n');
1382 /* Otherwise, break the loop. If we have hit EOF, set yield = TRUE. */
1386 if (len == 0) yield = TRUE;
1391 /* Tidying up code. If yield = FALSE there has been an error and errno is set
1392 to something. Ensure the pipes are all closed and the processes are removed. If
1393 there has been an error, kill the processes before waiting for them, just to be
1394 sure. Also apply a paranoia timeout. */
1399 (void)close(fd_read);
1400 if (fd_write > 0) (void)close(fd_write);
1404 if (filter_pid > 0) kill(filter_pid, SIGKILL);
1405 if (write_pid > 0) kill(write_pid, SIGKILL);
1408 /* Wait for the filter process to complete. */
1410 DEBUG(D_transport) debug_printf("waiting for filter process\n");
1411 if (filter_pid > 0 && (rc = child_close(filter_pid, 30)) != 0 && yield)
1414 save_errno = ERRNO_FILTER_FAIL;
1415 tctx->addr->more_errno = rc;
1416 DEBUG(D_transport) debug_printf("filter process returned %d\n", rc);
1419 /* Wait for the writing process to complete. If it ends successfully,
1420 read the results from its pipe, provided we haven't already had a filter
1423 DEBUG(D_transport) debug_printf("waiting for writing process\n");
1426 rc = child_close(write_pid, 30);
1432 int dummy = read(pfd[pipe_read], (void *)&ok, sizeof(BOOL));
1435 dummy = read(pfd[pipe_read], (void *)&save_errno, sizeof(int));
1436 dummy = read(pfd[pipe_read], (void *)&(tctx->addr->more_errno), sizeof(int));
1443 save_errno = ERRNO_FILTER_FAIL;
1444 tctx->addr->more_errno = rc;
1445 DEBUG(D_transport) debug_printf("writing process returned %d\n", rc);
1449 (void)close(pfd[pipe_read]);
1451 /* If there have been no problems we can now add the terminating "." if this is
1452 SMTP output, turning off escaping beforehand. If the last character from the
1453 filter was not NL, insert a NL to make the SMTP protocol work. */
1457 nl_check_length = nl_escape_length = 0;
1458 if ( tctx->options & topt_end_dot
1459 && ( last_filter_was_NL
1460 ? !write_chunk(fd, tctx, US".\n", 2)
1461 : !write_chunk(fd, tctx, US"\n.\n", 3)
1465 /* Write out any remaining data in the buffer. */
1468 yield = (len = chunk_ptr - deliver_out_buffer) <= 0
1469 || transport_write_block(fd, deliver_out_buffer, len);
1472 errno = save_errno; /* From some earlier error */
1476 debug_printf("end of filtering transport writing: yield=%d\n", yield);
1478 debug_printf("errno=%d more_errno=%d\n", errno, tctx->addr->more_errno);
1488 /*************************************************
1489 * Update waiting database *
1490 *************************************************/
1492 /* This is called when an address is deferred by remote transports that are
1493 capable of sending more than one message over one connection. A database is
1494 maintained for each transport, keeping track of which messages are waiting for
1495 which hosts. The transport can then consult this when eventually a successful
1496 delivery happens, and if it finds that another message is waiting for the same
1497 host, it can fire up a new process to deal with it using the same connection.
1499 The database records are keyed by host name. They can get full if there are
1500 lots of messages waiting, and so there is a continuation mechanism for them.
1502 Each record contains a list of message ids, packed end to end without any
1503 zeros. Each one is MESSAGE_ID_LENGTH bytes long. The count field says how many
1504 in this record, and the sequence field says if there are any other records for
1505 this host. If the sequence field is 0, there are none. If it is 1, then another
1506 record with the name <hostname>:0 exists; if it is 2, then two other records
1507 with sequence numbers 0 and 1 exist, and so on.
1509 Currently, an exhaustive search of all continuation records has to be done to
1510 determine whether to add a message id to a given record. This shouldn't be
1511 too bad except in extreme cases. I can't figure out a *simple* way of doing
1514 Old records should eventually get swept up by the exim_tidydb utility.
1517 hostlist list of hosts that this message could be sent to
1518 tpname name of the transport
1524 transport_update_waiting(host_item *hostlist, uschar *tpname)
1527 const uschar *prevname = US"";
1532 DEBUG(D_transport) debug_printf("updating wait-%s database\n", tpname);
1534 /* Open the database for this transport */
1536 sprintf(CS buffer, "wait-%.200s", tpname);
1537 dbm_file = dbfn_open(buffer, O_RDWR, &dbblock, TRUE);
1538 if (dbm_file == NULL) return;
1540 /* Scan the list of hosts for which this message is waiting, and ensure
1541 that the message id is in each host record. */
1543 for (host = hostlist; host!= NULL; host = host->next)
1545 BOOL already = FALSE;
1546 dbdata_wait *host_record;
1550 /* Skip if this is the same host as we just processed; otherwise remember
1551 the name for next time. */
1553 if (Ustrcmp(prevname, host->name) == 0) continue;
1554 prevname = host->name;
1556 /* Look up the host record; if there isn't one, make an empty one. */
1558 host_record = dbfn_read(dbm_file, host->name);
1559 if (host_record == NULL)
1561 host_record = store_get(sizeof(dbdata_wait) + MESSAGE_ID_LENGTH);
1562 host_record->count = host_record->sequence = 0;
1565 /* Compute the current length */
1567 host_length = host_record->count * MESSAGE_ID_LENGTH;
1569 /* Search the record to see if the current message is already in it. */
1571 for (s = host_record->text; s < host_record->text + host_length;
1572 s += MESSAGE_ID_LENGTH)
1574 if (Ustrncmp(s, message_id, MESSAGE_ID_LENGTH) == 0)
1575 { already = TRUE; break; }
1578 /* If we haven't found this message in the main record, search any
1579 continuation records that exist. */
1581 for (i = host_record->sequence - 1; i >= 0 && !already; i--)
1584 sprintf(CS buffer, "%.200s:%d", host->name, i);
1585 cont = dbfn_read(dbm_file, buffer);
1588 int clen = cont->count * MESSAGE_ID_LENGTH;
1589 for (s = cont->text; s < cont->text + clen; s += MESSAGE_ID_LENGTH)
1591 if (Ustrncmp(s, message_id, MESSAGE_ID_LENGTH) == 0)
1592 { already = TRUE; break; }
1597 /* If this message is already in a record, no need to update. */
1601 DEBUG(D_transport) debug_printf("already listed for %s\n", host->name);
1606 /* If this record is full, write it out with a new name constructed
1607 from the sequence number, increase the sequence number, and empty
1610 if (host_record->count >= WAIT_NAME_MAX)
1612 sprintf(CS buffer, "%.200s:%d", host->name, host_record->sequence);
1613 dbfn_write(dbm_file, buffer, host_record, sizeof(dbdata_wait) + host_length);
1614 host_record->sequence++;
1615 host_record->count = 0;
1619 /* If this record is not full, increase the size of the record to
1620 allow for one new message id. */
1625 store_get(sizeof(dbdata_wait) + host_length + MESSAGE_ID_LENGTH);
1626 memcpy(newr, host_record, sizeof(dbdata_wait) + host_length);
1630 /* Now add the new name on the end */
1632 memcpy(host_record->text + host_length, message_id, MESSAGE_ID_LENGTH);
1633 host_record->count++;
1634 host_length += MESSAGE_ID_LENGTH;
1636 /* Update the database */
1638 dbfn_write(dbm_file, host->name, host_record, sizeof(dbdata_wait) + host_length);
1639 DEBUG(D_transport) debug_printf("added to list for %s\n", host->name);
1644 dbfn_close(dbm_file);
1650 /*************************************************
1651 * Test for waiting messages *
1652 *************************************************/
1654 /* This function is called by a remote transport which uses the previous
1655 function to remember which messages are waiting for which remote hosts. It's
1656 called after a successful delivery and its job is to check whether there is
1657 another message waiting for the same host. However, it doesn't do this if the
1658 current continue sequence is greater than the maximum supplied as an argument,
1659 or greater than the global connection_max_messages, which, if set, overrides.
1662 transport_name name of the transport
1663 hostname name of the host
1664 local_message_max maximum number of messages down one connection
1665 as set by the caller transport
1666 new_message_id set to the message id of a waiting message
1667 more set TRUE if there are yet more messages waiting
1668 oicf_func function to call to validate if it is ok to send
1669 to this message_id from the current instance.
1670 oicf_data opaque data for oicf_func
1672 Returns: TRUE if new_message_id set; FALSE otherwise
1675 typedef struct msgq_s
1677 uschar message_id [MESSAGE_ID_LENGTH + 1];
1682 transport_check_waiting(const uschar *transport_name, const uschar *hostname,
1683 int local_message_max, uschar *new_message_id, BOOL *more, oicf oicf_func, void *oicf_data)
1685 dbdata_wait *host_record;
1692 struct stat statbuf;
1698 debug_printf("transport_check_waiting entered\n");
1699 debug_printf(" sequence=%d local_max=%d global_max=%d\n",
1700 continue_sequence, local_message_max, connection_max_messages);
1703 /* Do nothing if we have hit the maximum number that can be send down one
1706 if (connection_max_messages >= 0) local_message_max = connection_max_messages;
1707 if (local_message_max > 0 && continue_sequence >= local_message_max)
1710 debug_printf("max messages for one connection reached: returning\n");
1714 /* Open the waiting information database. */
1716 sprintf(CS buffer, "wait-%.200s", transport_name);
1717 dbm_file = dbfn_open(buffer, O_RDWR, &dbblock, TRUE);
1718 if (dbm_file == NULL) return FALSE;
1720 /* See if there is a record for this host; if not, there's nothing to do. */
1722 if (!(host_record = dbfn_read(dbm_file, hostname)))
1724 dbfn_close(dbm_file);
1725 DEBUG(D_transport) debug_printf("no messages waiting for %s\n", hostname);
1729 /* If the data in the record looks corrupt, just log something and
1730 don't try to use it. */
1732 if (host_record->count > WAIT_NAME_MAX)
1734 dbfn_close(dbm_file);
1735 log_write(0, LOG_MAIN|LOG_PANIC, "smtp-wait database entry for %s has bad "
1736 "count=%d (max=%d)", hostname, host_record->count, WAIT_NAME_MAX);
1740 /* Scan the message ids in the record from the end towards the beginning,
1741 until one is found for which a spool file actually exists. If the record gets
1742 emptied, delete it and continue with any continuation records that may exist.
1745 /* For Bug 1141, I refactored this major portion of the routine, it is risky
1746 but the 1 off will remain without it. This code now allows me to SKIP over
1747 a message I do not want to send out on this run. */
1749 host_length = host_record->count * MESSAGE_ID_LENGTH;
1755 int msgq_actual = 0;
1756 BOOL bFound = FALSE;
1757 BOOL bContinuation = FALSE;
1759 /* create an array to read entire message queue into memory for processing */
1761 msgq = (msgq_t*) malloc(sizeof(msgq_t) * host_record->count);
1762 msgq_count = host_record->count;
1763 msgq_actual = msgq_count;
1765 for (i = 0; i < host_record->count; ++i)
1767 msgq[i].bKeep = TRUE;
1769 Ustrncpy(msgq[i].message_id, host_record->text + (i * MESSAGE_ID_LENGTH),
1771 msgq[i].message_id[MESSAGE_ID_LENGTH] = 0;
1774 /* first thing remove current message id if it exists */
1776 for (i = 0; i < msgq_count; ++i)
1777 if (Ustrcmp(msgq[i].message_id, message_id) == 0)
1779 msgq[i].bKeep = FALSE;
1783 /* now find the next acceptable message_id */
1785 for (i = msgq_count - 1; i >= 0; --i) if (msgq[i].bKeep)
1789 subdir[0] = split_spool_directory ? msgq[i].message_id[5] : 0;
1792 if (Ustat(spool_fname(US"input", subdir, msgq[i].message_id, US"-D"),
1794 msgq[i].bKeep = FALSE;
1795 else if (!oicf_func || oicf_func(msgq[i].message_id, oicf_data))
1797 Ustrcpy(new_message_id, msgq[i].message_id);
1798 msgq[i].bKeep = FALSE;
1805 for (msgq_actual = 0, i = 0; i < msgq_count; ++i)
1809 /* reassemble the host record, based on removed message ids, from in
1812 if (msgq_actual <= 0)
1815 host_record->count = 0;
1819 host_length = msgq_actual * MESSAGE_ID_LENGTH;
1820 host_record->count = msgq_actual;
1822 if (msgq_actual < msgq_count)
1825 for (new_count = 0, i = 0; i < msgq_count; ++i)
1827 Ustrncpy(&host_record->text[new_count++ * MESSAGE_ID_LENGTH],
1828 msgq[i].message_id, MESSAGE_ID_LENGTH);
1830 host_record->text[new_count * MESSAGE_ID_LENGTH] = 0;
1834 /* Jeremy: check for a continuation record, this code I do not know how to
1835 test but the code should work */
1837 while (host_length <= 0)
1840 dbdata_wait * newr = NULL;
1842 /* Search for a continuation */
1844 for (i = host_record->sequence - 1; i >= 0 && !newr; i--)
1846 sprintf(CS buffer, "%.200s:%d", hostname, i);
1847 newr = dbfn_read(dbm_file, buffer);
1850 /* If no continuation, delete the current and break the loop */
1854 dbfn_delete(dbm_file, hostname);
1858 /* Else replace the current with the continuation */
1860 dbfn_delete(dbm_file, buffer);
1862 host_length = host_record->count * MESSAGE_ID_LENGTH;
1864 bContinuation = TRUE;
1867 if (bFound) /* Usual exit from main loop */
1873 /* If host_length <= 0 we have emptied a record and not found a good message,
1874 and there are no continuation records. Otherwise there is a continuation
1875 record to process. */
1877 if (host_length <= 0)
1879 dbfn_close(dbm_file);
1880 DEBUG(D_transport) debug_printf("waiting messages already delivered\n");
1884 /* we were not able to find an acceptable message, nor was there a
1885 * continuation record. So bug out, outer logic will clean this up.
1890 Ustrcpy(new_message_id, message_id);
1891 dbfn_close(dbm_file);
1896 } /* we need to process a continuation record */
1898 /* Control gets here when an existing message has been encountered; its
1899 id is in new_message_id, and host_length is the revised length of the
1900 host record. If it is zero, the record has been removed. Update the
1901 record if required, close the database, and return TRUE. */
1903 if (host_length > 0)
1905 host_record->count = host_length/MESSAGE_ID_LENGTH;
1907 dbfn_write(dbm_file, hostname, host_record, (int)sizeof(dbdata_wait) + host_length);
1911 dbfn_close(dbm_file);
1915 /*************************************************
1916 * Deliver waiting message down same socket *
1917 *************************************************/
1919 /* Fork a new exim process to deliver the message, and do a re-exec, both to
1920 get a clean delivery process, and to regain root privilege in cases where it
1921 has been given away.
1924 transport_name to pass to the new process
1927 id the new message to process
1928 socket_fd the connected socket
1930 Returns: FALSE if fork fails; TRUE otherwise
1934 transport_pass_socket(const uschar *transport_name, const uschar *hostname,
1935 const uschar *hostaddress, uschar *id, int socket_fd)
1940 DEBUG(D_transport) debug_printf("transport_pass_socket entered\n");
1942 if ((pid = fork()) == 0)
1945 const uschar **argv;
1947 /* Disconnect entirely from the parent process. If we are running in the
1948 test harness, wait for a bit to allow the previous process time to finish,
1949 write the log, etc., so that the output is always in the same order for
1950 automatic comparison. */
1952 if ((pid = fork()) != 0) _exit(EXIT_SUCCESS);
1953 if (running_in_test_harness) sleep(1);
1955 /* Set up the calling arguments; use the standard function for the basics,
1956 but we have a number of extras that may be added. */
1958 argv = CUSS child_exec_exim(CEE_RETURN_ARGV, TRUE, &i, FALSE, 0);
1960 if (smtp_authenticated) argv[i++] = US"-MCA";
1962 if (smtp_peer_options & PEER_OFFERED_CHUNKING) argv[i++] = US"-MCK";
1963 if (smtp_peer_options & PEER_OFFERED_DSN) argv[i++] = US"-MCD";
1964 if (smtp_peer_options & PEER_OFFERED_PIPE) argv[i++] = US"-MCP";
1965 if (smtp_peer_options & PEER_OFFERED_SIZE) argv[i++] = US"-MCS";
1967 if (smtp_peer_options & PEER_OFFERED_TLS) argv[i++] = US"-MCT";
1970 if (queue_run_pid != (pid_t)0)
1972 argv[i++] = US"-MCQ";
1973 argv[i++] = string_sprintf("%d", queue_run_pid);
1974 argv[i++] = string_sprintf("%d", queue_run_pipe);
1977 argv[i++] = US"-MC";
1978 argv[i++] = US transport_name;
1979 argv[i++] = US hostname;
1980 argv[i++] = US hostaddress;
1981 argv[i++] = string_sprintf("%d", continue_sequence + 1);
1985 /* Arrange for the channel to be on stdin. */
1989 (void)dup2(socket_fd, 0);
1990 (void)close(socket_fd);
1993 DEBUG(D_exec) debug_print_argv(argv);
1994 exim_nullstd(); /* Ensure std{out,err} exist */
1995 execv(CS argv[0], (char *const *)argv);
1997 DEBUG(D_any) debug_printf("execv failed: %s\n", strerror(errno));
1998 _exit(errno); /* Note: must be _exit(), NOT exit() */
2001 /* If the process creation succeeded, wait for the first-level child, which
2002 immediately exits, leaving the second level process entirely disconnected from
2008 while ((rc = wait(&status)) != pid && (rc >= 0 || errno != ECHILD));
2009 DEBUG(D_transport) debug_printf("transport_pass_socket succeeded\n");
2014 DEBUG(D_transport) debug_printf("transport_pass_socket failed to fork: %s\n",
2022 /*************************************************
2023 * Set up direct (non-shell) command *
2024 *************************************************/
2026 /* This function is called when a command line is to be parsed and executed
2027 directly, without the use of /bin/sh. It is called by the pipe transport,
2028 the queryprogram router, and also from the main delivery code when setting up a
2029 transport filter process. The code for ETRN also makes use of this; in that
2030 case, no addresses are passed.
2033 argvptr pointer to anchor for argv vector
2034 cmd points to the command string (modified IN PLACE)
2035 expand_arguments true if expansion is to occur
2036 expand_failed error value to set if expansion fails; not relevant if
2038 addr chain of addresses, or NULL
2039 etext text for use in error messages
2040 errptr where to put error message if addr is NULL;
2041 otherwise it is put in the first address
2043 Returns: TRUE if all went well; otherwise an error will be
2044 set in the first address and FALSE returned
2048 transport_set_up_command(const uschar ***argvptr, uschar *cmd,
2049 BOOL expand_arguments, int expand_failed, address_item *addr,
2050 uschar *etext, uschar **errptr)
2053 const uschar **argv;
2055 int address_count = 0;
2059 /* Get store in which to build an argument list. Count the number of addresses
2060 supplied, and allow for that many arguments, plus an additional 60, which
2061 should be enough for anybody. Multiple addresses happen only when the local
2062 delivery batch option is set. */
2064 for (ad = addr; ad != NULL; ad = ad->next) address_count++;
2065 max_args = address_count + 60;
2066 *argvptr = argv = store_get((max_args+1)*sizeof(uschar *));
2068 /* Split the command up into arguments terminated by white space. Lose
2069 trailing space at the start and end. Double-quoted arguments can contain \\ and
2070 \" escapes and so can be handled by the standard function; single-quoted
2071 arguments are verbatim. Copy each argument into a new string. */
2074 while (isspace(*s)) s++;
2076 while (*s != 0 && argcount < max_args)
2081 while (*ss != 0 && *ss != '\'') ss++;
2082 argv[argcount++] = ss = store_get(ss - s++);
2083 while (*s != 0 && *s != '\'') *ss++ = *s++;
2087 else argv[argcount++] = string_copy(string_dequote(CUSS &s));
2088 while (isspace(*s)) s++;
2091 argv[argcount] = (uschar *)0;
2093 /* If *s != 0 we have run out of argument slots. */
2097 uschar *msg = string_sprintf("Too many arguments in command \"%s\" in "
2101 addr->transport_return = FAIL;
2102 addr->message = msg;
2108 /* Expand each individual argument if required. Expansion happens for pipes set
2109 up in filter files and with directly-supplied commands. It does not happen if
2110 the pipe comes from a traditional .forward file. A failing expansion is a big
2111 disaster if the command came from Exim's configuration; if it came from a user
2112 it is just a normal failure. The expand_failed value is used as the error value
2113 to cater for these two cases.
2115 An argument consisting just of the text "$pipe_addresses" is treated specially.
2116 It is not passed to the general expansion function. Instead, it is replaced by
2117 a number of arguments, one for each address. This avoids problems with shell
2118 metacharacters and spaces in addresses.
2120 If the parent of the top address has an original part of "system-filter", this
2121 pipe was set up by the system filter, and we can permit the expansion of
2126 debug_printf("direct command:\n");
2127 for (i = 0; argv[i] != (uschar *)0; i++)
2128 debug_printf(" argv[%d] = %s\n", i, string_printing(argv[i]));
2131 if (expand_arguments)
2133 BOOL allow_dollar_recipients = addr != NULL &&
2134 addr->parent != NULL &&
2135 Ustrcmp(addr->parent->address, "system-filter") == 0;
2137 for (i = 0; argv[i] != (uschar *)0; i++)
2140 /* Handle special fudge for passing an address list */
2143 (Ustrcmp(argv[i], "$pipe_addresses") == 0 ||
2144 Ustrcmp(argv[i], "${pipe_addresses}") == 0))
2148 if (argcount + address_count - 1 > max_args)
2150 addr->transport_return = FAIL;
2151 addr->message = string_sprintf("Too many arguments to command \"%s\" "
2152 "in %s", cmd, etext);
2156 additional = address_count - 1;
2158 memmove(argv + i + 1 + additional, argv + i + 1,
2159 (argcount - i)*sizeof(uschar *));
2161 for (ad = addr; ad != NULL; ad = ad->next) {
2162 argv[i++] = ad->address;
2166 /* Subtract one since we replace $pipe_addresses */
2171 /* Handle special case of $address_pipe when af_force_command is set */
2173 else if (addr != NULL && testflag(addr,af_force_command) &&
2174 (Ustrcmp(argv[i], "$address_pipe") == 0 ||
2175 Ustrcmp(argv[i], "${address_pipe}") == 0))
2178 int address_pipe_argcount = 0;
2179 int address_pipe_max_args;
2180 uschar **address_pipe_argv;
2182 /* We can never have more then the argv we will be loading into */
2183 address_pipe_max_args = max_args - argcount + 1;
2186 debug_printf("address_pipe_max_args=%d\n", address_pipe_max_args);
2188 /* We allocate an additional for (uschar *)0 */
2189 address_pipe_argv = store_get((address_pipe_max_args+1)*sizeof(uschar *));
2191 /* +1 because addr->local_part[0] == '|' since af_force_command is set */
2192 s = expand_string(addr->local_part + 1);
2194 if (s == NULL || *s == '\0')
2196 addr->transport_return = FAIL;
2197 addr->message = string_sprintf("Expansion of \"%s\" "
2198 "from command \"%s\" in %s failed: %s",
2199 (addr->local_part + 1), cmd, etext, expand_string_message);
2203 while (isspace(*s)) s++; /* strip leading space */
2205 while (*s != 0 && address_pipe_argcount < address_pipe_max_args)
2210 while (*ss != 0 && *ss != '\'') ss++;
2211 address_pipe_argv[address_pipe_argcount++] = ss = store_get(ss - s++);
2212 while (*s != 0 && *s != '\'') *ss++ = *s++;
2216 else address_pipe_argv[address_pipe_argcount++] =
2217 string_copy(string_dequote(CUSS &s));
2218 while (isspace(*s)) s++; /* strip space after arg */
2221 address_pipe_argv[address_pipe_argcount] = (uschar *)0;
2223 /* If *s != 0 we have run out of argument slots. */
2226 uschar *msg = string_sprintf("Too many arguments in $address_pipe "
2227 "\"%s\" in %s", addr->local_part + 1, etext);
2230 addr->transport_return = FAIL;
2231 addr->message = msg;
2237 /* address_pipe_argcount - 1
2238 * because we are replacing $address_pipe in the argument list
2239 * with the first thing it expands to */
2240 if (argcount + address_pipe_argcount - 1 > max_args)
2242 addr->transport_return = FAIL;
2243 addr->message = string_sprintf("Too many arguments to command "
2244 "\"%s\" after expanding $address_pipe in %s", cmd, etext);
2248 /* If we are not just able to replace the slot that contained
2249 * $address_pipe (address_pipe_argcount == 1)
2250 * We have to move the existing argv by address_pipe_argcount - 1
2251 * Visually if address_pipe_argcount == 2:
2252 * [argv 0][argv 1][argv 2($address_pipe)][argv 3][0]
2253 * [argv 0][argv 1][ap_arg0][ap_arg1][old argv 3][0]
2255 if (address_pipe_argcount > 1)
2257 /* current position + additonal args */
2258 argv + i + address_pipe_argcount,
2259 /* current position + 1 (for the (uschar *)0 at the end) */
2261 /* -1 for the (uschar *)0 at the end)*/
2262 (argcount - i)*sizeof(uschar *)
2265 /* Now we fill in the slots we just moved argv out of
2266 * [argv 0][argv 1][argv 2=pipeargv[0]][argv 3=pipeargv[1]][old argv 3][0]
2268 for (address_pipe_i = 0;
2269 address_pipe_argv[address_pipe_i] != (uschar *)0;
2272 argv[i++] = address_pipe_argv[address_pipe_i];
2276 /* Subtract one since we replace $address_pipe */
2281 /* Handle normal expansion string */
2285 const uschar *expanded_arg;
2286 enable_dollar_recipients = allow_dollar_recipients;
2287 expanded_arg = expand_cstring(argv[i]);
2288 enable_dollar_recipients = FALSE;
2290 if (expanded_arg == NULL)
2292 uschar *msg = string_sprintf("Expansion of \"%s\" "
2293 "from command \"%s\" in %s failed: %s",
2294 argv[i], cmd, etext, expand_string_message);
2297 addr->transport_return = expand_failed;
2298 addr->message = msg;
2303 argv[i] = expanded_arg;
2309 debug_printf("direct command after expansion:\n");
2310 for (i = 0; argv[i] != (uschar *)0; i++)
2311 debug_printf(" argv[%d] = %s\n", i, string_printing(argv[i]));
2320 /* End of transport.c */