1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) The Exim maintainers 2020 - 2023 */
6 /* Copyright (c) University of Cambridge 1995 - 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
8 /* SPDX-License-Identifier: GPL-2.0-or-later */
12 #include "appendfile.h"
14 #ifdef SUPPORT_MAILDIR
15 #include "tf_maildir.h"
19 /* Options specific to the appendfile transport. They must be in alphabetic
20 order (note that "_" comes before the lower case letters). Some of them are
21 stored in the publicly visible instance block - these are flagged with the
23 #define LOFF(field) OPT_OFF(appendfile_transport_options_block, field)
25 optionlist appendfile_transport_options[] = {
26 #ifdef SUPPORT_MAILDIR
27 { "*expand_maildir_use_size_file", opt_stringptr, LOFF(expand_maildir_use_size_file) },
29 { "*set_use_fcntl_lock",opt_bool | opt_hidden, LOFF(set_use_fcntl) },
30 { "*set_use_flock_lock",opt_bool | opt_hidden, LOFF(set_use_flock) },
31 { "*set_use_lockfile", opt_bool | opt_hidden, LOFF(set_use_lockfile) },
33 { "*set_use_mbx_lock", opt_bool | opt_hidden, LOFF(set_use_mbx_lock) },
35 { "allow_fifo", opt_bool, LOFF(allow_fifo) },
36 { "allow_symlink", opt_bool, LOFF(allow_symlink) },
37 { "batch_id", opt_stringptr | opt_public, OPT_OFF(transport_instance, batch_id) },
38 { "batch_max", opt_int | opt_public, OPT_OFF(transport_instance, batch_max) },
39 { "check_group", opt_bool, LOFF(check_group) },
40 { "check_owner", opt_bool, LOFF(check_owner) },
41 { "check_string", opt_stringptr, LOFF(check_string) },
42 { "create_directory", opt_bool, LOFF(create_directory) },
43 { "create_file", opt_stringptr, LOFF(create_file_string) },
44 { "directory", opt_stringptr, LOFF(dirname) },
45 { "directory_file", opt_stringptr, LOFF(dirfilename) },
46 { "directory_mode", opt_octint, LOFF(dirmode) },
47 { "escape_string", opt_stringptr, LOFF(escape_string) },
48 { "file", opt_stringptr, LOFF(filename) },
49 { "file_format", opt_stringptr, LOFF(file_format) },
50 { "file_must_exist", opt_bool, LOFF(file_must_exist) },
51 { "lock_fcntl_timeout", opt_time, LOFF(lock_fcntl_timeout) },
52 { "lock_flock_timeout", opt_time, LOFF(lock_flock_timeout) },
53 { "lock_interval", opt_time, LOFF(lock_interval) },
54 { "lock_retries", opt_int, LOFF(lock_retries) },
55 { "lockfile_mode", opt_octint, LOFF(lockfile_mode) },
56 { "lockfile_timeout", opt_time, LOFF(lockfile_timeout) },
57 { "mailbox_filecount", opt_stringptr, LOFF(mailbox_filecount_string) },
58 { "mailbox_size", opt_stringptr, LOFF(mailbox_size_string) },
59 #ifdef SUPPORT_MAILDIR
60 { "maildir_format", opt_bool, LOFF(maildir_format ) } ,
61 { "maildir_quota_directory_regex", opt_stringptr, LOFF(maildir_dir_regex) },
62 { "maildir_retries", opt_int, LOFF(maildir_retries) },
63 { "maildir_tag", opt_stringptr, LOFF(maildir_tag) },
64 { "maildir_use_size_file", opt_expand_bool, LOFF(maildir_use_size_file ) } ,
65 { "maildirfolder_create_regex", opt_stringptr, LOFF(maildirfolder_create_regex ) },
66 #endif /* SUPPORT_MAILDIR */
67 #ifdef SUPPORT_MAILSTORE
68 { "mailstore_format", opt_bool, LOFF(mailstore_format ) },
69 { "mailstore_prefix", opt_stringptr, LOFF(mailstore_prefix ) },
70 { "mailstore_suffix", opt_stringptr, LOFF(mailstore_suffix ) },
71 #endif /* SUPPORT_MAILSTORE */
73 { "mbx_format", opt_bool, LOFF(mbx_format ) } ,
74 #endif /* SUPPORT_MBX */
75 { "message_prefix", opt_stringptr, LOFF(message_prefix) },
76 { "message_suffix", opt_stringptr, LOFF(message_suffix) },
77 { "mode", opt_octint, LOFF(mode) },
78 { "mode_fail_narrower",opt_bool, LOFF(mode_fail_narrower) },
79 { "notify_comsat", opt_bool, LOFF(notify_comsat) },
80 { "quota", opt_stringptr, LOFF(quota) },
81 { "quota_directory", opt_stringptr, LOFF(quota_directory) },
82 { "quota_filecount", opt_stringptr, LOFF(quota_filecount) },
83 { "quota_is_inclusive", opt_bool, LOFF(quota_is_inclusive) },
84 { "quota_size_regex", opt_stringptr, LOFF(quota_size_regex) },
85 { "quota_warn_message", opt_stringptr | opt_public, OPT_OFF(transport_instance, warn_message) },
86 { "quota_warn_threshold", opt_stringptr, LOFF(quota_warn_threshold) },
87 { "use_bsmtp", opt_bool, LOFF(use_bsmtp) },
88 { "use_crlf", opt_bool, LOFF(use_crlf) },
89 { "use_fcntl_lock", opt_bool_set, LOFF(use_fcntl) },
90 { "use_flock_lock", opt_bool_set, LOFF(use_flock) },
91 { "use_lockfile", opt_bool_set, LOFF(use_lockfile) },
93 { "use_mbx_lock", opt_bool_set, LOFF(use_mbx_lock) },
94 #endif /* SUPPORT_MBX */
97 /* Size of the options list. An extern variable has to be used so that its
98 address can appear in the tables drtables.c. */
100 int appendfile_transport_options_count =
101 sizeof(appendfile_transport_options)/sizeof(optionlist);
107 appendfile_transport_options_block appendfile_transport_option_defaults = {0};
108 void appendfile_transport_init(transport_instance *tblock) {}
109 BOOL appendfile_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;}
111 #else /*!MACRO_PREDEF*/
113 /* Default private options block for the appendfile transport. */
115 appendfile_transport_options_block appendfile_transport_option_defaults = {
116 /* all non-mentioned members zero/null/false */
117 .dirfilename = US"q${base62:$tod_epoch}-$inode",
118 .create_file_string = US"anywhere",
119 .maildir_dir_regex = US"^(?:cur|new|\\..*)$",
120 .mailbox_size_value = -1,
121 .mailbox_filecount_value = -1,
122 .mode = APPENDFILE_MODE,
123 .dirmode = APPENDFILE_DIRECTORY_MODE,
124 .lockfile_mode = APPENDFILE_LOCKFILE_MODE,
125 .lockfile_timeout = 30*60,
128 .maildir_retries = 10,
129 .create_file = create_anywhere,
131 .create_directory = TRUE,
132 .notify_comsat = FALSE,
133 .use_lockfile = TRUE,
135 .mode_fail_narrower = TRUE,
136 .quota_is_inclusive = TRUE,
140 /* Encodings for mailbox formats, and their names. MBX format is actually
141 supported only if SUPPORT_MBX is set. */
143 enum { mbf_unix, mbf_mbx, mbf_smail, mbf_maildir, mbf_mailstore };
145 static const char *mailbox_formats[] = {
146 "unix", "mbx", "smail", "maildir", "mailstore" };
149 /* Check warn threshold only if quota size set or not a percentage threshold
150 percentage check should only be done if quota > 0 */
152 #define THRESHOLD_CHECK (ob->quota_warn_threshold_value > 0 && \
153 (!ob->quota_warn_threshold_is_percent || ob->quota_value > 0))
156 /*************************************************
157 * Setup entry point *
158 *************************************************/
160 /* Called for each delivery in the privileged state, just before the uid/gid
161 are changed and the main entry point is called. We use this function to
162 expand any quota settings, so that it can access files that may not be readable
163 by the user. It is also used to pick up external mailbox size information, if
167 tblock points to the transport instance
168 addrlist addresses about to be delivered (not used)
169 dummy not used (doesn't pass back data)
170 uid the uid that will be set (not used)
171 gid the gid that will be set (not used)
172 errmsg where to put an error message
174 Returns: OK, FAIL, or DEFER
178 appendfile_transport_setup(transport_instance *tblock, address_item *addrlist,
179 transport_feedback *dummy, uid_t uid, gid_t gid, uschar **errmsg)
181 appendfile_transport_options_block *ob =
182 (appendfile_transport_options_block *)(tblock->options_block);
183 uschar *q = ob->quota;
184 double default_value = 0.0;
186 if (ob->expand_maildir_use_size_file)
187 ob->maildir_use_size_file = expand_check_condition(ob->expand_maildir_use_size_file,
188 US"`maildir_use_size_file` in transport", tblock->name);
190 /* Loop for quota, quota_filecount, quota_warn_threshold, mailbox_size,
193 for (int i = 0; i < 5; i++)
195 double d = default_value;
197 uschar *which = NULL;
203 if (!(s = expand_string(q)))
205 *errmsg = string_sprintf("Expansion of \"%s\" in %s transport failed: "
206 "%s", q, tblock->name, expand_string_message);
207 return f.search_find_defer ? DEFER : FAIL;
210 d = Ustrtod(s, &rest);
212 /* Handle following characters K, M, G, %, the latter being permitted
213 for quota_warn_threshold only. A threshold with no quota setting is
216 if (tolower(*rest) == 'k') { d *= 1024.0; rest++; }
217 else if (tolower(*rest) == 'm') { d *= 1024.0*1024.0; rest++; }
218 else if (tolower(*rest) == 'g') { d *= 1024.0*1024.0*1024.0; rest++; }
219 else if (*rest == '%' && i == 2)
221 if (ob->quota_value <= 0 && !ob->maildir_use_size_file)
223 else if ((int)d < 0 || (int)d > 100)
225 *errmsg = string_sprintf("Invalid quota_warn_threshold percentage (%d)"
226 " for %s transport", (int)d, tblock->name);
229 ob->quota_warn_threshold_is_percent = TRUE;
234 /* For quota and quota_filecount there may be options
235 appended. Currently only "no_check", so we can be lazy parsing it */
236 if (i < 2 && Ustrstr(rest, "/no_check") == rest)
239 rest += sizeof("/no_check") - 1;
242 Uskip_whitespace(&rest);
246 *errmsg = string_sprintf("Malformed value \"%s\" (expansion of \"%s\") "
247 "in %s transport", s, q, tblock->name);
252 /* Set each value, checking for possible overflow. */
257 if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4)
259 ob->quota_value = (off_t)d;
260 ob->quota_no_check = no_check;
261 q = ob->quota_filecount;
265 if (d >= 2.0*1024.0*1024.0*1024.0)
266 which = US"quota_filecount";
267 ob->quota_filecount_value = (int)d;
268 ob->quota_filecount_no_check = no_check;
269 q = ob->quota_warn_threshold;
273 if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4)
274 which = US"quota_warn_threshold";
275 ob->quota_warn_threshold_value = (off_t)d;
276 q = ob->mailbox_size_string;
277 default_value = -1.0;
281 if (d >= 2.0*1024.0*1024.0*1024.0 && sizeof(off_t) <= 4)
282 which = US"mailbox_size";;
283 ob->mailbox_size_value = (off_t)d;
284 q = ob->mailbox_filecount_string;
288 if (d >= 2.0*1024.0*1024.0*1024.0)
289 which = US"mailbox_filecount";
290 ob->mailbox_filecount_value = (int)d;
296 *errmsg = string_sprintf("%s value %.10g is too large (overflow) in "
297 "%s transport", which, d, tblock->name);
307 /*************************************************
308 * Initialization entry point *
309 *************************************************/
311 /* Called for each instance, after its options have been read, to
312 enable consistency checks to be done, or anything else that needs
316 appendfile_transport_init(transport_instance *tblock)
318 appendfile_transport_options_block *ob =
319 (appendfile_transport_options_block *)(tblock->options_block);
322 /* Set up the setup entry point, to be called in the privileged state */
324 tblock->setup = appendfile_transport_setup;
326 /* Lock_retries must be greater than zero */
328 if (ob->lock_retries == 0) ob->lock_retries = 1;
330 /* Only one of a file name or directory name must be given. */
332 if (ob->filename && ob->dirname)
333 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
334 "only one of \"file\" or \"directory\" can be specified", tblock->name);
336 /* If a file name was specified, neither quota_filecount nor quota_directory
341 if (ob->quota_filecount)
342 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
343 "quota_filecount must not be set without \"directory\"", tblock->name);
344 if (ob->quota_directory)
345 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
346 "quota_directory must not be set without \"directory\"", tblock->name);
349 /* The default locking depends on whether MBX is set or not. Change the
350 built-in default if none of the lock options has been explicitly set. At least
351 one form of locking is required in all cases, but mbx locking changes the
352 meaning of fcntl and flock locking. */
354 /* Not all operating systems provide flock(). For those that do, if flock is
355 requested, the default for fcntl is FALSE. */
360 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
361 "flock() support was not available in the operating system when this "
362 "binary was built", tblock->name);
363 #endif /* NO_FLOCK */
364 if (!ob->set_use_fcntl) ob->use_fcntl = FALSE;
369 if (!ob->set_use_lockfile && !ob->set_use_fcntl && !ob->set_use_flock &&
370 !ob->set_use_mbx_lock)
372 ob->use_lockfile = ob->use_flock = FALSE;
373 ob->use_mbx_lock = ob->use_fcntl = TRUE;
375 else if (ob->use_mbx_lock)
377 if (!ob->set_use_lockfile) ob->use_lockfile = FALSE;
378 if (!ob->set_use_fcntl) ob->use_fcntl = FALSE;
379 if (!ob->set_use_flock) ob->use_flock = FALSE;
380 if (!ob->use_fcntl && !ob->use_flock) ob->use_fcntl = TRUE;
382 #endif /* SUPPORT_MBX */
384 if (!ob->use_fcntl && !ob->use_flock && !ob->use_lockfile && !ob->use_mbx_lock)
385 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
386 "no locking configured", tblock->name);
388 /* Unset timeouts for non-used locking types */
390 if (!ob->use_fcntl) ob->lock_fcntl_timeout = 0;
391 if (!ob->use_flock) ob->lock_flock_timeout = 0;
393 /* If a directory name was specified, only one of maildir or mailstore may be
394 specified, and if quota_filecount or quota_directory is given, quota must
399 if (ob->maildir_format && ob->mailstore_format)
400 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
401 "only one of maildir and mailstore may be specified", tblock->name);
402 if (ob->quota_filecount != NULL && ob->quota == NULL)
403 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
404 "quota must be set if quota_filecount is set", tblock->name);
405 if (ob->quota_directory != NULL && ob->quota == NULL)
406 log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s transport:\n "
407 "quota must be set if quota_directory is set", tblock->name);
410 /* If a fixed uid field is set, then a gid field must also be set. */
412 if (tblock->uid_set && !tblock->gid_set && !tblock->expand_gid)
413 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
414 "user set without group for the %s transport", tblock->name);
416 /* If "create_file" is set, check that a valid option is given, and set the
419 if ((s = ob->create_file_string ) && *s)
422 if (Ustrcmp(s, "anywhere") == 0) val = create_anywhere;
423 else if (*s == '/' || Ustrcmp(s, "belowhome") == 0) val = create_belowhome;
424 else if (Ustrcmp(s, "inhome") == 0) val = create_inhome;
426 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
427 "invalid value given for \"create_file\" for the %s transport: '%s'",
429 ob->create_file = val;
432 /* If quota_warn_threshold is set, set up default for warn_message. It may
433 not be used if the actual threshold for a given delivery ends up as zero,
434 of if it's given as a percentage and there's no quota setting. */
436 if (ob->quota_warn_threshold)
438 if (!tblock->warn_message) tblock->warn_message = US
439 "To: $local_part@$domain\n"
440 "Subject: Your mailbox\n\n"
441 "This message is automatically created by mail delivery software (Exim).\n\n"
442 "The size of your mailbox has exceeded a warning threshold that is\n"
443 "set by the system administrator.\n";
446 /* If batch SMTP is set, force the check and escape strings, and arrange that
447 headers are also escaped. */
451 ob->check_string = US".";
452 ob->escape_string = US"..";
453 ob->options |= topt_escape_headers;
456 /* If not batch SMTP, not maildir, not mailstore, and directory is not set,
457 insert default values for for the affixes and the check/escape strings. */
459 else if (!ob->dirname && !ob->maildir_format && !ob->mailstore_format)
461 if (!ob->message_prefix) ob->message_prefix =
462 US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n";
463 if (!ob->message_suffix) ob->message_suffix = US"\n";
464 if (!ob->check_string) ob->check_string = US"From ";
465 if (!ob->escape_string) ob->escape_string = US">From ";
469 /* Set up the bitwise options for transport_write_message from the various
470 driver options. Only one of body_only and headers_only can be set. */
473 (tblock->body_only ? topt_no_headers : 0) |
474 (tblock->headers_only ? topt_no_body : 0) |
475 (tblock->return_path_add ? topt_add_return_path : 0) |
476 (tblock->delivery_date_add ? topt_add_delivery_date : 0) |
477 (tblock->envelope_to_add ? topt_add_envelope_to : 0) |
478 ((ob->use_crlf || ob->mbx_format) ? topt_use_crlf : 0);
483 /*************************************************
485 *************************************************/
487 /* The comsat daemon is the thing that provides asynchronous notification of
488 the arrival of local messages, if requested by the user by "biff y". It is a
489 BSD thing that uses a TCP/IP protocol for communication. A message consisting
490 of the text "user@offset" must be sent, where offset is the place in the
491 mailbox where new mail starts. There is no scope for telling it which file to
492 look at, which makes it a less than useful if mail is being delivered into a
493 non-standard place such as the user's home directory. In fact, it doesn't seem
494 to pay much attention to the offset.
498 offset offset in mailbox
504 notify_comsat(const uschar * user, off_t offset)
510 DEBUG(D_transport) debug_printf("notify_comsat called\n");
512 s = string_sprintf("%.200s@" OFF_T_FMT "\n", user, offset);
514 if ((sp = getservbyname("biff", "udp")) == NULL)
516 DEBUG(D_transport) debug_printf("biff/udp is an unknown service");
520 host.name = US"localhost";
524 /* This code is all set up to look up "localhost" and use all its addresses
525 until one succeeds. However, it appears that at least on some systems, comsat
526 doesn't listen on the ::1 address. So for the moment, just force the address to
527 be 127.0.0.1. At some future stage, when IPv6 really is superseding IPv4, this
528 can be changed. (But actually, comsat is probably dying out anyway.) */
531 if (host_find_byname(&host, NULL, 0, NULL, FALSE) == HOST_FIND_FAILED)
533 DEBUG(D_transport) debug_printf("\"localhost\" unknown\n");
538 host.address = US"127.0.0.1";
541 for (host_item * h = &host; h; h = h->next)
544 int host_af = Ustrchr(h->address, ':') != NULL ? AF_INET6 : AF_INET;
546 DEBUG(D_transport) debug_printf("calling comsat on %s\n", h->address);
548 if ((sock = ip_socket(SOCK_DGRAM, host_af)) < 0) continue;
550 /* Connect never fails for a UDP socket, so don't set a timeout. */
552 (void)ip_connect(sock, host_af, h->address, ntohs(sp->s_port), 0, NULL);
553 rc = send(sock, s, Ustrlen(s) + 1, 0);
558 debug_printf("send to comsat failed for %s: %s\n", strerror(errno),
565 /*************************************************
566 * Check the format of a file *
567 *************************************************/
569 /* This function is called when file_format is set, to check that an existing
570 file has the right format. The format string contains text/transport pairs. The
571 string matching is literal. we just read big_buffer_size bytes, because this is
572 all about the first few bytes of a file.
576 tblock the transport block
577 addr the address block - for inserting error data
579 Returns: pointer to the required transport, or NULL
583 check_file_format(int cfd, transport_instance *tblock, address_item *addr)
585 const uschar *format =
586 ((appendfile_transport_options_block *)(tblock->options_block))->file_format;
588 int len = read(cfd, data, sizeof(data));
592 DEBUG(D_transport) debug_printf("checking file format\n");
594 /* An empty file matches the current transport */
596 if (len == 0) return tblock;
598 /* Search the formats for a match */
600 /* not expanded so cannot be tainted */
601 while ((s = string_nextinlist(&format, &sep, big_buffer, big_buffer_size)))
603 int slen = Ustrlen(s);
604 BOOL match = len >= slen && Ustrncmp(data, s, slen) == 0;
605 uschar *tp = string_nextinlist(&format, &sep, big_buffer, big_buffer_size);
609 for (transport_instance * tt = transports; tt; tt = tt->next)
610 if (Ustrcmp(tp, tt->name) == 0)
613 debug_printf("file format -> %s transport\n", tt->name);
616 addr->basic_errno = ERRNO_BADTRANSPORT;
617 addr->message = string_sprintf("%s transport (for %.*s format) not found",
623 /* Failed to find a match */
625 addr->basic_errno = ERRNO_FORMATUNKNOWN;
626 addr->message = US"mailbox file format unrecognized";
633 /*************************************************
634 * Check directory's files for quota *
635 *************************************************/
637 /* This function is called if quota is set for one of the delivery modes that
638 delivers into a specific directory. It scans the directory and stats all the
639 files in order to get a total size and count. This is an expensive thing to do,
640 but some people are prepared to bear the cost. Alternatively, if size_regex is
641 set, it is used as a regex to try to extract the size from the file name, a
642 strategy that some people use on maildir files on systems where the users have
645 The function is global, because it is also called from tf_maildir.c for maildir
646 folders (which should contain only regular files).
648 Note: Any problems can be written to debugging output, but cannot be written to
649 the log, because we are running as an unprivileged user here.
652 dirname the name of the directory
653 countptr where to add the file count (because this function recurses)
654 re a compiled regex to get the size from a name
656 Returns: the sum of the sizes of the stattable files
657 zero if the directory cannot be opened
661 check_dir_size(const uschar * dirname, int * countptr, const pcre2_code * re)
665 int count = *countptr, lcount = REGEX_LOOPCOUNT_STORE_RESET;
666 rmark reset_point = store_mark();
668 if (!(dir = exim_opendir(dirname))) return 0;
670 for (struct dirent * ent; ent = readdir(dir); )
672 uschar * path, * name = US ent->d_name;
675 if (Ustrcmp(name, ".") == 0 || Ustrcmp(name, "..") == 0) continue;
680 store_reset(reset_point); reset_point = store_mark();
681 lcount = REGEX_LOOPCOUNT_STORE_RESET;
684 /* If there's a regex, try to find the size using it */
688 pcre2_match_data * md = pcre2_match_data_create(2, pcre_gen_ctx);
689 int rc = pcre2_match(re, (PCRE2_SPTR)name, PCRE2_ZERO_TERMINATED,
690 0, 0, md, pcre_gen_mtc_ctx);
691 PCRE2_SIZE * ovec = pcre2_get_ovector_pointer(md);
693 && (rc = pcre2_get_ovector_count(md)) >= 2)
696 off_t size = (off_t)Ustrtod(name + ovec[2], &endptr);
697 if (endptr == name + ovec[3])
701 debug_printf("check_dir_size: size from %s is " OFF_T_FMT "\n", name,
703 /* pcre2_match_data_free(md); gen ctx needs no free */
707 /* pcre2_match_data_free(md); gen ctx needs no free */
709 debug_printf("check_dir_size: regex did not match %s\n", name);
712 /* No regex or no match for the regex, or captured non-digits */
714 path = string_sprintf("%s/%s", dirname, name);
716 if (Ustat(path, &statbuf) < 0)
719 debug_printf("check_dir_size: stat error %d for %s: %s\n", errno, path,
723 if ((statbuf.st_mode & S_IFMT) == S_IFREG)
724 sum += statbuf.st_size / statbuf.st_nlink;
725 else if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
726 sum += check_dir_size(path, &count, re);
731 debug_printf("check_dir_size: dir=%s sum=" OFF_T_FMT " count=%d\n", dirname,
734 store_reset(reset_point);
742 /*************************************************
743 * Apply a lock to a file descriptor *
744 *************************************************/
746 /* This function applies a lock to a file descriptor, using a blocking or
747 non-blocking lock, depending on the timeout value. It can apply either or
748 both of a fcntl() and a flock() lock. However, not all OS support flock();
749 for those that don't, the use_flock option cannot be set.
752 fd the file descriptor
753 fcntltype type of lock, specified as F_WRLCK or F_RDLCK (that is, in
754 fcntl() format); the flock() type is deduced if needed
755 dofcntl do fcntl() locking
756 fcntltime non-zero to use blocking fcntl()
757 doflock do flock() locking
758 flocktime non-zero to use blocking flock()
760 Returns: yield of the fcntl() or flock() call, with errno preserved;
761 sigalrm_seen set if there has been a timeout
765 apply_lock(int fd, int fcntltype, BOOL dofcntl, int fcntltime, BOOL doflock,
770 struct flock lock_data;
771 lock_data.l_type = fcntltype;
772 lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
774 sigalrm_seen = FALSE;
781 yield = fcntl(fd, F_SETLKW, &lock_data);
786 else yield = fcntl(fd, F_SETLK, &lock_data);
790 if (doflock && (yield >= 0))
792 int flocktype = (fcntltype == F_WRLCK) ? LOCK_EX : LOCK_SH;
796 yield = flock(fd, flocktype);
801 else yield = flock(fd, flocktype | LOCK_NB);
803 #endif /* NO_FLOCK */
812 /*************************************************
813 * Copy message into MBX mailbox *
814 *************************************************/
816 /* This function is called when a message intended for a MBX mailbox has been
817 written to a temporary file. We can now get the size of the message and then
818 copy it in MBX format to the mailbox.
821 to_fd fd to write to (the real mailbox)
822 from_fd fd to read from (the temporary file)
823 saved_size current size of mailbox
825 Returns: OK if all went well, DEFER otherwise, with errno preserved
826 the number of bytes written are added to transport_count
827 by virtue of calling transport_write_block()
830 /* Values taken from c-client */
832 #define MBX_HDRSIZE 2048
833 #define MBX_NUSERFLAGS 30
836 copy_mbx_message(int to_fd, int from_fd, off_t saved_size)
841 transport_ctx tctx = { .u={.fd = to_fd}, .options = topt_not_socket };
843 /* If the current mailbox size is zero, write a header block */
848 memset (deliver_out_buffer, '\0', MBX_HDRSIZE);
849 sprintf(CS(s = deliver_out_buffer), "*mbx*\015\012%08lx00000000\015\012",
850 (long int)time(NULL));
851 for (int i = 0; i < MBX_NUSERFLAGS; i++)
852 sprintf (CS(s += Ustrlen(s)), "\015\012");
853 if (!transport_write_block (&tctx, deliver_out_buffer, MBX_HDRSIZE, FALSE))
857 DEBUG(D_transport) debug_printf("copying MBX message from temporary file\n");
859 /* Now construct the message's header from the time and the RFC822 file
860 size, including CRLFs, which is the size of the input (temporary) file. */
862 if (fstat(from_fd, &statbuf) < 0) return DEFER;
863 size = statbuf.st_size;
865 sprintf (CS deliver_out_buffer, "%s," OFF_T_FMT ";%08lx%04x-%08x\015\012",
866 tod_stamp(tod_mbx), size, 0L, 0, 0);
867 used = Ustrlen(deliver_out_buffer);
869 /* Rewind the temporary file, and copy it over in chunks. */
871 if (lseek(from_fd, 0 , SEEK_SET) < 0) return DEFER;
875 int len = read(from_fd, deliver_out_buffer + used,
876 DELIVER_OUT_BUFFER_SIZE - used);
879 if (len == 0) errno = ERRNO_MBXLENGTH;
882 if (!transport_write_block(&tctx, deliver_out_buffer, used + len, FALSE))
890 #endif /* SUPPORT_MBX */
894 /*************************************************
895 * Check creation is permitted *
896 *************************************************/
898 /* This function checks whether a given file name is permitted to be created,
899 as controlled by the create_file option. If no home directory is set, however,
900 we can't do any tests.
903 filename the file name
904 create_file the ob->create_file option
905 deliver_dir the delivery directory
907 Returns: TRUE if creation is permitted
911 check_creation(uschar *filename, int create_file, const uschar * deliver_dir)
915 if (deliver_dir && create_file != create_anywhere)
917 int len = Ustrlen(deliver_dir);
918 uschar *file = filename;
920 while (file[0] == '/' && file[1] == '/') file++;
921 if ( Ustrncmp(file, deliver_dir, len) != 0
923 || Ustrchr(file+len+2, '/') != NULL
924 && ( create_file != create_belowhome
925 || Ustrstr(file+len, "/../") != NULL
929 /* If yield is TRUE, the file name starts with the home directory, and does
930 not contain any instances of "/../" in the "belowhome" case. However, it may
931 still contain symbolic links. We can check for this by making use of
932 realpath(), which most Unixes seem to have (but make it possible to cut this
933 out). We can't just use realpath() on the whole file name, because we know
934 the file itself doesn't exist, and intermediate directories may also not
935 exist. What we want to know is the real path of the longest existing part of
936 the path. That must match the home directory's beginning, whichever is the
940 if (yield && create_file == create_belowhome)
944 for (uschar * slash = Ustrrchr(file, '/'); /* There is known to be one */
945 !rp && slash > file; /* Stop if reached beginning */
949 rp = US realpath(CS file, CS big_buffer);
950 next = Ustrrchr(file, '/');
954 /* If rp == NULL it means that none of the relevant directories exist.
955 This is not a problem here - it means that no symbolic links can exist,
956 which is all we are worried about. Otherwise, we must compare it
957 against the start of the home directory. However, that may itself
958 contain symbolic links, so we have to "realpath" it as well, if
963 uschar hdbuffer[PATH_MAX+1];
964 const uschar * rph = deliver_dir;
965 int rlen = Ustrlen(big_buffer);
967 if ((rp = US realpath(CS deliver_dir, CS hdbuffer)))
973 if (rlen > len) rlen = len;
974 if (Ustrncmp(rph, big_buffer, rlen) != 0)
977 DEBUG(D_transport) debug_printf("Real path \"%s\" does not match \"%s\"\n",
978 big_buffer, deliver_dir);
982 #endif /* NO_REALPATH */
990 /*************************************************
992 *************************************************/
994 /* See local README for general interface details. This transport always
995 returns FALSE, indicating that the status which has been placed in the first
996 address should be copied to any other addresses in a batch.
998 Appendfile delivery is tricky and has led to various security problems in other
999 mailers. The logic used here is therefore laid out in some detail. When this
1000 function is called, we are running in a subprocess which has had its gid and
1001 uid set to the appropriate values. Therefore, we cannot write directly to the
1002 exim logs. Any errors must be handled by setting appropriate return codes.
1003 Note that the default setting for addr->transport_return is DEFER, so it need
1004 not be set unless some other value is required.
1006 The code below calls geteuid() rather than getuid() to get the current uid
1007 because in weird configurations not running setuid root there may be a
1008 difference. In the standard configuration, where setuid() has been used in the
1009 delivery process, there will be no difference between the uid and the euid.
1011 (1) If the af_file flag is set, this is a delivery to a file after .forward or
1012 alias expansion. Otherwise, there must be a configured file name or
1015 The following items apply in the case when a file name (as opposed to a
1016 directory name) is given, that is, when appending to a single file:
1018 (2f) Expand the file name.
1020 (3f) If the file name is /dev/null, return success (optimization).
1022 (4f) If the file_format options is set, open the file for reading, and check
1023 that the bytes at the start of the file match one of the given strings.
1024 If the check indicates a transport other than the current one should be
1025 used, pass control to that other transport. Otherwise continue. An empty
1026 or non-existent file matches the current transport. The file is closed
1029 (5f) If a lock file is required, create it (see extensive separate comments
1030 below about the algorithm for doing this). It is important to do this
1031 before opening the mailbox if NFS is in use.
1033 (6f) Stat the file, using lstat() rather than stat(), in order to pick up
1034 details of any symbolic link.
1036 (7f) If the file already exists:
1038 Check the owner and group if necessary, and defer if they are wrong.
1040 If it is a symbolic link AND the allow_symlink option is set (NOT the
1041 default), go back to (6f) but this time use stat() instead of lstat().
1043 If it's not a regular file (or FIFO when permitted), defer delivery.
1045 Check permissions. If the required permissions are *less* than the
1046 existing ones, or supplied by the address (often by the user via filter),
1047 chmod() the file. Otherwise, defer.
1049 Save the inode number.
1051 Open with O_RDRW + O_APPEND, thus failing if the file has vanished.
1053 If open fails because the file does not exist, go to (6f); on any other
1056 Check the inode number hasn't changed - I realize this isn't perfect (an
1057 inode can be reused) but it's cheap and will catch some of the races.
1059 Check it's still a regular file (or FIFO if permitted).
1061 Check that the owner and permissions haven't changed.
1063 If file_format is set, check that the file still matches the format for
1064 the current transport. If not, defer delivery.
1066 (8f) If file does not exist initially:
1068 Open with O_WRONLY + O_EXCL + O_CREAT with configured mode, unless we know
1069 this is via a symbolic link (only possible if allow_symlinks is set), in
1070 which case don't use O_EXCL, as it doesn't work.
1072 If open fails because the file already exists, go to (6f). To avoid
1073 looping for ever in a situation where the file is continuously being
1074 created and deleted, all of this happens inside a loop that operates
1075 lock_retries times and includes the fcntl and flock locking. If the
1076 loop completes without the file getting opened, defer and request
1077 freezing, because something really weird is happening.
1079 If open fails for any other reason, defer for subsequent delivery except
1080 when this is a file delivery resulting from an alias or forward expansion
1081 and the error is EPERM or ENOENT or EACCES, in which case FAIL as this is
1082 most likely a user rather than a configuration error.
1084 (9f) We now have the file checked and open for writing. If so configured, lock
1085 it using fcntl, flock, or MBX locking rules. If this fails, close the file
1086 and goto (6f), up to lock_retries times, after sleeping for a while. If it
1087 still fails, give up and defer delivery.
1089 (10f)Save the access time (for subsequent restoration) and the size of the
1090 file, for comsat and for re-setting if delivery fails in the middle -
1091 e.g. for quota exceeded.
1093 The following items apply in the case when a directory name is given:
1095 (2d) Create a new file in the directory using a temporary name, by opening for
1096 writing and with O_CREAT. If maildir format is being used, the file
1097 is created in a temporary subdirectory with a prescribed name. If
1098 mailstore format is being used, the envelope file is first created with a
1099 temporary name, then the data file.
1101 The following items apply in all cases:
1103 (11) We now have the file open for writing, and locked if it was given as a
1104 file name. Write the message and flush the file, unless there is a setting
1105 of the local quota option, in which case we can check for its excession
1106 without doing any writing.
1108 In the case of MBX format mailboxes, the message is first written to a
1109 temporary file, in order to get its correct length. This is then copied to
1110 the real file, preceded by an MBX header.
1112 If there is a quota error on writing, defer the address. Timeout logic
1113 will determine for how long retries are attempted. We restore the mailbox
1114 to its original length if it's a single file. There doesn't seem to be a
1115 uniform error code for quota excession (it even differs between SunOS4
1116 and some versions of SunOS5) so a system-dependent macro called
1117 ERRNO_QUOTA is used for it, and the value gets put into errno_quota at
1120 For any other error (most commonly disk full), do the same.
1122 The following applies after appending to a file:
1124 (12f)Restore the atime; notify_comsat if required; close the file (which
1125 unlocks it if it was locked). Delete the lock file if it exists.
1127 The following applies after writing a unique file in a directory:
1129 (12d)For maildir format, rename the file into the new directory. For mailstore
1130 format, rename the envelope file to its correct name. Otherwise, generate
1131 a unique name from the directory_file option, and rename to that, possibly
1132 trying a few times if the file exists and re-expanding the name gives a
1135 This transport yields FAIL only when a file name is generated by an alias or
1136 forwarding operation and attempting to open it gives EPERM, ENOENT, or EACCES.
1137 All other failures return DEFER (in addr->transport_return). */
1141 appendfile_transport_entry(
1142 transport_instance *tblock, /* data for this instantiation */
1143 address_item *addr) /* address we are working on */
1145 appendfile_transport_options_block *ob =
1146 (appendfile_transport_options_block *)(tblock->options_block);
1147 struct stat statbuf;
1148 const uschar * deliver_dir;
1149 uschar *fdname = NULL;
1150 uschar *filename = NULL;
1151 uschar *hitchname = NULL;
1152 uschar *dataname = NULL;
1153 uschar *lockname = NULL;
1154 uschar *newname = NULL;
1155 uschar *nametag = NULL;
1157 uschar *filecount_msg = US"";
1159 struct utimbuf times;
1160 struct timeval msg_tv;
1161 BOOL disable_quota = FALSE;
1162 BOOL isdirectory = FALSE;
1163 BOOL isfifo = FALSE;
1164 BOOL wait_for_tick = FALSE;
1165 uid_t uid = geteuid(); /* See note above */
1166 gid_t gid = getegid();
1168 int mode = (addr->mode > 0) ? addr->mode : ob->mode;
1169 off_t saved_size = -1;
1170 off_t mailbox_size = ob->mailbox_size_value;
1171 int mailbox_filecount = ob->mailbox_filecount_value;
1179 int mbx_lockfd = -1;
1180 uschar mbx_lockname[40];
1181 FILE *temp_file = NULL;
1182 #endif /* SUPPORT_MBX */
1184 #ifdef SUPPORT_MAILDIR
1185 int maildirsize_fd = -1; /* fd for maildirsize file */
1186 int maildir_save_errno;
1190 DEBUG(D_transport) debug_printf("appendfile transport entered\n");
1192 /* An "address_file" or "address_directory" transport is used to deliver to
1193 files specified via .forward or an alias file. Prior to release 4.20, the
1194 "file" and "directory" options were ignored in this case. This has been changed
1195 to allow the redirection data to specify what is in effect a folder, whose
1196 location is determined by the options on the transport.
1198 Compatibility with the case when neither option is set is retained by forcing a
1199 value for the file or directory name. A directory delivery is assumed if the
1200 last character of the path from the router is '/'.
1202 The file path is in the local part of the address, but not in the $local_part
1203 variable (that holds the parent local part). It is, however, in the
1204 $address_file variable. Below, we update the local part in the address if it
1205 changes by expansion, so that the final path ends up in the log. */
1207 if (testflag(addr, af_file) && !ob->filename && !ob->dirname)
1209 fdname = US"$address_file";
1210 if (address_file[Ustrlen(address_file)-1] == '/' ||
1211 ob->maildir_format ||
1212 ob->mailstore_format)
1216 /* Handle (a) an "address file" delivery where "file" or "directory" is
1217 explicitly set and (b) a non-address_file delivery, where one of "file" or
1218 "directory" must be set; initialization ensures that they are not both set. */
1222 if (!(fdname = ob->filename))
1224 fdname = ob->dirname;
1229 addr->message = string_sprintf("Mandatory file or directory option "
1230 "missing from %s transport", tblock->name);
1235 /* Maildir and mailstore require a directory */
1237 if ((ob->maildir_format || ob->mailstore_format) && !isdirectory)
1239 addr->message = string_sprintf("mail%s_format requires \"directory\" "
1240 "to be specified for the %s transport",
1241 ob->maildir_format ? "dir" : "store", tblock->name);
1245 if (!(path = expand_string(fdname)))
1247 addr->message = string_sprintf("Expansion of \"%s\" (file or directory "
1248 "name for %s transport) failed: %s", fdname, tblock->name,
1249 expand_string_message);
1255 addr->message = string_sprintf("appendfile: file or directory name "
1256 "\"%s\" is not absolute", path);
1257 addr->basic_errno = ERRNO_NOTABSOLUTE;
1261 /* For a file delivery, make sure the local part in the address(es) is updated
1262 to the true local part. */
1264 if (testflag(addr, af_file))
1265 for (address_item * addr2 = addr; addr2; addr2 = addr2->next)
1266 addr2->local_part = string_copy(path);
1268 /* The available mailbox formats depend on whether it is a directory or a file
1274 #ifdef SUPPORT_MAILDIR
1275 ob->maildir_format ? mbf_maildir :
1277 #ifdef SUPPORT_MAILSTORE
1278 ob->mailstore_format ? mbf_mailstore :
1286 ob->mbx_format ? mbf_mbx :
1293 debug_printf("appendfile: mode=%o notify_comsat=%d quota=" OFF_T_FMT
1295 " warning=" OFF_T_FMT "%s\n"
1296 " %s=%s format=%s\n message_prefix=%s\n message_suffix=%s\n "
1297 "maildir_use_size_file=%s\n",
1298 mode, ob->notify_comsat, ob->quota_value,
1299 ob->quota_no_check ? " (no_check)" : "",
1300 ob->quota_filecount_no_check ? " (no_check_filecount)" : "",
1301 ob->quota_warn_threshold_value,
1302 ob->quota_warn_threshold_is_percent ? "%" : "",
1303 isdirectory ? "directory" : "file",
1304 path, mailbox_formats[mbformat],
1305 !ob->message_prefix ? US"null" : string_printing(ob->message_prefix),
1306 !ob->message_suffix ? US"null" : string_printing(ob->message_suffix),
1307 ob->maildir_use_size_file ? "yes" : "no");
1309 if (!isdirectory) debug_printf(" locking by %s%s%s%s%s\n",
1310 ob->use_lockfile ? "lockfile " : "",
1311 ob->use_mbx_lock ? "mbx locking (" : "",
1312 ob->use_fcntl ? "fcntl " : "",
1313 ob->use_flock ? "flock" : "",
1314 ob->use_mbx_lock ? ")" : "");
1317 /* If the -N option is set, can't do any more. */
1322 debug_printf("*** delivery by %s transport bypassed by -N option\n",
1324 addr->transport_return = OK;
1328 /* If an absolute path was given for create_file the it overrides deliver_home
1329 (here) and de-taints the filename (below, after check_creation() */
1331 deliver_dir = *ob->create_file_string == '/'
1332 ? ob->create_file_string : deliver_home;
1334 /* Handle the case of a file name. If the file name is /dev/null, we can save
1335 ourselves some effort and just give a success return right away. */
1339 BOOL use_lstat = TRUE;
1340 BOOL file_opened = FALSE;
1341 BOOL allow_creation_here = TRUE;
1343 if (Ustrcmp(path, "/dev/null") == 0)
1345 addr->transport_return = OK;
1349 /* Set the name of the file to be opened, and the file to which the data
1350 is written, and find out if we are permitted to create a non-existent file.
1351 If the create_file option is an absolute path and the file was within it,
1352 de-taint. Chaeck for a tainted path. */
1354 if ( (allow_creation_here = check_creation(path, ob->create_file, deliver_dir))
1355 && ob->create_file == create_belowhome)
1356 if (is_tainted(path))
1358 DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path);
1359 path = string_copy_taint(path, GET_UNTAINTED);
1362 if (is_tainted(path)) goto tainted_ret_panic;
1363 dataname = filename = path;
1365 /* If ob->create_directory is set, attempt to create the directories in
1366 which this mailbox lives, but only if we are permitted to create the file
1367 itself. We know we are dealing with an absolute path, because this was
1370 if (ob->create_directory && allow_creation_here)
1372 uschar *p = Ustrrchr(path, '/');
1373 p = string_copyn(path, p - path);
1374 if (!directory_make(NULL, p, ob->dirmode, FALSE))
1376 addr->basic_errno = errno;
1378 string_sprintf("failed to create directories for %s: %s", path,
1379 exim_errstr(errno));
1380 DEBUG(D_transport) debug_printf("%s transport: %s\n", tblock->name, path);
1385 /* If file_format is set we must check that any existing file matches one of
1386 the configured formats by checking the bytes it starts with. A match then
1387 indicates a specific transport - if it is not this one, pass control to it.
1388 Otherwise carry on here. An empty or non-existent file matches the current
1389 transport. We don't need to distinguish between non-existence and other open
1390 failures because if an existing file fails to open here, it will also fail
1391 again later when O_RDWR is used. */
1393 if (ob->file_format)
1395 int cfd = Uopen(path, O_RDONLY, 0);
1398 transport_instance *tt = check_file_format(cfd, tblock, addr);
1401 /* If another transport is indicated, call it and return; if no transport
1402 was found, just return - the error data will have been set up.*/
1408 set_process_info("delivering %s to %s using %s", message_id,
1409 addr->local_part, tt->name);
1410 debug_print_string(tt->debug_string);
1411 addr->transport = tt;
1412 (tt->info->code)(tt, addr);
1419 /* The locking of mailbox files is worse than the naming of cats, which is
1420 known to be "a difficult matter" (T.S. Eliot) and just as cats must have
1421 three different names, so several different styles of locking are used.
1423 Research in other programs that lock mailboxes shows that there is no
1424 universally standard method. Having mailboxes NFS-mounted on the system that
1425 is delivering mail is not the best thing, but people do run like this,
1426 and so the code must do its best to cope.
1428 Three different locking mechanisms are supported. The initialization function
1429 checks that at least one is configured.
1433 Unless no_use_lockfile is set, we attempt to build a lock file in a way that
1434 will work over NFS. Only after that is done do we actually open the mailbox
1435 and apply locks to it (if configured).
1437 Originally, Exim got the file opened before doing anything about locking.
1438 However, a very occasional problem was observed on Solaris 2 when delivering
1439 over NFS. It is seems that when a file is opened with O_APPEND, the file size
1440 gets remembered at open time. If another process on another host (that's
1441 important) has the file open and locked and writes to it and then releases
1442 the lock while the first process is waiting to get the lock, the first
1443 process may fail to write at the new end point of the file - despite the very
1444 definite statement about O_APPEND in the man page for write(). Experiments
1445 have reproduced this problem, but I do not know any way of forcing a host to
1446 update its attribute cache for an open NFS file. It would be nice if it did
1447 so when a lock was taken out, but this does not seem to happen. Anyway, to
1448 reduce the risk of this problem happening, we now create the lock file
1449 (if configured) *before* opening the mailbox. That will prevent two different
1450 Exims opening the file simultaneously. It may not prevent clashes with MUAs,
1451 however, but Pine at least seems to operate in the same way.
1453 Lockfiles should normally be used when NFS is involved, because of the above
1456 The logic for creating the lock file is:
1458 . The name of the lock file is <mailbox-name>.lock
1460 . First, create a "hitching post" name by adding the primary host name,
1461 current time and pid to the lock file name. This should be unique.
1463 . Create the hitching post file using WRONLY + CREAT + EXCL.
1465 . If that fails EACCES, we assume it means that the user is unable to create
1466 files in the mail spool directory. Some installations might operate in this
1467 manner, so there is a configuration option to allow this state not to be an
1468 error - we proceed to lock using fcntl only, after the file is open.
1470 . Otherwise, an error causes a deferment of the address.
1472 . Hard link the hitching post to the lock file name.
1474 . If the link succeeds, we have successfully created the lock file. Simply
1475 close and unlink the hitching post file.
1477 . If the link does not succeed, proceed as follows:
1479 o Fstat the hitching post file, and then close and unlink it.
1481 o Now examine the stat data. If the number of links to the file is exactly
1482 2, the linking succeeded but for some reason, e.g. an NFS server crash,
1483 the return never made it back, so the link() function gave a failure
1486 . This method allows for the lock file to be created by some other process
1487 right up to the moment of the attempt to hard link it, and is also robust
1488 against NFS server crash-reboots, which would probably result in timeouts
1489 in the middle of link().
1491 . System crashes may cause lock files to get left lying around, and some means
1492 of flushing them is required. The approach of writing a pid (used by smail
1493 and by elm) into the file isn't useful when NFS may be in use. Pine uses a
1494 timeout, which seems a better approach. Since any program that writes to a
1495 mailbox using a lock file should complete its task very quickly, Pine
1496 removes lock files that are older than 5 minutes. We allow the value to be
1497 configurable on the transport.
1501 If use_fcntl_lock is set, then Exim gets an exclusive fcntl() lock on the
1502 mailbox once it is open. This is done by default with a non-blocking lock.
1503 Failures to lock cause retries after a sleep, but only for a certain number
1504 of tries. A blocking lock is deliberately not used so that we don't hold the
1505 mailbox open. This minimizes the possibility of the NFS problem described
1506 under LOCK FILES above, if for some reason NFS deliveries are happening
1507 without lock files. However, the use of a non-blocking lock and sleep, though
1508 the safest approach, does not give the best performance on very busy systems.
1509 A blocking lock plus timeout does better. Therefore Exim has an option to
1510 allow it to work this way. If lock_fcntl_timeout is set greater than zero, it
1511 enables the use of blocking fcntl() calls.
1515 If use_flock_lock is set, then Exim gets an exclusive flock() lock in the
1516 same manner as for fcntl locking above. No-blocking/timeout is also set as
1517 above in lock_flock_timeout. Not all operating systems provide or support
1518 flock(). For those that don't (as determined by the definition of LOCK_SH in
1519 /usr/include/sys/file.h), use_flock_lock may not be set. For some OS, flock()
1520 is implemented (not precisely) on top of fcntl(), which means there's no
1521 point in actually using it.
1525 If use_mbx_lock is set (this is supported only if SUPPORT_MBX is defined)
1526 then the rules used for locking in c-client are used. Exim takes out a shared
1527 lock on the mailbox file, and an exclusive lock on the file whose name is
1528 /tmp/.<device-number>.<inode-number>. The shared lock on the mailbox stops
1529 any other MBX client from getting an exclusive lock on it and expunging it.
1530 It also stops any other MBX client from unlinking the /tmp lock when it has
1533 The exclusive lock on the /tmp file prevents any other MBX client from
1534 updating the mailbox in any way. When writing is finished, if an exclusive
1535 lock on the mailbox can be obtained, indicating there are no current sharers,
1536 the /tmp file is unlinked.
1538 MBX locking can use either fcntl() or flock() locking. If neither
1539 use_fcntl_lock or use_flock_lock is set, it defaults to using fcntl() only.
1540 The calls for getting these locks are by default non-blocking, as for non-mbx
1541 locking, but can be made blocking by setting lock_fcntl_timeout and/or
1542 lock_flock_timeout as appropriate. As MBX delivery doesn't work over NFS, it
1543 probably makes sense to set timeouts for any MBX deliveries. */
1546 /* Build a lock file if configured to do so - the existence of a lock
1547 file is subsequently checked by looking for a non-negative value of the
1548 file descriptor hd - even though the file is no longer open. */
1550 if (ob->use_lockfile)
1552 /* cf. exim_lock.c */
1553 lockname = string_sprintf("%s.lock", filename);
1554 hitchname = string_sprintf( "%s.%s.%08x.%08x", lockname, primary_hostname,
1555 (unsigned int)(time(NULL)), (unsigned int)getpid());
1557 DEBUG(D_transport) debug_printf("lock name: %s\nhitch name: %s\n", lockname,
1560 /* Lock file creation retry loop */
1562 for (i = 0; i < ob->lock_retries; sleep(ob->lock_interval), i++)
1566 hd = Uopen(hitchname, O_WRONLY | O_CREAT | O_EXCL, ob->lockfile_mode);
1569 addr->basic_errno = errno;
1571 string_sprintf("creating lock file hitching post %s "
1572 "(euid=%ld egid=%ld)", hitchname, (long int)geteuid(),
1573 (long int)getegid());
1577 /* Attempt to hitch the hitching post to the lock file. If link()
1578 succeeds (the common case, we hope) all is well. Otherwise, fstat the
1579 file, and get rid of the hitching post. If the number of links was 2,
1580 the link was created, despite the failure of link(). If the hitch was
1581 not successful, try again, having unlinked the lock file if it is too
1584 There's a version of Linux (2.0.27) which doesn't update its local cache
1585 of the inode after link() by default - which many think is a bug - but
1586 if the link succeeds, this code will be OK. It just won't work in the
1587 case when link() fails after having actually created the link. The Linux
1588 NFS person is fixing this; a temporary patch is available if anyone is
1589 sufficiently worried. */
1591 if ((rc = Ulink(hitchname, lockname)) != 0) fstat(hd, &statbuf);
1594 if (rc != 0 && statbuf.st_nlink != 2)
1596 if (ob->lockfile_timeout > 0 && Ustat(lockname, &statbuf) == 0 &&
1597 time(NULL) - statbuf.st_ctime > ob->lockfile_timeout)
1599 DEBUG(D_transport) debug_printf("unlinking timed-out lock file\n");
1602 DEBUG(D_transport) debug_printf("link of hitching post failed - retrying\n");
1606 DEBUG(D_transport) debug_printf("lock file created\n");
1610 /* Check for too many tries at creating the lock file */
1612 if (i >= ob->lock_retries)
1614 addr->basic_errno = ERRNO_LOCKFAILED;
1615 addr->message = string_sprintf("failed to lock mailbox %s (lock file)",
1622 /* We now have to get the file open. First, stat() it and act on existence or
1623 non-existence. This is in a loop to handle the case of a file's being created
1624 or deleted as we watch, and also to handle retries when the locking fails.
1625 Rather than holding the file open while waiting for the fcntl() and/or
1626 flock() lock, we close and do the whole thing again. This should be safer,
1627 especially for NFS files, which might get altered from other hosts, making
1628 their cached sizes incorrect.
1630 With the default settings, no symlinks are permitted, but there is an option
1631 to permit symlinks for those sysadmins that know what they are doing.
1632 Shudder. However, insist that the initial symlink is owned by the right user.
1633 Thus lstat() is used initially; if a symlink is discovered, the loop is
1634 repeated such that stat() is used, to look at the end file. */
1636 for (i = 0; i < ob->lock_retries; i++)
1638 int sleep_before_retry = TRUE;
1639 file_opened = FALSE;
1641 if ((use_lstat ? Ulstat(filename, &statbuf) : Ustat(filename, &statbuf)) != 0)
1643 /* Let's hope that failure to stat (other than non-existence) is a
1646 if (errno != ENOENT)
1648 addr->basic_errno = errno;
1649 addr->message = string_sprintf("attempting to stat mailbox %s",
1654 /* File does not exist. If it is required to pre-exist this state is an
1657 if (ob->file_must_exist)
1659 addr->basic_errno = errno;
1660 addr->message = string_sprintf("mailbox %s does not exist, "
1661 "but file_must_exist is set", filename);
1665 /* If not permitted to create this file because it isn't in or below
1666 the home directory, generate an error. */
1668 if (!allow_creation_here)
1670 addr->basic_errno = ERRNO_BADCREATE;
1671 addr->message = string_sprintf("mailbox %s does not exist, "
1672 "but creation outside the home directory is not permitted",
1677 /* Attempt to create and open the file. If open fails because of
1678 pre-existence, go round the loop again. For any other error, defer the
1679 address, except for an alias or forward generated file name with EPERM,
1680 ENOENT, or EACCES, as those are most likely to be user errors rather
1681 than Exim config errors. When a symbolic link is permitted and points
1682 to a non-existent file, we get here with use_lstat = FALSE. In this case
1683 we mustn't use O_EXCL, since it doesn't work. The file is opened RDRW for
1684 consistency and because MBX locking requires it in order to be able to
1685 get a shared lock. */
1687 fd = Uopen(filename, O_RDWR | O_APPEND | O_CREAT |
1688 (use_lstat ? O_EXCL : 0), mode);
1691 if (errno == EEXIST) continue;
1692 addr->basic_errno = errno;
1693 addr->message = string_sprintf("while creating mailbox %s",
1695 if (testflag(addr, af_file) &&
1696 (errno == EPERM || errno == ENOENT || errno == EACCES))
1697 addr->transport_return = FAIL;
1701 /* We have successfully created and opened the file. Ensure that the group
1702 and the mode are correct. */
1704 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
1706 addr->basic_errno = errno;
1707 addr->message = string_sprintf("while setting perms on mailbox %s",
1709 addr->transport_return = FAIL;
1715 /* The file already exists. Test its type, ownership, and permissions, and
1716 save the inode for checking later. If symlinks are permitted (not the
1717 default or recommended state) it may be a symlink that already exists.
1718 Check its ownership and then look for the file at the end of the link(s).
1719 This at least prevents one user creating a symlink for another user in
1720 a sticky directory. */
1724 int oldmode = (int)statbuf.st_mode;
1725 ino_t inode = statbuf.st_ino;
1726 BOOL islink = (oldmode & S_IFMT) == S_IFLNK;
1728 isfifo = FALSE; /* In case things are changing */
1730 /* Check owner if required - the default. */
1732 if (ob->check_owner && statbuf.st_uid != uid)
1734 addr->basic_errno = ERRNO_BADUGID;
1735 addr->message = string_sprintf("mailbox %s%s has wrong uid "
1736 "(%ld != %ld)", filename,
1737 islink ? " (symlink)" : "",
1738 (long int)(statbuf.st_uid), (long int)uid);
1742 /* Group is checked only if check_group is set. */
1744 if (ob->check_group && statbuf.st_gid != gid)
1746 addr->basic_errno = ERRNO_BADUGID;
1747 addr->message = string_sprintf("mailbox %s%s has wrong gid (%d != %d)",
1748 filename, islink ? " (symlink)" : "", statbuf.st_gid, gid);
1752 /* Just in case this is a sticky-bit mail directory, we don't want
1753 users to be able to create hard links to other users' files. */
1755 if (statbuf.st_nlink != 1)
1757 addr->basic_errno = ERRNO_NOTREGULAR;
1758 addr->message = string_sprintf("mailbox %s%s has too many links (%lu)",
1759 filename, islink ? " (symlink)" : "", (unsigned long)statbuf.st_nlink);
1764 /* If symlinks are permitted (not recommended), the lstat() above will
1765 have found the symlink. Its ownership has just been checked; go round
1766 the loop again, using stat() instead of lstat(). That will never yield a
1769 if (islink && ob->allow_symlink)
1772 i--; /* Don't count this time round */
1776 /* An actual file exists. Check that it is a regular file, or FIFO
1779 if (ob->allow_fifo && (oldmode & S_IFMT) == S_IFIFO) isfifo = TRUE;
1781 else if ((oldmode & S_IFMT) != S_IFREG)
1783 addr->basic_errno = ERRNO_NOTREGULAR;
1784 addr->message = string_sprintf("mailbox %s is not a regular file%s",
1785 filename, ob->allow_fifo ? " or named pipe" : "");
1789 /* If the mode is not what it would be for a newly created file, change
1790 the permissions if the mode is supplied for the address. Otherwise,
1791 reduce but do not extend the permissions. If the newly created
1792 permissions are greater than the existing permissions, don't change
1793 things when the mode is not from the address. */
1795 if ((oldmode &= 07777) != mode)
1797 int diffs = oldmode ^ mode;
1798 if (addr->mode > 0 || (diffs & oldmode) == diffs)
1800 DEBUG(D_transport) debug_printf("chmod %o %s\n", mode, filename);
1801 if (Uchmod(filename, mode) < 0)
1803 addr->basic_errno = errno;
1804 addr->message = string_sprintf("attempting to chmod mailbox %s",
1811 /* Mode not from address, and newly-created permissions are greater
1812 than existing permissions. Default is to complain, but it can be
1813 configured to go ahead and try to deliver anyway if that's what
1814 the administration wants. */
1816 else if (ob->mode_fail_narrower)
1818 addr->basic_errno = ERRNO_BADMODE;
1819 addr->message = string_sprintf("mailbox %s has the wrong mode %o "
1820 "(%o expected)", filename, oldmode, mode);
1825 /* We are happy with the existing file. Open it, and then do further
1826 tests to ensure that it is the same file that we were just looking at.
1827 If the file does not now exist, restart this loop, going back to using
1828 lstat again. For an NFS error, just defer; other opening errors are
1829 more serious. The file is opened RDWR so that its format can be checked,
1830 and also MBX locking requires the use of a shared (read) lock. However,
1831 a FIFO is opened WRONLY + NDELAY so that it fails if there is no process
1832 reading the pipe. */
1834 fd = Uopen(filename, isfifo ? (O_WRONLY|O_NDELAY) : (O_RDWR|O_APPEND),
1838 if (errno == ENOENT)
1843 addr->basic_errno = errno;
1845 addr->message = string_sprintf("while opening named pipe %s "
1846 "(could mean no process is reading it)", filename);
1847 else if (errno != EWOULDBLOCK)
1848 addr->message = string_sprintf("while opening mailbox %s", filename);
1852 /* This fstat really shouldn't fail, as we have an open file! There's a
1853 dilemma here. We use fstat in order to be sure we are peering at the file
1854 we have got open. However, that won't tell us if the file was reached
1855 via a symbolic link. We checked this above, but there is a race exposure
1856 if the link was created between the previous lstat and the open. However,
1857 it would have to be created with the same inode in order to pass the
1858 check below. If ob->allow_symlink is set, causing the use of stat rather
1859 than lstat above, symbolic links may be there anyway, and the checking is
1862 if (fstat(fd, &statbuf) < 0)
1864 addr->basic_errno = errno;
1865 addr->message = string_sprintf("attempting to stat open mailbox %s",
1870 /* Check the inode; this is isn't a perfect check, but gives some
1873 if (inode != statbuf.st_ino)
1875 addr->basic_errno = ERRNO_INODECHANGED;
1876 addr->message = string_sprintf("opened mailbox %s inode number changed "
1877 "from " INO_T_FMT " to " INO_T_FMT, filename, inode, statbuf.st_ino);
1878 addr->special_action = SPECIAL_FREEZE;
1882 /* Check it's still a regular file or FIFO, and the uid, gid, and
1883 permissions have not changed. */
1885 if ((!isfifo && (statbuf.st_mode & S_IFMT) != S_IFREG) ||
1886 (isfifo && (statbuf.st_mode & S_IFMT) != S_IFIFO))
1888 addr->basic_errno = ERRNO_NOTREGULAR;
1890 string_sprintf("opened mailbox %s is no longer a %s", filename,
1891 isfifo ? "named pipe" : "regular file");
1892 addr->special_action = SPECIAL_FREEZE;
1896 if ((ob->check_owner && statbuf.st_uid != uid) ||
1897 (ob->check_group && statbuf.st_gid != gid))
1899 addr->basic_errno = ERRNO_BADUGID;
1901 string_sprintf("opened mailbox %s has wrong uid or gid", filename);
1902 addr->special_action = SPECIAL_FREEZE;
1906 if ((statbuf.st_mode & 07777) != oldmode)
1908 addr->basic_errno = ERRNO_BADMODE;
1909 addr->message = string_sprintf("opened mailbox %s has wrong mode %o "
1910 "(%o expected)", filename, statbuf.st_mode & 07777, mode);
1911 addr->special_action = SPECIAL_FREEZE;
1915 /* If file_format is set, check that the format of the file has not
1916 changed. Error data is set by the testing function. */
1918 if (ob->file_format && check_file_format(fd, tblock, addr) != tblock)
1920 addr->message = US"open mailbox has changed format";
1924 /* The file is OK. Carry on to do the locking. */
1927 /* We now have an open file, and must lock it using fcntl(), flock() or MBX
1928 locking rules if configured to do so. If a lock file is also required, it
1929 was created above and hd was left >= 0. At least one form of locking is
1930 required by the initialization function. If locking fails here, close the
1931 file and go round the loop all over again, after waiting for a bit, unless
1932 blocking locking was used. */
1935 if ((ob->lock_fcntl_timeout > 0) || (ob->lock_flock_timeout > 0))
1936 sleep_before_retry = FALSE;
1938 /* Simple fcntl() and/or flock() locking */
1940 if (!ob->use_mbx_lock && (ob->use_fcntl || ob->use_flock))
1942 if (apply_lock(fd, F_WRLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
1943 ob->use_flock, ob->lock_flock_timeout) >= 0) break;
1946 /* MBX locking rules */
1949 else if (ob->use_mbx_lock)
1952 struct stat lstatbuf, statbuf2;
1953 if (apply_lock(fd, F_RDLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
1954 ob->use_flock, ob->lock_flock_timeout) >= 0 &&
1955 fstat(fd, &statbuf) >= 0)
1957 sprintf(CS mbx_lockname, "/tmp/.%lx.%lx", (long)statbuf.st_dev,
1958 (long)statbuf.st_ino);
1961 * 2010-05-29: SECURITY
1962 * Dan Rosenberg reported the presence of a race-condition in the
1963 * original code here. Beware that many systems still allow symlinks
1964 * to be followed in /tmp so an attacker can create a symlink pointing
1965 * elsewhere between a stat and an open, which we should avoid
1968 * It's unfortunate that we can't just use all the heavily debugged
1969 * locking from above.
1971 * Also: remember to mirror changes into exim_lock.c */
1973 /* first leave the old pre-check in place, it provides better
1974 * diagnostics for common cases */
1975 if (Ulstat(mbx_lockname, &statbuf) >= 0)
1977 if ((statbuf.st_mode & S_IFMT) == S_IFLNK)
1979 addr->basic_errno = ERRNO_LOCKFAILED;
1980 addr->message = string_sprintf("symbolic link on MBX lock file %s",
1984 if (statbuf.st_nlink > 1)
1986 addr->basic_errno = ERRNO_LOCKFAILED;
1987 addr->message = string_sprintf("hard link to MBX lock file %s",
1993 /* If we could just declare "we must be the ones who create this
1994 * file" then a hitching post in a subdir would work, since a
1995 * subdir directly in /tmp/ which we create wouldn't follow links
1996 * but this isn't our locking logic, so we can't safely change the
1997 * file existence rules. */
1999 /* On systems which support O_NOFOLLOW, it's the easiest and most
2000 * obviously correct security fix */
2001 mbx_tmp_oflags = O_RDWR | O_CREAT;
2003 mbx_tmp_oflags |= O_NOFOLLOW;
2005 mbx_lockfd = Uopen(mbx_lockname, mbx_tmp_oflags, ob->lockfile_mode);
2008 addr->basic_errno = ERRNO_LOCKFAILED;
2009 addr->message = string_sprintf("failed to open MBX lock file %s :%s",
2010 mbx_lockname, strerror(errno));
2014 if (Ulstat(mbx_lockname, &lstatbuf) < 0)
2016 addr->basic_errno = ERRNO_LOCKFAILED;
2017 addr->message = string_sprintf("attempting to lstat open MBX "
2018 "lock file %s: %s", mbx_lockname, strerror(errno));
2021 if (fstat(mbx_lockfd, &statbuf2) < 0)
2023 addr->basic_errno = ERRNO_LOCKFAILED;
2024 addr->message = string_sprintf("attempting to stat fd of open MBX "
2025 "lock file %s: %s", mbx_lockname, strerror(errno));
2031 * statbuf: if exists, is file which existed prior to opening the
2032 * lockfile, might have been replaced since then
2033 * statbuf2: result of stat'ing the open fd, is what was actually
2035 * lstatbuf: result of lstat'ing the filename immediately after
2036 * the open but there's a race condition again between
2037 * those two steps: before open, symlink to foo, after
2038 * open but before lstat have one of:
2039 * * was no symlink, so is the opened file
2040 * (we created it, no messing possible after that point)
2042 * * symlink elsewhere
2043 * * hardlink elsewhere
2045 * Don't want to compare to device of /tmp because some modern systems
2046 * have regressed to having /tmp be the safe actual filesystem as
2047 * valuable data, so is mostly worthless, unless we assume that *only*
2048 * Linux systems do this and that all Linux has O_NOFOLLOW. Something
2049 * for further consideration.
2050 * No point in doing a readlink on the lockfile as that will always be
2051 * at a different point in time from when we open it, so tells us
2052 * nothing; attempts to clean up and delete after ourselves would risk
2053 * deleting a *third* filename.
2055 if ((statbuf2.st_nlink > 1) ||
2056 (lstatbuf.st_nlink > 1) ||
2057 (!S_ISREG(lstatbuf.st_mode)) ||
2058 (lstatbuf.st_dev != statbuf2.st_dev) ||
2059 (lstatbuf.st_ino != statbuf2.st_ino))
2061 addr->basic_errno = ERRNO_LOCKFAILED;
2062 addr->message = string_sprintf("RACE CONDITION detected: "
2063 "mismatch post-initial-checks between \"%s\" and opened "
2064 "fd lead us to abort!", mbx_lockname);
2068 (void)Uchmod(mbx_lockname, ob->lockfile_mode);
2070 if (apply_lock(mbx_lockfd, F_WRLCK, ob->use_fcntl,
2071 ob->lock_fcntl_timeout, ob->use_flock, ob->lock_flock_timeout) >= 0)
2073 struct stat ostatbuf;
2075 /* This tests for a specific race condition. Ensure that we still
2076 have the same file. */
2078 if (Ulstat(mbx_lockname, &statbuf) == 0 &&
2079 fstat(mbx_lockfd, &ostatbuf) == 0 &&
2080 statbuf.st_dev == ostatbuf.st_dev &&
2081 statbuf.st_ino == ostatbuf.st_ino)
2083 DEBUG(D_transport) debug_printf("MBX lockfile %s changed "
2084 "between creation and locking\n", mbx_lockname);
2087 DEBUG(D_transport) debug_printf("failed to lock %s: %s\n", mbx_lockname,
2089 (void)close(mbx_lockfd);
2094 DEBUG(D_transport) debug_printf("failed to fstat or get read lock on %s: %s\n",
2095 filename, strerror(errno));
2098 #endif /* SUPPORT_MBX */
2100 else break; /* No on-file locking required; break the open/lock loop */
2103 debug_printf("fcntl(), flock(), or MBX locking failed - retrying\n");
2107 use_lstat = TRUE; /* Reset to use lstat first */
2110 /* If a blocking call timed out, break the retry loop if the total time
2111 so far is not less than than retries * interval. Use the larger of the
2112 flock() and fcntl() timeouts. */
2115 (i+1) * ((ob->lock_fcntl_timeout > ob->lock_flock_timeout)?
2116 ob->lock_fcntl_timeout : ob->lock_flock_timeout) >=
2117 ob->lock_retries * ob->lock_interval)
2118 i = ob->lock_retries;
2120 /* Wait a bit before retrying, except when it was a blocked fcntl() or
2121 flock() that caused the problem. */
2123 if (i < ob->lock_retries && sleep_before_retry) sleep(ob->lock_interval);
2126 /* Test for exceeding the maximum number of tries. Either the file remains
2127 locked, or, if we haven't got it open, something is terribly wrong... */
2129 if (i >= ob->lock_retries)
2133 addr->basic_errno = ERRNO_EXISTRACE;
2134 addr->message = string_sprintf("mailbox %s: existence unclear", filename);
2135 addr->special_action = SPECIAL_FREEZE;
2139 addr->basic_errno = ERRNO_LOCKFAILED;
2140 addr->message = string_sprintf("failed to lock mailbox %s (fcntl/flock)",
2146 DEBUG(D_transport) debug_printf("mailbox %s is locked\n", filename);
2148 /* Save access time (for subsequent restoration), modification time (for
2149 restoration if updating fails), size of file (for comsat and for re-setting if
2150 delivery fails in the middle - e.g. for quota exceeded). */
2152 if (fstat(fd, &statbuf) < 0)
2154 addr->basic_errno = errno;
2155 addr->message = string_sprintf("while fstatting opened mailbox %s",
2160 times.actime = statbuf.st_atime;
2161 times.modtime = statbuf.st_mtime;
2162 saved_size = statbuf.st_size;
2163 if (mailbox_size < 0) mailbox_size = saved_size;
2164 mailbox_filecount = 0; /* Not actually relevant for single-file mailbox */
2167 /* Prepare for writing to a new file (as opposed to appending to an old one).
2168 There are several different formats, but there is preliminary stuff concerned
2169 with quotas that applies to all of them. Finding the current size by directory
2170 scanning is expensive; for maildirs some fudges have been invented:
2172 (1) A regex can be used to extract a file size from its name;
2173 (2) If maildir_use_size is set, a maildirsize file is used to cache the
2179 uschar *check_path; /* Default quota check path */
2180 const pcre2_code * re = NULL; /* Regex for file size from file name */
2182 if (!check_creation(string_sprintf("%s/any", path),
2183 ob->create_file, deliver_dir))
2185 addr->basic_errno = ERRNO_BADCREATE;
2186 addr->message = string_sprintf("tried to create file in %s, but "
2187 "file creation outside the home directory is not permitted", path);
2191 /* If the create_file option is an absolute path and the file was within
2192 it, de-taint. Otherwise check for taint. */
2194 if (is_tainted(path))
2195 if (ob->create_file == create_belowhome)
2197 DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path);
2198 path = string_copy_taint(path, GET_UNTAINTED);
2201 goto tainted_ret_panic;
2205 #ifdef SUPPORT_MAILDIR
2206 /* For a maildir delivery, ensure that all the relevant directories exist,
2207 and a maildirfolder file if necessary. */
2209 if (mbformat == mbf_maildir && !maildir_ensure_directories(path, addr,
2210 ob->create_directory, ob->dirmode, ob->maildirfolder_create_regex))
2212 #endif /* SUPPORT_MAILDIR */
2214 /* If we are going to do a quota check, of if maildir_use_size_file is set
2215 for a maildir delivery, compile the regular expression if there is one. We
2216 may also need to adjust the path that is used. We need to do this for
2217 maildir_use_size_file even if the quota is unset, because we still want to
2218 create the file. When maildir support is not compiled,
2219 ob->maildir_use_size_file is always FALSE. */
2221 if (ob->quota_value > 0 || THRESHOLD_CHECK || ob->maildir_use_size_file)
2223 /* Compile the regex if there is one. */
2225 if (ob->quota_size_regex)
2227 if (!(re = regex_compile(ob->quota_size_regex,
2228 MCS_NOFLAGS, &addr->message, pcre_gen_cmp_ctx)))
2231 DEBUG(D_transport) debug_printf("using regex for file sizes: %s\n",
2232 ob->quota_size_regex);
2235 /* Use an explicitly configured directory if set */
2237 if (ob->quota_directory)
2239 if (!(check_path = expand_string(ob->quota_directory)))
2241 addr->message = string_sprintf("Expansion of \"%s\" (quota_directory "
2242 "name for %s transport) failed: %s", ob->quota_directory,
2243 tblock->name, expand_string_message);
2247 if (check_path[0] != '/')
2249 addr->message = string_sprintf("appendfile: quota_directory name "
2250 "\"%s\" is not absolute", check_path);
2251 addr->basic_errno = ERRNO_NOTABSOLUTE;
2256 #ifdef SUPPORT_MAILDIR
2257 /* Otherwise, if we are handling a maildir delivery, and the directory
2258 contains a file called maildirfolder, this is a maildir++ feature telling
2259 us that this is a sub-directory of the real inbox. We should therefore do
2260 the quota check on the parent directory. Beware of the special case when
2261 the directory name itself ends in a slash. */
2263 else if (mbformat == mbf_maildir)
2265 struct stat statbuf;
2266 if (Ustat(string_sprintf("%s/maildirfolder", path), &statbuf) >= 0)
2268 uschar *new_check_path = string_copy(check_path);
2269 uschar *slash = Ustrrchr(new_check_path, '/');
2275 slash = Ustrrchr(new_check_path, '/');
2280 check_path = new_check_path;
2281 DEBUG(D_transport) debug_printf("maildirfolder file exists: "
2282 "quota check directory changed to %s\n", check_path);
2287 #endif /* SUPPORT_MAILDIR */
2290 /* If we are using maildirsize files, we need to ensure that such a file
2291 exists and, if necessary, recalculate its contents. As a byproduct of this,
2292 we obtain the current size of the maildir. If no quota is to be enforced
2293 (ob->quota_value == 0), we still need the size if a threshold check will
2296 Another regular expression is used to determine which directories inside the
2297 maildir are going to be counted. */
2299 #ifdef SUPPORT_MAILDIR
2300 if (ob->maildir_use_size_file)
2302 const pcre2_code * dir_regex = NULL;
2304 if (ob->maildir_dir_regex)
2306 int check_path_len = Ustrlen(check_path);
2308 if (!(dir_regex = regex_compile(ob->maildir_dir_regex,
2309 MCS_NOFLAGS, &addr->message, pcre_gen_cmp_ctx)))
2313 debug_printf("using regex for maildir directory selection: %s\n",
2314 ob->maildir_dir_regex);
2316 /* Check to see if we are delivering into an ignored directory, that is,
2317 if the delivery path starts with the quota check path, and the rest
2318 of the deliver path matches the regex; if so, set a flag to disable quota
2319 checking and maildirsize updating. */
2321 if (Ustrncmp(path, check_path, check_path_len) == 0)
2323 uschar *s = path + check_path_len;
2324 while (*s == '/') s++;
2325 s = *s ? string_sprintf("%s/new", s) : US"new";
2326 if (!regex_match(dir_regex, s, -1, NULL))
2328 disable_quota = TRUE;
2329 DEBUG(D_transport) debug_printf("delivery directory does not match "
2330 "maildir_quota_directory_regex: disabling quota\n");
2335 /* Quota enforcement; create and check the file. There is some discussion
2336 about whether this should happen if the quota is unset. At present, Exim
2337 always creates the file. If we ever want to change this, uncomment
2338 appropriate lines below, possibly doing a check on some option. */
2340 /* if (???? || ob->quota_value > 0) */
2347 if ((maildirsize_fd = maildir_ensure_sizefile(check_path, ob, re, dir_regex,
2348 &size, &filecount)) == -1)
2350 addr->basic_errno = errno;
2351 addr->message = string_sprintf("while opening or reading "
2352 "%s/maildirsize", check_path);
2355 /* can also return -2, which means that the file was removed because of
2356 raciness; but in this case, the size & filecount will still have been
2359 if (mailbox_size < 0) mailbox_size = size;
2360 if (mailbox_filecount < 0) mailbox_filecount = filecount;
2363 /* No quota enforcement; ensure file does *not* exist; calculate size if
2368 * time_t old_latest;
2369 * (void)unlink(CS string_sprintf("%s/maildirsize", check_path));
2370 * if (THRESHOLD_CHECK)
2371 * mailbox_size = maildir_compute_size(check_path, &mailbox_filecount, &old_latest,
2372 * re, dir_regex, FALSE);
2377 #endif /* SUPPORT_MAILDIR */
2379 /* Otherwise if we are going to do a quota check later on, and the mailbox
2380 size is not set, find the current size of the mailbox. Ditto for the file
2381 count. Note that ob->quota_filecount_value cannot be set without
2382 ob->quota_value being set. */
2385 && (ob->quota_value > 0 || THRESHOLD_CHECK)
2386 && ( mailbox_size < 0
2387 || mailbox_filecount < 0 && ob->quota_filecount_value > 0
2393 debug_printf("quota checks on directory %s\n", check_path);
2394 size = check_dir_size(check_path, &filecount, re);
2395 if (mailbox_size < 0) mailbox_size = size;
2396 if (mailbox_filecount < 0) mailbox_filecount = filecount;
2399 /* Handle the case of creating a unique file in a given directory (not in
2400 maildir or mailstore format - this is how smail did it). A temporary name is
2401 used to create the file. Later, when it is written, the name is changed to a
2402 unique one. There is no need to lock the file. An attempt is made to create
2403 the directory if it does not exist. */
2405 if (mbformat == mbf_smail)
2408 debug_printf("delivering to new file in %s\n", path);
2409 filename = dataname =
2410 string_sprintf("%s/temp.%d.%s", path, (int)getpid(), primary_hostname);
2411 fd = Uopen(filename, O_WRONLY|O_CREAT, mode);
2412 if (fd < 0 && /* failed to open, and */
2413 (errno != ENOENT || /* either not non-exist */
2414 !ob->create_directory || /* or not allowed to make */
2415 !directory_make(NULL, path, ob->dirmode, FALSE) || /* or failed to create dir */
2416 (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)) /* or then failed to open */
2418 addr->basic_errno = errno;
2419 addr->message = string_sprintf("while creating file %s", filename);
2424 #ifdef SUPPORT_MAILDIR
2426 /* Handle the case of a unique file in maildir format. The file is written to
2427 the tmp subdirectory, with a prescribed form of name. */
2429 else if (mbformat == mbf_maildir)
2432 debug_printf("delivering in maildir format in %s\n", path);
2434 nametag = ob->maildir_tag;
2436 /* Check that nametag expands successfully; a hard failure causes a panic
2437 return. The actual expansion for use happens again later, when
2438 $message_size is accurately known. */
2440 if (nametag && !expand_string(nametag) && !f.expand_string_forcedfail)
2442 addr->message = string_sprintf("Expansion of \"%s\" (maildir_tag "
2443 "for %s transport) failed: %s", nametag, tblock->name,
2444 expand_string_message);
2448 /* We ensured the existence of all the relevant directories above. Attempt
2449 to open the temporary file a limited number of times. I think this rather
2450 scary-looking for statement is actually OK. If open succeeds, the loop is
2451 broken; if not, there is a test on the value of i. Get the time again
2452 afresh each time round the loop. Its value goes into a variable that is
2453 checked at the end, to make sure we don't release this process until the
2454 clock has ticked. */
2456 for (int i = 1;; i++)
2460 (void)gettimeofday(&msg_tv, NULL);
2461 basename = string_sprintf(TIME_T_FMT ".M%luP" PID_T_FMT ".%s",
2462 msg_tv.tv_sec, msg_tv.tv_usec, getpid(), primary_hostname);
2464 filename = dataname = string_sprintf("tmp/%s", basename);
2465 newname = string_sprintf("new/%s", basename);
2467 if (Ustat(filename, &statbuf) == 0)
2469 else if (errno == ENOENT)
2471 if ((fd = Uopen(filename, O_WRONLY | O_CREAT | O_EXCL, mode)) >= 0)
2473 DEBUG (D_transport) debug_printf ("open failed for %s: %s\n",
2474 filename, strerror(errno));
2477 /* Too many retries - give up */
2479 if (i >= ob->maildir_retries)
2481 addr->message = string_sprintf ("failed to open %s (%d tr%s)",
2482 filename, i, (i == 1) ? "y" : "ies");
2483 addr->basic_errno = errno;
2484 if (errno == errno_quota || errno == ENOSPC)
2485 addr->user_message = US"mailbox is full";
2489 /* Open or stat failed but we haven't tried too many times yet. */
2494 /* Note that we have to ensure the clock has ticked before leaving */
2496 wait_for_tick = TRUE;
2498 /* Why are these here? Put in because they are present in the non-maildir
2499 directory case above. */
2501 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2503 addr->basic_errno = errno;
2504 addr->message = string_sprintf("while setting perms on maildir %s",
2510 #endif /* SUPPORT_MAILDIR */
2512 #ifdef SUPPORT_MAILSTORE
2514 /* Handle the case of a unique file in mailstore format. First write the
2515 envelope to a temporary file, then open the main file. The unique base name
2516 for the files consists of the message id plus the pid of this delivery
2522 mailstore_basename = string_sprintf("%s/%s-%s", path, message_id,
2523 string_base62_64((long int)getpid()));
2526 debug_printf("delivering in mailstore format in %s\n", path);
2528 filename = string_sprintf("%s.tmp", mailstore_basename);
2529 newname = string_sprintf("%s.env", mailstore_basename);
2530 dataname = string_sprintf("%s.msg", mailstore_basename);
2532 fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode);
2533 if ( fd < 0 /* failed to open, and */
2534 && ( errno != ENOENT /* either not non-exist */
2535 || !ob->create_directory /* or not allowed to make */
2536 || !directory_make(NULL, path, ob->dirmode, FALSE) /* or failed to create dir */
2537 || (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0 /* or then failed to open */
2540 addr->basic_errno = errno;
2541 addr->message = string_sprintf("while creating file %s", filename);
2545 /* Why are these here? Put in because they are present in the non-maildir
2546 directory case above. */
2548 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2550 addr->basic_errno = errno;
2551 addr->message = string_sprintf("while setting perms on file %s",
2556 /* Built a C stream from the open file descriptor. */
2558 if (!(env_file = fdopen(fd, "wb")))
2560 addr->basic_errno = errno;
2561 addr->message = string_sprintf("fdopen of %s ("
2562 "for %s transport) failed", filename, tblock->name);
2568 /* Write the envelope file, then close it. */
2570 if (ob->mailstore_prefix)
2572 uschar *s = expand_string(ob->mailstore_prefix);
2575 if (!f.expand_string_forcedfail)
2577 addr->message = string_sprintf("Expansion of \"%s\" (mailstore "
2578 "prefix for %s transport) failed: %s", ob->mailstore_prefix,
2579 tblock->name, expand_string_message);
2580 (void)fclose(env_file);
2588 fprintf(env_file, "%s", CS s);
2589 if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n");
2593 fprintf(env_file, "%s\n", sender_address);
2595 for (address_item * taddr = addr; taddr; taddr = taddr->next)
2596 fprintf(env_file, "%s@%s\n", taddr->local_part, taddr->domain);
2598 if (ob->mailstore_suffix)
2600 uschar *s = expand_string(ob->mailstore_suffix);
2603 if (!f.expand_string_forcedfail)
2605 addr->message = string_sprintf("Expansion of \"%s\" (mailstore "
2606 "suffix for %s transport) failed: %s", ob->mailstore_suffix,
2607 tblock->name, expand_string_message);
2608 (void)fclose(env_file);
2616 fprintf(env_file, "%s", CS s);
2617 if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n");
2621 if (fclose(env_file) != 0)
2623 addr->basic_errno = errno;
2624 addr->message = string_sprintf("while closing %s", filename);
2629 DEBUG(D_transport) debug_printf("Envelope file %s written\n", filename);
2631 /* Now open the data file, and ensure that it has the correct ownership and
2634 if ((fd = Uopen(dataname, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)
2636 addr->basic_errno = errno;
2637 addr->message = string_sprintf("while creating file %s", dataname);
2641 if (exim_chown(dataname, uid, gid) || Uchmod(dataname, mode))
2643 addr->basic_errno = errno;
2644 addr->message = string_sprintf("while setting perms on file %s",
2650 #endif /* SUPPORT_MAILSTORE */
2653 /* In all cases of writing to a new file, ensure that the file which is
2654 going to be renamed has the correct ownership and mode. */
2656 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2658 addr->basic_errno = errno;
2659 addr->message = string_sprintf("while setting perms on file %s",
2666 /* At last we can write the message to the file, preceded by any configured
2667 prefix line, and followed by any configured suffix line. If there are any
2668 writing errors, we must defer. */
2670 DEBUG(D_transport) debug_printf("writing to file %s\n", dataname);
2675 /* If there is a local quota setting, check that we are not going to exceed it
2676 with this message if quota_is_inclusive is set; if it is not set, the check
2677 is for the mailbox already being over quota (i.e. the current message is not
2678 included in the check). */
2680 if (!disable_quota && ob->quota_value > 0)
2684 debug_printf("Exim quota = " OFF_T_FMT " old size = " OFF_T_FMT
2685 " this message = %d (%sincluded)\n",
2686 ob->quota_value, mailbox_size, message_size,
2687 ob->quota_is_inclusive ? "" : "not ");
2688 debug_printf(" file count quota = %d count = %d\n",
2689 ob->quota_filecount_value, mailbox_filecount);
2692 if (mailbox_size + (ob->quota_is_inclusive ? message_size:0) > ob->quota_value)
2693 if (!ob->quota_no_check)
2695 DEBUG(D_transport) debug_printf("mailbox quota exceeded\n");
2697 errno = ERRNO_EXIMQUOTA;
2700 DEBUG(D_transport) debug_printf("mailbox quota exceeded but ignored\n");
2702 if (ob->quota_filecount_value > 0
2703 && mailbox_filecount + (ob->quota_is_inclusive ? 1:0) >
2704 ob->quota_filecount_value)
2705 if (!ob->quota_filecount_no_check)
2707 DEBUG(D_transport) debug_printf("mailbox file count quota exceeded\n");
2709 errno = ERRNO_EXIMQUOTA;
2710 filecount_msg = US" filecount";
2712 else DEBUG(D_transport) if (ob->quota_filecount_no_check)
2713 debug_printf("mailbox file count quota exceeded but ignored\n");
2719 addr->basic_errno = errno;
2720 addr->message = US"Over quota";
2721 addr->transport_return = yield;
2723 debug_printf("appendfile (verify) yields %d with errno=%d more_errno=%d\n",
2724 yield, addr->basic_errno, addr->more_errno);
2729 /* If we are writing in MBX format, what we actually do is to write the message
2730 to a temporary file, and then copy it to the real file once we know its size.
2731 This is the most straightforward way of getting the correct length in the
2732 separator line. So, what we do here is to save the real file descriptor, and
2733 replace it with one for a temporary file. The temporary file gets unlinked once
2734 opened, so that it goes away on closure. */
2737 if (yield == OK && ob->mbx_format)
2739 if (!(temp_file = tmpfile()))
2741 addr->basic_errno = errno;
2742 addr->message = US"while setting up temporary file";
2747 fd = fileno(temp_file);
2748 DEBUG(D_transport) debug_printf("writing to temporary file\n");
2750 #endif /* SUPPORT_MBX */
2752 /* Zero the count of bytes written. It is incremented by the transport_xxx()
2755 transport_count = 0;
2756 transport_newlines = 0;
2758 /* Write any configured prefix text first */
2760 if (yield == OK && ob->message_prefix && *ob->message_prefix)
2762 uschar *prefix = expand_string(ob->message_prefix);
2765 errno = ERRNO_EXPANDFAIL;
2766 addr->transport_return = PANIC;
2767 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
2768 "transport) failed", ob->message_prefix, tblock->name);
2771 else if (!transport_write_string(fd, "%s", prefix)) yield = DEFER;
2774 /* If the use_bsmtp option is on, we need to write SMTP prefix information. The
2775 various different values for batching are handled outside; if there is more
2776 than one address available here, all must be included. If any address is a
2777 file, use its parent in the RCPT TO. */
2779 if (yield == OK && ob->use_bsmtp)
2781 transport_count = 0;
2782 transport_newlines = 0;
2783 if (ob->use_crlf) cr = US"\r";
2784 if (!transport_write_string(fd, "MAIL FROM:<%s>%s\n", return_path, cr))
2788 transport_newlines++;
2789 for (address_item * a = addr; a; a = a->next)
2791 address_item * b = testflag(a, af_pfr) ? a->parent : a;
2792 if (!transport_write_string(fd, "RCPT TO:<%s>%s\n",
2793 transport_rcpt_address(b, tblock->rcpt_include_affixes), cr))
2794 { yield = DEFER; break; }
2795 transport_newlines++;
2797 if (yield == OK && !transport_write_string(fd, "DATA%s\n", cr))
2800 transport_newlines++;
2804 /* Now the message itself. The options for transport_write_message were set up
2805 at initialization time. */
2809 transport_ctx tctx = {
2813 .check_string = ob->check_string,
2814 .escape_string = ob->escape_string,
2815 .options = ob->options | topt_not_socket
2817 if (!transport_write_message(&tctx, 0))
2821 /* Now a configured suffix. */
2823 if (yield == OK && ob->message_suffix && *ob->message_suffix)
2825 uschar *suffix = expand_string(ob->message_suffix);
2828 errno = ERRNO_EXPANDFAIL;
2829 addr->transport_return = PANIC;
2830 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
2831 "transport) failed", ob->message_suffix, tblock->name);
2834 else if (!transport_write_string(fd, "%s", suffix)) yield = DEFER;
2837 /* If batch smtp, write the terminating dot. */
2839 if (yield == OK && ob->use_bsmtp)
2840 if (!transport_write_string(fd, ".%s\n", cr)) yield = DEFER;
2841 else transport_newlines++;
2843 /* If MBX format is being used, all that writing was to the temporary file.
2844 However, if there was an earlier failure (Exim quota exceeded, for example),
2845 the temporary file won't have got opened - and no writing will have been done.
2846 If writing was OK, we restore the fd, and call a function that copies the
2847 message in MBX format into the real file. Otherwise use the temporary name in
2851 if (temp_file && ob->mbx_format)
2858 transport_count = 0; /* Reset transport count for actual write */
2859 /* No need to reset transport_newlines as we're just using a block copy
2860 * routine so the number won't be affected */
2861 yield = copy_mbx_message(fd, fileno(temp_file), saved_size);
2863 else if (errno >= 0) dataname = US"temporary file";
2865 /* Preserve errno while closing the temporary file. */
2867 mbx_save_errno = errno;
2868 (void)fclose(temp_file);
2869 errno = mbx_save_errno;
2871 #endif /* SUPPORT_MBX */
2873 /* Force out the remaining data to check for any errors; some OS don't allow
2874 fsync() to be called for a FIFO. */
2876 if (yield == OK && !isfifo && EXIMfsync(fd) < 0) yield = DEFER;
2878 /* Update message_size and message_linecount to the accurate count of bytes
2879 written, including added headers. Note; we subtract 1 from message_linecount as
2880 this variable doesn't count the new line between the header and the body of the
2883 message_size = transport_count;
2884 message_linecount = transport_newlines - 1;
2886 /* If using a maildir++ quota file, add this message's size to it, and
2887 close the file descriptor, except when the quota has been disabled because we
2888 are delivering into an uncounted folder. */
2890 #ifdef SUPPORT_MAILDIR
2893 if (yield == OK && maildirsize_fd >= 0)
2894 maildir_record_length(maildirsize_fd, message_size);
2895 maildir_save_errno = errno; /* Preserve errno while closing the file */
2896 if (maildirsize_fd >= 0)
2897 (void)close(maildirsize_fd);
2898 errno = maildir_save_errno;
2900 #endif /* SUPPORT_MAILDIR */
2902 /* If there is a quota warning threshold and we are have crossed it with this
2903 message, set the SPECIAL_WARN flag in the address, to cause a warning message
2906 if (!disable_quota && THRESHOLD_CHECK)
2908 off_t threshold = ob->quota_warn_threshold_value;
2909 if (ob->quota_warn_threshold_is_percent)
2910 threshold = (off_t)(((double)ob->quota_value * threshold) / 100);
2912 debug_printf("quota = " OFF_T_FMT
2913 " threshold = " OFF_T_FMT
2914 " old size = " OFF_T_FMT
2915 " message size = %d\n",
2916 ob->quota_value, threshold, mailbox_size,
2918 if (mailbox_size <= threshold && mailbox_size + message_size > threshold)
2919 addr->special_action = SPECIAL_WARN;
2921 /******* You might think that the test ought to be this:
2923 * if (ob->quota_value > 0 && threshold > 0 && mailbox_size > 0 &&
2924 * mailbox_size <= threshold && mailbox_size + message_size > threshold)
2926 * (indeed, I was sent a patch with that in). However, it is possible to
2927 * have a warning threshold without actually imposing a quota, and I have
2928 * therefore kept Exim backwards compatible.
2933 /* Handle error while writing the file. Control should come here directly after
2934 the error, with the reason in errno. In the case of expansion failure in prefix
2935 or suffix, it will be ERRNO_EXPANDFAIL. */
2939 addr->special_action = SPECIAL_NONE; /* Cancel any quota warning */
2941 /* Save the error number. If positive, it will ultimately cause a strerror()
2942 call to generate some text. */
2944 addr->basic_errno = errno;
2946 /* For system or Exim quota excession, or disk full, set more_errno to the
2947 time since the file was last read. If delivery was into a directory, the
2948 time since last read logic is not relevant, in general. However, for maildir
2949 deliveries we can approximate it by looking at the last modified time of the
2950 "new" subdirectory. Since Exim won't be adding new messages, a change to the
2951 "new" subdirectory implies that an MUA has moved a message from there to the
2954 if (errno == errno_quota || errno == ERRNO_EXIMQUOTA || errno == ENOSPC)
2956 addr->more_errno = 0;
2957 if (!isdirectory) addr->more_errno = (int)(time(NULL) - times.actime);
2959 #ifdef SUPPORT_MAILDIR
2960 else if (mbformat == mbf_maildir)
2962 struct stat statbuf;
2963 if (Ustat("new", &statbuf) < 0)
2965 DEBUG(D_transport) debug_printf("maildir quota exceeded: "
2966 "stat error %d for \"new\": %s\n", errno, strerror(errno));
2968 else /* Want a repeatable time when in test harness */
2969 addr->more_errno = f.running_in_test_harness ? 10 :
2970 (int)time(NULL) - statbuf.st_mtime;
2973 debug_printf("maildir: time since \"new\" directory modified = %s\n",
2974 readconf_printtime(addr->more_errno));
2976 #endif /* SUPPORT_MAILDIR */
2979 /* Handle system quota excession. Add an explanatory phrase for the error
2980 message, since some systems don't have special quota-excession errors,
2981 and on those that do, "quota" doesn't always mean anything to the user. */
2983 if (errno == errno_quota)
2986 addr->message = string_sprintf("mailbox is full "
2987 "(quota exceeded while writing to file %s)", filename);
2989 addr->message = US"mailbox is full";
2991 addr->user_message = US"mailbox is full";
2992 DEBUG(D_transport) debug_printf("System quota exceeded for %s%s%s\n",
2994 isdirectory ? US"" : US": time since file read = ",
2995 isdirectory ? US"" : readconf_printtime(addr->more_errno));
2998 /* Handle Exim's own quota-imposition */
3000 else if (errno == ERRNO_EXIMQUOTA)
3002 addr->message = string_sprintf("mailbox is full "
3003 "(MTA-imposed%s quota exceeded while writing to %s)", filecount_msg,
3005 addr->user_message = US"mailbox is full";
3006 DEBUG(D_transport) debug_printf("Exim%s quota exceeded for %s%s%s\n",
3007 filecount_msg, dataname,
3008 isdirectory ? US"" : US": time since file read = ",
3009 isdirectory ? US"" : readconf_printtime(addr->more_errno));
3012 /* Handle a process failure while writing via a filter; the return
3013 from child_close() is in more_errno. */
3015 else if (errno == ERRNO_FILTER_FAIL)
3018 addr->message = string_sprintf("transport filter process failed (%d) "
3019 "while writing to %s%s", addr->more_errno, dataname,
3020 (addr->more_errno == EX_EXECFAILED) ? ": unable to execute command" : "");
3023 /* Handle failure to expand header changes */
3025 else if (errno == ERRNO_CHHEADER_FAIL)
3029 string_sprintf("failed to expand headers_add or headers_remove while "
3030 "writing to %s: %s", dataname, expand_string_message);
3033 /* Handle failure to complete writing of a data block */
3035 else if (errno == ERRNO_WRITEINCOMPLETE)
3036 addr->message = string_sprintf("failed to write data block while "
3037 "writing to %s", dataname);
3039 /* Handle length mismatch on MBX copying */
3042 else if (errno == ERRNO_MBXLENGTH)
3043 addr->message = string_sprintf("length mismatch while copying MBX "
3044 "temporary file to %s", dataname);
3045 #endif /* SUPPORT_MBX */
3047 /* For other errors, a general-purpose explanation, if the message is
3050 else if (addr->message == NULL)
3051 addr->message = string_sprintf("error while writing to %s", dataname);
3053 /* For a file, reset the file size to what it was before we started, leaving
3054 the last modification time unchanged, so it will get reset also. All systems
3055 investigated so far have ftruncate(), whereas not all have the F_FREESP
3056 fcntl() call (BSDI & FreeBSD do not). */
3058 if (!isdirectory && ftruncate(fd, saved_size))
3059 DEBUG(D_transport) debug_printf("Error resetting file size\n");
3062 /* Handle successful writing - we want the modification time to be now for
3063 appended files. Remove the default backstop error number. For a directory, now
3064 is the time to rename the file with a unique name. As soon as such a name
3065 appears it may get used by another process, so we close the file first and
3066 check that all is well. */
3070 times.modtime = time(NULL);
3071 addr->basic_errno = 0;
3073 /* Handle the case of writing to a new file in a directory. This applies
3074 to all single-file formats - maildir, mailstore, and "smail format". */
3078 if (fstat(fd, &statbuf) < 0)
3080 addr->basic_errno = errno;
3081 addr->message = string_sprintf("while fstatting opened message file %s",
3086 else if (close(fd) < 0)
3088 addr->basic_errno = errno;
3089 addr->message = string_sprintf("close() error for %s",
3090 (ob->mailstore_format) ? dataname : filename);
3094 /* File is successfully written and closed. Arrange to rename it. For the
3095 different kinds of single-file delivery, some games can be played with the
3096 name. The message size is by this time set to the accurate value so that
3097 its value can be used in expansions. */
3101 uschar *renamename = newname;
3104 DEBUG(D_transport) debug_printf("renaming temporary file\n");
3106 /* If there is no rename name set, we are in a non-maildir, non-mailstore
3107 situation. The name is built by expanding the directory_file option, and
3108 we make the inode number available for use in this. The expansion was
3109 checked for syntactic validity above, before we wrote the file.
3111 We have to be careful here, in case the file name exists. (In the other
3112 cases, the names used are constructed to be unique.) The rename()
3113 function just replaces an existing file - we don't want that! So instead
3114 of calling rename(), we must use link() and unlink().
3116 In this case, if the link fails because of an existing file, we wait
3117 for one second and try the expansion again, to see if it produces a
3118 different value. Do this up to 5 times unless the name stops changing.
3119 This makes it possible to build values that are based on the time, and
3120 still cope with races from multiple simultaneous deliveries. */
3125 uschar *old_renameleaf = US"";
3127 for (int i = 0; ; sleep(1), i++)
3129 deliver_inode = statbuf.st_ino;
3130 renameleaf = expand_string(ob->dirfilename);
3135 addr->transport_return = PANIC;
3136 addr->message = string_sprintf("Expansion of \"%s\" "
3137 "(directory_file for %s transport) failed: %s",
3138 ob->dirfilename, tblock->name, expand_string_message);
3142 renamename = string_sprintf("%s/%s", path, renameleaf);
3143 if (Ulink(filename, renamename) < 0)
3145 DEBUG(D_transport) debug_printf("link failed: %s\n",
3147 if (errno != EEXIST || i >= 4 ||
3148 Ustrcmp(renameleaf, old_renameleaf) == 0)
3150 addr->basic_errno = errno;
3151 addr->message = string_sprintf("while renaming %s as %s",
3152 filename, renamename);
3156 old_renameleaf = renameleaf;
3157 DEBUG(D_transport) debug_printf("%s exists - trying again\n",
3166 } /* re-expand loop */
3167 } /* not mailstore or maildir */
3169 /* For maildir and mailstore formats, the new name was created earlier,
3170 except that for maildir, there is the possibility of adding a "tag" on
3171 the end of the name by expanding the value of nametag. This usually
3172 includes a reference to the message size. The expansion of nametag was
3173 checked above, before the file was opened. It either succeeded, or
3174 provoked a soft failure. So any failure here can be treated as soft.
3175 Ignore non-printing characters and / and put a colon at the start if the
3176 first character is alphanumeric. */
3182 uschar *iptr = expand_string(nametag);
3185 uschar *etag = store_get(Ustrlen(iptr) + 2, iptr);
3186 uschar *optr = etag;
3187 for ( ; *iptr; iptr++)
3188 if (mac_isgraph(*iptr) && *iptr != '/')
3190 if (optr == etag && isalnum(*iptr)) *optr++ = ':';
3194 renamename = string_sprintf("%s%s", newname, etag);
3198 /* Do the rename. If the name is too long and a tag exists, try again
3201 if (Urename(filename, renamename) < 0 &&
3202 (nametag == NULL || errno != ENAMETOOLONG ||
3203 (renamename = newname, Urename(filename, renamename) < 0)))
3205 addr->basic_errno = errno;
3206 addr->message = string_sprintf("while renaming %s as %s",
3207 filename, renamename);
3211 /* Rename succeeded */
3215 DEBUG(D_transport) debug_printf("renamed %s as %s\n", filename,
3217 filename = dataname = NULL; /* Prevents attempt to unlink at end */
3219 } /* maildir or mailstore */
3220 } /* successful write + close */
3222 } /* write success */
3225 /* For a file, restore the last access time (atime), and set the modification
3226 time as required - changed if write succeeded, unchanged if not. */
3228 if (!isdirectory) utime(CS filename, ×);
3230 /* Notify comsat if configured to do so. It only makes sense if the configured
3231 file is the one that the comsat daemon knows about. */
3233 if (ob->notify_comsat && yield == OK && deliver_localpart)
3234 notify_comsat(deliver_localpart, saved_size);
3236 /* Pass back the final return code in the address structure */
3239 debug_printf("appendfile yields %d with errno=%d more_errno=%d\n",
3240 yield, addr->basic_errno, addr->more_errno);
3242 addr->transport_return = yield;
3244 /* Close the file, which will release the fcntl lock. For a directory write it
3245 is closed above, except in cases of error which goto RETURN, when we also need
3246 to remove the original file(s). For MBX locking, if all has gone well, before
3247 closing the file, see if we can get an exclusive lock on it, in which case we
3248 can unlink the /tmp lock file before closing it. This is always a non-blocking
3249 lock; there's no need to wait if we can't get it. If everything has gone right
3250 but close fails, defer the message. Then unlink the lock file, if present. This
3251 point in the code is jumped to from a number of places when errors are
3252 detected, in order to get the file closed and the lock file tidied away. */
3257 if (mbx_lockfd >= 0)
3259 if (yield == OK && apply_lock(fd, F_WRLCK, ob->use_fcntl, 0,
3260 ob->use_flock, 0) >= 0)
3263 debug_printf("unlinking MBX lock file %s\n", mbx_lockname);
3264 Uunlink(mbx_lockname);
3266 (void)close(mbx_lockfd);
3268 #endif /* SUPPORT_MBX */
3270 if (fd >= 0 && close(fd) < 0 && yield == OK)
3272 addr->basic_errno = errno;
3273 addr->message = string_sprintf("while closing %s", filename);
3274 addr->transport_return = DEFER;
3277 if (hd >= 0) Uunlink(lockname);
3279 /* We get here with isdirectory and filename set only in error situations. */
3281 if (isdirectory && filename)
3284 if (dataname != filename) Uunlink(dataname);
3287 /* If wait_for_tick is TRUE, we have done a delivery where the uniqueness of a
3288 file name relies on time + pid. We must not allow the process to finish until
3289 the clock has move on by at least one microsecond. Usually we expect this
3290 already to be the case, but machines keep getting faster... */
3292 if (wait_for_tick) exim_wait_tick(&msg_tv, 1);
3294 /* A return of FALSE means that if there was an error, a common error was
3295 put in the first address of a batch. */
3300 addr->message = string_sprintf("Tainted '%s' (file or directory "
3301 "name for %s transport) not permitted", path, tblock->name);
3303 addr->transport_return = PANIC;
3307 #endif /*!MACRO_PREDEF*/
3308 /* End of transport/appendfile.c */