1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2020 */
6 /* Copyright (c) The Exim maintainers 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
11 #include "appendfile.h"
13 #ifdef SUPPORT_MAILDIR
14 #include "tf_maildir.h"
18 /* Options specific to the appendfile transport. They must be in alphabetic
19 order (note that "_" comes before the lower case letters). Some of them are
20 stored in the publicly visible instance block - these are flagged with the
22 #define LOFF(field) OPT_OFF(appendfile_transport_options_block, field)
24 optionlist appendfile_transport_options[] = {
25 #ifdef SUPPORT_MAILDIR
26 { "*expand_maildir_use_size_file", opt_stringptr, LOFF(expand_maildir_use_size_file) },
28 { "*set_use_fcntl_lock",opt_bool | opt_hidden, LOFF(set_use_fcntl) },
29 { "*set_use_flock_lock",opt_bool | opt_hidden, LOFF(set_use_flock) },
30 { "*set_use_lockfile", opt_bool | opt_hidden, LOFF(set_use_lockfile) },
32 { "*set_use_mbx_lock", opt_bool | opt_hidden, LOFF(set_use_mbx_lock) },
34 { "allow_fifo", opt_bool, LOFF(allow_fifo) },
35 { "allow_symlink", opt_bool, LOFF(allow_symlink) },
36 { "batch_id", opt_stringptr | opt_public, OPT_OFF(transport_instance, batch_id) },
37 { "batch_max", opt_int | opt_public, OPT_OFF(transport_instance, batch_max) },
38 { "check_group", opt_bool, LOFF(check_group) },
39 { "check_owner", opt_bool, LOFF(check_owner) },
40 { "check_string", opt_stringptr, LOFF(check_string) },
41 { "create_directory", opt_bool, LOFF(create_directory) },
42 { "create_file", opt_stringptr, LOFF(create_file_string) },
43 { "directory", opt_stringptr, LOFF(dirname) },
44 { "directory_file", opt_stringptr, LOFF(dirfilename) },
45 { "directory_mode", opt_octint, LOFF(dirmode) },
46 { "escape_string", opt_stringptr, LOFF(escape_string) },
47 { "file", opt_stringptr, LOFF(filename) },
48 { "file_format", opt_stringptr, LOFF(file_format) },
49 { "file_must_exist", opt_bool, LOFF(file_must_exist) },
50 { "lock_fcntl_timeout", opt_time, LOFF(lock_fcntl_timeout) },
51 { "lock_flock_timeout", opt_time, LOFF(lock_flock_timeout) },
52 { "lock_interval", opt_time, LOFF(lock_interval) },
53 { "lock_retries", opt_int, LOFF(lock_retries) },
54 { "lockfile_mode", opt_octint, LOFF(lockfile_mode) },
55 { "lockfile_timeout", opt_time, LOFF(lockfile_timeout) },
56 { "mailbox_filecount", opt_stringptr, LOFF(mailbox_filecount_string) },
57 { "mailbox_size", opt_stringptr, LOFF(mailbox_size_string) },
58 #ifdef SUPPORT_MAILDIR
59 { "maildir_format", opt_bool, LOFF(maildir_format ) } ,
60 { "maildir_quota_directory_regex", opt_stringptr, LOFF(maildir_dir_regex) },
61 { "maildir_retries", opt_int, LOFF(maildir_retries) },
62 { "maildir_tag", opt_stringptr, LOFF(maildir_tag) },
63 { "maildir_use_size_file", opt_expand_bool, LOFF(maildir_use_size_file ) } ,
64 { "maildirfolder_create_regex", opt_stringptr, LOFF(maildirfolder_create_regex ) },
65 #endif /* SUPPORT_MAILDIR */
66 #ifdef SUPPORT_MAILSTORE
67 { "mailstore_format", opt_bool, LOFF(mailstore_format ) },
68 { "mailstore_prefix", opt_stringptr, LOFF(mailstore_prefix ) },
69 { "mailstore_suffix", opt_stringptr, LOFF(mailstore_suffix ) },
70 #endif /* SUPPORT_MAILSTORE */
72 { "mbx_format", opt_bool, LOFF(mbx_format ) } ,
73 #endif /* SUPPORT_MBX */
74 { "message_prefix", opt_stringptr, LOFF(message_prefix) },
75 { "message_suffix", opt_stringptr, LOFF(message_suffix) },
76 { "mode", opt_octint, LOFF(mode) },
77 { "mode_fail_narrower",opt_bool, LOFF(mode_fail_narrower) },
78 { "notify_comsat", opt_bool, LOFF(notify_comsat) },
79 { "quota", opt_stringptr, LOFF(quota) },
80 { "quota_directory", opt_stringptr, LOFF(quota_directory) },
81 { "quota_filecount", opt_stringptr, LOFF(quota_filecount) },
82 { "quota_is_inclusive", opt_bool, LOFF(quota_is_inclusive) },
83 { "quota_size_regex", opt_stringptr, LOFF(quota_size_regex) },
84 { "quota_warn_message", opt_stringptr | opt_public, OPT_OFF(transport_instance, warn_message) },
85 { "quota_warn_threshold", opt_stringptr, LOFF(quota_warn_threshold) },
86 { "use_bsmtp", opt_bool, LOFF(use_bsmtp) },
87 { "use_crlf", opt_bool, LOFF(use_crlf) },
88 { "use_fcntl_lock", opt_bool_set, LOFF(use_fcntl) },
89 { "use_flock_lock", opt_bool_set, LOFF(use_flock) },
90 { "use_lockfile", opt_bool_set, LOFF(use_lockfile) },
92 { "use_mbx_lock", opt_bool_set, LOFF(use_mbx_lock) },
93 #endif /* SUPPORT_MBX */
96 /* Size of the options list. An extern variable has to be used so that its
97 address can appear in the tables drtables.c. */
99 int appendfile_transport_options_count =
100 sizeof(appendfile_transport_options)/sizeof(optionlist);
106 appendfile_transport_options_block appendfile_transport_option_defaults = {0};
107 void appendfile_transport_init(transport_instance *tblock) {}
108 BOOL appendfile_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;}
110 #else /*!MACRO_PREDEF*/
112 /* Default private options block for the appendfile transport. */
114 appendfile_transport_options_block appendfile_transport_option_defaults = {
115 /* all non-mentioned members zero/null/false */
116 .dirfilename = US"q${base62:$tod_epoch}-$inode",
117 .create_file_string = US"anywhere",
118 .maildir_dir_regex = US"^(?:cur|new|\\..*)$",
119 .mailbox_size_value = -1,
120 .mailbox_filecount_value = -1,
121 .mode = APPENDFILE_MODE,
122 .dirmode = APPENDFILE_DIRECTORY_MODE,
123 .lockfile_mode = APPENDFILE_LOCKFILE_MODE,
124 .lockfile_timeout = 30*60,
127 .maildir_retries = 10,
128 .create_file = create_anywhere,
130 .create_directory = TRUE,
131 .notify_comsat = FALSE,
132 .use_lockfile = TRUE,
134 .mode_fail_narrower = TRUE,
135 .quota_is_inclusive = TRUE,
139 /* Encodings for mailbox formats, and their names. MBX format is actually
140 supported only if SUPPORT_MBX is set. */
142 enum { mbf_unix, mbf_mbx, mbf_smail, mbf_maildir, mbf_mailstore };
144 static const char *mailbox_formats[] = {
145 "unix", "mbx", "smail", "maildir", "mailstore" };
148 /* Check warn threshold only if quota size set or not a percentage threshold
149 percentage check should only be done if quota > 0 */
151 #define THRESHOLD_CHECK (ob->quota_warn_threshold_value > 0 && \
152 (!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 \"file_create\" 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(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 while ((s = string_nextinlist(&format,&sep,big_buffer,big_buffer_size)))
602 int slen = Ustrlen(s);
603 BOOL match = len >= slen && Ustrncmp(data, s, slen) == 0;
604 uschar *tp = string_nextinlist(&format, &sep, big_buffer, big_buffer_size);
608 for (transport_instance * tt = transports; tt; tt = tt->next)
609 if (Ustrcmp(tp, tt->name) == 0)
612 debug_printf("file format -> %s transport\n", tt->name);
615 addr->basic_errno = ERRNO_BADTRANSPORT;
616 addr->message = string_sprintf("%s transport (for %.*s format) not found",
622 /* Failed to find a match */
624 addr->basic_errno = ERRNO_FORMATUNKNOWN;
625 addr->message = US"mailbox file format unrecognized";
632 /*************************************************
633 * Check directory's files for quota *
634 *************************************************/
636 /* This function is called if quota is set for one of the delivery modes that
637 delivers into a specific directory. It scans the directory and stats all the
638 files in order to get a total size and count. This is an expensive thing to do,
639 but some people are prepared to bear the cost. Alternatively, if size_regex is
640 set, it is used as a regex to try to extract the size from the file name, a
641 strategy that some people use on maildir files on systems where the users have
644 The function is global, because it is also called from tf_maildir.c for maildir
645 folders (which should contain only regular files).
647 Note: Any problems can be written to debugging output, but cannot be written to
648 the log, because we are running as an unprivileged user here.
651 dirname the name of the directory
652 countptr where to add the file count (because this function recurses)
653 regex a compiled regex to get the size from a name
655 Returns: the sum of the sizes of the stattable files
656 zero if the directory cannot be opened
660 check_dir_size(const uschar * dirname, int *countptr, const pcre *regex)
664 int count = *countptr;
666 if (!(dir = exim_opendir(dirname))) return 0;
668 for (struct dirent *ent; ent = readdir(dir); )
670 uschar * path, * name = US ent->d_name;
673 if (Ustrcmp(name, ".") == 0 || Ustrcmp(name, "..") == 0) continue;
677 /* If there's a regex, try to find the size using it */
682 if (pcre_exec(regex, NULL, CS name, Ustrlen(name), 0, 0, ovector,6) >= 2)
685 off_t size = (off_t)Ustrtod(name + ovector[2], &endptr);
686 if (endptr == name + ovector[3])
690 debug_printf("check_dir_size: size from %s is " OFF_T_FMT "\n", name,
696 debug_printf("check_dir_size: regex did not match %s\n", name);
699 /* No regex or no match for the regex, or captured non-digits */
701 path = string_sprintf("%s/%s", dirname, name);
703 if (Ustat(path, &statbuf) < 0)
706 debug_printf("check_dir_size: stat error %d for %s: %s\n", errno, path,
710 if ((statbuf.st_mode & S_IFMT) == S_IFREG)
711 sum += statbuf.st_size / statbuf.st_nlink;
712 else if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
713 sum += check_dir_size(path, &count, regex);
718 debug_printf("check_dir_size: dir=%s sum=" OFF_T_FMT " count=%d\n", dirname,
728 /*************************************************
729 * Apply a lock to a file descriptor *
730 *************************************************/
732 /* This function applies a lock to a file descriptor, using a blocking or
733 non-blocking lock, depending on the timeout value. It can apply either or
734 both of a fcntl() and a flock() lock. However, not all OS support flock();
735 for those that don't, the use_flock option cannot be set.
738 fd the file descriptor
739 fcntltype type of lock, specified as F_WRLCK or F_RDLCK (that is, in
740 fcntl() format); the flock() type is deduced if needed
741 dofcntl do fcntl() locking
742 fcntltime non-zero to use blocking fcntl()
743 doflock do flock() locking
744 flocktime non-zero to use blocking flock()
746 Returns: yield of the fcntl() or flock() call, with errno preserved;
747 sigalrm_seen set if there has been a timeout
751 apply_lock(int fd, int fcntltype, BOOL dofcntl, int fcntltime, BOOL doflock,
756 struct flock lock_data;
757 lock_data.l_type = fcntltype;
758 lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
760 sigalrm_seen = FALSE;
767 yield = fcntl(fd, F_SETLKW, &lock_data);
772 else yield = fcntl(fd, F_SETLK, &lock_data);
776 if (doflock && (yield >= 0))
778 int flocktype = (fcntltype == F_WRLCK) ? LOCK_EX : LOCK_SH;
782 yield = flock(fd, flocktype);
787 else yield = flock(fd, flocktype | LOCK_NB);
789 #endif /* NO_FLOCK */
798 /*************************************************
799 * Copy message into MBX mailbox *
800 *************************************************/
802 /* This function is called when a message intended for a MBX mailbox has been
803 written to a temporary file. We can now get the size of the message and then
804 copy it in MBX format to the mailbox.
807 to_fd fd to write to (the real mailbox)
808 from_fd fd to read from (the temporary file)
809 saved_size current size of mailbox
811 Returns: OK if all went well, DEFER otherwise, with errno preserved
812 the number of bytes written are added to transport_count
813 by virtue of calling transport_write_block()
816 /* Values taken from c-client */
818 #define MBX_HDRSIZE 2048
819 #define MBX_NUSERFLAGS 30
822 copy_mbx_message(int to_fd, int from_fd, off_t saved_size)
827 transport_ctx tctx = { .u={.fd = to_fd}, .options = topt_not_socket };
829 /* If the current mailbox size is zero, write a header block */
834 memset (deliver_out_buffer, '\0', MBX_HDRSIZE);
835 sprintf(CS(s = deliver_out_buffer), "*mbx*\015\012%08lx00000000\015\012",
836 (long int)time(NULL));
837 for (int i = 0; i < MBX_NUSERFLAGS; i++)
838 sprintf (CS(s += Ustrlen(s)), "\015\012");
839 if (!transport_write_block (&tctx, deliver_out_buffer, MBX_HDRSIZE, FALSE))
843 DEBUG(D_transport) debug_printf("copying MBX message from temporary file\n");
845 /* Now construct the message's header from the time and the RFC822 file
846 size, including CRLFs, which is the size of the input (temporary) file. */
848 if (fstat(from_fd, &statbuf) < 0) return DEFER;
849 size = statbuf.st_size;
851 sprintf (CS deliver_out_buffer, "%s," OFF_T_FMT ";%08lx%04x-%08x\015\012",
852 tod_stamp(tod_mbx), size, 0L, 0, 0);
853 used = Ustrlen(deliver_out_buffer);
855 /* Rewind the temporary file, and copy it over in chunks. */
857 if (lseek(from_fd, 0 , SEEK_SET) < 0) return DEFER;
861 int len = read(from_fd, deliver_out_buffer + used,
862 DELIVER_OUT_BUFFER_SIZE - used);
865 if (len == 0) errno = ERRNO_MBXLENGTH;
868 if (!transport_write_block(&tctx, deliver_out_buffer, used + len, FALSE))
876 #endif /* SUPPORT_MBX */
880 /*************************************************
881 * Check creation is permitted *
882 *************************************************/
884 /* This function checks whether a given file name is permitted to be created,
885 as controlled by the create_file option. If no home directory is set, however,
886 we can't do any tests.
889 filename the file name
890 create_file the ob->create_file option
892 Returns: TRUE if creation is permitted
896 check_creation(uschar *filename, int create_file)
900 if (deliver_home && create_file != create_anywhere)
902 int len = Ustrlen(deliver_home);
903 uschar *file = filename;
905 while (file[0] == '/' && file[1] == '/') file++;
906 if ( Ustrncmp(file, deliver_home, len) != 0
908 || Ustrchr(file+len+2, '/') != NULL
909 && ( create_file != create_belowhome
910 || Ustrstr(file+len, "/../") != NULL
914 /* If yield is TRUE, the file name starts with the home directory, and does
915 not contain any instances of "/../" in the "belowhome" case. However, it may
916 still contain symbolic links. We can check for this by making use of
917 realpath(), which most Unixes seem to have (but make it possible to cut this
918 out). We can't just use realpath() on the whole file name, because we know
919 the file itself doesn't exist, and intermediate directories may also not
920 exist. What we want to know is the real path of the longest existing part of
921 the path. That must match the home directory's beginning, whichever is the
925 if (yield && create_file == create_belowhome)
929 for (uschar * slash = Ustrrchr(file, '/'); /* There is known to be one */
930 !rp && slash > file; /* Stop if reached beginning */
934 rp = US realpath(CS file, CS big_buffer);
935 next = Ustrrchr(file, '/');
939 /* If rp == NULL it means that none of the relevant directories exist.
940 This is not a problem here - it means that no symbolic links can exist,
941 which is all we are worried about. Otherwise, we must compare it
942 against the start of the home directory. However, that may itself
943 contain symbolic links, so we have to "realpath" it as well, if
948 uschar hdbuffer[PATH_MAX+1];
949 uschar *rph = deliver_home;
950 int rlen = Ustrlen(big_buffer);
952 if ((rp = US realpath(CS deliver_home, CS hdbuffer)))
958 if (rlen > len) rlen = len;
959 if (Ustrncmp(rph, big_buffer, rlen) != 0)
962 DEBUG(D_transport) debug_printf("Real path \"%s\" does not match \"%s\"\n",
963 big_buffer, deliver_home);
967 #endif /* NO_REALPATH */
975 /*************************************************
977 *************************************************/
979 /* See local README for general interface details. This transport always
980 returns FALSE, indicating that the status which has been placed in the first
981 address should be copied to any other addresses in a batch.
983 Appendfile delivery is tricky and has led to various security problems in other
984 mailers. The logic used here is therefore laid out in some detail. When this
985 function is called, we are running in a subprocess which has had its gid and
986 uid set to the appropriate values. Therefore, we cannot write directly to the
987 exim logs. Any errors must be handled by setting appropriate return codes.
988 Note that the default setting for addr->transport_return is DEFER, so it need
989 not be set unless some other value is required.
991 The code below calls geteuid() rather than getuid() to get the current uid
992 because in weird configurations not running setuid root there may be a
993 difference. In the standard configuration, where setuid() has been used in the
994 delivery process, there will be no difference between the uid and the euid.
996 (1) If the af_file flag is set, this is a delivery to a file after .forward or
997 alias expansion. Otherwise, there must be a configured file name or
1000 The following items apply in the case when a file name (as opposed to a
1001 directory name) is given, that is, when appending to a single file:
1003 (2f) Expand the file name.
1005 (3f) If the file name is /dev/null, return success (optimization).
1007 (4f) If the file_format options is set, open the file for reading, and check
1008 that the bytes at the start of the file match one of the given strings.
1009 If the check indicates a transport other than the current one should be
1010 used, pass control to that other transport. Otherwise continue. An empty
1011 or non-existent file matches the current transport. The file is closed
1014 (5f) If a lock file is required, create it (see extensive separate comments
1015 below about the algorithm for doing this). It is important to do this
1016 before opening the mailbox if NFS is in use.
1018 (6f) Stat the file, using lstat() rather than stat(), in order to pick up
1019 details of any symbolic link.
1021 (7f) If the file already exists:
1023 Check the owner and group if necessary, and defer if they are wrong.
1025 If it is a symbolic link AND the allow_symlink option is set (NOT the
1026 default), go back to (6f) but this time use stat() instead of lstat().
1028 If it's not a regular file (or FIFO when permitted), defer delivery.
1030 Check permissions. If the required permissions are *less* than the
1031 existing ones, or supplied by the address (often by the user via filter),
1032 chmod() the file. Otherwise, defer.
1034 Save the inode number.
1036 Open with O_RDRW + O_APPEND, thus failing if the file has vanished.
1038 If open fails because the file does not exist, go to (6f); on any other
1041 Check the inode number hasn't changed - I realize this isn't perfect (an
1042 inode can be reused) but it's cheap and will catch some of the races.
1044 Check it's still a regular file (or FIFO if permitted).
1046 Check that the owner and permissions haven't changed.
1048 If file_format is set, check that the file still matches the format for
1049 the current transport. If not, defer delivery.
1051 (8f) If file does not exist initially:
1053 Open with O_WRONLY + O_EXCL + O_CREAT with configured mode, unless we know
1054 this is via a symbolic link (only possible if allow_symlinks is set), in
1055 which case don't use O_EXCL, as it doesn't work.
1057 If open fails because the file already exists, go to (6f). To avoid
1058 looping for ever in a situation where the file is continuously being
1059 created and deleted, all of this happens inside a loop that operates
1060 lock_retries times and includes the fcntl and flock locking. If the
1061 loop completes without the file getting opened, defer and request
1062 freezing, because something really weird is happening.
1064 If open fails for any other reason, defer for subsequent delivery except
1065 when this is a file delivery resulting from an alias or forward expansion
1066 and the error is EPERM or ENOENT or EACCES, in which case FAIL as this is
1067 most likely a user rather than a configuration error.
1069 (9f) We now have the file checked and open for writing. If so configured, lock
1070 it using fcntl, flock, or MBX locking rules. If this fails, close the file
1071 and goto (6f), up to lock_retries times, after sleeping for a while. If it
1072 still fails, give up and defer delivery.
1074 (10f)Save the access time (for subsequent restoration) and the size of the
1075 file, for comsat and for re-setting if delivery fails in the middle -
1076 e.g. for quota exceeded.
1078 The following items apply in the case when a directory name is given:
1080 (2d) Create a new file in the directory using a temporary name, by opening for
1081 writing and with O_CREAT. If maildir format is being used, the file
1082 is created in a temporary subdirectory with a prescribed name. If
1083 mailstore format is being used, the envelope file is first created with a
1084 temporary name, then the data file.
1086 The following items apply in all cases:
1088 (11) We now have the file open for writing, and locked if it was given as a
1089 file name. Write the message and flush the file, unless there is a setting
1090 of the local quota option, in which case we can check for its excession
1091 without doing any writing.
1093 In the case of MBX format mailboxes, the message is first written to a
1094 temporary file, in order to get its correct length. This is then copied to
1095 the real file, preceded by an MBX header.
1097 If there is a quota error on writing, defer the address. Timeout logic
1098 will determine for how long retries are attempted. We restore the mailbox
1099 to its original length if it's a single file. There doesn't seem to be a
1100 uniform error code for quota excession (it even differs between SunOS4
1101 and some versions of SunOS5) so a system-dependent macro called
1102 ERRNO_QUOTA is used for it, and the value gets put into errno_quota at
1105 For any other error (most commonly disk full), do the same.
1107 The following applies after appending to a file:
1109 (12f)Restore the atime; notify_comsat if required; close the file (which
1110 unlocks it if it was locked). Delete the lock file if it exists.
1112 The following applies after writing a unique file in a directory:
1114 (12d)For maildir format, rename the file into the new directory. For mailstore
1115 format, rename the envelope file to its correct name. Otherwise, generate
1116 a unique name from the directory_file option, and rename to that, possibly
1117 trying a few times if the file exists and re-expanding the name gives a
1120 This transport yields FAIL only when a file name is generated by an alias or
1121 forwarding operation and attempting to open it gives EPERM, ENOENT, or EACCES.
1122 All other failures return DEFER (in addr->transport_return). */
1126 appendfile_transport_entry(
1127 transport_instance *tblock, /* data for this instantiation */
1128 address_item *addr) /* address we are working on */
1130 appendfile_transport_options_block *ob =
1131 (appendfile_transport_options_block *)(tblock->options_block);
1132 struct stat statbuf;
1133 uschar *fdname = NULL;
1134 uschar *filename = NULL;
1135 uschar *hitchname = NULL;
1136 uschar *dataname = NULL;
1137 uschar *lockname = NULL;
1138 uschar *newname = NULL;
1139 uschar *nametag = NULL;
1141 uschar *filecount_msg = US"";
1143 struct utimbuf times;
1144 struct timeval msg_tv;
1145 BOOL disable_quota = FALSE;
1146 BOOL isdirectory = FALSE;
1147 BOOL isfifo = FALSE;
1148 BOOL wait_for_tick = FALSE;
1149 uid_t uid = geteuid(); /* See note above */
1150 gid_t gid = getegid();
1152 int mode = (addr->mode > 0) ? addr->mode : ob->mode;
1153 off_t saved_size = -1;
1154 off_t mailbox_size = ob->mailbox_size_value;
1155 int mailbox_filecount = ob->mailbox_filecount_value;
1163 int mbx_lockfd = -1;
1164 uschar mbx_lockname[40];
1165 FILE *temp_file = NULL;
1166 #endif /* SUPPORT_MBX */
1168 #ifdef SUPPORT_MAILDIR
1169 int maildirsize_fd = -1; /* fd for maildirsize file */
1170 int maildir_save_errno;
1174 DEBUG(D_transport) debug_printf("appendfile transport entered\n");
1176 /* An "address_file" or "address_directory" transport is used to deliver to
1177 files specified via .forward or an alias file. Prior to release 4.20, the
1178 "file" and "directory" options were ignored in this case. This has been changed
1179 to allow the redirection data to specify what is in effect a folder, whose
1180 location is determined by the options on the transport.
1182 Compatibility with the case when neither option is set is retained by forcing a
1183 value for the file or directory name. A directory delivery is assumed if the
1184 last character of the path from the router is '/'.
1186 The file path is in the local part of the address, but not in the $local_part
1187 variable (that holds the parent local part). It is, however, in the
1188 $address_file variable. Below, we update the local part in the address if it
1189 changes by expansion, so that the final path ends up in the log. */
1191 if (testflag(addr, af_file) && !ob->filename && !ob->dirname)
1193 fdname = US"$address_file";
1194 if (address_file[Ustrlen(address_file)-1] == '/' ||
1195 ob->maildir_format ||
1196 ob->mailstore_format)
1200 /* Handle (a) an "address file" delivery where "file" or "directory" is
1201 explicitly set and (b) a non-address_file delivery, where one of "file" or
1202 "directory" must be set; initialization ensures that they are not both set. */
1206 if (!(fdname = ob->filename))
1208 fdname = ob->dirname;
1213 addr->message = string_sprintf("Mandatory file or directory option "
1214 "missing from %s transport", tblock->name);
1219 /* Maildir and mailstore require a directory */
1221 if ((ob->maildir_format || ob->mailstore_format) && !isdirectory)
1223 addr->message = string_sprintf("mail%s_format requires \"directory\" "
1224 "to be specified for the %s transport",
1225 ob->maildir_format ? "dir" : "store", tblock->name);
1229 if (!(path = expand_string(fdname)))
1231 addr->message = string_sprintf("Expansion of \"%s\" (file or directory "
1232 "name for %s transport) failed: %s", fdname, tblock->name,
1233 expand_string_message);
1239 addr->message = string_sprintf("appendfile: file or directory name "
1240 "\"%s\" is not absolute", path);
1241 addr->basic_errno = ERRNO_NOTABSOLUTE;
1245 /* For a file delivery, make sure the local part in the address(es) is updated
1246 to the true local part. */
1248 if (testflag(addr, af_file))
1249 for (address_item * addr2 = addr; addr2; addr2 = addr2->next)
1250 addr2->local_part = string_copy(path);
1252 /* The available mailbox formats depend on whether it is a directory or a file
1258 #ifdef SUPPORT_MAILDIR
1259 ob->maildir_format ? mbf_maildir :
1261 #ifdef SUPPORT_MAILSTORE
1262 ob->mailstore_format ? mbf_mailstore :
1270 ob->mbx_format ? mbf_mbx :
1277 debug_printf("appendfile: mode=%o notify_comsat=%d quota=" OFF_T_FMT
1279 " warning=" OFF_T_FMT "%s\n"
1280 " %s=%s format=%s\n message_prefix=%s\n message_suffix=%s\n "
1281 "maildir_use_size_file=%s\n",
1282 mode, ob->notify_comsat, ob->quota_value,
1283 ob->quota_no_check ? " (no_check)" : "",
1284 ob->quota_filecount_no_check ? " (no_check_filecount)" : "",
1285 ob->quota_warn_threshold_value,
1286 ob->quota_warn_threshold_is_percent ? "%" : "",
1287 isdirectory ? "directory" : "file",
1288 path, mailbox_formats[mbformat],
1289 !ob->message_prefix ? US"null" : string_printing(ob->message_prefix),
1290 !ob->message_suffix ? US"null" : string_printing(ob->message_suffix),
1291 ob->maildir_use_size_file ? "yes" : "no");
1293 if (!isdirectory) debug_printf(" locking by %s%s%s%s%s\n",
1294 ob->use_lockfile ? "lockfile " : "",
1295 ob->use_mbx_lock ? "mbx locking (" : "",
1296 ob->use_fcntl ? "fcntl " : "",
1297 ob->use_flock ? "flock" : "",
1298 ob->use_mbx_lock ? ")" : "");
1301 /* If the -N option is set, can't do any more. */
1306 debug_printf("*** delivery by %s transport bypassed by -N option\n",
1308 addr->transport_return = OK;
1312 /* If an absolute path was given for create_file the it overrides deliver_home
1313 (here) and de-taints the filename (below, after check_creation() */
1315 if (*ob->create_file_string == '/')
1316 deliver_home = ob->create_file_string;
1318 /* Handle the case of a file name. If the file name is /dev/null, we can save
1319 ourselves some effort and just give a success return right away. */
1323 BOOL use_lstat = TRUE;
1324 BOOL file_opened = FALSE;
1325 BOOL allow_creation_here = TRUE;
1327 if (Ustrcmp(path, "/dev/null") == 0)
1329 addr->transport_return = OK;
1333 /* Set the name of the file to be opened, and the file to which the data
1334 is written, and find out if we are permitted to create a non-existent file.
1335 If the create_file option is an absolute path and the file was within it,
1336 de-taint. Chaeck for a tainted path. */
1337 /*XXX could we just de-taint on belowhome? */
1339 if ( (allow_creation_here = check_creation(path, ob->create_file))
1340 && ob->create_file == create_belowhome)
1341 if (is_tainted(path))
1343 DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path);
1344 path = string_copy_taint(path, FALSE);
1347 if (is_tainted(path)) goto tainted_ret_panic;
1348 dataname = filename = path;
1350 /* If ob->create_directory is set, attempt to create the directories in
1351 which this mailbox lives, but only if we are permitted to create the file
1352 itself. We know we are dealing with an absolute path, because this was
1355 if (ob->create_directory && allow_creation_here)
1357 uschar *p = Ustrrchr(path, '/');
1359 if (!directory_make(NULL, path, ob->dirmode, FALSE))
1361 addr->basic_errno = errno;
1363 string_sprintf("failed to create directories for %s: %s", path,
1364 exim_errstr(errno));
1365 DEBUG(D_transport) debug_printf("%s transport: %s\n", tblock->name, path);
1371 /* If file_format is set we must check that any existing file matches one of
1372 the configured formats by checking the bytes it starts with. A match then
1373 indicates a specific transport - if it is not this one, pass control to it.
1374 Otherwise carry on here. An empty or non-existent file matches the current
1375 transport. We don't need to distinguish between non-existence and other open
1376 failures because if an existing file fails to open here, it will also fail
1377 again later when O_RDWR is used. */
1379 if (ob->file_format)
1381 int cfd = Uopen(path, O_RDONLY, 0);
1384 transport_instance *tt = check_file_format(cfd, tblock, addr);
1387 /* If another transport is indicated, call it and return; if no transport
1388 was found, just return - the error data will have been set up.*/
1394 set_process_info("delivering %s to %s using %s", message_id,
1395 addr->local_part, tt->name);
1396 debug_print_string(tt->debug_string);
1397 addr->transport = tt;
1398 (tt->info->code)(tt, addr);
1405 /* The locking of mailbox files is worse than the naming of cats, which is
1406 known to be "a difficult matter" (T.S. Eliot) and just as cats must have
1407 three different names, so several different styles of locking are used.
1409 Research in other programs that lock mailboxes shows that there is no
1410 universally standard method. Having mailboxes NFS-mounted on the system that
1411 is delivering mail is not the best thing, but people do run like this,
1412 and so the code must do its best to cope.
1414 Three different locking mechanisms are supported. The initialization function
1415 checks that at least one is configured.
1419 Unless no_use_lockfile is set, we attempt to build a lock file in a way that
1420 will work over NFS. Only after that is done do we actually open the mailbox
1421 and apply locks to it (if configured).
1423 Originally, Exim got the file opened before doing anything about locking.
1424 However, a very occasional problem was observed on Solaris 2 when delivering
1425 over NFS. It is seems that when a file is opened with O_APPEND, the file size
1426 gets remembered at open time. If another process on another host (that's
1427 important) has the file open and locked and writes to it and then releases
1428 the lock while the first process is waiting to get the lock, the first
1429 process may fail to write at the new end point of the file - despite the very
1430 definite statement about O_APPEND in the man page for write(). Experiments
1431 have reproduced this problem, but I do not know any way of forcing a host to
1432 update its attribute cache for an open NFS file. It would be nice if it did
1433 so when a lock was taken out, but this does not seem to happen. Anyway, to
1434 reduce the risk of this problem happening, we now create the lock file
1435 (if configured) *before* opening the mailbox. That will prevent two different
1436 Exims opening the file simultaneously. It may not prevent clashes with MUAs,
1437 however, but Pine at least seems to operate in the same way.
1439 Lockfiles should normally be used when NFS is involved, because of the above
1442 The logic for creating the lock file is:
1444 . The name of the lock file is <mailbox-name>.lock
1446 . First, create a "hitching post" name by adding the primary host name,
1447 current time and pid to the lock file name. This should be unique.
1449 . Create the hitching post file using WRONLY + CREAT + EXCL.
1451 . If that fails EACCES, we assume it means that the user is unable to create
1452 files in the mail spool directory. Some installations might operate in this
1453 manner, so there is a configuration option to allow this state not to be an
1454 error - we proceed to lock using fcntl only, after the file is open.
1456 . Otherwise, an error causes a deferment of the address.
1458 . Hard link the hitching post to the lock file name.
1460 . If the link succeeds, we have successfully created the lock file. Simply
1461 close and unlink the hitching post file.
1463 . If the link does not succeed, proceed as follows:
1465 o Fstat the hitching post file, and then close and unlink it.
1467 o Now examine the stat data. If the number of links to the file is exactly
1468 2, the linking succeeded but for some reason, e.g. an NFS server crash,
1469 the return never made it back, so the link() function gave a failure
1472 . This method allows for the lock file to be created by some other process
1473 right up to the moment of the attempt to hard link it, and is also robust
1474 against NFS server crash-reboots, which would probably result in timeouts
1475 in the middle of link().
1477 . System crashes may cause lock files to get left lying around, and some means
1478 of flushing them is required. The approach of writing a pid (used by smail
1479 and by elm) into the file isn't useful when NFS may be in use. Pine uses a
1480 timeout, which seems a better approach. Since any program that writes to a
1481 mailbox using a lock file should complete its task very quickly, Pine
1482 removes lock files that are older than 5 minutes. We allow the value to be
1483 configurable on the transport.
1487 If use_fcntl_lock is set, then Exim gets an exclusive fcntl() lock on the
1488 mailbox once it is open. This is done by default with a non-blocking lock.
1489 Failures to lock cause retries after a sleep, but only for a certain number
1490 of tries. A blocking lock is deliberately not used so that we don't hold the
1491 mailbox open. This minimizes the possibility of the NFS problem described
1492 under LOCK FILES above, if for some reason NFS deliveries are happening
1493 without lock files. However, the use of a non-blocking lock and sleep, though
1494 the safest approach, does not give the best performance on very busy systems.
1495 A blocking lock plus timeout does better. Therefore Exim has an option to
1496 allow it to work this way. If lock_fcntl_timeout is set greater than zero, it
1497 enables the use of blocking fcntl() calls.
1501 If use_flock_lock is set, then Exim gets an exclusive flock() lock in the
1502 same manner as for fcntl locking above. No-blocking/timeout is also set as
1503 above in lock_flock_timeout. Not all operating systems provide or support
1504 flock(). For those that don't (as determined by the definition of LOCK_SH in
1505 /usr/include/sys/file.h), use_flock_lock may not be set. For some OS, flock()
1506 is implemented (not precisely) on top of fcntl(), which means there's no
1507 point in actually using it.
1511 If use_mbx_lock is set (this is supported only if SUPPORT_MBX is defined)
1512 then the rules used for locking in c-client are used. Exim takes out a shared
1513 lock on the mailbox file, and an exclusive lock on the file whose name is
1514 /tmp/.<device-number>.<inode-number>. The shared lock on the mailbox stops
1515 any other MBX client from getting an exclusive lock on it and expunging it.
1516 It also stops any other MBX client from unlinking the /tmp lock when it has
1519 The exclusive lock on the /tmp file prevents any other MBX client from
1520 updating the mailbox in any way. When writing is finished, if an exclusive
1521 lock on the mailbox can be obtained, indicating there are no current sharers,
1522 the /tmp file is unlinked.
1524 MBX locking can use either fcntl() or flock() locking. If neither
1525 use_fcntl_lock or use_flock_lock is set, it defaults to using fcntl() only.
1526 The calls for getting these locks are by default non-blocking, as for non-mbx
1527 locking, but can be made blocking by setting lock_fcntl_timeout and/or
1528 lock_flock_timeout as appropriate. As MBX delivery doesn't work over NFS, it
1529 probably makes sense to set timeouts for any MBX deliveries. */
1532 /* Build a lock file if configured to do so - the existence of a lock
1533 file is subsequently checked by looking for a non-negative value of the
1534 file descriptor hd - even though the file is no longer open. */
1536 if (ob->use_lockfile)
1538 /* cf. exim_lock.c */
1539 lockname = string_sprintf("%s.lock", filename);
1540 hitchname = string_sprintf( "%s.%s.%08x.%08x", lockname, primary_hostname,
1541 (unsigned int)(time(NULL)), (unsigned int)getpid());
1543 DEBUG(D_transport) debug_printf("lock name: %s\nhitch name: %s\n", lockname,
1546 /* Lock file creation retry loop */
1548 for (i = 0; i < ob->lock_retries; sleep(ob->lock_interval), i++)
1552 hd = Uopen(hitchname, O_WRONLY | O_CREAT | O_EXCL, ob->lockfile_mode);
1555 addr->basic_errno = errno;
1557 string_sprintf("creating lock file hitching post %s "
1558 "(euid=%ld egid=%ld)", hitchname, (long int)geteuid(),
1559 (long int)getegid());
1563 /* Attempt to hitch the hitching post to the lock file. If link()
1564 succeeds (the common case, we hope) all is well. Otherwise, fstat the
1565 file, and get rid of the hitching post. If the number of links was 2,
1566 the link was created, despite the failure of link(). If the hitch was
1567 not successful, try again, having unlinked the lock file if it is too
1570 There's a version of Linux (2.0.27) which doesn't update its local cache
1571 of the inode after link() by default - which many think is a bug - but
1572 if the link succeeds, this code will be OK. It just won't work in the
1573 case when link() fails after having actually created the link. The Linux
1574 NFS person is fixing this; a temporary patch is available if anyone is
1575 sufficiently worried. */
1577 if ((rc = Ulink(hitchname, lockname)) != 0) fstat(hd, &statbuf);
1580 if (rc != 0 && statbuf.st_nlink != 2)
1582 if (ob->lockfile_timeout > 0 && Ustat(lockname, &statbuf) == 0 &&
1583 time(NULL) - statbuf.st_ctime > ob->lockfile_timeout)
1585 DEBUG(D_transport) debug_printf("unlinking timed-out lock file\n");
1588 DEBUG(D_transport) debug_printf("link of hitching post failed - retrying\n");
1592 DEBUG(D_transport) debug_printf("lock file created\n");
1596 /* Check for too many tries at creating the lock file */
1598 if (i >= ob->lock_retries)
1600 addr->basic_errno = ERRNO_LOCKFAILED;
1601 addr->message = string_sprintf("failed to lock mailbox %s (lock file)",
1608 /* We now have to get the file open. First, stat() it and act on existence or
1609 non-existence. This is in a loop to handle the case of a file's being created
1610 or deleted as we watch, and also to handle retries when the locking fails.
1611 Rather than holding the file open while waiting for the fcntl() and/or
1612 flock() lock, we close and do the whole thing again. This should be safer,
1613 especially for NFS files, which might get altered from other hosts, making
1614 their cached sizes incorrect.
1616 With the default settings, no symlinks are permitted, but there is an option
1617 to permit symlinks for those sysadmins that know what they are doing.
1618 Shudder. However, insist that the initial symlink is owned by the right user.
1619 Thus lstat() is used initially; if a symlink is discovered, the loop is
1620 repeated such that stat() is used, to look at the end file. */
1622 for (i = 0; i < ob->lock_retries; i++)
1624 int sleep_before_retry = TRUE;
1625 file_opened = FALSE;
1627 if ((use_lstat ? Ulstat(filename, &statbuf) : Ustat(filename, &statbuf)) != 0)
1629 /* Let's hope that failure to stat (other than non-existence) is a
1632 if (errno != ENOENT)
1634 addr->basic_errno = errno;
1635 addr->message = string_sprintf("attempting to stat mailbox %s",
1640 /* File does not exist. If it is required to pre-exist this state is an
1643 if (ob->file_must_exist)
1645 addr->basic_errno = errno;
1646 addr->message = string_sprintf("mailbox %s does not exist, "
1647 "but file_must_exist is set", filename);
1651 /* If not permitted to create this file because it isn't in or below
1652 the home directory, generate an error. */
1654 if (!allow_creation_here)
1656 addr->basic_errno = ERRNO_BADCREATE;
1657 addr->message = string_sprintf("mailbox %s does not exist, "
1658 "but creation outside the home directory is not permitted",
1663 /* Attempt to create and open the file. If open fails because of
1664 pre-existence, go round the loop again. For any other error, defer the
1665 address, except for an alias or forward generated file name with EPERM,
1666 ENOENT, or EACCES, as those are most likely to be user errors rather
1667 than Exim config errors. When a symbolic link is permitted and points
1668 to a non-existent file, we get here with use_lstat = FALSE. In this case
1669 we mustn't use O_EXCL, since it doesn't work. The file is opened RDRW for
1670 consistency and because MBX locking requires it in order to be able to
1671 get a shared lock. */
1673 fd = Uopen(filename, O_RDWR | O_APPEND | O_CREAT |
1674 (use_lstat ? O_EXCL : 0), mode);
1677 if (errno == EEXIST) continue;
1678 addr->basic_errno = errno;
1679 addr->message = string_sprintf("while creating mailbox %s",
1681 if (testflag(addr, af_file) &&
1682 (errno == EPERM || errno == ENOENT || errno == EACCES))
1683 addr->transport_return = FAIL;
1687 /* We have successfully created and opened the file. Ensure that the group
1688 and the mode are correct. */
1690 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
1692 addr->basic_errno = errno;
1693 addr->message = string_sprintf("while setting perms on mailbox %s",
1695 addr->transport_return = FAIL;
1701 /* The file already exists. Test its type, ownership, and permissions, and
1702 save the inode for checking later. If symlinks are permitted (not the
1703 default or recommended state) it may be a symlink that already exists.
1704 Check its ownership and then look for the file at the end of the link(s).
1705 This at least prevents one user creating a symlink for another user in
1706 a sticky directory. */
1710 int oldmode = (int)statbuf.st_mode;
1711 ino_t inode = statbuf.st_ino;
1712 BOOL islink = (oldmode & S_IFMT) == S_IFLNK;
1714 isfifo = FALSE; /* In case things are changing */
1716 /* Check owner if required - the default. */
1718 if (ob->check_owner && statbuf.st_uid != uid)
1720 addr->basic_errno = ERRNO_BADUGID;
1721 addr->message = string_sprintf("mailbox %s%s has wrong uid "
1722 "(%ld != %ld)", filename,
1723 islink ? " (symlink)" : "",
1724 (long int)(statbuf.st_uid), (long int)uid);
1728 /* Group is checked only if check_group is set. */
1730 if (ob->check_group && statbuf.st_gid != gid)
1732 addr->basic_errno = ERRNO_BADUGID;
1733 addr->message = string_sprintf("mailbox %s%s has wrong gid (%d != %d)",
1734 filename, islink ? " (symlink)" : "", statbuf.st_gid, gid);
1738 /* Just in case this is a sticky-bit mail directory, we don't want
1739 users to be able to create hard links to other users' files. */
1741 if (statbuf.st_nlink != 1)
1743 addr->basic_errno = ERRNO_NOTREGULAR;
1744 addr->message = string_sprintf("mailbox %s%s has too many links (%d)",
1745 filename, islink ? " (symlink)" : "", statbuf.st_nlink);
1750 /* If symlinks are permitted (not recommended), the lstat() above will
1751 have found the symlink. Its ownership has just been checked; go round
1752 the loop again, using stat() instead of lstat(). That will never yield a
1755 if (islink && ob->allow_symlink)
1758 i--; /* Don't count this time round */
1762 /* An actual file exists. Check that it is a regular file, or FIFO
1765 if (ob->allow_fifo && (oldmode & S_IFMT) == S_IFIFO) isfifo = TRUE;
1767 else if ((oldmode & S_IFMT) != S_IFREG)
1769 addr->basic_errno = ERRNO_NOTREGULAR;
1770 addr->message = string_sprintf("mailbox %s is not a regular file%s",
1771 filename, ob->allow_fifo ? " or named pipe" : "");
1775 /* If the mode is not what it would be for a newly created file, change
1776 the permissions if the mode is supplied for the address. Otherwise,
1777 reduce but do not extend the permissions. If the newly created
1778 permissions are greater than the existing permissions, don't change
1779 things when the mode is not from the address. */
1781 if ((oldmode &= 07777) != mode)
1783 int diffs = oldmode ^ mode;
1784 if (addr->mode > 0 || (diffs & oldmode) == diffs)
1786 DEBUG(D_transport) debug_printf("chmod %o %s\n", mode, filename);
1787 if (Uchmod(filename, mode) < 0)
1789 addr->basic_errno = errno;
1790 addr->message = string_sprintf("attempting to chmod mailbox %s",
1797 /* Mode not from address, and newly-created permissions are greater
1798 than existing permissions. Default is to complain, but it can be
1799 configured to go ahead and try to deliver anyway if that's what
1800 the administration wants. */
1802 else if (ob->mode_fail_narrower)
1804 addr->basic_errno = ERRNO_BADMODE;
1805 addr->message = string_sprintf("mailbox %s has the wrong mode %o "
1806 "(%o expected)", filename, oldmode, mode);
1811 /* We are happy with the existing file. Open it, and then do further
1812 tests to ensure that it is the same file that we were just looking at.
1813 If the file does not now exist, restart this loop, going back to using
1814 lstat again. For an NFS error, just defer; other opening errors are
1815 more serious. The file is opened RDWR so that its format can be checked,
1816 and also MBX locking requires the use of a shared (read) lock. However,
1817 a FIFO is opened WRONLY + NDELAY so that it fails if there is no process
1818 reading the pipe. */
1820 fd = Uopen(filename, isfifo ? (O_WRONLY|O_NDELAY) : (O_RDWR|O_APPEND),
1824 if (errno == ENOENT)
1829 addr->basic_errno = errno;
1831 addr->message = string_sprintf("while opening named pipe %s "
1832 "(could mean no process is reading it)", filename);
1833 else if (errno != EWOULDBLOCK)
1834 addr->message = string_sprintf("while opening mailbox %s", filename);
1838 /* This fstat really shouldn't fail, as we have an open file! There's a
1839 dilemma here. We use fstat in order to be sure we are peering at the file
1840 we have got open. However, that won't tell us if the file was reached
1841 via a symbolic link. We checked this above, but there is a race exposure
1842 if the link was created between the previous lstat and the open. However,
1843 it would have to be created with the same inode in order to pass the
1844 check below. If ob->allow_symlink is set, causing the use of stat rather
1845 than lstat above, symbolic links may be there anyway, and the checking is
1848 if (fstat(fd, &statbuf) < 0)
1850 addr->basic_errno = errno;
1851 addr->message = string_sprintf("attempting to stat open mailbox %s",
1856 /* Check the inode; this is isn't a perfect check, but gives some
1859 if (inode != statbuf.st_ino)
1861 addr->basic_errno = ERRNO_INODECHANGED;
1862 addr->message = string_sprintf("opened mailbox %s inode number changed "
1863 "from " INO_T_FMT " to " INO_T_FMT, filename, inode, statbuf.st_ino);
1864 addr->special_action = SPECIAL_FREEZE;
1868 /* Check it's still a regular file or FIFO, and the uid, gid, and
1869 permissions have not changed. */
1871 if ((!isfifo && (statbuf.st_mode & S_IFMT) != S_IFREG) ||
1872 (isfifo && (statbuf.st_mode & S_IFMT) != S_IFIFO))
1874 addr->basic_errno = ERRNO_NOTREGULAR;
1876 string_sprintf("opened mailbox %s is no longer a %s", filename,
1877 isfifo ? "named pipe" : "regular file");
1878 addr->special_action = SPECIAL_FREEZE;
1882 if ((ob->check_owner && statbuf.st_uid != uid) ||
1883 (ob->check_group && statbuf.st_gid != gid))
1885 addr->basic_errno = ERRNO_BADUGID;
1887 string_sprintf("opened mailbox %s has wrong uid or gid", filename);
1888 addr->special_action = SPECIAL_FREEZE;
1892 if ((statbuf.st_mode & 07777) != oldmode)
1894 addr->basic_errno = ERRNO_BADMODE;
1895 addr->message = string_sprintf("opened mailbox %s has wrong mode %o "
1896 "(%o expected)", filename, statbuf.st_mode & 07777, mode);
1897 addr->special_action = SPECIAL_FREEZE;
1901 /* If file_format is set, check that the format of the file has not
1902 changed. Error data is set by the testing function. */
1904 if (ob->file_format && check_file_format(fd, tblock, addr) != tblock)
1906 addr->message = US"open mailbox has changed format";
1910 /* The file is OK. Carry on to do the locking. */
1913 /* We now have an open file, and must lock it using fcntl(), flock() or MBX
1914 locking rules if configured to do so. If a lock file is also required, it
1915 was created above and hd was left >= 0. At least one form of locking is
1916 required by the initialization function. If locking fails here, close the
1917 file and go round the loop all over again, after waiting for a bit, unless
1918 blocking locking was used. */
1921 if ((ob->lock_fcntl_timeout > 0) || (ob->lock_flock_timeout > 0))
1922 sleep_before_retry = FALSE;
1924 /* Simple fcntl() and/or flock() locking */
1926 if (!ob->use_mbx_lock && (ob->use_fcntl || ob->use_flock))
1928 if (apply_lock(fd, F_WRLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
1929 ob->use_flock, ob->lock_flock_timeout) >= 0) break;
1932 /* MBX locking rules */
1935 else if (ob->use_mbx_lock)
1938 struct stat lstatbuf, statbuf2;
1939 if (apply_lock(fd, F_RDLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
1940 ob->use_flock, ob->lock_flock_timeout) >= 0 &&
1941 fstat(fd, &statbuf) >= 0)
1943 sprintf(CS mbx_lockname, "/tmp/.%lx.%lx", (long)statbuf.st_dev,
1944 (long)statbuf.st_ino);
1947 * 2010-05-29: SECURITY
1948 * Dan Rosenberg reported the presence of a race-condition in the
1949 * original code here. Beware that many systems still allow symlinks
1950 * to be followed in /tmp so an attacker can create a symlink pointing
1951 * elsewhere between a stat and an open, which we should avoid
1954 * It's unfortunate that we can't just use all the heavily debugged
1955 * locking from above.
1957 * Also: remember to mirror changes into exim_lock.c */
1959 /* first leave the old pre-check in place, it provides better
1960 * diagnostics for common cases */
1961 if (Ulstat(mbx_lockname, &statbuf) >= 0)
1963 if ((statbuf.st_mode & S_IFMT) == S_IFLNK)
1965 addr->basic_errno = ERRNO_LOCKFAILED;
1966 addr->message = string_sprintf("symbolic link on MBX lock file %s",
1970 if (statbuf.st_nlink > 1)
1972 addr->basic_errno = ERRNO_LOCKFAILED;
1973 addr->message = string_sprintf("hard link to MBX lock file %s",
1979 /* If we could just declare "we must be the ones who create this
1980 * file" then a hitching post in a subdir would work, since a
1981 * subdir directly in /tmp/ which we create wouldn't follow links
1982 * but this isn't our locking logic, so we can't safely change the
1983 * file existence rules. */
1985 /* On systems which support O_NOFOLLOW, it's the easiest and most
1986 * obviously correct security fix */
1987 mbx_tmp_oflags = O_RDWR | O_CREAT;
1989 mbx_tmp_oflags |= O_NOFOLLOW;
1991 mbx_lockfd = Uopen(mbx_lockname, mbx_tmp_oflags, ob->lockfile_mode);
1994 addr->basic_errno = ERRNO_LOCKFAILED;
1995 addr->message = string_sprintf("failed to open MBX lock file %s :%s",
1996 mbx_lockname, strerror(errno));
2000 if (Ulstat(mbx_lockname, &lstatbuf) < 0)
2002 addr->basic_errno = ERRNO_LOCKFAILED;
2003 addr->message = string_sprintf("attempting to lstat open MBX "
2004 "lock file %s: %s", mbx_lockname, strerror(errno));
2007 if (fstat(mbx_lockfd, &statbuf2) < 0)
2009 addr->basic_errno = ERRNO_LOCKFAILED;
2010 addr->message = string_sprintf("attempting to stat fd of open MBX "
2011 "lock file %s: %s", mbx_lockname, strerror(errno));
2017 * statbuf: if exists, is file which existed prior to opening the
2018 * lockfile, might have been replaced since then
2019 * statbuf2: result of stat'ing the open fd, is what was actually
2021 * lstatbuf: result of lstat'ing the filename immediately after
2022 * the open but there's a race condition again between
2023 * those two steps: before open, symlink to foo, after
2024 * open but before lstat have one of:
2025 * * was no symlink, so is the opened file
2026 * (we created it, no messing possible after that point)
2028 * * symlink elsewhere
2029 * * hardlink elsewhere
2031 * Don't want to compare to device of /tmp because some modern systems
2032 * have regressed to having /tmp be the safe actual filesystem as
2033 * valuable data, so is mostly worthless, unless we assume that *only*
2034 * Linux systems do this and that all Linux has O_NOFOLLOW. Something
2035 * for further consideration.
2036 * No point in doing a readlink on the lockfile as that will always be
2037 * at a different point in time from when we open it, so tells us
2038 * nothing; attempts to clean up and delete after ourselves would risk
2039 * deleting a *third* filename.
2041 if ((statbuf2.st_nlink > 1) ||
2042 (lstatbuf.st_nlink > 1) ||
2043 (!S_ISREG(lstatbuf.st_mode)) ||
2044 (lstatbuf.st_dev != statbuf2.st_dev) ||
2045 (lstatbuf.st_ino != statbuf2.st_ino))
2047 addr->basic_errno = ERRNO_LOCKFAILED;
2048 addr->message = string_sprintf("RACE CONDITION detected: "
2049 "mismatch post-initial-checks between \"%s\" and opened "
2050 "fd lead us to abort!", mbx_lockname);
2054 (void)Uchmod(mbx_lockname, ob->lockfile_mode);
2056 if (apply_lock(mbx_lockfd, F_WRLCK, ob->use_fcntl,
2057 ob->lock_fcntl_timeout, ob->use_flock, ob->lock_flock_timeout) >= 0)
2059 struct stat ostatbuf;
2061 /* This tests for a specific race condition. Ensure that we still
2062 have the same file. */
2064 if (Ulstat(mbx_lockname, &statbuf) == 0 &&
2065 fstat(mbx_lockfd, &ostatbuf) == 0 &&
2066 statbuf.st_dev == ostatbuf.st_dev &&
2067 statbuf.st_ino == ostatbuf.st_ino)
2069 DEBUG(D_transport) debug_printf("MBX lockfile %s changed "
2070 "between creation and locking\n", mbx_lockname);
2073 DEBUG(D_transport) debug_printf("failed to lock %s: %s\n", mbx_lockname,
2075 (void)close(mbx_lockfd);
2080 DEBUG(D_transport) debug_printf("failed to fstat or get read lock on %s: %s\n",
2081 filename, strerror(errno));
2084 #endif /* SUPPORT_MBX */
2086 else break; /* No on-file locking required; break the open/lock loop */
2089 debug_printf("fcntl(), flock(), or MBX locking failed - retrying\n");
2093 use_lstat = TRUE; /* Reset to use lstat first */
2096 /* If a blocking call timed out, break the retry loop if the total time
2097 so far is not less than than retries * interval. Use the larger of the
2098 flock() and fcntl() timeouts. */
2101 (i+1) * ((ob->lock_fcntl_timeout > ob->lock_flock_timeout)?
2102 ob->lock_fcntl_timeout : ob->lock_flock_timeout) >=
2103 ob->lock_retries * ob->lock_interval)
2104 i = ob->lock_retries;
2106 /* Wait a bit before retrying, except when it was a blocked fcntl() or
2107 flock() that caused the problem. */
2109 if (i < ob->lock_retries && sleep_before_retry) sleep(ob->lock_interval);
2112 /* Test for exceeding the maximum number of tries. Either the file remains
2113 locked, or, if we haven't got it open, something is terribly wrong... */
2115 if (i >= ob->lock_retries)
2119 addr->basic_errno = ERRNO_EXISTRACE;
2120 addr->message = string_sprintf("mailbox %s: existence unclear", filename);
2121 addr->special_action = SPECIAL_FREEZE;
2125 addr->basic_errno = ERRNO_LOCKFAILED;
2126 addr->message = string_sprintf("failed to lock mailbox %s (fcntl/flock)",
2132 DEBUG(D_transport) debug_printf("mailbox %s is locked\n", filename);
2134 /* Save access time (for subsequent restoration), modification time (for
2135 restoration if updating fails), size of file (for comsat and for re-setting if
2136 delivery fails in the middle - e.g. for quota exceeded). */
2138 if (fstat(fd, &statbuf) < 0)
2140 addr->basic_errno = errno;
2141 addr->message = string_sprintf("while fstatting opened mailbox %s",
2146 times.actime = statbuf.st_atime;
2147 times.modtime = statbuf.st_mtime;
2148 saved_size = statbuf.st_size;
2149 if (mailbox_size < 0) mailbox_size = saved_size;
2150 mailbox_filecount = 0; /* Not actually relevant for single-file mailbox */
2153 /* Prepare for writing to a new file (as opposed to appending to an old one).
2154 There are several different formats, but there is preliminary stuff concerned
2155 with quotas that applies to all of them. Finding the current size by directory
2156 scanning is expensive; for maildirs some fudges have been invented:
2158 (1) A regex can be used to extract a file size from its name;
2159 (2) If maildir_use_size is set, a maildirsize file is used to cache the
2165 uschar *check_path; /* Default quota check path */
2166 const pcre *regex = NULL; /* Regex for file size from file name */
2168 if (!check_creation(string_sprintf("%s/any", path), ob->create_file))
2170 addr->basic_errno = ERRNO_BADCREATE;
2171 addr->message = string_sprintf("tried to create file in %s, but "
2172 "file creation outside the home directory is not permitted", path);
2176 /* If the create_file option is an absolute path and the file was within
2177 it, de-taint. Otherwise check for taint. */
2179 if (is_tainted(path))
2180 if (ob->create_file == create_belowhome)
2182 DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path);
2183 path = string_copy_taint(path, FALSE);
2186 goto tainted_ret_panic;
2190 #ifdef SUPPORT_MAILDIR
2191 /* For a maildir delivery, ensure that all the relevant directories exist,
2192 and a maildirfolder file if necessary. */
2194 if (mbformat == mbf_maildir && !maildir_ensure_directories(path, addr,
2195 ob->create_directory, ob->dirmode, ob->maildirfolder_create_regex))
2197 #endif /* SUPPORT_MAILDIR */
2199 /* If we are going to do a quota check, of if maildir_use_size_file is set
2200 for a maildir delivery, compile the regular expression if there is one. We
2201 may also need to adjust the path that is used. We need to do this for
2202 maildir_use_size_file even if the quota is unset, because we still want to
2203 create the file. When maildir support is not compiled,
2204 ob->maildir_use_size_file is always FALSE. */
2206 if (ob->quota_value > 0 || THRESHOLD_CHECK || ob->maildir_use_size_file)
2208 const uschar *error;
2211 /* Compile the regex if there is one. */
2213 if (ob->quota_size_regex)
2215 if (!(regex = pcre_compile(CS ob->quota_size_regex, PCRE_COPT,
2216 CCSS &error, &offset, NULL)))
2218 addr->message = string_sprintf("appendfile: regular expression "
2219 "error: %s at offset %d while compiling %s", error, offset,
2220 ob->quota_size_regex);
2223 DEBUG(D_transport) debug_printf("using regex for file sizes: %s\n",
2224 ob->quota_size_regex);
2227 /* Use an explicitly configured directory if set */
2229 if (ob->quota_directory)
2231 if (!(check_path = expand_string(ob->quota_directory)))
2233 addr->message = string_sprintf("Expansion of \"%s\" (quota_directory "
2234 "name for %s transport) failed: %s", ob->quota_directory,
2235 tblock->name, expand_string_message);
2239 if (check_path[0] != '/')
2241 addr->message = string_sprintf("appendfile: quota_directory name "
2242 "\"%s\" is not absolute", check_path);
2243 addr->basic_errno = ERRNO_NOTABSOLUTE;
2248 #ifdef SUPPORT_MAILDIR
2249 /* Otherwise, if we are handling a maildir delivery, and the directory
2250 contains a file called maildirfolder, this is a maildir++ feature telling
2251 us that this is a sub-directory of the real inbox. We should therefore do
2252 the quota check on the parent directory. Beware of the special case when
2253 the directory name itself ends in a slash. */
2255 else if (mbformat == mbf_maildir)
2257 struct stat statbuf;
2258 if (Ustat(string_sprintf("%s/maildirfolder", path), &statbuf) >= 0)
2260 uschar *new_check_path = string_copy(check_path);
2261 uschar *slash = Ustrrchr(new_check_path, '/');
2267 slash = Ustrrchr(new_check_path, '/');
2272 check_path = new_check_path;
2273 DEBUG(D_transport) debug_printf("maildirfolder file exists: "
2274 "quota check directory changed to %s\n", check_path);
2279 #endif /* SUPPORT_MAILDIR */
2282 /* If we are using maildirsize files, we need to ensure that such a file
2283 exists and, if necessary, recalculate its contents. As a byproduct of this,
2284 we obtain the current size of the maildir. If no quota is to be enforced
2285 (ob->quota_value == 0), we still need the size if a threshold check will
2288 Another regular expression is used to determine which directories inside the
2289 maildir are going to be counted. */
2291 #ifdef SUPPORT_MAILDIR
2292 if (ob->maildir_use_size_file)
2294 const pcre *dir_regex = NULL;
2295 const uschar *error;
2298 if (ob->maildir_dir_regex)
2300 int check_path_len = Ustrlen(check_path);
2302 if (!(dir_regex = pcre_compile(CS ob->maildir_dir_regex, PCRE_COPT,
2303 CCSS &error, &offset, NULL)))
2305 addr->message = string_sprintf("appendfile: regular expression "
2306 "error: %s at offset %d while compiling %s", error, offset,
2307 ob->maildir_dir_regex);
2312 debug_printf("using regex for maildir directory selection: %s\n",
2313 ob->maildir_dir_regex);
2315 /* Check to see if we are delivering into an ignored directory, that is,
2316 if the delivery path starts with the quota check path, and the rest
2317 of the deliver path matches the regex; if so, set a flag to disable quota
2318 checking and maildirsize updating. */
2320 if (Ustrncmp(path, check_path, check_path_len) == 0)
2322 uschar *s = path + check_path_len;
2323 while (*s == '/') s++;
2324 s = *s ? string_sprintf("%s/new", s) : US"new";
2325 if (pcre_exec(dir_regex, NULL, CS s, Ustrlen(s), 0, 0, NULL, 0) < 0)
2327 disable_quota = TRUE;
2328 DEBUG(D_transport) debug_printf("delivery directory does not match "
2329 "maildir_quota_directory_regex: disabling quota\n");
2334 /* Quota enforcement; create and check the file. There is some discussion
2335 about whether this should happen if the quota is unset. At present, Exim
2336 always creates the file. If we ever want to change this, uncomment
2337 appropriate lines below, possibly doing a check on some option. */
2339 /* if (???? || ob->quota_value > 0) */
2346 if ((maildirsize_fd = maildir_ensure_sizefile(check_path, ob, regex, dir_regex,
2347 &size, &filecount)) == -1)
2349 addr->basic_errno = errno;
2350 addr->message = string_sprintf("while opening or reading "
2351 "%s/maildirsize", check_path);
2354 /* can also return -2, which means that the file was removed because of
2355 raciness; but in this case, the size & filecount will still have been
2358 if (mailbox_size < 0) mailbox_size = size;
2359 if (mailbox_filecount < 0) mailbox_filecount = filecount;
2362 /* No quota enforcement; ensure file does *not* exist; calculate size if
2367 * time_t old_latest;
2368 * (void)unlink(CS string_sprintf("%s/maildirsize", check_path));
2369 * if (THRESHOLD_CHECK)
2370 * mailbox_size = maildir_compute_size(check_path, &mailbox_filecount, &old_latest,
2371 * regex, dir_regex, FALSE);
2376 #endif /* SUPPORT_MAILDIR */
2378 /* Otherwise if we are going to do a quota check later on, and the mailbox
2379 size is not set, find the current size of the mailbox. Ditto for the file
2380 count. Note that ob->quota_filecount_value cannot be set without
2381 ob->quota_value being set. */
2384 && (ob->quota_value > 0 || THRESHOLD_CHECK)
2385 && ( mailbox_size < 0
2386 || mailbox_filecount < 0 && ob->quota_filecount_value > 0
2392 debug_printf("quota checks on directory %s\n", check_path);
2393 size = check_dir_size(check_path, &filecount, regex);
2394 if (mailbox_size < 0) mailbox_size = size;
2395 if (mailbox_filecount < 0) mailbox_filecount = filecount;
2398 /* Handle the case of creating a unique file in a given directory (not in
2399 maildir or mailstore format - this is how smail did it). A temporary name is
2400 used to create the file. Later, when it is written, the name is changed to a
2401 unique one. There is no need to lock the file. An attempt is made to create
2402 the directory if it does not exist. */
2404 if (mbformat == mbf_smail)
2407 debug_printf("delivering to new file in %s\n", path);
2408 filename = dataname =
2409 string_sprintf("%s/temp.%d.%s", path, (int)getpid(), primary_hostname);
2410 fd = Uopen(filename, O_WRONLY|O_CREAT, mode);
2411 if (fd < 0 && /* failed to open, and */
2412 (errno != ENOENT || /* either not non-exist */
2413 !ob->create_directory || /* or not allowed to make */
2414 !directory_make(NULL, path, ob->dirmode, FALSE) || /* or failed to create dir */
2415 (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)) /* or then failed to open */
2417 addr->basic_errno = errno;
2418 addr->message = string_sprintf("while creating file %s", filename);
2423 #ifdef SUPPORT_MAILDIR
2425 /* Handle the case of a unique file in maildir format. The file is written to
2426 the tmp subdirectory, with a prescribed form of name. */
2428 else if (mbformat == mbf_maildir)
2431 debug_printf("delivering in maildir format in %s\n", path);
2433 nametag = ob->maildir_tag;
2435 /* Check that nametag expands successfully; a hard failure causes a panic
2436 return. The actual expansion for use happens again later, when
2437 $message_size is accurately known. */
2439 if (nametag && !expand_string(nametag) && !f.expand_string_forcedfail)
2441 addr->message = string_sprintf("Expansion of \"%s\" (maildir_tag "
2442 "for %s transport) failed: %s", nametag, tblock->name,
2443 expand_string_message);
2447 /* We ensured the existence of all the relevant directories above. Attempt
2448 to open the temporary file a limited number of times. I think this rather
2449 scary-looking for statement is actually OK. If open succeeds, the loop is
2450 broken; if not, there is a test on the value of i. Get the time again
2451 afresh each time round the loop. Its value goes into a variable that is
2452 checked at the end, to make sure we don't release this process until the
2453 clock has ticked. */
2455 for (int i = 1;; i++)
2459 (void)gettimeofday(&msg_tv, NULL);
2460 basename = string_sprintf(TIME_T_FMT ".M%luP" PID_T_FMT ".%s",
2461 msg_tv.tv_sec, msg_tv.tv_usec, getpid(), primary_hostname);
2463 filename = dataname = string_sprintf("tmp/%s", basename);
2464 newname = string_sprintf("new/%s", basename);
2466 if (Ustat(filename, &statbuf) == 0)
2468 else if (errno == ENOENT)
2470 if ((fd = Uopen(filename, O_WRONLY | O_CREAT | O_EXCL, mode)) >= 0)
2472 DEBUG (D_transport) debug_printf ("open failed for %s: %s\n",
2473 filename, strerror(errno));
2476 /* Too many retries - give up */
2478 if (i >= ob->maildir_retries)
2480 addr->message = string_sprintf ("failed to open %s (%d tr%s)",
2481 filename, i, (i == 1) ? "y" : "ies");
2482 addr->basic_errno = errno;
2483 if (errno == errno_quota || errno == ENOSPC)
2484 addr->user_message = US"mailbox is full";
2488 /* Open or stat failed but we haven't tried too many times yet. */
2493 /* Note that we have to ensure the clock has ticked before leaving */
2495 wait_for_tick = TRUE;
2497 /* Why are these here? Put in because they are present in the non-maildir
2498 directory case above. */
2500 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2502 addr->basic_errno = errno;
2503 addr->message = string_sprintf("while setting perms on maildir %s",
2509 #endif /* SUPPORT_MAILDIR */
2511 #ifdef SUPPORT_MAILSTORE
2513 /* Handle the case of a unique file in mailstore format. First write the
2514 envelope to a temporary file, then open the main file. The unique base name
2515 for the files consists of the message id plus the pid of this delivery
2521 mailstore_basename = string_sprintf("%s/%s-%s", path, message_id,
2522 string_base62((long int)getpid()));
2525 debug_printf("delivering in mailstore format in %s\n", path);
2527 filename = string_sprintf("%s.tmp", mailstore_basename);
2528 newname = string_sprintf("%s.env", mailstore_basename);
2529 dataname = string_sprintf("%s.msg", mailstore_basename);
2531 fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode);
2532 if ( fd < 0 /* failed to open, and */
2533 && ( errno != ENOENT /* either not non-exist */
2534 || !ob->create_directory /* or not allowed to make */
2535 || !directory_make(NULL, path, ob->dirmode, FALSE) /* or failed to create dir */
2536 || (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0 /* or then failed to open */
2539 addr->basic_errno = errno;
2540 addr->message = string_sprintf("while creating file %s", filename);
2544 /* Why are these here? Put in because they are present in the non-maildir
2545 directory case above. */
2547 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2549 addr->basic_errno = errno;
2550 addr->message = string_sprintf("while setting perms on file %s",
2555 /* Built a C stream from the open file descriptor. */
2557 if (!(env_file = fdopen(fd, "wb")))
2559 addr->basic_errno = errno;
2560 addr->message = string_sprintf("fdopen of %s ("
2561 "for %s transport) failed", filename, tblock->name);
2567 /* Write the envelope file, then close it. */
2569 if (ob->mailstore_prefix)
2571 uschar *s = expand_string(ob->mailstore_prefix);
2574 if (!f.expand_string_forcedfail)
2576 addr->message = string_sprintf("Expansion of \"%s\" (mailstore "
2577 "prefix for %s transport) failed: %s", ob->mailstore_prefix,
2578 tblock->name, expand_string_message);
2579 (void)fclose(env_file);
2587 fprintf(env_file, "%s", CS s);
2588 if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n");
2592 fprintf(env_file, "%s\n", sender_address);
2594 for (address_item * taddr = addr; taddr; taddr = taddr->next)
2595 fprintf(env_file, "%s@%s\n", taddr->local_part, taddr->domain);
2597 if (ob->mailstore_suffix)
2599 uschar *s = expand_string(ob->mailstore_suffix);
2602 if (!f.expand_string_forcedfail)
2604 addr->message = string_sprintf("Expansion of \"%s\" (mailstore "
2605 "suffix for %s transport) failed: %s", ob->mailstore_suffix,
2606 tblock->name, expand_string_message);
2607 (void)fclose(env_file);
2615 fprintf(env_file, "%s", CS s);
2616 if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n");
2620 if (fclose(env_file) != 0)
2622 addr->basic_errno = errno;
2623 addr->message = string_sprintf("while closing %s", filename);
2628 DEBUG(D_transport) debug_printf("Envelope file %s written\n", filename);
2630 /* Now open the data file, and ensure that it has the correct ownership and
2633 if ((fd = Uopen(dataname, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)
2635 addr->basic_errno = errno;
2636 addr->message = string_sprintf("while creating file %s", dataname);
2640 if (exim_chown(dataname, uid, gid) || Uchmod(dataname, mode))
2642 addr->basic_errno = errno;
2643 addr->message = string_sprintf("while setting perms on file %s",
2649 #endif /* SUPPORT_MAILSTORE */
2652 /* In all cases of writing to a new file, ensure that the file which is
2653 going to be renamed has the correct ownership and mode. */
2655 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2657 addr->basic_errno = errno;
2658 addr->message = string_sprintf("while setting perms on file %s",
2665 /* At last we can write the message to the file, preceded by any configured
2666 prefix line, and followed by any configured suffix line. If there are any
2667 writing errors, we must defer. */
2669 DEBUG(D_transport) debug_printf("writing to file %s\n", dataname);
2674 /* If there is a local quota setting, check that we are not going to exceed it
2675 with this message if quota_is_inclusive is set; if it is not set, the check
2676 is for the mailbox already being over quota (i.e. the current message is not
2677 included in the check). */
2679 if (!disable_quota && ob->quota_value > 0)
2683 debug_printf("Exim quota = " OFF_T_FMT " old size = " OFF_T_FMT
2684 " this message = %d (%sincluded)\n",
2685 ob->quota_value, mailbox_size, message_size,
2686 ob->quota_is_inclusive ? "" : "not ");
2687 debug_printf(" file count quota = %d count = %d\n",
2688 ob->quota_filecount_value, mailbox_filecount);
2691 if (mailbox_size + (ob->quota_is_inclusive ? message_size:0) > ob->quota_value)
2692 if (!ob->quota_no_check)
2694 DEBUG(D_transport) debug_printf("mailbox quota exceeded\n");
2696 errno = ERRNO_EXIMQUOTA;
2699 DEBUG(D_transport) debug_printf("mailbox quota exceeded but ignored\n");
2701 if (ob->quota_filecount_value > 0
2702 && mailbox_filecount + (ob->quota_is_inclusive ? 1:0) >
2703 ob->quota_filecount_value)
2704 if (!ob->quota_filecount_no_check)
2706 DEBUG(D_transport) debug_printf("mailbox file count quota exceeded\n");
2708 errno = ERRNO_EXIMQUOTA;
2709 filecount_msg = US" filecount";
2711 else DEBUG(D_transport) if (ob->quota_filecount_no_check)
2712 debug_printf("mailbox file count quota exceeded but ignored\n");
2718 addr->basic_errno = errno;
2719 addr->message = US"Over quota";
2720 addr->transport_return = yield;
2722 debug_printf("appendfile (verify) yields %d with errno=%d more_errno=%d\n",
2723 yield, addr->basic_errno, addr->more_errno);
2728 /* If we are writing in MBX format, what we actually do is to write the message
2729 to a temporary file, and then copy it to the real file once we know its size.
2730 This is the most straightforward way of getting the correct length in the
2731 separator line. So, what we do here is to save the real file descriptor, and
2732 replace it with one for a temporary file. The temporary file gets unlinked once
2733 opened, so that it goes away on closure. */
2736 if (yield == OK && ob->mbx_format)
2738 if (!(temp_file = tmpfile()))
2740 addr->basic_errno = errno;
2741 addr->message = US"while setting up temporary file";
2746 fd = fileno(temp_file);
2747 DEBUG(D_transport) debug_printf("writing to temporary file\n");
2749 #endif /* SUPPORT_MBX */
2751 /* Zero the count of bytes written. It is incremented by the transport_xxx()
2754 transport_count = 0;
2755 transport_newlines = 0;
2757 /* Write any configured prefix text first */
2759 if (yield == OK && ob->message_prefix && *ob->message_prefix)
2761 uschar *prefix = expand_string(ob->message_prefix);
2764 errno = ERRNO_EXPANDFAIL;
2765 addr->transport_return = PANIC;
2766 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
2767 "transport) failed", ob->message_prefix, tblock->name);
2770 else if (!transport_write_string(fd, "%s", prefix)) yield = DEFER;
2773 /* If the use_bsmtp option is on, we need to write SMTP prefix information. The
2774 various different values for batching are handled outside; if there is more
2775 than one address available here, all must be included. If any address is a
2776 file, use its parent in the RCPT TO. */
2778 if (yield == OK && ob->use_bsmtp)
2780 transport_count = 0;
2781 transport_newlines = 0;
2782 if (ob->use_crlf) cr = US"\r";
2783 if (!transport_write_string(fd, "MAIL FROM:<%s>%s\n", return_path, cr))
2787 transport_newlines++;
2788 for (address_item * a = addr; a; a = a->next)
2790 address_item * b = testflag(a, af_pfr) ? a->parent : a;
2791 if (!transport_write_string(fd, "RCPT TO:<%s>%s\n",
2792 transport_rcpt_address(b, tblock->rcpt_include_affixes), cr))
2793 { yield = DEFER; break; }
2794 transport_newlines++;
2796 if (yield == OK && !transport_write_string(fd, "DATA%s\n", cr))
2799 transport_newlines++;
2803 /* Now the message itself. The options for transport_write_message were set up
2804 at initialization time. */
2808 transport_ctx tctx = {
2812 .check_string = ob->check_string,
2813 .escape_string = ob->escape_string,
2814 .options = ob->options | topt_not_socket
2816 if (!transport_write_message(&tctx, 0))
2820 /* Now a configured suffix. */
2822 if (yield == OK && ob->message_suffix && *ob->message_suffix)
2824 uschar *suffix = expand_string(ob->message_suffix);
2827 errno = ERRNO_EXPANDFAIL;
2828 addr->transport_return = PANIC;
2829 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
2830 "transport) failed", ob->message_suffix, tblock->name);
2833 else if (!transport_write_string(fd, "%s", suffix)) yield = DEFER;
2836 /* If batch smtp, write the terminating dot. */
2838 if (yield == OK && ob->use_bsmtp)
2839 if (!transport_write_string(fd, ".%s\n", cr)) yield = DEFER;
2840 else transport_newlines++;
2842 /* If MBX format is being used, all that writing was to the temporary file.
2843 However, if there was an earlier failure (Exim quota exceeded, for example),
2844 the temporary file won't have got opened - and no writing will have been done.
2845 If writing was OK, we restore the fd, and call a function that copies the
2846 message in MBX format into the real file. Otherwise use the temporary name in
2850 if (temp_file && ob->mbx_format)
2857 transport_count = 0; /* Reset transport count for actual write */
2858 /* No need to reset transport_newlines as we're just using a block copy
2859 * routine so the number won't be affected */
2860 yield = copy_mbx_message(fd, fileno(temp_file), saved_size);
2862 else if (errno >= 0) dataname = US"temporary file";
2864 /* Preserve errno while closing the temporary file. */
2866 mbx_save_errno = errno;
2867 (void)fclose(temp_file);
2868 errno = mbx_save_errno;
2870 #endif /* SUPPORT_MBX */
2872 /* Force out the remaining data to check for any errors; some OS don't allow
2873 fsync() to be called for a FIFO. */
2875 if (yield == OK && !isfifo && EXIMfsync(fd) < 0) yield = DEFER;
2877 /* Update message_size and message_linecount to the accurate count of bytes
2878 written, including added headers. Note; we subtract 1 from message_linecount as
2879 this variable doesn't count the new line between the header and the body of the
2882 message_size = transport_count;
2883 message_linecount = transport_newlines - 1;
2885 /* If using a maildir++ quota file, add this message's size to it, and
2886 close the file descriptor, except when the quota has been disabled because we
2887 are delivering into an uncounted folder. */
2889 #ifdef SUPPORT_MAILDIR
2892 if (yield == OK && maildirsize_fd >= 0)
2893 maildir_record_length(maildirsize_fd, message_size);
2894 maildir_save_errno = errno; /* Preserve errno while closing the file */
2895 if (maildirsize_fd >= 0)
2896 (void)close(maildirsize_fd);
2897 errno = maildir_save_errno;
2899 #endif /* SUPPORT_MAILDIR */
2901 /* If there is a quota warning threshold and we are have crossed it with this
2902 message, set the SPECIAL_WARN flag in the address, to cause a warning message
2905 if (!disable_quota && THRESHOLD_CHECK)
2907 off_t threshold = ob->quota_warn_threshold_value;
2908 if (ob->quota_warn_threshold_is_percent)
2909 threshold = (off_t)(((double)ob->quota_value * threshold) / 100);
2911 debug_printf("quota = " OFF_T_FMT
2912 " threshold = " OFF_T_FMT
2913 " old size = " OFF_T_FMT
2914 " message size = %d\n",
2915 ob->quota_value, threshold, mailbox_size,
2917 if (mailbox_size <= threshold && mailbox_size + message_size > threshold)
2918 addr->special_action = SPECIAL_WARN;
2920 /******* You might think that the test ought to be this:
2922 * if (ob->quota_value > 0 && threshold > 0 && mailbox_size > 0 &&
2923 * mailbox_size <= threshold && mailbox_size + message_size > threshold)
2925 * (indeed, I was sent a patch with that in). However, it is possible to
2926 * have a warning threshold without actually imposing a quota, and I have
2927 * therefore kept Exim backwards compatible.
2932 /* Handle error while writing the file. Control should come here directly after
2933 the error, with the reason in errno. In the case of expansion failure in prefix
2934 or suffix, it will be ERRNO_EXPANDFAIL. */
2938 addr->special_action = SPECIAL_NONE; /* Cancel any quota warning */
2940 /* Save the error number. If positive, it will ultimately cause a strerror()
2941 call to generate some text. */
2943 addr->basic_errno = errno;
2945 /* For system or Exim quota excession, or disk full, set more_errno to the
2946 time since the file was last read. If delivery was into a directory, the
2947 time since last read logic is not relevant, in general. However, for maildir
2948 deliveries we can approximate it by looking at the last modified time of the
2949 "new" subdirectory. Since Exim won't be adding new messages, a change to the
2950 "new" subdirectory implies that an MUA has moved a message from there to the
2953 if (errno == errno_quota || errno == ERRNO_EXIMQUOTA || errno == ENOSPC)
2955 addr->more_errno = 0;
2956 if (!isdirectory) addr->more_errno = (int)(time(NULL) - times.actime);
2958 #ifdef SUPPORT_MAILDIR
2959 else if (mbformat == mbf_maildir)
2961 struct stat statbuf;
2962 if (Ustat("new", &statbuf) < 0)
2964 DEBUG(D_transport) debug_printf("maildir quota exceeded: "
2965 "stat error %d for \"new\": %s\n", errno, strerror(errno));
2967 else /* Want a repeatable time when in test harness */
2968 addr->more_errno = f.running_in_test_harness ? 10 :
2969 (int)time(NULL) - statbuf.st_mtime;
2972 debug_printf("maildir: time since \"new\" directory modified = %s\n",
2973 readconf_printtime(addr->more_errno));
2975 #endif /* SUPPORT_MAILDIR */
2978 /* Handle system quota excession. Add an explanatory phrase for the error
2979 message, since some systems don't have special quota-excession errors,
2980 and on those that do, "quota" doesn't always mean anything to the user. */
2982 if (errno == errno_quota)
2985 addr->message = string_sprintf("mailbox is full "
2986 "(quota exceeded while writing to file %s)", filename);
2988 addr->message = US"mailbox is full";
2990 addr->user_message = US"mailbox is full";
2991 DEBUG(D_transport) debug_printf("System quota exceeded for %s%s%s\n",
2993 isdirectory ? US"" : US": time since file read = ",
2994 isdirectory ? US"" : readconf_printtime(addr->more_errno));
2997 /* Handle Exim's own quota-imposition */
2999 else if (errno == ERRNO_EXIMQUOTA)
3001 addr->message = string_sprintf("mailbox is full "
3002 "(MTA-imposed%s quota exceeded while writing to %s)", filecount_msg,
3004 addr->user_message = US"mailbox is full";
3005 DEBUG(D_transport) debug_printf("Exim%s quota exceeded for %s%s%s\n",
3006 filecount_msg, dataname,
3007 isdirectory ? US"" : US": time since file read = ",
3008 isdirectory ? US"" : readconf_printtime(addr->more_errno));
3011 /* Handle a process failure while writing via a filter; the return
3012 from child_close() is in more_errno. */
3014 else if (errno == ERRNO_FILTER_FAIL)
3017 addr->message = string_sprintf("transport filter process failed (%d) "
3018 "while writing to %s%s", addr->more_errno, dataname,
3019 (addr->more_errno == EX_EXECFAILED) ? ": unable to execute command" : "");
3022 /* Handle failure to expand header changes */
3024 else if (errno == ERRNO_CHHEADER_FAIL)
3028 string_sprintf("failed to expand headers_add or headers_remove while "
3029 "writing to %s: %s", dataname, expand_string_message);
3032 /* Handle failure to complete writing of a data block */
3034 else if (errno == ERRNO_WRITEINCOMPLETE)
3035 addr->message = string_sprintf("failed to write data block while "
3036 "writing to %s", dataname);
3038 /* Handle length mismatch on MBX copying */
3041 else if (errno == ERRNO_MBXLENGTH)
3042 addr->message = string_sprintf("length mismatch while copying MBX "
3043 "temporary file to %s", dataname);
3044 #endif /* SUPPORT_MBX */
3046 /* For other errors, a general-purpose explanation, if the message is
3049 else if (addr->message == NULL)
3050 addr->message = string_sprintf("error while writing to %s", dataname);
3052 /* For a file, reset the file size to what it was before we started, leaving
3053 the last modification time unchanged, so it will get reset also. All systems
3054 investigated so far have ftruncate(), whereas not all have the F_FREESP
3055 fcntl() call (BSDI & FreeBSD do not). */
3057 if (!isdirectory && ftruncate(fd, saved_size))
3058 DEBUG(D_transport) debug_printf("Error resetting file size\n");
3061 /* Handle successful writing - we want the modification time to be now for
3062 appended files. Remove the default backstop error number. For a directory, now
3063 is the time to rename the file with a unique name. As soon as such a name
3064 appears it may get used by another process, so we close the file first and
3065 check that all is well. */
3069 times.modtime = time(NULL);
3070 addr->basic_errno = 0;
3072 /* Handle the case of writing to a new file in a directory. This applies
3073 to all single-file formats - maildir, mailstore, and "smail format". */
3077 if (fstat(fd, &statbuf) < 0)
3079 addr->basic_errno = errno;
3080 addr->message = string_sprintf("while fstatting opened message file %s",
3085 else if (close(fd) < 0)
3087 addr->basic_errno = errno;
3088 addr->message = string_sprintf("close() error for %s",
3089 (ob->mailstore_format) ? dataname : filename);
3093 /* File is successfully written and closed. Arrange to rename it. For the
3094 different kinds of single-file delivery, some games can be played with the
3095 name. The message size is by this time set to the accurate value so that
3096 its value can be used in expansions. */
3100 uschar *renamename = newname;
3103 DEBUG(D_transport) debug_printf("renaming temporary file\n");
3105 /* If there is no rename name set, we are in a non-maildir, non-mailstore
3106 situation. The name is built by expanding the directory_file option, and
3107 we make the inode number available for use in this. The expansion was
3108 checked for syntactic validity above, before we wrote the file.
3110 We have to be careful here, in case the file name exists. (In the other
3111 cases, the names used are constructed to be unique.) The rename()
3112 function just replaces an existing file - we don't want that! So instead
3113 of calling rename(), we must use link() and unlink().
3115 In this case, if the link fails because of an existing file, we wait
3116 for one second and try the expansion again, to see if it produces a
3117 different value. Do this up to 5 times unless the name stops changing.
3118 This makes it possible to build values that are based on the time, and
3119 still cope with races from multiple simultaneous deliveries. */
3124 uschar *old_renameleaf = US"";
3126 for (int i = 0; ; sleep(1), i++)
3128 deliver_inode = statbuf.st_ino;
3129 renameleaf = expand_string(ob->dirfilename);
3134 addr->transport_return = PANIC;
3135 addr->message = string_sprintf("Expansion of \"%s\" "
3136 "(directory_file for %s transport) failed: %s",
3137 ob->dirfilename, tblock->name, expand_string_message);
3141 renamename = string_sprintf("%s/%s", path, renameleaf);
3142 if (Ulink(filename, renamename) < 0)
3144 DEBUG(D_transport) debug_printf("link failed: %s\n",
3146 if (errno != EEXIST || i >= 4 ||
3147 Ustrcmp(renameleaf, old_renameleaf) == 0)
3149 addr->basic_errno = errno;
3150 addr->message = string_sprintf("while renaming %s as %s",
3151 filename, renamename);
3155 old_renameleaf = renameleaf;
3156 DEBUG(D_transport) debug_printf("%s exists - trying again\n",
3165 } /* re-expand loop */
3166 } /* not mailstore or maildir */
3168 /* For maildir and mailstore formats, the new name was created earlier,
3169 except that for maildir, there is the possibility of adding a "tag" on
3170 the end of the name by expanding the value of nametag. This usually
3171 includes a reference to the message size. The expansion of nametag was
3172 checked above, before the file was opened. It either succeeded, or
3173 provoked a soft failure. So any failure here can be treated as soft.
3174 Ignore non-printing characters and / and put a colon at the start if the
3175 first character is alphanumeric. */
3181 uschar *iptr = expand_string(nametag);
3184 uschar *etag = store_get(Ustrlen(iptr) + 2, is_tainted(iptr));
3185 uschar *optr = etag;
3186 for ( ; *iptr; iptr++)
3187 if (mac_isgraph(*iptr) && *iptr != '/')
3189 if (optr == etag && isalnum(*iptr)) *optr++ = ':';
3193 renamename = string_sprintf("%s%s", newname, etag);
3197 /* Do the rename. If the name is too long and a tag exists, try again
3200 if (Urename(filename, renamename) < 0 &&
3201 (nametag == NULL || errno != ENAMETOOLONG ||
3202 (renamename = newname, Urename(filename, renamename) < 0)))
3204 addr->basic_errno = errno;
3205 addr->message = string_sprintf("while renaming %s as %s",
3206 filename, renamename);
3210 /* Rename succeeded */
3214 DEBUG(D_transport) debug_printf("renamed %s as %s\n", filename,
3216 filename = dataname = NULL; /* Prevents attempt to unlink at end */
3218 } /* maildir or mailstore */
3219 } /* successful write + close */
3221 } /* write success */
3224 /* For a file, restore the last access time (atime), and set the modification
3225 time as required - changed if write succeeded, unchanged if not. */
3227 if (!isdirectory) utime(CS filename, ×);
3229 /* Notify comsat if configured to do so. It only makes sense if the configured
3230 file is the one that the comsat daemon knows about. */
3232 if (ob->notify_comsat && yield == OK && deliver_localpart)
3233 notify_comsat(deliver_localpart, saved_size);
3235 /* Pass back the final return code in the address structure */
3238 debug_printf("appendfile yields %d with errno=%d more_errno=%d\n",
3239 yield, addr->basic_errno, addr->more_errno);
3241 addr->transport_return = yield;
3243 /* Close the file, which will release the fcntl lock. For a directory write it
3244 is closed above, except in cases of error which goto RETURN, when we also need
3245 to remove the original file(s). For MBX locking, if all has gone well, before
3246 closing the file, see if we can get an exclusive lock on it, in which case we
3247 can unlink the /tmp lock file before closing it. This is always a non-blocking
3248 lock; there's no need to wait if we can't get it. If everything has gone right
3249 but close fails, defer the message. Then unlink the lock file, if present. This
3250 point in the code is jumped to from a number of places when errors are
3251 detected, in order to get the file closed and the lock file tidied away. */
3256 if (mbx_lockfd >= 0)
3258 if (yield == OK && apply_lock(fd, F_WRLCK, ob->use_fcntl, 0,
3259 ob->use_flock, 0) >= 0)
3262 debug_printf("unlinking MBX lock file %s\n", mbx_lockname);
3263 Uunlink(mbx_lockname);
3265 (void)close(mbx_lockfd);
3267 #endif /* SUPPORT_MBX */
3269 if (fd >= 0 && close(fd) < 0 && yield == OK)
3271 addr->basic_errno = errno;
3272 addr->message = string_sprintf("while closing %s", filename);
3273 addr->transport_return = DEFER;
3276 if (hd >= 0) Uunlink(lockname);
3278 /* We get here with isdirectory and filename set only in error situations. */
3280 if (isdirectory && filename)
3283 if (dataname != filename) Uunlink(dataname);
3286 /* If wait_for_tick is TRUE, we have done a delivery where the uniqueness of a
3287 file name relies on time + pid. We must not allow the process to finish until
3288 the clock has move on by at least one microsecond. Usually we expect this
3289 already to be the case, but machines keep getting faster... */
3291 if (wait_for_tick) exim_wait_tick(&msg_tv, 1);
3293 /* A return of FALSE means that if there was an error, a common error was
3294 put in the first address of a batch. */
3299 addr->message = string_sprintf("Tainted '%s' (file or directory "
3300 "name for %s transport) not permitted", path, tblock->name);
3302 addr->transport_return = PANIC;
3306 #endif /*!MACRO_PREDEF*/
3307 /* End of transport/appendfile.c */