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
891 deliver_dir the delivery directory
893 Returns: TRUE if creation is permitted
897 check_creation(uschar *filename, int create_file, const uschar * deliver_dir)
901 if (deliver_dir && create_file != create_anywhere)
903 int len = Ustrlen(deliver_dir);
904 uschar *file = filename;
906 while (file[0] == '/' && file[1] == '/') file++;
907 if ( Ustrncmp(file, deliver_dir, len) != 0
909 || Ustrchr(file+len+2, '/') != NULL
910 && ( create_file != create_belowhome
911 || Ustrstr(file+len, "/../") != NULL
915 /* If yield is TRUE, the file name starts with the home directory, and does
916 not contain any instances of "/../" in the "belowhome" case. However, it may
917 still contain symbolic links. We can check for this by making use of
918 realpath(), which most Unixes seem to have (but make it possible to cut this
919 out). We can't just use realpath() on the whole file name, because we know
920 the file itself doesn't exist, and intermediate directories may also not
921 exist. What we want to know is the real path of the longest existing part of
922 the path. That must match the home directory's beginning, whichever is the
926 if (yield && create_file == create_belowhome)
930 for (uschar * slash = Ustrrchr(file, '/'); /* There is known to be one */
931 !rp && slash > file; /* Stop if reached beginning */
935 rp = US realpath(CS file, CS big_buffer);
936 next = Ustrrchr(file, '/');
940 /* If rp == NULL it means that none of the relevant directories exist.
941 This is not a problem here - it means that no symbolic links can exist,
942 which is all we are worried about. Otherwise, we must compare it
943 against the start of the home directory. However, that may itself
944 contain symbolic links, so we have to "realpath" it as well, if
949 uschar hdbuffer[PATH_MAX+1];
950 const uschar * rph = deliver_dir;
951 int rlen = Ustrlen(big_buffer);
953 if ((rp = US realpath(CS deliver_dir, CS hdbuffer)))
959 if (rlen > len) rlen = len;
960 if (Ustrncmp(rph, big_buffer, rlen) != 0)
963 DEBUG(D_transport) debug_printf("Real path \"%s\" does not match \"%s\"\n",
964 big_buffer, deliver_dir);
968 #endif /* NO_REALPATH */
976 /*************************************************
978 *************************************************/
980 /* See local README for general interface details. This transport always
981 returns FALSE, indicating that the status which has been placed in the first
982 address should be copied to any other addresses in a batch.
984 Appendfile delivery is tricky and has led to various security problems in other
985 mailers. The logic used here is therefore laid out in some detail. When this
986 function is called, we are running in a subprocess which has had its gid and
987 uid set to the appropriate values. Therefore, we cannot write directly to the
988 exim logs. Any errors must be handled by setting appropriate return codes.
989 Note that the default setting for addr->transport_return is DEFER, so it need
990 not be set unless some other value is required.
992 The code below calls geteuid() rather than getuid() to get the current uid
993 because in weird configurations not running setuid root there may be a
994 difference. In the standard configuration, where setuid() has been used in the
995 delivery process, there will be no difference between the uid and the euid.
997 (1) If the af_file flag is set, this is a delivery to a file after .forward or
998 alias expansion. Otherwise, there must be a configured file name or
1001 The following items apply in the case when a file name (as opposed to a
1002 directory name) is given, that is, when appending to a single file:
1004 (2f) Expand the file name.
1006 (3f) If the file name is /dev/null, return success (optimization).
1008 (4f) If the file_format options is set, open the file for reading, and check
1009 that the bytes at the start of the file match one of the given strings.
1010 If the check indicates a transport other than the current one should be
1011 used, pass control to that other transport. Otherwise continue. An empty
1012 or non-existent file matches the current transport. The file is closed
1015 (5f) If a lock file is required, create it (see extensive separate comments
1016 below about the algorithm for doing this). It is important to do this
1017 before opening the mailbox if NFS is in use.
1019 (6f) Stat the file, using lstat() rather than stat(), in order to pick up
1020 details of any symbolic link.
1022 (7f) If the file already exists:
1024 Check the owner and group if necessary, and defer if they are wrong.
1026 If it is a symbolic link AND the allow_symlink option is set (NOT the
1027 default), go back to (6f) but this time use stat() instead of lstat().
1029 If it's not a regular file (or FIFO when permitted), defer delivery.
1031 Check permissions. If the required permissions are *less* than the
1032 existing ones, or supplied by the address (often by the user via filter),
1033 chmod() the file. Otherwise, defer.
1035 Save the inode number.
1037 Open with O_RDRW + O_APPEND, thus failing if the file has vanished.
1039 If open fails because the file does not exist, go to (6f); on any other
1042 Check the inode number hasn't changed - I realize this isn't perfect (an
1043 inode can be reused) but it's cheap and will catch some of the races.
1045 Check it's still a regular file (or FIFO if permitted).
1047 Check that the owner and permissions haven't changed.
1049 If file_format is set, check that the file still matches the format for
1050 the current transport. If not, defer delivery.
1052 (8f) If file does not exist initially:
1054 Open with O_WRONLY + O_EXCL + O_CREAT with configured mode, unless we know
1055 this is via a symbolic link (only possible if allow_symlinks is set), in
1056 which case don't use O_EXCL, as it doesn't work.
1058 If open fails because the file already exists, go to (6f). To avoid
1059 looping for ever in a situation where the file is continuously being
1060 created and deleted, all of this happens inside a loop that operates
1061 lock_retries times and includes the fcntl and flock locking. If the
1062 loop completes without the file getting opened, defer and request
1063 freezing, because something really weird is happening.
1065 If open fails for any other reason, defer for subsequent delivery except
1066 when this is a file delivery resulting from an alias or forward expansion
1067 and the error is EPERM or ENOENT or EACCES, in which case FAIL as this is
1068 most likely a user rather than a configuration error.
1070 (9f) We now have the file checked and open for writing. If so configured, lock
1071 it using fcntl, flock, or MBX locking rules. If this fails, close the file
1072 and goto (6f), up to lock_retries times, after sleeping for a while. If it
1073 still fails, give up and defer delivery.
1075 (10f)Save the access time (for subsequent restoration) and the size of the
1076 file, for comsat and for re-setting if delivery fails in the middle -
1077 e.g. for quota exceeded.
1079 The following items apply in the case when a directory name is given:
1081 (2d) Create a new file in the directory using a temporary name, by opening for
1082 writing and with O_CREAT. If maildir format is being used, the file
1083 is created in a temporary subdirectory with a prescribed name. If
1084 mailstore format is being used, the envelope file is first created with a
1085 temporary name, then the data file.
1087 The following items apply in all cases:
1089 (11) We now have the file open for writing, and locked if it was given as a
1090 file name. Write the message and flush the file, unless there is a setting
1091 of the local quota option, in which case we can check for its excession
1092 without doing any writing.
1094 In the case of MBX format mailboxes, the message is first written to a
1095 temporary file, in order to get its correct length. This is then copied to
1096 the real file, preceded by an MBX header.
1098 If there is a quota error on writing, defer the address. Timeout logic
1099 will determine for how long retries are attempted. We restore the mailbox
1100 to its original length if it's a single file. There doesn't seem to be a
1101 uniform error code for quota excession (it even differs between SunOS4
1102 and some versions of SunOS5) so a system-dependent macro called
1103 ERRNO_QUOTA is used for it, and the value gets put into errno_quota at
1106 For any other error (most commonly disk full), do the same.
1108 The following applies after appending to a file:
1110 (12f)Restore the atime; notify_comsat if required; close the file (which
1111 unlocks it if it was locked). Delete the lock file if it exists.
1113 The following applies after writing a unique file in a directory:
1115 (12d)For maildir format, rename the file into the new directory. For mailstore
1116 format, rename the envelope file to its correct name. Otherwise, generate
1117 a unique name from the directory_file option, and rename to that, possibly
1118 trying a few times if the file exists and re-expanding the name gives a
1121 This transport yields FAIL only when a file name is generated by an alias or
1122 forwarding operation and attempting to open it gives EPERM, ENOENT, or EACCES.
1123 All other failures return DEFER (in addr->transport_return). */
1127 appendfile_transport_entry(
1128 transport_instance *tblock, /* data for this instantiation */
1129 address_item *addr) /* address we are working on */
1131 appendfile_transport_options_block *ob =
1132 (appendfile_transport_options_block *)(tblock->options_block);
1133 struct stat statbuf;
1134 const uschar * deliver_dir;
1135 uschar *fdname = NULL;
1136 uschar *filename = NULL;
1137 uschar *hitchname = NULL;
1138 uschar *dataname = NULL;
1139 uschar *lockname = NULL;
1140 uschar *newname = NULL;
1141 uschar *nametag = NULL;
1143 uschar *filecount_msg = US"";
1145 struct utimbuf times;
1146 struct timeval msg_tv;
1147 BOOL disable_quota = FALSE;
1148 BOOL isdirectory = FALSE;
1149 BOOL isfifo = FALSE;
1150 BOOL wait_for_tick = FALSE;
1151 uid_t uid = geteuid(); /* See note above */
1152 gid_t gid = getegid();
1154 int mode = (addr->mode > 0) ? addr->mode : ob->mode;
1155 off_t saved_size = -1;
1156 off_t mailbox_size = ob->mailbox_size_value;
1157 int mailbox_filecount = ob->mailbox_filecount_value;
1165 int mbx_lockfd = -1;
1166 uschar mbx_lockname[40];
1167 FILE *temp_file = NULL;
1168 #endif /* SUPPORT_MBX */
1170 #ifdef SUPPORT_MAILDIR
1171 int maildirsize_fd = -1; /* fd for maildirsize file */
1172 int maildir_save_errno;
1176 DEBUG(D_transport) debug_printf("appendfile transport entered\n");
1178 /* An "address_file" or "address_directory" transport is used to deliver to
1179 files specified via .forward or an alias file. Prior to release 4.20, the
1180 "file" and "directory" options were ignored in this case. This has been changed
1181 to allow the redirection data to specify what is in effect a folder, whose
1182 location is determined by the options on the transport.
1184 Compatibility with the case when neither option is set is retained by forcing a
1185 value for the file or directory name. A directory delivery is assumed if the
1186 last character of the path from the router is '/'.
1188 The file path is in the local part of the address, but not in the $local_part
1189 variable (that holds the parent local part). It is, however, in the
1190 $address_file variable. Below, we update the local part in the address if it
1191 changes by expansion, so that the final path ends up in the log. */
1193 if (testflag(addr, af_file) && !ob->filename && !ob->dirname)
1195 fdname = US"$address_file";
1196 if (address_file[Ustrlen(address_file)-1] == '/' ||
1197 ob->maildir_format ||
1198 ob->mailstore_format)
1202 /* Handle (a) an "address file" delivery where "file" or "directory" is
1203 explicitly set and (b) a non-address_file delivery, where one of "file" or
1204 "directory" must be set; initialization ensures that they are not both set. */
1208 if (!(fdname = ob->filename))
1210 fdname = ob->dirname;
1215 addr->message = string_sprintf("Mandatory file or directory option "
1216 "missing from %s transport", tblock->name);
1221 /* Maildir and mailstore require a directory */
1223 if ((ob->maildir_format || ob->mailstore_format) && !isdirectory)
1225 addr->message = string_sprintf("mail%s_format requires \"directory\" "
1226 "to be specified for the %s transport",
1227 ob->maildir_format ? "dir" : "store", tblock->name);
1231 if (!(path = expand_string(fdname)))
1233 addr->message = string_sprintf("Expansion of \"%s\" (file or directory "
1234 "name for %s transport) failed: %s", fdname, tblock->name,
1235 expand_string_message);
1241 addr->message = string_sprintf("appendfile: file or directory name "
1242 "\"%s\" is not absolute", path);
1243 addr->basic_errno = ERRNO_NOTABSOLUTE;
1247 /* For a file delivery, make sure the local part in the address(es) is updated
1248 to the true local part. */
1250 if (testflag(addr, af_file))
1251 for (address_item * addr2 = addr; addr2; addr2 = addr2->next)
1252 addr2->local_part = string_copy(path);
1254 /* The available mailbox formats depend on whether it is a directory or a file
1260 #ifdef SUPPORT_MAILDIR
1261 ob->maildir_format ? mbf_maildir :
1263 #ifdef SUPPORT_MAILSTORE
1264 ob->mailstore_format ? mbf_mailstore :
1272 ob->mbx_format ? mbf_mbx :
1279 debug_printf("appendfile: mode=%o notify_comsat=%d quota=" OFF_T_FMT
1281 " warning=" OFF_T_FMT "%s\n"
1282 " %s=%s format=%s\n message_prefix=%s\n message_suffix=%s\n "
1283 "maildir_use_size_file=%s\n",
1284 mode, ob->notify_comsat, ob->quota_value,
1285 ob->quota_no_check ? " (no_check)" : "",
1286 ob->quota_filecount_no_check ? " (no_check_filecount)" : "",
1287 ob->quota_warn_threshold_value,
1288 ob->quota_warn_threshold_is_percent ? "%" : "",
1289 isdirectory ? "directory" : "file",
1290 path, mailbox_formats[mbformat],
1291 !ob->message_prefix ? US"null" : string_printing(ob->message_prefix),
1292 !ob->message_suffix ? US"null" : string_printing(ob->message_suffix),
1293 ob->maildir_use_size_file ? "yes" : "no");
1295 if (!isdirectory) debug_printf(" locking by %s%s%s%s%s\n",
1296 ob->use_lockfile ? "lockfile " : "",
1297 ob->use_mbx_lock ? "mbx locking (" : "",
1298 ob->use_fcntl ? "fcntl " : "",
1299 ob->use_flock ? "flock" : "",
1300 ob->use_mbx_lock ? ")" : "");
1303 /* If the -N option is set, can't do any more. */
1308 debug_printf("*** delivery by %s transport bypassed by -N option\n",
1310 addr->transport_return = OK;
1314 /* If an absolute path was given for create_file the it overrides deliver_home
1315 (here) and de-taints the filename (below, after check_creation() */
1317 deliver_dir = *ob->create_file_string == '/'
1318 ? ob->create_file_string : deliver_home;
1320 /* Handle the case of a file name. If the file name is /dev/null, we can save
1321 ourselves some effort and just give a success return right away. */
1325 BOOL use_lstat = TRUE;
1326 BOOL file_opened = FALSE;
1327 BOOL allow_creation_here = TRUE;
1329 if (Ustrcmp(path, "/dev/null") == 0)
1331 addr->transport_return = OK;
1335 /* Set the name of the file to be opened, and the file to which the data
1336 is written, and find out if we are permitted to create a non-existent file.
1337 If the create_file option is an absolute path and the file was within it,
1338 de-taint. Chaeck for a tainted path. */
1340 if ( (allow_creation_here = check_creation(path, ob->create_file, deliver_dir))
1341 && ob->create_file == create_belowhome)
1342 if (is_tainted(path))
1344 DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path);
1345 path = string_copy_taint(path, FALSE);
1348 if (is_tainted(path)) goto tainted_ret_panic;
1349 dataname = filename = path;
1351 /* If ob->create_directory is set, attempt to create the directories in
1352 which this mailbox lives, but only if we are permitted to create the file
1353 itself. We know we are dealing with an absolute path, because this was
1356 if (ob->create_directory && allow_creation_here)
1358 uschar *p = Ustrrchr(path, '/');
1360 if (!directory_make(NULL, path, ob->dirmode, FALSE))
1362 addr->basic_errno = errno;
1364 string_sprintf("failed to create directories for %s: %s", path,
1365 exim_errstr(errno));
1366 DEBUG(D_transport) debug_printf("%s transport: %s\n", tblock->name, path);
1372 /* If file_format is set we must check that any existing file matches one of
1373 the configured formats by checking the bytes it starts with. A match then
1374 indicates a specific transport - if it is not this one, pass control to it.
1375 Otherwise carry on here. An empty or non-existent file matches the current
1376 transport. We don't need to distinguish between non-existence and other open
1377 failures because if an existing file fails to open here, it will also fail
1378 again later when O_RDWR is used. */
1380 if (ob->file_format)
1382 int cfd = Uopen(path, O_RDONLY, 0);
1385 transport_instance *tt = check_file_format(cfd, tblock, addr);
1388 /* If another transport is indicated, call it and return; if no transport
1389 was found, just return - the error data will have been set up.*/
1395 set_process_info("delivering %s to %s using %s", message_id,
1396 addr->local_part, tt->name);
1397 debug_print_string(tt->debug_string);
1398 addr->transport = tt;
1399 (tt->info->code)(tt, addr);
1406 /* The locking of mailbox files is worse than the naming of cats, which is
1407 known to be "a difficult matter" (T.S. Eliot) and just as cats must have
1408 three different names, so several different styles of locking are used.
1410 Research in other programs that lock mailboxes shows that there is no
1411 universally standard method. Having mailboxes NFS-mounted on the system that
1412 is delivering mail is not the best thing, but people do run like this,
1413 and so the code must do its best to cope.
1415 Three different locking mechanisms are supported. The initialization function
1416 checks that at least one is configured.
1420 Unless no_use_lockfile is set, we attempt to build a lock file in a way that
1421 will work over NFS. Only after that is done do we actually open the mailbox
1422 and apply locks to it (if configured).
1424 Originally, Exim got the file opened before doing anything about locking.
1425 However, a very occasional problem was observed on Solaris 2 when delivering
1426 over NFS. It is seems that when a file is opened with O_APPEND, the file size
1427 gets remembered at open time. If another process on another host (that's
1428 important) has the file open and locked and writes to it and then releases
1429 the lock while the first process is waiting to get the lock, the first
1430 process may fail to write at the new end point of the file - despite the very
1431 definite statement about O_APPEND in the man page for write(). Experiments
1432 have reproduced this problem, but I do not know any way of forcing a host to
1433 update its attribute cache for an open NFS file. It would be nice if it did
1434 so when a lock was taken out, but this does not seem to happen. Anyway, to
1435 reduce the risk of this problem happening, we now create the lock file
1436 (if configured) *before* opening the mailbox. That will prevent two different
1437 Exims opening the file simultaneously. It may not prevent clashes with MUAs,
1438 however, but Pine at least seems to operate in the same way.
1440 Lockfiles should normally be used when NFS is involved, because of the above
1443 The logic for creating the lock file is:
1445 . The name of the lock file is <mailbox-name>.lock
1447 . First, create a "hitching post" name by adding the primary host name,
1448 current time and pid to the lock file name. This should be unique.
1450 . Create the hitching post file using WRONLY + CREAT + EXCL.
1452 . If that fails EACCES, we assume it means that the user is unable to create
1453 files in the mail spool directory. Some installations might operate in this
1454 manner, so there is a configuration option to allow this state not to be an
1455 error - we proceed to lock using fcntl only, after the file is open.
1457 . Otherwise, an error causes a deferment of the address.
1459 . Hard link the hitching post to the lock file name.
1461 . If the link succeeds, we have successfully created the lock file. Simply
1462 close and unlink the hitching post file.
1464 . If the link does not succeed, proceed as follows:
1466 o Fstat the hitching post file, and then close and unlink it.
1468 o Now examine the stat data. If the number of links to the file is exactly
1469 2, the linking succeeded but for some reason, e.g. an NFS server crash,
1470 the return never made it back, so the link() function gave a failure
1473 . This method allows for the lock file to be created by some other process
1474 right up to the moment of the attempt to hard link it, and is also robust
1475 against NFS server crash-reboots, which would probably result in timeouts
1476 in the middle of link().
1478 . System crashes may cause lock files to get left lying around, and some means
1479 of flushing them is required. The approach of writing a pid (used by smail
1480 and by elm) into the file isn't useful when NFS may be in use. Pine uses a
1481 timeout, which seems a better approach. Since any program that writes to a
1482 mailbox using a lock file should complete its task very quickly, Pine
1483 removes lock files that are older than 5 minutes. We allow the value to be
1484 configurable on the transport.
1488 If use_fcntl_lock is set, then Exim gets an exclusive fcntl() lock on the
1489 mailbox once it is open. This is done by default with a non-blocking lock.
1490 Failures to lock cause retries after a sleep, but only for a certain number
1491 of tries. A blocking lock is deliberately not used so that we don't hold the
1492 mailbox open. This minimizes the possibility of the NFS problem described
1493 under LOCK FILES above, if for some reason NFS deliveries are happening
1494 without lock files. However, the use of a non-blocking lock and sleep, though
1495 the safest approach, does not give the best performance on very busy systems.
1496 A blocking lock plus timeout does better. Therefore Exim has an option to
1497 allow it to work this way. If lock_fcntl_timeout is set greater than zero, it
1498 enables the use of blocking fcntl() calls.
1502 If use_flock_lock is set, then Exim gets an exclusive flock() lock in the
1503 same manner as for fcntl locking above. No-blocking/timeout is also set as
1504 above in lock_flock_timeout. Not all operating systems provide or support
1505 flock(). For those that don't (as determined by the definition of LOCK_SH in
1506 /usr/include/sys/file.h), use_flock_lock may not be set. For some OS, flock()
1507 is implemented (not precisely) on top of fcntl(), which means there's no
1508 point in actually using it.
1512 If use_mbx_lock is set (this is supported only if SUPPORT_MBX is defined)
1513 then the rules used for locking in c-client are used. Exim takes out a shared
1514 lock on the mailbox file, and an exclusive lock on the file whose name is
1515 /tmp/.<device-number>.<inode-number>. The shared lock on the mailbox stops
1516 any other MBX client from getting an exclusive lock on it and expunging it.
1517 It also stops any other MBX client from unlinking the /tmp lock when it has
1520 The exclusive lock on the /tmp file prevents any other MBX client from
1521 updating the mailbox in any way. When writing is finished, if an exclusive
1522 lock on the mailbox can be obtained, indicating there are no current sharers,
1523 the /tmp file is unlinked.
1525 MBX locking can use either fcntl() or flock() locking. If neither
1526 use_fcntl_lock or use_flock_lock is set, it defaults to using fcntl() only.
1527 The calls for getting these locks are by default non-blocking, as for non-mbx
1528 locking, but can be made blocking by setting lock_fcntl_timeout and/or
1529 lock_flock_timeout as appropriate. As MBX delivery doesn't work over NFS, it
1530 probably makes sense to set timeouts for any MBX deliveries. */
1533 /* Build a lock file if configured to do so - the existence of a lock
1534 file is subsequently checked by looking for a non-negative value of the
1535 file descriptor hd - even though the file is no longer open. */
1537 if (ob->use_lockfile)
1539 /* cf. exim_lock.c */
1540 lockname = string_sprintf("%s.lock", filename);
1541 hitchname = string_sprintf( "%s.%s.%08x.%08x", lockname, primary_hostname,
1542 (unsigned int)(time(NULL)), (unsigned int)getpid());
1544 DEBUG(D_transport) debug_printf("lock name: %s\nhitch name: %s\n", lockname,
1547 /* Lock file creation retry loop */
1549 for (i = 0; i < ob->lock_retries; sleep(ob->lock_interval), i++)
1553 hd = Uopen(hitchname, O_WRONLY | O_CREAT | O_EXCL, ob->lockfile_mode);
1556 addr->basic_errno = errno;
1558 string_sprintf("creating lock file hitching post %s "
1559 "(euid=%ld egid=%ld)", hitchname, (long int)geteuid(),
1560 (long int)getegid());
1564 /* Attempt to hitch the hitching post to the lock file. If link()
1565 succeeds (the common case, we hope) all is well. Otherwise, fstat the
1566 file, and get rid of the hitching post. If the number of links was 2,
1567 the link was created, despite the failure of link(). If the hitch was
1568 not successful, try again, having unlinked the lock file if it is too
1571 There's a version of Linux (2.0.27) which doesn't update its local cache
1572 of the inode after link() by default - which many think is a bug - but
1573 if the link succeeds, this code will be OK. It just won't work in the
1574 case when link() fails after having actually created the link. The Linux
1575 NFS person is fixing this; a temporary patch is available if anyone is
1576 sufficiently worried. */
1578 if ((rc = Ulink(hitchname, lockname)) != 0) fstat(hd, &statbuf);
1581 if (rc != 0 && statbuf.st_nlink != 2)
1583 if (ob->lockfile_timeout > 0 && Ustat(lockname, &statbuf) == 0 &&
1584 time(NULL) - statbuf.st_ctime > ob->lockfile_timeout)
1586 DEBUG(D_transport) debug_printf("unlinking timed-out lock file\n");
1589 DEBUG(D_transport) debug_printf("link of hitching post failed - retrying\n");
1593 DEBUG(D_transport) debug_printf("lock file created\n");
1597 /* Check for too many tries at creating the lock file */
1599 if (i >= ob->lock_retries)
1601 addr->basic_errno = ERRNO_LOCKFAILED;
1602 addr->message = string_sprintf("failed to lock mailbox %s (lock file)",
1609 /* We now have to get the file open. First, stat() it and act on existence or
1610 non-existence. This is in a loop to handle the case of a file's being created
1611 or deleted as we watch, and also to handle retries when the locking fails.
1612 Rather than holding the file open while waiting for the fcntl() and/or
1613 flock() lock, we close and do the whole thing again. This should be safer,
1614 especially for NFS files, which might get altered from other hosts, making
1615 their cached sizes incorrect.
1617 With the default settings, no symlinks are permitted, but there is an option
1618 to permit symlinks for those sysadmins that know what they are doing.
1619 Shudder. However, insist that the initial symlink is owned by the right user.
1620 Thus lstat() is used initially; if a symlink is discovered, the loop is
1621 repeated such that stat() is used, to look at the end file. */
1623 for (i = 0; i < ob->lock_retries; i++)
1625 int sleep_before_retry = TRUE;
1626 file_opened = FALSE;
1628 if ((use_lstat ? Ulstat(filename, &statbuf) : Ustat(filename, &statbuf)) != 0)
1630 /* Let's hope that failure to stat (other than non-existence) is a
1633 if (errno != ENOENT)
1635 addr->basic_errno = errno;
1636 addr->message = string_sprintf("attempting to stat mailbox %s",
1641 /* File does not exist. If it is required to pre-exist this state is an
1644 if (ob->file_must_exist)
1646 addr->basic_errno = errno;
1647 addr->message = string_sprintf("mailbox %s does not exist, "
1648 "but file_must_exist is set", filename);
1652 /* If not permitted to create this file because it isn't in or below
1653 the home directory, generate an error. */
1655 if (!allow_creation_here)
1657 addr->basic_errno = ERRNO_BADCREATE;
1658 addr->message = string_sprintf("mailbox %s does not exist, "
1659 "but creation outside the home directory is not permitted",
1664 /* Attempt to create and open the file. If open fails because of
1665 pre-existence, go round the loop again. For any other error, defer the
1666 address, except for an alias or forward generated file name with EPERM,
1667 ENOENT, or EACCES, as those are most likely to be user errors rather
1668 than Exim config errors. When a symbolic link is permitted and points
1669 to a non-existent file, we get here with use_lstat = FALSE. In this case
1670 we mustn't use O_EXCL, since it doesn't work. The file is opened RDRW for
1671 consistency and because MBX locking requires it in order to be able to
1672 get a shared lock. */
1674 fd = Uopen(filename, O_RDWR | O_APPEND | O_CREAT |
1675 (use_lstat ? O_EXCL : 0), mode);
1678 if (errno == EEXIST) continue;
1679 addr->basic_errno = errno;
1680 addr->message = string_sprintf("while creating mailbox %s",
1682 if (testflag(addr, af_file) &&
1683 (errno == EPERM || errno == ENOENT || errno == EACCES))
1684 addr->transport_return = FAIL;
1688 /* We have successfully created and opened the file. Ensure that the group
1689 and the mode are correct. */
1691 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
1693 addr->basic_errno = errno;
1694 addr->message = string_sprintf("while setting perms on mailbox %s",
1696 addr->transport_return = FAIL;
1702 /* The file already exists. Test its type, ownership, and permissions, and
1703 save the inode for checking later. If symlinks are permitted (not the
1704 default or recommended state) it may be a symlink that already exists.
1705 Check its ownership and then look for the file at the end of the link(s).
1706 This at least prevents one user creating a symlink for another user in
1707 a sticky directory. */
1711 int oldmode = (int)statbuf.st_mode;
1712 ino_t inode = statbuf.st_ino;
1713 BOOL islink = (oldmode & S_IFMT) == S_IFLNK;
1715 isfifo = FALSE; /* In case things are changing */
1717 /* Check owner if required - the default. */
1719 if (ob->check_owner && statbuf.st_uid != uid)
1721 addr->basic_errno = ERRNO_BADUGID;
1722 addr->message = string_sprintf("mailbox %s%s has wrong uid "
1723 "(%ld != %ld)", filename,
1724 islink ? " (symlink)" : "",
1725 (long int)(statbuf.st_uid), (long int)uid);
1729 /* Group is checked only if check_group is set. */
1731 if (ob->check_group && statbuf.st_gid != gid)
1733 addr->basic_errno = ERRNO_BADUGID;
1734 addr->message = string_sprintf("mailbox %s%s has wrong gid (%d != %d)",
1735 filename, islink ? " (symlink)" : "", statbuf.st_gid, gid);
1739 /* Just in case this is a sticky-bit mail directory, we don't want
1740 users to be able to create hard links to other users' files. */
1742 if (statbuf.st_nlink != 1)
1744 addr->basic_errno = ERRNO_NOTREGULAR;
1745 addr->message = string_sprintf("mailbox %s%s has too many links (%d)",
1746 filename, islink ? " (symlink)" : "", statbuf.st_nlink);
1751 /* If symlinks are permitted (not recommended), the lstat() above will
1752 have found the symlink. Its ownership has just been checked; go round
1753 the loop again, using stat() instead of lstat(). That will never yield a
1756 if (islink && ob->allow_symlink)
1759 i--; /* Don't count this time round */
1763 /* An actual file exists. Check that it is a regular file, or FIFO
1766 if (ob->allow_fifo && (oldmode & S_IFMT) == S_IFIFO) isfifo = TRUE;
1768 else if ((oldmode & S_IFMT) != S_IFREG)
1770 addr->basic_errno = ERRNO_NOTREGULAR;
1771 addr->message = string_sprintf("mailbox %s is not a regular file%s",
1772 filename, ob->allow_fifo ? " or named pipe" : "");
1776 /* If the mode is not what it would be for a newly created file, change
1777 the permissions if the mode is supplied for the address. Otherwise,
1778 reduce but do not extend the permissions. If the newly created
1779 permissions are greater than the existing permissions, don't change
1780 things when the mode is not from the address. */
1782 if ((oldmode &= 07777) != mode)
1784 int diffs = oldmode ^ mode;
1785 if (addr->mode > 0 || (diffs & oldmode) == diffs)
1787 DEBUG(D_transport) debug_printf("chmod %o %s\n", mode, filename);
1788 if (Uchmod(filename, mode) < 0)
1790 addr->basic_errno = errno;
1791 addr->message = string_sprintf("attempting to chmod mailbox %s",
1798 /* Mode not from address, and newly-created permissions are greater
1799 than existing permissions. Default is to complain, but it can be
1800 configured to go ahead and try to deliver anyway if that's what
1801 the administration wants. */
1803 else if (ob->mode_fail_narrower)
1805 addr->basic_errno = ERRNO_BADMODE;
1806 addr->message = string_sprintf("mailbox %s has the wrong mode %o "
1807 "(%o expected)", filename, oldmode, mode);
1812 /* We are happy with the existing file. Open it, and then do further
1813 tests to ensure that it is the same file that we were just looking at.
1814 If the file does not now exist, restart this loop, going back to using
1815 lstat again. For an NFS error, just defer; other opening errors are
1816 more serious. The file is opened RDWR so that its format can be checked,
1817 and also MBX locking requires the use of a shared (read) lock. However,
1818 a FIFO is opened WRONLY + NDELAY so that it fails if there is no process
1819 reading the pipe. */
1821 fd = Uopen(filename, isfifo ? (O_WRONLY|O_NDELAY) : (O_RDWR|O_APPEND),
1825 if (errno == ENOENT)
1830 addr->basic_errno = errno;
1832 addr->message = string_sprintf("while opening named pipe %s "
1833 "(could mean no process is reading it)", filename);
1834 else if (errno != EWOULDBLOCK)
1835 addr->message = string_sprintf("while opening mailbox %s", filename);
1839 /* This fstat really shouldn't fail, as we have an open file! There's a
1840 dilemma here. We use fstat in order to be sure we are peering at the file
1841 we have got open. However, that won't tell us if the file was reached
1842 via a symbolic link. We checked this above, but there is a race exposure
1843 if the link was created between the previous lstat and the open. However,
1844 it would have to be created with the same inode in order to pass the
1845 check below. If ob->allow_symlink is set, causing the use of stat rather
1846 than lstat above, symbolic links may be there anyway, and the checking is
1849 if (fstat(fd, &statbuf) < 0)
1851 addr->basic_errno = errno;
1852 addr->message = string_sprintf("attempting to stat open mailbox %s",
1857 /* Check the inode; this is isn't a perfect check, but gives some
1860 if (inode != statbuf.st_ino)
1862 addr->basic_errno = ERRNO_INODECHANGED;
1863 addr->message = string_sprintf("opened mailbox %s inode number changed "
1864 "from " INO_T_FMT " to " INO_T_FMT, filename, inode, statbuf.st_ino);
1865 addr->special_action = SPECIAL_FREEZE;
1869 /* Check it's still a regular file or FIFO, and the uid, gid, and
1870 permissions have not changed. */
1872 if ((!isfifo && (statbuf.st_mode & S_IFMT) != S_IFREG) ||
1873 (isfifo && (statbuf.st_mode & S_IFMT) != S_IFIFO))
1875 addr->basic_errno = ERRNO_NOTREGULAR;
1877 string_sprintf("opened mailbox %s is no longer a %s", filename,
1878 isfifo ? "named pipe" : "regular file");
1879 addr->special_action = SPECIAL_FREEZE;
1883 if ((ob->check_owner && statbuf.st_uid != uid) ||
1884 (ob->check_group && statbuf.st_gid != gid))
1886 addr->basic_errno = ERRNO_BADUGID;
1888 string_sprintf("opened mailbox %s has wrong uid or gid", filename);
1889 addr->special_action = SPECIAL_FREEZE;
1893 if ((statbuf.st_mode & 07777) != oldmode)
1895 addr->basic_errno = ERRNO_BADMODE;
1896 addr->message = string_sprintf("opened mailbox %s has wrong mode %o "
1897 "(%o expected)", filename, statbuf.st_mode & 07777, mode);
1898 addr->special_action = SPECIAL_FREEZE;
1902 /* If file_format is set, check that the format of the file has not
1903 changed. Error data is set by the testing function. */
1905 if (ob->file_format && check_file_format(fd, tblock, addr) != tblock)
1907 addr->message = US"open mailbox has changed format";
1911 /* The file is OK. Carry on to do the locking. */
1914 /* We now have an open file, and must lock it using fcntl(), flock() or MBX
1915 locking rules if configured to do so. If a lock file is also required, it
1916 was created above and hd was left >= 0. At least one form of locking is
1917 required by the initialization function. If locking fails here, close the
1918 file and go round the loop all over again, after waiting for a bit, unless
1919 blocking locking was used. */
1922 if ((ob->lock_fcntl_timeout > 0) || (ob->lock_flock_timeout > 0))
1923 sleep_before_retry = FALSE;
1925 /* Simple fcntl() and/or flock() locking */
1927 if (!ob->use_mbx_lock && (ob->use_fcntl || ob->use_flock))
1929 if (apply_lock(fd, F_WRLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
1930 ob->use_flock, ob->lock_flock_timeout) >= 0) break;
1933 /* MBX locking rules */
1936 else if (ob->use_mbx_lock)
1939 struct stat lstatbuf, statbuf2;
1940 if (apply_lock(fd, F_RDLCK, ob->use_fcntl, ob->lock_fcntl_timeout,
1941 ob->use_flock, ob->lock_flock_timeout) >= 0 &&
1942 fstat(fd, &statbuf) >= 0)
1944 sprintf(CS mbx_lockname, "/tmp/.%lx.%lx", (long)statbuf.st_dev,
1945 (long)statbuf.st_ino);
1948 * 2010-05-29: SECURITY
1949 * Dan Rosenberg reported the presence of a race-condition in the
1950 * original code here. Beware that many systems still allow symlinks
1951 * to be followed in /tmp so an attacker can create a symlink pointing
1952 * elsewhere between a stat and an open, which we should avoid
1955 * It's unfortunate that we can't just use all the heavily debugged
1956 * locking from above.
1958 * Also: remember to mirror changes into exim_lock.c */
1960 /* first leave the old pre-check in place, it provides better
1961 * diagnostics for common cases */
1962 if (Ulstat(mbx_lockname, &statbuf) >= 0)
1964 if ((statbuf.st_mode & S_IFMT) == S_IFLNK)
1966 addr->basic_errno = ERRNO_LOCKFAILED;
1967 addr->message = string_sprintf("symbolic link on MBX lock file %s",
1971 if (statbuf.st_nlink > 1)
1973 addr->basic_errno = ERRNO_LOCKFAILED;
1974 addr->message = string_sprintf("hard link to MBX lock file %s",
1980 /* If we could just declare "we must be the ones who create this
1981 * file" then a hitching post in a subdir would work, since a
1982 * subdir directly in /tmp/ which we create wouldn't follow links
1983 * but this isn't our locking logic, so we can't safely change the
1984 * file existence rules. */
1986 /* On systems which support O_NOFOLLOW, it's the easiest and most
1987 * obviously correct security fix */
1988 mbx_tmp_oflags = O_RDWR | O_CREAT;
1990 mbx_tmp_oflags |= O_NOFOLLOW;
1992 mbx_lockfd = Uopen(mbx_lockname, mbx_tmp_oflags, ob->lockfile_mode);
1995 addr->basic_errno = ERRNO_LOCKFAILED;
1996 addr->message = string_sprintf("failed to open MBX lock file %s :%s",
1997 mbx_lockname, strerror(errno));
2001 if (Ulstat(mbx_lockname, &lstatbuf) < 0)
2003 addr->basic_errno = ERRNO_LOCKFAILED;
2004 addr->message = string_sprintf("attempting to lstat open MBX "
2005 "lock file %s: %s", mbx_lockname, strerror(errno));
2008 if (fstat(mbx_lockfd, &statbuf2) < 0)
2010 addr->basic_errno = ERRNO_LOCKFAILED;
2011 addr->message = string_sprintf("attempting to stat fd of open MBX "
2012 "lock file %s: %s", mbx_lockname, strerror(errno));
2018 * statbuf: if exists, is file which existed prior to opening the
2019 * lockfile, might have been replaced since then
2020 * statbuf2: result of stat'ing the open fd, is what was actually
2022 * lstatbuf: result of lstat'ing the filename immediately after
2023 * the open but there's a race condition again between
2024 * those two steps: before open, symlink to foo, after
2025 * open but before lstat have one of:
2026 * * was no symlink, so is the opened file
2027 * (we created it, no messing possible after that point)
2029 * * symlink elsewhere
2030 * * hardlink elsewhere
2032 * Don't want to compare to device of /tmp because some modern systems
2033 * have regressed to having /tmp be the safe actual filesystem as
2034 * valuable data, so is mostly worthless, unless we assume that *only*
2035 * Linux systems do this and that all Linux has O_NOFOLLOW. Something
2036 * for further consideration.
2037 * No point in doing a readlink on the lockfile as that will always be
2038 * at a different point in time from when we open it, so tells us
2039 * nothing; attempts to clean up and delete after ourselves would risk
2040 * deleting a *third* filename.
2042 if ((statbuf2.st_nlink > 1) ||
2043 (lstatbuf.st_nlink > 1) ||
2044 (!S_ISREG(lstatbuf.st_mode)) ||
2045 (lstatbuf.st_dev != statbuf2.st_dev) ||
2046 (lstatbuf.st_ino != statbuf2.st_ino))
2048 addr->basic_errno = ERRNO_LOCKFAILED;
2049 addr->message = string_sprintf("RACE CONDITION detected: "
2050 "mismatch post-initial-checks between \"%s\" and opened "
2051 "fd lead us to abort!", mbx_lockname);
2055 (void)Uchmod(mbx_lockname, ob->lockfile_mode);
2057 if (apply_lock(mbx_lockfd, F_WRLCK, ob->use_fcntl,
2058 ob->lock_fcntl_timeout, ob->use_flock, ob->lock_flock_timeout) >= 0)
2060 struct stat ostatbuf;
2062 /* This tests for a specific race condition. Ensure that we still
2063 have the same file. */
2065 if (Ulstat(mbx_lockname, &statbuf) == 0 &&
2066 fstat(mbx_lockfd, &ostatbuf) == 0 &&
2067 statbuf.st_dev == ostatbuf.st_dev &&
2068 statbuf.st_ino == ostatbuf.st_ino)
2070 DEBUG(D_transport) debug_printf("MBX lockfile %s changed "
2071 "between creation and locking\n", mbx_lockname);
2074 DEBUG(D_transport) debug_printf("failed to lock %s: %s\n", mbx_lockname,
2076 (void)close(mbx_lockfd);
2081 DEBUG(D_transport) debug_printf("failed to fstat or get read lock on %s: %s\n",
2082 filename, strerror(errno));
2085 #endif /* SUPPORT_MBX */
2087 else break; /* No on-file locking required; break the open/lock loop */
2090 debug_printf("fcntl(), flock(), or MBX locking failed - retrying\n");
2094 use_lstat = TRUE; /* Reset to use lstat first */
2097 /* If a blocking call timed out, break the retry loop if the total time
2098 so far is not less than than retries * interval. Use the larger of the
2099 flock() and fcntl() timeouts. */
2102 (i+1) * ((ob->lock_fcntl_timeout > ob->lock_flock_timeout)?
2103 ob->lock_fcntl_timeout : ob->lock_flock_timeout) >=
2104 ob->lock_retries * ob->lock_interval)
2105 i = ob->lock_retries;
2107 /* Wait a bit before retrying, except when it was a blocked fcntl() or
2108 flock() that caused the problem. */
2110 if (i < ob->lock_retries && sleep_before_retry) sleep(ob->lock_interval);
2113 /* Test for exceeding the maximum number of tries. Either the file remains
2114 locked, or, if we haven't got it open, something is terribly wrong... */
2116 if (i >= ob->lock_retries)
2120 addr->basic_errno = ERRNO_EXISTRACE;
2121 addr->message = string_sprintf("mailbox %s: existence unclear", filename);
2122 addr->special_action = SPECIAL_FREEZE;
2126 addr->basic_errno = ERRNO_LOCKFAILED;
2127 addr->message = string_sprintf("failed to lock mailbox %s (fcntl/flock)",
2133 DEBUG(D_transport) debug_printf("mailbox %s is locked\n", filename);
2135 /* Save access time (for subsequent restoration), modification time (for
2136 restoration if updating fails), size of file (for comsat and for re-setting if
2137 delivery fails in the middle - e.g. for quota exceeded). */
2139 if (fstat(fd, &statbuf) < 0)
2141 addr->basic_errno = errno;
2142 addr->message = string_sprintf("while fstatting opened mailbox %s",
2147 times.actime = statbuf.st_atime;
2148 times.modtime = statbuf.st_mtime;
2149 saved_size = statbuf.st_size;
2150 if (mailbox_size < 0) mailbox_size = saved_size;
2151 mailbox_filecount = 0; /* Not actually relevant for single-file mailbox */
2154 /* Prepare for writing to a new file (as opposed to appending to an old one).
2155 There are several different formats, but there is preliminary stuff concerned
2156 with quotas that applies to all of them. Finding the current size by directory
2157 scanning is expensive; for maildirs some fudges have been invented:
2159 (1) A regex can be used to extract a file size from its name;
2160 (2) If maildir_use_size is set, a maildirsize file is used to cache the
2166 uschar *check_path; /* Default quota check path */
2167 const pcre *regex = NULL; /* Regex for file size from file name */
2169 if (!check_creation(string_sprintf("%s/any", path),
2170 ob->create_file, deliver_dir))
2172 addr->basic_errno = ERRNO_BADCREATE;
2173 addr->message = string_sprintf("tried to create file in %s, but "
2174 "file creation outside the home directory is not permitted", path);
2178 /* If the create_file option is an absolute path and the file was within
2179 it, de-taint. Otherwise check for taint. */
2181 if (is_tainted(path))
2182 if (ob->create_file == create_belowhome)
2184 DEBUG(D_transport) debug_printf("de-tainting path '%s'\n", path);
2185 path = string_copy_taint(path, FALSE);
2188 goto tainted_ret_panic;
2192 #ifdef SUPPORT_MAILDIR
2193 /* For a maildir delivery, ensure that all the relevant directories exist,
2194 and a maildirfolder file if necessary. */
2196 if (mbformat == mbf_maildir && !maildir_ensure_directories(path, addr,
2197 ob->create_directory, ob->dirmode, ob->maildirfolder_create_regex))
2199 #endif /* SUPPORT_MAILDIR */
2201 /* If we are going to do a quota check, of if maildir_use_size_file is set
2202 for a maildir delivery, compile the regular expression if there is one. We
2203 may also need to adjust the path that is used. We need to do this for
2204 maildir_use_size_file even if the quota is unset, because we still want to
2205 create the file. When maildir support is not compiled,
2206 ob->maildir_use_size_file is always FALSE. */
2208 if (ob->quota_value > 0 || THRESHOLD_CHECK || ob->maildir_use_size_file)
2210 const uschar *error;
2213 /* Compile the regex if there is one. */
2215 if (ob->quota_size_regex)
2217 if (!(regex = pcre_compile(CS ob->quota_size_regex, PCRE_COPT,
2218 CCSS &error, &offset, NULL)))
2220 addr->message = string_sprintf("appendfile: regular expression "
2221 "error: %s at offset %d while compiling %s", error, offset,
2222 ob->quota_size_regex);
2225 DEBUG(D_transport) debug_printf("using regex for file sizes: %s\n",
2226 ob->quota_size_regex);
2229 /* Use an explicitly configured directory if set */
2231 if (ob->quota_directory)
2233 if (!(check_path = expand_string(ob->quota_directory)))
2235 addr->message = string_sprintf("Expansion of \"%s\" (quota_directory "
2236 "name for %s transport) failed: %s", ob->quota_directory,
2237 tblock->name, expand_string_message);
2241 if (check_path[0] != '/')
2243 addr->message = string_sprintf("appendfile: quota_directory name "
2244 "\"%s\" is not absolute", check_path);
2245 addr->basic_errno = ERRNO_NOTABSOLUTE;
2250 #ifdef SUPPORT_MAILDIR
2251 /* Otherwise, if we are handling a maildir delivery, and the directory
2252 contains a file called maildirfolder, this is a maildir++ feature telling
2253 us that this is a sub-directory of the real inbox. We should therefore do
2254 the quota check on the parent directory. Beware of the special case when
2255 the directory name itself ends in a slash. */
2257 else if (mbformat == mbf_maildir)
2259 struct stat statbuf;
2260 if (Ustat(string_sprintf("%s/maildirfolder", path), &statbuf) >= 0)
2262 uschar *new_check_path = string_copy(check_path);
2263 uschar *slash = Ustrrchr(new_check_path, '/');
2269 slash = Ustrrchr(new_check_path, '/');
2274 check_path = new_check_path;
2275 DEBUG(D_transport) debug_printf("maildirfolder file exists: "
2276 "quota check directory changed to %s\n", check_path);
2281 #endif /* SUPPORT_MAILDIR */
2284 /* If we are using maildirsize files, we need to ensure that such a file
2285 exists and, if necessary, recalculate its contents. As a byproduct of this,
2286 we obtain the current size of the maildir. If no quota is to be enforced
2287 (ob->quota_value == 0), we still need the size if a threshold check will
2290 Another regular expression is used to determine which directories inside the
2291 maildir are going to be counted. */
2293 #ifdef SUPPORT_MAILDIR
2294 if (ob->maildir_use_size_file)
2296 const pcre *dir_regex = NULL;
2297 const uschar *error;
2300 if (ob->maildir_dir_regex)
2302 int check_path_len = Ustrlen(check_path);
2304 if (!(dir_regex = pcre_compile(CS ob->maildir_dir_regex, PCRE_COPT,
2305 CCSS &error, &offset, NULL)))
2307 addr->message = string_sprintf("appendfile: regular expression "
2308 "error: %s at offset %d while compiling %s", error, offset,
2309 ob->maildir_dir_regex);
2314 debug_printf("using regex for maildir directory selection: %s\n",
2315 ob->maildir_dir_regex);
2317 /* Check to see if we are delivering into an ignored directory, that is,
2318 if the delivery path starts with the quota check path, and the rest
2319 of the deliver path matches the regex; if so, set a flag to disable quota
2320 checking and maildirsize updating. */
2322 if (Ustrncmp(path, check_path, check_path_len) == 0)
2324 uschar *s = path + check_path_len;
2325 while (*s == '/') s++;
2326 s = *s ? string_sprintf("%s/new", s) : US"new";
2327 if (pcre_exec(dir_regex, NULL, CS s, Ustrlen(s), 0, 0, NULL, 0) < 0)
2329 disable_quota = TRUE;
2330 DEBUG(D_transport) debug_printf("delivery directory does not match "
2331 "maildir_quota_directory_regex: disabling quota\n");
2336 /* Quota enforcement; create and check the file. There is some discussion
2337 about whether this should happen if the quota is unset. At present, Exim
2338 always creates the file. If we ever want to change this, uncomment
2339 appropriate lines below, possibly doing a check on some option. */
2341 /* if (???? || ob->quota_value > 0) */
2348 if ((maildirsize_fd = maildir_ensure_sizefile(check_path, ob, regex, dir_regex,
2349 &size, &filecount)) == -1)
2351 addr->basic_errno = errno;
2352 addr->message = string_sprintf("while opening or reading "
2353 "%s/maildirsize", check_path);
2356 /* can also return -2, which means that the file was removed because of
2357 raciness; but in this case, the size & filecount will still have been
2360 if (mailbox_size < 0) mailbox_size = size;
2361 if (mailbox_filecount < 0) mailbox_filecount = filecount;
2364 /* No quota enforcement; ensure file does *not* exist; calculate size if
2369 * time_t old_latest;
2370 * (void)unlink(CS string_sprintf("%s/maildirsize", check_path));
2371 * if (THRESHOLD_CHECK)
2372 * mailbox_size = maildir_compute_size(check_path, &mailbox_filecount, &old_latest,
2373 * regex, dir_regex, FALSE);
2378 #endif /* SUPPORT_MAILDIR */
2380 /* Otherwise if we are going to do a quota check later on, and the mailbox
2381 size is not set, find the current size of the mailbox. Ditto for the file
2382 count. Note that ob->quota_filecount_value cannot be set without
2383 ob->quota_value being set. */
2386 && (ob->quota_value > 0 || THRESHOLD_CHECK)
2387 && ( mailbox_size < 0
2388 || mailbox_filecount < 0 && ob->quota_filecount_value > 0
2394 debug_printf("quota checks on directory %s\n", check_path);
2395 size = check_dir_size(check_path, &filecount, regex);
2396 if (mailbox_size < 0) mailbox_size = size;
2397 if (mailbox_filecount < 0) mailbox_filecount = filecount;
2400 /* Handle the case of creating a unique file in a given directory (not in
2401 maildir or mailstore format - this is how smail did it). A temporary name is
2402 used to create the file. Later, when it is written, the name is changed to a
2403 unique one. There is no need to lock the file. An attempt is made to create
2404 the directory if it does not exist. */
2406 if (mbformat == mbf_smail)
2409 debug_printf("delivering to new file in %s\n", path);
2410 filename = dataname =
2411 string_sprintf("%s/temp.%d.%s", path, (int)getpid(), primary_hostname);
2412 fd = Uopen(filename, O_WRONLY|O_CREAT, mode);
2413 if (fd < 0 && /* failed to open, and */
2414 (errno != ENOENT || /* either not non-exist */
2415 !ob->create_directory || /* or not allowed to make */
2416 !directory_make(NULL, path, ob->dirmode, FALSE) || /* or failed to create dir */
2417 (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)) /* or then failed to open */
2419 addr->basic_errno = errno;
2420 addr->message = string_sprintf("while creating file %s", filename);
2425 #ifdef SUPPORT_MAILDIR
2427 /* Handle the case of a unique file in maildir format. The file is written to
2428 the tmp subdirectory, with a prescribed form of name. */
2430 else if (mbformat == mbf_maildir)
2433 debug_printf("delivering in maildir format in %s\n", path);
2435 nametag = ob->maildir_tag;
2437 /* Check that nametag expands successfully; a hard failure causes a panic
2438 return. The actual expansion for use happens again later, when
2439 $message_size is accurately known. */
2441 if (nametag && !expand_string(nametag) && !f.expand_string_forcedfail)
2443 addr->message = string_sprintf("Expansion of \"%s\" (maildir_tag "
2444 "for %s transport) failed: %s", nametag, tblock->name,
2445 expand_string_message);
2449 /* We ensured the existence of all the relevant directories above. Attempt
2450 to open the temporary file a limited number of times. I think this rather
2451 scary-looking for statement is actually OK. If open succeeds, the loop is
2452 broken; if not, there is a test on the value of i. Get the time again
2453 afresh each time round the loop. Its value goes into a variable that is
2454 checked at the end, to make sure we don't release this process until the
2455 clock has ticked. */
2457 for (int i = 1;; i++)
2461 (void)gettimeofday(&msg_tv, NULL);
2462 basename = string_sprintf(TIME_T_FMT ".M%luP" PID_T_FMT ".%s",
2463 msg_tv.tv_sec, msg_tv.tv_usec, getpid(), primary_hostname);
2465 filename = dataname = string_sprintf("tmp/%s", basename);
2466 newname = string_sprintf("new/%s", basename);
2468 if (Ustat(filename, &statbuf) == 0)
2470 else if (errno == ENOENT)
2472 if ((fd = Uopen(filename, O_WRONLY | O_CREAT | O_EXCL, mode)) >= 0)
2474 DEBUG (D_transport) debug_printf ("open failed for %s: %s\n",
2475 filename, strerror(errno));
2478 /* Too many retries - give up */
2480 if (i >= ob->maildir_retries)
2482 addr->message = string_sprintf ("failed to open %s (%d tr%s)",
2483 filename, i, (i == 1) ? "y" : "ies");
2484 addr->basic_errno = errno;
2485 if (errno == errno_quota || errno == ENOSPC)
2486 addr->user_message = US"mailbox is full";
2490 /* Open or stat failed but we haven't tried too many times yet. */
2495 /* Note that we have to ensure the clock has ticked before leaving */
2497 wait_for_tick = TRUE;
2499 /* Why are these here? Put in because they are present in the non-maildir
2500 directory case above. */
2502 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2504 addr->basic_errno = errno;
2505 addr->message = string_sprintf("while setting perms on maildir %s",
2511 #endif /* SUPPORT_MAILDIR */
2513 #ifdef SUPPORT_MAILSTORE
2515 /* Handle the case of a unique file in mailstore format. First write the
2516 envelope to a temporary file, then open the main file. The unique base name
2517 for the files consists of the message id plus the pid of this delivery
2523 mailstore_basename = string_sprintf("%s/%s-%s", path, message_id,
2524 string_base62((long int)getpid()));
2527 debug_printf("delivering in mailstore format in %s\n", path);
2529 filename = string_sprintf("%s.tmp", mailstore_basename);
2530 newname = string_sprintf("%s.env", mailstore_basename);
2531 dataname = string_sprintf("%s.msg", mailstore_basename);
2533 fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode);
2534 if ( fd < 0 /* failed to open, and */
2535 && ( errno != ENOENT /* either not non-exist */
2536 || !ob->create_directory /* or not allowed to make */
2537 || !directory_make(NULL, path, ob->dirmode, FALSE) /* or failed to create dir */
2538 || (fd = Uopen(filename, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0 /* or then failed to open */
2541 addr->basic_errno = errno;
2542 addr->message = string_sprintf("while creating file %s", filename);
2546 /* Why are these here? Put in because they are present in the non-maildir
2547 directory case above. */
2549 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2551 addr->basic_errno = errno;
2552 addr->message = string_sprintf("while setting perms on file %s",
2557 /* Built a C stream from the open file descriptor. */
2559 if (!(env_file = fdopen(fd, "wb")))
2561 addr->basic_errno = errno;
2562 addr->message = string_sprintf("fdopen of %s ("
2563 "for %s transport) failed", filename, tblock->name);
2569 /* Write the envelope file, then close it. */
2571 if (ob->mailstore_prefix)
2573 uschar *s = expand_string(ob->mailstore_prefix);
2576 if (!f.expand_string_forcedfail)
2578 addr->message = string_sprintf("Expansion of \"%s\" (mailstore "
2579 "prefix for %s transport) failed: %s", ob->mailstore_prefix,
2580 tblock->name, expand_string_message);
2581 (void)fclose(env_file);
2589 fprintf(env_file, "%s", CS s);
2590 if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n");
2594 fprintf(env_file, "%s\n", sender_address);
2596 for (address_item * taddr = addr; taddr; taddr = taddr->next)
2597 fprintf(env_file, "%s@%s\n", taddr->local_part, taddr->domain);
2599 if (ob->mailstore_suffix)
2601 uschar *s = expand_string(ob->mailstore_suffix);
2604 if (!f.expand_string_forcedfail)
2606 addr->message = string_sprintf("Expansion of \"%s\" (mailstore "
2607 "suffix for %s transport) failed: %s", ob->mailstore_suffix,
2608 tblock->name, expand_string_message);
2609 (void)fclose(env_file);
2617 fprintf(env_file, "%s", CS s);
2618 if (n == 0 || s[n-1] != '\n') fprintf(env_file, "\n");
2622 if (fclose(env_file) != 0)
2624 addr->basic_errno = errno;
2625 addr->message = string_sprintf("while closing %s", filename);
2630 DEBUG(D_transport) debug_printf("Envelope file %s written\n", filename);
2632 /* Now open the data file, and ensure that it has the correct ownership and
2635 if ((fd = Uopen(dataname, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)
2637 addr->basic_errno = errno;
2638 addr->message = string_sprintf("while creating file %s", dataname);
2642 if (exim_chown(dataname, uid, gid) || Uchmod(dataname, mode))
2644 addr->basic_errno = errno;
2645 addr->message = string_sprintf("while setting perms on file %s",
2651 #endif /* SUPPORT_MAILSTORE */
2654 /* In all cases of writing to a new file, ensure that the file which is
2655 going to be renamed has the correct ownership and mode. */
2657 if (exim_chown(filename, uid, gid) || Uchmod(filename, mode))
2659 addr->basic_errno = errno;
2660 addr->message = string_sprintf("while setting perms on file %s",
2667 /* At last we can write the message to the file, preceded by any configured
2668 prefix line, and followed by any configured suffix line. If there are any
2669 writing errors, we must defer. */
2671 DEBUG(D_transport) debug_printf("writing to file %s\n", dataname);
2676 /* If there is a local quota setting, check that we are not going to exceed it
2677 with this message if quota_is_inclusive is set; if it is not set, the check
2678 is for the mailbox already being over quota (i.e. the current message is not
2679 included in the check). */
2681 if (!disable_quota && ob->quota_value > 0)
2685 debug_printf("Exim quota = " OFF_T_FMT " old size = " OFF_T_FMT
2686 " this message = %d (%sincluded)\n",
2687 ob->quota_value, mailbox_size, message_size,
2688 ob->quota_is_inclusive ? "" : "not ");
2689 debug_printf(" file count quota = %d count = %d\n",
2690 ob->quota_filecount_value, mailbox_filecount);
2693 if (mailbox_size + (ob->quota_is_inclusive ? message_size:0) > ob->quota_value)
2694 if (!ob->quota_no_check)
2696 DEBUG(D_transport) debug_printf("mailbox quota exceeded\n");
2698 errno = ERRNO_EXIMQUOTA;
2701 DEBUG(D_transport) debug_printf("mailbox quota exceeded but ignored\n");
2703 if (ob->quota_filecount_value > 0
2704 && mailbox_filecount + (ob->quota_is_inclusive ? 1:0) >
2705 ob->quota_filecount_value)
2706 if (!ob->quota_filecount_no_check)
2708 DEBUG(D_transport) debug_printf("mailbox file count quota exceeded\n");
2710 errno = ERRNO_EXIMQUOTA;
2711 filecount_msg = US" filecount";
2713 else DEBUG(D_transport) if (ob->quota_filecount_no_check)
2714 debug_printf("mailbox file count quota exceeded but ignored\n");
2720 addr->basic_errno = errno;
2721 addr->message = US"Over quota";
2722 addr->transport_return = yield;
2724 debug_printf("appendfile (verify) yields %d with errno=%d more_errno=%d\n",
2725 yield, addr->basic_errno, addr->more_errno);
2730 /* If we are writing in MBX format, what we actually do is to write the message
2731 to a temporary file, and then copy it to the real file once we know its size.
2732 This is the most straightforward way of getting the correct length in the
2733 separator line. So, what we do here is to save the real file descriptor, and
2734 replace it with one for a temporary file. The temporary file gets unlinked once
2735 opened, so that it goes away on closure. */
2738 if (yield == OK && ob->mbx_format)
2740 if (!(temp_file = tmpfile()))
2742 addr->basic_errno = errno;
2743 addr->message = US"while setting up temporary file";
2748 fd = fileno(temp_file);
2749 DEBUG(D_transport) debug_printf("writing to temporary file\n");
2751 #endif /* SUPPORT_MBX */
2753 /* Zero the count of bytes written. It is incremented by the transport_xxx()
2756 transport_count = 0;
2757 transport_newlines = 0;
2759 /* Write any configured prefix text first */
2761 if (yield == OK && ob->message_prefix && *ob->message_prefix)
2763 uschar *prefix = expand_string(ob->message_prefix);
2766 errno = ERRNO_EXPANDFAIL;
2767 addr->transport_return = PANIC;
2768 addr->message = string_sprintf("Expansion of \"%s\" (prefix for %s "
2769 "transport) failed", ob->message_prefix, tblock->name);
2772 else if (!transport_write_string(fd, "%s", prefix)) yield = DEFER;
2775 /* If the use_bsmtp option is on, we need to write SMTP prefix information. The
2776 various different values for batching are handled outside; if there is more
2777 than one address available here, all must be included. If any address is a
2778 file, use its parent in the RCPT TO. */
2780 if (yield == OK && ob->use_bsmtp)
2782 transport_count = 0;
2783 transport_newlines = 0;
2784 if (ob->use_crlf) cr = US"\r";
2785 if (!transport_write_string(fd, "MAIL FROM:<%s>%s\n", return_path, cr))
2789 transport_newlines++;
2790 for (address_item * a = addr; a; a = a->next)
2792 address_item * b = testflag(a, af_pfr) ? a->parent : a;
2793 if (!transport_write_string(fd, "RCPT TO:<%s>%s\n",
2794 transport_rcpt_address(b, tblock->rcpt_include_affixes), cr))
2795 { yield = DEFER; break; }
2796 transport_newlines++;
2798 if (yield == OK && !transport_write_string(fd, "DATA%s\n", cr))
2801 transport_newlines++;
2805 /* Now the message itself. The options for transport_write_message were set up
2806 at initialization time. */
2810 transport_ctx tctx = {
2814 .check_string = ob->check_string,
2815 .escape_string = ob->escape_string,
2816 .options = ob->options | topt_not_socket
2818 if (!transport_write_message(&tctx, 0))
2822 /* Now a configured suffix. */
2824 if (yield == OK && ob->message_suffix && *ob->message_suffix)
2826 uschar *suffix = expand_string(ob->message_suffix);
2829 errno = ERRNO_EXPANDFAIL;
2830 addr->transport_return = PANIC;
2831 addr->message = string_sprintf("Expansion of \"%s\" (suffix for %s "
2832 "transport) failed", ob->message_suffix, tblock->name);
2835 else if (!transport_write_string(fd, "%s", suffix)) yield = DEFER;
2838 /* If batch smtp, write the terminating dot. */
2840 if (yield == OK && ob->use_bsmtp)
2841 if (!transport_write_string(fd, ".%s\n", cr)) yield = DEFER;
2842 else transport_newlines++;
2844 /* If MBX format is being used, all that writing was to the temporary file.
2845 However, if there was an earlier failure (Exim quota exceeded, for example),
2846 the temporary file won't have got opened - and no writing will have been done.
2847 If writing was OK, we restore the fd, and call a function that copies the
2848 message in MBX format into the real file. Otherwise use the temporary name in
2852 if (temp_file && ob->mbx_format)
2859 transport_count = 0; /* Reset transport count for actual write */
2860 /* No need to reset transport_newlines as we're just using a block copy
2861 * routine so the number won't be affected */
2862 yield = copy_mbx_message(fd, fileno(temp_file), saved_size);
2864 else if (errno >= 0) dataname = US"temporary file";
2866 /* Preserve errno while closing the temporary file. */
2868 mbx_save_errno = errno;
2869 (void)fclose(temp_file);
2870 errno = mbx_save_errno;
2872 #endif /* SUPPORT_MBX */
2874 /* Force out the remaining data to check for any errors; some OS don't allow
2875 fsync() to be called for a FIFO. */
2877 if (yield == OK && !isfifo && EXIMfsync(fd) < 0) yield = DEFER;
2879 /* Update message_size and message_linecount to the accurate count of bytes
2880 written, including added headers. Note; we subtract 1 from message_linecount as
2881 this variable doesn't count the new line between the header and the body of the
2884 message_size = transport_count;
2885 message_linecount = transport_newlines - 1;
2887 /* If using a maildir++ quota file, add this message's size to it, and
2888 close the file descriptor, except when the quota has been disabled because we
2889 are delivering into an uncounted folder. */
2891 #ifdef SUPPORT_MAILDIR
2894 if (yield == OK && maildirsize_fd >= 0)
2895 maildir_record_length(maildirsize_fd, message_size);
2896 maildir_save_errno = errno; /* Preserve errno while closing the file */
2897 if (maildirsize_fd >= 0)
2898 (void)close(maildirsize_fd);
2899 errno = maildir_save_errno;
2901 #endif /* SUPPORT_MAILDIR */
2903 /* If there is a quota warning threshold and we are have crossed it with this
2904 message, set the SPECIAL_WARN flag in the address, to cause a warning message
2907 if (!disable_quota && THRESHOLD_CHECK)
2909 off_t threshold = ob->quota_warn_threshold_value;
2910 if (ob->quota_warn_threshold_is_percent)
2911 threshold = (off_t)(((double)ob->quota_value * threshold) / 100);
2913 debug_printf("quota = " OFF_T_FMT
2914 " threshold = " OFF_T_FMT
2915 " old size = " OFF_T_FMT
2916 " message size = %d\n",
2917 ob->quota_value, threshold, mailbox_size,
2919 if (mailbox_size <= threshold && mailbox_size + message_size > threshold)
2920 addr->special_action = SPECIAL_WARN;
2922 /******* You might think that the test ought to be this:
2924 * if (ob->quota_value > 0 && threshold > 0 && mailbox_size > 0 &&
2925 * mailbox_size <= threshold && mailbox_size + message_size > threshold)
2927 * (indeed, I was sent a patch with that in). However, it is possible to
2928 * have a warning threshold without actually imposing a quota, and I have
2929 * therefore kept Exim backwards compatible.
2934 /* Handle error while writing the file. Control should come here directly after
2935 the error, with the reason in errno. In the case of expansion failure in prefix
2936 or suffix, it will be ERRNO_EXPANDFAIL. */
2940 addr->special_action = SPECIAL_NONE; /* Cancel any quota warning */
2942 /* Save the error number. If positive, it will ultimately cause a strerror()
2943 call to generate some text. */
2945 addr->basic_errno = errno;
2947 /* For system or Exim quota excession, or disk full, set more_errno to the
2948 time since the file was last read. If delivery was into a directory, the
2949 time since last read logic is not relevant, in general. However, for maildir
2950 deliveries we can approximate it by looking at the last modified time of the
2951 "new" subdirectory. Since Exim won't be adding new messages, a change to the
2952 "new" subdirectory implies that an MUA has moved a message from there to the
2955 if (errno == errno_quota || errno == ERRNO_EXIMQUOTA || errno == ENOSPC)
2957 addr->more_errno = 0;
2958 if (!isdirectory) addr->more_errno = (int)(time(NULL) - times.actime);
2960 #ifdef SUPPORT_MAILDIR
2961 else if (mbformat == mbf_maildir)
2963 struct stat statbuf;
2964 if (Ustat("new", &statbuf) < 0)
2966 DEBUG(D_transport) debug_printf("maildir quota exceeded: "
2967 "stat error %d for \"new\": %s\n", errno, strerror(errno));
2969 else /* Want a repeatable time when in test harness */
2970 addr->more_errno = f.running_in_test_harness ? 10 :
2971 (int)time(NULL) - statbuf.st_mtime;
2974 debug_printf("maildir: time since \"new\" directory modified = %s\n",
2975 readconf_printtime(addr->more_errno));
2977 #endif /* SUPPORT_MAILDIR */
2980 /* Handle system quota excession. Add an explanatory phrase for the error
2981 message, since some systems don't have special quota-excession errors,
2982 and on those that do, "quota" doesn't always mean anything to the user. */
2984 if (errno == errno_quota)
2987 addr->message = string_sprintf("mailbox is full "
2988 "(quota exceeded while writing to file %s)", filename);
2990 addr->message = US"mailbox is full";
2992 addr->user_message = US"mailbox is full";
2993 DEBUG(D_transport) debug_printf("System quota exceeded for %s%s%s\n",
2995 isdirectory ? US"" : US": time since file read = ",
2996 isdirectory ? US"" : readconf_printtime(addr->more_errno));
2999 /* Handle Exim's own quota-imposition */
3001 else if (errno == ERRNO_EXIMQUOTA)
3003 addr->message = string_sprintf("mailbox is full "
3004 "(MTA-imposed%s quota exceeded while writing to %s)", filecount_msg,
3006 addr->user_message = US"mailbox is full";
3007 DEBUG(D_transport) debug_printf("Exim%s quota exceeded for %s%s%s\n",
3008 filecount_msg, dataname,
3009 isdirectory ? US"" : US": time since file read = ",
3010 isdirectory ? US"" : readconf_printtime(addr->more_errno));
3013 /* Handle a process failure while writing via a filter; the return
3014 from child_close() is in more_errno. */
3016 else if (errno == ERRNO_FILTER_FAIL)
3019 addr->message = string_sprintf("transport filter process failed (%d) "
3020 "while writing to %s%s", addr->more_errno, dataname,
3021 (addr->more_errno == EX_EXECFAILED) ? ": unable to execute command" : "");
3024 /* Handle failure to expand header changes */
3026 else if (errno == ERRNO_CHHEADER_FAIL)
3030 string_sprintf("failed to expand headers_add or headers_remove while "
3031 "writing to %s: %s", dataname, expand_string_message);
3034 /* Handle failure to complete writing of a data block */
3036 else if (errno == ERRNO_WRITEINCOMPLETE)
3037 addr->message = string_sprintf("failed to write data block while "
3038 "writing to %s", dataname);
3040 /* Handle length mismatch on MBX copying */
3043 else if (errno == ERRNO_MBXLENGTH)
3044 addr->message = string_sprintf("length mismatch while copying MBX "
3045 "temporary file to %s", dataname);
3046 #endif /* SUPPORT_MBX */
3048 /* For other errors, a general-purpose explanation, if the message is
3051 else if (addr->message == NULL)
3052 addr->message = string_sprintf("error while writing to %s", dataname);
3054 /* For a file, reset the file size to what it was before we started, leaving
3055 the last modification time unchanged, so it will get reset also. All systems
3056 investigated so far have ftruncate(), whereas not all have the F_FREESP
3057 fcntl() call (BSDI & FreeBSD do not). */
3059 if (!isdirectory && ftruncate(fd, saved_size))
3060 DEBUG(D_transport) debug_printf("Error resetting file size\n");
3063 /* Handle successful writing - we want the modification time to be now for
3064 appended files. Remove the default backstop error number. For a directory, now
3065 is the time to rename the file with a unique name. As soon as such a name
3066 appears it may get used by another process, so we close the file first and
3067 check that all is well. */
3071 times.modtime = time(NULL);
3072 addr->basic_errno = 0;
3074 /* Handle the case of writing to a new file in a directory. This applies
3075 to all single-file formats - maildir, mailstore, and "smail format". */
3079 if (fstat(fd, &statbuf) < 0)
3081 addr->basic_errno = errno;
3082 addr->message = string_sprintf("while fstatting opened message file %s",
3087 else if (close(fd) < 0)
3089 addr->basic_errno = errno;
3090 addr->message = string_sprintf("close() error for %s",
3091 (ob->mailstore_format) ? dataname : filename);
3095 /* File is successfully written and closed. Arrange to rename it. For the
3096 different kinds of single-file delivery, some games can be played with the
3097 name. The message size is by this time set to the accurate value so that
3098 its value can be used in expansions. */
3102 uschar *renamename = newname;
3105 DEBUG(D_transport) debug_printf("renaming temporary file\n");
3107 /* If there is no rename name set, we are in a non-maildir, non-mailstore
3108 situation. The name is built by expanding the directory_file option, and
3109 we make the inode number available for use in this. The expansion was
3110 checked for syntactic validity above, before we wrote the file.
3112 We have to be careful here, in case the file name exists. (In the other
3113 cases, the names used are constructed to be unique.) The rename()
3114 function just replaces an existing file - we don't want that! So instead
3115 of calling rename(), we must use link() and unlink().
3117 In this case, if the link fails because of an existing file, we wait
3118 for one second and try the expansion again, to see if it produces a
3119 different value. Do this up to 5 times unless the name stops changing.
3120 This makes it possible to build values that are based on the time, and
3121 still cope with races from multiple simultaneous deliveries. */
3126 uschar *old_renameleaf = US"";
3128 for (int i = 0; ; sleep(1), i++)
3130 deliver_inode = statbuf.st_ino;
3131 renameleaf = expand_string(ob->dirfilename);
3136 addr->transport_return = PANIC;
3137 addr->message = string_sprintf("Expansion of \"%s\" "
3138 "(directory_file for %s transport) failed: %s",
3139 ob->dirfilename, tblock->name, expand_string_message);
3143 renamename = string_sprintf("%s/%s", path, renameleaf);
3144 if (Ulink(filename, renamename) < 0)
3146 DEBUG(D_transport) debug_printf("link failed: %s\n",
3148 if (errno != EEXIST || i >= 4 ||
3149 Ustrcmp(renameleaf, old_renameleaf) == 0)
3151 addr->basic_errno = errno;
3152 addr->message = string_sprintf("while renaming %s as %s",
3153 filename, renamename);
3157 old_renameleaf = renameleaf;
3158 DEBUG(D_transport) debug_printf("%s exists - trying again\n",
3167 } /* re-expand loop */
3168 } /* not mailstore or maildir */
3170 /* For maildir and mailstore formats, the new name was created earlier,
3171 except that for maildir, there is the possibility of adding a "tag" on
3172 the end of the name by expanding the value of nametag. This usually
3173 includes a reference to the message size. The expansion of nametag was
3174 checked above, before the file was opened. It either succeeded, or
3175 provoked a soft failure. So any failure here can be treated as soft.
3176 Ignore non-printing characters and / and put a colon at the start if the
3177 first character is alphanumeric. */
3183 uschar *iptr = expand_string(nametag);
3186 uschar *etag = store_get(Ustrlen(iptr) + 2, is_tainted(iptr));
3187 uschar *optr = etag;
3188 for ( ; *iptr; iptr++)
3189 if (mac_isgraph(*iptr) && *iptr != '/')
3191 if (optr == etag && isalnum(*iptr)) *optr++ = ':';
3195 renamename = string_sprintf("%s%s", newname, etag);
3199 /* Do the rename. If the name is too long and a tag exists, try again
3202 if (Urename(filename, renamename) < 0 &&
3203 (nametag == NULL || errno != ENAMETOOLONG ||
3204 (renamename = newname, Urename(filename, renamename) < 0)))
3206 addr->basic_errno = errno;
3207 addr->message = string_sprintf("while renaming %s as %s",
3208 filename, renamename);
3212 /* Rename succeeded */
3216 DEBUG(D_transport) debug_printf("renamed %s as %s\n", filename,
3218 filename = dataname = NULL; /* Prevents attempt to unlink at end */
3220 } /* maildir or mailstore */
3221 } /* successful write + close */
3223 } /* write success */
3226 /* For a file, restore the last access time (atime), and set the modification
3227 time as required - changed if write succeeded, unchanged if not. */
3229 if (!isdirectory) utime(CS filename, ×);
3231 /* Notify comsat if configured to do so. It only makes sense if the configured
3232 file is the one that the comsat daemon knows about. */
3234 if (ob->notify_comsat && yield == OK && deliver_localpart)
3235 notify_comsat(deliver_localpart, saved_size);
3237 /* Pass back the final return code in the address structure */
3240 debug_printf("appendfile yields %d with errno=%d more_errno=%d\n",
3241 yield, addr->basic_errno, addr->more_errno);
3243 addr->transport_return = yield;
3245 /* Close the file, which will release the fcntl lock. For a directory write it
3246 is closed above, except in cases of error which goto RETURN, when we also need
3247 to remove the original file(s). For MBX locking, if all has gone well, before
3248 closing the file, see if we can get an exclusive lock on it, in which case we
3249 can unlink the /tmp lock file before closing it. This is always a non-blocking
3250 lock; there's no need to wait if we can't get it. If everything has gone right
3251 but close fails, defer the message. Then unlink the lock file, if present. This
3252 point in the code is jumped to from a number of places when errors are
3253 detected, in order to get the file closed and the lock file tidied away. */
3258 if (mbx_lockfd >= 0)
3260 if (yield == OK && apply_lock(fd, F_WRLCK, ob->use_fcntl, 0,
3261 ob->use_flock, 0) >= 0)
3264 debug_printf("unlinking MBX lock file %s\n", mbx_lockname);
3265 Uunlink(mbx_lockname);
3267 (void)close(mbx_lockfd);
3269 #endif /* SUPPORT_MBX */
3271 if (fd >= 0 && close(fd) < 0 && yield == OK)
3273 addr->basic_errno = errno;
3274 addr->message = string_sprintf("while closing %s", filename);
3275 addr->transport_return = DEFER;
3278 if (hd >= 0) Uunlink(lockname);
3280 /* We get here with isdirectory and filename set only in error situations. */
3282 if (isdirectory && filename)
3285 if (dataname != filename) Uunlink(dataname);
3288 /* If wait_for_tick is TRUE, we have done a delivery where the uniqueness of a
3289 file name relies on time + pid. We must not allow the process to finish until
3290 the clock has move on by at least one microsecond. Usually we expect this
3291 already to be the case, but machines keep getting faster... */
3293 if (wait_for_tick) exim_wait_tick(&msg_tv, 1);
3295 /* A return of FALSE means that if there was an error, a common error was
3296 put in the first address of a batch. */
3301 addr->message = string_sprintf("Tainted '%s' (file or directory "
3302 "name for %s transport) not permitted", path, tblock->name);
3304 addr->transport_return = PANIC;
3308 #endif /*!MACRO_PREDEF*/
3309 /* End of transport/appendfile.c */