1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim Maintainers 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
9 /* Functions for writing log files. The code for maintaining datestamped
10 log files was originally contributed by Tony Sheen. */
15 #define LOG_NAME_SIZE 256
16 #define MAX_SYSLOG_LEN 870
18 #define LOG_MODE_FILE 1
19 #define LOG_MODE_SYSLOG 2
21 enum { lt_main, lt_reject, lt_panic, lt_debug };
23 static uschar *log_names[] = { US"main", US"reject", US"panic", US"debug" };
27 /*************************************************
28 * Local static variables *
29 *************************************************/
31 static uschar mainlog_name[LOG_NAME_SIZE];
32 static uschar rejectlog_name[LOG_NAME_SIZE];
33 static uschar debuglog_name[LOG_NAME_SIZE];
35 static uschar *mainlog_datestamp = NULL;
36 static uschar *rejectlog_datestamp = NULL;
38 static int mainlogfd = -1;
39 static int rejectlogfd = -1;
40 static ino_t mainlog_inode = 0;
41 static ino_t rejectlog_inode = 0;
43 static uschar *panic_save_buffer = NULL;
44 static BOOL panic_recurseflag = FALSE;
46 static BOOL syslog_open = FALSE;
47 static BOOL path_inspected = FALSE;
48 static int logging_mode = LOG_MODE_FILE;
49 static uschar *file_path = US"";
51 static size_t pid_position[2];
54 /* These should be kept in-step with the private delivery error
55 number definitions in macros.h */
57 static const uschar * exim_errstrings[] = {
80 US"Exim-imposed quota",
82 US"Delivery filter process failure",
83 US"Delivery add/remove header failure",
84 US"Delivery write incomplete error",
85 US"Some expansion failed",
86 US"Failed to get gid",
87 US"Failed to get uid",
88 US"Unset or non-existent transport",
89 US"MBX length mismatch",
90 US"Lookup failed routing or in smtp tpt",
91 US"Can't match format in appendfile",
92 US"Creation outside home in appendfile",
93 US"Can't check a list; lookup defer",
95 US"Failed to start TLS session",
96 US"Mandatory TLS session not started",
97 US"Failed to chown a file",
98 US"Failed to create a pipe",
100 US"When required by client",
101 US"Used internally in smtp transport",
102 US"RCPT gave 4xx error",
103 US"MAIL gave 4xx error",
104 US"DATA gave 4xx error",
105 US"Negotiation failed for proxy configured host",
106 US"Authenticator 'other' failure",
107 US"target not supporting SMTPUTF8",
109 US"tainted filename",
111 US"Not time for routing",
112 US"Not time for local delivery",
113 US"Not time for any remote host",
114 US"Local-only delivery",
115 US"Domain in queue_domains",
116 US"Transport concurrency limit",
117 US"Event requests alternate response",
121 /************************************************/
125 return err < 0 ? exim_errstrings[-err] : CUS strerror(err);
128 /*************************************************
130 *************************************************/
132 /* The given string is split into sections according to length, or at embedded
133 newlines, and syslogged as a numbered sequence if it is overlong or if there is
134 more than one line. However, if we are running in the test harness, do not do
135 anything. (The test harness doesn't use syslog - for obvious reasons - but we
136 can get here if there is a failure to open the panic log.)
139 priority syslog priority
140 s the string to be written
146 write_syslog(int priority, const uschar *s)
151 if (!syslog_pid && LOGGING(pid))
152 s = string_sprintf("%.*s%s", (int)pid_position[0], s, s + pid_position[1]);
153 if (!syslog_timestamp)
155 len = log_timezone ? 26 : 20;
156 if (LOGGING(millisec)) len += 4;
163 if (!syslog_open && !f.running_in_test_harness)
165 # ifdef SYSLOG_LOG_PID
166 openlog(CS syslog_processname, LOG_PID|LOG_CONS, syslog_facility);
168 openlog(CS syslog_processname, LOG_CONS, syslog_facility);
174 /* First do a scan through the message in order to determine how many lines
175 it is going to end up as. Then rescan to output it. */
177 for (int pass = 0; pass < 2; pass++)
179 const uschar * ss = s;
180 for (int i = 1, tlen = len; tlen > 0; i++)
183 uschar *nlptr = Ustrchr(ss, '\n');
184 if (nlptr != NULL) plen = nlptr - ss;
185 #ifndef SYSLOG_LONG_LINES
186 if (plen > MAX_SYSLOG_LEN) plen = MAX_SYSLOG_LEN;
189 if (ss[plen] == '\n') tlen--; /* chars left */
193 else if (f.running_in_test_harness)
195 fprintf(stderr, "SYSLOG: '%.*s'\n", plen, ss);
197 fprintf(stderr, "SYSLOG: '[%d%c%d] %.*s'\n", i,
198 ss[plen] == '\n' && tlen != 0 ? '\\' : '/',
199 linecount, plen, ss);
202 syslog(priority, "%.*s", plen, ss);
204 syslog(priority, "[%d%c%d] %.*s", i,
205 ss[plen] == '\n' && tlen != 0 ? '\\' : '/',
206 linecount, plen, ss);
209 if (*ss == '\n') ss++;
216 /*************************************************
218 *************************************************/
220 /* This is called when Exim is dying as a result of something going wrong in
221 the logging, or after a log call with LOG_PANIC_DIE set. Optionally write a
222 message to debug_file or a stderr file, if they exist. Then, if in the middle
223 of accepting a message, throw it away tidily by calling receive_bomb_out();
224 this will attempt to send an SMTP response if appropriate. Passing NULL as the
225 first argument stops it trying to run the NOTQUIT ACL (which might try further
226 logging and thus cause problems). Otherwise, try to close down an outstanding
230 s1 Error message to write to debug_file and/or stderr and syslog
231 s2 Error message for any SMTP call that is in progress
232 Returns: The function does not return
236 die(uschar *s1, uschar *s2)
240 write_syslog(LOG_CRIT, s1);
241 if (debug_file) debug_printf("%s\n", s1);
242 if (log_stderr && log_stderr != debug_file)
243 fprintf(log_stderr, "%s\n", s1);
245 if (f.receive_call_bombout) receive_bomb_out(NULL, s2); /* does not return */
246 if (smtp_input) smtp_closedown(s2);
247 exim_exit(EXIT_FAILURE);
252 /*************************************************
253 * Create a log file *
254 *************************************************/
256 /* This function is called to create and open a log file. It may be called in a
257 subprocess when the original process is root.
262 The file name has been build in a working buffer, so it is permissible to
263 overwrite it temporarily if it is necessary to create the directory.
265 Returns: a file descriptor, or < 0 on failure (errno set)
269 log_open_already_exim(uschar * const name)
272 const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NONBLOCK;
274 if (geteuid() != exim_uid)
280 fd = Uopen(name, flags, LOG_MODE);
282 /* If creation failed, attempt to build a log directory in case that is the
285 if (fd < 0 && errno == ENOENT)
288 uschar *lastslash = Ustrrchr(name, '/');
290 created = directory_make(NULL, name, LOG_DIRECTORY_MODE, FALSE);
291 DEBUG(D_any) debug_printf("%s log directory %s\n",
292 created ? "created" : "failed to create", name);
294 if (created) fd = Uopen(name, flags, LOG_MODE);
302 /* Inspired by OpenSSH's mm_send_fd(). Thanks!
303 Send fd over socketpair.
304 Return: true iff good.
308 log_send_fd(const int sock, const int fd)
313 char buf[CMSG_SPACE(sizeof(int))];
315 struct cmsghdr *cmsg;
317 struct iovec vec = {.iov_base = &ch, .iov_len = 1};
320 memset(&msg, 0, sizeof(msg));
321 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
322 msg.msg_control = &cmsgbuf.buf;
323 msg.msg_controllen = sizeof(cmsgbuf.buf);
325 cmsg = CMSG_FIRSTHDR(&msg);
326 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
327 cmsg->cmsg_level = SOL_SOCKET;
328 cmsg->cmsg_type = SCM_RIGHTS;
329 *(int *)CMSG_DATA(cmsg) = fd;
334 while ((n = sendmsg(sock, &msg, 0)) == -1 && errno == EINTR);
338 /* Inspired by OpenSSH's mm_receive_fd(). Thanks!
339 Return fd passed over socketpair, or -1 on error.
343 log_recv_fd(const int sock)
348 char buf[CMSG_SPACE(sizeof(int))];
350 struct cmsghdr *cmsg;
352 struct iovec vec = {.iov_base = &ch, .iov_len = 1};
356 memset(&msg, 0, sizeof(msg));
360 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
361 msg.msg_control = &cmsgbuf.buf;
362 msg.msg_controllen = sizeof(cmsgbuf.buf);
364 while ((n = recvmsg(sock, &msg, 0)) == -1 && errno == EINTR) ;
365 if (n != 1 || ch != 'A') return -1;
367 if (!(cmsg = CMSG_FIRSTHDR(&msg))) return -1;
368 if (cmsg->cmsg_type != SCM_RIGHTS) return -1;
369 if ((fd = *(const int *)CMSG_DATA(cmsg)) < 0) return -1;
375 /*************************************************
376 * Create a log file as the exim user *
377 *************************************************/
379 /* This function is called when we are root to spawn an exim:exim subprocess
380 in which we can create a log file. It must be signal-safe since it is called
381 by the usr1_handler().
386 Returns: a file descriptor, or < 0 on failure (errno set)
390 log_open_as_exim(uschar * const name)
393 const uid_t euid = geteuid();
395 if (euid == exim_uid)
396 fd = log_open_already_exim(name);
397 else if (euid == root_uid)
400 if (socketpair(AF_UNIX, SOCK_STREAM, 0, sock) == 0)
402 const pid_t pid = fork();
405 (void)close(sock[0]);
406 if ( setgroups(1, &exim_gid) != 0
407 || setgid(exim_gid) != 0
408 || setuid(exim_uid) != 0
410 || getuid() != exim_uid || geteuid() != exim_uid
411 || getgid() != exim_gid || getegid() != exim_gid
413 || (fd = log_open_already_exim(name)) < 0
414 || !log_send_fd(sock[1], fd)
415 ) _exit(EXIT_FAILURE);
416 (void)close(sock[1]);
420 (void)close(sock[1]);
423 fd = log_recv_fd(sock[0]);
424 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR);
426 (void)close(sock[0]);
433 flags = fcntl(fd, F_GETFD);
434 if (flags != -1) (void)fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
435 flags = fcntl(fd, F_GETFL);
436 if (flags != -1) (void)fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
447 /*************************************************
449 *************************************************/
451 /* This function opens one of a number of logs, creating the log directory if
452 it does not exist. This may be called recursively on failure, in order to open
455 The directory is in the static variable file_path. This is static so that it
456 the work of sorting out the path is done just once per Exim process.
458 Exim is normally configured to avoid running as root wherever possible, the log
459 files must be owned by the non-privileged exim user. To ensure this, first try
460 an open without O_CREAT - most of the time this will succeed. If it fails, try
461 to create the file; if running as root, this must be done in a subprocess to
465 fd where to return the resulting file descriptor
466 type lt_main, lt_reject, lt_panic, or lt_debug
467 tag optional tag to include in the name (only hooked up for debug)
473 open_log(int *fd, int type, uschar *tag)
477 uschar buffer[LOG_NAME_SIZE];
479 /* The names of the log files are controlled by file_path. The panic log is
480 written to the same directory as the main and reject logs, but its name does
481 not have a datestamp. The use of datestamps is indicated by %D/%M in file_path.
482 When opening the panic log, if %D or %M is present, we remove the datestamp
483 from the generated name; if it is at the start, remove a following
484 non-alphanumeric character as well; otherwise, remove a preceding
485 non-alphanumeric character. This is definitely kludgy, but it sort of does what
486 people want, I hope. */
488 ok = string_format(buffer, sizeof(buffer), CS file_path, log_names[type]);
493 /* Save the name of the mainlog for rollover processing. Without a datestamp,
494 it gets statted to see if it has been cycled. With a datestamp, the datestamp
495 will be compared. The static slot for saving it is the same size as buffer,
496 and the text has been checked above to fit, so this use of strcpy() is OK. */
497 Ustrcpy(mainlog_name, buffer);
498 if (string_datestamp_offset > 0)
499 mainlog_datestamp = mainlog_name + string_datestamp_offset;
501 /* Ditto for the reject log */
502 Ustrcpy(rejectlog_name, buffer);
503 if (string_datestamp_offset > 0)
504 rejectlog_datestamp = rejectlog_name + string_datestamp_offset;
506 /* and deal with the debug log (which keeps the datestamp, but does not
508 Ustrcpy(debuglog_name, buffer);
511 /* this won't change the offset of the datestamp */
512 ok2 = string_format(buffer, sizeof(buffer), "%s%s",
515 Ustrcpy(debuglog_name, buffer);
518 /* Remove any datestamp if this is the panic log. This is rare, so there's no
519 need to optimize getting the datestamp length. We remove one non-alphanumeric
520 char afterwards if at the start, otherwise one before. */
521 if (string_datestamp_offset >= 0)
523 uschar * from = buffer + string_datestamp_offset;
524 uschar * to = from + string_datestamp_length;
526 if (from == buffer || from[-1] == '/')
528 if (!isalnum(*to)) to++;
531 if (!isalnum(from[-1])) from--;
533 /* This copy is ok, because we know that to is a substring of from. But
534 due to overlap we must use memmove() not Ustrcpy(). */
535 memmove(from, to, Ustrlen(to)+1);
539 /* If the file name is too long, it is an unrecoverable disaster */
542 die(US"exim: log file path too long: aborting",
543 US"Logging failure; please try later");
545 /* We now have the file name. After a successful open, return. */
547 *fd = log_open_as_exim(buffer);
556 /* Creation failed. There are some circumstances in which we get here when
557 the effective uid is not root or exim, which is the problem. (For example, a
558 non-setuid binary with log_arguments set, called in certain ways.) Rather than
559 just bombing out, force the log to stderr and carry on if stderr is available.
562 if (euid != root_uid && euid != exim_uid && log_stderr)
564 *fd = fileno(log_stderr);
568 /* Otherwise this is a disaster. This call is deliberately ONLY to the panic
569 log. If possible, save a copy of the original line that was being logged. If we
570 are recursing (can't open the panic log either), the pointer will already be
571 set. Also, when we had to use a subprocess for the create we didn't retrieve
572 errno from it, so get the error from the open attempt above (which is often
573 meaningful enough, so leave it). */
575 if (!panic_save_buffer)
576 if ((panic_save_buffer = US malloc(LOG_BUFFER_SIZE)))
577 memcpy(panic_save_buffer, log_buffer, LOG_BUFFER_SIZE);
579 log_write(0, LOG_PANIC_DIE, "Cannot open %s log file \"%s\": %s: "
580 "euid=%d egid=%d", log_names[type], buffer, strerror(errno), euid, getegid());
588 if (type == lt_debug) unlink(CS debuglog_name);
593 /*************************************************
594 * Add configuration file info to log line *
595 *************************************************/
597 /* This is put in a function because it's needed twice (once for debugging,
601 ptr pointer to the end of the line we are building
604 Returns: updated pointer
608 log_config_info(gstring * g, int flags)
610 g = string_cat(g, US"Exim configuration error");
612 if (flags & (LOG_CONFIG_FOR & ~LOG_CONFIG))
613 return string_cat(g, US" for ");
615 if (flags & (LOG_CONFIG_IN & ~LOG_CONFIG))
616 g = string_fmt_append(g, " in line %d of %s", config_lineno, config_filename);
618 return string_catn(g, US":\n ", 4);
622 /*************************************************
623 * A write() operation failed *
624 *************************************************/
626 /* This function is called when write() fails on anything other than the panic
627 log, which can happen if a disk gets full or a file gets too large or whatever.
628 We try to save the relevant message in the panic_save buffer before crashing
631 The potential invoker should probably not call us for EINTR -1 writes. But
632 otherwise, short writes are bad as we don't do non-blocking writes to fds
633 subject to flow control. (If we do, that's new and the logic of this should
637 name the name of the log being written
638 length the string length being written
639 rc the return value from write()
641 Returns: does not return
645 log_write_failed(uschar *name, int length, int rc)
647 int save_errno = errno;
649 if (!panic_save_buffer)
650 if ((panic_save_buffer = US malloc(LOG_BUFFER_SIZE)))
651 memcpy(panic_save_buffer, log_buffer, LOG_BUFFER_SIZE);
653 log_write(0, LOG_PANIC_DIE, "failed to write to %s: length=%d result=%d "
654 "errno=%d (%s)", name, length, rc, save_errno,
655 (save_errno == 0)? "write incomplete" : strerror(save_errno));
661 /*************************************************
662 * Write to an fd, retrying after signals *
663 *************************************************/
665 /* Basic write to fd for logs, handling EINTR.
668 fd the fd to write to
669 buf the string to write
670 length the string length being written
673 length actually written, persisting an errno from write()
676 write_to_fd_buf(int fd, const uschar *buf, size_t length)
679 size_t total_written = 0;
680 const uschar *p = buf;
681 size_t left = length;
685 wrote = write(fd, p, left);
686 if (wrote == (ssize_t)-1)
688 if (errno == EINTR) continue;
691 total_written += wrote;
700 return total_written;
705 set_file_path(BOOL *multiple)
708 int sep = ':'; /* Fixed separator - outside use */
709 const uschar *ss = *log_file_path ? log_file_path : US LOG_FILE_PATH;
712 while ((s = string_nextinlist(&ss, &sep, log_buffer, LOG_BUFFER_SIZE)))
714 if (Ustrcmp(s, "syslog") == 0)
715 logging_mode |= LOG_MODE_SYSLOG;
716 else if (logging_mode & LOG_MODE_FILE) /* we know a file already */
718 if (multiple) *multiple = TRUE;
722 logging_mode |= LOG_MODE_FILE;
724 /* If a non-empty path is given, use it */
727 file_path = string_copy(s);
729 /* If the path is empty, we want to use the first non-empty, non-
730 syslog item in LOG_FILE_PATH, if there is one, since the value of
731 log_file_path may have been set at runtime. If there is no such item,
732 use the ultimate default in the spool directory. */
741 /* avoid closing it if it is closed already or if we do not see a chance
742 to open the file mainlog later again */
743 if (mainlogfd < 0 /* already closed */
744 || !(geteuid() == 0 || geteuid() == exim_uid))
746 (void)close(mainlogfd);
751 /*************************************************
752 * Write message to log file *
753 *************************************************/
755 /* Exim can be configured to log to local files, or use syslog, or both. This
756 is controlled by the setting of log_file_path. The following cases are
759 log_file_path = "" write files in the spool/log directory
760 log_file_path = "xxx" write files in the xxx directory
761 log_file_path = "syslog" write to syslog
762 log_file_path = "syslog : xxx" write to syslog and to files (any order)
764 The message always gets '\n' added on the end of it, since more than one
765 process may be writing to the log at once and we don't want intermingling to
766 happen in the middle of lines. To be absolutely sure of this we write the data
767 into a private buffer and then put it out in a single write() call.
769 The flags determine which log(s) the message is written to, or for syslogging,
770 which priority to use, and in the case of the panic log, whether the process
771 should die afterwards.
773 The variable really_exim is TRUE only when exim is running in privileged state
774 (i.e. not with a changed configuration or with testing options such as -brw).
775 If it is not, don't try to write to the log because permission will probably be
778 Avoid actually writing to the logs when exim is called with -bv or -bt to
779 test an address, but take other actions, such as panicking.
781 In Exim proper, the buffer for building the message is got at start-up, so that
782 nothing gets done if it can't be got. However, some functions that are also
783 used in utilities occasionally obey log_write calls in error situations, and it
784 is simplest to put a single malloc() here rather than put one in each utility.
785 Malloc is used directly because the store functions may call log_write().
787 If a message_id exists, we include it after the timestamp.
790 selector write to main log or LOG_INFO only if this value is zero, or if
791 its bit is set in log_selector[0]
792 flags each bit indicates some independent action:
793 LOG_SENDER add raw sender to the message
794 LOG_RECIPIENTS add raw recipients list to message
795 LOG_CONFIG add "Exim configuration error"
796 LOG_CONFIG_FOR add " for " instead of ":\n "
797 LOG_CONFIG_IN add " in line x[ of file y]"
798 LOG_MAIN write to main log or syslog LOG_INFO
799 LOG_REJECT write to reject log or syslog LOG_NOTICE
800 LOG_PANIC write to panic log or syslog LOG_ALERT
801 LOG_PANIC_DIE write to panic log or LOG_ALERT and then crash
802 format a printf() format
803 ... arguments for format
809 log_write(unsigned int selector, int flags, const char *format, ...)
813 gstring gs = { .size = LOG_BUFFER_SIZE-1, .ptr = 0, .s = log_buffer };
817 /* If panic_recurseflag is set, we have failed to open the panic log. This is
818 the ultimate disaster. First try to write the message to a debug file and/or
819 stderr and also to syslog. If panic_save_buffer is not NULL, it contains the
820 original log line that caused the problem. Afterwards, expire. */
822 if (panic_recurseflag)
824 uschar *extra = panic_save_buffer ? panic_save_buffer : US"";
825 if (debug_file) debug_printf("%s%s", extra, log_buffer);
826 if (log_stderr && log_stderr != debug_file)
827 fprintf(log_stderr, "%s%s", extra, log_buffer);
828 if (*extra) write_syslog(LOG_CRIT, extra);
829 write_syslog(LOG_CRIT, log_buffer);
830 die(US"exim: could not open panic log - aborting: see message(s) above",
831 US"Unexpected log failure, please try later");
834 /* Ensure we have a buffer (see comment above); this should never be obeyed
835 when running Exim proper, only when running utilities. */
838 if (!(log_buffer = US malloc(LOG_BUFFER_SIZE)))
840 fprintf(stderr, "exim: failed to get store for log buffer\n");
841 exim_exit(EXIT_FAILURE);
844 /* If we haven't already done so, inspect the setting of log_file_path to
845 determine whether to log to files and/or to syslog. Bits in logging_mode
846 control this, and for file logging, the path must end up in file_path. This
847 variable must be in permanent store because it may be required again later in
852 BOOL multiple = FALSE;
853 int old_pool = store_pool;
855 store_pool = POOL_PERM;
857 /* If nothing has been set, don't waste effort... the default values for the
858 statics are file_path="" and logging_mode = LOG_MODE_FILE. */
860 if (*log_file_path) set_file_path(&multiple);
862 /* If no modes have been selected, it is a major disaster */
864 if (logging_mode == 0)
865 die(US"Neither syslog nor file logging set in log_file_path",
866 US"Unexpected logging failure");
868 /* Set up the ultimate default if necessary. Then revert to the old store
869 pool, and record that we've sorted out the path. */
871 if (logging_mode & LOG_MODE_FILE && !file_path[0])
872 file_path = string_sprintf("%s/log/%%slog", spool_directory);
873 store_pool = old_pool;
874 path_inspected = TRUE;
876 /* If more than one file path was given, log a complaint. This recursive call
877 should work since we have now set up the routing. */
880 log_write(0, LOG_MAIN|LOG_PANIC,
881 "More than one path given in log_file_path: using %s", file_path);
884 /* If debugging, show all log entries, but don't show headers. Do it all
885 in one go so that it doesn't get split when multi-processing. */
891 g = string_catn(&gs, US"LOG:", 4);
893 /* Show the selector that was passed into the call. */
895 for (i = 0; i < log_options_count; i++)
897 unsigned int bitnum = log_options[i].bit;
898 if (bitnum < BITWORDSIZE && selector == BIT(bitnum))
899 g = string_fmt_append(g, " %s", log_options[i].name);
902 g = string_fmt_append(g, "%s%s%s%s\n ",
903 flags & LOG_MAIN ? " MAIN" : "",
904 flags & LOG_PANIC ? " PANIC" : "",
905 (flags & LOG_PANIC_DIE) == LOG_PANIC_DIE ? " DIE" : "",
906 flags & LOG_REJECT ? " REJECT" : "");
908 if (flags & LOG_CONFIG) g = log_config_info(g, flags);
910 /* We want to be able to log tainted info, but log_buffer is directly
911 malloc'd. So use deliberately taint-nonchecking routines to build into
912 it, trusting that we will never expand the results. */
914 va_start(ap, format);
916 if (!string_vformat(g, SVFMT_TAINT_NOCHK, format, ap))
919 g = string_cat(g, US"**** log string overflowed log buffer ****");
923 g->size = LOG_BUFFER_SIZE;
924 g = string_catn(g, US"\n", 1);
925 debug_printf("%s", string_from_gstring(g));
927 gs.size = LOG_BUFFER_SIZE-1; /* Having used the buffer for debug output, */
928 gs.ptr = 0; /* reset it for the real use. */
931 /* If no log file is specified, we are in a mess. */
933 if (!(flags & (LOG_MAIN|LOG_PANIC|LOG_REJECT)))
934 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "log_write called with no log "
937 /* There are some weird circumstances in which logging is disabled. */
939 if (f.disable_logging)
941 DEBUG(D_any) debug_printf("log writing disabled\n");
942 if ((flags & LOG_PANIC_DIE) == LOG_PANIC_DIE) exim_exit(EXIT_FAILURE);
946 /* Handle disabled reject log */
948 if (!write_rejectlog) flags &= ~LOG_REJECT;
950 /* Create the main message in the log buffer. Do not include the message id
951 when called by a utility. */
953 g = string_fmt_append(&gs, "%s ", tod_stamp(tod_log));
957 if (!syslog_pid) pid_position[0] = g->ptr; /* remember begin … */
958 g = string_fmt_append(g, "[%d] ", (int)getpid());
959 if (!syslog_pid) pid_position[1] = g->ptr; /* … and end+1 of the PID */
962 if (f.really_exim && message_id[0] != 0)
963 g = string_fmt_append(g, "%s ", message_id);
965 if (flags & LOG_CONFIG)
966 g = log_config_info(g, flags);
968 va_start(ap, format);
972 /* We want to be able to log tainted info, but log_buffer is directly
973 malloc'd. So use deliberately taint-nonchecking routines to build into
974 it, trusting that we will never expand the results. */
976 if (!string_vformat(g, SVFMT_TAINT_NOCHK, format, ap))
979 g = string_cat(g, US"**** log string overflowed log buffer ****\n");
984 /* Add the raw, unrewritten, sender to the message if required. This is done
985 this way because it kind of fits with LOG_RECIPIENTS. */
987 if ( flags & LOG_SENDER
988 && g->ptr < LOG_BUFFER_SIZE - 10 - Ustrlen(raw_sender))
989 g = string_fmt_append_f(g, SVFMT_TAINT_NOCHK, " from <%s>", raw_sender);
991 /* Add list of recipients to the message if required; the raw list,
992 before rewriting, was saved in raw_recipients. There may be none, if an ACL
993 discarded them all. */
995 if ( flags & LOG_RECIPIENTS
996 && g->ptr < LOG_BUFFER_SIZE - 6
997 && raw_recipients_count > 0)
1000 g = string_fmt_append_f(g, SVFMT_TAINT_NOCHK, " for", NULL);
1001 for (i = 0; i < raw_recipients_count; i++)
1003 uschar * s = raw_recipients[i];
1004 if (LOG_BUFFER_SIZE - g->ptr < Ustrlen(s) + 3) break;
1005 g = string_fmt_append_f(g, SVFMT_TAINT_NOCHK, " %s", s);
1009 g = string_catn(g, US"\n", 1);
1010 string_from_gstring(g);
1012 /* Handle loggable errors when running a utility, or when address testing.
1013 Write to log_stderr unless debugging (when it will already have been written),
1014 or unless there is no log_stderr (expn called from daemon, for example). */
1016 if (!f.really_exim || f.log_testing_mode)
1018 if ( !debug_selector
1020 && (selector == 0 || (selector & log_selector[0]) != 0)
1023 fprintf(log_stderr, "LOG: %s", CS(log_buffer + 20)); /* no timestamp */
1025 fprintf(log_stderr, "%s", CS log_buffer);
1027 if ((flags & LOG_PANIC_DIE) == LOG_PANIC_DIE) exim_exit(EXIT_FAILURE);
1031 /* Handle the main log. We know that either syslog or file logging (or both) is
1032 set up. A real file gets left open during reception or delivery once it has
1033 been opened, but we don't want to keep on writing to it for too long after it
1034 has been renamed. Therefore, do a stat() and see if the inode has changed, and
1037 if ( flags & LOG_MAIN
1038 && (!selector || selector & log_selector[0]))
1040 if ( logging_mode & LOG_MODE_SYSLOG
1041 && (syslog_duplication || !(flags & (LOG_REJECT|LOG_PANIC))))
1042 write_syslog(LOG_INFO, log_buffer);
1044 if (logging_mode & LOG_MODE_FILE)
1046 struct stat statbuf;
1048 /* Check for a change to the mainlog file name when datestamping is in
1049 operation. This happens at midnight, at which point we want to roll over
1050 the file. Closing it has the desired effect. */
1052 if (mainlog_datestamp)
1054 uschar *nowstamp = tod_stamp(string_datestamp_type);
1055 if (Ustrncmp (mainlog_datestamp, nowstamp, Ustrlen(nowstamp)) != 0)
1057 (void)close(mainlogfd); /* Close the file */
1058 mainlogfd = -1; /* Clear the file descriptor */
1059 mainlog_inode = 0; /* Unset the inode */
1060 mainlog_datestamp = NULL; /* Clear the datestamp */
1064 /* Otherwise, we want to check whether the file has been renamed by a
1065 cycling script. This could be "if else", but for safety's sake, leave it as
1066 "if" so that renaming the log starts a new file even when datestamping is
1070 if (Ustat(mainlog_name, &statbuf) < 0 || statbuf.st_ino != mainlog_inode)
1073 /* If the log is closed, open it. Then write the line. */
1077 open_log(&mainlogfd, lt_main, NULL); /* No return on error */
1078 if (fstat(mainlogfd, &statbuf) >= 0) mainlog_inode = statbuf.st_ino;
1081 /* Failing to write to the log is disastrous */
1083 written_len = write_to_fd_buf(mainlogfd, g->s, g->ptr);
1084 if (written_len != g->ptr)
1086 log_write_failed(US"main log", g->ptr, written_len);
1087 /* That function does not return */
1092 /* Handle the log for rejected messages. This can be globally disabled, in
1093 which case the flags are altered above. If there are any header lines (i.e. if
1094 the rejection is happening after the DATA phase), log the recipients and the
1097 if (flags & LOG_REJECT)
1099 if (header_list && LOGGING(rejected_header))
1104 if (recipients_count > 0)
1106 /* List the sender */
1108 g2 = string_fmt_append_f(g, SVFMT_TAINT_NOCHK,
1109 "Envelope-from: <%s>\n", sender_address);
1112 /* List up to 5 recipients */
1114 g2 = string_fmt_append_f(g, SVFMT_TAINT_NOCHK,
1115 "Envelope-to: <%s>\n", recipients_list[0].address);
1118 for (i = 1; i < recipients_count && i < 5; i++)
1120 g2 = string_fmt_append_f(g, SVFMT_TAINT_NOCHK,
1121 " <%s>\n", recipients_list[i].address);
1125 if (i < recipients_count)
1127 g2 = string_fmt_append_f(g, SVFMT_TAINT_NOCHK, " ...\n", NULL);
1132 /* A header with a NULL text is an unfilled in Received: header */
1134 for (header_line * h = header_list; h; h = h->next) if (h->text)
1136 g2 = string_fmt_append_f(g, SVFMT_TAINT_NOCHK,
1137 "%c %s", h->type, h->text);
1140 else /* Buffer is full; truncate */
1142 g->ptr -= 100; /* For message and separator */
1143 if (g->s[g->ptr-1] == '\n') g->ptr--;
1144 g = string_cat(g, US"\n*** truncated ***\n");
1150 /* Write to syslog or to a log file */
1152 if ( logging_mode & LOG_MODE_SYSLOG
1153 && (syslog_duplication || !(flags & LOG_PANIC)))
1154 write_syslog(LOG_NOTICE, string_from_gstring(g));
1156 /* Check for a change to the rejectlog file name when datestamping is in
1157 operation. This happens at midnight, at which point we want to roll over
1158 the file. Closing it has the desired effect. */
1160 if (logging_mode & LOG_MODE_FILE)
1162 struct stat statbuf;
1164 if (rejectlog_datestamp)
1166 uschar *nowstamp = tod_stamp(string_datestamp_type);
1167 if (Ustrncmp (rejectlog_datestamp, nowstamp, Ustrlen(nowstamp)) != 0)
1169 (void)close(rejectlogfd); /* Close the file */
1170 rejectlogfd = -1; /* Clear the file descriptor */
1171 rejectlog_inode = 0; /* Unset the inode */
1172 rejectlog_datestamp = NULL; /* Clear the datestamp */
1176 /* Otherwise, we want to check whether the file has been renamed by a
1177 cycling script. This could be "if else", but for safety's sake, leave it as
1178 "if" so that renaming the log starts a new file even when datestamping is
1181 if (rejectlogfd >= 0)
1182 if (Ustat(rejectlog_name, &statbuf) < 0 ||
1183 statbuf.st_ino != rejectlog_inode)
1185 (void)close(rejectlogfd);
1187 rejectlog_inode = 0;
1190 /* Open the file if necessary, and write the data */
1192 if (rejectlogfd < 0)
1194 open_log(&rejectlogfd, lt_reject, NULL); /* No return on error */
1195 if (fstat(rejectlogfd, &statbuf) >= 0) rejectlog_inode = statbuf.st_ino;
1198 written_len = write_to_fd_buf(rejectlogfd, g->s, g->ptr);
1199 if (written_len != g->ptr)
1201 log_write_failed(US"reject log", g->ptr, written_len);
1202 /* That function does not return */
1208 /* Handle the panic log, which is not kept open like the others. If it fails to
1209 open, there will be a recursive call to log_write(). We detect this above and
1210 attempt to write to the system log as a last-ditch try at telling somebody. In
1211 all cases except mua_wrapper, try to write to log_stderr. */
1213 if (flags & LOG_PANIC)
1215 if (log_stderr && log_stderr != debug_file && !mua_wrapper)
1216 fprintf(log_stderr, "%s", CS string_from_gstring(g));
1218 if (logging_mode & LOG_MODE_SYSLOG)
1219 write_syslog(LOG_ALERT, log_buffer);
1221 /* If this panic logging was caused by a failure to open the main log,
1222 the original log line is in panic_save_buffer. Make an attempt to write it. */
1224 if (logging_mode & LOG_MODE_FILE)
1226 panic_recurseflag = TRUE;
1227 open_log(&paniclogfd, lt_panic, NULL); /* Won't return on failure */
1228 panic_recurseflag = FALSE;
1230 if (panic_save_buffer)
1231 (void) write(paniclogfd, panic_save_buffer, Ustrlen(panic_save_buffer));
1233 written_len = write_to_fd_buf(paniclogfd, g->s, g->ptr);
1234 if (written_len != g->ptr)
1236 int save_errno = errno;
1237 write_syslog(LOG_CRIT, log_buffer);
1238 sprintf(CS log_buffer, "write failed on panic log: length=%d result=%d "
1239 "errno=%d (%s)", g->ptr, (int)written_len, save_errno, strerror(save_errno));
1240 write_syslog(LOG_CRIT, string_from_gstring(g));
1241 flags |= LOG_PANIC_DIE;
1244 (void)close(paniclogfd);
1247 /* Give up if the DIE flag is set */
1249 if ((flags & LOG_PANIC_DIE) != LOG_PANIC)
1250 die(NULL, US"Unexpected failure, please try later");
1256 /*************************************************
1257 * Close any open log files *
1258 *************************************************/
1264 { (void)close(mainlogfd); mainlogfd = -1; }
1265 if (rejectlogfd >= 0)
1266 { (void)close(rejectlogfd); rejectlogfd = -1; }
1268 syslog_open = FALSE;
1273 /*************************************************
1274 * Multi-bit set or clear *
1275 *************************************************/
1277 /* These functions take a list of bit indexes (terminated by -1) and
1278 clear or set the corresponding bits in the selector.
1281 selector address of the bit string
1282 selsize number of words in the bit string
1283 bits list of bits to set
1287 bits_clear(unsigned int *selector, size_t selsize, int *bits)
1289 for(; *bits != -1; ++bits)
1290 BIT_CLEAR(selector, selsize, *bits);
1294 bits_set(unsigned int *selector, size_t selsize, int *bits)
1296 for(; *bits != -1; ++bits)
1297 BIT_SET(selector, selsize, *bits);
1302 /*************************************************
1303 * Decode bit settings for log/debug *
1304 *************************************************/
1306 /* This function decodes a string containing bit settings in the form of +name
1307 and/or -name sequences, and sets/unsets bits in a bit string accordingly. It
1308 also recognizes a numeric setting of the form =<number>, but this is not
1309 intended for user use. It's an easy way for Exim to pass the debug settings
1310 when it is re-exec'ed.
1312 The option table is a list of names and bit indexes. The index -1
1313 means "set all bits, except for those listed in notall". The notall
1314 list is terminated by -1.
1316 The action taken for bad values varies depending upon why we're here.
1317 For log messages, or if the debugging is triggered from config, then we write
1318 to the log on the way out. For debug setting triggered from the command-line,
1319 we treat it as an unknown option: error message to stderr and die.
1322 selector address of the bit string
1323 selsize number of words in the bit string
1324 notall list of bits to exclude from "all"
1325 string the configured string
1326 options the table of option names
1328 which "log" or "debug"
1329 flags DEBUG_FROM_CONFIG
1331 Returns: nothing on success - bomb out on failure
1335 decode_bits(unsigned int *selector, size_t selsize, int *notall,
1336 uschar *string, bit_table *options, int count, uschar *which, int flags)
1339 if (!string) return;
1343 char *end; /* Not uschar */
1344 memset(selector, 0, sizeof(*selector)*selsize);
1345 *selector = strtoul(CS string+1, &end, 0);
1347 errmsg = string_sprintf("malformed numeric %s_selector setting: %s", which,
1352 /* Handle symbolic setting */
1359 bit_table *start, *end;
1361 Uskip_whitespace(&string);
1362 if (!*string) return;
1364 if (*string != '+' && *string != '-')
1366 errmsg = string_sprintf("malformed %s_selector setting: "
1367 "+ or - expected but found \"%s\"", which, string);
1371 adding = *string++ == '+';
1373 while (isalnum(*string) || *string == '_') string++;
1377 end = options + count;
1381 bit_table *middle = start + (end - start)/2;
1382 int c = Ustrncmp(s, middle->name, len);
1384 if (middle->name[len] != 0) c = -1; else
1386 unsigned int bit = middle->bit;
1392 memset(selector, -1, sizeof(*selector)*selsize);
1393 bits_clear(selector, selsize, notall);
1396 memset(selector, 0, sizeof(*selector)*selsize);
1399 BIT_SET(selector, selsize, bit);
1401 BIT_CLEAR(selector, selsize, bit);
1403 break; /* Out of loop to match selector name */
1405 if (c < 0) end = middle; else start = middle + 1;
1406 } /* Loop to match selector name */
1410 errmsg = string_sprintf("unknown %s_selector setting: %c%.*s", which,
1411 adding? '+' : '-', len, s);
1414 } /* Loop for selector names */
1416 /* Handle disasters */
1419 if (Ustrcmp(which, "debug") == 0)
1421 if (flags & DEBUG_FROM_CONFIG)
1423 log_write(0, LOG_CONFIG|LOG_PANIC, "%s", errmsg);
1426 fprintf(stderr, "exim: %s\n", errmsg);
1429 else log_write(0, LOG_CONFIG|LOG_PANIC_DIE, "%s", errmsg);
1434 /*************************************************
1435 * Activate a debug logfile (late) *
1436 *************************************************/
1438 /* Normally, debugging is activated from the command-line; it may be useful
1439 within the configuration to activate debugging later, based on certain
1440 conditions. If debugging is already in progress, we return early, no action
1441 taken (besides debug-logging that we wanted debug-logging).
1443 Failures in options are not fatal but will result in paniclog entries for the
1446 The first use of this is in ACL logic, "control = debug/tag=foo/opts=+expand"
1447 which can be combined with conditions, etc, to activate extra logging only
1448 for certain sources. The second use is inetd wait mode debug preservation. */
1451 debug_logging_activate(uschar *tag_name, uschar *opts)
1457 debug_printf("DEBUGGING ACTIVATED FROM WITHIN CONFIG.\n"
1458 "DEBUG: Tag=\"%s\" opts=\"%s\"\n", tag_name, opts ? opts : US"");
1462 if (tag_name != NULL && (Ustrchr(tag_name, '/') != NULL))
1464 log_write(0, LOG_MAIN|LOG_PANIC, "debug tag may not contain a '/' in: %s",
1469 debug_selector = D_default;
1471 decode_bits(&debug_selector, 1, debug_notall, opts,
1472 debug_options, debug_options_count, US"debug", DEBUG_FROM_CONFIG);
1474 /* When activating from a transport process we may never have logged at all
1475 resulting in certain setup not having been done. Hack this for now so we
1476 do not segfault; note that nondefault log locations will not work */
1478 if (!*file_path) set_file_path(NULL);
1480 open_log(&fd, lt_debug, tag_name);
1483 debug_file = fdopen(fd, "w");
1485 log_write(0, LOG_MAIN|LOG_PANIC, "unable to open debug log");
1490 debug_logging_stop(void)
1492 if (!debug_file || !debuglog_name[0]) return;
1497 unlink_log(lt_debug);
1503 set_file_path(NULL);
1504 open_log(&mainlogfd, lt_main, 0);
1505 open_log(&rejectlogfd, lt_reject, 0);