inetd wait mode support with -bw
[exim.git] / src / src / log.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2009 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Functions for writing log files. The code for maintaining datestamped
9 log files was originally contributed by Tony Sheen. */
10
11
12 #include "exim.h"
13
14 #define LOG_NAME_SIZE 256
15 #define MAX_SYSLOG_LEN 870
16
17 #define LOG_MODE_FILE 1
18 #define LOG_MODE_SYSLOG 2
19
20 enum { lt_main, lt_reject, lt_panic, lt_debug };
21
22 static uschar *log_names[] = { US"main", US"reject", US"panic", US"debug" };
23
24
25
26 /*************************************************
27 * Local static variables *
28 *************************************************/
29
30 static uschar mainlog_name[LOG_NAME_SIZE];
31 static uschar rejectlog_name[LOG_NAME_SIZE];
32 static uschar debuglog_name[LOG_NAME_SIZE];
33
34 static uschar *mainlog_datestamp = NULL;
35 static uschar *rejectlog_datestamp = NULL;
36
37 static int mainlogfd = -1;
38 static int rejectlogfd = -1;
39 static ino_t mainlog_inode = 0;
40 static ino_t rejectlog_inode = 0;
41
42 static uschar *panic_save_buffer = NULL;
43 static BOOL panic_recurseflag = FALSE;
44
45 static BOOL syslog_open = FALSE;
46 static BOOL path_inspected = FALSE;
47 static int logging_mode = LOG_MODE_FILE;
48 static uschar *file_path = US"";
49
50
51
52
53 /*************************************************
54 * Write to syslog *
55 *************************************************/
56
57 /* The given string is split into sections according to length, or at embedded
58 newlines, and syslogged as a numbered sequence if it is overlong or if there is
59 more than one line. However, if we are running in the test harness, do not do
60 anything. (The test harness doesn't use syslog - for obvious reasons - but we
61 can get here if there is a failure to open the panic log.)
62
63 Arguments:
64 priority syslog priority
65 s the string to be written
66
67 Returns: nothing
68 */
69
70 static void
71 write_syslog(int priority, uschar *s)
72 {
73 int len, pass;
74 int linecount = 0;
75
76 if (running_in_test_harness) return;
77
78 if (!syslog_timestamp) s += log_timezone? 26 : 20;
79
80 len = Ustrlen(s);
81
82 #ifndef NO_OPENLOG
83 if (!syslog_open)
84 {
85 #ifdef SYSLOG_LOG_PID
86 openlog(CS syslog_processname, LOG_PID|LOG_CONS, syslog_facility);
87 #else
88 openlog(CS syslog_processname, LOG_CONS, syslog_facility);
89 #endif
90 syslog_open = TRUE;
91 }
92 #endif
93
94 /* First do a scan through the message in order to determine how many lines
95 it is going to end up as. Then rescan to output it. */
96
97 for (pass = 0; pass < 2; pass++)
98 {
99 int i;
100 int tlen;
101 uschar *ss = s;
102 for (i = 1, tlen = len; tlen > 0; i++)
103 {
104 int plen = tlen;
105 uschar *nlptr = Ustrchr(ss, '\n');
106 if (nlptr != NULL) plen = nlptr - ss;
107 #ifndef SYSLOG_LONG_LINES
108 if (plen > MAX_SYSLOG_LEN) plen = MAX_SYSLOG_LEN;
109 #endif
110 tlen -= plen;
111 if (ss[plen] == '\n') tlen--; /* chars left */
112
113 if (pass == 0) linecount++; else
114 {
115 if (linecount == 1)
116 syslog(priority, "%.*s", plen, ss);
117 else
118 syslog(priority, "[%d%c%d] %.*s", i,
119 (ss[plen] == '\n' && tlen != 0)? '\\' : '/',
120 linecount, plen, ss);
121 }
122 ss += plen;
123 if (*ss == '\n') ss++;
124 }
125 }
126 }
127
128
129
130 /*************************************************
131 * Die tidily *
132 *************************************************/
133
134 /* This is called when Exim is dying as a result of something going wrong in
135 the logging, or after a log call with LOG_PANIC_DIE set. Optionally write a
136 message to debug_file or a stderr file, if they exist. Then, if in the middle
137 of accepting a message, throw it away tidily by calling receive_bomb_out();
138 this will attempt to send an SMTP response if appropriate. Passing NULL as the
139 first argument stops it trying to run the NOTQUIT ACL (which might try further
140 logging and thus cause problems). Otherwise, try to close down an outstanding
141 SMTP call tidily.
142
143 Arguments:
144 s1 Error message to write to debug_file and/or stderr and syslog
145 s2 Error message for any SMTP call that is in progress
146 Returns: The function does not return
147 */
148
149 static void
150 die(uschar *s1, uschar *s2)
151 {
152 if (s1 != NULL)
153 {
154 write_syslog(LOG_CRIT, s1);
155 if (debug_file != NULL) debug_printf("%s\n", s1);
156 if (log_stderr != NULL && log_stderr != debug_file)
157 fprintf(log_stderr, "%s\n", s1);
158 }
159 if (receive_call_bombout) receive_bomb_out(NULL, s2); /* does not return */
160 if (smtp_input) smtp_closedown(s2);
161 exim_exit(EXIT_FAILURE);
162 }
163
164
165
166 /*************************************************
167 * Create a log file *
168 *************************************************/
169
170 /* This function is called to create and open a log file. It may be called in a
171 subprocess when the original process is root.
172
173 Arguments:
174 name the file name
175
176 The file name has been build in a working buffer, so it is permissible to
177 overwrite it temporarily if it is necessary to create the directory.
178
179 Returns: a file descriptor, or < 0 on failure (errno set)
180 */
181
182 static int
183 log_create(uschar *name)
184 {
185 int fd = Uopen(name, O_CREAT|O_APPEND|O_WRONLY, LOG_MODE);
186
187 /* If creation failed, attempt to build a log directory in case that is the
188 problem. */
189
190 if (fd < 0 && errno == ENOENT)
191 {
192 BOOL created;
193 uschar *lastslash = Ustrrchr(name, '/');
194 *lastslash = 0;
195 created = directory_make(NULL, name, LOG_DIRECTORY_MODE, FALSE);
196 DEBUG(D_any) debug_printf("%s log directory %s\n",
197 created? "created" : "failed to create", name);
198 *lastslash = '/';
199 if (created) fd = Uopen(name, O_CREAT|O_APPEND|O_WRONLY, LOG_MODE);
200 }
201
202 return fd;
203 }
204
205
206
207 /*************************************************
208 * Create a log file as the exim user *
209 *************************************************/
210
211 /* This function is called when we are root to spawn an exim:exim subprocess
212 in which we can create a log file. It must be signal-safe since it is called
213 by the usr1_handler().
214
215 Arguments:
216 name the file name
217
218 Returns: a file descriptor, or < 0 on failure (errno set)
219 */
220
221 int
222 log_create_as_exim(uschar *name)
223 {
224 pid_t pid = fork();
225 int status = 1;
226 int fd = -1;
227
228 /* In the subprocess, change uid/gid and do the creation. Return 0 from the
229 subprocess on success. If we don't check for setuid failures, then the file
230 can be created as root, so vulnerabilities which cause setuid to fail mean
231 that the Exim user can use symlinks to cause a file to be opened/created as
232 root. We always open for append, so can't nuke existing content but it would
233 still be Rather Bad. */
234
235 if (pid == 0)
236 {
237 if (setgid(exim_gid) < 0)
238 die(US"exim: setgid for log-file creation failed, aborting",
239 US"Unexpected log failure, please try later");
240 if (setuid(exim_uid) < 0)
241 die(US"exim: setuid for log-file creation failed, aborting",
242 US"Unexpected log failure, please try later");
243 _exit((log_create(name) < 0)? 1 : 0);
244 }
245
246 /* If we created a subprocess, wait for it. If it succeeded, try the open. */
247
248 while (pid > 0 && waitpid(pid, &status, 0) != pid);
249 if (status == 0) fd = Uopen(name, O_APPEND|O_WRONLY, LOG_MODE);
250
251 /* If we failed to create a subprocess, we are in a bad way. We return
252 with fd still < 0, and errno set, letting the caller handle the error. */
253
254 return fd;
255 }
256
257
258
259
260 /*************************************************
261 * Open a log file *
262 *************************************************/
263
264 /* This function opens one of a number of logs, creating the log directory if
265 it does not exist. This may be called recursively on failure, in order to open
266 the panic log.
267
268 The directory is in the static variable file_path. This is static so that it
269 the work of sorting out the path is done just once per Exim process.
270
271 Exim is normally configured to avoid running as root wherever possible, the log
272 files must be owned by the non-privileged exim user. To ensure this, first try
273 an open without O_CREAT - most of the time this will succeed. If it fails, try
274 to create the file; if running as root, this must be done in a subprocess to
275 avoid races.
276
277 Arguments:
278 fd where to return the resulting file descriptor
279 type lt_main, lt_reject, lt_panic, or lt_debug
280 tag optional tag to include in the name (only hooked up for debug)
281
282 Returns: nothing
283 */
284
285 static void
286 open_log(int *fd, int type, uschar *tag)
287 {
288 uid_t euid;
289 BOOL ok, ok2;
290 uschar buffer[LOG_NAME_SIZE];
291
292 /* The names of the log files are controlled by file_path. The panic log is
293 written to the same directory as the main and reject logs, but its name does
294 not have a datestamp. The use of datestamps is indicated by %D/%M in file_path.
295 When opening the panic log, if %D or %M is present, we remove the datestamp
296 from the generated name; if it is at the start, remove a following
297 non-alphanumeric character as well; otherwise, remove a preceding
298 non-alphanumeric character. This is definitely kludgy, but it sort of does what
299 people want, I hope. */
300
301 ok = string_format(buffer, sizeof(buffer), CS file_path, log_names[type]);
302
303 /* Save the name of the mainlog for rollover processing. Without a datestamp,
304 it gets statted to see if it has been cycled. With a datestamp, the datestamp
305 will be compared. The static slot for saving it is the same size as buffer,
306 and the text has been checked above to fit, so this use of strcpy() is OK. */
307
308 if (type == lt_main)
309 {
310 Ustrcpy(mainlog_name, buffer);
311 mainlog_datestamp = mainlog_name + string_datestamp_offset;
312 }
313
314 /* Ditto for the reject log */
315
316 else if (type == lt_reject)
317 {
318 Ustrcpy(rejectlog_name, buffer);
319 rejectlog_datestamp = rejectlog_name + string_datestamp_offset;
320 }
321
322 /* and deal with the debug log (which keeps the datestamp, but does not
323 update it) */
324
325 else if (type == lt_debug)
326 {
327 Ustrcpy(debuglog_name, buffer);
328 if (tag)
329 {
330 /* this won't change the offset of the datestamp */
331 ok2 = string_format(buffer, sizeof(buffer), "%s%s",
332 debuglog_name, tag);
333 if (ok2)
334 Ustrcpy(debuglog_name, buffer);
335 }
336 }
337
338 /* Remove any datestamp if this is the panic log. This is rare, so there's no
339 need to optimize getting the datestamp length. We remove one non-alphanumeric
340 char afterwards if at the start, otherwise one before. */
341
342 else if (string_datestamp_offset >= 0)
343 {
344 uschar *from = buffer + string_datestamp_offset;
345 uschar *to = from + string_datestamp_length;
346 if (from == buffer || from[-1] == '/')
347 {
348 if (!isalnum(*to)) to++;
349 }
350 else
351 {
352 if (!isalnum(from[-1])) from--;
353 }
354
355 /* This strcpy is ok, because we know that to is a substring of from. */
356
357 Ustrcpy(from, to);
358 }
359
360 /* If the file name is too long, it is an unrecoverable disaster */
361
362 if (!ok)
363 {
364 die(US"exim: log file path too long: aborting",
365 US"Logging failure; please try later");
366 }
367
368 /* We now have the file name. Try to open an existing file. After a successful
369 open, arrange for automatic closure on exec(), and then return. */
370
371 *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE);
372
373 if (*fd >= 0)
374 {
375 (void)fcntl(*fd, F_SETFD, fcntl(*fd, F_GETFD) | FD_CLOEXEC);
376 return;
377 }
378
379 /* Open was not successful: try creating the file. If this is a root process,
380 we must do the creating in a subprocess set to exim:exim in order to ensure
381 that the file is created with the right ownership. Otherwise, there can be a
382 race if another Exim process is trying to write to the log at the same time.
383 The use of SIGUSR1 by the exiwhat utility can provoke a lot of simultaneous
384 writing. */
385
386 euid = geteuid();
387
388 /* If we are already running as the Exim user (even if that user is root),
389 we can go ahead and create in the current process. */
390
391 if (euid == exim_uid) *fd = log_create(buffer);
392
393 /* Otherwise, if we are root, do the creation in an exim:exim subprocess. If we
394 are neither exim nor root, creation is not attempted. */
395
396 else if (euid == root_uid) *fd = log_create_as_exim(buffer);
397
398 /* If we now have an open file, set the close-on-exec flag and return. */
399
400 if (*fd >= 0)
401 {
402 (void)fcntl(*fd, F_SETFD, fcntl(*fd, F_GETFD) | FD_CLOEXEC);
403 return;
404 }
405
406 /* Creation failed. There are some circumstances in which we get here when
407 the effective uid is not root or exim, which is the problem. (For example, a
408 non-setuid binary with log_arguments set, called in certain ways.) Rather than
409 just bombing out, force the log to stderr and carry on if stderr is available.
410 */
411
412 if (euid != root_uid && euid != exim_uid && log_stderr != NULL)
413 {
414 *fd = fileno(log_stderr);
415 return;
416 }
417
418 /* Otherwise this is a disaster. This call is deliberately ONLY to the panic
419 log. If possible, save a copy of the original line that was being logged. If we
420 are recursing (can't open the panic log either), the pointer will already be
421 set. */
422
423 if (panic_save_buffer == NULL)
424 {
425 panic_save_buffer = (uschar *)malloc(LOG_BUFFER_SIZE);
426 if (panic_save_buffer != NULL)
427 memcpy(panic_save_buffer, log_buffer, LOG_BUFFER_SIZE);
428 }
429
430 log_write(0, LOG_PANIC_DIE, "Cannot open %s log file \"%s\": %s: "
431 "euid=%d egid=%d", log_names[type], buffer, strerror(errno), euid, getegid());
432 /* Never returns */
433 }
434
435
436
437 /*************************************************
438 * Add configuration file info to log line *
439 *************************************************/
440
441 /* This is put in a function because it's needed twice (once for debugging,
442 once for real).
443
444 Arguments:
445 ptr pointer to the end of the line we are building
446 flags log flags
447
448 Returns: updated pointer
449 */
450
451 static uschar *
452 log_config_info(uschar *ptr, int flags)
453 {
454 Ustrcpy(ptr, "Exim configuration error");
455 ptr += 24;
456
457 if ((flags & (LOG_CONFIG_FOR & ~LOG_CONFIG)) != 0)
458 {
459 Ustrcpy(ptr, " for ");
460 return ptr + 5;
461 }
462
463 if ((flags & (LOG_CONFIG_IN & ~LOG_CONFIG)) != 0)
464 {
465 sprintf(CS ptr, " in line %d of %s", config_lineno, config_filename);
466 while (*ptr) ptr++;
467 }
468
469 Ustrcpy(ptr, ":\n ");
470 return ptr + 4;
471 }
472
473
474 /*************************************************
475 * A write() operation failed *
476 *************************************************/
477
478 /* This function is called when write() fails on anything other than the panic
479 log, which can happen if a disk gets full or a file gets too large or whatever.
480 We try to save the relevant message in the panic_save buffer before crashing
481 out.
482
483 The potential invoker should probably not call us for EINTR -1 writes. But
484 otherwise, short writes are bad as we don't do non-blocking writes to fds
485 subject to flow control. (If we do, that's new and the logic of this should
486 be reconsidered).
487
488 Arguments:
489 name the name of the log being written
490 length the string length being written
491 rc the return value from write()
492
493 Returns: does not return
494 */
495
496 static void
497 log_write_failed(uschar *name, int length, int rc)
498 {
499 int save_errno = errno;
500
501 if (panic_save_buffer == NULL)
502 {
503 panic_save_buffer = (uschar *)malloc(LOG_BUFFER_SIZE);
504 if (panic_save_buffer != NULL)
505 memcpy(panic_save_buffer, log_buffer, LOG_BUFFER_SIZE);
506 }
507
508 log_write(0, LOG_PANIC_DIE, "failed to write to %s: length=%d result=%d "
509 "errno=%d (%s)", name, length, rc, save_errno,
510 (save_errno == 0)? "write incomplete" : strerror(save_errno));
511 /* Never returns */
512 }
513
514
515
516 /*************************************************
517 * Write to an fd, retrying after signals *
518 *************************************************/
519
520 /* Basic write to fd for logs, handling EINTR.
521
522 Arguments:
523 fd the fd to write to
524 buf the string to write
525 length the string length being written
526
527 Returns:
528 length actually written, persisting an errno from write()
529 */
530 ssize_t
531 write_to_fd_buf(int fd, uschar *buf, size_t length)
532 {
533 ssize_t wrote;
534 size_t total_written = 0;
535 uschar *p = buf;
536 size_t left = length;
537
538 while (1)
539 {
540 wrote = write(fd, p, left);
541 if (wrote == (ssize_t)-1)
542 {
543 if (errno == EINTR) continue;
544 return wrote;
545 }
546 total_written += wrote;
547 if (wrote == left)
548 break;
549 else
550 {
551 p += wrote;
552 left -= wrote;
553 }
554 }
555 return total_written;
556 }
557
558
559 /*************************************************
560 * Write message to log file *
561 *************************************************/
562
563 /* Exim can be configured to log to local files, or use syslog, or both. This
564 is controlled by the setting of log_file_path. The following cases are
565 recognized:
566
567 log_file_path = "" write files in the spool/log directory
568 log_file_path = "xxx" write files in the xxx directory
569 log_file_path = "syslog" write to syslog
570 log_file_path = "syslog : xxx" write to syslog and to files (any order)
571
572 The message always gets '\n' added on the end of it, since more than one
573 process may be writing to the log at once and we don't want intermingling to
574 happen in the middle of lines. To be absolutely sure of this we write the data
575 into a private buffer and then put it out in a single write() call.
576
577 The flags determine which log(s) the message is written to, or for syslogging,
578 which priority to use, and in the case of the panic log, whether the process
579 should die afterwards.
580
581 The variable really_exim is TRUE only when exim is running in privileged state
582 (i.e. not with a changed configuration or with testing options such as -brw).
583 If it is not, don't try to write to the log because permission will probably be
584 denied.
585
586 Avoid actually writing to the logs when exim is called with -bv or -bt to
587 test an address, but take other actions, such as panicing.
588
589 In Exim proper, the buffer for building the message is got at start-up, so that
590 nothing gets done if it can't be got. However, some functions that are also
591 used in utilities occasionally obey log_write calls in error situations, and it
592 is simplest to put a single malloc() here rather than put one in each utility.
593 Malloc is used directly because the store functions may call log_write().
594
595 If a message_id exists, we include it after the timestamp.
596
597 Arguments:
598 selector write to main log or LOG_INFO only if this value is zero, or if
599 its bit is set in log_write_selector
600 flags each bit indicates some independent action:
601 LOG_SENDER add raw sender to the message
602 LOG_RECIPIENTS add raw recipients list to message
603 LOG_CONFIG add "Exim configuration error"
604 LOG_CONFIG_FOR add " for " instead of ":\n "
605 LOG_CONFIG_IN add " in line x[ of file y]"
606 LOG_MAIN write to main log or syslog LOG_INFO
607 LOG_REJECT write to reject log or syslog LOG_NOTICE
608 LOG_PANIC write to panic log or syslog LOG_ALERT
609 LOG_PANIC_DIE write to panic log or LOG_ALERT and then crash
610 format a printf() format
611 ... arguments for format
612
613 Returns: nothing
614 */
615
616 void
617 log_write(unsigned int selector, int flags, const char *format, ...)
618 {
619 uschar *ptr;
620 int length;
621 int paniclogfd;
622 ssize_t written_len;
623 va_list ap;
624
625 /* If panic_recurseflag is set, we have failed to open the panic log. This is
626 the ultimate disaster. First try to write the message to a debug file and/or
627 stderr and also to syslog. If panic_save_buffer is not NULL, it contains the
628 original log line that caused the problem. Afterwards, expire. */
629
630 if (panic_recurseflag)
631 {
632 uschar *extra = (panic_save_buffer == NULL)? US"" : panic_save_buffer;
633 if (debug_file != NULL) debug_printf("%s%s", extra, log_buffer);
634 if (log_stderr != NULL && log_stderr != debug_file)
635 fprintf(log_stderr, "%s%s", extra, log_buffer);
636 if (*extra != 0) write_syslog(LOG_CRIT, extra);
637 write_syslog(LOG_CRIT, log_buffer);
638 die(US"exim: could not open panic log - aborting: see message(s) above",
639 US"Unexpected log failure, please try later");
640 }
641
642 /* Ensure we have a buffer (see comment above); this should never be obeyed
643 when running Exim proper, only when running utilities. */
644
645 if (log_buffer == NULL)
646 {
647 log_buffer = (uschar *)malloc(LOG_BUFFER_SIZE);
648 if (log_buffer == NULL)
649 {
650 fprintf(stderr, "exim: failed to get store for log buffer\n");
651 exim_exit(EXIT_FAILURE);
652 }
653 }
654
655 /* If we haven't already done so, inspect the setting of log_file_path to
656 determine whether to log to files and/or to syslog. Bits in logging_mode
657 control this, and for file logging, the path must end up in file_path. This
658 variable must be in permanent store because it may be required again later in
659 the process. */
660
661 if (!path_inspected)
662 {
663 BOOL multiple = FALSE;
664 int old_pool = store_pool;
665
666 store_pool = POOL_PERM;
667
668 /* If nothing has been set, don't waste effort... the default values for the
669 statics are file_path="" and logging_mode = LOG_MODE_FILE. */
670
671 if (log_file_path[0] != 0)
672 {
673 int sep = ':'; /* Fixed separator - outside use */
674 uschar *s;
675 uschar *ss = log_file_path;
676 logging_mode = 0;
677 while ((s = string_nextinlist(&ss,&sep,log_buffer,LOG_BUFFER_SIZE)) != NULL)
678 {
679 if (Ustrcmp(s, "syslog") == 0)
680 logging_mode |= LOG_MODE_SYSLOG;
681 else if ((logging_mode & LOG_MODE_FILE) != 0) multiple = TRUE;
682 else
683 {
684 logging_mode |= LOG_MODE_FILE;
685
686 /* If a non-empty path is given, use it */
687
688 if (s[0] != 0)
689 {
690 file_path = string_copy(s);
691 }
692
693 /* If the path is empty, we want to use the first non-empty, non-
694 syslog item in LOG_FILE_PATH, if there is one, since the value of
695 log_file_path may have been set at runtime. If there is no such item,
696 use the ultimate default in the spool directory. */
697
698 else
699 {
700 uschar *t;
701 uschar *tt = US LOG_FILE_PATH;
702 while ((t = string_nextinlist(&tt,&sep,log_buffer,LOG_BUFFER_SIZE))
703 != NULL)
704 {
705 if (Ustrcmp(t, "syslog") == 0 || t[0] == 0) continue;
706 file_path = string_copy(t);
707 break;
708 }
709 } /* Empty item in log_file_path */
710 } /* First non-syslog item in log_file_path */
711 } /* Scan of log_file_path */
712 }
713
714 /* If no modes have been selected, it is a major disaster */
715
716 if (logging_mode == 0)
717 die(US"Neither syslog nor file logging set in log_file_path",
718 US"Unexpected logging failure");
719
720 /* Set up the ultimate default if necessary. Then revert to the old store
721 pool, and record that we've sorted out the path. */
722
723 if ((logging_mode & LOG_MODE_FILE) != 0 && file_path[0] == 0)
724 file_path = string_sprintf("%s/log/%%slog", spool_directory);
725 store_pool = old_pool;
726 path_inspected = TRUE;
727
728 /* If more than one file path was given, log a complaint. This recursive call
729 should work since we have now set up the routing. */
730
731 if (multiple)
732 {
733 log_write(0, LOG_MAIN|LOG_PANIC,
734 "More than one path given in log_file_path: using %s", file_path);
735 }
736 }
737
738 /* If debugging, show all log entries, but don't show headers. Do it all
739 in one go so that it doesn't get split when multi-processing. */
740
741 DEBUG(D_any|D_v)
742 {
743 int i;
744 ptr = log_buffer;
745
746 Ustrcpy(ptr, "LOG:");
747 ptr += 4;
748
749 /* Show the options that were passed into the call. These are those whose
750 flag values do not have the 0x80000000 bit in them. Note that this
751 automatically exclude the "all" setting. */
752
753 for (i = 0; i < log_options_count; i++)
754 {
755 unsigned int bit = log_options[i].bit;
756 if ((bit & 0x80000000) != 0) continue;
757 if ((selector & bit) != 0)
758 {
759 *ptr++ = ' ';
760 Ustrcpy(ptr, log_options[i].name);
761 while (*ptr) ptr++;
762 }
763 }
764
765 sprintf(CS ptr, "%s%s%s%s\n ",
766 ((flags & LOG_MAIN) != 0)? " MAIN" : "",
767 ((flags & LOG_PANIC) != 0)? " PANIC" : "",
768 ((flags & LOG_PANIC_DIE) == LOG_PANIC_DIE)? " DIE" : "",
769 ((flags & LOG_REJECT) != 0)? " REJECT" : "");
770
771 while(*ptr) ptr++;
772 if ((flags & LOG_CONFIG) != 0) ptr = log_config_info(ptr, flags);
773
774 va_start(ap, format);
775 if (!string_vformat(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer)-1, format, ap))
776 Ustrcpy(ptr, "**** log string overflowed log buffer ****");
777 va_end(ap);
778
779 while(*ptr) ptr++;
780 Ustrcat(ptr, "\n");
781 debug_printf("%s", log_buffer);
782 }
783
784 /* If no log file is specified, we are in a mess. */
785
786 if ((flags & (LOG_MAIN|LOG_PANIC|LOG_REJECT)) == 0)
787 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "log_write called with no log "
788 "flags set");
789
790 /* There are some weird circumstances in which logging is disabled. */
791
792 if (disable_logging)
793 {
794 DEBUG(D_any) debug_printf("log writing disabled\n");
795 return;
796 }
797
798 /* Handle disabled reject log */
799
800 if (!write_rejectlog) flags &= ~LOG_REJECT;
801
802 /* Create the main message in the log buffer. Do not include the message id
803 when called by a utility. */
804
805 ptr = log_buffer;
806 sprintf(CS ptr, "%s ", tod_stamp(tod_log));
807 while(*ptr) ptr++;
808
809 if ((log_extra_selector & LX_pid) != 0)
810 {
811 sprintf(CS ptr, "[%d] ", (int)getpid());
812 while (*ptr) ptr++;
813 }
814
815 if (really_exim && message_id[0] != 0)
816 {
817 sprintf(CS ptr, "%s ", message_id);
818 while(*ptr) ptr++;
819 }
820
821 if ((flags & LOG_CONFIG) != 0) ptr = log_config_info(ptr, flags);
822
823 va_start(ap, format);
824 if (!string_vformat(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer)-1, format, ap))
825 Ustrcpy(ptr, "**** log string overflowed log buffer ****\n");
826 while(*ptr) ptr++;
827 va_end(ap);
828
829 /* Add the raw, unrewritten, sender to the message if required. This is done
830 this way because it kind of fits with LOG_RECIPIENTS. */
831
832 if ((flags & LOG_SENDER) != 0 &&
833 ptr < log_buffer + LOG_BUFFER_SIZE - 10 - Ustrlen(raw_sender))
834 {
835 sprintf(CS ptr, " from <%s>", raw_sender);
836 while (*ptr) ptr++;
837 }
838
839 /* Add list of recipients to the message if required; the raw list,
840 before rewriting, was saved in raw_recipients. There may be none, if an ACL
841 discarded them all. */
842
843 if ((flags & LOG_RECIPIENTS) != 0 && ptr < log_buffer + LOG_BUFFER_SIZE - 6 &&
844 raw_recipients_count > 0)
845 {
846 int i;
847 sprintf(CS ptr, " for");
848 while (*ptr) ptr++;
849 for (i = 0; i < raw_recipients_count; i++)
850 {
851 uschar *s = raw_recipients[i];
852 if (log_buffer + LOG_BUFFER_SIZE - ptr < Ustrlen(s) + 3) break;
853 sprintf(CS ptr, " %s", s);
854 while (*ptr) ptr++;
855 }
856 }
857
858 sprintf(CS ptr, "\n");
859 while(*ptr) ptr++;
860 length = ptr - log_buffer;
861
862 /* Handle loggable errors when running a utility, or when address testing.
863 Write to log_stderr unless debugging (when it will already have been written),
864 or unless there is no log_stderr (expn called from daemon, for example). */
865
866 if (!really_exim || log_testing_mode)
867 {
868 if (debug_selector == 0 && log_stderr != NULL &&
869 (selector == 0 || (selector & log_write_selector) != 0))
870 {
871 if (host_checking)
872 fprintf(log_stderr, "LOG: %s", CS(log_buffer + 20)); /* no timestamp */
873 else
874 fprintf(log_stderr, "%s", CS log_buffer);
875 }
876 if ((flags & LOG_PANIC_DIE) == LOG_PANIC_DIE) exim_exit(EXIT_FAILURE);
877 return;
878 }
879
880 /* Handle the main log. We know that either syslog or file logging (or both) is
881 set up. A real file gets left open during reception or delivery once it has
882 been opened, but we don't want to keep on writing to it for too long after it
883 has been renamed. Therefore, do a stat() and see if the inode has changed, and
884 if so, re-open. */
885
886 if ((flags & LOG_MAIN) != 0 &&
887 (selector == 0 || (selector & log_write_selector) != 0))
888 {
889 if ((logging_mode & LOG_MODE_SYSLOG) != 0 &&
890 (syslog_duplication || (flags & (LOG_REJECT|LOG_PANIC)) == 0))
891 write_syslog(LOG_INFO, log_buffer);
892
893 if ((logging_mode & LOG_MODE_FILE) != 0)
894 {
895 struct stat statbuf;
896
897 /* Check for a change to the mainlog file name when datestamping is in
898 operation. This happens at midnight, at which point we want to roll over
899 the file. Closing it has the desired effect. */
900
901 if (mainlog_datestamp != NULL)
902 {
903 uschar *nowstamp = tod_stamp(string_datestamp_type);
904 if (Ustrncmp (mainlog_datestamp, nowstamp, Ustrlen(nowstamp)) != 0)
905 {
906 (void)close(mainlogfd); /* Close the file */
907 mainlogfd = -1; /* Clear the file descriptor */
908 mainlog_inode = 0; /* Unset the inode */
909 mainlog_datestamp = NULL; /* Clear the datestamp */
910 }
911 }
912
913 /* Otherwise, we want to check whether the file has been renamed by a
914 cycling script. This could be "if else", but for safety's sake, leave it as
915 "if" so that renaming the log starts a new file even when datestamping is
916 happening. */
917
918 if (mainlogfd >= 0)
919 {
920 if (Ustat(mainlog_name, &statbuf) < 0 || statbuf.st_ino != mainlog_inode)
921 {
922 (void)close(mainlogfd);
923 mainlogfd = -1;
924 mainlog_inode = 0;
925 }
926 }
927
928 /* If the log is closed, open it. Then write the line. */
929
930 if (mainlogfd < 0)
931 {
932 open_log(&mainlogfd, lt_main, NULL); /* No return on error */
933 if (fstat(mainlogfd, &statbuf) >= 0) mainlog_inode = statbuf.st_ino;
934 }
935
936 /* Failing to write to the log is disastrous */
937
938 written_len = write_to_fd_buf(mainlogfd, log_buffer, length);
939 if (written_len != length)
940 {
941 log_write_failed(US"main log", length, written_len);
942 /* That function does not return */
943 }
944 }
945 }
946
947 /* Handle the log for rejected messages. This can be globally disabled, in
948 which case the flags are altered above. If there are any header lines (i.e. if
949 the rejection is happening after the DATA phase), log the recipients and the
950 headers. */
951
952 if ((flags & LOG_REJECT) != 0)
953 {
954 header_line *h;
955
956 if (header_list != NULL && (log_extra_selector & LX_rejected_header) != 0)
957 {
958 if (recipients_count > 0)
959 {
960 int i;
961
962 /* List the sender */
963
964 string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer),
965 "Envelope-from: <%s>\n", sender_address);
966 while (*ptr) ptr++;
967
968 /* List up to 5 recipients */
969
970 string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer),
971 "Envelope-to: <%s>\n", recipients_list[0].address);
972 while (*ptr) ptr++;
973
974 for (i = 1; i < recipients_count && i < 5; i++)
975 {
976 string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer), " <%s>\n",
977 recipients_list[i].address);
978 while (*ptr) ptr++;
979 }
980
981 if (i < recipients_count)
982 {
983 (void)string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer),
984 " ...\n");
985 while (*ptr) ptr++;
986 }
987 }
988
989 /* A header with a NULL text is an unfilled in Received: header */
990
991 for (h = header_list; h != NULL; h = h->next)
992 {
993 BOOL fitted;
994 if (h->text == NULL) continue;
995 fitted = string_format(ptr, LOG_BUFFER_SIZE - (ptr-log_buffer),
996 "%c %s", h->type, h->text);
997 while(*ptr) ptr++;
998 if (!fitted) /* Buffer is full; truncate */
999 {
1000 ptr -= 100; /* For message and separator */
1001 if (ptr[-1] == '\n') ptr--;
1002 Ustrcpy(ptr, "\n*** truncated ***\n");
1003 while (*ptr) ptr++;
1004 break;
1005 }
1006 }
1007
1008 length = ptr - log_buffer;
1009 }
1010
1011 /* Write to syslog or to a log file */
1012
1013 if ((logging_mode & LOG_MODE_SYSLOG) != 0 &&
1014 (syslog_duplication || (flags & LOG_PANIC) == 0))
1015 write_syslog(LOG_NOTICE, log_buffer);
1016
1017 /* Check for a change to the rejectlog file name when datestamping is in
1018 operation. This happens at midnight, at which point we want to roll over
1019 the file. Closing it has the desired effect. */
1020
1021 if ((logging_mode & LOG_MODE_FILE) != 0)
1022 {
1023 struct stat statbuf;
1024
1025 if (rejectlog_datestamp != NULL)
1026 {
1027 uschar *nowstamp = tod_stamp(string_datestamp_type);
1028 if (Ustrncmp (rejectlog_datestamp, nowstamp, Ustrlen(nowstamp)) != 0)
1029 {
1030 (void)close(rejectlogfd); /* Close the file */
1031 rejectlogfd = -1; /* Clear the file descriptor */
1032 rejectlog_inode = 0; /* Unset the inode */
1033 rejectlog_datestamp = NULL; /* Clear the datestamp */
1034 }
1035 }
1036
1037 /* Otherwise, we want to check whether the file has been renamed by a
1038 cycling script. This could be "if else", but for safety's sake, leave it as
1039 "if" so that renaming the log starts a new file even when datestamping is
1040 happening. */
1041
1042 if (rejectlogfd >= 0)
1043 {
1044 if (Ustat(rejectlog_name, &statbuf) < 0 ||
1045 statbuf.st_ino != rejectlog_inode)
1046 {
1047 (void)close(rejectlogfd);
1048 rejectlogfd = -1;
1049 rejectlog_inode = 0;
1050 }
1051 }
1052
1053 /* Open the file if necessary, and write the data */
1054
1055 if (rejectlogfd < 0)
1056 {
1057 open_log(&rejectlogfd, lt_reject, NULL); /* No return on error */
1058 if (fstat(rejectlogfd, &statbuf) >= 0) rejectlog_inode = statbuf.st_ino;
1059 }
1060
1061 written_len = write_to_fd_buf(rejectlogfd, log_buffer, length);
1062 if (written_len != length)
1063 {
1064 log_write_failed(US"reject log", length, written_len);
1065 /* That function does not return */
1066 }
1067 }
1068 }
1069
1070
1071 /* Handle the panic log, which is not kept open like the others. If it fails to
1072 open, there will be a recursive call to log_write(). We detect this above and
1073 attempt to write to the system log as a last-ditch try at telling somebody. In
1074 all cases except mua_wrapper, try to write to log_stderr. */
1075
1076 if ((flags & LOG_PANIC) != 0)
1077 {
1078 if (log_stderr != NULL && log_stderr != debug_file && !mua_wrapper)
1079 fprintf(log_stderr, "%s", CS log_buffer);
1080
1081 if ((logging_mode & LOG_MODE_SYSLOG) != 0)
1082 {
1083 write_syslog(LOG_ALERT, log_buffer);
1084 }
1085
1086 /* If this panic logging was caused by a failure to open the main log,
1087 the original log line is in panic_save_buffer. Make an attempt to write it. */
1088
1089 if ((logging_mode & LOG_MODE_FILE) != 0)
1090 {
1091 panic_recurseflag = TRUE;
1092 open_log(&paniclogfd, lt_panic, NULL); /* Won't return on failure */
1093 panic_recurseflag = FALSE;
1094
1095 if (panic_save_buffer != NULL)
1096 (void) write(paniclogfd, panic_save_buffer, Ustrlen(panic_save_buffer));
1097
1098 written_len = write_to_fd_buf(paniclogfd, log_buffer, length);
1099 if (written_len != length)
1100 {
1101 int save_errno = errno;
1102 write_syslog(LOG_CRIT, log_buffer);
1103 sprintf(CS log_buffer, "write failed on panic log: length=%d result=%d "
1104 "errno=%d (%s)", length, (int)written_len, save_errno, strerror(save_errno));
1105 write_syslog(LOG_CRIT, log_buffer);
1106 flags |= LOG_PANIC_DIE;
1107 }
1108
1109 (void)close(paniclogfd);
1110 }
1111
1112 /* Give up if the DIE flag is set */
1113
1114 if ((flags & LOG_PANIC_DIE) != LOG_PANIC)
1115 die(NULL, US"Unexpected failure, please try later");
1116 }
1117 }
1118
1119
1120
1121 /*************************************************
1122 * Close any open log files *
1123 *************************************************/
1124
1125 void
1126 log_close_all(void)
1127 {
1128 if (mainlogfd >= 0)
1129 { (void)close(mainlogfd); mainlogfd = -1; }
1130 if (rejectlogfd >= 0)
1131 { (void)close(rejectlogfd); rejectlogfd = -1; }
1132 closelog();
1133 syslog_open = FALSE;
1134 }
1135
1136
1137
1138 /*************************************************
1139 * Decode bit settings for log/debug *
1140 *************************************************/
1141
1142 /* This function decodes a string containing bit settings in the form of +name
1143 and/or -name sequences, and sets/unsets bits in a bit string accordingly. It
1144 also recognizes a numeric setting of the form =<number>, but this is not
1145 intended for user use. It's an easy way for Exim to pass the debug settings
1146 when it is re-exec'ed.
1147
1148 The log options are held in two unsigned ints (because there became too many
1149 for one). The top bit in the table means "put in 2nd selector". This does not
1150 yet apply to debug options, so the "=" facility sets only the first selector.
1151
1152 The "all" selector, which must be equal to 0xffffffff, is recognized specially.
1153 It sets all the bits in both selectors. However, there is a facility for then
1154 unsetting certain bits, because we want to turn off "memory" in the debug case.
1155
1156 The action taken for bad values varies depending upon why we're here.
1157 For log messages, or if the debugging is triggered from config, then we write
1158 to the log on the way out. For debug setting triggered from the command-line,
1159 we treat it as an unknown option: error message to stderr and die.
1160
1161 Arguments:
1162 selector1 address of the first bit string
1163 selector2 address of the second bit string, or NULL
1164 notall1 bits to exclude from "all" for selector1
1165 notall2 bits to exclude from "all" for selector2
1166 string the configured string
1167 options the table of option names
1168 count size of table
1169 which "log" or "debug"
1170 flags DEBUG_FROM_CONFIG
1171
1172 Returns: nothing on success - bomb out on failure
1173 */
1174
1175 void
1176 decode_bits(unsigned int *selector1, unsigned int *selector2, int notall1,
1177 int notall2, uschar *string, bit_table *options, int count, uschar *which,
1178 int flags)
1179 {
1180 uschar *errmsg;
1181 if (string == NULL) return;
1182
1183 if (*string == '=')
1184 {
1185 char *end; /* Not uschar */
1186 *selector1 = strtoul(CS string+1, &end, 0);
1187 if (*end == 0) return;
1188 errmsg = string_sprintf("malformed numeric %s_selector setting: %s", which,
1189 string);
1190 goto ERROR_RETURN;
1191 }
1192
1193 /* Handle symbolic setting */
1194
1195 else for(;;)
1196 {
1197 BOOL adding;
1198 uschar *s;
1199 int len;
1200 bit_table *start, *end;
1201
1202 while (isspace(*string)) string++;
1203 if (*string == 0) return;
1204
1205 if (*string != '+' && *string != '-')
1206 {
1207 errmsg = string_sprintf("malformed %s_selector setting: "
1208 "+ or - expected but found \"%s\"", which, string);
1209 goto ERROR_RETURN;
1210 }
1211
1212 adding = *string++ == '+';
1213 s = string;
1214 while (isalnum(*string) || *string == '_') string++;
1215 len = string - s;
1216
1217 start = options;
1218 end = options + count;
1219
1220 while (start < end)
1221 {
1222 bit_table *middle = start + (end - start)/2;
1223 int c = Ustrncmp(s, middle->name, len);
1224 if (c == 0)
1225 {
1226 if (middle->name[len] != 0) c = -1; else
1227 {
1228 unsigned int bit = middle->bit;
1229 unsigned int *selector;
1230
1231 /* The value with all bits set means "force all bits in both selectors"
1232 in the case where two are being handled. However, the top bit in the
1233 second selector is never set. When setting, some bits can be excluded.
1234 */
1235
1236 if (bit == 0xffffffff)
1237 {
1238 if (adding)
1239 {
1240 *selector1 = 0xffffffff ^ notall1;
1241 if (selector2 != NULL) *selector2 = 0x7fffffff ^ notall2;
1242 }
1243 else
1244 {
1245 *selector1 = 0;
1246 if (selector2 != NULL) *selector2 = 0;
1247 }
1248 }
1249
1250 /* Otherwise, the 0x80000000 bit means "this value, without the top
1251 bit, belongs in the second selector". */
1252
1253 else
1254 {
1255 if ((bit & 0x80000000) != 0)
1256 {
1257 selector = selector2;
1258 bit &= 0x7fffffff;
1259 }
1260 else selector = selector1;
1261 if (adding) *selector |= bit; else *selector &= ~bit;
1262 }
1263 break; /* Out of loop to match selector name */
1264 }
1265 }
1266 if (c < 0) end = middle; else start = middle + 1;
1267 } /* Loop to match selector name */
1268
1269 if (start >= end)
1270 {
1271 errmsg = string_sprintf("unknown %s_selector setting: %c%.*s", which,
1272 adding? '+' : '-', len, s);
1273 goto ERROR_RETURN;
1274 }
1275 } /* Loop for selector names */
1276
1277 /* Handle disasters */
1278
1279 ERROR_RETURN:
1280 if (Ustrcmp(which, "debug") == 0)
1281 {
1282 if (flags & DEBUG_FROM_CONFIG)
1283 {
1284 log_write(0, LOG_CONFIG|LOG_PANIC, "%s", errmsg);
1285 return;
1286 }
1287 fprintf(stderr, "exim: %s\n", errmsg);
1288 exit(EXIT_FAILURE);
1289 }
1290 else log_write(0, LOG_CONFIG|LOG_PANIC_DIE, "%s", errmsg);
1291 }
1292
1293
1294
1295 /*************************************************
1296 * Activate a debug logfile (late) *
1297 *************************************************/
1298
1299 /* Normally, debugging is activated from the command-line; it may be useful
1300 within the configuration to activate debugging later, based on certain
1301 conditions. If debugging is already in progress, we return early, no action
1302 taken (besides debug-logging that we wanted debug-logging).
1303
1304 Failures in options are not fatal but will result in paniclog entries for the
1305 misconfiguration.
1306
1307 The first use of this is in ACL logic, "control = debug/tag=foo/opts=+expand"
1308 which can be combined with conditions, etc, to activate extra logging only
1309 for certain sources. The second use is inetd wait mode debug preservation. */
1310
1311 void
1312 debug_logging_activate(uschar *tag_name, uschar *opts)
1313 {
1314 int fd = -1;
1315
1316 if (debug_file)
1317 {
1318 debug_printf("DEBUGGING ACTIVATED FROM WITHIN CONFIG.\n"
1319 "DEBUG: Tag=\"%s\" Opts=\"%s\"\n", tag_name, opts ? opts : US"");
1320 return;
1321 }
1322
1323 if (tag_name != NULL && (Ustrchr(tag_name, '/') != NULL))
1324 {
1325 log_write(0, LOG_MAIN|LOG_PANIC, "debug tag may not contain a '/' in: %s",
1326 tag_name);
1327 return;
1328 }
1329
1330 debug_selector = D_default;
1331 if (opts)
1332 {
1333 decode_bits(&debug_selector, NULL, D_memory, 0, opts,
1334 debug_options, debug_options_count, US"debug", DEBUG_FROM_CONFIG);
1335 }
1336
1337 open_log(&fd, lt_debug, tag_name);
1338
1339 if (fd != -1)
1340 debug_file = fdopen(fd, "w");
1341 else
1342 log_write(0, LOG_MAIN|LOG_PANIC, "unable to open debug log");
1343 }
1344
1345
1346 /* End of log.c */