1 /* movemail foo bar -- move file foo to file bar,
2 locking file foo the way /bin/mail respects.
4 Copyright (C) 1986, 1992-1994, 1996, 1999, 2001-2013 Free Software
7 This file is part of GNU Emacs.
9 GNU Emacs is free software: you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation, either version 3 of the License, or
12 (at your option) any later version.
14 GNU Emacs is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
23 /* Important notice: defining MAIL_USE_FLOCK or MAIL_USE_LOCKF *will
24 cause loss of mail* if you do it on a system that does not normally
25 use flock/lockf as its way of interlocking access to inbox files. The
26 setting of MAIL_USE_FLOCK and MAIL_USE_LOCKF *must agree* with the
27 system's own conventions. It is not a choice that is up to you.
29 So, if your system uses lock files rather than flock, then the only way
30 you can get proper operation is to enable movemail to write lockfiles there.
31 This means you must either give that directory access modes
32 that permit everyone to write lockfiles in it, or you must make movemail
33 a setuid or setgid program. */
36 * Modified January, 1986 by Michael R. Gretzinger (Project Athena)
38 * Added POP (Post Office Protocol) service. When compiled -DMAIL_USE_POP
39 * movemail will accept input filename arguments of the form
40 * "po:username". This will cause movemail to open a connection to
41 * a pop server running on $MAILHOST (environment variable). Movemail
42 * must be setuid to root in order to work with POP.
44 * New module: popmail.c
46 * main - added code within #ifdef MAIL_USE_POP; added setuid (getuid ())
48 * New routines in movemail.c:
49 * get_errmsg - return pointer to system error message
51 * Modified August, 1993 by Jonathan Kamens (OpenVision Technologies)
53 * Move all of the POP code into a separate file, "pop.c".
54 * Use strerror instead of get_errmsg.
59 #include <sys/types.h>
84 #define wait(var) (*(var) = 0)
85 /* Unfortunately, Samba doesn't seem to properly lock Unix files even
86 though the locking call succeeds (and indeed blocks local access from
87 other NT programs). If you have direct file access using an NFS
88 client or something other than Samba, the locking call might work
89 properly - make sure it does before you enable this!
91 [18-Feb-97 andrewi] I now believe my comment above to be incorrect,
92 since it was based on a misunderstanding of how locking calls are
93 implemented and used on Unix. */
94 //#define DISABLE_DIRECT_ACCESS
97 #endif /* WINDOWSNT */
100 #include <sys/locking.h>
103 /* If your system uses the `flock' or `lockf' system call for mail locking,
104 define MAIL_USE_SYSTEM_LOCK. If your system type should always define
105 MAIL_USE_LOCKF or MAIL_USE_FLOCK but configure does not do this,
106 please make a bug report. */
108 #ifdef MAIL_USE_LOCKF
109 #define MAIL_USE_SYSTEM_LOCK
112 #ifdef MAIL_USE_FLOCK
113 #define MAIL_USE_SYSTEM_LOCK
117 extern int lk_open (), lk_close ();
120 #if !defined (MAIL_USE_SYSTEM_LOCK) && !defined (MAIL_USE_MMDF) && \
121 (defined (HAVE_LIBMAIL) || defined (HAVE_LIBLOCKFILE)) && \
122 defined (HAVE_MAILLOCK_H)
123 #include <maillock.h>
124 /* We can't use maillock unless we know what directory system mail
127 #define MAIL_USE_MAILLOCK
128 static char *mail_spool_name (char *);
132 static _Noreturn
void fatal (const char *s1
, const char *s2
, const char *s3
);
133 static void error (const char *s1
, const char *s2
, const char *s3
);
134 static _Noreturn
void pfatal_with_name (char *name
);
135 static _Noreturn
void pfatal_and_delete (char *name
);
137 static int popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
);
138 static int pop_retr (popserver server
, int msgno
, FILE *arg
);
139 static int mbx_write (char *line
, int len
, FILE *mbf
);
140 static int mbx_delimit_begin (FILE *mbf
);
141 static int mbx_delimit_end (FILE *mbf
);
144 #if (defined MAIL_USE_MAILLOCK \
145 || (!defined DISABLE_DIRECT_ACCESS && !defined MAIL_USE_MMDF \
146 && !defined MAIL_USE_SYSTEM_LOCK))
147 /* Like malloc but get fatal error if memory is exhausted. */
150 xmalloc (size_t size
)
152 void *result
= malloc (size
);
154 fatal ("virtual memory exhausted", 0, 0);
159 /* Nonzero means this is name of a lock file to delete on fatal error. */
160 static char *delete_lockname
;
163 main (int argc
, char **argv
)
165 char *inname
, *outname
;
169 int c
, preserve_mail
= 0;
171 #ifndef MAIL_USE_SYSTEM_LOCK
176 size_t inname_len
, inname_dirlen
;
178 #endif /* not MAIL_USE_SYSTEM_LOCK */
180 #ifdef MAIL_USE_MAILLOCK
185 int pop_reverse_order
= 0;
187 #else /* ! MAIL_USE_POP */
189 #endif /* MAIL_USE_POP */
191 uid_t real_gid
= getgid ();
192 uid_t priv_gid
= getegid ();
195 /* Ensure all file i/o is in binary mode. */
201 while ((c
= getopt (argc
, argv
, ARGSTR
)) != EOF
)
206 pop_reverse_order
= 1;
219 (argc
- optind
< 2) || (argc
- optind
> 3)
226 fprintf (stderr
, "Usage: movemail [-p] [-r] inbox destfile%s\n",
229 fprintf (stderr
, "Usage: movemail [-p] inbox destfile%s\n", "");
234 inname
= argv
[optind
];
235 outname
= argv
[optind
+1];
242 fatal ("Destination file name is empty", 0, 0);
245 if (!strncmp (inname
, "po:", 3))
249 status
= popmail (inname
+ 3, outname
, preserve_mail
,
250 (argc
- optind
== 3) ? argv
[optind
+2] : NULL
,
255 if (setuid (getuid ()) < 0)
256 fatal ("Failed to drop privileges", 0, 0);
258 #endif /* MAIL_USE_POP */
260 #ifndef DISABLE_DIRECT_ACCESS
261 #ifndef MAIL_USE_MMDF
262 #ifndef MAIL_USE_SYSTEM_LOCK
263 #ifdef MAIL_USE_MAILLOCK
264 spool_name
= mail_spool_name (inname
);
274 /* Use a lock file named after our first argument with .lock appended:
275 If it exists, the mail file is locked. */
276 /* Note: this locking mechanism is *required* by the mailer
277 (on systems which use it) to prevent loss of mail.
279 On systems that use a lock file, extracting the mail without locking
280 WILL occasionally cause loss of mail due to timing errors!
282 So, if creation of the lock file fails due to access
283 permission on the mail spool directory, you simply MUST
284 change the permission and/or make movemail a setgid program
285 so it can create lock files properly.
287 You might also wish to verify that your system is one which
288 uses lock files for this purpose. Some systems use other methods. */
290 inname_len
= strlen (inname
);
291 lockname
= xmalloc (inname_len
+ sizeof ".lock");
292 strcpy (lockname
, inname
);
293 strcpy (lockname
+ inname_len
, ".lock");
294 for (inname_dirlen
= inname_len
;
295 inname_dirlen
&& !IS_DIRECTORY_SEP (inname
[inname_dirlen
- 1]);
298 tempname
= xmalloc (inname_dirlen
+ sizeof "EXXXXXX");
302 /* Create the lock file, but not under the lock file name. */
303 /* Give up if cannot do that. */
305 memcpy (tempname
, inname
, inname_dirlen
);
306 strcpy (tempname
+ inname_dirlen
, "EXXXXXX");
308 desc
= mkstemp (tempname
);
316 desc
= open (tempname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0600);
321 int mkstemp_errno
= errno
;
322 error ("error while creating what would become the lock file",
324 errno
= mkstemp_errno
;
325 pfatal_with_name (tempname
);
329 tem
= link (tempname
, lockname
);
331 if (tem
< 0 && errno
!= EEXIST
)
332 pfatal_with_name (lockname
);
339 /* If lock file is five minutes old, unlock it.
340 Five minutes should be good enough to cope with crashes
341 and wedgitude, and long enough to avoid being fooled
342 by time differences between machines. */
343 if (stat (lockname
, &st
) >= 0)
345 time_t now
= time (0);
346 if (st
.st_ctime
< now
- 300)
351 delete_lockname
= lockname
;
353 #endif /* not MAIL_USE_SYSTEM_LOCK */
354 #endif /* not MAIL_USE_MMDF */
360 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
367 if (setuid (getuid ()) < 0 || setregid (-1, real_gid
) < 0)
368 fatal ("Failed to drop privileges", 0, 0);
370 #ifndef MAIL_USE_MMDF
371 #ifdef MAIL_USE_SYSTEM_LOCK
372 indesc
= open (inname
, O_RDWR
);
373 #else /* if not MAIL_USE_SYSTEM_LOCK */
374 indesc
= open (inname
, O_RDONLY
);
375 #endif /* not MAIL_USE_SYSTEM_LOCK */
376 #else /* MAIL_USE_MMDF */
377 indesc
= lk_open (inname
, O_RDONLY
, 0, 0, 10);
378 #endif /* MAIL_USE_MMDF */
381 pfatal_with_name (inname
);
383 /* Make sure the user can read the output file. */
384 umask (umask (0) & 0377);
386 outdesc
= open (outname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
388 pfatal_with_name (outname
);
390 if (setregid (-1, priv_gid
) < 0)
391 fatal ("Failed to regain privileges", 0, 0);
393 /* This label exists so we can retry locking
394 after a delay, if it got EAGAIN or EBUSY. */
397 /* Try to lock it. */
398 #ifdef MAIL_USE_MAILLOCK
401 /* The "0 - " is to make it a negative number if maillock returns
403 status
= 0 - maillock (spool_name
, 1);
404 #ifdef HAVE_TOUCHLOCK
405 touched_lock
= time (0);
410 #endif /* MAIL_USE_MAILLOCK */
412 #ifdef MAIL_USE_SYSTEM_LOCK
413 #ifdef MAIL_USE_LOCKF
414 status
= lockf (indesc
, F_LOCK
, 0);
415 #else /* not MAIL_USE_LOCKF */
417 status
= locking (indesc
, LK_RLCK
, -1L);
419 status
= flock (indesc
, LOCK_EX
);
421 #endif /* not MAIL_USE_LOCKF */
422 #endif /* MAIL_USE_SYSTEM_LOCK */
425 /* If it fails, retry up to 5 times
426 for certain failure codes. */
429 if (++lockcount
<= 5 && (errno
== EAGAIN
|| errno
== EBUSY
))
435 pfatal_with_name (inname
);
443 nread
= read (indesc
, buf
, sizeof buf
);
445 pfatal_with_name (inname
);
446 if (nread
!= write (outdesc
, buf
, nread
))
448 int saved_errno
= errno
;
451 pfatal_with_name (outname
);
453 if (nread
< sizeof buf
)
455 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
458 time_t now
= time (0);
459 if (now
- touched_lock
> 60)
465 #endif /* MAIL_USE_MAILLOCK */
469 if (fsync (outdesc
) != 0 && errno
!= EINVAL
)
470 pfatal_and_delete (outname
);
472 /* Prevent symlink attacks truncating other users' mailboxes */
473 if (setregid (-1, real_gid
) < 0)
474 fatal ("Failed to drop privileges", 0, 0);
476 /* Check to make sure no errors before we zap the inbox. */
477 if (close (outdesc
) != 0)
478 pfatal_and_delete (outname
);
480 #ifdef MAIL_USE_SYSTEM_LOCK
483 if (ftruncate (indesc
, 0L) != 0)
484 pfatal_with_name (inname
);
486 #endif /* MAIL_USE_SYSTEM_LOCK */
489 lk_close (indesc
, 0, 0, 0);
494 #ifndef MAIL_USE_SYSTEM_LOCK
497 /* Delete the input file; if we can't, at least get rid of its
499 #ifdef MAIL_UNLINK_SPOOL
500 /* This is generally bad to do, because it destroys the permissions
501 that were set on the file. Better to just empty the file. */
502 if (unlink (inname
) < 0 && errno
!= ENOENT
)
503 #endif /* MAIL_UNLINK_SPOOL */
504 creat (inname
, 0600);
506 #endif /* not MAIL_USE_SYSTEM_LOCK */
508 /* End of mailbox truncation */
509 if (setregid (-1, priv_gid
) < 0)
510 fatal ("Failed to regain privileges", 0, 0);
512 #ifdef MAIL_USE_MAILLOCK
513 /* This has to occur in the child, i.e., in the process that
514 acquired the lock! */
522 if (!WIFEXITED (wait_status
))
524 else if (WEXITSTATUS (wait_status
) != 0)
525 exit (WEXITSTATUS (wait_status
));
527 #if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK)
528 #ifdef MAIL_USE_MAILLOCK
530 #endif /* MAIL_USE_MAILLOCK */
532 #endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */
534 #endif /* ! DISABLE_DIRECT_ACCESS */
539 #ifdef MAIL_USE_MAILLOCK
540 /* This function uses stat to confirm that the mail directory is
541 identical to the directory of the input file, rather than just
542 string-comparing the two paths, because one or both of them might
543 be symbolic links pointing to some other directory. */
545 mail_spool_name (char *inname
)
547 struct stat stat1
, stat2
;
551 if (! (fname
= strrchr (inname
, '/')))
556 if (stat (MAILDIR
, &stat1
) < 0)
559 indir
= xmalloc (fname
- inname
+ 1);
560 memcpy (indir
, inname
, fname
- inname
);
561 indir
[fname
-inname
] = '\0';
564 status
= stat (indir
, &stat2
);
571 if (stat1
.st_dev
== stat2
.st_dev
572 && stat1
.st_ino
== stat2
.st_ino
)
577 #endif /* MAIL_USE_MAILLOCK */
579 /* Print error message and exit. */
582 fatal (const char *s1
, const char *s2
, const char *s3
)
585 unlink (delete_lockname
);
590 /* Print error message. `s1' is printf control string, `s2' and `s3'
591 are args for it or null. */
594 error (const char *s1
, const char *s2
, const char *s3
)
596 fprintf (stderr
, "movemail: ");
598 fprintf (stderr
, s1
, s2
, s3
);
600 fprintf (stderr
, s1
, s2
);
602 fprintf (stderr
, "%s", s1
);
603 fprintf (stderr
, "\n");
607 pfatal_with_name (char *name
)
609 fatal ("%s for %s", strerror (errno
), name
);
613 pfatal_and_delete (char *name
)
615 char *s
= strerror (errno
);
617 fatal ("%s for %s", s
, name
);
620 /* This is the guts of the interface to the Post Office Protocol. */
625 #include <sys/socket.h>
626 #include <netinet/in.h>
638 static char Errmsg
[200]; /* POP errors, at least, can exceed
639 the original length of 80. */
642 * The full valid syntax for a POP mailbox specification for movemail
643 * is "po:username:hostname". The ":hostname" is optional; if it is
644 * omitted, the MAILHOST environment variable will be consulted. Note
645 * that by the time popmail() is called the "po:" has been stripped
646 * off of the front of the mailbox name.
648 * If the mailbox is in the form "po:username:hostname", then it is
649 * modified by this function -- the second colon is replaced by a
652 * Return a value suitable for passing to `exit'.
656 popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
)
663 int start
, end
, increment
;
664 char *user
, *hostname
;
667 if ((hostname
= strchr (mailbox
, ':')))
670 server
= pop_open (hostname
, user
, password
, POP_NO_GETPASS
);
673 error ("Error connecting to POP server: %s", pop_error
, 0);
677 if (pop_stat (server
, &nmsgs
, &nbytes
))
679 error ("Error getting message count from POP server: %s", pop_error
, 0);
689 mbfi
= open (outfile
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
693 error ("Error in open: %s, %s", strerror (errno
), outfile
);
697 if (fchown (mbfi
, getuid (), -1) != 0)
699 int fchown_errno
= errno
;
701 if (fstat (mbfi
, &st
) != 0 || st
.st_uid
!= getuid ())
704 error ("Error in fchown: %s, %s", strerror (fchown_errno
), outfile
);
709 if ((mbf
= fdopen (mbfi
, "wb")) == NULL
)
712 error ("Error in fdopen: %s", strerror (errno
), 0);
731 for (i
= start
; i
* increment
<= end
* increment
; i
+= increment
)
733 mbx_delimit_begin (mbf
);
734 if (pop_retr (server
, i
, mbf
) != OK
)
736 error ("%s", Errmsg
, 0);
740 mbx_delimit_end (mbf
);
744 error ("Error in fflush: %s", strerror (errno
), 0);
751 if (fsync (mbfi
) != 0 && errno
!= EINVAL
)
753 error ("Error in fsync: %s", strerror (errno
), 0);
758 if (close (mbfi
) != 0)
760 error ("Error in close: %s", strerror (errno
), 0);
765 for (i
= 1; i
<= nmsgs
; i
++)
767 if (pop_delete (server
, i
))
769 error ("Error from POP server: %s", pop_error
, 0);
775 if (pop_quit (server
))
777 error ("Error from POP server: %s", pop_error
, 0);
785 pop_retr (popserver server
, int msgno
, FILE *arg
)
790 if (pop_retrieve_first (server
, msgno
, &line
))
792 snprintf (Errmsg
, sizeof Errmsg
, "Error from POP server: %s", pop_error
);
796 while ((ret
= pop_retrieve_next (server
, &line
)) >= 0)
801 if (mbx_write (line
, ret
, arg
) != OK
)
803 strcpy (Errmsg
, strerror (errno
));
811 snprintf (Errmsg
, sizeof Errmsg
, "Error from POP server: %s", pop_error
);
819 mbx_write (char *line
, int len
, FILE *mbf
)
821 #ifdef MOVEMAIL_QUOTE_POP_FROM_LINES
822 /* Do this as a macro instead of using strcmp to save on execution time. */
823 # define IS_FROM_LINE(a) ((a[0] == 'F') \
828 if (IS_FROM_LINE (line
))
830 if (fputc ('>', mbf
) == EOF
)
834 if (line
[0] == '\037')
836 if (fputs ("^_", mbf
) == EOF
)
841 if (fwrite (line
, 1, len
, mbf
) != len
)
843 if (fputc (0x0a, mbf
) == EOF
)
849 mbx_delimit_begin (FILE *mbf
)
853 char fromline
[40] = "From movemail ";
856 ltime
= localtime (&now
);
858 strcat (fromline
, asctime (ltime
));
860 if (fputs (fromline
, mbf
) == EOF
)
866 mbx_delimit_end (FILE *mbf
)
868 if (putc ('\n', mbf
) == EOF
)
873 #endif /* MAIL_USE_POP */