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, 2001-2012
5 Free Software Foundation, Inc.
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 */
107 #include <sys/locking.h>
110 /* If your system uses the `flock' or `lockf' system call for mail locking,
111 define MAIL_USE_SYSTEM_LOCK. If your system type should always define
112 MAIL_USE_LOCKF or MAIL_USE_FLOCK but configure does not do this,
113 please make a bug report. */
115 #ifdef MAIL_USE_LOCKF
116 #define MAIL_USE_SYSTEM_LOCK
119 #ifdef MAIL_USE_FLOCK
120 #define MAIL_USE_SYSTEM_LOCK
124 extern int lk_open (), lk_close ();
127 #if !defined (MAIL_USE_SYSTEM_LOCK) && !defined (MAIL_USE_MMDF) && \
128 (defined (HAVE_LIBMAIL) || defined (HAVE_LIBLOCKFILE)) && \
129 defined (HAVE_MAILLOCK_H)
130 #include <maillock.h>
131 /* We can't use maillock unless we know what directory system mail
134 #define MAIL_USE_MAILLOCK
135 static char *mail_spool_name (char *);
139 static _Noreturn
void fatal (const char *s1
, const char *s2
, const char *s3
);
140 static void error (const char *s1
, const char *s2
, const char *s3
);
141 static _Noreturn
void pfatal_with_name (char *name
);
142 static _Noreturn
void pfatal_and_delete (char *name
);
144 static int popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
);
145 static int pop_retr (popserver server
, int msgno
, FILE *arg
);
146 static int mbx_write (char *line
, int len
, FILE *mbf
);
147 static int mbx_delimit_begin (FILE *mbf
);
148 static int mbx_delimit_end (FILE *mbf
);
151 #if (defined MAIL_USE_MAILLOCK \
152 || (!defined DISABLE_DIRECT_ACCESS && !defined MAIL_USE_MMDF \
153 && !defined MAIL_USE_SYSTEM_LOCK))
154 /* Like malloc but get fatal error if memory is exhausted. */
157 xmalloc (size_t size
)
159 void *result
= malloc (size
);
161 fatal ("virtual memory exhausted", 0, 0);
166 /* Nonzero means this is name of a lock file to delete on fatal error. */
167 static char *delete_lockname
;
170 main (int argc
, char **argv
)
172 char *inname
, *outname
;
176 int c
, preserve_mail
= 0;
178 #ifndef MAIL_USE_SYSTEM_LOCK
183 size_t inname_len
, inname_dirlen
;
185 #endif /* not MAIL_USE_SYSTEM_LOCK */
187 #ifdef MAIL_USE_MAILLOCK
192 int pop_reverse_order
= 0;
194 #else /* ! MAIL_USE_POP */
196 #endif /* MAIL_USE_POP */
198 uid_t real_gid
= getgid ();
199 uid_t priv_gid
= getegid ();
202 /* Ensure all file i/o is in binary mode. */
208 while ((c
= getopt (argc
, argv
, ARGSTR
)) != EOF
)
213 pop_reverse_order
= 1;
226 (argc
- optind
< 2) || (argc
- optind
> 3)
233 fprintf (stderr
, "Usage: movemail [-p] [-r] inbox destfile%s\n",
236 fprintf (stderr
, "Usage: movemail [-p] inbox destfile%s\n", "");
241 inname
= argv
[optind
];
242 outname
= argv
[optind
+1];
249 fatal ("Destination file name is empty", 0, 0);
252 if (!strncmp (inname
, "po:", 3))
256 status
= popmail (inname
+ 3, outname
, preserve_mail
,
257 (argc
- optind
== 3) ? argv
[optind
+2] : NULL
,
262 if (setuid (getuid ()) < 0)
263 fatal ("Failed to drop privileges", 0, 0);
265 #endif /* MAIL_USE_POP */
267 #ifndef DISABLE_DIRECT_ACCESS
268 #ifndef MAIL_USE_MMDF
269 #ifndef MAIL_USE_SYSTEM_LOCK
270 #ifdef MAIL_USE_MAILLOCK
271 spool_name
= mail_spool_name (inname
);
281 /* Use a lock file named after our first argument with .lock appended:
282 If it exists, the mail file is locked. */
283 /* Note: this locking mechanism is *required* by the mailer
284 (on systems which use it) to prevent loss of mail.
286 On systems that use a lock file, extracting the mail without locking
287 WILL occasionally cause loss of mail due to timing errors!
289 So, if creation of the lock file fails due to access
290 permission on the mail spool directory, you simply MUST
291 change the permission and/or make movemail a setgid program
292 so it can create lock files properly.
294 You might also wish to verify that your system is one which
295 uses lock files for this purpose. Some systems use other methods. */
297 inname_len
= strlen (inname
);
298 lockname
= xmalloc (inname_len
+ sizeof ".lock");
299 strcpy (lockname
, inname
);
300 strcpy (lockname
+ inname_len
, ".lock");
301 for (inname_dirlen
= inname_len
;
302 inname_dirlen
&& !IS_DIRECTORY_SEP (inname
[inname_dirlen
- 1]);
305 tempname
= xmalloc (inname_dirlen
+ sizeof "EXXXXXX");
309 /* Create the lock file, but not under the lock file name. */
310 /* Give up if cannot do that. */
312 memcpy (tempname
, inname
, inname_dirlen
);
313 strcpy (tempname
+ inname_dirlen
, "EXXXXXX");
315 desc
= mkstemp (tempname
);
323 desc
= open (tempname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0600);
328 int mkstemp_errno
= errno
;
329 error ("error while creating what would become the lock file",
331 errno
= mkstemp_errno
;
332 pfatal_with_name (tempname
);
336 tem
= link (tempname
, lockname
);
339 if (tem
< 0 && errno
== EPERM
)
340 fatal ("Unable to create hard link between %s and %s",
349 /* If lock file is five minutes old, unlock it.
350 Five minutes should be good enough to cope with crashes
351 and wedgitude, and long enough to avoid being fooled
352 by time differences between machines. */
353 if (stat (lockname
, &st
) >= 0)
355 time_t now
= time (0);
356 if (st
.st_ctime
< now
- 300)
361 delete_lockname
= lockname
;
363 #endif /* not MAIL_USE_SYSTEM_LOCK */
364 #endif /* not MAIL_USE_MMDF */
370 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
377 if (setuid (getuid ()) < 0 || setregid (-1, real_gid
) < 0)
378 fatal ("Failed to drop privileges", 0, 0);
380 #ifndef MAIL_USE_MMDF
381 #ifdef MAIL_USE_SYSTEM_LOCK
382 indesc
= open (inname
, O_RDWR
);
383 #else /* if not MAIL_USE_SYSTEM_LOCK */
384 indesc
= open (inname
, O_RDONLY
);
385 #endif /* not MAIL_USE_SYSTEM_LOCK */
386 #else /* MAIL_USE_MMDF */
387 indesc
= lk_open (inname
, O_RDONLY
, 0, 0, 10);
388 #endif /* MAIL_USE_MMDF */
391 pfatal_with_name (inname
);
394 /* In case movemail is setuid to root, make sure the user can
395 read the output file. */
396 /* This is desirable for all systems
397 but I don't want to assume all have the umask system call */
398 umask (umask (0) & 0333);
399 #endif /* BSD_SYSTEM */
400 outdesc
= open (outname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
402 pfatal_with_name (outname
);
404 if (setregid (-1, priv_gid
) < 0)
405 fatal ("Failed to regain privileges", 0, 0);
407 /* This label exists so we can retry locking
408 after a delay, if it got EAGAIN or EBUSY. */
411 /* Try to lock it. */
412 #ifdef MAIL_USE_MAILLOCK
415 /* The "0 - " is to make it a negative number if maillock returns
417 status
= 0 - maillock (spool_name
, 1);
418 #ifdef HAVE_TOUCHLOCK
419 touched_lock
= time (0);
424 #endif /* MAIL_USE_MAILLOCK */
426 #ifdef MAIL_USE_SYSTEM_LOCK
427 #ifdef MAIL_USE_LOCKF
428 status
= lockf (indesc
, F_LOCK
, 0);
429 #else /* not MAIL_USE_LOCKF */
431 status
= locking (indesc
, LK_RLCK
, -1L);
433 status
= flock (indesc
, LOCK_EX
);
435 #endif /* not MAIL_USE_LOCKF */
436 #endif /* MAIL_USE_SYSTEM_LOCK */
439 /* If it fails, retry up to 5 times
440 for certain failure codes. */
443 if (++lockcount
<= 5)
461 pfatal_with_name (inname
);
469 nread
= read (indesc
, buf
, sizeof buf
);
471 pfatal_with_name (inname
);
472 if (nread
!= write (outdesc
, buf
, nread
))
474 int saved_errno
= errno
;
477 pfatal_with_name (outname
);
479 if (nread
< sizeof buf
)
481 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
484 time_t now
= time (0);
485 if (now
- touched_lock
> 60)
491 #endif /* MAIL_USE_MAILLOCK */
496 if (fsync (outdesc
) < 0)
497 pfatal_and_delete (outname
);
500 /* Prevent symlink attacks truncating other users' mailboxes */
501 if (setregid (-1, real_gid
) < 0)
502 fatal ("Failed to drop privileges", 0, 0);
504 /* Check to make sure no errors before we zap the inbox. */
505 if (close (outdesc
) != 0)
506 pfatal_and_delete (outname
);
508 #ifdef MAIL_USE_SYSTEM_LOCK
511 if (ftruncate (indesc
, 0L) != 0)
512 pfatal_with_name (inname
);
514 #endif /* MAIL_USE_SYSTEM_LOCK */
517 lk_close (indesc
, 0, 0, 0);
522 #ifndef MAIL_USE_SYSTEM_LOCK
525 /* Delete the input file; if we can't, at least get rid of its
527 #ifdef MAIL_UNLINK_SPOOL
528 /* This is generally bad to do, because it destroys the permissions
529 that were set on the file. Better to just empty the file. */
530 if (unlink (inname
) < 0 && errno
!= ENOENT
)
531 #endif /* MAIL_UNLINK_SPOOL */
532 creat (inname
, 0600);
534 #endif /* not MAIL_USE_SYSTEM_LOCK */
536 /* End of mailbox truncation */
537 if (setregid (-1, priv_gid
) < 0)
538 fatal ("Failed to regain privileges", 0, 0);
540 #ifdef MAIL_USE_MAILLOCK
541 /* This has to occur in the child, i.e., in the process that
542 acquired the lock! */
550 if (!WIFEXITED (wait_status
))
552 else if (WEXITSTATUS (wait_status
) != 0)
553 exit (WEXITSTATUS (wait_status
));
555 #if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK)
556 #ifdef MAIL_USE_MAILLOCK
558 #endif /* MAIL_USE_MAILLOCK */
560 #endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */
562 #endif /* ! DISABLE_DIRECT_ACCESS */
567 #ifdef MAIL_USE_MAILLOCK
568 /* This function uses stat to confirm that the mail directory is
569 identical to the directory of the input file, rather than just
570 string-comparing the two paths, because one or both of them might
571 be symbolic links pointing to some other directory. */
573 mail_spool_name (char *inname
)
575 struct stat stat1
, stat2
;
579 if (! (fname
= strrchr (inname
, '/')))
584 if (stat (MAILDIR
, &stat1
) < 0)
587 indir
= xmalloc (fname
- inname
+ 1);
588 memcpy (indir
, inname
, fname
- inname
);
589 indir
[fname
-inname
] = '\0';
592 status
= stat (indir
, &stat2
);
599 if (stat1
.st_dev
== stat2
.st_dev
600 && stat1
.st_ino
== stat2
.st_ino
)
605 #endif /* MAIL_USE_MAILLOCK */
607 /* Print error message and exit. */
610 fatal (const char *s1
, const char *s2
, const char *s3
)
613 unlink (delete_lockname
);
618 /* Print error message. `s1' is printf control string, `s2' and `s3'
619 are args for it or null. */
622 error (const char *s1
, const char *s2
, const char *s3
)
624 fprintf (stderr
, "movemail: ");
626 fprintf (stderr
, s1
, s2
, s3
);
628 fprintf (stderr
, s1
, s2
);
630 fprintf (stderr
, "%s", s1
);
631 fprintf (stderr
, "\n");
635 pfatal_with_name (char *name
)
637 fatal ("%s for %s", strerror (errno
), name
);
641 pfatal_and_delete (char *name
)
643 char *s
= strerror (errno
);
645 fatal ("%s for %s", s
, name
);
648 /* This is the guts of the interface to the Post Office Protocol. */
653 #include <sys/socket.h>
654 #include <netinet/in.h>
666 static char Errmsg
[200]; /* POP errors, at least, can exceed
667 the original length of 80. */
670 * The full valid syntax for a POP mailbox specification for movemail
671 * is "po:username:hostname". The ":hostname" is optional; if it is
672 * omitted, the MAILHOST environment variable will be consulted. Note
673 * that by the time popmail() is called the "po:" has been stripped
674 * off of the front of the mailbox name.
676 * If the mailbox is in the form "po:username:hostname", then it is
677 * modified by this function -- the second colon is replaced by a
680 * Return a value suitable for passing to `exit'.
684 popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
)
690 char *getenv (const char *);
692 int start
, end
, increment
;
693 char *user
, *hostname
;
696 if ((hostname
= strchr (mailbox
, ':')))
699 server
= pop_open (hostname
, user
, password
, POP_NO_GETPASS
);
702 error ("Error connecting to POP server: %s", pop_error
, 0);
706 if (pop_stat (server
, &nmsgs
, &nbytes
))
708 error ("Error getting message count from POP server: %s", pop_error
, 0);
718 mbfi
= open (outfile
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
722 error ("Error in open: %s, %s", strerror (errno
), outfile
);
726 if (fchown (mbfi
, getuid (), -1) != 0)
728 int fchown_errno
= errno
;
730 if (fstat (mbfi
, &st
) != 0 || st
.st_uid
!= getuid ())
733 error ("Error in fchown: %s, %s", strerror (fchown_errno
), outfile
);
738 if ((mbf
= fdopen (mbfi
, "wb")) == NULL
)
741 error ("Error in fdopen: %s", strerror (errno
), 0);
760 for (i
= start
; i
* increment
<= end
* increment
; i
+= increment
)
762 mbx_delimit_begin (mbf
);
763 if (pop_retr (server
, i
, mbf
) != OK
)
765 error ("%s", Errmsg
, 0);
769 mbx_delimit_end (mbf
);
773 error ("Error in fflush: %s", strerror (errno
), 0);
780 /* On AFS, a call to write only modifies the file in the local
781 * workstation's AFS cache. The changes are not written to the server
782 * until a call to fsync or close is made. Users with AFS home
783 * directories have lost mail when over quota because these checks were
784 * not made in previous versions of movemail. */
787 if (fsync (mbfi
) < 0)
789 error ("Error in fsync: %s", strerror (errno
), 0);
794 if (close (mbfi
) == -1)
796 error ("Error in close: %s", strerror (errno
), 0);
801 for (i
= 1; i
<= nmsgs
; i
++)
803 if (pop_delete (server
, i
))
805 error ("Error from POP server: %s", pop_error
, 0);
811 if (pop_quit (server
))
813 error ("Error from POP server: %s", pop_error
, 0);
821 pop_retr (popserver server
, int msgno
, FILE *arg
)
826 if (pop_retrieve_first (server
, msgno
, &line
))
828 snprintf (Errmsg
, sizeof Errmsg
, "Error from POP server: %s", pop_error
);
832 while ((ret
= pop_retrieve_next (server
, &line
)) >= 0)
837 if (mbx_write (line
, ret
, arg
) != OK
)
839 strcpy (Errmsg
, strerror (errno
));
847 snprintf (Errmsg
, sizeof Errmsg
, "Error from POP server: %s", pop_error
);
855 mbx_write (char *line
, int len
, FILE *mbf
)
857 #ifdef MOVEMAIL_QUOTE_POP_FROM_LINES
858 /* Do this as a macro instead of using strcmp to save on execution time. */
859 # define IS_FROM_LINE(a) ((a[0] == 'F') \
864 if (IS_FROM_LINE (line
))
866 if (fputc ('>', mbf
) == EOF
)
870 if (line
[0] == '\037')
872 if (fputs ("^_", mbf
) == EOF
)
877 if (fwrite (line
, 1, len
, mbf
) != len
)
879 if (fputc (0x0a, mbf
) == EOF
)
885 mbx_delimit_begin (FILE *mbf
)
889 char fromline
[40] = "From movemail ";
892 ltime
= localtime (&now
);
894 strcat (fromline
, asctime (ltime
));
896 if (fputs (fromline
, mbf
) == EOF
)
902 mbx_delimit_end (FILE *mbf
)
904 if (putc ('\n', mbf
) == EOF
)
909 #endif /* MAIL_USE_POP */