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>
86 #define wait(var) (*(var) = 0)
87 /* Unfortunately, Samba doesn't seem to properly lock Unix files even
88 though the locking call succeeds (and indeed blocks local access from
89 other NT programs). If you have direct file access using an NFS
90 client or something other than Samba, the locking call might work
91 properly - make sure it does before you enable this!
93 [18-Feb-97 andrewi] I now believe my comment above to be incorrect,
94 since it was based on a misunderstanding of how locking calls are
95 implemented and used on Unix. */
96 //#define DISABLE_DIRECT_ACCESS
99 #endif /* WINDOWSNT */
109 #include <sys/locking.h>
112 /* If your system uses the `flock' or `lockf' system call for mail locking,
113 define MAIL_USE_SYSTEM_LOCK. If your system type should always define
114 MAIL_USE_LOCKF or MAIL_USE_FLOCK but configure does not do this,
115 please make a bug report. */
117 #ifdef MAIL_USE_LOCKF
118 #define MAIL_USE_SYSTEM_LOCK
121 #ifdef MAIL_USE_FLOCK
122 #define MAIL_USE_SYSTEM_LOCK
126 extern int lk_open (), lk_close ();
129 #if !defined (MAIL_USE_SYSTEM_LOCK) && !defined (MAIL_USE_MMDF) && \
130 (defined (HAVE_LIBMAIL) || defined (HAVE_LIBLOCKFILE)) && \
131 defined (HAVE_MAILLOCK_H)
132 #include <maillock.h>
133 /* We can't use maillock unless we know what directory system mail
136 #define MAIL_USE_MAILLOCK
137 static char *mail_spool_name (char *);
141 static _Noreturn
void fatal (const char *s1
, const char *s2
, const char *s3
);
142 static void error (const char *s1
, const char *s2
, const char *s3
);
143 static _Noreturn
void pfatal_with_name (char *name
);
144 static _Noreturn
void pfatal_and_delete (char *name
);
146 static int popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
);
147 static int pop_retr (popserver server
, int msgno
, FILE *arg
);
148 static int mbx_write (char *line
, int len
, FILE *mbf
);
149 static int mbx_delimit_begin (FILE *mbf
);
150 static int mbx_delimit_end (FILE *mbf
);
153 #if (defined MAIL_USE_MAILLOCK \
154 || (!defined DISABLE_DIRECT_ACCESS && !defined MAIL_USE_MMDF \
155 && !defined MAIL_USE_SYSTEM_LOCK))
156 /* Like malloc but get fatal error if memory is exhausted. */
159 xmalloc (size_t size
)
161 void *result
= malloc (size
);
163 fatal ("virtual memory exhausted", 0, 0);
168 /* Nonzero means this is name of a lock file to delete on fatal error. */
169 static char *delete_lockname
;
172 main (int argc
, char **argv
)
174 char *inname
, *outname
;
178 int c
, preserve_mail
= 0;
180 #ifndef MAIL_USE_SYSTEM_LOCK
185 size_t inname_len
, inname_dirlen
;
187 #endif /* not MAIL_USE_SYSTEM_LOCK */
189 #ifdef MAIL_USE_MAILLOCK
194 int pop_reverse_order
= 0;
196 #else /* ! MAIL_USE_POP */
198 #endif /* MAIL_USE_POP */
200 uid_t real_gid
= getgid ();
201 uid_t priv_gid
= getegid ();
204 /* Ensure all file i/o is in binary mode. */
210 while ((c
= getopt (argc
, argv
, ARGSTR
)) != EOF
)
215 pop_reverse_order
= 1;
228 (argc
- optind
< 2) || (argc
- optind
> 3)
235 fprintf (stderr
, "Usage: movemail [-p] [-r] inbox destfile%s\n",
238 fprintf (stderr
, "Usage: movemail [-p] inbox destfile%s\n", "");
243 inname
= argv
[optind
];
244 outname
= argv
[optind
+1];
251 fatal ("Destination file name is empty", 0, 0);
254 if (!strncmp (inname
, "po:", 3))
258 status
= popmail (inname
+ 3, outname
, preserve_mail
,
259 (argc
- optind
== 3) ? argv
[optind
+2] : NULL
,
264 if (setuid (getuid ()) < 0)
265 fatal ("Failed to drop privileges", 0, 0);
267 #endif /* MAIL_USE_POP */
269 #ifndef DISABLE_DIRECT_ACCESS
270 #ifndef MAIL_USE_MMDF
271 #ifndef MAIL_USE_SYSTEM_LOCK
272 #ifdef MAIL_USE_MAILLOCK
273 spool_name
= mail_spool_name (inname
);
283 /* Use a lock file named after our first argument with .lock appended:
284 If it exists, the mail file is locked. */
285 /* Note: this locking mechanism is *required* by the mailer
286 (on systems which use it) to prevent loss of mail.
288 On systems that use a lock file, extracting the mail without locking
289 WILL occasionally cause loss of mail due to timing errors!
291 So, if creation of the lock file fails due to access
292 permission on the mail spool directory, you simply MUST
293 change the permission and/or make movemail a setgid program
294 so it can create lock files properly.
296 You might also wish to verify that your system is one which
297 uses lock files for this purpose. Some systems use other methods. */
299 inname_len
= strlen (inname
);
300 lockname
= xmalloc (inname_len
+ sizeof ".lock");
301 strcpy (lockname
, inname
);
302 strcpy (lockname
+ inname_len
, ".lock");
303 for (inname_dirlen
= inname_len
;
304 inname_dirlen
&& !IS_DIRECTORY_SEP (inname
[inname_dirlen
- 1]);
307 tempname
= xmalloc (inname_dirlen
+ sizeof "EXXXXXX");
311 /* Create the lock file, but not under the lock file name. */
312 /* Give up if cannot do that. */
314 memcpy (tempname
, inname
, inname_dirlen
);
315 strcpy (tempname
+ inname_dirlen
, "EXXXXXX");
317 desc
= mkstemp (tempname
);
325 desc
= open (tempname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0600);
330 int mkstemp_errno
= errno
;
331 error ("error while creating what would become the lock file",
333 errno
= mkstemp_errno
;
334 pfatal_with_name (tempname
);
338 tem
= link (tempname
, lockname
);
341 if (tem
< 0 && errno
== EPERM
)
342 fatal ("Unable to create hard link between %s and %s",
351 /* If lock file is five minutes old, unlock it.
352 Five minutes should be good enough to cope with crashes
353 and wedgitude, and long enough to avoid being fooled
354 by time differences between machines. */
355 if (stat (lockname
, &st
) >= 0)
357 time_t now
= time (0);
358 if (st
.st_ctime
< now
- 300)
363 delete_lockname
= lockname
;
365 #endif /* not MAIL_USE_SYSTEM_LOCK */
366 #endif /* not MAIL_USE_MMDF */
372 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
379 if (setuid (getuid ()) < 0 || setregid (-1, real_gid
) < 0)
380 fatal ("Failed to drop privileges", 0, 0);
382 #ifndef MAIL_USE_MMDF
383 #ifdef MAIL_USE_SYSTEM_LOCK
384 indesc
= open (inname
, O_RDWR
);
385 #else /* if not MAIL_USE_SYSTEM_LOCK */
386 indesc
= open (inname
, O_RDONLY
);
387 #endif /* not MAIL_USE_SYSTEM_LOCK */
388 #else /* MAIL_USE_MMDF */
389 indesc
= lk_open (inname
, O_RDONLY
, 0, 0, 10);
390 #endif /* MAIL_USE_MMDF */
393 pfatal_with_name (inname
);
396 /* In case movemail is setuid to root, make sure the user can
397 read the output file. */
398 /* This is desirable for all systems
399 but I don't want to assume all have the umask system call */
400 umask (umask (0) & 0333);
401 #endif /* BSD_SYSTEM */
402 outdesc
= open (outname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
404 pfatal_with_name (outname
);
406 if (setregid (-1, priv_gid
) < 0)
407 fatal ("Failed to regain privileges", 0, 0);
409 /* This label exists so we can retry locking
410 after a delay, if it got EAGAIN or EBUSY. */
413 /* Try to lock it. */
414 #ifdef MAIL_USE_MAILLOCK
417 /* The "0 - " is to make it a negative number if maillock returns
419 status
= 0 - maillock (spool_name
, 1);
420 #ifdef HAVE_TOUCHLOCK
421 touched_lock
= time (0);
426 #endif /* MAIL_USE_MAILLOCK */
428 #ifdef MAIL_USE_SYSTEM_LOCK
429 #ifdef MAIL_USE_LOCKF
430 status
= lockf (indesc
, F_LOCK
, 0);
431 #else /* not MAIL_USE_LOCKF */
433 status
= locking (indesc
, LK_RLCK
, -1L);
435 status
= flock (indesc
, LOCK_EX
);
437 #endif /* not MAIL_USE_LOCKF */
438 #endif /* MAIL_USE_SYSTEM_LOCK */
441 /* If it fails, retry up to 5 times
442 for certain failure codes. */
445 if (++lockcount
<= 5)
463 pfatal_with_name (inname
);
471 nread
= read (indesc
, buf
, sizeof buf
);
473 pfatal_with_name (inname
);
474 if (nread
!= write (outdesc
, buf
, nread
))
476 int saved_errno
= errno
;
479 pfatal_with_name (outname
);
481 if (nread
< sizeof buf
)
483 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
486 time_t now
= time (0);
487 if (now
- touched_lock
> 60)
493 #endif /* MAIL_USE_MAILLOCK */
498 if (fsync (outdesc
) < 0)
499 pfatal_and_delete (outname
);
502 /* Prevent symlink attacks truncating other users' mailboxes */
503 if (setregid (-1, real_gid
) < 0)
504 fatal ("Failed to drop privileges", 0, 0);
506 /* Check to make sure no errors before we zap the inbox. */
507 if (close (outdesc
) != 0)
508 pfatal_and_delete (outname
);
510 #ifdef MAIL_USE_SYSTEM_LOCK
513 if (ftruncate (indesc
, 0L) != 0)
514 pfatal_with_name (inname
);
516 #endif /* MAIL_USE_SYSTEM_LOCK */
519 lk_close (indesc
, 0, 0, 0);
524 #ifndef MAIL_USE_SYSTEM_LOCK
527 /* Delete the input file; if we can't, at least get rid of its
529 #ifdef MAIL_UNLINK_SPOOL
530 /* This is generally bad to do, because it destroys the permissions
531 that were set on the file. Better to just empty the file. */
532 if (unlink (inname
) < 0 && errno
!= ENOENT
)
533 #endif /* MAIL_UNLINK_SPOOL */
534 creat (inname
, 0600);
536 #endif /* not MAIL_USE_SYSTEM_LOCK */
538 /* End of mailbox truncation */
539 if (setregid (-1, priv_gid
) < 0)
540 fatal ("Failed to regain privileges", 0, 0);
542 #ifdef MAIL_USE_MAILLOCK
543 /* This has to occur in the child, i.e., in the process that
544 acquired the lock! */
552 if (!WIFEXITED (wait_status
))
554 else if (WEXITSTATUS (wait_status
) != 0)
555 exit (WEXITSTATUS (wait_status
));
557 #if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK)
558 #ifdef MAIL_USE_MAILLOCK
560 #endif /* MAIL_USE_MAILLOCK */
562 #endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */
564 #endif /* ! DISABLE_DIRECT_ACCESS */
569 #ifdef MAIL_USE_MAILLOCK
570 /* This function uses stat to confirm that the mail directory is
571 identical to the directory of the input file, rather than just
572 string-comparing the two paths, because one or both of them might
573 be symbolic links pointing to some other directory. */
575 mail_spool_name (char *inname
)
577 struct stat stat1
, stat2
;
581 if (! (fname
= strrchr (inname
, '/')))
586 if (stat (MAILDIR
, &stat1
) < 0)
589 indir
= xmalloc (fname
- inname
+ 1);
590 memcpy (indir
, inname
, fname
- inname
);
591 indir
[fname
-inname
] = '\0';
594 status
= stat (indir
, &stat2
);
601 if (stat1
.st_dev
== stat2
.st_dev
602 && stat1
.st_ino
== stat2
.st_ino
)
607 #endif /* MAIL_USE_MAILLOCK */
609 /* Print error message and exit. */
612 fatal (const char *s1
, const char *s2
, const char *s3
)
615 unlink (delete_lockname
);
620 /* Print error message. `s1' is printf control string, `s2' and `s3'
621 are args for it or null. */
624 error (const char *s1
, const char *s2
, const char *s3
)
626 fprintf (stderr
, "movemail: ");
628 fprintf (stderr
, s1
, s2
, s3
);
630 fprintf (stderr
, s1
, s2
);
632 fprintf (stderr
, "%s", s1
);
633 fprintf (stderr
, "\n");
637 pfatal_with_name (char *name
)
639 fatal ("%s for %s", strerror (errno
), name
);
643 pfatal_and_delete (char *name
)
645 char *s
= strerror (errno
);
647 fatal ("%s for %s", s
, name
);
650 /* This is the guts of the interface to the Post Office Protocol. */
655 #include <sys/socket.h>
656 #include <netinet/in.h>
668 static char Errmsg
[200]; /* POP errors, at least, can exceed
669 the original length of 80. */
672 * The full valid syntax for a POP mailbox specification for movemail
673 * is "po:username:hostname". The ":hostname" is optional; if it is
674 * omitted, the MAILHOST environment variable will be consulted. Note
675 * that by the time popmail() is called the "po:" has been stripped
676 * off of the front of the mailbox name.
678 * If the mailbox is in the form "po:username:hostname", then it is
679 * modified by this function -- the second colon is replaced by a
682 * Return a value suitable for passing to `exit'.
686 popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
)
692 char *getenv (const char *);
694 int start
, end
, increment
;
695 char *user
, *hostname
;
698 if ((hostname
= strchr (mailbox
, ':')))
701 server
= pop_open (hostname
, user
, password
, POP_NO_GETPASS
);
704 error ("Error connecting to POP server: %s", pop_error
, 0);
708 if (pop_stat (server
, &nmsgs
, &nbytes
))
710 error ("Error getting message count from POP server: %s", pop_error
, 0);
720 mbfi
= open (outfile
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
724 error ("Error in open: %s, %s", strerror (errno
), outfile
);
728 if (fchown (mbfi
, getuid (), -1) != 0)
730 int fchown_errno
= errno
;
732 if (fstat (mbfi
, &st
) != 0 || st
.st_uid
!= getuid ())
735 error ("Error in fchown: %s, %s", strerror (fchown_errno
), outfile
);
740 if ((mbf
= fdopen (mbfi
, "wb")) == NULL
)
743 error ("Error in fdopen: %s", strerror (errno
), 0);
762 for (i
= start
; i
* increment
<= end
* increment
; i
+= increment
)
764 mbx_delimit_begin (mbf
);
765 if (pop_retr (server
, i
, mbf
) != OK
)
767 error ("%s", Errmsg
, 0);
771 mbx_delimit_end (mbf
);
775 error ("Error in fflush: %s", strerror (errno
), 0);
782 /* On AFS, a call to write only modifies the file in the local
783 * workstation's AFS cache. The changes are not written to the server
784 * until a call to fsync or close is made. Users with AFS home
785 * directories have lost mail when over quota because these checks were
786 * not made in previous versions of movemail. */
789 if (fsync (mbfi
) < 0)
791 error ("Error in fsync: %s", strerror (errno
), 0);
796 if (close (mbfi
) == -1)
798 error ("Error in close: %s", strerror (errno
), 0);
803 for (i
= 1; i
<= nmsgs
; i
++)
805 if (pop_delete (server
, i
))
807 error ("Error from POP server: %s", pop_error
, 0);
813 if (pop_quit (server
))
815 error ("Error from POP server: %s", pop_error
, 0);
823 pop_retr (popserver server
, int msgno
, FILE *arg
)
828 if (pop_retrieve_first (server
, msgno
, &line
))
830 snprintf (Errmsg
, sizeof Errmsg
, "Error from POP server: %s", pop_error
);
834 while ((ret
= pop_retrieve_next (server
, &line
)) >= 0)
839 if (mbx_write (line
, ret
, arg
) != OK
)
841 strcpy (Errmsg
, strerror (errno
));
849 snprintf (Errmsg
, sizeof Errmsg
, "Error from POP server: %s", pop_error
);
857 mbx_write (char *line
, int len
, FILE *mbf
)
859 #ifdef MOVEMAIL_QUOTE_POP_FROM_LINES
860 /* Do this as a macro instead of using strcmp to save on execution time. */
861 # define IS_FROM_LINE(a) ((a[0] == 'F') \
866 if (IS_FROM_LINE (line
))
868 if (fputc ('>', mbf
) == EOF
)
872 if (line
[0] == '\037')
874 if (fputs ("^_", mbf
) == EOF
)
879 if (fwrite (line
, 1, len
, mbf
) != len
)
881 if (fputc (0x0a, mbf
) == EOF
)
887 mbx_delimit_begin (FILE *mbf
)
891 char fromline
[40] = "From movemail ";
894 ltime
= localtime (&now
);
896 strcat (fromline
, asctime (ltime
));
898 if (fputs (fromline
, mbf
) == EOF
)
904 mbx_delimit_end (FILE *mbf
)
906 if (putc ('\n', mbf
) == EOF
)
911 #endif /* MAIL_USE_POP */