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, 2001-2011
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 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>
88 #define wait(var) (*(var) = 0)
89 /* Unfortunately, Samba doesn't seem to properly lock Unix files even
90 though the locking call succeeds (and indeed blocks local access from
91 other NT programs). If you have direct file access using an NFS
92 client or something other than Samba, the locking call might work
93 properly - make sure it does before you enable this!
95 [18-Feb-97 andrewi] I now believe my comment above to be incorrect,
96 since it was based on a misunderstanding of how locking calls are
97 implemented and used on Unix. */
98 //#define DISABLE_DIRECT_ACCESS
101 #endif /* WINDOWSNT */
111 #include <sys/locking.h>
114 #ifdef MAIL_USE_LOCKF
115 #define MAIL_USE_SYSTEM_LOCK
118 #ifdef MAIL_USE_FLOCK
119 #define MAIL_USE_SYSTEM_LOCK
123 extern int lk_open (), lk_close ();
126 #if !defined (MAIL_USE_SYSTEM_LOCK) && !defined (MAIL_USE_MMDF) && \
127 (defined (HAVE_LIBMAIL) || defined (HAVE_LIBLOCKFILE)) && \
128 defined (HAVE_MAILLOCK_H)
129 #include <maillock.h>
130 /* We can't use maillock unless we know what directory system mail
133 #define MAIL_USE_MAILLOCK
134 static char *mail_spool_name ();
138 #ifndef HAVE_STRERROR
139 char *strerror (int);
142 static void fatal (const char *s1
, const char *s2
, const char *s3
) NO_RETURN
;
143 static void error (const char *s1
, const char *s2
, const char *s3
);
144 static void pfatal_with_name (char *name
) NO_RETURN
;
145 static void pfatal_and_delete (char *name
) NO_RETURN
;
146 static char *concat (const char *s1
, const char *s2
, const char *s3
);
147 static long *xmalloc (unsigned int size
);
149 static int popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
);
150 static int pop_retr (popserver server
, int msgno
, FILE *arg
);
151 static int mbx_write (char *line
, int len
, FILE *mbf
);
152 static int mbx_delimit_begin (FILE *mbf
);
153 static int mbx_delimit_end (FILE *mbf
);
156 /* Nonzero means this is name of a lock file to delete on fatal error. */
157 static char *delete_lockname
;
160 main (int argc
, char **argv
)
162 char *inname
, *outname
;
166 int c
, preserve_mail
= 0;
168 #ifndef MAIL_USE_SYSTEM_LOCK
175 #endif /* not MAIL_USE_SYSTEM_LOCK */
177 #ifdef MAIL_USE_MAILLOCK
182 int pop_reverse_order
= 0;
184 #else /* ! MAIL_USE_POP */
186 #endif /* MAIL_USE_POP */
188 uid_t real_gid
= getgid();
189 uid_t priv_gid
= getegid();
192 /* Ensure all file i/o is in binary mode. */
198 while ((c
= getopt (argc
, argv
, ARGSTR
)) != EOF
)
203 pop_reverse_order
= 1;
216 (argc
- optind
< 2) || (argc
- optind
> 3)
223 fprintf (stderr
, "Usage: movemail [-p] [-r] inbox destfile%s\n",
226 fprintf (stderr
, "Usage: movemail [-p] inbox destfile%s\n", "");
231 inname
= argv
[optind
];
232 outname
= argv
[optind
+1];
239 fatal ("Destination file name is empty", 0, 0);
242 if (!strncmp (inname
, "po:", 3))
246 status
= popmail (inname
+ 3, outname
, preserve_mail
,
247 (argc
- optind
== 3) ? argv
[optind
+2] : NULL
,
252 if (setuid (getuid ()) < 0)
253 fatal ("Failed to drop privileges", 0, 0);
255 #endif /* MAIL_USE_POP */
257 #ifndef DISABLE_DIRECT_ACCESS
258 #ifndef MAIL_USE_MMDF
259 #ifndef MAIL_USE_SYSTEM_LOCK
260 #ifdef MAIL_USE_MAILLOCK
261 spool_name
= mail_spool_name (inname
);
265 #ifndef DIRECTORY_SEP
266 #define DIRECTORY_SEP '/'
268 #ifndef IS_DIRECTORY_SEP
269 #define IS_DIRECTORY_SEP(_c_) ((_c_) == DIRECTORY_SEP)
272 /* Use a lock file named after our first argument with .lock appended:
273 If it exists, the mail file is locked. */
274 /* Note: this locking mechanism is *required* by the mailer
275 (on systems which use it) to prevent loss of mail.
277 On systems that use a lock file, extracting the mail without locking
278 WILL occasionally cause loss of mail due to timing errors!
280 So, if creation of the lock file fails
281 due to access permission on the mail spool directory,
282 you simply MUST change the permission
283 and/or make movemail a setgid program
284 so it can create lock files properly.
286 You might also wish to verify that your system is one
287 which uses lock files for this purpose. Some systems use other methods.
289 If your system uses the `flock' system call for mail locking,
290 define MAIL_USE_SYSTEM_LOCK in config.h or the s-*.h file
291 and recompile movemail. If the s- file for your system
292 should define MAIL_USE_SYSTEM_LOCK but does not, send a bug report
293 to bug-gnu-emacs@prep.ai.mit.edu so we can fix it. */
295 lockname
= concat (inname
, ".lock", "");
296 tempname
= (char *) xmalloc (strlen (inname
) + strlen ("EXXXXXX") + 1);
297 strcpy (tempname
, inname
);
298 p
= tempname
+ strlen (tempname
);
299 while (p
!= tempname
&& !IS_DIRECTORY_SEP (p
[-1]))
302 strcpy (p
, "EXXXXXX");
308 /* Create the lock file, but not under the lock file name. */
309 /* Give up if cannot do that. */
310 desc
= open (tempname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
313 char *message
= (char *) xmalloc (strlen (tempname
) + 50);
314 sprintf (message
, "creating %s, which would become the lock file",
316 pfatal_with_name (message
);
320 tem
= link (tempname
, lockname
);
323 if (tem
< 0 && errno
== EPERM
)
324 fatal ("Unable to create hard link between %s and %s",
333 /* If lock file is five minutes old, unlock it.
334 Five minutes should be good enough to cope with crashes
335 and wedgitude, and long enough to avoid being fooled
336 by time differences between machines. */
337 if (stat (lockname
, &st
) >= 0)
340 if (st
.st_ctime
< now
- 300)
345 delete_lockname
= lockname
;
347 #endif /* not MAIL_USE_SYSTEM_LOCK */
348 #endif /* not MAIL_USE_MMDF */
354 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
355 time_t touched_lock
, now
;
358 if (setuid (getuid ()) < 0 || setregid (-1, real_gid
) < 0)
359 fatal ("Failed to drop privileges", 0, 0);
361 #ifndef MAIL_USE_MMDF
362 #ifdef MAIL_USE_SYSTEM_LOCK
363 indesc
= open (inname
, O_RDWR
);
364 #else /* if not MAIL_USE_SYSTEM_LOCK */
365 indesc
= open (inname
, O_RDONLY
);
366 #endif /* not MAIL_USE_SYSTEM_LOCK */
367 #else /* MAIL_USE_MMDF */
368 indesc
= lk_open (inname
, O_RDONLY
, 0, 0, 10);
369 #endif /* MAIL_USE_MMDF */
372 pfatal_with_name (inname
);
375 /* In case movemail is setuid to root, make sure the user can
376 read the output file. */
377 /* This is desirable for all systems
378 but I don't want to assume all have the umask system call */
379 umask (umask (0) & 0333);
380 #endif /* BSD_SYSTEM */
381 outdesc
= open (outname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
383 pfatal_with_name (outname
);
385 if (setregid (-1, priv_gid
) < 0)
386 fatal ("Failed to regain privileges", 0, 0);
388 /* This label exists so we can retry locking
389 after a delay, if it got EAGAIN or EBUSY. */
392 /* Try to lock it. */
393 #ifdef MAIL_USE_MAILLOCK
396 /* The "0 - " is to make it a negative number if maillock returns
398 status
= 0 - maillock (spool_name
, 1);
399 #ifdef HAVE_TOUCHLOCK
400 touched_lock
= time (0);
405 #endif /* MAIL_USE_MAILLOCK */
407 #ifdef MAIL_USE_SYSTEM_LOCK
408 #ifdef MAIL_USE_LOCKF
409 status
= lockf (indesc
, F_LOCK
, 0);
410 #else /* not MAIL_USE_LOCKF */
412 status
= locking (indesc
, LK_RLCK
, -1L);
414 status
= flock (indesc
, LOCK_EX
);
416 #endif /* not MAIL_USE_LOCKF */
417 #endif /* MAIL_USE_SYSTEM_LOCK */
420 /* If it fails, retry up to 5 times
421 for certain failure codes. */
424 if (++lockcount
<= 5)
442 pfatal_with_name (inname
);
450 nread
= read (indesc
, buf
, sizeof buf
);
452 pfatal_with_name (inname
);
453 if (nread
!= write (outdesc
, buf
, nread
))
455 int saved_errno
= errno
;
458 pfatal_with_name (outname
);
460 if (nread
< sizeof buf
)
462 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
466 if (now
- touched_lock
> 60)
472 #endif /* MAIL_USE_MAILLOCK */
477 if (fsync (outdesc
) < 0)
478 pfatal_and_delete (outname
);
481 /* Prevent symlink attacks truncating other users' mailboxes */
482 if (setregid (-1, real_gid
) < 0)
483 fatal ("Failed to drop privileges", 0, 0);
485 /* Check to make sure no errors before we zap the inbox. */
486 if (close (outdesc
) != 0)
487 pfatal_and_delete (outname
);
489 #ifdef MAIL_USE_SYSTEM_LOCK
492 if (ftruncate (indesc
, 0L) != 0)
493 pfatal_with_name (inname
);
495 #endif /* MAIL_USE_SYSTEM_LOCK */
498 lk_close (indesc
, 0, 0, 0);
503 #ifndef MAIL_USE_SYSTEM_LOCK
506 /* Delete the input file; if we can't, at least get rid of its
508 #ifdef MAIL_UNLINK_SPOOL
509 /* This is generally bad to do, because it destroys the permissions
510 that were set on the file. Better to just empty the file. */
511 if (unlink (inname
) < 0 && errno
!= ENOENT
)
512 #endif /* MAIL_UNLINK_SPOOL */
513 creat (inname
, 0600);
515 #endif /* not MAIL_USE_SYSTEM_LOCK */
517 /* End of mailbox truncation */
518 if (setregid (-1, priv_gid
) < 0)
519 fatal ("Failed to regain privileges", 0, 0);
521 #ifdef MAIL_USE_MAILLOCK
522 /* This has to occur in the child, i.e., in the process that
523 acquired the lock! */
531 if (!WIFEXITED (wait_status
))
533 else if (WRETCODE (wait_status
) != 0)
534 exit (WRETCODE (wait_status
));
536 #if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK)
537 #ifdef MAIL_USE_MAILLOCK
539 #endif /* MAIL_USE_MAILLOCK */
541 #endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */
543 #endif /* ! DISABLE_DIRECT_ACCESS */
548 #ifdef MAIL_USE_MAILLOCK
549 /* This function uses stat to confirm that the mail directory is
550 identical to the directory of the input file, rather than just
551 string-comparing the two paths, because one or both of them might
552 be symbolic links pointing to some other directory. */
554 mail_spool_name (char *inname
)
556 struct stat stat1
, stat2
;
560 if (! (fname
= strrchr (inname
, '/')))
565 if (stat (MAILDIR
, &stat1
) < 0)
568 indir
= (char *) xmalloc (fname
- inname
+ 1);
569 strncpy (indir
, inname
, fname
- inname
);
570 indir
[fname
-inname
] = '\0';
573 status
= stat (indir
, &stat2
);
580 if (stat1
.st_dev
== stat2
.st_dev
581 && stat1
.st_ino
== stat2
.st_ino
)
586 #endif /* MAIL_USE_MAILLOCK */
588 /* Print error message and exit. */
591 fatal (const char *s1
, const char *s2
, const char *s3
)
594 unlink (delete_lockname
);
599 /* Print error message. `s1' is printf control string, `s2' and `s3'
600 are args for it or null. */
603 error (const char *s1
, const char *s2
, const char *s3
)
605 fprintf (stderr
, "movemail: ");
607 fprintf (stderr
, s1
, s2
, s3
);
609 fprintf (stderr
, s1
, s2
);
611 fprintf (stderr
, "%s", s1
);
612 fprintf (stderr
, "\n");
616 pfatal_with_name (char *name
)
618 fatal ("%s for %s", strerror (errno
), name
);
622 pfatal_and_delete (char *name
)
624 char *s
= strerror (errno
);
626 fatal ("%s for %s", s
, name
);
629 /* Return a newly-allocated string whose contents concatenate those of s1, s2, s3. */
632 concat (const char *s1
, const char *s2
, const char *s3
)
634 size_t len1
= strlen (s1
), len2
= strlen (s2
), len3
= strlen (s3
);
635 char *result
= (char *) xmalloc (len1
+ len2
+ len3
+ 1);
638 strcpy (result
+ len1
, s2
);
639 strcpy (result
+ len1
+ len2
, s3
);
640 *(result
+ len1
+ len2
+ len3
) = 0;
645 /* Like malloc but get fatal error if memory is exhausted. */
648 xmalloc (unsigned int size
)
650 long *result
= (long *) malloc (size
);
652 fatal ("virtual memory exhausted", 0, 0);
656 /* This is the guts of the interface to the Post Office Protocol. */
661 #include <sys/socket.h>
662 #include <netinet/in.h>
674 static char Errmsg
[200]; /* POP errors, at least, can exceed
675 the original length of 80. */
678 * The full valid syntax for a POP mailbox specification for movemail
679 * is "po:username:hostname". The ":hostname" is optional; if it is
680 * omitted, the MAILHOST environment variable will be consulted. Note
681 * that by the time popmail() is called the "po:" has been stripped
682 * off of the front of the mailbox name.
684 * If the mailbox is in the form "po:username:hostname", then it is
685 * modified by this function -- the second colon is replaced by a
688 * Return a value suitable for passing to `exit'.
692 popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
)
698 char *getenv (const char *);
700 int start
, end
, increment
;
701 char *user
, *hostname
;
704 if ((hostname
= strchr (mailbox
, ':')))
707 server
= pop_open (hostname
, user
, password
, POP_NO_GETPASS
);
710 error ("Error connecting to POP server: %s", pop_error
, 0);
714 if (pop_stat (server
, &nmsgs
, &nbytes
))
716 error ("Error getting message count from POP server: %s", pop_error
, 0);
726 mbfi
= open (outfile
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
730 error ("Error in open: %s, %s", strerror (errno
), outfile
);
734 if (fchown (mbfi
, getuid (), -1) != 0)
736 int fchown_errno
= errno
;
738 if (fstat (mbfi
, &st
) != 0 || st
.st_uid
!= getuid ())
741 error ("Error in fchown: %s, %s", strerror (fchown_errno
), outfile
);
746 if ((mbf
= fdopen (mbfi
, "wb")) == NULL
)
749 error ("Error in fdopen: %s", strerror (errno
), 0);
768 for (i
= start
; i
* increment
<= end
* increment
; i
+= increment
)
770 mbx_delimit_begin (mbf
);
771 if (pop_retr (server
, i
, mbf
) != OK
)
773 error ("%s", Errmsg
, 0);
777 mbx_delimit_end (mbf
);
781 error ("Error in fflush: %s", strerror (errno
), 0);
788 /* On AFS, a call to write only modifies the file in the local
789 * workstation's AFS cache. The changes are not written to the server
790 * until a call to fsync or close is made. Users with AFS home
791 * directories have lost mail when over quota because these checks were
792 * not made in previous versions of movemail. */
795 if (fsync (mbfi
) < 0)
797 error ("Error in fsync: %s", strerror (errno
), 0);
802 if (close (mbfi
) == -1)
804 error ("Error in close: %s", strerror (errno
), 0);
809 for (i
= 1; i
<= nmsgs
; i
++)
811 if (pop_delete (server
, i
))
813 error ("Error from POP server: %s", pop_error
, 0);
819 if (pop_quit (server
))
821 error ("Error from POP server: %s", pop_error
, 0);
829 pop_retr (popserver server
, int msgno
, FILE *arg
)
834 if (pop_retrieve_first (server
, msgno
, &line
))
836 char *msg
= concat ("Error from POP server: ", pop_error
, "");
837 strncpy (Errmsg
, msg
, sizeof (Errmsg
));
838 Errmsg
[sizeof (Errmsg
)-1] = '\0';
843 while ((ret
= pop_retrieve_next (server
, &line
)) >= 0)
848 if (mbx_write (line
, ret
, arg
) != OK
)
850 strcpy (Errmsg
, strerror (errno
));
858 char *msg
= concat ("Error from POP server: ", pop_error
, "");
859 strncpy (Errmsg
, msg
, sizeof (Errmsg
));
860 Errmsg
[sizeof (Errmsg
)-1] = '\0';
869 mbx_write (char *line
, int len
, FILE *mbf
)
871 #ifdef MOVEMAIL_QUOTE_POP_FROM_LINES
872 /* Do this as a macro instead of using strcmp to save on execution time. */
873 # define IS_FROM_LINE(a) ((a[0] == 'F') \
878 if (IS_FROM_LINE (line
))
880 if (fputc ('>', mbf
) == EOF
)
884 if (line
[0] == '\037')
886 if (fputs ("^_", mbf
) == EOF
)
891 if (fwrite (line
, 1, len
, mbf
) != len
)
893 if (fputc (0x0a, mbf
) == EOF
)
899 mbx_delimit_begin (FILE *mbf
)
903 char fromline
[40] = "From movemail ";
906 ltime
= localtime (&now
);
908 strcat (fromline
, asctime (ltime
));
910 if (fputs (fromline
, mbf
) == EOF
)
916 mbx_delimit_end (FILE *mbf
)
918 if (putc ('\n', mbf
) == EOF
)
923 #endif /* MAIL_USE_POP */
925 #ifndef HAVE_STRERROR
930 extern char *sys_errlist
[];
933 if (errnum
>= 0 && errnum
< sys_nerr
)
934 return sys_errlist
[errnum
];
935 return (char *) "Unknown error";
938 #endif /* ! HAVE_STRERROR */
941 /* movemail.c ends here */