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 (char *);
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
174 #endif /* not MAIL_USE_SYSTEM_LOCK */
176 #ifdef MAIL_USE_MAILLOCK
181 int pop_reverse_order
= 0;
183 #else /* ! MAIL_USE_POP */
185 #endif /* MAIL_USE_POP */
187 uid_t real_gid
= getgid();
188 uid_t priv_gid
= getegid();
191 /* Ensure all file i/o is in binary mode. */
197 while ((c
= getopt (argc
, argv
, ARGSTR
)) != EOF
)
202 pop_reverse_order
= 1;
215 (argc
- optind
< 2) || (argc
- optind
> 3)
222 fprintf (stderr
, "Usage: movemail [-p] [-r] inbox destfile%s\n",
225 fprintf (stderr
, "Usage: movemail [-p] inbox destfile%s\n", "");
230 inname
= argv
[optind
];
231 outname
= argv
[optind
+1];
238 fatal ("Destination file name is empty", 0, 0);
241 if (!strncmp (inname
, "po:", 3))
245 status
= popmail (inname
+ 3, outname
, preserve_mail
,
246 (argc
- optind
== 3) ? argv
[optind
+2] : NULL
,
251 if (setuid (getuid ()) < 0)
252 fatal ("Failed to drop privileges", 0, 0);
254 #endif /* MAIL_USE_POP */
256 #ifndef DISABLE_DIRECT_ACCESS
257 #ifndef MAIL_USE_MMDF
258 #ifndef MAIL_USE_SYSTEM_LOCK
259 #ifdef MAIL_USE_MAILLOCK
260 spool_name
= mail_spool_name (inname
);
270 #ifndef DIRECTORY_SEP
271 #define DIRECTORY_SEP '/'
273 #ifndef IS_DIRECTORY_SEP
274 #define IS_DIRECTORY_SEP(_c_) ((_c_) == DIRECTORY_SEP)
277 /* Use a lock file named after our first argument with .lock appended:
278 If it exists, the mail file is locked. */
279 /* Note: this locking mechanism is *required* by the mailer
280 (on systems which use it) to prevent loss of mail.
282 On systems that use a lock file, extracting the mail without locking
283 WILL occasionally cause loss of mail due to timing errors!
285 So, if creation of the lock file fails
286 due to access permission on the mail spool directory,
287 you simply MUST change the permission
288 and/or make movemail a setgid program
289 so it can create lock files properly.
291 You might also wish to verify that your system is one
292 which uses lock files for this purpose. Some systems use other methods.
294 If your system uses the `flock' system call for mail locking,
295 define MAIL_USE_SYSTEM_LOCK in config.h or the s-*.h file
296 and recompile movemail. If the s- file for your system
297 should define MAIL_USE_SYSTEM_LOCK but does not, send a bug report
298 to bug-gnu-emacs@prep.ai.mit.edu so we can fix it. */
300 lockname
= concat (inname
, ".lock", "");
301 tempname
= (char *) xmalloc (strlen (inname
) + strlen ("EXXXXXX") + 1);
302 strcpy (tempname
, inname
);
303 p
= tempname
+ strlen (tempname
);
304 while (p
!= tempname
&& !IS_DIRECTORY_SEP (p
[-1]))
307 strcpy (p
, "EXXXXXX");
313 /* Create the lock file, but not under the lock file name. */
314 /* Give up if cannot do that. */
315 desc
= open (tempname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
318 char *message
= (char *) xmalloc (strlen (tempname
) + 50);
319 sprintf (message
, "creating %s, which would become the lock file",
321 pfatal_with_name (message
);
325 tem
= link (tempname
, lockname
);
328 if (tem
< 0 && errno
== EPERM
)
329 fatal ("Unable to create hard link between %s and %s",
338 /* If lock file is five minutes old, unlock it.
339 Five minutes should be good enough to cope with crashes
340 and wedgitude, and long enough to avoid being fooled
341 by time differences between machines. */
342 if (stat (lockname
, &st
) >= 0)
344 time_t now
= time (0);
345 if (st
.st_ctime
< now
- 300)
350 delete_lockname
= lockname
;
352 #endif /* not MAIL_USE_SYSTEM_LOCK */
353 #endif /* not MAIL_USE_MMDF */
359 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
366 if (setuid (getuid ()) < 0 || setregid (-1, real_gid
) < 0)
367 fatal ("Failed to drop privileges", 0, 0);
369 #ifndef MAIL_USE_MMDF
370 #ifdef MAIL_USE_SYSTEM_LOCK
371 indesc
= open (inname
, O_RDWR
);
372 #else /* if not MAIL_USE_SYSTEM_LOCK */
373 indesc
= open (inname
, O_RDONLY
);
374 #endif /* not MAIL_USE_SYSTEM_LOCK */
375 #else /* MAIL_USE_MMDF */
376 indesc
= lk_open (inname
, O_RDONLY
, 0, 0, 10);
377 #endif /* MAIL_USE_MMDF */
380 pfatal_with_name (inname
);
383 /* In case movemail is setuid to root, make sure the user can
384 read the output file. */
385 /* This is desirable for all systems
386 but I don't want to assume all have the umask system call */
387 umask (umask (0) & 0333);
388 #endif /* BSD_SYSTEM */
389 outdesc
= open (outname
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
391 pfatal_with_name (outname
);
393 if (setregid (-1, priv_gid
) < 0)
394 fatal ("Failed to regain privileges", 0, 0);
396 /* This label exists so we can retry locking
397 after a delay, if it got EAGAIN or EBUSY. */
400 /* Try to lock it. */
401 #ifdef MAIL_USE_MAILLOCK
404 /* The "0 - " is to make it a negative number if maillock returns
406 status
= 0 - maillock (spool_name
, 1);
407 #ifdef HAVE_TOUCHLOCK
408 touched_lock
= time (0);
413 #endif /* MAIL_USE_MAILLOCK */
415 #ifdef MAIL_USE_SYSTEM_LOCK
416 #ifdef MAIL_USE_LOCKF
417 status
= lockf (indesc
, F_LOCK
, 0);
418 #else /* not MAIL_USE_LOCKF */
420 status
= locking (indesc
, LK_RLCK
, -1L);
422 status
= flock (indesc
, LOCK_EX
);
424 #endif /* not MAIL_USE_LOCKF */
425 #endif /* MAIL_USE_SYSTEM_LOCK */
428 /* If it fails, retry up to 5 times
429 for certain failure codes. */
432 if (++lockcount
<= 5)
450 pfatal_with_name (inname
);
458 nread
= read (indesc
, buf
, sizeof buf
);
460 pfatal_with_name (inname
);
461 if (nread
!= write (outdesc
, buf
, nread
))
463 int saved_errno
= errno
;
466 pfatal_with_name (outname
);
468 if (nread
< sizeof buf
)
470 #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK)
473 time_t now
= time (0);
474 if (now
- touched_lock
> 60)
480 #endif /* MAIL_USE_MAILLOCK */
485 if (fsync (outdesc
) < 0)
486 pfatal_and_delete (outname
);
489 /* Prevent symlink attacks truncating other users' mailboxes */
490 if (setregid (-1, real_gid
) < 0)
491 fatal ("Failed to drop privileges", 0, 0);
493 /* Check to make sure no errors before we zap the inbox. */
494 if (close (outdesc
) != 0)
495 pfatal_and_delete (outname
);
497 #ifdef MAIL_USE_SYSTEM_LOCK
500 if (ftruncate (indesc
, 0L) != 0)
501 pfatal_with_name (inname
);
503 #endif /* MAIL_USE_SYSTEM_LOCK */
506 lk_close (indesc
, 0, 0, 0);
511 #ifndef MAIL_USE_SYSTEM_LOCK
514 /* Delete the input file; if we can't, at least get rid of its
516 #ifdef MAIL_UNLINK_SPOOL
517 /* This is generally bad to do, because it destroys the permissions
518 that were set on the file. Better to just empty the file. */
519 if (unlink (inname
) < 0 && errno
!= ENOENT
)
520 #endif /* MAIL_UNLINK_SPOOL */
521 creat (inname
, 0600);
523 #endif /* not MAIL_USE_SYSTEM_LOCK */
525 /* End of mailbox truncation */
526 if (setregid (-1, priv_gid
) < 0)
527 fatal ("Failed to regain privileges", 0, 0);
529 #ifdef MAIL_USE_MAILLOCK
530 /* This has to occur in the child, i.e., in the process that
531 acquired the lock! */
539 if (!WIFEXITED (wait_status
))
541 else if (WRETCODE (wait_status
) != 0)
542 exit (WRETCODE (wait_status
));
544 #if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK)
545 #ifdef MAIL_USE_MAILLOCK
547 #endif /* MAIL_USE_MAILLOCK */
549 #endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */
551 #endif /* ! DISABLE_DIRECT_ACCESS */
556 #ifdef MAIL_USE_MAILLOCK
557 /* This function uses stat to confirm that the mail directory is
558 identical to the directory of the input file, rather than just
559 string-comparing the two paths, because one or both of them might
560 be symbolic links pointing to some other directory. */
562 mail_spool_name (char *inname
)
564 struct stat stat1
, stat2
;
568 if (! (fname
= strrchr (inname
, '/')))
573 if (stat (MAILDIR
, &stat1
) < 0)
576 indir
= (char *) xmalloc (fname
- inname
+ 1);
577 strncpy (indir
, inname
, fname
- inname
);
578 indir
[fname
-inname
] = '\0';
581 status
= stat (indir
, &stat2
);
588 if (stat1
.st_dev
== stat2
.st_dev
589 && stat1
.st_ino
== stat2
.st_ino
)
594 #endif /* MAIL_USE_MAILLOCK */
596 /* Print error message and exit. */
599 fatal (const char *s1
, const char *s2
, const char *s3
)
602 unlink (delete_lockname
);
607 /* Print error message. `s1' is printf control string, `s2' and `s3'
608 are args for it or null. */
611 error (const char *s1
, const char *s2
, const char *s3
)
613 fprintf (stderr
, "movemail: ");
615 fprintf (stderr
, s1
, s2
, s3
);
617 fprintf (stderr
, s1
, s2
);
619 fprintf (stderr
, "%s", s1
);
620 fprintf (stderr
, "\n");
624 pfatal_with_name (char *name
)
626 fatal ("%s for %s", strerror (errno
), name
);
630 pfatal_and_delete (char *name
)
632 char *s
= strerror (errno
);
634 fatal ("%s for %s", s
, name
);
637 /* Return a newly-allocated string whose contents concatenate those of s1, s2, s3. */
640 concat (const char *s1
, const char *s2
, const char *s3
)
642 size_t len1
= strlen (s1
), len2
= strlen (s2
), len3
= strlen (s3
);
643 char *result
= (char *) xmalloc (len1
+ len2
+ len3
+ 1);
646 strcpy (result
+ len1
, s2
);
647 strcpy (result
+ len1
+ len2
, s3
);
648 *(result
+ len1
+ len2
+ len3
) = 0;
653 /* Like malloc but get fatal error if memory is exhausted. */
656 xmalloc (unsigned int size
)
658 long *result
= (long *) malloc (size
);
660 fatal ("virtual memory exhausted", 0, 0);
664 /* This is the guts of the interface to the Post Office Protocol. */
669 #include <sys/socket.h>
670 #include <netinet/in.h>
682 static char Errmsg
[200]; /* POP errors, at least, can exceed
683 the original length of 80. */
686 * The full valid syntax for a POP mailbox specification for movemail
687 * is "po:username:hostname". The ":hostname" is optional; if it is
688 * omitted, the MAILHOST environment variable will be consulted. Note
689 * that by the time popmail() is called the "po:" has been stripped
690 * off of the front of the mailbox name.
692 * If the mailbox is in the form "po:username:hostname", then it is
693 * modified by this function -- the second colon is replaced by a
696 * Return a value suitable for passing to `exit'.
700 popmail (char *mailbox
, char *outfile
, int preserve
, char *password
, int reverse_order
)
706 char *getenv (const char *);
708 int start
, end
, increment
;
709 char *user
, *hostname
;
712 if ((hostname
= strchr (mailbox
, ':')))
715 server
= pop_open (hostname
, user
, password
, POP_NO_GETPASS
);
718 error ("Error connecting to POP server: %s", pop_error
, 0);
722 if (pop_stat (server
, &nmsgs
, &nbytes
))
724 error ("Error getting message count from POP server: %s", pop_error
, 0);
734 mbfi
= open (outfile
, O_WRONLY
| O_CREAT
| O_EXCL
, 0666);
738 error ("Error in open: %s, %s", strerror (errno
), outfile
);
742 if (fchown (mbfi
, getuid (), -1) != 0)
744 int fchown_errno
= errno
;
746 if (fstat (mbfi
, &st
) != 0 || st
.st_uid
!= getuid ())
749 error ("Error in fchown: %s, %s", strerror (fchown_errno
), outfile
);
754 if ((mbf
= fdopen (mbfi
, "wb")) == NULL
)
757 error ("Error in fdopen: %s", strerror (errno
), 0);
776 for (i
= start
; i
* increment
<= end
* increment
; i
+= increment
)
778 mbx_delimit_begin (mbf
);
779 if (pop_retr (server
, i
, mbf
) != OK
)
781 error ("%s", Errmsg
, 0);
785 mbx_delimit_end (mbf
);
789 error ("Error in fflush: %s", strerror (errno
), 0);
796 /* On AFS, a call to write only modifies the file in the local
797 * workstation's AFS cache. The changes are not written to the server
798 * until a call to fsync or close is made. Users with AFS home
799 * directories have lost mail when over quota because these checks were
800 * not made in previous versions of movemail. */
803 if (fsync (mbfi
) < 0)
805 error ("Error in fsync: %s", strerror (errno
), 0);
810 if (close (mbfi
) == -1)
812 error ("Error in close: %s", strerror (errno
), 0);
817 for (i
= 1; i
<= nmsgs
; i
++)
819 if (pop_delete (server
, i
))
821 error ("Error from POP server: %s", pop_error
, 0);
827 if (pop_quit (server
))
829 error ("Error from POP server: %s", pop_error
, 0);
837 pop_retr (popserver server
, int msgno
, FILE *arg
)
842 if (pop_retrieve_first (server
, msgno
, &line
))
844 char *msg
= concat ("Error from POP server: ", pop_error
, "");
845 strncpy (Errmsg
, msg
, sizeof (Errmsg
));
846 Errmsg
[sizeof (Errmsg
)-1] = '\0';
851 while ((ret
= pop_retrieve_next (server
, &line
)) >= 0)
856 if (mbx_write (line
, ret
, arg
) != OK
)
858 strcpy (Errmsg
, strerror (errno
));
866 char *msg
= concat ("Error from POP server: ", pop_error
, "");
867 strncpy (Errmsg
, msg
, sizeof (Errmsg
));
868 Errmsg
[sizeof (Errmsg
)-1] = '\0';
877 mbx_write (char *line
, int len
, FILE *mbf
)
879 #ifdef MOVEMAIL_QUOTE_POP_FROM_LINES
880 /* Do this as a macro instead of using strcmp to save on execution time. */
881 # define IS_FROM_LINE(a) ((a[0] == 'F') \
886 if (IS_FROM_LINE (line
))
888 if (fputc ('>', mbf
) == EOF
)
892 if (line
[0] == '\037')
894 if (fputs ("^_", mbf
) == EOF
)
899 if (fwrite (line
, 1, len
, mbf
) != len
)
901 if (fputc (0x0a, mbf
) == EOF
)
907 mbx_delimit_begin (FILE *mbf
)
911 char fromline
[40] = "From movemail ";
914 ltime
= localtime (&now
);
916 strcat (fromline
, asctime (ltime
));
918 if (fputs (fromline
, mbf
) == EOF
)
924 mbx_delimit_end (FILE *mbf
)
926 if (putc ('\n', mbf
) == EOF
)
931 #endif /* MAIL_USE_POP */
933 #ifndef HAVE_STRERROR
938 extern char *sys_errlist
[];
941 if (errnum
>= 0 && errnum
< sys_nerr
)
942 return sys_errlist
[errnum
];
943 return (char *) "Unknown error";
946 #endif /* ! HAVE_STRERROR */
949 /* movemail.c ends here */