/* movemail foo bar -- move file foo to file bar, locking file foo the way /bin/mail respects. Copyright (C) 1986, 1992-1994, 1996, 1999, 2001-2012 Free Software Foundation, Inc. This file is part of GNU Emacs. GNU Emacs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. GNU Emacs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Emacs. If not, see . */ /* Important notice: defining MAIL_USE_FLOCK or MAIL_USE_LOCKF *will cause loss of mail* if you do it on a system that does not normally use flock/lockf as its way of interlocking access to inbox files. The setting of MAIL_USE_FLOCK and MAIL_USE_LOCKF *must agree* with the system's own conventions. It is not a choice that is up to you. So, if your system uses lock files rather than flock, then the only way you can get proper operation is to enable movemail to write lockfiles there. This means you must either give that directory access modes that permit everyone to write lockfiles in it, or you must make movemail a setuid or setgid program. */ /* * Modified January, 1986 by Michael R. Gretzinger (Project Athena) * * Added POP (Post Office Protocol) service. When compiled -DMAIL_USE_POP * movemail will accept input filename arguments of the form * "po:username". This will cause movemail to open a connection to * a pop server running on $MAILHOST (environment variable). Movemail * must be setuid to root in order to work with POP. * * New module: popmail.c * Modified routines: * main - added code within #ifdef MAIL_USE_POP; added setuid (getuid ()) * after POP code. * New routines in movemail.c: * get_errmsg - return pointer to system error message * * Modified August, 1993 by Jonathan Kamens (OpenVision Technologies) * * Move all of the POP code into a separate file, "pop.c". * Use strerror instead of get_errmsg. * */ #include #include #include #include #include #include #include #include #include #include #include #include "syswait.h" #ifdef MAIL_USE_POP #include "pop.h" #endif #ifdef MSDOS #undef access #endif /* MSDOS */ #ifdef WINDOWSNT #include "ntlib.h" #undef access #undef unlink #define fork() 0 #define wait(var) (*(var) = 0) /* Unfortunately, Samba doesn't seem to properly lock Unix files even though the locking call succeeds (and indeed blocks local access from other NT programs). If you have direct file access using an NFS client or something other than Samba, the locking call might work properly - make sure it does before you enable this! [18-Feb-97 andrewi] I now believe my comment above to be incorrect, since it was based on a misunderstanding of how locking calls are implemented and used on Unix. */ //#define DISABLE_DIRECT_ACCESS #include #endif /* WINDOWSNT */ #ifndef F_OK #define F_OK 0 #define X_OK 1 #define W_OK 2 #define R_OK 4 #endif #ifdef WINDOWSNT #include #endif /* If your system uses the `flock' or `lockf' system call for mail locking, define MAIL_USE_SYSTEM_LOCK. If your system type should always define MAIL_USE_LOCKF or MAIL_USE_FLOCK but configure does not do this, please make a bug report. */ #ifdef MAIL_USE_LOCKF #define MAIL_USE_SYSTEM_LOCK #endif #ifdef MAIL_USE_FLOCK #define MAIL_USE_SYSTEM_LOCK #endif #ifdef MAIL_USE_MMDF extern int lk_open (), lk_close (); #endif #if !defined (MAIL_USE_SYSTEM_LOCK) && !defined (MAIL_USE_MMDF) && \ (defined (HAVE_LIBMAIL) || defined (HAVE_LIBLOCKFILE)) && \ defined (HAVE_MAILLOCK_H) #include /* We can't use maillock unless we know what directory system mail files appear in. */ #ifdef MAILDIR #define MAIL_USE_MAILLOCK static char *mail_spool_name (char *); #endif #endif static _Noreturn void fatal (const char *s1, const char *s2, const char *s3); static void error (const char *s1, const char *s2, const char *s3); static _Noreturn void pfatal_with_name (char *name); static _Noreturn void pfatal_and_delete (char *name); #ifdef MAIL_USE_POP static int popmail (char *mailbox, char *outfile, int preserve, char *password, int reverse_order); static int pop_retr (popserver server, int msgno, FILE *arg); static int mbx_write (char *line, int len, FILE *mbf); static int mbx_delimit_begin (FILE *mbf); static int mbx_delimit_end (FILE *mbf); #endif #if (defined MAIL_USE_MAILLOCK \ || (!defined DISABLE_DIRECT_ACCESS && !defined MAIL_USE_MMDF \ && !defined MAIL_USE_SYSTEM_LOCK)) /* Like malloc but get fatal error if memory is exhausted. */ static void * xmalloc (size_t size) { void *result = malloc (size); if (!result) fatal ("virtual memory exhausted", 0, 0); return result; } #endif /* Nonzero means this is name of a lock file to delete on fatal error. */ static char *delete_lockname; int main (int argc, char **argv) { char *inname, *outname; int indesc, outdesc; ssize_t nread; int wait_status; int c, preserve_mail = 0; #ifndef MAIL_USE_SYSTEM_LOCK struct stat st; int tem; char *lockname; char *tempname; size_t inname_len, inname_dirlen; int desc; #endif /* not MAIL_USE_SYSTEM_LOCK */ #ifdef MAIL_USE_MAILLOCK char *spool_name; #endif #ifdef MAIL_USE_POP int pop_reverse_order = 0; # define ARGSTR "pr" #else /* ! MAIL_USE_POP */ # define ARGSTR "p" #endif /* MAIL_USE_POP */ uid_t real_gid = getgid (); uid_t priv_gid = getegid (); #ifdef WINDOWSNT /* Ensure all file i/o is in binary mode. */ _fmode = _O_BINARY; #endif delete_lockname = 0; while ((c = getopt (argc, argv, ARGSTR)) != EOF) { switch (c) { #ifdef MAIL_USE_POP case 'r': pop_reverse_order = 1; break; #endif case 'p': preserve_mail++; break; default: exit (EXIT_FAILURE); } } if ( #ifdef MAIL_USE_POP (argc - optind < 2) || (argc - optind > 3) #else (argc - optind != 2) #endif ) { #ifdef MAIL_USE_POP fprintf (stderr, "Usage: movemail [-p] [-r] inbox destfile%s\n", " [POP-password]"); #else fprintf (stderr, "Usage: movemail [-p] inbox destfile%s\n", ""); #endif exit (EXIT_FAILURE); } inname = argv[optind]; outname = argv[optind+1]; #ifdef MAIL_USE_MMDF mmdf_init (argv[0]); #endif if (*outname == 0) fatal ("Destination file name is empty", 0, 0); #ifdef MAIL_USE_POP if (!strncmp (inname, "po:", 3)) { int status; status = popmail (inname + 3, outname, preserve_mail, (argc - optind == 3) ? argv[optind+2] : NULL, pop_reverse_order); exit (status); } if (setuid (getuid ()) < 0) fatal ("Failed to drop privileges", 0, 0); #endif /* MAIL_USE_POP */ #ifndef DISABLE_DIRECT_ACCESS #ifndef MAIL_USE_MMDF #ifndef MAIL_USE_SYSTEM_LOCK #ifdef MAIL_USE_MAILLOCK spool_name = mail_spool_name (inname); if (spool_name) { #ifdef lint lockname = 0; #endif } else #endif { /* Use a lock file named after our first argument with .lock appended: If it exists, the mail file is locked. */ /* Note: this locking mechanism is *required* by the mailer (on systems which use it) to prevent loss of mail. On systems that use a lock file, extracting the mail without locking WILL occasionally cause loss of mail due to timing errors! So, if creation of the lock file fails due to access permission on the mail spool directory, you simply MUST change the permission and/or make movemail a setgid program so it can create lock files properly. You might also wish to verify that your system is one which uses lock files for this purpose. Some systems use other methods. */ inname_len = strlen (inname); lockname = xmalloc (inname_len + sizeof ".lock"); strcpy (lockname, inname); strcpy (lockname + inname_len, ".lock"); for (inname_dirlen = inname_len; inname_dirlen && !IS_DIRECTORY_SEP (inname[inname_dirlen - 1]); inname_dirlen--) continue; tempname = xmalloc (inname_dirlen + sizeof "EXXXXXX"); while (1) { /* Create the lock file, but not under the lock file name. */ /* Give up if cannot do that. */ memcpy (tempname, inname, inname_dirlen); strcpy (tempname + inname_dirlen, "EXXXXXX"); #ifdef HAVE_MKSTEMP desc = mkstemp (tempname); #else mktemp (tempname); if (!*tempname) desc = -1; else { unlink (tempname); desc = open (tempname, O_WRONLY | O_CREAT | O_EXCL, 0600); } #endif if (desc < 0) { int mkstemp_errno = errno; error ("error while creating what would become the lock file", 0, 0); errno = mkstemp_errno; pfatal_with_name (tempname); } close (desc); tem = link (tempname, lockname); #ifdef EPERM if (tem < 0 && errno == EPERM) fatal ("Unable to create hard link between %s and %s", tempname, lockname); #endif unlink (tempname); if (tem >= 0) break; sleep (1); /* If lock file is five minutes old, unlock it. Five minutes should be good enough to cope with crashes and wedgitude, and long enough to avoid being fooled by time differences between machines. */ if (stat (lockname, &st) >= 0) { time_t now = time (0); if (st.st_ctime < now - 300) unlink (lockname); } } delete_lockname = lockname; } #endif /* not MAIL_USE_SYSTEM_LOCK */ #endif /* not MAIL_USE_MMDF */ if (fork () == 0) { int lockcount = 0; int status = 0; #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK) time_t touched_lock; # ifdef lint touched_lock = 0; # endif #endif if (setuid (getuid ()) < 0 || setregid (-1, real_gid) < 0) fatal ("Failed to drop privileges", 0, 0); #ifndef MAIL_USE_MMDF #ifdef MAIL_USE_SYSTEM_LOCK indesc = open (inname, O_RDWR); #else /* if not MAIL_USE_SYSTEM_LOCK */ indesc = open (inname, O_RDONLY); #endif /* not MAIL_USE_SYSTEM_LOCK */ #else /* MAIL_USE_MMDF */ indesc = lk_open (inname, O_RDONLY, 0, 0, 10); #endif /* MAIL_USE_MMDF */ if (indesc < 0) pfatal_with_name (inname); #ifdef BSD_SYSTEM /* In case movemail is setuid to root, make sure the user can read the output file. */ /* This is desirable for all systems but I don't want to assume all have the umask system call */ umask (umask (0) & 0333); #endif /* BSD_SYSTEM */ outdesc = open (outname, O_WRONLY | O_CREAT | O_EXCL, 0666); if (outdesc < 0) pfatal_with_name (outname); if (setregid (-1, priv_gid) < 0) fatal ("Failed to regain privileges", 0, 0); /* This label exists so we can retry locking after a delay, if it got EAGAIN or EBUSY. */ retry_lock: /* Try to lock it. */ #ifdef MAIL_USE_MAILLOCK if (spool_name) { /* The "0 - " is to make it a negative number if maillock returns non-zero. */ status = 0 - maillock (spool_name, 1); #ifdef HAVE_TOUCHLOCK touched_lock = time (0); #endif lockcount = 5; } else #endif /* MAIL_USE_MAILLOCK */ { #ifdef MAIL_USE_SYSTEM_LOCK #ifdef MAIL_USE_LOCKF status = lockf (indesc, F_LOCK, 0); #else /* not MAIL_USE_LOCKF */ #ifdef WINDOWSNT status = locking (indesc, LK_RLCK, -1L); #else status = flock (indesc, LOCK_EX); #endif #endif /* not MAIL_USE_LOCKF */ #endif /* MAIL_USE_SYSTEM_LOCK */ } /* If it fails, retry up to 5 times for certain failure codes. */ if (status < 0) { if (++lockcount <= 5) { #ifdef EAGAIN if (errno == EAGAIN) { sleep (1); goto retry_lock; } #endif #ifdef EBUSY if (errno == EBUSY) { sleep (1); goto retry_lock; } #endif } pfatal_with_name (inname); } { char buf[1024]; while (1) { nread = read (indesc, buf, sizeof buf); if (nread < 0) pfatal_with_name (inname); if (nread != write (outdesc, buf, nread)) { int saved_errno = errno; unlink (outname); errno = saved_errno; pfatal_with_name (outname); } if (nread < sizeof buf) break; #if defined (MAIL_USE_MAILLOCK) && defined (HAVE_TOUCHLOCK) if (spool_name) { time_t now = time (0); if (now - touched_lock > 60) { touchlock (); touched_lock = now; } } #endif /* MAIL_USE_MAILLOCK */ } } #ifdef BSD_SYSTEM if (fsync (outdesc) < 0) pfatal_and_delete (outname); #endif /* Prevent symlink attacks truncating other users' mailboxes */ if (setregid (-1, real_gid) < 0) fatal ("Failed to drop privileges", 0, 0); /* Check to make sure no errors before we zap the inbox. */ if (close (outdesc) != 0) pfatal_and_delete (outname); #ifdef MAIL_USE_SYSTEM_LOCK if (! preserve_mail) { if (ftruncate (indesc, 0L) != 0) pfatal_with_name (inname); } #endif /* MAIL_USE_SYSTEM_LOCK */ #ifdef MAIL_USE_MMDF lk_close (indesc, 0, 0, 0); #else close (indesc); #endif #ifndef MAIL_USE_SYSTEM_LOCK if (! preserve_mail) { /* Delete the input file; if we can't, at least get rid of its contents. */ #ifdef MAIL_UNLINK_SPOOL /* This is generally bad to do, because it destroys the permissions that were set on the file. Better to just empty the file. */ if (unlink (inname) < 0 && errno != ENOENT) #endif /* MAIL_UNLINK_SPOOL */ creat (inname, 0600); } #endif /* not MAIL_USE_SYSTEM_LOCK */ /* End of mailbox truncation */ if (setregid (-1, priv_gid) < 0) fatal ("Failed to regain privileges", 0, 0); #ifdef MAIL_USE_MAILLOCK /* This has to occur in the child, i.e., in the process that acquired the lock! */ if (spool_name) mailunlock (); #endif exit (EXIT_SUCCESS); } wait (&wait_status); if (!WIFEXITED (wait_status)) exit (EXIT_FAILURE); else if (WEXITSTATUS (wait_status) != 0) exit (WEXITSTATUS (wait_status)); #if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK) #ifdef MAIL_USE_MAILLOCK if (! spool_name) #endif /* MAIL_USE_MAILLOCK */ unlink (lockname); #endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */ #endif /* ! DISABLE_DIRECT_ACCESS */ return EXIT_SUCCESS; } #ifdef MAIL_USE_MAILLOCK /* This function uses stat to confirm that the mail directory is identical to the directory of the input file, rather than just string-comparing the two paths, because one or both of them might be symbolic links pointing to some other directory. */ static char * mail_spool_name (char *inname) { struct stat stat1, stat2; char *indir, *fname; int status; if (! (fname = strrchr (inname, '/'))) return NULL; fname++; if (stat (MAILDIR, &stat1) < 0) return NULL; indir = xmalloc (fname - inname + 1); memcpy (indir, inname, fname - inname); indir[fname-inname] = '\0'; status = stat (indir, &stat2); free (indir); if (status < 0) return NULL; if (stat1.st_dev == stat2.st_dev && stat1.st_ino == stat2.st_ino) return fname; return NULL; } #endif /* MAIL_USE_MAILLOCK */ /* Print error message and exit. */ static void fatal (const char *s1, const char *s2, const char *s3) { if (delete_lockname) unlink (delete_lockname); error (s1, s2, s3); exit (EXIT_FAILURE); } /* Print error message. `s1' is printf control string, `s2' and `s3' are args for it or null. */ static void error (const char *s1, const char *s2, const char *s3) { fprintf (stderr, "movemail: "); if (s3) fprintf (stderr, s1, s2, s3); else if (s2) fprintf (stderr, s1, s2); else fprintf (stderr, "%s", s1); fprintf (stderr, "\n"); } static void pfatal_with_name (char *name) { fatal ("%s for %s", strerror (errno), name); } static void pfatal_and_delete (char *name) { char *s = strerror (errno); unlink (name); fatal ("%s for %s", s, name); } /* This is the guts of the interface to the Post Office Protocol. */ #ifdef MAIL_USE_POP #ifndef WINDOWSNT #include #include #include #else #undef _WINSOCKAPI_ #include #endif #include #include #define NOTOK (-1) #define OK 0 static char Errmsg[200]; /* POP errors, at least, can exceed the original length of 80. */ /* * The full valid syntax for a POP mailbox specification for movemail * is "po:username:hostname". The ":hostname" is optional; if it is * omitted, the MAILHOST environment variable will be consulted. Note * that by the time popmail() is called the "po:" has been stripped * off of the front of the mailbox name. * * If the mailbox is in the form "po:username:hostname", then it is * modified by this function -- the second colon is replaced by a * null. * * Return a value suitable for passing to `exit'. */ static int popmail (char *mailbox, char *outfile, int preserve, char *password, int reverse_order) { int nmsgs, nbytes; register int i; int mbfi; FILE *mbf; char *getenv (const char *); popserver server; int start, end, increment; char *user, *hostname; user = mailbox; if ((hostname = strchr (mailbox, ':'))) *hostname++ = '\0'; server = pop_open (hostname, user, password, POP_NO_GETPASS); if (! server) { error ("Error connecting to POP server: %s", pop_error, 0); return EXIT_FAILURE; } if (pop_stat (server, &nmsgs, &nbytes)) { error ("Error getting message count from POP server: %s", pop_error, 0); return EXIT_FAILURE; } if (!nmsgs) { pop_close (server); return EXIT_SUCCESS; } mbfi = open (outfile, O_WRONLY | O_CREAT | O_EXCL, 0666); if (mbfi < 0) { pop_close (server); error ("Error in open: %s, %s", strerror (errno), outfile); return EXIT_FAILURE; } if (fchown (mbfi, getuid (), -1) != 0) { int fchown_errno = errno; struct stat st; if (fstat (mbfi, &st) != 0 || st.st_uid != getuid ()) { pop_close (server); error ("Error in fchown: %s, %s", strerror (fchown_errno), outfile); return EXIT_FAILURE; } } if ((mbf = fdopen (mbfi, "wb")) == NULL) { pop_close (server); error ("Error in fdopen: %s", strerror (errno), 0); close (mbfi); unlink (outfile); return EXIT_FAILURE; } if (reverse_order) { start = nmsgs; end = 1; increment = -1; } else { start = 1; end = nmsgs; increment = 1; } for (i = start; i * increment <= end * increment; i += increment) { mbx_delimit_begin (mbf); if (pop_retr (server, i, mbf) != OK) { error ("%s", Errmsg, 0); close (mbfi); return EXIT_FAILURE; } mbx_delimit_end (mbf); fflush (mbf); if (ferror (mbf)) { error ("Error in fflush: %s", strerror (errno), 0); pop_close (server); close (mbfi); return EXIT_FAILURE; } } /* On AFS, a call to write only modifies the file in the local * workstation's AFS cache. The changes are not written to the server * until a call to fsync or close is made. Users with AFS home * directories have lost mail when over quota because these checks were * not made in previous versions of movemail. */ #ifdef BSD_SYSTEM if (fsync (mbfi) < 0) { error ("Error in fsync: %s", strerror (errno), 0); return EXIT_FAILURE; } #endif if (close (mbfi) == -1) { error ("Error in close: %s", strerror (errno), 0); return EXIT_FAILURE; } if (! preserve) for (i = 1; i <= nmsgs; i++) { if (pop_delete (server, i)) { error ("Error from POP server: %s", pop_error, 0); pop_close (server); return EXIT_FAILURE; } } if (pop_quit (server)) { error ("Error from POP server: %s", pop_error, 0); return EXIT_FAILURE; } return EXIT_SUCCESS; } static int pop_retr (popserver server, int msgno, FILE *arg) { char *line; int ret; if (pop_retrieve_first (server, msgno, &line)) { snprintf (Errmsg, sizeof Errmsg, "Error from POP server: %s", pop_error); return (NOTOK); } while ((ret = pop_retrieve_next (server, &line)) >= 0) { if (! line) break; if (mbx_write (line, ret, arg) != OK) { strcpy (Errmsg, strerror (errno)); pop_close (server); return (NOTOK); } } if (ret) { snprintf (Errmsg, sizeof Errmsg, "Error from POP server: %s", pop_error); return (NOTOK); } return (OK); } static int mbx_write (char *line, int len, FILE *mbf) { #ifdef MOVEMAIL_QUOTE_POP_FROM_LINES /* Do this as a macro instead of using strcmp to save on execution time. */ # define IS_FROM_LINE(a) ((a[0] == 'F') \ && (a[1] == 'r') \ && (a[2] == 'o') \ && (a[3] == 'm') \ && (a[4] == ' ')) if (IS_FROM_LINE (line)) { if (fputc ('>', mbf) == EOF) return (NOTOK); } #endif if (line[0] == '\037') { if (fputs ("^_", mbf) == EOF) return (NOTOK); line++; len--; } if (fwrite (line, 1, len, mbf) != len) return (NOTOK); if (fputc (0x0a, mbf) == EOF) return (NOTOK); return (OK); } static int mbx_delimit_begin (FILE *mbf) { time_t now; struct tm *ltime; char fromline[40] = "From movemail "; now = time (NULL); ltime = localtime (&now); strcat (fromline, asctime (ltime)); if (fputs (fromline, mbf) == EOF) return (NOTOK); return (OK); } static int mbx_delimit_end (FILE *mbf) { if (putc ('\n', mbf) == EOF) return (NOTOK); return (OK); } #endif /* MAIL_USE_POP */