2 ** inc.c -- incorporate messages from a maildrop into a folder
4 ** This code is Copyright (c) 2002, by the authors of nmh. See the
5 ** COPYRIGHT file in the root directory of the nmh distribution for
6 ** complete copyright information.
11 ** Revised: Sat Apr 14 17:08:17 PDT 1990 (marvit@hplabs)
12 ** Added hpux hacks to set and reset gid to be "mail" as needed. The reset
13 ** is necessary so inc'ed mail is the group of the inc'er, rather than
14 ** "mail". We setgid to egid only when [un]locking the mail file. This
15 ** is also a major security precaution which will not be explained here.
17 ** Fri Feb 7 16:04:57 PST 1992 John Romine <bug-mh@ics.uci.edu>
18 ** NB: I'm not 100% sure that this setgid stuff is secure even now.
20 ** See the *GROUPPRIVS() macros later. I'm reasonably happy with the setgid
21 ** attribute. Running setuid root is probably not a terribly good idea, though.
22 ** -- Peter Maydell <pmaydell@chiark.greenend.org.uk>, 04/1998
24 ** Peter Maydell's patch slightly modified for nmh 0.28-pre2.
25 ** Ruud de Rooij <ruud@debian.org> Wed, 22 Jul 1998 13:24:22 +0200
33 #include <h/fmt_scan.h>
34 #include <h/scansbr.h>
35 #include <h/signals.h>
41 static struct swit switches[] = {
43 { "audit audit-file", 0 },
53 { "form formatfile", 0 },
55 { "format string", 5 },
65 { "width columns", 0 },
73 ** This is an attempt to simplify things by putting all the
74 ** privilege ops into macros.
75 ** *GROUPPRIVS() is related to handling the setgid MAIL property,
76 ** and only applies if MAILGROUP is defined.
77 ** Basically, SAVEGROUPPRIVS() is called right at the top of main()
78 ** to initialise things, and then DROPGROUPPRIVS() and GETGROUPPRIVS()
79 ** do the obvious thing. TRYDROPGROUPPRIVS() has to be safe to call
80 ** before DROPUSERPRIVS() is called [this is needed because setgid()
81 ** sets both effective and real uids if euid is root.]
83 ** There's probably a better implementation if we're allowed to use
84 ** BSD-style setreuid() rather than using POSIX saved-ids.
85 ** Anyway, if you're euid root it's a bit pointless to drop the group
88 ** I'm pretty happy that the security is good provided we aren't setuid root.
89 ** The only things we trust with group=mail privilege are lkfopen()
94 ** For setting and returning to "mail" gid
97 static int return_gid;
99 ** easy case; we're not setuid root, so can drop group privs immediately.
101 #define TRYDROPGROUPPRIVS() DROPGROUPPRIVS()
102 #define DROPGROUPPRIVS() setgid(getgid())
103 #define GETGROUPPRIVS() setgid(return_gid)
104 #define SAVEGROUPPRIVS() return_gid = getegid()
106 /* define *GROUPPRIVS() as null; this avoids having lots of "#ifdef MAILGROUP"s */
107 #define TRYDROPGROUPPRIVS()
108 #define DROPGROUPPRIVS()
109 #define GETGROUPPRIVS()
110 #define SAVEGROUPPRIVS()
111 #endif /* not MAILGROUP */
114 ** these variables have to be globals so that done() can correctly clean
117 static int locked = 0;
118 static char *newmail;
124 char *map_name(char *);
126 static void inc_done(int) NORETURN;
130 main (int argc, char **argv)
132 int chgflag = 1, trnflag = 1;
133 int noisy = 1, width = 0;
134 int hghnum = 0, msgnum = 0;
136 ** <0 if inc hits an error which means it should
137 ** not truncate mailspool
139 char *cp, *maildir = NULL, *folder = NULL;
140 char *format = NULL, *form = NULL;
141 char *audfile = NULL, *from = NULL;
142 char buf[BUFSIZ], **argp, *nfs, **arguments;
143 struct msgs *mp = NULL;
146 char b[MAXPATHLEN + 1];
147 /* copy of mail directory because the static gets overwritten */
148 char *maildir_copy = NULL;
157 ** absolutely the first thing we do is save our privileges,
158 ** and drop them if we can.
164 setlocale(LC_ALL, "");
166 invo_name = r1bindex (argv[0], '/');
168 /* read user profile/context */
171 mts_init (invo_name);
172 arguments = getarguments (invo_name, argc, argv, 1);
175 while ((cp = *argp++)) {
177 switch (smatch (++cp, switches)) {
179 ambigsw (cp, switches);
182 adios (NULL, "-%s unknown", cp);
185 snprintf (buf, sizeof(buf), "%s [+folder] [switches]", invo_name);
186 print_help (buf, switches, 1);
189 print_version(invo_name);
193 if (!(cp = *argp++) || *cp == '-')
194 adios (NULL, "missing argument to %s", argp[-2]);
195 audfile = getcpy (m_maildir (cp));
209 ** The flag `trnflag' has the value:
211 ** 2 if -truncate is given
212 ** 1 by default (truncating is default)
213 ** 0 if -notruncate is given
223 if (!(cp = *argp++) || *cp == '-')
224 adios (NULL, "missing argument to %s", argp[-2]);
225 from = path (cp, TFILE);
228 ** If the truncate file is in default state,
229 ** change to not truncate.
243 if (!(form = *argp++) || *form == '-')
244 adios (NULL, "missing argument to %s", argp[-2]);
248 if (!(format = *argp++) || *format == '-')
249 adios (NULL, "missing argument to %s", argp[-2]);
254 if (!(cp = *argp++) || *cp == '-')
255 adios (NULL, "missing argument to %s", argp[-2]);
260 if (*cp == '+' || *cp == '@') {
262 adios (NULL, "only one folder at a time!");
264 folder = pluspath (cp);
266 adios (NULL, "usage: %s [+folder] [switches]", invo_name);
271 ** NOTE: above this point you should use TRYDROPGROUPPRIVS(),
272 ** not DROPGROUPPRIVS().
274 /* guarantee dropping group priveleges; we might not have done so earlier */
278 ** We will get the mail from a file
279 ** (typically the standard maildrop)
283 else if ((newmail = getenv ("MAILDROP")) && *newmail)
284 newmail = m_mailpath (newmail);
285 else if ((newmail = context_find ("maildrop")) && *newmail)
286 newmail = m_mailpath (newmail);
288 newmail = concat (MAILDIR, "/", MAILFIL, NULL);
290 if (stat (newmail, &s1) == NOTOK || s1.st_size == 0)
291 adios (NULL, "no mail to incorporate");
293 if ((cp = strdup(newmail)) == (char *)0)
294 adios (NULL, "error allocating memory to copy newmail");
298 if (!context_find ("path"))
299 free (path ("./", TFOLDER));
301 folder = getfolder (0);
302 maildir = m_maildir (folder);
304 if ((maildir_copy = strdup(maildir)) == (char *)0)
305 adios (maildir, "error allocating memory to copy maildir");
307 if (!folder_exists(maildir)) {
309 ** If the folder doesn't exist, and we're given the -silent
313 create_folder(maildir, 0, done);
318 if (chdir (maildir) == NOTOK)
319 adios (maildir, "unable to change directory to");
321 /* read folder and create message structure */
322 if (!(mp = folder_read (folder)))
323 adios (NULL, "unable to read folder %s", folder);
325 if (access (newmail, W_OK) != NOTOK) {
328 SIGNAL (SIGHUP, SIG_IGN);
329 SIGNAL (SIGINT, SIG_IGN);
330 SIGNAL (SIGQUIT, SIG_IGN);
331 SIGNAL (SIGTERM, SIG_IGN);
334 GETGROUPPRIVS(); /* Reset gid to lock mail file */
335 in = lkfopen (newmail, "r");
338 adios (NULL, "unable to lock and fopen %s", newmail);
339 fstat (fileno(in), &s1);
342 if ((in = fopen (newmail, "r")) == NULL)
343 adios (newmail, "unable to read");
346 /* This shouldn't be necessary but it can't hurt. */
351 if ((i = stat (audfile, &st)) == NOTOK)
352 advise (NULL, "Creating Receive-Audit: %s", audfile);
353 if ((aud = fopen (audfile, "a")) == NULL)
354 adios (audfile, "unable to append to");
356 chmod (audfile, m_gmprot ());
358 fprintf (aud, from ? "<<inc>> %s -ms %s\n" : "<<inc>> %s\n",
363 if (context_find ("mhe")) {
365 cp = concat (maildir, "/++", NULL);
367 if ((mhe = fopen (cp, "a")) == NULL)
368 admonish (cp, "unable to append to");
371 chmod (cp, m_gmprot ());
376 /* Get new format string */
377 nfs = new_fs (form, format, FORMAT);
380 printf ("Incorporating new mail into %s...\n\n", folder);
385 ** Get the mail from file (usually mail spool)
387 m_unknown (in); /* the MAGIC invocation... */
388 hghnum = msgnum = mp->hghmsg;
391 ** Check if we need to allocate more space for message status.
392 ** If so, then add space for an additional 100 messages.
394 if (msgnum >= mp->hghoff
395 && !(mp = folder_realloc (mp, mp->lowoff, mp->hghoff + 100))) {
396 advise (NULL, "unable to allocate folder storage");
401 /* create scanline for new message */
402 switch (incerr = scan (in, msgnum + 1, msgnum + 1, nfs, width,
403 msgnum == hghnum && chgflag, 1, NULL, 0L, noisy)) {
410 fputs ("inc aborted!\n", aud);
411 /* doesn't clean up locks! */
412 advise (NULL, "aborted!");
416 advise (NULL, "BUG in %s, number out of range", invo_name);
420 advise (NULL, "BUG in %s, scan() botch (%d)", invo_name, incerr);
426 ** Run the external program hook on the message.
429 (void)snprintf(b, sizeof (b), "%s/%d", maildir_copy, msgnum + 1);
430 (void)ext_hook("add-hook", b, (char *)0);
445 clear_msg_flags (mp, msgnum);
446 set_exists (mp, msgnum);
447 set_unseen (mp, msgnum);
448 mp->msgflags |= SEQMOD;
452 ** If we get here there was some sort of error from scan(),
453 ** so stop processing anything more from the spool.
458 if (incerr < 0) { /* error */
460 GETGROUPPRIVS(); /* Be sure we can unlock mail file */
461 (void) lkfclose (in, newmail); in = NULL;
463 ** And then return us to normal
467 fclose (in); in = NULL;
469 adios (NULL, "failed");
484 ** truncate file we are incorporating from
487 if (stat (newmail, &st) != NOTOK && s1.st_mtime != st.st_mtime)
488 advise (NULL, "new messages have arrived!\007");
491 if ((newfd = creat (newmail, 0600)) != NOTOK)
494 admonish (newmail, "error zero'ing");
495 unlink(map_name(newmail));
498 printf ("%s not zero'd\n", newmail);
501 if (msgnum == hghnum) {
502 admonish (NULL, "no messages incorporated");
504 context_replace (pfolder, folder); /* update current folder */
506 mp->curmsg = hghnum + 1;
510 if (chgflag) /* sigh... */
511 seq_setcur (mp, mp->curmsg);
515 ** unlock the mail spool
518 GETGROUPPRIVS(); /* Be sure we can unlock mail file */
519 (void) lkfclose (in, newmail); in = NULL;
520 DROPGROUPPRIVS(); /* And then return us to normal privileges */
522 fclose (in); in = NULL;
525 seq_setunseen (mp, 0); /* set the Unseen-Sequence */
526 seq_save (mp); /* synchronize sequences */
527 context_save (); /* save the context file */
533 inc_done (int status)
537 lkfclose(in, newmail);