diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/uip/umhook.c

   1 /* umhook.c - one attempt at a rcvmail hook for UUCP mail */
   2 #ifndef lint
   3 static char ident[] = "@(#)$Id: umhook.c,v 1.4 1993/08/25 17:29:36 jromine Exp $";
   4 #endif  lint
   5
   6 /* I don't comment my code heavily, so read this...
   7
   8     You run this program from your .login file.  The invocation is simply
   9     "umhook".  The program "detaches" itself and runs unattended until you
  10     logout.  Whenever you get UUCP mail (or upto a minute afterwards),
  11     umhook will filter your UUCP mail drop to a temporary file.  The mail
  12     drop is *NOT* touched beyond this (even the access time remains the
  13     same).  For each message that was new in the mail drop, umhook will
  14     fork a process to interpret your .maildelivery file.
  15
  16     The umhook program uses the -ljobs control facility to do two things:
  17         - determine when the controlling tty has gone away
  18         - kill a child that's run away (the child sets up a process group)
  19  */
  20
  21 #include "../h/mh.h"
  22 #include "../zotnet/mf.h"
  23 #include <stdio.h>
  24 #include "../zotnet/mts.h"
  25 #include <pwd.h>
  26 #include <signal.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #ifdef LOCALE
  31 #include        <locale.h>
  32 #endif
  33
  34 /* \f */
  35
  36 static struct swit switches[] = {
  37 #define SLEEPSW 0
  38     "sleep seconds", 0,
  39
  40 #define HELPSW  1
  41     "help", 4,
  42
  43     NULL, NULL
  44 };
  45
  46 /* \f */
  47
  48 static int  snooze = 60;
  49
  50 static int  uucp = NOTOK;
  51
  52 extern char *environ;
  53
  54 static char myhome[BUFSIZ] = "";
  55 static char mymail[BUFSIZ] = "";
  56 static char myaddr[BUFSIZ] = "";
  57 static char mystat[BUFSIZ] = "";
  58 static char myuser[BUFSIZ] = "";
  59
  60 int     sigser ();
  61
  62 off_t    lseek ();
  63 #ifdef  SYS5
  64 #ifndef __STDC__
  65 struct passwd  *getpwuid ();
  66 #endif /* !__STDC__ */
  67 #endif  SYS5
  68
  69 /* \f */
  70
  71 /* ARGSUSED */
  72
  73 main (argc, argv)
  74 int     argc;
  75 char  **argv;
  76 {
  77     char   *cp,
  78           **ap,
  79           **argp,
  80             buf[100],
  81            *arguments[MAXARGS];
  82     struct passwd  *pw;
  83
  84 #ifdef LOCALE
  85         setlocale(LC_ALL, "");
  86 #endif
  87     invo_name = r1bindex (argv[0], '/');
  88     mts_init (invo_name);
  89     if ((cp = m_find (invo_name)) != NULL) {
  90         ap = brkstring (cp = getcpy (cp), " ", "\n");
  91         ap = copyip (ap, arguments);
  92     }
  93     else
  94         ap = arguments;
  95     (void) copyip (argv + 1, ap);
  96     argp = arguments;
  97
  98 /* \f */
  99
 100     while (cp = *argp++) {
 101         if (*cp == '-')
 102             switch (smatch (++cp, switches)) {
 103                 case AMBIGSW:
 104                     ambigsw (cp, switches);
 105                     done (1);
 106                 case UNKWNSW:
 107                     adios (NULLCP, "-%s unknown", cp);
 108                 case HELPSW:
 109                     (void) sprintf (buf, "%s [switches]", invo_name);
 110                     help (buf, switches);
 111                     done (1);
 112
 113                 case SLEEPSW:
 114                     if (!(cp = *argp++) || *cp == '-')
 115                         adios (NULLCP, "missing argument to %s", argp[-2]);
 116                     if ((snooze = atoi (cp)) < 0)
 117                         adios (NULLCP, "bad argument %s %s", argp[-2], cp);
 118                     continue;
 119             }
 120         adios (NULLCP, "usage: %s [switches]", invo_name);
 121     }
 122
 123 /* \f */
 124
 125     if ((pw = getpwuid (getuid ())) == NULL)
 126         adios (NULLCP, "you lose big");
 127
 128     *environ = NULL;
 129     (void) m_putenv ("USER", pw -> pw_name);
 130     (void) m_putenv ("HOME", pw -> pw_dir);
 131     (void) m_putenv ("SHELL", pw -> pw_shell);
 132     if (chdir (pw -> pw_dir) == NOTOK)
 133         (void) chdir ("/");
 134     (void) umask (0077);
 135
 136     if (geteuid () == 0) {
 137 #ifdef  BSD41A
 138         (void) inigrp (pw -> pw_name, pw -> pw_gid);
 139 #endif  BSD41A
 140         (void) setgid (pw -> pw_gid);
 141 #ifdef  BSD42
 142         (void) initgroups (pw -> pw_name, pw -> pw_gid);
 143 #endif  BSD42
 144         (void) setuid (pw -> pw_uid);
 145     }
 146
 147     (void) sprintf (mymail, "%s/%s",
 148             uucpldir[0] ? uucpldir : pw -> pw_dir,
 149             uucplfil[0] ? uucplfil : pw -> pw_name);
 150     (void) strcpy (myuser, pw -> pw_name);
 151     (void) sprintf (myaddr, "%s@%s", pw -> pw_name, LocalName ());
 152     (void) strcpy (myhome, pw -> pw_dir);
 153     (void) sprintf (mystat, ".%s_%d", invo_name, pw -> pw_uid);
 154
 155     if (access (slocalproc, 1) == NOTOK)
 156         adios (slocalproc, "unable to execute");
 157
 158     closefds (fileno (stderr) + 1);
 159
 160     (void) signal (SIGINT, SIG_IGN);
 161     (void) signal (SIGHUP, sigser);
 162     (void) signal (SIGQUIT, SIG_IGN);
 163     (void) signal (SIGTERM, sigser);
 164
 165     switch (fork ()) {
 166         case NOTOK:
 167         case OK:
 168             umhook ();
 169             break;
 170
 171         default:
 172             break;
 173     }
 174
 175     exit (0);
 176 }
 177
 178 /* \f */
 179
 180 #ifndef TIOCGPGRP
 181 #define pgrp_ok(pg)     1
 182 #else   TIOCGPGRP
 183 #define pgrp_ok(pg)     (ioctl (2, TIOCGPGRP, (char *) &pg) != NOTOK)
 184 #endif  TIOCGPGRP
 185
 186 static  umhook () {
 187     int     pg;
 188     struct stat st1,
 189                 st2;
 190
 191     st_init (&st1);
 192
 193     for (; pgrp_ok (pg);) {
 194         if (stat (mymail, &st2) == NOTOK) {
 195             st2.st_ino = (ino_t) 0;
 196             st2.st_size = (off_t) 0;
 197             st2.st_mtime = (time_t) 0;
 198         }
 199         else
 200             if (st1.st_mtime != st2.st_mtime)
 201                 if (st1.st_ino != st2.st_ino)
 202                     process ((off_t) 0, &st2);
 203                 else
 204                     if (st1.st_size < st2.st_size)
 205                         process (st1.st_size, &st2);
 206
 207         st1.st_ino = st2.st_ino;
 208         st1.st_size = st2.st_size;
 209         st1.st_mtime = st2.st_mtime;
 210
 211         sleep ((unsigned) snooze);
 212     }
 213 }
 214
 215 /* \f */
 216
 217 static  process (offset, st)
 218 off_t offset;
 219 struct stat *st;
 220 {
 221     int     td1,
 222             td2;
 223     time_t timep[2];
 224     char    tmpfil[BUFSIZ];
 225     register FILE *fp;
 226
 227     if ((uucp = lkopen (mymail, 0)) == NOTOK)
 228         adios (NULLCP, "unable to lock and open %s", mymail);
 229     if (lseek (uucp, (off_t) offset, 0) == (off_t) NOTOK)
 230         adios (mymail, "unable to position to %ld offset on", (long) offset);
 231
 232     (void) strcpy (tmpfil, m_tmpfil (invo_name));
 233     if ((td1 = creat (tmpfil, TMPMODE)) == NOTOK)
 234         adios (tmpfil, "unable to create");
 235     (void) close (td1);
 236
 237     if ((td1 = open (tmpfil, 2)) == NOTOK)
 238         adios (tmpfil, "unable to open");
 239     (void) unlink (tmpfil);
 240     if ((td2 = dup (td1)) == NOTOK)
 241         adios ("file descriptor", "unable to dup");
 242
 243     switch (uucp2mmdf (uucp, td1, FALSE)) {
 244         case MFPRM:
 245             adios (NULLCP, "internal error while filtering UUCP mail");
 246
 247         case MFSIO:
 248             adios (NULLCP, "no free file pointers");
 249
 250         case MFERR:
 251             adios ("UUCP mail", "i/o error while filtering");
 252
 253         case MFOK:
 254         case MFROM:
 255         case MFHDR:
 256         case MFTXT:
 257             timep[0] = st -> st_atime;
 258             timep[1] = st -> st_mtime;
 259             utime (mymail, timep);
 260             st_update (st);
 261             break;
 262     }
 263     (void) lkclose (uucp, mymail), uucp = NOTOK;
 264
 265 /* \f */
 266
 267     (void) close (td1);
 268
 269     (void) lseek (td2, (off_t)0, 0);
 270     if ((fp = fdopen (td2, "r")) == NULL)
 271         adios (NULLCP, "no free file pointers");
 272
 273     while (hook (fp))
 274         continue;
 275     (void) fclose (fp);
 276 }
 277
 278 /* \f */
 279
 280 static int  hook (in)
 281 register FILE *in;
 282 {
 283     int     child_id,
 284             done,
 285             fd1,
 286             fd2,
 287             i;
 288     char    buffer[BUFSIZ],
 289             mysndr[BUFSIZ],
 290             myfile[BUFSIZ];
 291     register FILE *out;
 292
 293     if (fgets (buffer, sizeof buffer, in) == NULL)
 294         return FALSE;
 295
 296 /* should insist on isdlm1 (buffer) here... */
 297
 298     (void) strcpy (myfile, m_tmpfil (invo_name));
 299     if ((fd1 = creat (myfile, TMPMODE)) == NOTOK)
 300         adios (myfile, "unable to create");
 301     (void) close (fd1);
 302
 303     if ((fd1 = open (myfile, 2)) == NOTOK)
 304         adios (myfile, "unable to open");
 305     (void) unlink (myfile);
 306     if ((fd2 = dup (fd1)) == NOTOK)
 307         adios ("file descriptor", "unable to dup");
 308
 309     if ((out = fdopen (fd1, "w")) == NULL)
 310         adios (NULLCP, "no free file pointers");
 311
 312     for (done = TRUE;;) {
 313         if (fgets (buffer, sizeof buffer, in) == NULL)
 314             break;              /* should be error */
 315         if (done && isdlm2 (buffer))
 316             break;
 317         done = buffer[strlen (buffer) - 1] == '\n';
 318         fputs (buffer, out);
 319     }
 320     (void) fclose (out);
 321
 322     (void) lseek (fd2, (off_t)0, 0);
 323     seeksndr (fd2, mysndr);
 324
 325 /* \f */
 326
 327     switch (child_id = fork ()) {
 328         case NOTOK:
 329             adios ("fork", "unable to");/* NOTREACHED */
 330
 331         case OK:
 332             (void) lseek (fd2, (off_t)0, 0);
 333             if (fd2 != 0)
 334                 (void) dup2 (fd2, 0);
 335             (void) freopen ("/dev/null", "w", stdout);
 336             (void) freopen ("/dev/null", "w", stderr);
 337             if (fd2 != 3)
 338                 (void) dup2 (fd2, 3);
 339             closefds (4);
 340 #ifdef  TIOCNOTTY
 341             if ((i = open ("/dev/tty", 2)) != NOTOK) {
 342                 (void) ioctl (i, TIOCNOTTY, NULLCP);
 343                 (void) close (i);
 344             }
 345 #endif  TIOCNOTTY
 346 #ifdef  BSD42
 347             (void) setpgrp (0, getpid ());
 348 #endif  BSD42
 349
 350             execlp (slocalproc, r1bindex (slocalproc, '/'),
 351                     "-file", myfile, "-mailbox", mymail,
 352                     "-home", myhome, "-addr", myaddr,
 353                     "-user", myuser, "-sender", mysndr, NULLCP);
 354             adios (slocalproc, "unable to exec");/* NOTREACHED */
 355
 356         default:
 357             (void) close (fd2);
 358             (void) pidwait (child_id, OK);
 359             return TRUE;
 360     }
 361 }
 362
 363 /* \f */
 364
 365 static  seeksndr (fd1, mysndr)
 366 int     fd1;
 367 char   *mysndr;
 368 {
 369     int     fd2;
 370     char   *bp,
 371            *hp,
 372             from[BUFSIZ],
 373             sender[BUFSIZ];
 374     register FILE *in;
 375
 376     if ((fd2 = dup (fd1)) == NOTOK)
 377         adios ("file descriptor", "unable to dup");
 378     if ((in = fdopen (fd2, "r")) == NULL)
 379         adios (NULLCP, "no free file pointers");
 380
 381     for (from[0] = sender[0] = NULL; mfgets (in, &hp) != DONE;)
 382         if ((bp = index (hp, ':')) != NULL) {
 383             *bp++ = NULL;
 384             if (lequal (hp, "From"))
 385                 seekaddr (from, bp);
 386             else
 387                 if (lequal (hp, "Sender"))
 388                     seekaddr (sender, bp);
 389         }
 390     (void) fclose (in);
 391
 392     (void) strcpy (mysndr, sender[0] ? sender : from[0] ? from : myaddr);
 393 }
 394
 395 /* \f */
 396
 397 static  seekaddr (addr, bp)
 398 char   *addr,
 399        *bp;
 400 {
 401     struct adrx *adrxp;
 402
 403     if ((adrxp = seekadrx (bp)) == NULL)
 404         return;
 405     if (adrxp -> err || !adrxp -> mbox)
 406         return;
 407
 408     if (adrxp -> host)
 409         (void) sprintf (addr, "%s@%s", adrxp -> mbox, adrxp -> host);
 410     else
 411         (void) strcpy (addr, adrxp -> mbox);
 412
 413     while (seekadrx (NULLCP))
 414         continue;
 415 }
 416
 417 /* \f */
 418
 419 static st_init(st)
 420 struct stat *st;
 421 {
 422     int     fd;
 423
 424     if ((fd = open (mystat, 0)) == NOTOK
 425             || read (fd, (char *) st, sizeof *st) != (sizeof *st)) {
 426         st -> st_ino = (ino_t) 0;
 427         st -> st_size = (off_t) 0;
 428         st -> st_mtime = (time_t) 0;
 429     }
 430     if (fd != NOTOK)
 431         (void) close (fd);
 432 }
 433
 434
 435 static st_update(st)
 436 struct stat *st;
 437 {
 438     static int  fd = NOTOK;
 439
 440     if (fd == NOTOK
 441             && (fd = creat (mystat, TMPMODE)) == NOTOK)
 442         adios (mystat, "unable to write");
 443
 444     (void) lseek (fd, (off_t)0, 0);
 445     if (write (fd, (char *) st, sizeof *st) != (sizeof *st))
 446         adios (mystat, "error writing");
 447 }
 448
 449 /* \f */
 450
 451 #ifdef  BSD42
 452 /* ARGSUSED */
 453 #endif  BSD42
 454
 455 static int  sigser (sig)
 456 int     sig;
 457 {
 458 #ifndef BSD42
 459     (void) signal (sig, SIG_IGN);
 460 #endif  BSD42
 461
 462     done (1);
 463 }
 464
 465 /* \f */
 466
 467 void    done (status)
 468 int     status;
 469 {
 470     (void) lkclose (uucp, mymail), uucp = NOTOK;
 471     exit (status);
 472 }