diplodocus.org Git - nmh/blob - uip/rcvtty.c

   1
   2 /*
   3  * rcvtty.c -- a rcvmail program (a lot like rcvalert) handling IPC ttys
   4  *
   5  * $Id$
   6  */
   7
   8 /* Changed to use getutent() and friends.  Assumes that when getutent() exists,
   9  * a number of other things also exist.  Please check.
  10  * Ruud de Rooij <ruud@ruud.org>  Sun, 28 May 2000 17:28:55 +0200
  11  */
  12
  13 #include <h/mh.h>
  14 #include <h/signals.h>
  15 #include <h/rcvmail.h>
  16 #include <h/scansbr.h>
  17 #include <h/tws.h>
  18 #include <zotnet/mts/mts.h>
  19 #include <signal.h>
  20 #include <fcntl.h>
  21
  22 #include <utmp.h>
  23
  24 #ifndef HAVE_GETUTENT
  25 # ifndef UTMP_FILE
  26 #  ifdef _PATH_UTMP
  27 #   define UTMP_FILE _PATH_UTMP
  28 #  else
  29 #   define UTMP_FILE "/etc/utmp"
  30 #  endif
  31 # endif
  32 #endif
  33
  34 #define SCANFMT \
  35 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  36 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  37 %{subject}%<{body}<<%{body}>>%>"
  38
  39 static struct swit switches[] = {
  40 #define BIFFSW  0
  41     { "biff", 0 },
  42 #define FORMSW  1
  43     { "form formatfile", 0 },
  44 #define FMTSW   2
  45     { "format string", 5 },
  46 #define WIDTHSW 3
  47     { "width columns", 0 },
  48 #define NLSW    4
  49     { "newline", 0 },
  50 #define NNLSW   5
  51     { "nonewline", 0 },
  52 #define BELSW   6
  53     { "bell", 0 },
  54 #define NBELSW  7
  55     { "nobell", 0 },
  56 #define VERSIONSW 8
  57     { "version", 0 },
  58 #define HELPSW  9
  59     { "help", 0 },
  60     { NULL, 0 }
  61 };
  62
  63 static jmp_buf myctx;
  64 static int bell = 1;
  65 static int newline = 1;
  66 static int biff = 0;
  67 static int width = 0;
  68 static char *form = NULL;
  69 static char *format = NULL;
  70
  71 /*
  72  * external prototypes
  73  */
  74 char *getusername(void);
  75
  76 /*
  77  * static prototypes
  78  */
  79 static RETSIGTYPE alrmser (int);
  80 static int message_fd (char **);
  81 static int header_fd (void);
  82 static void alert (char *, int);
  83
  84
  85 int
  86 main (int argc, char **argv)
  87 {
  88     int md, vecp = 0;
  89     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  90     char **argp, **arguments, *vec[MAXARGS];
  91 #ifdef HAVE_GETUTENT
  92     struct utmp * utp;
  93 #else
  94     struct utmp ut;
  95     register FILE *uf;
  96 #endif
  97
  98 #ifdef LOCALE
  99     setlocale(LC_ALL, "");
 100 #endif
 101     invo_name = r1bindex (argv[0], '/');
 102
 103     /* read user profile/context */
 104     context_read();
 105
 106     mts_init (invo_name);
 107     arguments = getarguments (invo_name, argc, argv, 1);
 108     argp = arguments;
 109
 110     while ((cp = *argp++)) {
 111         if (*cp == '-') {
 112             switch (smatch (++cp, switches)) {
 113                 case AMBIGSW:
 114                     ambigsw (cp, switches);
 115                     done (1);
 116                 case UNKWNSW:
 117                     vec[vecp++] = --cp;
 118                     continue;
 119
 120                 case HELPSW:
 121                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 122                     print_help (buf, switches, 1);
 123                     done (1);
 124                 case VERSIONSW:
 125                     print_version(invo_name);
 126                     done (1);
 127
 128                 case BIFFSW:
 129                     biff = 1;
 130                     continue;
 131
 132                 case FORMSW:
 133                     if (!(form = *argp++) || *form == '-')
 134                         adios (NULL, "missing argument to %s", argp[-2]);
 135                     format = NULL;
 136                     continue;
 137                 case FMTSW:
 138                     if (!(format = *argp++) || *format == '-')
 139                         adios (NULL, "missing argument to %s", argp[-2]);
 140                     form = NULL;
 141                     continue;
 142
 143                 case WIDTHSW:
 144                     if (!(cp = *argp++) || *cp == '-')
 145                         adios(NULL, "missing argument to %s", argp[-2]);
 146                     width = atoi(cp);
 147                     continue;
 148                 case NLSW:
 149                     newline = 1;
 150                     continue;
 151                 case NNLSW:
 152                     newline = 0;
 153                     continue;
 154                 case BELSW:
 155                     bell = 1;
 156                     continue;
 157                 case NBELSW:
 158                     bell = 0;
 159                     continue;
 160
 161             }
 162         }
 163         vec[vecp++] = cp;
 164     }
 165     vec[vecp] = 0;
 166
 167     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 168         exit (RCV_MBX);
 169
 170     user = getusername();
 171
 172 #ifdef HAVE_GETUTENT
 173     setutent();
 174     while ((utp = getutent()) != NULL) {
 175         if (utp->ut_type == USER_PROCESS
 176                && utp->ut_user[0] != 0
 177                && utp->ut_line[0] != 0
 178                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 179             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 180             alert (tty, md);
 181         }
 182     }
 183     endutent();
 184 #else
 185     if ((uf = fopen (UTMP_FILE, "r")) == NULL)
 186         exit (RCV_MBX);
 187     while (fread ((char *) &ut, sizeof(ut), 1, uf) == 1)
 188         if (ut.ut_name[0] != 0
 189                 && strncmp (user, ut.ut_name, sizeof(ut.ut_name)) == 0) {
 190             strncpy (tty, ut.ut_line, sizeof(ut.ut_line));
 191             alert (tty, md);
 192         }
 193     fclose (uf);
 194 #endif
 195
 196     exit (RCV_MOK);
 197     return 0;  /* dead code to satisfy the compiler */
 198 }
 199
 200
 201 static RETSIGTYPE
 202 alrmser (int i)
 203 {
 204 #ifndef RELIABLE_SIGNALS
 205     SIGNAL (SIGALRM, alrmser);
 206 #endif
 207
 208     longjmp (myctx, 1);
 209 }
 210
 211
 212 static int
 213 message_fd (char **vec)
 214 {
 215     pid_t child_id;
 216     int bytes, fd, seconds;
 217     char tmpfil[BUFSIZ];
 218     struct stat st;
 219
 220 #ifdef HAVE_MKSTEMP
 221     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 222 #else
 223     unlink (mktemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 224     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 225         return header_fd ();
 226 #endif
 227     unlink (tmpfil);
 228
 229     if ((child_id = vfork()) == NOTOK) {
 230         /* fork error */
 231         close (fd);
 232         return header_fd ();
 233     } else if (child_id) {
 234         /* parent process */
 235         if (!setjmp (myctx)) {
 236             SIGNAL (SIGALRM, alrmser);
 237             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 238
 239             /* amount of time to wait depends on message size */
 240             if (bytes <= 100) {
 241                 /* give at least 5 minutes */
 242                 seconds = 300;
 243             } else if (bytes >= 90000) {
 244                 /* but 30 minutes should be long enough */
 245                 seconds = 1800;
 246             } else {
 247                 seconds = (bytes / 60) + 300;
 248             }
 249             alarm ((unsigned int) seconds);
 250             pidwait(child_id, OK);
 251             alarm (0);
 252
 253             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 254                 return fd;
 255         } else {
 256             /*
 257              * Ruthlessly kill the child and anything
 258              * else in its process group.
 259              */
 260             KILLPG(child_id, SIGKILL);
 261         }
 262         close (fd);
 263         return header_fd ();
 264     }
 265
 266     /* child process */
 267     rewind (stdin);
 268     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 269         _exit (-1);
 270     closefds (3);
 271     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 272     execvp (vec[0], vec);
 273     _exit (-1);
 274     return 1;  /* dead code to satisfy compiler */
 275 }
 276
 277
 278 static int
 279 header_fd (void)
 280 {
 281     int fd;
 282     char *nfs, tmpfil[BUFSIZ];
 283
 284     strncpy (tmpfil, m_tmpfil (invo_name), sizeof(tmpfil));
 285     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 286         return NOTOK;
 287     unlink (tmpfil);
 288
 289     rewind (stdin);
 290
 291     /* get new format string */
 292     nfs = new_fs (form, format, SCANFMT);
 293     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 294     if (newline)
 295         write (fd, "\n\r", 2);
 296     write (fd, scanl, strlen (scanl));
 297     if (bell)
 298         write (fd, "\007", 1);
 299
 300     return fd;
 301 }
 302
 303
 304 static void
 305 alert (char *tty, int md)
 306 {
 307     int i, td, mask;
 308     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 309     struct stat st;
 310
 311     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 312
 313     /*
 314      * The mask depends on whether we are checking for
 315      * write permission based on `biff' or `mesg'.
 316      */
 317     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 318     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 319         return;
 320
 321     if (!setjmp (myctx)) {
 322         SIGNAL (SIGALRM, alrmser);
 323         alarm (2);
 324         td = open (ttyspec, O_WRONLY);
 325         alarm (0);
 326         if (td == NOTOK)
 327             return;
 328     } else {
 329         alarm (0);
 330         return;
 331     }
 332
 333     lseek (md, (off_t) 0, SEEK_SET);
 334
 335     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 336         if (write (td, buffer, i) != i)
 337             break;
 338
 339     close (td);
 340 }
 341