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  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 /* Changed to use getutent() and friends.  Assumes that when getutent() exists,
  13  * a number of other things also exist.  Please check.
  14  * Ruud de Rooij <ruud@ruud.org>  Sun, 28 May 2000 17:28:55 +0200
  15  */
  16
  17 #include <h/mh.h>
  18 #include <h/signals.h>
  19 #include <h/rcvmail.h>
  20 #include <h/scansbr.h>
  21 #include <h/tws.h>
  22 #include <h/mts.h>
  23 #include <signal.h>
  24 #include <fcntl.h>
  25
  26 #include <utmp.h>
  27
  28 #ifndef HAVE_GETUTENT
  29 # ifndef UTMP_FILE
  30 #  ifdef _PATH_UTMP
  31 #   define UTMP_FILE _PATH_UTMP
  32 #  else
  33 #   define UTMP_FILE "/etc/utmp"
  34 #  endif
  35 # endif
  36 #endif
  37
  38 #define SCANFMT \
  39 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  40 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  41 %{subject}%<{body}<<%{body}>>%>"
  42
  43 static struct swit switches[] = {
  44 #define BIFFSW  0
  45     { "biff", 0 },
  46 #define FORMSW  1
  47     { "form formatfile", 0 },
  48 #define FMTSW   2
  49     { "format string", 5 },
  50 #define WIDTHSW 3
  51     { "width columns", 0 },
  52 #define NLSW    4
  53     { "newline", 0 },
  54 #define NNLSW   5
  55     { "nonewline", 0 },
  56 #define BELSW   6
  57     { "bell", 0 },
  58 #define NBELSW  7
  59     { "nobell", 0 },
  60 #define VERSIONSW 8
  61     { "version", 0 },
  62 #define HELPSW  9
  63     { "help", 0 },
  64     { NULL, 0 }
  65 };
  66
  67 static jmp_buf myctx;
  68 static int bell = 1;
  69 static int newline = 1;
  70 static int biff = 0;
  71 static int width = 0;
  72 static char *form = NULL;
  73 static char *format = NULL;
  74
  75 /*
  76  * external prototypes
  77  */
  78 char *getusername(void);
  79
  80 /*
  81  * static prototypes
  82  */
  83 static RETSIGTYPE alrmser (int);
  84 static int message_fd (char **);
  85 static int header_fd (void);
  86 static void alert (char *, int);
  87
  88
  89 int
  90 main (int argc, char **argv)
  91 {
  92     int md, vecp = 0;
  93     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  94     char **argp, **arguments, *vec[MAXARGS];
  95 #ifdef HAVE_GETUTENT
  96     struct utmp * utp;
  97 #else
  98     struct utmp ut;
  99     register FILE *uf;
 100 #endif
 101
 102 #ifdef LOCALE
 103     setlocale(LC_ALL, "");
 104 #endif
 105     invo_name = r1bindex (argv[0], '/');
 106
 107     /* read user profile/context */
 108     context_read();
 109
 110     mts_init (invo_name);
 111     arguments = getarguments (invo_name, argc, argv, 1);
 112     argp = arguments;
 113
 114     while ((cp = *argp++)) {
 115         if (*cp == '-') {
 116             switch (smatch (++cp, switches)) {
 117                 case AMBIGSW:
 118                     ambigsw (cp, switches);
 119                     done (1);
 120                 case UNKWNSW:
 121                     vec[vecp++] = --cp;
 122                     continue;
 123
 124                 case HELPSW:
 125                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 126                     print_help (buf, switches, 1);
 127                     done (1);
 128                 case VERSIONSW:
 129                     print_version(invo_name);
 130                     done (1);
 131
 132                 case BIFFSW:
 133                     biff = 1;
 134                     continue;
 135
 136                 case FORMSW:
 137                     if (!(form = *argp++) || *form == '-')
 138                         adios (NULL, "missing argument to %s", argp[-2]);
 139                     format = NULL;
 140                     continue;
 141                 case FMTSW:
 142                     if (!(format = *argp++) || *format == '-')
 143                         adios (NULL, "missing argument to %s", argp[-2]);
 144                     form = NULL;
 145                     continue;
 146
 147                 case WIDTHSW:
 148                     if (!(cp = *argp++) || *cp == '-')
 149                         adios(NULL, "missing argument to %s", argp[-2]);
 150                     width = atoi(cp);
 151                     continue;
 152                 case NLSW:
 153                     newline = 1;
 154                     continue;
 155                 case NNLSW:
 156                     newline = 0;
 157                     continue;
 158                 case BELSW:
 159                     bell = 1;
 160                     continue;
 161                 case NBELSW:
 162                     bell = 0;
 163                     continue;
 164
 165             }
 166         }
 167         vec[vecp++] = cp;
 168     }
 169     vec[vecp] = 0;
 170
 171     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 172         exit (RCV_MBX);
 173
 174     user = getusername();
 175
 176 #ifdef HAVE_GETUTENT
 177     setutent();
 178     while ((utp = getutent()) != NULL) {
 179         if (utp->ut_type == USER_PROCESS
 180                && utp->ut_user[0] != 0
 181                && utp->ut_line[0] != 0
 182                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 183             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 184             alert (tty, md);
 185         }
 186     }
 187     endutent();
 188 #else
 189     if ((uf = fopen (UTMP_FILE, "r")) == NULL)
 190         exit (RCV_MBX);
 191     while (fread ((char *) &ut, sizeof(ut), 1, uf) == 1)
 192         if (ut.ut_name[0] != 0
 193                 && strncmp (user, ut.ut_name, sizeof(ut.ut_name)) == 0) {
 194             strncpy (tty, ut.ut_line, sizeof(ut.ut_line));
 195             alert (tty, md);
 196         }
 197     fclose (uf);
 198 #endif
 199
 200     exit (RCV_MOK);
 201     return 0;  /* dead code to satisfy the compiler */
 202 }
 203
 204
 205 static RETSIGTYPE
 206 alrmser (int i)
 207 {
 208 #ifndef RELIABLE_SIGNALS
 209     SIGNAL (SIGALRM, alrmser);
 210 #endif
 211
 212     longjmp (myctx, 1);
 213 }
 214
 215
 216 static int
 217 message_fd (char **vec)
 218 {
 219     pid_t child_id;
 220     int bytes, fd, seconds;
 221     char tmpfil[BUFSIZ];
 222     struct stat st;
 223
 224 #ifdef HAVE_MKSTEMP
 225     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 226 #else
 227     unlink (mktemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 228     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 229         return header_fd ();
 230 #endif
 231     unlink (tmpfil);
 232
 233     if ((child_id = vfork()) == NOTOK) {
 234         /* fork error */
 235         close (fd);
 236         return header_fd ();
 237     } else if (child_id) {
 238         /* parent process */
 239         if (!setjmp (myctx)) {
 240             SIGNAL (SIGALRM, alrmser);
 241             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 242
 243             /* amount of time to wait depends on message size */
 244             if (bytes <= 100) {
 245                 /* give at least 5 minutes */
 246                 seconds = 300;
 247             } else if (bytes >= 90000) {
 248                 /* but 30 minutes should be long enough */
 249                 seconds = 1800;
 250             } else {
 251                 seconds = (bytes / 60) + 300;
 252             }
 253             alarm ((unsigned int) seconds);
 254             pidwait(child_id, OK);
 255             alarm (0);
 256
 257             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 258                 return fd;
 259         } else {
 260             /*
 261              * Ruthlessly kill the child and anything
 262              * else in its process group.
 263              */
 264             KILLPG(child_id, SIGKILL);
 265         }
 266         close (fd);
 267         return header_fd ();
 268     }
 269
 270     /* child process */
 271     rewind (stdin);
 272     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 273         _exit (-1);
 274     closefds (3);
 275     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 276     execvp (vec[0], vec);
 277     _exit (-1);
 278     return 1;  /* dead code to satisfy compiler */
 279 }
 280
 281
 282 static int
 283 header_fd (void)
 284 {
 285     int fd;
 286     char *nfs, tmpfil[BUFSIZ];
 287
 288     strncpy (tmpfil, m_tmpfil (invo_name), sizeof(tmpfil));
 289     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 290         return NOTOK;
 291     unlink (tmpfil);
 292
 293     rewind (stdin);
 294
 295     /* get new format string */
 296     nfs = new_fs (form, format, SCANFMT);
 297     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 298     if (newline)
 299         write (fd, "\n\r", 2);
 300     write (fd, scanl, strlen (scanl));
 301     if (bell)
 302         write (fd, "\007", 1);
 303
 304     return fd;
 305 }
 306
 307
 308 static void
 309 alert (char *tty, int md)
 310 {
 311     int i, td, mask;
 312     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 313     struct stat st;
 314
 315     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 316
 317     /*
 318      * The mask depends on whether we are checking for
 319      * write permission based on `biff' or `mesg'.
 320      */
 321     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 322     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 323         return;
 324
 325     if (!setjmp (myctx)) {
 326         SIGNAL (SIGALRM, alrmser);
 327         alarm (2);
 328         td = open (ttyspec, O_WRONLY);
 329         alarm (0);
 330         if (td == NOTOK)
 331             return;
 332     } else {
 333         alarm (0);
 334         return;
 335     }
 336
 337     lseek (md, (off_t) 0, SEEK_SET);
 338
 339     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 340         if (write (td, buffer, i) != i)
 341             break;
 342
 343     close (td);
 344 }
 345