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  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 /* Changed to use getutent() and friends.  Assumes that when getutent() exists,
  11  * a number of other things also exist.  Please check.
  12  * Ruud de Rooij <ruud@ruud.org>  Sun, 28 May 2000 17:28:55 +0200
  13  */
  14
  15 #include <h/mh.h>
  16 #include <h/signals.h>
  17 #include <setjmp.h>
  18 #include <h/rcvmail.h>
  19 #include <h/scansbr.h>
  20 #include <h/tws.h>
  21 #include <h/mts.h>
  22 #include <fcntl.h>
  23
  24 #ifdef HAVE_GETUTXENT
  25 #include <utmpx.h>
  26 #endif /* HAVE_GETUTXENT */
  27
  28 #define SCANFMT \
  29 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  30 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  31 %{subject}%<{body}<<%{body}>>%>"
  32
  33 #define RCVTTY_SWITCHES \
  34     X("biff", 0, BIFFSW) \
  35     X("form formatfile", 0, FORMSW) \
  36     X("format string", 5, FMTSW) \
  37     X("width columns", 0, WIDTHSW) \
  38     X("newline", 0, NLSW) \
  39     X("nonewline", 0, NNLSW) \
  40     X("bell", 0, BELSW) \
  41     X("nobell", 0, NBELSW) \
  42     X("version", 0, VERSIONSW) \
  43     X("help", 0, HELPSW) \
  44
  45 #define X(sw, minchars, id) id,
  46 DEFINE_SWITCH_ENUM(RCVTTY);
  47 #undef X
  48
  49 #define X(sw, minchars, id) { sw, minchars, id },
  50 DEFINE_SWITCH_ARRAY(RCVTTY, switches);
  51 #undef X
  52
  53 static jmp_buf myctx;
  54 static int bell = 1;
  55 static int newline = 1;
  56 static int biff = 0;
  57 static int width = 0;
  58 static char *form = NULL;
  59 static char *format = NULL;
  60
  61 /*
  62  * external prototypes
  63  */
  64 char *getusername(void);
  65
  66 /*
  67  * static prototypes
  68  */
  69 static void alrmser (int);
  70 static int message_fd (char **);
  71 static int header_fd (void);
  72 #if HAVE_GETUTXENT
  73 static void alert (char *, int);
  74 #endif /* HAVE_GETUTXENT */
  75
  76
  77 int
  78 main (int argc, char **argv)
  79 {
  80     int md, vecp = 0;
  81     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  82     char **argp, **arguments, *vec[MAXARGS];
  83     struct utmpx *utp;
  84 #ifdef LOCALE
  85     setlocale(LC_ALL, "");
  86 #endif
  87     invo_name = r1bindex (argv[0], '/');
  88
  89     /* read user profile/context */
  90     context_read();
  91
  92     mts_init (invo_name);
  93     arguments = getarguments (invo_name, argc, argv, 1);
  94     argp = arguments;
  95
  96     while ((cp = *argp++)) {
  97         if (*cp == '-') {
  98             switch (smatch (++cp, switches)) {
  99                 case AMBIGSW:
 100                     ambigsw (cp, switches);
 101                     done (1);
 102                 case UNKWNSW:
 103                     vec[vecp++] = --cp;
 104                     continue;
 105
 106                 case HELPSW:
 107                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 108                     print_help (buf, switches, 1);
 109                     done (0);
 110                 case VERSIONSW:
 111                     print_version(invo_name);
 112                     done (0);
 113
 114                 case BIFFSW:
 115                     biff = 1;
 116                     continue;
 117
 118                 case FORMSW:
 119                     if (!(form = *argp++) || *form == '-')
 120                         adios (NULL, "missing argument to %s", argp[-2]);
 121                     format = NULL;
 122                     continue;
 123                 case FMTSW:
 124                     if (!(format = *argp++) || *format == '-')
 125                         adios (NULL, "missing argument to %s", argp[-2]);
 126                     form = NULL;
 127                     continue;
 128
 129                 case WIDTHSW:
 130                     if (!(cp = *argp++) || *cp == '-')
 131                         adios(NULL, "missing argument to %s", argp[-2]);
 132                     width = atoi(cp);
 133                     continue;
 134                 case NLSW:
 135                     newline = 1;
 136                     continue;
 137                 case NNLSW:
 138                     newline = 0;
 139                     continue;
 140                 case BELSW:
 141                     bell = 1;
 142                     continue;
 143                 case NBELSW:
 144                     bell = 0;
 145                     continue;
 146
 147             }
 148         }
 149         vec[vecp++] = cp;
 150     }
 151     vec[vecp] = 0;
 152
 153     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 154         exit (RCV_MBX);
 155
 156     user = getusername();
 157
 158 #if HAVE_GETUTXENT
 159     setutxent();
 160     while ((utp = getutxent()) != NULL) {
 161         if (utp->ut_type == USER_PROCESS && utp->ut_user[0] != 0
 162                && utp->ut_line[0] != 0
 163                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 164             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 165             alert (tty, md);
 166         }
 167     }
 168     endutxent();
 169 #else
 170     NMH_UNUSED (tty);
 171     NMH_UNUSED (utp);
 172 #endif /* HAVE_GETUTXENT */
 173
 174     exit (RCV_MOK);
 175 }
 176
 177
 178 static void
 179 alrmser (int i)
 180 {
 181     NMH_UNUSED (i);
 182
 183     longjmp (myctx, 1);
 184 }
 185
 186
 187 static int
 188 message_fd (char **vec)
 189 {
 190     pid_t child_id;
 191     int bytes, seconds;
 192     /* volatile to prevent "might be clobbered" warning from gcc: */
 193     volatile int fd;
 194     char tmpfil[BUFSIZ];
 195     struct stat st;
 196
 197     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 198     unlink (tmpfil);
 199
 200     if ((child_id = fork()) == NOTOK) {
 201         /* fork error */
 202         close (fd);
 203         return header_fd ();
 204     } else if (child_id) {
 205         /* parent process */
 206         if (!setjmp (myctx)) {
 207             SIGNAL (SIGALRM, alrmser);
 208             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 209
 210             /* amount of time to wait depends on message size */
 211             if (bytes <= 100) {
 212                 /* give at least 5 minutes */
 213                 seconds = 300;
 214             } else if (bytes >= 90000) {
 215                 /* but 30 minutes should be long enough */
 216                 seconds = 1800;
 217             } else {
 218                 seconds = (bytes / 60) + 300;
 219             }
 220             alarm ((unsigned int) seconds);
 221             pidwait(child_id, OK);
 222             alarm (0);
 223
 224             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 225                 return fd;
 226         } else {
 227             /*
 228              * Ruthlessly kill the child and anything
 229              * else in its process group.
 230              */
 231             killpg(child_id, SIGKILL);
 232         }
 233         close (fd);
 234         return header_fd ();
 235     }
 236
 237     /* child process */
 238     rewind (stdin);
 239     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 240         _exit (-1);
 241     closefds (3);
 242     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 243     if (execvp (vec[0], vec) == NOTOK) {
 244         _exit (-1);
 245     }
 246
 247     return NOTOK;
 248 }
 249
 250
 251 static int
 252 header_fd (void)
 253 {
 254     int fd;
 255     char *nfs;
 256     char *tfile = NULL;
 257
 258     tfile = m_mktemp2(NULL, invo_name, &fd, NULL);
 259     if (tfile == NULL) return NOTOK;
 260     unlink (tfile);
 261
 262     rewind (stdin);
 263
 264     /* get new format string */
 265     nfs = new_fs (form, format, SCANFMT);
 266     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 267     scan_finished ();
 268     if (newline)
 269         write (fd, "\n\r", 2);
 270     write (fd, scanl, strlen (scanl));
 271     if (bell)
 272         write (fd, "\007", 1);
 273
 274     return fd;
 275 }
 276
 277
 278 #if HAVE_GETUTXENT
 279 static void
 280 alert (char *tty, int md)
 281 {
 282     int i, td, mask;
 283     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 284     struct stat st;
 285
 286     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 287
 288     /*
 289      * The mask depends on whether we are checking for
 290      * write permission based on `biff' or `mesg'.
 291      */
 292     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 293     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 294         return;
 295
 296     if (!setjmp (myctx)) {
 297         SIGNAL (SIGALRM, alrmser);
 298         alarm (2);
 299         td = open (ttyspec, O_WRONLY);
 300         alarm (0);
 301         if (td == NOTOK)
 302             return;
 303     } else {
 304         alarm (0);
 305         return;
 306     }
 307
 308     lseek (md, (off_t) 0, SEEK_SET);
 309
 310     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 311         if (write (td, buffer, i) != i)
 312             break;
 313
 314     close (td);
 315 }
 316 #endif /* HAVE_GETUTXENT */