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
  85     setlocale(LC_ALL, "");
  86     invo_name = r1bindex (argv[0], '/');
  87
  88     /* read user profile/context */
  89     context_read();
  90
  91     mts_init (invo_name);
  92     arguments = getarguments (invo_name, argc, argv, 1);
  93     argp = arguments;
  94
  95     while ((cp = *argp++)) {
  96         if (*cp == '-') {
  97             switch (smatch (++cp, switches)) {
  98                 case AMBIGSW:
  99                     ambigsw (cp, switches);
 100                     done (1);
 101                 case UNKWNSW:
 102                     vec[vecp++] = --cp;
 103                     continue;
 104
 105                 case HELPSW:
 106                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 107                     print_help (buf, switches, 1);
 108                     done (0);
 109                 case VERSIONSW:
 110                     print_version(invo_name);
 111                     done (0);
 112
 113                 case BIFFSW:
 114                     biff = 1;
 115                     continue;
 116
 117                 case FORMSW:
 118                     if (!(form = *argp++) || *form == '-')
 119                         adios (NULL, "missing argument to %s", argp[-2]);
 120                     format = NULL;
 121                     continue;
 122                 case FMTSW:
 123                     if (!(format = *argp++) || *format == '-')
 124                         adios (NULL, "missing argument to %s", argp[-2]);
 125                     form = NULL;
 126                     continue;
 127
 128                 case WIDTHSW:
 129                     if (!(cp = *argp++) || *cp == '-')
 130                         adios(NULL, "missing argument to %s", argp[-2]);
 131                     width = atoi(cp);
 132                     continue;
 133                 case NLSW:
 134                     newline = 1;
 135                     continue;
 136                 case NNLSW:
 137                     newline = 0;
 138                     continue;
 139                 case BELSW:
 140                     bell = 1;
 141                     continue;
 142                 case NBELSW:
 143                     bell = 0;
 144                     continue;
 145
 146             }
 147         }
 148         vec[vecp++] = cp;
 149     }
 150     vec[vecp] = 0;
 151
 152     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 153         exit (RCV_MBX);
 154
 155     user = getusername();
 156
 157 #if HAVE_GETUTXENT
 158     setutxent();
 159     while ((utp = getutxent()) != NULL) {
 160         if (utp->ut_type == USER_PROCESS && utp->ut_user[0] != 0
 161                && utp->ut_line[0] != 0
 162                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 163             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 164             alert (tty, md);
 165         }
 166     }
 167     endutxent();
 168 #else
 169     NMH_UNUSED (tty);
 170     NMH_UNUSED (utp);
 171 #endif /* HAVE_GETUTXENT */
 172
 173     exit (RCV_MOK);
 174 }
 175
 176
 177 static void
 178 alrmser (int i)
 179 {
 180     NMH_UNUSED (i);
 181
 182     longjmp (myctx, 1);
 183 }
 184
 185
 186 static int
 187 message_fd (char **vec)
 188 {
 189     pid_t child_id;
 190     int bytes, seconds;
 191     /* volatile to prevent "might be clobbered" warning from gcc: */
 192     volatile int fd;
 193     char tmpfil[BUFSIZ];
 194     struct stat st;
 195
 196     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 197     unlink (tmpfil);
 198
 199     if ((child_id = fork()) == NOTOK) {
 200         /* fork error */
 201         close (fd);
 202         return header_fd ();
 203     } else if (child_id) {
 204         /* parent process */
 205         if (!setjmp (myctx)) {
 206             SIGNAL (SIGALRM, alrmser);
 207             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 208
 209             /* amount of time to wait depends on message size */
 210             if (bytes <= 100) {
 211                 /* give at least 5 minutes */
 212                 seconds = 300;
 213             } else if (bytes >= 90000) {
 214                 /* but 30 minutes should be long enough */
 215                 seconds = 1800;
 216             } else {
 217                 seconds = (bytes / 60) + 300;
 218             }
 219             alarm ((unsigned int) seconds);
 220             pidwait(child_id, OK);
 221             alarm (0);
 222
 223             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 224                 return fd;
 225         } else {
 226             /*
 227              * Ruthlessly kill the child and anything
 228              * else in its process group.
 229              */
 230             killpg(child_id, SIGKILL);
 231         }
 232         close (fd);
 233         return header_fd ();
 234     }
 235
 236     /* child process */
 237     rewind (stdin);
 238     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 239         _exit (-1);
 240     closefds (3);
 241     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 242     if (execvp (vec[0], vec) == NOTOK) {
 243         _exit (-1);
 244     }
 245
 246     return NOTOK;
 247 }
 248
 249
 250 static int
 251 header_fd (void)
 252 {
 253     int fd;
 254     char *nfs;
 255     char *tfile = NULL;
 256
 257     tfile = m_mktemp2(NULL, invo_name, &fd, NULL);
 258     if (tfile == NULL) return NOTOK;
 259     unlink (tfile);
 260
 261     rewind (stdin);
 262
 263     /* get new format string */
 264     nfs = new_fs (form, format, SCANFMT);
 265     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 266     scan_finished ();
 267     if (newline)
 268         write (fd, "\n\r", 2);
 269     write (fd, scanl, strlen (scanl));
 270     if (bell)
 271         write (fd, "\007", 1);
 272
 273     return fd;
 274 }
 275
 276
 277 #if HAVE_GETUTXENT
 278 static void
 279 alert (char *tty, int md)
 280 {
 281     int i, td, mask;
 282     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 283     struct stat st;
 284
 285     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 286
 287     /*
 288      * The mask depends on whether we are checking for
 289      * write permission based on `biff' or `mesg'.
 290      */
 291     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 292     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 293         return;
 294
 295     if (!setjmp (myctx)) {
 296         SIGNAL (SIGALRM, alrmser);
 297         alarm (2);
 298         td = open (ttyspec, O_WRONLY);
 299         alarm (0);
 300         if (td == NOTOK)
 301             return;
 302     } else {
 303         alarm (0);
 304         return;
 305     }
 306
 307     lseek (md, (off_t) 0, SEEK_SET);
 308
 309     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 310         if (write (td, buffer, i) != i)
 311             break;
 312
 313     close (td);
 314 }
 315 #endif /* HAVE_GETUTXENT */