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 = -1;
  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     if (nmh_init(argv[0], 1)) { return 1; }
  86
  87     mts_init (invo_name);
  88     arguments = getarguments (invo_name, argc, argv, 1);
  89     argp = arguments;
  90
  91     while ((cp = *argp++)) {
  92         if (*cp == '-') {
  93             switch (smatch (++cp, switches)) {
  94                 case AMBIGSW:
  95                     ambigsw (cp, switches);
  96                     done (1);
  97                 case UNKWNSW:
  98                     vec[vecp++] = --cp;
  99                     continue;
 100
 101                 case HELPSW:
 102                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 103                     print_help (buf, switches, 1);
 104                     done (0);
 105                 case VERSIONSW:
 106                     print_version(invo_name);
 107                     done (0);
 108
 109                 case BIFFSW:
 110                     biff = 1;
 111                     continue;
 112
 113                 case FORMSW:
 114                     if (!(form = *argp++) || *form == '-')
 115                         adios (NULL, "missing argument to %s", argp[-2]);
 116                     format = NULL;
 117                     continue;
 118                 case FMTSW:
 119                     if (!(format = *argp++) || *format == '-')
 120                         adios (NULL, "missing argument to %s", argp[-2]);
 121                     form = NULL;
 122                     continue;
 123
 124                 case WIDTHSW:
 125                     if (!(cp = *argp++) || *cp == '-')
 126                         adios(NULL, "missing argument to %s", argp[-2]);
 127                     width = atoi(cp);
 128                     continue;
 129                 case NLSW:
 130                     newline = 1;
 131                     continue;
 132                 case NNLSW:
 133                     newline = 0;
 134                     continue;
 135                 case BELSW:
 136                     bell = 1;
 137                     continue;
 138                 case NBELSW:
 139                     bell = 0;
 140                     continue;
 141
 142             }
 143         }
 144         vec[vecp++] = cp;
 145     }
 146     vec[vecp] = 0;
 147
 148     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 149         exit (RCV_MBX);
 150
 151     user = getusername();
 152
 153 #if HAVE_GETUTXENT
 154     setutxent();
 155     while ((utp = getutxent()) != NULL) {
 156         if (utp->ut_type == USER_PROCESS && utp->ut_user[0] != 0
 157                && utp->ut_line[0] != 0
 158                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 159             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 160             alert (tty, md);
 161         }
 162     }
 163     endutxent();
 164 #else
 165     NMH_UNUSED (tty);
 166     NMH_UNUSED (utp);
 167 #endif /* HAVE_GETUTXENT */
 168
 169     exit (RCV_MOK);
 170 }
 171
 172
 173 static void
 174 alrmser (int i)
 175 {
 176     NMH_UNUSED (i);
 177
 178     longjmp (myctx, 1);
 179 }
 180
 181
 182 static int
 183 message_fd (char **vec)
 184 {
 185     pid_t child_id;
 186     int bytes, seconds;
 187     int fd;
 188     char *tfile;
 189     struct stat st;
 190
 191     if ((tfile = m_mktemp2(NULL, invo_name, &fd, NULL)) == NULL) {
 192         advise(NULL, "unable to create temporary file in %s", get_temp_dir());
 193         return NOTOK;
 194     }
 195     (void) m_unlink(tfile);  /* Use fd, no longer need the file name. */
 196
 197     if ((child_id = fork()) == NOTOK) {
 198         /* fork error */
 199         close (fd);
 200         return header_fd ();
 201     } else if (child_id) {
 202         /* parent process */
 203         if (!setjmp (myctx)) {
 204             SIGNAL (SIGALRM, alrmser);
 205             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 206
 207             /* amount of time to wait depends on message size */
 208             if (bytes <= 100) {
 209                 /* give at least 5 minutes */
 210                 seconds = 300;
 211             } else if (bytes >= 90000) {
 212                 /* but 30 minutes should be long enough */
 213                 seconds = 1800;
 214             } else {
 215                 seconds = (bytes / 60) + 300;
 216             }
 217             alarm ((unsigned int) seconds);
 218             pidwait(child_id, OK);
 219             alarm (0);
 220
 221             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 222                 return fd;
 223         } else {
 224             /*
 225              * Ruthlessly kill the child and anything
 226              * else in its process group.
 227              */
 228             killpg(child_id, SIGKILL);
 229         }
 230         close (fd);
 231         return header_fd ();
 232     }
 233
 234     /* child process */
 235     rewind (stdin);
 236     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 237         _exit (-1);
 238     closefds (3);
 239     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 240     if (execvp (vec[0], vec) == NOTOK) {
 241         _exit (-1);
 242     }
 243
 244     return NOTOK;
 245 }
 246
 247
 248 static int
 249 header_fd (void)
 250 {
 251     int fd;
 252     char *nfs;
 253     char *tfile = NULL;
 254     charstring_t scanl = NULL;
 255
 256     if ((tfile = m_mktemp2(NULL, invo_name, &fd, NULL)) == NULL) {
 257         advise(NULL, "unable to create temporary file in %s", get_temp_dir());
 258         return NOTOK;
 259     }
 260     (void) m_unlink(tfile);  /* Use fd, no longer need the file name. */
 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, &scanl);
 267     scan_finished ();
 268     if (newline) {
 269         if (write (fd, "\n\r", 2) < 0) {
 270             advise (tfile, "write LF/CR");
 271         }
 272     }
 273     if (write (fd, charstring_buffer (scanl), charstring_bytes (scanl)) < 0) {
 274         advise (tfile, "write");
 275     }
 276     charstring_free (scanl);
 277     if (bell) {
 278         if (write (fd, "\007", 1) < 0) {
 279             advise (tfile, "write BEL");
 280         }
 281     }
 282
 283     return fd;
 284 }
 285
 286
 287 #if HAVE_GETUTXENT
 288 static void
 289 alert (char *tty, int md)
 290 {
 291     int i, td, mask;
 292     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 293     struct stat st;
 294
 295     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 296
 297     /*
 298      * The mask depends on whether we are checking for
 299      * write permission based on `biff' or `mesg'.
 300      */
 301     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 302     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 303         return;
 304
 305     if (!setjmp (myctx)) {
 306         SIGNAL (SIGALRM, alrmser);
 307         alarm (2);
 308         td = open (ttyspec, O_WRONLY);
 309         alarm (0);
 310         if (td == NOTOK)
 311             return;
 312     } else {
 313         alarm (0);
 314         return;
 315     }
 316
 317     lseek (md, (off_t) 0, SEEK_SET);
 318
 319     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 320         if (write (td, buffer, i) != i)
 321             break;
 322
 323     close (td);
 324 }
 325 #endif /* HAVE_GETUTXENT */