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

   1 /* rcvtty.c -- a rcvmail program (a lot like rcvalert) handling IPC ttys
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   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 <setjmp.h>
  16 #include <h/rcvmail.h>
  17 #include <h/scansbr.h>
  18 #include <h/tws.h>
  19 #include <h/mts.h>
  20 #include <fcntl.h>
  21
  22 #ifdef HAVE_GETUTXENT
  23 #include <utmpx.h>
  24 #endif /* HAVE_GETUTXENT */
  25
  26 #define SCANFMT \
  27 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  28 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  29 %{subject}%<{body}<<%{body}>>%>"
  30
  31 #define RCVTTY_SWITCHES \
  32     X("biff", 0, BIFFSW) \
  33     X("form formatfile", 0, FORMSW) \
  34     X("format string", 5, FMTSW) \
  35     X("width columns", 0, WIDTHSW) \
  36     X("newline", 0, NLSW) \
  37     X("nonewline", 0, NNLSW) \
  38     X("bell", 0, BELSW) \
  39     X("nobell", 0, NBELSW) \
  40     X("version", 0, VERSIONSW) \
  41     X("help", 0, HELPSW) \
  42
  43 #define X(sw, minchars, id) id,
  44 DEFINE_SWITCH_ENUM(RCVTTY);
  45 #undef X
  46
  47 #define X(sw, minchars, id) { sw, minchars, id },
  48 DEFINE_SWITCH_ARRAY(RCVTTY, switches);
  49 #undef X
  50
  51 static jmp_buf myctx;
  52 static int bell = 1;
  53 static int newline = 1;
  54 static int biff = 0;
  55 static int width = -1;
  56 static char *form = NULL;
  57 static char *format = NULL;
  58
  59 /*
  60  * external prototypes
  61  */
  62 char *getusername(void);
  63
  64 /*
  65  * static prototypes
  66  */
  67 static void alrmser (int);
  68 static int message_fd (char **);
  69 static int header_fd (void);
  70 #if HAVE_GETUTXENT
  71 static void alert (char *, int);
  72 #endif /* HAVE_GETUTXENT */
  73
  74
  75 int
  76 main (int argc, char **argv)
  77 {
  78     int md, vecp = 0;
  79     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  80     char **argp, **arguments, *vec[MAXARGS];
  81     struct utmpx *utp;
  82
  83     if (nmh_init(argv[0], 2)) { return 1; }
  84
  85     mts_init ();
  86     arguments = getarguments (invo_name, argc, argv, 1);
  87     argp = arguments;
  88
  89     while ((cp = *argp++)) {
  90         if (*cp == '-') {
  91             switch (smatch (++cp, switches)) {
  92                 case AMBIGSW:
  93                     ambigsw (cp, switches);
  94                     done (1);
  95                 case UNKWNSW:
  96                     vec[vecp++] = --cp;
  97                     continue;
  98
  99                 case HELPSW:
 100                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 101                     print_help (buf, switches, 1);
 102                     done (0);
 103                 case VERSIONSW:
 104                     print_version(invo_name);
 105                     done (0);
 106
 107                 case BIFFSW:
 108                     biff = 1;
 109                     continue;
 110
 111                 case FORMSW:
 112                     if (!(form = *argp++) || *form == '-')
 113                         adios (NULL, "missing argument to %s", argp[-2]);
 114                     format = NULL;
 115                     continue;
 116                 case FMTSW:
 117                     if (!(format = *argp++) || *format == '-')
 118                         adios (NULL, "missing argument to %s", argp[-2]);
 119                     form = NULL;
 120                     continue;
 121
 122                 case WIDTHSW:
 123                     if (!(cp = *argp++) || *cp == '-')
 124                         adios(NULL, "missing argument to %s", argp[-2]);
 125                     width = atoi(cp);
 126                     continue;
 127                 case NLSW:
 128                     newline = 1;
 129                     continue;
 130                 case NNLSW:
 131                     newline = 0;
 132                     continue;
 133                 case BELSW:
 134                     bell = 1;
 135                     continue;
 136                 case NBELSW:
 137                     bell = 0;
 138                     continue;
 139
 140             }
 141         }
 142         vec[vecp++] = cp;
 143     }
 144     vec[vecp] = 0;
 145
 146     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 147         exit (RCV_MBX);
 148
 149     user = getusername();
 150
 151 #if HAVE_GETUTXENT
 152     setutxent();
 153     while ((utp = getutxent()) != NULL) {
 154         if (utp->ut_type == USER_PROCESS && utp->ut_user[0] != 0
 155                && utp->ut_line[0] != 0
 156                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 157             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 158             alert (tty, md);
 159         }
 160     }
 161     endutxent();
 162 #else
 163     NMH_UNUSED (tty);
 164     NMH_UNUSED (utp);
 165 #endif /* HAVE_GETUTXENT */
 166
 167     exit (RCV_MOK);
 168 }
 169
 170
 171 static void
 172 alrmser (int i)
 173 {
 174     NMH_UNUSED (i);
 175
 176     longjmp (myctx, 1);
 177 }
 178
 179
 180 static int
 181 message_fd (char **vec)
 182 {
 183     pid_t child_id;
 184     int bytes, seconds;
 185     int fd;
 186     char *tfile;
 187     struct stat st;
 188
 189     if ((tfile = m_mktemp2(NULL, invo_name, &fd, NULL)) == NULL) {
 190         inform("unable to create temporary file in %s", get_temp_dir());
 191         return NOTOK;
 192     }
 193     (void) m_unlink(tfile);  /* Use fd, no longer need the file name. */
 194
 195     if ((child_id = fork()) == NOTOK) {
 196         /* fork error */
 197         close (fd);
 198         return header_fd ();
 199     }
 200     if (child_id) {
 201         /* parent process */
 202         if (!setjmp (myctx)) {
 203             SIGNAL (SIGALRM, alrmser);
 204             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 205
 206             /* amount of time to wait depends on message size */
 207             if (bytes <= 100) {
 208                 /* give at least 5 minutes */
 209                 seconds = 300;
 210             } else if (bytes >= 90000) {
 211                 /* but 30 minutes should be long enough */
 212                 seconds = 1800;
 213             } else {
 214                 seconds = (bytes / 60) + 300;
 215             }
 216             alarm ((unsigned int) seconds);
 217             pidwait(child_id, OK);
 218             alarm (0);
 219
 220             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 221                 return fd;
 222         } else {
 223             /*
 224              * Ruthlessly kill the child and anything
 225              * else in its process group.
 226              */
 227             killpg(child_id, SIGKILL);
 228         }
 229         close (fd);
 230         return header_fd ();
 231     }
 232
 233     /* child process */
 234     rewind (stdin);
 235     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 236         _exit (-1);
 237     closefds (3);
 238     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 239     if (execvp (vec[0], vec) == NOTOK) {
 240         _exit (-1);
 241     }
 242
 243     return NOTOK;
 244 }
 245
 246
 247 static int
 248 header_fd (void)
 249 {
 250     int fd;
 251     char *nfs;
 252     char *tfile = NULL;
 253     charstring_t scanl = NULL;
 254
 255     if ((tfile = m_mktemp2(NULL, invo_name, &fd, NULL)) == NULL) {
 256         inform("unable to create temporary file in %s", get_temp_dir());
 257         return NOTOK;
 258     }
 259     (void) m_unlink(tfile);  /* Use fd, no longer need the file name. */
 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, &scanl);
 266     scan_finished ();
 267     if (newline) {
 268         if (write (fd, "\n\r", 2) < 0) {
 269             advise (tfile, "write LF/CR");
 270         }
 271     }
 272     if (write (fd, charstring_buffer (scanl), charstring_bytes (scanl)) < 0) {
 273         advise (tfile, "write");
 274     }
 275     charstring_free (scanl);
 276     if (bell) {
 277         if (write (fd, "\007", 1) < 0) {
 278             advise (tfile, "write BEL");
 279         }
 280     }
 281
 282     return fd;
 283 }
 284
 285
 286 #if HAVE_GETUTXENT
 287 static void
 288 alert (char *tty, int md)
 289 {
 290     int i, td, mask;
 291     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 292     struct stat st;
 293
 294     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 295
 296     /*
 297      * The mask depends on whether we are checking for
 298      * write permission based on `biff' or `mesg'.
 299      */
 300     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 301     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 302         return;
 303
 304     if (!setjmp (myctx)) {
 305         SIGNAL (SIGALRM, alrmser);
 306         alarm (2);
 307         td = open (ttyspec, O_WRONLY);
 308         alarm (0);
 309         if (td == NOTOK)
 310             return;
 311     } else {
 312         alarm (0);
 313         return;
 314     }
 315
 316     lseek (md, (off_t) 0, SEEK_SET);
 317
 318     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 319         if (write (td, buffer, i) != i)
 320             break;
 321
 322     close (td);
 323 }
 324 #endif /* HAVE_GETUTXENT */