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
   8 #include <h/mh.h>
   9 #include <h/signals.h>
  10 #include <h/rcvmail.h>
  11 #include <h/scansbr.h>
  12 #include <zotnet/tws/tws.h>
  13 #include <signal.h>
  14 #include <fcntl.h>
  15
  16 #include <utmp.h>
  17 #ifndef UTMP_FILE
  18 # ifdef _PATH_UTMP
  19 #  define UTMP_FILE _PATH_UTMP
  20 # else
  21 #  define UTMP_FILE "/etc/utmp"
  22 # endif
  23 #endif
  24
  25 #define SCANFMT \
  26 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  27 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  28 %{subject}%<{body}<<%{body}>>%>"
  29
  30 static struct swit switches[] = {
  31 #define BIFFSW  0
  32     { "biff", 0 },
  33 #define FORMSW  1
  34     { "form formatfile", 0 },
  35 #define FMTSW   2
  36     { "format string", 5 },
  37 #define WIDTHSW 3
  38     { "width columns", 0 },
  39 #define NLSW    4
  40     { "newline", 0 },
  41 #define NNLSW   5
  42     { "nonewline", 0 },
  43 #define BELSW   6
  44     { "bell", 0 },
  45 #define NBELSW  7
  46     { "nobell", 0 },
  47 #define VERSIONSW 8
  48     { "version", 0 },
  49 #define HELPSW  9
  50     { "help", 4 },
  51     { NULL, 0 }
  52 };
  53
  54 static jmp_buf myctx;
  55 static int bell = 1;
  56 static int newline = 1;
  57 static int biff = 0;
  58 static int width = 0;
  59 static char *form = NULL;
  60 static char *format = NULL;
  61
  62 /*
  63  * external prototypes
  64  */
  65 char *getusername(void);
  66
  67 /*
  68  * static prototypes
  69  */
  70 static RETSIGTYPE alrmser (int);
  71 static int message_fd (char **);
  72 static int header_fd (void);
  73 static void alert (char *, int);
  74
  75
  76 int
  77 main (int argc, char **argv)
  78 {
  79     int md, vecp = 0;
  80     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  81     char **argp, **arguments, *vec[MAXARGS];
  82     struct utmp ut;
  83     register FILE *uf;
  84
  85 #ifdef LOCALE
  86     setlocale(LC_ALL, "");
  87 #endif
  88     invo_name = r1bindex (argv[0], '/');
  89
  90     /* read user profile/context */
  91     context_read();
  92
  93     mts_init (invo_name);
  94     arguments = getarguments (invo_name, argc, argv, 1);
  95     argp = arguments;
  96
  97     while ((cp = *argp++)) {
  98         if (*cp == '-') {
  99             switch (smatch (++cp, switches)) {
 100                 case AMBIGSW:
 101                     ambigsw (cp, switches);
 102                     done (1);
 103                 case UNKWNSW:
 104                     vec[vecp++] = --cp;
 105                     continue;
 106
 107                 case HELPSW:
 108                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 109                     print_help (buf, switches, 1);
 110                     done (1);
 111                 case VERSIONSW:
 112                     print_version(invo_name);
 113                     done (1);
 114
 115                 case BIFFSW:
 116                     biff = 1;
 117                     continue;
 118
 119                 case FORMSW:
 120                     if (!(form = *argp++) || *form == '-')
 121                         adios (NULL, "missing argument to %s", argp[-2]);
 122                     format = NULL;
 123                     continue;
 124                 case FMTSW:
 125                     if (!(format = *argp++) || *format == '-')
 126                         adios (NULL, "missing argument to %s", argp[-2]);
 127                     form = NULL;
 128                     continue;
 129
 130                 case WIDTHSW:
 131                     if (!(cp = *argp++) || *cp == '-')
 132                         adios(NULL, "missing argument to %s", argp[-2]);
 133                     width = atoi(cp);
 134                     continue;
 135                 case NLSW:
 136                     newline = 1;
 137                     continue;
 138                 case NNLSW:
 139                     newline = 0;
 140                     continue;
 141                 case BELSW:
 142                     bell = 1;
 143                     continue;
 144                 case NBELSW:
 145                     bell = 0;
 146                     continue;
 147
 148             }
 149         }
 150         vec[vecp++] = cp;
 151     }
 152     vec[vecp] = 0;
 153
 154     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 155         exit (RCV_MBX);
 156
 157     user = getusername();
 158     if ((uf = fopen (UTMP_FILE, "r")) == NULL)
 159         exit (RCV_MBX);
 160
 161     while (fread ((char *) &ut, sizeof(ut), 1, uf) == 1)
 162         if (ut.ut_name[0] != 0
 163                 && strncmp (user, ut.ut_name, sizeof(ut.ut_name)) == 0) {
 164             strncpy (tty, ut.ut_line, sizeof(ut.ut_line));
 165             alert (tty, md);
 166         }
 167
 168     fclose (uf);
 169     exit (RCV_MOK);
 170 }
 171
 172
 173 static RETSIGTYPE
 174 alrmser (int i)
 175 {
 176 #ifndef RELIABLE_SIGNALS
 177     SIGNAL (SIGALRM, alrmser);
 178 #endif
 179
 180     longjmp (myctx, 1);
 181 }
 182
 183
 184 static int
 185 message_fd (char **vec)
 186 {
 187     pid_t child_id;
 188     int bytes, fd, seconds;
 189     char tmpfil[BUFSIZ];
 190     struct stat st;
 191
 192     unlink (mktemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 193     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 194         return header_fd ();
 195     unlink (tmpfil);
 196
 197     if ((child_id = vfork()) == 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     execvp (vec[0], vec);
 241     _exit (-1);
 242 }
 243
 244
 245 static int
 246 header_fd (void)
 247 {
 248     int fd;
 249     char *nfs, tmpfil[BUFSIZ];
 250
 251     strncpy (tmpfil, m_tmpfil (invo_name), sizeof(tmpfil));
 252     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 253         return NOTOK;
 254     unlink (tmpfil);
 255
 256     rewind (stdin);
 257
 258     /* get new format string */
 259     nfs = new_fs (form, format, SCANFMT);
 260     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 261     if (newline)
 262         write (fd, "\n\r", 2);
 263     write (fd, scanl, strlen (scanl));
 264     if (bell)
 265         write (fd, "\007", 1);
 266
 267     return fd;
 268 }
 269
 270
 271 static void
 272 alert (char *tty, int md)
 273 {
 274     int i, td, mask;
 275     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 276     struct stat st;
 277
 278     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 279
 280     /*
 281      * The mask depends on whether we are checking for
 282      * write permission based on `biff' or `mesg'.
 283      */
 284     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 285     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 286         return;
 287
 288     if (!setjmp (myctx)) {
 289         SIGNAL (SIGALRM, alrmser);
 290         alarm (2);
 291         td = open (ttyspec, O_WRONLY);
 292         alarm (0);
 293         if (td == NOTOK)
 294             return;
 295     } else {
 296         alarm (0);
 297         return;
 298     }
 299
 300     lseek (md, (off_t) 0, SEEK_SET);
 301
 302     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 303         if (write (td, buffer, i) != i)
 304             break;
 305
 306     close (td);
 307 }
 308