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 <zotnet/mts/mts.h>
  14 #include <signal.h>
  15 #include <fcntl.h>
  16
  17 #include <utmp.h>
  18 #ifndef UTMP_FILE
  19 # ifdef _PATH_UTMP
  20 #  define UTMP_FILE _PATH_UTMP
  21 # else
  22 #  define UTMP_FILE "/etc/utmp"
  23 # endif
  24 #endif
  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 static struct swit switches[] = {
  32 #define BIFFSW  0
  33     { "biff", 0 },
  34 #define FORMSW  1
  35     { "form formatfile", 0 },
  36 #define FMTSW   2
  37     { "format string", 5 },
  38 #define WIDTHSW 3
  39     { "width columns", 0 },
  40 #define NLSW    4
  41     { "newline", 0 },
  42 #define NNLSW   5
  43     { "nonewline", 0 },
  44 #define BELSW   6
  45     { "bell", 0 },
  46 #define NBELSW  7
  47     { "nobell", 0 },
  48 #define VERSIONSW 8
  49     { "version", 0 },
  50 #define HELPSW  9
  51     { "help", 0 },
  52     { NULL, 0 }
  53 };
  54
  55 static jmp_buf myctx;
  56 static int bell = 1;
  57 static int newline = 1;
  58 static int biff = 0;
  59 static int width = 0;
  60 static char *form = NULL;
  61 static char *format = NULL;
  62
  63 /*
  64  * external prototypes
  65  */
  66 char *getusername(void);
  67
  68 /*
  69  * static prototypes
  70  */
  71 static RETSIGTYPE alrmser (int);
  72 static int message_fd (char **);
  73 static int header_fd (void);
  74 static void alert (char *, int);
  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 utmp ut;
  84     register FILE *uf;
  85
  86 #ifdef LOCALE
  87     setlocale(LC_ALL, "");
  88 #endif
  89     invo_name = r1bindex (argv[0], '/');
  90
  91     /* read user profile/context */
  92     context_read();
  93
  94     mts_init (invo_name);
  95     arguments = getarguments (invo_name, argc, argv, 1);
  96     argp = arguments;
  97
  98     while ((cp = *argp++)) {
  99         if (*cp == '-') {
 100             switch (smatch (++cp, switches)) {
 101                 case AMBIGSW:
 102                     ambigsw (cp, switches);
 103                     done (1);
 104                 case UNKWNSW:
 105                     vec[vecp++] = --cp;
 106                     continue;
 107
 108                 case HELPSW:
 109                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 110                     print_help (buf, switches, 1);
 111                     done (1);
 112                 case VERSIONSW:
 113                     print_version(invo_name);
 114                     done (1);
 115
 116                 case BIFFSW:
 117                     biff = 1;
 118                     continue;
 119
 120                 case FORMSW:
 121                     if (!(form = *argp++) || *form == '-')
 122                         adios (NULL, "missing argument to %s", argp[-2]);
 123                     format = NULL;
 124                     continue;
 125                 case FMTSW:
 126                     if (!(format = *argp++) || *format == '-')
 127                         adios (NULL, "missing argument to %s", argp[-2]);
 128                     form = NULL;
 129                     continue;
 130
 131                 case WIDTHSW:
 132                     if (!(cp = *argp++) || *cp == '-')
 133                         adios(NULL, "missing argument to %s", argp[-2]);
 134                     width = atoi(cp);
 135                     continue;
 136                 case NLSW:
 137                     newline = 1;
 138                     continue;
 139                 case NNLSW:
 140                     newline = 0;
 141                     continue;
 142                 case BELSW:
 143                     bell = 1;
 144                     continue;
 145                 case NBELSW:
 146                     bell = 0;
 147                     continue;
 148
 149             }
 150         }
 151         vec[vecp++] = cp;
 152     }
 153     vec[vecp] = 0;
 154
 155     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 156         exit (RCV_MBX);
 157
 158     user = getusername();
 159     if ((uf = fopen (UTMP_FILE, "r")) == NULL)
 160         exit (RCV_MBX);
 161
 162     while (fread ((char *) &ut, sizeof(ut), 1, uf) == 1)
 163         if (ut.ut_name[0] != 0
 164                 && strncmp (user, ut.ut_name, sizeof(ut.ut_name)) == 0) {
 165             strncpy (tty, ut.ut_line, sizeof(ut.ut_line));
 166             alert (tty, md);
 167         }
 168
 169     fclose (uf);
 170     exit (RCV_MOK);
 171     return 0;  /* dead code to satisfy the compiler */
 172 }
 173
 174
 175 static RETSIGTYPE
 176 alrmser (int i)
 177 {
 178 #ifndef RELIABLE_SIGNALS
 179     SIGNAL (SIGALRM, alrmser);
 180 #endif
 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, fd, seconds;
 191     char tmpfil[BUFSIZ];
 192     struct stat st;
 193
 194 #ifdef HAVE_MKSTEMP
 195     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 196 #else
 197     unlink (mktemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 198     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 199         return header_fd ();
 200     unlink (tmpfil);
 201 #endif
 202
 203     if ((child_id = vfork()) == NOTOK) {
 204         /* fork error */
 205         close (fd);
 206         return header_fd ();
 207     } else if (child_id) {
 208         /* parent process */
 209         if (!setjmp (myctx)) {
 210             SIGNAL (SIGALRM, alrmser);
 211             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 212
 213             /* amount of time to wait depends on message size */
 214             if (bytes <= 100) {
 215                 /* give at least 5 minutes */
 216                 seconds = 300;
 217             } else if (bytes >= 90000) {
 218                 /* but 30 minutes should be long enough */
 219                 seconds = 1800;
 220             } else {
 221                 seconds = (bytes / 60) + 300;
 222             }
 223             alarm ((unsigned int) seconds);
 224             pidwait(child_id, OK);
 225             alarm (0);
 226
 227             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 228                 return fd;
 229         } else {
 230             /*
 231              * Ruthlessly kill the child and anything
 232              * else in its process group.
 233              */
 234             KILLPG(child_id, SIGKILL);
 235         }
 236         close (fd);
 237         return header_fd ();
 238     }
 239
 240     /* child process */
 241     rewind (stdin);
 242     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 243         _exit (-1);
 244     closefds (3);
 245     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 246     execvp (vec[0], vec);
 247     _exit (-1);
 248     return 1;  /* dead code to satisfy compiler */
 249 }
 250
 251
 252 static int
 253 header_fd (void)
 254 {
 255     int fd;
 256     char *nfs, tmpfil[BUFSIZ];
 257
 258     strncpy (tmpfil, m_tmpfil (invo_name), sizeof(tmpfil));
 259     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 260         return NOTOK;
 261     unlink (tmpfil);
 262
 263     rewind (stdin);
 264
 265     /* get new format string */
 266     nfs = new_fs (form, format, SCANFMT);
 267     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 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 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