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     return 0;  /* dead code to satisfy the compiler */
 171 }
 172
 173
 174 static RETSIGTYPE
 175 alrmser (int i)
 176 {
 177 #ifndef RELIABLE_SIGNALS
 178     SIGNAL (SIGALRM, alrmser);
 179 #endif
 180
 181     longjmp (myctx, 1);
 182 }
 183
 184
 185 static int
 186 message_fd (char **vec)
 187 {
 188     pid_t child_id;
 189     int bytes, fd, seconds;
 190     char tmpfil[BUFSIZ];
 191     struct stat st;
 192
 193 #ifdef HAVE_MKSTEMP
 194     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 195 #else
 196     unlink (mktemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 197     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 198         return header_fd ();
 199     unlink (tmpfil);
 200 #endif
 201
 202     if ((child_id = vfork()) == NOTOK) {
 203         /* fork error */
 204         close (fd);
 205         return header_fd ();
 206     } else if (child_id) {
 207         /* parent process */
 208         if (!setjmp (myctx)) {
 209             SIGNAL (SIGALRM, alrmser);
 210             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 211
 212             /* amount of time to wait depends on message size */
 213             if (bytes <= 100) {
 214                 /* give at least 5 minutes */
 215                 seconds = 300;
 216             } else if (bytes >= 90000) {
 217                 /* but 30 minutes should be long enough */
 218                 seconds = 1800;
 219             } else {
 220                 seconds = (bytes / 60) + 300;
 221             }
 222             alarm ((unsigned int) seconds);
 223             pidwait(child_id, OK);
 224             alarm (0);
 225
 226             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 227                 return fd;
 228         } else {
 229             /*
 230              * Ruthlessly kill the child and anything
 231              * else in its process group.
 232              */
 233             KILLPG(child_id, SIGKILL);
 234         }
 235         close (fd);
 236         return header_fd ();
 237     }
 238
 239     /* child process */
 240     rewind (stdin);
 241     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 242         _exit (-1);
 243     closefds (3);
 244     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 245     execvp (vec[0], vec);
 246     _exit (-1);
 247     return 1;  /* dead code to satisfy compiler */
 248 }
 249
 250
 251 static int
 252 header_fd (void)
 253 {
 254     int fd;
 255     char *nfs, tmpfil[BUFSIZ];
 256
 257     strncpy (tmpfil, m_tmpfil (invo_name), sizeof(tmpfil));
 258     if ((fd = open (tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 259         return NOTOK;
 260     unlink (tmpfil);
 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);
 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 static void
 278 alert (char *tty, int md)
 279 {
 280     int i, td, mask;
 281     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 282     struct stat st;
 283
 284     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 285
 286     /*
 287      * The mask depends on whether we are checking for
 288      * write permission based on `biff' or `mesg'.
 289      */
 290     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 291     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 292         return;
 293
 294     if (!setjmp (myctx)) {
 295         SIGNAL (SIGALRM, alrmser);
 296         alarm (2);
 297         td = open (ttyspec, O_WRONLY);
 298         alarm (0);
 299         if (td == NOTOK)
 300             return;
 301     } else {
 302         alarm (0);
 303         return;
 304     }
 305
 306     lseek (md, (off_t) 0, SEEK_SET);
 307
 308     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 309         if (write (td, buffer, i) != i)
 310             break;
 311
 312     close (td);
 313 }
 314