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 <h/rcvmail.h>
  18 #include <h/scansbr.h>
  19 #include <h/tws.h>
  20 #include <h/mts.h>
  21 #include <signal.h>
  22 #include <fcntl.h>
  23
  24 #include <utmp.h>
  25
  26 #ifndef HAVE_GETUTENT
  27 # ifndef UTMP_FILE
  28 #  ifdef _PATH_UTMP
  29 #   define UTMP_FILE _PATH_UTMP
  30 #  else
  31 #   define UTMP_FILE "/etc/utmp"
  32 #  endif
  33 # endif
  34 #endif
  35
  36 #define SCANFMT \
  37 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  38 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  39 %{subject}%<{body}<<%{body}>>%>"
  40
  41 static struct swit switches[] = {
  42 #define BIFFSW  0
  43     { "biff", 0 },
  44 #define FORMSW  1
  45     { "form formatfile", 0 },
  46 #define FMTSW   2
  47     { "format string", 5 },
  48 #define WIDTHSW 3
  49     { "width columns", 0 },
  50 #define NLSW    4
  51     { "newline", 0 },
  52 #define NNLSW   5
  53     { "nonewline", 0 },
  54 #define BELSW   6
  55     { "bell", 0 },
  56 #define NBELSW  7
  57     { "nobell", 0 },
  58 #define VERSIONSW 8
  59     { "version", 0 },
  60 #define HELPSW  9
  61     { "help", 0 },
  62     { NULL, 0 }
  63 };
  64
  65 static jmp_buf myctx;
  66 static int bell = 1;
  67 static int newline = 1;
  68 static int biff = 0;
  69 static int width = 0;
  70 static char *form = NULL;
  71 static char *format = NULL;
  72
  73 /*
  74  * external prototypes
  75  */
  76 char *getusername(void);
  77
  78 /*
  79  * static prototypes
  80  */
  81 static RETSIGTYPE alrmser (int);
  82 static int message_fd (char **);
  83 static int header_fd (void);
  84 static void alert (char *, int);
  85
  86
  87 int
  88 main (int argc, char **argv)
  89 {
  90     int md, vecp = 0;
  91     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  92     char **argp, **arguments, *vec[MAXARGS];
  93 #ifdef HAVE_GETUTENT
  94     struct utmp * utp;
  95 #else
  96     struct utmp ut;
  97     register FILE *uf;
  98 #endif
  99
 100 #ifdef LOCALE
 101     setlocale(LC_ALL, "");
 102 #endif
 103     invo_name = r1bindex (argv[0], '/');
 104
 105     /* read user profile/context */
 106     context_read();
 107
 108     mts_init (invo_name);
 109     arguments = getarguments (invo_name, argc, argv, 1);
 110     argp = arguments;
 111
 112     while ((cp = *argp++)) {
 113         if (*cp == '-') {
 114             switch (smatch (++cp, switches)) {
 115                 case AMBIGSW:
 116                     ambigsw (cp, switches);
 117                     done (1);
 118                 case UNKWNSW:
 119                     vec[vecp++] = --cp;
 120                     continue;
 121
 122                 case HELPSW:
 123                     snprintf (buf, sizeof(buf), "%s [command ...]", invo_name);
 124                     print_help (buf, switches, 1);
 125                     done (1);
 126                 case VERSIONSW:
 127                     print_version(invo_name);
 128                     done (1);
 129
 130                 case BIFFSW:
 131                     biff = 1;
 132                     continue;
 133
 134                 case FORMSW:
 135                     if (!(form = *argp++) || *form == '-')
 136                         adios (NULL, "missing argument to %s", argp[-2]);
 137                     format = NULL;
 138                     continue;
 139                 case FMTSW:
 140                     if (!(format = *argp++) || *format == '-')
 141                         adios (NULL, "missing argument to %s", argp[-2]);
 142                     form = NULL;
 143                     continue;
 144
 145                 case WIDTHSW:
 146                     if (!(cp = *argp++) || *cp == '-')
 147                         adios(NULL, "missing argument to %s", argp[-2]);
 148                     width = atoi(cp);
 149                     continue;
 150                 case NLSW:
 151                     newline = 1;
 152                     continue;
 153                 case NNLSW:
 154                     newline = 0;
 155                     continue;
 156                 case BELSW:
 157                     bell = 1;
 158                     continue;
 159                 case NBELSW:
 160                     bell = 0;
 161                     continue;
 162
 163             }
 164         }
 165         vec[vecp++] = cp;
 166     }
 167     vec[vecp] = 0;
 168
 169     if ((md = vecp ? message_fd (vec) : header_fd ()) == NOTOK)
 170         exit (RCV_MBX);
 171
 172     user = getusername();
 173
 174 #ifdef HAVE_GETUTENT
 175     setutent();
 176     while ((utp = getutent()) != NULL) {
 177         if (
 178 #ifdef HAVE_STRUCT_UTMP_UT_TYPE
 179                utp->ut_type == USER_PROCESS
 180                &&
 181 #endif
 182                utp->ut_name[0] != 0
 183                && utp->ut_line[0] != 0
 184                && strncmp (user, utp->ut_name, sizeof(utp->ut_name)) == 0) {
 185             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 186             alert (tty, md);
 187         }
 188     }
 189     endutent();
 190 #else
 191     if ((uf = fopen (UTMP_FILE, "r")) == NULL)
 192         exit (RCV_MBX);
 193     while (fread ((char *) &ut, sizeof(ut), 1, uf) == 1)
 194         if (ut.ut_name[0] != 0
 195                 && strncmp (user, ut.ut_name, sizeof(ut.ut_name)) == 0) {
 196             strncpy (tty, ut.ut_line, sizeof(ut.ut_line));
 197             alert (tty, md);
 198         }
 199     fclose (uf);
 200 #endif
 201
 202     exit (RCV_MOK);
 203     return 0;  /* dead code to satisfy the compiler */
 204 }
 205
 206
 207 static RETSIGTYPE
 208 alrmser (int i)
 209 {
 210 #ifndef RELIABLE_SIGNALS
 211     SIGNAL (SIGALRM, alrmser);
 212 #endif
 213
 214     longjmp (myctx, 1);
 215 }
 216
 217
 218 static int
 219 message_fd (char **vec)
 220 {
 221     pid_t child_id;
 222     int bytes, fd, seconds;
 223     char tmpfil[BUFSIZ];
 224     struct stat st;
 225
 226     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 227     unlink (tmpfil);
 228
 229     if ((child_id = vfork()) == NOTOK) {
 230         /* fork error */
 231         close (fd);
 232         return header_fd ();
 233     } else if (child_id) {
 234         /* parent process */
 235         if (!setjmp (myctx)) {
 236             SIGNAL (SIGALRM, alrmser);
 237             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 238
 239             /* amount of time to wait depends on message size */
 240             if (bytes <= 100) {
 241                 /* give at least 5 minutes */
 242                 seconds = 300;
 243             } else if (bytes >= 90000) {
 244                 /* but 30 minutes should be long enough */
 245                 seconds = 1800;
 246             } else {
 247                 seconds = (bytes / 60) + 300;
 248             }
 249             alarm ((unsigned int) seconds);
 250             pidwait(child_id, OK);
 251             alarm (0);
 252
 253             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 254                 return fd;
 255         } else {
 256             /*
 257              * Ruthlessly kill the child and anything
 258              * else in its process group.
 259              */
 260             killpg(child_id, SIGKILL);
 261         }
 262         close (fd);
 263         return header_fd ();
 264     }
 265
 266     /* child process */
 267     rewind (stdin);
 268     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 269         _exit (-1);
 270     closefds (3);
 271     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 272     execvp (vec[0], vec);
 273     _exit (-1);
 274     return 1;  /* dead code to satisfy compiler */
 275 }
 276
 277
 278 static int
 279 header_fd (void)
 280 {
 281     int fd;
 282     char *nfs;
 283     char *tfile = NULL;
 284
 285     tfile = m_mktemp2(NULL, invo_name, &fd, NULL);
 286     if (tfile == NULL) return NOTOK;
 287     unlink (tfile);
 288
 289     rewind (stdin);
 290
 291     /* get new format string */
 292     nfs = new_fs (form, format, SCANFMT);
 293     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 294     if (newline)
 295         write (fd, "\n\r", 2);
 296     write (fd, scanl, strlen (scanl));
 297     if (bell)
 298         write (fd, "\007", 1);
 299
 300     return fd;
 301 }
 302
 303
 304 static void
 305 alert (char *tty, int md)
 306 {
 307     int i, td, mask;
 308     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 309     struct stat st;
 310
 311     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 312
 313     /*
 314      * The mask depends on whether we are checking for
 315      * write permission based on `biff' or `mesg'.
 316      */
 317     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 318     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 319         return;
 320
 321     if (!setjmp (myctx)) {
 322         SIGNAL (SIGALRM, alrmser);
 323         alarm (2);
 324         td = open (ttyspec, O_WRONLY);
 325         alarm (0);
 326         if (td == NOTOK)
 327             return;
 328     } else {
 329         alarm (0);
 330         return;
 331     }
 332
 333     lseek (md, (off_t) 0, SEEK_SET);
 334
 335     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 336         if (write (td, buffer, i) != i)
 337             break;
 338
 339     close (td);
 340 }
 341