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/m_setjmp.h>
  18 #include <h/rcvmail.h>
  19 #include <h/scansbr.h>
  20 #include <h/tws.h>
  21 #include <h/mts.h>
  22 #include <signal.h>
  23 #include <fcntl.h>
  24
  25 #include <utmpx.h>
  26
  27 #define SCANFMT \
  28 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  29 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  30 %{subject}%<{body}<<%{body}>>%>"
  31
  32 static struct swit switches[] = {
  33 #define BIFFSW  0
  34     { "biff", 0 },
  35 #define FORMSW  1
  36     { "form formatfile", 0 },
  37 #define FMTSW   2
  38     { "format string", 5 },
  39 #define WIDTHSW 3
  40     { "width columns", 0 },
  41 #define NLSW    4
  42     { "newline", 0 },
  43 #define NNLSW   5
  44     { "nonewline", 0 },
  45 #define BELSW   6
  46     { "bell", 0 },
  47 #define NBELSW  7
  48     { "nobell", 0 },
  49 #define VERSIONSW 8
  50     { "version", 0 },
  51 #define HELPSW  9
  52     { "help", 0 },
  53     { NULL, 0 }
  54 };
  55
  56 static jmp_buf myctx;
  57 static int bell = 1;
  58 static int newline = 1;
  59 static int biff = 0;
  60 static int width = 0;
  61 static char *form = NULL;
  62 static char *format = NULL;
  63
  64 /*
  65  * external prototypes
  66  */
  67 char *getusername(void);
  68
  69 /*
  70  * static prototypes
  71  */
  72 static void alrmser (int);
  73 static int message_fd (char **);
  74 static int header_fd (void);
  75 static void alert (char *, int);
  76
  77
  78 int
  79 main (int argc, char **argv)
  80 {
  81     int md, vecp = 0;
  82     char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  83     char **argp, **arguments, *vec[MAXARGS];
  84     struct utmpx *utp;
  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
 159     setutxent();
 160     while ((utp = getutxent()) != NULL) {
 161         if (utp->ut_type == USER_PROCESS && utp->ut_user[0] != 0
 162                && utp->ut_line[0] != 0
 163                && strncmp (user, utp->ut_user, sizeof(utp->ut_user)) == 0) {
 164             strncpy (tty, utp->ut_line, sizeof(utp->ut_line));
 165             alert (tty, md);
 166         }
 167     }
 168     endutxent();
 169
 170     exit (RCV_MOK);
 171     return 0;  /* dead code to satisfy the compiler */
 172 }
 173
 174
 175 static void
 176 alrmser (int i)
 177 {
 178     NMH_UNUSED (i);
 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     fd = mkstemp (strncpy (tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 193     unlink (tmpfil);
 194
 195     if ((child_id = vfork()) == NOTOK) {
 196         /* fork error */
 197         close (fd);
 198         return header_fd ();
 199     } else if (child_id) {
 200         /* parent process */
 201         if (!m_setjmp (myctx)) {
 202             SIGNAL (SIGALRM, alrmser);
 203             bytes = fstat(fileno (stdin), &st) != NOTOK ? (int) st.st_size : 100;
 204
 205             /* amount of time to wait depends on message size */
 206             if (bytes <= 100) {
 207                 /* give at least 5 minutes */
 208                 seconds = 300;
 209             } else if (bytes >= 90000) {
 210                 /* but 30 minutes should be long enough */
 211                 seconds = 1800;
 212             } else {
 213                 seconds = (bytes / 60) + 300;
 214             }
 215             alarm ((unsigned int) seconds);
 216             pidwait(child_id, OK);
 217             alarm (0);
 218
 219             if (fstat (fd, &st) != NOTOK && st.st_size > (off_t) 0)
 220                 return fd;
 221         } else {
 222             /*
 223              * Ruthlessly kill the child and anything
 224              * else in its process group.
 225              */
 226             killpg(child_id, SIGKILL);
 227         }
 228         close (fd);
 229         return header_fd ();
 230     }
 231
 232     /* child process */
 233     rewind (stdin);
 234     if (dup2 (fd, 1) == NOTOK || dup2 (fd, 2) == NOTOK)
 235         _exit (-1);
 236     closefds (3);
 237     setpgid ((pid_t) 0, getpid ());     /* put in own process group */
 238     execvp (vec[0], vec);
 239     _exit (-1);
 240     return 1;  /* dead code to satisfy compiler */
 241 }
 242
 243
 244 static int
 245 header_fd (void)
 246 {
 247     int fd;
 248     char *nfs;
 249     char *tfile = NULL;
 250
 251     tfile = m_mktemp2(NULL, invo_name, &fd, NULL);
 252     if (tfile == NULL) return NOTOK;
 253     unlink (tfile);
 254
 255     rewind (stdin);
 256
 257     /* get new format string */
 258     nfs = new_fs (form, format, SCANFMT);
 259     scan (stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 260     if (newline)
 261         write (fd, "\n\r", 2);
 262     write (fd, scanl, strlen (scanl));
 263     if (bell)
 264         write (fd, "\007", 1);
 265
 266     return fd;
 267 }
 268
 269
 270 static void
 271 alert (char *tty, int md)
 272 {
 273     int i, td, mask;
 274     char buffer[BUFSIZ], ttyspec[BUFSIZ];
 275     struct stat st;
 276
 277     snprintf (ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 278
 279     /*
 280      * The mask depends on whether we are checking for
 281      * write permission based on `biff' or `mesg'.
 282      */
 283     mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 284     if (stat (ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 285         return;
 286
 287     if (!m_setjmp (myctx)) {
 288         SIGNAL (SIGALRM, alrmser);
 289         alarm (2);
 290         td = open (ttyspec, O_WRONLY);
 291         alarm (0);
 292         if (td == NOTOK)
 293             return;
 294     } else {
 295         alarm (0);
 296         return;
 297     }
 298
 299     lseek (md, (off_t) 0, SEEK_SET);
 300
 301     while ((i = read (md, buffer, sizeof(buffer))) > 0)
 302         if (write (td, buffer, i) != i)
 303             break;
 304
 305     close (td);
 306 }
 307