commands/telnetd/term.c

   1 /*
   2  * TNET         A server program for MINIX which implements the TCP/IP
   3  *              suite of networking protocols.  It is based on the
   4  *              TCP/IP code written by Phil Karn et al, as found in
   5  *              his NET package for Packet Radio communications.
   6  *
   7  *              Handle the TERMINAL module.
   8  *
   9  * Author:      Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  10  *              Michael Temari, <temari@temari.ae.ge.com>
  11  *
  12  * 07/29/92 MT  Telnet options hack which seems to work okay
  13  * 01/12/93 MT  Better telnet options processing instead of hack
  14  */
  15 #include <sys/types.h>
  16 #include <errno.h>
  17 #if 0
  18 #include <fcntl.h>
  19 #endif
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <string.h>
  23 #include <stdio.h>
  24 #include <signal.h>
  25 #include "telnet.h"
  26 #include "telnetd.h"
  27
  28 _PROTOTYPE(void sig_done, (int sig));
  29
  30 static char buff[4096];
  31
  32 void term_init()
  33 {
  34   tel_init();
  35
  36   telopt(1, WILL, TELOPT_SGA);
  37   telopt(1, DO,   TELOPT_SGA);
  38   telopt(1, WILL, TELOPT_BINARY);
  39   telopt(1, DO,   TELOPT_BINARY);
  40   telopt(1, WILL, TELOPT_ECHO);
  41   telopt(1, DO,   TELOPT_WINCH);
  42 }
  43
  44 static int io_done = 0;
  45
  46 void term_inout(pty_fd)
  47 int pty_fd;
  48 {
  49 register int i;
  50 pid_t pid;
  51 struct sigaction sa;
  52
  53   sigemptyset(&sa.sa_mask);
  54   sa.sa_flags = 0;
  55   sa.sa_handler = sig_done;
  56   sigaction(SIGALRM, &sa, (struct sigaction *) NULL);
  57
  58   if ((pid = fork()) == -1) {
  59         sprintf(buff, "telnetd: fork() failed: %s\r\n", strerror(errno));
  60         (void) write(1, buff, strlen(buff));
  61   }
  62
  63   if (pid != 0) {
  64         /* network -> login process */
  65         while (!io_done && (i = read(0, buff, sizeof(buff))) > 0) {
  66                 tel_in(pty_fd, 1, buff, i);
  67         }
  68         /* EOF, kill opposite number and exit. */
  69         (void) kill(pid, SIGKILL);
  70   } else {
  71         /* login process -> network */
  72         while ((i = read(pty_fd, buff, sizeof(buff))) > 0) {
  73                 tel_out(1, buff, i);
  74         }
  75         /* EOF, alert opposite number and exit. */
  76         (void) kill(getppid(), SIGALRM);
  77   }
  78   /* EOF. */
  79 }
  80
  81 void sig_done(sig)
  82 int sig;
  83 {
  84   io_done = 1;
  85   alarm(1);                     /* there is always a chance... */
  86 }