usr.bin/telnet/network.c

   1 /*      $NetBSD: network.c,v 1.17 2004/03/20 23:26:05 heas Exp $        */
   2
   3 /*
   4  * Copyright (c) 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)network.c   8.2 (Berkeley) 12/15/93";
  36 #else
  37 __RCSID("$NetBSD: network.c,v 1.17 2004/03/20 23:26:05 heas Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <sys/types.h>
  42 #include <sys/socket.h>
  43 #include <sys/time.h>
  44
  45 #include <errno.h>
  46 #include <unistd.h>
  47 #include <poll.h>
  48
  49 #include <arpa/telnet.h>
  50
  51 #include "ring.h"
  52 #include "defines.h"
  53 #include "externs.h"
  54
  55 Ring            netoring, netiring;
  56 unsigned char   netobuf[2*BUFSIZ], netibuf[BUFSIZ];
  57
  58 /*
  59  * Initialize internal network data structures.
  60  */
  61
  62 void
  63 init_network(void)
  64 {
  65     if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
  66         exit(1);
  67     }
  68     if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
  69         exit(1);
  70     }
  71     NetTrace = stdout;
  72 }
  73
  74
  75 /*
  76  * Check to see if any out-of-band data exists on a socket (for
  77  * Telnet "synch" processing).
  78  */
  79
  80 int
  81 stilloob(void)
  82 {
  83     struct pollfd set[1];
  84     int value;
  85
  86     set[0].fd = net;
  87     set[0].events = POLLPRI;
  88     do {
  89         value = poll(set, 1, 0);
  90     } while ((value == -1) && (errno == EINTR));
  91
  92     if (value < 0) {
  93         perror("poll");
  94         (void) quit(0, NULL);
  95         /* NOTREACHED */
  96     }
  97     if (set[0].revents & POLLPRI) {
  98         return 1;
  99     } else {
 100         return 0;
 101     }
 102 }
 103
 104
 105 /*
 106  *  setneturg()
 107  *
 108  *      Sets "neturg" to the current location.
 109  */
 110
 111 void
 112 setneturg(void)
 113 {
 114     ring_mark(&netoring);
 115 }
 116
 117
 118 /*
 119  *  netflush
 120  *              Send as much data as possible to the network,
 121  *      handling requests for urgent data.
 122  *
 123  *              The return value indicates whether we did any
 124  *      useful work.
 125  */
 126
 127
 128 int
 129 netflush(void)
 130 {
 131     int n, n1;
 132
 133 #ifdef  ENCRYPTION
 134     if (encrypt_output)
 135         ring_encrypt(&netoring, encrypt_output);
 136 #endif  /* ENCRYPTION */
 137     if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
 138         if (!ring_at_mark(&netoring)) {
 139             n = send(net, (char *)netoring.consume, n, 0); /* normal write */
 140         } else {
 141             /*
 142              * In 4.2 (and 4.3) systems, there is some question about
 143              * what byte in a sendOOB operation is the "OOB" data.
 144              * To make ourselves compatible, we only send ONE byte
 145              * out of band, the one WE THINK should be OOB (though
 146              * we really have more the TCP philosophy of urgent data
 147              * rather than the Unix philosophy of OOB data).
 148              */
 149             n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
 150         }
 151     }
 152     if (n < 0) {
 153         if (errno != ENOBUFS && errno != EWOULDBLOCK) {
 154             setcommandmode();
 155             perror(hostname);
 156             (void)NetClose(net);
 157             ring_clear_mark(&netoring);
 158             ExitString("Connection closed by foreign host.\n", 1);
 159             /*NOTREACHED*/
 160         }
 161         n = 0;
 162     }
 163     if (netdata && n) {
 164         Dump('>', netoring.consume, n);
 165     }
 166     if (n) {
 167         ring_consumed(&netoring, n);
 168         /*
 169          * If we sent all, and more to send, then recurse to pick
 170          * up the other half.
 171          */
 172         if ((n1 == n) && ring_full_consecutive(&netoring)) {
 173             (void) netflush();
 174         }
 175         return 1;
 176     } else {
 177         return 0;
 178     }
 179 }