telnet.tproj/network.c

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35
  36 #ifdef __FBSDID
  37 __FBSDID("$FreeBSD: src/crypto/telnet/telnet/network.c,v 1.2.8.2 2002/04/13 10:59:08 markm Exp $");
  38 #endif
  39
  40 #ifndef lint
  41 static const char sccsid[] = "@(#)network.c     8.2 (Berkeley) 12/15/93";
  42 #endif
  43
  44 #include <sys/types.h>
  45 #include <sys/socket.h>
  46 #include <sys/time.h>
  47
  48 #include <errno.h>
  49
  50 #include <arpa/telnet.h>
  51 #include <unistd.h>
  52
  53 #include "ring.h"
  54
  55 #include "defines.h"
  56 #include "externs.h"
  57 #include "fdset.h"
  58
  59 Ring            netoring, netiring;
  60 unsigned char   netobuf[2*BUFSIZ], netibuf[BUFSIZ];
  61
  62 /*
  63  * Initialize internal network data structures.
  64  */
  65
  66 void
  67 init_network(void)
  68 {
  69     if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
  70         exit(1);
  71     }
  72     if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
  73         exit(1);
  74     }
  75     NetTrace = stdout;
  76 }
  77
  78
  79 /*
  80  * Check to see if any out-of-band data exists on a socket (for
  81  * Telnet "synch" processing).
  82  */
  83
  84 int
  85 stilloob(void)
  86 {
  87     static struct timeval timeout = { 0, 0 };
  88     fd_set      excepts;
  89     int value;
  90
  91     do {
  92         FD_ZERO(&excepts);
  93         FD_SET(net, &excepts);
  94         value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
  95     } while ((value == -1) && (errno == EINTR));
  96
  97     if (value < 0) {
  98         perror("select");
  99         (void) quit();
 100         /* NOTREACHED */
 101     }
 102     if (FD_ISSET(net, &excepts)) {
 103         return 1;
 104     } else {
 105         return 0;
 106     }
 107 }
 108
 109
 110 /*
 111  *  setneturg()
 112  *
 113  *      Sets "neturg" to the current location.
 114  */
 115
 116 void
 117 setneturg(void)
 118 {
 119     ring_mark(&netoring);
 120 }
 121
 122
 123 /*
 124  *  netflush
 125  *              Send as much data as possible to the network,
 126  *      handling requests for urgent data.
 127  *
 128  *              The return value indicates whether we did any
 129  *      useful work.
 130  */
 131
 132 int
 133 netflush(void)
 134 {
 135     int n, n1;
 136
 137 #ifdef  ENCRYPTION
 138     if (encrypt_output)
 139         ring_encrypt(&netoring, encrypt_output);
 140 #endif  /* ENCRYPTION */
 141     if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
 142         if (!ring_at_mark(&netoring)) {
 143             n = send(net, (char *)netoring.consume, n, 0); /* normal write */
 144         } else {
 145             /*
 146              * In 4.2 (and 4.3) systems, there is some question about
 147              * what byte in a sendOOB operation is the "OOB" data.
 148              * To make ourselves compatible, we only send ONE byte
 149              * out of band, the one WE THINK should be OOB (though
 150              * we really have more the TCP philosophy of urgent data
 151              * rather than the Unix philosophy of OOB data).
 152              */
 153             n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
 154         }
 155     }
 156     if (n < 0) {
 157         if (errno != ENOBUFS && errno != EWOULDBLOCK) {
 158             setcommandmode();
 159             perror(hostname);
 160             (void)NetClose(net);
 161             ring_clear_mark(&netoring);
 162             longjmp(peerdied, -1);
 163             /*NOTREACHED*/
 164         }
 165         n = 0;
 166     }
 167     if (netdata && n) {
 168         Dump('>', netoring.consume, n);
 169     }
 170     if (n) {
 171         ring_consumed(&netoring, n);
 172         /*
 173          * If we sent all, and more to send, then recurse to pick
 174          * up the other half.
 175          */
 176         if ((n1 == n) && ring_full_consecutive(&netoring)) {
 177             (void) netflush();
 178         }
 179         return 1;
 180     } else {
 181         return 0;
 182     }
 183 }