telnet.tproj/network.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1988, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  */
  56
  57 #ifndef lint
  58 static char sccsid[] = "@(#)network.c   8.2 (Berkeley) 12/15/93";
  59 #endif /* not lint */
  60
  61 #include <sys/types.h>
  62 #include <sys/socket.h>
  63 #include <sys/time.h>
  64
  65 #include <errno.h>
  66
  67 #include <arpa/telnet.h>
  68
  69 #include "ring.h"
  70
  71 #include "defines.h"
  72 #include "externs.h"
  73 #include "fdset.h"
  74
  75 Ring            netoring, netiring;
  76 unsigned char   netobuf[2*BUFSIZ], netibuf[BUFSIZ];
  77
  78 /*
  79  * Initialize internal network data structures.
  80  */
  81
  82     void
  83 init_network()
  84 {
  85     if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
  86         exit(1);
  87     }
  88     if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
  89         exit(1);
  90     }
  91     NetTrace = stdout;
  92 }
  93
  94
  95 /*
  96  * Check to see if any out-of-band data exists on a socket (for
  97  * Telnet "synch" processing).
  98  */
  99
 100     int
 101 stilloob()
 102 {
 103     static struct timeval timeout = { 0 };
 104     fd_set      excepts;
 105     int value;
 106
 107     do {
 108         FD_ZERO(&excepts);
 109         FD_SET(net, &excepts);
 110         value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
 111     } while ((value == -1) && (errno == EINTR));
 112
 113     if (value < 0) {
 114         perror("select");
 115         (void) quit();
 116         /* NOTREACHED */
 117     }
 118     if (FD_ISSET(net, &excepts)) {
 119         return 1;
 120     } else {
 121         return 0;
 122     }
 123 }
 124
 125
 126 /*
 127  *  setneturg()
 128  *
 129  *      Sets "neturg" to the current location.
 130  */
 131
 132     void
 133 setneturg()
 134 {
 135     ring_mark(&netoring);
 136 }
 137
 138
 139 /*
 140  *  netflush
 141  *              Send as much data as possible to the network,
 142  *      handling requests for urgent data.
 143  *
 144  *              The return value indicates whether we did any
 145  *      useful work.
 146  */
 147
 148
 149     int
 150 netflush()
 151 {
 152     register int n, n1;
 153
 154 #ifdef  ENCRYPTION
 155     if (encrypt_output)
 156         ring_encrypt(&netoring, encrypt_output);
 157 #endif  /* ENCRYPTION */
 158     if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
 159         if (!ring_at_mark(&netoring)) {
 160             n = send(net, (char *)netoring.consume, n, 0); /* normal write */
 161         } else {
 162             /*
 163              * In 4.2 (and 4.3) systems, there is some question about
 164              * what byte in a sendOOB operation is the "OOB" data.
 165              * To make ourselves compatible, we only send ONE byte
 166              * out of band, the one WE THINK should be OOB (though
 167              * we really have more the TCP philosophy of urgent data
 168              * rather than the Unix philosophy of OOB data).
 169              */
 170             n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
 171         }
 172     }
 173     if (n < 0) {
 174         if (errno != ENOBUFS && errno != EWOULDBLOCK) {
 175             setcommandmode();
 176             perror(hostname);
 177             (void)NetClose(net);
 178             ring_clear_mark(&netoring);
 179             longjmp(peerdied, -1);
 180             /*NOTREACHED*/
 181         }
 182         n = 0;
 183     }
 184     if (netdata && n) {
 185         Dump('>', netoring.consume, n);
 186     }
 187     if (n) {
 188         ring_consumed(&netoring, n);
 189         /*
 190          * If we sent all, and more to send, then recurse to pick
 191          * up the other half.
 192          */
 193         if ((n1 == n) && ring_full_consecutive(&netoring)) {
 194             (void) netflush();
 195         }
 196         return 1;
 197     } else {
 198         return 0;
 199     }
 200 }