usr/src/cmd/cmd-inet/usr.bin/telnet/network.c

   1 #pragma ident   "%Z%%M% %I%     %E% SMI"
   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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  36  * Use is subject to license terms.
  37  */
  38
  39 static char sccsid[] = "@(#)network.c   8.1 (Berkeley) 6/6/93";
  40
  41 #include <sys/types.h>
  42 #include <sys/socket.h>
  43 #include <sys/time.h>
  44
  45 #include <errno.h>
  46
  47 #include <arpa/telnet.h>
  48
  49 #include "ring.h"
  50
  51 #include "defines.h"
  52 #include "externs.h"
  53
  54 Ring    netoring;
  55 Ring    netiring;
  56
  57 /*
  58  * Use large buffers to handle larger tickets when doing
  59  * Kerberos authentication.  Microsoft generates large
  60  * tickets that exceed the buffer size which causes authentication
  61  * to fail.
  62  */
  63 static unsigned char netobuf[10*BUFSIZ];
  64 static unsigned char netibuf[10*BUFSIZ];
  65
  66 /*
  67  * Initialize internal network data structures.
  68  */
  69
  70 void
  71 init_network()
  72 {
  73         if (ring_init(&netoring, netobuf, sizeof (netobuf)) != 1) {
  74                 exit(1);
  75         }
  76         if (ring_init(&netiring, netibuf, sizeof (netibuf)) != 1) {
  77                 exit(1);
  78         }
  79         NetTrace = stdout;
  80 }
  81
  82
  83 /*
  84  * Check to see if any out-of-band data exists on a socket (for
  85  * Telnet "synch" processing).
  86  */
  87
  88 int
  89 stilloob()
  90 {
  91         static struct timeval timeout = { 0 };
  92         fd_set  excepts;
  93         int value;
  94
  95         do {
  96                 FD_ZERO(&excepts);
  97                 FD_SET(net, &excepts);
  98                 value = select(net+1, NULL, NULL, &excepts, &timeout);
  99         } while ((value == -1) && (errno == EINTR));
 100
 101         if (value < 0) {
 102                 perror("select");
 103                 (void) quit();
 104                 /* NOTREACHED */
 105         }
 106         if (FD_ISSET(net, &excepts)) {
 107                 return (1);
 108         } else {
 109                 return (0);
 110         }
 111 }
 112
 113
 114 /*
 115  *  setneturg()
 116  *
 117  *      Sets "neturg" to the current location.
 118  */
 119
 120 void
 121 setneturg()
 122 {
 123         ring_mark(&netoring);
 124 }
 125
 126
 127 /*
 128  *  netflush
 129  *              Send as much data as possible to the network,
 130  *      handling requests for urgent data.
 131  *
 132  *              The return value indicates whether we did any
 133  *      useful work.
 134  */
 135
 136
 137 int
 138 netflush()
 139 {
 140         register int n, n1;
 141
 142         if (encrypt_output)
 143                 ring_encrypt(&netoring, encrypt_output);
 144
 145         if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
 146                 if (!ring_at_mark(&netoring)) {
 147                         /* normal write */
 148                         n = send(net, netoring.consume, n, 0);
 149                 } else {
 150                         /*
 151                          * In 4.2(and 4.3) systems, there is some question about
 152                          * what byte in a sendOOB operation is the "OOB" data.
 153                          * To make ourselves compatible, we only send ONE byte
 154                          * out of band, the one WE THINK should be OOB (though
 155                          * we really have more the TCP philosophy of urgent data
 156                          * rather than the Unix philosophy of OOB data).
 157                          */
 158                         n = send(net, netoring.consume, 1, MSG_OOB);
 159                 }
 160         }
 161         if (n < 0) {
 162                 if (errno != ENOBUFS && errno != EWOULDBLOCK) {
 163                         setcommandmode();
 164                         perror(hostname);
 165                         ring_clear_mark(&netoring);
 166                         longjmp(peerdied, -1);
 167                         /*NOTREACHED*/
 168                 }
 169                 n = 0;
 170         }
 171         if (netdata && n) {
 172                 Dump('>', netoring.consume, n);
 173         }
 174         if (n) {
 175                 ring_consumed(&netoring, n);
 176                 /*
 177                  * If we sent all, and more to send, then recurse to pick
 178                  * up the other half.
 179                  */
 180                 if ((n1 == n) && ring_full_consecutive(&netoring)) {
 181                         (void) netflush();
 182                 }
 183                 return (1);
 184         } else {
 185                 return (0);
 186         }
 187 }