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 * @(#)network.c 8.2 (Berkeley) 12/15/93 34 * $FreeBSD: src/usr.bin/telnet/network.c,v 1.2.14.1 2002/04/13 11:07:13 markm Exp $ 35 * $DragonFly: src/usr.bin/telnet/network.c,v 1.3 2007/11/25 01:28:23 swildner Exp $ 36 */ 37 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 #include <sys/time.h> 41 42 #include <errno.h> 43 44 #include <arpa/telnet.h> 45 #include <stdlib.h> 46 #include <unistd.h> 47 48 #include "ring.h" 49 50 #include "defines.h" 51 #include "externs.h" 52 #include "fdset.h" 53 54 Ring netoring, netiring; 55 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ]; 56 57 /* 58 * Initialize internal network data structures. 59 */ 60 61 void 62 init_network(void) 63 { 64 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) { 65 exit(1); 66 } 67 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) { 68 exit(1); 69 } 70 NetTrace = stdout; 71 } 72 73 74 /* 75 * Check to see if any out-of-band data exists on a socket (for 76 * Telnet "synch" processing). 77 */ 78 79 int 80 stilloob(void) 81 { 82 static struct timeval timeout = { 0, 0 }; 83 fd_set excepts; 84 int value; 85 86 do { 87 FD_ZERO(&excepts); 88 FD_SET(net, &excepts); 89 value = select(net+1, NULL, NULL, &excepts, &timeout); 90 } while ((value == -1) && (errno == EINTR)); 91 92 if (value < 0) { 93 perror("select"); 94 (void) quit(); 95 /* NOTREACHED */ 96 } 97 if (FD_ISSET(net, &excepts)) { 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 int 128 netflush(void) 129 { 130 int n, n1; 131 132 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) { 133 if (!ring_at_mark(&netoring)) { 134 n = send(net, (char *)netoring.consume, n, 0); /* normal write */ 135 } else { 136 /* 137 * In 4.2 (and 4.3) systems, there is some question about 138 * what byte in a sendOOB operation is the "OOB" data. 139 * To make ourselves compatible, we only send ONE byte 140 * out of band, the one WE THINK should be OOB (though 141 * we really have more the TCP philosophy of urgent data 142 * rather than the Unix philosophy of OOB data). 143 */ 144 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */ 145 } 146 } 147 if (n < 0) { 148 if (errno != ENOBUFS && errno != EWOULDBLOCK) { 149 setcommandmode(); 150 perror(hostname); 151 (void)NetClose(net); 152 ring_clear_mark(&netoring); 153 longjmp(peerdied, -1); 154 /*NOTREACHED*/ 155 } 156 n = 0; 157 } 158 if (netdata && n) { 159 Dump('>', netoring.consume, n); 160 } 161 if (n) { 162 ring_consumed(&netoring, n); 163 /* 164 * If we sent all, and more to send, then recurse to pick 165 * up the other half. 166 */ 167 if ((n1 == n) && ring_full_consecutive(&netoring)) { 168 (void) netflush(); 169 } 170 return 1; 171 } else { 172 return 0; 173 } 174 } 175