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 __FBSDID("$FreeBSD: src/usr.bin/telnet/network.c,v 1.2.14.1 2002/04/13 11:07:13 markm Exp $"); 37 38 #ifndef lint 39 static const char sccsid[] = "@(#)network.c 8.2 (Berkeley) 12/15/93"; 40 #endif 41 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #include <sys/time.h> 45 46 #include <errno.h> 47 48 #include <arpa/telnet.h> 49 #include <unistd.h> 50 51 #include "ring.h" 52 53 #include "defines.h" 54 #include "externs.h" 55 #include "fdset.h" 56 57 Ring netoring, netiring; 58 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ]; 59 60 /* 61 * Initialize internal network data structures. 62 */ 63 64 void 65 init_network(void) 66 { 67 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) { 68 exit(1); 69 } 70 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) { 71 exit(1); 72 } 73 NetTrace = stdout; 74 } 75 76 77 /* 78 * Check to see if any out-of-band data exists on a socket (for 79 * Telnet "synch" processing). 80 */ 81 82 int 83 stilloob(void) 84 { 85 static struct timeval timeout = { 0, 0 }; 86 fd_set excepts; 87 int value; 88 89 do { 90 FD_ZERO(&excepts); 91 FD_SET(net, &excepts); 92 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout); 93 } while ((value == -1) && (errno == EINTR)); 94 95 if (value < 0) { 96 perror("select"); 97 (void) quit(); 98 /* NOTREACHED */ 99 } 100 if (FD_ISSET(net, &excepts)) { 101 return 1; 102 } else { 103 return 0; 104 } 105 } 106 107 108 /* 109 * setneturg() 110 * 111 * Sets "neturg" to the current location. 112 */ 113 114 void 115 setneturg(void) 116 { 117 ring_mark(&netoring); 118 } 119 120 121 /* 122 * netflush 123 * Send as much data as possible to the network, 124 * handling requests for urgent data. 125 * 126 * The return value indicates whether we did any 127 * useful work. 128 */ 129 130 int 131 netflush(void) 132 { 133 int n, n1; 134 135 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) { 136 if (!ring_at_mark(&netoring)) { 137 n = send(net, (char *)netoring.consume, n, 0); /* normal write */ 138 } else { 139 /* 140 * In 4.2 (and 4.3) systems, there is some question about 141 * what byte in a sendOOB operation is the "OOB" data. 142 * To make ourselves compatible, we only send ONE byte 143 * out of band, the one WE THINK should be OOB (though 144 * we really have more the TCP philosophy of urgent data 145 * rather than the Unix philosophy of OOB data). 146 */ 147 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */ 148 } 149 } 150 if (n < 0) { 151 if (errno != ENOBUFS && errno != EWOULDBLOCK) { 152 setcommandmode(); 153 perror(hostname); 154 (void)NetClose(net); 155 ring_clear_mark(&netoring); 156 longjmp(peerdied, -1); 157 /*NOTREACHED*/ 158 } 159 n = 0; 160 } 161 if (netdata && n) { 162 Dump('>', netoring.consume, n); 163 } 164 if (n) { 165 ring_consumed(&netoring, n); 166 /* 167 * If we sent all, and more to send, then recurse to pick 168 * up the other half. 169 */ 170 if ((n1 == n) && ring_full_consecutive(&netoring)) { 171 (void) netflush(); 172 } 173 return 1; 174 } else { 175 return 0; 176 } 177 } 178