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 #if 0 35 #ifndef lint 36 static const char sccsid[] = "@(#)network.c 8.2 (Berkeley) 12/15/93"; 37 #endif 38 #endif 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #include <sys/time.h> 45 46 #include <errno.h> 47 #include <stdlib.h> 48 49 #include <arpa/telnet.h> 50 #include <unistd.h> 51 52 #include "ring.h" 53 54 #include "defines.h" 55 #include "externs.h" 56 #include "fdset.h" 57 58 Ring netoring, netiring; 59 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ]; 60 61 /* 62 * Initialize internal network data structures. 63 */ 64 65 void 66 init_network(void) 67 { 68 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) { 69 exit(1); 70 } 71 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) { 72 exit(1); 73 } 74 NetTrace = stdout; 75 } 76 77 78 /* 79 * Check to see if any out-of-band data exists on a socket (for 80 * Telnet "synch" processing). 81 */ 82 83 int 84 stilloob(void) 85 { 86 static struct timeval timeout = { 0, 0 }; 87 fd_set excepts; 88 int value; 89 90 do { 91 FD_ZERO(&excepts); 92 FD_SET(net, &excepts); 93 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout); 94 } while ((value == -1) && (errno == EINTR)); 95 96 if (value < 0) { 97 perror("select"); 98 (void) quit(); 99 /* NOTREACHED */ 100 } 101 if (FD_ISSET(net, &excepts)) { 102 return 1; 103 } else { 104 return 0; 105 } 106 } 107 108 109 /* 110 * setneturg() 111 * 112 * Sets "neturg" to the current location. 113 */ 114 115 void 116 setneturg(void) 117 { 118 ring_mark(&netoring); 119 } 120 121 122 /* 123 * netflush 124 * Send as much data as possible to the network, 125 * handling requests for urgent data. 126 * 127 * The return value indicates whether we did any 128 * useful work. 129 */ 130 131 int 132 netflush(void) 133 { 134 int n, n1; 135 136 #ifdef ENCRYPTION 137 if (encrypt_output) 138 ring_encrypt(&netoring, encrypt_output); 139 #endif /* ENCRYPTION */ 140 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) { 141 if (!ring_at_mark(&netoring)) { 142 n = send(net, (char *)netoring.consume, n, 0); /* normal write */ 143 } else { 144 /* 145 * In 4.2 (and 4.3) systems, there is some question about 146 * what byte in a sendOOB operation is the "OOB" data. 147 * To make ourselves compatible, we only send ONE byte 148 * out of band, the one WE THINK should be OOB (though 149 * we really have more the TCP philosophy of urgent data 150 * rather than the Unix philosophy of OOB data). 151 */ 152 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */ 153 } 154 } 155 if (n < 0) { 156 if (errno != ENOBUFS && errno != EWOULDBLOCK) { 157 setcommandmode(); 158 perror(hostname); 159 (void)NetClose(net); 160 ring_clear_mark(&netoring); 161 ExitString("Connection closed by foreign host.\n", 1); 162 /*NOTREACHED*/ 163 } 164 n = 0; 165 } 166 if (netdata && n) { 167 Dump('>', netoring.consume, n); 168 } 169 if (n) { 170 ring_consumed(&netoring, n); 171 /* 172 * If we sent all, and more to send, then recurse to pick 173 * up the other half. 174 */ 175 if ((n1 == n) && ring_full_consecutive(&netoring)) { 176 (void) netflush(); 177 } 178 return 1; 179 } else { 180 return 0; 181 } 182 } 183