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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if 0 31 #ifndef lint 32 static const char sccsid[] = "@(#)network.c 8.2 (Berkeley) 12/15/93"; 33 #endif 34 #endif 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 #include <sys/time.h> 41 42 #include <errno.h> 43 #include <stdlib.h> 44 45 #include <arpa/telnet.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, (fd_set *)0, (fd_set *)0, &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 #ifdef ENCRYPTION 133 if (encrypt_output) 134 ring_encrypt(&netoring, encrypt_output); 135 #endif /* ENCRYPTION */ 136 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) { 137 if (!ring_at_mark(&netoring)) { 138 n = send(net, (char *)netoring.consume, n, 0); /* normal write */ 139 } else { 140 /* 141 * In 4.2 (and 4.3) systems, there is some question about 142 * what byte in a sendOOB operation is the "OOB" data. 143 * To make ourselves compatible, we only send ONE byte 144 * out of band, the one WE THINK should be OOB (though 145 * we really have more the TCP philosophy of urgent data 146 * rather than the Unix philosophy of OOB data). 147 */ 148 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */ 149 } 150 } 151 if (n < 0) { 152 if (errno != ENOBUFS && errno != EWOULDBLOCK) { 153 setcommandmode(); 154 perror(hostname); 155 (void)NetClose(net); 156 ring_clear_mark(&netoring); 157 ExitString("Connection closed by foreign host.\n", 1); 158 /*NOTREACHED*/ 159 } 160 n = 0; 161 } 162 if (netdata && n) { 163 Dump('>', netoring.consume, n); 164 } 165 if (n) { 166 ring_consumed(&netoring, n); 167 /* 168 * If we sent all, and more to send, then recurse to pick 169 * up the other half. 170 */ 171 if ((n1 == n) && ring_full_consecutive(&netoring)) { 172 (void) netflush(); 173 } 174 return 1; 175 } else { 176 return 0; 177 } 178 } 179