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