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 #ifndef lint 35 /* from: static char sccsid[] = "@(#)network.c 8.1 (Berkeley) 6/6/93"; */ 36 static char *rcsid = "$Id: network.c,v 1.3 1994/02/25 03:00:31 cgd Exp $"; 37 #endif /* not lint */ 38 39 #include <sys/types.h> 40 #include <sys/socket.h> 41 #include <sys/time.h> 42 43 #include <errno.h> 44 45 #include <arpa/telnet.h> 46 47 #include "ring.h" 48 49 #include "defines.h" 50 #include "externs.h" 51 #include "fdset.h" 52 53 Ring netoring, netiring; 54 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ]; 55 56 /* 57 * Initialize internal network data structures. 58 */ 59 60 void 61 init_network() 62 { 63 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) { 64 exit(1); 65 } 66 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) { 67 exit(1); 68 } 69 NetTrace = stdout; 70 } 71 72 73 /* 74 * Check to see if any out-of-band data exists on a socket (for 75 * Telnet "synch" processing). 76 */ 77 78 int 79 stilloob() 80 { 81 static struct timeval timeout = { 0 }; 82 fd_set excepts; 83 int value; 84 85 do { 86 FD_ZERO(&excepts); 87 FD_SET(net, &excepts); 88 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout); 89 } while ((value == -1) && (errno == EINTR)); 90 91 if (value < 0) { 92 perror("select"); 93 (void) quit(); 94 /* NOTREACHED */ 95 } 96 if (FD_ISSET(net, &excepts)) { 97 return 1; 98 } else { 99 return 0; 100 } 101 } 102 103 104 /* 105 * setneturg() 106 * 107 * Sets "neturg" to the current location. 108 */ 109 110 void 111 setneturg() 112 { 113 ring_mark(&netoring); 114 } 115 116 117 /* 118 * netflush 119 * Send as much data as possible to the network, 120 * handling requests for urgent data. 121 * 122 * The return value indicates whether we did any 123 * useful work. 124 */ 125 126 127 int 128 netflush() 129 { 130 register 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