1 /* $OpenBSD: network.c,v 1.17 2014/07/22 07:30:24 jsg Exp $ */ 2 /* $NetBSD: network.c,v 1.5 1996/02/28 21:04:06 thorpej Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include "telnet_locl.h" 34 35 #include <sys/socket.h> 36 #include <errno.h> 37 #include <poll.h> 38 #include <unistd.h> 39 40 Ring netoring, netiring; 41 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ]; 42 43 /* 44 * Initialize internal network data structures. 45 */ 46 47 void 48 init_network(void) 49 { 50 ring_init(&netoring, netobuf, sizeof netobuf); 51 ring_init(&netiring, netibuf, sizeof netibuf); 52 SetNetTrace(NULL); 53 } 54 55 56 /* 57 * Check to see if any out-of-band data exists on a socket (for 58 * Telnet "synch" processing). 59 */ 60 61 int 62 stilloob(void) 63 { 64 struct pollfd pfd[1]; 65 int value; 66 67 do { 68 pfd[0].fd = net; 69 pfd[0].events = POLLRDBAND; 70 value = poll(pfd, 1, 0); 71 } while ((value == -1) && (errno == EINTR)); 72 73 if (value < 0) { 74 perror("poll"); 75 quit(); 76 } 77 if (pfd[0].revents & POLLRDBAND) 78 return 1; 79 else 80 return 0; 81 } 82 83 /* 84 * setneturg() 85 * 86 * Sets "neturg" to the current location. 87 */ 88 89 void 90 setneturg(void) 91 { 92 ring_mark(&netoring); 93 } 94 95 /* 96 * netflush 97 * Send as much data as possible to the network, 98 * handling requests for urgent data. 99 * 100 * The return value indicates whether we did any 101 * useful work. 102 */ 103 104 int 105 netflush(void) 106 { 107 int n, n1; 108 109 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) { 110 if (!ring_at_mark(&netoring)) { 111 n = send(net, (char *)netoring.consume, n, 0); /* normal write */ 112 } else { 113 /* 114 * In 4.2 (and 4.3) systems, there is some question about 115 * what byte in a sendOOB operation is the "OOB" data. 116 * To make ourselves compatible, we only send ONE byte 117 * out of band, the one WE THINK should be OOB (though 118 * we really have more the TCP philosophy of urgent data 119 * rather than the Unix philosophy of OOB data). 120 */ 121 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */ 122 } 123 } 124 if (n < 0) { 125 if (errno != ENOBUFS && errno != EWOULDBLOCK) { 126 setcommandmode(); 127 perror(hostname); 128 (void)close(net); 129 ring_clear_mark(&netoring); 130 longjmp(peerdied, -1); 131 } 132 n = 0; 133 } 134 if (netdata && n) { 135 Dump('>', netoring.consume, n); 136 } 137 if (n) { 138 ring_consumed(&netoring, n); 139 /* 140 * If we sent all, and more to send, then recurse to pick 141 * up the other half. 142 */ 143 if ((n1 == n) && ring_full_consecutive(&netoring)) { 144 (void) netflush(); 145 } 146 return 1; 147 } else { 148 return 0; 149 } 150 } 151