2 * Copyright (c) 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
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10 * 2. Redistributions in binary form must reproduce the above copyright
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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.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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32 static const char sccsid[] = "@(#)network.c 8.2 (Berkeley) 12/15/93";
36 #include <sys/types.h>
37 #include <sys/socket.h>
43 #include <arpa/telnet.h>
52 Ring netoring, netiring;
53 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ];
56 * Initialize internal network data structures.
62 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
65 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
73 * Check to see if any out-of-band data exists on a socket (for
74 * Telnet "synch" processing).
80 static struct timeval timeout = { 0, 0 };
86 FD_SET(net, &excepts);
87 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
88 } while ((value == -1) && (errno == EINTR));
95 if (FD_ISSET(net, &excepts)) {
106 * Sets "neturg" to the current location.
112 ring_mark(&netoring);
118 * Send as much data as possible to the network,
119 * handling requests for urgent data.
121 * The return value indicates whether we did any
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 */
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).
146 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
150 if (errno != ENOBUFS && errno != EWOULDBLOCK) {
154 ring_clear_mark(&netoring);
155 ExitString("Connection closed by foreign host.\n", 1);
161 Dump('>', netoring.consume, n);
164 ring_consumed(&netoring, n);
166 * If we sent all, and more to send, then recurse to pick
169 if ((n1 == n) && ring_full_consecutive(&netoring)) {