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 * @(#)network.c 8.2 (Berkeley) 12/15/93
30 * $FreeBSD: src/crypto/telnet/telnet/network.c,v 1.2.8.2 2002/04/13 10:59:08 markm Exp $
31 */
32
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <sys/time.h>
36
37 #include <errno.h>
38
39 #include <arpa/telnet.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42
43 #include "ring.h"
44
45 #include "defines.h"
46 #include "externs.h"
47 #include "fdset.h"
48
49 Ring netoring, netiring;
50 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ];
51
52 /*
53 * Initialize internal network data structures.
54 */
55
56 void
init_network(void)57 init_network(void)
58 {
59 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
60 exit(1);
61 }
62 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
63 exit(1);
64 }
65 NetTrace = stdout;
66 }
67
68
69 /*
70 * Check to see if any out-of-band data exists on a socket (for
71 * Telnet "synch" processing).
72 */
73
74 int
stilloob(void)75 stilloob(void)
76 {
77 static struct timeval timeout = { 0, 0 };
78 fd_set excepts;
79 int value;
80
81 do {
82 FD_ZERO(&excepts);
83 FD_SET(net, &excepts);
84 value = select(net+1, NULL, NULL, &excepts, &timeout);
85 } while ((value == -1) && (errno == EINTR));
86
87 if (value < 0) {
88 perror("select");
89 (void) quit();
90 /* NOTREACHED */
91 }
92 if (FD_ISSET(net, &excepts)) {
93 return 1;
94 } else {
95 return 0;
96 }
97 }
98
99
100 /*
101 * setneturg()
102 *
103 * Sets "neturg" to the current location.
104 */
105
106 void
setneturg(void)107 setneturg(void)
108 {
109 ring_mark(&netoring);
110 }
111
112
113 /*
114 * netflush
115 * Send as much data as possible to the network,
116 * handling requests for urgent data.
117 *
118 * The return value indicates whether we did any
119 * useful work.
120 */
121
122 int
netflush(void)123 netflush(void)
124 {
125 int n, n1;
126
127 #ifdef ENCRYPTION
128 if (encrypt_output)
129 ring_encrypt(&netoring, encrypt_output);
130 #endif /* ENCRYPTION */
131 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
132 if (!ring_at_mark(&netoring)) {
133 n = send(net, (char *)netoring.consume, n, 0); /* normal write */
134 } else {
135 /*
136 * In 4.2 (and 4.3) systems, there is some question about
137 * what byte in a sendOOB operation is the "OOB" data.
138 * To make ourselves compatible, we only send ONE byte
139 * out of band, the one WE THINK should be OOB (though
140 * we really have more the TCP philosophy of urgent data
141 * rather than the Unix philosophy of OOB data).
142 */
143 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
144 }
145 }
146 if (n < 0) {
147 if (errno != ENOBUFS && errno != EWOULDBLOCK) {
148 setcommandmode();
149 perror(hostname);
150 (void)NetClose(net);
151 ring_clear_mark(&netoring);
152 longjmp(peerdied, -1);
153 /*NOTREACHED*/
154 }
155 n = 0;
156 }
157 if (netdata && n) {
158 Dump('>', netoring.consume, n);
159 }
160 if (n) {
161 ring_consumed(&netoring, n);
162 /*
163 * If we sent all, and more to send, then recurse to pick
164 * up the other half.
165 */
166 if ((n1 == n) && ring_full_consecutive(&netoring)) {
167 (void) netflush();
168 }
169 return 1;
170 } else {
171 return 0;
172 }
173 }
174