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 /* based on @(#)network.c 8.1 (Berkeley) 6/6/93 */
35
36 #include <autoconf.h>
37
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/time.h>
41
42 #ifdef HAVE_SYS_SELECT_H
43 #include <sys/select.h>
44 #endif
45
46 #include <errno.h>
47
48 #include <arpa/telnet.h>
49
50 #include "ring.h"
51
52 #include "defines.h"
53 #include "externs.h"
54 #include "fdset.h"
55
56 Ring netoring, netiring;
57 unsigned char netobuf[2*TELNET_BUFSIZE], netibuf[TELNET_BUFSIZE];
58
59 /*
60 * Initialize internal network data structures.
61 */
62
63 void
init_network()64 init_network()
65 {
66 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
67 exit(1);
68 }
69 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
70 exit(1);
71 }
72 NetTrace = stdout;
73 }
74
75
76 /*
77 * Check to see if any out-of-band data exists on a socket (for
78 * Telnet "synch" processing).
79 */
80
81 int
stilloob()82 stilloob()
83 {
84 static struct timeval timeout = { 0 };
85 fd_set excepts;
86 int value;
87
88 do {
89 FD_ZERO(&excepts);
90 FD_SET(net, &excepts);
91 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
92 } while ((value == -1) && (errno == EINTR));
93
94 if (value < 0) {
95 perror("select");
96 (void) quit(0, NULL);
97 /* NOTREACHED */
98 }
99 if (FD_ISSET(net, &excepts)) {
100 return 1;
101 } else {
102 return 0;
103 }
104 }
105
106
107 /*
108 * setneturg()
109 *
110 * Sets "neturg" to the current location.
111 */
112
113 void
setneturg()114 setneturg()
115 {
116 ring_mark(&netoring);
117 }
118
119
120 /*
121 * netflush
122 * Send as much data as possible to the network,
123 * handling requests for urgent data.
124 *
125 * The return value indicates whether we did any
126 * useful work.
127 */
128
129
130 int
netflush()131 netflush()
132 {
133 register int n, n1;
134
135 #ifdef ENCRYPTION
136 if (encrypt_output)
137 ring_encrypt(&netoring, encrypt_output);
138 #endif /* ENCRYPTION */
139 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
140 if (!ring_at_mark(&netoring)) {
141 n = send(net, (char *)netoring.consume, n, 0); /* normal write */
142 } else {
143 /*
144 * In 4.2 (and 4.3) systems, there is some question about
145 * what byte in a sendOOB operation is the "OOB" data.
146 * To make ourselves compatible, we only send ONE byte
147 * out of band, the one WE THINK should be OOB (though
148 * we really have more the TCP philosophy of urgent data
149 * rather than the Unix philosophy of OOB data).
150 */
151 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
152 }
153 }
154 if (n < 0) {
155 if (errno != ENOBUFS && errno != EWOULDBLOCK) {
156 setcommandmode();
157 perror(hostname);
158 (void)NetClose(net);
159 ring_clear_mark(&netoring);
160 longjmp(peerdied, -1);
161 /*NOTREACHED*/
162 }
163 n = 0;
164 }
165 if (netdata && n) {
166 Dump('>', netoring.consume, n);
167 }
168 if (n) {
169 ring_consumed(&netoring, n);
170 /*
171 * If we sent all, and more to send, then recurse to pick
172 * up the other half.
173 */
174 if ((n1 == n) && ring_full_consecutive(&netoring)) {
175 (void) netflush();
176 }
177 return 1;
178 } else {
179 return 0;
180 }
181 }
182