1 /*
2 * Copyright (c) 1988 Regents of the University of California.
3 * 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 static char sccsid[] = "@(#)network.c 5.2 (Berkeley) 3/1/91";
36 #endif /* not lint */
37
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/time.h>
41
42 #include <errno.h>
43
44 #include <arpa/telnet.h>
45
46 #include "ring.h"
47
48 #include "defines.h"
49 #include "externs.h"
50 #include "fdset.h"
51
52 Ring netoring, netiring;
53 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ];
54
55 /*
56 * Initialize internal network data structures.
57 */
58
59 void
init_network()60 init_network()
61 {
62 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
63 exit(1);
64 }
65 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
66 exit(1);
67 }
68 NetTrace = stdout;
69 }
70
71
72 /*
73 * Check to see if any out-of-band data exists on a socket (for
74 * Telnet "synch" processing).
75 */
76
77 int
stilloob()78 stilloob()
79 {
80 static struct timeval timeout = { 0 };
81 fd_set excepts;
82 int value;
83
84 do {
85 FD_ZERO(&excepts);
86 FD_SET(net, &excepts);
87 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
88 } while ((value == -1) && (errno == EINTR));
89
90 if (value < 0) {
91 perror("select");
92 (void) quit();
93 /* NOTREACHED */
94 }
95 if (FD_ISSET(net, &excepts)) {
96 return 1;
97 } else {
98 return 0;
99 }
100 }
101
102
103 /*
104 * setneturg()
105 *
106 * Sets "neturg" to the current location.
107 */
108
109 void
setneturg()110 setneturg()
111 {
112 ring_mark(&netoring);
113 }
114
115
116 /*
117 * netflush
118 * Send as much data as possible to the network,
119 * handling requests for urgent data.
120 *
121 * The return value indicates whether we did any
122 * useful work.
123 */
124
125
126 int
netflush()127 netflush()
128 {
129 register int n, n1;
130
131 #if defined(ENCRYPT)
132 if (encrypt_output)
133 ring_encrypt(&netoring, encrypt_output);
134 #endif
135 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
136 if (!ring_at_mark(&netoring)) {
137 n = send(net, netoring.consume, n, 0); /* normal write */
138 } else {
139 /*
140 * In 4.2 (and 4.3) systems, there is some question about
141 * what byte in a sendOOB operation is the "OOB" data.
142 * To make ourselves compatible, we only send ONE byte
143 * out of band, the one WE THINK should be OOB (though
144 * we really have more the TCP philosophy of urgent data
145 * rather than the Unix philosophy of OOB data).
146 */
147 n = send(net, netoring.consume, 1, MSG_OOB);/* URGENT data */
148 }
149 }
150 if (n < 0) {
151 if (errno != ENOBUFS && errno != EWOULDBLOCK) {
152 setcommandmode();
153 perror(hostname);
154 (void)NetClose(net);
155 ring_clear_mark(&netoring);
156 longjmp(peerdied, -1);
157 /*NOTREACHED*/
158 }
159 n = 0;
160 }
161 if (netdata && n) {
162 Dump('>', netoring.consume, n);
163 }
164 if (n) {
165 ring_consumed(&netoring, n);
166 /*
167 * If we sent all, and more to send, then recurse to pick
168 * up the other half.
169 */
170 if ((n1 == n) && ring_full_consecutive(&netoring)) {
171 (void) netflush();
172 }
173 return 1;
174 } else {
175 return 0;
176 }
177 }
178