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
init_network(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
stilloob(void)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
setneturg(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
netflush(void)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