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#include "telnet_locl.h"
35
36RCSID("$Id$");
37
38Ring		netoring, netiring;
39size_t		netobufsize = 64*1024;
40size_t		netibufsize = 64*1024;
41
42/*
43 * Initialize internal network data structures.
44 */
45
46void
47init_network(void)
48{
49    void *obuf, *ibuf;
50
51    if ((obuf = malloc(netobufsize)) == NULL)
52	exit(1);
53    if ((ibuf = malloc(netibufsize)) == NULL)
54	exit(1);
55
56    if (ring_init(&netoring, obuf, netobufsize) != 1) {
57	exit(1);
58    }
59    if (ring_init(&netiring, ibuf, netibufsize) != 1) {
60	exit(1);
61    }
62    NetTrace = stdout;
63}
64
65
66/*
67 * Check to see if any out-of-band data exists on a socket (for
68 * Telnet "synch" processing).
69 */
70
71int
72stilloob(void)
73{
74    static struct timeval timeout = { 0 };
75    fd_set	excepts;
76    int value;
77
78    do {
79	FD_ZERO(&excepts);
80	if (net >= FD_SETSIZE)
81	    errx (1, "fd too large");
82	FD_SET(net, &excepts);
83	value = select(net+1, 0, 0, &excepts, &timeout);
84    } while ((value == -1) && (errno == EINTR));
85
86    if (value < 0) {
87	perror("select");
88	quit();
89	/* NOTREACHED */
90    }
91    if (FD_ISSET(net, &excepts)) {
92	return 1;
93    } else {
94	return 0;
95    }
96}
97
98
99/*
100 *  setneturg()
101 *
102 *	Sets "neturg" to the current location.
103 */
104
105void
106setneturg(void)
107{
108    ring_mark(&netoring);
109}
110
111
112/*
113 *  netflush
114 *		Send as much data as possible to the network,
115 *	handling requests for urgent data.
116 *
117 *		The return value indicates whether we did any
118 *	useful work.
119 */
120
121
122int
123netflush(void)
124{
125    int n, n1;
126
127#if	defined(ENCRYPTION)
128    if (encrypt_output)
129	ring_encrypt(&netoring, encrypt_output);
130#endif
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	    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	    netflush();
168	}
169	return 1;
170    } else {
171	return 0;
172    }
173}
174