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#if 0
35#ifndef lint
36static const char sccsid[] = "@(#)network.c	8.2 (Berkeley) 12/15/93";
37#endif
38#endif
39#include <sys/cdefs.h>
40__FBSDID("$FreeBSD: src/contrib/telnet/telnet/network.c,v 1.7 2003/05/04 02:54:48 obrien Exp $");
41
42#include <sys/types.h>
43#include <sys/socket.h>
44#include <sys/time.h>
45
46#include <errno.h>
47#include <stdlib.h>
48
49#include <arpa/telnet.h>
50#include <unistd.h>
51
52#include "ring.h"
53
54#include "defines.h"
55#include "externs.h"
56#include "fdset.h"
57
58Ring		netoring, netiring;
59unsigned char	netobuf[2*BUFSIZ], netibuf[BUFSIZ];
60
61/*
62 * Initialize internal network data structures.
63 */
64
65void
66init_network(void)
67{
68    if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
69	exit(1);
70    }
71    if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
72	exit(1);
73    }
74    NetTrace = stdout;
75}
76
77
78/*
79 * Check to see if any out-of-band data exists on a socket (for
80 * Telnet "synch" processing).
81 */
82
83int
84stilloob(void)
85{
86    static struct timeval timeout = { 0, 0 };
87    fd_set	excepts;
88    int value;
89
90    do {
91	FD_ZERO(&excepts);
92	FD_SET(net, &excepts);
93	value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
94    } while ((value == -1) && (errno == EINTR));
95
96    if (value < 0) {
97	perror("select");
98	(void) quit();
99	/* NOTREACHED */
100    }
101    if (FD_ISSET(net, &excepts)) {
102	return 1;
103    } else {
104	return 0;
105    }
106}
107
108
109/*
110 *  setneturg()
111 *
112 *	Sets "neturg" to the current location.
113 */
114
115void
116setneturg(void)
117{
118    ring_mark(&netoring);
119}
120
121
122/*
123 *  netflush
124 *		Send as much data as possible to the network,
125 *	handling requests for urgent data.
126 *
127 *		The return value indicates whether we did any
128 *	useful work.
129 */
130
131int
132netflush(void)
133{
134    int n, n1;
135
136#ifdef	ENCRYPTION
137    if (encrypt_output)
138	ring_encrypt(&netoring, encrypt_output);
139#endif	/* ENCRYPTION */
140    if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
141	if (!ring_at_mark(&netoring)) {
142	    n = send(net, (char *)netoring.consume, n, 0); /* normal write */
143	} else {
144	    /*
145	     * In 4.2 (and 4.3) systems, there is some question about
146	     * what byte in a sendOOB operation is the "OOB" data.
147	     * To make ourselves compatible, we only send ONE byte
148	     * out of band, the one WE THINK should be OOB (though
149	     * we really have more the TCP philosophy of urgent data
150	     * rather than the Unix philosophy of OOB data).
151	     */
152	    n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
153	}
154    }
155    if (n < 0) {
156	if (errno != ENOBUFS && errno != EWOULDBLOCK) {
157	    setcommandmode();
158	    perror(hostname);
159	    (void)NetClose(net);
160	    ring_clear_mark(&netoring);
161	    longjmp(peerdied, -1);
162	    /*NOTREACHED*/
163	}
164	n = 0;
165    }
166    if (netdata && n) {
167	Dump('>', netoring.consume, n);
168    }
169    if (n) {
170	ring_consumed(&netoring, n);
171	/*
172	 * If we sent all, and more to send, then recurse to pick
173	 * up the other half.
174	 */
175	if ((n1 == n) && ring_full_consecutive(&netoring)) {
176	    (void) netflush();
177	}
178	return 1;
179    } else {
180	return 0;
181    }
182}
183