xref: /netbsd/usr.bin/telnet/network.c (revision c4a72b64)
1 /*	$NetBSD: network.c,v 1.13 2002/09/23 12:48:04 mycroft Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)network.c	8.2 (Berkeley) 12/15/93";
40 #else
41 __RCSID("$NetBSD: network.c,v 1.13 2002/09/23 12:48:04 mycroft Exp $");
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <sys/socket.h>
47 #include <sys/time.h>
48 
49 #include <errno.h>
50 #include <unistd.h>
51 #include <poll.h>
52 
53 #include <arpa/telnet.h>
54 
55 #include "ring.h"
56 
57 #include "defines.h"
58 #include "externs.h"
59 #include "fdset.h"
60 
61 Ring		netoring, netiring;
62 unsigned char	netobuf[2*BUFSIZ], netibuf[BUFSIZ];
63 
64 /*
65  * Initialize internal network data structures.
66  */
67 
68     void
69 init_network()
70 {
71     if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
72 	exit(1);
73     }
74     if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
75 	exit(1);
76     }
77     NetTrace = stdout;
78 }
79 
80 
81 /*
82  * Check to see if any out-of-band data exists on a socket (for
83  * Telnet "synch" processing).
84  */
85 
86     int
87 stilloob()
88 {
89     struct pollfd set[1];
90     int value;
91 
92     set[0].fd = net;
93     set[0].events = POLLPRI;
94     do {
95 	value = poll(set, 1, 0);
96     } while ((value == -1) && (errno == EINTR));
97 
98     if (value < 0) {
99 	perror("poll");
100 	(void) quit(0, NULL);
101 	/* NOTREACHED */
102     }
103     if (set[0].revents & POLLPRI) {
104 	return 1;
105     } else {
106 	return 0;
107     }
108 }
109 
110 
111 /*
112  *  setneturg()
113  *
114  *	Sets "neturg" to the current location.
115  */
116 
117     void
118 setneturg()
119 {
120     ring_mark(&netoring);
121 }
122 
123 
124 /*
125  *  netflush
126  *		Send as much data as possible to the network,
127  *	handling requests for urgent data.
128  *
129  *		The return value indicates whether we did any
130  *	useful work.
131  */
132 
133 
134     int
135 netflush()
136 {
137     int n, n1;
138 
139 #ifdef	ENCRYPTION
140     if (encrypt_output)
141 	ring_encrypt(&netoring, encrypt_output);
142 #endif	/* ENCRYPTION */
143     if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
144 	if (!ring_at_mark(&netoring)) {
145 	    n = send(net, (char *)netoring.consume, n, 0); /* normal write */
146 	} else {
147 	    /*
148 	     * In 4.2 (and 4.3) systems, there is some question about
149 	     * what byte in a sendOOB operation is the "OOB" data.
150 	     * To make ourselves compatible, we only send ONE byte
151 	     * out of band, the one WE THINK should be OOB (though
152 	     * we really have more the TCP philosophy of urgent data
153 	     * rather than the Unix philosophy of OOB data).
154 	     */
155 	    n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
156 	}
157     }
158     if (n < 0) {
159 	if (errno != ENOBUFS && errno != EWOULDBLOCK) {
160 	    setcommandmode();
161 	    perror(hostname);
162 	    (void)NetClose(net);
163 	    ring_clear_mark(&netoring);
164 	    longjmp(peerdied, -1);
165 	    /*NOTREACHED*/
166 	}
167 	n = 0;
168     }
169     if (netdata && n) {
170 	Dump('>', netoring.consume, n);
171     }
172     if (n) {
173 	ring_consumed(&netoring, n);
174 	/*
175 	 * If we sent all, and more to send, then recurse to pick
176 	 * up the other half.
177 	 */
178 	if ((n1 == n) && ring_full_consecutive(&netoring)) {
179 	    (void) netflush();
180 	}
181 	return 1;
182     } else {
183 	return 0;
184     }
185 }
186