network.c revision 1.6 
1/*	$NetBSD: network.c,v 1.6 1998/02/27 10:44:13 christos 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
39static char sccsid[] = "@(#)network.c	8.2 (Berkeley) 12/15/93";
40#else
41__RCSID("$NetBSD: network.c,v 1.6 1998/02/27 10:44:13 christos 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
52#include <arpa/telnet.h>
53
54#include "ring.h"
55
56#include "defines.h"
57#include "externs.h"
58#include "fdset.h"
59
60Ring		netoring, netiring;
61unsigned char	netobuf[2*BUFSIZ], netibuf[BUFSIZ];
62
63/*
64 * Initialize internal network data structures.
65 */
66
67    void
68init_network()
69{
70    if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
71	exit(1);
72    }
73    if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
74	exit(1);
75    }
76    NetTrace = stdout;
77}
78
79
80/*
81 * Check to see if any out-of-band data exists on a socket (for
82 * Telnet "synch" processing).
83 */
84
85    int
86stilloob()
87{
88    static struct timeval timeout = { 0 };
89    fd_set	excepts;
90    int value;
91
92    do {
93	FD_ZERO(&excepts);
94	FD_SET(net, &excepts);
95	value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
96    } while ((value == -1) && (errno == EINTR));
97
98    if (value < 0) {
99	perror("select");
100	(void) quit(0, NULL);
101	/* NOTREACHED */
102    }
103    if (FD_ISSET(net, &excepts)) {
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
118setneturg()
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
135netflush()
136{
137    register int n, n1;
138
139    if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
140	if (!ring_at_mark(&netoring)) {
141	    n = send(net, (char *)netoring.consume, n, 0); /* normal write */
142	} else {
143	    /*
144	     * In 4.2 (and 4.3) systems, there is some question about
145	     * what byte in a sendOOB operation is the "OOB" data.
146	     * To make ourselves compatible, we only send ONE byte
147	     * out of band, the one WE THINK should be OOB (though
148	     * we really have more the TCP philosophy of urgent data
149	     * rather than the Unix philosophy of OOB data).
150	     */
151	    n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
152	}
153    }
154    if (n < 0) {
155	if (errno != ENOBUFS && errno != EWOULDBLOCK) {
156	    setcommandmode();
157	    perror(hostname);
158	    (void)NetClose(net);
159	    ring_clear_mark(&netoring);
160	    longjmp(peerdied, -1);
161	    /*NOTREACHED*/
162	}
163	n = 0;
164    }
165    if (netdata && n) {
166	Dump('>', netoring.consume, n);
167    }
168    if (n) {
169	ring_consumed(&netoring, n);
170	/*
171	 * If we sent all, and more to send, then recurse to pick
172	 * up the other half.
173	 */
174	if ((n1 == n) && ring_full_consecutive(&netoring)) {
175	    (void) netflush();
176	}
177	return 1;
178    } else {
179	return 0;
180    }
181}
182