1 #pragma ident	"%Z%%M%	%I%	%E% SMI"
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  * Copyright 1994-2002 Sun Microsystems, Inc.  All rights reserved.
36  * Use is subject to license terms.
37  */
38 
39 #ifndef lint
40 static char sccsid[] = "@(#)network.c	8.1 (Berkeley) 6/6/93";
41 #endif /* not lint */
42 
43 #include <sys/types.h>
44 #include <sys/socket.h>
45 #include <sys/time.h>
46 
47 #include <errno.h>
48 
49 #include <arpa/telnet.h>
50 
51 #include "ring.h"
52 
53 #include "defines.h"
54 #include "externs.h"
55 
56 Ring	netoring;
57 Ring	netiring;
58 static unsigned char netobuf[2*BUFSIZ];
59 static unsigned char netibuf[BUFSIZ];
60 
61 /*
62  * Initialize internal network data structures.
63  */
64 
65 void
66 init_network()
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 
83 int
84 stilloob()
85 {
86 	static struct timeval timeout = { 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, NULL, NULL, &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 
115 void
116 setneturg()
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 
131 
132 int
133 netflush()
134 {
135 	register int n, n1;
136 
137 	if (encrypt_output)
138 		ring_encrypt(&netoring, encrypt_output);
139 
140 	if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
141 		if (!ring_at_mark(&netoring)) {
142 			/* normal write */
143 			n = send(net, netoring.consume, n, 0);
144 		} else {
145 			/*
146 			 * In 4.2(and 4.3) systems, there is some question about
147 			 * what byte in a sendOOB operation is the "OOB" data.
148 			 * To make ourselves compatible, we only send ONE byte
149 			 * out of band, the one WE THINK should be OOB (though
150 			 * we really have more the TCP philosophy of urgent data
151 			 * rather than the Unix philosophy of OOB data).
152 			 */
153 			n = send(net, netoring.consume, 1, MSG_OOB);
154 		}
155 	}
156 	if (n < 0) {
157 		if (errno != ENOBUFS && errno != EWOULDBLOCK) {
158 			setcommandmode();
159 			perror(hostname);
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