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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
34  * Use is subject to license terms.
35  */
36 
37 #ifndef lint
38 static char sccsid[] = "@(#)network.c	8.1 (Berkeley) 6/6/93";
39 #endif /* not lint */
40 
41 #include <sys/types.h>
42 #include <sys/socket.h>
43 #include <sys/time.h>
44 
45 #include <errno.h>
46 
47 #include <arpa/telnet.h>
48 
49 #include "ring.h"
50 
51 #include "defines.h"
52 #include "externs.h"
53 
54 Ring	netoring;
55 Ring	netiring;
56 
57 /*
58  * Use large buffers to handle larger tickets when doing
59  * Kerberos authentication.  Microsoft generates large
60  * tickets that exceed the buffer size which causes authentication
61  * to fail.
62  */
63 static unsigned char netobuf[10*BUFSIZ];
64 static unsigned char netibuf[10*BUFSIZ];
65 
66 /*
67  * Initialize internal network data structures.
68  */
69 
70 void
init_network()71 init_network()
72 {
73 	if (ring_init(&netoring, netobuf, sizeof (netobuf)) != 1) {
74 		exit(1);
75 	}
76 	if (ring_init(&netiring, netibuf, sizeof (netibuf)) != 1) {
77 		exit(1);
78 	}
79 	NetTrace = stdout;
80 }
81 
82 
83 /*
84  * Check to see if any out-of-band data exists on a socket (for
85  * Telnet "synch" processing).
86  */
87 
88 int
stilloob()89 stilloob()
90 {
91 	static struct timeval timeout = { 0 };
92 	fd_set	excepts;
93 	int value;
94 
95 	do {
96 		FD_ZERO(&excepts);
97 		FD_SET(net, &excepts);
98 		value = select(net+1, NULL, NULL, &excepts, &timeout);
99 	} while ((value == -1) && (errno == EINTR));
100 
101 	if (value < 0) {
102 		perror("select");
103 		(void) quit();
104 		/* NOTREACHED */
105 	}
106 	if (FD_ISSET(net, &excepts)) {
107 		return (1);
108 	} else {
109 		return (0);
110 	}
111 }
112 
113 
114 /*
115  *  setneturg()
116  *
117  *	Sets "neturg" to the current location.
118  */
119 
120 void
setneturg()121 setneturg()
122 {
123 	ring_mark(&netoring);
124 }
125 
126 
127 /*
128  *  netflush
129  *		Send as much data as possible to the network,
130  *	handling requests for urgent data.
131  *
132  *		The return value indicates whether we did any
133  *	useful work.
134  */
135 
136 
137 int
netflush()138 netflush()
139 {
140 	register int n, n1;
141 
142 	if (encrypt_output)
143 		ring_encrypt(&netoring, encrypt_output);
144 
145 	if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
146 		if (!ring_at_mark(&netoring)) {
147 			/* normal write */
148 			n = send(net, netoring.consume, n, 0);
149 		} else {
150 			/*
151 			 * In 4.2(and 4.3) systems, there is some question about
152 			 * what byte in a sendOOB operation is the "OOB" data.
153 			 * To make ourselves compatible, we only send ONE byte
154 			 * out of band, the one WE THINK should be OOB (though
155 			 * we really have more the TCP philosophy of urgent data
156 			 * rather than the Unix philosophy of OOB data).
157 			 */
158 			n = send(net, netoring.consume, 1, MSG_OOB);
159 		}
160 	}
161 	if (n < 0) {
162 		if (errno != ENOBUFS && errno != EWOULDBLOCK) {
163 			setcommandmode();
164 			perror(hostname);
165 			ring_clear_mark(&netoring);
166 			longjmp(peerdied, -1);
167 			/*NOTREACHED*/
168 		}
169 		n = 0;
170 	}
171 	if (netdata && n) {
172 		Dump('>', netoring.consume, n);
173 	}
174 	if (n) {
175 		ring_consumed(&netoring, n);
176 		/*
177 		 * If we sent all, and more to send, then recurse to pick
178 		 * up the other half.
179 		 */
180 		if ((n1 == n) && ring_full_consecutive(&netoring)) {
181 			(void) netflush();
182 		}
183 		return (1);
184 	} else {
185 		return (0);
186 	}
187 }
188