1 /*
2 * Copyright (c) 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 */
7
8 #ifndef lint
9 static char sccsid[] = "@(#)network.c 8.2 (Berkeley) 12/15/93";
10 #endif /* not lint */
11
12 #include <sys/types.h>
13 #include <sys/socket.h>
14 #include <sys/time.h>
15
16 #include <errno.h>
17
18 #include <arpa/telnet.h>
19
20 #include "ring.h"
21
22 #include "defines.h"
23 #include "externs.h"
24 #include "fdset.h"
25
26 Ring netoring, netiring;
27 unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ];
28
29 /*
30 * Initialize internal network data structures.
31 */
32
33 void
init_network()34 init_network()
35 {
36 if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
37 exit(1);
38 }
39 if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
40 exit(1);
41 }
42 NetTrace = stdout;
43 }
44
45
46 /*
47 * Check to see if any out-of-band data exists on a socket (for
48 * Telnet "synch" processing).
49 */
50
51 int
stilloob()52 stilloob()
53 {
54 static struct timeval timeout = { 0 };
55 fd_set excepts;
56 int value;
57
58 do {
59 FD_ZERO(&excepts);
60 FD_SET(net, &excepts);
61 value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
62 } while ((value == -1) && (errno == EINTR));
63
64 if (value < 0) {
65 perror("select");
66 (void) quit();
67 /* NOTREACHED */
68 }
69 if (FD_ISSET(net, &excepts)) {
70 return 1;
71 } else {
72 return 0;
73 }
74 }
75
76
77 /*
78 * setneturg()
79 *
80 * Sets "neturg" to the current location.
81 */
82
83 void
setneturg()84 setneturg()
85 {
86 ring_mark(&netoring);
87 }
88
89
90 /*
91 * netflush
92 * Send as much data as possible to the network,
93 * handling requests for urgent data.
94 *
95 * The return value indicates whether we did any
96 * useful work.
97 */
98
99
100 int
netflush()101 netflush()
102 {
103 register int n, n1;
104
105 #ifdef ENCRYPTION
106 if (encrypt_output)
107 ring_encrypt(&netoring, encrypt_output);
108 #endif /* ENCRYPTION */
109 if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
110 if (!ring_at_mark(&netoring)) {
111 n = send(net, (char *)netoring.consume, n, 0); /* normal write */
112 } else {
113 /*
114 * In 4.2 (and 4.3) systems, there is some question about
115 * what byte in a sendOOB operation is the "OOB" data.
116 * To make ourselves compatible, we only send ONE byte
117 * out of band, the one WE THINK should be OOB (though
118 * we really have more the TCP philosophy of urgent data
119 * rather than the Unix philosophy of OOB data).
120 */
121 n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
122 }
123 }
124 if (n < 0) {
125 if (errno != ENOBUFS && errno != EWOULDBLOCK) {
126 setcommandmode();
127 perror(hostname);
128 (void)NetClose(net);
129 ring_clear_mark(&netoring);
130 longjmp(peerdied, -1);
131 /*NOTREACHED*/
132 }
133 n = 0;
134 }
135 if (netdata && n) {
136 Dump('>', netoring.consume, n);
137 }
138 if (n) {
139 ring_consumed(&netoring, n);
140 /*
141 * If we sent all, and more to send, then recurse to pick
142 * up the other half.
143 */
144 if ((n1 == n) && ring_full_consecutive(&netoring)) {
145 (void) netflush();
146 }
147 return 1;
148 } else {
149 return 0;
150 }
151 }
152