xref: /netbsd-src/usr.bin/telnet/terminal.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: terminal.c,v 1.14 2004/03/20 23:26:05 heas Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1990, 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)terminal.c	8.2 (Berkeley) 2/16/95";
36 #else
37 __RCSID("$NetBSD: terminal.c,v 1.14 2004/03/20 23:26:05 heas Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <arpa/telnet.h>
42 #include <sys/types.h>
43 
44 #include "ring.h"
45 
46 #include "externs.h"
47 #include "types.h"
48 
49 #ifdef ENCRYPTION
50 #include <libtelnet/encrypt.h>
51 #endif
52 
53 Ring		ttyoring, ttyiring;
54 unsigned char	ttyobuf[2*BUFSIZ], ttyibuf[BUFSIZ];
55 
56 int termdata;			/* Debugging flag */
57 
58 /*
59  * initialize the terminal data structures.
60  */
61 
62 void
63 init_terminal(void)
64 {
65     if (ring_init(&ttyoring, ttyobuf, sizeof ttyobuf) != 1) {
66 	exit(1);
67     }
68     if (ring_init(&ttyiring, ttyibuf, sizeof ttyibuf) != 1) {
69 	exit(1);
70     }
71     autoflush = TerminalAutoFlush();
72 }
73 
74 
75 /*
76  *		Send as much data as possible to the terminal, else exits if
77  *		it encounters a permanent failure when writing to the tty.
78  *
79  *		Return value:
80  *			-1: No useful work done, data waiting to go out.
81  *			 0: No data was waiting, so nothing was done.
82  *			 1: All waiting data was written out.
83  *			 n: All data - n was written out.
84  */
85 
86 
87 int
88 ttyflush(int drop)
89 {
90     int n, n0, n1;
91 
92     n0 = ring_full_count(&ttyoring);
93     if ((n1 = n = ring_full_consecutive(&ttyoring)) > 0) {
94 	if (drop) {
95 	    TerminalFlushOutput();
96 	    /* we leave 'n' alone! */
97 	} else {
98 	    n = TerminalWrite(ttyoring.consume, n);
99 	}
100     }
101     if (n > 0) {
102 	if (termdata && n) {
103 	    Dump('>', ttyoring.consume, n);
104 	}
105 	/*
106 	 * If we wrote everything, and the full count is
107 	 * larger than what we wrote, then write the
108 	 * rest of the buffer.
109 	 */
110 	if (n1 == n && n0 > n) {
111 		n1 = n0 - n;
112 		if (!drop)
113 			n1 = TerminalWrite(ttyoring.bottom, n1);
114 		if (n1 > 0)
115 			n += n1;
116 	}
117 	ring_consumed(&ttyoring, n);
118     }
119     if (n < 0) {
120 	if (errno == EAGAIN || errno == EINTR) {
121 	    return -1;
122 	} else {
123 	    ring_consumed(&ttyoring, ring_full_count(&ttyoring));
124 	    setconnmode(0);
125 	    setcommandmode();
126 	    NetClose(net);
127 	    fprintf(stderr, "Connection closed by foreign host.\n");
128 	    exit(1);
129 	}
130     }
131     if (n == n0) {
132 	if (n0)
133 	    return -1;
134 	return 0;
135     }
136     return n0 - n + 1;
137 }
138 
139 
140 /*
141  * These routines decides on what the mode should be (based on the values
142  * of various global variables).
143  */
144 
145 
146 int
147 getconnmode(void)
148 {
149     extern int linemode;
150     int mode = 0;
151 #ifdef	KLUDGELINEMODE
152     extern int kludgelinemode;
153 #endif
154 
155     if (In3270)
156 	return(MODE_FLOW);
157 
158     if (my_want_state_is_dont(TELOPT_ECHO))
159 	mode |= MODE_ECHO;
160 
161     if (localflow)
162 	mode |= MODE_FLOW;
163 
164     if (my_want_state_is_will(TELOPT_BINARY))
165 	mode |= MODE_INBIN;
166 
167     if (his_want_state_is_will(TELOPT_BINARY))
168 	mode |= MODE_OUTBIN;
169 
170 #ifdef	KLUDGELINEMODE
171     if (kludgelinemode) {
172 	if (my_want_state_is_dont(TELOPT_SGA)) {
173 	    mode |= (MODE_TRAPSIG|MODE_EDIT);
174 	    if (dontlecho && (clocks.echotoggle > clocks.modenegotiated)) {
175 		mode &= ~MODE_ECHO;
176 	    }
177 	}
178 	return(mode);
179     }
180 #endif
181     if (my_want_state_is_will(TELOPT_LINEMODE))
182 	mode |= linemode;
183     return(mode);
184 }
185 
186 void
187 setconnmode(int force)
188 {
189 #ifdef	ENCRYPTION
190     static int enc_passwd = 0;
191 #endif
192     int newmode;
193 
194     newmode = getconnmode()|(force?MODE_FORCE:0);
195 
196     TerminalNewMode(newmode);
197 
198 #ifdef	ENCRYPTION
199     if ((newmode & (MODE_ECHO|MODE_EDIT)) == MODE_EDIT) {
200 	if (my_want_state_is_will(TELOPT_ENCRYPT)
201 				&& (enc_passwd == 0) && !encrypt_output) {
202 	    encrypt_request_start(0, 0);
203 	    enc_passwd = 1;
204 	}
205     } else {
206 	if (enc_passwd) {
207 	    encrypt_request_end();
208 	    enc_passwd = 0;
209 	}
210     }
211 #endif	/* ENCRYPTION */
212 }
213 
214 
215 void
216 setcommandmode(void)
217 {
218     TerminalNewMode(-1);
219 }
220