xref: /freebsd/contrib/telnet/telnet/terminal.c (revision b00ab754)
1 /*
2  * Copyright (c) 1988, 1990, 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 
34 #if 0
35 #ifndef lint
36 static const char sccsid[] = "@(#)terminal.c	8.2 (Berkeley) 2/16/95";
37 #endif
38 #endif
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include <arpa/telnet.h>
43 #include <sys/types.h>
44 
45 #include <stdlib.h>
46 
47 #include "ring.h"
48 
49 #include "externs.h"
50 #include "types.h"
51 
52 #ifdef	ENCRYPTION
53 #include <libtelnet/encrypt.h>
54 #endif
55 
56 Ring		ttyoring, ttyiring;
57 unsigned char	ttyobuf[2*BUFSIZ], ttyibuf[BUFSIZ];
58 
59 int termdata;			/* Debugging flag */
60 
61 #ifdef	USE_TERMIO
62 # ifndef VDISCARD
63 cc_t termFlushChar;
64 # endif
65 # ifndef VLNEXT
66 cc_t termLiteralNextChar;
67 # endif
68 # ifndef VSUSP
69 cc_t termSuspChar;
70 # endif
71 # ifndef VWERASE
72 cc_t termWerasChar;
73 # endif
74 # ifndef VREPRINT
75 cc_t termRprntChar;
76 # endif
77 # ifndef VSTART
78 cc_t termStartChar;
79 # endif
80 # ifndef VSTOP
81 cc_t termStopChar;
82 # endif
83 # ifndef VEOL
84 cc_t termForw1Char;
85 # endif
86 # ifndef VEOL2
87 cc_t termForw2Char;
88 # endif
89 # ifndef VSTATUS
90 cc_t termAytChar;
91 # endif
92 #else
93 cc_t termForw2Char;
94 cc_t termAytChar;
95 #endif
96 
97 /*
98  * initialize the terminal data structures.
99  */
100 
101 void
102 init_terminal(void)
103 {
104     if (ring_init(&ttyoring, ttyobuf, sizeof ttyobuf) != 1) {
105 	exit(1);
106     }
107     if (ring_init(&ttyiring, ttyibuf, sizeof ttyibuf) != 1) {
108 	exit(1);
109     }
110     autoflush = TerminalAutoFlush();
111 }
112 
113 /*
114  *		Send as much data as possible to the terminal, else exits if
115  *		it encounters a permanent failure when writing to the tty.
116  *
117  *		Return value:
118  *			-1: No useful work done, data waiting to go out.
119  *			 0: No data was waiting, so nothing was done.
120  *			 1: All waiting data was written out.
121  *			 n: All data - n was written out.
122  */
123 
124 int
125 ttyflush(int drop)
126 {
127     int n, n0, n1;
128 
129     n0 = ring_full_count(&ttyoring);
130     if ((n1 = n = ring_full_consecutive(&ttyoring)) > 0) {
131 	if (drop) {
132 	    TerminalFlushOutput();
133 	    /* we leave 'n' alone! */
134 	} else {
135 	    n = TerminalWrite(ttyoring.consume, n);
136 	}
137     }
138     if (n > 0) {
139 	if (termdata && n) {
140 	    Dump('>', ttyoring.consume, n);
141 	}
142 	/*
143 	 * If we wrote everything, and the full count is
144 	 * larger than what we wrote, then write the
145 	 * rest of the buffer.
146 	 */
147 	if (n1 == n && n0 > n) {
148 		n1 = n0 - n;
149 		if (!drop)
150 			n1 = TerminalWrite(ttyoring.bottom, n1);
151 		if (n1 > 0)
152 			n += n1;
153 	}
154 	ring_consumed(&ttyoring, n);
155     }
156     if (n < 0) {
157 	if (errno == EAGAIN || errno == EINTR) {
158 	    return -1;
159 	} else {
160 	    ring_consumed(&ttyoring, ring_full_count(&ttyoring));
161 	    setconnmode(0);
162 	    setcommandmode();
163 	    NetClose(net);
164 	    fprintf(stderr, "Write error on local output.\n");
165 	    exit(1);
166 	}
167 	return -1;
168     }
169     if (n == n0) {
170 	if (n0)
171 	    return -1;
172 	return 0;
173     }
174     return n0 - n + 1;
175 }
176 
177 
178 /*
179  * These routines decides on what the mode should be (based on the values
180  * of various global variables).
181  */
182 
183 
184 int
185 getconnmode(void)
186 {
187     extern int linemode;
188     int mode = 0;
189 #ifdef	KLUDGELINEMODE
190     extern int kludgelinemode;
191 #endif
192 
193     if (my_want_state_is_dont(TELOPT_ECHO))
194 	mode |= MODE_ECHO;
195 
196     if (localflow)
197 	mode |= MODE_FLOW;
198 
199     if (my_want_state_is_will(TELOPT_BINARY))
200 	mode |= MODE_INBIN;
201 
202     if (his_want_state_is_will(TELOPT_BINARY))
203 	mode |= MODE_OUTBIN;
204 
205 #ifdef	KLUDGELINEMODE
206     if (kludgelinemode) {
207 	if (my_want_state_is_dont(TELOPT_SGA)) {
208 	    mode |= (MODE_TRAPSIG|MODE_EDIT);
209 	    if (dontlecho && (clocks.echotoggle > clocks.modenegotiated)) {
210 		mode &= ~MODE_ECHO;
211 	    }
212 	}
213 	return(mode);
214     }
215 #endif
216     if (my_want_state_is_will(TELOPT_LINEMODE))
217 	mode |= linemode;
218     return(mode);
219 }
220 
221 void
222 setconnmode(int force)
223 {
224 #ifdef	ENCRYPTION
225     static int enc_passwd = 0;
226 #endif	/* ENCRYPTION */
227     int newmode;
228 
229     newmode = getconnmode()|(force?MODE_FORCE:0);
230 
231     TerminalNewMode(newmode);
232 
233 #ifdef  ENCRYPTION
234     if ((newmode & (MODE_ECHO|MODE_EDIT)) == MODE_EDIT) {
235 	if (my_want_state_is_will(TELOPT_ENCRYPT)
236 				&& (enc_passwd == 0) && !encrypt_output) {
237 	    encrypt_request_start(0, 0);
238 	    enc_passwd = 1;
239 	}
240     } else {
241 	if (enc_passwd) {
242 	    encrypt_request_end();
243 	    enc_passwd = 0;
244 	}
245     }
246 #endif	/* ENCRYPTION */
247 
248 }
249 
250 void
251 setcommandmode(void)
252 {
253     TerminalNewMode(-1);
254 }
255