xref: /freebsd/contrib/telnet/telnet/terminal.c (revision e17f5b1d)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static const char sccsid[] = "@(#)terminal.c	8.2 (Berkeley) 2/16/95";
33 #endif
34 #endif
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <arpa/telnet.h>
39 #include <sys/types.h>
40 
41 #include <stdlib.h>
42 
43 #include "ring.h"
44 
45 #include "externs.h"
46 #include "types.h"
47 
48 #ifdef	ENCRYPTION
49 #include <libtelnet/encrypt.h>
50 #endif
51 
52 Ring		ttyoring, ttyiring;
53 unsigned char	ttyobuf[2*BUFSIZ], ttyibuf[BUFSIZ];
54 
55 int termdata;			/* Debugging flag */
56 
57 #ifdef	USE_TERMIO
58 # ifndef VDISCARD
59 cc_t termFlushChar;
60 # endif
61 # ifndef VLNEXT
62 cc_t termLiteralNextChar;
63 # endif
64 # ifndef VSUSP
65 cc_t termSuspChar;
66 # endif
67 # ifndef VWERASE
68 cc_t termWerasChar;
69 # endif
70 # ifndef VREPRINT
71 cc_t termRprntChar;
72 # endif
73 # ifndef VSTART
74 cc_t termStartChar;
75 # endif
76 # ifndef VSTOP
77 cc_t termStopChar;
78 # endif
79 # ifndef VEOL
80 cc_t termForw1Char;
81 # endif
82 # ifndef VEOL2
83 cc_t termForw2Char;
84 # endif
85 # ifndef VSTATUS
86 cc_t termAytChar;
87 # endif
88 #else
89 cc_t termForw2Char;
90 cc_t termAytChar;
91 #endif
92 
93 /*
94  * initialize the terminal data structures.
95  */
96 
97 void
98 init_terminal(void)
99 {
100     if (ring_init(&ttyoring, ttyobuf, sizeof ttyobuf) != 1) {
101 	exit(1);
102     }
103     if (ring_init(&ttyiring, ttyibuf, sizeof ttyibuf) != 1) {
104 	exit(1);
105     }
106     autoflush = TerminalAutoFlush();
107 }
108 
109 /*
110  *		Send as much data as possible to the terminal, else exits if
111  *		it encounters a permanent failure when writing to the tty.
112  *
113  *		Return value:
114  *			-1: No useful work done, data waiting to go out.
115  *			 0: No data was waiting, so nothing was done.
116  *			 1: All waiting data was written out.
117  *			 n: All data - n was written out.
118  */
119 
120 int
121 ttyflush(int drop)
122 {
123     int n, n0, n1;
124 
125     n0 = ring_full_count(&ttyoring);
126     if ((n1 = n = ring_full_consecutive(&ttyoring)) > 0) {
127 	if (drop) {
128 	    TerminalFlushOutput();
129 	    /* we leave 'n' alone! */
130 	} else {
131 	    n = TerminalWrite(ttyoring.consume, n);
132 	}
133     }
134     if (n > 0) {
135 	if (termdata && n) {
136 	    Dump('>', ttyoring.consume, n);
137 	}
138 	/*
139 	 * If we wrote everything, and the full count is
140 	 * larger than what we wrote, then write the
141 	 * rest of the buffer.
142 	 */
143 	if (n1 == n && n0 > n) {
144 		n1 = n0 - n;
145 		if (!drop)
146 			n1 = TerminalWrite(ttyoring.bottom, n1);
147 		if (n1 > 0)
148 			n += n1;
149 	}
150 	ring_consumed(&ttyoring, n);
151     }
152     if (n < 0) {
153 	if (errno == EAGAIN || errno == EINTR) {
154 	    return -1;
155 	} else {
156 	    ring_consumed(&ttyoring, ring_full_count(&ttyoring));
157 	    setconnmode(0);
158 	    setcommandmode();
159 	    NetClose(net);
160 	    fprintf(stderr, "Write error on local output.\n");
161 	    exit(1);
162 	}
163 	return -1;
164     }
165     if (n == n0) {
166 	if (n0)
167 	    return -1;
168 	return 0;
169     }
170     return n0 - n + 1;
171 }
172 
173 
174 /*
175  * These routines decides on what the mode should be (based on the values
176  * of various global variables).
177  */
178 
179 
180 int
181 getconnmode(void)
182 {
183     extern int linemode;
184     int mode = 0;
185 #ifdef	KLUDGELINEMODE
186     extern int kludgelinemode;
187 #endif
188 
189     if (my_want_state_is_dont(TELOPT_ECHO))
190 	mode |= MODE_ECHO;
191 
192     if (localflow)
193 	mode |= MODE_FLOW;
194 
195     if (my_want_state_is_will(TELOPT_BINARY))
196 	mode |= MODE_INBIN;
197 
198     if (his_want_state_is_will(TELOPT_BINARY))
199 	mode |= MODE_OUTBIN;
200 
201 #ifdef	KLUDGELINEMODE
202     if (kludgelinemode) {
203 	if (my_want_state_is_dont(TELOPT_SGA)) {
204 	    mode |= (MODE_TRAPSIG|MODE_EDIT);
205 	    if (dontlecho && (clocks.echotoggle > clocks.modenegotiated)) {
206 		mode &= ~MODE_ECHO;
207 	    }
208 	}
209 	return(mode);
210     }
211 #endif
212     if (my_want_state_is_will(TELOPT_LINEMODE))
213 	mode |= linemode;
214     return(mode);
215 }
216 
217 void
218 setconnmode(int force)
219 {
220 #ifdef	ENCRYPTION
221     static int enc_passwd = 0;
222 #endif	/* ENCRYPTION */
223     int newmode;
224 
225     newmode = getconnmode()|(force?MODE_FORCE:0);
226 
227     TerminalNewMode(newmode);
228 
229 #ifdef  ENCRYPTION
230     if ((newmode & (MODE_ECHO|MODE_EDIT)) == MODE_EDIT) {
231 	if (my_want_state_is_will(TELOPT_ENCRYPT)
232 				&& (enc_passwd == 0) && !encrypt_output) {
233 	    encrypt_request_start(0, 0);
234 	    enc_passwd = 1;
235 	}
236     } else {
237 	if (enc_passwd) {
238 	    encrypt_request_end();
239 	    enc_passwd = 0;
240 	}
241     }
242 #endif	/* ENCRYPTION */
243 
244 }
245 
246 void
247 setcommandmode(void)
248 {
249     TerminalNewMode(-1);
250 }
251