xref: /netbsd/usr.bin/telnet/terminal.c (revision dfc96eaf)
1 /*	$NetBSD: terminal.c,v 1.16 2018/12/14 06:08:18 maya 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 1.16 2018/12/14 06:08:18 maya 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 char line[] = { '\0' };
56 
57 int termdata;			/* Debugging flag */
58 
59 /*
60  * initialize the terminal data structures.
61  */
62 
63 void
init_terminal(void)64 init_terminal(void)
65 {
66     if (ring_init(&ttyoring, ttyobuf, sizeof ttyobuf) != 1) {
67 	exit(1);
68     }
69     if (ring_init(&ttyiring, ttyibuf, sizeof ttyibuf) != 1) {
70 	exit(1);
71     }
72     autoflush = TerminalAutoFlush();
73 }
74 
75 
76 /*
77  *		Send as much data as possible to the terminal, else exits if
78  *		it encounters a permanent failure when writing to the tty.
79  *
80  *		Return value:
81  *			-1: No useful work done, data waiting to go out.
82  *			 0: No data was waiting, so nothing was done.
83  *			 1: All waiting data was written out.
84  *			 n: All data - n was written out.
85  */
86 
87 
88 int
ttyflush(int drop)89 ttyflush(int drop)
90 {
91     int n, n0, n1;
92 
93     n0 = ring_full_count(&ttyoring);
94     if ((n1 = n = ring_full_consecutive(&ttyoring)) > 0) {
95 	if (drop) {
96 	    TerminalFlushOutput();
97 	    /* we leave 'n' alone! */
98 	} else {
99 	    n = TerminalWrite(ttyoring.consume, n);
100 	}
101     }
102     if (n > 0) {
103 	if (termdata && n) {
104 	    Dump('>', ttyoring.consume, n);
105 	}
106 	/*
107 	 * If we wrote everything, and the full count is
108 	 * larger than what we wrote, then write the
109 	 * rest of the buffer.
110 	 */
111 	if (n1 == n && n0 > n) {
112 		n1 = n0 - n;
113 		if (!drop)
114 			n1 = TerminalWrite(ttyoring.bottom, n1);
115 		if (n1 > 0)
116 			n += n1;
117 	}
118 	ring_consumed(&ttyoring, n);
119     }
120     if (n < 0) {
121 	if (errno == EAGAIN || errno == EINTR) {
122 	    return -1;
123 	} else {
124 	    ring_consumed(&ttyoring, ring_full_count(&ttyoring));
125 	    setconnmode(0);
126 	    setcommandmode();
127 	    NetClose(net);
128 	    fprintf(stderr, "Connection closed by foreign host.\n");
129 	    exit(1);
130 	}
131     }
132     if (n == n0) {
133 	if (n0)
134 	    return -1;
135 	return 0;
136     }
137     return n0 - n + 1;
138 }
139 
140 
141 /*
142  * These routines decides on what the mode should be (based on the values
143  * of various global variables).
144  */
145 
146 
147 int
getconnmode(void)148 getconnmode(void)
149 {
150     extern int linemode;
151     int mode = 0;
152 #ifdef	KLUDGELINEMODE
153     extern int kludgelinemode;
154 #endif
155 
156     if (my_want_state_is_dont(TELOPT_ECHO))
157 	mode |= MODE_ECHO;
158 
159     if (localflow)
160 	mode |= MODE_FLOW;
161 
162     if (my_want_state_is_will(TELOPT_BINARY))
163 	mode |= MODE_INBIN;
164 
165     if (his_want_state_is_will(TELOPT_BINARY))
166 	mode |= MODE_OUTBIN;
167 
168 #ifdef	KLUDGELINEMODE
169     if (kludgelinemode) {
170 	if (my_want_state_is_dont(TELOPT_SGA)) {
171 	    mode |= (MODE_TRAPSIG|MODE_EDIT);
172 	    if (dontlecho && (clocks.echotoggle > clocks.modenegotiated)) {
173 		mode &= ~MODE_ECHO;
174 	    }
175 	}
176 	return(mode);
177     }
178 #endif
179     if (my_want_state_is_will(TELOPT_LINEMODE))
180 	mode |= linemode;
181     return(mode);
182 }
183 
184 void
setconnmode(int force)185 setconnmode(int force)
186 {
187 #ifdef	ENCRYPTION
188     static int enc_passwd = 0;
189 #endif
190     int newmode;
191 
192     newmode = getconnmode()|(force?MODE_FORCE:0);
193 
194     TerminalNewMode(newmode);
195 
196 #ifdef	ENCRYPTION
197     if ((newmode & (MODE_ECHO|MODE_EDIT)) == MODE_EDIT) {
198 	if (my_want_state_is_will(TELOPT_ENCRYPT)
199 				&& (enc_passwd == 0) && !encrypt_output) {
200 	    encrypt_request_start(0, 0);
201 	    enc_passwd = 1;
202 	}
203     } else {
204 	if (enc_passwd) {
205 	    encrypt_request_end();
206 	    enc_passwd = 0;
207 	}
208     }
209 #endif	/* ENCRYPTION */
210 }
211 
212 
213 void
setcommandmode(void)214 setcommandmode(void)
215 {
216     TerminalNewMode(-1);
217 }
218