xref: /openbsd/usr.bin/telnet/terminal.c (revision 73471bf0)
1 /*	$OpenBSD: terminal.c,v 1.14 2017/07/07 09:14:26 fcambus Exp $	*/
2 /*	$NetBSD: terminal.c,v 1.5 1996/02/28 21:04:17 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "telnet_locl.h"
34 
35 #include <arpa/telnet.h>
36 #include <errno.h>
37 #include <unistd.h>
38 
39 Ring		ttyoring, ttyiring;
40 unsigned char	ttyobuf[2*BUFSIZ], ttyibuf[BUFSIZ];
41 
42 int termdata;			/* Debugging flag */
43 
44 /*
45  * initialize the terminal data structures.
46  */
47 
48 void
49 init_terminal(void)
50 {
51 	struct termios tc;
52 
53 	ring_init(&ttyoring, ttyobuf, sizeof ttyobuf);
54 	ring_init(&ttyiring, ttyibuf, sizeof ttyibuf);
55 
56 	tcgetattr(0, &tc);
57 	autoflush = (tc.c_lflag & NOFLSH) == 0;
58 }
59 
60 /*
61  *		Send as much data as possible to the terminal.
62  *
63  *		Return value:
64  *			-1: No useful work done, data waiting to go out.
65  *			 0: No data was waiting, so nothing was done.
66  *			 1: All waiting data was written out.
67  *			 n: All data - n was written out.
68  */
69 
70 int
71 ttyflush(int drop)
72 {
73     int n, n0, n1;
74 
75     n0 = ring_full_count(&ttyoring);
76     if ((n1 = n = ring_full_consecutive(&ttyoring)) > 0) {
77 	if (drop) {
78 	    tcflush(fileno(stdout), TCOFLUSH);
79 	    /* we leave 'n' alone! */
80 	} else {
81 	    n = write(tout, ttyoring.consume, n);
82 	}
83     }
84     if (n > 0) {
85 	if (termdata && n) {
86 	    Dump('>', ttyoring.consume, n);
87 	}
88 	/*
89 	 * If we wrote everything, and the full count is
90 	 * larger than what we wrote, then write the
91 	 * rest of the buffer.
92 	 */
93 	if (n1 == n && n0 > n) {
94 		n1 = n0 - n;
95 		if (!drop)
96 			n1 = write(tout, ttyoring.bottom, n1);
97 		if (n1 > 0)
98 			n += n1;
99 	}
100 	ring_consumed(&ttyoring, n);
101     }
102     if (n < 0) {
103 	if (errno == EPIPE)
104 		kill(0, SIGQUIT);
105 	return -1;
106     }
107     if (n == n0) {
108 	if (n0)
109 	    return -1;
110 	return 0;
111     }
112     return n0 - n + 1;
113 }
114 
115 
116 /*
117  * These routines decides on what the mode should be (based on the values
118  * of various global variables).
119  */
120 
121 int
122 getconnmode(void)
123 {
124     int mode = 0;
125 
126     if (my_want_state_is_dont(TELOPT_ECHO))
127 	mode |= MODE_ECHO;
128 
129     if (localflow)
130 	mode |= MODE_FLOW;
131 
132     if ((eight & 1) || my_want_state_is_will(TELOPT_BINARY))
133 	mode |= MODE_INBIN;
134 
135     if (eight & 2)
136 	mode |= MODE_OUT8;
137     if (his_want_state_is_will(TELOPT_BINARY))
138 	mode |= MODE_OUTBIN;
139 
140 #ifdef	KLUDGELINEMODE
141     if (kludgelinemode) {
142 	if (my_want_state_is_dont(TELOPT_SGA)) {
143 	    mode |= (MODE_TRAPSIG|MODE_EDIT);
144 	    if (dontlecho && (clocks.echotoggle > clocks.modenegotiated)) {
145 		mode &= ~MODE_ECHO;
146 	    }
147 	}
148 	return(mode);
149     }
150 #endif
151     if (my_want_state_is_will(TELOPT_LINEMODE))
152 	mode |= linemode;
153     return(mode);
154 }
155 
156 void
157 setconnmode(int force)
158 {
159     int newmode;
160 
161     newmode = getconnmode()|(force?MODE_FORCE:0);
162 
163     TerminalNewMode(newmode);
164 }
165 
166 void
167 setcommandmode(void)
168 {
169     TerminalNewMode(-1);
170 }
171