1/*	$OpenBSD: getttyent.c,v 1.15 2015/09/13 11:47:54 guenther Exp $ */
2/*
3 * Copyright (c) 1989, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <ttyent.h>
32#include <stdio.h>
33#include <ctype.h>
34#include <string.h>
35
36static char zapchar;
37static FILE *tf;
38
39static char *skip(char *);
40static char *value(char *);
41
42struct ttyent *
43getttynam(const char *tty)
44{
45	struct ttyent *t;
46
47	setttyent();
48	while ((t = getttyent()))
49		if (!strcmp(tty, t->ty_name))
50			break;
51	endttyent();
52	return (t);
53}
54
55struct ttyent *
56getttyent(void)
57{
58	static struct ttyent tty;
59	int c;
60	char *p;
61#define	MAXLINELENGTH	200
62	static char line[MAXLINELENGTH];
63
64	if (!tf && !setttyent())
65		return (NULL);
66	for (;;) {
67		if (!fgets(p = line, sizeof(line), tf))
68			return (NULL);
69		/* skip lines that are too big */
70		if (!strchr(p, '\n')) {
71			while ((c = getc_unlocked(tf)) != '\n' && c != EOF)
72				;
73			continue;
74		}
75		while (isspace((unsigned char)*p))
76			++p;
77		if (*p && *p != '#')
78			break;
79	}
80
81	zapchar = 0;
82	tty.ty_name = p;
83	p = skip(p);
84	if (!*(tty.ty_getty = p))
85		tty.ty_getty = tty.ty_type = NULL;
86	else {
87		p = skip(p);
88		if (!*(tty.ty_type = p))
89			tty.ty_type = NULL;
90		else
91			p = skip(p);
92	}
93	tty.ty_status = 0;
94	tty.ty_window = NULL;
95
96#define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && \
97		isspace((unsigned char)p[sizeof(e) - 1])
98#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
99	for (; *p; p = skip(p)) {
100		if (scmp(_TTYS_OFF))
101			tty.ty_status &= ~TTY_ON;
102		else if (scmp(_TTYS_ON))
103			tty.ty_status |= TTY_ON;
104		else if (scmp(_TTYS_SECURE))
105			tty.ty_status |= TTY_SECURE;
106		else if (scmp(_TTYS_LOCAL))
107			tty.ty_status |= TTY_LOCAL;
108		else if (scmp(_TTYS_RTSCTS))
109			tty.ty_status |= TTY_RTSCTS;
110		else if (scmp(_TTYS_SOFTCAR))
111			tty.ty_status |= TTY_SOFTCAR;
112		else if (scmp(_TTYS_MDMBUF))
113			tty.ty_status |= TTY_MDMBUF;
114		else if (vcmp(_TTYS_WINDOW))
115			tty.ty_window = value(p);
116		else
117			break;
118	}
119
120	if (zapchar == '#' || *p == '#')
121		while ((c = *++p) == ' ' || c == '\t')
122			;
123	tty.ty_comment = p;
124	if (*p == 0)
125		tty.ty_comment = 0;
126	if ((p = strchr(p, '\n')))
127		*p = '\0';
128	return (&tty);
129}
130DEF_WEAK(getttyent);
131
132#define	QUOTED	1
133
134/*
135 * Skip over the current field, removing quotes, and return a pointer to
136 * the next field.
137 */
138static char *
139skip(char *p)
140{
141	char *t;
142	int c, q;
143
144	for (q = 0, t = p; (c = *p) != '\0'; p++) {
145		if (c == '"') {
146			q ^= QUOTED;	/* obscure, but nice */
147			continue;
148		}
149		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
150			p++;
151		*t++ = *p;
152		if (q == QUOTED)
153			continue;
154		if (c == '#') {
155			zapchar = c;
156			*p = 0;
157			break;
158		}
159		if (c == '\t' || c == ' ' || c == '\n') {
160			zapchar = c;
161			*p++ = 0;
162			while ((c = *p) == '\t' || c == ' ' || c == '\n')
163				p++;
164			break;
165		}
166	}
167	*--t = '\0';
168	return (p);
169}
170
171static char *
172value(char *p)
173{
174
175	return ((p = strchr(p, '=')) ? ++p : NULL);
176}
177
178int
179setttyent(void)
180{
181
182	if (tf) {
183		rewind(tf);
184		return (1);
185	} else if ((tf = fopen(_PATH_TTYS, "re")))
186		return (1);
187	return (0);
188}
189DEF_WEAK(setttyent);
190
191int
192endttyent(void)
193{
194	int rval;
195
196	if (tf) {
197		rval = !(fclose(tf) == EOF);
198		tf = NULL;
199		return (rval);
200	}
201	return (1);
202}
203DEF_WEAK(endttyent);
204