getttyent.c revision 203068 
1/*
2 * Copyright (c) 1989, 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 * 4. 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 defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: head/lib/libc/gen/getttyent.c 203068 2010-01-27 11:54:42Z ed $");
35
36#include <ttyent.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <ctype.h>
40#include <string.h>
41
42static char zapchar;
43static FILE *tf;
44static size_t lbsize;
45static char *line;
46
47#define	MALLOCCHUNK	100
48
49static char *skip(char *);
50static char *value(char *);
51
52struct ttyent *
53getttynam(const char *tty)
54{
55	struct ttyent *t;
56
57	if (strncmp(tty, "/dev/", 5) == 0)
58		tty += 5;
59	setttyent();
60	while ( (t = getttyent()) )
61		if (!strcmp(tty, t->ty_name))
62			break;
63	endttyent();
64	return (t);
65}
66
67struct ttyent *
68getttyent(void)
69{
70	static struct ttyent tty;
71	char *p;
72	int c;
73	size_t i;
74
75	if (!tf && !setttyent())
76		return (NULL);
77	for (;;) {
78		if (!fgets(p = line, lbsize, tf))
79			return (NULL);
80		/* extend buffer if line was too big, and retry */
81		while (!index(p, '\n') && !feof(tf)) {
82			i = strlen(p);
83			lbsize += MALLOCCHUNK;
84			if ((p = realloc(line, lbsize)) == NULL) {
85				(void)endttyent();
86				return (NULL);
87			}
88			line = p;
89			if (!fgets(&line[i], lbsize - i, tf))
90				return (NULL);
91		}
92		while (isspace((unsigned char)*p))
93			++p;
94		if (*p && *p != '#')
95			break;
96	}
97
98#define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
99#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
100
101	zapchar = 0;
102	tty.ty_name = p;
103	tty.ty_status = 0;
104	tty.ty_window = NULL;
105	tty.ty_group  = _TTYS_NOGROUP;
106
107	p = skip(p);
108	if (!*(tty.ty_getty = p))
109		tty.ty_getty = tty.ty_type = NULL;
110	else {
111		p = skip(p);
112		if (!*(tty.ty_type = p))
113			tty.ty_type = NULL;
114		else {
115			/* compatibility kludge: handle network/dialup specially */
116			if (scmp(_TTYS_DIALUP))
117				tty.ty_status |= TTY_DIALUP;
118			else if (scmp(_TTYS_NETWORK))
119				tty.ty_status |= TTY_NETWORK;
120			p = skip(p);
121		}
122	}
123
124	for (; *p; p = skip(p)) {
125		if (scmp(_TTYS_OFF))
126			tty.ty_status &= ~TTY_ON;
127		else if (scmp(_TTYS_ON))
128			tty.ty_status |= TTY_ON;
129		else if (scmp(_TTYS_SECURE))
130			tty.ty_status |= TTY_SECURE;
131		else if (scmp(_TTYS_INSECURE))
132			tty.ty_status &= ~TTY_SECURE;
133		else if (scmp(_TTYS_DIALUP))
134			tty.ty_status |= TTY_DIALUP;
135		else if (scmp(_TTYS_NETWORK))
136			tty.ty_status |= TTY_NETWORK;
137		else if (vcmp(_TTYS_WINDOW))
138			tty.ty_window = value(p);
139		else if (vcmp(_TTYS_GROUP))
140			tty.ty_group = value(p);
141		else
142			break;
143	}
144
145	if (zapchar == '#' || *p == '#')
146		while ((c = *++p) == ' ' || c == '\t')
147			;
148	tty.ty_comment = p;
149	if (*p == 0)
150		tty.ty_comment = 0;
151	if ( (p = index(p, '\n')) )
152		*p = '\0';
153	return (&tty);
154}
155
156#define	QUOTED	1
157
158/*
159 * Skip over the current field, removing quotes, and return a pointer to
160 * the next field.
161 */
162static char *
163skip(char *p)
164{
165	char *t;
166	int c, q;
167
168	for (q = 0, t = p; (c = *p) != '\0'; p++) {
169		if (c == '"') {
170			q ^= QUOTED;	/* obscure, but nice */
171			continue;
172		}
173		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
174			p++;
175		*t++ = *p;
176		if (q == QUOTED)
177			continue;
178		if (c == '#') {
179			zapchar = c;
180			*p = 0;
181			break;
182		}
183		if (c == '\t' || c == ' ' || c == '\n') {
184			zapchar = c;
185			*p++ = 0;
186			while ((c = *p) == '\t' || c == ' ' || c == '\n')
187				p++;
188			break;
189		}
190	}
191	*--t = '\0';
192	return (p);
193}
194
195static char *
196value(char *p)
197{
198
199	return ((p = index(p, '=')) ? ++p : NULL);
200}
201
202int
203setttyent(void)
204{
205
206	if (line == NULL) {
207		if ((line = malloc(MALLOCCHUNK)) == NULL)
208			return (0);
209		lbsize = MALLOCCHUNK;
210	}
211	if (tf) {
212		rewind(tf);
213		return (1);
214	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
215		return (1);
216	return (0);
217}
218
219int
220endttyent(void)
221{
222	int rval;
223
224	/*
225         * NB: Don't free `line' because getttynam()
226	 * may still be referencing it
227	 */
228	if (tf) {
229		rval = (fclose(tf) != EOF);
230		tf = NULL;
231		return (rval);
232	}
233	return (1);
234}
235
236static int
237isttystat(const char *tty, int flag)
238{
239	struct ttyent *t;
240
241	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
242}
243
244
245int
246isdialuptty(const char *tty)
247{
248
249	return isttystat(tty, TTY_DIALUP);
250}
251
252int
253isnettty(const char *tty)
254{
255
256	return isttystat(tty, TTY_NETWORK);
257}
258