getttyent.c revision 267236 
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: stable/10/lib/libc/gen/getttyent.c 267236 2014-06-08 17:50:07Z nwhitehorn $");
35
36#include <ttyent.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <ctype.h>
40#include <string.h>
41
42#include <sys/types.h>
43#include <sys/sysctl.h>
44
45static char zapchar;
46static FILE *tf;
47static size_t lbsize;
48static char *line;
49
50#define	MALLOCCHUNK	100
51
52static char *skip(char *);
53static char *value(char *);
54
55struct ttyent *
56getttynam(const char *tty)
57{
58	struct ttyent *t;
59
60	if (strncmp(tty, "/dev/", 5) == 0)
61		tty += 5;
62	setttyent();
63	while ( (t = getttyent()) )
64		if (!strcmp(tty, t->ty_name))
65			break;
66	endttyent();
67	return (t);
68}
69
70static int
71auto_tty_status(const char *ty_name)
72{
73	size_t len;
74	char *buf, *cons, *nextcons;
75
76	/* Check if this is an enabled kernel console line */
77	buf = NULL;
78	if (sysctlbyname("kern.console", NULL, &len, NULL, 0) == -1)
79		return (0); /* Errors mean don't enable */
80	buf = malloc(len);
81	if (sysctlbyname("kern.console", buf, &len, NULL, 0) == -1)
82		goto done;
83
84	if ((cons = strchr(buf, '/')) == NULL)
85		goto done;
86	*cons = '\0';
87	nextcons = buf;
88	while ((cons = strsep(&nextcons, ",")) != NULL && strlen(cons) != 0) {
89		if (strcmp(cons, ty_name) == 0) {
90			free(buf);
91			return (TTY_ON);
92		}
93	}
94
95done:
96	free(buf);
97	return (0);
98}
99
100struct ttyent *
101getttyent(void)
102{
103	static struct ttyent tty;
104	char *p;
105	int c;
106	size_t i;
107
108	if (!tf && !setttyent())
109		return (NULL);
110	for (;;) {
111		if (!fgets(p = line, lbsize, tf))
112			return (NULL);
113		/* extend buffer if line was too big, and retry */
114		while (!strchr(p, '\n') && !feof(tf)) {
115			i = strlen(p);
116			lbsize += MALLOCCHUNK;
117			if ((p = realloc(line, lbsize)) == NULL) {
118				(void)endttyent();
119				return (NULL);
120			}
121			line = p;
122			if (!fgets(&line[i], lbsize - i, tf))
123				return (NULL);
124		}
125		while (isspace((unsigned char)*p))
126			++p;
127		if (*p && *p != '#')
128			break;
129	}
130
131#define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
132#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
133
134	zapchar = 0;
135	tty.ty_name = p;
136	tty.ty_status = 0;
137	tty.ty_window = NULL;
138	tty.ty_group  = _TTYS_NOGROUP;
139
140	p = skip(p);
141	if (!*(tty.ty_getty = p))
142		tty.ty_getty = tty.ty_type = NULL;
143	else {
144		p = skip(p);
145		if (!*(tty.ty_type = p))
146			tty.ty_type = NULL;
147		else {
148			/* compatibility kludge: handle network/dialup specially */
149			if (scmp(_TTYS_DIALUP))
150				tty.ty_status |= TTY_DIALUP;
151			else if (scmp(_TTYS_NETWORK))
152				tty.ty_status |= TTY_NETWORK;
153			p = skip(p);
154		}
155	}
156
157	for (; *p; p = skip(p)) {
158		if (scmp(_TTYS_OFF))
159			tty.ty_status &= ~TTY_ON;
160		else if (scmp(_TTYS_ON))
161			tty.ty_status |= TTY_ON;
162		else if (scmp(_TTYS_ONIFCONSOLE))
163			tty.ty_status |= auto_tty_status(tty.ty_name);
164		else if (scmp(_TTYS_SECURE))
165			tty.ty_status |= TTY_SECURE;
166		else if (scmp(_TTYS_INSECURE))
167			tty.ty_status &= ~TTY_SECURE;
168		else if (scmp(_TTYS_DIALUP))
169			tty.ty_status |= TTY_DIALUP;
170		else if (scmp(_TTYS_NETWORK))
171			tty.ty_status |= TTY_NETWORK;
172		else if (vcmp(_TTYS_WINDOW))
173			tty.ty_window = value(p);
174		else if (vcmp(_TTYS_GROUP))
175			tty.ty_group = value(p);
176		else
177			break;
178	}
179
180	if (zapchar == '#' || *p == '#')
181		while ((c = *++p) == ' ' || c == '\t')
182			;
183	tty.ty_comment = p;
184	if (*p == 0)
185		tty.ty_comment = 0;
186	if ((p = strchr(p, '\n')))
187		*p = '\0';
188	return (&tty);
189}
190
191#define	QUOTED	1
192
193/*
194 * Skip over the current field, removing quotes, and return a pointer to
195 * the next field.
196 */
197static char *
198skip(char *p)
199{
200	char *t;
201	int c, q;
202
203	for (q = 0, t = p; (c = *p) != '\0'; p++) {
204		if (c == '"') {
205			q ^= QUOTED;	/* obscure, but nice */
206			continue;
207		}
208		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
209			p++;
210		*t++ = *p;
211		if (q == QUOTED)
212			continue;
213		if (c == '#') {
214			zapchar = c;
215			*p = 0;
216			break;
217		}
218		if (c == '\t' || c == ' ' || c == '\n') {
219			zapchar = c;
220			*p++ = 0;
221			while ((c = *p) == '\t' || c == ' ' || c == '\n')
222				p++;
223			break;
224		}
225	}
226	*--t = '\0';
227	return (p);
228}
229
230static char *
231value(char *p)
232{
233
234	return ((p = strchr(p, '=')) ? ++p : NULL);
235}
236
237int
238setttyent(void)
239{
240
241	if (line == NULL) {
242		if ((line = malloc(MALLOCCHUNK)) == NULL)
243			return (0);
244		lbsize = MALLOCCHUNK;
245	}
246	if (tf) {
247		rewind(tf);
248		return (1);
249	} else if ( (tf = fopen(_PATH_TTYS, "re")) )
250		return (1);
251	return (0);
252}
253
254int
255endttyent(void)
256{
257	int rval;
258
259	/*
260         * NB: Don't free `line' because getttynam()
261	 * may still be referencing it
262	 */
263	if (tf) {
264		rval = (fclose(tf) != EOF);
265		tf = NULL;
266		return (rval);
267	}
268	return (1);
269}
270
271static int
272isttystat(const char *tty, int flag)
273{
274	struct ttyent *t;
275
276	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
277}
278
279
280int
281isdialuptty(const char *tty)
282{
283
284	return isttystat(tty, TTY_DIALUP);
285}
286
287int
288isnettty(const char *tty)
289{
290
291	return isttystat(tty, TTY_NETWORK);
292}
293