getttyent.c revision 154838 
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
36#endif /* LIBC_SCCS and not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: head/lib/libc/gen/getttyent.c 154838 2006-01-26 01:34:26Z cognet $");
39
40#include <ttyent.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <ctype.h>
44#include <string.h>
45#include <dirent.h>
46#include <paths.h>
47
48static char zapchar;
49static FILE *tf;
50static int maxpts = 0;
51static int curpts = 0;
52static int pts_valid = 0;
53static size_t lbsize;
54static char *line;
55
56#define PTS "pts/"
57#define	MALLOCCHUNK	100
58
59static char *skip(char *);
60static char *value(char *);
61
62struct ttyent *
63getttynam(tty)
64	const char *tty;
65{
66	struct ttyent *t;
67
68	if (strncmp(tty, "/dev/", 5) == 0)
69		tty += 5;
70	setttyent();
71	while ( (t = getttyent()) )
72		if (!strcmp(tty, t->ty_name))
73			break;
74	endttyent();
75	return (t);
76}
77
78struct ttyent *
79getttyent()
80{
81	static struct ttyent tty;
82	static char devpts_name[] = "pts/4294967295";
83	char *p;
84	int c;
85	size_t i;
86
87	if (!tf && !setttyent())
88		return (NULL);
89	for (;;) {
90		if (!fgets(p = line, lbsize, tf)) {
91			if (pts_valid == 1 && curpts <= maxpts) {
92				sprintf(devpts_name, "pts/%d", curpts++);
93				tty.ty_name = devpts_name;
94				tty.ty_getty = tty.ty_type = NULL;
95				tty.ty_status = TTY_NETWORK;
96				tty.ty_window = NULL;
97				tty.ty_comment = NULL;
98				tty.ty_group  = _TTYS_NOGROUP;
99				return (&tty);
100			}
101			return (NULL);
102		}
103		/* extend buffer if line was too big, and retry */
104		while (!index(p, '\n')) {
105			i = strlen(p);
106			lbsize += MALLOCCHUNK;
107			if ((p = realloc(line, lbsize)) == NULL) {
108				(void)endttyent();
109				return (NULL);
110			}
111			line = p;
112			if (!fgets(&line[i], lbsize - i, tf))
113				return (NULL);
114		}
115		while (isspace((unsigned char)*p))
116			++p;
117		if (*p && *p != '#')
118			break;
119	}
120
121#define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
122#define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
123
124	zapchar = 0;
125	tty.ty_name = p;
126	tty.ty_status = 0;
127	tty.ty_window = NULL;
128	tty.ty_group  = _TTYS_NOGROUP;
129
130	p = skip(p);
131	if (!*(tty.ty_getty = p))
132		tty.ty_getty = tty.ty_type = NULL;
133	else {
134		p = skip(p);
135		if (!*(tty.ty_type = p))
136			tty.ty_type = NULL;
137		else {
138			/* compatibility kludge: handle network/dialup specially */
139			if (scmp(_TTYS_DIALUP))
140				tty.ty_status |= TTY_DIALUP;
141			else if (scmp(_TTYS_NETWORK))
142				tty.ty_status |= TTY_NETWORK;
143			p = skip(p);
144		}
145	}
146
147	for (; *p; p = skip(p)) {
148		if (scmp(_TTYS_OFF))
149			tty.ty_status &= ~TTY_ON;
150		else if (scmp(_TTYS_ON))
151			tty.ty_status |= TTY_ON;
152		else if (scmp(_TTYS_SECURE))
153			tty.ty_status |= TTY_SECURE;
154		else if (scmp(_TTYS_INSECURE))
155			tty.ty_status &= ~TTY_SECURE;
156		else if (scmp(_TTYS_DIALUP))
157			tty.ty_status |= TTY_DIALUP;
158		else if (scmp(_TTYS_NETWORK))
159			tty.ty_status |= TTY_NETWORK;
160		else if (vcmp(_TTYS_WINDOW))
161			tty.ty_window = value(p);
162		else if (vcmp(_TTYS_GROUP))
163			tty.ty_group = value(p);
164		else
165			break;
166	}
167
168	if (zapchar == '#' || *p == '#')
169		while ((c = *++p) == ' ' || c == '\t')
170			;
171	tty.ty_comment = p;
172	if (*p == 0)
173		tty.ty_comment = 0;
174	if ( (p = index(p, '\n')) )
175		*p = '\0';
176	return (&tty);
177}
178
179#define	QUOTED	1
180
181/*
182 * Skip over the current field, removing quotes, and return a pointer to
183 * the next field.
184 */
185static char *
186skip(p)
187	char *p;
188{
189	char *t;
190	int c, q;
191
192	for (q = 0, t = p; (c = *p) != '\0'; p++) {
193		if (c == '"') {
194			q ^= QUOTED;	/* obscure, but nice */
195			continue;
196		}
197		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
198			p++;
199		*t++ = *p;
200		if (q == QUOTED)
201			continue;
202		if (c == '#') {
203			zapchar = c;
204			*p = 0;
205			break;
206		}
207		if (c == '\t' || c == ' ' || c == '\n') {
208			zapchar = c;
209			*p++ = 0;
210			while ((c = *p) == '\t' || c == ' ' || c == '\n')
211				p++;
212			break;
213		}
214	}
215	*--t = '\0';
216	return (p);
217}
218
219static char *
220value(p)
221	char *p;
222{
223
224	return ((p = index(p, '=')) ? ++p : NULL);
225}
226
227int
228setttyent()
229{
230	DIR *devpts_dir;
231
232	if (line == NULL) {
233		if ((line = malloc(MALLOCCHUNK)) == NULL)
234			return (0);
235		lbsize = MALLOCCHUNK;
236	}
237	devpts_dir = opendir(_PATH_DEV PTS);
238	if (devpts_dir) {
239		struct dirent *dp;
240
241		while ((dp = readdir(devpts_dir))) {
242			if (strcmp(dp->d_name, ".") != 0 &&
243			    strcmp(dp->d_name, "..") != 0) {
244				if (atoi(dp->d_name) > maxpts) {
245					maxpts = atoi(dp->d_name);
246					pts_valid = 1;
247					curpts = 0;
248				}
249			}
250		}
251		closedir(devpts_dir);
252	}
253	printf("it is %d %d\n", maxpts, curpts);
254	if (tf) {
255		rewind(tf);
256		return (1);
257	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
258		return (1);
259	return (0);
260}
261
262int
263endttyent()
264{
265	int rval;
266
267	pts_valid = 0;
268	/*
269         * NB: Don't free `line' because getttynam()
270	 * may still be referencing it
271	 */
272	if (tf) {
273		rval = (fclose(tf) != EOF);
274		tf = NULL;
275		return (rval);
276	}
277	return (1);
278}
279
280static int
281isttystat(tty, flag)
282	const char *tty;
283	int flag;
284{
285	struct ttyent *t;
286
287	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
288}
289
290
291int
292isdialuptty(tty)
293	const char *tty;
294{
295
296	return isttystat(tty, TTY_DIALUP);
297}
298
299int isnettty(tty)
300	const char *tty;
301{
302
303	return isttystat(tty, TTY_NETWORK);
304}
305