xref: /freebsd/lib/libc/gen/getttyent.c (revision c96ae1968a6ab7056427a739bce81bf07447c2d4)
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)
31 static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <ttyent.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <ctype.h>
40 #include <string.h>
41 #include <dirent.h>
42 #include <paths.h>
43 
44 static char zapchar;
45 static FILE *tf;
46 static int maxpts = 0;
47 static int curpts = 0;
48 static int pts_valid = 0;
49 static size_t lbsize;
50 static char *line;
51 
52 #define PTS "pts/"
53 #define	MALLOCCHUNK	100
54 
55 static char *skip(char *);
56 static char *value(char *);
57 
58 struct ttyent *
59 getttynam(tty)
60 	const char *tty;
61 {
62 	struct ttyent *t;
63 
64 	if (strncmp(tty, "/dev/", 5) == 0)
65 		tty += 5;
66 	setttyent();
67 	while ( (t = getttyent()) )
68 		if (!strcmp(tty, t->ty_name))
69 			break;
70 	endttyent();
71 	return (t);
72 }
73 
74 struct ttyent *
75 getttyent()
76 {
77 	static struct ttyent tty;
78 	static char devpts_name[] = "pts/4294967295";
79 	char *p;
80 	int c;
81 	size_t i;
82 
83 	if (!tf && !setttyent())
84 		return (NULL);
85 	for (;;) {
86 		if (!fgets(p = line, lbsize, tf)) {
87 			if (pts_valid == 1 && curpts <= maxpts) {
88 				sprintf(devpts_name, "pts/%d", curpts++);
89 				tty.ty_name = devpts_name;
90 				tty.ty_getty = tty.ty_type = NULL;
91 				tty.ty_status = TTY_NETWORK;
92 				tty.ty_window = NULL;
93 				tty.ty_comment = NULL;
94 				tty.ty_group  = _TTYS_NOGROUP;
95 				return (&tty);
96 			}
97 			return (NULL);
98 		}
99 		/* extend buffer if line was too big, and retry */
100 		while (!index(p, '\n')) {
101 			i = strlen(p);
102 			lbsize += MALLOCCHUNK;
103 			if ((p = realloc(line, lbsize)) == NULL) {
104 				(void)endttyent();
105 				return (NULL);
106 			}
107 			line = p;
108 			if (!fgets(&line[i], lbsize - i, tf))
109 				return (NULL);
110 		}
111 		while (isspace((unsigned char)*p))
112 			++p;
113 		if (*p && *p != '#')
114 			break;
115 	}
116 
117 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
118 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
119 
120 	zapchar = 0;
121 	tty.ty_name = p;
122 	tty.ty_status = 0;
123 	tty.ty_window = NULL;
124 	tty.ty_group  = _TTYS_NOGROUP;
125 
126 	p = skip(p);
127 	if (!*(tty.ty_getty = p))
128 		tty.ty_getty = tty.ty_type = NULL;
129 	else {
130 		p = skip(p);
131 		if (!*(tty.ty_type = p))
132 			tty.ty_type = NULL;
133 		else {
134 			/* compatibility kludge: handle network/dialup specially */
135 			if (scmp(_TTYS_DIALUP))
136 				tty.ty_status |= TTY_DIALUP;
137 			else if (scmp(_TTYS_NETWORK))
138 				tty.ty_status |= TTY_NETWORK;
139 			p = skip(p);
140 		}
141 	}
142 
143 	for (; *p; p = skip(p)) {
144 		if (scmp(_TTYS_OFF))
145 			tty.ty_status &= ~TTY_ON;
146 		else if (scmp(_TTYS_ON))
147 			tty.ty_status |= TTY_ON;
148 		else if (scmp(_TTYS_SECURE))
149 			tty.ty_status |= TTY_SECURE;
150 		else if (scmp(_TTYS_INSECURE))
151 			tty.ty_status &= ~TTY_SECURE;
152 		else if (scmp(_TTYS_DIALUP))
153 			tty.ty_status |= TTY_DIALUP;
154 		else if (scmp(_TTYS_NETWORK))
155 			tty.ty_status |= TTY_NETWORK;
156 		else if (vcmp(_TTYS_WINDOW))
157 			tty.ty_window = value(p);
158 		else if (vcmp(_TTYS_GROUP))
159 			tty.ty_group = value(p);
160 		else
161 			break;
162 	}
163 
164 	if (zapchar == '#' || *p == '#')
165 		while ((c = *++p) == ' ' || c == '\t')
166 			;
167 	tty.ty_comment = p;
168 	if (*p == 0)
169 		tty.ty_comment = 0;
170 	if ( (p = index(p, '\n')) )
171 		*p = '\0';
172 	return (&tty);
173 }
174 
175 #define	QUOTED	1
176 
177 /*
178  * Skip over the current field, removing quotes, and return a pointer to
179  * the next field.
180  */
181 static char *
182 skip(p)
183 	char *p;
184 {
185 	char *t;
186 	int c, q;
187 
188 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
189 		if (c == '"') {
190 			q ^= QUOTED;	/* obscure, but nice */
191 			continue;
192 		}
193 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
194 			p++;
195 		*t++ = *p;
196 		if (q == QUOTED)
197 			continue;
198 		if (c == '#') {
199 			zapchar = c;
200 			*p = 0;
201 			break;
202 		}
203 		if (c == '\t' || c == ' ' || c == '\n') {
204 			zapchar = c;
205 			*p++ = 0;
206 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
207 				p++;
208 			break;
209 		}
210 	}
211 	*--t = '\0';
212 	return (p);
213 }
214 
215 static char *
216 value(p)
217 	char *p;
218 {
219 
220 	return ((p = index(p, '=')) ? ++p : NULL);
221 }
222 
223 int
224 setttyent()
225 {
226 	DIR *devpts_dir;
227 
228 	if (line == NULL) {
229 		if ((line = malloc(MALLOCCHUNK)) == NULL)
230 			return (0);
231 		lbsize = MALLOCCHUNK;
232 	}
233 	devpts_dir = opendir(_PATH_DEV PTS);
234 	if (devpts_dir) {
235 		struct dirent *dp;
236 
237 		while ((dp = readdir(devpts_dir))) {
238 			if (strcmp(dp->d_name, ".") != 0 &&
239 			    strcmp(dp->d_name, "..") != 0) {
240 				if (atoi(dp->d_name) > maxpts) {
241 					maxpts = atoi(dp->d_name);
242 					pts_valid = 1;
243 					curpts = 0;
244 				}
245 			}
246 		}
247 		closedir(devpts_dir);
248 	}
249 	if (tf) {
250 		rewind(tf);
251 		return (1);
252 	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
253 		return (1);
254 	return (0);
255 }
256 
257 int
258 endttyent()
259 {
260 	int rval;
261 
262 	pts_valid = 0;
263 	/*
264          * NB: Don't free `line' because getttynam()
265 	 * may still be referencing it
266 	 */
267 	if (tf) {
268 		rval = (fclose(tf) != EOF);
269 		tf = NULL;
270 		return (rval);
271 	}
272 	return (1);
273 }
274 
275 static int
276 isttystat(tty, flag)
277 	const char *tty;
278 	int flag;
279 {
280 	struct ttyent *t;
281 
282 	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
283 }
284 
285 
286 int
287 isdialuptty(tty)
288 	const char *tty;
289 {
290 
291 	return isttystat(tty, TTY_DIALUP);
292 }
293 
294 int isnettty(tty)
295 	const char *tty;
296 {
297 
298 	return isttystat(tty, TTY_NETWORK);
299 }
300