xref: /dragonfly/lib/libc/gen/getttyent.c (revision 73e0051e)
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  * $FreeBSD: src/lib/libc/gen/getttyent.c,v 1.13 2005/07/25 17:57:15 mdodd Exp $
34  * $DragonFly: src/lib/libc/gen/getttyent.c,v 1.5 2005/11/13 00:07:42 swildner Exp $
35  *
36  * @(#)getttyent.c	8.1 (Berkeley) 6/4/93
37  */
38 
39 #include <sys/cdefs.h>
40 
41 #include <ttyent.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <ctype.h>
45 #include <string.h>
46 #include <dirent.h>
47 #include <paths.h>
48 
49 static char zapchar;
50 static FILE *tf;
51 static int maxpts = -1;
52 static int curpts = 0;
53 static size_t lbsize;
54 static char *line;
55 
56 #define PTS	"pts/"
57 #define	MALLOCCHUNK	100
58 
59 static char *skip (char *);
60 static char *value (char *);
61 
62 struct ttyent *
63 getttynam(const char *tty)
64 {
65 	struct ttyent *t;
66 
67 	if (strncmp(tty, "/dev/", 5) == 0)
68 		tty += 5;
69 	setttyent();
70 	while ( (t = getttyent()) )
71 		if (!strcmp(tty, t->ty_name))
72 			break;
73 	endttyent();
74 	return (t);
75 }
76 
77 struct ttyent *
78 getttyent(void)
79 {
80 	static struct ttyent tty;
81 	static char devpts_name[] = "pts/9999999999";
82 	char *p;
83 	int c;
84 	size_t i;
85 
86 	if (!tf && !setttyent())
87 		return (NULL);
88 	for (;;) {
89 		if (!fgets(p = line, lbsize, tf)) {
90 			if (curpts <= maxpts) {
91 				sprintf(devpts_name, "pts/%d", curpts++);
92 				tty.ty_name = devpts_name;
93 				tty.ty_getty = NULL;
94 				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') && !feof(tf)) {
105 			i = strlen(p);
106 			lbsize += MALLOCCHUNK;
107 			if ((p = realloc(line, lbsize)) == NULL) {
108 				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  */
185 static char *
186 skip(char *p)
187 {
188 	char *t;
189 	int c, q;
190 
191 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
192 		if (c == '"') {
193 			q ^= QUOTED;	/* obscure, but nice */
194 			continue;
195 		}
196 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
197 			p++;
198 		*t++ = *p;
199 		if (q == QUOTED)
200 			continue;
201 		if (c == '#') {
202 			zapchar = c;
203 			*p = 0;
204 			break;
205 		}
206 		if (c == '\t' || c == ' ' || c == '\n') {
207 			zapchar = c;
208 			*p++ = 0;
209 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
210 				p++;
211 			break;
212 		}
213 	}
214 	*--t = '\0';
215 	return (p);
216 }
217 
218 static char *
219 value(char *p)
220 {
221 
222 	return ((p = index(p, '=')) ? ++p : NULL);
223 }
224 
225 int
226 setttyent(void)
227 {
228 	DIR *devpts_dir;
229 	struct dirent *dp;
230 	int unit;
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 		maxpts = -1;
240 		while ((dp = readdir(devpts_dir))) {
241 			if (strcmp(dp->d_name, ".") == 0 ||
242 			    strcmp(dp->d_name, "..") == 0)
243 				continue;
244 
245 			unit = (int)strtol(dp->d_name, NULL, 10);
246 
247 			if (unit > maxpts) {
248 				maxpts = unit;
249 				curpts = 0;
250 			}
251 		}
252 		closedir(devpts_dir);
253 	}
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 
262 int
263 endttyent(void)
264 {
265 	int rval;
266 
267 	maxpts = -1;
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 
280 static int
281 isttystat(const char *tty, int flag)
282 {
283 	struct ttyent *t;
284 
285 	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
286 }
287 
288 
289 int
290 isdialuptty(const char *tty)
291 {
292 
293 	return isttystat(tty, TTY_DIALUP);
294 }
295 
296 int
297 isnettty(const char *tty)
298 {
299 
300 	return isttystat(tty, TTY_NETWORK);
301 }
302