xref: /dragonfly/lib/libc/gen/getttyent.c (revision 73610d44)
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  *
35  * @(#)getttyent.c	8.1 (Berkeley) 6/4/93
36  */
37 
38 #include <ttyent.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <ctype.h>
42 #include <string.h>
43 #include <dirent.h>
44 #include <paths.h>
45 
46 static char zapchar;
47 static FILE *tf;
48 static int maxpts = -1;
49 static int curpts = 0;
50 static size_t lbsize;
51 static char *line;
52 
53 #define PTS	"pts/"
54 #define	MALLOCCHUNK	100
55 
56 static char *skip (char *);
57 static char *value (char *);
58 
59 struct ttyent *
60 getttynam(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(void)
76 {
77 	static struct ttyent tty;
78 	static char devpts_name[] = "pts/9999999999";
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 (curpts <= maxpts) {
88 				sprintf(devpts_name, "pts/%d", curpts++);
89 				tty.ty_name = devpts_name;
90 				tty.ty_getty = NULL;
91 				tty.ty_type = NULL;
92 				tty.ty_status = TTY_NETWORK;
93 				tty.ty_window = NULL;
94 				tty.ty_comment = NULL;
95 				tty.ty_group = _TTYS_NOGROUP;
96 				return (&tty);
97 			}
98 			return (NULL);
99 		}
100 		/* extend buffer if line was too big, and retry */
101 		while (!index(p, '\n') && !feof(tf)) {
102 			i = strlen(p);
103 			lbsize += MALLOCCHUNK;
104 			if ((p = realloc(line, lbsize)) == NULL) {
105 				endttyent();
106 				return (NULL);
107 			}
108 			line = p;
109 			if (!fgets(&line[i], lbsize - i, tf))
110 				return (NULL);
111 		}
112 		while (isspace((unsigned char)*p))
113 			++p;
114 		if (*p && *p != '#')
115 			break;
116 	}
117 
118 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
119 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
120 
121 	zapchar = 0;
122 	tty.ty_name = p;
123 	tty.ty_status = 0;
124 	tty.ty_window = NULL;
125 	tty.ty_group  = _TTYS_NOGROUP;
126 
127 	p = skip(p);
128 	if (!*(tty.ty_getty = p))
129 		tty.ty_getty = tty.ty_type = NULL;
130 	else {
131 		p = skip(p);
132 		if (!*(tty.ty_type = p))
133 			tty.ty_type = NULL;
134 		else {
135 			/* compatibility kludge: handle network/dialup specially */
136 			if (scmp(_TTYS_DIALUP))
137 				tty.ty_status |= TTY_DIALUP;
138 			else if (scmp(_TTYS_NETWORK))
139 				tty.ty_status |= TTY_NETWORK;
140 			p = skip(p);
141 		}
142 	}
143 
144 	for (; *p; p = skip(p)) {
145 		if (scmp(_TTYS_OFF))
146 			tty.ty_status &= ~TTY_ON;
147 		else if (scmp(_TTYS_ON))
148 			tty.ty_status |= TTY_ON;
149 		else if (scmp(_TTYS_SECURE))
150 			tty.ty_status |= TTY_SECURE;
151 		else if (scmp(_TTYS_INSECURE))
152 			tty.ty_status &= ~TTY_SECURE;
153 		else if (scmp(_TTYS_DIALUP))
154 			tty.ty_status |= TTY_DIALUP;
155 		else if (scmp(_TTYS_NETWORK))
156 			tty.ty_status |= TTY_NETWORK;
157 		else if (scmp(_TTYS_IFCONSOLE))
158 			tty.ty_status |= TTY_IFCONSOLE;
159 		else if (vcmp(_TTYS_WINDOW))
160 			tty.ty_window = value(p);
161 		else if (vcmp(_TTYS_GROUP))
162 			tty.ty_group = value(p);
163 		else
164 			break;
165 	}
166 
167 	if (zapchar == '#' || *p == '#')
168 		while ((c = *++p) == ' ' || c == '\t')
169 			;
170 	tty.ty_comment = p;
171 	if (*p == 0)
172 		tty.ty_comment = 0;
173 	if ( (p = index(p, '\n')) )
174 		*p = '\0';
175 	return (&tty);
176 }
177 
178 #define	QUOTED	1
179 
180 /*
181  * Skip over the current field, removing quotes, and return a pointer to
182  * the next field.
183  */
184 static char *
185 skip(char *p)
186 {
187 	char *t;
188 	int c, q;
189 
190 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
191 		if (c == '"') {
192 			q ^= QUOTED;	/* obscure, but nice */
193 			continue;
194 		}
195 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
196 			p++;
197 		*t++ = *p;
198 		if (q == QUOTED)
199 			continue;
200 		if (c == '#') {
201 			zapchar = c;
202 			*p = 0;
203 			break;
204 		}
205 		if (c == '\t' || c == ' ' || c == '\n') {
206 			zapchar = c;
207 			*p++ = 0;
208 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
209 				p++;
210 			break;
211 		}
212 	}
213 	*--t = '\0';
214 	return (p);
215 }
216 
217 static char *
218 value(char *p)
219 {
220 
221 	return ((p = index(p, '=')) ? ++p : NULL);
222 }
223 
224 int
225 setttyent(void)
226 {
227 	DIR *devpts_dir;
228 	struct dirent *dp;
229 	int unit;
230 
231 	if (line == NULL) {
232 		if ((line = malloc(MALLOCCHUNK)) == NULL)
233 			return (0);
234 		lbsize = MALLOCCHUNK;
235 	}
236 	devpts_dir = opendir(_PATH_DEV PTS);
237 	if (devpts_dir) {
238 		maxpts = -1;
239 		while ((dp = readdir(devpts_dir))) {
240 			if (strcmp(dp->d_name, ".") == 0 ||
241 			    strcmp(dp->d_name, "..") == 0)
242 				continue;
243 
244 			unit = (int)strtol(dp->d_name, NULL, 10);
245 
246 			if (unit > maxpts) {
247 				maxpts = unit;
248 				curpts = 0;
249 			}
250 		}
251 		closedir(devpts_dir);
252 	}
253 	if (tf) {
254 		rewind(tf);
255 		return (1);
256 	} else if ( (tf = fopen(_PATH_TTYS, "r")) )
257 		return (1);
258 	return (0);
259 }
260 
261 int
262 endttyent(void)
263 {
264 	int rval;
265 
266 	maxpts = -1;
267 	/*
268          * NB: Don't free `line' because getttynam()
269 	 * may still be referencing it
270 	 */
271 	if (tf) {
272 		rval = (fclose(tf) != EOF);
273 		tf = NULL;
274 		return (rval);
275 	}
276 	return (1);
277 }
278 
279 static int
280 isttystat(const char *tty, int flag)
281 {
282 	struct ttyent *t;
283 
284 	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
285 }
286 
287 
288 int
289 isdialuptty(const char *tty)
290 {
291 
292 	return isttystat(tty, TTY_DIALUP);
293 }
294 
295 int
296 isnettty(const char *tty)
297 {
298 
299 	return isttystat(tty, TTY_NETWORK);
300 }
301