xref: /freebsd/lib/libc/gen/getttyent.c (revision 595e514d0df2bac5b813d35f83e32875dbf16a83)
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 
42 static char zapchar;
43 static FILE *tf;
44 static size_t lbsize;
45 static char *line;
46 
47 #define	MALLOCCHUNK	100
48 
49 static char *skip(char *);
50 static char *value(char *);
51 
52 struct ttyent *
53 getttynam(const char *tty)
54 {
55 	struct ttyent *t;
56 
57 	if (strncmp(tty, "/dev/", 5) == 0)
58 		tty += 5;
59 	setttyent();
60 	while ( (t = getttyent()) )
61 		if (!strcmp(tty, t->ty_name))
62 			break;
63 	endttyent();
64 	return (t);
65 }
66 
67 struct ttyent *
68 getttyent(void)
69 {
70 	static struct ttyent tty;
71 	char *p;
72 	int c;
73 	size_t i;
74 
75 	if (!tf && !setttyent())
76 		return (NULL);
77 	for (;;) {
78 		if (!fgets(p = line, lbsize, tf))
79 			return (NULL);
80 		/* extend buffer if line was too big, and retry */
81 		while (!strchr(p, '\n') && !feof(tf)) {
82 			i = strlen(p);
83 			lbsize += MALLOCCHUNK;
84 			if ((p = realloc(line, lbsize)) == NULL) {
85 				(void)endttyent();
86 				return (NULL);
87 			}
88 			line = p;
89 			if (!fgets(&line[i], lbsize - i, tf))
90 				return (NULL);
91 		}
92 		while (isspace((unsigned char)*p))
93 			++p;
94 		if (*p && *p != '#')
95 			break;
96 	}
97 
98 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
99 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
100 
101 	zapchar = 0;
102 	tty.ty_name = p;
103 	tty.ty_status = 0;
104 	tty.ty_window = NULL;
105 	tty.ty_group  = _TTYS_NOGROUP;
106 
107 	p = skip(p);
108 	if (!*(tty.ty_getty = p))
109 		tty.ty_getty = tty.ty_type = NULL;
110 	else {
111 		p = skip(p);
112 		if (!*(tty.ty_type = p))
113 			tty.ty_type = NULL;
114 		else {
115 			/* compatibility kludge: handle network/dialup specially */
116 			if (scmp(_TTYS_DIALUP))
117 				tty.ty_status |= TTY_DIALUP;
118 			else if (scmp(_TTYS_NETWORK))
119 				tty.ty_status |= TTY_NETWORK;
120 			p = skip(p);
121 		}
122 	}
123 
124 	for (; *p; p = skip(p)) {
125 		if (scmp(_TTYS_OFF))
126 			tty.ty_status &= ~TTY_ON;
127 		else if (scmp(_TTYS_ON))
128 			tty.ty_status |= TTY_ON;
129 		else if (scmp(_TTYS_SECURE))
130 			tty.ty_status |= TTY_SECURE;
131 		else if (scmp(_TTYS_INSECURE))
132 			tty.ty_status &= ~TTY_SECURE;
133 		else if (scmp(_TTYS_DIALUP))
134 			tty.ty_status |= TTY_DIALUP;
135 		else if (scmp(_TTYS_NETWORK))
136 			tty.ty_status |= TTY_NETWORK;
137 		else if (vcmp(_TTYS_WINDOW))
138 			tty.ty_window = value(p);
139 		else if (vcmp(_TTYS_GROUP))
140 			tty.ty_group = value(p);
141 		else
142 			break;
143 	}
144 
145 	if (zapchar == '#' || *p == '#')
146 		while ((c = *++p) == ' ' || c == '\t')
147 			;
148 	tty.ty_comment = p;
149 	if (*p == 0)
150 		tty.ty_comment = 0;
151 	if ((p = strchr(p, '\n')))
152 		*p = '\0';
153 	return (&tty);
154 }
155 
156 #define	QUOTED	1
157 
158 /*
159  * Skip over the current field, removing quotes, and return a pointer to
160  * the next field.
161  */
162 static char *
163 skip(char *p)
164 {
165 	char *t;
166 	int c, q;
167 
168 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
169 		if (c == '"') {
170 			q ^= QUOTED;	/* obscure, but nice */
171 			continue;
172 		}
173 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
174 			p++;
175 		*t++ = *p;
176 		if (q == QUOTED)
177 			continue;
178 		if (c == '#') {
179 			zapchar = c;
180 			*p = 0;
181 			break;
182 		}
183 		if (c == '\t' || c == ' ' || c == '\n') {
184 			zapchar = c;
185 			*p++ = 0;
186 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
187 				p++;
188 			break;
189 		}
190 	}
191 	*--t = '\0';
192 	return (p);
193 }
194 
195 static char *
196 value(char *p)
197 {
198 
199 	return ((p = strchr(p, '=')) ? ++p : NULL);
200 }
201 
202 int
203 setttyent(void)
204 {
205 
206 	if (line == NULL) {
207 		if ((line = malloc(MALLOCCHUNK)) == NULL)
208 			return (0);
209 		lbsize = MALLOCCHUNK;
210 	}
211 	if (tf) {
212 		rewind(tf);
213 		return (1);
214 	} else if ( (tf = fopen(_PATH_TTYS, "re")) )
215 		return (1);
216 	return (0);
217 }
218 
219 int
220 endttyent(void)
221 {
222 	int rval;
223 
224 	/*
225          * NB: Don't free `line' because getttynam()
226 	 * may still be referencing it
227 	 */
228 	if (tf) {
229 		rval = (fclose(tf) != EOF);
230 		tf = NULL;
231 		return (rval);
232 	}
233 	return (1);
234 }
235 
236 static int
237 isttystat(const char *tty, int flag)
238 {
239 	struct ttyent *t;
240 
241 	return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
242 }
243 
244 
245 int
246 isdialuptty(const char *tty)
247 {
248 
249 	return isttystat(tty, TTY_DIALUP);
250 }
251 
252 int
253 isnettty(const char *tty)
254 {
255 
256 	return isttystat(tty, TTY_NETWORK);
257 }
258