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 
34 #include <ttyent.h>
35 #include <stdio.h>
36 #include <stdio_ext.h>
37 #include <ctype.h>
38 #include <string.h>
39 
40 #define flockfile(s) _IO_flockfile (s)
41 #define funlockfile(s) _IO_funlockfile (s)
42 
43 static char zapchar;
44 static FILE *tf;
45 
46 struct ttyent *
__getttynam(const char * tty)47 __getttynam (const char *tty)
48 {
49 	struct ttyent *t;
50 
51 	__setttyent();
52 	while ((t = __getttyent()))
53 		if (!strcmp(tty, t->ty_name))
54 			break;
55 	__endttyent();
56 	return (t);
57 }
58 weak_alias (__getttynam, getttynam)
59 
60 static char *skip (char *) __THROW;
61 static char *value (char *) __THROW;
62 
63 struct ttyent *
__getttyent(void)64 __getttyent (void)
65 {
66 	static struct ttyent tty;
67 	int c;
68 	char *p;
69 #define	MAXLINELENGTH	100
70 	static char line[MAXLINELENGTH];
71 
72 	if (!tf && !__setttyent())
73 		return (NULL);
74 	flockfile (tf);
75 	for (;;) {
76 		if (!__fgets_unlocked(p = line, sizeof(line), tf)) {
77 			funlockfile (tf);
78 			return (NULL);
79 		}
80 		/* skip lines that are too big */
81 		if (!strchr (p, '\n')) {
82 			while ((c = __getc_unlocked(tf)) != '\n' && c != EOF)
83 				;
84 			continue;
85 		}
86 		while (isspace(*p))
87 			++p;
88 		if (*p && *p != '#')
89 			break;
90 	}
91 
92 	zapchar = 0;
93 	tty.ty_name = p;
94 	p = skip(p);
95 	if (!*(tty.ty_getty = p))
96 		tty.ty_getty = tty.ty_type = NULL;
97 	else {
98 		p = skip(p);
99 		if (!*(tty.ty_type = p))
100 			tty.ty_type = NULL;
101 		else
102 			p = skip(p);
103 	}
104 	tty.ty_status = 0;
105 	tty.ty_window = NULL;
106 
107 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
108 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
109 	for (; *p; p = skip(p)) {
110 		if (scmp(_TTYS_OFF))
111 			tty.ty_status &= ~TTY_ON;
112 		else if (scmp(_TTYS_ON))
113 			tty.ty_status |= TTY_ON;
114 		else if (scmp(_TTYS_SECURE))
115 			tty.ty_status |= TTY_SECURE;
116 		else if (vcmp(_TTYS_WINDOW))
117 			tty.ty_window = value(p);
118 		else
119 			break;
120 	}
121 	/* We can release the lock only here since `zapchar' is global.  */
122 	funlockfile(tf);
123 
124 	if (zapchar == '#' || *p == '#')
125 		while ((c = *++p) == ' ' || c == '\t')
126 			;
127 	tty.ty_comment = p;
128 	if (*p == 0)
129 		tty.ty_comment = 0;
130 	if ((p = strchr (p, '\n')))
131 		*p = '\0';
132 	return (&tty);
133 }
134 libc_hidden_def (__getttyent)
weak_alias(__getttyent,getttyent)135 weak_alias (__getttyent, getttyent)
136 
137 #define	QUOTED	1
138 
139 /*
140  * Skip over the current field, removing quotes, and return a pointer to
141  * the next field.
142  */
143 static char *
144 skip (char *p)
145 {
146 	char *t;
147 	int c, q;
148 
149 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
150 		if (c == '"') {
151 			q ^= QUOTED;	/* obscure, but nice */
152 			continue;
153 		}
154 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
155 			p++;
156 		*t++ = *p;
157 		if (q == QUOTED)
158 			continue;
159 		if (c == '#') {
160 			zapchar = c;
161 			*p = 0;
162 			break;
163 		}
164 		if (c == '\t' || c == ' ' || c == '\n') {
165 			zapchar = c;
166 			*p++ = 0;
167 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
168 				p++;
169 			break;
170 		}
171 	}
172 	*--t = '\0';
173 	return (p);
174 }
175 
176 static char *
value(char * p)177 value (char *p)
178 {
179 
180 	return ((p = strchr (p, '=')) ? ++p : NULL);
181 }
182 
183 int
__setttyent(void)184 __setttyent (void)
185 {
186 
187 	if (tf) {
188 		(void)rewind(tf);
189 		return (1);
190 	} else if ((tf = fopen(_PATH_TTYS, "rce"))) {
191 		/* We do the locking ourselves.  */
192 		__fsetlocking (tf, FSETLOCKING_BYCALLER);
193 		return (1);
194 	}
195 	return (0);
196 }
197 libc_hidden_def (__setttyent)
weak_alias(__setttyent,setttyent)198 weak_alias (__setttyent, setttyent)
199 
200 int
201 __endttyent (void)
202 {
203 	int rval;
204 
205 	if (tf) {
206 		rval = !(fclose(tf) == EOF);
207 		tf = NULL;
208 		return (rval);
209 	}
210 	return (1);
211 }
212 libc_hidden_def (__endttyent)
213 weak_alias (__endttyent, endttyent)
214