xref: /illumos-gate/usr/src/lib/libc/port/gen/deflt.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*	Copyright (c) 1987, 1988 Microsoft Corporation	*/
31 /*	  All Rights Reserved	*/
32 
33 #include "lint.h"
34 #include "libc.h"
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <deflt.h>
38 #include <sys/types.h>
39 #include <string.h>
40 #include <ctype.h>
41 #include <unistd.h>
42 #include "tsd.h"
43 
44 #define	TSTBITS(flags, mask)	(((flags) & (mask)) == (mask))
45 
46 struct thr_data {
47 	int  Dcflags;	/* [re-]initialized on each call to defopen() */
48 	FILE *fp;
49 	char *buf;
50 };
51 
52 static int	defopen_common(const char *, struct thr_data *);
53 static void strip_quotes(char *);
54 
55 #define	BUFFERSIZE	1024
56 
57 /*
58  * destructor for per-thread data, registered with tsdalloc()
59  */
60 static void
61 free_thr_data(void *arg)
62 {
63 	struct thr_data *thr_data = (struct thr_data *)arg;
64 
65 	if (thr_data->fp) {
66 		(void) fclose(thr_data->fp);
67 		thr_data->fp = NULL;
68 	}
69 	if (thr_data->buf) {
70 		lfree(thr_data->buf, BUFFERSIZE);
71 		thr_data->buf = NULL;
72 	}
73 }
74 
75 /*
76  * get the per-thread-data-item for the calling thread
77  */
78 static struct thr_data *
79 get_thr_data(void)
80 {
81 	struct thr_data *thr_data =
82 	    tsdalloc(_T_DEFREAD, sizeof (*thr_data), free_thr_data);
83 
84 	return (thr_data);
85 }
86 
87 /*
88  *	defopen() - declare defopen filename
89  *
90  *	defopen(fn)
91  *		char *fn
92  *
93  *	If 'fn' is non-null; it is a full pathname of a file
94  *	which becomes the one read by subsequent defread() calls.
95  *	If 'fn' is null the defopen file is closed.
96  *
97  *	see defread() for more details.
98  *
99  *	EXIT    returns 0 if ok
100  *		returns -1 if error
101  */
102 int
103 defopen(char *fn)
104 {
105 	struct thr_data *thr_data = get_thr_data();
106 
107 	return (defopen_common(fn, thr_data));
108 }
109 
110 /*
111  *	defopen_r() - declare defopen filename (reentrant)
112  *
113  *	defopen_r(const char *fn)
114  *
115  *	'fn' is a full pathname of a file which becomes the one read
116  *	by subsequent defread_r() calls.  defopen_r returns a pointer
117  *	to the internally allocated buffer containing the file descriptor.
118  *	The pointer should be specified to the following defread_r and
119  *	defcntl_r functions.  As the pointer to be returned points to
120  *	the libc lmalloc'd memory, defclose_r must be used to close
121  *	the defopen file and to release the allocated memory.  Caller
122  *	must not try to release the memory by free().
123  *
124  *	see defread_r() for more details.
125  *
126  *	EXIT    returns non-NULL pointer if success
127  *		returns NULL if error
128  */
129 void *
130 defopen_r(const char *fn)
131 {
132 	/* memory allocated by lmalloc gets initialized to zeros */
133 	struct thr_data	*thr_data = lmalloc(sizeof (struct thr_data));
134 
135 	if (defopen_common(fn, thr_data) < 0) {
136 		if (thr_data != NULL)
137 			lfree(thr_data, sizeof (struct thr_data));
138 		return (NULL);
139 	}
140 
141 	return ((void *)thr_data);
142 }
143 
144 static int
145 defopen_common(const char *fn, struct thr_data *thr_data)
146 {
147 	if (thr_data == NULL)
148 		return (-1);
149 
150 	if (thr_data->fp != NULL) {
151 		(void) fclose(thr_data->fp);
152 		thr_data->fp = NULL;
153 	}
154 
155 	if (fn == NULL)
156 		return (0);
157 
158 	if ((thr_data->fp = fopen(fn, "rF")) == NULL)
159 		return (-1);
160 
161 	/*
162 	 * We allocate the big buffer only if the fopen() succeeds.
163 	 * Notice that we deallocate the buffer only when the thread exits
164 	 * for defopen().
165 	 * There are misguided applications that assume that data returned
166 	 * by defread() continues to exist after defopen(NULL) is called.
167 	 */
168 	if (thr_data->buf == NULL &&
169 	    (thr_data->buf = lmalloc(BUFFERSIZE)) == NULL) {
170 		(void) fclose(thr_data->fp);
171 		thr_data->fp = NULL;
172 		return (-1);
173 	}
174 
175 	thr_data->Dcflags = DC_STD;
176 
177 	return (0);
178 }
179 
180 /*
181  *	defread() - read an entry from the defopen file
182  *
183  *	defread(cp)
184  *		char *cp
185  *
186  *	The defopen data file must have been previously opened by
187  *	defopen().  defread scans the data file looking for a line
188  *	which begins with the string '*cp'.  If such a line is found,
189  *	defread returns a pointer to the first character following
190  *	the matched string (*cp).  If no line is found or no file
191  *	is open, defread() returns NULL.
192  *
193  *	Note that there is no way to simultaneously peruse multiple
194  *	defopen files; since there is no way of indicating 'which one'
195  *	to defread().  If you want to peruse a secondary file you must
196  *	recall defopen().  If you need to go back to the first file,
197  *	you must call defopen() again.
198  */
199 char *
200 defread(char *cp)
201 {
202 	struct thr_data *thr_data = get_thr_data();
203 
204 	return (defread_r(cp, thr_data));
205 }
206 
207 /*
208  *	defread_r() - read an entry from the defopen file
209  *
210  *	defread_r(const char *cp, void *defp)
211  *
212  *	defread_r scans the data file associated with the pointer
213  *	specified by 'defp' that was returned by defopen_r(), and
214  *	looks for a line which begins with the string '*cp'.
215  *	If such a line is found, defread_r returns a pointer to
216  *	the first character following the matched string (*cp).
217  *	If no line is found or no file is open, defread_r() returns NULL.
218  */
219 char *
220 defread_r(const char *cp, void *ptr)
221 {
222 	struct thr_data *thr_data = (struct thr_data *)ptr;
223 	int (*compare)(const char *, const char *, size_t);
224 	char *buf_tmp;
225 	char *ret_ptr = NULL;
226 	size_t off, patlen;
227 
228 	if (thr_data == NULL || thr_data->fp == NULL)
229 		return (NULL);
230 
231 	compare = TSTBITS(thr_data->Dcflags, DC_CASE) ? strncmp : strncasecmp;
232 	patlen = strlen(cp);
233 
234 	if (!TSTBITS(thr_data->Dcflags, DC_NOREWIND))
235 		rewind(thr_data->fp);
236 
237 	while (fgets(thr_data->buf, BUFFERSIZE, thr_data->fp)) {
238 		for (buf_tmp = thr_data->buf; *buf_tmp == ' '; buf_tmp++)
239 			;
240 		off = strlen(buf_tmp) - 1;
241 		if (buf_tmp[off] == '\n')
242 			buf_tmp[off] = 0;
243 		else
244 			break;	/* line too long */
245 		if ((*compare)(cp, buf_tmp, patlen) == 0) {
246 			/* found it */
247 			/* strip quotes if requested */
248 			if (TSTBITS(thr_data->Dcflags, DC_STRIP_QUOTES)) {
249 				strip_quotes(buf_tmp);
250 			}
251 			ret_ptr = &buf_tmp[patlen];
252 			break;
253 		}
254 	}
255 
256 	return (ret_ptr);
257 }
258 
259 /*
260  *	defcntl -- default control
261  *
262  *	SYNOPSIS
263  *	  oldflags = defcntl(cmd, arg);
264  *
265  *	ENTRY
266  *	  cmd		Command.  One of DC_GET, DC_SET.
267  *	  arg		Depends on command.  If DC_GET, ignored.
268  *			If DC_SET, new flags value, created by ORing
269  *			the DC_* bits.
270  *	RETURN
271  *	  oldflags	Old value of flags.  -1 on error.
272  *	NOTES
273  *	  The following commands are implemented:
274  *
275  *	  DC_CASE:		respect(on)/ignore(off) case
276  *	  DC_NOREWIND:		don't(on)/do(off) reqind in defread
277  *	  DC_STRIP_QUOTES:	strip(on)/leave(off) qoates
278  */
279 int
280 defcntl(int cmd, int newflags)
281 {
282 	struct thr_data *thr_data = get_thr_data();
283 
284 	return (defcntl_r(cmd, newflags, thr_data));
285 }
286 
287 /*
288  *	defcntl_r -- default control
289  *
290  *	SYNOPSIS
291  *	  oldflags = defcntl_r(int cmd, int arg, void *defp);
292  *
293  *	ENTRY
294  *	  cmd		Command.  One of DC_GET, DC_SET.
295  *	  arg		Depends on command.  If DC_GET, ignored.
296  *			If DC_SET, new flags value, created by ORing
297  *			the DC_* bits.
298  *	  defp		pointer to the defopen'd descriptor
299  *
300  *	RETURN
301  *	  oldflags	Old value of flags.  -1 on error.
302  *	NOTES
303  *	  The following commands are implemented:
304  *
305  *	  DC_CASE:		respect(on)/ignore(off) case
306  *	  DC_NOREWIND:		don't(on)/do(off) reqind in defread
307  *	  DC_STRIP_QUOTES:	strip(on)/leave(off) qoates
308  */
309 int
310 defcntl_r(int cmd, int newflags, void *ptr)
311 {
312 	struct thr_data *thr_data = (struct thr_data *)ptr;
313 	int  oldflags;
314 
315 	if (thr_data == NULL)
316 		return (-1);
317 
318 	switch (cmd) {
319 	case DC_GETFLAGS:		/* query */
320 		oldflags = thr_data->Dcflags;
321 		break;
322 	case DC_SETFLAGS:		/* set */
323 		oldflags = thr_data->Dcflags;
324 		thr_data->Dcflags = newflags;
325 		break;
326 	default:			/* error */
327 		oldflags = -1;
328 		break;
329 	}
330 
331 	return (oldflags);
332 }
333 
334 /*
335  *	defclose_r() - close defopen file
336  *
337  *	defclose_r(void *defp)
338  *
339  *	defclose_r closes the defopen file associated with the specified
340  *	pointer and releases the allocated resources.
341  */
342 void
343 defclose_r(void *ptr)
344 {
345 	struct thr_data *thr_data = (struct thr_data *)ptr;
346 
347 	(void) fclose(thr_data->fp);
348 	lfree(thr_data->buf, BUFFERSIZE);
349 	lfree(thr_data, sizeof (struct thr_data));
350 }
351 
352 /*
353  *	strip_quotes -- strip double (") or single (') quotes from a buffer
354  *
355  *	ENTRY
356  *	  ptr		initial string
357  *
358  *	EXIT
359  *	  ptr		string with quotes (if any) removed
360  */
361 static void
362 strip_quotes(char *ptr)
363 {
364 	char *strip_ptr = NULL;
365 
366 	while (*ptr != '\0') {
367 		if ((*ptr == '"') || (*ptr == '\'')) {
368 			if (strip_ptr == NULL)
369 				strip_ptr = ptr;	/* skip over quote */
370 		} else {
371 			if (strip_ptr != NULL) {
372 				*strip_ptr = *ptr;
373 				strip_ptr++;
374 			}
375 		}
376 		ptr++;
377 	}
378 	if (strip_ptr != NULL) {
379 		*strip_ptr = '\0';
380 	}
381 }
382