xref: /freebsd/bin/pax/cache.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992 Keith Muller.
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Keith Muller of the University of California, San Diego.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)cache.c	8.1 (Berkeley) 5/31/93";
39 #endif
40 #endif /* not lint */
41 #include <sys/cdefs.h>
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <string.h>
45 #include <stdio.h>
46 #include <pwd.h>
47 #include <grp.h>
48 #include <stdlib.h>
49 #include "pax.h"
50 #include "cache.h"
51 #include "extern.h"
52 
53 /*
54  * routines that control user, group, uid and gid caches (for the archive
55  * member print routine).
56  * IMPORTANT:
57  * these routines cache BOTH hits and misses, a major performance improvement
58  */
59 
60 static	int pwopn = 0;		/* is password file open */
61 static	int gropn = 0;		/* is group file open */
62 static UIDC **uidtb = NULL;	/* uid to name cache */
63 static GIDC **gidtb = NULL;	/* gid to name cache */
64 static UIDC **usrtb = NULL;	/* user name to uid cache */
65 static GIDC **grptb = NULL;	/* group name to gid cache */
66 
67 /*
68  * uidtb_start
69  *	creates an empty uidtb
70  * Return:
71  *	0 if ok, -1 otherwise
72  */
73 
74 int
75 uidtb_start(void)
76 {
77 	static int fail = 0;
78 
79 	if (uidtb != NULL)
80 		return(0);
81 	if (fail)
82 		return(-1);
83 	if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
84 		++fail;
85 		paxwarn(1, "Unable to allocate memory for user id cache table");
86 		return(-1);
87 	}
88 	return(0);
89 }
90 
91 /*
92  * gidtb_start
93  *	creates an empty gidtb
94  * Return:
95  *	0 if ok, -1 otherwise
96  */
97 
98 int
99 gidtb_start(void)
100 {
101 	static int fail = 0;
102 
103 	if (gidtb != NULL)
104 		return(0);
105 	if (fail)
106 		return(-1);
107 	if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
108 		++fail;
109 		paxwarn(1, "Unable to allocate memory for group id cache table");
110 		return(-1);
111 	}
112 	return(0);
113 }
114 
115 /*
116  * usrtb_start
117  *	creates an empty usrtb
118  * Return:
119  *	0 if ok, -1 otherwise
120  */
121 
122 int
123 usrtb_start(void)
124 {
125 	static int fail = 0;
126 
127 	if (usrtb != NULL)
128 		return(0);
129 	if (fail)
130 		return(-1);
131 	if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
132 		++fail;
133 		paxwarn(1, "Unable to allocate memory for user name cache table");
134 		return(-1);
135 	}
136 	return(0);
137 }
138 
139 /*
140  * grptb_start
141  *	creates an empty grptb
142  * Return:
143  *	0 if ok, -1 otherwise
144  */
145 
146 int
147 grptb_start(void)
148 {
149 	static int fail = 0;
150 
151 	if (grptb != NULL)
152 		return(0);
153 	if (fail)
154 		return(-1);
155 	if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
156 		++fail;
157 		paxwarn(1,"Unable to allocate memory for group name cache table");
158 		return(-1);
159 	}
160 	return(0);
161 }
162 
163 /*
164  * name_uid()
165  *	caches the name (if any) for the uid. If frc set, we always return the
166  *	the stored name (if valid or invalid match). We use a simple hash table.
167  * Return
168  *	Pointer to stored name (or an empty string).
169  */
170 
171 const char *
172 name_uid(uid_t uid, int frc)
173 {
174 	struct passwd *pw;
175 	UIDC *ptr;
176 
177 	if ((uidtb == NULL) && (uidtb_start() < 0))
178 		return("");
179 
180 	/*
181 	 * see if we have this uid cached
182 	 */
183 	ptr = uidtb[uid % UID_SZ];
184 	if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
185 		/*
186 		 * have an entry for this uid
187 		 */
188 		if (frc || (ptr->valid == VALID))
189 			return(ptr->name);
190 		return("");
191 	}
192 
193 	/*
194 	 * No entry for this uid, we will add it
195 	 */
196 	if (!pwopn) {
197 		setpassent(1);
198 		++pwopn;
199 	}
200 	if (ptr == NULL)
201 		ptr = uidtb[uid % UID_SZ] = (UIDC *)malloc(sizeof(UIDC));
202 
203 	if ((pw = getpwuid(uid)) == NULL) {
204 		/*
205 		 * no match for this uid in the local password file
206 		 * a string that is the uid in numeric format
207 		 */
208 		if (ptr == NULL)
209 			return("");
210 		ptr->uid = uid;
211 		ptr->valid = INVALID;
212 		(void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
213 			       (unsigned long)uid);
214 		if (frc == 0)
215 			return("");
216 	} else {
217 		/*
218 		 * there is an entry for this uid in the password file
219 		 */
220 		if (ptr == NULL)
221 			return(pw->pw_name);
222 		ptr->uid = uid;
223 		(void)strncpy(ptr->name, pw->pw_name, UNMLEN - 1);
224 		ptr->name[UNMLEN-1] = '\0';
225 		ptr->valid = VALID;
226 	}
227 	return(ptr->name);
228 }
229 
230 /*
231  * name_gid()
232  *	caches the name (if any) for the gid. If frc set, we always return the
233  *	the stored name (if valid or invalid match). We use a simple hash table.
234  * Return
235  *	Pointer to stored name (or an empty string).
236  */
237 
238 const char *
239 name_gid(gid_t gid, int frc)
240 {
241 	struct group *gr;
242 	GIDC *ptr;
243 
244 	if ((gidtb == NULL) && (gidtb_start() < 0))
245 		return("");
246 
247 	/*
248 	 * see if we have this gid cached
249 	 */
250 	ptr = gidtb[gid % GID_SZ];
251 	if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
252 		/*
253 		 * have an entry for this gid
254 		 */
255 		if (frc || (ptr->valid == VALID))
256 			return(ptr->name);
257 		return("");
258 	}
259 
260 	/*
261 	 * No entry for this gid, we will add it
262 	 */
263 	if (!gropn) {
264 		setgroupent(1);
265 		++gropn;
266 	}
267 	if (ptr == NULL)
268 		ptr = gidtb[gid % GID_SZ] = (GIDC *)malloc(sizeof(GIDC));
269 
270 	if ((gr = getgrgid(gid)) == NULL) {
271 		/*
272 		 * no match for this gid in the local group file, put in
273 		 * a string that is the gid in numeric format
274 		 */
275 		if (ptr == NULL)
276 			return("");
277 		ptr->gid = gid;
278 		ptr->valid = INVALID;
279 		(void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
280 			       (unsigned long)gid);
281 		if (frc == 0)
282 			return("");
283 	} else {
284 		/*
285 		 * there is an entry for this group in the group file
286 		 */
287 		if (ptr == NULL)
288 			return(gr->gr_name);
289 		ptr->gid = gid;
290 		(void)strncpy(ptr->name, gr->gr_name, GNMLEN - 1);
291 		ptr->name[GNMLEN-1] = '\0';
292 		ptr->valid = VALID;
293 	}
294 	return(ptr->name);
295 }
296 
297 /*
298  * uid_name()
299  *	caches the uid for a given user name. We use a simple hash table.
300  * Return
301  *	the uid (if any) for a user name, or a -1 if no match can be found
302  */
303 
304 int
305 uid_name(char *name, uid_t *uid)
306 {
307 	struct passwd *pw;
308 	UIDC *ptr;
309 	int namelen;
310 
311 	/*
312 	 * return -1 for mangled names
313 	 */
314 	if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
315 		return(-1);
316 	if ((usrtb == NULL) && (usrtb_start() < 0))
317 		return(-1);
318 
319 	/*
320 	 * look up in hash table, if found and valid return the uid,
321 	 * if found and invalid, return a -1
322 	 */
323 	ptr = usrtb[st_hash(name, namelen, UNM_SZ)];
324 	if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
325 		if (ptr->valid == INVALID)
326 			return(-1);
327 		*uid = ptr->uid;
328 		return(0);
329 	}
330 
331 	if (!pwopn) {
332 		setpassent(1);
333 		++pwopn;
334 	}
335 
336 	if (ptr == NULL)
337 		ptr = usrtb[st_hash(name, namelen, UNM_SZ)] =
338 		  (UIDC *)malloc(sizeof(UIDC));
339 
340 	/*
341 	 * no match, look it up, if no match store it as an invalid entry,
342 	 * or store the matching uid
343 	 */
344 	if (ptr == NULL) {
345 		if ((pw = getpwnam(name)) == NULL)
346 			return(-1);
347 		*uid = pw->pw_uid;
348 		return(0);
349 	}
350 	(void)strncpy(ptr->name, name, UNMLEN - 1);
351 	ptr->name[UNMLEN-1] = '\0';
352 	if ((pw = getpwnam(name)) == NULL) {
353 		ptr->valid = INVALID;
354 		return(-1);
355 	}
356 	ptr->valid = VALID;
357 	*uid = ptr->uid = pw->pw_uid;
358 	return(0);
359 }
360 
361 /*
362  * gid_name()
363  *	caches the gid for a given group name. We use a simple hash table.
364  * Return
365  *	the gid (if any) for a group name, or a -1 if no match can be found
366  */
367 
368 int
369 gid_name(char *name, gid_t *gid)
370 {
371 	struct group *gr;
372 	GIDC *ptr;
373 	int namelen;
374 
375 	/*
376 	 * return -1 for mangled names
377 	 */
378 	if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
379 		return(-1);
380 	if ((grptb == NULL) && (grptb_start() < 0))
381 		return(-1);
382 
383 	/*
384 	 * look up in hash table, if found and valid return the uid,
385 	 * if found and invalid, return a -1
386 	 */
387 	ptr = grptb[st_hash(name, namelen, GID_SZ)];
388 	if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
389 		if (ptr->valid == INVALID)
390 			return(-1);
391 		*gid = ptr->gid;
392 		return(0);
393 	}
394 
395 	if (!gropn) {
396 		setgroupent(1);
397 		++gropn;
398 	}
399 	if (ptr == NULL)
400 		ptr = grptb[st_hash(name, namelen, GID_SZ)] =
401 		  (GIDC *)malloc(sizeof(GIDC));
402 
403 	/*
404 	 * no match, look it up, if no match store it as an invalid entry,
405 	 * or store the matching gid
406 	 */
407 	if (ptr == NULL) {
408 		if ((gr = getgrnam(name)) == NULL)
409 			return(-1);
410 		*gid = gr->gr_gid;
411 		return(0);
412 	}
413 
414 	(void)strncpy(ptr->name, name, GNMLEN - 1);
415 	ptr->name[GNMLEN-1] = '\0';
416 	if ((gr = getgrnam(name)) == NULL) {
417 		ptr->valid = INVALID;
418 		return(-1);
419 	}
420 	ptr->valid = VALID;
421 	*gid = ptr->gid = gr->gr_gid;
422 	return(0);
423 }
424