xref: /freebsd/bin/pax/cache.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 1992 Keith Muller.
3  * Copyright (c) 1992, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Keith Muller of the University of California, San Diego.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. 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 
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)cache.c	8.1 (Berkeley) 5/31/93";
37 #endif
38 #endif /* not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
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 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 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 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 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 #		ifdef NET2_STAT
213 		(void)snprintf(ptr->name, sizeof(ptr->name), "%u", uid);
214 #		else
215 		(void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
216 			       (unsigned long)uid);
217 #		endif
218 		if (frc == 0)
219 			return("");
220 	} else {
221 		/*
222 		 * there is an entry for this uid in the password file
223 		 */
224 		if (ptr == NULL)
225 			return(pw->pw_name);
226 		ptr->uid = uid;
227 		(void)strncpy(ptr->name, pw->pw_name, UNMLEN - 1);
228 		ptr->name[UNMLEN-1] = '\0';
229 		ptr->valid = VALID;
230 	}
231 	return(ptr->name);
232 }
233 
234 /*
235  * name_gid()
236  *	caches the name (if any) for the gid. If frc set, we always return the
237  *	the stored name (if valid or invalid match). We use a simple hash table.
238  * Return
239  *	Pointer to stored name (or an empty string).
240  */
241 
242 const char *
243 name_gid(gid_t gid, int frc)
244 {
245 	struct group *gr;
246 	GIDC *ptr;
247 
248 	if ((gidtb == NULL) && (gidtb_start() < 0))
249 		return("");
250 
251 	/*
252 	 * see if we have this gid cached
253 	 */
254 	ptr = gidtb[gid % GID_SZ];
255 	if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
256 		/*
257 		 * have an entry for this gid
258 		 */
259 		if (frc || (ptr->valid == VALID))
260 			return(ptr->name);
261 		return("");
262 	}
263 
264 	/*
265 	 * No entry for this gid, we will add it
266 	 */
267 	if (!gropn) {
268 		setgroupent(1);
269 		++gropn;
270 	}
271 	if (ptr == NULL)
272 		ptr = gidtb[gid % GID_SZ] = (GIDC *)malloc(sizeof(GIDC));
273 
274 	if ((gr = getgrgid(gid)) == NULL) {
275 		/*
276 		 * no match for this gid in the local group file, put in
277 		 * a string that is the gid in numeric format
278 		 */
279 		if (ptr == NULL)
280 			return("");
281 		ptr->gid = gid;
282 		ptr->valid = INVALID;
283 #		ifdef NET2_STAT
284 		(void)snprintf(ptr->name, sizeof(ptr->name), "%u", gid);
285 #		else
286 		(void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
287 			       (unsigned long)gid);
288 #		endif
289 		if (frc == 0)
290 			return("");
291 	} else {
292 		/*
293 		 * there is an entry for this group in the group file
294 		 */
295 		if (ptr == NULL)
296 			return(gr->gr_name);
297 		ptr->gid = gid;
298 		(void)strncpy(ptr->name, gr->gr_name, GNMLEN - 1);
299 		ptr->name[GNMLEN-1] = '\0';
300 		ptr->valid = VALID;
301 	}
302 	return(ptr->name);
303 }
304 
305 /*
306  * uid_name()
307  *	caches the uid for a given user name. We use a simple hash table.
308  * Return
309  *	the uid (if any) for a user name, or a -1 if no match can be found
310  */
311 
312 int
313 uid_name(char *name, uid_t *uid)
314 {
315 	struct passwd *pw;
316 	UIDC *ptr;
317 	int namelen;
318 
319 	/*
320 	 * return -1 for mangled names
321 	 */
322 	if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
323 		return(-1);
324 	if ((usrtb == NULL) && (usrtb_start() < 0))
325 		return(-1);
326 
327 	/*
328 	 * look up in hash table, if found and valid return the uid,
329 	 * if found and invalid, return a -1
330 	 */
331 	ptr = usrtb[st_hash(name, namelen, UNM_SZ)];
332 	if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
333 		if (ptr->valid == INVALID)
334 			return(-1);
335 		*uid = ptr->uid;
336 		return(0);
337 	}
338 
339 	if (!pwopn) {
340 		setpassent(1);
341 		++pwopn;
342 	}
343 
344 	if (ptr == NULL)
345 		ptr = usrtb[st_hash(name, namelen, UNM_SZ)] =
346 		  (UIDC *)malloc(sizeof(UIDC));
347 
348 	/*
349 	 * no match, look it up, if no match store it as an invalid entry,
350 	 * or store the matching uid
351 	 */
352 	if (ptr == NULL) {
353 		if ((pw = getpwnam(name)) == NULL)
354 			return(-1);
355 		*uid = pw->pw_uid;
356 		return(0);
357 	}
358 	(void)strncpy(ptr->name, name, UNMLEN - 1);
359 	ptr->name[UNMLEN-1] = '\0';
360 	if ((pw = getpwnam(name)) == NULL) {
361 		ptr->valid = INVALID;
362 		return(-1);
363 	}
364 	ptr->valid = VALID;
365 	*uid = ptr->uid = pw->pw_uid;
366 	return(0);
367 }
368 
369 /*
370  * gid_name()
371  *	caches the gid for a given group name. We use a simple hash table.
372  * Return
373  *	the gid (if any) for a group name, or a -1 if no match can be found
374  */
375 
376 int
377 gid_name(char *name, gid_t *gid)
378 {
379 	struct group *gr;
380 	GIDC *ptr;
381 	int namelen;
382 
383 	/*
384 	 * return -1 for mangled names
385 	 */
386 	if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
387 		return(-1);
388 	if ((grptb == NULL) && (grptb_start() < 0))
389 		return(-1);
390 
391 	/*
392 	 * look up in hash table, if found and valid return the uid,
393 	 * if found and invalid, return a -1
394 	 */
395 	ptr = grptb[st_hash(name, namelen, GID_SZ)];
396 	if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
397 		if (ptr->valid == INVALID)
398 			return(-1);
399 		*gid = ptr->gid;
400 		return(0);
401 	}
402 
403 	if (!gropn) {
404 		setgroupent(1);
405 		++gropn;
406 	}
407 	if (ptr == NULL)
408 		ptr = grptb[st_hash(name, namelen, GID_SZ)] =
409 		  (GIDC *)malloc(sizeof(GIDC));
410 
411 	/*
412 	 * no match, look it up, if no match store it as an invalid entry,
413 	 * or store the matching gid
414 	 */
415 	if (ptr == NULL) {
416 		if ((gr = getgrnam(name)) == NULL)
417 			return(-1);
418 		*gid = gr->gr_gid;
419 		return(0);
420 	}
421 
422 	(void)strncpy(ptr->name, name, GNMLEN - 1);
423 	ptr->name[GNMLEN-1] = '\0';
424 	if ((gr = getgrnam(name)) == NULL) {
425 		ptr->valid = INVALID;
426 		return(-1);
427 	}
428 	ptr->valid = VALID;
429 	*gid = ptr->gid = gr->gr_gid;
430 	return(0);
431 }
432