xref: /freebsd/bin/pax/cache.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <string.h>
39 #include <stdio.h>
40 #include <pwd.h>
41 #include <grp.h>
42 #include <stdlib.h>
43 #include "pax.h"
44 #include "cache.h"
45 #include "extern.h"
46 
47 /*
48  * routines that control user, group, uid and gid caches (for the archive
49  * member print routine).
50  * IMPORTANT:
51  * these routines cache BOTH hits and misses, a major performance improvement
52  */
53 
54 static	int pwopn = 0;		/* is password file open */
55 static	int gropn = 0;		/* is group file open */
56 static UIDC **uidtb = NULL;	/* uid to name cache */
57 static GIDC **gidtb = NULL;	/* gid to name cache */
58 static UIDC **usrtb = NULL;	/* user name to uid cache */
59 static GIDC **grptb = NULL;	/* group name to gid cache */
60 
61 /*
62  * uidtb_start
63  *	creates an empty uidtb
64  * Return:
65  *	0 if ok, -1 otherwise
66  */
67 
68 int
69 uidtb_start(void)
70 {
71 	static int fail = 0;
72 
73 	if (uidtb != NULL)
74 		return(0);
75 	if (fail)
76 		return(-1);
77 	if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
78 		++fail;
79 		paxwarn(1, "Unable to allocate memory for user id cache table");
80 		return(-1);
81 	}
82 	return(0);
83 }
84 
85 /*
86  * gidtb_start
87  *	creates an empty gidtb
88  * Return:
89  *	0 if ok, -1 otherwise
90  */
91 
92 int
93 gidtb_start(void)
94 {
95 	static int fail = 0;
96 
97 	if (gidtb != NULL)
98 		return(0);
99 	if (fail)
100 		return(-1);
101 	if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
102 		++fail;
103 		paxwarn(1, "Unable to allocate memory for group id cache table");
104 		return(-1);
105 	}
106 	return(0);
107 }
108 
109 /*
110  * usrtb_start
111  *	creates an empty usrtb
112  * Return:
113  *	0 if ok, -1 otherwise
114  */
115 
116 int
117 usrtb_start(void)
118 {
119 	static int fail = 0;
120 
121 	if (usrtb != NULL)
122 		return(0);
123 	if (fail)
124 		return(-1);
125 	if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
126 		++fail;
127 		paxwarn(1, "Unable to allocate memory for user name cache table");
128 		return(-1);
129 	}
130 	return(0);
131 }
132 
133 /*
134  * grptb_start
135  *	creates an empty grptb
136  * Return:
137  *	0 if ok, -1 otherwise
138  */
139 
140 int
141 grptb_start(void)
142 {
143 	static int fail = 0;
144 
145 	if (grptb != NULL)
146 		return(0);
147 	if (fail)
148 		return(-1);
149 	if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
150 		++fail;
151 		paxwarn(1,"Unable to allocate memory for group name cache table");
152 		return(-1);
153 	}
154 	return(0);
155 }
156 
157 /*
158  * name_uid()
159  *	caches the name (if any) for the uid. If frc set, we always return the
160  *	the stored name (if valid or invalid match). We use a simple hash table.
161  * Return
162  *	Pointer to stored name (or an empty string).
163  */
164 
165 const char *
166 name_uid(uid_t uid, int frc)
167 {
168 	struct passwd *pw;
169 	UIDC *ptr;
170 
171 	if ((uidtb == NULL) && (uidtb_start() < 0))
172 		return("");
173 
174 	/*
175 	 * see if we have this uid cached
176 	 */
177 	ptr = uidtb[uid % UID_SZ];
178 	if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
179 		/*
180 		 * have an entry for this uid
181 		 */
182 		if (frc || (ptr->valid == VALID))
183 			return(ptr->name);
184 		return("");
185 	}
186 
187 	/*
188 	 * No entry for this uid, we will add it
189 	 */
190 	if (!pwopn) {
191 		setpassent(1);
192 		++pwopn;
193 	}
194 	if (ptr == NULL)
195 		ptr = uidtb[uid % UID_SZ] = (UIDC *)malloc(sizeof(UIDC));
196 
197 	if ((pw = getpwuid(uid)) == NULL) {
198 		/*
199 		 * no match for this uid in the local password file
200 		 * a string that is the uid in numeric format
201 		 */
202 		if (ptr == NULL)
203 			return("");
204 		ptr->uid = uid;
205 		ptr->valid = INVALID;
206 		(void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
207 			       (unsigned long)uid);
208 		if (frc == 0)
209 			return("");
210 	} else {
211 		/*
212 		 * there is an entry for this uid in the password file
213 		 */
214 		if (ptr == NULL)
215 			return(pw->pw_name);
216 		ptr->uid = uid;
217 		(void)strncpy(ptr->name, pw->pw_name, UNMLEN - 1);
218 		ptr->name[UNMLEN-1] = '\0';
219 		ptr->valid = VALID;
220 	}
221 	return(ptr->name);
222 }
223 
224 /*
225  * name_gid()
226  *	caches the name (if any) for the gid. If frc set, we always return the
227  *	the stored name (if valid or invalid match). We use a simple hash table.
228  * Return
229  *	Pointer to stored name (or an empty string).
230  */
231 
232 const char *
233 name_gid(gid_t gid, int frc)
234 {
235 	struct group *gr;
236 	GIDC *ptr;
237 
238 	if ((gidtb == NULL) && (gidtb_start() < 0))
239 		return("");
240 
241 	/*
242 	 * see if we have this gid cached
243 	 */
244 	ptr = gidtb[gid % GID_SZ];
245 	if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
246 		/*
247 		 * have an entry for this gid
248 		 */
249 		if (frc || (ptr->valid == VALID))
250 			return(ptr->name);
251 		return("");
252 	}
253 
254 	/*
255 	 * No entry for this gid, we will add it
256 	 */
257 	if (!gropn) {
258 		setgroupent(1);
259 		++gropn;
260 	}
261 	if (ptr == NULL)
262 		ptr = gidtb[gid % GID_SZ] = (GIDC *)malloc(sizeof(GIDC));
263 
264 	if ((gr = getgrgid(gid)) == NULL) {
265 		/*
266 		 * no match for this gid in the local group file, put in
267 		 * a string that is the gid in numeric format
268 		 */
269 		if (ptr == NULL)
270 			return("");
271 		ptr->gid = gid;
272 		ptr->valid = INVALID;
273 		(void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
274 			       (unsigned long)gid);
275 		if (frc == 0)
276 			return("");
277 	} else {
278 		/*
279 		 * there is an entry for this group in the group file
280 		 */
281 		if (ptr == NULL)
282 			return(gr->gr_name);
283 		ptr->gid = gid;
284 		(void)strncpy(ptr->name, gr->gr_name, GNMLEN - 1);
285 		ptr->name[GNMLEN-1] = '\0';
286 		ptr->valid = VALID;
287 	}
288 	return(ptr->name);
289 }
290 
291 /*
292  * uid_name()
293  *	caches the uid for a given user name. We use a simple hash table.
294  * Return
295  *	the uid (if any) for a user name, or a -1 if no match can be found
296  */
297 
298 int
299 uid_name(char *name, uid_t *uid)
300 {
301 	struct passwd *pw;
302 	UIDC *ptr;
303 	int namelen;
304 
305 	/*
306 	 * return -1 for mangled names
307 	 */
308 	if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
309 		return(-1);
310 	if ((usrtb == NULL) && (usrtb_start() < 0))
311 		return(-1);
312 
313 	/*
314 	 * look up in hash table, if found and valid return the uid,
315 	 * if found and invalid, return a -1
316 	 */
317 	ptr = usrtb[st_hash(name, namelen, UNM_SZ)];
318 	if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
319 		if (ptr->valid == INVALID)
320 			return(-1);
321 		*uid = ptr->uid;
322 		return(0);
323 	}
324 
325 	if (!pwopn) {
326 		setpassent(1);
327 		++pwopn;
328 	}
329 
330 	if (ptr == NULL)
331 		ptr = usrtb[st_hash(name, namelen, UNM_SZ)] =
332 		  (UIDC *)malloc(sizeof(UIDC));
333 
334 	/*
335 	 * no match, look it up, if no match store it as an invalid entry,
336 	 * or store the matching uid
337 	 */
338 	if (ptr == NULL) {
339 		if ((pw = getpwnam(name)) == NULL)
340 			return(-1);
341 		*uid = pw->pw_uid;
342 		return(0);
343 	}
344 	(void)strncpy(ptr->name, name, UNMLEN - 1);
345 	ptr->name[UNMLEN-1] = '\0';
346 	if ((pw = getpwnam(name)) == NULL) {
347 		ptr->valid = INVALID;
348 		return(-1);
349 	}
350 	ptr->valid = VALID;
351 	*uid = ptr->uid = pw->pw_uid;
352 	return(0);
353 }
354 
355 /*
356  * gid_name()
357  *	caches the gid for a given group name. We use a simple hash table.
358  * Return
359  *	the gid (if any) for a group name, or a -1 if no match can be found
360  */
361 
362 int
363 gid_name(char *name, gid_t *gid)
364 {
365 	struct group *gr;
366 	GIDC *ptr;
367 	int namelen;
368 
369 	/*
370 	 * return -1 for mangled names
371 	 */
372 	if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
373 		return(-1);
374 	if ((grptb == NULL) && (grptb_start() < 0))
375 		return(-1);
376 
377 	/*
378 	 * look up in hash table, if found and valid return the uid,
379 	 * if found and invalid, return a -1
380 	 */
381 	ptr = grptb[st_hash(name, namelen, GID_SZ)];
382 	if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
383 		if (ptr->valid == INVALID)
384 			return(-1);
385 		*gid = ptr->gid;
386 		return(0);
387 	}
388 
389 	if (!gropn) {
390 		setgroupent(1);
391 		++gropn;
392 	}
393 	if (ptr == NULL)
394 		ptr = grptb[st_hash(name, namelen, GID_SZ)] =
395 		  (GIDC *)malloc(sizeof(GIDC));
396 
397 	/*
398 	 * no match, look it up, if no match store it as an invalid entry,
399 	 * or store the matching gid
400 	 */
401 	if (ptr == NULL) {
402 		if ((gr = getgrnam(name)) == NULL)
403 			return(-1);
404 		*gid = gr->gr_gid;
405 		return(0);
406 	}
407 
408 	(void)strncpy(ptr->name, name, GNMLEN - 1);
409 	ptr->name[GNMLEN-1] = '\0';
410 	if ((gr = getgrnam(name)) == NULL) {
411 		ptr->valid = INVALID;
412 		return(-1);
413 	}
414 	ptr->valid = VALID;
415 	*gid = ptr->gid = gr->gr_gid;
416 	return(0);
417 }
418