pax/cache.c

   1 /*      $OpenBSD: cache.c,v 1.17 2004/03/16 03:28:34 tedu Exp $ */
   2 /*      $NetBSD: cache.c,v 1.4 1995/03/21 09:07:10 cgd Exp $    */
   3
   4 /*-
   5  * Copyright (c) 1992 Keith Muller.
   6  * Copyright (c) 1992, 1993
   7  *      The Regents of the University of California.  All rights reserved.
   8  *
   9  * This code is derived from software contributed to Berkeley by
  10  * Keith Muller of the University of California, San Diego.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #ifndef lint
  38 #if 0
  39 static const char sccsid[] = "@(#)cache.c       8.1 (Berkeley) 5/31/93";
  40 #else
  41 static const char rcsid[] = "$OpenBSD: cache.c,v 1.17 2004/03/16 03:28:34 tedu Exp $";
  42 #endif
  43 #endif /* not lint */
  44
  45 #include <sys/types.h>
  46 #include <sys/time.h>
  47 #include <sys/stat.h>
  48 #include <sys/param.h>
  49 #include <string.h>
  50 #include <stdio.h>
  51 #include <pwd.h>
  52 #include <grp.h>
  53 #include <unistd.h>
  54 #include <stdlib.h>
  55 #include "pax.h"
  56 #include "cache.h"
  57 #include "extern.h"
  58
  59 /*
  60  * routines that control user, group, uid and gid caches (for the archive
  61  * member print routine).
  62  * IMPORTANT:
  63  * these routines cache BOTH hits and misses, a major performance improvement
  64  */
  65
  66 static  int pwopn = 0;          /* is password file open */
  67 static  int gropn = 0;          /* is group file open */
  68 static UIDC **uidtb = NULL;     /* uid to name cache */
  69 static GIDC **gidtb = NULL;     /* gid to name cache */
  70 static UIDC **usrtb = NULL;     /* user name to uid cache */
  71 static GIDC **grptb = NULL;     /* group name to gid cache */
  72
  73 /*
  74  * uidtb_start
  75  *      creates an empty uidtb
  76  * Return:
  77  *      0 if ok, -1 otherwise
  78  */
  79
  80 int
  81 uidtb_start(void)
  82 {
  83         static int fail = 0;
  84
  85         if (uidtb != NULL)
  86                 return(0);
  87         if (fail)
  88                 return(-1);
  89         if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
  90                 ++fail;
  91                 paxwarn(1, "Unable to allocate memory for user id cache table");
  92                 return(-1);
  93         }
  94         return(0);
  95 }
  96
  97 /*
  98  * gidtb_start
  99  *      creates an empty gidtb
 100  * Return:
 101  *      0 if ok, -1 otherwise
 102  */
 103
 104 int
 105 gidtb_start(void)
 106 {
 107         static int fail = 0;
 108
 109         if (gidtb != NULL)
 110                 return(0);
 111         if (fail)
 112                 return(-1);
 113         if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
 114                 ++fail;
 115                 paxwarn(1, "Unable to allocate memory for group id cache table");
 116                 return(-1);
 117         }
 118         return(0);
 119 }
 120
 121 /*
 122  * usrtb_start
 123  *      creates an empty usrtb
 124  * Return:
 125  *      0 if ok, -1 otherwise
 126  */
 127
 128 int
 129 usrtb_start(void)
 130 {
 131         static int fail = 0;
 132
 133         if (usrtb != NULL)
 134                 return(0);
 135         if (fail)
 136                 return(-1);
 137         if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
 138                 ++fail;
 139                 paxwarn(1, "Unable to allocate memory for user name cache table");
 140                 return(-1);
 141         }
 142         return(0);
 143 }
 144
 145 /*
 146  * grptb_start
 147  *      creates an empty grptb
 148  * Return:
 149  *      0 if ok, -1 otherwise
 150  */
 151
 152 int
 153 grptb_start(void)
 154 {
 155         static int fail = 0;
 156
 157         if (grptb != NULL)
 158                 return(0);
 159         if (fail)
 160                 return(-1);
 161         if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
 162                 ++fail;
 163                 paxwarn(1,"Unable to allocate memory for group name cache table");
 164                 return(-1);
 165         }
 166         return(0);
 167 }
 168
 169 /*
 170  * name_uid()
 171  *      caches the name (if any) for the uid. If frc set, we always return the
 172  *      the stored name (if valid or invalid match). We use a simple hash table.
 173  * Return
 174  *      Pointer to stored name (or a empty string)
 175  */
 176
 177 char *
 178 name_uid(uid_t uid, int frc)
 179 {
 180         struct passwd *pw;
 181         UIDC *ptr;
 182
 183         if ((uidtb == NULL) && (uidtb_start() < 0))
 184                 return("");
 185
 186         /*
 187          * see if we have this uid cached
 188          */
 189         ptr = uidtb[uid % UID_SZ];
 190         if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
 191                 /*
 192                  * have an entry for this uid
 193                  */
 194                 if (frc || (ptr->valid == VALID))
 195                         return(ptr->name);
 196                 return("");
 197         }
 198
 199         /*
 200          * No entry for this uid, we will add it
 201          */
 202         if (!pwopn) {
 203                 setpassent(1);
 204                 ++pwopn;
 205         }
 206         if (ptr == NULL)
 207                 ptr = uidtb[uid % UID_SZ] = malloc(sizeof(UIDC));
 208
 209         if ((pw = getpwuid(uid)) == NULL) {
 210                 /*
 211                  * no match for this uid in the local password file
 212                  * a string that is the uid in numeric format
 213                  */
 214                 if (ptr == NULL)
 215                         return("");
 216                 ptr->uid = uid;
 217                 ptr->valid = INVALID;
 218                 (void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
 219                                (unsigned long)uid);
 220                 if (frc == 0)
 221                         return("");
 222         } else {
 223                 /*
 224                  * there is an entry for this uid in the password file
 225                  */
 226                 if (ptr == NULL)
 227                         return(pw->pw_name);
 228                 ptr->uid = uid;
 229                 (void)strlcpy(ptr->name, pw->pw_name, sizeof(ptr->name));
 230                 ptr->valid = VALID;
 231         }
 232         return(ptr->name);
 233 }
 234
 235 /*
 236  * name_gid()
 237  *      caches the name (if any) for the gid. If frc set, we always return the
 238  *      the stored name (if valid or invalid match). We use a simple hash table.
 239  * Return
 240  *      Pointer to stored name (or a empty string)
 241  */
 242
 243 char *
 244 name_gid(gid_t gid, int frc)
 245 {
 246         struct group *gr;
 247         GIDC *ptr;
 248
 249         if ((gidtb == NULL) && (gidtb_start() < 0))
 250                 return("");
 251
 252         /*
 253          * see if we have this gid cached
 254          */
 255         ptr = gidtb[gid % GID_SZ];
 256         if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
 257                 /*
 258                  * have an entry for this gid
 259                  */
 260                 if (frc || (ptr->valid == VALID))
 261                         return(ptr->name);
 262                 return("");
 263         }
 264
 265         /*
 266          * No entry for this gid, we will add it
 267          */
 268         if (!gropn) {
 269                 setgroupent(1);
 270                 ++gropn;
 271         }
 272         if (ptr == NULL)
 273                 ptr = gidtb[gid % GID_SZ] = malloc(sizeof(GIDC));
 274
 275         if ((gr = getgrgid(gid)) == NULL) {
 276                 /*
 277                  * no match for this gid in the local group file, put in
 278                  * a string that is the gid in numberic format
 279                  */
 280                 if (ptr == NULL)
 281                         return("");
 282                 ptr->gid = gid;
 283                 ptr->valid = INVALID;
 284                 (void)snprintf(ptr->name, sizeof(ptr->name), "%lu",
 285                                (unsigned long)gid);
 286                 if (frc == 0)
 287                         return("");
 288         } else {
 289                 /*
 290                  * there is an entry for this group in the group file
 291                  */
 292                 if (ptr == NULL)
 293                         return(gr->gr_name);
 294                 ptr->gid = gid;
 295                 (void)strlcpy(ptr->name, gr->gr_name, sizeof(ptr->name));
 296                 ptr->valid = VALID;
 297         }
 298         return(ptr->name);
 299 }
 300
 301 /*
 302  * uid_name()
 303  *      caches the uid for a given user name. We use a simple hash table.
 304  * Return
 305  *      the uid (if any) for a user name, or a -1 if no match can be found
 306  */
 307
 308 int
 309 uid_name(char *name, uid_t *uid)
 310 {
 311         struct passwd *pw;
 312         UIDC *ptr;
 313         int namelen;
 314
 315         /*
 316          * return -1 for mangled names
 317          */
 318         if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
 319                 return(-1);
 320         if ((usrtb == NULL) && (usrtb_start() < 0))
 321                 return(-1);
 322
 323         /*
 324          * look up in hash table, if found and valid return the uid,
 325          * if found and invalid, return a -1
 326          */
 327         ptr = usrtb[st_hash(name, namelen, UNM_SZ)];
 328         if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
 329                 if (ptr->valid == INVALID)
 330                         return(-1);
 331                 *uid = ptr->uid;
 332                 return(0);
 333         }
 334
 335         if (!pwopn) {
 336                 setpassent(1);
 337                 ++pwopn;
 338         }
 339
 340         if (ptr == NULL)
 341                 ptr = usrtb[st_hash(name, namelen, UNM_SZ)] =
 342                   (UIDC *)malloc(sizeof(UIDC));
 343
 344         /*
 345          * no match, look it up, if no match store it as an invalid entry,
 346          * or store the matching uid
 347          */
 348         if (ptr == NULL) {
 349                 if ((pw = getpwnam(name)) == NULL)
 350                         return(-1);
 351                 *uid = pw->pw_uid;
 352                 return(0);
 353         }
 354         (void)strlcpy(ptr->name, name, sizeof(ptr->name));
 355         if ((pw = getpwnam(name)) == NULL) {
 356                 ptr->valid = INVALID;
 357                 return(-1);
 358         }
 359         ptr->valid = VALID;
 360         *uid = ptr->uid = pw->pw_uid;
 361         return(0);
 362 }
 363
 364 /*
 365  * gid_name()
 366  *      caches the gid for a given group name. We use a simple hash table.
 367  * Return
 368  *      the gid (if any) for a group name, or a -1 if no match can be found
 369  */
 370
 371 int
 372 gid_name(char *name, gid_t *gid)
 373 {
 374         struct group *gr;
 375         GIDC *ptr;
 376         int namelen;
 377
 378         /*
 379          * return -1 for mangled names
 380          */
 381         if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
 382                 return(-1);
 383         if ((grptb == NULL) && (grptb_start() < 0))
 384                 return(-1);
 385
 386         /*
 387          * look up in hash table, if found and valid return the uid,
 388          * if found and invalid, return a -1
 389          */
 390         ptr = grptb[st_hash(name, namelen, GID_SZ)];
 391         if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
 392                 if (ptr->valid == INVALID)
 393                         return(-1);
 394                 *gid = ptr->gid;
 395                 return(0);
 396         }
 397
 398         if (!gropn) {
 399                 setgroupent(1);
 400                 ++gropn;
 401         }
 402         if (ptr == NULL)
 403                 ptr = grptb[st_hash(name, namelen, GID_SZ)] =
 404                   (GIDC *)malloc(sizeof(GIDC));
 405
 406         /*
 407          * no match, look it up, if no match store it as an invalid entry,
 408          * or store the matching gid
 409          */
 410         if (ptr == NULL) {
 411                 if ((gr = getgrnam(name)) == NULL)
 412                         return(-1);
 413                 *gid = gr->gr_gid;
 414                 return(0);
 415         }
 416
 417         (void)strlcpy(ptr->name, name, sizeof(ptr->name));
 418         if ((gr = getgrnam(name)) == NULL) {
 419                 ptr->valid = INVALID;
 420                 return(-1);
 421         }
 422         ptr->valid = VALID;
 423         *gid = ptr->gid = gr->gr_gid;
 424         return(0);
 425 }