bin/pax/cache.c

   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  * @(#)cache.c  8.1 (Berkeley) 5/31/93
  34  * $FreeBSD: src/bin/pax/cache.c,v 1.12.2.1 2001/08/01 05:03:11 obrien Exp $
  35  * $DragonFly: src/bin/pax/cache.c,v 1.7 2006/09/27 21:58:08 pavalos Exp $
  36  */
  37
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <string.h>
  41 #include <stdio.h>
  42 #include <pwd.h>
  43 #include <grp.h>
  44 #include <unistd.h>
  45 #include <stdlib.h>
  46 #include "pax.h"
  47 #include "cache.h"
  48 #include "extern.h"
  49
  50 /*
  51  * routines that control user, group, uid and gid caches (for the archive
  52  * member print routine).
  53  * IMPORTANT:
  54  * these routines cache BOTH hits and misses, a major performance improvement
  55  */
  56
  57 static  int pwopn = 0;          /* is password file open */
  58 static  int gropn = 0;          /* is group file open */
  59 static UIDC **uidtb = NULL;     /* uid to name cache */
  60 static GIDC **gidtb = NULL;     /* gid to name cache */
  61 static UIDC **usrtb = NULL;     /* user name to uid cache */
  62 static GIDC **grptb = NULL;     /* group name to gid cache */
  63
  64 /*
  65  * uidtb_start
  66  *      creates an empty uidtb
  67  * Return:
  68  *      0 if ok, -1 otherwise
  69  */
  70
  71 int
  72 uidtb_start(void)
  73 {
  74         static int fail = 0;
  75
  76         if (uidtb != NULL)
  77                 return(0);
  78         if (fail)
  79                 return(-1);
  80         if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
  81                 ++fail;
  82                 paxwarn(1, "Unable to allocate memory for user id cache table");
  83                 return(-1);
  84         }
  85         return(0);
  86 }
  87
  88 /*
  89  * gidtb_start
  90  *      creates an empty gidtb
  91  * Return:
  92  *      0 if ok, -1 otherwise
  93  */
  94
  95 int
  96 gidtb_start(void)
  97 {
  98         static int fail = 0;
  99
 100         if (gidtb != NULL)
 101                 return(0);
 102         if (fail)
 103                 return(-1);
 104         if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
 105                 ++fail;
 106                 paxwarn(1, "Unable to allocate memory for group id cache table");
 107                 return(-1);
 108         }
 109         return(0);
 110 }
 111
 112 /*
 113  * usrtb_start
 114  *      creates an empty usrtb
 115  * Return:
 116  *      0 if ok, -1 otherwise
 117  */
 118
 119 int
 120 usrtb_start(void)
 121 {
 122         static int fail = 0;
 123
 124         if (usrtb != NULL)
 125                 return(0);
 126         if (fail)
 127                 return(-1);
 128         if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
 129                 ++fail;
 130                 paxwarn(1, "Unable to allocate memory for user name cache table");
 131                 return(-1);
 132         }
 133         return(0);
 134 }
 135
 136 /*
 137  * grptb_start
 138  *      creates an empty grptb
 139  * Return:
 140  *      0 if ok, -1 otherwise
 141  */
 142
 143 int
 144 grptb_start(void)
 145 {
 146         static int fail = 0;
 147
 148         if (grptb != NULL)
 149                 return(0);
 150         if (fail)
 151                 return(-1);
 152         if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
 153                 ++fail;
 154                 paxwarn(1,"Unable to allocate memory for group name cache table");
 155                 return(-1);
 156         }
 157         return(0);
 158 }
 159
 160 /*
 161  * name_uid()
 162  *      caches the name (if any) for the uid. If frc set, we always return the
 163  *      the stored name (if valid or invalid match). We use a simple hash table.
 164  * Return
 165  *      Pointer to stored name (or a empty string)
 166  */
 167
 168 char *
 169 name_uid(uid_t uid, int frc)
 170 {
 171         struct passwd *pw;
 172         UIDC *ptr;
 173
 174         if ((uidtb == NULL) && (uidtb_start() < 0))
 175                 return("");
 176
 177         /*
 178          * see if we have this uid cached
 179          */
 180         ptr = uidtb[uid % UID_SZ];
 181         if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
 182                 /*
 183                  * have an entry for this uid
 184                  */
 185                 if (frc || (ptr->valid == VALID))
 186                         return(ptr->name);
 187                 return("");
 188         }
 189
 190         /*
 191          * No entry for this uid, we will add it
 192          */
 193         if (!pwopn) {
 194                 setpassent(1);
 195                 ++pwopn;
 196         }
 197         if (ptr == NULL)
 198                 ptr = (UIDC *)malloc(sizeof(UIDC));
 199
 200         if ((pw = getpwuid(uid)) == NULL) {
 201                 /*
 202                  * no match for this uid in the local password file
 203                  * a string that is the uid in numeric format
 204                  */
 205                 if (ptr == NULL)
 206                         return("");
 207                 ptr->uid = uid;
 208                 ptr->valid = INVALID;
 209                 snprintf(ptr->name, sizeof(ptr->name), "%lu",
 210                                (unsigned long)uid);
 211                 if (frc == 0)
 212                         return("");
 213         } else {
 214                 /*
 215                  * there is an entry for this uid in the password file
 216                  */
 217                 if (ptr == NULL)
 218                         return(pw->pw_name);
 219                 ptr->uid = uid;
 220                 strncpy(ptr->name, pw->pw_name, UNMLEN - 1);
 221                 ptr->name[UNMLEN-1] = '\0';
 222                 ptr->valid = VALID;
 223         }
 224         return(ptr->name);
 225 }
 226
 227 /*
 228  * name_gid()
 229  *      caches the name (if any) for the gid. If frc set, we always return the
 230  *      the stored name (if valid or invalid match). We use a simple hash table.
 231  * Return
 232  *      Pointer to stored name (or a empty string)
 233  */
 234
 235 char *
 236 name_gid(gid_t gid, int frc)
 237 {
 238         struct group *gr;
 239         GIDC *ptr;
 240
 241         if ((gidtb == NULL) && (gidtb_start() < 0))
 242                 return("");
 243
 244         /*
 245          * see if we have this gid cached
 246          */
 247         ptr = gidtb[gid % GID_SZ];
 248         if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
 249                 /*
 250                  * have an entry for this gid
 251                  */
 252                 if (frc || (ptr->valid == VALID))
 253                         return(ptr->name);
 254                 return("");
 255         }
 256
 257         /*
 258          * No entry for this gid, we will add it
 259          */
 260         if (!gropn) {
 261                 setgroupent(1);
 262                 ++gropn;
 263         }
 264         if (ptr == NULL)
 265                 ptr = (GIDC *)malloc(sizeof(GIDC));
 266
 267         if ((gr = getgrgid(gid)) == NULL) {
 268                 /*
 269                  * no match for this gid in the local group file, put in
 270                  * a string that is the gid in numeric format
 271                  */
 272                 if (ptr == NULL)
 273                         return("");
 274                 ptr->gid = gid;
 275                 ptr->valid = INVALID;
 276                 snprintf(ptr->name, sizeof(ptr->name), "%lu",
 277                                (unsigned long)gid);
 278                 if (frc == 0)
 279                         return("");
 280         } else {
 281                 /*
 282                  * there is an entry for this group in the group file
 283                  */
 284                 if (ptr == NULL)
 285                         return(gr->gr_name);
 286                 ptr->gid = gid;
 287                 strncpy(ptr->name, gr->gr_name, GNMLEN - 1);
 288                 ptr->name[GNMLEN-1] = '\0';
 289                 ptr->valid = VALID;
 290         }
 291         return(ptr->name);
 292 }
 293
 294 /*
 295  * uid_name()
 296  *      caches the uid for a given user name. We use a simple hash table.
 297  * Return
 298  *      the uid (if any) for a user name, or a -1 if no match can be found
 299  */
 300
 301 int
 302 uid_name(char *name, uid_t *uid)
 303 {
 304         struct passwd *pw;
 305         UIDC *ptr;
 306         int namelen;
 307
 308         /*
 309          * return -1 for mangled names
 310          */
 311         if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
 312                 return(-1);
 313         if ((usrtb == NULL) && (usrtb_start() < 0))
 314                 return(-1);
 315
 316         /*
 317          * look up in hash table, if found and valid return the uid,
 318          * if found and invalid, return a -1
 319          */
 320         ptr = usrtb[st_hash(name, namelen, UNM_SZ)];
 321         if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
 322                 if (ptr->valid == INVALID)
 323                         return(-1);
 324                 *uid = ptr->uid;
 325                 return(0);
 326         }
 327
 328         if (!pwopn) {
 329                 setpassent(1);
 330                 ++pwopn;
 331         }
 332
 333         if (ptr == NULL)
 334                 ptr = usrtb[st_hash(name, namelen, UNM_SZ)] =
 335                   (UIDC *)malloc(sizeof(UIDC));
 336
 337         /*
 338          * no match, look it up, if no match store it as an invalid entry,
 339          * or store the matching uid
 340          */
 341         if (ptr == NULL) {
 342                 if ((pw = getpwnam(name)) == NULL)
 343                         return(-1);
 344                 *uid = pw->pw_uid;
 345                 return(0);
 346         }
 347         strncpy(ptr->name, name, UNMLEN - 1);
 348         ptr->name[UNMLEN-1] = '\0';
 349         if ((pw = getpwnam(name)) == NULL) {
 350                 ptr->valid = INVALID;
 351                 return(-1);
 352         }
 353         ptr->valid = VALID;
 354         *uid = ptr->uid = pw->pw_uid;
 355         return(0);
 356 }
 357
 358 /*
 359  * gid_name()
 360  *      caches the gid for a given group name. We use a simple hash table.
 361  * Return
 362  *      the gid (if any) for a group name, or a -1 if no match can be found
 363  */
 364
 365 int
 366 gid_name(char *name, gid_t *gid)
 367 {
 368         struct group *gr;
 369         GIDC *ptr;
 370         int namelen;
 371
 372         /*
 373          * return -1 for mangled names
 374          */
 375         if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
 376                 return(-1);
 377         if ((grptb == NULL) && (grptb_start() < 0))
 378                 return(-1);
 379
 380         /*
 381          * look up in hash table, if found and valid return the uid,
 382          * if found and invalid, return a -1
 383          */
 384         ptr = grptb[st_hash(name, namelen, GID_SZ)];
 385         if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
 386                 if (ptr->valid == INVALID)
 387                         return(-1);
 388                 *gid = ptr->gid;
 389                 return(0);
 390         }
 391
 392         if (!gropn) {
 393                 setgroupent(1);
 394                 ++gropn;
 395         }
 396         if (ptr == NULL)
 397                 ptr = grptb[st_hash(name, namelen, GID_SZ)] =
 398                   (GIDC *)malloc(sizeof(GIDC));
 399
 400         /*
 401          * no match, look it up, if no match store it as an invalid entry,
 402          * or store the matching gid
 403          */
 404         if (ptr == NULL) {
 405                 if ((gr = getgrnam(name)) == NULL)
 406                         return(-1);
 407                 *gid = gr->gr_gid;
 408                 return(0);
 409         }
 410
 411         strncpy(ptr->name, name, GNMLEN - 1);
 412         ptr->name[GNMLEN-1] = '\0';
 413         if ((gr = getgrnam(name)) == NULL) {
 414                 ptr->valid = INVALID;
 415                 return(-1);
 416         }
 417         ptr->valid = VALID;
 418         *gid = ptr->gid = gr->gr_gid;
 419         return(0);
 420 }