2 * Copyright (c) 2003-2007 Tim Kientzle
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 #include "archive_platform.h"
27 __FBSDID("$FreeBSD$");
29 #ifdef HAVE_SYS_TYPES_H
30 #include <sys/types.h>
35 #ifdef HAVE_ATTR_XATTR_H
36 #include <attr/xattr.h>
38 #ifdef HAVE_SYS_IOCTL_H
39 #include <sys/ioctl.h>
41 #ifdef HAVE_SYS_STAT_H
44 #ifdef HAVE_SYS_TIME_H
65 #include "archive_private.h"
66 #include "archive_read_private.h"
67 #include "archive_write_disk_private.h"
75 static const size_t cache_size = 127;
76 static unsigned int hash(const char *);
77 static gid_t lookup_gid(void *, const char *uname, gid_t);
78 static uid_t lookup_uid(void *, const char *uname, uid_t);
79 static void cleanup(void *);
82 * Installs functions that use getpwnam()/getgrnam()---along with
83 * a simple cache to accelerate such lookups---into the archive_write_disk
84 * object. This is in a separate file because getpwnam()/getgrnam()
85 * can pull in a LOT of library code (including NIS/LDAP functions, which
86 * pull in DNS resolveers, etc). This can easily top 500kB, which makes
87 * it inappropriate for some space-constrained applications.
89 * Applications that are size-sensitive may want to just use the
90 * real default functions (defined in archive_write_disk.c) that just
91 * use the uid/gid without the lookup. Or define your own custom functions
94 * TODO: Replace these hash tables with simpler move-to-front LRU
95 * lists with a bounded size (128 items?). The hash is a bit faster,
96 * but has a bad pathology in which it thrashes a single bucket. Even
97 * walking a list of 128 items is a lot faster than calling
101 archive_write_disk_set_standard_lookup(struct archive *a)
103 struct bucket *ucache = malloc(sizeof(struct bucket[cache_size]));
104 struct bucket *gcache = malloc(sizeof(struct bucket[cache_size]));
105 memset(ucache, 0, sizeof(struct bucket[cache_size]));
106 memset(gcache, 0, sizeof(struct bucket[cache_size]));
107 archive_write_disk_set_group_lookup(a, gcache, lookup_gid, cleanup);
108 archive_write_disk_set_user_lookup(a, ucache, lookup_uid, cleanup);
113 lookup_gid(void *private_data, const char *gname, gid_t gid)
117 struct bucket *gcache = (struct bucket *)private_data;
119 /* If no gname, just use the gid provided. */
120 if (gname == NULL || *gname == '\0')
123 /* Try to find gname in the cache. */
125 b = &gcache[h % cache_size ];
126 if (b->name != NULL && b->hash == h && strcmp(gname, b->name) == 0)
127 return ((gid_t)b->id);
129 /* Free the cache slot for a new entry. */
132 b->name = strdup(gname);
133 /* Note: If strdup fails, that's okay; we just won't cache. */
137 struct group *grent = getgrnam(gname);
142 /* TODO: do a gname->gid lookup for Windows. */
150 lookup_uid(void *private_data, const char *uname, uid_t uid)
154 struct bucket *ucache = (struct bucket *)private_data;
156 /* If no uname, just use the uid provided. */
157 if (uname == NULL || *uname == '\0')
160 /* Try to find uname in the cache. */
162 b = &ucache[h % cache_size ];
163 if (b->name != NULL && b->hash == h && strcmp(uname, b->name) == 0)
164 return ((uid_t)b->id);
166 /* Free the cache slot for a new entry. */
169 b->name = strdup(uname);
170 /* Note: If strdup fails, that's okay; we just won't cache. */
174 struct passwd *pwent = getpwnam(uname);
179 /* TODO: do a uname->uid lookup for Windows. */
187 cleanup(void *private)
190 struct bucket *cache = (struct bucket *)private;
192 for (i = 0; i < cache_size; i++)
201 /* A 32-bit version of Peter Weinberger's (PJW) hash algorithm,
202 as used by ELF for hashing function names. */
205 h = ( h << 4 ) + *p++;
206 if (( g = h & 0xF0000000 )) {