blob: 97a568e057af31b04e48e56c1cbc2952026b7218 [file] [log] [blame]
/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD: head/lib/libarchive/archive_read_disk_set_standard_lookup.c 201109 2009-12-28 03:30:31Z kientzle $");
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_GRP_H
#include <grp.h>
#endif
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "archive.h"
#if defined(_WIN32) && !defined(__CYGWIN__)
int
archive_read_disk_set_standard_lookup(struct archive *a)
{
archive_set_error(a, -1, "Standard lookups not available on Windows");
return (ARCHIVE_FATAL);
}
#else /* ! (_WIN32 && !__CYGWIN__) */
#define name_cache_size 127
static const char * const NO_NAME = "(noname)";
struct name_cache {
struct archive *archive;
char *buff;
size_t buff_size;
int probes;
int hits;
size_t size;
struct {
id_t id;
const char *name;
} cache[name_cache_size];
};
static const char * lookup_gname(void *, gid_t);
static const char * lookup_uname(void *, uid_t);
static void cleanup(void *);
static const char * lookup_gname_helper(struct name_cache *, id_t gid);
static const char * lookup_uname_helper(struct name_cache *, id_t uid);
/*
* Installs functions that use getpwuid()/getgrgid()---along with
* a simple cache to accelerate such lookups---into the archive_read_disk
* object. This is in a separate file because getpwuid()/getgrgid()
* can pull in a LOT of library code (including NIS/LDAP functions, which
* pull in DNS resolveers, etc). This can easily top 500kB, which makes
* it inappropriate for some space-constrained applications.
*
* Applications that are size-sensitive may want to just use the
* real default functions (defined in archive_read_disk.c) that just
* use the uid/gid without the lookup. Or define your own custom functions
* if you prefer.
*/
int
archive_read_disk_set_standard_lookup(struct archive *a)
{
struct name_cache *ucache = malloc(sizeof(struct name_cache));
struct name_cache *gcache = malloc(sizeof(struct name_cache));
if (ucache == NULL || gcache == NULL) {
archive_set_error(a, ENOMEM,
"Can't allocate uname/gname lookup cache");
free(ucache);
free(gcache);
return (ARCHIVE_FATAL);
}
memset(ucache, 0, sizeof(*ucache));
ucache->archive = a;
ucache->size = name_cache_size;
memset(gcache, 0, sizeof(*gcache));
gcache->archive = a;
gcache->size = name_cache_size;
archive_read_disk_set_gname_lookup(a, gcache, lookup_gname, cleanup);
archive_read_disk_set_uname_lookup(a, ucache, lookup_uname, cleanup);
return (ARCHIVE_OK);
}
static void
cleanup(void *data)
{
struct name_cache *cache = (struct name_cache *)data;
size_t i;
if (cache != NULL) {
for (i = 0; i < cache->size; i++) {
if (cache->cache[i].name != NULL &&
cache->cache[i].name != NO_NAME)
free((void *)(uintptr_t)cache->cache[i].name);
}
free(cache->buff);
free(cache);
}
}
/*
* Lookup uid/gid from uname/gname, return NULL if no match.
*/
static const char *
lookup_name(struct name_cache *cache,
const char * (*lookup_fn)(struct name_cache *, id_t), id_t id)
{
const char *name;
int slot;
cache->probes++;
slot = id % cache->size;
if (cache->cache[slot].name != NULL) {
if (cache->cache[slot].id == id) {
cache->hits++;
if (cache->cache[slot].name == NO_NAME)
return (NULL);
return (cache->cache[slot].name);
}
if (cache->cache[slot].name != NO_NAME)
free((void *)(uintptr_t)cache->cache[slot].name);
cache->cache[slot].name = NULL;
}
name = (lookup_fn)(cache, id);
if (name == NULL) {
/* Cache and return the negative response. */
cache->cache[slot].name = NO_NAME;
cache->cache[slot].id = id;
return (NULL);
}
cache->cache[slot].name = name;
cache->cache[slot].id = id;
return (cache->cache[slot].name);
}
static const char *
lookup_uname(void *data, uid_t uid)
{
struct name_cache *uname_cache = (struct name_cache *)data;
return (lookup_name(uname_cache,
&lookup_uname_helper, (id_t)uid));
}
#if HAVE_GETPWUID_R
static const char *
lookup_uname_helper(struct name_cache *cache, id_t id)
{
struct passwd pwent, *result;
int r;
if (cache->buff_size == 0) {
cache->buff_size = 256;
cache->buff = malloc(cache->buff_size);
}
if (cache->buff == NULL)
return (NULL);
for (;;) {
result = &pwent; /* Old getpwuid_r ignores last arg. */
r = getpwuid_r((uid_t)id, &pwent,
cache->buff, cache->buff_size, &result);
if (r == 0)
break;
if (r != ERANGE)
break;
/* ERANGE means our buffer was too small, but POSIX
* doesn't tell us how big the buffer should be, so
* we just double it and try again. Because the buffer
* is kept around in the cache object, we shouldn't
* have to do this very often. */
cache->buff_size *= 2;
cache->buff = realloc(cache->buff, cache->buff_size);
if (cache->buff == NULL)
break;
}
if (r != 0) {
archive_set_error(cache->archive, errno,
"Can't lookup user for id %d", (int)id);
return (NULL);
}
if (result == NULL)
return (NULL);
return strdup(result->pw_name);
}
#else
static const char *
lookup_uname_helper(struct name_cache *cache, id_t id)
{
struct passwd *result;
result = getpwuid((uid_t)id);
if (result == NULL)
return (NULL);
return strdup(result->pw_name);
}
#endif
static const char *
lookup_gname(void *data, gid_t gid)
{
struct name_cache *gname_cache = (struct name_cache *)data;
return (lookup_name(gname_cache,
&lookup_gname_helper, (id_t)gid));
}
#if HAVE_GETGRGID_R
static const char *
lookup_gname_helper(struct name_cache *cache, id_t id)
{
struct group grent, *result;
int r;
if (cache->buff_size == 0) {
cache->buff_size = 256;
cache->buff = malloc(cache->buff_size);
}
if (cache->buff == NULL)
return (NULL);
for (;;) {
result = &grent; /* Old getgrgid_r ignores last arg. */
r = getgrgid_r((gid_t)id, &grent,
cache->buff, cache->buff_size, &result);
if (r == 0)
break;
if (r != ERANGE)
break;
/* ERANGE means our buffer was too small, but POSIX
* doesn't tell us how big the buffer should be, so
* we just double it and try again. */
cache->buff_size *= 2;
cache->buff = realloc(cache->buff, cache->buff_size);
if (cache->buff == NULL)
break;
}
if (r != 0) {
archive_set_error(cache->archive, errno,
"Can't lookup group for id %d", (int)id);
return (NULL);
}
if (result == NULL)
return (NULL);
return strdup(result->gr_name);
}
#else
static const char *
lookup_gname_helper(struct name_cache *cache, id_t id)
{
struct group *result;
result = getgrgid((gid_t)id);
if (result == NULL)
return (NULL);
return strdup(result->gr_name);
}
#endif
#endif /* ! (_WIN32 && !__CYGWIN__) */