archive_write_disk_set_standard_lookup.c [plain text]
#include "archive_platform.h"
__FBSDID("$FreeBSD: head/lib/libarchive/archive_write_disk_set_standard_lookup.c 201083 2009-12-28 02:09:57Z 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"
#include "archive_private.h"
#include "archive_read_private.h"
#include "archive_write_disk_private.h"
struct bucket {
char *name;
int hash;
id_t id;
};
static const size_t cache_size = 127;
static unsigned int hash(const char *);
static gid_t lookup_gid(void *, const char *uname, gid_t);
static uid_t lookup_uid(void *, const char *uname, uid_t);
static void cleanup(void *);
int
archive_write_disk_set_standard_lookup(struct archive *a)
{
struct bucket *ucache = malloc(cache_size * sizeof(struct bucket));
struct bucket *gcache = malloc(cache_size * sizeof(struct bucket));
memset(ucache, 0, cache_size * sizeof(struct bucket));
memset(gcache, 0, cache_size * sizeof(struct bucket));
archive_write_disk_set_group_lookup(a, gcache, lookup_gid, cleanup);
archive_write_disk_set_user_lookup(a, ucache, lookup_uid, cleanup);
return (ARCHIVE_OK);
}
static gid_t
lookup_gid(void *private_data, const char *gname, gid_t gid)
{
int h;
struct bucket *b;
struct bucket *gcache = (struct bucket *)private_data;
if (gname == NULL || *gname == '\0')
return (gid);
h = hash(gname);
b = &gcache[h % cache_size ];
if (b->name != NULL && b->hash == h && strcmp(gname, b->name) == 0)
return ((gid_t)b->id);
if (b->name != NULL)
free(b->name);
b->name = strdup(gname);
b->hash = h;
#if HAVE_GRP_H
{
char _buffer[128];
size_t bufsize = 128;
char *buffer = _buffer;
struct group grent, *result;
int r;
for (;;) {
result = &grent;
r = getgrnam_r(gname, &grent, buffer, bufsize, &result);
if (r == 0)
break;
if (r != ERANGE)
break;
bufsize *= 2;
if (buffer != _buffer)
free(buffer);
buffer = malloc(bufsize);
if (buffer == NULL)
break;
}
if (result != NULL)
gid = result->gr_gid;
if (buffer != _buffer)
free(buffer);
}
#elif defined(_WIN32) && !defined(__CYGWIN__)
#else
#error No way to perform gid lookups on this platform
#endif
b->id = gid;
return (gid);
}
static uid_t
lookup_uid(void *private_data, const char *uname, uid_t uid)
{
int h;
struct bucket *b;
struct bucket *ucache = (struct bucket *)private_data;
if (uname == NULL || *uname == '\0')
return (uid);
h = hash(uname);
b = &ucache[h % cache_size ];
if (b->name != NULL && b->hash == h && strcmp(uname, b->name) == 0)
return ((uid_t)b->id);
if (b->name != NULL)
free(b->name);
b->name = strdup(uname);
b->hash = h;
#if HAVE_PWD_H
{
char _buffer[128];
size_t bufsize = 128;
char *buffer = _buffer;
struct passwd pwent, *result;
int r;
for (;;) {
result = &pwent;
r = getpwnam_r(uname, &pwent, buffer, bufsize, &result);
if (r == 0)
break;
if (r != ERANGE)
break;
bufsize *= 2;
if (buffer != _buffer)
free(buffer);
buffer = malloc(bufsize);
if (buffer == NULL)
break;
}
if (result != NULL)
uid = result->pw_uid;
if (buffer != _buffer)
free(buffer);
}
#elif defined(_WIN32) && !defined(__CYGWIN__)
#else
#error No way to look up uids on this platform
#endif
b->id = uid;
return (uid);
}
static void
cleanup(void *private)
{
size_t i;
struct bucket *cache = (struct bucket *)private;
for (i = 0; i < cache_size; i++)
free(cache[i].name);
free(cache);
}
static unsigned int
hash(const char *p)
{
unsigned g, h = 0;
while (*p != '\0') {
h = (h << 4) + *p++;
if ((g = h & 0xF0000000) != 0) {
h ^= g >> 24;
h &= 0x0FFFFFFF;
}
}
return h;
}