blob: 064ba9ba6bdef479eef1f641cf65e7626aab3f20 [file] [log] [blame]
/*
** Copyright 1998-2003 University of Illinois Board of Trustees
** Copyright 1998-2003 Mark D. Roth
** All rights reserved.
**
** extract.c - libtar code to extract a file from a tar archive
**
** Mark D. Roth <roth@uiuc.edu>
** Campus Information Technologies and Educational Services
** University of Illinois at Urbana-Champaign
*/
#include <internal.h>
#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <sys/param.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <utime.h>
#include <sys/capability.h>
#include <sys/xattr.h>
#include <linux/xattr.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <selinux/selinux.h>
#ifdef USE_FSCRYPT
#include "fscrypt_policy.h"
#endif
#ifdef TW_LIBTAR_DEBUG
#define DEBUG 1
#endif
#include "android_utils.h"
const unsigned long long progress_size = (unsigned long long)(T_BLOCKSIZE);
static int
tar_set_file_perms(TAR *t, const char *realname)
{
mode_t mode;
uid_t uid;
gid_t gid;
struct utimbuf ut;
const char *filename;
char *pn;
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
mode = th_get_mode(t);
uid = th_get_uid(t);
gid = th_get_gid(t);
ut.modtime = ut.actime = th_get_mtime(t);
#ifdef DEBUG
printf("tar_set_file_perms(): setting perms: %s (mode %04o, uid %d, gid %d)\n",
filename, mode, uid, gid);
#endif
/* change owner/group */
if (geteuid() == 0)
#ifdef HAVE_LCHOWN
if (lchown(filename, uid, gid) == -1)
{
# ifdef DEBUG
fprintf(stderr, "lchown(\"%s\", %d, %d): %s\n",
filename, uid, gid, strerror(errno));
# endif
#else /* ! HAVE_LCHOWN */
if (!TH_ISSYM(t) && chown(filename, uid, gid) == -1)
{
# ifdef DEBUG
fprintf(stderr, "chown(\"%s\", %d, %d): %s\n",
filename, uid, gid, strerror(errno));
# endif
#endif /* HAVE_LCHOWN */
return -1;
}
/* change access/modification time */
if (!TH_ISSYM(t) && utime(filename, &ut) == -1)
{
#ifdef DEBUG
perror("utime()");
#endif
return -1;
}
/* change permissions */
if (!TH_ISSYM(t) && chmod(filename, mode) == -1)
{
#ifdef DEBUG
perror("chmod()");
#endif
return -1;
}
return 0;
}
/* switchboard */
int
tar_extract_file(TAR *t, const char *realname, const char *prefix, const int *progress_fd)
{
int i;
#ifdef LIBTAR_FILE_HASH
char *lnp;
char *pn;
int pathname_len;
int realname_len;
#endif
if (t->options & TAR_NOOVERWRITE)
{
struct stat s;
if (lstat(realname, &s) == 0 || errno != ENOENT)
{
errno = EEXIST;
return -1;
}
}
if (TH_ISDIR(t))
{
i = tar_extract_dir(t, realname);
if (i == 1)
i = 0;
}
else if (TH_ISLNK(t))
i = tar_extract_hardlink(t, realname, prefix);
else if (TH_ISSYM(t))
i = tar_extract_symlink(t, realname);
else if (TH_ISCHR(t))
i = tar_extract_chardev(t, realname);
else if (TH_ISBLK(t))
i = tar_extract_blockdev(t, realname);
else if (TH_ISFIFO(t))
i = tar_extract_fifo(t, realname);
else /* if (TH_ISREG(t)) */
i = tar_extract_regfile(t, realname, progress_fd);
if (i != 0) {
fprintf(stderr, "tar_extract_file(): failed to extract %s !!!\n", realname);
return i;
}
i = tar_set_file_perms(t, realname);
if (i != 0) {
fprintf(stderr, "tar_extract_file(): failed to set permissions on %s !!!\n", realname);
return i;
}
if((t->options & TAR_STORE_SELINUX) && t->th_buf.selinux_context != NULL)
{
#ifdef DEBUG
printf("tar_extract_file(): restoring SELinux context %s to file %s\n", t->th_buf.selinux_context, realname);
#endif
if (lsetfilecon(realname, t->th_buf.selinux_context) < 0)
fprintf(stderr, "tar_extract_file(): failed to restore SELinux context %s to file %s !!!\n", t->th_buf.selinux_context, realname);
}
if((t->options & TAR_STORE_POSIX_CAP) && t->th_buf.has_cap_data)
{
#if 1 //def DEBUG
printf("tar_extract_file(): restoring posix capabilities to file %s\n", realname);
print_caps(&t->th_buf.cap_data);
#endif
if (setxattr(realname, XATTR_NAME_CAPS, &t->th_buf.cap_data, sizeof(struct vfs_cap_data), 0) < 0)
fprintf(stderr, "tar_extract_file(): failed to restore posix capabilities to file %s !!!\n", realname);
}
#ifdef LIBTAR_FILE_HASH
pn = th_get_pathname(t);
pathname_len = strlen(pn) + 1;
realname_len = strlen(realname) + 1;
lnp = (char *)calloc(1, pathname_len + realname_len);
if (lnp == NULL)
return -1;
strcpy(&lnp[0], pn);
strcpy(&lnp[pathname_len], realname);
#ifdef DEBUG
printf("tar_extract_file(): calling libtar_hash_add(): key=\"%s\", "
"value=\"%s\"\n", pn, realname);
#endif
if (libtar_hash_add(t->h, lnp) != 0)
return -1;
free(lnp);
#endif
return 0;
}
/* extract regular file */
int
tar_extract_regfile(TAR *t, const char *realname, const int *progress_fd)
{
int64_t size, i;
ssize_t k;
int fdout;
char buf[T_BLOCKSIZE];
const char *filename;
char *pn;
#ifdef DEBUG
printf(" ==> tar_extract_regfile(realname=\"%s\")\n", realname);
#endif
if (!TH_ISREG(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
size = th_get_size(t);
if (mkdirhier(dirname(filename)) == -1)
return -1;
printf(" ==> extracting: %s (file size %" PRId64 " bytes)\n",
filename, size);
fdout = open(filename, O_WRONLY | O_CREAT | O_TRUNC
#ifdef O_BINARY
| O_BINARY
#endif
, 0666);
if (fdout == -1)
{
#ifdef DEBUG
perror("open()");
#endif
return -1;
}
/* extract the file */
for (i = size; i > 0; i -= T_BLOCKSIZE)
{
k = tar_block_read(t, buf);
if (k != T_BLOCKSIZE)
{
if (k != -1)
errno = EINVAL;
close(fdout);
return -1;
}
/* write block to output file */
if (write(fdout, buf,
((i > T_BLOCKSIZE) ? T_BLOCKSIZE : i)) == -1)
{
close(fdout);
return -1;
}
else
{
if (*progress_fd != 0)
write(*progress_fd, &progress_size, sizeof(progress_size));
}
}
/* close output file */
if (close(fdout) == -1)
return -1;
#ifdef DEBUG
printf("### done extracting %s\n", filename);
#endif
return 0;
}
/* skip regfile */
int
tar_skip_regfile(TAR *t)
{
int64_t size, i;
ssize_t k;
char buf[T_BLOCKSIZE];
if (!TH_ISREG(t))
{
errno = EINVAL;
return -1;
}
size = th_get_size(t);
for (i = size; i > 0; i -= T_BLOCKSIZE)
{
k = tar_block_read(t, buf);
if (k != T_BLOCKSIZE)
{
if (k != -1)
errno = EINVAL;
return -1;
}
}
return 0;
}
/* hardlink */
int
tar_extract_hardlink(TAR * t, const char *realname, const char *prefix)
{
const char *filename;
char *pn;
char *linktgt = NULL;
char *newtgt = NULL;
char *lnp;
libtar_hashptr_t hp;
if (!TH_ISLNK(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
if (mkdirhier(dirname(filename)) == -1)
return -1;
if (unlink(filename) == -1 && errno != ENOENT)
return -1;
libtar_hashptr_reset(&hp);
if (libtar_hash_getkey(t->h, &hp, th_get_linkname(t),
(libtar_matchfunc_t)libtar_str_match) != 0)
{
lnp = (char *)libtar_hashptr_data(&hp);
linktgt = &lnp[strlen(lnp) + 1];
}
else
linktgt = th_get_linkname(t);
newtgt = strdup(linktgt);
sprintf(linktgt, "%s/%s", prefix, newtgt);
printf(" ==> extracting: %s (link to %s)\n", filename, linktgt);
if (link(linktgt, filename) == -1)
{
fprintf(stderr, "tar_extract_hardlink(): failed restore of hardlink '%s' but returning as if nothing bad happened\n", filename);
return 0; // Used to be -1
}
return 0;
}
/* symlink */
int
tar_extract_symlink(TAR *t, const char *realname)
{
const char *filename;
char *pn;
if (!TH_ISSYM(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
if (mkdirhier(dirname(filename)) == -1)
return -1;
if (unlink(filename) == -1 && errno != ENOENT)
return -1;
printf(" ==> extracting: %s (symlink to %s)\n",
filename, th_get_linkname(t));
if (symlink(th_get_linkname(t), filename) == -1)
{
#ifdef DEBUG
perror("symlink()");
#endif
return -1;
}
return 0;
}
/* character device */
int
tar_extract_chardev(TAR *t, const char *realname)
{
mode_t mode;
unsigned long devmaj, devmin;
const char *filename;
char *pn;
if (!TH_ISCHR(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
mode = th_get_mode(t);
devmaj = th_get_devmajor(t);
devmin = th_get_devminor(t);
if (mkdirhier(dirname(filename)) == -1)
return -1;
printf(" ==> extracting: %s (character device %ld,%ld)\n",
filename, devmaj, devmin);
if (mknod(filename, mode | S_IFCHR,
compat_makedev(devmaj, devmin)) == -1)
{
fprintf(stderr, "tar_extract_chardev(): failed restore of character device '%s' but returning as if nothing bad happened\n", filename);
return 0; // Used to be -1
}
return 0;
}
/* block device */
int
tar_extract_blockdev(TAR *t, const char *realname)
{
mode_t mode;
unsigned long devmaj, devmin;
const char *filename;
char *pn;
if (!TH_ISBLK(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
mode = th_get_mode(t);
devmaj = th_get_devmajor(t);
devmin = th_get_devminor(t);
if (mkdirhier(dirname(filename)) == -1)
return -1;
printf(" ==> extracting: %s (block device %ld,%ld)\n",
filename, devmaj, devmin);
if (mknod(filename, mode | S_IFBLK,
compat_makedev(devmaj, devmin)) == -1)
{
fprintf(stderr, "tar_extract_blockdev(): failed restore of block device '%s' but returning as if nothing bad happened\n", filename);
return 0; // Used to be -1
}
return 0;
}
/* directory */
int
tar_extract_dir(TAR *t, const char *realname)
{
mode_t mode;
const char *filename;
char *pn;
if (!TH_ISDIR(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
mode = th_get_mode(t);
if (mkdirhier(dirname(filename)) == -1)
return -1;
printf(" ==> extracting: %s (mode %04o, directory)\n", filename,
mode);
if (mkdir(filename, mode) == -1)
{
if (errno == EEXIST)
{
if (chmod(filename, mode) == -1)
{
#ifdef DEBUG
perror("chmod()");
#endif
return -1;
}
else
{
#if 1 //def DEBUG
puts(" *** using existing directory");
#endif
return 1;
}
}
else
{
#ifdef DEBUG
perror("mkdir()");
#endif
return -1;
}
}
if (t->options & TAR_STORE_ANDROID_USER_XATTR)
{
if (t->th_buf.has_user_default) {
#if 1 //def DEBUG
printf("tar_extract_file(): restoring android user.default xattr to %s\n", realname);
#endif
if (setxattr(realname, "user.default", NULL, 0, 0) < 0) {
fprintf(stderr, "tar_extract_file(): failed to restore android user.default to file %s !!!\n", realname);
return -1;
}
}
if (t->th_buf.has_user_cache) {
#if 1 //def DEBUG
printf("tar_extract_file(): restoring android user.inode_cache xattr to %s\n", realname);
#endif
if (write_path_inode(realname, "cache", "user.inode_cache"))
return -1;
}
if (t->th_buf.has_user_code_cache) {
#if 1 //def DEBUG
printf("tar_extract_file(): restoring android user.inode_code_cache xattr to %s\n", realname);
#endif
if (write_path_inode(realname, "code_cache", "user.inode_code_cache"))
return -1;
}
}
#ifdef USE_FSCRYPT
if(t->th_buf.fep != NULL)
{
char policy_hex[FSCRYPT_KEY_IDENTIFIER_HEX_SIZE];
#ifdef DEBUG
bytes_to_hex(t->th_buf.fep->master_key_identifier, FSCRYPT_KEY_IDENTIFIER_SIZE, policy_hex);
printf("tar_extract_dir(): restoring fscrypt policy %s to dir %s\n", (char *)policy_hex, realname);
#endif
uint8_t binary_policy[FSCRYPT_KEY_IDENTIFIER_SIZE];
memset(&binary_policy, 0, FSCRYPT_KEY_IDENTIFIER_SIZE);
if (!lookup_ref_tar(t->th_buf.fep->master_key_identifier, &binary_policy[0])) {
printf("error looking up fscrypt policy for '%s' - %s\n", realname, t->th_buf.fep->master_key_identifier);
return -1;
}
memcpy(&t->th_buf.fep->master_key_identifier, binary_policy, FSCRYPT_KEY_IDENTIFIER_SIZE);
bytes_to_hex(t->th_buf.fep->master_key_identifier, FSCRYPT_KEY_IDENTIFIER_SIZE, policy_hex);
printf("attempting to restore policy: %s\n", policy_hex);
if (!fscrypt_policy_set_struct(realname, t->th_buf.fep))
{
printf("tar_extract_file(): failed to restore fscrypt policy to dir '%s' '%s'!!!\n", realname, policy_hex);
//return -1; // This may not be an error in some cases, so log and ignore
}
}
else
printf("NULL FSCRYPT\n");
#endif
return 0;
}
/* FIFO */
int
tar_extract_fifo(TAR *t, const char *realname)
{
mode_t mode;
const char *filename;
char *pn;
if (!TH_ISFIFO(t))
{
errno = EINVAL;
return -1;
}
pn = th_get_pathname(t);
filename = (realname ? realname : pn);
mode = th_get_mode(t);
if (mkdirhier(dirname(filename)) == -1)
return -1;
printf(" ==> extracting: %s (fifo)\n", filename);
if (mkfifo(filename, mode) == -1)
{
#ifdef DEBUG
perror("mkfifo()");
#endif
return -1;
}
return 0;
}
/* extract file contents from a tarchive */
int
tar_extract_file_contents(TAR *t, void *buf, size_t *lenp)
{
char block[T_BLOCKSIZE];
int64_t size, i;
ssize_t k;
#ifdef DEBUG
printf(" ==> tar_extract_file_contents\n");
#endif
if (!TH_ISREG(t))
{
errno = EINVAL;
return -1;
}
size = th_get_size(t);
if ((uint64_t)size > *lenp)
{
errno = ENOSPC;
return -1;
}
/* extract the file */
for (i = size; i >= T_BLOCKSIZE; i -= T_BLOCKSIZE)
{
k = tar_block_read(t, buf);
if (k != T_BLOCKSIZE)
{
if (k != -1)
errno = EINVAL;
return -1;
}
buf = (char *)buf + T_BLOCKSIZE;
}
if (i > 0) {
k = tar_block_read(t, block);
if (k != T_BLOCKSIZE)
{
if (k != -1)
errno = EINVAL;
return -1;
}
memcpy(buf, block, i);
}
*lenp = (size_t)size;
#ifdef DEBUG
printf("### done extracting contents\n");
#endif
return 0;
}