android_mt6572_jiabo/external/libtar/lib/extract.c
2025-09-05 16:56:03 +08:00

669 lines
11 KiB
C

/*
** 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 <stdio.h>
#include <sys/param.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <utime.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <string.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_SELINUX
# include <selinux/selinux.h>
#endif
#ifdef __linux__
#include <linux/fs.h>
#endif
struct linkname
{
char ln_save[MAXPATHLEN];
char ln_real[MAXPATHLEN];
};
typedef struct linkname linkname_t;
static int
tar_set_file_perms(TAR *t, const char *realname)
{
unsigned int mode;
uid_t uid;
gid_t gid;
struct utimbuf ut;
const char *filename;
char *pn;
int compress;
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);
compress = (mode & TH_MODE_COMPRESSED);
mode &= ~TH_MODE_COMPRESSED;
/* 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 */
free (pn);
return -1;
}
/* change access/modification time */
if (!TH_ISSYM(t) && utime(filename, &ut) == -1)
{
#ifdef DEBUG
perror("utime()");
#endif
free (pn);
return -1;
}
/* change permissions */
if (!TH_ISSYM(t) && chmod(filename, mode) == -1)
{
#ifdef DEBUG
perror("chmod()");
#endif
free (pn);
return -1;
}
#ifdef FS_COMPR_FL
if (compress)
{
int fd;
long flags;
fd = open(filename, O_RDWR);
if (fd >= 0)
{
ioctl(fd, FS_IOC_GETFLAGS, &flags);
flags |= FS_COMPR_FL;
ioctl(fd, FS_IOC_SETFLAGS, &flags);
close(fd);
}
}
#endif
free (pn);
return 0;
}
/* switchboard */
int
tar_extract_file(TAR *t, const char *realname)
{
int i;
linkname_t *lnp;
char *pathname;
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);
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);
if (i != 0)
return i;
i = tar_set_file_perms(t, realname);
if (i != 0)
return i;
#ifdef HAVE_SELINUX
if((t->options & TAR_STORE_SELINUX) && t->th_buf.selinux_context != NULL)
{
#ifdef DEBUG
printf(" 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, "Failed to restore SELinux context %s!\n", strerror(errno));
}
#endif
lnp = (linkname_t *)calloc(1, sizeof(linkname_t));
if (lnp == NULL)
return -1;
pathname = th_get_pathname(t);
strlcpy(lnp->ln_save, pathname, sizeof(lnp->ln_save));
strlcpy(lnp->ln_real, realname, sizeof(lnp->ln_real));
#ifdef DEBUG
printf("tar_extract_file(): calling libtar_hash_add(): key=\"%s\", "
"value=\"%s\"\n", pathname, realname);
#endif
free(pathname);
if (libtar_hash_add(t->h, lnp) != 0)
return -1;
return 0;
}
/* extract regular file */
int
tar_extract_regfile(TAR *t, const char *realname)
{
int64_t size, i;
ssize_t k;
int fdout;
char buf[T_BLOCKSIZE];
const char *filename;
char *pn;
#ifdef DEBUG
printf("==> tar_extract_regfile(t=0x%lx, realname=\"%s\")\n", t,
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)
{
free (pn);
return -1;
}
#ifdef DEBUG
printf(" ==> extracting: %s (file size %d bytes)\n",
filename, size);
#endif
fdout = open(filename, O_WRONLY | O_CREAT | O_TRUNC
#ifdef O_BINARY
| O_BINARY
#endif
, 0666);
if (fdout == -1)
{
#ifdef DEBUG
perror("open()");
#endif
free (pn);
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;
free (pn);
return -1;
}
/* write block to output file */
if (write(fdout, buf,
((i > T_BLOCKSIZE) ? T_BLOCKSIZE : i)) == -1)
{
free (pn);
return -1;
}
}
/* close output file */
if (close(fdout) == -1)
{
free (pn);
return -1;
}
#ifdef DEBUG
printf("### done extracting %s\n", filename);
#endif
free (pn);
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 *filename;
char *pn;
char *linktgt = NULL;
linkname_t *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)
{
free (pn);
return -1;
}
if (unlink(filename) == -1 && errno != ENOENT)
{
free (pn);
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 = (linkname_t *)libtar_hashptr_data(&hp);
linktgt = lnp->ln_real;
}
else
linktgt = th_get_linkname(t);
#ifdef DEBUG
printf(" ==> extracting: %s (link to %s)\n", filename, linktgt);
#endif
if (link(linktgt, filename) == -1)
{
#ifdef DEBUG
perror("link()");
#endif
free (pn);
return -1;
}
free (pn);
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)
{
free (pn);
return -1;
}
if (unlink(filename) == -1 && errno != ENOENT) {
free (pn);
return -1;
}
#ifdef DEBUG
printf(" ==> extracting: %s (symlink to %s)\n",
filename, th_get_linkname(t));
#endif
if (symlink(th_get_linkname(t), filename) == -1)
{
#ifdef DEBUG
perror("symlink()");
#endif
free (pn);
return -1;
}
free (pn);
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)
{
free (pn);
return -1;
}
#ifdef DEBUG
printf(" ==> extracting: %s (character device %ld,%ld)\n",
filename, devmaj, devmin);
#endif
if (mknod(filename, mode | S_IFCHR,
compat_makedev(devmaj, devmin)) == -1)
{
#ifdef DEBUG
perror("mknod()");
#endif
free (pn);
return -1;
}
free (pn);
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)
{
free (pn);
return -1;
}
#ifdef DEBUG
printf(" ==> extracting: %s (block device %ld,%ld)\n",
filename, devmaj, devmin);
#endif
if (mknod(filename, mode | S_IFBLK,
compat_makedev(devmaj, devmin)) == -1)
{
#ifdef DEBUG
perror("mknod()");
#endif
free (pn);
return -1;
}
free (pn);
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)
{
free (pn);
return -1;
}
#ifdef DEBUG
printf(" ==> extracting: %s (mode %04o, directory)\n", filename,
mode);
#endif
if (mkdir(filename, mode) == -1)
{
if (errno == EEXIST)
{
if (chmod(filename, mode) == -1)
{
#ifdef DEBUG
perror("chmod()");
#endif
free (pn);
return -1;
}
else
{
#ifdef DEBUG
puts(" *** using existing directory");
#endif
free (pn);
return 1;
}
}
else
{
#ifdef DEBUG
perror("mkdir()");
#endif
free (pn);
return -1;
}
}
free (pn);
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)
{
free (pn);
return -1;
}
#ifdef DEBUG
printf(" ==> extracting: %s (fifo)\n", filename);
#endif
if (mkfifo(filename, mode) == -1)
{
#ifdef DEBUG
perror("mkfifo()");
#endif
free (pn);
return -1;
}
free (pn);
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(t=0x%lx, buf=%p)\n", t,
buf);
#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;
}