FreeBSD-5.3/lib/libarchive/archive_read_extract.c
/*-
* Copyright (c) 2003-2004 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
* in this position and unchanged.
* 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: src/lib/libarchive/archive_read_extract.c,v 1.33.2.2 2004/09/02 04:00:12 kientzle Exp $");
#include <sys/types.h>
#ifdef HAVE_SYS_ACL_H
#include <sys/acl.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#include <sys/stat.h>
#include <sys/time.h>
#ifdef HAVE_EXT2FS_EXT2_FS_H
#include <ext2fs/ext2_fs.h> /* for Linux file flags */
#endif
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#ifdef HAVE_LINUX_EXT2_FS_H
#include <linux/ext2_fs.h> /* for Linux file flags */
#endif
#include <limits.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "archive.h"
#include "archive_string.h"
#include "archive_entry.h"
#include "archive_private.h"
struct fixup_entry {
struct fixup_entry *next;
mode_t mode;
int64_t mtime;
int64_t atime;
unsigned long mtime_nanos;
unsigned long atime_nanos;
unsigned long fflags_set;
int fixup; /* bitmask of what needs fixing */
char *name;
};
#define FIXUP_MODE 1
#define FIXUP_TIMES 2
#define FIXUP_FFLAGS 4
struct bucket {
char *name;
int hash;
id_t id;
};
struct extract {
mode_t umask;
mode_t default_dir_mode;
struct archive_string create_parent_dir;
struct fixup_entry *fixup_list;
struct fixup_entry *current_fixup;
struct bucket ucache[127];
struct bucket gcache[127];
/*
* Cached stat data from disk for the current entry.
* If this is valid, pst points to st. Otherwise,
* pst is null.
*
* TODO: Have all of the stat calls use this cached data
* if possible.
*/
struct stat st;
struct stat *pst;
};
/* Default mode for dirs created automatically (will be modified by umask). */
#define DEFAULT_DIR_MODE 0777
/*
* Mode to use for newly-created dirs during extraction; the correct
* mode will be set at the end of the extraction.
*/
#define SECURE_DIR_MODE 0700
static void archive_extract_cleanup(struct archive *);
static int extract_block_device(struct archive *,
struct archive_entry *, int);
static int extract_char_device(struct archive *,
struct archive_entry *, int);
static int extract_device(struct archive *,
struct archive_entry *, int flags, mode_t mode);
static int extract_dir(struct archive *, struct archive_entry *, int);
static int extract_fifo(struct archive *, struct archive_entry *, int);
static int extract_file(struct archive *, struct archive_entry *, int);
static int extract_hard_link(struct archive *, struct archive_entry *, int);
static int extract_symlink(struct archive *, struct archive_entry *, int);
static unsigned int hash(const char *);
static gid_t lookup_gid(struct archive *, const char *uname, gid_t);
static uid_t lookup_uid(struct archive *, const char *uname, uid_t);
static int create_parent_dir(struct archive *, const char *, int flags);
static int create_parent_dir_internal(struct archive *, char *,
int flags);
static int create_parent_dir_recursive(struct archive *, char *,
int flags);
static int restore_metadata(struct archive *, struct archive_entry *,
int flags);
#ifdef HAVE_POSIX_ACL
static int set_acl(struct archive *, struct archive_entry *,
acl_type_t, int archive_entry_acl_type, const char *tn);
#endif
static int set_acls(struct archive *, struct archive_entry *);
static int set_fflags(struct archive *, const char *name, mode_t mode,
unsigned long fflags_set, unsigned long fflags_clear);
static int set_ownership(struct archive *, struct archive_entry *, int);
static int set_perm(struct archive *, struct archive_entry *, int mode,
int flags);
static int set_time(struct archive *, struct archive_entry *, int);
static struct fixup_entry *sort_dir_list(struct fixup_entry *p);
/*
* Extract this entry to disk.
*
* TODO: Validate hardlinks. According to the standards, we're
* supposed to check each extracted hardlink and squawk if it refers
* to a file that we didn't restore. I'm not entirely convinced this
* is a good idea, but more importantly: Is there any way to validate
* hardlinks without keeping a complete list of filenames from the
* entire archive?? Ugh.
*
*/
int
archive_read_extract(struct archive *a, struct archive_entry *entry, int flags)
{
mode_t mode;
struct extract *extract;
int ret;
int restore_pwd;
if (a->extract == NULL) {
a->extract = malloc(sizeof(*a->extract));
if (a->extract == NULL) {
archive_set_error(a, ENOMEM, "Can't extract");
return (ARCHIVE_FATAL);
}
a->cleanup_archive_extract = archive_extract_cleanup;
memset(a->extract, 0, sizeof(*a->extract));
}
extract = a->extract;
umask(extract->umask = umask(0)); /* Read the current umask. */
extract->default_dir_mode = DEFAULT_DIR_MODE & ~extract->umask;
extract->pst = NULL;
extract->current_fixup = NULL;
restore_pwd = -1;
/*
* TODO: If pathname is longer than PATH_MAX, record starting
* directory and move to a suitable intermediate dir, which
* might require creating them!
*/
if (strlen(archive_entry_pathname(entry)) > PATH_MAX) {
restore_pwd = open(".", O_RDONLY);
/* XXX chdir() to a suitable intermediate dir XXX */
/* XXX Update pathname in 'entry' XXX */
}
if (stat(archive_entry_pathname(entry), &extract->st) == 0)
extract->pst = &extract->st;
if (extract->pst != NULL &&
extract->pst->st_dev == a->skip_file_dev &&
extract->pst->st_ino == a->skip_file_ino) {
archive_set_error(a, 0, "Refusing to overwrite archive");
ret = ARCHIVE_WARN;
} else if (archive_entry_hardlink(entry) != NULL)
ret = extract_hard_link(a, entry, flags);
else {
mode = archive_entry_mode(entry);
switch (mode & S_IFMT) {
default:
/* Fall through, as required by POSIX. */
case S_IFREG:
ret = extract_file(a, entry, flags);
break;
case S_IFLNK: /* Symlink */
ret = extract_symlink(a, entry, flags);
break;
case S_IFCHR:
ret = extract_char_device(a, entry, flags);
break;
case S_IFBLK:
ret = extract_block_device(a, entry, flags);
break;
case S_IFDIR:
ret = extract_dir(a, entry, flags);
break;
case S_IFIFO:
ret = extract_fifo(a, entry, flags);
break;
}
}
/* If we changed directory above, restore it here. */
if (restore_pwd >= 0)
fchdir(restore_pwd);
return (ret);
}
/*
* Cleanup function for archive_extract. Mostly, this involves processing
* the fixup list, which is used to address a number of problems:
* * Dir permissions might prevent us from restoring a file in that
* dir, so we restore the dir 0700 first, then correct the
* mode at the end.
* * Similarly, the act of restoring a file touches the directory
* and changes the timestamp on the dir, so we have to touch-up the
* timestamps at the end as well.
* * Some file flags can interfere with the restore by, for example,
* preventing the creation of hardlinks to those files.
*
* Note that tar/cpio do not require that archives be in a particular
* order; there is no way to know when the last file has been restored
* within a directory, so there's no way to optimize the memory usage
* here by fixing up the directory any earlier than the
* end-of-archive.
*
* XXX TODO: Directory ACLs should be restored here, for the same
* reason we set directory perms here. XXX
*
* Registering this function (rather than calling it explicitly by
* name from archive_read_finish) reduces static link pollution, since
* applications that don't use this API won't get this file linked in.
*/
static void
archive_extract_cleanup(struct archive *a)
{
struct fixup_entry *next, *p;
struct extract *extract;
/* Sort dir list so directories are fixed up in depth-first order. */
extract = a->extract;
p = sort_dir_list(extract->fixup_list);
while (p != NULL) {
extract->pst = NULL; /* Mark stat buff as out-of-date. */
if (p->fixup & FIXUP_TIMES) {
struct timeval times[2];
times[1].tv_sec = p->mtime;
times[1].tv_usec = p->mtime_nanos / 1000;
times[0].tv_sec = p->atime;
times[0].tv_usec = p->atime_nanos / 1000;
utimes(p->name, times);
}
if (p->fixup & FIXUP_MODE)
chmod(p->name, p->mode);
if (p->fixup & FIXUP_FFLAGS)
set_fflags(a, p->name, p->mode, p->fflags_set, 0);
next = p->next;
free(p->name);
free(p);
p = next;
}
extract->fixup_list = NULL;
archive_string_free(&extract->create_parent_dir);
free(a->extract);
a->extract = NULL;
}
/*
* Simple O(n log n) merge sort to order the fixup list. In
* particular, we want to restore dir timestamps depth-first.
*/
static struct fixup_entry *
sort_dir_list(struct fixup_entry *p)
{
struct fixup_entry *a, *b, *t;
if (p == NULL)
return (NULL);
/* A one-item list is already sorted. */
if (p->next == NULL)
return (p);
/* Step 1: split the list. */
t = p;
a = p->next->next;
while (a != NULL) {
/* Step a twice, t once. */
a = a->next;
if (a != NULL)
a = a->next;
t = t->next;
}
/* Now, t is at the mid-point, so break the list here. */
b = t->next;
t->next = NULL;
a = p;
/* Step 2: Recursively sort the two sub-lists. */
a = sort_dir_list(a);
b = sort_dir_list(b);
/* Step 3: Merge the returned lists. */
/* Pick the first element for the merged list. */
if (strcmp(a->name, b->name) > 0) {
t = p = a;
a = a->next;
} else {
t = p = b;
b = b->next;
}
/* Always put the later element on the list first. */
while (a != NULL && b != NULL) {
if (strcmp(a->name, b->name) > 0) {
t->next = a;
a = a->next;
} else {
t->next = b;
b = b->next;
}
t = t->next;
}
/* Only one list is non-empty, so just splice it on. */
if (a != NULL)
t->next = a;
if (b != NULL)
t->next = b;
return (p);
}
/*
* Returns a new, initialized fixup entry.
*/
static struct fixup_entry *
new_fixup(struct archive *a, const char *pathname)
{
struct extract *extract;
struct fixup_entry *fe;
extract = a->extract;
fe = malloc(sizeof(struct fixup_entry));
if (fe == NULL)
return (NULL);
fe->next = extract->fixup_list;
extract->fixup_list = fe;
fe->fixup = 0;
fe->name = strdup(pathname);
return (fe);
}
/*
* Returns a fixup structure for the current entry.
*/
static struct fixup_entry *
current_fixup(struct archive *a, const char *pathname)
{
struct extract *extract;
extract = a->extract;
if (extract->current_fixup == NULL)
extract->current_fixup = new_fixup(a, pathname);
return (extract->current_fixup);
}
static int
extract_file(struct archive *a, struct archive_entry *entry, int flags)
{
struct extract *extract;
const char *name;
mode_t mode;
int fd, r, r2;
extract = a->extract;
name = archive_entry_pathname(entry);
mode = archive_entry_mode(entry) & 0777;
r = ARCHIVE_OK;
/*
* If we're not supposed to overwrite pre-existing files,
* use O_EXCL. Otherwise, use O_TRUNC.
*/
if (flags & (ARCHIVE_EXTRACT_UNLINK | ARCHIVE_EXTRACT_NO_OVERWRITE))
fd = open(name, O_WRONLY | O_CREAT | O_EXCL, mode);
else
fd = open(name, O_WRONLY | O_CREAT | O_TRUNC, mode);
/* Try removing a pre-existing file. */
if (fd < 0 && !(flags & ARCHIVE_EXTRACT_NO_OVERWRITE)) {
unlink(name);
fd = open(name, O_WRONLY | O_CREAT | O_EXCL, mode);
}
/* Might be a non-existent parent dir; try fixing that. */
if (fd < 0) {
create_parent_dir(a, name, flags);
fd = open(name, O_WRONLY | O_CREAT | O_EXCL, mode);
}
if (fd < 0) {
archive_set_error(a, errno, "Can't open '%s'", name);
return (ARCHIVE_WARN);
}
r = archive_read_data_into_fd(a, fd);
extract->pst = NULL; /* Cached stat data no longer valid. */
r2 = restore_metadata(a, entry, flags);
close(fd);
return (err_combine(r, r2));
}
static int
extract_dir(struct archive *a, struct archive_entry *entry, int flags)
{
struct extract *extract;
struct fixup_entry *fe;
char *path, *p;
extract = a->extract;
extract->pst = NULL; /* Invalidate cached stat data. */
/* Copy path to mutable storage. */
archive_strcpy(&(extract->create_parent_dir),
archive_entry_pathname(entry));
path = extract->create_parent_dir.s;
/* Deal with any troublesome trailing path elements. */
for (;;) {
if (*path == '\0')
return (ARCHIVE_OK);
/* Locate last element; trim trailing '/'. */
p = strrchr(path, '/');
if (p != NULL) {
if (p[1] == '\0') {
*p = '\0';
continue;
}
p++;
} else
p = path;
/* Trim trailing '.'. */
if (p[0] == '.' && p[1] == '\0') {
p[0] = '\0';
continue;
}
/* Just exit on trailing '..'. */
if (p[0] == '.' && p[1] == '.' && p[2] == '\0')
return (ARCHIVE_OK);
break;
}
if (mkdir(path, SECURE_DIR_MODE) == 0)
goto success;
if (extract->pst == NULL && stat(path, &extract->st) == 0)
extract->pst = &extract->st;
if (extract->pst != NULL) {
extract->pst = &extract->st;
if (S_ISDIR(extract->pst->st_mode))
return (ARCHIVE_OK);
/* It exists but isn't a dir. */
if ((flags & ARCHIVE_EXTRACT_UNLINK))
unlink(path);
} else {
/* Doesn't already exist; try building the parent path. */
if (create_parent_dir_internal(a, path, flags) != ARCHIVE_OK)
return (ARCHIVE_WARN);
}
/* One final attempt to create the dir. */
if (mkdir(path, SECURE_DIR_MODE) != 0) {
archive_set_error(a, errno, "Can't create directory");
return (ARCHIVE_WARN);
}
success:
/* Add this dir to the fixup list. */
fe = current_fixup(a, path);
fe->fixup |= FIXUP_MODE;
fe->mode = archive_entry_mode(entry);
if ((flags & ARCHIVE_EXTRACT_PERM) == 0)
fe->mode &= ~extract->umask;
if (flags & ARCHIVE_EXTRACT_TIME) {
fe->fixup |= FIXUP_TIMES;
fe->mtime = archive_entry_mtime(entry);
fe->mtime_nanos = archive_entry_mtime_nsec(entry);
fe->atime = archive_entry_atime(entry);
fe->atime_nanos = archive_entry_atime_nsec(entry);
}
/* For now, set the mode to SECURE_DIR_MODE. */
archive_entry_set_mode(entry, SECURE_DIR_MODE);
return (restore_metadata(a, entry, flags));
}
/*
* Create the parent of the specified path. Copy the provided
* path into mutable storage first.
*/
static int
create_parent_dir(struct archive *a, const char *path, int flags)
{
struct extract *extract;
int r;
extract = a->extract;
/* Copy path to mutable storage. */
archive_strcpy(&(extract->create_parent_dir), path);
r = create_parent_dir_internal(a, extract->create_parent_dir.s, flags);
return (r);
}
/*
* Handle remaining setup for create_parent_dir_recursive(), assuming
* path is already in mutable storage.
*/
static int
create_parent_dir_internal(struct archive *a, char *path, int flags)
{
char *slash;
mode_t old_umask;
int r;
/* Remove tail element to obtain parent name. */
slash = strrchr(path, '/');
if (slash == NULL)
return (ARCHIVE_OK);
*slash = '\0';
old_umask = umask(~SECURE_DIR_MODE);
r = create_parent_dir_recursive(a, path, flags);
umask(old_umask);
*slash = '/';
return (r);
}
/*
* Create the specified dir, recursing to create parents as necessary.
*
* Returns ARCHIVE_OK if the path exists when we're done here.
* Otherwise, returns ARCHIVE_WARN.
*/
static int
create_parent_dir_recursive(struct archive *a, char *path, int flags)
{
struct stat st;
struct extract *extract;
struct fixup_entry *le;
char *slash, *base;
int r;
extract = a->extract;
r = ARCHIVE_OK;
/* Check for special names and just skip them. */
slash = strrchr(path, '/');
base = strrchr(path, '/');
if (slash == NULL)
base = path;
else
base = slash + 1;
if (base[0] == '\0' ||
(base[0] == '.' && base[1] == '\0') ||
(base[0] == '.' && base[1] == '.' && base[2] == '\0')) {
/* Don't bother trying to create null path, '.', or '..'. */
if (slash != NULL) {
*slash = '\0';
r = create_parent_dir_recursive(a, path, flags);
*slash = '/';
return (r);
}
return (ARCHIVE_OK);
}
/*
* Yes, this should be stat() and not lstat(). Using lstat()
* here loses the ability to extract through symlinks. Also note
* that this should not use the extract->st cache.
*/
if (stat(path, &st) == 0) {
if (S_ISDIR(st.st_mode))
return (ARCHIVE_OK);
if ((flags & ARCHIVE_EXTRACT_NO_OVERWRITE)) {
archive_set_error(a, EEXIST,
"Can't create directory '%s'", path);
return (ARCHIVE_WARN);
}
if (unlink(path) != 0) {
archive_set_error(a, errno,
"Can't create directory '%s': "
"Conflicting file cannot be removed");
return (ARCHIVE_WARN);
}
} else if (errno != ENOENT && errno != ENOTDIR) {
/* Stat failed? */
archive_set_error(a, errno, "Can't test directory '%s'", path);
return (ARCHIVE_WARN);
} else if (slash != NULL) {
*slash = '\0';
r = create_parent_dir_recursive(a, path, flags);
*slash = '/';
if (r != ARCHIVE_OK)
return (r);
}
if (mkdir(path, SECURE_DIR_MODE) == 0) {
le = new_fixup(a, path);
le->fixup |= FIXUP_MODE;
le->mode = extract->default_dir_mode;
return (ARCHIVE_OK);
}
/*
* Without the following check, a/b/../b/c/d fails at the
* second visit to 'b', so 'd' can't be created. Note that we
* don't add it to the fixup list here, as it's already been
* added.
*/
if (stat(path, &st) == 0 && S_ISDIR(st.st_mode))
return (ARCHIVE_OK);
archive_set_error(a, errno, "Failed to create dir '%s'", path);
return (ARCHIVE_WARN);
}
static int
extract_hard_link(struct archive *a, struct archive_entry *entry, int flags)
{
struct extract *extract;
int r;
const char *pathname;
const char *linkname;
extract = a->extract;
pathname = archive_entry_pathname(entry);
linkname = archive_entry_hardlink(entry);
/* Just remove any pre-existing file with this name. */
if (!(flags & ARCHIVE_EXTRACT_NO_OVERWRITE))
unlink(pathname);
r = link(linkname, pathname);
extract->pst = NULL; /* Invalidate cached stat data. */
if (r != 0) {
/* Might be a non-existent parent dir; try fixing that. */
create_parent_dir(a, pathname, flags);
r = link(linkname, pathname);
}
if (r != 0) {
/* XXX Better error message here XXX */
archive_set_error(a, errno,
"Can't restore hardlink to '%s'", linkname);
return (ARCHIVE_WARN);
}
/* Set ownership, time, permission information. */
r = restore_metadata(a, entry, flags);
return (r);
}
static int
extract_symlink(struct archive *a, struct archive_entry *entry, int flags)
{
struct extract *extract;
int r;
const char *pathname;
const char *linkname;
extract = a->extract;
pathname = archive_entry_pathname(entry);
linkname = archive_entry_symlink(entry);
/* Just remove any pre-existing file with this name. */
if (!(flags & ARCHIVE_EXTRACT_NO_OVERWRITE))
unlink(pathname);
r = symlink(linkname, pathname);
extract->pst = NULL; /* Invalidate cached stat data. */
if (r != 0) {
/* Might be a non-existent parent dir; try fixing that. */
create_parent_dir(a, pathname, flags);
r = symlink(linkname, pathname);
}
if (r != 0) {
/* XXX Better error message here XXX */
archive_set_error(a, errno,
"Can't restore symlink to '%s'", linkname);
return (ARCHIVE_WARN);
}
r = restore_metadata(a, entry, flags);
return (r);
}
static int
extract_device(struct archive *a, struct archive_entry *entry,
int flags, mode_t mode)
{
struct extract *extract;
int r;
extract = a->extract;
/* Just remove any pre-existing file with this name. */
if (!(flags & ARCHIVE_EXTRACT_NO_OVERWRITE))
unlink(archive_entry_pathname(entry));
r = mknod(archive_entry_pathname(entry), mode,
archive_entry_rdev(entry));
extract->pst = NULL; /* Invalidate cached stat data. */
/* Might be a non-existent parent dir; try fixing that. */
if (r != 0 && errno == ENOENT) {
create_parent_dir(a, archive_entry_pathname(entry), flags);
r = mknod(archive_entry_pathname(entry), mode,
archive_entry_rdev(entry));
}
if (r != 0) {
archive_set_error(a, errno, "Can't restore device node");
return (ARCHIVE_WARN);
}
r = restore_metadata(a, entry, flags);
return (r);
}
static int
extract_char_device(struct archive *a, struct archive_entry *entry, int flags)
{
mode_t mode;
mode = (archive_entry_mode(entry) & ~S_IFMT) | S_IFCHR;
return (extract_device(a, entry, flags, mode));
}
static int
extract_block_device(struct archive *a, struct archive_entry *entry, int flags)
{
mode_t mode;
mode = (archive_entry_mode(entry) & ~S_IFMT) | S_IFBLK;
return (extract_device(a, entry, flags, mode));
}
static int
extract_fifo(struct archive *a, struct archive_entry *entry, int flags)
{
struct extract *extract;
int r;
extract = a->extract;
/* Just remove any pre-existing file with this name. */
if (!(flags & ARCHIVE_EXTRACT_NO_OVERWRITE))
unlink(archive_entry_pathname(entry));
r = mkfifo(archive_entry_pathname(entry),
archive_entry_mode(entry));
extract->pst = NULL; /* Invalidate cached stat data. */
/* Might be a non-existent parent dir; try fixing that. */
if (r != 0 && errno == ENOENT) {
create_parent_dir(a, archive_entry_pathname(entry), flags);
r = mkfifo(archive_entry_pathname(entry),
archive_entry_mode(entry));
}
if (r != 0) {
archive_set_error(a, errno, "Can't restore fifo");
return (ARCHIVE_WARN);
}
r = restore_metadata(a, entry, flags);
return (r);
}
static int
restore_metadata(struct archive *a, struct archive_entry *entry, int flags)
{
int r, r2;
r = set_ownership(a, entry, flags);
r2 = set_time(a, entry, flags);
r = err_combine(r, r2);
r2 = set_perm(a, entry, archive_entry_mode(entry), flags);
return (err_combine(r, r2));
}
static int
set_ownership(struct archive *a, struct archive_entry *entry, int flags)
{
uid_t uid;
gid_t gid;
/* Not changed. */
if ((flags & ARCHIVE_EXTRACT_OWNER) == 0)
return (ARCHIVE_OK);
uid = lookup_uid(a, archive_entry_uname(entry),
archive_entry_uid(entry));
gid = lookup_gid(a, archive_entry_gname(entry),
archive_entry_gid(entry));
/* If we know we can't change it, don't bother trying. */
if (a->user_uid != 0 && a->user_uid != uid)
return (ARCHIVE_OK);
#ifdef HAVE_LCHOWN
if (lchown(archive_entry_pathname(entry), uid, gid))
#else
if (!S_ISLNK(archive_entry_mode(entry))
&& chown(archive_entry_pathname(entry), uid, gid) != 0)
#endif
{
archive_set_error(a, errno,
"Can't set user=%d/group=%d for %s", uid, gid,
archive_entry_pathname(entry));
return (ARCHIVE_WARN);
}
return (ARCHIVE_OK);
}
static int
set_time(struct archive *a, struct archive_entry *entry, int flags)
{
const struct stat *st;
struct timeval times[2];
(void)a; /* UNUSED */
st = archive_entry_stat(entry);
if ((flags & ARCHIVE_EXTRACT_TIME) == 0)
return (ARCHIVE_OK);
/* It's a waste of time to mess with dir timestamps here. */
if (S_ISDIR(archive_entry_mode(entry)))
return (ARCHIVE_OK);
times[1].tv_sec = st->st_mtime;
times[1].tv_usec = ARCHIVE_STAT_MTIME_NANOS(st) / 1000;
times[0].tv_sec = st->st_atime;
times[0].tv_usec = ARCHIVE_STAT_ATIME_NANOS(st) / 1000;
#ifdef HAVE_LUTIMES
if (lutimes(archive_entry_pathname(entry), times) != 0) {
#else
if ((archive_entry_mode(entry) & S_IFMT) != S_IFLNK &&
utimes(archive_entry_pathname(entry), times) != 0) {
#endif
archive_set_error(a, errno, "Can't update time for %s",
archive_entry_pathname(entry));
return (ARCHIVE_WARN);
}
/*
* Note: POSIX does not provide a portable way to restore ctime.
* (Apart from resetting the system clock, which is distasteful.)
* So, any restoration of ctime will necessarily be OS-specific.
*/
/* XXX TODO: Can FreeBSD restore ctime? XXX */
return (ARCHIVE_OK);
}
static int
set_perm(struct archive *a, struct archive_entry *entry, int mode, int flags)
{
struct extract *extract;
struct fixup_entry *le;
const char *name;
unsigned long set, clear;
int r;
int critical_flags;
extract = a->extract;
/* Obey umask unless ARCHIVE_EXTRACT_PERM. */
if ((flags & ARCHIVE_EXTRACT_PERM) == 0)
mode &= ~extract->umask; /* Enforce umask. */
name = archive_entry_pathname(entry);
if (mode & (S_ISUID | S_ISGID)) {
if (extract->pst == NULL && stat(name, &extract->st) != 0) {
archive_set_error(a, errno, "Can't check ownership");
return (ARCHIVE_WARN);
}
extract->pst = &extract->st;
/*
* TODO: Use the uid/gid looked up in set_ownership
* above rather than the uid/gid stored in the entry.
*/
if (extract->pst->st_uid != archive_entry_uid(entry))
mode &= ~ S_ISUID;
if (extract->pst->st_gid != archive_entry_gid(entry))
mode &= ~ S_ISGID;
}
/*
* Ensure we change permissions on the object we extracted,
* and not any incidental symlink that might have gotten in
* the way.
*/
if (!S_ISLNK(archive_entry_mode(entry))) {
if (chmod(name, mode) != 0) {
archive_set_error(a, errno, "Can't set permissions");
return (ARCHIVE_WARN);
}
#ifdef HAVE_LCHMOD
} else {
/*
* If lchmod() isn't supported, it's no big deal.
* Permissions on symlinks are actually ignored on
* most platforms.
*/
if (lchmod(name, mode) != 0) {
archive_set_error(a, errno, "Can't set permissions");
return (ARCHIVE_WARN);
}
#endif
}
if (flags & ARCHIVE_EXTRACT_ACL) {
r = set_acls(a, entry);
if (r != ARCHIVE_OK)
return (r);
}
/*
* Make 'critical_flags' hold all file flags that can't be
* immediately restored. For example, on BSD systems,
* SF_IMMUTABLE prevents hardlinks from being created, so
* should not be set until after any hardlinks are created. To
* preserve some semblance of portability, this uses #ifdef
* extensively. Ugly, but it works.
*
* Yes, Virginia, this does create a security race. It's mitigated
* somewhat by the practice of creating dirs 0700 until the extract
* is done, but it would be nice if we could do more than that.
* People restoring critical file systems should be wary of
* other programs that might try to muck with files as they're
* being restored.
*/
/* Hopefully, the compiler will optimize this mess into a constant. */
critical_flags = 0;
#ifdef SF_IMMUTABLE
critical_flags |= SF_IMMUTABLE;
#endif
#ifdef UF_IMMUTABLE
critical_flags |= UF_IMMUTABLE;
#endif
#ifdef SF_APPEND
critical_flags |= SF_APPEND;
#endif
#ifdef UF_APPEND
critical_flags |= UF_APPEND;
#endif
#ifdef EXT2_APPEND_FL
critical_flags |= EXT2_APPEND_FL;
#endif
#ifdef EXT2_IMMUTABLE_FL
critical_flags |= EXT2_IMMUTABLE_FL;
#endif
if (flags & ARCHIVE_EXTRACT_FFLAGS) {
archive_entry_fflags(entry, &set, &clear);
/*
* The first test encourages the compiler to eliminate
* all of this if it's not necessary.
*/
if ((critical_flags != 0) && (set & critical_flags)) {
le = current_fixup(a, archive_entry_pathname(entry));
le->fixup |= FIXUP_FFLAGS;
le->fflags_set = set;
} else {
r = set_fflags(a, archive_entry_pathname(entry),
archive_entry_mode(entry), set, clear);
if (r != ARCHIVE_OK)
return (r);
}
}
return (ARCHIVE_OK);
}
static int
set_fflags(struct archive *a, const char *name, mode_t mode,
unsigned long set, unsigned long clear)
{
struct extract *extract;
int ret;
#ifdef linux
int fd;
int err;
unsigned long newflags, oldflags;
#endif
extract = a->extract;
ret = ARCHIVE_OK;
if (set == 0 && clear == 0)
return (ret);
#ifdef HAVE_CHFLAGS
(void)mode; /* UNUSED */
/*
* XXX Is the stat here really necessary? Or can I just use
* the 'set' flags directly? In particular, I'm not sure
* about the correct approach if we're overwriting an existing
* file that already has flags on it. XXX
*/
if (stat(name, &extract->st) == 0) {
extract->st.st_flags &= ~clear;
extract->st.st_flags |= set;
if (chflags(name, extract->st.st_flags) != 0) {
archive_set_error(a, errno,
"Failed to set file flags");
ret = ARCHIVE_WARN;
}
extract->pst = &extract->st;
}
#else
#ifdef linux
/* Linux has flags too, but no chflags syscall */
/*
* Linux has no define for the flags that are only settable
* by the root user...
*/
#define SF_MASK (EXT2_IMMUTABLE_FL|EXT2_APPEND_FL)
/*
* XXX As above, this would be way simpler if we didn't have
* to read the current flags from disk. XXX
*/
if ((S_ISREG(mode) || S_ISDIR(mode)) &&
((fd = open(name, O_RDONLY|O_NONBLOCK)) >= 0)) {
err = 1;
if (fd >= 0 && (ioctl(fd, EXT2_IOC_GETFLAGS, &oldflags) >= 0)) {
newflags = (oldflags & ~clear) | set;
if (ioctl(fd, EXT2_IOC_SETFLAGS, &newflags) >= 0) {
err = 0;
} else if (errno == EPERM) {
if (ioctl(fd, EXT2_IOC_GETFLAGS, &oldflags) >= 0) {
newflags &= ~SF_MASK;
oldflags &= SF_MASK;
newflags |= oldflags;
if (ioctl(fd, EXT2_IOC_SETFLAGS, &newflags) >= 0)
err = 0;
}
}
}
close(fd);
if (err) {
archive_set_error(a, errno,
"Failed to set file flags");
ret = ARCHIVE_WARN;
}
}
#endif /* linux */
#endif /* HAVE_CHFLAGS */
return (ret);
}
#ifndef HAVE_POSIX_ACL
/* Default empty function body to satisfy mainline code. */
static int
set_acls(struct archive *a, struct archive_entry *entry)
{
(void)a;
(void)entry;
return (ARCHIVE_OK);
}
#else
/*
* XXX TODO: What about ACL types other than ACCESS and DEFAULT?
*/
static int
set_acls(struct archive *a, struct archive_entry *entry)
{
int ret;
ret = set_acl(a, entry, ACL_TYPE_ACCESS,
ARCHIVE_ENTRY_ACL_TYPE_ACCESS, "access");
if (ret != ARCHIVE_OK)
return (ret);
ret = set_acl(a, entry, ACL_TYPE_DEFAULT,
ARCHIVE_ENTRY_ACL_TYPE_DEFAULT, "default");
return (ret);
}
static int
set_acl(struct archive *a, struct archive_entry *entry, acl_type_t acl_type,
int ae_requested_type, const char *typename)
{
acl_t acl;
acl_entry_t acl_entry;
acl_permset_t acl_permset;
int ret;
int ae_type, ae_permset, ae_tag, ae_id;
uid_t ae_uid;
gid_t ae_gid;
const char *ae_name;
int entries;
const char *name;
ret = ARCHIVE_OK;
entries = archive_entry_acl_reset(entry, ae_requested_type);
if (entries == 0)
return (ARCHIVE_OK);
acl = acl_init(entries);
while (archive_entry_acl_next(entry, ae_requested_type, &ae_type,
&ae_permset, &ae_tag, &ae_id, &ae_name) == ARCHIVE_OK) {
acl_create_entry(&acl, &acl_entry);
switch (ae_tag) {
case ARCHIVE_ENTRY_ACL_USER:
acl_set_tag_type(acl_entry, ACL_USER);
ae_uid = lookup_uid(a, ae_name, ae_id);
acl_set_qualifier(acl_entry, &ae_uid);
break;
case ARCHIVE_ENTRY_ACL_GROUP:
acl_set_tag_type(acl_entry, ACL_GROUP);
ae_gid = lookup_gid(a, ae_name, ae_id);
acl_set_qualifier(acl_entry, &ae_gid);
break;
case ARCHIVE_ENTRY_ACL_USER_OBJ:
acl_set_tag_type(acl_entry, ACL_USER_OBJ);
break;
case ARCHIVE_ENTRY_ACL_GROUP_OBJ:
acl_set_tag_type(acl_entry, ACL_GROUP_OBJ);
break;
case ARCHIVE_ENTRY_ACL_MASK:
acl_set_tag_type(acl_entry, ACL_MASK);
break;
case ARCHIVE_ENTRY_ACL_OTHER:
acl_set_tag_type(acl_entry, ACL_OTHER);
break;
default:
/* XXX */
break;
}
acl_get_permset(acl_entry, &acl_permset);
acl_clear_perms(acl_permset);
if (ae_permset & ARCHIVE_ENTRY_ACL_EXECUTE)
acl_add_perm(acl_permset, ACL_EXECUTE);
if (ae_permset & ARCHIVE_ENTRY_ACL_WRITE)
acl_add_perm(acl_permset, ACL_WRITE);
if (ae_permset & ARCHIVE_ENTRY_ACL_READ)
acl_add_perm(acl_permset, ACL_READ);
}
name = archive_entry_pathname(entry);
if (acl_set_file(name, acl_type, acl) != 0) {
archive_set_error(a, errno, "Failed to set %s acl", typename);
ret = ARCHIVE_WARN;
}
acl_free(acl);
return (ret);
}
#endif
/*
* The following routines do some basic caching of uname/gname lookups.
* All such lookups go through these routines, including ACL conversions.
*
* TODO: Provide an API for clients to override these routines.
*/
static gid_t
lookup_gid(struct archive *a, const char *gname, gid_t gid)
{
struct group *grent;
struct extract *extract;
int h;
struct bucket *b;
int cache_size;
extract = a->extract;
cache_size = sizeof(extract->gcache) / sizeof(extract->gcache[0]);
/* If no gname, just use the gid provided. */
if (gname == NULL || *gname == '\0')
return (gid);
/* Try to find gname in the cache. */
h = hash(gname);
b = &extract->gcache[h % cache_size ];
if (b->name != NULL && b->hash == h && strcmp(gname, b->name) == 0)
return ((gid_t)b->id);
/* Free the cache slot for a new entry. */
if (b->name != NULL)
free(b->name);
b->name = strdup(gname);
/* Note: If strdup fails, that's okay; we just won't cache. */
b->hash = h;
grent = getgrnam(gname);
if (grent != NULL)
gid = grent->gr_gid;
b->id = gid;
return (gid);
}
static uid_t
lookup_uid(struct archive *a, const char *uname, uid_t uid)
{
struct passwd *pwent;
struct extract *extract;
int h;
struct bucket *b;
int cache_size;
extract = a->extract;
cache_size = sizeof(extract->ucache) / sizeof(extract->ucache[0]);
/* If no uname, just use the uid provided. */
if (uname == NULL || *uname == '\0')
return (uid);
/* Try to find uname in the cache. */
h = hash(uname);
b = &extract->ucache[h % cache_size ];
if (b->name != NULL && b->hash == h && strcmp(uname, b->name) == 0)
return ((uid_t)b->id);
/* Free the cache slot for a new entry. */
if (b->name != NULL)
free(b->name);
b->name = strdup(uname);
/* Note: If strdup fails, that's okay; we just won't cache. */
b->hash = h;
pwent = getpwnam(uname);
if (pwent != NULL)
uid = pwent->pw_uid;
b->id = uid;
return (uid);
}
static unsigned int
hash(const char *p)
{
/* A 32-bit version of Peter Weinberger's (PJW) hash algorithm,
as used by ELF for hashing function names. */
unsigned g,h = 0;
while(*p != '\0') {
h = ( h << 4 ) + *p++;
if (( g = h & 0xF0000000 )) {
h ^= g >> 24;
h &= 0x0FFFFFFF;
}
}
return h;
}
void
archive_read_extract_set_progress_callback(struct archive *a,
void (*progress_func)(void *), void *user_data)
{
a->extract_progress = progress_func;
a->extract_progress_user_data = user_data;
}