/*-

 * Copyright (c) 2003-2009 Tim Kientzle

 * Copyright (c) 2010-2012 Michihiro NAKAJIMA

 * Copyright (c) 2016 Martin Matuska

 * 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");

/* This is the tree-walking code for POSIX systems. */

#if !defined(_WIN32) || defined(__CYGWIN__)

#ifdef HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif

#ifdef HAVE_SYS_EXTATTR_H

#include <sys/extattr.h>

#endif

#ifdef HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#ifdef HAVE_SYS_PARAM_H

#include <sys/param.h>

#endif

#ifdef HAVE_SYS_STAT_H

#include <sys/stat.h>

#endif

#if defined(HAVE_SYS_XATTR_H)

#include <sys/xattr.h>

#elif defined(HAVE_ATTR_XATTR_H)

#include <attr/xattr.h>

#endif

#ifdef HAVE_SYS_EA_H

#include <sys/ea.h>

#endif

#ifdef HAVE_COPYFILE_H

#include <copyfile.h>

#endif

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif

#ifdef HAVE_LIMITS_H

#include <limits.h>

#endif

#ifdef HAVE_LINUX_TYPES_H

#include <linux/types.h>

#endif

#ifdef HAVE_LINUX_FIEMAP_H

#include <linux/fiemap.h>

#endif

#ifdef HAVE_LINUX_FS_H

#include <linux/fs.h>

#endif

/*

 * Some Linux distributions have both linux/ext2_fs.h and ext2fs/ext2_fs.h.

 * As the include guards don't agree, the order of include is important.

 */

#ifdef HAVE_LINUX_EXT2_FS_H

#include <linux/ext2_fs.h>      /* for Linux file flags */

#endif

#if defined(HAVE_EXT2FS_EXT2_FS_H) && !defined(__CYGWIN__)

#include <ext2fs/ext2_fs.h>     /* Linux file flags, broken on Cygwin */

#endif

#ifdef HAVE_PATHS_H

#include <paths.h>

#endif

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include "archive.h"

#include "archive_entry.h"

#include "archive_private.h"

#include "archive_read_disk_private.h"

#ifndef O_CLOEXEC

#define O_CLOEXEC	0

#endif

static int setup_mac_metadata(struct archive_read_disk *,

    struct archive_entry *, int *fd);

static int setup_xattrs(struct archive_read_disk *,

    struct archive_entry *, int *fd);

static int setup_sparse(struct archive_read_disk *,

    struct archive_entry *, int *fd);

#if defined(HAVE_LINUX_FIEMAP_H)

static int setup_sparse_fiemap(struct archive_read_disk *,

    struct archive_entry *, int *fd);

#endif

#if !ARCHIVE_ACL_SUPPORT

int

archive_read_disk_entry_setup_acls(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	(void)a;      /* UNUSED */

	(void)entry;  /* UNUSED */

	(void)fd;     /* UNUSED */

	return (ARCHIVE_OK);

}

#endif

/*

 * Enter working directory and return working pathname of archive_entry.

 * If a pointer to an integer is provided and its value is below zero

 * open a file descriptor on this pathname.

 */

const char *

archive_read_disk_entry_setup_path(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	const char *path;

	path = archive_entry_sourcepath(entry);

	if (path == NULL || (a->tree != NULL &&

	    a->tree_enter_working_dir(a->tree) != 0))

		path = archive_entry_pathname(entry);

	if (path == NULL) {

		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,

		   "Couldn't determine path");

	} else if (fd != NULL && *fd < 0 && a->tree != NULL &&

	    (a->follow_symlinks || archive_entry_filetype(entry) != AE_IFLNK)) {

		*fd = a->open_on_current_dir(a->tree, path,

		    O_RDONLY | O_NONBLOCK);

	}

	return (path);

}

int

archive_read_disk_entry_from_file(struct archive *_a,

    struct archive_entry *entry,

    int fd,

    const struct stat *st)

{

	struct archive_read_disk *a = (struct archive_read_disk *)_a;

	const char *path, *name;

	struct stat s;

	int initial_fd = fd;

	int r, r1;

	archive_clear_error(_a);

	path = archive_entry_sourcepath(entry);

	if (path == NULL)

		path = archive_entry_pathname(entry);

	if (a->tree == NULL) {

		if (st == NULL) {

#if HAVE_FSTAT

			if (fd >= 0) {

				if (fstat(fd, &s) != 0) {

					archive_set_error(&a->archive, errno,

					    "Can't fstat");

					return (ARCHIVE_FAILED);

				}

			} else

#endif

#if HAVE_LSTAT

			if (!a->follow_symlinks) {

				if (lstat(path, &s) != 0) {

					archive_set_error(&a->archive, errno,

					    "Can't lstat %s", path);

					return (ARCHIVE_FAILED);

				}

			} else

#endif

			if (stat(path, &s) != 0) {

				archive_set_error(&a->archive, errno,

				    "Can't stat %s", path);

				return (ARCHIVE_FAILED);

			}

			st = &s;

		}

		archive_entry_copy_stat(entry, st);

	}

	/* Lookup uname/gname */

	name = archive_read_disk_uname(_a, archive_entry_uid(entry));

	if (name != NULL)

		archive_entry_copy_uname(entry, name);

	name = archive_read_disk_gname(_a, archive_entry_gid(entry));

	if (name != NULL)

		archive_entry_copy_gname(entry, name);

#ifdef HAVE_STRUCT_STAT_ST_FLAGS

	/* On FreeBSD, we get flags for free with the stat. */

	/* TODO: Does this belong in copy_stat()? */

	if ((a->flags & ARCHIVE_READDISK_NO_FFLAGS) == 0 && st->st_flags != 0)

		archive_entry_set_fflags(entry, st->st_flags, 0);

#endif

#if (defined(FS_IOC_GETFLAGS) && defined(HAVE_WORKING_FS_IOC_GETFLAGS)) || \

    (defined(EXT2_IOC_GETFLAGS) && defined(HAVE_WORKING_EXT2_IOC_GETFLAGS))

	/* Linux requires an extra ioctl to pull the flags.  Although

	 * this is an extra step, it has a nice side-effect: We get an

	 * open file descriptor which we can use in the subsequent lookups. */

	if ((a->flags & ARCHIVE_READDISK_NO_FFLAGS) == 0 &&

	    (S_ISREG(st->st_mode) || S_ISDIR(st->st_mode))) {

		if (fd < 0) {

			if (a->tree != NULL)

				fd = a->open_on_current_dir(a->tree, path,

					O_RDONLY | O_NONBLOCK | O_CLOEXEC);

			else

				fd = open(path, O_RDONLY | O_NONBLOCK |

						O_CLOEXEC);

			__archive_ensure_cloexec_flag(fd);

		}

		if (fd >= 0) {

			int stflags;

			r = ioctl(fd,

#if defined(FS_IOC_GETFLAGS)

			    FS_IOC_GETFLAGS,

#else

			    EXT2_IOC_GETFLAGS,

#endif

			    &stflags);

			if (r == 0 && stflags != 0)

				archive_entry_set_fflags(entry, stflags, 0);

		}

	}

#endif

#if defined(HAVE_READLINK) || defined(HAVE_READLINKAT)

	if (S_ISLNK(st->st_mode)) {

		size_t linkbuffer_len = st->st_size + 1;

		char *linkbuffer;

		int lnklen;

		linkbuffer = malloc(linkbuffer_len);

		if (linkbuffer == NULL) {

			archive_set_error(&a->archive, ENOMEM,

			    "Couldn't read link data");

			return (ARCHIVE_FAILED);

		}

		if (a->tree != NULL) {

#ifdef HAVE_READLINKAT

			lnklen = readlinkat(a->tree_current_dir_fd(a->tree),

			    path, linkbuffer, linkbuffer_len);

#else

			if (a->tree_enter_working_dir(a->tree) != 0) {

				archive_set_error(&a->archive, errno,

				    "Couldn't read link data");

				free(linkbuffer);

				return (ARCHIVE_FAILED);

			}

			lnklen = readlink(path, linkbuffer, linkbuffer_len);

#endif /* HAVE_READLINKAT */

		} else

			lnklen = readlink(path, linkbuffer, linkbuffer_len);

		if (lnklen < 0) {

			archive_set_error(&a->archive, errno,

			    "Couldn't read link data");

			free(linkbuffer);

			return (ARCHIVE_FAILED);

		}

		linkbuffer[lnklen] = 0;

		archive_entry_set_symlink(entry, linkbuffer);

		free(linkbuffer);

	}

#endif /* HAVE_READLINK || HAVE_READLINKAT */

	r = 0;

	if ((a->flags & ARCHIVE_READDISK_NO_ACL) == 0)

		r = archive_read_disk_entry_setup_acls(a, entry, &fd;;

	if ((a->flags & ARCHIVE_READDISK_NO_XATTR) == 0) {

		r1 = setup_xattrs(a, entry, &fd;;

		if (r1 < r)

			r = r1;

	}

	if (a->flags & ARCHIVE_READDISK_MAC_COPYFILE) {

		r1 = setup_mac_metadata(a, entry, &fd;;

		if (r1 < r)

			r = r1;

	}

	r1 = setup_sparse(a, entry, &fd;;

	if (r1 < r)

		r = r1;

	/* If we opened the file earlier in this function, close it. */

	if (initial_fd != fd)

		close(fd);

	return (r);

}

#if defined(__APPLE__) && defined(HAVE_COPYFILE_H)

/*

 * The Mac OS "copyfile()" API copies the extended metadata for a

 * file into a separate file in AppleDouble format (see RFC 1740).

 *

 * Mac OS tar and cpio implementations store this extended

 * metadata as a separate entry just before the regular entry

 * with a "._" prefix added to the filename.

 *

 * Note that this is currently done unconditionally; the tar program has

 * an option to discard this information before the archive is written.

 *

 * TODO: If there's a failure, report it and return ARCHIVE_WARN.

 */

static int

setup_mac_metadata(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	int tempfd = -1;

	int copyfile_flags = COPYFILE_NOFOLLOW | COPYFILE_ACL | COPYFILE_XATTR;

	struct stat copyfile_stat;

	int ret = ARCHIVE_OK;

	void *buff = NULL;

	int have_attrs;

	const char *name, *tempdir;

	struct archive_string tempfile;

	(void)fd; /* UNUSED */

	name = archive_read_disk_entry_setup_path(a, entry, NULL);

	if (name == NULL)

		return (ARCHIVE_WARN);

	/* Short-circuit if there's nothing to do. */

	have_attrs = copyfile(name, NULL, 0, copyfile_flags | COPYFILE_CHECK);

	if (have_attrs == -1) {

		archive_set_error(&a->archive, errno,

			"Could not check extended attributes");

		return (ARCHIVE_WARN);

	}

	if (have_attrs == 0)

		return (ARCHIVE_OK);

	tempdir = NULL;

	if (issetugid() == 0)

		tempdir = getenv("TMPDIR");

	if (tempdir == NULL)

		tempdir = _PATH_TMP;

	archive_string_init(&tempfile);

	archive_strcpy(&tempfile, tempdir);

	archive_strcat(&tempfile, "tar.md.XXXXXX");

	tempfd = mkstemp(tempfile.s);

	if (tempfd < 0) {

		archive_set_error(&a->archive, errno,

		    "Could not open extended attribute file");

		ret = ARCHIVE_WARN;

		goto cleanup;

	}

	__archive_ensure_cloexec_flag(tempfd);

	/* XXX I wish copyfile() could pack directly to a memory

	 * buffer; that would avoid the temp file here.  For that

	 * matter, it would be nice if fcopyfile() actually worked,

	 * that would reduce the many open/close races here. */

	if (copyfile(name, tempfile.s, 0, copyfile_flags | COPYFILE_PACK)) {

		archive_set_error(&a->archive, errno,

		    "Could not pack extended attributes");

		ret = ARCHIVE_WARN;

		goto cleanup;

	}

	if (fstat(tempfd, &copyfile_stat)) {

		archive_set_error(&a->archive, errno,

		    "Could not check size of extended attributes");

		ret = ARCHIVE_WARN;

		goto cleanup;

	}

	buff = malloc(copyfile_stat.st_size);

	if (buff == NULL) {

		archive_set_error(&a->archive, errno,

		    "Could not allocate memory for extended attributes");

		ret = ARCHIVE_WARN;

		goto cleanup;

	}

	if (copyfile_stat.st_size != read(tempfd, buff, copyfile_stat.st_size)) {

		archive_set_error(&a->archive, errno,

		    "Could not read extended attributes into memory");

		ret = ARCHIVE_WARN;

		goto cleanup;

	}

	archive_entry_copy_mac_metadata(entry, buff, copyfile_stat.st_size);

cleanup:

	if (tempfd >= 0) {

		close(tempfd);

		unlink(tempfile.s);

	}

	archive_string_free(&tempfile);

	free(buff);

	return (ret);

}

#else

/*

 * Stub implementation for non-Mac systems.

 */

static int

setup_mac_metadata(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	(void)a; /* UNUSED */

	(void)entry; /* UNUSED */

	(void)fd; /* UNUSED */

	return (ARCHIVE_OK);

}

#endif

#if ARCHIVE_XATTR_LINUX || ARCHIVE_XATTR_DARWIN || ARCHIVE_XATTR_AIX

/*

 * Linux, Darwin and AIX extended attribute support.

 *

 * TODO:  By using a stack-allocated buffer for the first

 * call to getxattr(), we might be able to avoid the second

 * call entirely.  We only need the second call if the

 * stack-allocated buffer is too small.  But a modest buffer

 * of 1024 bytes or so will often be big enough.  Same applies

 * to listxattr().

 */

static int

setup_xattr(struct archive_read_disk *a,

    struct archive_entry *entry, const char *name, int fd, const char *accpath)

{

	ssize_t size;

	void *value = NULL;

	if (fd >= 0) {

#if ARCHIVE_XATTR_LINUX

		size = fgetxattr(fd, name, NULL, 0);

#elif ARCHIVE_XATTR_DARWIN

		size = fgetxattr(fd, name, NULL, 0, 0, 0);

#elif ARCHIVE_XATTR_AIX

		size = fgetea(fd, name, NULL, 0);

#endif

	} else if (!a->follow_symlinks) {

#if ARCHIVE_XATTR_LINUX

		size = lgetxattr(accpath, name, NULL, 0);

#elif ARCHIVE_XATTR_DARWIN

		size = getxattr(accpath, name, NULL, 0, 0, XATTR_NOFOLLOW);

#elif ARCHIVE_XATTR_AIX

		size = lgetea(accpath, name, NULL, 0);

#endif

	} else {

#if ARCHIVE_XATTR_LINUX

		size = getxattr(accpath, name, NULL, 0);

#elif ARCHIVE_XATTR_DARWIN

		size = getxattr(accpath, name, NULL, 0, 0, 0);

#elif ARCHIVE_XATTR_AIX

		size = getea(accpath, name, NULL, 0);

#endif

	}

	if (size == -1) {

		archive_set_error(&a->archive, errno,

		    "Couldn't query extended attribute");

		return (ARCHIVE_WARN);

	}

	if (size > 0 && (value = malloc(size)) == NULL) {

		archive_set_error(&a->archive, errno, "Out of memory");

		return (ARCHIVE_FATAL);

	}

	if (fd >= 0) {

#if ARCHIVE_XATTR_LINUX

		size = fgetxattr(fd, name, value, size);

#elif ARCHIVE_XATTR_DARWIN

		size = fgetxattr(fd, name, value, size, 0, 0);

#elif ARCHIVE_XATTR_AIX

		size = fgetea(fd, name, value, size);

#endif

	} else if (!a->follow_symlinks) {

#if ARCHIVE_XATTR_LINUX

		size = lgetxattr(accpath, name, value, size);

#elif ARCHIVE_XATTR_DARWIN

		size = getxattr(accpath, name, value, size, 0, XATTR_NOFOLLOW);

#elif ARCHIVE_XATTR_AIX

		size = lgetea(accpath, name, value, size);

#endif

	} else {

#if ARCHIVE_XATTR_LINUX

		size = getxattr(accpath, name, value, size);

#elif ARCHIVE_XATTR_DARWIN

		size = getxattr(accpath, name, value, size, 0, 0);

#elif ARCHIVE_XATTR_AIX

		size = getea(accpath, name, value, size);

#endif

	}

	if (size == -1) {

		archive_set_error(&a->archive, errno,

		    "Couldn't read extended attribute");

		return (ARCHIVE_WARN);

	}

	archive_entry_xattr_add_entry(entry, name, value, size);

	free(value);

	return (ARCHIVE_OK);

}

static int

setup_xattrs(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	char *list, *p;

	const char *path;

	ssize_t list_size;

	path = NULL;

	if (*fd < 0) {

		path = archive_read_disk_entry_setup_path(a, entry, fd);

		if (path == NULL)

			return (ARCHIVE_WARN);

	}

	if (*fd >= 0) {

#if ARCHIVE_XATTR_LINUX

		list_size = flistxattr(*fd, NULL, 0);

#elif ARCHIVE_XATTR_DARWIN

		list_size = flistxattr(*fd, NULL, 0, 0);

#elif ARCHIVE_XATTR_AIX

		list_size = flistea(*fd, NULL, 0);

#endif

	} else if (!a->follow_symlinks) {

#if ARCHIVE_XATTR_LINUX

		list_size = llistxattr(path, NULL, 0);

#elif ARCHIVE_XATTR_DARWIN

		list_size = listxattr(path, NULL, 0, XATTR_NOFOLLOW);

#elif ARCHIVE_XATTR_AIX

		list_size = llistea(path, NULL, 0);

#endif

	} else {

#if ARCHIVE_XATTR_LINUX

		list_size = listxattr(path, NULL, 0);

#elif ARCHIVE_XATTR_DARWIN

		list_size = listxattr(path, NULL, 0, 0);

#elif ARCHIVE_XATTR_AIX

		list_size = listea(path, NULL, 0);

#endif

	}

	if (list_size == -1) {

		if (errno == ENOTSUP || errno == ENOSYS)

			return (ARCHIVE_OK);

		archive_set_error(&a->archive, errno,

			"Couldn't list extended attributes");

		return (ARCHIVE_WARN);

	}

	if (list_size == 0)

		return (ARCHIVE_OK);

	if ((list = malloc(list_size)) == NULL) {

		archive_set_error(&a->archive, errno, "Out of memory");

		return (ARCHIVE_FATAL);

	}

	if (*fd >= 0) {

#if ARCHIVE_XATTR_LINUX

		list_size = flistxattr(*fd, list, list_size);

#elif ARCHIVE_XATTR_DARWIN

		list_size = flistxattr(*fd, list, list_size, 0);

#elif ARCHIVE_XATTR_AIX

		list_size = flistea(*fd, list, list_size);

#endif

	} else if (!a->follow_symlinks) {

#if ARCHIVE_XATTR_LINUX

		list_size = llistxattr(path, list, list_size);

#elif ARCHIVE_XATTR_DARWIN

		list_size = listxattr(path, list, list_size, XATTR_NOFOLLOW);

#elif ARCHIVE_XATTR_AIX

		list_size = llistea(path, list, list_size);

#endif

	} else {

#if ARCHIVE_XATTR_LINUX

		list_size = listxattr(path, list, list_size);

#elif ARCHIVE_XATTR_DARWIN

		list_size = listxattr(path, list, list_size, 0);

#elif ARCHIVE_XATTR_AIX

		list_size = listea(path, list, list_size);

#endif

	}

	if (list_size == -1) {

		archive_set_error(&a->archive, errno,

			"Couldn't retrieve extended attributes");

		free(list);

		return (ARCHIVE_WARN);

	}

	for (p = list; (p - list) < list_size; p += strlen(p) + 1) {

#if ARCHIVE_XATTR_LINUX

		/* Linux: skip POSIX.1e ACL extended attributes */

		if (strncmp(p, "system.", 7) == 0 &&

		   (strcmp(p + 7, "posix_acl_access") == 0 ||

		    strcmp(p + 7, "posix_acl_default") == 0))

			continue;

		if (strncmp(p, "trusted.SGI_", 12) == 0 &&

		   (strcmp(p + 12, "ACL_DEFAULT") == 0 ||

		    strcmp(p + 12, "ACL_FILE") == 0))

			continue;

		/* Linux: xfsroot namespace is obsolete and unsupported */

		if (strncmp(p, "xfsroot.", 8) == 0)

			continue;

#endif

		setup_xattr(a, entry, p, *fd, path);

	}

	free(list);

	return (ARCHIVE_OK);

}

#elif ARCHIVE_XATTR_FREEBSD

/*

 * FreeBSD extattr interface.

 */

/* TODO: Implement this.  Follow the Linux model above, but

 * with FreeBSD-specific system calls, of course.  Be careful

 * to not include the system extattrs that hold ACLs; we handle

 * those separately.

 */

static int

setup_xattr(struct archive_read_disk *a, struct archive_entry *entry,

    int namespace, const char *name, const char *fullname, int fd,

    const char *path);

static int

setup_xattr(struct archive_read_disk *a, struct archive_entry *entry,

    int namespace, const char *name, const char *fullname, int fd,

    const char *accpath)

{

	ssize_t size;

	void *value = NULL;

	if (fd >= 0)

		size = extattr_get_fd(fd, namespace, name, NULL, 0);

	else if (!a->follow_symlinks)

		size = extattr_get_link(accpath, namespace, name, NULL, 0);

	else

		size = extattr_get_file(accpath, namespace, name, NULL, 0);

	if (size == -1) {

		archive_set_error(&a->archive, errno,

		    "Couldn't query extended attribute");

		return (ARCHIVE_WARN);

	}

	if (size > 0 && (value = malloc(size)) == NULL) {

		archive_set_error(&a->archive, errno, "Out of memory");

		return (ARCHIVE_FATAL);

	}

	if (fd >= 0)

		size = extattr_get_fd(fd, namespace, name, value, size);

	else if (!a->follow_symlinks)

		size = extattr_get_link(accpath, namespace, name, value, size);

	else

		size = extattr_get_file(accpath, namespace, name, value, size);

	if (size == -1) {

		free(value);

		archive_set_error(&a->archive, errno,

		    "Couldn't read extended attribute");

		return (ARCHIVE_WARN);

	}

	archive_entry_xattr_add_entry(entry, fullname, value, size);

	free(value);

	return (ARCHIVE_OK);

}

static int

setup_xattrs(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	char buff[512];

	char *list, *p;

	ssize_t list_size;

	const char *path;

	int namespace = EXTATTR_NAMESPACE_USER;

	path = NULL;

	if (*fd < 0) {

		path = archive_read_disk_entry_setup_path(a, entry, fd);

		if (path == NULL)

			return (ARCHIVE_WARN);

	}

	if (*fd >= 0)

		list_size = extattr_list_fd(*fd, namespace, NULL, 0);

	else if (!a->follow_symlinks)

		list_size = extattr_list_link(path, namespace, NULL, 0);

	else

		list_size = extattr_list_file(path, namespace, NULL, 0);

	if (list_size == -1 && errno == EOPNOTSUPP)

		return (ARCHIVE_OK);

	if (list_size == -1) {

		archive_set_error(&a->archive, errno,

			"Couldn't list extended attributes");

		return (ARCHIVE_WARN);

	}

	if (list_size == 0)

		return (ARCHIVE_OK);

	if ((list = malloc(list_size)) == NULL) {

		archive_set_error(&a->archive, errno, "Out of memory");

		return (ARCHIVE_FATAL);

	}

	if (*fd >= 0)

		list_size = extattr_list_fd(*fd, namespace, list, list_size);

	else if (!a->follow_symlinks)

		list_size = extattr_list_link(path, namespace, list, list_size);

	else

		list_size = extattr_list_file(path, namespace, list, list_size);

	if (list_size == -1) {

		archive_set_error(&a->archive, errno,

			"Couldn't retrieve extended attributes");

		free(list);

		return (ARCHIVE_WARN);

	}

	p = list;

	while ((p - list) < list_size) {

		size_t len = 255 & (int)*p;

		char *name;

		strcpy(buff, "user.");

		name = buff + strlen(buff);

		memcpy(name, p + 1, len);

		name[len] = '\0';

		setup_xattr(a, entry, namespace, name, buff, *fd, path);

		p += 1 + len;

	}

	free(list);

	return (ARCHIVE_OK);

}

#else

/*

 * Generic (stub) extended attribute support.

 */

static int

setup_xattrs(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	(void)a;     /* UNUSED */

	(void)entry; /* UNUSED */

	(void)fd;    /* UNUSED */

	return (ARCHIVE_OK);

}

#endif

#if defined(HAVE_LINUX_FIEMAP_H)

/*

 * Linux FIEMAP sparse interface.

 *

 * The FIEMAP ioctl returns an "extent" for each physical allocation

 * on disk.  We need to process those to generate a more compact list

 * of logical file blocks.  We also need to be very careful to use

 * FIEMAP_FLAG_SYNC here, since there are reports that Linux sometimes

 * does not report allocations for newly-written data that hasn't

 * been synced to disk.

 *

 * It's important to return a minimal sparse file list because we want

 * to not trigger sparse file extensions if we don't have to, since

 * not all readers support them.

 */

static int

setup_sparse_fiemap(struct archive_read_disk *a,

    struct archive_entry *entry, int *fd)

{

	char buff[4096];

	struct fiemap *fm;

	struct fiemap_extent *fe;

	int64_t size;

	int count, do_fiemap, iters;

	int exit_sts = ARCHIVE_OK;

	const char *path;

	if (archive_entry_filetype(entry) != AE_IFREG

	    || archive_entry_size(entry) <= 0

	    || archive_entry_hardlink(entry) != NULL)

		return (ARCHIVE_OK);

	if (*fd < 0) {

		path = archive_read_disk_entry_setup_path(a, entry, NULL);

		if (path == NULL)

			return (ARCHIVE_FAILED);

		if (a->tree != NULL)

			*fd = a->open_on_current_dir(a->tree, path,

				O_RDONLY | O_NONBLOCK | O_CLOEXEC);

		else

			*fd = open(path, O_RDONLY | O_NONBLOCK | O_CLOEXEC);

		if (*fd < 0) {

			archive_set_error(&a->archive, errno,

			    "Can't open `%s'", path);

			return (ARCHIVE_FAILED);

		}

		__archive_ensure_cloexec_flag(*fd);

	}

	/* Initialize buffer to avoid the error valgrind complains about. */

	memset(buff, 0, sizeof(buff));

	count = (sizeof(buff) - sizeof(*fm))/sizeof(*fe);

	fm = (struct fiemap *)buff;

	fm->fm_start = 0;

	fm->fm_length = ~0ULL;;

	fm->fm_flags = FIEMAP_FLAG_SYNC;

	fm->fm_extent_count = count;

	do_fiemap = 1;

	size = archive_entry_size(entry);

	for (iters = 0; ; ++iters) {

		int i, r;

		r = ioctl(*fd, FS_IOC_FIEMAP, fm); 

		if (r < 0) {

			/* When something error happens, it is better we

			 * should return ARCHIVE_OK because an earlier

			 * version(<2.6.28) cannot perform FS_IOC_FIEMAP. */

			goto exit_setup_sparse_fiemap;

		}

		if (fm->fm_mapped_extents == 0) {

			if (iters == 0) {

				/* Fully sparse file; insert a zero-length "data" entry */

				archive_entry_sparse_add_entry(entry, 0, 0);

			}

			break;

		}

		fe = fm->fm_extents;

		for (i = 0; i < (int)fm->fm_mapped_extents; i++, fe++) {

			if (!(fe->fe_flags & FIEMAP_EXTENT_UNWRITTEN)) {

				/* The fe_length of the last block does not

				 * adjust itself to its size files. */

				int64_t length = fe->fe_length;

				if (fe->fe_logical + length > (uint64_t)size)

					length -= fe->fe_logical + length - size;

				if (fe->fe_logical == 0 && length == size) {

					/* This is not sparse. */

					do_fiemap = 0;

					break;

				}