libarchive/archive_read_disk_acl_linux.c

/*-
 * Copyright (c) 2003-2009 Tim Kientzle
 * Copyright (c) 2010-2012 Michihiro NAKAJIMA
 * Copyright (c) 2016-2017 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"

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#if HAVE_ACL_LIBACL_H && HAVE_LIBACL
#include <acl/libacl.h>
#endif
#ifdef HAVE_SYS_ACL_H
#include <sys/acl.h>
#endif

#include "archive_entry.h"
#include "archive_private.h"
#include "archive_read_disk_private.h"
#include "archive_acl_maps.h"

#if HAVE_LIBACL
#include <acl/libacl.h>
#endif

/*
 * Translate POSIX.1e ACLs into libarchive internal structure
 */
static int
translate_acl(struct archive_read_disk *a,
    struct archive_entry *entry, acl_t acl, int default_entry_acl_type)
{
	acl_tag_t	 acl_tag;
	acl_entry_t	 acl_entry;
	acl_permset_t	 acl_permset;
	int		 i, entry_acl_type;
	int		 r, s, ae_id, ae_tag, ae_perm;
	void		*q;
	const char	*ae_name;

	s = acl_get_entry(acl, ACL_FIRST_ENTRY, &acl_entry);
	if (s == -1) {
		archive_set_error(&a->archive, errno,
		    "Failed to get first ACL entry");
		return (ARCHIVE_WARN);
	}

	while (s == 1) {
		ae_id = -1;
		ae_name = NULL;
		ae_perm = 0;

		if (acl_get_tag_type(acl_entry, &acl_tag) != 0) {
			archive_set_error(&a->archive, errno,
			    "Failed to get ACL tag type");
			return (ARCHIVE_WARN);
		}
		switch (acl_tag) {
		case ACL_USER:
			q = acl_get_qualifier(acl_entry);
			if (q != NULL) {
				ae_id = (int)*(uid_t *)q;
				acl_free(q);
				ae_name = archive_read_disk_uname(&a->archive,
				    ae_id);
			}
			ae_tag = ARCHIVE_ENTRY_ACL_USER;
			break;
		case ACL_GROUP:
			q = acl_get_qualifier(acl_entry);
			if (q != NULL) {
				ae_id = (int)*(gid_t *)q;
				acl_free(q);
				ae_name = archive_read_disk_gname(&a->archive,
				    ae_id);
			}
			ae_tag = ARCHIVE_ENTRY_ACL_GROUP;
			break;
		case ACL_MASK:
			ae_tag = ARCHIVE_ENTRY_ACL_MASK;
			break;
		case ACL_USER_OBJ:
			ae_tag = ARCHIVE_ENTRY_ACL_USER_OBJ;
			break;
		case ACL_GROUP_OBJ:
			ae_tag = ARCHIVE_ENTRY_ACL_GROUP_OBJ;
			break;
		case ACL_OTHER:
			ae_tag = ARCHIVE_ENTRY_ACL_OTHER;
			break;
		default:
			/* Skip types that libarchive can't support. */
			s = acl_get_entry(acl, ACL_NEXT_ENTRY, &acl_entry);
			continue;
		}

		// XXX acl_type maps to allow/deny/audit/YYYY bits
		entry_acl_type = default_entry_acl_type;

		if (acl_get_permset(acl_entry, &acl_permset) != 0) {
			archive_set_error(&a->archive, errno,
			    "Failed to get ACL permission set");
			return (ARCHIVE_WARN);
		}

		for (i = 0; i < acl_posix_perm_map_size; ++i) {
			r = acl_get_perm(acl_permset,
			    acl_posix_perm_map[i].p_perm);
			if (r == -1) {
				archive_set_error(&a->archive, errno,
				    "Failed to check permission in an ACL "
				    "permission set");
				return (ARCHIVE_WARN);
			} else if (r)
				ae_perm |= acl_posix_perm_map[i].a_perm;
		}

		archive_entry_acl_add_entry(entry, entry_acl_type,
					    ae_perm, ae_tag,
					    ae_id, ae_name);

		s = acl_get_entry(acl, ACL_NEXT_ENTRY, &acl_entry);
		if (s == -1) {
			archive_set_error(&a->archive, errno,
			    "Failed to get next ACL entry");
			return (ARCHIVE_WARN);
		}
	}
	return (ARCHIVE_OK);
}
int
archive_read_disk_entry_setup_acls(struct archive_read_disk *a,
    struct archive_entry *entry, int *fd)
{
	const char	*accpath;
	acl_t		acl;
	int		r;

	accpath = NULL;

	/* For default ACLs we need reachable accpath */
	if (*fd < 0 || S_ISDIR(archive_entry_mode(entry)))
	{
		accpath = archive_entry_sourcepath(entry);
		if (accpath == NULL || (a->tree != NULL &&
		    a->tree_enter_working_dir(a->tree) != 0))
			accpath = archive_entry_pathname(entry);
		if (accpath == NULL) {
			archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
			    "Couldn't determine file path to read ACLs");
			return (ARCHIVE_WARN);
		}
		if (a->tree != NULL && *fd < 0 && (a->follow_symlinks ||
		    archive_entry_filetype(entry) != AE_IFLNK)) {
			*fd = a->open_on_current_dir(a->tree,
			    accpath, O_RDONLY | O_NONBLOCK);
		}
	}

	archive_entry_acl_clear(entry);

	acl = NULL;

	/* Retrieve access ACL from file. */
	if (*fd >= 0)
		acl = acl_get_fd(*fd);
	else if ((!a->follow_symlinks)
	    && (archive_entry_filetype(entry) == AE_IFLNK))
		/* We can't get the ACL of a symlink, so we assume it can't
		   have one. */
		acl = NULL;
	else
		acl = acl_get_file(accpath, ACL_TYPE_ACCESS);

	if (acl != NULL) {
		r = translate_acl(a, entry, acl, ARCHIVE_ENTRY_ACL_TYPE_ACCESS);
		acl_free(acl);
		acl = NULL;

		if (r != ARCHIVE_OK) {
			archive_set_error(&a->archive, errno,
			    "Couldn't translate access ACLs");
			return (r);
		}
	}

	/* Only directories can have default ACLs. */
	if (S_ISDIR(archive_entry_mode(entry))) {
		acl = acl_get_file(accpath, ACL_TYPE_DEFAULT);
		if (acl != NULL) {
			r = translate_acl(a, entry, acl,
			    ARCHIVE_ENTRY_ACL_TYPE_DEFAULT);
			acl_free(acl);
			if (r != ARCHIVE_OK) {
				archive_set_error(&a->archive, errno,
				    "Couldn't translate default ACLs");
				return (r);
			}
		}
	}
	return (ARCHIVE_OK);
}