acls.c

Rsync 3.0.5 source code

				  sxp->st.st_mode) < 0) {
			free_acl(sxp);
			return -1;
		}
	}

	return 0;
}

/* === Send functions === */

/* Send the ida list over the file descriptor. */
static void send_ida_entries(const ida_entries *idal, int f)
{
	id_access *ida;
	size_t count = idal->count;

	write_varint(f, idal->count);

	for (ida = idal->idas; count--; ida++) {
		uint32 xbits = ida->access << 2;
		const char *name;
		if (ida->access & NAME_IS_USER) {
			xbits |= XFLAG_NAME_IS_USER;
			name = add_uid(ida->id);
		} else
			name = add_gid(ida->id);
		write_varint(f, ida->id);
		if (inc_recurse && name) {
			int len = strlen(name);
			write_varint(f, xbits | XFLAG_NAME_FOLLOWS);
			write_byte(f, len);
			write_buf(f, name, len);
		} else
			write_varint(f, xbits);
	}
}

static void send_rsync_acl(rsync_acl *racl, SMB_ACL_TYPE_T type,
			   item_list *racl_list, int f)
{
	int ndx = find_matching_rsync_acl(racl, type, racl_list);

	/* Send 0 (-1 + 1) to indicate that literal ACL data follows. */
	write_varint(f, ndx + 1);

	if (ndx < 0) {
		rsync_acl *new_racl = EXPAND_ITEM_LIST(racl_list, rsync_acl, 1000);
		uchar flags = 0;

		if (racl->user_obj != NO_ENTRY)
			flags |= XMIT_USER_OBJ;
		if (racl->group_obj != NO_ENTRY)
			flags |= XMIT_GROUP_OBJ;
		if (racl->mask_obj != NO_ENTRY)
			flags |= XMIT_MASK_OBJ;
		if (racl->other_obj != NO_ENTRY)
			flags |= XMIT_OTHER_OBJ;
		if (racl->names.count)
			flags |= XMIT_NAME_LIST;

		write_byte(f, flags);

		if (flags & XMIT_USER_OBJ)
			write_varint(f, racl->user_obj);
		if (flags & XMIT_GROUP_OBJ)
			write_varint(f, racl->group_obj);
		if (flags & XMIT_MASK_OBJ)
			write_varint(f, racl->mask_obj);
		if (flags & XMIT_OTHER_OBJ)
			write_varint(f, racl->other_obj);
		if (flags & XMIT_NAME_LIST)
			send_ida_entries(&racl->names, f);

		/* Give the allocated data to the new list object. */
		*new_racl = *racl;
		*racl = empty_rsync_acl;
	}
}

/* Send the ACL from the stat_x structure down the indicated file descriptor.
 * This also frees the ACL data. */
void send_acl(stat_x *sxp, int f)
{
	if (!sxp->acc_acl) {
		sxp->acc_acl = create_racl();
		rsync_acl_fake_perms(sxp->acc_acl, sxp->st.st_mode);
	}
	/* Avoid sending values that can be inferred from other data. */
	rsync_acl_strip_perms(sxp->acc_acl);

	send_rsync_acl(sxp->acc_acl, SMB_ACL_TYPE_ACCESS, &access_acl_list, f);

	if (S_ISDIR(sxp->st.st_mode)) {
		if (!sxp->def_acl)
			sxp->def_acl = create_racl();

		send_rsync_acl(sxp->def_acl, SMB_ACL_TYPE_DEFAULT, &default_acl_list, f);
	}
}

/* === Receive functions === */

static uint32 recv_acl_access(uchar *name_follows_ptr, int f)
{
	uint32 access = read_varint(f);

	if (name_follows_ptr) {
		int flags = access & 3;
		access >>= 2;
		if (am_root >= 0 && access & ~SMB_ACL_VALID_NAME_BITS)
			goto value_error;
		if (flags & XFLAG_NAME_FOLLOWS)
			*name_follows_ptr = 1;
		else
			*name_follows_ptr = 0;
		if (flags & XFLAG_NAME_IS_USER)
			access |= NAME_IS_USER;
	} else if (am_root >= 0 && access & ~SMB_ACL_VALID_OBJ_BITS) {
	  value_error:
		rprintf(FERROR_XFER, "recv_acl_access: value out of range: %x\n",
			access);
		exit_cleanup(RERR_STREAMIO);
	}

	return access;
}

static uchar recv_ida_entries(ida_entries *ent, int f)
{
	uchar computed_mask_bits = 0;
	int i, count = read_varint(f);

	if (count) {
		if (!(ent->idas = new_array(id_access, count)))
			out_of_memory("recv_ida_entries");
	} else
		ent->idas = NULL;

	ent->count = count;

	for (i = 0; i < count; i++) {
		uchar has_name;
		id_t id = read_varint(f);
		uint32 access = recv_acl_access(&has_name, f);

		if (has_name) {
			if (access & NAME_IS_USER)
				id = recv_user_name(f, id);
			else
				id = recv_group_name(f, id, NULL);
		} else if (access & NAME_IS_USER) {
			if (inc_recurse && am_root && !numeric_ids)
				id = match_uid(id);
		} else {
			if (inc_recurse && (!am_root || !numeric_ids))
				id = match_gid(id, NULL);
		}

		ent->idas[i].id = id;
		ent->idas[i].access = access;
		computed_mask_bits |= access;
	}

	return computed_mask_bits & ~NO_ENTRY;
}

static int recv_rsync_acl(item_list *racl_list, SMB_ACL_TYPE_T type, int f)
{
	uchar computed_mask_bits = 0;
	acl_duo *duo_item;
	uchar flags;
	int ndx = read_varint(f);

	if (ndx < 0 || (size_t)ndx > racl_list->count) {
		rprintf(FERROR_XFER, "recv_acl_index: %s ACL index %d > %d\n",
			str_acl_type(type), ndx, (int)racl_list->count);
		exit_cleanup(RERR_STREAMIO);
	}

	if (ndx != 0)
		return ndx - 1;
	
	ndx = racl_list->count;
	duo_item = EXPAND_ITEM_LIST(racl_list, acl_duo, 1000);
	duo_item->racl = empty_rsync_acl;

	flags = read_byte(f);

	if (flags & XMIT_USER_OBJ)
		duo_item->racl.user_obj = recv_acl_access(NULL, f);
	if (flags & XMIT_GROUP_OBJ)
		duo_item->racl.group_obj = recv_acl_access(NULL, f);
	if (flags & XMIT_MASK_OBJ)
		duo_item->racl.mask_obj = recv_acl_access(NULL, f);
	if (flags & XMIT_OTHER_OBJ)
		duo_item->racl.other_obj = recv_acl_access(NULL, f);
	if (flags & XMIT_NAME_LIST)
		computed_mask_bits |= recv_ida_entries(&duo_item->racl.names, f);

#ifdef HAVE_OSX_ACLS
	/* If we received a superfluous mask, throw it away. */
	duo_item->racl.mask_obj = NO_ENTRY;
#else
	if (!duo_item->racl.names.count) {
		/* If we received a superfluous mask, throw it away. */
		if (duo_item->racl.mask_obj != NO_ENTRY) {
			/* Mask off the group perms with it first. */
			duo_item->racl.group_obj &= duo_item->racl.mask_obj | NO_ENTRY;
			duo_item->racl.mask_obj = NO_ENTRY;
		}
	} else if (duo_item->racl.mask_obj == NO_ENTRY) /* Must be non-empty with lists. */
		duo_item->racl.mask_obj = (computed_mask_bits | duo_item->racl.group_obj) & ~NO_ENTRY;
#endif

	duo_item->sacl = NULL;

	return ndx;
}

/* Receive the ACL info the sender has included for this file-list entry. */
void receive_acl(struct file_struct *file, int f)
{
	F_ACL(file) = recv_rsync_acl(&access_acl_list, SMB_ACL_TYPE_ACCESS, f);

	if (S_ISDIR(file->mode))
		F_DIR_DEFACL(file) = recv_rsync_acl(&default_acl_list, SMB_ACL_TYPE_DEFAULT, f);
}

static int cache_rsync_acl(rsync_acl *racl, SMB_ACL_TYPE_T type, item_list *racl_list)
{
	int ndx;

	if (!racl)
		ndx = -1;
	else if ((ndx = find_matching_rsync_acl(racl, type, racl_list)) == -1) {
		acl_duo *new_duo;
		ndx = racl_list->count;
		new_duo = EXPAND_ITEM_LIST(racl_list, acl_duo, 1000);
		new_duo->racl = *racl;
		new_duo->sacl = NULL;
		*racl = empty_rsync_acl;
	}

	return ndx;
}

/* Turn the ACL data in stat_x into cached ACL data, setting the index
 * values in the file struct. */
void cache_acl(struct file_struct *file, stat_x *sxp)
{
	F_ACL(file) = cache_rsync_acl(sxp->acc_acl,
				      SMB_ACL_TYPE_ACCESS, &access_acl_list);

	if (S_ISDIR(sxp->st.st_mode)) {
		F_DIR_DEFACL(file) = cache_rsync_acl(sxp->def_acl,
				      SMB_ACL_TYPE_DEFAULT, &default_acl_list);
	}
}

#ifndef HAVE_OSX_ACLS
static mode_t change_sacl_perms(SMB_ACL_T sacl, rsync_acl *racl, mode_t old_mode, mode_t mode)
{
	SMB_ACL_ENTRY_T entry;
	const char *errfun;
	int rc;

	if (S_ISDIR(mode)) {
		/* If the sticky bit is going on, it's not safe to allow all
		 * the new ACL to go into effect before it gets set. */
#ifdef SMB_ACL_LOSES_SPECIAL_MODE_BITS
		if (mode & S_ISVTX)
			mode &= ~0077;
#else
		if (mode & S_ISVTX && !(old_mode & S_ISVTX))
			mode &= ~0077;
	} else {
		/* If setuid or setgid is going off, it's not safe to allow all
		 * the new ACL to go into effect before they get cleared. */
		if ((old_mode & S_ISUID && !(mode & S_ISUID))
		 || (old_mode & S_ISGID && !(mode & S_ISGID)))
			mode &= ~0077;
#endif
	}

	errfun = "sys_acl_get_entry";
	for (rc = sys_acl_get_entry(sacl, SMB_ACL_FIRST_ENTRY, &entry);
	     rc == 1;
	     rc = sys_acl_get_entry(sacl, SMB_ACL_NEXT_ENTRY, &entry)) {
		SMB_ACL_TAG_T tag_type;
		if ((rc = sys_acl_get_tag_type(entry, &tag_type)) != 0) {
			errfun = "sys_acl_get_tag_type";
			break;
		}
		switch (tag_type) {
		case SMB_ACL_USER_OBJ:
			COE2( store_access_in_entry,((mode >> 6) & 7, entry) );
			break;
		case SMB_ACL_GROUP_OBJ:
			/* group is only empty when identical to group perms. */
			if (racl->group_obj != NO_ENTRY)
				break;
			COE2( store_access_in_entry,((mode >> 3) & 7, entry) );
			break;
		case SMB_ACL_MASK:
#ifndef ACLS_NEED_MASK
			/* mask is only empty when we don't need it. */
			if (racl->mask_obj == NO_ENTRY)
				break;
#endif
			COE2( store_access_in_entry,((mode >> 3) & 7, entry) );
			break;
		case SMB_ACL_OTHER:
			COE2( store_access_in_entry,(mode & 7, entry) );
			break;
		}
	}
	if (rc) {
	  error_exit:
		if (errfun) {
			rsyserr(FERROR_XFER, errno, "change_sacl_perms: %s()",
				errfun);
		}
		return (mode_t)~0;
	}

#ifdef SMB_ACL_LOSES_SPECIAL_MODE_BITS
	/* Ensure that chmod() will be called to restore any lost setid bits. */
	if (old_mode & (S_ISUID | S_ISGID | S_ISVTX)
	 && BITS_EQUAL(old_mode, mode, CHMOD_BITS))
		old_mode &= ~(S_ISUID | S_ISGID | S_ISVTX);
#endif

	/* Return the mode of the file on disk, as we will set them. */
	return (old_mode & ~ACCESSPERMS) | (mode & ACCESSPERMS);
}
#endif

static int set_rsync_acl(const char *fname, acl_duo *duo_item,
			 SMB_ACL_TYPE_T type, stat_x *sxp, mode_t mode)
{
	if (type == SMB_ACL_TYPE_DEFAULT
	 && duo_item->racl.user_obj == NO_ENTRY) {
		int rc;
#ifdef SUPPORT_XATTRS
		/* --fake-super support: delete default ACL from xattrs. */
		if (am_root < 0)
			rc = del_def_xattr_acl(fname);
		else
#endif
			rc = sys_acl_delete_def_file(fname);
		if (rc < 0) {
			rsyserr(FERROR_XFER, errno, "set_acl: sys_acl_delete_def_file(%s)",
				fname);
			return -1;
		}
#ifdef SUPPORT_XATTRS
	} else if (am_root < 0) {
		/* --fake-super support: store ACLs in an xattr. */
		int cnt = duo_item->racl.names.count;
		size_t len = 4*4 + cnt * (4+4);
		char *buf = new_array(char, len);
		int rc;

		SIVAL(buf, 0, duo_item->racl.user_obj);
		SIVAL(buf, 4, duo_item->racl.group_obj);
		SIVAL(buf, 8, duo_item->racl.mask_obj);
		SIVAL(buf, 12, duo_item->racl.other_obj);

		if (cnt) {
			char *bp = buf + 4*4;
			id_access *ida = duo_item->racl.names.idas;
			for ( ; cnt--; ida++, bp += 4+4) {
				SIVAL(bp, 0, ida->id);
				SIVAL(bp, 4, ida->access);
			}
		}
		rc = set_xattr_acl(fname, type == SMB_ACL_TYPE_ACCESS, buf, len);
		free(buf);
		return rc;
#endif
	} else {
		mode_t cur_mode = sxp->st.st_mode;
		if (!duo_item->sacl
		 && !pack_smb_acl(&duo_item->sacl, &duo_item->racl))
			return -1;
#ifdef HAVE_OSX_ACLS
		mode = 0; /* eliminate compiler warning */
#else
		if (type == SMB_ACL_TYPE_ACCESS) {
			cur_mode = change_sacl_perms(duo_item->sacl, &duo_item->racl,
						     cur_mode, mode);
			if (cur_mode == (mode_t)~0)
				return 0;
		}
#endif
		if (sys_acl_set_file(fname, type, duo_item->sacl) < 0) {
			rsyserr(FERROR_XFER, errno, "set_acl: sys_acl_set_file(%s, %s)",
				fname, str_acl_type(type));
			return -1;
		}
		if (type == SMB_ACL_TYPE_ACCESS)
			sxp->st.st_mode = cur_mode;
	}

	return 0;
}

/* Set ACL on indicated filename.
 *
 * This sets extended access ACL entries and default ACL.  If convenient,
 * it sets permission bits along with the access ACL and signals having
 * done so by modifying sxp->st.st_mode.
 *
 * Returns 1 for unchanged, 0 for changed, -1 for failed.  Call this
 * with fname set to NULL to just check if the ACL is unchanged. */
int set_acl(const char *fname, const struct file_struct *file, stat_x *sxp)
{
	int unchanged = 1;
	int32 ndx;
	BOOL eq;

	if (!dry_run && (read_only || list_only)) {
		errno = EROFS;
		return -1;
	}

	ndx = F_ACL(file);
	if (ndx >= 0 && (size_t)ndx < access_acl_list.count) {
		acl_duo *duo_item = access_acl_list.items;
		duo_item += ndx;
		eq = sxp->acc_acl
		  && rsync_acl_equal_enough(sxp->acc_acl, &duo_item->racl, file->mode);
		if (!eq) {
			unchanged = 0;
			if (!dry_run && fname
			 && set_rsync_acl(fname, duo_item, SMB_ACL_TYPE_ACCESS,
					  sxp, file->mode) < 0)
				unchanged = -1;
		}
	}

	if (!S_ISDIR(sxp->st.st_mode))
		return unchanged;

	ndx = F_DIR_DEFACL(file);
	if (ndx >= 0 && (size_t)ndx < default_acl_list.count) {
		acl_duo *duo_item = default_acl_list.items;
		duo_item += ndx;
		eq = sxp->def_acl && rsync_acl_equal(sxp->def_acl, &duo_item->racl);
		if (!eq) {
			if (unchanged > 0)
				unchanged = 0;
			if (!dry_run && fname
			 && set_rsync_acl(fname, duo_item, SMB_ACL_TYPE_DEFAULT,
					  sxp, file->mode) < 0)
				unchanged = -1;
		}
	}

	return unchanged;
}

/* Non-incremental recursion needs to convert all the received IDs.
 * This is done in a single pass after receiving the whole file-list. */
static void match_racl_ids(const item_list *racl_list)
{
	int list_cnt, name_cnt;
	acl_duo *duo_item = racl_list->items;
	for (list_cnt = racl_list->count; list_cnt--; duo_item++) {
		ida_entries *idal = &duo_item->racl.names;
		id_access *ida = idal->idas;
		for (name_cnt = idal->count; name_cnt--; ida++) {
			if (ida->access & NAME_IS_USER)
				ida->id = match_uid(ida->id);
			else
				ida->id = match_gid(ida->id, NULL);
		}
	}
}

void match_acl_ids(void)
{
	match_racl_ids(&access_acl_list);
	match_racl_ids(&default_acl_list);
}

/* This is used by dest_mode(). */
int default_perms_for_dir(const char *dir)
{
	rsync_acl racl;
	SMB_ACL_T sacl;
	BOOL ok;
	int perms;

	if (dir == NULL)
		dir = ".";
	perms = ACCESSPERMS & ~orig_umask;
	/* Read the directory's default ACL.  If it has none, this will successfully return an empty ACL. */
	sacl = sys_acl_get_file(dir, SMB_ACL_TYPE_DEFAULT);
	if (sacl == NULL) {
		/* Couldn't get an ACL.  Darn. */
		switch (errno) {
#ifdef ENOTSUP
		case ENOTSUP:
#endif
		case ENOSYS:
			/* No ACLs are available. */
			break;
		case ENOENT:
			if (dry_run) {
				/* We're doing a dry run, so the containing directory
				 * wasn't actually created.  Don't worry about it. */
				break;
			}
			/* Otherwise fall through. */
		default:
			rprintf(FWARNING,
				"default_perms_for_dir: sys_acl_get_file(%s, %s): %s, falling back on umask\n",
				dir, str_acl_type(SMB_ACL_TYPE_DEFAULT), strerror(errno));
		}
		return perms;
	}

	/* Convert it. */
	racl = empty_rsync_acl;
	ok = unpack_smb_acl(sacl, &racl);
	sys_acl_free_acl(sacl);
	if (!ok) {
		rprintf(FWARNING, "default_perms_for_dir: unpack_smb_acl failed, falling back on umask\n");
		return perms;
	}

	/* Apply the permission-bit entries of the default ACL, if any. */
	if (racl.user_obj != NO_ENTRY) {
		perms = rsync_acl_get_perms(&racl);
		if (verbose > 2)
			rprintf(FINFO, "got ACL-based default perms %o for directory %s\n", perms, dir);
	}

	rsync_acl_free(&racl);
	return perms;
}

#endif /* SUPPORT_ACLS */