NetBSD/bin/setfacl/merge.c

/*	$NetBSD: merge.c,v 1.1 2020/05/16 18:31:45 christos Exp $	*/

/*-
 * Copyright (c) 2001 Chris D. Faulhaber
 * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/cdefs.h>
#if 0
__FBSDID("$FreeBSD: head/bin/setfacl/merge.c 333065 2018-04-27 15:25:24Z emaste $");
#else
__RCSID("$NetBSD: merge.c,v 1.1 2020/05/16 18:31:45 christos Exp $");
#endif

#include <sys/types.h>
#include <sys/acl.h>
#include <sys/stat.h>

#include <err.h>
#include <stdio.h>

#include "setfacl.h"

static int merge_user_group(acl_entry_t *entry, acl_entry_t *entry_new,
    int acl_brand);

static int
merge_user_group(acl_entry_t *entry, acl_entry_t *entry_new, int acl_brand)
{
	acl_permset_t permset;
	acl_entry_type_t entry_type;
	acl_flagset_t flagset;
	int have_entry;
	uid_t *id, *id_new;

	have_entry = 0;

	id = acl_get_qualifier(*entry);
	if (id == NULL)
		err(1, "acl_get_qualifier() failed");
	id_new = acl_get_qualifier(*entry_new);
	if (id_new == NULL)
		err(1, "acl_get_qualifier() failed");
	if (*id == *id_new) {
		/* any other matches */
		if (acl_get_permset(*entry, &permset) == -1)
			err(1, "acl_get_permset() failed");
		if (acl_set_permset(*entry_new, permset) == -1)
			err(1, "acl_set_permset() failed");

		if (acl_brand == ACL_BRAND_NFS4) {
			if (acl_get_entry_type_np(*entry, &entry_type))
				err(1, "acl_get_entry_type_np() failed");
			if (acl_set_entry_type_np(*entry_new, entry_type))
				err(1, "acl_set_entry_type_np() failed");
			if (acl_get_flagset_np(*entry, &flagset))
				err(1, "acl_get_flagset_np() failed");
			if (acl_set_flagset_np(*entry_new, flagset))
				err(1, "acl_set_flagset_np() failed");
		}

		have_entry = 1;
	}
	acl_free(id);
	acl_free(id_new);

	return (have_entry);
}

/*
 * merge an ACL into existing file's ACL
 */
int
merge_acl(acl_t acl, acl_t *prev_acl, const char *filename)
{
	acl_entry_t entry, entry_new;
	acl_permset_t permset;
	acl_t acl_new;
	acl_tag_t tag, tag_new;
	acl_entry_type_t entry_type, entry_type_new;
	acl_flagset_t flagset;
	int entry_id, entry_id_new, have_entry, had_entry, entry_number = 0;
	int acl_brand, prev_acl_brand;

	acl_get_brand_np(acl, &acl_brand);
	acl_get_brand_np(*prev_acl, &prev_acl_brand);

	if (branding_mismatch(acl_brand, prev_acl_brand)) {
		warnx("%s: branding mismatch; existing ACL is %s, "
		    "entry to be merged is %s", filename,
		    brand_name(prev_acl_brand), brand_name(acl_brand));
		return (-1);
	}

	acl_new = acl_dup(*prev_acl);
	if (acl_new == NULL)
		err(1, "%s: acl_dup() failed", filename);

	entry_id = ACL_FIRST_ENTRY;

	while (acl_get_entry(acl, entry_id, &entry) == 1) {
		entry_id = ACL_NEXT_ENTRY;
		have_entry = 0;
		had_entry = 0;

		/* keep track of existing ACL_MASK entries */
		if (acl_get_tag_type(entry, &tag) == -1)
			err(1, "%s: acl_get_tag_type() failed - "
			    "invalid ACL entry", filename);
		if (tag == ACL_MASK)
			have_mask = true;

		/* check against the existing ACL entries */
		entry_id_new = ACL_FIRST_ENTRY;
		while (acl_get_entry(acl_new, entry_id_new, &entry_new) == 1) {
			entry_id_new = ACL_NEXT_ENTRY;

			if (acl_get_tag_type(entry, &tag) == -1)
				err(1, "%s: acl_get_tag_type() failed",
				    filename);
			if (acl_get_tag_type(entry_new, &tag_new) == -1)
				err(1, "%s: acl_get_tag_type() failed",
				    filename);
			if (tag != tag_new)
				continue;

			/*
			 * For NFSv4, in addition to "tag" and "id" we also
			 * compare "entry_type".
			 */
			if (acl_brand == ACL_BRAND_NFS4) {
				if (acl_get_entry_type_np(entry, &entry_type))
					err(1, "%s: acl_get_entry_type_np() "
					    "failed", filename);
				if (acl_get_entry_type_np(entry_new, &entry_type_new))
					err(1, "%s: acl_get_entry_type_np() "
					    "failed", filename);
				if (entry_type != entry_type_new)
					continue;
			}
		
			switch(tag) {
			case ACL_USER:
			case ACL_GROUP:
				have_entry = merge_user_group(&entry,
				    &entry_new, acl_brand);
				if (have_entry == 0)
					break;
				/* FALLTHROUGH */
			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_OTHER:
			case ACL_MASK:
			case ACL_EVERYONE:
				if (acl_get_permset(entry, &permset) == -1)
					err(1, "%s: acl_get_permset() failed",
					    filename);
				if (acl_set_permset(entry_new, permset) == -1)
					err(1, "%s: acl_set_permset() failed",
					    filename);

				if (acl_brand == ACL_BRAND_NFS4) {
					if (acl_get_entry_type_np(entry, &entry_type))
						err(1, "%s: acl_get_entry_type_np() failed",
						    filename);
					if (acl_set_entry_type_np(entry_new, entry_type))
						err(1, "%s: acl_set_entry_type_np() failed",
						    filename);
					if (acl_get_flagset_np(entry, &flagset))
						err(1, "%s: acl_get_flagset_np() failed",
						    filename);
					if (acl_set_flagset_np(entry_new, flagset))
						err(1, "%s: acl_set_flagset_np() failed",
						    filename);
				}
				had_entry = have_entry = 1;
				break;
			default:
				/* should never be here */
				errx(1, "%s: invalid tag type: %i", filename, tag);
				break;
			}
		}

		/* if this entry has not been found, it must be new */
		if (had_entry == 0) {

			/*
			 * NFSv4 ACL entries must be prepended to the ACL.
			 * Appending them at the end makes no sense, since
			 * in most cases they wouldn't even get evaluated.
			 */
			if (acl_brand == ACL_BRAND_NFS4) {
				if (acl_create_entry_np(&acl_new, &entry_new, entry_number) == -1) {
					warn("%s: acl_create_entry_np() failed", filename); 
					acl_free(acl_new);
					return (-1);
				}
				/*
				 * Without this increment, adding several
				 * entries at once, for example
				 * "setfacl -m user:1:r:allow,user:2:r:allow",
				 * would make them appear in reverse order.
				 */
				entry_number++;
			} else {
				if (acl_create_entry(&acl_new, &entry_new) == -1) {
					warn("%s: acl_create_entry() failed", filename); 
					acl_free(acl_new);
					return (-1);
				}
			}
			if (acl_copy_entry(entry_new, entry) == -1)
				err(1, "%s: acl_copy_entry() failed", filename);
		}
	}

	acl_free(*prev_acl);
	*prev_acl = acl_new;

	return (0);
}

int
add_acl(acl_t acl, uint entry_number, acl_t *prev_acl, const char *filename)
{
	acl_entry_t entry, entry_new;
	acl_t acl_new;
	int entry_id, acl_brand, prev_acl_brand;

	acl_get_brand_np(acl, &acl_brand);
	acl_get_brand_np(*prev_acl, &prev_acl_brand);

	if (prev_acl_brand != ACL_BRAND_NFS4) {
		warnx("%s: the '-a' option is only applicable to NFSv4 ACLs",
		    filename);
		return (-1);
	}

	if (branding_mismatch(acl_brand, ACL_BRAND_NFS4)) {
		warnx("%s: branding mismatch; existing ACL is NFSv4, "
		    "entry to be added is %s", filename,
		    brand_name(acl_brand));
		return (-1);
	}

	acl_new = acl_dup(*prev_acl);
	if (acl_new == NULL)
		err(1, "%s: acl_dup() failed", filename);

	entry_id = ACL_FIRST_ENTRY;

	while (acl_get_entry(acl, entry_id, &entry) == 1) {
		entry_id = ACL_NEXT_ENTRY;

		if (acl_create_entry_np(&acl_new, &entry_new, entry_number) == -1) {
			warn("%s: acl_create_entry_np() failed", filename); 
			acl_free(acl_new);
			return (-1);
		}

		/*
		 * Without this increment, adding several
		 * entries at once, for example
		 * "setfacl -m user:1:r:allow,user:2:r:allow",
		 * would make them appear in reverse order.
		 */
		entry_number++;

		if (acl_copy_entry(entry_new, entry) == -1)
			err(1, "%s: acl_copy_entry() failed", filename);
	}

	acl_free(*prev_acl);
	*prev_acl = acl_new;

	return (0);
}