path: root/usr/src/cmd/svc/common/manifest_hash.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

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

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <libintl.h>
#include <libscf.h>
#include <libuutil.h>
#include <limits.h>
#include <md5.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>

#include <manifest_hash.h>

/*
 * Translate a file name to property name.  Return an allocated string or NULL
 * if realpath() fails.
 */
char *
mhash_filename_to_propname(const char *in)
{
	char *out, *cp, *base;
	size_t len, piece_len;

	out = uu_zalloc(PATH_MAX + 1);
	if (realpath(in, out) == NULL) {
		uu_free(out);
		return (NULL);
	}

	base = getenv("PKG_INSTALL_ROOT");

	/*
	 * We copy-shift over the basedir and the leading slash, since it's
	 * not relevant to when we boot with this repository.
	 */

	cp = out + ((base != NULL)? strlen(base) : 0);
	if (*cp == '/')
		cp++;
	(void) memmove(out, cp, strlen(cp) + 1);

	len = strlen(out);
	if (len > scf_limit(SCF_LIMIT_MAX_NAME_LENGTH)) {
		/* Use the first half and the second half. */
		piece_len = (scf_limit(SCF_LIMIT_MAX_NAME_LENGTH) - 3) / 2;

		(void) strncpy(out + piece_len, "__", 2);

		(void) memmove(out + piece_len + 2, out + (len - piece_len),
		    piece_len + 1);
	}

	/*
	 * Translate non-property characters to '_', first making sure that
	 * we don't begin with '_'.
	 */

	if (!isalpha(*out))
		*out = 'A';

	for (cp = out + 1; *cp != '\0'; ++cp) {
		if (!(isalnum(*cp) || *cp == '_' || *cp == '-'))
			*cp = '_';
	}

	return (out);
}

int
mhash_retrieve_entry(scf_handle_t *hndl, const char *name, uchar_t *hash)
{
	scf_scope_t *scope;
	scf_service_t *svc;
	scf_propertygroup_t *pg;
	scf_property_t *prop;
	scf_value_t *val;
	ssize_t szret;
	int result = 0;

	/*
	 * In this implementation the hash for name is the opaque value of
	 * svc:/MHASH_SVC/:properties/name/MHASH_PROP
	 */

	if ((scope = scf_scope_create(hndl)) == NULL ||
	    (svc = scf_service_create(hndl)) == NULL ||
	    (pg = scf_pg_create(hndl)) == NULL ||
	    (prop = scf_property_create(hndl)) == NULL ||
	    (val = scf_value_create(hndl)) == NULL) {
		result = -1;
		goto out;
	}

	if (scf_handle_get_local_scope(hndl, scope) < 0) {
		result = -1;
		goto out;
	}

	if (scf_scope_get_service(scope, MHASH_SVC, svc) < 0) {
		result = -1;
		goto out;
	}

	if (scf_service_get_pg(svc, name, pg) != SCF_SUCCESS) {
		result = -1;
		goto out;
	}

	if (scf_pg_get_property(pg, MHASH_PROP, prop) != SCF_SUCCESS) {
		result = -1;
		goto out;
	}

	if (scf_property_get_value(prop, val) != SCF_SUCCESS) {
		result = -1;
		goto out;
	}

	szret = scf_value_get_opaque(val, hash, MHASH_SIZE);
	if (szret < 0) {
		result = -1;
		goto out;
	}

	if (szret != MHASH_SIZE) {
		scf_value_destroy(val);
		result = -1;
		goto out;
	}

out:
	(void) scf_value_destroy(val);
	scf_property_destroy(prop);
	scf_pg_destroy(pg);
	scf_service_destroy(svc);
	scf_scope_destroy(scope);

	return (result);
}

int
mhash_store_entry(scf_handle_t *hndl, const char *name, uchar_t *hash,
    char **errstr)
{
	scf_scope_t *scope = NULL;
	scf_service_t *svc = NULL;
	scf_propertygroup_t *pg = NULL;
	scf_property_t *prop = NULL;
	scf_value_t *val = NULL;
	scf_transaction_t *tx = NULL;
	scf_transaction_entry_t *e = NULL;
	int ret, result = 0;

	int i;

	if ((scope = scf_scope_create(hndl)) == NULL ||
	    (svc = scf_service_create(hndl)) == NULL ||
	    (pg = scf_pg_create(hndl)) == NULL ||
	    (prop = scf_property_create(hndl)) == NULL) {
		if (errstr != NULL)
			*errstr = gettext("Could not create scf objects");
		result = -1;
		goto out;
	}

	if (scf_handle_get_local_scope(hndl, scope) != SCF_SUCCESS) {
		if (errstr != NULL)
			*errstr = gettext("Could not get local scope");
		result = -1;
		goto out;
	}

	for (i = 0; i < 5; ++i) {
		scf_error_t err;

		if (scf_scope_get_service(scope, MHASH_SVC, svc) ==
		    SCF_SUCCESS)
			break;

		if (scf_error() != SCF_ERROR_NOT_FOUND) {
			if (errstr != NULL)
				*errstr = gettext("Could not get manifest hash "
				    "service");
			result = -1;
			goto out;
		}

		if (scf_scope_add_service(scope, MHASH_SVC, svc) ==
		    SCF_SUCCESS)
			break;

		err = scf_error();

		if (err == SCF_ERROR_EXISTS)
			/* Try again. */
			continue;
		else if (err == SCF_ERROR_PERMISSION_DENIED) {
			if (errstr != NULL)
				*errstr = gettext("Could not store file hash: "
				    "permission denied.\n");
			result = -1;
			goto out;
		}

		if (errstr != NULL)
			*errstr = gettext("Could not add manifest hash "
			    "service");
		result = -1;
		goto out;
	}

	if (i == 5) {
		if (errstr != NULL)
			*errstr = gettext("Could not store file hash: "
			    "service addition contention.\n");
		result = -1;
		goto out;
	}

	for (i = 0; i < 5; ++i) {
		scf_error_t err;

		if (scf_service_get_pg(svc, name, pg) == SCF_SUCCESS)
			break;

		if (scf_error() != SCF_ERROR_NOT_FOUND) {
			if (errstr != NULL)
				*errstr = gettext("Could not get service's "
				    "hash record)");
			result = -1;
			goto out;
		}

		if (scf_service_add_pg(svc, name, MHASH_PG_TYPE,
		    MHASH_PG_FLAGS, pg) == SCF_SUCCESS)
			break;

		err = scf_error();

		if (err == SCF_ERROR_EXISTS)
			/* Try again. */
			continue;
		else if (err == SCF_ERROR_PERMISSION_DENIED) {
			if (errstr != NULL)
				*errstr = gettext("Could not store file hash: "
				    "permission denied.\n");
			result = -1;
			goto out;
		}

		if (errstr != NULL)
			*errstr = gettext("Could not store file hash");
		result = -1;
		goto out;
	}
	if (i == 5) {
		if (errstr != NULL)
			*errstr = gettext("Could not store file hash: "
			    "property group addition contention.\n");
		result = -1;
		goto out;
	}

	if ((e = scf_entry_create(hndl)) == NULL ||
	    (val = scf_value_create(hndl)) == NULL) {
		if (errstr != NULL)
			*errstr = gettext("Could not store file hash: "
			    "permission denied.\n");
		result = -1;
		goto out;
	}

	ret = scf_value_set_opaque(val, hash, MHASH_SIZE);
	assert(ret == SCF_SUCCESS);

	tx = scf_transaction_create(hndl);
	if (tx == NULL) {
		if (errstr != NULL)
			*errstr = gettext("Could not create transaction");
		result = -1;
		goto out;
	}

	do {
		if (scf_pg_update(pg) == -1) {
			if (errstr != NULL)
				*errstr = gettext("Could not update hash "
				    "entry");
			result = -1;
			goto out;
		}
		if (scf_transaction_start(tx, pg) != SCF_SUCCESS) {
			if (scf_error() != SCF_ERROR_PERMISSION_DENIED) {
				if (errstr != NULL)
					*errstr = gettext("Could not start "
					    "hash transaction.\n");
				result = -1;
				goto out;
			}

			if (errstr != NULL)
				*errstr = gettext("Could not store file hash: "
				    "permission denied.\n");
			result = -1;

			scf_transaction_destroy(tx);
			(void) scf_entry_destroy(e);
			goto out;
		}

		if (scf_transaction_property_new(tx, e, MHASH_PROP,
		    SCF_TYPE_OPAQUE) != SCF_SUCCESS &&
		    scf_transaction_property_change_type(tx, e, MHASH_PROP,
		    SCF_TYPE_OPAQUE) != SCF_SUCCESS) {
			if (errstr != NULL)
				*errstr = gettext("Could not modify hash "
				    "entry");
			result = -1;
			goto out;
		}

		ret = scf_entry_add_value(e, val);
		assert(ret == SCF_SUCCESS);

		ret = scf_transaction_commit(tx);

		if (ret == 0)
			scf_transaction_reset(tx);
	} while (ret == 0);

	if (ret < 0) {
		if (scf_error() != SCF_ERROR_PERMISSION_DENIED) {
			if (errstr != NULL)
				*errstr = gettext("Could not store file hash: "
				    "permission denied.\n");
			result = -1;
			goto out;
		}

		if (errstr != NULL)
			*errstr = gettext("Could not commit transaction");
		result = -1;
	}

	scf_transaction_destroy(tx);
	(void) scf_entry_destroy(e);

out:
	(void) scf_value_destroy(val);
	scf_property_destroy(prop);
	scf_pg_destroy(pg);
	scf_service_destroy(svc);
	scf_scope_destroy(scope);

	return (result);
}

/*
 * int mhash_test_file(scf_handle_t *, const char *, uint_t, char **, uchar_t *)
 *   Test the given filename against the hashed metadata in the repository.
 *   The behaviours for import and apply are slightly different.  For imports,
 *   if the hash value is absent or different, then the import operation
 *   continues.  For profile application, the operation continues only if the
 *   hash value for the file is absent.
 *
 *   Return non-zero if we should skip the file because it is unchanged or
 *   nonexistent.
 */
int
mhash_test_file(scf_handle_t *hndl, const char *file, uint_t is_profile,
    char **pnamep, uchar_t *hash)
{
	boolean_t do_hash;
	struct stat64 st;
	char *cp;
	char *data;
	uchar_t stored_hash[MHASH_SIZE];
	char *pname;
	int ret;

	/*
	 * In the case where we are doing automated imports, we reduce the UID,
	 * the GID, the size, and the mtime into a string (to eliminate
	 * endianness) which we then make opaque as a single MD5 digest.
	 *
	 * The previous hash was composed of the inode number, the UID, the file
	 * size, and the mtime.  This formulation was found to be insufficiently
	 * portable for use in highly replicated deployments.  The current
	 * algorithm will allow matches of this "v1" hash, but always returns
	 * the effective "v2" hash, such that updates result in the more
	 * portable hash being used.
	 *
	 * If neither calculated digest matches the stored value, we consider
	 * the test to have failed, implying that some aspect of the manifest
	 * has changed.
	 */

	cp = getenv("SVCCFG_CHECKHASH");
	do_hash = (cp != NULL && *cp != '\0');
	if (!do_hash) {
		*pnamep = NULL;
		return (0);
	}

	do
		ret = stat64(file, &st);
	while (ret < 0 && errno == EINTR);
	if (ret < 0) {
		return (-1);
	}

	data = uu_msprintf(MHASH_FORMAT_V2, st.st_uid, st.st_gid,
	    st.st_size, st.st_mtime);
	if (data == NULL) {
		return (-1);
	}

	md5_calc(hash, (uchar_t *)data, strlen(data));

	uu_free(data);

	pname = mhash_filename_to_propname(file);
	if (pname == NULL)
		return (-1);

	if (mhash_retrieve_entry(hndl, pname, stored_hash) == 0) {
		uchar_t hash_v1[MHASH_SIZE];

		if (is_profile) {
			return (1);
		}

		/*
		 * Manifest import.
		 */
		if (memcmp(hash, stored_hash, MHASH_SIZE) == 0)
			return (1);

		/*
		 * No match on V2 hash; compare V1 hash.
		 */
		data = uu_msprintf(MHASH_FORMAT_V1, st.st_ino, st.st_uid,
		    st.st_size, st.st_mtime);
		if (data == NULL)
			return (-1);

		md5_calc(hash_v1, (uchar_t *)data, strlen(data));

		uu_free(data);

		if (memcmp(hash_v1, stored_hash, MHASH_SIZE) == 0)
			return (1);
	}

	*pnamep = pname;

	return (0);
}