org.apache.sentry.provider.file.SimplePolicyEngine.java Source code

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.sentry.provider.file;

import static org.apache.sentry.provider.file.PolicyFileConstants.DATABASES;
import static org.apache.sentry.provider.file.PolicyFileConstants.GROUPS;
import static org.apache.sentry.provider.file.PolicyFileConstants.ROLES;
import static org.apache.sentry.provider.file.PolicyFileConstants.ROLE_SPLITTER;
import static org.apache.sentry.provider.file.PolicyFileConstants.USERS;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URI;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReference;

import javax.annotation.Nullable;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.sentry.core.AccessURI;
import org.apache.sentry.core.Authorizable;
import org.apache.sentry.core.Database;
import org.apache.shiro.config.ConfigurationException;
import org.apache.shiro.config.Ini;
import org.apache.shiro.util.PermissionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSetMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;
import com.google.common.collect.Sets;

public class SimplePolicyEngine implements PolicyEngine {

    private static final Logger LOGGER = LoggerFactory.getLogger(SimplePolicyEngine.class);

    private final FileSystem fileSystem;
    private final Path resourcePath;
    private final String serverName;
    private final List<Path> perDbResources = Lists.newArrayList();
    private final AtomicReference<Roles> rolesReference;
    public final static String ACCESS_ALLOW_URI_PER_DB_POLICYFILE = "sentry.allow.uri.db.policyfile";

    public SimplePolicyEngine(String resourcePath, String serverName) throws IOException {
        this(new Configuration(), new Path(resourcePath), serverName);
    }

    @VisibleForTesting
    public SimplePolicyEngine(Configuration conf, Path resourcePath, String serverName) throws IOException {
        this.resourcePath = resourcePath;
        this.serverName = serverName;
        this.fileSystem = resourcePath.getFileSystem(conf);
        this.rolesReference = new AtomicReference<Roles>();
        this.rolesReference.set(new Roles());
        parse();
    }

    /**
     * Parse the resource. Should not be used in the normal course
     */
    protected void parse() {
        LOGGER.info("Parsing " + resourcePath);
        Roles roles = new Roles();
        try {
            perDbResources.clear();
            Ini ini = PolicyFiles.loadFromPath(fileSystem, resourcePath);
            if (LOGGER.isDebugEnabled()) {
                for (String sectionName : ini.getSectionNames()) {
                    LOGGER.debug("Section: " + sectionName);
                    Ini.Section section = ini.get(sectionName);
                    for (String key : section.keySet()) {
                        String value = section.get(key);
                        LOGGER.debug(key + " = " + value);
                    }
                }
            }
            ImmutableSetMultimap<String, String> globalRoles;
            Map<String, ImmutableSetMultimap<String, String>> perDatabaseRoles = Maps.newHashMap();
            globalRoles = parseIni(null, ini);
            Ini.Section filesSection = ini.getSection(DATABASES);
            if (filesSection == null) {
                LOGGER.info("Section " + DATABASES + " needs no further processing");
            } else {
                for (Map.Entry<String, String> entry : filesSection.entrySet()) {
                    String database = Strings.nullToEmpty(entry.getKey()).trim().toLowerCase();
                    Path perDbPolicy = new Path(Strings.nullToEmpty(entry.getValue()).trim());
                    if (isRelative(perDbPolicy)) {
                        perDbPolicy = new Path(resourcePath.getParent(), perDbPolicy);
                    }
                    try {
                        LOGGER.info("Parsing " + perDbPolicy);
                        Ini perDbIni = PolicyFiles.loadFromPath(fileSystem, perDbPolicy);
                        if (perDbIni.containsKey(USERS)) {
                            throw new ConfigurationException(
                                    "Per-db policy files cannot contain " + USERS + " section");
                        }
                        if (perDbIni.containsKey(DATABASES)) {
                            throw new ConfigurationException(
                                    "Per-db policy files cannot contain " + DATABASES + " section");
                        }
                        ImmutableSetMultimap<String, String> currentDbRoles = parseIni(database, perDbIni);
                        perDatabaseRoles.put(database, currentDbRoles);
                        perDbResources.add(perDbPolicy);
                    } catch (Exception e) {
                        LOGGER.error("Error processing key " + entry.getKey() + ", skipping " + entry.getValue(),
                                e);
                    }
                }
            }
            roles = new Roles(globalRoles, ImmutableMap.copyOf(perDatabaseRoles));
        } catch (Exception e) {
            LOGGER.error("Error processing file, ignoring " + resourcePath, e);
        }
        rolesReference.set(roles);
    }

    /**
     * Relative for our purposes is no scheme, no authority
     * and a non-absolute path portion.
     */
    private boolean isRelative(Path path) {
        URI uri = path.toUri();
        return uri.getAuthority() == null && uri.getScheme() == null && !path.isUriPathAbsolute();
    }

    protected long getModificationTime() throws IOException {
        // if resource path has been deleted, throw all exceptions
        long result = fileSystem.getFileStatus(resourcePath).getModificationTime();
        for (Path perDbPolicy : perDbResources) {
            try {
                result = Math.max(result, fileSystem.getFileStatus(perDbPolicy).getModificationTime());
            } catch (FileNotFoundException e) {
                // if a per-db file has been deleted, wait until the main
                // policy file has been updated before refreshing
            }
        }
        return result;
    }

    private ImmutableSetMultimap<String, String> parseIni(String database, Ini ini) {
        Ini.Section privilegesSection = ini.getSection(ROLES);
        boolean invalidConfiguration = false;
        if (privilegesSection == null) {
            LOGGER.warn("Section {} empty for {}", ROLES, resourcePath);
            invalidConfiguration = true;
        }
        Ini.Section groupsSection = ini.getSection(GROUPS);
        if (groupsSection == null) {
            LOGGER.warn("Section {} empty for {}", GROUPS, resourcePath);
            invalidConfiguration = true;
        }
        if (!invalidConfiguration) {
            return parsePermissions(database, privilegesSection, groupsSection);
        }
        return ImmutableSetMultimap.of();
    }

    private ImmutableSetMultimap<String, String> parsePermissions(@Nullable String database,
            Ini.Section rolesSection, Ini.Section groupsSection) {
        ImmutableSetMultimap.Builder<String, String> resultBuilder = ImmutableSetMultimap.builder();
        Multimap<String, String> roleNameToPrivilegeMap = HashMultimap.create();
        List<? extends RoleValidator> validators = Lists.newArrayList(new ServersAllIsInvalid(),
                new DatabaseMustMatch(), new DatabaseRequiredInRole(), new ServerNameMustMatch(serverName));
        for (Map.Entry<String, String> entry : rolesSection.entrySet()) {
            String roleName = Strings.nullToEmpty(entry.getKey()).trim();
            String roleValue = Strings.nullToEmpty(entry.getValue()).trim();
            boolean invalidConfiguration = false;
            if (roleName.isEmpty()) {
                LOGGER.warn("Empty role name encountered in {}", resourcePath);
                invalidConfiguration = true;
            }
            if (roleValue.isEmpty()) {
                LOGGER.warn("Empty role value encountered in {}", resourcePath);
                invalidConfiguration = true;
            }
            if (roleNameToPrivilegeMap.containsKey(roleName)) {
                LOGGER.warn("Role {} defined twice in {}", roleName, resourcePath);
            }
            Set<String> roles = PermissionUtils.toPermissionStrings(roleValue);
            if (!invalidConfiguration && roles != null) {
                for (String role : roles) {
                    for (RoleValidator validator : validators) {
                        validator.validate(database, role.trim());
                    }
                }
                roleNameToPrivilegeMap.putAll(roleName, roles);
            }
        }
        Splitter roleSplitter = ROLE_SPLITTER.omitEmptyStrings().trimResults();
        for (Map.Entry<String, String> entry : groupsSection.entrySet()) {
            String groupName = Strings.nullToEmpty(entry.getKey()).trim();
            String groupPrivileges = Strings.nullToEmpty(entry.getValue()).trim();
            Collection<String> resolvedGroupPrivileges = Sets.newHashSet();
            for (String roleName : roleSplitter.split(groupPrivileges)) {
                if (roleNameToPrivilegeMap.containsKey(roleName)) {
                    resolvedGroupPrivileges.addAll(roleNameToPrivilegeMap.get(roleName));
                } else {
                    LOGGER.warn("Role {} for group {} does not exist in privileges section in {}",
                            new Object[] { roleName, groupName, resourcePath });
                }
            }
            resultBuilder.putAll(groupName, resolvedGroupPrivileges);
        }
        return resultBuilder.build();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public ImmutableSetMultimap<String, String> getPermissions(List<Authorizable> authorizables,
            List<String> groups) {
        Roles roles = rolesReference.get();
        String database = null;
        Boolean isURI = false;
        for (Authorizable authorizable : authorizables) {
            if (authorizable instanceof Database) {
                database = authorizable.getName();
            }
            if (authorizable instanceof AccessURI) {
                isURI = true;
            }
        }

        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("Getting permissions for {} via {}", groups, database);
        }
        ImmutableSetMultimap.Builder<String, String> resultBuilder = ImmutableSetMultimap.builder();
        for (String group : groups) {
            resultBuilder.putAll(group, roles.getRoles(database, group, isURI));
        }
        ImmutableSetMultimap<String, String> result = resultBuilder.build();
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("result = " + result);
        }
        return result;
    }
}