| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // Licensed 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 com.google.devtools.build.lib.sandbox; |
| |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.Maps; |
| import com.google.common.io.ByteStreams; |
| import com.google.devtools.build.lib.actions.ExecException; |
| import com.google.devtools.build.lib.actions.Spawn; |
| import com.google.devtools.build.lib.actions.SpawnResult; |
| import com.google.devtools.build.lib.actions.UserExecException; |
| import com.google.devtools.build.lib.analysis.BlazeDirectories; |
| import com.google.devtools.build.lib.exec.local.LocalEnvProvider; |
| import com.google.devtools.build.lib.runtime.CommandEnvironment; |
| import com.google.devtools.build.lib.shell.Command; |
| import com.google.devtools.build.lib.shell.CommandException; |
| import com.google.devtools.build.lib.util.OS; |
| import com.google.devtools.build.lib.vfs.FileSystem; |
| import com.google.devtools.build.lib.vfs.Path; |
| import com.google.devtools.build.lib.vfs.PathFragment; |
| import com.google.devtools.build.lib.vfs.Symlinks; |
| import java.io.File; |
| import java.io.IOException; |
| import java.time.Duration; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.SortedMap; |
| |
| /** Spawn runner that uses linux sandboxing APIs to execute a local subprocess. */ |
| final class LinuxSandboxedSpawnRunner extends AbstractSandboxSpawnRunner { |
| private static final String LINUX_SANDBOX = "linux-sandbox"; |
| |
| public static boolean isSupported(CommandEnvironment cmdEnv) { |
| if (OS.getCurrent() != OS.LINUX) { |
| return false; |
| } |
| Path embeddedTool = getLinuxSandbox(cmdEnv); |
| if (embeddedTool == null) { |
| // The embedded tool does not exist, meaning that we don't support sandboxing (e.g., while |
| // bootstrapping). |
| return false; |
| } |
| |
| Path execRoot = cmdEnv.getExecRoot(); |
| |
| List<String> args = new ArrayList<>(); |
| args.add(embeddedTool.getPathString()); |
| args.add("--"); |
| args.add("/bin/true"); |
| |
| ImmutableMap<String, String> env = ImmutableMap.of(); |
| File cwd = execRoot.getPathFile(); |
| |
| Command cmd = new Command(args.toArray(new String[0]), env, cwd); |
| try { |
| cmd.execute(ByteStreams.nullOutputStream(), ByteStreams.nullOutputStream()); |
| } catch (CommandException e) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| private static Path getLinuxSandbox(CommandEnvironment cmdEnv) { |
| PathFragment execPath = cmdEnv.getBlazeWorkspace().getBinTools().getExecPath(LINUX_SANDBOX); |
| return execPath != null ? cmdEnv.getExecRoot().getRelative(execPath) : null; |
| } |
| |
| private final FileSystem fileSystem; |
| private final BlazeDirectories blazeDirs; |
| private final Path execRoot; |
| private final boolean allowNetwork; |
| private final Path linuxSandbox; |
| private final Path inaccessibleHelperFile; |
| private final Path inaccessibleHelperDir; |
| private final LocalEnvProvider localEnvProvider; |
| private final int timeoutGraceSeconds; |
| private final String productName; |
| |
| LinuxSandboxedSpawnRunner( |
| CommandEnvironment cmdEnv, |
| Path sandboxBase, |
| String productName, |
| Path inaccessibleHelperFile, |
| Path inaccessibleHelperDir, |
| int timeoutGraceSeconds) { |
| super(cmdEnv, sandboxBase); |
| this.fileSystem = cmdEnv.getRuntime().getFileSystem(); |
| this.blazeDirs = cmdEnv.getDirectories(); |
| this.execRoot = cmdEnv.getExecRoot(); |
| this.productName = productName; |
| this.allowNetwork = SandboxHelpers.shouldAllowNetwork(cmdEnv.getOptions()); |
| this.linuxSandbox = getLinuxSandbox(cmdEnv); |
| this.inaccessibleHelperFile = inaccessibleHelperFile; |
| this.inaccessibleHelperDir = inaccessibleHelperDir; |
| this.timeoutGraceSeconds = timeoutGraceSeconds; |
| this.localEnvProvider = LocalEnvProvider.ADD_TEMP_POSIX; |
| } |
| |
| @Override |
| protected SpawnResult actuallyExec(Spawn spawn, SpawnExecutionPolicy policy) |
| throws IOException, ExecException, InterruptedException { |
| // Each invocation of "exec" gets its own sandbox. |
| Path sandboxPath = getSandboxRoot(); |
| Path sandboxExecRoot = sandboxPath.getRelative("execroot").getRelative(execRoot.getBaseName()); |
| |
| // Each sandboxed action runs in its own execroot, so we don't need to make the temp directory's |
| // name unique (like we have to with standalone execution strategy). |
| Path tmpDir = sandboxExecRoot.getRelative("tmp"); |
| |
| Set<Path> writableDirs = getWritableDirs(sandboxExecRoot, spawn.getEnvironment(), tmpDir); |
| ImmutableSet<PathFragment> outputs = SandboxHelpers.getOutputFiles(spawn); |
| Duration timeout = policy.getTimeout(); |
| List<String> arguments = |
| computeCommandLine( |
| spawn, |
| timeout, |
| linuxSandbox, |
| writableDirs, |
| getTmpfsPaths(), |
| getReadOnlyBindMounts(blazeDirs, sandboxExecRoot), |
| allowNetwork || SandboxHelpers.shouldAllowNetwork(spawn), |
| spawn.getExecutionInfo().containsKey("requires-fakeroot")); |
| Map<String, String> environment = |
| localEnvProvider.rewriteLocalEnv(spawn.getEnvironment(), execRoot, tmpDir, productName); |
| |
| SandboxedSpawn sandbox = |
| new SymlinkedSandboxedSpawn( |
| sandboxPath, |
| sandboxExecRoot, |
| arguments, |
| environment, |
| SandboxHelpers.getInputFiles(spawn, policy, execRoot), |
| outputs, |
| writableDirs); |
| return runSpawn(spawn, sandbox, policy, execRoot, tmpDir, timeout); |
| } |
| |
| private List<String> computeCommandLine( |
| Spawn spawn, |
| Duration timeout, |
| Path linuxSandbox, |
| Set<Path> writableDirs, |
| Set<Path> tmpfsPaths, |
| Map<Path, Path> bindMounts, |
| boolean allowNetwork, |
| boolean requiresFakeRoot) { |
| List<String> commandLineArgs = new ArrayList<>(); |
| commandLineArgs.add(linuxSandbox.getPathString()); |
| |
| if (getSandboxOptions().sandboxDebug) { |
| commandLineArgs.add("-D"); |
| } |
| |
| // Kill the process after a timeout. |
| if (!timeout.isZero()) { |
| commandLineArgs.add("-T"); |
| commandLineArgs.add(Long.toString(timeout.getSeconds())); |
| } |
| |
| if (timeoutGraceSeconds != -1) { |
| commandLineArgs.add("-t"); |
| commandLineArgs.add(Integer.toString(timeoutGraceSeconds)); |
| } |
| |
| // Create all needed directories. |
| for (Path writablePath : writableDirs) { |
| commandLineArgs.add("-w"); |
| commandLineArgs.add(writablePath.getPathString()); |
| } |
| |
| for (Path tmpfsPath : tmpfsPaths) { |
| commandLineArgs.add("-e"); |
| commandLineArgs.add(tmpfsPath.getPathString()); |
| } |
| |
| for (ImmutableMap.Entry<Path, Path> bindMount : bindMounts.entrySet()) { |
| commandLineArgs.add("-M"); |
| commandLineArgs.add(bindMount.getValue().getPathString()); |
| |
| // The file is mounted in a custom location inside the sandbox. |
| if (!bindMount.getKey().equals(bindMount.getValue())) { |
| commandLineArgs.add("-m"); |
| commandLineArgs.add(bindMount.getKey().getPathString()); |
| } |
| } |
| |
| if (!allowNetwork) { |
| // Block network access out of the namespace. |
| commandLineArgs.add("-N"); |
| } |
| |
| if (getSandboxOptions().sandboxFakeHostname) { |
| // Use a fake hostname ("localhost") inside the sandbox. |
| commandLineArgs.add("-H"); |
| } |
| |
| if (requiresFakeRoot) { |
| // Use fake root. |
| commandLineArgs.add("-R"); |
| } else if (getSandboxOptions().sandboxFakeUsername) { |
| // Use a fake username ("nobody") inside the sandbox. |
| commandLineArgs.add("-U"); |
| } |
| |
| commandLineArgs.add("--"); |
| commandLineArgs.addAll(spawn.getArguments()); |
| return commandLineArgs; |
| } |
| |
| @Override |
| protected String getName() { |
| return "linux-sandbox"; |
| } |
| |
| @Override |
| protected ImmutableSet<Path> getWritableDirs( |
| Path sandboxExecRoot, Map<String, String> env, Path tmpDir) throws IOException { |
| ImmutableSet.Builder<Path> writableDirs = ImmutableSet.builder(); |
| writableDirs.addAll(super.getWritableDirs(sandboxExecRoot, env, tmpDir)); |
| |
| FileSystem fs = sandboxExecRoot.getFileSystem(); |
| writableDirs.add(fs.getPath("/dev/shm").resolveSymbolicLinks()); |
| writableDirs.add(fs.getPath("/tmp")); |
| |
| return writableDirs.build(); |
| } |
| |
| private ImmutableSet<Path> getTmpfsPaths() { |
| ImmutableSet.Builder<Path> tmpfsPaths = ImmutableSet.builder(); |
| for (String tmpfsPath : getSandboxOptions().sandboxTmpfsPath) { |
| tmpfsPaths.add(fileSystem.getPath(tmpfsPath)); |
| } |
| return tmpfsPaths.build(); |
| } |
| |
| private SortedMap<Path, Path> getReadOnlyBindMounts( |
| BlazeDirectories blazeDirs, Path sandboxExecRoot) throws UserExecException { |
| Path tmpPath = fileSystem.getPath("/tmp"); |
| final SortedMap<Path, Path> bindMounts = Maps.newTreeMap(); |
| if (blazeDirs.getWorkspace().startsWith(tmpPath)) { |
| bindMounts.put(blazeDirs.getWorkspace(), blazeDirs.getWorkspace()); |
| } |
| if (blazeDirs.getOutputBase().startsWith(tmpPath)) { |
| bindMounts.put(blazeDirs.getOutputBase(), blazeDirs.getOutputBase()); |
| } |
| for (ImmutableMap.Entry<String, String> additionalMountPath : |
| getSandboxOptions().sandboxAdditionalMounts) { |
| try { |
| final Path mountTarget = fileSystem.getPath(additionalMountPath.getValue()); |
| // If source path is relative, treat it as a relative path inside the execution root |
| final Path mountSource = sandboxExecRoot.getRelative(additionalMountPath.getKey()); |
| // If a target has more than one source path, the latter one will take effect. |
| bindMounts.put(mountTarget, mountSource); |
| } catch (IllegalArgumentException e) { |
| throw new UserExecException( |
| String.format("Error occurred when analyzing bind mount pairs. %s", e.getMessage())); |
| } |
| } |
| for (Path inaccessiblePath : getInaccessiblePaths()) { |
| if (inaccessiblePath.isDirectory(Symlinks.NOFOLLOW)) { |
| bindMounts.put(inaccessiblePath, inaccessibleHelperDir); |
| } else { |
| bindMounts.put(inaccessiblePath, inaccessibleHelperFile); |
| } |
| } |
| validateBindMounts(bindMounts); |
| return bindMounts; |
| } |
| |
| /** |
| * This method does the following things: - If mount source does not exist on the host system, |
| * throw an error message - If mount target exists, check whether the source and target are of the |
| * same type - If mount target does not exist on the host system, throw an error message |
| * |
| * @param bindMounts the bind mounts map with target as key and source as value |
| * @throws UserExecException |
| */ |
| private void validateBindMounts(SortedMap<Path, Path> bindMounts) throws UserExecException { |
| for (SortedMap.Entry<Path, Path> bindMount : bindMounts.entrySet()) { |
| final Path source = bindMount.getValue(); |
| final Path target = bindMount.getKey(); |
| // Mount source should exist in the file system |
| if (!source.exists()) { |
| throw new UserExecException(String.format("Mount source '%s' does not exist.", source)); |
| } |
| // If target exists, but is not of the same type as the source, then we cannot mount it. |
| if (target.exists()) { |
| boolean areBothDirectories = source.isDirectory() && target.isDirectory(); |
| boolean isSourceFile = source.isFile() || source.isSymbolicLink(); |
| boolean isTargetFile = target.isFile() || target.isSymbolicLink(); |
| boolean areBothFiles = isSourceFile && isTargetFile; |
| if (!(areBothDirectories || areBothFiles)) { |
| // Source and target are not of the same type; we cannot mount it. |
| throw new UserExecException( |
| String.format( |
| "Mount target '%s' is not of the same type as mount source '%s'.", |
| target, source)); |
| } |
| } else { |
| // Mount target should exist in the file system |
| throw new UserExecException( |
| String.format( |
| "Mount target '%s' does not exist. Bazel only supports bind mounting on top of " |
| + "existing files/directories. Please create an empty file or directory at " |
| + "the mount target path according to the type of mount source.", |
| target)); |
| } |
| } |
| } |
| } |