| // Copyright 2016 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. |
| |
| #include "src/main/tools/linux-sandbox-options.h" |
| |
| #include <errno.h> |
| #include <sched.h> |
| #include <stdarg.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| #include <fstream> |
| #include <iostream> |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "src/main/tools/logging.h" |
| #include "src/main/tools/process-tools.h" |
| |
| using std::ifstream; |
| using std::unique_ptr; |
| using std::vector; |
| |
| struct Options opt; |
| |
| // Print out a usage error. argc and argv are the argument counter and vector, |
| // fmt is a format, string for the error message to print. |
| static void Usage(char *program_name, const char *fmt, ...) { |
| va_list ap; |
| va_start(ap, fmt); |
| vfprintf(stderr, fmt, ap); |
| va_end(ap); |
| |
| fprintf(stderr, "\nUsage: %s -- command arg1 @args\n", program_name); |
| fprintf(stderr, |
| "\nPossible arguments:\n" |
| " -W <working-dir> working directory (uses current directory if " |
| "not specified)\n" |
| " -T <timeout> timeout after which the child process will be " |
| "terminated with SIGTERM\n" |
| " -t <timeout> in case timeout occurs, how long to wait before " |
| "killing the child with SIGKILL\n" |
| " -i on receipt of a SIGINT, forward it to the child process as a " |
| "SIGTERM first and then as a SIGKILL after the -T timeout\n" |
| " -l <file> redirect stdout to a file\n" |
| " -L <file> redirect stderr to a file\n" |
| " -w <file> make a file or directory writable for the sandboxed " |
| "process\n" |
| " -e <dir> mount an empty tmpfs on a directory\n" |
| " -M/-m <source/target> directory to mount inside the sandbox\n" |
| " Multiple directories can be specified and each of them will be " |
| "mounted readonly.\n" |
| " The -M option specifies which directory to mount, the -m option " |
| "specifies where to\n" |
| " -S <file> if set, write stats in protobuf format to a file\n" |
| " -H if set, make hostname in the sandbox equal to 'localhost'\n" |
| " -N if set, a new network namespace will be created\n" |
| " -R if set, make the uid/gid be root\n" |
| " -U if set, make the uid/gid be nobody\n" |
| " -P if set, make the gid be tty and make /dev/pts writable\n" |
| " -D if set, debug info will be printed\n" |
| " -h <sandbox-dir> if set, chroot to sandbox-dir and only " |
| " mount whats been specified with -M/-m for improved hermeticity. " |
| " The working-dir should be a folder inside the sandbox-dir\n" |
| " @FILE read newline-separated arguments from FILE\n" |
| " -- command to run inside sandbox, followed by arguments\n"); |
| exit(EXIT_FAILURE); |
| } |
| |
| static void ValidateIsAbsolutePath(char *path, char *program_name, char flag) { |
| if (path[0] != '/') { |
| Usage(program_name, "The -%c option must be used with absolute paths only.", |
| flag); |
| } |
| } |
| |
| // Parses command line flags from an argv array and puts the results into an |
| // Options structure passed in as an argument. |
| static void ParseCommandLine(unique_ptr<vector<char *>> args) { |
| extern char *optarg; |
| extern int optind, optopt; |
| int c; |
| bool source_specified = false; |
| |
| while ((c = getopt(args->size(), args->data(), |
| ":W:T:t:il:L:w:e:M:m:S:h:HNRUPD")) != -1) { |
| if (c != 'M' && c != 'm') source_specified = false; |
| switch (c) { |
| case 'W': |
| if (opt.working_dir.empty()) { |
| ValidateIsAbsolutePath(optarg, args->front(), static_cast<char>(c)); |
| opt.working_dir.assign(optarg); |
| } else { |
| Usage(args->front(), |
| "Multiple working directories (-W) specified, expected one."); |
| } |
| break; |
| case 'T': |
| if (sscanf(optarg, "%d", &opt.timeout_secs) != 1 || |
| opt.timeout_secs < 0) { |
| Usage(args->front(), "Invalid timeout (-T) value: %s", optarg); |
| } |
| break; |
| case 't': |
| if (sscanf(optarg, "%d", &opt.kill_delay_secs) != 1 || |
| opt.kill_delay_secs < 0) { |
| Usage(args->front(), "Invalid kill delay (-t) value: %s", optarg); |
| } |
| break; |
| case 'i': |
| opt.sigint_sends_sigterm = true; |
| break; |
| case 'l': |
| if (opt.stdout_path.empty()) { |
| opt.stdout_path.assign(optarg); |
| } else { |
| Usage(args->front(), |
| "Cannot redirect stdout to more than one destination."); |
| } |
| break; |
| case 'L': |
| if (opt.stderr_path.empty()) { |
| opt.stderr_path.assign(optarg); |
| } else { |
| Usage(args->front(), |
| "Cannot redirect stderr to more than one destination."); |
| } |
| break; |
| case 'w': |
| ValidateIsAbsolutePath(optarg, args->front(), static_cast<char>(c)); |
| opt.writable_files.emplace_back(optarg); |
| break; |
| case 'e': |
| ValidateIsAbsolutePath(optarg, args->front(), static_cast<char>(c)); |
| opt.tmpfs_dirs.emplace_back(optarg); |
| break; |
| case 'M': |
| ValidateIsAbsolutePath(optarg, args->front(), static_cast<char>(c)); |
| // Add the current source path to both source and target lists |
| opt.bind_mount_sources.emplace_back(optarg); |
| opt.bind_mount_targets.emplace_back(optarg); |
| source_specified = true; |
| break; |
| case 'm': |
| ValidateIsAbsolutePath(optarg, args->front(), static_cast<char>(c)); |
| if (!source_specified) { |
| Usage(args->front(), |
| "The -m option must be strictly preceded by an -M option."); |
| } |
| opt.bind_mount_targets.pop_back(); |
| opt.bind_mount_targets.emplace_back(optarg); |
| source_specified = false; |
| break; |
| case 'S': |
| if (opt.stats_path.empty()) { |
| opt.stats_path.assign(optarg); |
| } else { |
| Usage(args->front(), |
| "Cannot write stats to more than one destination."); |
| } |
| break; |
| case 'h': |
| opt.hermetic = true; |
| if (opt.sandbox_root.empty()) { |
| std::string sandbox_root(optarg); |
| // Make sure that the sandbox_root path has no trailing slash. |
| if (sandbox_root.back() == '/') { |
| ValidateIsAbsolutePath(optarg, args->front(), static_cast<char>(c)); |
| opt.sandbox_root.assign(sandbox_root, 0, sandbox_root.length() - 1); |
| if (opt.sandbox_root.back() == '/') { |
| Usage(args->front(), |
| "Sandbox root path should not have trailing slashes"); |
| } |
| } else { |
| opt.sandbox_root.assign(sandbox_root); |
| } |
| } else { |
| Usage(args->front(), |
| "Multiple sandbox roots (-s) specified, expected one."); |
| } |
| break; |
| case 'H': |
| opt.fake_hostname = true; |
| break; |
| case 'N': |
| opt.create_netns = true; |
| break; |
| case 'R': |
| if (opt.fake_username) { |
| Usage(args->front(), |
| "The -R option cannot be used at the same time us the -U " |
| "option."); |
| } |
| opt.fake_root = true; |
| break; |
| case 'U': |
| if (opt.fake_root) { |
| Usage(args->front(), |
| "The -U option cannot be used at the same time us the -R " |
| "option."); |
| } |
| opt.fake_username = true; |
| break; |
| case 'P': |
| opt.enable_pty = true; |
| break; |
| case 'D': |
| opt.debug = true; |
| break; |
| case '?': |
| Usage(args->front(), "Unrecognized argument: -%c (%d)", optopt, optind); |
| break; |
| case ':': |
| Usage(args->front(), "Flag -%c requires an argument", optopt); |
| break; |
| } |
| } |
| |
| if (!opt.working_dir.empty() && !opt.sandbox_root.empty() && |
| opt.working_dir.find(opt.sandbox_root) == std::string::npos) { |
| Usage(args->front(), |
| "working-dir %s (-W) should be a " |
| "subdirectory of sandbox-dir %s (-h)", |
| opt.working_dir.c_str(), opt.sandbox_root.c_str()); |
| } |
| if (optind < static_cast<int>(args->size())) { |
| if (opt.args.empty()) { |
| opt.args.assign(args->begin() + optind, args->end()); |
| } else { |
| Usage(args->front(), "Merging commands not supported."); |
| } |
| } |
| } |
| |
| // Expands a single argument, expanding options @filename to read in the content |
| // of the file and add it to the list of processed arguments. |
| static unique_ptr<vector<char *>> ExpandArgument( |
| unique_ptr<vector<char *>> expanded, char *arg) { |
| if (arg[0] == '@') { |
| const char *filename = arg + 1; // strip off the '@'. |
| ifstream f(filename); |
| |
| if (!f.is_open()) { |
| DIE("opening argument file %s failed", filename); |
| } |
| |
| for (std::string line; std::getline(f, line);) { |
| if (line.length() > 0) { |
| expanded = ExpandArgument(std::move(expanded), strdup(line.c_str())); |
| } |
| } |
| |
| if (f.bad()) { |
| DIE("error while reading from argument file %s", filename); |
| } |
| } else { |
| expanded->push_back(arg); |
| } |
| |
| return expanded; |
| } |
| |
| // Pre-processes an argument list, expanding options @filename to read in the |
| // content of the file and add it to the list of arguments. Stops expanding |
| // arguments once it encounters "--". |
| static unique_ptr<vector<char *>> ExpandArguments(const vector<char *> &args) { |
| unique_ptr<vector<char *>> expanded(new vector<char *>()); |
| expanded->reserve(args.size()); |
| for (auto arg = args.begin(); arg != args.end(); ++arg) { |
| if (strcmp(*arg, "--") != 0) { |
| expanded = ExpandArgument(std::move(expanded), *arg); |
| } else { |
| expanded->insert(expanded->end(), arg, args.end()); |
| break; |
| } |
| } |
| return expanded; |
| } |
| |
| void ParseOptions(int argc, char *argv[]) { |
| vector<char *> args(argv, argv + argc); |
| ParseCommandLine(ExpandArguments(args)); |
| |
| if (opt.args.empty()) { |
| Usage(args.front(), "No command specified."); |
| } |
| |
| if (opt.working_dir.empty()) { |
| char *working_dir = getcwd(nullptr, 0); |
| if (working_dir == nullptr) { |
| DIE("getcwd"); |
| } |
| opt.working_dir = working_dir; |
| free(working_dir); |
| } |
| } |
