diff options
Diffstat (limited to 'chromium/third_party/webrtc/base/posix.cc')
-rw-r--r-- | chromium/third_party/webrtc/base/posix.cc | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/chromium/third_party/webrtc/base/posix.cc b/chromium/third_party/webrtc/base/posix.cc new file mode 100644 index 00000000000..0eb24ee64a5 --- /dev/null +++ b/chromium/third_party/webrtc/base/posix.cc @@ -0,0 +1,131 @@ +/* + * Copyright 2004 The WebRTC Project Authors. All rights reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include "webrtc/base/posix.h" + +#include <sys/wait.h> +#include <errno.h> +#include <unistd.h> + +#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID) +#include "webrtc/base/linuxfdwalk.h" +#endif +#include "webrtc/base/logging.h" + +namespace rtc { + +#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID) +static void closefds(void *close_errors, int fd) { + if (fd <= 2) { + // We leave stdin/out/err open to the browser's terminal, if any. + return; + } + if (close(fd) < 0) { + *static_cast<bool *>(close_errors) = true; + } +} +#endif + +enum { + EXIT_FLAG_CHDIR_ERRORS = 1 << 0, +#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID) + EXIT_FLAG_FDWALK_ERRORS = 1 << 1, + EXIT_FLAG_CLOSE_ERRORS = 1 << 2, +#endif + EXIT_FLAG_SECOND_FORK_FAILED = 1 << 3, +}; + +bool RunAsDaemon(const char *file, const char *const argv[]) { + // Fork intermediate child to daemonize. + pid_t pid = fork(); + if (pid < 0) { + LOG_ERR(LS_ERROR) << "fork()"; + return false; + } else if (!pid) { + // Child. + + // We try to close all fds and change directory to /, but if that fails we + // keep going because it's not critical. + int exit_code = 0; + if (chdir("/") < 0) { + exit_code |= EXIT_FLAG_CHDIR_ERRORS; + } +#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID) + bool close_errors = false; + if (fdwalk(&closefds, &close_errors) < 0) { + exit_code |= EXIT_FLAG_FDWALK_ERRORS; + } + if (close_errors) { + exit_code |= EXIT_FLAG_CLOSE_ERRORS; + } +#endif + + // Fork again to become a daemon. + pid = fork(); + // It is important that everything here use _exit() and not exit(), because + // exit() would call the destructors of all global variables in the whole + // process, which is both unnecessary and unsafe. + if (pid < 0) { + exit_code |= EXIT_FLAG_SECOND_FORK_FAILED; + _exit(exit_code); // if second fork failed + } else if (!pid) { + // Child. + // Successfully daemonized. Run command. + // WEBRTC_POSIX requires the args to be typed as non-const for historical + // reasons, but it mandates that the actual implementation be const, so + // the cast is safe. + execvp(file, const_cast<char *const *>(argv)); + _exit(255); // if execvp failed + } + + // Parent. + // Successfully spawned process, but report any problems to the parent where + // we can log them. + _exit(exit_code); + } + + // Parent. Reap intermediate child. + int status; + pid_t child = waitpid(pid, &status, 0); + if (child < 0) { + LOG_ERR(LS_ERROR) << "Error in waitpid()"; + return false; + } + if (child != pid) { + // Should never happen (see man page). + LOG(LS_ERROR) << "waitpid() chose wrong child???"; + return false; + } + if (!WIFEXITED(status)) { + LOG(LS_ERROR) << "Intermediate child killed uncleanly"; // Probably crashed + return false; + } + + int exit_code = WEXITSTATUS(status); + if (exit_code & EXIT_FLAG_CHDIR_ERRORS) { + LOG(LS_WARNING) << "Child reported probles calling chdir()"; + } +#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID) + if (exit_code & EXIT_FLAG_FDWALK_ERRORS) { + LOG(LS_WARNING) << "Child reported problems calling fdwalk()"; + } + if (exit_code & EXIT_FLAG_CLOSE_ERRORS) { + LOG(LS_WARNING) << "Child reported problems calling close()"; + } +#endif + if (exit_code & EXIT_FLAG_SECOND_FORK_FAILED) { + LOG(LS_ERROR) << "Failed to daemonize"; + // This means the command was not launched, so failure. + return false; + } + return true; +} + +} // namespace rtc |