diff options
Diffstat (limited to 'Utilities/cmlibuv/src/unix/process.c')
-rw-r--r-- | Utilities/cmlibuv/src/unix/process.c | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/process.c b/Utilities/cmlibuv/src/unix/process.c new file mode 100644 index 0000000..45f5b45 --- /dev/null +++ b/Utilities/cmlibuv/src/unix/process.c @@ -0,0 +1,563 @@ +/* Copyright Joyent, Inc. and other Node contributors. All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include "uv.h" +#include "internal.h" + +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> +#include <errno.h> + +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> +#include <fcntl.h> +#include <poll.h> + +#if defined(__APPLE__) && !TARGET_OS_IPHONE +# include <crt_externs.h> +# define environ (*_NSGetEnviron()) +#else +extern char **environ; +#endif + +#if defined(__linux__) || defined(__GLIBC__) +# include <grp.h> +#endif + + +static void uv__chld(uv_signal_t* handle, int signum) { + uv_process_t* process; + uv_loop_t* loop; + int exit_status; + int term_signal; + int status; + pid_t pid; + QUEUE pending; + QUEUE* q; + QUEUE* h; + + assert(signum == SIGCHLD); + + QUEUE_INIT(&pending); + loop = handle->loop; + + h = &loop->process_handles; + q = QUEUE_HEAD(h); + while (q != h) { + process = QUEUE_DATA(q, uv_process_t, queue); + q = QUEUE_NEXT(q); + + do + pid = waitpid(process->pid, &status, WNOHANG); + while (pid == -1 && errno == EINTR); + + if (pid == 0) + continue; + + if (pid == -1) { + if (errno != ECHILD) + abort(); + continue; + } + + process->status = status; + QUEUE_REMOVE(&process->queue); + QUEUE_INSERT_TAIL(&pending, &process->queue); + } + + h = &pending; + q = QUEUE_HEAD(h); + while (q != h) { + process = QUEUE_DATA(q, uv_process_t, queue); + q = QUEUE_NEXT(q); + + QUEUE_REMOVE(&process->queue); + QUEUE_INIT(&process->queue); + uv__handle_stop(process); + + if (process->exit_cb == NULL) + continue; + + exit_status = 0; + if (WIFEXITED(process->status)) + exit_status = WEXITSTATUS(process->status); + + term_signal = 0; + if (WIFSIGNALED(process->status)) + term_signal = WTERMSIG(process->status); + + process->exit_cb(process, exit_status, term_signal); + } + assert(QUEUE_EMPTY(&pending)); +} + + +int uv__make_socketpair(int fds[2], int flags) { +#if defined(__linux__) + static int no_cloexec; + + if (no_cloexec) + goto skip; + + if (socketpair(AF_UNIX, SOCK_STREAM | UV__SOCK_CLOEXEC | flags, 0, fds) == 0) + return 0; + + /* Retry on EINVAL, it means SOCK_CLOEXEC is not supported. + * Anything else is a genuine error. + */ + if (errno != EINVAL) + return -errno; + + no_cloexec = 1; + +skip: +#endif + + if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds)) + return -errno; + + uv__cloexec(fds[0], 1); + uv__cloexec(fds[1], 1); + + if (flags & UV__F_NONBLOCK) { + uv__nonblock(fds[0], 1); + uv__nonblock(fds[1], 1); + } + + return 0; +} + + +int uv__make_pipe(int fds[2], int flags) { +#if defined(__linux__) + static int no_pipe2; + + if (no_pipe2) + goto skip; + + if (uv__pipe2(fds, flags | UV__O_CLOEXEC) == 0) + return 0; + + if (errno != ENOSYS) + return -errno; + + no_pipe2 = 1; + +skip: +#endif + + if (pipe(fds)) + return -errno; + + uv__cloexec(fds[0], 1); + uv__cloexec(fds[1], 1); + + if (flags & UV__F_NONBLOCK) { + uv__nonblock(fds[0], 1); + uv__nonblock(fds[1], 1); + } + + return 0; +} + + +/* + * Used for initializing stdio streams like options.stdin_stream. Returns + * zero on success. See also the cleanup section in uv_spawn(). + */ +static int uv__process_init_stdio(uv_stdio_container_t* container, int fds[2]) { + int mask; + int fd; + + mask = UV_IGNORE | UV_CREATE_PIPE | UV_INHERIT_FD | UV_INHERIT_STREAM; + + switch (container->flags & mask) { + case UV_IGNORE: + return 0; + + case UV_CREATE_PIPE: + assert(container->data.stream != NULL); + if (container->data.stream->type != UV_NAMED_PIPE) + return -EINVAL; + else + return uv__make_socketpair(fds, 0); + + case UV_INHERIT_FD: + case UV_INHERIT_STREAM: + if (container->flags & UV_INHERIT_FD) + fd = container->data.fd; + else + fd = uv__stream_fd(container->data.stream); + + if (fd == -1) + return -EINVAL; + + fds[1] = fd; + return 0; + + default: + assert(0 && "Unexpected flags"); + return -EINVAL; + } +} + + +static int uv__process_open_stream(uv_stdio_container_t* container, + int pipefds[2], + int writable) { + int flags; + int err; + + if (!(container->flags & UV_CREATE_PIPE) || pipefds[0] < 0) + return 0; + + err = uv__close(pipefds[1]); + if (err != 0) + abort(); + + pipefds[1] = -1; + uv__nonblock(pipefds[0], 1); + + if (container->data.stream->type == UV_NAMED_PIPE && + ((uv_pipe_t*)container->data.stream)->ipc) + flags = UV_STREAM_READABLE | UV_STREAM_WRITABLE; + else if (writable) + flags = UV_STREAM_WRITABLE; + else + flags = UV_STREAM_READABLE; + + return uv__stream_open(container->data.stream, pipefds[0], flags); +} + + +static void uv__process_close_stream(uv_stdio_container_t* container) { + if (!(container->flags & UV_CREATE_PIPE)) return; + uv__stream_close((uv_stream_t*)container->data.stream); +} + + +static void uv__write_int(int fd, int val) { + ssize_t n; + + do + n = write(fd, &val, sizeof(val)); + while (n == -1 && errno == EINTR); + + if (n == -1 && errno == EPIPE) + return; /* parent process has quit */ + + assert(n == sizeof(val)); +} + + +#if !(defined(__APPLE__) && (TARGET_OS_TV || TARGET_OS_WATCH)) +/* execvp is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED, so must be + * avoided. Since this isn't called on those targets, the function + * doesn't even need to be defined for them. + */ +static void uv__process_child_init(const uv_process_options_t* options, + int stdio_count, + int (*pipes)[2], + int error_fd) { + int close_fd; + int use_fd; + int fd; + + if (options->flags & UV_PROCESS_DETACHED) + setsid(); + + /* First duplicate low numbered fds, since it's not safe to duplicate them, + * they could get replaced. Example: swapping stdout and stderr; without + * this fd 2 (stderr) would be duplicated into fd 1, thus making both + * stdout and stderr go to the same fd, which was not the intention. */ + for (fd = 0; fd < stdio_count; fd++) { + use_fd = pipes[fd][1]; + if (use_fd < 0 || use_fd >= fd) + continue; + pipes[fd][1] = fcntl(use_fd, F_DUPFD, stdio_count); + if (pipes[fd][1] == -1) { + uv__write_int(error_fd, -errno); + _exit(127); + } + } + + for (fd = 0; fd < stdio_count; fd++) { + close_fd = pipes[fd][0]; + use_fd = pipes[fd][1]; + + if (use_fd < 0) { + if (fd >= 3) + continue; + else { + /* redirect stdin, stdout and stderr to /dev/null even if UV_IGNORE is + * set + */ + use_fd = open("/dev/null", fd == 0 ? O_RDONLY : O_RDWR); + close_fd = use_fd; + + if (use_fd == -1) { + uv__write_int(error_fd, -errno); + _exit(127); + } + } + } + + if (fd == use_fd) + uv__cloexec(use_fd, 0); + else + fd = dup2(use_fd, fd); + + if (fd == -1) { + uv__write_int(error_fd, -errno); + _exit(127); + } + + if (fd <= 2) + uv__nonblock(fd, 0); + + if (close_fd >= stdio_count) + uv__close(close_fd); + } + + for (fd = 0; fd < stdio_count; fd++) { + use_fd = pipes[fd][1]; + + if (use_fd >= stdio_count) + uv__close(use_fd); + } + + if (options->cwd != NULL && chdir(options->cwd)) { + uv__write_int(error_fd, -errno); + _exit(127); + } + + if (options->flags & (UV_PROCESS_SETUID | UV_PROCESS_SETGID)) { + /* When dropping privileges from root, the `setgroups` call will + * remove any extraneous groups. If we don't call this, then + * even though our uid has dropped, we may still have groups + * that enable us to do super-user things. This will fail if we + * aren't root, so don't bother checking the return value, this + * is just done as an optimistic privilege dropping function. + */ + SAVE_ERRNO(setgroups(0, NULL)); + } + + if ((options->flags & UV_PROCESS_SETGID) && setgid(options->gid)) { + uv__write_int(error_fd, -errno); + _exit(127); + } + + if ((options->flags & UV_PROCESS_SETUID) && setuid(options->uid)) { + uv__write_int(error_fd, -errno); + _exit(127); + } + + if (options->env != NULL) { + environ = options->env; + } + + execvp(options->file, options->args); + uv__write_int(error_fd, -errno); + _exit(127); +} +#endif + + +int uv_spawn(uv_loop_t* loop, + uv_process_t* process, + const uv_process_options_t* options) { +#if defined(__APPLE__) && (TARGET_OS_TV || TARGET_OS_WATCH) + /* fork is marked __WATCHOS_PROHIBITED __TVOS_PROHIBITED. */ + return -ENOSYS; +#else + int signal_pipe[2] = { -1, -1 }; + int (*pipes)[2]; + int stdio_count; + ssize_t r; + pid_t pid; + int err; + int exec_errorno; + int i; + int status; + + assert(options->file != NULL); + assert(!(options->flags & ~(UV_PROCESS_DETACHED | + UV_PROCESS_SETGID | + UV_PROCESS_SETUID | + UV_PROCESS_WINDOWS_HIDE | + UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS))); + + uv__handle_init(loop, (uv_handle_t*)process, UV_PROCESS); + QUEUE_INIT(&process->queue); + + stdio_count = options->stdio_count; + if (stdio_count < 3) + stdio_count = 3; + + err = -ENOMEM; + pipes = uv__malloc(stdio_count * sizeof(*pipes)); + if (pipes == NULL) + goto error; + + for (i = 0; i < stdio_count; i++) { + pipes[i][0] = -1; + pipes[i][1] = -1; + } + + for (i = 0; i < options->stdio_count; i++) { + err = uv__process_init_stdio(options->stdio + i, pipes[i]); + if (err) + goto error; + } + + /* This pipe is used by the parent to wait until + * the child has called `execve()`. We need this + * to avoid the following race condition: + * + * if ((pid = fork()) > 0) { + * kill(pid, SIGTERM); + * } + * else if (pid == 0) { + * execve("/bin/cat", argp, envp); + * } + * + * The parent sends a signal immediately after forking. + * Since the child may not have called `execve()` yet, + * there is no telling what process receives the signal, + * our fork or /bin/cat. + * + * To avoid ambiguity, we create a pipe with both ends + * marked close-on-exec. Then, after the call to `fork()`, + * the parent polls the read end until it EOFs or errors with EPIPE. + */ + err = uv__make_pipe(signal_pipe, 0); + if (err) + goto error; + + uv_signal_start(&loop->child_watcher, uv__chld, SIGCHLD); + + /* Acquire write lock to prevent opening new fds in worker threads */ + uv_rwlock_wrlock(&loop->cloexec_lock); + pid = fork(); + + if (pid == -1) { + err = -errno; + uv_rwlock_wrunlock(&loop->cloexec_lock); + uv__close(signal_pipe[0]); + uv__close(signal_pipe[1]); + goto error; + } + + if (pid == 0) { + uv__process_child_init(options, stdio_count, pipes, signal_pipe[1]); + abort(); + } + + /* Release lock in parent process */ + uv_rwlock_wrunlock(&loop->cloexec_lock); + uv__close(signal_pipe[1]); + + process->status = 0; + exec_errorno = 0; + do + r = read(signal_pipe[0], &exec_errorno, sizeof(exec_errorno)); + while (r == -1 && errno == EINTR); + + if (r == 0) + ; /* okay, EOF */ + else if (r == sizeof(exec_errorno)) { + do + err = waitpid(pid, &status, 0); /* okay, read errorno */ + while (err == -1 && errno == EINTR); + assert(err == pid); + } else if (r == -1 && errno == EPIPE) { + do + err = waitpid(pid, &status, 0); /* okay, got EPIPE */ + while (err == -1 && errno == EINTR); + assert(err == pid); + } else + abort(); + + uv__close_nocheckstdio(signal_pipe[0]); + + for (i = 0; i < options->stdio_count; i++) { + err = uv__process_open_stream(options->stdio + i, pipes[i], i == 0); + if (err == 0) + continue; + + while (i--) + uv__process_close_stream(options->stdio + i); + + goto error; + } + + /* Only activate this handle if exec() happened successfully */ + if (exec_errorno == 0) { + QUEUE_INSERT_TAIL(&loop->process_handles, &process->queue); + uv__handle_start(process); + } + + process->pid = pid; + process->exit_cb = options->exit_cb; + + uv__free(pipes); + return exec_errorno; + +error: + if (pipes != NULL) { + for (i = 0; i < stdio_count; i++) { + if (i < options->stdio_count) + if (options->stdio[i].flags & (UV_INHERIT_FD | UV_INHERIT_STREAM)) + continue; + if (pipes[i][0] != -1) + uv__close_nocheckstdio(pipes[i][0]); + if (pipes[i][1] != -1) + uv__close_nocheckstdio(pipes[i][1]); + } + uv__free(pipes); + } + + return err; +#endif +} + + +int uv_process_kill(uv_process_t* process, int signum) { + return uv_kill(process->pid, signum); +} + + +int uv_kill(int pid, int signum) { + if (kill(pid, signum)) + return -errno; + else + return 0; +} + + +void uv__process_close(uv_process_t* handle) { + QUEUE_REMOVE(&handle->queue); + uv__handle_stop(handle); + if (QUEUE_EMPTY(&handle->loop->process_handles)) + uv_signal_stop(&handle->loop->child_watcher); +} |