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-rw-r--r--src/unix/process.c517
1 files changed, 517 insertions, 0 deletions
diff --git a/src/unix/process.c b/src/unix/process.c
new file mode 100644
index 0000000000..6f96b754d8
--- /dev/null
+++ b/src/unix/process.c
@@ -0,0 +1,517 @@
+/* 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
+
+
+static QUEUE* uv__process_queue(uv_loop_t* loop, int pid) {
+ assert(pid > 0);
+ return loop->process_handles + pid % ARRAY_SIZE(loop->process_handles);
+}
+
+
+static void uv__chld(uv_signal_t* handle, int signum) {
+ uv_process_t* process;
+ uv_loop_t* loop;
+ int exit_status;
+ int term_signal;
+ unsigned int i;
+ int status;
+ pid_t pid;
+ QUEUE pending;
+ QUEUE* h;
+ QUEUE* q;
+
+ assert(signum == SIGCHLD);
+
+ QUEUE_INIT(&pending);
+ loop = handle->loop;
+
+ for (i = 0; i < ARRAY_SIZE(loop->process_handles); i++) {
+ h = loop->process_handles + i;
+ 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);
+ }
+
+ while (!QUEUE_EMPTY(&pending)) {
+ q = QUEUE_HEAD(&pending);
+ QUEUE_REMOVE(q);
+ QUEUE_INIT(q);
+
+ process = QUEUE_DATA(q, uv_process_t, 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);
+ }
+ }
+}
+
+
+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;
+
+ if (!(container->flags & UV_CREATE_PIPE) || pipefds[0] < 0)
+ return 0;
+
+ if (uv__close(pipefds[1]))
+ if (errno != EINTR && errno != EINPROGRESS)
+ 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));
+}
+
+
+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();
+
+ 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);
+ perror("failed to open stdio");
+ _exit(127);
+ }
+ }
+ }
+
+ if (fd == use_fd)
+ uv__cloexec(use_fd, 0);
+ else
+ dup2(use_fd, fd);
+
+ if (fd <= 2)
+ uv__nonblock(fd, 0);
+
+ if (close_fd != -1)
+ uv__close(close_fd);
+ }
+
+ for (fd = 0; fd < stdio_count; fd++) {
+ use_fd = pipes[fd][1];
+
+ if (use_fd >= 0 && fd != use_fd)
+ close(use_fd);
+ }
+
+ if (options->cwd != NULL && chdir(options->cwd)) {
+ uv__write_int(error_fd, -errno);
+ perror("chdir()");
+ _exit(127);
+ }
+
+ if ((options->flags & UV_PROCESS_SETGID) && setgid(options->gid)) {
+ uv__write_int(error_fd, -errno);
+ perror("setgid()");
+ _exit(127);
+ }
+
+ if ((options->flags & UV_PROCESS_SETUID) && setuid(options->uid)) {
+ uv__write_int(error_fd, -errno);
+ perror("setuid()");
+ _exit(127);
+ }
+
+ if (options->env != NULL) {
+ environ = options->env;
+ }
+
+ execvp(options->file, options->args);
+ uv__write_int(error_fd, -errno);
+ perror("execvp()");
+ _exit(127);
+}
+
+
+int uv_spawn(uv_loop_t* loop,
+ uv_process_t* process,
+ const uv_process_options_t* options) {
+ int signal_pipe[2] = { -1, -1 };
+ int (*pipes)[2];
+ int stdio_count;
+ QUEUE* q;
+ ssize_t r;
+ pid_t pid;
+ int err;
+ int exec_errorno;
+ int i;
+
+ 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 = 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);
+
+ pid = fork();
+
+ if (pid == -1) {
+ err = -errno;
+ 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();
+ }
+
+ 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))
+ ; /* okay, read errorno */
+ else if (r == -1 && errno == EPIPE)
+ ; /* okay, got EPIPE */
+ else
+ abort();
+
+ uv__close(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) {
+ q = uv__process_queue(loop, pid);
+ QUEUE_INSERT_TAIL(q, &process->queue);
+ uv__handle_start(process);
+ }
+
+ process->pid = pid;
+ process->exit_cb = options->exit_cb;
+
+ 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)
+ close(pipes[i][0]);
+ if (pipes[i][1] != -1)
+ close(pipes[i][1]);
+ }
+ free(pipes);
+ }
+
+ return err;
+}
+
+
+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) {
+ /* TODO stop signal watcher when this is the last handle */
+ QUEUE_REMOVE(&handle->queue);
+ uv__handle_stop(handle);
+}
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