* [Tarantool-patches] [PATCH v9 2/4] popen: introduce a backend engine
2020-01-10 8:25 [Tarantool-patches] [PATCH v9 0/4] popen: add ability to run external process Cyrill Gorcunov
2020-01-10 8:25 ` [Tarantool-patches] [PATCH v9 1/4] coio: export helpers Cyrill Gorcunov
@ 2020-01-10 8:25 ` Cyrill Gorcunov
2020-01-10 8:25 ` [Tarantool-patches] [PATCH v9 3/4] popen/lua: add popen module Cyrill Gorcunov
2020-01-10 8:25 ` [Tarantool-patches] [PATCH v9 4/4] popen/test: add base test cases Cyrill Gorcunov
3 siblings, 0 replies; 5+ messages in thread
From: Cyrill Gorcunov @ 2020-01-10 8:25 UTC (permalink / raw)
To: tml
In the patch we introduce popen backend engine which provides
a way to execute external programs and communicate with their
stdin/stdout/stderr streams.
It is possible to run a child process with:
a) completely closed stdX descriptors
b) provide /dev/null descriptors to appropritate stdX
c) pass new transport into a child (currently we use
pipes for this sake, but may extend to tty/sockets)
d) inherit stdX from a parent, iow do nothing
On tarantool start we create @popen_pids_map hash which maps
created processes PIDs to popen_handle structure, this structure
keeps everything needed to control and communicate with the children.
The hash will allow us to find a hild process quickly from inside
of a signal handler.
Each handle links into @popen_head list, which is need to be able
to destory children processes on exit procedure (ie when we exit
tarantool and need to cleanup the resources used).
Every new process is born by vfork() call - we can't use fork()
because of at_fork() handlers in libeio which cause deadlocking
in internal mutex usage. Thus the caller waits until vfork()
finishes its work and runs exec (or exit with error).
Because children processes are running without any limitations
they can exit by self or can be killed by some other third side
(say user of a hw node), we need to watch their state which is
done by setting a hook with ev_child_start() helper. This helper
allows us to catch SIGCHLD when a child get exited/signaled
and unregister it from a pool or currently running children.
Note the libev wait() reaps child zomby by self. Another
interesting detail is that libev catches signal in async way
but our SIGCHLD hook is called in sync way before child reap.
This engine provides the following API:
- popen_init
to initialize engine
- popen_free
to finalize engine and free all reasources
allocated so far
- popen_new
to create a new child process and start it
- popen_delete
to release resources occupied and
terminate a child process
- popen_stat
to fetch statistics about a child process
- popen_command
to fetch command line string formerly used
on the popen object creation
- popen_write_timeout
to write data into child's stdin with
timeout
- popen_read_timeout
to read data from child's stdout/stderr
with timeout
- popen_state
to fetch state (alive, exited or killed) and
exit code of a child process
- popen_state_str
to get state of a child process in string
form, for Lua usage mostly
- popen_send_signal
to send signal to a child process (for
example to kill it)
Known issues to fix in next series:
- environment variables for non-linux systems do not support
inheritance for now due to lack of testing on my side;
- for linux base systems we use popen2 system call passing
O_CLOEXEC flag so that two concurrent popen_create calls
would not affect each other with pipes inheritance (while
currently we don't have a case where concurrent calls could
be done as far as I know, still better to be on a safe side
from the beginning);
- there are some files (such as xlog) which tarantool opens
for own needs without setting O_CLOEXEC flag and it get
propagated to a children process; for linux based systems
we use close_inherited_fds helper which walks over opened
files of a process and close them. But for other targets
like MachO or FreeBSD this helper just zapped simply because
I don't have such machines to experimant with; we should
investigate this moment in more details later once base
code is merged in;
- need to consider a case where we will be using piping for
descriptors (for example we might be writting into stdin
of a child from another pipe, for this sake we could use
splice() syscall which gonna be a way faster than copying
data inside kernel between process). Still the question
is -- do we really need it? Since we use interanal flags
in popen handle this should not be a big problem to extend
this interfaces;
this particular feature is considered to have a very low
priority but I left it here just to not forget.
Part-of #4031
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
src/lib/core/CMakeLists.txt | 1 +
src/lib/core/popen.c | 1093 +++++++++++++++++++++++++++++++++++
src/lib/core/popen.h | 207 +++++++
src/main.cc | 4 +
4 files changed, 1305 insertions(+)
create mode 100644 src/lib/core/popen.c
create mode 100644 src/lib/core/popen.h
diff --git a/src/lib/core/CMakeLists.txt b/src/lib/core/CMakeLists.txt
index 8623aa0de..3f13ff904 100644
--- a/src/lib/core/CMakeLists.txt
+++ b/src/lib/core/CMakeLists.txt
@@ -15,6 +15,7 @@ set(core_sources
coio.cc
coio_task.c
coio_file.c
+ popen.c
coio_buf.cc
fio.c
exception.cc
diff --git a/src/lib/core/popen.c b/src/lib/core/popen.c
new file mode 100644
index 000000000..289f73948
--- /dev/null
+++ b/src/lib/core/popen.c
@@ -0,0 +1,1093 @@
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <signal.h>
+#include <poll.h>
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/wait.h>
+
+#include "popen.h"
+#include "fiber.h"
+#include "assoc.h"
+#include "coio.h"
+#include "say.h"
+
+/* A mapping to find popens by their pids in a signal handler */
+static struct mh_i32ptr_t *popen_pids_map = NULL;
+
+/* All popen handles to be able to cleanup them at exit */
+static RLIST_HEAD(popen_head);
+
+/*
+ * A user may request to use /dev/null inside a child process
+ * instead of stdin/out/err, for this sake we will open these
+ * fds once on initialization and pass to children
+ */
+static int dev_null_fd_ro = -1;
+static int dev_null_fd_wr = -1;
+
+/**
+ * Register popen handle in a pids map
+ */
+static void
+popen_register(struct popen_handle *handle)
+{
+ struct mh_i32ptr_node_t node = {
+ .key = handle->pid,
+ .val = handle,
+ };
+ say_debug("popen: register %d", handle->pid);
+ mh_i32ptr_put(popen_pids_map, &node, NULL, NULL);
+}
+
+/**
+ * Find popen handler by its pid
+ */
+static struct popen_handle *
+popen_find(pid_t pid)
+{
+ mh_int_t k = mh_i32ptr_find(popen_pids_map, pid, NULL);
+ if (k == mh_end(popen_pids_map))
+ return NULL;
+ return mh_i32ptr_node(popen_pids_map, k)->val;
+}
+
+/**
+ * Remove popen handler from a pids map
+ */
+static void
+popen_unregister(struct popen_handle *handle)
+{
+ struct mh_i32ptr_node_t node = {
+ .key = handle->pid,
+ .val = NULL,
+ };
+ say_debug("popen: unregister %d", handle->pid);
+ mh_i32ptr_remove(popen_pids_map, &node, NULL);
+}
+
+/**
+ * handle_new - allocate new popen hanldle with flags specified
+ * @opts: pointer to options to be used
+ *
+ * Returns pointer to a new initialized popen object
+ * or NULL on error.
+ */
+static struct popen_handle *
+handle_new(struct popen_opts *opts)
+{
+ struct popen_handle *handle;
+ size_t size = 0, i;
+ char *pos;
+
+ assert(opts->argv != NULL && opts->nr_argv > 0);
+
+ for (i = 0; i < opts->nr_argv; i++) {
+ if (opts->argv[i] == NULL)
+ continue;
+ size += strlen(opts->argv[i]) + 1;
+ }
+
+ handle = malloc(sizeof(*handle) + size);
+ if (!handle) {
+ diag_set(OutOfMemory, sizeof(*handle) + size,
+ "malloc", "popen handle");
+ return NULL;
+ }
+
+ pos = handle->command = (void *)handle + sizeof(*handle);
+ for (i = 0; i < opts->nr_argv-1; i++) {
+ if (opts->argv[i] == NULL)
+ continue;
+ strcpy(pos, opts->argv[i]);
+ pos += strlen(opts->argv[i]);
+ *pos++ = ' ';
+ }
+ pos[-1] = '\0';
+
+ handle->wstatus = 0;
+ handle->pid = -1;
+ handle->flags = opts->flags;
+
+ rlist_create(&handle->list);
+
+ /*
+ * No need to initialize the whole ios structure,
+ * just set fd value to mark as unused.
+ */
+ for (i = 0; i < lengthof(handle->ios); i++)
+ handle->ios[i].fd = -1;
+
+ say_debug("popen: alloc handle %p command '%s' flags %#x",
+ handle, handle->command, opts->flags);
+ return handle;
+}
+
+/**
+ * Free memory allocated for a handle. To pair with handle_new().
+ */
+static inline void
+handle_free(struct popen_handle *handle)
+{
+ say_debug("popen: handle %p free %p", handle);
+ free(handle);
+}
+
+/**
+ * popen_may_io - test if handle can run io operation
+ * @handle: popen handle
+ * @idx: index of a file descriptor to operate on
+ * @io_flags: popen_flag_bits flags
+ *
+ * Returns true if IO is allowed and false otherwise
+ * (setting @errno).
+ */
+static inline bool
+popen_may_io(struct popen_handle *handle, unsigned int idx,
+ unsigned int io_flags)
+{
+ if (!handle) {
+ errno = ESRCH;
+ return false;
+ }
+
+ if (!(io_flags & handle->flags)) {
+ errno = EINVAL;
+ return false;
+ }
+
+ if (handle->ios[idx].fd < 0) {
+ errno = EPIPE;
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * Test if handle is not nil and still have
+ * a living child process.
+ */
+static inline bool
+popen_may_pidop(struct popen_handle *handle)
+{
+ if (!handle || handle->pid == -1) {
+ errno = ESRCH;
+ return false;
+ }
+ return true;
+}
+
+/**
+ * popen_stat - fill popen object statistics
+ * @handle: popen handle
+ * @st: destination popen_stat to fill
+ *
+ * Returns 0 on succes, -1 otherwise (setting @errno).
+ */
+int
+popen_stat(struct popen_handle *handle, struct popen_stat *st)
+{
+ if (!handle) {
+ errno = ESRCH;
+ return -1;
+ }
+
+ st->pid = handle->pid;
+ st->flags = handle->flags;
+
+ static_assert(lengthof(st->fds) == lengthof(handle->ios),
+ "Statistics fds are screwed");
+
+ for (size_t i = 0; i < lengthof(handle->ios); i++)
+ st->fds[i] = handle->ios[i].fd;
+ return 0;
+}
+
+/**
+ * popen_command - get a pointer to former command line
+ * @handle: popen handle
+ *
+ * Returns pointer to a former command line for executiion.
+ * Since it might be big enough it is moved out of popen_stat.
+ *
+ * On error NULL returned.
+ */
+const char *
+popen_command(struct popen_handle *handle)
+{
+ if (!handle) {
+ errno = ESRCH;
+ return NULL;
+ }
+
+ return (const char *)handle->command;
+}
+
+/**
+ * Get stdX descriptor string representation
+ */
+static inline const char *
+stdX_str(unsigned int index)
+{
+ static const char * stdX_names[] = {
+ [STDIN_FILENO] = "stdin",
+ [STDOUT_FILENO] = "stdout",
+ [STDERR_FILENO] = "stderr",
+ };
+
+ return index < lengthof(stdX_names) ?
+ stdX_names[index] : "unknown";
+}
+
+/**
+ * popen_write - write data to the child stdin
+ * @handle: popen handle
+ * @buf: data to write
+ * @count: number of bytes to write
+ * @flags: a flag representing stdin peer
+ * @timeout: timeout in seconds; ignored if negative
+ *
+ * Returns 0 on succes or -1 on error (setting @errno).
+ */
+int
+popen_write_timeout(struct popen_handle *handle, void *buf,
+ size_t count, unsigned int flags,
+ ev_tstamp timeout)
+{
+ int idx = STDIN_FILENO;
+
+ if (!popen_may_io(handle, STDIN_FILENO, flags))
+ return -1;
+
+ if (count > (size_t)SSIZE_MAX) {
+ errno = E2BIG;
+ return -1;
+ }
+
+ say_debug("popen: %d: write idx [%s:%d] buf %p count %zu "
+ "fds %d timeout %.9g",
+ handle->pid, stdX_str(idx), idx, buf, count,
+ handle->ios[idx].fd, timeout);
+
+ return coio_write_timeout(&handle->ios[idx], buf,
+ count, timeout);
+}
+
+/**
+ * popen_read_timeout - read data from a child's peer with timeout
+ * @handle: popen handle
+ * @buf: destination buffer
+ * @count: number of bytes to read
+ * @flags: POPEN_FLAG_FD_STDOUT or POPEN_FLAG_FD_STDERR
+ * @timeout: timeout in seconds; ignored if negative
+ *
+ * Returns number of bytes read, otherwise -1 returned and
+ * @errno set accordingly.
+ */
+ssize_t
+popen_read_timeout(struct popen_handle *handle, void *buf,
+ size_t count, unsigned int flags,
+ ev_tstamp timeout)
+{
+ int idx = flags & POPEN_FLAG_FD_STDOUT ?
+ STDOUT_FILENO : STDERR_FILENO;
+
+ if (!popen_may_io(handle, idx, flags))
+ return -1;
+
+ if (count > (size_t)SSIZE_MAX) {
+ errno = E2BIG;
+ return -1;
+ }
+
+ if (timeout < 0.)
+ timeout = TIMEOUT_INFINITY;
+
+ say_debug("popen: %d: read idx [%s:%d] buf %p count %zu "
+ "fds %d timeout %.9g",
+ handle->pid, stdX_str(idx), idx, buf, count,
+ handle->ios[idx].fd, timeout);
+
+ return coio_read_timeout(&handle->ios[idx], buf,
+ count, timeout);
+}
+
+/**
+ * Encode signal status into a human readable form
+ *
+ * Operates on S_DEBUG level only simply because snprintf
+ * is pretty heavy in performance, otherwise @buf remains
+ * untouched.
+ */
+static char *
+wstatus_str(char *buf, size_t size, int wstatus)
+{
+ static const char fmt[] =
+ "wstatus %#x exited %d status %d "
+ "signaled %d wtermsig %d "
+ "stopped %d stopsig %d "
+ "coredump %d continued %d";
+
+ assert(size > 0);
+
+ if (say_log_level_is_enabled(S_DEBUG)) {
+ snprintf(buf, size, fmt, wstatus,
+ WIFEXITED(wstatus),
+ WIFEXITED(wstatus) ?
+ WEXITSTATUS(wstatus) : -1,
+ WIFSIGNALED(wstatus),
+ WIFSIGNALED(wstatus) ?
+ WTERMSIG(wstatus) : -1,
+ WIFSTOPPED(wstatus),
+ WIFSTOPPED(wstatus) ?
+ WSTOPSIG(wstatus) : -1,
+ WCOREDUMP(wstatus),
+ WIFCONTINUED(wstatus));
+ }
+
+ return buf;
+}
+
+/**
+ * Handle SIGCHLD when a child process exit.
+ */
+static void
+popen_sigchld_handler(EV_P_ ev_child *w, int revents)
+{
+ struct popen_handle *handle;
+ (void)revents;
+
+ /*
+ * Stop watching this child, libev will
+ * remove it from own hashtable.
+ */
+ ev_child_stop(EV_A_ w);
+
+ if (say_log_level_is_enabled(S_DEBUG)) {
+ char buf[128], *str;
+
+ str = wstatus_str(buf, sizeof(buf), w->rstatus);
+ say_debug("popen: sigchld notify %d (%s)", w->rpid, str);
+ }
+
+ handle = popen_find(w->rpid);
+ if (handle) {
+ assert(handle->pid == w->rpid);
+ assert(w == &handle->ev_sigchld);
+
+ handle->wstatus = w->rstatus;
+ if (WIFEXITED(w->rstatus) || WIFSIGNALED(w->rstatus)) {
+ say_debug("popen: ev_child_stop %d", handle->pid);
+ /*
+ * libev calls for waitpid by self so
+ * we don't have to wait here.
+ */
+ popen_unregister(handle);
+ handle->pid = -1;
+ }
+ }
+}
+
+/**
+ * popen_state - get current child state
+ * @handle: popen handle
+ * @state: state of a child process
+ * @exit_code: exit code of a child process
+ *
+ * On success returns 0 sets @state to POPEN_STATE_
+ * constant and @exit_code. On error -1 returned with @errno.
+ */
+int
+popen_state(struct popen_handle *handle, int *state, int *exit_code)
+{
+ if (!handle) {
+ errno = ESRCH;
+ return -1;
+ }
+
+ if (handle->pid != -1) {
+ *state = POPEN_STATE_ALIVE;
+ *exit_code = 0;
+ } else {
+ if (WIFEXITED(handle->wstatus)) {
+ *state = POPEN_STATE_EXITED;
+ *exit_code = WEXITSTATUS(handle->wstatus);
+ } else {
+ *state = POPEN_STATE_SIGNALED;
+ *exit_code = WTERMSIG(handle->wstatus);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * popen_state_str - get process state string representation
+ * @state: process state
+ */
+const char *
+popen_state_str(unsigned int state)
+{
+ /*
+ * A process may be in a number of states,
+ * running/sleeping/disk sleep/stopped and etc
+ * but we are interested only if it is alive
+ * or dead (via plain exit or kill signal).
+ *
+ * Thus while it present in a system and not
+ * yet reaped we call it "alive".
+ *
+ * Note this is API for lua, so change with
+ * caution if needed.
+ */
+ static const char *state_str[POPEN_STATE_MAX] = {
+ [POPEN_STATE_NONE] = "none",
+ [POPEN_STATE_ALIVE] = "alive",
+ [POPEN_STATE_EXITED] = "exited",
+ [POPEN_STATE_SIGNALED] = "signaled",
+ };
+
+ return state < POPEN_STATE_MAX ? state_str[state] : "unknown";
+}
+
+/**
+ * popen_send_signal - send a signal to a child process
+ * @handle: popen handle
+ * @signo: signal number
+ *
+ * Returns 0 on success, -1 otherwise.
+ */
+int
+popen_send_signal(struct popen_handle *handle, int signo)
+{
+ int ret;
+
+ /*
+ * A child may be killed or exited already.
+ */
+ if (!popen_may_pidop(handle))
+ return -1;
+
+ say_debug("popen: kill %d signo %d", handle->pid, signo);
+ ret = kill(handle->pid, signo);
+ if (ret < 0) {
+ diag_set(SystemError, "Unable to kill %d signo %d",
+ handle->pid, signo);
+ }
+ return ret;
+}
+
+/**
+ * popen_delete - delete a popen handle
+ * @handle: a popen handle to delete
+ *
+ * The function kills a child process and
+ * close all fds and remove the handle from
+ * a living list and finally frees the handle.
+ *
+ * Returns 0 on success, -1 otherwise.
+ */
+int
+popen_delete(struct popen_handle *handle)
+{
+ size_t i;
+
+ if (!handle) {
+ errno = ESRCH;
+ return -1;
+ }
+
+ if (popen_send_signal(handle, SIGKILL) && errno != ESRCH)
+ return -1;
+
+ for (i = 0; i < lengthof(handle->ios); i++) {
+ if (handle->ios[i].fd != -1)
+ coio_close_io(loop(), &handle->ios[i]);
+ }
+
+ /*
+ * We won't be wathcing this child anymore if
+ * kill signal is not yet delivered.
+ */
+ if (handle->pid != -1) {
+ say_debug("popen: ev_child_stop %d", handle->pid);
+ ev_child_stop(EV_DEFAULT_ &handle->ev_sigchld);
+ }
+
+ rlist_del(&handle->list);
+ handle_free(handle);
+ return 0;
+}
+
+/**
+ * Create O_CLOEXEC pipes
+ */
+static int
+make_pipe(int pfd[2])
+{
+#ifdef TARGET_OS_LINUX
+ if (pipe2(pfd, O_CLOEXEC)) {
+ diag_set(SystemError, "Can't create pipe2");
+ return -1;
+ }
+#else
+ if (pipe(pfd)) {
+ diag_set(SystemError, "Can't create pipe");
+ return -1;
+ }
+ if (fcntl(pfd[0], F_SETFL, O_CLOEXEC) ||
+ fcntl(pfd[1], F_SETFL, O_CLOEXEC)) {
+ int saved_errno = errno;
+ diag_set(SystemError, "Can't unblock pipe");
+ close(pfd[0]), pfd[0] = -1;
+ close(pfd[1]), pfd[1] = -1;
+ errno = saved_errno;
+ return -1;
+ }
+#endif
+ return 0;
+}
+
+/**
+ * Close inherited file descriptors
+ *
+ * @skip_fds is an array of @nr_skip_fds elements with
+ * descriptors which should be kept opened.
+ */
+static int
+close_inherited_fds(int *skip_fds, size_t nr_skip_fds)
+{
+#ifdef TARGET_OS_LINUX
+ static const char path[] = "/proc/self/fd";
+ struct dirent *de;
+ int fd_no, fd_dir;
+ DIR *dir;
+ size_t i;
+
+ dir = opendir(path);
+ if (!dir) {
+ diag_set(SystemError, "fdin: Can't open %s", path);
+ return -1;
+ }
+ fd_dir = dirfd(dir);
+
+ for (de = readdir(dir); de; de = readdir(dir)) {
+ if (!strcmp(de->d_name, ".") ||
+ !strcmp(de->d_name, ".."))
+ continue;
+
+ fd_no = atoi(de->d_name);
+
+ if (fd_no == fd_dir)
+ continue;
+
+ /* We don't expect many numbers here */
+ for (i = 0; i < nr_skip_fds; i++) {
+ if (fd_no == skip_fds[i]) {
+ fd_no = -1;
+ break;
+ }
+ }
+
+ if (fd_no == -1)
+ continue;
+
+ if (close(fd_no)) {
+ int saved_errno = errno;
+ diag_set(SystemError, "fdin: Can't close %d", fd_no);
+ closedir(dir);
+ errno = saved_errno;
+ return -1;
+ }
+ }
+
+ if (closedir(dir)) {
+ diag_set(SystemError, "fdin: Can't close %s", path);
+ return -1;
+ }
+#else
+ /* FIXME: What about FreeBSD/MachO? */
+ (void)skip_fds;
+ (void)nr_skip_fds;
+
+ static bool said = false;
+ if (!said) {
+ say_warn("popen: fdin: Skip closing inherited");
+ said = true;
+ }
+#endif
+ return 0;
+}
+
+#ifdef TARGET_OS_LINUX
+extern char **environ;
+#endif
+
+/**
+ * Get pointer to environment variables to use in
+ * a child process.
+ */
+static inline char **
+get_envp(struct popen_opts *opts)
+{
+ if (!opts->env) {
+#ifdef TARGET_OS_LINUX
+ /* Inherit existing ones if not specified */
+ return environ;
+#else
+ static const char **empty_envp[] = { NULL };
+ static bool said = false;
+ if (!said)
+ say_warn("popen: Environment inheritance "
+ "unsupported, passing empty");
+ return (char *)empty_envp;
+#endif
+ }
+ return opts->env;
+}
+
+/**
+ * Reset signals to default before executing a program.
+ *
+ * FIXME: This is a code duplication fomr main.cc. Need to rework
+ * signal handing otherwise it will become utter crap very fast.
+ */
+static void
+signal_reset(void)
+{
+ struct sigaction sa = { };
+ sigset_t sigset;
+
+ /* Reset all signals to their defaults. */
+ sigemptyset(&sa.sa_mask);
+ sa.sa_handler = SIG_DFL;
+
+ if (sigaction(SIGUSR1, &sa, NULL) == -1 ||
+ sigaction(SIGINT, &sa, NULL) == -1 ||
+ sigaction(SIGTERM, &sa, NULL) == -1 ||
+ sigaction(SIGHUP, &sa, NULL) == -1 ||
+ sigaction(SIGWINCH, &sa, NULL) == -1 ||
+ sigaction(SIGSEGV, &sa, NULL) == -1 ||
+ sigaction(SIGFPE, &sa, NULL) == -1)
+ _exit(errno);
+
+ /* Unblock any signals blocked by libev */
+ sigfillset(&sigset);
+ if (sigprocmask(SIG_UNBLOCK, &sigset, NULL) == -1)
+ _exit(errno);
+}
+
+/**
+ * popen_new - Create new popen handle
+ * @opts: options for popen handle
+ *
+ * This function creates a new child process and passes it
+ * pipe ends to communicate with child's stdin/stdout/stderr
+ * depending on @opts:flags. Where @opts:flags could be
+ * the bitwise "OR" for the following values:
+ *
+ * POPEN_FLAG_FD_STDIN - to write to stdin
+ * POPEN_FLAG_FD_STDOUT - to read from stdout
+ * POPEN_FLAG_FD_STDERR - to read from stderr
+ *
+ * When need to pass /dev/null descriptor into a child
+ * the following values can be used:
+ *
+ * POPEN_FLAG_FD_STDIN_DEVNULL
+ * POPEN_FLAG_FD_STDOUT_DEVNULL
+ * POPEN_FLAG_FD_STDERR_DEVNULL
+ *
+ * These flags have no effect if appropriate POPEN_FLAG_FD_STDx
+ * flags are set.
+ *
+ * When need to completely close the descriptors the
+ * following values can be used:
+ *
+ * POPEN_FLAG_FD_STDIN_CLOSE
+ * POPEN_FLAG_FD_STDOUT_CLOSE
+ * POPEN_FLAG_FD_STDERR_CLOSE
+ *
+ * These flags have no effect if appropriate POPEN_FLAG_FD_STDx
+ * flags are set.
+ *
+ * If none of POPEN_FLAG_FD_STDx flags are specified the child
+ * process will run with all files inherited from a parent.
+ *
+ * Returns pointer to a new popen handle on success,
+ * otherwise NULL returned setting @errno.
+ */
+struct popen_handle *
+popen_new(struct popen_opts *opts)
+{
+ struct popen_handle *handle = NULL;
+
+ int pfd[POPEN_FLAG_FD_STDEND_BIT][2] = {
+ {-1, -1}, {-1, -1}, {-1, -1},
+ };
+
+ char **envp = get_envp(opts);
+ int saved_errno;
+ size_t i;
+
+ static const struct {
+ unsigned int mask;
+ unsigned int mask_devnull;
+ unsigned int mask_close;
+ int fileno;
+ int *dev_null_fd;
+ int parent_idx;
+ int child_idx;
+ bool nonblock;
+ } pfd_map[POPEN_FLAG_FD_STDEND_BIT] = {
+ {
+ .mask = POPEN_FLAG_FD_STDIN,
+ .mask_devnull = POPEN_FLAG_FD_STDIN_DEVNULL,
+ .mask_close = POPEN_FLAG_FD_STDIN_CLOSE,
+ .fileno = STDIN_FILENO,
+ .dev_null_fd = &dev_null_fd_ro,
+ .parent_idx = 1,
+ .child_idx = 0,
+ }, {
+ .mask = POPEN_FLAG_FD_STDOUT,
+ .mask_devnull = POPEN_FLAG_FD_STDOUT_DEVNULL,
+ .mask_close = POPEN_FLAG_FD_STDOUT_CLOSE,
+ .fileno = STDOUT_FILENO,
+ .dev_null_fd = &dev_null_fd_wr,
+ .parent_idx = 0,
+ .child_idx = 1,
+ }, {
+ .mask = POPEN_FLAG_FD_STDERR,
+ .mask_devnull = POPEN_FLAG_FD_STDERR_DEVNULL,
+ .mask_close = POPEN_FLAG_FD_STDERR_CLOSE,
+ .fileno = STDERR_FILENO,
+ .dev_null_fd = &dev_null_fd_wr,
+ .parent_idx = 0,
+ .child_idx = 1,
+ },
+ };
+ /*
+ * At max we could be skipping each pipe end
+ * plus dev/null variants.
+ */
+ int skip_fds[POPEN_FLAG_FD_STDEND_BIT * 2 + 2];
+ size_t nr_skip_fds = 0;
+
+ /*
+ * A caller must preserve space for this.
+ */
+ if (opts->flags & POPEN_FLAG_SHELL) {
+ opts->argv[0] = "sh";
+ opts->argv[1] = "-c";
+ }
+
+ static_assert(STDIN_FILENO == 0 &&
+ STDOUT_FILENO == 1 &&
+ STDERR_FILENO == 2,
+ "stdin/out/err are not posix compatible");
+
+ static_assert(lengthof(pfd) == lengthof(pfd_map),
+ "Pipes number does not map to fd bits");
+
+ static_assert(POPEN_FLAG_FD_STDIN_BIT == STDIN_FILENO &&
+ POPEN_FLAG_FD_STDOUT_BIT == STDOUT_FILENO &&
+ POPEN_FLAG_FD_STDERR_BIT == STDERR_FILENO,
+ "Popen flags do not match stdX");
+
+ handle = handle_new(opts);
+ if (!handle)
+ return NULL;
+
+ skip_fds[nr_skip_fds++] = dev_null_fd_ro;
+ skip_fds[nr_skip_fds++] = dev_null_fd_wr;
+ assert(nr_skip_fds <= lengthof(skip_fds));
+
+ for (i = 0; i < lengthof(pfd_map); i++) {
+ if (opts->flags & pfd_map[i].mask) {
+ if (make_pipe(pfd[i]))
+ goto out_err;
+
+ /*
+ * FIXME: Rather force make_pipe
+ * to allocate new fds with higher
+ * number.
+ */
+ if (pfd[i][0] <= STDERR_FILENO ||
+ pfd[i][1] <= STDERR_FILENO) {
+ errno = EBADF;
+ diag_set(SystemError,
+ "Low fds number [%s:%d:%d]",
+ stdX_str(i), pfd[i][0],
+ pfd[i][1]);
+ goto out_err;
+ }
+
+ skip_fds[nr_skip_fds++] = pfd[i][0];
+ skip_fds[nr_skip_fds++] = pfd[i][1];
+ assert(nr_skip_fds <= lengthof(skip_fds));
+
+ say_debug("popen: created pipe [%s:%d:%d]",
+ stdX_str(i), pfd[i][0], pfd[i][1]);
+ } else if (!(opts->flags & pfd_map[i].mask_devnull) &&
+ !(opts->flags & pfd_map[i].mask_close)) {
+ skip_fds[nr_skip_fds++] = pfd_map[i].fileno;
+
+ say_debug("popen: inherit [%s:%d]",
+ stdX_str(i), pfd_map[i].fileno);
+ }
+ }
+
+ /*
+ * We have to use vfork here because libev has own
+ * at_fork helpers with mutex, so we will have double
+ * lock here and stuck forever otherwise.
+ *
+ * The good news that this affect tx only the
+ * other tarantoll threads are not waiting for
+ * vfork to complete. Also we try to do as minimum
+ * operations before the exec() as possible.
+ */
+ handle->pid = vfork();
+ if (handle->pid < 0) {
+ goto out_err;
+ } else if (handle->pid == 0) {
+ /*
+ * The documentation for libev says that
+ * each new fork should call ev_loop_fork(EV_DEFAULT)
+ * on every new child process, but we're going
+ * to execute bew binary anyway thus everything
+ * related to OS resources will be eliminated except
+ * file descriptors we use for piping. Thus don't
+ * do anything special.
+ */
+
+ /*
+ * Also don't forget to drop signal handlers
+ * to default inside a child process since we're
+ * inheriting them from a caller process.
+ */
+ if (opts->flags & POPEN_FLAGS_RESTORE_SIGNALS)
+ signal_reset();
+
+ /*
+ * We have to be a session leader otherwise
+ * won't be able to kill a group of children.
+ */
+ if (opts->flags & POPEN_FLAGS_SETSID) {
+ if (setsid() == -1)
+ goto exit_child;
+ }
+
+ if (opts->flags & POPEN_FLAG_CLOSE_FDS) {
+ if (close_inherited_fds(skip_fds, nr_skip_fds))
+ goto exit_child;
+ }
+
+ for (i = 0; i < lengthof(pfd_map); i++) {
+ int fileno = pfd_map[i].fileno;
+ /*
+ * Pass pipe peer to a child.
+ */
+ if (opts->flags & pfd_map[i].mask) {
+ int child_idx = pfd_map[i].child_idx;
+
+ /* put child peer end at known place */
+ if (dup2(pfd[i][child_idx], fileno) < 0)
+ goto exit_child;
+
+ /* parent's pipe no longer needed */
+ if (close(pfd[i][0]) ||
+ close(pfd[i][1]))
+ goto exit_child;
+ continue;
+ }
+
+ /*
+ * Use /dev/null if requested.
+ */
+ if (opts->flags & pfd_map[i].mask_devnull) {
+ if (dup2(*pfd_map[i].dev_null_fd,
+ fileno) < 0) {
+ goto exit_child;
+ }
+ continue;
+ }
+
+ /*
+ * Or close the destination completely, since
+ * we don't if the file in question is already
+ * closed by some other code we don't care if
+ * EBADF happens.
+ */
+ if (opts->flags & pfd_map[i].mask_close) {
+ if (close(fileno) && errno != EBADF)
+ goto exit_child;
+ continue;
+ }
+
+ /*
+ * Otherwise inherit file descriptor
+ * from a parent.
+ */
+ }
+
+ if (close(dev_null_fd_ro) || close(dev_null_fd_wr))
+ goto exit_child;
+
+ if (opts->flags & POPEN_FLAG_SHELL)
+ execve(_PATH_BSHELL, opts->argv, envp);
+ else
+ execve(opts->argv[2], &opts->argv[2], envp);
+exit_child:
+ _exit(errno);
+ unreachable();
+ }
+
+ for (i = 0; i < lengthof(pfd_map); i++) {
+ if (opts->flags & pfd_map[i].mask) {
+ int parent_idx = pfd_map[i].parent_idx;
+ int child_idx = pfd_map[i].child_idx;
+ int parent_fd = pfd[i][parent_idx];
+
+ coio_create(&handle->ios[i], parent_fd);
+ if (fcntl(parent_fd, F_SETFL, O_NONBLOCK)) {
+ diag_set(SystemError, "Can't set O_NONBLOCK [%s:%d]",
+ stdX_str(i), parent_fd);
+ goto out_err;
+ }
+
+ say_debug("popen: keep pipe [%s:%d]",
+ stdX_str(i), parent_fd);
+
+ if (close(pfd[i][child_idx])) {
+ diag_set(SystemError, "Can't close child [%s:%d]",
+ stdX_str(i), pfd[i][child_idx]);
+ goto out_err;
+ }
+
+ pfd[i][child_idx] = -1;
+ }
+ }
+
+ /*
+ * Link it into global list for force
+ * cleanup on exit.
+ */
+ rlist_add(&popen_head, &handle->list);
+
+ /*
+ * To watch when a child get exited.
+ */
+ popen_register(handle);
+
+ say_debug("popen: ev_child_start %d", handle->pid);
+ ev_child_init(&handle->ev_sigchld, popen_sigchld_handler, handle->pid, 0);
+ ev_child_start(EV_DEFAULT_ &handle->ev_sigchld);
+
+ say_debug("popen: created child %d", handle->pid);
+
+ return handle;
+
+out_err:
+ saved_errno = errno;
+ popen_delete(handle);
+ for (i = 0; i < lengthof(pfd); i++) {
+ if (pfd[i][0] != -1)
+ close(pfd[i][0]);
+ if (pfd[i][1] != -1)
+ close(pfd[i][1]);
+ }
+ errno = saved_errno;
+ return NULL;
+}
+
+/**
+ * popen_init - initialize popen subsystem
+ *
+ * Allocates resource needed for popen management.
+ */
+void
+popen_init(void)
+{
+ static const int flags = O_CLOEXEC;
+ static const char dev_null_path[] = "/dev/null";
+
+ say_debug("popen: initialize subsystem");
+ popen_pids_map = mh_i32ptr_new();
+
+ dev_null_fd_ro = open(dev_null_path, O_RDONLY | flags);
+ if (dev_null_fd_ro < 0)
+ goto out_err;
+ dev_null_fd_wr = open(dev_null_path, O_WRONLY | flags);
+ if (dev_null_fd_wr < 0)
+ goto out_err;
+
+ /*
+ * FIXME: We should allocate them somewhere
+ * after STDERR_FILENO so the child would be
+ * able to find these fd numbers not occupied.
+ * Other option is to use unix scm and send
+ * them to the child on demand.
+ *
+ * For now left as is since we don't close
+ * our main stdX descriptors and they are
+ * inherited when we call first vfork.
+ */
+ if (dev_null_fd_ro <= STDERR_FILENO ||
+ dev_null_fd_wr <= STDERR_FILENO) {
+ say_error("popen: /dev/null %d %d numbers are too low",
+ dev_null_fd_ro, dev_null_fd_wr);
+ goto out_err;
+ }
+
+ return;
+
+out_err:
+ say_syserror("popen: Can't open %s", dev_null_path);
+ if (dev_null_fd_ro >= 0)
+ close(dev_null_fd_ro);
+ if (dev_null_fd_wr >= 0)
+ close(dev_null_fd_wr);
+ mh_i32ptr_delete(popen_pids_map);
+ exit(EXIT_FAILURE);
+}
+
+/**
+ * popen_free - free popen subsystem
+ *
+ * Kills all running children and frees resources.
+ */
+void
+popen_free(void)
+{
+ struct popen_handle *handle, *tmp;
+
+ say_debug("popen: free subsystem");
+
+ close(dev_null_fd_ro);
+ close(dev_null_fd_wr);
+ dev_null_fd_ro = -1;
+ dev_null_fd_wr = -1;
+
+ rlist_foreach_entry_safe(handle, &popen_head, list, tmp) {
+ /*
+ * If children are still running we should move
+ * them out of the pool and kill them all then.
+ * Note though that we don't do an explicit wait
+ * here, OS will reap them anyway, just release
+ * the memory occupied for popen handles.
+ */
+ if (popen_may_pidop(handle))
+ popen_unregister(handle);
+ popen_delete(handle);
+ }
+
+ if (popen_pids_map) {
+ mh_i32ptr_delete(popen_pids_map);
+ popen_pids_map = NULL;
+ }
+}
diff --git a/src/lib/core/popen.h b/src/lib/core/popen.h
new file mode 100644
index 000000000..514c8b9aa
--- /dev/null
+++ b/src/lib/core/popen.h
@@ -0,0 +1,207 @@
+#ifndef TARANTOOL_LIB_CORE_POPEN_H_INCLUDED
+#define TARANTOOL_LIB_CORE_POPEN_H_INCLUDED
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#include <signal.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include <small/rlist.h>
+
+#include "trivia/util.h"
+#include "third_party/tarantool_ev.h"
+
+/*
+ * Describes popen object creation. This is API with Lua.
+ */
+enum popen_flag_bits {
+ POPEN_FLAG_NONE = (0 << 0),
+
+ /*
+ * Which fd we should handle as new pipes.
+ */
+ POPEN_FLAG_FD_STDIN_BIT = 0,
+ POPEN_FLAG_FD_STDIN = (1 << POPEN_FLAG_FD_STDIN_BIT),
+
+ POPEN_FLAG_FD_STDOUT_BIT = 1,
+ POPEN_FLAG_FD_STDOUT = (1 << POPEN_FLAG_FD_STDOUT_BIT),
+
+ POPEN_FLAG_FD_STDERR_BIT = 2,
+ POPEN_FLAG_FD_STDERR = (1 << POPEN_FLAG_FD_STDERR_BIT),
+
+ /*
+ * Number of bits occupied for stdX descriptors.
+ */
+ POPEN_FLAG_FD_STDEND_BIT = POPEN_FLAG_FD_STDERR_BIT + 1,
+
+ /*
+ * Instead of inheriting fds from a parent
+ * rather use /dev/null.
+ */
+ POPEN_FLAG_FD_STDIN_DEVNULL_BIT = 3,
+ POPEN_FLAG_FD_STDIN_DEVNULL = (1 << POPEN_FLAG_FD_STDIN_DEVNULL_BIT),
+ POPEN_FLAG_FD_STDOUT_DEVNULL_BIT= 4,
+ POPEN_FLAG_FD_STDOUT_DEVNULL = (1 << POPEN_FLAG_FD_STDOUT_DEVNULL_BIT),
+ POPEN_FLAG_FD_STDERR_DEVNULL_BIT= 5,
+ POPEN_FLAG_FD_STDERR_DEVNULL = (1 << POPEN_FLAG_FD_STDERR_DEVNULL_BIT),
+
+ /*
+ * Instead of inheriting fds from a parent
+ * close fds completely.
+ */
+ POPEN_FLAG_FD_STDIN_CLOSE_BIT = 6,
+ POPEN_FLAG_FD_STDIN_CLOSE = (1 << POPEN_FLAG_FD_STDIN_CLOSE_BIT),
+ POPEN_FLAG_FD_STDOUT_CLOSE_BIT = 7,
+ POPEN_FLAG_FD_STDOUT_CLOSE = (1 << POPEN_FLAG_FD_STDOUT_CLOSE_BIT),
+ POPEN_FLAG_FD_STDERR_CLOSE_BIT = 8,
+ POPEN_FLAG_FD_STDERR_CLOSE = (1 << POPEN_FLAG_FD_STDERR_CLOSE_BIT),
+
+ /*
+ * Reserved for a case where we will handle
+ * other fds as a source for stdin/out/err.
+ * Ie piping from child process to our side
+ * via splices and etc.
+ */
+ POPEN_FLAG_FD_STDIN_EPIPE_BIT = 9,
+ POPEN_FLAG_FD_STDIN_EPIPE = (1 << POPEN_FLAG_FD_STDIN_EPIPE_BIT),
+ POPEN_FLAG_FD_STDOUT_EPIPE_BIT = 10,
+ POPEN_FLAG_FD_STDOUT_EPIPE = (1 << POPEN_FLAG_FD_STDOUT_EPIPE_BIT),
+ POPEN_FLAG_FD_STDERR_EPIPE_BIT = 11,
+ POPEN_FLAG_FD_STDERR_EPIPE = (1 << POPEN_FLAG_FD_STDERR_EPIPE_BIT),
+
+ /*
+ * Call exec directly or via shell.
+ */
+ POPEN_FLAG_SHELL_BIT = 12,
+ POPEN_FLAG_SHELL = (1 << POPEN_FLAG_SHELL_BIT),
+
+ /*
+ * Create a new session.
+ */
+ POPEN_FLAGS_SETSID_BIT = 13,
+ POPEN_FLAGS_SETSID = (1 << POPEN_FLAGS_SETSID_BIT),
+
+ /*
+ * Close all inherited fds except stdin/out/err.
+ */
+ POPEN_FLAG_CLOSE_FDS_BIT = 14,
+ POPEN_FLAG_CLOSE_FDS = (1 << POPEN_FLAG_CLOSE_FDS_BIT),
+
+ /*
+ * Restore signal handlers to default.
+ */
+ POPEN_FLAGS_RESTORE_SIGNALS_BIT = 15,
+ POPEN_FLAGS_RESTORE_SIGNALS = (1 << POPEN_FLAGS_RESTORE_SIGNALS_BIT),
+};
+
+/*
+ * Popen object states. This is API with Lua.
+ */
+enum popen_states {
+ POPEN_STATE_NONE = 0,
+ POPEN_STATE_ALIVE = 1,
+ POPEN_STATE_EXITED = 2,
+ POPEN_STATE_SIGNALED = 3,
+
+ POPEN_STATE_MAX,
+};
+
+/**
+ * struct popen_handle - an instance of popen object
+ *
+ * @pid: pid of a child process
+ * @command: copy of a command line for statistics
+ * @wstatus: exit status of a child process
+ * @ev_sigchld: needed by the libev to watch children
+ * @flags: popen_flag_bits
+ * @ios: io objects for std(in|out|err)
+ */
+struct popen_handle {
+ pid_t pid;
+ char *command;
+ int wstatus;
+ ev_child ev_sigchld;
+ struct rlist list;
+ unsigned int flags;
+ struct ev_io ios[POPEN_FLAG_FD_STDEND_BIT];
+};
+
+/**
+ * struct popen_opts - options for popen creation
+ *
+ * @argv: argv to execute
+ * @nr_argv: number of elements in @argv
+ * @env: environment (can be empty)
+ * @flags: popen_flag_bits
+ */
+struct popen_opts {
+ char **argv;
+ size_t nr_argv;
+ char **env;
+ unsigned int flags;
+};
+
+/**
+ * struct popen_stat - popen object statistics
+ *
+ * @pid: pid of a child process
+ * @flags: popen_flag_bits
+ * @fds: std(in|out|err)
+ *
+ * This is a short version of struct popen_handle which should
+ * be used by external code and which should be changed/extended
+ * with extreme caution since it is used in Lua code. Consider it
+ * as API for external modules.
+ */
+struct popen_stat {
+ pid_t pid;
+ unsigned int flags;
+ int fds[POPEN_FLAG_FD_STDEND_BIT];
+};
+
+extern int
+popen_stat(struct popen_handle *handle, struct popen_stat *st);
+
+extern const char *
+popen_command(struct popen_handle *handle);
+
+extern int
+popen_write_timeout(struct popen_handle *handle, void *buf,
+ size_t count, unsigned int flags,
+ ev_tstamp timeout);
+
+extern ssize_t
+popen_read_timeout(struct popen_handle *handle, void *buf,
+ size_t count, unsigned int flags,
+ ev_tstamp timeout);
+
+extern int
+popen_state(struct popen_handle *handle, int *state, int *exit_code);
+
+extern const char *
+popen_state_str(unsigned int state);
+
+extern int
+popen_send_signal(struct popen_handle *handle, int signo);
+
+extern int
+popen_delete(struct popen_handle *handle);
+
+extern struct popen_handle *
+popen_new(struct popen_opts *opts);
+
+extern void
+popen_init(void);
+
+extern void
+popen_free(void);
+
+#if defined(__cplusplus)
+} /* extern "C" */
+#endif
+
+#endif /* TARANTOOL_LIB_CORE_POPEN_H_INCLUDED */
diff --git a/src/main.cc b/src/main.cc
index e674d85b1..8df94c9e4 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -77,6 +77,7 @@
#include "box/session.h"
#include "systemd.h"
#include "crypto/crypto.h"
+#include "core/popen.h"
static pid_t master_pid = getpid();
static struct pidfh *pid_file_handle;
@@ -642,6 +643,8 @@ tarantool_free(void)
title_free(main_argc, main_argv);
+ popen_free();
+
/* unlink pidfile. */
if (pid_file_handle != NULL && pidfile_remove(pid_file_handle) == -1)
say_syserror("failed to remove pid file '%s'", pid_file);
@@ -819,6 +822,7 @@ main(int argc, char **argv)
exception_init();
fiber_init(fiber_cxx_invoke);
+ popen_init();
coio_init();
coio_enable();
signal_init();
--
2.20.1
^ permalink raw reply [flat|nested] 5+ messages in thread* [Tarantool-patches] [PATCH v9 3/4] popen/lua: add popen module
2020-01-10 8:25 [Tarantool-patches] [PATCH v9 0/4] popen: add ability to run external process Cyrill Gorcunov
2020-01-10 8:25 ` [Tarantool-patches] [PATCH v9 1/4] coio: export helpers Cyrill Gorcunov
2020-01-10 8:25 ` [Tarantool-patches] [PATCH v9 2/4] popen: introduce a backend engine Cyrill Gorcunov
@ 2020-01-10 8:25 ` Cyrill Gorcunov
2020-01-10 8:25 ` [Tarantool-patches] [PATCH v9 4/4] popen/test: add base test cases Cyrill Gorcunov
3 siblings, 0 replies; 5+ messages in thread
From: Cyrill Gorcunov @ 2020-01-10 8:25 UTC (permalink / raw)
To: tml
@TarantoolBot document
Title: popen module
Overview
========
Tarantool supports execution of external programs similarly
to well known Python's `subprocess` or Ruby's `Open3`. Note
though the `popen` module does not match one to one to the
helpers these languages provide and provides only basic
functions. The popen object creation is implemented via
`vfork()` system call which means the caller thread is
blocked until execution of a child process begins.
Functions
=========
The `popen` module provides two functions to create that named
popen object `popen.posix` which is the similar to libc `posix`
syscall and `popen.popen` to create popen object with more
specific options.
`handler, err = popen.posix(command, mode)`
-------------------------------------------
Creates a new child process and executes a command as the "sh -c command".
Parameters
```
command is the command to run
mode 'r' - to grab child's stdout for read
'w' - to write into child's stdin stream
'rw' - combined mode to read and write
```
If `mode` has `r` then `stderr` output stream is always opened to be
able to redirect `stderr` to `stdout` by well known `2>&1` statement.
If `mode` is not specified at all then non of the std stram will be
opened inside a child process.
On success returns popen object handler setting `err` to nil,
otherwise error reported.
__Example 1__
```
ph = require('popen').posix("date", "r")
ph:read()
ph:close()
```
Executes "sh -c date" then reads the output and closes the popen object.
`handler, err = popen.popen(opts)`
----------------------------------
Creates a new child process and execute a program inside. The `opts` is
options table with the following keys
```
argv an array containing the binary to execute together
with command line arguments; this is the only mandatory
key in the options table
env an array of environment variables, if not set then they
are inherited; if env=nil then environment will be empty
flags a dictionary to describe communication pipes and other
parameters of a process to run
stdin=true
to write into STDIN_FILENO of a child process
stdin=false
to close STDIN_FILENO inside a child process, default
stdin="devnull"
a child will get /dev/null as STDIN_FILENO
stdout=true
to read STDOUT_FILENO of a child process
stdout=false
to close STDOUT_FILENO inside a child process, default
stdout="devnull"
a child will get /dev/null as STDOUT_FILENO
stderr=true
to read STDERR_FILENO of a child process
stderr=false
to close STDERR_FILENO inside a child process, default
stderr="devnull"
a child will get /dev/null as STDERR_FILENO
shell=true
runs a child process via "sh -c", default
shell=false
invokes a child process executable directly
close_fds=true
close all inherited fds from a parent, default
restore_signals=true
all signals modified by a caller reset
to default handler, default
start_new_session=true
start executable inside a new session, default
```
On success returns popen object handler setting `err` to nil,
otherwise error reported.
__Example 2__
```
ph, err = require('popen').popen({argv = {"/usr/bin/echo", "-n", "hello"},
flags = {stdout=true, shell=false}})
```
`str, err = popen:read([stderr=true|false,timeout])`
----------------------------------------------------
Reads data from `stdout` or `stderr` streams with `timeout`. By default
it reads from `stdout` stream, to read from `stderr` stream set
`stderr=true`.
On success returns string `str` read and `err=nil`, otherwise `err ~= nil`.
__Example 3__
```
ph = require('popen').popen({argv = {"/usr/bin/echo", "-n", "hello"},
flags = {stdout=true, shell=false}})
ph:read()
---
- hello
```
`err = popen:write(str[,timeout])`
----------------------------------
Writes string `str` to `stdin` stream of a child process. Since the internal
buffer on the reader side is limited in size and depends on OS settings the `write`
may hang forever if buffer is full. For this wake `timeout` (float number) parameter
allows to specify number of seconds which once elapsed interrupt `write` attempts
and exit from this function. When not provided the `write` blocks until data is
written or error happened.
On success returns `err = nil`, otherwise `err ~= nil`.
__Example 4__
```
script = "prompt=''; read -n 5 prompt && echo -n $prompt;"
ph = require('popen').posix(script, "rw")
ph:write("12345")
ph:read()
---
- '12345'
```
`err = popen:write2(opts)`
--------------------------
Writes data from a buffer to a stream of a child process. `opts` is
a table of options with the following keys
```
buf buffer with raw data to write
size number of bytes to write
flags dictionary to specify the input stream
stdin=true
to write into stdin stream
timeout write timeout in seconds, optional
```
Basically the `popen:write` is a wrapper over `popen:write2` call
with `opts` similar to `{timeout = -1, {flags = {stdin = true}}`.
On success `err = nil`, otherwise `err ~= nil`.
The reason for passing `{flags = {stdin = true}}` while we have only
one `stdin` is that we reserve the interface for future where we
might extend it without breaking backward compatibility.
`bytes, err = popen:read2(opts)`
--------------------------------
Reads data from a stream of a child process to a buffer. `opts` is
a table of options with the following keys
```
buf destination buffer
size number of bytes to read
flags dictionary to specify the input stream
stdout=true
to read from stdout stream
stderr=true
to read from stderr stream
timeout read timeout in seconds, optional
```
Basically the `popen:read` is a wrapper over `popen:read2` call
with `opts` similar to `{timeout = -1, {flags = {stdout = true}}`.
On success returns number of `bytes` read and `err = nil`,
otherwise `err ~= nil`.
__Example 5__
```
buffer = require('buffer')
popen = require('popen')
ffi = require('ffi')
script = "echo -n 1 2 3 4 5 1>&2"
buf = buffer.ibuf()
ph = popen.posix(script, "rw")
ph:wait()
size = 128
dst = buf:reserve(size)
res, err = ph:read2({buf = dst, size = size, nil, flags = {stderr = true}})
res = buf:alloc(res)
ffi.string(buf.rpos, buf:size())
---
- 1 2 3 4 5
...
buf:recycle()
ph:close()
```
`res, err = popen:terminate()`
-----------------------------
Terminates a child process in a soft way sending `SIGTERM` signal.
On success returns `res = true, err = nil`, `err ~= nil` otherwise.
`res, err = popen:kill()`
-------------------------
Terminates a child process in a soft way sending `SIGKILL` signal.
On success returns `res = true, err = nil`, `err ~= nil` otherwise.
`res, err = popen:send_signal(signo)`
-------------------------------------
Sends signal with number `signo` to a child process.
On success returns `res = true, err = nil`, `err ~= nil`
otherwise.
`info, err = popen:info()`
--------------------------
Returns information about a child process in form of table
with the following keys
```
pid PID of a child process, if already terminated
the it set to -1
flags flags been used to create the popen object; this
is bitmap of popen.c.flag constants
stdout file descriptor number associated with stdout
stream on a parent side, -1 if not set
stderr file descriptor number associated with stderr
stream on a parent side, -1 if not set
stdint file descriptor number associated with stdin
stream on a parent side, -1 if not set
state state of a child proces: "alive" if process
is running, "exited" if finished execution,
"signaled" is terminated by a signal
exit_code if process is in "signaled" state then this
number represent the signal number process
been terminated with, if process is in "exited"
state then it represent the exit code
```
__Example 6__
```
ph = require('popen').posix("echo -n 1 2 3 4 5 1>&2", "r")
ph:info()
---
- stdout: 12
command: sh -c echo -n 1 2 3 4 5 1>&2
stderr: 23
flags: 61510
state: exited
stdin: -1
exit_code: 0
pid: -1
```
`err, state, exit_code = popen:state()`
--------------------------------------
Returns the current state of a chile process.
On success returns `err = nil`, `state` is one of the
constants `popen.c.state.ALIVE=1` when process is running,
`popen.c.state.EXITED=2` when it exited by self or
`popen.c.state.SIGNALED=3` when terminated via signal.
In case if the child process is terminated by a signal
the `exit_code` contains the signal number, otherwise
it is an error code the child set by self.
__Example 7__
```
ph = require('popen').posix("echo -n 1 2 3 4 5 1>&2", "r")
ph:state()
---
- null
- 2
- 0
```
`err, state, exit_code = popen:wait()`
--------------------------------------
Waits until a child process get exited or terminated.
Returns the same data as `popen:state()`. Basically
the `popen:wait()` is simply polling for the child state
with `popen:wait()` in a cycle.
`err = popen:close`
-------------------
Closes popen object releasing all resources occupied.
If a child process is running then it get killed first. Once
popen object is closed it no longed usable and any attempt
to call function over will cause an error.
On success `err = nil`.
Part-of #4031
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
src/CMakeLists.txt | 2 +
src/lua/init.c | 4 +
src/lua/popen.c | 590 +++++++++++++++++++++++++++++++++++++++++++++
src/lua/popen.h | 44 ++++
src/lua/popen.lua | 523 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 1163 insertions(+)
create mode 100644 src/lua/popen.c
create mode 100644 src/lua/popen.h
create mode 100644 src/lua/popen.lua
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e12de6005..e68030c5e 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -38,6 +38,7 @@ lua_source(lua_sources lua/help.lua)
lua_source(lua_sources lua/help_en_US.lua)
lua_source(lua_sources lua/tap.lua)
lua_source(lua_sources lua/fio.lua)
+lua_source(lua_sources lua/popen.lua)
lua_source(lua_sources lua/csv.lua)
lua_source(lua_sources lua/strict.lua)
lua_source(lua_sources lua/clock.lua)
@@ -114,6 +115,7 @@ set (server_sources
lua/socket.c
lua/pickle.c
lua/fio.c
+ lua/popen.c
lua/httpc.c
lua/utf8.c
lua/info.c
diff --git a/src/lua/init.c b/src/lua/init.c
index 097dd8495..09f34d614 100644
--- a/src/lua/init.c
+++ b/src/lua/init.c
@@ -56,6 +56,7 @@
#include "lua/msgpack.h"
#include "lua/pickle.h"
#include "lua/fio.h"
+#include "lua/popen.h"
#include "lua/httpc.h"
#include "lua/utf8.h"
#include "lua/swim.h"
@@ -99,6 +100,7 @@ extern char strict_lua[],
help_en_US_lua[],
tap_lua[],
fio_lua[],
+ popen_lua[],
error_lua[],
argparse_lua[],
iconv_lua[],
@@ -141,6 +143,7 @@ static const char *lua_modules[] = {
"log", log_lua,
"uri", uri_lua,
"fio", fio_lua,
+ "popen", popen_lua,
"error", error_lua,
"csv", csv_lua,
"clock", clock_lua,
@@ -455,6 +458,7 @@ tarantool_lua_init(const char *tarantool_bin, int argc, char **argv)
tarantool_lua_errno_init(L);
tarantool_lua_error_init(L);
tarantool_lua_fio_init(L);
+ tarantool_lua_popen_init(L);
tarantool_lua_socket_init(L);
tarantool_lua_pickle_init(L);
tarantool_lua_digest_init(L);
diff --git a/src/lua/popen.c b/src/lua/popen.c
new file mode 100644
index 000000000..7be3c280a
--- /dev/null
+++ b/src/lua/popen.c
@@ -0,0 +1,590 @@
+/*
+ * Copyright 2010-2019, Tarantool AUTHORS, please see AUTHORS file.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the
+ * following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+#include "diag.h"
+#include "core/popen.h"
+
+#include "lua/utils.h"
+#include "lua/popen.h"
+
+static inline int
+lbox_pushsyserror(struct lua_State *L)
+{
+ diag_set(SystemError, "popen: %s", strerror(errno));
+ return luaT_push_nil_and_error(L);
+}
+
+static inline int
+lbox_push_error(struct lua_State *L)
+{
+ diag_set(SystemError, "popen: %s", strerror(errno));
+ struct error *e = diag_last_error(diag_get());
+ assert(e != NULL);
+ luaT_pusherror(L, e);
+ return 1;
+}
+
+static inline int
+lbox_pushbool(struct lua_State *L, bool res)
+{
+ lua_pushboolean(L, res);
+ if (!res) {
+ lbox_push_error(L);
+ return 2;
+ }
+ return 1;
+}
+
+/**
+ * lbox_fio_popen_new - creates a new popen handle and runs a command inside
+ * @command: a command to run
+ * @flags: popen_flag_bits
+ *
+ * Returns pair @handle = data, @err = nil on success,
+ * @handle = nil, err ~= nil on error.
+ */
+static int
+lbox_popen_new(struct lua_State *L)
+{
+ struct popen_handle *handle;
+ struct popen_opts opts = { };
+ size_t i, argv_size;
+ ssize_t nr_env;
+
+ if (lua_gettop(L) < 1 || !lua_istable(L, 1))
+ luaL_error(L, "Usage: fio.run({opts}])");
+
+ lua_pushstring(L, "argv");
+ lua_gettable(L, -2);
+ if (!lua_istable(L, -1))
+ luaL_error(L, "fio.run: {argv=...} is not a table");
+ lua_pop(L, 1);
+
+ lua_pushstring(L, "flags");
+ lua_gettable(L, -2);
+ if (!lua_isnumber(L, -1))
+ luaL_error(L, "fio.run: {flags=...} is not a number");
+ opts.flags = lua_tonumber(L, -1);
+ lua_pop(L, 1);
+
+ lua_pushstring(L, "argc");
+ lua_gettable(L, -2);
+ if (!lua_isnumber(L, -1))
+ luaL_error(L, "fio.run: {argc=...} is not a number");
+ opts.nr_argv = lua_tonumber(L, -1);
+ lua_pop(L, 1);
+
+ if (opts.nr_argv < 1)
+ luaL_error(L, "fio.run: {argc} is too small");
+
+ /*
+ * argv array should contain NULL element at the
+ * end and probably "sh", "-c" at the start, so
+ * reserve enough space for any flags.
+ */
+ opts.nr_argv += 3;
+ argv_size = sizeof(char *) * opts.nr_argv;
+ opts.argv = malloc(argv_size);
+ if (!opts.argv)
+ luaL_error(L, "fio.run: can't allocate argv");
+
+ lua_pushstring(L, "argv");
+ lua_gettable(L, -2);
+ lua_pushnil(L);
+ for (i = 2; lua_next(L, -2) != 0; i++) {
+ assert(i < opts.nr_argv);
+ opts.argv[i] = (char *)lua_tostring(L, -1);
+ lua_pop(L, 1);
+ }
+ lua_pop(L, 1);
+
+ opts.argv[0] = NULL;
+ opts.argv[1] = NULL;
+ opts.argv[opts.nr_argv - 1] = NULL;
+
+ /*
+ * Environment can be filled, empty
+ * to inherit or contain one NULL to
+ * be zapped.
+ */
+ lua_pushstring(L, "envc");
+ lua_gettable(L, -2);
+ if (!lua_isnumber(L, -1)) {
+ free(opts.argv);
+ luaL_error(L, "fio.run: {envc=...} is not a number");
+ }
+ nr_env = lua_tonumber(L, -1);
+ lua_pop(L, 1);
+
+ if (nr_env >= 0) {
+ /* Should be NULL terminating */
+ opts.env = malloc((nr_env + 1) * sizeof(char *));
+ if (!opts.env) {
+ free(opts.argv);
+ luaL_error(L, "fio.run: can't allocate env");
+ }
+
+ lua_pushstring(L, "env");
+ lua_gettable(L, -2);
+ if (!lua_istable(L, -1)) {
+ free(opts.argv);
+ free(opts.env);
+ luaL_error(L, "fio.run: {env=...} is not a table");
+ }
+ lua_pushnil(L);
+ for (i = 0; lua_next(L, -2) != 0; i++) {
+ assert((ssize_t)i <= nr_env);
+ opts.env[i] = (char *)lua_tostring(L, -1);
+ lua_pop(L, 1);
+ }
+ lua_pop(L, 1);
+
+ opts.env[nr_env] = NULL;
+ } else {
+ /*
+ * Just zap it to nil, the popen will
+ * process inheriting by self.
+ */
+ opts.env = NULL;
+ }
+
+ handle = popen_new(&opts);
+
+ free(opts.argv);
+ free(opts.env);
+
+ if (!handle)
+ return lbox_pushsyserror(L);
+
+ lua_pushlightuserdata(L, handle);
+ return 1;
+}
+
+/**
+ * lbox_fio_popen_kill - kill popen's child process
+ * @handle: a handle carries child process to kill
+ *
+ * Returns true if process is killed and false
+ * otherwise. Note the process is simply signaled
+ * and it doesn't mean it is killed immediately,
+ * Poll lbox_fio_pstatus if need to find out when
+ * exactly the child is reaped out.
+ */
+static int
+lbox_popen_kill(struct lua_State *L)
+{
+ struct popen_handle *p = lua_touserdata(L, 1);
+ return lbox_pushbool(L, popen_send_signal(p, SIGKILL) == 0);
+}
+
+/**
+ * lbox_fio_popen_term - terminate popen's child process
+ * @handle: a handle carries child process to terminate
+ *
+ * Returns true if process is terminated and false
+ * otherwise.
+ */
+static int
+lbox_popen_term(struct lua_State *L)
+{
+ struct popen_handle *p = lua_touserdata(L, 1);
+ return lbox_pushbool(L, popen_send_signal(p, SIGTERM) == 0);
+}
+
+/**
+ * lbox_fio_popen_signal - send signal to a child process
+ * @handle: a handle carries child process to terminate
+ * @signo: signal number to send
+ *
+ * Returns true if signal is sent.
+ */
+static int
+lbox_popen_signal(struct lua_State *L)
+{
+ struct popen_handle *p = lua_touserdata(L, 1);
+ int signo = lua_tonumber(L, 2);
+ return lbox_pushbool(L, popen_send_signal(p, signo) == 0);
+}
+
+/**
+ * lbox_popen_state - fetch popen child process status
+ * @handle: a handle to fetch status from
+ *
+ * Returns @err = nil, @reason = POPEN_STATE_x,
+ * @exit_code = 'number' on success, @err ~= nil on error.
+ */
+static int
+lbox_popen_state(struct lua_State *L)
+{
+ struct popen_handle *p = lua_touserdata(L, 1);
+ int state, exit_code, ret;
+
+ ret = popen_state(p, &state, &exit_code);
+ if (ret < 0)
+ return lbox_push_error(L);
+
+ lua_pushnil(L);
+ lua_pushinteger(L, state);
+ lua_pushinteger(L, exit_code);
+ return 3;
+}
+
+/**
+ * lbox_popen_read - read data from a child peer
+ * @handle: handle of a child process
+ * @buf: destination buffer
+ * @count: number of bytes to read
+ * @flags: which peer to read (stdout,stderr)
+ * @timeout: timeout in seconds; ignored if negative
+ *
+ * Returns @size = 'read bytes', @err = nil on success,
+ * @size = nil, @err ~= nil on error.
+ */
+static int
+lbox_popen_read(struct lua_State *L)
+{
+ struct popen_handle *handle = lua_touserdata(L, 1);
+ uint32_t ctypeid;
+ void *buf = *(char **)luaL_checkcdata(L, 2, &ctypeid);
+ size_t count = lua_tonumber(L, 3);
+ unsigned int flags = lua_tonumber(L, 4);
+ ev_tstamp timeout = lua_tonumber(L, 5);
+ ssize_t ret;
+
+ ret = popen_read_timeout(handle, buf, count,
+ flags, timeout);
+ if (ret < 0)
+ return lbox_pushsyserror(L);
+
+ lua_pushinteger(L, ret);
+ return 1;
+}
+
+/**
+ * lbox_popen_write - write data to a child peer
+ * @handle: a handle of a child process
+ * @buf: source buffer
+ * @count: number of bytes to write
+ * @flags: which peer to write (stdin)
+ * @timeout: timeout in seconds; ignored if negative
+ *
+ * Returns @err = nil on succes, @err ~= nil on error.
+ */
+static int
+lbox_popen_write(struct lua_State *L)
+{
+ struct popen_handle *handle = lua_touserdata(L, 1);
+ void *buf = (void *)lua_tostring(L, 2);
+ uint32_t ctypeid = 0;
+ if (buf == NULL)
+ buf = *(char **)luaL_checkcdata(L, 2, &ctypeid);
+ size_t count = lua_tonumber(L, 3);
+ unsigned int flags = lua_tonumber(L, 4);
+ ev_tstamp timeout = lua_tonumber(L, 5);
+ ssize_t ret;
+
+ ret = popen_write_timeout(handle, buf, count, flags, timeout);
+ if (ret < 0)
+ return lbox_pushsyserror(L);
+ return lbox_pushbool(L, ret == 0);
+}
+
+/**
+ * lbox_popen_info - return information about popen handle
+ * @handle: a handle of a child process
+ *
+ * Returns a @table ~= nil, @err = nil on success,
+ * @table = nil, @err ~= nil on error.
+ */
+static int
+lbox_popen_info(struct lua_State *L)
+{
+ struct popen_handle *handle = lua_touserdata(L, 1);
+ int state, exit_code, ret;
+ struct popen_stat st = { };
+
+ if (popen_stat(handle, &st))
+ return lbox_pushsyserror(L);
+
+ ret = popen_state(handle, &state, &exit_code);
+ if (ret < 0)
+ return lbox_pushsyserror(L);
+
+ assert(state < POPEN_STATE_MAX);
+
+ lua_newtable(L);
+
+ lua_pushliteral(L, "pid");
+ lua_pushinteger(L, st.pid);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "command");
+ lua_pushstring(L, popen_command(handle));
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "flags");
+ lua_pushinteger(L, st.flags);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "state");
+ lua_pushstring(L, popen_state_str(state));
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "exit_code");
+ lua_pushinteger(L, exit_code);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "stdin");
+ lua_pushinteger(L, st.fds[STDIN_FILENO]);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "stdout");
+ lua_pushinteger(L, st.fds[STDOUT_FILENO]);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "stderr");
+ lua_pushinteger(L, st.fds[STDERR_FILENO]);
+ lua_settable(L, -3);
+
+ return 1;
+}
+
+/**
+ * lbox_popen_delete - close a popen handle
+ * @handle: a handle to close
+ *
+ * If there is a running child it get killed first.
+ *
+ * Returns true if a handle is closeed, false otherwise.
+ */
+static int
+lbox_popen_delete(struct lua_State *L)
+{
+ void *handle = lua_touserdata(L, 1);
+ return lbox_pushbool(L, popen_delete(handle) == 0);
+}
+
+/**
+ * tarantool_lua_popen_init - Create popen methods
+ */
+void
+tarantool_lua_popen_init(struct lua_State *L)
+{
+ static const struct luaL_Reg popen_methods[] = {
+ { },
+ };
+
+ /* public methods */
+ luaL_register_module(L, "popen", popen_methods);
+
+ static const struct luaL_Reg builtin_methods[] = {
+ { "new", lbox_popen_new, },
+ { "delete", lbox_popen_delete, },
+ { "kill", lbox_popen_kill, },
+ { "term", lbox_popen_term, },
+ { "signal", lbox_popen_signal, },
+ { "state", lbox_popen_state, },
+ { "read", lbox_popen_read, },
+ { "write", lbox_popen_write, },
+ { "info", lbox_popen_info, },
+ { },
+ };
+
+ /* builtin methods */
+ lua_pushliteral(L, "builtin");
+ lua_newtable(L);
+
+ luaL_register(L, NULL, builtin_methods);
+ lua_settable(L, -3);
+
+ /*
+ * Popen constants.
+ */
+#define lua_gen_const(_n, _v) \
+ lua_pushliteral(L, _n); \
+ lua_pushinteger(L, _v); \
+ lua_settable(L, -3)
+
+ lua_pushliteral(L, "c");
+ lua_newtable(L);
+
+ /*
+ * Flag masks.
+ */
+ lua_pushliteral(L, "flag");
+ lua_newtable(L);
+
+ lua_gen_const("NONE", POPEN_FLAG_NONE);
+
+ lua_gen_const("STDIN", POPEN_FLAG_FD_STDIN);
+ lua_gen_const("STDOUT", POPEN_FLAG_FD_STDOUT);
+ lua_gen_const("STDERR", POPEN_FLAG_FD_STDERR);
+
+ lua_gen_const("STDIN_DEVNULL", POPEN_FLAG_FD_STDIN_DEVNULL);
+ lua_gen_const("STDOUT_DEVNULL", POPEN_FLAG_FD_STDOUT_DEVNULL);
+ lua_gen_const("STDERR_DEVNULL", POPEN_FLAG_FD_STDERR_DEVNULL);
+
+ lua_gen_const("STDIN_CLOSE", POPEN_FLAG_FD_STDIN_CLOSE);
+ lua_gen_const("STDOUT_CLOSE", POPEN_FLAG_FD_STDOUT_CLOSE);
+ lua_gen_const("STDERR_CLOSE", POPEN_FLAG_FD_STDERR_CLOSE);
+
+ lua_gen_const("SHELL", POPEN_FLAG_SHELL);
+ lua_gen_const("SETSID", POPEN_FLAGS_SETSID);
+ lua_gen_const("CLOSE_FDS", POPEN_FLAG_CLOSE_FDS);
+ lua_gen_const("RESTORE_SIGNALS", POPEN_FLAGS_RESTORE_SIGNALS);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "state");
+ lua_newtable(L);
+
+ lua_gen_const("ALIVE", POPEN_STATE_ALIVE);
+ lua_gen_const("EXITED", POPEN_STATE_EXITED);
+ lua_gen_const("SIGNALED", POPEN_STATE_SIGNALED);
+ lua_settable(L, -3);
+
+ lua_pushliteral(L, "signal");
+ lua_newtable(L);
+#define lua_gen_signal(_signo) \
+ lua_gen_const(#_signo, _signo)
+
+#ifdef SIGHUP
+ lua_gen_signal(SIGHUP);
+#endif
+#ifdef SIGINT
+ lua_gen_signal(SIGINT);
+#endif
+#ifdef SIGQUIT
+ lua_gen_signal(SIGQUIT);
+#endif
+#ifdef SIGILL
+ lua_gen_signal(SIGILL);
+#endif
+#ifdef SIGTRAP
+ lua_gen_signal(SIGTRAP);
+#endif
+#ifdef SIGABRT
+ lua_gen_signal(SIGABRT);
+#endif
+#ifdef SIGIOT
+ lua_gen_signal(SIGIOT);
+#endif
+#ifdef SIGBUS
+ lua_gen_signal(SIGBUS);
+#endif
+#ifdef SIGFPE
+ lua_gen_signal(SIGFPE);
+#endif
+#ifdef SIGKILL
+ lua_gen_signal(SIGKILL);
+#endif
+#ifdef SIGUSR1
+ lua_gen_signal(SIGUSR1);
+#endif
+#ifdef SIGSEGV
+ lua_gen_signal(SIGSEGV);
+#endif
+#ifdef SIGUSR2
+ lua_gen_signal(SIGUSR2);
+#endif
+#ifdef SIGPIPE
+ lua_gen_signal(SIGPIPE);
+#endif
+#ifdef SIGALRM
+ lua_gen_signal(SIGALRM);
+#endif
+#ifdef SIGTERM
+ lua_gen_signal(SIGTERM);
+#endif
+#ifdef SIGSTKFLT
+ lua_gen_signal(SIGSTKFLT);
+#endif
+#ifdef SIGCHLD
+ lua_gen_signal(SIGCHLD);
+#endif
+#ifdef SIGCONT
+ lua_gen_signal(SIGCONT);
+#endif
+#ifdef SIGSTOP
+ lua_gen_signal(SIGSTOP);
+#endif
+#ifdef SIGTSTP
+ lua_gen_signal(SIGTSTP);
+#endif
+#ifdef SIGTTIN
+ lua_gen_signal(SIGTTIN);
+#endif
+#ifdef SIGTTOU
+ lua_gen_signal(SIGTTOU);
+#endif
+#ifdef SIGURG
+ lua_gen_signal(SIGURG);
+#endif
+#ifdef SIGXCPU
+ lua_gen_signal(SIGXCPU);
+#endif
+#ifdef SIGXFSZ
+ lua_gen_signal(SIGXFSZ);
+#endif
+#ifdef SIGVTALRM
+ lua_gen_signal(SIGVTALRM);
+#endif
+#ifdef SIGPROF
+ lua_gen_signal(SIGPROF);
+#endif
+#ifdef SIGWINCH
+ lua_gen_signal(SIGWINCH);
+#endif
+#ifdef SIGIO
+ lua_gen_signal(SIGIO);
+#endif
+#ifdef SIGPOLL
+ lua_gen_signal(SIGPOLL);
+#endif
+#ifdef SIGPWR
+ lua_gen_signal(SIGPWR);
+#endif
+#ifdef SIGSYS
+ lua_gen_signal(SIGSYS);
+#endif
+#undef lua_gen_signal
+ lua_settable(L, -3);
+
+#undef lua_gen_const
+
+ lua_settable(L, -3);
+ lua_pop(L, 1);
+}
diff --git a/src/lua/popen.h b/src/lua/popen.h
new file mode 100644
index 000000000..4e3f137c5
--- /dev/null
+++ b/src/lua/popen.h
@@ -0,0 +1,44 @@
+#ifndef INCLUDES_TARANTOOL_LUA_POPEN_H
+#define INCLUDES_TARANTOOL_LUA_POPEN_H
+/*
+ * Copyright 2010-2019, Tarantool AUTHORS, please see AUTHORS file.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the
+ * following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#if defined(__cplusplus)
+extern "C" {
+#endif /* defined(__cplusplus) */
+
+struct lua_State;
+void tarantool_lua_popen_init(struct lua_State *L);
+
+#if defined(__cplusplus)
+} /* extern "C" */
+#endif /* defined(__cplusplus) */
+
+#endif /* INCLUDES_TARANTOOL_LUA_POPEN_H */
diff --git a/src/lua/popen.lua b/src/lua/popen.lua
new file mode 100644
index 000000000..2186e252a
--- /dev/null
+++ b/src/lua/popen.lua
@@ -0,0 +1,523 @@
+-- popen.lua (builtin file)
+--
+-- vim: ts=4 sw=4 et
+
+local buffer = require('buffer')
+local popen = require('popen')
+local fiber = require('fiber')
+local ffi = require('ffi')
+local bit = require('bit')
+
+local const_char_ptr_t = ffi.typeof('const char *')
+
+local builtin = popen.builtin
+popen.builtin = nil
+
+local popen_methods = { }
+
+local function default_flags()
+ local flags = popen.c.flag.NONE
+
+ -- default flags: close everything and use shell
+ flags = bit.bor(flags, popen.c.flag.STDIN_CLOSE)
+ flags = bit.bor(flags, popen.c.flag.STDOUT_CLOSE)
+ flags = bit.bor(flags, popen.c.flag.STDERR_CLOSE)
+ flags = bit.bor(flags, popen.c.flag.SHELL)
+ flags = bit.bor(flags, popen.c.flag.SETSID)
+ flags = bit.bor(flags, popen.c.flag.CLOSE_FDS)
+ flags = bit.bor(flags, popen.c.flag.RESTORE_SIGNALS)
+
+ return flags
+end
+
+--
+-- A map for popen option keys into tfn ('true|false|nil') values
+-- where bits are just set without additional manipulations.
+--
+-- For example stdin=true means to open stdin end for write,
+-- stdin=false to close the end, finally stdin[=nil] means to
+-- provide /dev/null into a child peer.
+local flags_map_tfn = {
+ stdin = {
+ popen.c.flag.STDIN,
+ popen.c.flag.STDIN_CLOSE,
+ popen.c.flag.STDIN_DEVNULL,
+ },
+ stdout = {
+ popen.c.flag.STDOUT,
+ popen.c.flag.STDOUT_CLOSE,
+ popen.c.flag.STDOUT_DEVNULL,
+ },
+ stderr = {
+ popen.c.flag.STDERR,
+ popen.c.flag.STDERR_CLOSE,
+ popen.c.flag.STDERR_DEVNULL,
+ },
+}
+
+--
+-- A map for popen option keys into tf ('true|false') values
+-- where bits are set on 'true' and clear on 'false'.
+local flags_map_tf = {
+ shell = {
+ popen.c.flag.SHELL,
+ },
+ close_fds = {
+ popen.c.flag.CLOSE_FDS
+ },
+ restore_signals = {
+ popen.c.flag.RESTORE_SIGNALS
+ },
+ start_new_session = {
+ popen.c.flag.SETSID
+ },
+}
+
+--
+-- Parses flags options from flags_map_tfn and
+-- flags_map_tf tables.
+local function parse_flags(epfx, flags, opts)
+ if opts == nil then
+ return flags
+ end
+ for k,v in pairs(opts) do
+ if flags_map_tfn[k] == nil then
+ if flags_map_tf[k] == nil then
+ error(string.format("%s: Unknown key %s", epfx, k))
+ end
+ if v == true then
+ flags = bit.bor(flags, flags_map_tf[k][1])
+ elseif v == false then
+ flags = bit.band(flags, bit.bnot(flags_map_tf[k][1]))
+ else
+ error(string.format("%s: Unknown value %s", epfx, v))
+ end
+ else
+ if v == true then
+ flags = bit.band(flags, bit.bnot(flags_map_tfn[k][2]))
+ flags = bit.band(flags, bit.bnot(flags_map_tfn[k][3]))
+ flags = bit.bor(flags, flags_map_tfn[k][1])
+ elseif v == false then
+ flags = bit.band(flags, bit.bnot(flags_map_tfn[k][1]))
+ flags = bit.band(flags, bit.bnot(flags_map_tfn[k][3]))
+ flags = bit.bor(flags, flags_map_tfn[k][2])
+ elseif v == "devnull" then
+ flags = bit.band(flags, bit.bnot(flags_map_tfn[k][1]))
+ flags = bit.band(flags, bit.bnot(flags_map_tfn[k][2]))
+ flags = bit.bor(flags, flags_map_tfn[k][3])
+ else
+ error(string.format("%s: Unknown value %s", epfx, v))
+ end
+ end
+ end
+ return flags
+end
+
+--
+-- Parse "mode" string to flags
+local function parse_mode(epfx, flags, mode)
+ if mode == nil then
+ return flags
+ end
+ for i = 1, #mode do
+ local c = mode:sub(i, i)
+ if c == 'r' then
+ flags = bit.band(flags, bit.bnot(popen.c.flag.STDOUT_CLOSE))
+ flags = bit.bor(flags, popen.c.flag.STDOUT)
+ flags = bit.band(flags, bit.bnot(popen.c.flag.STDERR_CLOSE))
+ flags = bit.bor(flags, popen.c.flag.STDERR)
+ elseif c == 'w' then
+ flags = bit.band(flags, bit.bnot(popen.c.flag.STDIN_CLOSE))
+ flags = bit.bor(flags, popen.c.flag.STDIN)
+ else
+ error(string.format("%s: Unknown mode %s", epfx, c))
+ end
+ end
+ return flags
+end
+
+--
+-- Close a popen object and release all resources.
+-- In case if there is a running child process
+-- it will be killed.
+--
+-- Returns @ret = true if popen object is closed, and
+-- @ret = false, @err ~= nil on error.
+popen_methods.close = function(self)
+ local ret, err = builtin.delete(self.cdata)
+ if err ~= nil then
+ return false, err
+ end
+ self.cdata = nil
+ return true
+end
+
+--
+-- Kill a child process
+--
+-- Returns @ret = true on success,
+-- @ret = false, @err ~= nil on error.
+popen_methods.kill = function(self)
+ return builtin.kill(self.cdata)
+end
+
+--
+-- Terminate a child process
+--
+-- Returns @ret = true on success,
+-- @ret = false, @err ~= nil on error.
+popen_methods.terminate = function(self)
+ return builtin.term(self.cdata)
+end
+
+--
+-- Send signal with number @signo to a child process
+--
+-- Returns @ret = true on success,
+-- @ret = false, @err ~= nil on error.
+popen_methods.send_signal = function(self, signo)
+ return builtin.signal(self.cdata, signo)
+end
+
+--
+-- Fetch a child process state
+--
+-- Returns @err = nil, @state = popen.c.state, @exit_code = num,
+-- otherwise @err ~= nil.
+popen_methods.state = function(self)
+ return builtin.state(self.cdata)
+end
+
+--
+-- Wait until a child process get exited.
+--
+-- Returns the same as popen_methods.status.
+popen_methods.wait = function(self)
+ local err, state, code
+ while true do
+ err, state, code = builtin.state(self.cdata)
+ if err or state ~= popen.c.state.ALIVE then
+ break
+ end
+ fiber.sleep(self.wait_secs)
+ end
+ return err, state, code
+end
+
+--
+-- popen:read2 - read a stream of a child process
+-- @opts: options table
+--
+-- The options should have the following keys
+--
+-- @buf: const_char_ptr_t buffer
+-- @size: size of the buffer
+-- @flags: stdout=true or stderr=true
+-- @timeout: read timeout in seconds, < 0 to ignore
+--
+-- Returns @res = bytes, err = nil in case if read processed
+-- without errors, @res = nil, @err ~= nil otherwise.
+popen_methods.read2 = function(self, opts)
+ local flags = parse_flags("popen:read2",
+ popen.c.flag.NONE,
+ opts['flags'])
+ local timeout = -1
+
+ if opts['buf'] == nil then
+ error("popen:read2 {'buf'} key is missed")
+ elseif opts['size'] == nil then
+ error("popen:read2 {'size'} key is missed")
+ elseif opts['timeout'] ~= nil then
+ timeout = tonumber(opts['timeout'])
+ end
+
+ return builtin.read(self.cdata, opts['buf'],
+ tonumber(opts['size']),
+ flags, timeout)
+end
+
+--
+-- popen:write2 - write to a child's streem
+-- @opts: options table
+--
+-- The options should have the following keys
+--
+-- @buf: const_char_ptr_t buffer
+-- @size: size of the buffer
+-- @flags: stdin=true
+-- @timeout: write timeout in seconds, < 0 to ignore
+--
+-- Returns @err = nil on success, @err ~= nil otherwise.
+popen_methods.write2 = function(self, opts)
+ local flags = parse_flags("popen:write2",
+ popen.c.flag.NONE,
+ opts['flags'])
+ local timeout = -1
+
+ if opts['buf'] == nil then
+ error("popen:write2 {'buf'} key is missed")
+ elseif opts['size'] == nil then
+ error("popen:write2 {'size'} key is missed")
+ elseif opts['timeout'] ~= nil then
+ timeout = tonumber(opts['timeout'])
+ end
+
+ return builtin.write(self.cdata, opts['buf'],
+ tonumber(opts['size']),
+ flags, timeout)
+end
+
+--
+-- popen:read - read string from a stream
+-- @stderr: set to true to read from stderr, optional
+-- @timeout: timeout in seconds, optional
+--
+-- Returns a result string, or res = nil, @err ~= nil on error.
+popen_methods.read = function(self, stderr, timeout)
+ local ibuf = buffer.ibuf()
+ local buf = ibuf:reserve(self.read_size)
+ local flags
+
+ if stderr ~= nil then
+ flags = { stderr = true }
+ else
+ flags = { stdout = true }
+ end
+
+ if timeout == nil then
+ timeout = -1
+ end
+
+ local res, err = self:read2({
+ buf = buf,
+ size = self.read_size,
+ flags = flags,
+ timeout = timeout,
+ })
+
+ if err ~= nil then
+ ibuf:recycle()
+ return nil, err
+ end
+
+ ibuf:alloc(res)
+ res = ffi.string(ibuf.rpos, ibuf:size())
+ ibuf:recycle()
+
+ return res
+end
+
+--
+-- popen:write - write string @str to stdin stream
+-- @str: string to write
+-- @timeout: timeout in seconds, optional
+--
+-- Returns @err = nil on success, @err ~= nil on error.
+popen_methods.write = function(self, str, timeout)
+ if timeout == nil then
+ timeout = -1
+ end
+ return self:write2({
+ buf = str,
+ size = #str,
+ flags = { stdin = true },
+ timeout = timeout,
+ })
+end
+
+--
+-- popen:info -- obtain information about a popen object
+--
+-- Returns @info table, err == nil on success,
+-- @info = nil, @err ~= nil otherwise.
+--
+-- The @info table contains the following keys:
+--
+-- @pid: pid of a child process
+-- @flags: flags associated (popen.c.flag bitmap)
+-- @stdout: parent peer for stdout, -1 if closed
+-- @stderr: parent peer for stderr, -1 if closed
+-- @stdin: parent peer for stdin, -1 if closed
+-- @state: alive | exited | signaled
+-- @exit_code: exit code of a child process if been
+-- exited or killed by a signal
+--
+-- The child should never be in "unknown" state, reserved
+-- for unexpected errors.
+--
+popen_methods.info = function(self)
+ return builtin.info(self.cdata)
+end
+
+--
+-- Create a new popen object from options
+--
+-- Returns ret ~= nil, err = nil on success,
+-- ret = nil, err ~= nil on failure.
+local function popen_reify(opts)
+ local cdata, err = builtin.new(opts)
+ if err ~= nil then
+ return nil, err
+ end
+
+ local handle = {
+ -- a handle itself for future use
+ cdata = cdata,
+
+ -- sleeping period for the @wait method
+ wait_secs = 0.3,
+
+ -- size of a read buffer to allocate
+ -- in case of implicit read, this number
+ -- is taken from luatest repo to fit the
+ -- value people are familiar with
+ read_size = 4096,
+ }
+
+ setmetatable(handle, {
+ __index = popen_methods,
+ })
+
+ return handle
+end
+
+--
+-- popen.posix - create a new child process and execute a command inside
+-- @command: a command to run
+-- @mode: r - to grab child's stdout for read
+-- (stderr kept opened as well for 2>&1 redirection)
+-- w - to obtain stdin for write
+--
+-- Returns handle ~= nil, err = nil on success, err ~= nil otherwise.
+--
+-- Note: Since there are two options only the following parameters
+-- are implied (see default_flags): all fds except stdin/out/err
+-- are closed, signals are restored to default handlers, the command
+-- is executed in a new session.
+--
+-- Examples:
+--
+-- ph = require('popen').posix("date", "r")
+-- runs date as "sh -c date" to read the output,
+-- closing all file descriptors except stdout/err
+-- inside a child process
+--
+popen.posix = function(command, mode)
+ local flags = default_flags()
+
+ if type(command) ~= 'string' then
+ error("Usage: popen.posix(command[, rw])")
+ end
+
+ -- Mode gives simplified flags
+ flags = parse_mode("popen.posix", flags, mode)
+
+ local opts = {
+ argv = { command },
+ argc = 1,
+ flags = flags,
+ envc = -1,
+ }
+
+ return popen_reify(opts)
+end
+
+-- popen.popen - execute a child program in a new process
+-- @opt: options table
+--
+-- @opts carries of the following options:
+--
+-- @argv: an array of a program to run with
+-- command line options, mandatory
+--
+-- @env: an array of environment variables to
+-- be used inside a process, if not
+-- set then the current environment is
+-- inherited, if set to an empty array
+-- then the environment will be dropped
+--
+-- @flags: a dictionary to describe communication pipes
+-- and other parameters of a process to run
+--
+-- stdin=true to write into STDIN_FILENO of a child process
+-- stdin=false to close STDIN_FILENO inside a child process [*]
+-- stdin="devnull" a child will get /dev/null as STDIN_FILENO
+--
+-- stdout=true to read STDOUT_FILENO of a child process
+-- stdout=false to close STDOUT_FILENO inside a child process [*]
+-- stdout="devnull" a child will get /dev/null as STDOUT_FILENO
+--
+-- stderr=true to read STDERR_FILENO from a child process
+-- stderr=false to close STDERR_FILENO inside a child process [*]
+-- stderr="devnull" a child will get /dev/null as STDERR_FILENO
+--
+-- shell=true runs a child process via "sh -c" [*]
+-- shell=false invokes a child process executable directly
+--
+-- close_fds=true close all inherited fds from a parent [*]
+--
+-- restore_signals=true
+-- all signals modified by a caller reset
+-- to default handler [*]
+--
+-- start_new_session=true
+-- start executable inside a new session [*]
+--
+-- [*] are default values
+--
+-- Returns handle ~= nil, err = nil on success, err ~= nil otherwise.
+--
+-- Examples:
+--
+-- ph = require('popen').popen({argv = {"date"}, flags = {stdout=true}})
+-- ph:read()
+-- ph:close()
+--
+-- Execute 'date' command inside a shell, read the result
+-- and close the popen object
+--
+-- ph = require('popen').popen({argv = {"/usr/bin/echo", "-n", "hello"},
+-- flags = {stdout=true, shell=false}})
+-- ph:read()
+-- ph:close()
+--
+-- Execute /usr/bin/echo with arguments '-n','hello' directly
+-- without using a shell, read the result from stdout and close
+-- the popen object
+--
+popen.popen = function(opts)
+ local flags = default_flags()
+
+ if opts == nil or type(opts) ~= 'table' then
+ error("Usage: popen({argv={}[, envp={}, flags={}]")
+ end
+
+ -- Test for required arguments
+ if opts["argv"] == nil then
+ error("popen: argv key is missing")
+ end
+
+ -- Process flags and save updated mask
+ -- to pass into engine (in case of missing
+ -- flags we just use defaults).
+ if opts["flags"] ~= nil then
+ flags = parse_flags("popen", flags, opts["flags"])
+ end
+ opts["flags"] = flags
+
+ -- We will need a number of args for speed sake
+ opts["argc"] = #opts["argv"]
+
+ -- Same applies to the environment (note though
+ -- that env={} is pretty valid and env=nil
+ -- as well.
+ if opts["env"] ~= nil then
+ opts["envc"] = #opts["env"]
+ else
+ opts["envc"] = -1
+ end
+
+ return popen_reify(opts)
+end
+
+return popen
--
2.20.1
^ permalink raw reply [flat|nested] 5+ messages in thread