/*
* Copyright (C) Igor Sysoev
* Copyright (C) NGINX, Inc.
*/
#include <nxt_main.h>
#include <nxt_main_process.h>
#if (NXT_HAVE_CLONE)
#include <nxt_clone.h>
#endif
#include <signal.h>
static void nxt_process_start(nxt_task_t *task, nxt_process_t *process);
static nxt_int_t nxt_process_worker_setup(nxt_task_t *task,
nxt_process_t *process, int parentfd);
/* A cached process pid. */
nxt_pid_t nxt_pid;
/* An original parent process pid. */
nxt_pid_t nxt_ppid;
/* A cached process effective uid */
nxt_uid_t nxt_euid;
/* A cached process effective gid */
nxt_gid_t nxt_egid;
nxt_bool_t nxt_proc_conn_matrix[NXT_PROCESS_MAX][NXT_PROCESS_MAX] = {
{ 1, 1, 1, 1, 1 },
{ 1, 0, 0, 0, 0 },
{ 1, 0, 0, 1, 0 },
{ 1, 0, 1, 0, 1 },
{ 1, 0, 0, 0, 0 },
};
nxt_bool_t nxt_proc_remove_notify_matrix[NXT_PROCESS_MAX][NXT_PROCESS_MAX] = {
{ 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0 },
{ 0, 0, 0, 1, 0 },
{ 0, 0, 1, 0, 1 },
{ 0, 0, 0, 1, 0 },
};
static nxt_int_t
nxt_process_worker_setup(nxt_task_t *task, nxt_process_t *process, int parentfd)
{
pid_t rpid, pid;
ssize_t n;
nxt_int_t parent_status;
nxt_process_t *p;
nxt_runtime_t *rt;
nxt_process_init_t *init;
nxt_process_type_t ptype;
pid = getpid();
rpid = 0;
rt = task->thread->runtime;
init = process->init;
/* Setup the worker process. */
n = read(parentfd, &rpid, sizeof(rpid));
if (nxt_slow_path(n == -1 || n != sizeof(rpid))) {
nxt_alert(task, "failed to read real pid");
return NXT_ERROR;
}
if (nxt_slow_path(rpid == 0)) {
nxt_alert(task, "failed to get real pid from parent");
return NXT_ERROR;
}
nxt_pid = rpid;
/* Clean inherited cached thread tid. */
task->thread->tid = 0;
process->pid = nxt_pid;
if (nxt_pid != pid) {
nxt_debug(task, "app \"%s\" real pid %d", init->name, nxt_pid);
nxt_debug(task, "app \"%s\" isolated pid: %d", init->name, pid);
}
n = read(parentfd, &parent_status, sizeof(parent_status));
if (nxt_slow_path(n == -1 || n != sizeof(parent_status))) {
nxt_alert(task, "failed to read parent status");
return NXT_ERROR;
}
if (nxt_slow_path(parent_status != NXT_OK)) {
return parent_status;
}
ptype = init->type;
nxt_port_reset_next_id();
nxt_event_engine_thread_adopt(task->thread->engine);
/* Remove not ready processes. */
nxt_runtime_process_each(rt, p) {
if (nxt_proc_conn_matrix[ptype][nxt_process_type(p)] == 0) {
nxt_debug(task, "remove not required process %PI", p->pid);
nxt_process_close_ports(task, p);
continue;
}
if (!p->ready) {
nxt_debug(task, "remove not ready process %PI", p->pid);
nxt_process_close_ports(task, p);
continue;
}
nxt_port_mmaps_destroy(&p->incoming, 0);
nxt_port_mmaps_destroy(&p->outgoing, 0);
} nxt_runtime_process_loop;
nxt_runtime_process_add(task, process);
nxt_process_start(task, process);
process->ready = 1;
return NXT_OK;
}
nxt_pid_t
nxt_process_create(nxt_task_t *task, nxt_process_t *process)
{
int pipefd[2];
nxt_int_t ret;
nxt_pid_t pid;
nxt_process_init_t *init;
if (nxt_slow_path(pipe(pipefd) == -1)) {
nxt_alert(task, "failed to create process pipe for passing rpid");
return -1;
}
init = process->init;
#if (NXT_HAVE_CLONE)
pid = nxt_clone(SIGCHLD | init->isolation.clone.flags);
if (nxt_slow_path(pid < 0)) {
nxt_alert(task, "clone() failed while creating \"%s\" %E",
init->name, nxt_errno);
goto cleanup;
}
#else
pid = fork();
if (nxt_slow_path(pid < 0)) {
nxt_alert(task, "fork() failed while creating \"%s\" %E",
init->name, nxt_errno);
goto cleanup;
}
#endif
if (pid == 0) {
/* Child. */
if (nxt_slow_path(close(pipefd[1]) == -1)) {
nxt_alert(task, "failed to close writer pipe fd");
}
ret = nxt_process_worker_setup(task, process, pipefd[0]);
if (nxt_slow_path(ret != NXT_OK)) {
exit(1);
}
if (nxt_slow_path(close(pipefd[0]) == -1)) {
nxt_alert(task, "failed to close writer pipe fd");
}
/*
* Explicitly return 0 to notice the caller function this is the child.
* The caller must return to the event engine work queue loop.
*/
return 0;
}
/* Parent. */
/*
* At this point, the child process is blocked reading the
* pipe fd to get its real pid (rpid).
*
* If anything goes wrong now, we need to terminate the child
* process by sending a NXT_ERROR in the pipe.
*/
#if (NXT_HAVE_CLONE)
nxt_debug(task, "clone(\"%s\"): %PI", init->name, pid);
#else
nxt_debug(task, "fork(\"%s\"): %PI", init->name, pid);
#endif
if (nxt_slow_path(write(pipefd[1], &pid, sizeof(pid)) == -1)) {
nxt_alert(task, "failed to write real pid");
goto fail;
}
#if (NXT_HAVE_CLONE && NXT_HAVE_CLONE_NEWUSER)
if (NXT_CLONE_USER(init->isolation.clone.flags)) {
ret = nxt_clone_credential_map(task, pid, init->user_cred,
&init->isolation.clone);
if (nxt_slow_path(ret != NXT_OK)) {
goto fail;
}
}
#endif
ret = NXT_OK;
if (nxt_slow_path(write(pipefd[1], &ret, sizeof(ret)) == -1)) {
nxt_alert(task, "failed to write status");
goto fail;
}
process->pid = pid;
nxt_runtime_process_add(task, process);
goto cleanup;
fail:
ret = NXT_ERROR;
if (nxt_slow_path(write(pipefd[1], &ret, sizeof(ret)) == -1)) {
nxt_alert(task, "failed to write status");
}
waitpid(pid, NULL, 0);
pid = -1;
cleanup:
if (nxt_slow_path(close(pipefd[0]) != 0)) {
nxt_alert(task, "failed to close pipe: %E", nxt_errno);
}
if (nxt_slow_path(close(pipefd[1]) != 0)) {
nxt_alert(task, "failed to close pipe: %E", nxt_errno);
}
return pid;
}
static void
nxt_process_start(nxt_task_t *task, nxt_process_t *process)
{
nxt_int_t ret, cap_setid;
nxt_port_t *port, *main_port;
nxt_thread_t *thread;
nxt_runtime_t *rt;
nxt_process_init_t *init;
nxt_event_engine_t *engine;
const nxt_event_interface_t *interface;
init = process->init;
nxt_log(task, NXT_LOG_INFO, "%s started", init->name);
nxt_process_title(task, "unit: %s", init->name);
thread = task->thread;
rt = thread->runtime;
nxt_random_init(&thread->random);
cap_setid = rt->capabilities.setid;
#if (NXT_HAVE_CLONE_NEWUSER)
if (!cap_setid && NXT_CLONE_USER(init->isolation.clone.flags)) {
cap_setid = 1;
}
#endif
if (cap_setid) {
ret = nxt_credential_setgids(task, init->user_cred);
if (nxt_slow_path(ret != NXT_OK)) {
goto fail;
}
ret = nxt_credential_setuid(task, init->user_cred);
if (nxt_slow_path(ret != NXT_OK)) {
goto fail;
}
}
rt->type = init->type;
engine = thread->engine;
/* Update inherited main process event engine and signals processing. */
engine->signals->sigev = init->signals;
interface = nxt_service_get(rt->services, "engine", rt->engine);
if (nxt_slow_path(interface == NULL)) {
goto fail;
}
if (nxt_event_engine_change(engine, interface, rt->batch) != NXT_OK) {
goto fail;
}
ret = nxt_runtime_thread_pool_create(thread, rt, rt->auxiliary_threads,
60000 * 1000000LL);
if (nxt_slow_path(ret != NXT_OK)) {
goto fail;
}
main_port = rt->port_by_type[NXT_PROCESS_MAIN];
nxt_port_read_close(main_port);
nxt_port_write_enable(task, main_port);
port = nxt_process_port_first(process);
nxt_port_write_close(port);
ret = init->start(task, init->data);
if (nxt_slow_path(ret != NXT_OK)) {
goto fail;
}
nxt_port_enable(task, port, init->port_handlers);
ret = nxt_port_socket_write(task, main_port, NXT_PORT_MSG_PROCESS_READY,
-1, init->stream, 0, NULL);
if (nxt_slow_path(ret != NXT_OK)) {
nxt_log(task, NXT_LOG_ERR, "failed to send READY message to main");
goto fail;
}
return;
fail:
exit(1);
}
#if (NXT_HAVE_POSIX_SPAWN)
/*
* Linux glibc 2.2 posix_spawn() is implemented via fork()/execve().
* Linux glibc 2.4 posix_spawn() without file actions and spawn
* attributes uses vfork()/execve().
*
* On FreeBSD 8.0 posix_spawn() is implemented via vfork()/execve().
*
* Solaris 10:
* In the Solaris 10 OS, posix_spawn() is currently implemented using
* private-to-libc vfork(), execve(), and exit() functions. They are
* identical to regular vfork(), execve(), and exit() in functionality,
* but they are not exported from libc and therefore don't cause the
* deadlock-in-the-dynamic-linker problem that any multithreaded code
* outside of libc that calls vfork() can cause.
*
* On MacOSX 10.5 (Leoprad) and NetBSD 6.0 posix_spawn() is implemented
* as syscall.
*/
nxt_pid_t
nxt_process_execute(nxt_task_t *task, char *name, char **argv, char **envp)
{
nxt_pid_t pid;
nxt_debug(task, "posix_spawn(\"%s\")", name);
if (posix_spawn(&pid, name, NULL, NULL, argv, envp) != 0) {
nxt_alert(task, "posix_spawn(\"%s\") failed %E", name, nxt_errno);
return -1;
}
return pid;
}
#else
nxt_pid_t
nxt_process_execute(nxt_task_t *task, char *name, char **argv, char **envp)
{
nxt_pid_t pid;
/*
* vfork() is better than fork() because:
* it is faster several times;
* its execution time does not depend on private memory mapping size;
* it has lesser chances to fail due to the ENOMEM error.
*/
pid = vfork();
switch (pid) {
case -1:
nxt_alert(task, "vfork() failed while executing \"%s\" %E",
name, nxt_errno);
break;
case 0:
/* A child. */
nxt_debug(task, "execve(\"%s\")", name);
(void) execve(name, argv, envp);
nxt_alert(task, "execve(\"%s\") failed %E", name, nxt_errno);
exit(1);
nxt_unreachable();
break;
default:
/* A parent. */
nxt_debug(task, "vfork(): %PI", pid);
break;
}
return pid;
}
#endif
nxt_int_t
nxt_process_daemon(nxt_task_t *task)
{
nxt_fd_t fd;
nxt_pid_t pid;
const char *msg;
fd = -1;
/*
* fork() followed by a parent process's exit() detaches a child process
* from an init script or terminal shell process which has started the
* parent process and allows the child process to run in background.
*/
pid = fork();
switch (pid) {
case -1:
msg = "fork() failed %E";
goto fail;
case 0:
/* A child. */
break;
default:
/* A parent. */
nxt_debug(task, "fork(): %PI", pid);
exit(0);
nxt_unreachable();
}
nxt_pid = getpid();
/* Clean inherited cached thread tid. */
task->thread->tid = 0;
nxt_debug(task, "daemon");
/* Detach from controlling terminal. */
if (setsid() == -1) {
nxt_alert(task, "setsid() failed %E", nxt_errno);
return NXT_ERROR;
}
/*
* Reset file mode creation mask: any access
* rights can be set on file creation.
*/
umask(0);
/* Redirect STDIN and STDOUT to the "/dev/null". */
fd = open("/dev/null", O_RDWR);
if (fd == -1) {
msg = "open(\"/dev/null\") failed %E";
goto fail;
}
if (dup2(fd, STDIN_FILENO) == -1) {
msg = "dup2(\"/dev/null\", STDIN) failed %E";
goto fail;
}
if (dup2(fd, STDOUT_FILENO) == -1) {
msg = "dup2(\"/dev/null\", STDOUT) failed %E";
goto fail;
}
if (fd > STDERR_FILENO) {
nxt_fd_close(fd);
}
return NXT_OK;
fail:
nxt_alert(task, msg, nxt_errno);
if (fd != -1) {
nxt_fd_close(fd);
}
return NXT_ERROR;
}
void
nxt_nanosleep(nxt_nsec_t ns)
{
struct timespec ts;
ts.tv_sec = ns / 1000000000;
ts.tv_nsec = ns % 1000000000;
(void) nanosleep(&ts, NULL);
}
void
nxt_process_use(nxt_task_t *task, nxt_process_t *process, int i)
{
process->use_count += i;
if (process->use_count == 0) {
nxt_runtime_process_release(task->thread->runtime, process);
}
}
void
nxt_process_port_add(nxt_task_t *task, nxt_process_t *process, nxt_port_t *port)
{
nxt_assert(port->process == NULL);
port->process = process;
nxt_queue_insert_tail(&process->ports, &port->link);
nxt_process_use(task, process, 1);
}
nxt_process_type_t
nxt_process_type(nxt_process_t *process)
{
return nxt_queue_is_empty(&process->ports) ? 0 :
(nxt_process_port_first(process))->type;
}
void
nxt_process_close_ports(nxt_task_t *task, nxt_process_t *process)
{
nxt_port_t *port;
nxt_process_port_each(process, port) {
nxt_port_close(task, port);
nxt_runtime_port_remove(task, port);
} nxt_process_port_loop;
}
void
nxt_process_connected_port_remove(nxt_process_t *process, nxt_port_t *port)
{
nxt_thread_mutex_lock(&process->cp_mutex);
nxt_port_hash_remove(&process->connected_ports, port);
nxt_thread_mutex_unlock(&process->cp_mutex);
}
nxt_port_t *
nxt_process_connected_port_find_add(nxt_process_t *process, nxt_port_t *port)
{
nxt_port_t *res;
nxt_thread_mutex_lock(&process->cp_mutex);
res = nxt_port_hash_find(&process->connected_ports, port->pid, port->id);
if (nxt_slow_path(res == NULL)) {
nxt_port_hash_add(&process->connected_ports, port);
}
nxt_thread_mutex_unlock(&process->cp_mutex);
return res;
}
