/* * Copyright (C) Igor Sysoev * Copyright (C) NGINX, Inc. */ #include #include #if (NXT_HAVE_CLONE) #include #endif #include 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; }