-/*
+/*
Unix SMB/CIFS implementation.
process model: prefork (n client connections per process)
Copyright (C) Stefan (metze) Metzmacher 2004
Copyright (C) Andrew Bartlett 2008 <abartlet@samba.org>
Copyright (C) David Disseldorp 2008 <ddiss@sgi.com>
-
+
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
-
+
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
+#include <unistd.h>
+
#include "lib/events/events.h"
-#include "../tdb/include/tdb.h"
+#include "lib/messaging/messaging.h"
#include "lib/socket/socket.h"
#include "smbd/process_model.h"
-#include "param/secrets.h"
-#include "system/filesys.h"
#include "cluster/cluster.h"
#include "param/param.h"
+#include "ldb_wrap.h"
+#include "lib/util/tfork.h"
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+
+NTSTATUS process_model_prefork_init(void);
+static void prefork_new_task(
+ struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *service_name,
+ struct task_server *(*new_task_fn)(struct tevent_context *,
+ struct loadparm_context *lp_ctx,
+ struct server_id,
+ void *,
+ void *),
+ void *private_data,
+ const struct service_details *service_details,
+ int from_parent_fd);
+static void prefork_fork_worker(struct task_server *task,
+ struct tevent_context *ev,
+ struct tevent_context *ev2,
+ struct loadparm_context *lp_ctx,
+ const struct service_details *service_details,
+ const char *service_name,
+ int control_pipe[2],
+ unsigned restart_delay,
+ struct process_details *pd);
+static void prefork_child_pipe_handler(struct tevent_context *ev,
+ struct tevent_fd *fde,
+ uint16_t flags,
+ void *private_data);
+static void setup_handlers(struct tevent_context *ev, int from_parent_fd);
-#ifdef HAVE_SETPROCTITLE
-#ifdef HAVE_SETPROCTITLE_H
-#include <setproctitle.h>
-#endif
-#else
-#define setproctitle none_setproctitle
-static int none_setproctitle(const char *fmt, ...) PRINTF_ATTRIBUTE(1, 2);
-static int none_setproctitle(const char *fmt, ...)
+/*
+ * State needed to restart the master process or a worker process if they
+ * terminate early.
+ */
+struct master_restart_context {
+ struct task_server *(*new_task_fn)(struct tevent_context *,
+ struct loadparm_context *lp_ctx,
+ struct server_id,
+ void *,
+ void *);
+ void *private_data;
+};
+
+struct worker_restart_context {
+ unsigned int instance;
+ struct task_server *task;
+ struct tevent_context *ev2;
+ int control_pipe[2];
+};
+
+struct restart_context {
+ struct loadparm_context *lp_ctx;
+ struct tfork *t;
+ int from_parent_fd;
+ const struct service_details *service_details;
+ const char *service_name;
+ unsigned restart_delay;
+ struct master_restart_context *master;
+ struct worker_restart_context *worker;
+};
+
+static void sighup_signal_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum, int count, void *siginfo,
+ void *private_data)
{
- return 0;
+ debug_schedule_reopen_logs();
}
+
+static void sigterm_signal_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum, int count, void *siginfo,
+ void *private_data)
+{
+#if HAVE_GETPGRP
+ if (getpgrp() == getpid()) {
+ /*
+ * We're the process group leader, send
+ * SIGTERM to our process group.
+ */
+ DBG_NOTICE("SIGTERM: killing children\n");
+ kill(-getpgrp(), SIGTERM);
+ }
#endif
+ DBG_NOTICE("Exiting pid %d on SIGTERM\n", getpid());
+ talloc_free(ev);
+ exit(127);
+}
/*
called when the process model is selected
*/
-static void prefork_model_init(struct event_context *ev)
+static void prefork_model_init(void)
{
- signal(SIGCHLD, SIG_IGN);
}
static void prefork_reload_after_fork(void)
{
- /* tdb needs special fork handling */
- if (tdb_reopen_all(1) == -1) {
- DEBUG(0,("prefork_reload_after_fork: tdb_reopen_all failed.\n"));
- }
+ NTSTATUS status;
- /* Ensure that the forked children do not expose identical random streams */
- set_need_random_reseed();
+ ldb_wrap_fork_hook();
+ /* Must be done after a fork() to reset messaging contexts. */
+ status = imessaging_reinit_all();
+ if (!NT_STATUS_IS_OK(status)) {
+ smb_panic("Failed to re-initialise imessaging after fork");
+ }
}
/*
- called when a listening socket becomes readable.
+ handle EOF on the parent-to-all-children pipe in the child
*/
-static void prefork_accept_connection(struct event_context *ev,
- struct loadparm_context *lp_ctx,
- struct socket_context *listen_socket,
- void (*new_conn)(struct event_context *,
- struct loadparm_context *, struct socket_context *,
- struct server_id , void *),
- void *private)
+static void prefork_pipe_handler(struct tevent_context *event_ctx,
+ struct tevent_fd *fde, uint16_t flags,
+ void *private_data)
{
- NTSTATUS status;
- struct socket_context *connected_socket;
- pid_t pid = getpid();
-
- /* accept an incoming connection. */
- status = socket_accept(listen_socket, &connected_socket);
- if (!NT_STATUS_IS_OK(status)) {
- return;
- }
-
- talloc_steal(private, connected_socket);
-
- new_conn(ev, lp_ctx, connected_socket, cluster_id(pid, socket_get_fd(connected_socket)), private);
+ /* free the fde which removes the event and stops it firing again */
+ TALLOC_FREE(fde);
+ DBG_NOTICE("Child %d exiting\n", getpid());
+ talloc_free(event_ctx);
+ exit(0);
}
+
/*
- called to create a new server task
-*/
-static void prefork_new_task(struct event_context *ev,
- struct loadparm_context *lp_ctx,
- const char *service_name,
- void (*new_task_fn)(struct event_context *, struct loadparm_context *lp_ctx, struct server_id , void *),
- void *private)
+ * called to create a new server task
+ */
+static void prefork_fork_master(
+ struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *service_name,
+ struct task_server *(*new_task_fn)(struct tevent_context *,
+ struct loadparm_context *lp_ctx,
+ struct server_id,
+ void *,
+ void *),
+ void *private_data,
+ const struct service_details *service_details,
+ unsigned restart_delay,
+ int from_parent_fd)
{
pid_t pid;
+ struct tfork* t = NULL;
int i, num_children;
- struct event_context *ev2, *ev_parent;
+ struct tevent_context *ev2;
+ struct task_server *task = NULL;
+ struct process_details pd = initial_process_details;
+ int control_pipe[2];
- pid = fork();
+ t = tfork_create();
+ if (t == NULL) {
+ smb_panic("failure in tfork\n");
+ }
+ DBG_NOTICE("Forking [%s] pre-fork master process\n", service_name);
+ pid = tfork_child_pid(t);
if (pid != 0) {
- /* parent or error code ... go back to the event loop */
+ struct tevent_fd *fde = NULL;
+ int fd = tfork_event_fd(t);
+ struct restart_context *rc = NULL;
+
+ /* Register a pipe handler that gets called when the prefork
+ * master process terminates.
+ */
+ rc = talloc_zero(ev, struct restart_context);
+ if (rc == NULL) {
+ smb_panic("OOM allocating restart context\n");
+ }
+ rc->t = t;
+ rc->lp_ctx = lp_ctx;
+ rc->service_name = service_name;
+ rc->service_details = service_details;
+ rc->from_parent_fd = from_parent_fd;
+ rc->restart_delay = restart_delay;
+ rc->master = talloc_zero(rc, struct master_restart_context);
+ if (rc->master == NULL) {
+ smb_panic("OOM allocating master restart context\n");
+ }
+
+ rc->master->new_task_fn = new_task_fn;
+ rc->master->private_data = private_data;
+
+ fde = tevent_add_fd(
+ ev, ev, fd, TEVENT_FD_READ, prefork_child_pipe_handler, rc);
+ if (fde == NULL) {
+ smb_panic("Failed to add child pipe handler, "
+ "after fork");
+ }
+ tevent_fd_set_auto_close(fde);
return;
}
pid = getpid();
+ setproctitle("task[%s] pre-fork master", service_name);
+
+ /*
+ * this will free all the listening sockets and all state that
+ * is not associated with this new connection
+ */
+ if (tevent_re_initialise(ev) != 0) {
+ smb_panic("Failed to re-initialise tevent after fork");
+ }
+ prefork_reload_after_fork();
+ setup_handlers(ev, from_parent_fd);
+
+ if (service_details->inhibit_pre_fork) {
+ task = new_task_fn(
+ ev, lp_ctx, cluster_id(pid, 0), private_data, NULL);
+ /*
+ * The task does not support pre-fork
+ */
+ if (task != NULL && service_details->post_fork != NULL) {
+ service_details->post_fork(task, &pd);
+ }
+ tevent_loop_wait(ev);
+ TALLOC_FREE(ev);
+ exit(0);
+ }
- /* This is now the child code. We need a completely new event_context to work with */
+ /*
+ * This is now the child code. We need a completely new event_context
+ * to work with
+ */
ev2 = s4_event_context_init(NULL);
- /* the service has given us a private pointer that
- encapsulates the context it needs for this new connection -
- everything else will be freed */
- talloc_steal(ev2, private);
+ /* setup this new connection: process will bind to it's sockets etc
+ *
+ * While we can use ev for the child, which has been re-initialised
+ * above we must run the new task under ev2 otherwise the children would
+ * be listening on the sockets. Also we don't want the top level
+ * process accepting and handling requests, it's responsible for
+ * monitoring and controlling the child work processes.
+ */
+ task = new_task_fn(ev2, lp_ctx, cluster_id(pid, 0), private_data, NULL);
+ if (task == NULL) {
+ TALLOC_FREE(ev);
+ TALLOC_FREE(ev2);
+ exit(0);
+ }
- /* this will free all the listening sockets and all state that
- is not associated with this new connection */
- talloc_free(ev);
+ {
+ int default_children;
+ default_children = lpcfg_prefork_children(lp_ctx);
+ num_children = lpcfg_parm_int(lp_ctx, NULL, "prefork children",
+ service_name, default_children);
+ }
+ if (num_children == 0) {
+ DBG_WARNING("Number of pre-fork children for %s is zero, "
+ "NO worker processes will be started for %s\n",
+ service_name, service_name);
+ }
+ DBG_NOTICE("Forking %d %s worker processes\n",
+ num_children, service_name);
+ {
+ int ret;
+ ret = pipe(control_pipe);
+ if (ret != 0) {
+ smb_panic("Unable to create worker control pipe\n");
+ }
+ smb_set_close_on_exec(control_pipe[0]);
+ smb_set_close_on_exec(control_pipe[1]);
+ }
- setproctitle("task %s server_id[%d]", service_name, pid);
+ /*
+ * We are now free to spawn some worker processes
+ */
+ for (i=0; i < num_children; i++) {
+ prefork_fork_worker(task,
+ ev,
+ ev2,
+ lp_ctx,
+ service_details,
+ service_name,
+ control_pipe,
+ 0,
+ &pd);
+ pd.instances++;
+ }
- prefork_reload_after_fork();
+ /* Don't listen on the sockets we just gave to the children */
+ tevent_loop_wait(ev);
+ TALLOC_FREE(ev);
+ /* We need to keep ev2 until we're finished for the messaging to work */
+ TALLOC_FREE(ev2);
+ exit(0);
+
+}
+static void prefork_restart(struct tevent_context *ev,
+ struct restart_context *rc)
+{
+ unsigned max_backoff = 0;
+ unsigned backoff = 0;
+ unsigned restart_delay = rc->restart_delay;
+ unsigned default_value = 0;
+
+ default_value = lpcfg_prefork_backoff_increment(rc->lp_ctx);
+ backoff = lpcfg_parm_int(rc->lp_ctx,
+ NULL,
+ "prefork backoff increment",
+ rc->service_name,
+ default_value);
+
+ default_value = lpcfg_prefork_maximum_backoff(rc->lp_ctx);
+ max_backoff = lpcfg_parm_int(rc->lp_ctx,
+ NULL,
+ "prefork maximum backoff",
+ rc->service_name,
+ default_value);
+
+ if (restart_delay > 0) {
+ DBG_ERR("Restarting [%s] pre-fork %s in (%d) seconds\n",
+ rc->service_name,
+ (rc->master == NULL) ? "worker" : "master",
+ restart_delay);
+ sleep(restart_delay);
+ }
+ restart_delay += backoff;
+ restart_delay = min(restart_delay, max_backoff);
+
+ if (rc->master != NULL) {
+ DBG_ERR("Restarting [%s] pre-fork master\n", rc->service_name);
+ prefork_fork_master(ev,
+ rc->lp_ctx,
+ rc->service_name,
+ rc->master->new_task_fn,
+ rc->master->private_data,
+ rc->service_details,
+ restart_delay,
+ rc->from_parent_fd);
+ } else if (rc->worker != NULL) {
+ struct process_details pd = initial_process_details;
+ DBG_ERR("Restarting [%s] pre-fork worker(%d)\n",
+ rc->service_name,
+ rc->worker->instance);
+ pd.instances = rc->worker->instance;
+ prefork_fork_worker(rc->worker->task,
+ ev,
+ rc->worker->ev2,
+ rc->lp_ctx,
+ rc->service_details,
+ rc->service_name,
+ rc->worker->control_pipe,
+ restart_delay,
+ &pd);
+ }
+}
+/*
+ handle EOF on the child pipe in the parent, so we know when a
+ process terminates without using SIGCHLD or waiting on all possible pids.
- /* setup this new connection: process will bind to it's sockets etc */
- new_task_fn(ev2, lp_ctx, cluster_id(pid, 0), private);
+ We need to ensure we do not ignore SIGCHLD because we need it to
+ work to get a valid error code from samba_runcmd_*().
+ */
+static void prefork_child_pipe_handler(struct tevent_context *ev,
+ struct tevent_fd *fde,
+ uint16_t flags,
+ void *private_data)
+{
+ struct restart_context *rc = NULL;
+ int status = 0;
+ pid_t pid = 0;
+
+ /* free the fde which removes the event and stops it firing again */
+ TALLOC_FREE(fde);
+
+ /* the child has closed the pipe, assume its dead */
+
+ rc = talloc_get_type_abort(private_data, struct restart_context);
+ pid = tfork_child_pid(rc->t);
+ errno = 0;
+ status = tfork_status(&rc->t, false);
+ if (status == -1) {
+ DBG_ERR("Parent %d, Child %d terminated, "
+ "unable to get status code from tfork\n",
+ getpid(), pid);
+ prefork_restart(ev, rc);
+ } else if (WIFEXITED(status)) {
+ status = WEXITSTATUS(status);
+ DBG_ERR("Parent %d, Child %d exited with status %d\n",
+ getpid(), pid, status);
+ if (status != 0) {
+ prefork_restart(ev, rc);
+ }
+ } else if (WIFSIGNALED(status)) {
+ status = WTERMSIG(status);
+ DBG_ERR("Parent %d, Child %d terminated with signal %d\n",
+ getpid(), pid, status);
+ if (status == SIGABRT || status == SIGBUS || status == SIGFPE ||
+ status == SIGILL || status == SIGSYS || status == SIGSEGV) {
+
+ prefork_restart(ev, rc);
+ }
+ }
+ /* tfork allocates tfork structures with malloc */
+ tfork_destroy(&rc->t);
+ free(rc->t);
+ TALLOC_FREE(rc);
+ return;
+}
- num_children = lp_parm_int(lp_ctx, NULL, "prefork children", service_name, 0);
- if (num_children == 0) {
+/*
+ called when a listening socket becomes readable.
+*/
+static void prefork_accept_connection(
+ struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ struct socket_context *listen_socket,
+ void (*new_conn)(struct tevent_context *,
+ struct loadparm_context *,
+ struct socket_context *,
+ struct server_id,
+ void *,
+ void *),
+ void *private_data,
+ void *process_context)
+{
+ NTSTATUS status;
+ struct socket_context *connected_socket;
+ pid_t pid = getpid();
- /* We don't want any kids hanging around for this one,
- * let the parent do all the work */
- event_loop_wait(ev2);
-
- talloc_free(ev2);
- exit(0);
+ /* accept an incoming connection. */
+ status = socket_accept(listen_socket, &connected_socket);
+ if (!NT_STATUS_IS_OK(status)) {
+ /*
+ * For prefork we can ignore STATUS_MORE_ENTRIES, as once a
+ * connection becomes available all waiting processes are
+ * woken, but only one gets work to process.
+ * AKA the thundering herd.
+ * In the short term this should not be an issue as the number
+ * of workers should be a small multiple of the number of cpus
+ * In the longer term socket_accept needs to implement a
+ * mutex/semaphore (like apache does) to serialise the accepts
+ */
+ if (!NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
+ DBG_ERR("Worker process (%d), error in accept [%s]\n",
+ getpid(), nt_errstr(status));
+ }
+ return;
}
- /* We are now free to spawn some child proccesses */
+ talloc_steal(private_data, connected_socket);
- for (i=0; i < num_children; i++) {
+ new_conn(ev, lp_ctx, connected_socket,
+ cluster_id(pid, socket_get_fd(connected_socket)),
+ private_data, process_context);
+}
- pid = fork();
- if (pid > 0) {
- continue;
- } else if (pid == -1) {
- return;
- } else {
- pid = getpid();
- setproctitle("task %s server_id[%d]", service_name, pid);
-
- prefork_reload_after_fork();
-
- /* we can't return to the top level here, as that event context is gone,
- so we now process events in the new event context until there are no
- more to process */
- event_loop_wait(ev2);
-
- talloc_free(ev2);
- exit(0);
- }
+static void setup_handlers(struct tevent_context *ev, int from_parent_fd) {
+ struct tevent_fd *fde = NULL;
+ struct tevent_signal *se = NULL;
+
+ fde = tevent_add_fd(ev, ev, from_parent_fd, TEVENT_FD_READ,
+ prefork_pipe_handler, NULL);
+ if (fde == NULL) {
+ smb_panic("Failed to add fd handler after fork");
}
- /* Don't listen on the sockets we just gave to the children */
- talloc_free(ev2);
-
- /* But we need a events system to handle reaping children */
- ev_parent = s4_event_context_init(NULL);
-
- /* TODO: Handle some events... */
-
- /* we can't return to the top level here, as that event context is gone,
- so we now process events in the new event context until there are no
- more to process */
- event_loop_wait(ev_parent);
-
- talloc_free(ev_parent);
- exit(0);
+ se = tevent_add_signal(ev,
+ ev,
+ SIGHUP,
+ 0,
+ sighup_signal_handler,
+ NULL);
+ if (se == NULL) {
+ smb_panic("Failed to add SIGHUP handler after fork");
+ }
+ se = tevent_add_signal(ev,
+ ev,
+ SIGTERM,
+ 0,
+ sigterm_signal_handler,
+ NULL);
+ if (se == NULL) {
+ smb_panic("Failed to add SIGTERM handler after fork");
+ }
}
+static void prefork_fork_worker(struct task_server *task,
+ struct tevent_context *ev,
+ struct tevent_context *ev2,
+ struct loadparm_context *lp_ctx,
+ const struct service_details *service_details,
+ const char *service_name,
+ int control_pipe[2],
+ unsigned restart_delay,
+ struct process_details *pd)
+{
+ struct tfork *w = NULL;
+ pid_t pid;
+
+ w = tfork_create();
+ if (w == NULL) {
+ smb_panic("failure in tfork\n");
+ }
+
+ pid = tfork_child_pid(w);
+ if (pid != 0) {
+ struct tevent_fd *fde = NULL;
+ int fd = tfork_event_fd(w);
+ struct restart_context *rc = NULL;
-/* called when a task goes down */
-_NORETURN_ static void prefork_terminate(struct event_context *ev, const char *reason)
+ rc = talloc_zero(ev, struct restart_context);
+ if (rc == NULL) {
+ smb_panic("OOM allocating restart context\n");
+ }
+ rc->t = w;
+ rc->lp_ctx = lp_ctx;
+ rc->service_name = service_name;
+ rc->service_details = service_details;
+ rc->restart_delay = restart_delay;
+ rc->master = NULL;
+ rc->worker = talloc_zero(rc, struct worker_restart_context);
+ if (rc->worker == NULL) {
+ smb_panic("OOM allocating master restart context\n");
+ }
+ rc->worker->ev2 = ev2;
+ rc->worker->instance = pd->instances;
+ rc->worker->task = task;
+ rc->worker->control_pipe[0] = control_pipe[0];
+ rc->worker->control_pipe[1] = control_pipe[1];
+
+ fde = tevent_add_fd(
+ ev, ev, fd, TEVENT_FD_READ, prefork_child_pipe_handler, rc);
+ if (fde == NULL) {
+ smb_panic("Failed to add child pipe handler, "
+ "after fork");
+ }
+ tevent_fd_set_auto_close(fde);
+ } else {
+ close(control_pipe[1]);
+ setup_handlers(ev2, control_pipe[0]);
+ /*
+ * tfork uses malloc
+ */
+ free(w);
+
+ TALLOC_FREE(ev);
+ setproctitle("task[%s] pre-forked worker(%d)",
+ service_name,
+ pd->instances);
+ prefork_reload_after_fork();
+ if (service_details->post_fork != NULL) {
+ service_details->post_fork(task, pd);
+ }
+ tevent_loop_wait(ev2);
+ talloc_free(ev2);
+ exit(0);
+ }
+}
+/*
+ * called to create a new server task
+ */
+static void prefork_new_task(
+ struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *service_name,
+ struct task_server *(*new_task_fn)(struct tevent_context *,
+ struct loadparm_context *lp_ctx,
+ struct server_id , void *, void *),
+ void *private_data,
+ const struct service_details *service_details,
+ int from_parent_fd)
{
- DEBUG(2,("prefork_terminate: reason[%s]\n",reason));
+ prefork_fork_master(ev,
+ lp_ctx,
+ service_name,
+ new_task_fn,
+ private_data,
+ service_details,
+ 0,
+ from_parent_fd);
+
}
-/* called to set a title of a task or connection */
-static void prefork_set_title(struct event_context *ev, const char *title)
+/*
+ * called when a task terminates
+ */
+static void prefork_terminate_task(struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *reason,
+ bool fatal,
+ void *process_context)
{
- if (title) {
- setproctitle("%s", title);
+ DBG_DEBUG("called with reason[%s]\n", reason);
+ if (fatal == true) {
+ exit(127);
} else {
- setproctitle(NULL);
+ exit(0);
}
}
+/*
+ * called when a connection completes
+ */
+static void prefork_terminate_connection(struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *reason,
+ void *process_context)
+{
+}
+
+/* called to set a title of a task or connection */
+static void prefork_set_title(struct tevent_context *ev, const char *title)
+{
+}
+
static const struct model_ops prefork_ops = {
.name = "prefork",
.model_init = prefork_model_init,
.accept_connection = prefork_accept_connection,
- .new_task = prefork_new_task,
- .terminate = prefork_terminate,
- .set_title = prefork_set_title,
+ .new_task = prefork_new_task,
+ .terminate_task = prefork_terminate_task,
+ .terminate_connection = prefork_terminate_connection,
+ .set_title = prefork_set_title,
};
/*
- initialise the prefork process model, registering ourselves with the process model subsystem
+ * initialise the prefork process model, registering ourselves with the
+ * process model subsystem
*/
NTSTATUS process_model_prefork_init(void)
{
git.samba.org / samba.git / blobdiff