--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+
+ process model: prefork (n client connections per process)
+
+ Copyright (C) Andrew Tridgell 1992-2005
+ Copyright (C) James J Myers 2003 <myersjj@samba.org>
+ 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 "lib/events/events.h"
+#include "lib/messaging/messaging.h"
+#include "lib/socket/socket.h"
+#include "smbd/process_model.h"
+#include "cluster/cluster.h"
+#include "param/param.h"
+#include "ldb_wrap.h"
+#include "lib/util/tfork.h"
+
+NTSTATUS process_model_prefork_init(void);
+
+static void sighup_signal_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum, int count, void *siginfo,
+ void *private_data)
+{
+ 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(void)
+{
+}
+
+static void prefork_reload_after_fork(void)
+{
+ NTSTATUS status;
+
+ 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");
+ }
+}
+
+/*
+ handle EOF on the parent-to-all-children pipe in the child
+*/
+static void prefork_pipe_handler(struct tevent_context *event_ctx,
+ struct tevent_fd *fde, uint16_t flags,
+ void *private_data)
+{
+ /* 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);
+}
+
+/*
+ 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.
+
+ 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 tfork *t = 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 */
+
+ /* tfork allocates tfork structures with malloc */
+ t = (struct tfork*)private_data;
+ pid = tfork_child_pid(t);
+ errno = 0;
+ status = tfork_status(&t, false);
+ if (status == -1) {
+ DBG_ERR("Parent %d, Child %d terminated, "
+ "unable to get status code from tfork\n",
+ getpid(), pid);
+ } else if (WIFEXITED(status)) {
+ status = WEXITSTATUS(status);
+ DBG_ERR("Parent %d, Child %d exited with status %d\n",
+ getpid(), pid, status);
+ } else if (WIFSIGNALED(status)) {
+ status = WTERMSIG(status);
+ DBG_ERR("Parent %d, Child %d terminated with signal %d\n",
+ getpid(), pid, status);
+ }
+ /* tfork allocates tfork structures with malloc */
+ free(t);
+ return;
+}
+
+/*
+ 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();
+
+ /* 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;
+ }
+
+ talloc_steal(private_data, connected_socket);
+
+ new_conn(ev, lp_ctx, connected_socket,
+ cluster_id(pid, socket_get_fd(connected_socket)),
+ private_data, process_context);
+}
+
+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");
+ }
+
+ 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");
+ }
+}
+
+/*
+ * 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,
+ void (*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)
+{
+ pid_t pid;
+ struct tfork* t = NULL;
+ int i, num_children;
+
+ struct tevent_context *ev2;
+
+ t = tfork_create();
+ if (t == NULL) {
+ smb_panic("failure in tfork\n");
+ }
+
+ pid = tfork_child_pid(t);
+ if (pid != 0) {
+ struct tevent_fd *fde = NULL;
+ int fd = tfork_event_fd(t);
+
+ /* Register a pipe handler that gets called when the prefork
+ * master process terminates.
+ */
+ fde = tevent_add_fd(ev, ev, fd, TEVENT_FD_READ,
+ prefork_child_pipe_handler, t);
+ 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) {
+ new_task_fn(ev, lp_ctx, cluster_id(pid, 0), private_data, NULL);
+ /* The task does not support pre-fork */
+ 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
+ */
+ ev2 = s4_event_context_init(NULL);
+
+ /* 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.
+ */
+ new_task_fn(ev2, lp_ctx, cluster_id(pid, 0), private_data, NULL);
+
+ {
+ 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);
+ /* We are now free to spawn some worker processes */
+ for (i=0; i < num_children; i++) {
+ struct tfork* w = NULL;
+
+ w = tfork_create();
+ if (t == 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);
+
+ fde = tevent_add_fd(ev, ev, fd, TEVENT_FD_READ,
+ prefork_child_pipe_handler, w);
+ if (fde == NULL) {
+ smb_panic("Failed to add child pipe handler, "
+ "after fork");
+ }
+ tevent_fd_set_auto_close(fde);
+ } else {
+ /* tfork uses malloc */
+ free(w);
+
+ TALLOC_FREE(ev);
+ pid = getpid();
+ setproctitle("task[%s] pre-forked worker",
+ service_name);
+ prefork_reload_after_fork();
+ setup_handlers(ev2, from_parent_fd);
+ tevent_loop_wait(ev2);
+ talloc_free(ev2);
+ exit(0);
+ }
+ }
+
+ /* 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);
+
+}
+
+
+/* called when a task goes down */
+static void prefork_terminate(struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *reason,
+ void *process_context)
+{
+ DBG_DEBUG("called with reason[%s]\n", reason);
+}
+
+/* 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,
+};
+
+/*
+ * initialise the prefork process model, registering ourselves with the
+ * process model subsystem
+ */
+NTSTATUS process_model_prefork_init(void)
+{
+ return register_process_model(&prefork_ops);
+}
git.samba.org / metze / samba / wip.git / commitdiff