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-rw-r--r--source4/samba/process_standard.c626
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diff --git a/source4/samba/process_standard.c b/source4/samba/process_standard.c
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+++ b/source4/samba/process_standard.c
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+/*
+ Unix SMB/CIFS implementation.
+
+ process model: standard (1 process per client connection)
+
+ Copyright (C) Andrew Tridgell 1992-2005
+ Copyright (C) James J Myers 2003 <myersjj@samba.org>
+ Copyright (C) Stefan (metze) Metzmacher 2004
+
+ 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 "samba/process_model.h"
+#include "system/filesys.h"
+#include "cluster/cluster.h"
+#include "param/param.h"
+#include "ldb_wrap.h"
+#include "lib/messaging/messaging.h"
+#include "lib/util/debug.h"
+#include "lib/messaging/messages_dgm.h"
+#include "lib/util/util_process.h"
+
+static unsigned connections_active = 0;
+static unsigned smbd_max_processes = 0;
+
+struct standard_child_state {
+ const char *name;
+ pid_t pid;
+ int to_parent_fd;
+ int from_child_fd;
+ struct tevent_fd *from_child_fde;
+};
+
+NTSTATUS process_model_standard_init(TALLOC_CTX *);
+struct process_context {
+ char *name;
+ int from_parent_fd;
+ bool inhibit_fork_on_accept;
+ bool forked_on_accept;
+};
+
+/*
+ called when the process model is selected
+*/
+static void standard_model_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)
+{
+#ifdef HAVE_GETPGRP
+ if (getpgrp() == getpid()) {
+ /*
+ * We're the process group leader, send
+ * SIGTERM to our process group.
+ */
+ DBG_ERR("SIGTERM: killing children\n");
+ kill(-getpgrp(), SIGTERM);
+ }
+#endif
+ DBG_ERR("Exiting pid %u on SIGTERM\n", (unsigned int)getpid());
+ talloc_free(ev);
+ exit(127);
+}
+
+/*
+ handle EOF on the parent-to-all-children pipe in the child
+*/
+static void standard_pipe_handler(struct tevent_context *event_ctx, struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ DBG_DEBUG("Child %d exiting\n", (int)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 standard_child_pipe_handler(struct tevent_context *ev,
+ struct tevent_fd *fde,
+ uint16_t flags,
+ void *private_data)
+{
+ struct standard_child_state *state
+ = talloc_get_type_abort(private_data, struct standard_child_state);
+ int status = 0;
+ pid_t pid;
+
+ messaging_dgm_cleanup(state->pid);
+
+ /* the child has closed the pipe, assume its dead */
+ errno = 0;
+ pid = waitpid(state->pid, &status, 0);
+
+ if (pid != state->pid) {
+ if (errno == ECHILD) {
+ /*
+ * this happens when the
+ * parent has set SIGCHLD to
+ * SIG_IGN. In that case we
+ * can only get error
+ * information for the child
+ * via its logging. We should
+ * stop using SIG_IGN on
+ * SIGCHLD in the standard
+ * process model.
+ */
+ DBG_ERR("Error in waitpid() unexpectedly got ECHILD "
+ "for child %d (%s) - %s, someone has set SIGCHLD "
+ "to SIG_IGN!\n",
+ (int)state->pid, state->name,
+ strerror(errno));
+ TALLOC_FREE(state);
+ return;
+ }
+ DBG_ERR("Error in waitpid() for child %d (%s) - %s \n",
+ (int)state->pid, state->name, strerror(errno));
+ if (errno == 0) {
+ errno = ECHILD;
+ }
+ goto done;
+ }
+ if (WIFEXITED(status)) {
+ status = WEXITSTATUS(status);
+ if (status != 0) {
+ DBG_ERR("Child %d (%s) exited with status %d\n",
+ (int)state->pid, state->name, status);
+ }
+ } else if (WIFSIGNALED(status)) {
+ status = WTERMSIG(status);
+ DBG_ERR("Child %d (%s) terminated with signal %d\n",
+ (int)state->pid, state->name, status);
+ }
+done:
+ TALLOC_FREE(state);
+ if (smbd_max_processes > 0) {
+ if (connections_active < 1) {
+ DBG_ERR("Number of active connections "
+ "less than 1 (%d)\n",
+ connections_active);
+ connections_active = 1;
+ }
+ connections_active--;
+ }
+ return;
+}
+
+static struct standard_child_state *setup_standard_child_pipe(struct tevent_context *ev,
+ const char *name)
+{
+ struct standard_child_state *state;
+ int parent_child_pipe[2];
+ int ret;
+
+ /*
+ * Prepare a pipe to allow us to know when the child exits,
+ * because it will trigger a read event on this private
+ * pipe.
+ *
+ * We do all this before the accept and fork(), so we can
+ * clean up if it fails.
+ */
+ state = talloc_zero(ev, struct standard_child_state);
+ if (state == NULL) {
+ return NULL;
+ }
+
+ if (name == NULL) {
+ name = "";
+ }
+
+ state->name = talloc_strdup(state, name);
+ if (state->name == NULL) {
+ TALLOC_FREE(state);
+ return NULL;
+ }
+
+ ret = pipe(parent_child_pipe);
+ if (ret == -1) {
+ DBG_ERR("Failed to create parent-child pipe to handle "
+ "SIGCHLD to track new process for socket\n");
+ TALLOC_FREE(state);
+ return NULL;
+ }
+
+ smb_set_close_on_exec(parent_child_pipe[0]);
+ smb_set_close_on_exec(parent_child_pipe[1]);
+
+ state->from_child_fd = parent_child_pipe[0];
+ state->to_parent_fd = parent_child_pipe[1];
+
+ /*
+ * The basic purpose of calling this handler is to ensure we
+ * call waitpid() and so avoid zombies (now that we no longer
+ * user SIGIGN on for SIGCHLD), but it also allows us to clean
+ * up other resources in the future.
+ */
+ state->from_child_fde = tevent_add_fd(ev, state,
+ state->from_child_fd,
+ TEVENT_FD_READ,
+ standard_child_pipe_handler,
+ state);
+ if (state->from_child_fde == NULL) {
+ TALLOC_FREE(state);
+ return NULL;
+ }
+ tevent_fd_set_auto_close(state->from_child_fde);
+
+ return state;
+}
+
+/*
+ called when a listening socket becomes readable.
+*/
+static void standard_accept_connection(
+ struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ struct socket_context *sock,
+ 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 *sock2;
+ pid_t pid;
+ struct socket_address *c, *s;
+ struct standard_child_state *state;
+ struct tevent_fd *fde = NULL;
+ struct tevent_signal *se = NULL;
+ struct process_context *proc_ctx = NULL;
+
+
+ /* accept an incoming connection. */
+ status = socket_accept(sock, &sock2);
+ if (!NT_STATUS_IS_OK(status)) {
+ DBG_DEBUG("standard_accept_connection: accept: %s\n",
+ nt_errstr(status));
+ /* this looks strange, but is correct. We need to throttle
+ * things until the system clears enough resources to handle
+ * this new socket
+ */
+ sleep(1);
+ return;
+ }
+
+ proc_ctx = talloc_get_type_abort(process_context,
+ struct process_context);
+
+ if (proc_ctx->inhibit_fork_on_accept) {
+ pid = getpid();
+ /*
+ * Service does not support forking a new process on a
+ * new connection, either it's maintaining shared
+ * state or the overhead of forking a new process is a
+ * significant fraction of the response time.
+ */
+ talloc_steal(private_data, sock2);
+ new_conn(ev, lp_ctx, sock2,
+ cluster_id(pid, socket_get_fd(sock2)), private_data,
+ process_context);
+ return;
+ }
+
+ if (smbd_max_processes > 0) {
+ if (connections_active >= smbd_max_processes) {
+ DBG_ERR("(%d) connections already active, "
+ "maximum is (%d). Dropping request\n",
+ connections_active,
+ smbd_max_processes);
+ /*
+ * Drop the connection as we're overloaded at the moment
+ */
+ talloc_free(sock2);
+ return;
+ }
+ connections_active++;
+ }
+
+ state = setup_standard_child_pipe(ev, NULL);
+ if (state == NULL) {
+ return;
+ }
+ pid = fork();
+
+ if (pid != 0) {
+ close(state->to_parent_fd);
+ state->to_parent_fd = -1;
+
+ if (pid > 0) {
+ state->pid = pid;
+ } else {
+ TALLOC_FREE(state);
+ }
+
+ /* parent or error code ... */
+ talloc_free(sock2);
+ /* go back to the event loop */
+ return;
+ }
+
+ /* this leaves state->to_parent_fd open */
+ TALLOC_FREE(state);
+
+ /* Now in the child code so indicate that we forked
+ * so the terminate code knows what to do
+ */
+ proc_ctx->forked_on_accept = true;
+
+ pid = getpid();
+
+ process_set_title("%s[work]", "task[%s] standard worker", proc_ctx->name);
+
+ /* This is now the child code. We need a completely new event_context to work with */
+
+ if (tevent_re_initialise(ev) != 0) {
+ smb_panic("Failed to re-initialise tevent after fork");
+ }
+
+ /* this will free all the listening sockets and all state that
+ is not associated with this new connection */
+ talloc_free(sock);
+
+ /* we don't care if the dup fails, as its only a select()
+ speed optimisation */
+ socket_dup(sock2);
+
+ /* tdb needs special fork handling */
+ 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");
+ }
+
+ fde = tevent_add_fd(ev, ev, proc_ctx->from_parent_fd, TEVENT_FD_READ,
+ standard_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");
+ }
+
+ /* setup the process title */
+ c = socket_get_peer_addr(sock2, ev);
+ s = socket_get_my_addr(sock2, ev);
+ if (s && c) {
+ setproctitle("conn c[%s:%u] s[%s:%u] server_id[%d]",
+ c->addr, c->port, s->addr, s->port, (int)pid);
+ }
+ talloc_free(c);
+ talloc_free(s);
+
+ force_check_log_size();
+
+ /* setup this new connection. Cluster ID is PID based for this process model */
+ new_conn(ev, lp_ctx, sock2, cluster_id(pid, 0), private_data,
+ process_context);
+
+ /* 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 */
+ tevent_loop_wait(ev);
+
+ talloc_free(ev);
+ exit(0);
+}
+
+/*
+ called to create a new server task
+*/
+static void standard_new_task(struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *service_name,
+ struct task_server *(*new_task)(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;
+ NTSTATUS status;
+ struct standard_child_state *state;
+ struct tevent_fd *fde = NULL;
+ struct tevent_signal *se = NULL;
+ struct process_context *proc_ctx = NULL;
+ struct task_server* task = NULL;
+
+ state = setup_standard_child_pipe(ev, service_name);
+ if (state == NULL) {
+ return;
+ }
+
+ pid = fork();
+
+ if (pid != 0) {
+ close(state->to_parent_fd);
+ state->to_parent_fd = -1;
+
+ if (pid > 0) {
+ state->pid = pid;
+ } else {
+ TALLOC_FREE(state);
+ }
+
+ /* parent or error code ... go back to the event loop */
+ return;
+ }
+
+ /* this leaves state->to_parent_fd open */
+ TALLOC_FREE(state);
+
+ pid = getpid();
+
+ /* 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");
+ }
+
+ /* ldb/tdb need special fork handling */
+ 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");
+ }
+
+ fde = tevent_add_fd(ev, ev, from_parent_fd, TEVENT_FD_READ,
+ standard_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");
+ }
+
+ process_set_title("%s[task]", "task[%s]", service_name);
+
+ force_check_log_size();
+
+ /*
+ * Set up the process context to be passed through to the terminate
+ * and accept_connection functions
+ */
+ proc_ctx = talloc(ev, struct process_context);
+ proc_ctx->name = talloc_strdup(ev, service_name);
+ proc_ctx->from_parent_fd = from_parent_fd;
+ proc_ctx->inhibit_fork_on_accept =
+ service_details->inhibit_fork_on_accept;
+ proc_ctx->forked_on_accept = false;
+
+ smbd_max_processes = lpcfg_max_smbd_processes(lp_ctx);
+
+ /* setup this new task. Cluster ID is PID based for this process model */
+ task = new_task(ev, lp_ctx, cluster_id(pid, 0), private_data, proc_ctx);
+ /*
+ * Currently we don't support the post_fork functionality in the
+ * standard model, i.e. it is only called here not after a new process
+ * is forked in standard_accept_connection.
+ */
+ if (task != NULL && service_details->post_fork != NULL) {
+ struct process_details pd = initial_process_details;
+ service_details->post_fork(task, &pd);
+ }
+
+ if (task != NULL && service_details->before_loop != NULL) {
+ service_details->before_loop(task);
+ }
+
+ /* 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 */
+ tevent_loop_wait(ev);
+
+ talloc_free(ev);
+ exit(0);
+}
+
+
+/* called when a task goes down */
+static void standard_terminate_task(struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *reason,
+ bool fatal,
+ void *process_context)
+{
+ if (fatal == true) {
+ exit(127);
+ }
+ exit(0);
+}
+
+/* called when a connection terminates*/
+static void standard_terminate_connection(struct tevent_context *ev,
+ struct loadparm_context *lp_ctx,
+ const char *reason,
+ void *process_context)
+{
+ struct process_context *proc_ctx = NULL;
+
+ DBG_DEBUG("connection terminating reason[%s]\n", reason);
+ if (process_context == NULL) {
+ smb_panic("Panicking process_context is NULL");
+ }
+
+ proc_ctx = talloc_get_type(process_context, struct process_context);
+ if (proc_ctx->forked_on_accept == false) {
+ /*
+ * The current task was not forked on accept, so it needs to
+ * keep running and process requests from other connections
+ */
+ return;
+ }
+ /*
+ * The current process was forked on accept to handle a single
+ * connection/request. That request has now finished and the process
+ * should terminate
+ */
+
+ /* this reload_charcnv() has the effect of freeing the iconv context memory,
+ which makes leak checking easier */
+ reload_charcnv(lp_ctx);
+
+ /* Always free event context last before exit. */
+ talloc_free(ev);
+
+ /* terminate this process */
+ exit(0);
+}
+/* called to set a title of a task or connection */
+static void standard_set_title(struct tevent_context *ev, const char *title)
+{
+ if (title) {
+ setproctitle("%s", title);
+ } else {
+ setproctitle(NULL);
+ }
+}
+
+static const struct model_ops standard_ops = {
+ .name = "standard",
+ .model_init = standard_model_init,
+ .accept_connection = standard_accept_connection,
+ .new_task = standard_new_task,
+ .terminate_task = standard_terminate_task,
+ .terminate_connection = standard_terminate_connection,
+ .set_title = standard_set_title,
+};
+
+/*
+ initialise the standard process model, registering ourselves with the process model subsystem
+ */
+NTSTATUS process_model_standard_init(TALLOC_CTX *ctx)
+{
+ return register_process_model(&standard_ops);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-17 08:02:26 +0000