2 Unix SMB/CIFS implementation.
4 process model: standard (1 process per client connection)
6 Copyright (C) Andrew Tridgell 1992-2005
7 Copyright (C) James J Myers 2003 <myersjj@samba.org>
8 Copyright (C) Stefan (metze) Metzmacher 2004
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>.
25 #include "lib/events/events.h"
26 #include "smbd/process_model.h"
27 #include "system/filesys.h"
28 #include "cluster/cluster.h"
29 #include "param/param.h"
31 #include "lib/messaging/messaging.h"
32 #include "lib/util/debug.h"
33 #include "source3/lib/messages_dgm.h"
35 struct standard_child_state {
40 struct tevent_fd *from_child_fde;
43 NTSTATUS process_model_standard_init(TALLOC_CTX *);
44 struct process_context {
47 bool inhibit_fork_on_accept;
48 bool forked_on_accept;
52 called when the process model is selected
54 static void standard_model_init(void)
58 static void sighup_signal_handler(struct tevent_context *ev,
59 struct tevent_signal *se,
60 int signum, int count, void *siginfo,
63 debug_schedule_reopen_logs();
66 static void sigterm_signal_handler(struct tevent_context *ev,
67 struct tevent_signal *se,
68 int signum, int count, void *siginfo,
72 if (getpgrp() == getpid()) {
74 * We're the process group leader, send
75 * SIGTERM to our process group.
77 DEBUG(0,("SIGTERM: killing children\n"));
78 kill(-getpgrp(), SIGTERM);
81 DEBUG(0,("Exiting pid %u on SIGTERM\n", (unsigned int)getpid()));
87 handle EOF on the parent-to-all-children pipe in the child
89 static void standard_pipe_handler(struct tevent_context *event_ctx, struct tevent_fd *fde,
90 uint16_t flags, void *private_data)
92 DEBUG(10,("Child %d exiting\n", (int)getpid()));
93 talloc_free(event_ctx);
98 handle EOF on the child pipe in the parent, so we know when a
99 process terminates without using SIGCHLD or waiting on all possible pids.
101 We need to ensure we do not ignore SIGCHLD because we need it to
102 work to get a valid error code from samba_runcmd_*().
104 static void standard_child_pipe_handler(struct tevent_context *ev,
105 struct tevent_fd *fde,
109 struct standard_child_state *state
110 = talloc_get_type_abort(private_data, struct standard_child_state);
114 messaging_dgm_cleanup(state->pid);
116 /* the child has closed the pipe, assume its dead */
118 pid = waitpid(state->pid, &status, 0);
120 if (pid != state->pid) {
121 if (errno == ECHILD) {
123 * this happens when the
124 * parent has set SIGCHLD to
125 * SIG_IGN. In that case we
127 * information for the child
128 * via its logging. We should
129 * stop using SIG_IGN on
130 * SIGCHLD in the standard
133 DEBUG(0, ("Error in waitpid() unexpectedly got ECHILD "
134 "for child %d (%s) - %s, someone has set SIGCHLD "
136 (int)state->pid, state->name,
141 DEBUG(0, ("Error in waitpid() for child %d (%s) - %s \n",
142 (int)state->pid, state->name, strerror(errno)));
149 if (WIFEXITED(status)) {
150 status = WEXITSTATUS(status);
151 DEBUG(2, ("Child %d (%s) exited with status %d\n",
152 (int)state->pid, state->name, status));
153 } else if (WIFSIGNALED(status)) {
154 status = WTERMSIG(status);
155 DEBUG(0, ("Child %d (%s) terminated with signal %d\n",
156 (int)state->pid, state->name, status));
162 static struct standard_child_state *setup_standard_child_pipe(struct tevent_context *ev,
165 struct standard_child_state *state;
166 int parent_child_pipe[2];
170 * Prepare a pipe to allow us to know when the child exits,
171 * because it will trigger a read event on this private
174 * We do all this before the accept and fork(), so we can
175 * clean up if it fails.
177 state = talloc_zero(ev, struct standard_child_state);
186 state->name = talloc_strdup(state, name);
187 if (state->name == NULL) {
192 ret = pipe(parent_child_pipe);
194 DEBUG(0, ("Failed to create parent-child pipe to handle "
195 "SIGCHLD to track new process for socket\n"));
200 smb_set_close_on_exec(parent_child_pipe[0]);
201 smb_set_close_on_exec(parent_child_pipe[1]);
203 state->from_child_fd = parent_child_pipe[0];
204 state->to_parent_fd = parent_child_pipe[1];
207 * The basic purpose of calling this handler is to ensure we
208 * call waitpid() and so avoid zombies (now that we no longer
209 * user SIGIGN on for SIGCHLD), but it also allows us to clean
210 * up other resources in the future.
212 state->from_child_fde = tevent_add_fd(ev, state,
213 state->from_child_fd,
215 standard_child_pipe_handler,
217 if (state->from_child_fde == NULL) {
221 tevent_fd_set_auto_close(state->from_child_fde);
227 called when a listening socket becomes readable.
229 static void standard_accept_connection(
230 struct tevent_context *ev,
231 struct loadparm_context *lp_ctx,
232 struct socket_context *sock,
233 void (*new_conn)(struct tevent_context *,
234 struct loadparm_context *,
235 struct socket_context *,
240 void *process_context)
243 struct socket_context *sock2;
245 struct socket_address *c, *s;
246 struct standard_child_state *state;
247 struct tevent_fd *fde = NULL;
248 struct tevent_signal *se = NULL;
249 struct process_context *proc_ctx = NULL;
252 /* accept an incoming connection. */
253 status = socket_accept(sock, &sock2);
254 if (!NT_STATUS_IS_OK(status)) {
255 DEBUG(0,("standard_accept_connection: accept: %s\n",
257 /* this looks strange, but is correct. We need to throttle things until
258 the system clears enough resources to handle this new socket */
263 proc_ctx = talloc_get_type_abort(process_context,
264 struct process_context);
266 state = setup_standard_child_pipe(ev, NULL);
273 close(state->to_parent_fd);
274 state->to_parent_fd = -1;
282 /* parent or error code ... */
284 /* go back to the event loop */
288 /* this leaves state->to_parent_fd open */
291 /* Now in the child code so indicate that we forked
292 * so the terminate code knows what to do
294 proc_ctx->forked_on_accept = true;
297 setproctitle("task[%s] standard worker", proc_ctx->name);
299 /* This is now the child code. We need a completely new event_context to work with */
301 if (tevent_re_initialise(ev) != 0) {
302 smb_panic("Failed to re-initialise tevent after fork");
305 /* this will free all the listening sockets and all state that
306 is not associated with this new connection */
309 /* we don't care if the dup fails, as its only a select()
310 speed optimisation */
313 /* tdb needs special fork handling */
314 ldb_wrap_fork_hook();
316 /* Must be done after a fork() to reset messaging contexts. */
317 status = imessaging_reinit_all();
318 if (!NT_STATUS_IS_OK(status)) {
319 smb_panic("Failed to re-initialise imessaging after fork");
322 fde = tevent_add_fd(ev, ev, proc_ctx->from_parent_fd, TEVENT_FD_READ,
323 standard_pipe_handler, NULL);
325 smb_panic("Failed to add fd handler after fork");
328 se = tevent_add_signal(ev,
332 sighup_signal_handler,
335 smb_panic("Failed to add SIGHUP handler after fork");
338 se = tevent_add_signal(ev,
342 sigterm_signal_handler,
345 smb_panic("Failed to add SIGTERM handler after fork");
348 /* setup the process title */
349 c = socket_get_peer_addr(sock2, ev);
350 s = socket_get_my_addr(sock2, ev);
352 setproctitle("conn c[%s:%u] s[%s:%u] server_id[%d]",
353 c->addr, c->port, s->addr, s->port, (int)pid);
358 /* setup this new connection. Cluster ID is PID based for this process model */
359 new_conn(ev, lp_ctx, sock2, cluster_id(pid, 0), private_data,
362 /* we can't return to the top level here, as that event context is gone,
363 so we now process events in the new event context until there are no
365 tevent_loop_wait(ev);
372 called to create a new server task
374 static void standard_new_task(struct tevent_context *ev,
375 struct loadparm_context *lp_ctx,
376 const char *service_name,
377 void (*new_task)(struct tevent_context *, struct loadparm_context *lp_ctx, struct server_id , void *, void *),
379 const struct service_details *service_details,
384 struct standard_child_state *state;
385 struct tevent_fd *fde = NULL;
386 struct tevent_signal *se = NULL;
387 struct process_context *proc_ctx = NULL;
389 state = setup_standard_child_pipe(ev, service_name);
397 close(state->to_parent_fd);
398 state->to_parent_fd = -1;
406 /* parent or error code ... go back to the event loop */
410 /* this leaves state->to_parent_fd open */
415 /* this will free all the listening sockets and all state that
416 is not associated with this new connection */
417 if (tevent_re_initialise(ev) != 0) {
418 smb_panic("Failed to re-initialise tevent after fork");
421 /* ldb/tdb need special fork handling */
422 ldb_wrap_fork_hook();
424 /* Must be done after a fork() to reset messaging contexts. */
425 status = imessaging_reinit_all();
426 if (!NT_STATUS_IS_OK(status)) {
427 smb_panic("Failed to re-initialise imessaging after fork");
430 fde = tevent_add_fd(ev, ev, from_parent_fd, TEVENT_FD_READ,
431 standard_pipe_handler, NULL);
433 smb_panic("Failed to add fd handler after fork");
436 se = tevent_add_signal(ev,
440 sighup_signal_handler,
443 smb_panic("Failed to add SIGHUP handler after fork");
446 se = tevent_add_signal(ev,
450 sigterm_signal_handler,
453 smb_panic("Failed to add SIGTERM handler after fork");
456 setproctitle("task[%s]", service_name);
459 * Set up the process context to be passed through to the terminate
460 * and accept_connection functions
462 proc_ctx = talloc(ev, struct process_context);
463 proc_ctx->name = talloc_strdup(ev, service_name);
464 proc_ctx->from_parent_fd = from_parent_fd;
465 proc_ctx->inhibit_fork_on_accept =
466 service_details->inhibit_fork_on_accept;
467 proc_ctx->forked_on_accept = false;
469 /* setup this new task. Cluster ID is PID based for this process model */
470 new_task(ev, lp_ctx, cluster_id(pid, 0), private_data, proc_ctx);
472 /* we can't return to the top level here, as that event context is gone,
473 so we now process events in the new event context until there are no
475 tevent_loop_wait(ev);
482 /* called when a task goes down */
483 static void standard_terminate(struct tevent_context *ev,
484 struct loadparm_context *lp_ctx,
486 void *process_context)
488 struct process_context *proc_ctx = NULL;
490 DBG_DEBUG("process terminating reason[%s]\n", reason);
491 if (process_context == NULL) {
492 smb_panic("Panicking process_context is NULL");
495 proc_ctx = talloc_get_type(process_context, struct process_context);
496 if (proc_ctx->forked_on_accept == false) {
498 * The current task was not forked on accept, so it needs to
499 * keep running and process requests from other connections
504 * The current process was forked on accept to handle a single
505 * connection/request. That request has now finished and the process
509 /* this reload_charcnv() has the effect of freeing the iconv context memory,
510 which makes leak checking easier */
511 reload_charcnv(lp_ctx);
513 /* Always free event context last before exit. */
516 /* terminate this process */
520 /* called to set a title of a task or connection */
521 static void standard_set_title(struct tevent_context *ev, const char *title)
524 setproctitle("%s", title);
530 static const struct model_ops standard_ops = {
532 .model_init = standard_model_init,
533 .accept_connection = standard_accept_connection,
534 .new_task = standard_new_task,
535 .terminate = standard_terminate,
536 .set_title = standard_set_title,
540 initialise the standard process model, registering ourselves with the process model subsystem
542 NTSTATUS process_model_standard_init(TALLOC_CTX *ctx)
544 return register_process_model(&standard_ops);