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"
34 struct standard_child_state {
39 struct tevent_fd *from_child_fde;
42 NTSTATUS process_model_standard_init(void);
44 /* we hold a pipe open in the parent, and the any child
45 processes wait for EOF on that pipe. This ensures that
46 children die when the parent dies */
47 static int child_pipe[2] = { -1, -1 };
50 called when the process model is selected
52 static void standard_model_init(void)
56 rc = pipe(child_pipe);
58 smb_panic("Failed to initialize pipe!");
62 static void sighup_signal_handler(struct tevent_context *ev,
63 struct tevent_signal *se,
64 int signum, int count, void *siginfo,
67 debug_schedule_reopen_logs();
70 static void sigterm_signal_handler(struct tevent_context *ev,
71 struct tevent_signal *se,
72 int signum, int count, void *siginfo,
76 if (getpgrp() == getpid()) {
78 * We're the process group leader, send
79 * SIGTERM to our process group.
81 DEBUG(0,("SIGTERM: killing children\n"));
82 kill(-getpgrp(), SIGTERM);
85 DEBUG(0,("Exiting pid %u on SIGTERM\n", (unsigned int)getpid()));
91 handle EOF on the parent-to-all-children pipe in the child
93 static void standard_pipe_handler(struct tevent_context *event_ctx, struct tevent_fd *fde,
94 uint16_t flags, void *private_data)
96 DEBUG(10,("Child %d exiting\n", (int)getpid()));
97 talloc_free(event_ctx);
102 handle EOF on the child pipe in the parent, so we know when a
103 process terminates without using SIGCHLD or waiting on all possible pids.
105 We need to ensure we do not ignore SIGCHLD because we need it to
106 work to get a valid error code from samba_runcmd_*().
108 static void standard_child_pipe_handler(struct tevent_context *ev,
109 struct tevent_fd *fde,
113 struct standard_child_state *state
114 = talloc_get_type_abort(private_data, struct standard_child_state);
118 /* the child has closed the pipe, assume its dead */
120 pid = waitpid(state->pid, &status, 0);
122 if (pid != state->pid) {
123 if (errno == ECHILD) {
125 * this happens when the
126 * parent has set SIGCHLD to
127 * SIG_IGN. In that case we
129 * information for the child
130 * via its logging. We should
131 * stop using SIG_IGN on
132 * SIGCHLD in the standard
135 DEBUG(0, ("Error in waitpid() unexpectedly got ECHILD "
136 "for child %d (%s) - %s, someone has set SIGCHLD "
138 (int)state->pid, state->name,
143 DEBUG(0, ("Error in waitpid() for child %d (%s) - %s \n",
144 (int)state->pid, state->name, strerror(errno)));
151 if (WIFEXITED(status)) {
152 status = WEXITSTATUS(status);
153 DEBUG(2, ("Child %d (%s) exited with status %d\n",
154 (int)state->pid, state->name, status));
155 } else if (WIFSIGNALED(status)) {
156 status = WTERMSIG(status);
157 DEBUG(0, ("Child %d (%s) terminated with signal %d\n",
158 (int)state->pid, state->name, status));
164 static struct standard_child_state *setup_standard_child_pipe(struct tevent_context *ev,
167 struct standard_child_state *state;
168 int parent_child_pipe[2];
172 * Prepare a pipe to allow us to know when the child exits,
173 * because it will trigger a read event on this private
176 * We do all this before the accept and fork(), so we can
177 * clean up if it fails.
179 state = talloc_zero(ev, struct standard_child_state);
188 state->name = talloc_strdup(state, name);
189 if (state->name == NULL) {
194 ret = pipe(parent_child_pipe);
196 DEBUG(0, ("Failed to create parent-child pipe to handle "
197 "SIGCHLD to track new process for socket\n"));
202 smb_set_close_on_exec(parent_child_pipe[0]);
203 smb_set_close_on_exec(parent_child_pipe[1]);
205 state->from_child_fd = parent_child_pipe[0];
206 state->to_parent_fd = parent_child_pipe[1];
209 * The basic purpose of calling this handler is to ensure we
210 * call waitpid() and so avoid zombies (now that we no longer
211 * user SIGIGN on for SIGCHLD), but it also allows us to clean
212 * up other resources in the future.
214 state->from_child_fde = tevent_add_fd(ev, state,
215 state->from_child_fd,
217 standard_child_pipe_handler,
219 if (state->from_child_fde == NULL) {
223 tevent_fd_set_auto_close(state->from_child_fde);
229 called when a listening socket becomes readable.
231 static void standard_accept_connection(struct tevent_context *ev,
232 struct loadparm_context *lp_ctx,
233 struct socket_context *sock,
234 void (*new_conn)(struct tevent_context *,
235 struct loadparm_context *, struct socket_context *,
236 struct server_id , void *),
240 struct socket_context *sock2;
242 struct socket_address *c, *s;
243 struct standard_child_state *state;
244 struct tevent_fd *fde = NULL;
245 struct tevent_signal *se = NULL;
247 state = setup_standard_child_pipe(ev, 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 */
260 close(state->to_parent_fd);
261 state->to_parent_fd = -1;
269 close(state->to_parent_fd);
270 state->to_parent_fd = -1;
278 /* parent or error code ... */
280 /* go back to the event loop */
284 /* this leaves state->to_parent_fd open */
289 /* This is now the child code. We need a completely new event_context to work with */
291 if (tevent_re_initialise(ev) != 0) {
292 smb_panic("Failed to re-initialise tevent after fork");
295 /* this will free all the listening sockets and all state that
296 is not associated with this new connection */
299 /* we don't care if the dup fails, as its only a select()
300 speed optimisation */
303 /* tdb needs special fork handling */
304 ldb_wrap_fork_hook();
306 /* Must be done after a fork() to reset messaging contexts. */
307 status = imessaging_reinit_all();
308 if (!NT_STATUS_IS_OK(status)) {
309 smb_panic("Failed to re-initialise imessaging after fork");
312 fde = tevent_add_fd(ev, ev, child_pipe[0], TEVENT_FD_READ,
313 standard_pipe_handler, NULL);
315 smb_panic("Failed to add fd handler after fork");
318 if (child_pipe[1] != -1) {
319 close(child_pipe[1]);
323 se = tevent_add_signal(ev,
327 sighup_signal_handler,
330 smb_panic("Failed to add SIGHUP handler after fork");
333 se = tevent_add_signal(ev,
337 sigterm_signal_handler,
340 smb_panic("Failed to add SIGTERM handler after fork");
343 /* setup the process title */
344 c = socket_get_peer_addr(sock2, ev);
345 s = socket_get_my_addr(sock2, ev);
347 setproctitle("conn c[%s:%u] s[%s:%u] server_id[%d]",
348 c->addr, c->port, s->addr, s->port, (int)pid);
353 /* setup this new connection. Cluster ID is PID based for this process model */
354 new_conn(ev, lp_ctx, sock2, cluster_id(pid, 0), private_data);
356 /* we can't return to the top level here, as that event context is gone,
357 so we now process events in the new event context until there are no
359 tevent_loop_wait(ev);
366 called to create a new server task
368 static void standard_new_task(struct tevent_context *ev,
369 struct loadparm_context *lp_ctx,
370 const char *service_name,
371 void (*new_task)(struct tevent_context *, struct loadparm_context *lp_ctx, struct server_id , void *),
376 struct standard_child_state *state;
377 struct tevent_fd *fde = NULL;
378 struct tevent_signal *se = NULL;
380 state = setup_standard_child_pipe(ev, service_name);
388 close(state->to_parent_fd);
389 state->to_parent_fd = -1;
397 /* parent or error code ... go back to the event loop */
401 /* this leaves state->to_parent_fd open */
406 /* this will free all the listening sockets and all state that
407 is not associated with this new connection */
408 if (tevent_re_initialise(ev) != 0) {
409 smb_panic("Failed to re-initialise tevent after fork");
412 /* ldb/tdb need special fork handling */
413 ldb_wrap_fork_hook();
415 /* Must be done after a fork() to reset messaging contexts. */
416 status = imessaging_reinit_all();
417 if (!NT_STATUS_IS_OK(status)) {
418 smb_panic("Failed to re-initialise imessaging after fork");
421 fde = tevent_add_fd(ev, ev, child_pipe[0], TEVENT_FD_READ,
422 standard_pipe_handler, NULL);
424 smb_panic("Failed to add fd handler after fork");
426 if (child_pipe[1] != -1) {
427 close(child_pipe[1]);
431 se = tevent_add_signal(ev,
435 sighup_signal_handler,
438 smb_panic("Failed to add SIGHUP handler after fork");
441 se = tevent_add_signal(ev,
445 sigterm_signal_handler,
448 smb_panic("Failed to add SIGTERM handler after fork");
451 setproctitle("task %s server_id[%d]", service_name, (int)pid);
453 /* setup this new task. Cluster ID is PID based for this process model */
454 new_task(ev, lp_ctx, cluster_id(pid, 0), private_data);
456 /* we can't return to the top level here, as that event context is gone,
457 so we now process events in the new event context until there are no
459 tevent_loop_wait(ev);
466 /* called when a task goes down */
467 _NORETURN_ static void standard_terminate(struct tevent_context *ev, struct loadparm_context *lp_ctx,
470 DEBUG(2,("standard_terminate: reason[%s]\n",reason));
472 /* this reload_charcnv() has the effect of freeing the iconv context memory,
473 which makes leak checking easier */
474 reload_charcnv(lp_ctx);
476 /* Always free event context last before exit. */
479 /* terminate this process */
483 /* called to set a title of a task or connection */
484 static void standard_set_title(struct tevent_context *ev, const char *title)
487 setproctitle("%s", title);
493 static const struct model_ops standard_ops = {
495 .model_init = standard_model_init,
496 .accept_connection = standard_accept_connection,
497 .new_task = standard_new_task,
498 .terminate = standard_terminate,
499 .set_title = standard_set_title,
503 initialise the standard process model, registering ourselves with the process model subsystem
505 NTSTATUS process_model_standard_init(void)
507 return register_process_model(&standard_ops);