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"
32 struct standard_child_state {
37 struct tevent_fd *from_child_fde;
40 NTSTATUS process_model_standard_init(void);
42 /* we hold a pipe open in the parent, and the any child
43 processes wait for EOF on that pipe. This ensures that
44 children die when the parent dies */
45 static int child_pipe[2] = { -1, -1 };
48 called when the process model is selected
50 static void standard_model_init(void)
54 rc = pipe(child_pipe);
56 smb_panic("Failed to initialze pipe!");
61 handle EOF on the parent-to-all-children pipe in the child
63 static void standard_pipe_handler(struct tevent_context *event_ctx, struct tevent_fd *fde,
64 uint16_t flags, void *private_data)
66 DEBUG(10,("Child %d exiting\n", (int)getpid()));
71 handle EOF on the child pipe in the parent, so we know when a
72 process terminates without using SIGCHLD or waiting on all possible pids.
74 We need to ensure we do not ignore SIGCHLD because we need it to
75 work to get a valid error code from samba_runcmd_*().
77 static void standard_child_pipe_handler(struct tevent_context *ev,
78 struct tevent_fd *fde,
82 struct standard_child_state *state
83 = talloc_get_type_abort(private_data, struct standard_child_state);
87 /* the child has closed the pipe, assume its dead */
89 pid = waitpid(state->pid, &status, 0);
91 if (pid != state->pid) {
92 if (errno == ECHILD) {
94 * this happens when the
95 * parent has set SIGCHLD to
96 * SIG_IGN. In that case we
98 * information for the child
99 * via its logging. We should
100 * stop using SIG_IGN on
101 * SIGCHLD in the standard
104 DEBUG(0, ("Error in waitpid() unexpectedly got ECHILD "
105 "for child %d (%s) - %s, someone has set SIGCHLD "
107 state->pid, state->name, strerror(errno)));
111 DEBUG(0, ("Error in waitpid() for child %d (%s) - %s \n",
112 state->pid, state->name, strerror(errno)));
119 if (WIFEXITED(status)) {
120 status = WEXITSTATUS(status);
121 DEBUG(2, ("Child %d (%s) exited with status %d\n",
122 state->pid, state->name, status));
123 } else if (WIFSIGNALED(status)) {
124 status = WTERMSIG(status);
125 DEBUG(0, ("Child %d (%s) terminated with signal %d\n",
126 state->pid, state->name, status));
132 static struct standard_child_state *setup_standard_child_pipe(struct tevent_context *ev,
135 struct standard_child_state *state;
136 int parent_child_pipe[2];
140 * Prepare a pipe to allow us to know when the child exits,
141 * because it will trigger a read event on this private
144 * We do all this before the accept and fork(), so we can
145 * clean up if it fails.
147 state = talloc_zero(ev, struct standard_child_state);
156 state->name = talloc_strdup(state, name);
157 if (state->name == NULL) {
162 ret = pipe(parent_child_pipe);
164 DEBUG(0, ("Failed to create parent-child pipe to handle "
165 "SIGCHLD to track new process for socket\n"));
170 smb_set_close_on_exec(parent_child_pipe[0]);
171 smb_set_close_on_exec(parent_child_pipe[1]);
173 state->from_child_fd = parent_child_pipe[0];
174 state->to_parent_fd = parent_child_pipe[1];
177 * The basic purpose of calling this handler is to ensure we
178 * call waitpid() and so avoid zombies (now that we no longer
179 * user SIGIGN on for SIGCHLD), but it also allows us to clean
180 * up other resources in the future.
182 state->from_child_fde = tevent_add_fd(ev, state,
183 state->from_child_fd,
185 standard_child_pipe_handler,
187 if (state->from_child_fde == NULL) {
191 tevent_fd_set_auto_close(state->from_child_fde);
197 called when a listening socket becomes readable.
199 static void standard_accept_connection(struct tevent_context *ev,
200 struct loadparm_context *lp_ctx,
201 struct socket_context *sock,
202 void (*new_conn)(struct tevent_context *,
203 struct loadparm_context *, struct socket_context *,
204 struct server_id , void *),
208 struct socket_context *sock2;
210 struct socket_address *c, *s;
211 struct standard_child_state *state;
213 state = setup_standard_child_pipe(ev, NULL);
218 /* accept an incoming connection. */
219 status = socket_accept(sock, &sock2);
220 if (!NT_STATUS_IS_OK(status)) {
221 DEBUG(0,("standard_accept_connection: accept: %s\n",
223 /* this looks strange, but is correct. We need to throttle things until
224 the system clears enough resources to handle this new socket */
226 close(state->to_parent_fd);
227 state->to_parent_fd = -1;
235 close(state->to_parent_fd);
236 state->to_parent_fd = -1;
244 /* parent or error code ... */
246 /* go back to the event loop */
250 /* this leaves state->to_parent_fd open */
255 /* This is now the child code. We need a completely new event_context to work with */
257 if (tevent_re_initialise(ev) != 0) {
258 smb_panic("Failed to re-initialise tevent after fork");
261 /* this will free all the listening sockets and all state that
262 is not associated with this new connection */
265 /* we don't care if the dup fails, as its only a select()
266 speed optimisation */
269 /* tdb needs special fork handling */
270 ldb_wrap_fork_hook();
272 tevent_add_fd(ev, ev, child_pipe[0], TEVENT_FD_READ,
273 standard_pipe_handler, NULL);
274 if (child_pipe[1] != -1) {
275 close(child_pipe[1]);
279 /* Ensure that the forked children do not expose identical random streams */
280 set_need_random_reseed();
282 /* setup the process title */
283 c = socket_get_peer_addr(sock2, ev);
284 s = socket_get_my_addr(sock2, ev);
286 setproctitle("conn c[%s:%u] s[%s:%u] server_id[%d]",
287 c->addr, c->port, s->addr, s->port, (int)pid);
292 /* setup this new connection. Cluster ID is PID based for this process model */
293 new_conn(ev, lp_ctx, sock2, cluster_id(pid, 0), private_data);
295 /* we can't return to the top level here, as that event context is gone,
296 so we now process events in the new event context until there are no
298 tevent_loop_wait(ev);
305 called to create a new server task
307 static void standard_new_task(struct tevent_context *ev,
308 struct loadparm_context *lp_ctx,
309 const char *service_name,
310 void (*new_task)(struct tevent_context *, struct loadparm_context *lp_ctx, struct server_id , void *),
314 struct standard_child_state *state;
316 state = setup_standard_child_pipe(ev, service_name);
324 close(state->to_parent_fd);
325 state->to_parent_fd = -1;
333 /* parent or error code ... go back to the event loop */
337 /* this leaves state->to_parent_fd open */
342 /* this will free all the listening sockets and all state that
343 is not associated with this new connection */
344 if (tevent_re_initialise(ev) != 0) {
345 smb_panic("Failed to re-initialise tevent after fork");
348 /* ldb/tdb need special fork handling */
349 ldb_wrap_fork_hook();
351 tevent_add_fd(ev, ev, child_pipe[0], TEVENT_FD_READ,
352 standard_pipe_handler, NULL);
353 if (child_pipe[1] != -1) {
354 close(child_pipe[1]);
358 /* Ensure that the forked children do not expose identical random streams */
359 set_need_random_reseed();
361 setproctitle("task %s server_id[%d]", service_name, (int)pid);
363 /* setup this new task. Cluster ID is PID based for this process model */
364 new_task(ev, lp_ctx, cluster_id(pid, 0), private_data);
366 /* we can't return to the top level here, as that event context is gone,
367 so we now process events in the new event context until there are no
369 tevent_loop_wait(ev);
376 /* called when a task goes down */
377 _NORETURN_ static void standard_terminate(struct tevent_context *ev, struct loadparm_context *lp_ctx,
380 DEBUG(2,("standard_terminate: reason[%s]\n",reason));
384 /* this reload_charcnv() has the effect of freeing the iconv context memory,
385 which makes leak checking easier */
386 reload_charcnv(lp_ctx);
388 /* terminate this process */
392 /* called to set a title of a task or connection */
393 static void standard_set_title(struct tevent_context *ev, const char *title)
396 setproctitle("%s", title);
402 static const struct model_ops standard_ops = {
404 .model_init = standard_model_init,
405 .accept_connection = standard_accept_connection,
406 .new_task = standard_new_task,
407 .terminate = standard_terminate,
408 .set_title = standard_set_title,
412 initialise the standard process model, registering ourselves with the process model subsystem
414 NTSTATUS process_model_standard_init(void)
416 return register_process_model(&standard_ops);