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/*
Unix SMB/CIFS implementation.
Winbind background daemon
Copyright (C) Andrew Tridgell 2002
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
the idea of the optional dual daemon mode is ot prevent slow domain
responses from clagging up the rest of the system. When in dual
daemon mode winbindd always responds to requests from cache if the
request is in cache, and if the cached answer is stale then it asks
the "dual daemon" to update the cache for that request
*/
#include "winbindd.h"
extern BOOL opt_dual_daemon;
BOOL backgroud_process = False;
int dual_daemon_pipe = -1;
/* a list of requests ready to be sent to the dual daemon */
struct dual_list {
struct dual_list *next;
char *data;
int length;
int offset;
};
static struct dual_list *dual_list;
static struct dual_list *dual_list_end;
/*
setup a select() including the dual daemon pipe
*/
int dual_select_setup(fd_set *fds, int maxfd)
{
if (dual_daemon_pipe == -1 ||
!dual_list) {
return maxfd;
}
FD_SET(dual_daemon_pipe, fds);
if (dual_daemon_pipe > maxfd) {
maxfd = dual_daemon_pipe;
}
return maxfd;
}
/*
a hook called from the main winbindd select() loop to handle writes
to the dual daemon pipe
*/
void dual_select(fd_set *fds)
{
int n;
if (dual_daemon_pipe == -1 ||
!dual_list ||
!FD_ISSET(dual_daemon_pipe, fds)) {
return;
}
n = write(dual_daemon_pipe,
&dual_list->data[dual_list->offset],
dual_list->length - dual_list->offset);
if (n <= 0) {
/* the pipe is dead! fall back to normal operation */
dual_daemon_pipe = -1;
return;
}
dual_list->offset += n;
if (dual_list->offset == dual_list->length) {
struct dual_list *next;
next = dual_list->next;
free(dual_list->data);
free(dual_list);
dual_list = next;
if (!dual_list) {
dual_list_end = NULL;
}
}
}
/*
send a request to the background daemon
this is called for stale cached entries
*/
void dual_send_request(struct winbindd_cli_state *state)
{
struct dual_list *list;
if (!backgroud_process) return;
list = malloc(sizeof(*list));
if (!list) return;
list->next = NULL;
list->data = memdup(&state->request, sizeof(state->request));
list->length = sizeof(state->request);
list->offset = 0;
if (!dual_list_end) {
dual_list = list;
dual_list_end = list;
} else {
dual_list_end->next = list;
dual_list_end = list;
}
backgroud_process = False;
}
/*
the main dual daemon
*/
void do_dual_daemon(void)
{
int fdpair[2];
struct winbindd_cli_state state;
if (pipe(fdpair) != 0) {
return;
}
ZERO_STRUCT(state);
state.pid = getpid();
dual_daemon_pipe = fdpair[1];
state.sock = fdpair[0];
if (fork() != 0) {
close(fdpair[0]);
return;
}
close(fdpair[1]);
if (winbind_setup_common() != 0) _exit(0);
dual_daemon_pipe = -1;
opt_dual_daemon = False;
while (1) {
/* free up any talloc memory */
lp_talloc_free();
main_loop_talloc_free();
/* fetch a request from the main daemon */
winbind_client_read(&state);
if (state.finished) {
/* we lost contact with our parent */
exit(0);
}
/* process full rquests */
if (state.read_buf_len == sizeof(state.request)) {
DEBUG(4,("dual daemon request %d\n", (int)state.request.cmd));
/* special handling for the stateful requests */
switch (state.request.cmd) {
case WINBINDD_GETPWENT:
winbindd_setpwent(&state);
break;
case WINBINDD_GETGRENT:
winbindd_setgrent(&state);
break;
default:
break;
}
winbind_process_packet(&state);
SAFE_FREE(state.response.extra_data);
free_getent_state(state.getpwent_state);
free_getent_state(state.getgrent_state);
state.getpwent_state = NULL;
state.getgrent_state = NULL;
}
}
}
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