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samba-mirror/source3/lib/server_prefork.c

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/*
Unix SMB/CIFS implementation.
Common server globals
Copyright (C) Simo Sorce <idra@samba.org> 2011
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 "serverid.h"
#include "messages.h"
#include "system/time.h"
#include "system/shmem.h"
#include "system/filesys.h"
#include "server_prefork.h"
#include "../lib/util/samba_util.h"
#include "../lib/util/tevent_unix.h"
struct prefork_pool {
int listen_fd_size;
int *listen_fds;
prefork_main_fn_t *main_fn;
void *private_data;
int pool_size;
struct pf_worker_data *pool;
int allowed_clients;
prefork_sigchld_fn_t *sigchld_fn;
void *sigchld_data;
};
static bool prefork_setup_sigchld_handler(struct tevent_context *ev_ctx,
struct prefork_pool *pfp);
static int prefork_pool_destructor(struct prefork_pool *pfp)
{
anonymous_shared_free(pfp->pool);
return 0;
}
bool prefork_create_pool(TALLOC_CTX *mem_ctx,
struct tevent_context *ev_ctx,
struct messaging_context *msg_ctx,
int listen_fd_size, int *listen_fds,
int min_children, int max_children,
prefork_main_fn_t *main_fn, void *private_data,
struct prefork_pool **pf_pool)
{
struct prefork_pool *pfp;
pid_t pid;
time_t now = time(NULL);
size_t data_size;
int ret;
int i;
bool ok;
pfp = talloc_zero(mem_ctx, struct prefork_pool);
if (!pfp) {
DEBUG(1, ("Out of memory!\n"));
return false;
}
pfp->listen_fd_size = listen_fd_size;
pfp->listen_fds = talloc_array(pfp, int, listen_fd_size);
if (!pfp->listen_fds) {
DEBUG(1, ("Out of memory!\n"));
return false;
}
for (i = 0; i < listen_fd_size; i++) {
pfp->listen_fds[i] = listen_fds[i];
/* force sockets in non-blocking mode */
set_blocking(listen_fds[i], false);
}
pfp->main_fn = main_fn;
pfp->private_data = private_data;
pfp->pool_size = max_children;
data_size = sizeof(struct pf_worker_data) * max_children;
2011-09-30 12:07:30 +04:00
pfp->pool = (struct pf_worker_data *)anonymous_shared_allocate(
data_size);
if (pfp->pool == NULL) {
DEBUG(1, ("Failed to mmap memory for prefork pool!\n"));
talloc_free(pfp);
return false;
}
talloc_set_destructor(pfp, prefork_pool_destructor);
for (i = 0; i < min_children; i++) {
pfp->pool[i].allowed_clients = 1;
pfp->pool[i].started = now;
pid = sys_fork();
switch (pid) {
case -1:
DEBUG(1, ("Failed to prefork child n. %d !\n", i));
break;
case 0: /* THE CHILD */
pfp->pool[i].status = PF_WORKER_ALIVE;
ret = pfp->main_fn(ev_ctx, msg_ctx,
&pfp->pool[i], i + 1,
pfp->listen_fd_size,
pfp->listen_fds,
pfp->private_data);
exit(ret);
default: /* THE PARENT */
pfp->pool[i].pid = pid;
break;
}
}
ok = prefork_setup_sigchld_handler(ev_ctx, pfp);
if (!ok) {
DEBUG(1, ("Failed to setup SIGCHLD Handler!\n"));
talloc_free(pfp);
return false;
}
*pf_pool = pfp;
return true;
}
/* Provide the new max children number in new_max
* (must be larger than current max).
* Returns: 0 if all fine
* ENOSPC if mremap fails to expand
* EINVAL if new_max is invalid
*/
int prefork_expand_pool(struct prefork_pool *pfp, int new_max)
{
struct prefork_pool *pool;
size_t old_size;
size_t new_size;
int ret;
if (new_max <= pfp->pool_size) {
return EINVAL;
}
old_size = sizeof(struct pf_worker_data) * pfp->pool_size;
new_size = sizeof(struct pf_worker_data) * new_max;
pool = anonymous_shared_resize(&pfp->pool, new_size, false);
if (pool == NULL) {
ret = errno;
DEBUG(3, ("Failed to mremap memory (%d: %s)!\n",
ret, strerror(ret)));
return ret;
}
memset(&pool[pfp->pool_size], 0, new_size - old_size);
pfp->pool_size = new_max;
return 0;
}
int prefork_add_children(struct tevent_context *ev_ctx,
struct messaging_context *msg_ctx,
struct prefork_pool *pfp,
int num_children)
{
pid_t pid;
time_t now = time(NULL);
int ret;
int i, j;
for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
if (pfp->pool[i].status != PF_WORKER_NONE) {
continue;
}
pfp->pool[i].allowed_clients = 1;
pfp->pool[i].started = now;
pid = sys_fork();
switch (pid) {
case -1:
DEBUG(1, ("Failed to prefork child n. %d !\n", j));
break;
case 0: /* THE CHILD */
pfp->pool[i].status = PF_WORKER_ALIVE;
ret = pfp->main_fn(ev_ctx, msg_ctx,
&pfp->pool[i], i + 1,
pfp->listen_fd_size,
pfp->listen_fds,
pfp->private_data);
pfp->pool[i].status = PF_WORKER_EXITING;
exit(ret);
default: /* THE PARENT */
pfp->pool[i].pid = pid;
j++;
break;
}
}
DEBUG(5, ("Added %d children!\n", j));
return j;
}
struct prefork_oldest {
int num;
time_t started;
};
/* sort in inverse order */
static int prefork_sort_oldest(const void *ap, const void *bp)
{
const struct prefork_oldest *a = (const struct prefork_oldest *)ap;
const struct prefork_oldest *b = (const struct prefork_oldest *)bp;
if (a->started == b->started) {
return 0;
}
if (a->started < b->started) {
return 1;
}
return -1;
}
int prefork_retire_children(struct messaging_context *msg_ctx,
struct prefork_pool *pfp,
int num_children, time_t age_limit)
{
const DATA_BLOB ping = data_blob_null;
time_t now = time(NULL);
struct prefork_oldest *oldest;
int i, j;
oldest = talloc_array(pfp, struct prefork_oldest, pfp->pool_size);
if (!oldest) {
return -1;
}
for (i = 0; i < pfp->pool_size; i++) {
oldest[i].num = i;
if (pfp->pool[i].status == PF_WORKER_ALIVE ||
pfp->pool[i].status == PF_WORKER_ACCEPTING) {
oldest[i].started = pfp->pool[i].started;
} else {
oldest[i].started = now;
}
}
qsort(oldest, pfp->pool_size,
sizeof(struct prefork_oldest),
prefork_sort_oldest);
for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
if (((pfp->pool[i].status == PF_WORKER_ALIVE) &&
(pfp->pool[i].num_clients < 1)) &&
(pfp->pool[i].started <= age_limit)) {
/* tell the child it's time to give up */
DEBUG(5, ("Retiring pid %d!\n", pfp->pool[i].pid));
pfp->pool[i].cmds = PF_SRV_MSG_EXIT;
messaging_send(msg_ctx,
pid_to_procid(pfp->pool[i].pid),
MSG_PREFORK_PARENT_EVENT, &ping);
j++;
}
}
return j;
}
int prefork_count_children(struct prefork_pool *pfp, int *active)
{
int i, a, t;
a = 0;
t = 0;
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE) {
continue;
}
t++;
if ((pfp->pool[i].status == PF_WORKER_EXITING) ||
(pfp->pool[i].num_clients <= 0)) {
continue;
}
a++;
}
if (active) {
*active = a;
}
return t;
}
static void prefork_cleanup_loop(struct prefork_pool *pfp)
{
int status;
pid_t pid;
int i;
/* TODO: should we use a process group id wait instead of looping ? */
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE ||
pfp->pool[i].pid == 0) {
continue;
}
pid = sys_waitpid(pfp->pool[i].pid, &status, WNOHANG);
if (pid > 0) {
if (pfp->pool[i].status != PF_WORKER_EXITING) {
DEBUG(3, ("Child (%d) terminated abnormally:"
" %d\n", (int)pid, status));
} else {
DEBUG(10, ("Child (%d) terminated with status:"
" %d\n", (int)pid, status));
}
/* reset all fields,
* this makes status = PF_WORK_NONE */
memset(&pfp->pool[i], 0,
sizeof(struct pf_worker_data));
}
}
}
int prefork_count_allowed_connections(struct prefork_pool *pfp)
{
int c;
int i;
c = 0;
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE ||
pfp->pool[i].status == PF_WORKER_EXITING) {
continue;
}
if (pfp->pool[i].num_clients < 0) {
continue;
}
c += pfp->pool[i].allowed_clients - pfp->pool[i].num_clients;
}
return c;
}
void prefork_increase_allowed_clients(struct prefork_pool *pfp, int max)
{
int i;
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE ||
pfp->pool[i].status == PF_WORKER_EXITING) {
continue;
}
if (pfp->pool[i].num_clients < 0) {
continue;
}
if (pfp->pool[i].allowed_clients < max) {
pfp->pool[i].allowed_clients++;
}
}
}
void prefork_decrease_allowed_clients(struct prefork_pool *pfp)
{
int i;
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE ||
pfp->pool[i].status == PF_WORKER_EXITING) {
continue;
}
if (pfp->pool[i].num_clients < 0) {
continue;
}
if (pfp->pool[i].allowed_clients > 1) {
pfp->pool[i].allowed_clients--;
}
}
}
void prefork_reset_allowed_clients(struct prefork_pool *pfp)
{
int i;
for (i = 0; i < pfp->pool_size; i++) {
pfp->pool[i].allowed_clients = 1;
}
}
void prefork_send_signal_to_all(struct prefork_pool *pfp, int signal_num)
{
int i;
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE) {
continue;
}
kill(pfp->pool[i].pid, signal_num);
}
}
void prefork_warn_active_children(struct messaging_context *msg_ctx,
struct prefork_pool *pfp)
{
const DATA_BLOB ping = data_blob_null;
int i;
for (i = 0; i < pfp->pool_size; i++) {
if (pfp->pool[i].status == PF_WORKER_NONE) {
continue;
}
messaging_send(msg_ctx,
pid_to_procid(pfp->pool[i].pid),
MSG_PREFORK_PARENT_EVENT, &ping);
}
}
static void prefork_sigchld_handler(struct tevent_context *ev_ctx,
struct tevent_signal *se,
int signum, int count,
void *siginfo, void *pvt)
{
struct prefork_pool *pfp;
pfp = talloc_get_type_abort(pvt, struct prefork_pool);
/* run the cleanup function to make sure all dead children are
* properly and timely retired. */
prefork_cleanup_loop(pfp);
if (pfp->sigchld_fn) {
pfp->sigchld_fn(ev_ctx, pfp, pfp->sigchld_data);
}
}
static bool prefork_setup_sigchld_handler(struct tevent_context *ev_ctx,
struct prefork_pool *pfp)
{
struct tevent_signal *se;
se = tevent_add_signal(ev_ctx, pfp, SIGCHLD, 0,
prefork_sigchld_handler, pfp);
if (!se) {
DEBUG(0, ("Failed to setup SIGCHLD handler!\n"));
return false;
}
return true;
}
void prefork_set_sigchld_callback(struct prefork_pool *pfp,
prefork_sigchld_fn_t *sigchld_fn,
void *private_data)
{
pfp->sigchld_fn = sigchld_fn;
pfp->sigchld_data = private_data;
}
/* ==== Functions used by children ==== */
struct pf_listen_state {
struct tevent_context *ev;
struct pf_worker_data *pf;
int listen_fd_size;
int *listen_fds;
int accept_fd;
struct tsocket_address *srv_addr;
struct tsocket_address *cli_addr;
int error;
};
struct pf_listen_ctx {
TALLOC_CTX *fde_ctx;
struct tevent_req *req;
int listen_fd;
};
static void prefork_listen_accept_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags, void *pvt);
struct tevent_req *prefork_listen_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct pf_worker_data *pf,
int listen_fd_size,
int *listen_fds)
{
struct tevent_req *req;
struct pf_listen_state *state;
struct pf_listen_ctx *ctx;
struct tevent_fd *fde;
TALLOC_CTX *fde_ctx;
int i;
req = tevent_req_create(mem_ctx, &state, struct pf_listen_state);
if (!req) {
return NULL;
}
state->ev = ev;
state->pf = pf;
state->listen_fd_size = listen_fd_size;
state->listen_fds = listen_fds;
state->accept_fd = -1;
state->error = 0;
fde_ctx = talloc_new(state);
if (tevent_req_nomem(fde_ctx, req)) {
return tevent_req_post(req, ev);
}
/* race on accept */
for (i = 0; i < state->listen_fd_size; i++) {
ctx = talloc(fde_ctx, struct pf_listen_ctx);
if (tevent_req_nomem(ctx, req)) {
return tevent_req_post(req, ev);
}
ctx->fde_ctx = fde_ctx;
ctx->req = req;
ctx->listen_fd = state->listen_fds[i];
fde = tevent_add_fd(state->ev, fde_ctx,
ctx->listen_fd, TEVENT_FD_READ,
prefork_listen_accept_handler, ctx);
if (tevent_req_nomem(fde, req)) {
return tevent_req_post(req, ev);
}
}
pf->status = PF_WORKER_ACCEPTING;
return req;
}
static void prefork_listen_accept_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags, void *pvt)
{
struct pf_listen_state *state;
struct tevent_req *req;
struct pf_listen_ctx *ctx;
struct sockaddr_storage addr;
socklen_t addrlen;
int soerr = 0;
socklen_t solen = sizeof(soerr);
int sd = -1;
int ret;
ctx = talloc_get_type_abort(pvt, struct pf_listen_ctx);
req = ctx->req;
state = tevent_req_data(ctx->req, struct pf_listen_state);
if ((state->pf->cmds == PF_SRV_MSG_EXIT) &&
(state->pf->num_clients <= 0)) {
/* We have been asked to exit, so drop here and the next
* child will pick it up */
state->pf->status = PF_WORKER_EXITING;
state->error = EINTR;
goto done;
}
/* before proceeding check that the listening fd is ok */
ret = getsockopt(ctx->listen_fd, SOL_SOCKET, SO_ERROR, &soerr, &solen);
if (ret == -1) {
/* this is a fatal error, we cannot continue listening */
state->error = EBADF;
goto done;
}
if (soerr != 0) {
/* this is a fatal error, we cannot continue listening */
state->error = soerr;
goto done;
}
ZERO_STRUCT(addr);
addrlen = sizeof(addr);
sd = accept(ctx->listen_fd, (struct sockaddr *)&addr, &addrlen);
if (sd == -1) {
state->error = errno;
DEBUG(6, ("Accept failed! (%d, %s)\n",
state->error, strerror(state->error)));
goto done;
}
state->accept_fd = sd;
ret = tsocket_address_bsd_from_sockaddr(state,
(struct sockaddr *)(void *)&addr,
addrlen, &state->cli_addr);
if (ret < 0) {
state->error = errno;
goto done;
}
ZERO_STRUCT(addr);
addrlen = sizeof(addr);
ret = getsockname(sd, (struct sockaddr *)(void *)&addr, &addrlen);
if (ret < 0) {
state->error = errno;
goto done;
}
ret = tsocket_address_bsd_from_sockaddr(state,
(struct sockaddr *)(void *)&addr,
addrlen, &state->srv_addr);
if (ret < 0) {
state->error = errno;
goto done;
}
done:
/* do not track the listen fds anymore */
talloc_free(ctx->fde_ctx);
tevent_req_done(req);
}
int prefork_listen_recv(struct tevent_req *req,
TALLOC_CTX *mem_ctx, int *fd,
struct tsocket_address **srv_addr,
struct tsocket_address **cli_addr)
{
struct pf_listen_state *state;
int ret = 0;
state = tevent_req_data(req, struct pf_listen_state);
if (state->error) {
ret = state->error;
} else {
tevent_req_is_unix_error(req, &ret);
}
if (ret) {
if (state->accept_fd != -1) {
close(state->accept_fd);
}
} else {
*fd = state->accept_fd;
*srv_addr = talloc_move(mem_ctx, &state->srv_addr);
*cli_addr = talloc_move(mem_ctx, &state->cli_addr);
state->pf->num_clients++;
}
if (state->pf->status == PF_WORKER_ACCEPTING) {
state->pf->status = PF_WORKER_ALIVE;
}
tevent_req_received(req);
return ret;
}