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samba-mirror/source3/lib/messages.c

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/*
Unix SMB/CIFS implementation.
Samba internal messaging functions
Copyright (C) Andrew Tridgell 2000
Copyright (C) 2001 by Martin Pool
Copyright (C) 2002 by Jeremy Allison
Copyright (C) 2007 by Volker Lendecke
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/>.
*/
/**
@defgroup messages Internal messaging framework
@{
@file messages.c
@brief Module for internal messaging between Samba daemons.
The idea is that if a part of Samba wants to do communication with
another Samba process then it will do a message_register() of a
dispatch function, and use message_send_pid() to send messages to
that process.
The dispatch function is given the pid of the sender, and it can
use that to reply by message_send_pid(). See ping_message() for a
simple example.
@caution Dispatch functions must be able to cope with incoming
messages on an *odd* byte boundary.
This system doesn't have any inherent size limitations but is not
very efficient for large messages or when messages are sent in very
quick succession.
*/
#include "includes.h"
#include "dbwrap/dbwrap.h"
#include "serverid.h"
#include "messages.h"
#include "lib/util/tevent_unix.h"
#include "lib/background.h"
struct messaging_callback {
struct messaging_callback *prev, *next;
uint32 msg_type;
void (*fn)(struct messaging_context *msg, void *private_data,
uint32_t msg_type,
struct server_id server_id, DATA_BLOB *data);
void *private_data;
};
/****************************************************************************
A useful function for testing the message system.
****************************************************************************/
static void ping_message(struct messaging_context *msg_ctx,
void *private_data,
uint32_t msg_type,
struct server_id src,
DATA_BLOB *data)
{
const char *msg = "none";
char *free_me = NULL;
if (data->data != NULL) {
free_me = talloc_strndup(talloc_tos(), (char *)data->data,
data->length);
msg = free_me;
}
DEBUG(1,("INFO: Received PING message from PID %s [%s]\n",
procid_str_static(&src), msg));
TALLOC_FREE(free_me);
messaging_send(msg_ctx, src, MSG_PONG, data);
}
/****************************************************************************
Register/replace a dispatch function for a particular message type.
JRA changed Dec 13 2006. Only one message handler now permitted per type.
*NOTE*: Dispatch functions must be able to cope with incoming
messages on an *odd* byte boundary.
****************************************************************************/
struct msg_all {
struct messaging_context *msg_ctx;
int msg_type;
uint32 msg_flag;
const void *buf;
size_t len;
int n_sent;
};
/****************************************************************************
Send one of the messages for the broadcast.
****************************************************************************/
s3: Fix a long-standing problem with recycled PIDs When a samba server process dies hard, it has no chance to clean up its entries in locking.tdb, brlock.tdb, connections.tdb and sessionid.tdb. For locking.tdb and brlock.tdb Samba is robust by checking every time we read an entry from the database if the corresponding process still exists. If it does not exist anymore, the entry is deleted. This is not 100% failsafe though: On systems with a limited PID space there is a non-zero chance that between the smbd's death and the fresh access, the PID is recycled by another long-running process. This renders all files that had been locked by the killed smbd potentially unusable until the new process also dies. This patch is supposed to fix the problem the following way: Every process ID in every database is augmented by a random 64-bit number that is stored in a serverid.tdb. Whenever we need to check if a process still exists we know its PID and the 64-bit number. We look up the PID in serverid.tdb and compare the 64-bit number. If it's the same, the process still is a valid smbd holding the lock. If it is different, a new smbd has taken over. I believe this is safe against an smbd that has died hard and the PID has been taken over by a non-samba process. This process would not have registered itself with a fresh 64-bit number in serverid.tdb, so the old one still exists in serverid.tdb. We protect against this case by the parent smbd taking care of deregistering PIDs from serverid.tdb and the fact that serverid.tdb is CLEAR_IF_FIRST. CLEAR_IF_FIRST does not work in a cluster, so the automatic cleanup does not work when all smbds are restarted. For this, "net serverid wipe" has to be run before smbd starts up. As a convenience, "net serverid wipedbs" also cleans up sessionid.tdb and connections.tdb. While there, this also cleans up overloading connections.tdb with all the process entries just for messaging_send_all(). Volker
2010-03-02 19:02:01 +03:00
static int traverse_fn(struct db_record *rec, const struct server_id *id,
uint32_t msg_flags, void *state)
{
struct msg_all *msg_all = (struct msg_all *)state;
NTSTATUS status;
/* Don't send if the receiver hasn't registered an interest. */
s3: Fix a long-standing problem with recycled PIDs When a samba server process dies hard, it has no chance to clean up its entries in locking.tdb, brlock.tdb, connections.tdb and sessionid.tdb. For locking.tdb and brlock.tdb Samba is robust by checking every time we read an entry from the database if the corresponding process still exists. If it does not exist anymore, the entry is deleted. This is not 100% failsafe though: On systems with a limited PID space there is a non-zero chance that between the smbd's death and the fresh access, the PID is recycled by another long-running process. This renders all files that had been locked by the killed smbd potentially unusable until the new process also dies. This patch is supposed to fix the problem the following way: Every process ID in every database is augmented by a random 64-bit number that is stored in a serverid.tdb. Whenever we need to check if a process still exists we know its PID and the 64-bit number. We look up the PID in serverid.tdb and compare the 64-bit number. If it's the same, the process still is a valid smbd holding the lock. If it is different, a new smbd has taken over. I believe this is safe against an smbd that has died hard and the PID has been taken over by a non-samba process. This process would not have registered itself with a fresh 64-bit number in serverid.tdb, so the old one still exists in serverid.tdb. We protect against this case by the parent smbd taking care of deregistering PIDs from serverid.tdb and the fact that serverid.tdb is CLEAR_IF_FIRST. CLEAR_IF_FIRST does not work in a cluster, so the automatic cleanup does not work when all smbds are restarted. For this, "net serverid wipe" has to be run before smbd starts up. As a convenience, "net serverid wipedbs" also cleans up sessionid.tdb and connections.tdb. While there, this also cleans up overloading connections.tdb with all the process entries just for messaging_send_all(). Volker
2010-03-02 19:02:01 +03:00
if((msg_flags & msg_all->msg_flag) == 0) {
return 0;
s3: Fix a long-standing problem with recycled PIDs When a samba server process dies hard, it has no chance to clean up its entries in locking.tdb, brlock.tdb, connections.tdb and sessionid.tdb. For locking.tdb and brlock.tdb Samba is robust by checking every time we read an entry from the database if the corresponding process still exists. If it does not exist anymore, the entry is deleted. This is not 100% failsafe though: On systems with a limited PID space there is a non-zero chance that between the smbd's death and the fresh access, the PID is recycled by another long-running process. This renders all files that had been locked by the killed smbd potentially unusable until the new process also dies. This patch is supposed to fix the problem the following way: Every process ID in every database is augmented by a random 64-bit number that is stored in a serverid.tdb. Whenever we need to check if a process still exists we know its PID and the 64-bit number. We look up the PID in serverid.tdb and compare the 64-bit number. If it's the same, the process still is a valid smbd holding the lock. If it is different, a new smbd has taken over. I believe this is safe against an smbd that has died hard and the PID has been taken over by a non-samba process. This process would not have registered itself with a fresh 64-bit number in serverid.tdb, so the old one still exists in serverid.tdb. We protect against this case by the parent smbd taking care of deregistering PIDs from serverid.tdb and the fact that serverid.tdb is CLEAR_IF_FIRST. CLEAR_IF_FIRST does not work in a cluster, so the automatic cleanup does not work when all smbds are restarted. For this, "net serverid wipe" has to be run before smbd starts up. As a convenience, "net serverid wipedbs" also cleans up sessionid.tdb and connections.tdb. While there, this also cleans up overloading connections.tdb with all the process entries just for messaging_send_all(). Volker
2010-03-02 19:02:01 +03:00
}
/* If the msg send fails because the pid was not found (i.e. smbd died),
* the msg has already been deleted from the messages.tdb.*/
s3: Fix a long-standing problem with recycled PIDs When a samba server process dies hard, it has no chance to clean up its entries in locking.tdb, brlock.tdb, connections.tdb and sessionid.tdb. For locking.tdb and brlock.tdb Samba is robust by checking every time we read an entry from the database if the corresponding process still exists. If it does not exist anymore, the entry is deleted. This is not 100% failsafe though: On systems with a limited PID space there is a non-zero chance that between the smbd's death and the fresh access, the PID is recycled by another long-running process. This renders all files that had been locked by the killed smbd potentially unusable until the new process also dies. This patch is supposed to fix the problem the following way: Every process ID in every database is augmented by a random 64-bit number that is stored in a serverid.tdb. Whenever we need to check if a process still exists we know its PID and the 64-bit number. We look up the PID in serverid.tdb and compare the 64-bit number. If it's the same, the process still is a valid smbd holding the lock. If it is different, a new smbd has taken over. I believe this is safe against an smbd that has died hard and the PID has been taken over by a non-samba process. This process would not have registered itself with a fresh 64-bit number in serverid.tdb, so the old one still exists in serverid.tdb. We protect against this case by the parent smbd taking care of deregistering PIDs from serverid.tdb and the fact that serverid.tdb is CLEAR_IF_FIRST. CLEAR_IF_FIRST does not work in a cluster, so the automatic cleanup does not work when all smbds are restarted. For this, "net serverid wipe" has to be run before smbd starts up. As a convenience, "net serverid wipedbs" also cleans up sessionid.tdb and connections.tdb. While there, this also cleans up overloading connections.tdb with all the process entries just for messaging_send_all(). Volker
2010-03-02 19:02:01 +03:00
status = messaging_send_buf(msg_all->msg_ctx, *id, msg_all->msg_type,
(const uint8_t *)msg_all->buf, msg_all->len);
if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
2011-10-31 15:40:58 +04:00
/*
* If the pid was not found delete the entry from
* serverid.tdb
*/
s3: Fix a long-standing problem with recycled PIDs When a samba server process dies hard, it has no chance to clean up its entries in locking.tdb, brlock.tdb, connections.tdb and sessionid.tdb. For locking.tdb and brlock.tdb Samba is robust by checking every time we read an entry from the database if the corresponding process still exists. If it does not exist anymore, the entry is deleted. This is not 100% failsafe though: On systems with a limited PID space there is a non-zero chance that between the smbd's death and the fresh access, the PID is recycled by another long-running process. This renders all files that had been locked by the killed smbd potentially unusable until the new process also dies. This patch is supposed to fix the problem the following way: Every process ID in every database is augmented by a random 64-bit number that is stored in a serverid.tdb. Whenever we need to check if a process still exists we know its PID and the 64-bit number. We look up the PID in serverid.tdb and compare the 64-bit number. If it's the same, the process still is a valid smbd holding the lock. If it is different, a new smbd has taken over. I believe this is safe against an smbd that has died hard and the PID has been taken over by a non-samba process. This process would not have registered itself with a fresh 64-bit number in serverid.tdb, so the old one still exists in serverid.tdb. We protect against this case by the parent smbd taking care of deregistering PIDs from serverid.tdb and the fact that serverid.tdb is CLEAR_IF_FIRST. CLEAR_IF_FIRST does not work in a cluster, so the automatic cleanup does not work when all smbds are restarted. For this, "net serverid wipe" has to be run before smbd starts up. As a convenience, "net serverid wipedbs" also cleans up sessionid.tdb and connections.tdb. While there, this also cleans up overloading connections.tdb with all the process entries just for messaging_send_all(). Volker
2010-03-02 19:02:01 +03:00
DEBUG(2, ("pid %s doesn't exist\n", procid_str_static(id)));
dbwrap_record_delete(rec);
}
msg_all->n_sent++;
return 0;
}
/**
* Send a message to all smbd processes.
*
* It isn't very efficient, but should be OK for the sorts of
* applications that use it. When we need efficient broadcast we can add
* it.
*
* @param n_sent Set to the number of messages sent. This should be
* equal to the number of processes, but be careful for races.
*
* @retval True for success.
**/
bool message_send_all(struct messaging_context *msg_ctx,
int msg_type,
const void *buf, size_t len,
int *n_sent)
{
struct msg_all msg_all;
msg_all.msg_type = msg_type;
if (msg_type < 0x100) {
msg_all.msg_flag = FLAG_MSG_GENERAL;
} else if (msg_type > 0x100 && msg_type < 0x200) {
msg_all.msg_flag = FLAG_MSG_NMBD;
} else if (msg_type > 0x200 && msg_type < 0x300) {
msg_all.msg_flag = FLAG_MSG_PRINT_GENERAL;
} else if (msg_type > 0x300 && msg_type < 0x400) {
msg_all.msg_flag = FLAG_MSG_SMBD;
} else if (msg_type > 0x400 && msg_type < 0x600) {
msg_all.msg_flag = FLAG_MSG_WINBIND;
} else if (msg_type > 4000 && msg_type < 5000) {
msg_all.msg_flag = FLAG_MSG_DBWRAP;
} else {
return false;
}
msg_all.buf = buf;
msg_all.len = len;
msg_all.n_sent = 0;
msg_all.msg_ctx = msg_ctx;
s3: Fix a long-standing problem with recycled PIDs When a samba server process dies hard, it has no chance to clean up its entries in locking.tdb, brlock.tdb, connections.tdb and sessionid.tdb. For locking.tdb and brlock.tdb Samba is robust by checking every time we read an entry from the database if the corresponding process still exists. If it does not exist anymore, the entry is deleted. This is not 100% failsafe though: On systems with a limited PID space there is a non-zero chance that between the smbd's death and the fresh access, the PID is recycled by another long-running process. This renders all files that had been locked by the killed smbd potentially unusable until the new process also dies. This patch is supposed to fix the problem the following way: Every process ID in every database is augmented by a random 64-bit number that is stored in a serverid.tdb. Whenever we need to check if a process still exists we know its PID and the 64-bit number. We look up the PID in serverid.tdb and compare the 64-bit number. If it's the same, the process still is a valid smbd holding the lock. If it is different, a new smbd has taken over. I believe this is safe against an smbd that has died hard and the PID has been taken over by a non-samba process. This process would not have registered itself with a fresh 64-bit number in serverid.tdb, so the old one still exists in serverid.tdb. We protect against this case by the parent smbd taking care of deregistering PIDs from serverid.tdb and the fact that serverid.tdb is CLEAR_IF_FIRST. CLEAR_IF_FIRST does not work in a cluster, so the automatic cleanup does not work when all smbds are restarted. For this, "net serverid wipe" has to be run before smbd starts up. As a convenience, "net serverid wipedbs" also cleans up sessionid.tdb and connections.tdb. While there, this also cleans up overloading connections.tdb with all the process entries just for messaging_send_all(). Volker
2010-03-02 19:02:01 +03:00
serverid_traverse(traverse_fn, &msg_all);
if (n_sent)
*n_sent = msg_all.n_sent;
return true;
}
struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
struct tevent_context *ev)
{
struct messaging_context *ctx;
NTSTATUS status;
if (!(ctx = talloc_zero(mem_ctx, struct messaging_context))) {
return NULL;
}
ctx->id = procid_self();
ctx->event_ctx = ev;
status = messaging_dgm_init(ctx, ctx, &ctx->local);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(2, ("messaging_dgm_init failed: %s\n",
nt_errstr(status)));
TALLOC_FREE(ctx);
return NULL;
}
if (lp_clustering()) {
status = messaging_ctdbd_init(ctx, ctx, &ctx->remote);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(2, ("messaging_ctdbd_init failed: %s\n",
nt_errstr(status)));
TALLOC_FREE(ctx);
return NULL;
}
}
ctx->id.vnn = get_my_vnn();
messaging_register(ctx, NULL, MSG_PING, ping_message);
/* Register some debugging related messages */
register_msg_pool_usage(ctx);
register_dmalloc_msgs(ctx);
debug_register_msgs(ctx);
return ctx;
}
2010-07-04 19:57:57 +04:00
struct server_id messaging_server_id(const struct messaging_context *msg_ctx)
{
return msg_ctx->id;
}
/*
* re-init after a fork
*/
NTSTATUS messaging_reinit(struct messaging_context *msg_ctx)
{
NTSTATUS status;
TALLOC_FREE(msg_ctx->local);
msg_ctx->id = procid_self();
status = messaging_dgm_init(msg_ctx, msg_ctx, &msg_ctx->local);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0, ("messaging_dgm_init failed: %s\n",
nt_errstr(status)));
return status;
}
TALLOC_FREE(msg_ctx->remote);
if (lp_clustering()) {
status = messaging_ctdbd_init(msg_ctx, msg_ctx,
&msg_ctx->remote);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("messaging_ctdbd_init failed: %s\n",
nt_errstr(status)));
return status;
}
}
return NT_STATUS_OK;
}
/*
* Register a dispatch function for a particular message type. Allow multiple
* registrants
*/
NTSTATUS messaging_register(struct messaging_context *msg_ctx,
void *private_data,
uint32_t msg_type,
void (*fn)(struct messaging_context *msg,
void *private_data,
uint32_t msg_type,
struct server_id server_id,
DATA_BLOB *data))
{
struct messaging_callback *cb;
DEBUG(5, ("Registering messaging pointer for type %u - "
"private_data=%p\n",
(unsigned)msg_type, private_data));
/*
* Only one callback per type
*/
for (cb = msg_ctx->callbacks; cb != NULL; cb = cb->next) {
/* we allow a second registration of the same message
type if it has a different private pointer. This is
needed in, for example, the internal notify code,
which creates a new notify context for each tree
connect, and expects to receive messages to each of
them. */
if (cb->msg_type == msg_type && private_data == cb->private_data) {
DEBUG(5,("Overriding messaging pointer for type %u - private_data=%p\n",
(unsigned)msg_type, private_data));
cb->fn = fn;
cb->private_data = private_data;
return NT_STATUS_OK;
}
}
if (!(cb = talloc(msg_ctx, struct messaging_callback))) {
return NT_STATUS_NO_MEMORY;
}
cb->msg_type = msg_type;
cb->fn = fn;
cb->private_data = private_data;
DLIST_ADD(msg_ctx->callbacks, cb);
return NT_STATUS_OK;
}
/*
De-register the function for a particular message type.
*/
void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
void *private_data)
{
struct messaging_callback *cb, *next;
for (cb = ctx->callbacks; cb; cb = next) {
next = cb->next;
if ((cb->msg_type == msg_type)
&& (cb->private_data == private_data)) {
DEBUG(5,("Deregistering messaging pointer for type %u - private_data=%p\n",
(unsigned)msg_type, private_data));
DLIST_REMOVE(ctx->callbacks, cb);
TALLOC_FREE(cb);
}
}
}
static bool messaging_is_self_send(const struct messaging_context *msg_ctx,
const struct server_id *dst)
{
return ((msg_ctx->id.vnn == dst->vnn) &&
(msg_ctx->id.pid == dst->pid));
}
/*
Send a message to a particular server
*/
NTSTATUS messaging_send(struct messaging_context *msg_ctx,
struct server_id server, uint32_t msg_type,
const DATA_BLOB *data)
{
if (server_id_is_disconnected(&server)) {
return NT_STATUS_INVALID_PARAMETER_MIX;
}
if (!procid_is_local(&server)) {
return msg_ctx->remote->send_fn(msg_ctx, server,
msg_type, data,
msg_ctx->remote);
}
if (messaging_is_self_send(msg_ctx, &server)) {
struct messaging_rec rec;
rec.msg_version = MESSAGE_VERSION;
rec.msg_type = msg_type & MSG_TYPE_MASK;
rec.dest = server;
rec.src = msg_ctx->id;
rec.buf = *data;
messaging_dispatch_rec(msg_ctx, &rec);
return NT_STATUS_OK;
}
return msg_ctx->local->send_fn(msg_ctx, server, msg_type, data,
msg_ctx->local);
}
NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx,
struct server_id server, uint32_t msg_type,
const uint8_t *buf, size_t len)
{
DATA_BLOB blob = data_blob_const(buf, len);
return messaging_send(msg_ctx, server, msg_type, &blob);
}
NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx,
struct server_id server, uint32_t msg_type,
const struct iovec *iov, int iovlen)
{
uint8_t *buf;
NTSTATUS status;
buf = iov_buf(talloc_tos(), iov, iovlen);
if (buf == NULL) {
return NT_STATUS_NO_MEMORY;
}
status = messaging_send_buf(msg_ctx, server, msg_type,
buf, talloc_get_size(buf));
TALLOC_FREE(buf);
return status;
}
static struct messaging_rec *messaging_rec_dup(TALLOC_CTX *mem_ctx,
struct messaging_rec *rec)
{
struct messaging_rec *result;
result = talloc_pooled_object(mem_ctx, struct messaging_rec,
1, rec->buf.length);
if (result == NULL) {
return NULL;
}
*result = *rec;
/* Doesn't fail, see talloc_pooled_object */
result->buf.data = talloc_memdup(result, rec->buf.data,
rec->buf.length);
return result;
}
struct messaging_filtered_read_state {
struct tevent_context *ev;
struct messaging_context *msg_ctx;
void *tevent_handle;
bool (*filter)(struct messaging_rec *rec, void *private_data);
void *private_data;
struct messaging_rec *rec;
};
static void messaging_filtered_read_cleanup(struct tevent_req *req,
enum tevent_req_state req_state);
struct tevent_req *messaging_filtered_read_send(
TALLOC_CTX *mem_ctx, struct tevent_context *ev,
struct messaging_context *msg_ctx,
bool (*filter)(struct messaging_rec *rec, void *private_data),
void *private_data)
{
struct tevent_req *req;
struct messaging_filtered_read_state *state;
size_t new_waiters_len;
req = tevent_req_create(mem_ctx, &state,
struct messaging_filtered_read_state);
if (req == NULL) {
return NULL;
}
state->ev = ev;
state->msg_ctx = msg_ctx;
state->filter = filter;
state->private_data = private_data;
/*
* We have to defer the callback here, as we might be called from
* within a different tevent_context than state->ev
*/
tevent_req_defer_callback(req, state->ev);
state->tevent_handle = messaging_dgm_register_tevent_context(
state, msg_ctx, ev);
if (tevent_req_nomem(state, req)) {
return tevent_req_post(req, ev);
}
/*
* We add ourselves to the "new_waiters" array, not the "waiters"
* array. If we are called from within messaging_read_done,
* messaging_dispatch_rec will be in an active for-loop on
* "waiters". We must be careful not to mess with this array, because
* it could mean that a single event is being delivered twice.
*/
new_waiters_len = talloc_array_length(msg_ctx->new_waiters);
if (new_waiters_len == msg_ctx->num_new_waiters) {
struct tevent_req **tmp;
tmp = talloc_realloc(msg_ctx, msg_ctx->new_waiters,
struct tevent_req *, new_waiters_len+1);
if (tevent_req_nomem(tmp, req)) {
return tevent_req_post(req, ev);
}
msg_ctx->new_waiters = tmp;
}
msg_ctx->new_waiters[msg_ctx->num_new_waiters] = req;
msg_ctx->num_new_waiters += 1;
tevent_req_set_cleanup_fn(req, messaging_filtered_read_cleanup);
return req;
}
static void messaging_filtered_read_cleanup(struct tevent_req *req,
enum tevent_req_state req_state)
{
struct messaging_filtered_read_state *state = tevent_req_data(
req, struct messaging_filtered_read_state);
struct messaging_context *msg_ctx = state->msg_ctx;
unsigned i;
tevent_req_set_cleanup_fn(req, NULL);
TALLOC_FREE(state->tevent_handle);
/*
* Just set the [new_]waiters entry to NULL, be careful not to mess
* with the other "waiters" array contents. We are often called from
* within "messaging_dispatch_rec", which loops over
* "waiters". Messing with the "waiters" array will mess up that
* for-loop.
*/
for (i=0; i<msg_ctx->num_waiters; i++) {
if (msg_ctx->waiters[i] == req) {
msg_ctx->waiters[i] = NULL;
return;
}
}
for (i=0; i<msg_ctx->num_new_waiters; i++) {
if (msg_ctx->new_waiters[i] == req) {
msg_ctx->new_waiters[i] = NULL;
return;
}
}
}
static void messaging_filtered_read_done(struct tevent_req *req,
struct messaging_rec *rec)
{
struct messaging_filtered_read_state *state = tevent_req_data(
req, struct messaging_filtered_read_state);
state->rec = messaging_rec_dup(state, rec);
if (tevent_req_nomem(state->rec, req)) {
return;
}
tevent_req_done(req);
}
int messaging_filtered_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
struct messaging_rec **presult)
{
struct messaging_filtered_read_state *state = tevent_req_data(
req, struct messaging_filtered_read_state);
int err;
if (tevent_req_is_unix_error(req, &err)) {
tevent_req_received(req);
return err;
}
*presult = talloc_move(mem_ctx, &state->rec);
return 0;
}
struct messaging_read_state {
uint32_t msg_type;
struct messaging_rec *rec;
};
static bool messaging_read_filter(struct messaging_rec *rec,
void *private_data);
static void messaging_read_done(struct tevent_req *subreq);
struct tevent_req *messaging_read_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct messaging_context *msg,
uint32_t msg_type)
{
struct tevent_req *req, *subreq;
struct messaging_read_state *state;
req = tevent_req_create(mem_ctx, &state,
struct messaging_read_state);
if (req == NULL) {
return NULL;
}
state->msg_type = msg_type;
subreq = messaging_filtered_read_send(state, ev, msg,
messaging_read_filter, state);
if (tevent_req_nomem(subreq, req)) {
return tevent_req_post(req, ev);
}
tevent_req_set_callback(subreq, messaging_read_done, req);
return req;
}
static bool messaging_read_filter(struct messaging_rec *rec,
void *private_data)
{
struct messaging_read_state *state = talloc_get_type_abort(
private_data, struct messaging_read_state);
return rec->msg_type == state->msg_type;
}
static void messaging_read_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(
subreq, struct tevent_req);
struct messaging_read_state *state = tevent_req_data(
req, struct messaging_read_state);
int ret;
ret = messaging_filtered_read_recv(subreq, state, &state->rec);
TALLOC_FREE(subreq);
if (tevent_req_error(req, ret)) {
return;
}
tevent_req_done(req);
}
int messaging_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
struct messaging_rec **presult)
{
struct messaging_read_state *state = tevent_req_data(
req, struct messaging_read_state);
int err;
if (tevent_req_is_unix_error(req, &err)) {
return err;
}
if (presult != NULL) {
*presult = talloc_move(mem_ctx, &state->rec);
}
return 0;
}
static bool messaging_append_new_waiters(struct messaging_context *msg_ctx)
{
if (msg_ctx->num_new_waiters == 0) {
return true;
}
if (talloc_array_length(msg_ctx->waiters) <
(msg_ctx->num_waiters + msg_ctx->num_new_waiters)) {
struct tevent_req **tmp;
tmp = talloc_realloc(
msg_ctx, msg_ctx->waiters, struct tevent_req *,
msg_ctx->num_waiters + msg_ctx->num_new_waiters);
if (tmp == NULL) {
DEBUG(1, ("%s: talloc failed\n", __func__));
return false;
}
msg_ctx->waiters = tmp;
}
memcpy(&msg_ctx->waiters[msg_ctx->num_waiters], msg_ctx->new_waiters,
sizeof(struct tevent_req *) * msg_ctx->num_new_waiters);
msg_ctx->num_waiters += msg_ctx->num_new_waiters;
msg_ctx->num_new_waiters = 0;
return true;
}
struct messaging_defer_callback_state {
struct messaging_context *msg_ctx;
struct messaging_rec *rec;
void (*fn)(struct messaging_context *msg, void *private_data,
uint32_t msg_type, struct server_id server_id,
DATA_BLOB *data);
void *private_data;
};
static void messaging_defer_callback_trigger(struct tevent_context *ev,
struct tevent_immediate *im,
void *private_data);
static void messaging_defer_callback(
struct messaging_context *msg_ctx, struct messaging_rec *rec,
void (*fn)(struct messaging_context *msg, void *private_data,
uint32_t msg_type, struct server_id server_id,
DATA_BLOB *data),
void *private_data)
{
struct messaging_defer_callback_state *state;
struct tevent_immediate *im;
state = talloc(msg_ctx, struct messaging_defer_callback_state);
if (state == NULL) {
DEBUG(1, ("talloc failed\n"));
return;
}
state->msg_ctx = msg_ctx;
state->fn = fn;
state->private_data = private_data;
state->rec = messaging_rec_dup(state, rec);
if (state->rec == NULL) {
DEBUG(1, ("talloc failed\n"));
TALLOC_FREE(state);
return;
}
im = tevent_create_immediate(state);
if (im == NULL) {
DEBUG(1, ("tevent_create_immediate failed\n"));
TALLOC_FREE(state);
return;
}
tevent_schedule_immediate(im, msg_ctx->event_ctx,
messaging_defer_callback_trigger, state);
}
static void messaging_defer_callback_trigger(struct tevent_context *ev,
struct tevent_immediate *im,
void *private_data)
{
struct messaging_defer_callback_state *state = talloc_get_type_abort(
private_data, struct messaging_defer_callback_state);
struct messaging_rec *rec = state->rec;
state->fn(state->msg_ctx, state->private_data, rec->msg_type, rec->src,
&rec->buf);
TALLOC_FREE(state);
}
/*
2010-08-28 15:10:30 +04:00
Dispatch one messaging_rec
*/
void messaging_dispatch_rec(struct messaging_context *msg_ctx,
struct messaging_rec *rec)
{
struct messaging_callback *cb, *next;
unsigned i;
for (cb = msg_ctx->callbacks; cb != NULL; cb = next) {
next = cb->next;
if (cb->msg_type != rec->msg_type) {
continue;
}
if (messaging_is_self_send(msg_ctx, &rec->dest)) {
/*
* This is a self-send. We are called here from
* messaging_send(), and we don't want to directly
* recurse into the callback but go via a
* tevent_loop_once
*/
messaging_defer_callback(msg_ctx, rec, cb->fn,
cb->private_data);
} else {
/*
* This comes from a different process. we are called
* from the event loop, so we should call back
* directly.
*/
cb->fn(msg_ctx, cb->private_data, rec->msg_type,
rec->src, &rec->buf);
}
/*
* we continue looking for matching messages after finding
* one. This matters for subsystems like the internal notify
* code which register more than one handler for the same
* message type
*/
}
if (!messaging_append_new_waiters(msg_ctx)) {
return;
}
i = 0;
while (i < msg_ctx->num_waiters) {
struct tevent_req *req;
struct messaging_filtered_read_state *state;
req = msg_ctx->waiters[i];
if (req == NULL) {
/*
* This got cleaned up. In the meantime,
* move everything down one. We need
* to keep the order of waiters, as
* other code may depend on this.
*/
if (i < msg_ctx->num_waiters - 1) {
memmove(&msg_ctx->waiters[i],
&msg_ctx->waiters[i+1],
sizeof(struct tevent_req *) *
(msg_ctx->num_waiters - i - 1));
}
msg_ctx->num_waiters -= 1;
continue;
}
state = tevent_req_data(
req, struct messaging_filtered_read_state);
if (state->filter(rec, state->private_data)) {
messaging_filtered_read_done(req, rec);
}
i += 1;
}
return;
}
static int mess_parent_dgm_cleanup(void *private_data);
static void mess_parent_dgm_cleanup_done(struct tevent_req *req);
bool messaging_parent_dgm_cleanup_init(struct messaging_context *msg)
{
struct tevent_req *req;
req = background_job_send(
msg, msg->event_ctx, msg, NULL, 0,
lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
60*15),
mess_parent_dgm_cleanup, msg);
if (req == NULL) {
return false;
}
tevent_req_set_callback(req, mess_parent_dgm_cleanup_done, msg);
return true;
}
static int mess_parent_dgm_cleanup(void *private_data)
{
struct messaging_context *msg_ctx = talloc_get_type_abort(
private_data, struct messaging_context);
NTSTATUS status;
status = messaging_dgm_wipe(msg_ctx);
DEBUG(10, ("messaging_dgm_wipe returned %s\n", nt_errstr(status)));
return lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
60*15);
}
static void mess_parent_dgm_cleanup_done(struct tevent_req *req)
{
struct messaging_context *msg = tevent_req_callback_data(
req, struct messaging_context);
NTSTATUS status;
status = background_job_recv(req);
TALLOC_FREE(req);
DEBUG(1, ("messaging dgm cleanup job ended with %s\n",
nt_errstr(status)));
req = background_job_send(
msg, msg->event_ctx, msg, NULL, 0,
lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
60*15),
mess_parent_dgm_cleanup, msg);
if (req == NULL) {
DEBUG(1, ("background_job_send failed\n"));
}
tevent_req_set_callback(req, mess_parent_dgm_cleanup_done, msg);
}
/** @} **/