DNS: Need to use the same serializer for a pjproject SIP transaction.

All send/receive processing for a SIP transaction needs to be done under
the same threadpool serializer to prevent reentrancy problems inside
pjproject when using an external DNS resolver to process messages for the
transaction.

* Add threadpool API call to get the current serializer associated with
the worker thread.

* Pick a serializer from a pool of default serializers if the caller of
res_pjsip.c:ast_sip_push_task() does not provide one.

This is a simple way to ensure that all outgoing SIP request messages are
processed under a serializer.  Otherwise, any place where a pushed task is
done that would result in an outgoing out-of-dialog request would need to
be modified to supply a serializer.  Serializers from the default
serializer pool are picked in a round robin sequence for simplicity.

A side effect is that the default serializer pool will limit the growth of
the thread pool from random tasks.  This is not necessarily a bad thing.

* Made pjsip_resolver.c use the requesting thread's serializer to execute
the async callback.

* Made pjsip_distributor.c save the thread's serializer name on the
outgoing request tdata struct so the response can be processed under the
same serializer.

ASTERISK-25115 #close
Reported by: John Bigelow

Change-Id: Iea71c16ce1132017b5791635e198b8c27973f40a
changes/27/627/3
Richard Mudgett 10 years ago
parent b23f33e7e5
commit 30cd559345

@ -195,6 +195,22 @@ int ast_threadpool_push(struct ast_threadpool *pool, int (*task)(void *data), vo
*/ */
void ast_threadpool_shutdown(struct ast_threadpool *pool); void ast_threadpool_shutdown(struct ast_threadpool *pool);
/*!
* \brief Get the threadpool serializer currently associated with this thread.
* \since 14.0.0
*
* \note The returned pointer is valid while the serializer
* thread is running.
*
* \note Use ao2_ref() on serializer if you are going to keep it
* for another thread. To unref it you must then use
* ast_taskprocessor_unreference().
*
* \retval serializer on success.
* \retval NULL on error or no serializer associated with the thread.
*/
struct ast_taskprocessor *ast_threadpool_serializer_get_current(void);
/*! /*!
* \brief Serialized execution of tasks within a \ref ast_threadpool. * \brief Serialized execution of tasks within a \ref ast_threadpool.
* *

@ -1150,13 +1150,17 @@ static struct serializer *serializer_create(struct ast_threadpool *pool)
return ser; return ser;
} }
AST_THREADSTORAGE_RAW(current_serializer);
static int execute_tasks(void *data) static int execute_tasks(void *data)
{ {
struct ast_taskprocessor *tps = data; struct ast_taskprocessor *tps = data;
ast_threadstorage_set_ptr(&current_serializer, tps);
while (ast_taskprocessor_execute(tps)) { while (ast_taskprocessor_execute(tps)) {
/* No-op */ /* No-op */
} }
ast_threadstorage_set_ptr(&current_serializer, NULL);
ast_taskprocessor_unreference(tps); ast_taskprocessor_unreference(tps);
return 0; return 0;
@ -1192,6 +1196,11 @@ static struct ast_taskprocessor_listener_callbacks serializer_tps_listener_callb
.shutdown = serializer_shutdown, .shutdown = serializer_shutdown,
}; };
struct ast_taskprocessor *ast_threadpool_serializer_get_current(void)
{
return ast_threadstorage_get_ptr(&current_serializer);
}
struct ast_taskprocessor *ast_threadpool_serializer(const char *name, struct ast_threadpool *pool) struct ast_taskprocessor *ast_threadpool_serializer(const char *name, struct ast_threadpool *pool)
{ {
RAII_VAR(struct serializer *, ser, NULL, ao2_cleanup); RAII_VAR(struct serializer *, ser, NULL, ao2_cleanup);

@ -1864,6 +1864,15 @@
#define MOD_DATA_CONTACT "contact" #define MOD_DATA_CONTACT "contact"
/*! Number of serializers in pool if one not supplied. */
#define SERIALIZER_POOL_SIZE 8
/*! Next serializer pool index to use. */
static int serializer_pool_pos;
/*! Pool of serializers to use if not supplied. */
static struct ast_taskprocessor *serializer_pool[SERIALIZER_POOL_SIZE];
static pjsip_endpoint *ast_pjsip_endpoint; static pjsip_endpoint *ast_pjsip_endpoint;
static struct ast_threadpool *sip_threadpool; static struct ast_threadpool *sip_threadpool;
@ -3323,8 +3332,62 @@ struct ast_taskprocessor *ast_sip_create_serializer(void)
return serializer; return serializer;
} }
/*!
* \internal
* \brief Shutdown the serializers in the default pool.
* \since 14.0.0
*
* \return Nothing
*/
static void serializer_pool_shutdown(void)
{
int idx;
for (idx = 0; idx < SERIALIZER_POOL_SIZE; ++idx) {
ast_taskprocessor_unreference(serializer_pool[idx]);
serializer_pool[idx] = NULL;
}
}
/*!
* \internal
* \brief Setup the serializers in the default pool.
* \since 14.0.0
*
* \retval 0 on success.
* \retval -1 on error.
*/
static int serializer_pool_setup(void)
{
int idx;
for (idx = 0; idx < SERIALIZER_POOL_SIZE; ++idx) {
serializer_pool[idx] = ast_sip_create_serializer();
if (!serializer_pool[idx]) {
serializer_pool_shutdown();
return -1;
}
}
return 0;
}
int ast_sip_push_task(struct ast_taskprocessor *serializer, int (*sip_task)(void *), void *task_data) int ast_sip_push_task(struct ast_taskprocessor *serializer, int (*sip_task)(void *), void *task_data)
{ {
if (!serializer) {
unsigned int pos;
/*
* Pick a serializer to use from the pool.
*
* Note: We don't care about any reentrancy behavior
* when incrementing serializer_pool_pos. If it gets
* incorrectly incremented it doesn't matter.
*/
pos = serializer_pool_pos++;
pos %= SERIALIZER_POOL_SIZE;
serializer = serializer_pool[pos];
}
if (serializer) { if (serializer) {
return ast_taskprocessor_push(serializer, sip_task, task_data); return ast_taskprocessor_push(serializer, sip_task, task_data);
} else { } else {
@ -3377,18 +3440,10 @@ int ast_sip_push_task_synchronous(struct ast_taskprocessor *serializer, int (*si
std.task = sip_task; std.task = sip_task;
std.task_data = task_data; std.task_data = task_data;
if (serializer) { if (ast_sip_push_task(serializer, sync_task, &std)) {
if (ast_taskprocessor_push(serializer, sync_task, &std)) { ast_mutex_destroy(&std.lock);
ast_mutex_destroy(&std.lock); ast_cond_destroy(&std.cond);
ast_cond_destroy(&std.cond); return -1;
return -1;
}
} else {
if (ast_threadpool_push(sip_threadpool, sync_task, &std)) {
ast_mutex_destroy(&std.lock);
ast_cond_destroy(&std.cond);
return -1;
}
} }
ast_mutex_lock(&std.lock); ast_mutex_lock(&std.lock);
@ -3679,6 +3734,18 @@ static int load_module(void)
return AST_MODULE_LOAD_DECLINE; return AST_MODULE_LOAD_DECLINE;
} }
if (serializer_pool_setup()) {
ast_log(LOG_ERROR, "Failed to create SIP serializer pool. Aborting load\n");
ast_threadpool_shutdown(sip_threadpool);
ast_sip_destroy_system();
pj_pool_release(memory_pool);
memory_pool = NULL;
pjsip_endpt_destroy(ast_pjsip_endpoint);
ast_pjsip_endpoint = NULL;
pj_caching_pool_destroy(&caching_pool);
return AST_MODULE_LOAD_DECLINE;
}
pjsip_tsx_layer_init_module(ast_pjsip_endpoint); pjsip_tsx_layer_init_module(ast_pjsip_endpoint);
pjsip_ua_init_module(ast_pjsip_endpoint, NULL); pjsip_ua_init_module(ast_pjsip_endpoint, NULL);
@ -3792,6 +3859,7 @@ static int unload_module(void)
*/ */
ast_sip_push_task_synchronous(NULL, unload_pjsip, NULL); ast_sip_push_task_synchronous(NULL, unload_pjsip, NULL);
serializer_pool_shutdown();
ast_threadpool_shutdown(sip_threadpool); ast_threadpool_shutdown(sip_threadpool);
ast_sip_destroy_cli(); ast_sip_destroy_cli();

@ -22,22 +22,106 @@
#include "asterisk/res_pjsip.h" #include "asterisk/res_pjsip.h"
#include "include/res_pjsip_private.h" #include "include/res_pjsip_private.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/threadpool.h"
static int distribute(void *data); static int distribute(void *data);
static pj_bool_t distributor(pjsip_rx_data *rdata); static pj_bool_t distributor(pjsip_rx_data *rdata);
static pj_status_t record_serializer(pjsip_tx_data *tdata);
static pjsip_module distributor_mod = { static pjsip_module distributor_mod = {
.name = {"Request Distributor", 19}, .name = {"Request Distributor", 19},
.priority = PJSIP_MOD_PRIORITY_TSX_LAYER - 6, .priority = PJSIP_MOD_PRIORITY_TSX_LAYER - 6,
.on_tx_request = record_serializer,
.on_rx_request = distributor, .on_rx_request = distributor,
.on_rx_response = distributor, .on_rx_response = distributor,
}; };
/*!
* \internal
* \brief Record the task's serializer name on the tdata structure.
* \since 14.0.0
*
* \param tdata The outgoing message.
*
* \retval PJ_SUCCESS.
*/
static pj_status_t record_serializer(pjsip_tx_data *tdata)
{
struct ast_taskprocessor *serializer;
serializer = ast_threadpool_serializer_get_current();
if (serializer) {
const char *name;
name = ast_taskprocessor_name(serializer);
if (!ast_strlen_zero(name)
&& (!tdata->mod_data[distributor_mod.id]
|| strcmp(tdata->mod_data[distributor_mod.id], name))) {
char *tdata_name;
/* The serializer in use changed. */
tdata_name = pj_pool_alloc(tdata->pool, strlen(name) + 1);
strcpy(tdata_name, name);/* Safe */
tdata->mod_data[distributor_mod.id] = tdata_name;
}
}
return PJ_SUCCESS;
}
/*!
* \internal
* \brief Find the request tdata to get the serializer it used.
* \since 14.0.0
*
* \param rdata The incoming message.
*
* \retval serializer on success.
* \retval NULL on error or could not find the serializer.
*/
static struct ast_taskprocessor *find_request_serializer(pjsip_rx_data *rdata)
{
struct ast_taskprocessor *serializer = NULL;
pj_str_t tsx_key;
pjsip_transaction *tsx;
pjsip_tsx_create_key(rdata->tp_info.pool, &tsx_key, PJSIP_ROLE_UAC,
&rdata->msg_info.cseq->method, rdata);
tsx = pjsip_tsx_layer_find_tsx(&tsx_key, PJ_TRUE);
if (!tsx) {
ast_debug(1, "Could not find %.*s transaction for %d response.\n",
(int) pj_strlen(&rdata->msg_info.cseq->method.name),
pj_strbuf(&rdata->msg_info.cseq->method.name),
rdata->msg_info.msg->line.status.code);
return NULL;
}
if (tsx->last_tx) {
const char *serializer_name;
serializer_name = tsx->last_tx->mod_data[distributor_mod.id];
if (!ast_strlen_zero(serializer_name)) {
serializer = ast_taskprocessor_get(serializer_name, TPS_REF_IF_EXISTS);
}
}
#ifdef HAVE_PJ_TRANSACTION_GRP_LOCK
pj_grp_lock_release(tsx->grp_lock);
#else
pj_mutex_unlock(tsx->mutex);
#endif
return serializer;
}
/*! Dialog-specific information the distributor uses */ /*! Dialog-specific information the distributor uses */
struct distributor_dialog_data { struct distributor_dialog_data {
/* Serializer to distribute tasks to for this dialog */ /*! Serializer to distribute tasks to for this dialog */
struct ast_taskprocessor *serializer; struct ast_taskprocessor *serializer;
/* Endpoint associated with this dialog */ /*! Endpoint associated with this dialog */
struct ast_sip_endpoint *endpoint; struct ast_sip_endpoint *endpoint;
}; };
@ -167,6 +251,7 @@ static pj_bool_t distributor(pjsip_rx_data *rdata)
pjsip_dialog *dlg = find_dialog(rdata); pjsip_dialog *dlg = find_dialog(rdata);
struct distributor_dialog_data *dist = NULL; struct distributor_dialog_data *dist = NULL;
struct ast_taskprocessor *serializer = NULL; struct ast_taskprocessor *serializer = NULL;
struct ast_taskprocessor *req_serializer = NULL;
pjsip_rx_data *clone; pjsip_rx_data *clone;
if (dlg) { if (dlg) {
@ -176,11 +261,16 @@ static pj_bool_t distributor(pjsip_rx_data *rdata)
} }
} }
if (rdata->msg_info.msg->type == PJSIP_REQUEST_MSG && ( if (serializer) {
!pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_cancel_method) || /* We have a serializer so we know where to send the message. */
!pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_bye_method)) && } else if (rdata->msg_info.msg->type == PJSIP_RESPONSE_MSG) {
!serializer) { req_serializer = find_request_serializer(rdata);
pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 481, NULL, NULL, NULL); serializer = req_serializer;
} else if (!pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_cancel_method)
|| !pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_bye_method)) {
/* We have a BYE or CANCEL request without a serializer. */
pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata,
PJSIP_SC_CALL_TSX_DOES_NOT_EXIST, NULL, NULL, NULL);
goto end; goto end;
} }
@ -196,6 +286,7 @@ end:
if (dlg) { if (dlg) {
pjsip_dlg_dec_lock(dlg); pjsip_dlg_dec_lock(dlg);
} }
ast_taskprocessor_unreference(req_serializer);
return PJ_TRUE; return PJ_TRUE;
} }

@ -30,6 +30,8 @@
#include "asterisk/dns_naptr.h" #include "asterisk/dns_naptr.h"
#include "asterisk/res_pjsip.h" #include "asterisk/res_pjsip.h"
#include "include/res_pjsip_private.h" #include "include/res_pjsip_private.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/threadpool.h"
#ifdef HAVE_PJSIP_EXTERNAL_RESOLVER #ifdef HAVE_PJSIP_EXTERNAL_RESOLVER
@ -52,6 +54,8 @@ struct sip_resolve {
struct ast_dns_query_set *queries; struct ast_dns_query_set *queries;
/*! \brief Current viable server addresses */ /*! \brief Current viable server addresses */
pjsip_server_addresses addresses; pjsip_server_addresses addresses;
/*! \brief Serializer to run async callback into pjlib. */
struct ast_taskprocessor *serializer;
/*! \brief Callback to invoke upon completion */ /*! \brief Callback to invoke upon completion */
pjsip_resolver_callback *callback; pjsip_resolver_callback *callback;
/*! \brief User provided data */ /*! \brief User provided data */
@ -97,6 +101,7 @@ static void sip_resolve_destroy(void *data)
AST_VECTOR_FREE(&resolve->resolving); AST_VECTOR_FREE(&resolve->resolving);
ao2_cleanup(resolve->queries); ao2_cleanup(resolve->queries);
ast_taskprocessor_unreference(resolve->serializer);
} }
/*! /*!
@ -398,7 +403,7 @@ static void sip_resolve_callback(const struct ast_dns_query_set *query_set)
/* Push a task to invoke the callback, we do this so it is guaranteed to run in a PJSIP thread */ /* Push a task to invoke the callback, we do this so it is guaranteed to run in a PJSIP thread */
ao2_ref(resolve, +1); ao2_ref(resolve, +1);
if (ast_sip_push_task(NULL, sip_resolve_invoke_user_callback, resolve)) { if (ast_sip_push_task(resolve->serializer, sip_resolve_invoke_user_callback, resolve)) {
ao2_ref(resolve, -1); ao2_ref(resolve, -1);
} }
@ -572,6 +577,8 @@ static void sip_resolve(pjsip_resolver_t *resolver, pj_pool_t *pool, const pjsip
return; return;
} }
resolve->serializer = ao2_bump(ast_threadpool_serializer_get_current());
ast_debug(2, "[%p] Starting initial resolution using parallel queries for target '%s'\n", resolve, host); ast_debug(2, "[%p] Starting initial resolution using parallel queries for target '%s'\n", resolve, host);
ast_dns_query_set_resolve_async(resolve->queries, sip_resolve_callback, resolve); ast_dns_query_set_resolve_async(resolve->queries, sip_resolve_callback, resolve);

Loading…
Cancel
Save