281 lines
9.7 KiB
C
281 lines
9.7 KiB
C
/* (C) 2021 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
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* All Rights Reserved
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*
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* Author: Philipp Maier
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <asm-generic/errno.h>
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#include <osmocom/mgcp_client/mgcp_client.h>
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#include <osmocom/mgcp_client/mgcp_client_internal.h>
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#include <osmocom/mgcp_client/mgcp_client_pool_internal.h>
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#include <osmocom/mgcp_client/mgcp_client_pool.h>
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#include <stddef.h>
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#define LOGPPMGW(pool_member, level, fmt, args...) \
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LOGP(DLMGCP, level, "MGW-pool(%s) " fmt, mgcp_client_pool_member_name(pool_member), ## args)
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/*! Allocate MGCP client pool. This is called once on startup and before the pool is used with
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* mgcp_client_pool_vty_init(). Since the pool is linked with the VTY it must exist througout the entire runtime.
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* \param[in] talloc_ctx talloc context. */
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struct mgcp_client_pool *mgcp_client_pool_alloc(void *talloc_ctx)
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{
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struct mgcp_client_pool *pool;
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pool = talloc_zero(talloc_ctx, struct mgcp_client_pool);
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if (!pool)
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return NULL;
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INIT_LLIST_HEAD(&pool->member_list);
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return pool;
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}
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/*! Initialize and connect an mcgp client pool.
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* \param[in,out] mgcp MGCP client pool descriptor.
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* \returns number of successfully initialized pool members. */
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unsigned int mgcp_client_pool_connect(struct mgcp_client_pool *pool)
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{
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struct mgcp_client_pool_member *pool_member;
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unsigned int pool_members_initialized = 0;
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llist_for_each_entry(pool_member, &pool->member_list, list) {
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/* Initialize client */
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if (mgcp_client_pool_member_reinit_client(pool_member, pool) == 0)
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pool_members_initialized++;
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}
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return pool_members_initialized;
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}
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/*! register a single mgcp_client instance to the pool.
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* \param[out] pool MGCP client pool descriptor.
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* \param[in] mgcp MGCP client descriptor. */
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void mgcp_client_pool_register_single(struct mgcp_client_pool *pool, struct mgcp_client *mgcp_client)
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{
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/*! Some applications still support the non-pooled MGW VTY configuration variant provided by
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* mgcp_client_vty_init(). If this is the case the mgcp_client instance created by mgcp_client_init()
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* can be registered here so that it will appear as if it were part of the pool. When the user actively
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* configures MGW pool members, the MGCP client registered here will be ignored. (The registration of
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* multiple singe mgcp_client instances is not possible.) */
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pool->mgcp_client_single = mgcp_client;
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}
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/*! Lookup the selected MGCP client config by its reference number */
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struct mgcp_client_pool_member *mgcp_client_pool_find_member_by_nr(struct mgcp_client_pool *pool, unsigned int nr)
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{
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struct mgcp_client_pool_member *pool_member;
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llist_for_each_entry(pool_member, &pool->member_list, list) {
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if (pool_member->nr == nr)
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return pool_member;
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}
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return NULL;
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}
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/* Not every pool member may have a functional MGCP client, we will run through the pool once until we meet a
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* pool member that is suitable (has a client, is not blocked, has a low load). */
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static struct mgcp_client_pool_member *mgcp_client_pool_pick(struct mgcp_client_pool *pool)
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{
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struct mgcp_client_pool_member *pool_member;
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struct mgcp_client_pool_member *pool_member_picked = NULL;
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unsigned int n_pool_members = 0;
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llist_for_each_entry(pool_member, &pool->member_list, list) {
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n_pool_members++;
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if (pool_member->blocked == false && pool_member->client) {
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if (!pool_member_picked)
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pool_member_picked = pool_member;
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else if (pool_member_picked->refcount > pool_member->refcount)
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pool_member_picked = pool_member;
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} else {
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LOGPPMGW(pool_member, LOGL_DEBUG, "%s -- MGW %u is unusable (blocked=%u, cli=%u)\n",
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__func__, pool_member->nr, pool_member->blocked, !!pool_member->client);
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}
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}
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if (pool_member_picked) {
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LOGPPMGW(pool_member_picked, LOGL_DEBUG, "MGW pool has %u members -- using MGW %u (active calls: %u)\n",
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n_pool_members, pool_member_picked->nr, pool_member_picked->refcount);
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return pool_member_picked;
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}
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LOGP(DLMGCP, LOGL_ERROR,
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"MGW pool has %u members, but no functional MGW pool member found -- check configuration!\n",
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n_pool_members);
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return NULL;
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}
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/*! get an MGCP client from the pool (increment reference counter).
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* \param[in,out] pool MGCP client pool descriptor.
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* \returns MGCP client descriptor, NULL if no member was found (empty pool). */
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struct mgcp_client *mgcp_client_pool_get(struct mgcp_client_pool *pool)
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{
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struct mgcp_client_pool_member *pool_member;
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/*! When an MGCP client is taken from the pool it is still available for other calls. In fact only a reference
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* counter is incremented to keep track on how many references to a specific MGCP client are currently used
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* by the application code. */
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/* When the pool is empty, return a single MGCP client if it is registered. */
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if (llist_empty(&pool->member_list) && pool->mgcp_client_single) {
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LOGP(DLMGCP, LOGL_DEBUG, "MGW pool is empty -- using (single) MGW %s\n",
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mgcp_client_name(pool->mgcp_client_single));
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return pool->mgcp_client_single;
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}
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/* Abort when the pool is empty */
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if (llist_empty(&pool->member_list)) {
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LOGP(DLMGCP, LOGL_ERROR, "MGW pool is empty -- no MGW available!\n");
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return NULL;
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}
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/* Pick a suitable pool member */
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pool_member = mgcp_client_pool_pick(pool);
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if (pool_member) {
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pool_member->refcount++;
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return pool_member->client;
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}
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return NULL;
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}
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/*! put an MGCP client back into the pool (decrement reference counter).
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* \param[in,out] pool MGCP client pool descriptor.
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* \param[in] mgcp MGCP client descriptor.
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*
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* This function is able to detect automatically to which pool the mgcp_client belongs. If the mgcp_client does
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* not belong to a pool at all, the function call will have no effect. */
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void mgcp_client_pool_put(struct mgcp_client *mgcp_client)
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{
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struct mgcp_client_pool_member *pool_member;
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struct mgcp_client_pool *pool;
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if (!mgcp_client)
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return;
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if (mgcp_client->pool)
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pool = mgcp_client->pool;
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else
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return;
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llist_for_each_entry(pool_member, &pool->member_list, list) {
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if (pool_member->client == mgcp_client) {
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if (pool_member->refcount == 0) {
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LOGPPMGW(pool_member, LOGL_ERROR, "MGW pool member has invalid refcount\n");
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return;
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}
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pool_member->refcount--;
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}
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}
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}
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/***************************
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* mgcp_client_pool_member:
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***************************/
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/*! Allocate an mgcp_client_pool_member.
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* \param[in] pool MGCP client pool descriptor.
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* \param[in] nr Reference number of the pool member.
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*/
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struct mgcp_client_pool_member *mgcp_client_pool_member_alloc(struct mgcp_client_pool *pool, unsigned int nr)
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{
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struct mgcp_client_pool_member *pool_member;
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pool_member = talloc_zero(pool, struct mgcp_client_pool_member);
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OSMO_ASSERT(pool_member);
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mgcp_client_conf_init(&pool_member->conf);
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pool_member->nr = nr;
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llist_add_tail(&pool_member->list, &pool->member_list);
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return pool_member;
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}
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/*! Free an mgcp_client_pool_member allocated through mgcp_client_pool_member_alloc().
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* \param[in] pool_member MGCP client pool descriptor.
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*
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* It also frees the associated MGCP client if present.
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*/
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void mgcp_client_pool_member_free(struct mgcp_client_pool_member *pool_member)
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{
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llist_del(&pool_member->list);
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if (pool_member->client) {
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mgcp_client_disconnect(pool_member->client);
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talloc_free(pool_member->client);
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}
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talloc_free(pool_member);
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}
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/*! Recreate and reconnect the MGCP client associated to the pool descriptor.
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* \param[in] pool_member MGCP client pool descriptor.
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*/
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int mgcp_client_pool_member_reinit_client(struct mgcp_client_pool_member *pool_member, struct mgcp_client_pool *pool)
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{
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/* Get rid of a possibly existing old MGCP client instance first */
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if (pool_member->client) {
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mgcp_client_disconnect(pool_member->client);
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talloc_free(pool_member->client);
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}
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/* Initialize client */
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pool_member->client = mgcp_client_init(pool_member, &pool_member->conf);
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if (!pool_member->client) {
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LOGPPMGW(pool_member, LOGL_ERROR, "MGCP client initialization failed\n");
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return -EINVAL;
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}
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/* Set backpointer so that we can detect later that this MGCP client is managed by this pool. */
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pool_member->client->pool = pool;
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/* Connect client */
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if (mgcp_client_connect2(pool_member->client, 0)) {
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LOGPPMGW(pool_member, LOGL_ERROR, "MGCP client connect failed at (%s:%u)\n",
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pool_member->conf.remote_addr, pool_member->conf.remote_port);
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talloc_free(pool_member->client);
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pool_member->client = NULL;
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return -ECONNABORTED;
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}
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return 0;
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}
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/* Get a human readable name for a given pool member. */
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const char *mgcp_client_pool_member_name(const struct mgcp_client_pool_member *pool_member)
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{
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const struct mgcp_client *mpcp_client;
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struct mgcp_client mpcp_client_dummy;
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static char name[512];
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const char *description;
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if (!pool_member)
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return "(null)";
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/* It is not guranteed that a pool_member has an MGCP client. The client may not yet be initialized or the
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* initalization may have been failed. In this case we will generate a dummy MGCP client to work with. */
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if (!pool_member->client) {
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memcpy(&mpcp_client_dummy.actual, &pool_member->conf, sizeof(mpcp_client_dummy.actual));
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mpcp_client = &mpcp_client_dummy;
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} else {
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mpcp_client = pool_member->client;
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}
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description = mgcp_client_name(mpcp_client);
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snprintf(name, sizeof(name), "%d:%s", pool_member->nr, description);
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return name;
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}
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