switch_core_port_allocator.c

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/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005-2014, Anthony Minessale II <anthm@freeswitch.org>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthm@freeswitch.org>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Anthony Minessale II <anthm@freeswitch.org>
 * Michael Jerris <mike@jerris.com>
 * Paul D. Tinsley <pdt at jackhammer.org>
 *
 *
 * switch_core_port_allocator.c -- Main Core Library (port allocator)
 *
 */

#include <switch.h>
#include "private/switch_core_pvt.h"

struct switch_core_port_allocator {
        char *ip;
        switch_port_t start;
        switch_port_t end;
        switch_port_t next;
        int8_t *track;
        uint32_t track_len;
        uint32_t track_used;
        switch_port_flag_t flags;
        switch_mutex_t *mutex;
        switch_memory_pool_t *pool;
};

SWITCH_DECLARE(switch_status_t) switch_core_port_allocator_new(const char *ip, switch_port_t start,
                                                                                                                           switch_port_t end, switch_port_flag_t flags, switch_core_port_allocator_t **new_allocator)
{
        switch_status_t status;
        switch_memory_pool_t *pool;
        switch_core_port_allocator_t *alloc;
        int even, odd;

        if ((status = switch_core_new_memory_pool(&pool)) != SWITCH_STATUS_SUCCESS) {
                return status;
        }

        if (!(alloc = switch_core_alloc(pool, sizeof(*alloc)))) {
                switch_core_destroy_memory_pool(&pool);
                return SWITCH_STATUS_MEMERR;
        }

        alloc->flags = flags;
        alloc->ip = switch_core_strdup(pool, ip);
        even = switch_test_flag(alloc, SPF_EVEN);
        odd = switch_test_flag(alloc, SPF_ODD);

        alloc->flags |= runtime.port_alloc_flags;
        

        if (!(even && odd)) {
                if (even) {
                        if ((start % 2) != 0) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Rounding odd start port %d to %d\n", start, start + 1);
                                start++;
                        }
                        if ((end % 2) != 0) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Rounding odd end port %d to %d\n", end, end - 1);
                                end--;
                        }
                } else if (odd) {
                        if ((start % 2) == 0) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Rounding even start port %d to %d\n", start, start + 1);
                                start++;
                        }
                        if ((end % 2) == 0) {
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Rounding even end port %d to %d\n", end, end - 1);
                                end--;
                        }
                }
        }

        alloc->track_len = (end - start) + 2;

        if (!(even && odd)) {
                alloc->track_len /= 2;
        }

        alloc->track = switch_core_alloc(pool, (alloc->track_len + 2) * sizeof(switch_byte_t));

        alloc->start = start;
        alloc->next = start;
        alloc->end = end;


        switch_mutex_init(&alloc->mutex, SWITCH_MUTEX_NESTED, pool);
        alloc->pool = pool;
        *new_allocator = alloc;

        return SWITCH_STATUS_SUCCESS;
}

static switch_bool_t test_port(switch_core_port_allocator_t *alloc, int family, int type, switch_port_t port)
{
        switch_memory_pool_t *pool = NULL;
        switch_sockaddr_t *local_addr = NULL;
        switch_socket_t *sock = NULL;
        switch_bool_t r = SWITCH_FALSE;

        if (switch_core_new_memory_pool(&pool) != SWITCH_STATUS_SUCCESS) {
                return SWITCH_FALSE;
        }
        
        if (switch_sockaddr_info_get(&local_addr, alloc->ip, SWITCH_UNSPEC, port, 0, pool) == SWITCH_STATUS_SUCCESS) {
                if (switch_socket_create(&sock, family, type, 0, pool) == SWITCH_STATUS_SUCCESS) {
                        if (switch_socket_bind(sock, local_addr) == SWITCH_STATUS_SUCCESS) {
                                r = SWITCH_TRUE;
                        }
                        switch_socket_close(sock);
                }
        }
        
        switch_core_destroy_memory_pool(&pool);
        
        return r;
}

SWITCH_DECLARE(switch_status_t) switch_core_port_allocator_request_port(switch_core_port_allocator_t *alloc, switch_port_t *port_ptr)
{
        switch_port_t port = 0;
        switch_status_t status = SWITCH_STATUS_FALSE;
        int even = switch_test_flag(alloc, SPF_EVEN);
        int odd = switch_test_flag(alloc, SPF_ODD);

        switch_mutex_lock(alloc->mutex);
        srand((unsigned) ((unsigned) (intptr_t) port_ptr + (unsigned) (intptr_t) switch_thread_self() + switch_micro_time_now()));

        while (alloc->track_used < alloc->track_len) {
                uint32_t index;
                uint32_t tries = 0;

                /* randomly pick a port */
                index = rand() % alloc->track_len;

                /* if it is used walk up the list to find a free one */
                while (alloc->track[index] && tries < alloc->track_len) {
                        tries++;
                        if (alloc->track[index] < 0) {
                                alloc->track[index]++;
                        }
                        if (++index >= alloc->track_len) {
                                index = 0;
                        }
                }

                if (tries < alloc->track_len) {
                        switch_bool_t r = SWITCH_TRUE;

                        if ((even && odd)) {
                                port = (switch_port_t) (index + alloc->start);
                        } else {
                                port = (switch_port_t) (index + (alloc->start / 2));
                                port *= 2;
                        }

                        if ((alloc->flags & SPF_ROBUST_UDP)) {
                                r = test_port(alloc, AF_INET, SOCK_DGRAM, port);
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "UDP port robustness check for port %d %s\n", port, r ? "pass" : "fail");
                        }

                        if ((alloc->flags & SPF_ROBUST_TCP)) {
                                r = test_port(alloc, AF_INET, SOCK_STREAM, port);
                                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "TCP port robustness check for port %d %s\n", port, r ? "pass" : "fail");
                        }

                        if (r) {
                                alloc->track[index] = 1;
                                alloc->track_used++;
                                status = SWITCH_STATUS_SUCCESS;
                                goto end;
                        } else {
                                alloc->track[index] = -4;
                        }
                }
        }


  end:

        switch_mutex_unlock(alloc->mutex);

        if (status == SWITCH_STATUS_SUCCESS) {
                *port_ptr = port;
        } else {
                *port_ptr = 0;
        }


        return status;

}

SWITCH_DECLARE(switch_status_t) switch_core_port_allocator_free_port(switch_core_port_allocator_t *alloc, switch_port_t port)
{
        switch_status_t status = SWITCH_STATUS_FALSE;
        int even = switch_test_flag(alloc, SPF_EVEN);
        int odd = switch_test_flag(alloc, SPF_ODD);
        int index;

        if (port < alloc->start) {
                return SWITCH_STATUS_GENERR;
        }

        index = port - alloc->start;

        if (!(even && odd)) {
                index /= 2;
        }

        switch_mutex_lock(alloc->mutex);
        if (alloc->track[index] > 0) {
                alloc->track[index] = -4;
                alloc->track_used--;
                status = SWITCH_STATUS_SUCCESS;
        }
        switch_mutex_unlock(alloc->mutex);

        return status;
}

SWITCH_DECLARE(void) switch_core_port_allocator_destroy(switch_core_port_allocator_t **alloc)
{
        switch_memory_pool_t *pool = (*alloc)->pool;
        switch_core_destroy_memory_pool(&pool);
        *alloc = NULL;
}

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