/*

netcode

Copyright © 2017 - 2026, Más Bandwidth LLC

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer

in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived

from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,

INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE

USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#include "netcode.h"

#include <stdlib.h>

#include <memory.h>

#include <stdio.h>

#include <stdarg.h>

#include <inttypes.h>

#include <math.h>

#include <time.h>

#ifdef _MSC_VER

#define SODIUM_STATIC

#pragma warning(disable:4996)

#endif // #ifdef _MSC_VER

#include <sodium.h>

#define NETCODE_SOCKET_IPV6 1

#define NETCODE_SOCKET_IPV4 2

#define NETCODE_CONNECT_TOKEN_NONCE_BYTES 24

#define NETCODE_CONNECT_TOKEN_PRIVATE_BYTES 1024

#define NETCODE_CHALLENGE_TOKEN_BYTES 300

#define NETCODE_VERSION_INFO_BYTES 13

#define NETCODE_MAX_PACKET_BYTES 1300

#define NETCODE_MAX_PAYLOAD_BYTES 1200

#define NETCODE_PACKET_QUEUE_SIZE 256

#define NETCODE_REPLAY_PROTECTION_BUFFER_SIZE 256

#define NETCODE_CLIENT_MAX_RECEIVE_PACKETS 64

#define NETCODE_SERVER_MAX_RECEIVE_PACKETS ( 64 * NETCODE_MAX_CLIENTS )

#define NETCODE_CLIENT_SOCKET_SNDBUF_SIZE ( 4 * 1024 * 1024 )

#define NETCODE_CLIENT_SOCKET_RCVBUF_SIZE ( 4 * 1024 * 1024 )

#define NETCODE_SERVER_SOCKET_SNDBUF_SIZE ( 4 * 1024 * 1024 )

#define NETCODE_SERVER_SOCKET_RCVBUF_SIZE ( 4 * 1024 * 1024 )

#define NETCODE_VERSION_INFO ( (uint8_t*) "NETCODE 1.02" )

#define NETCODE_PACKET_SEND_RATE 10.0

#define NETCODE_NUM_DISCONNECT_PACKETS 10

#ifndef NETCODE_ENABLE_TESTS

#define NETCODE_ENABLE_TESTS 0

#endif // #ifndef NETCODE_ENABLE_TESTS

#ifndef NETCODE_ENABLE_LOGGING

#define NETCODE_ENABLE_LOGGING 1

#endif // #ifndef NETCODE_ENABLE_LOGGING

// ------------------------------------------------------------------

#if NETCODE_PACKET_TAGGING

static int netcode_packet_tagging_enabled = 0;

void netcode_enable_packet_tagging()

{

netcode_packet_tagging_enabled = 1;

}

#else

void netcode_enable_packet_tagging() {}

#endif // #if NETCODE_PACKET_TAGGING

// ------------------------------------------------------------------

static void netcode_default_assert_handler( NETCODE_CONST char * condition, NETCODE_CONST char * function, NETCODE_CONST char * file, int line )

{

printf( "assert failed: ( %s ), function %s, file %s, line %d\n", condition, function, file, line );

#if defined( __GNUC__ )

__builtin_trap();

#elif defined( _MSC_VER )

__debugbreak();

#endif

exit( 1 );

}

static int log_level;

static int (*printf_function)( NETCODE_CONST char *, ... ) = ( int (*)( NETCODE_CONST char *, ... ) ) printf;

void (*netcode_assert_function)( NETCODE_CONST char *, NETCODE_CONST char *, NETCODE_CONST char * file, int line ) = netcode_default_assert_handler;

void netcode_log_level( int level )

{

log_level = level;

}

void netcode_set_printf_function( int (*function)( NETCODE_CONST char *, ... ) )

{

netcode_assert( function );

printf_function = function;

}

void netcode_set_assert_function( void (*function)( NETCODE_CONST char *, NETCODE_CONST char *, NETCODE_CONST char * file, int line ) )

{

netcode_assert_function = function;

}

#if NETCODE_ENABLE_LOGGING

void netcode_printf( int level, NETCODE_CONST char * format, ... )

{

if ( level > log_level )

return;

va_list args;

va_start( args, format );

char buffer[4*1024];

vsnprintf( buffer, sizeof(buffer), format, args );

printf_function( "%s", buffer );

va_end( args );

}

#else // #if NETCODE_ENABLE_LOGGING

void netcode_printf( int level, NETCODE_CONST char * format, ... )

{

(void) level;

(void) format;

}

#endif // #if NETCODE_ENABLE_LOGGING

void * netcode_default_allocate_function( void * context, size_t bytes )

{

(void) context;

return malloc( bytes );

}

void netcode_default_free_function( void * context, void * pointer )

{

(void) context;

free( pointer );

}

// ------------------------------------------------------------------

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

#ifndef NOMINMAX

#define NOMINMAX

#endif // #ifndef NOMINMAX

#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <winsock2.h>

#include <ws2def.h>

#include <ws2tcpip.h>

#include <ws2ipdef.h>

#include <iphlpapi.h>

#ifdef _MSC_VER

#pragma comment( lib, "WS2_32.lib" )

#pragma comment( lib, "IPHLPAPI.lib" )

#endif // #ifdef _MSC_VER

#ifdef SetPort

#undef SetPort

#endif // #ifdef SetPort

#include <iphlpapi.h>

#ifdef _MSC_VER

#pragma comment( lib, "IPHLPAPI.lib" )

#endif // #ifdef _MSC_VER

#elif NETCODE_PLATFORM == NETCODE_PLATFORM_MAC || NETCODE_PLATFORM == NETCODE_PLATFORM_UNIX

#include <netdb.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <ifaddrs.h>

#include <net/if.h>

#include <fcntl.h>

#include <netdb.h>

#include <arpa/inet.h>

#include <unistd.h>

#include <errno.h>

#else

#error netcode - unknown platform!

#endif

static int netcode_parse_port( NETCODE_CONST char * string, uint16_t * port )

{

// the port must be all digits and fit in [0,65535]. anything else is an error,

// rather than whatever atoi truncation used to produce.

if ( string[0] == '\0' )

return NETCODE_ERROR;

int value = 0;

int i;

for ( i = 0; string[i] != '\0'; i++ )

{

if ( string[i] < '0' || string[i] > '9' )

return NETCODE_ERROR;

value = value * 10 + ( string[i] - '0' );

if ( value > 65535 )

return NETCODE_ERROR;

}

*port = (uint16_t) value;

return NETCODE_OK;

}

int netcode_parse_address( NETCODE_CONST char * address_string_in, struct netcode_address_t * address )

{

netcode_assert( address_string_in );

netcode_assert( address );

memset( address, 0, sizeof( struct netcode_address_t ) );

// first try to parse the string as an IPv6 address:

// 1. if the first character is '[' then it's probably an ipv6 in form "[addr6]:portnum"

// 2. otherwise try to parse as a raw IPv6 address using inet_pton

char buffer[NETCODE_MAX_ADDRESS_STRING_LENGTH];

char * address_string = buffer;

strncpy( address_string, address_string_in, NETCODE_MAX_ADDRESS_STRING_LENGTH - 1 );

address_string[NETCODE_MAX_ADDRESS_STRING_LENGTH-1] = '\0';

int address_string_length = (int) strlen( address_string );

if ( address_string[0] == '[' )

{

int base_index = address_string_length - 1;

int i;

for ( i = 0; i < 6; i++ ) // note: no need to search past 6 characters as ":65535" is longest possible port value

{

int index = base_index - i;

if ( index < 3 )

break;

if ( address_string[index] == ':' && address_string[index-1] == ']' )

{

if ( netcode_parse_port( &address_string[index+1], &address->port ) != NETCODE_OK )

return NETCODE_ERROR;

address_string[index-1] = '\0';

break;

}

}

// if a port is omitted, it is assumed to be zero. strip the trailing ']' so "[addr]" parses as just the address

if ( address_string[base_index] == ']' )

address_string[base_index] = '\0';

address_string += 1;

}

struct in6_addr sockaddr6;

if ( inet_pton( AF_INET6, address_string, &sockaddr6 ) == 1 )

{

address->type = NETCODE_ADDRESS_IPV6;

uint16_t ipv6_network_order[8];

memcpy( ipv6_network_order, &sockaddr6, sizeof( ipv6_network_order ) );

int i;

for ( i = 0; i < 8; i++ )

{

address->data.ipv6[i] = ntohs( ipv6_network_order[i] );

}

return NETCODE_OK;

}

// otherwise it's probably an IPv4 address:

// 1. look for ":portnum", if found save the portnum and strip it out

// 2. parse remaining ipv4 address via inet_pton

address_string_length = (int) strlen( address_string );

int base_index = address_string_length - 1;

int i;

for ( i = 0; i < 6; i++ )

{

int index = base_index - i;

if ( index < 0 )

break;

if ( address_string[index] == ':' )

{

if ( netcode_parse_port( &address_string[index+1], &address->port ) != NETCODE_OK )

return NETCODE_ERROR;

address_string[index] = '\0';

break;

}

}

struct sockaddr_in sockaddr4;

if ( inet_pton( AF_INET, address_string, &sockaddr4.sin_addr ) == 1 )

{

address->type = NETCODE_ADDRESS_IPV4;

uint32_t ipv4_host_order = ntohl( sockaddr4.sin_addr.s_addr );

address->data.ipv4[0] = (uint8_t) ( ( ipv4_host_order >> 24 ) & 0xFF );

address->data.ipv4[1] = (uint8_t) ( ( ipv4_host_order >> 16 ) & 0xFF );

address->data.ipv4[2] = (uint8_t) ( ( ipv4_host_order >> 8 ) & 0xFF );

address->data.ipv4[3] = (uint8_t) ( ( ipv4_host_order ) & 0xFF );

return NETCODE_OK;

}

return NETCODE_ERROR;

}

char * netcode_address_to_string( struct netcode_address_t * address, char * buffer )

{

netcode_assert( address );

netcode_assert( buffer );

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

if ( address->port == 0 )

{

uint16_t ipv6_network_order[8];

int i;

for ( i = 0; i < 8; i++ )

ipv6_network_order[i] = htons( address->data.ipv6[i] );

struct in6_addr sockaddr6;

memcpy( &sockaddr6, ipv6_network_order, sizeof( ipv6_network_order ) );

inet_ntop( AF_INET6, &sockaddr6, buffer, NETCODE_MAX_ADDRESS_STRING_LENGTH );

return buffer;

}

else

{

char address_string[INET6_ADDRSTRLEN];

uint16_t ipv6_network_order[8];

int i;

for ( i = 0; i < 8; i++ )

ipv6_network_order[i] = htons( address->data.ipv6[i] );

struct in6_addr sockaddr6;

memcpy( &sockaddr6, ipv6_network_order, sizeof( ipv6_network_order ) );

inet_ntop( AF_INET6, &sockaddr6, address_string, INET6_ADDRSTRLEN );

snprintf( buffer, NETCODE_MAX_ADDRESS_STRING_LENGTH, "[%s]:%d", address_string, address->port );

return buffer;

}

}

else if ( address->type == NETCODE_ADDRESS_IPV4 )

{

if ( address->port != 0 )

{

snprintf( buffer, NETCODE_MAX_ADDRESS_STRING_LENGTH, "%d.%d.%d.%d:%d",

address->data.ipv4[0],

address->data.ipv4[1],

address->data.ipv4[2],

address->data.ipv4[3],

address->port );

}

else

{

snprintf( buffer, NETCODE_MAX_ADDRESS_STRING_LENGTH, "%d.%d.%d.%d",

address->data.ipv4[0],

address->data.ipv4[1],

address->data.ipv4[2],

address->data.ipv4[3] );

}

return buffer;

}

else

{

snprintf( buffer, NETCODE_MAX_ADDRESS_STRING_LENGTH, "%s", "NONE" );

return buffer;

}

}

int netcode_address_equal( struct netcode_address_t * a, struct netcode_address_t * b )

{

netcode_assert( a );

netcode_assert( b );

if ( a->type != b->type )

return 0;

if ( a->port != b->port )

return 0;

if ( a->type == NETCODE_ADDRESS_IPV4 )

{

int i;

for ( i = 0; i < 4; i++ )

{

if ( a->data.ipv4[i] != b->data.ipv4[i] )

return 0;

}

}

else if ( a->type == NETCODE_ADDRESS_IPV6 )

{

int i;

for ( i = 0; i < 8; i++ )

{

if ( a->data.ipv6[i] != b->data.ipv6[i] )

return 0;

}

}

else

{

return 0;

}

return 1;

}

// ----------------------------------------------------------------

struct netcode_t

{

int initialized;

};

static struct netcode_t netcode;

int netcode_init()

{

// reference counted so multiple subsystems in the same application can call

// netcode_init and netcode_term independently

if ( netcode.initialized )

{

netcode.initialized++;

return NETCODE_OK;

}

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

WSADATA WsaData;

if ( WSAStartup( MAKEWORD(2,2), &WsaData ) != NO_ERROR )

return NETCODE_ERROR;

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( sodium_init() == -1 )

return NETCODE_ERROR;

netcode.initialized = 1;

return NETCODE_OK;

}

void netcode_term()

{

netcode_assert( netcode.initialized );

if ( !netcode.initialized )

return;

netcode.initialized--;

if ( netcode.initialized )

return;

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

WSACleanup();

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

}

// ----------------------------------------------------------------

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

typedef uint32_t netcode_socket_handle_t;

#else // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

typedef size_t netcode_socket_handle_t;

#endif // #if NETCODE_PLATFORM == NETCODe_PLATFORM_WINDOWS

struct netcode_socket_t

{

struct netcode_address_t address;

netcode_socket_handle_t handle;

};

struct netcode_socket_holder_t

{

struct netcode_socket_t ipv4;

struct netcode_socket_t ipv6;

};

#define NETCODE_SOCKET_ERROR_NONE 0

#define NETCODE_SOCKET_ERROR_CREATE_FAILED 1

#define NETCODE_SOCKET_ERROR_SET_NON_BLOCKING_FAILED 2

#define NETCODE_SOCKET_ERROR_SOCKOPT_IPV6_ONLY_FAILED 3

#define NETCODE_SOCKET_ERROR_SOCKOPT_RCVBUF_FAILED 4

#define NETCODE_SOCKET_ERROR_SOCKOPT_SNDBUF_FAILED 5

#define NETCODE_SOCKET_ERROR_BIND_IPV4_FAILED 6

#define NETCODE_SOCKET_ERROR_BIND_IPV6_FAILED 7

#define NETCODE_SOCKET_ERROR_GET_SOCKNAME_IPV4_FAILED 8

#define NETCODE_SOCKET_ERROR_GET_SOCKNAME_IPV6_FAILED 9

#define NETCODE_SOCKET_ERROR_DISABLE_UDP_PORT_CONNRESET_FAILED 10

#define NETCODE_SOCKET_ERROR_ENABLE_PACKET_TAGGING_FAILED 11

void netcode_socket_destroy( struct netcode_socket_t * socket )

{

netcode_assert( socket );

netcode_assert( netcode.initialized );

if ( socket->handle != 0 )

{

#if NETCODE_PLATFORM == NETCODE_PLATFORM_MAC || NETCODE_PLATFORM == NETCODE_PLATFORM_UNIX

close( socket->handle );

#elif NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

closesocket( socket->handle );

#else

#error unsupported platform

#endif

socket->handle = 0;

}

}

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS && NETCODE_PACKET_TAGGING

#include <windows.h>

#include <winsock2.h>

#include <ws2tcpip.h>

#include <ws2ipdef.h>

#include <wininet.h>

#include <iphlpapi.h>

#ifdef __MINGW32__

typedef UINT32 QOS_FLOWID, *PQOS_FLOWID;

#ifndef QOS_NON_ADAPTIVE_FLOW

#define QOS_NON_ADAPTIVE_FLOW 0x00000002

#endif // #ifndef QOS_NON_ADAPTIVE_FLOW

#endif // #ifdef __MINGW32__

#include <qos2.h>

#ifdef _MSC_VER

#pragma comment( lib, "Qwave.lib" )

#endif // #ifdef _MSC_VER

static int netcode_set_socket_codepoint( SOCKET socket, QOS_TRAFFIC_TYPE trafficType, QOS_FLOWID flowId, PSOCKADDR addr )

{

// IMPORTANT: closing the QOS handle removes all flows added on it, so we create one handle

// on first use and share it across all sockets for the lifetime of the process.

static HANDLE qosHandle = NULL;

if ( qosHandle == NULL )

{

QOS_VERSION QosVersion = { 1 , 0 };

if ( QOSCreateHandle( &QosVersion, &qosHandle ) == FALSE )

{

qosHandle = NULL;

return GetLastError();

}

}

if ( QOSAddSocketToFlow( qosHandle, socket, addr, trafficType, QOS_NON_ADAPTIVE_FLOW, &flowId ) == FALSE )

{

return GetLastError();

}

return 0;

}

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS && NETCODE_PACKET_TAGGING

static socklen_t netcode_address_to_sockaddr( NETCODE_CONST struct netcode_address_t * address, struct sockaddr_storage * sockaddr )

{

netcode_assert( address );

netcode_assert( sockaddr );

netcode_assert( address->type == NETCODE_ADDRESS_IPV4 || address->type == NETCODE_ADDRESS_IPV6 );

memset( sockaddr, 0, sizeof( struct sockaddr_storage ) );

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

struct sockaddr_in6 * addr_ipv6 = (struct sockaddr_in6*) sockaddr;

addr_ipv6->sin6_family = AF_INET6;

int i;

uint16_t ipv6_network_order[8];

for ( i = 0; i < 8; i++ )

{

ipv6_network_order[i] = htons( address->data.ipv6[i] );

}

memcpy( &addr_ipv6->sin6_addr, ipv6_network_order, sizeof( ipv6_network_order ) );

addr_ipv6->sin6_port = htons( address->port );

return sizeof( struct sockaddr_in6 );

}

else

{

struct sockaddr_in * addr_ipv4 = (struct sockaddr_in*) sockaddr;

addr_ipv4->sin_family = AF_INET;

addr_ipv4->sin_addr.s_addr = htonl( ( ( (uint32_t) address->data.ipv4[0] ) << 24 ) |

( ( (uint32_t) address->data.ipv4[1] ) << 16 ) |

( ( (uint32_t) address->data.ipv4[2] ) << 8 ) |

( ( (uint32_t) address->data.ipv4[3] ) ) );

addr_ipv4->sin_port = htons( address->port );

return sizeof( struct sockaddr_in );

}

}

static int netcode_sockaddr_to_address( NETCODE_CONST struct sockaddr_storage * sockaddr, struct netcode_address_t * address )

{

netcode_assert( sockaddr );

netcode_assert( address );

if ( sockaddr->ss_family == AF_INET6 )

{

NETCODE_CONST struct sockaddr_in6 * addr_ipv6 = (NETCODE_CONST struct sockaddr_in6*) sockaddr;

address->type = NETCODE_ADDRESS_IPV6;

uint16_t ipv6_network_order[8];

memcpy( ipv6_network_order, &addr_ipv6->sin6_addr, sizeof( ipv6_network_order ) );

int i;

for ( i = 0; i < 8; i++ )

{

address->data.ipv6[i] = ntohs( ipv6_network_order[i] );

}

address->port = ntohs( addr_ipv6->sin6_port );

return NETCODE_OK;

}

else if ( sockaddr->ss_family == AF_INET )

{

NETCODE_CONST struct sockaddr_in * addr_ipv4 = (NETCODE_CONST struct sockaddr_in*) sockaddr;

address->type = NETCODE_ADDRESS_IPV4;

uint32_t ipv4_host_order = ntohl( addr_ipv4->sin_addr.s_addr );

address->data.ipv4[0] = (uint8_t) ( ( ipv4_host_order >> 24 ) & 0xFF );

address->data.ipv4[1] = (uint8_t) ( ( ipv4_host_order >> 16 ) & 0xFF );

address->data.ipv4[2] = (uint8_t) ( ( ipv4_host_order >> 8 ) & 0xFF );

address->data.ipv4[3] = (uint8_t) ( ( ipv4_host_order ) & 0xFF );

address->port = ntohs( addr_ipv4->sin_port );

return NETCODE_OK;

}

return NETCODE_ERROR;

}

int netcode_socket_create( struct netcode_socket_t * s, struct netcode_address_t * address, int send_buffer_size, int receive_buffer_size )

{

netcode_assert( s );

netcode_assert( address );

netcode_assert( netcode.initialized );

netcode_assert( address->type != NETCODE_ADDRESS_NONE );

s->address = *address;

// create socket

s->handle = socket( ( address->type == NETCODE_ADDRESS_IPV6 ) ? AF_INET6 : AF_INET, SOCK_DGRAM, IPPROTO_UDP );

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( s->handle == (uint32_t)INVALID_SOCKET )

#else // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( s->handle == 0 || s->handle == (netcode_socket_handle_t) -1 )

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to create socket\n" );

s->handle = 0;

return NETCODE_SOCKET_ERROR_CREATE_FAILED;

}

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

// IMPORTANT: tell windows we don't want to receive any connection reset messages for this socket

// If we don't do this, clients disconnecting hard will cause recvfrom on the server to repeatedly error out

// due to ICMP disconnected packets, causing long periods where the server doesn't receive any packets from clients.

#define SIO_UDP_CONNRESET _WSAIOW(IOC_VENDOR, 12)

BOOL bNewBehavior = FALSE;

DWORD dwBytesReturned = 0;

if ( WSAIoctl( s->handle, SIO_UDP_CONNRESET, &bNewBehavior, sizeof(bNewBehavior), NULL, 0, &dwBytesReturned, NULL, NULL ) != 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to disable UDP CONNRESET (port unreachable) message reporting on socket\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_DISABLE_UDP_PORT_CONNRESET_FAILED;

}

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

// force IPv6 only if necessary

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

int yes = 1;

if ( setsockopt( s->handle, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&yes, sizeof(yes) ) != 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to set socket ipv6 only\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_SOCKOPT_IPV6_ONLY_FAILED;

}

}

// increase socket send and receive buffer sizes. linux and windows clamp requests that

// exceed the OS limit, but the BSDs reject them instead, so back off until accepted.

{

int size = send_buffer_size;

while ( setsockopt( s->handle, SOL_SOCKET, SO_SNDBUF, (char*)&size, sizeof(int) ) != 0 )

{

size /= 2;

if ( size < 256 * 1024 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to set socket send buffer size\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_SOCKOPT_SNDBUF_FAILED;

}

}

if ( size != send_buffer_size )

{

netcode_printf( NETCODE_LOG_LEVEL_INFO, "socket send buffer size reduced from %d to %d\n", send_buffer_size, size );

}

}

{

int size = receive_buffer_size;

while ( setsockopt( s->handle, SOL_SOCKET, SO_RCVBUF, (char*)&size, sizeof(int) ) != 0 )

{

size /= 2;

if ( size < 256 * 1024 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to set socket receive buffer size\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_SOCKOPT_RCVBUF_FAILED;

}

}

if ( size != receive_buffer_size )

{

netcode_printf( NETCODE_LOG_LEVEL_INFO, "socket receive buffer size reduced from %d to %d\n", receive_buffer_size, size );

}

}

// bind to port

{

struct sockaddr_storage socket_address;

socklen_t socket_address_length = netcode_address_to_sockaddr( address, &socket_address );

if ( bind( s->handle, (struct sockaddr*) &socket_address, socket_address_length ) < 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to bind socket (%s)\n", ( address->type == NETCODE_ADDRESS_IPV6 ) ? "ipv6" : "ipv4" );

netcode_socket_destroy( s );

return ( address->type == NETCODE_ADDRESS_IPV6 ) ? NETCODE_SOCKET_ERROR_BIND_IPV6_FAILED : NETCODE_SOCKET_ERROR_BIND_IPV4_FAILED;

}

}

// if bound to port 0 find the actual port we got

if ( address->port == 0 )

{

struct sockaddr_storage socket_address;

socklen_t socket_address_length = sizeof( socket_address );

struct netcode_address_t bound_address;

if ( getsockname( s->handle, (struct sockaddr*) &socket_address, &socket_address_length ) == -1 ||

netcode_sockaddr_to_address( &socket_address, &bound_address ) != NETCODE_OK )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to get socket port (%s)\n", ( address->type == NETCODE_ADDRESS_IPV6 ) ? "ipv6" : "ipv4" );

netcode_socket_destroy( s );

return ( address->type == NETCODE_ADDRESS_IPV6 ) ? NETCODE_SOCKET_ERROR_GET_SOCKNAME_IPV6_FAILED : NETCODE_SOCKET_ERROR_GET_SOCKNAME_IPV4_FAILED;

}

s->address.port = bound_address.port;

}

// set non-blocking io

#if NETCODE_PLATFORM == NETCODE_PLATFORM_MAC || NETCODE_PLATFORM == NETCODE_PLATFORM_UNIX

int non_blocking = 1;

if ( fcntl( s->handle, F_SETFL, O_NONBLOCK, non_blocking ) == -1 )

{

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_SET_NON_BLOCKING_FAILED;

}

#elif NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

DWORD nonBlocking = 1;

if ( ioctlsocket( s->handle, FIONBIO, &nonBlocking ) != 0 )

{

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_SET_NON_BLOCKING_FAILED;

}

#else

#error unsupported platform

#endif

#if NETCODE_PACKET_TAGGING

// tag packets as low latency

#if NETCODE_PLATFORM == NETCODE_PLATFORM_MAC

if ( netcode_packet_tagging_enabled )

{

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

int tos = 46;

if ( setsockopt( s->handle, IPPROTO_IPV6, IPV6_TCLASS, (NETCODE_CONST char *)&tos, sizeof(tos) ) != 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to enable packet tagging (ipv6)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_ENABLE_PACKET_TAGGING_FAILED;

}

}

else

{

int tos = 46;

if ( setsockopt( s->handle, IPPROTO_IP, IP_TOS, (NETCODE_CONST char *)&tos, sizeof(tos) ) != 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to enable packet tagging (ipv4)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_ENABLE_PACKET_TAGGING_FAILED;

}

}

}

#elif NETCODE_PLATFORM == NETCODE_PLATFORM_UNIX

if ( netcode_packet_tagging_enabled )

{

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

int tos = 46;

if ( setsockopt( s->handle, IPPROTO_IPV6, IPV6_TCLASS, (NETCODE_CONST char *)&tos, sizeof(tos) ) != 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to enable packet tagging (ipv6)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_ENABLE_PACKET_TAGGING_FAILED;

}

}

else

{

int tos = 46;

if ( setsockopt( s->handle, IPPROTO_IP, IP_TOS, (NETCODE_CONST char *)&tos, sizeof(tos) ) != 0 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to enable packet tagging (ipv4)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_ENABLE_PACKET_TAGGING_FAILED;

}

}

}

#elif NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( netcode_packet_tagging_enabled )

{

struct sockaddr_storage addr;

memset( &addr, 0, sizeof(addr) );

addr.ss_family = ( address->type == NETCODE_ADDRESS_IPV6 ) ? AF_INET6 : AF_INET;

netcode_set_socket_codepoint( s->handle, QOSTrafficTypeAudioVideo, 0, (PSOCKADDR) &addr );

}

#endif

#endif // #if NETCODE_PACKET_TAGGING

return NETCODE_SOCKET_ERROR_NONE;

}

void netcode_socket_send_packet( struct netcode_socket_t * socket, struct netcode_address_t * to, void * packet_data, int packet_bytes )

{

netcode_assert( socket );

netcode_assert( socket->handle != 0 );

netcode_assert( to );

netcode_assert( to->type == NETCODE_ADDRESS_IPV6 || to->type == NETCODE_ADDRESS_IPV4 );

netcode_assert( packet_data );

netcode_assert( packet_bytes > 0 );

struct sockaddr_storage socket_address;

socklen_t socket_address_length = netcode_address_to_sockaddr( to, &socket_address );

int result = sendto( socket->handle, (NETCODE_CONST char*) packet_data, packet_bytes, 0, (struct sockaddr*) &socket_address, socket_address_length );

(void) result;

}

int netcode_socket_receive_packet( struct netcode_socket_t * socket, struct netcode_address_t * from, void * packet_data, int max_packet_size )

{

netcode_assert( socket );

netcode_assert( socket->handle != 0 );

netcode_assert( from );

netcode_assert( packet_data );

netcode_assert( max_packet_size > 0 );

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

typedef int socklen_t;

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

struct sockaddr_storage sockaddr_from;

memset( &sockaddr_from, 0, sizeof(sockaddr_from) );

socklen_t from_length = sizeof( sockaddr_from );

int result = recvfrom( socket->handle, (char*) packet_data, max_packet_size, 0, (struct sockaddr*) &sockaddr_from, &from_length );

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( result == SOCKET_ERROR )

{

int error = WSAGetLastError();

if ( error == WSAEWOULDBLOCK )

return 0;

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: recvfrom failed with error %d\n", error );

return 0;

}

#else // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( result <= 0 )

{

if ( errno == EAGAIN )

return 0;

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: recvfrom failed with error %d\n", errno );

return 0;

}

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( netcode_sockaddr_to_address( &sockaddr_from, from ) != NETCODE_OK )

{

netcode_assert( 0 );

return 0;

}

netcode_assert( result >= 0 );

int bytes_read = result;

return bytes_read;

}

// ----------------------------------------------------------------

void netcode_write_uint8( uint8_t ** p, uint8_t value )

{

**p = value;

++(*p);

}

void netcode_write_uint16( uint8_t ** p, uint16_t value )

{

(*p)[0] = value & 0xFF;

(*p)[1] = value >> 8;

*p += 2;

}

void netcode_write_uint32( uint8_t ** p, uint32_t value )

{

(*p)[0] = value & 0xFF;

(*p)[1] = ( value >> 8 ) & 0xFF;

(*p)[2] = ( value >> 16 ) & 0xFF;

(*p)[3] = value >> 24;

*p += 4;

}

void netcode_write_uint64( uint8_t ** p, uint64_t value )

{

(*p)[0] = value & 0xFF;

(*p)[1] = ( value >> 8 ) & 0xFF;

(*p)[2] = ( value >> 16 ) & 0xFF;

(*p)[3] = ( value >> 24 ) & 0xFF;

(*p)[4] = ( value >> 32 ) & 0xFF;

(*p)[5] = ( value >> 40 ) & 0xFF;

(*p)[6] = ( value >> 48 ) & 0xFF;

(*p)[7] = value >> 56;

*p += 8;

}

void netcode_write_bytes( uint8_t ** p, uint8_t * byte_array, int num_bytes )

{

int i;

for ( i = 0; i < num_bytes; i++ )

{

netcode_write_uint8( p, byte_array[i] );

}

}

uint8_t netcode_read_uint8( uint8_t ** p )

{

uint8_t value = **p;

++(*p);

return value;

}

uint16_t netcode_read_uint16( uint8_t ** p )

{

uint16_t value;

value = (*p)[0];

value |= ( ( (uint16_t)( (*p)[1] ) ) << 8 );

*p += 2;

return value;

}

uint32_t netcode_read_uint32( uint8_t ** p )