/*

netcode.io reference implementation

Copyright © 2017 - 2019, The Network Protocol Company, Inc.

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_MAX_ADDRESS_STRING_LENGTH 256

#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 ( 256 * 1024 )

#define NETCODE_CLIENT_SOCKET_RCVBUF_SIZE ( 256 * 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

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

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 = 0;

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];

vsprintf( 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, uint64_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

#define NOMINMAX

#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <winsock2.h>

#include <ws2tcpip.h>

#include <ws2ipdef.h>

#include <iphlpapi.h>

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

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

#ifdef SetPort

#undef SetPort

#endif // #ifdef SetPort

#include <iphlpapi.h>

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

#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.io - unknown platform!

#endif

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

#ifdef __MINGW32__

const char *inet_ntop(int af, const void *src, char *dst, socklen_t cnt)

{

if ( af == AF_INET )

{

struct sockaddr_in in;

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

in.sin_family = AF_INET;

memcpy(&in.sin_addr, src, sizeof(struct in_addr));

getnameinfo((struct sockaddr *)&in, sizeof(struct sockaddr_in), dst, cnt, NULL, 0, NI_NUMERICHOST);

return dst;

}

else if ( af == AF_INET6 )

{

struct sockaddr_in6 in;

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

in.sin6_family = AF_INET6;

memcpy(&in.sin6_addr, src, sizeof(struct in_addr6));

getnameinfo((struct sockaddr *)&in, sizeof(struct sockaddr_in6), dst, cnt, NULL, 0, NI_NUMERICHOST);

return dst;

}

return NULL;

}

#define NS_INADDRSZ 4

#define NS_IN6ADDRSZ 16

#define NS_INT16SZ 2

int inet_pton4(const char *src, char *dst)

{

uint8_t tmp[NS_INADDRSZ], *tp;

int saw_digit = 0;

int octets = 0;

*(tp = tmp) = 0;

int ch;

while ((ch = *src++) != '\0')

{

if ( ch >= '0' && ch <= '9' )

{

uint32_t n = *tp * 10 + (ch - '0');

if ( saw_digit && *tp == 0 )

return 0;

if ( n > 255 )

return 0;

*tp = n;

if ( !saw_digit )

{

if ( ++octets > 4 )

return 0;

saw_digit = 1;

}

}

else if ( ch == '.' && saw_digit )

{

if ( octets == 4 )

return 0;

*++tp = 0;

saw_digit = 0;

}

else

return 0;

}

if ( octets < 4 )

return 0;

memcpy(dst, tmp, NS_INADDRSZ);

return 1;

}

int inet_pton6(const char *src, char *dst)

{

static const char xdigits[] = "0123456789abcdef";

uint8_t tmp[NS_IN6ADDRSZ];

uint8_t *tp = (uint8_t*) memset(tmp, '\0', NS_IN6ADDRSZ);

uint8_t *endp = tp + NS_IN6ADDRSZ;

uint8_t *colonp = NULL;

// Leading :: requires some special handling

if ( *src == ':' )

{

if ( *++src != ':' )

return 0;

}

const char *curtok = src;

int saw_xdigit = 0;

uint32_t val = 0;

int ch;

while ( (ch = tolower(*src++)) != '\0' )

{

const char *pch = strchr(xdigits, ch);

if ( pch != NULL )

{

val <<= 4;

val |= (pch - xdigits);

if ( val > 0xffff )

return 0;

saw_xdigit = 1;

continue;

}

if ( ch == ':' )

{

curtok = src;

if ( !saw_xdigit )

{

if ( colonp )

return 0;

colonp = tp;

continue;

}

else if ( *src == '\0' )

{

return 0;

}

if ( tp + NS_INT16SZ > endp )

return 0;

*tp++ = (uint8_t) (val >> 8) & 0xff;

*tp++ = (uint8_t) val & 0xff;

saw_xdigit = 0;

val = 0;

continue;

}

if ( ch == '.' && ((tp + NS_INADDRSZ) <= endp) && inet_pton4(curtok, (char*) tp) > 0 )

{

tp += NS_INADDRSZ;

saw_xdigit = 0;

break;

}

return 0;

}

if ( saw_xdigit )

{

if ( tp + NS_INT16SZ > endp )

return 0;

*tp++ = (uint8_t) (val >> 8) & 0xff;

*tp++ = (uint8_t) val & 0xff;

}

if ( colonp != NULL )

{

const int n = tp - colonp;

if ( tp == endp )

return 0;

for (int i = 1; i <= n; i++)

{

endp[-i] = colonp[n - i];

colonp[n - i] = 0;

}

tp = endp;

}

if ( tp != endp )

return 0;

memcpy(dst, tmp, NS_IN6ADDRSZ);

return 1;

}

int inet_pton(int af, const char *src, void *dst)

{

switch ( af )

{

case AF_INET:

return inet_pton4(src, (char *) dst);

case AF_INET6:

return inet_pton6(src, (char *) dst);

default:

return -1;

}

}

#endif

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

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

#define NETCODE_ADDRESS_BUFFER_SAFETY 32

char buffer[NETCODE_MAX_ADDRESS_STRING_LENGTH + NETCODE_ADDRESS_BUFFER_SAFETY*2];

char * address_string = buffer + NETCODE_ADDRESS_BUFFER_SAFETY;

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 )

return NETCODE_ERROR;

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

{

address->port = (uint16_t) ( atoi( &address_string[index + 1] ) );

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

}

}

address_string += 1;

}

struct in6_addr sockaddr6;

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

{

address->type = NETCODE_ADDRESS_IPV6;

int i;

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

{

address->data.ipv6[i] = ntohs( ( (uint16_t*) &sockaddr6 ) [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] == ':' )

{

address->port = (uint16_t) atoi( &address_string[index+1] );

address_string[index] = '\0';

}

}

struct sockaddr_in sockaddr4;

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

{

address->type = NETCODE_ADDRESS_IPV4;

address->data.ipv4[3] = (uint8_t) ( ( sockaddr4.sin_addr.s_addr & 0xFF000000 ) >> 24 );

address->data.ipv4[2] = (uint8_t) ( ( sockaddr4.sin_addr.s_addr & 0x00FF0000 ) >> 16 );

address->data.ipv4[1] = (uint8_t) ( ( sockaddr4.sin_addr.s_addr & 0x0000FF00 ) >> 8 );

address->data.ipv4[0] = (uint8_t) ( ( sockaddr4.sin_addr.s_addr & 0x000000FF ) );

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] );

inet_ntop( AF_INET6, (void*) ipv6_network_order, 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] );

inet_ntop( AF_INET6, (void*) ipv6_network_order, 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_is_any_address(struct netcode_address_t *a) {

if (a->type == NETCODE_ADDRESS_IPV4) {

// 0.0.0.0

if (a->data.ipv4[0] == 0 &&

a->data.ipv4[1] == 0 &&

a->data.ipv4[2] == 0 &&

a->data.ipv4[3] == 0)

return 1;

} else if ( a->type == NETCODE_ADDRESS_IPV6 ) {

// [::] aka [0:0:0:0:0:0:0:0]

if (a->data.ipv6[0] == 0 &&

a->data.ipv6[1] == 0 &&

a->data.ipv6[2] == 0 &&

a->data.ipv6[3] == 0 &&

a->data.ipv6[4] == 0 &&

a->data.ipv6[5] == 0 &&

a->data.ipv6[6] == 0 &&

a->data.ipv6[7] == 0)

return 1;

}

return 0;

}

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;

// At this point, ports match. If either address is 0.0.0.0 or [::], then mark them as matching. These addresses are never routed, they're only used when listening.

if (netcode_address_is_any_address(a) || netcode_address_is_any_address(b))

return 1;

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()

{

netcode_assert( !netcode.initialized );

#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_PLATFORM == NETCODE_PLATFORM_WINDOWS

WSACleanup();

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

netcode.initialized = 0;

}

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

#if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

typedef uint64_t netcode_socket_handle_t;

#else // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

typedef int 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 7

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;

}

}

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 == INVALID_SOCKET )

#else // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

if ( s->handle <= 0 )

#endif // #if NETCODE_PLATFORM == NETCODE_PLATFORM_WINDOWS

{

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

return NETCODE_SOCKET_ERROR_CREATE_FAILED;

}

// 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

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

{

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

{

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;

}

// bind to port

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

struct sockaddr_in6 socket_address;

memset( &socket_address, 0, sizeof( struct sockaddr_in6 ) );

socket_address.sin6_family = AF_INET6;

int i;

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

{

( (uint16_t*) &socket_address.sin6_addr ) [i] = htons( address->data.ipv6[i] );

}

socket_address.sin6_port = htons( address->port );

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

{

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

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_BIND_IPV6_FAILED;

}

}

else

{

struct sockaddr_in socket_address;

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

socket_address.sin_family = AF_INET;

socket_address.sin_addr.s_addr = ( ( (uint32_t) address->data.ipv4[0] ) ) |

( ( (uint32_t) address->data.ipv4[1] ) << 8 ) |

( ( (uint32_t) address->data.ipv4[2] ) << 16 ) |

( ( (uint32_t) address->data.ipv4[3] ) << 24 );

socket_address.sin_port = htons( address->port );

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

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to bind socket (ipv4)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_BIND_IPV4_FAILED;

}

}

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

if ( address->port == 0 )

{

if ( address->type == NETCODE_ADDRESS_IPV6 )

{

struct sockaddr_in6 sin;

socklen_t len = sizeof( sin );

if ( getsockname( s->handle, (struct sockaddr*)&sin, &len ) == -1 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to get socket port (ipv6)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_GET_SOCKNAME_IPV6_FAILED;

}

s->address.port = ntohs( sin.sin6_port );

}

else

{

struct sockaddr_in sin;

socklen_t len = sizeof( sin );

if ( getsockname( s->handle, (struct sockaddr*)&sin, &len ) == -1 )

{

netcode_printf( NETCODE_LOG_LEVEL_ERROR, "error: failed to get socket port (ipv4)\n" );

netcode_socket_destroy( s );

return NETCODE_SOCKET_ERROR_GET_SOCKNAME_IPV4_FAILED;

}

s->address.port = ntohs( sin.sin_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

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 );

if ( to->type == NETCODE_ADDRESS_IPV6 )

{

struct sockaddr_in6 socket_address;

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

socket_address.sin6_family = AF_INET6;

int i;

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

{

( (uint16_t*) &socket_address.sin6_addr ) [i] = htons( to->data.ipv6[i] );

}

socket_address.sin6_port = htons( to->port );

int result = sendto( socket->handle, (char*) packet_data, packet_bytes, 0, (struct sockaddr*) &socket_address, sizeof( struct sockaddr_in6 ) );

(void) result;

}

else if ( to->type == NETCODE_ADDRESS_IPV4 )

{

struct sockaddr_in socket_address;

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

socket_address.sin_family = AF_INET;

socket_address.sin_addr.s_addr = ( ( (uint32_t) to->data.ipv4[0] ) ) |

( ( (uint32_t) to->data.ipv4[1] ) << 8 ) |

( ( (uint32_t) to->data.ipv4[2] ) << 16 ) |

( ( (uint32_t) to->data.ipv4[3] ) << 24 );

socket_address.sin_port = htons( to->port );

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

(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;

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 || error == WSAECONNRESET )

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 ( sockaddr_from.ss_family == AF_INET6 )

{

struct sockaddr_in6 * addr_ipv6 = (struct sockaddr_in6*) &sockaddr_from;

from->type = NETCODE_ADDRESS_IPV6;

int i;

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

{

from->data.ipv6[i] = ntohs( ( (uint16_t*) &addr_ipv6->sin6_addr ) [i] );

}

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

}

else if ( sockaddr_from.ss_family == AF_INET )

{

struct sockaddr_in * addr_ipv4 = (struct sockaddr_in*) &sockaddr_from;

from->type = NETCODE_ADDRESS_IPV4;

from->data.ipv4[0] = (uint8_t) ( ( addr_ipv4->sin_addr.s_addr & 0x000000FF ) );

from->data.ipv4[1] = (uint8_t) ( ( addr_ipv4->sin_addr.s_addr & 0x0000FF00 ) >> 8 );

from->data.ipv4[2] = (uint8_t) ( ( addr_ipv4->sin_addr.s_addr & 0x00FF0000 ) >> 16 );

from->data.ipv4[3] = (uint8_t) ( ( addr_ipv4->sin_addr.s_addr & 0xFF000000 ) >> 24 );

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

}

else

{

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 )

{

uint32_t value;

value = (*p)[0];

value |= ( ( (uint32_t)( (*p)[1] ) ) << 8 );

value |= ( ( (uint32_t)( (*p)[2] ) ) << 16 );

value |= ( ( (uint32_t)( (*p)[3] ) ) << 24 );

*p += 4;

return value;

}

uint64_t netcode_read_uint64( uint8_t ** p )

{

uint64_t value;