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/* network.h
*
* Functions for the core networking.
*
Copyright (C) 2013 Tox project All Rights Reserved.
This file is part of Tox.
Tox is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Tox is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Tox. If not, see <http://www.gnu.org/licenses/>.
*/
#include "network.h"
//returns current UNIX time in microseconds (us).
uint64_t current_time()
{
uint64_t time;
#ifdef WIN32
//This probably works fine
FILETIME ft;
GetSystemTimeAsFileTime(&ft);
time = ft.dwHighDateTime;
time <<=32;
time |= ft.dwLowDateTime;
time -= 116444736000000000UL;
return time/10;
#else
struct timeval a;
gettimeofday(&a, NULL);
time = 1000000UL*a.tv_sec + a.tv_usec;
return time;
#endif
}
//return a random number
//NOTE: this function should probably not be used where cryptographic randomness is absolutely necessary
uint32_t random_int()
{
#ifndef VANILLA_NACL
//NOTE: this function comes from libsodium
return randombytes_random();
#else
return random();
#endif
}
//our UDP socket, a global variable.
static int sock;
//Basic network functions:
//Function to send packet(data) of length length to ip_port
int sendpacket(IP_Port ip_port, uint8_t * data, uint32_t length)
{
ADDR addr = {AF_INET, ip_port.port, ip_port.ip};
return sendto(sock,(char *) data, length, 0, (struct sockaddr *)&addr, sizeof(addr));
}
//Function to receive data, ip and port of sender is put into ip_port
//the packet data into data
//the packet length into length.
//dump all empty packets.
int receivepacket(IP_Port * ip_port, uint8_t * data, uint32_t * length)
{
ADDR addr;
#ifdef WIN32
int addrlen = sizeof(addr);
#else
uint32_t addrlen = sizeof(addr);
#endif
(*(int32_t *)length) = recvfrom(sock,(char *) data, MAX_UDP_PACKET_SIZE, 0, (struct sockaddr *)&addr, &addrlen);
if(*(int32_t *)length <= 0)
{
//nothing received
//or empty packet
return -1;
}
ip_port->ip = addr.ip;
ip_port->port = addr.port;
return 0;
}
//initialize networking
//bind to ip and port
//ip must be in network order EX: 127.0.0.1 = (7F000001)
//port is in host byte order (this means don't worry about it)
//returns 0 if no problems
//TODO: add something to check if there are errors
int init_networking(IP ip ,uint16_t port)
{
#ifdef WIN32
WSADATA wsaData;
if(WSAStartup(MAKEWORD(2,2), &wsaData) != NO_ERROR)
{
return -1;
}
#else
srandom((uint32_t)current_time());
#endif
srand((uint32_t)current_time());
//initialize our socket
sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
//Functions to increase the size of the send and receive UDP buffers
//NOTE: uncomment if necessary
/*
int n = 1024 * 1024 * 2;
if(setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (char*)&n, sizeof(n)) == -1)
{
return -1;
}
if(setsockopt(sock, SOL_SOCKET, SO_SNDBUF, (char*)&n, sizeof(n)) == -1)
{
return -1;
}*/
//Set socket nonblocking
#ifdef WIN32
//I think this works for windows
u_long mode = 1;
//ioctl(sock, FIONBIO, &mode);
ioctlsocket(sock, FIONBIO, &mode);
#else
fcntl(sock, F_SETFL, O_NONBLOCK, 1);
#endif
//Bind our socket to port PORT and address 0.0.0.0
ADDR addr = {AF_INET, htons(port), ip};
bind(sock, (struct sockaddr*)&addr, sizeof(addr));
return 0;
}
//function to cleanup networking stuff
void shutdown_networking()
{
#ifdef WIN32
WSACleanup();
#endif
return;
}
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