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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(void)
{
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(void)
{
#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. */
static 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)
return -1; /* nothing received or empty packet */
ip_port->ip = addr.ip;
ip_port->port = addr.port;
return 0;
}
static packet_handler_callback packethandlers[256] = {0};
void networking_registerhandler(uint8_t byte, packet_handler_callback cb)
{
packethandlers[byte] = cb;
}
void networking_poll()
{
IP_Port ip_port;
uint8_t data[MAX_UDP_PACKET_SIZE];
uint32_t length;
while (receivepacket(&ip_port, data, &length))
{
if (length < 1) continue;
if (!packethandlers[data[0]]) continue;
packethandlers[data[0]](ip_port, data, length);
}
}
/* 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
returns -1 if there are problems */
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);
/* Check for socket error */
#ifdef WIN32
if (sock == INVALID_SOCKET) /* MSDN recommends this */
return -1;
#else
if (sock < 0)
return -1;
#endif
/* 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;
*/
/* Enable broadcast on socket */
int broadcast = 1;
setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char*)&broadcast, sizeof(broadcast));
/* 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(void)
{
#ifdef WIN32
closesocket(sock);
WSACleanup();
#else
close(sock);
#endif
return;
}
/*
resolve_addr():
address should represent IPv4 or a hostname with A record
returns a data in network byte order that can be used to set IP.i or IP_Port.ip.i
returns 0 on failure
TODO: Fix ipv6 support
*/
uint32_t resolve_addr(const char *address)
{
struct addrinfo *server = NULL;
struct addrinfo hints;
int rc;
uint32_t addr;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET; // IPv4 only right now.
hints.ai_socktype = SOCK_DGRAM; // type of socket Tox uses.
rc = getaddrinfo(address, "echo", &hints, &server);
// Lookup failed.
if(rc != 0) {
return 0;
}
// IPv4 records only..
if(server->ai_family != AF_INET) {
freeaddrinfo(server);
return 0;
}
addr = ((struct sockaddr_in*)server->ai_addr)->sin_addr.s_addr;
freeaddrinfo(server);
return addr;
}
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