net_udp_unix.c

#include "quakedef.h"
#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/types.h>

extern cvar_t hostname;

static int net_acceptsocket = -1; // socket for fielding new connections
static int net_controlsocket;
static int net_broadcastsocket = 0;
static Addr broadcastaddr;

static unsigned long myAddr;
Addr myip;

static int UDP_OpenSocket (int port);
static int UDP_GetSocketAddr (int socket, Addr *addr);
static int UDP_CloseSocket (int socket);

//=============================================================================

int UDP_Init (void)
{
	struct hostent *local;
	char buff[MAXHOSTNAMELEN];

	// determine my name & address
	gethostname(buff, MAXHOSTNAMELEN);
	local = gethostbyname(buff);
	myAddr = *(int *)local->h_addr_list[0];

	// if the quake hostname isn't set, set it to the machine name
	if (strcmp(hostname.string, "UNNAMED") == 0)
	{
		buff[15] = 0;
		setcvar ("hostname", buff);
	}

	if ((net_controlsocket = UDP_OpenSocket (0)) == -1)
		Host_Error("UDP_Init: Unable to open control socket\n");

	((struct sockaddr_in *)&broadcastaddr)->sin_family = AF_INET;
	((struct sockaddr_in *)&broadcastaddr)->sin_addr.s_addr = INADDR_BROADCAST;
	((struct sockaddr_in *)&broadcastaddr)->sin_port = htons(Udpport);

	UDP_GetSocketAddr (net_controlsocket, &myip);

	return net_controlsocket;
}

//=============================================================================

void UDP_Shutdown (void)
{
	UDP_Listen (false);
	UDP_CloseSocket (net_controlsocket);
}

//=============================================================================

void UDP_Listen (bool state)
{
	// enable listening
	if (state)
	{
		if (net_acceptsocket != -1)
			return;
		if ((net_acceptsocket = UDP_OpenSocket (Udpport)) == -1)
			Host_Error ("UDP_Listen: Unable to open accept socket\n");
		return;
	}

	// disable listening
	if (net_acceptsocket == -1)
		return;
	UDP_CloseSocket (net_acceptsocket);
	net_acceptsocket = -1;
}

//=============================================================================

static int UDP_OpenSocket (int port)
{
	int newsocket;
	struct sockaddr_in address;

	if ((newsocket = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
		return -1;

	address.sin_family = AF_INET;
	address.sin_addr.s_addr = INADDR_ANY;
	address.sin_port = htons(port);
	if( bind (newsocket, (void *)&address, sizeof(address)) == -1)
		goto ErrorReturn;

	return newsocket;

ErrorReturn:
	close (newsocket);
	return -1;
}

//=============================================================================

static int UDP_CloseSocket (int socket)
{
	if (socket == net_broadcastsocket)
		net_broadcastsocket = 0;
	return close (socket);
}

//=============================================================================
/*
============
PartialIPAddress

this lets you type only as much of the net address as required, using
the local network components to fill in the rest
============
*/
static int PartialIPAddress (char *in, Addr *hostaddr)
{
	char buff[256];
	char *b;
	int addr;
	int num;
	int mask;
	int run;
	int port;

	buff[0] = '.';
	b = buff;
	strcpy(buff+1, in);
	if (buff[1] == '.')
		b++;

	addr = 0;
	mask=-1;
	while (*b == '.')
	{
		b++;
		num = 0;
		run = 0;
		while (!( *b < '0' || *b > '9'))
		{
		  num = num*10 + *b++ - '0';
		  if (++run > 3)
		  	return -1;
		}
		if ((*b < '0' || *b > '9') && *b != '.' && *b != ':' && *b != 0)
			return -1;
		if (num < 0 || num > 255)
			return -1;
		mask<<=8;
		addr = (addr<<8) + num;
	}

	if (*b++ == ':')
		port = strtol(b, NULL, 0);
	else
		port = Udpport;

	((struct sockaddr_in *)hostaddr)->sin_port = htons((short)port);
	((struct sockaddr_in *)hostaddr)->sin_addr.s_addr = (myAddr & htonl(mask)) | htonl(addr);

	return 0;
}
//=============================================================================

int UDP_Connect (Addr *addr)
{
	USED(addr);
	return 0;
}

//=============================================================================

static int
UDP_CheckNewConnections(void)
{
	unsigned long available;

	if (net_acceptsocket == -1)
		return -1;

	if (ioctl (net_acceptsocket, FIONREAD, &available) == -1)
		Host_Error ("UDP: ioctlsocket (FIONREAD) failed\n");
	if (available)
		return net_acceptsocket;
	return -1;
}

//=============================================================================

static int
UDP_Read(int socket, uint8_t *buf, int len, Addr *addr)
{
	socklen_t addrlen = sizeof (Addr);
	int ret;

	ret = recvfrom (socket, buf, len, 0, (struct sockaddr *)addr, &addrlen);
	if (ret == -1 && (errno == EWOULDBLOCK || errno == ECONNREFUSED))
		return 0;
	return ret;
}

//=============================================================================

static int
UDP_MakeSocketBroadcastCapable (int socket)
{
	int i = 1;

	// make this socket broadcast capable
	if (setsockopt(socket, SOL_SOCKET, SO_BROADCAST, (char *)&i, sizeof(i)) < 0)
		return -1;
	net_broadcastsocket = socket;

	return 0;
}

//=============================================================================

static int
UDP_Write(int socket, uint8_t *buf, int len, Addr *addr)
{
	int ret;

	ret = sendto (socket, buf, len, 0, (struct sockaddr *)addr, sizeof(Addr));
	if (ret == -1 && errno == EWOULDBLOCK)
		return 0;
	return ret;
}

//=============================================================================

static int
UDP_Broadcast(int socket, uint8_t *buf, int len)
{
	int ret;

	if (socket != net_broadcastsocket)
	{
		if (net_broadcastsocket != 0)
			Host_Error("Attempted to use multiple broadcasts sockets\n");
		ret = UDP_MakeSocketBroadcastCapable (socket);
		if (ret == -1)
		{
			Con_Printf("Unable to make socket broadcast capable\n");
			return ret;
		}
	}

	return UDP_Write (socket, buf, len, &broadcastaddr);
}

//=============================================================================

char *UDP_AddrToString (Addr *addr)
{
	static char buffer[22];
	int haddr;

	haddr = ntohl(((struct sockaddr_in *)addr)->sin_addr.s_addr);
	sprintf(buffer, "%d.%d.%d.%d:%d", (haddr >> 24) & 0xff, (haddr >> 16) & 0xff, (haddr >> 8) & 0xff, haddr & 0xff, ntohs(((struct sockaddr_in *)addr)->sin_port));
	return buffer;
}

//=============================================================================

static int
UDP_StringToAddr(char *string, Addr *addr)
{
	int ha1, ha2, ha3, ha4, hp;
	int ipaddr;

	sscanf(string, "%d.%d.%d.%d:%d", &ha1, &ha2, &ha3, &ha4, &hp);
	ipaddr = (ha1 << 24) | (ha2 << 16) | (ha3 << 8) | ha4;

	((struct sockaddr_in *)addr)->sin_addr.s_addr = htonl(ipaddr);
	((struct sockaddr_in *)addr)->sin_port = htons(hp);
	return 0;
}

//=============================================================================

static int UDP_GetSocketAddr (int socket, Addr *addr)
{
	socklen_t addrlen = sizeof(Addr);
	unsigned int a;

	memset(addr, 0, sizeof(Addr));
	getsockname(socket, (struct sockaddr *)addr, &addrlen);
	a = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
	if (a == 0 || a == inet_addr("127.0.0.1"))
		((struct sockaddr_in *)addr)->sin_addr.s_addr = myAddr;

	return 0;
}

//=============================================================================

static int
UDP_GetNameFromAddr(Addr *addr, char *name)
{
	struct hostent *hostentry;

	hostentry = gethostbyaddr ((char *)&((struct sockaddr_in *)addr)->sin_addr, sizeof(struct in_addr), AF_INET);
	if (hostentry)
	{
		strncpy (name, (char *)hostentry->h_name, NET_NAMELEN - 1);
		return 0;
	}

	strcpy (name, UDP_AddrToString (addr));
	return 0;
}

//=============================================================================

static int
UDP_GetAddrFromName(char *name, Addr *addr)
{
	struct hostent *hostentry;

	if (name[0] >= '0' && name[0] <= '9')
		return PartialIPAddress (name, addr);

	hostentry = gethostbyname (name);
	if (!hostentry)
		return -1;

	((struct sockaddr_in *)addr)->sin_port = htons(Udpport);
	((struct sockaddr_in *)addr)->sin_addr.s_addr = *(int *)hostentry->h_addr_list[0];

	return 0;
}

//=============================================================================

int UDP_AddrCompare (Addr *addr1, Addr *addr2)
{
	if (((struct sockaddr_in *)addr1)->sin_addr.s_addr != ((struct sockaddr_in *)addr2)->sin_addr.s_addr)
		return -1;

	if (((struct sockaddr_in *)addr1)->sin_port != ((struct sockaddr_in *)addr2)->sin_port)
		return 1;

	return 0;
}

//=============================================================================

u16int UDP_GetSocketPort (Addr *addr)
{
	return ntohs(((struct sockaddr_in *)addr)->sin_port);
}

void UDP_SetSocketPort (Addr *addr, u16int port)
{
	((struct sockaddr_in *)addr)->sin_port = htons(port);
}

//=============================================================================