net.c

一款基于GTK的internet phone 程序。程序分为服务器端和客户端两部分。服务器端维护用户的IP

#include "phone.h"

long timebase;
long lastcheck;

void inittime(void)
{
struct timeval now;

	gettimeofday(&now,0);
	timebase=now.tv_sec*1000+now.tv_usec/1000;
	lastcheck=0;
}

// returns # of milliseconds since program started
unsigned long gtime2(void)
{
struct timeval now;
unsigned long t;
	gettimeofday(&now,0);
	t=now.tv_sec*1000+now.tv_usec/1000-timebase;
	if(t<lastcheck)
	{
		timebase-=1000*60*60*24;
		t+=1000*60*60*24;
	}
	lastcheck=t;
	return t;
}


int getmyip(unsigned char *dest)
{
char name[256];
int res;
struct hostent *h;
unsigned char **p;
int i;


	res=gethostname(name,sizeof(name));
	if(res)
		return -1;
	h=gethostbyname(name);
	p=(unsigned char **)h->h_addr_list;
	if(!p[0]) return -2;
	for(i=0;i<h->h_length;++i)
		dest[i]=p[0][i];
	return h->h_length;
}

unsigned long gtime(void)
{
	return gtime2()/1000;
}
#define MAXMSG 4096
int udpsocket;
struct sockaddr_in myname={0},servername={0},buddy={0};
int senderlength;
struct sockaddr_in sender={0};
unsigned char mesg[MAXMSG]="";

void getsocket(int port)
{
int status;
int val;

	udpsocket=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);
	if(udpsocket==-1)
	{
		perror("socket()");
		exit(1);
	}
	memset(&myname,0,sizeof(myname));
	myname.sin_family=AF_INET;
	myname.sin_addr.s_addr=htonl(INADDR_ANY);
	myname.sin_port=htons(port);
	status=bind(udpsocket,(struct sockaddr *) &myname,sizeof(myname));
	if(status==-1)
	{
		perror("bind()");
		exit(1);
	}
	val=sizeof(myname);
	status=getsockname(udpsocket,(struct sockaddr *)&myname,&val);
}
int putmsg(struct sockaddr_in *toname,unsigned char *msg,int len)
{
int status;

	status=sendto(udpsocket,msg,len,0,
		(struct sockaddr *)toname,sizeof(struct sockaddr_in));
	return status;
}

int getmsg(int msec)
{
int size;

		memset(&sender,0,sizeof(sender));
		senderlength=sizeof(sender);
		if(msec)
		{
			struct timeval timeout;
			fd_set readfds;
			int res;

			memset(&timeout,0,sizeof(timeout));
			timeout.tv_sec=msec/1000;
			timeout.tv_usec=(msec%1000)*1000;
			FD_ZERO(&readfds);
			FD_SET(udpsocket,&readfds);
			res=select(udpsocket+1,&readfds,0,0,&timeout);
			if(res<=0) return -1;
		}
		size=recvfrom(udpsocket,mesg,MAXMSG,0,
			(struct sockaddr *)&sender,&senderlength);
		return size;
}
void nomem(int code)
{
	printf("No memory! code %d\n",code);
	exit(20);
}

void encryptblock(uchar *data,int size,uchar *key)
{
int i;
	i=0;
	while(i<size)
	{
		encrypt1(data+i,data+i,key);
		i+=8;
	}
}

void printhash(uchar *h)
{
int i;
	for(i=0;i<8;++i)
		printf(" %02x",h[i]);
	printf("\n");
}

unsigned char specialkey[]="noda";

unsigned char hashkey[8]={0xc0,0x1f,0xde,0xfd,0x3d,0x8f,0x89,0xb9};
void computehash(unsigned char *dest,unsigned char *name)
{
int i;
unsigned char temp[8];
char namecopy[MAXNAMESIZE+1];

	memset(dest,0,8);
	memset(namecopy,0,sizeof(namecopy));
	strncpy(namecopy,name,MAXNAMESIZE);
	for(i=0;i<MAXNAMESIZE;i+=8)
	{
		encrypt1(temp,namecopy+i,hashkey);
		dest[0]^=temp[0];
		dest[1]^=temp[1];
		dest[2]^=temp[2];
		dest[3]^=temp[3];
		dest[4]^=temp[4];
		dest[5]^=temp[5];
		dest[6]^=temp[6];
		dest[7]^=temp[7];
	}
}