#include <iostream.h>		
#include <stdio.h>		
#include <string.h>		
#include <netinet/in.h>		
#include <unistd.h>		
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <time.h>
#include <stream.h>		
#include <stdlib.h>
#include <fstream.h>
#include <fcntl.h>

const int BUFSIZE=1024;

int MakeServerSocket(char *port) 
{
	const int MAXNAMELEN = 255; //longest a name can be
	const int BACKLOG = 3;	//max number of queued connections
	char localhostname[MAXNAMELEN]; // local host name
	int s; //file descriptor		
	struct sockaddr_in sa; //gotta love arcane socket types
	struct hostent *hp; //host entry
	struct servent *sp; //service entry
	int portnum;//stores the port	
	int ret; //error code form bind
	
	gethostname(localhostname,MAXNAMELEN);
	hp = gethostbyname(localhostname);
	//no need to check for error here because localhost will resolve	

	sscanf(port, "%d", &portnum);
	if (portnum ==  0) {
		sp=getservbyname(port, "tcp");
		if (sp==NULL)
		{
			return -1;
		}
		portnum = ntohs(sp->s_port);
	}
	sa.sin_port = htons(portnum);

	bcopy((char *)hp->h_addr, (char *)&sa.sin_addr, hp->h_length);
	sa.sin_family = hp->h_addrtype;

	s = socket(hp->h_addrtype, SOCK_STREAM, 0);
	if (s==-1)
	{
		return -1;
	}
	ret = bind(s, (struct sockaddr *)&sa, sizeof(sa));
	if (ret==-1)
	{
		return -1;
	}
	ret=listen(s, BACKLOG);
	if (ret==-1)
	{
		return -1;
	}
	
	cout << "Waiting for connection on port " << port << endl;
	return s;
}



int MakeClientSocket(char *host, char *port) 
{
	int s; //nice file descriptor			
	struct sockaddr_in sa; //window to the world
	struct hostent *hp; //host entry
	struct servent *sp; //service entry
	int portnum; //pretty self explanatory
	int ret;//connect error value

	hp = gethostbyname(host);
	if (hp==NULL)
	{
		return -1;
	}
	bcopy((char *)hp->h_addr, (char *)&sa.sin_addr, hp->h_length);
	sa.sin_family = hp->h_addrtype;
	sscanf(port, "%d", &portnum);
	if (portnum > 0) {
		sa.sin_port = htons(portnum);
	}
	else {
		sp=getservbyname(port, "tcp");
		if (sp==NULL)
		{
			return -1;
		}
		portnum = sp->s_port;
		sa.sin_port = sp->s_port;
	}
	s = socket(hp->h_addrtype, SOCK_STREAM, 0);
	if (s==-1)
	{
		return -1;
	}
	ret = connect(s, (struct sockaddr *)&sa, sizeof(sa));
	if (ret==-1)
	{
		return -1;
	}
	cout << "Client socket connected to host " << host  << " port " << port << endl;
	return s;
}

int banned(char *host)
{
	if (strcmp(host,"www.microsoft.com"))
		return 0;
	else 
		return 1;
}

int main(int argc, char *argv[]) 
{
	char temp[10];
	int s;
	ofstream log("proxy_log");
	if (argc<2)
	{
		cout << "Enter a port number:";
		cin >> temp;
		s=MakeServerSocket(temp);
	}
	else
		s = MakeServerSocket(argv[1]);

	if (s!=-1) while (1) 
	{
		char ip[BUFSIZE];	// used for turning 32 bit int into a human looking ip address	
		struct sockaddr_in sa;//window to the world
		int sa_len = sizeof(sa);//how big is our window
		int fd = accept(s, (struct sockaddr *)&sa, (unsigned int *)&sa_len); //file descriptor we talk out of
		int addr=sa.sin_addr.s_addr;
		sprintf(ip,"%i.%i.%i.%i",(addr)&0xFF,(addr>>8)&0xFF,(addr>>16)&0xFF,(addr>>24)&0xFF);
		cout << "Connection from "<< ip << " family " << sa.sin_family << " port " << ntohs(sa.sin_port) << endl;
		if(fork()>0)
		{
			//do proxy stuff here
			char buf[BUFSIZE];
			int len;
			len = read(fd, buf, BUFSIZE);
			buf[len]=0;
			time_t hmm=time(NULL);
	                struct tm *current=localtime(&hmm);
			log << ip << " - - " << "[" << current->tm_mday << "/" << current->tm_mon<< "/" << current->tm_year+1900 << " " << current->tm_hour << ":" << current->tm_min << ":" << current->tm_sec <<"] - "<<buf<< endl;

			char get[BUFSIZE],url[BUFSIZE],version[BUFSIZE];
			sscanf(buf,"%s %s %s",get,url,version);
			cout << "get=" << get << "= version=" << version << "= url=" << url <<"=" << endl;
			char *server=url+7;
			char host[BUFSIZE];
			for(int i=0;*(server+i)!='/';i++)
				host[i]=*(server+i);
			char *path=index(server,'/');
			cout << "host=" << host << endl << "path=" << path << endl;
			if (banned(host))
			{
				//write they suck
				write(fd,"HTTP/1.0 200 Ok\n\n<h1>microsoft sucks</h1>",41);
			}
			else
			{
				int remote=MakeClientSocket(host,"80");
			
				if (remote==-1) cout << "no connection to remote server" << endl;
				else
				{
					char tmp[BUFSIZE];
					int len2;
					len2=read(remote,tmp,strlen(tmp));
					int l=sprintf(tmp,"%s %s %s",get,path,version);
					len2=write(remote,tmp,l);
					len2=write(remote,"\n\n",2);
			
					if (len2==-1) cout << "get to remote failed" << endl;
					else cout << "wrote command =" << tmp <<"=" <<endl;				

					do
        	        	        {
                        		        len2=read(remote,buf,BUFSIZE);
						buf[len2]=0;
						len=write(fd,buf,len2);
	                	        }
        		                while(len2>0);
 					close(remote);
				}
			}
			close(fd);
			exit(1);
		}
		close(fd);
	}
	log.close();
	return 0;
}