/*
 *  Copyright (C) 1999 Peter Amstutz
 *
 *  This program 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 2 of *the
 *  License, or (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307 USA 
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "tcpcore.h"
#include "log.h"

/* Function: tcpListen()
	Purpose: Create a listening socket on the specified port.
*/
int tcpListen(unsigned short int port)
{
    struct sockaddr_in sa;
    int sock, set = 1;

    memset(&sa, 0, sizeof(struct sockaddr_in));
    sa.sin_port = htons(port);
    sa.sin_family = AF_INET;
    sa.sin_addr.s_addr = INADDR_ANY;
    if((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
	logPrintf(CRITICAL, "Error creating socket: %s\n",
		  strerror(errno));
	return -1;
    }
    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &set, sizeof(int));
    if(bind(sock, (struct sockaddr *) &sa, sizeof(struct sockaddr_in)) < 0)
    {
	logPrintf(CRITICAL, "Error binding socket: %s\n",
		  strerror(errno));
	return -1;
    }


    if(listen(sock, 10) < 0)
    {
	logPrintf(CRITICAL, "Error listening to socket: %s\n",
		  strerror(errno));
	return -1;
    }
/*    fcntl(sock, F_SETFL, O_NONBLOCK); */
    return sock;
}

/* Function: tcpGetNewConnection()
	Purpose: gets the next queued connection on a tcp/ip listen socket
*/
int tcpGetNewConnection(int listener)
{
    int ret;

    if(listener < 0 || (ret = accept(listener, NULL, 0)) < 0)
    {
	return -1;
    }
    return ret;
}

void tcpGetExact(int sock, char *store, int size)
{
    int gotten = 0;

    do
    {
	gotten = recv(sock, store, size, 0);
	store += gotten;
	size -= gotten;
    }
    while(size > 0);
}

/* Function: tcpGetPacket()
	Purpose: retrives the next packet waiting from a connection
*/
int tcpGetPacket(int sock, char *store, int maxlen)
{
    unsigned short int size;
    if(sock < 0 || store == NULL)
	return -1;
    tcpGetExact(sock, (char *) &size, 2);
    size = ntohs(size);
    tcpGetExact(sock, store, size > maxlen ? maxlen : size);
    return size;
}

/* Function: tcpSendPacket()
	Purpose: sends a packet out to a certain connection
*/
int tcpSendPacket(int sock, char *store, int datalen)
{
    char *data;
    short unsigned int len;
    int ret;

    if(sock < 0 || store == NULL)
	return -1;
    data = (char *) malloc(datalen + 2);
    len = htons(datalen);
    memcpy(data, &len, 2);
    memcpy(data + 2, store, datalen);
    ret = send(sock, data, datalen + 2, 0);
    free(data);
    return ret;
}

/* Function: tcpSendPacket()
	Purpose: sends a "typed" packet out to a certain connection
*/
int tcpSendTypedPacket(int sock, char *type, char *store, int datalen)
{
    char *data;
    short unsigned int len, tlen = strlen(type);
    int ret;

    if(sock < 0 || store == NULL)
	return -1;
    data = (char *) malloc(datalen + 2 + tlen);
    len = htons(datalen + tlen);
    memcpy(data, &len, 2);
    memcpy(data + 2, type, tlen);
    memcpy(data + 2 + tlen, store, datalen);
    ret = send(sock, data, datalen + 2 + tlen, 0);
    free(data);
    return ret;
}

/* Function: tcpDial()
	Purpose: establish a TCP/IP connection to some host
*/
int tcpDial(char *host, unsigned short int port)
{
    struct hostent *hp;
    struct sockaddr_in sa;
    int sock;

    if(host == NULL)
	return -1;
    if((hp = gethostbyname(host)) == NULL)
	return -1;
    memset(&sa, 0, sizeof(struct sockaddr_in));
    sa.sin_port = htons(port);
    sa.sin_family = AF_INET;
    sa.sin_addr = *((struct in_addr *) hp->h_addr);
    if((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
       connect(sock, (struct sockaddr *) &sa, sizeof(struct sockaddr_in)) < 0)
    {
	return -1;
    }
    return sock;
}

int tcpDataReady(int sock)
{
    fd_set rfds;
    struct timeval tv;

    FD_ZERO(&rfds);
    FD_SET(sock, &rfds);
    tv.tv_sec = 0;
    tv.tv_usec = 0;
    select(sock + 1, &rfds, NULL, NULL, &tv);
    return FD_ISSET(sock, &rfds);
}