/* net.c - net_init, netin, eth_hton */

#include 
#include 

struct  network NetData;
bpid32  netbufpool;
uint32  netportseed;

/*------------------------------------------------------------------------
 * net_init  -  Initialize network data structures and processes
 *------------------------------------------------------------------------
 */

void    net_init (void)
{
        int32   nbufs;                  /* Total no of buffers          */

        /* Initialize the network data structure */

        memset((char *)&NetData, NULLCH, sizeof(struct network));

        /* Obtain the Ethernet MAC address */

        control(ETHER0, ETH_CTRL_GET_MAC, (int32)NetData.ethucast, 0);

        memset((char *)NetData.ethbcast, 0xFF, ETH_ADDR_LEN);

        /* Initialize the random port seed */

        netportseed = getticks();

        /* Create the network buffer pool */

        nbufs = UDP_SLOTS * UDP_QSIZ + ICMP_SLOTS * ICMP_QSIZ + 1;

        netbufpool = mkbufpool(PACKLEN, nbufs);

        /* Initialize the ARP cache */

        arp_init();

        /* Initialize UDP */

        udp_init();

        /* Initialize ICMP */

        icmp_init();

        /* Initialize the IP output queue */

        ipoqueue.iqhead = 0;
        ipoqueue.iqtail = 0;
        ipoqueue.iqsem = semcreate(0);
        if((int32)ipoqueue.iqsem == SYSERR) {
                panic("Cannot create ip output queue semaphore");
                return;
        }

        /* Create the IP output process */

        resume(create(ipout, NETSTK, NETPRIO, "ipout", 0, NULL));

        /* Create a network input process */

        resume(create(netin, NETSTK, NETPRIO, "netin", 0, NULL));
}


/*------------------------------------------------------------------------
 * netin  -  Repeatedly read and process the next incoming packet
 *------------------------------------------------------------------------
 */

process netin ()
{
        struct  netpacket *pkt;         /* Ptr to current packet        */
        int32   retval;                 /* Return value from read       */

        /* Do forever: read a packet from the network and process */

        while(1) {

                /* Allocate a buffer */

                pkt = (struct netpacket *)getbuf(netbufpool);

                /* Obtain next packet that arrives */

                retval = read(ETHER0, (char *)pkt, PACKLEN);
                if(retval == SYSERR) {
                        panic("Cannot read from Ethernet\n");
                }

                /* Convert Ethernet Type to host order */

                eth_ntoh(pkt);

                /* Demultiplex on Ethernet type */

                switch (pkt->net_ethtype) {

                    case ETH_ARP:                       /* Handle ARP   */
                        arp_in((struct arppacket *)pkt);
                        continue;

                    case ETH_IP:                        /* Handle IP    */
                        ip_in(pkt);
                        continue;
        
                    case ETH_IPv6:                      /* Handle IPv6  */
                        freebuf((char *)pkt);
                        continue;

                    default:    /* Ignore all other incoming packets    */
                        freebuf((char *)pkt);
                        continue;
                }
        }
}

/*------------------------------------------------------------------------
 * eth_hton  -  Convert Ethernet type field to network byte order
 *------------------------------------------------------------------------
 */
void    eth_hton(
          struct netpacket *pktptr
        )
{
        pktptr->net_ethtype = htons(pktptr->net_ethtype);
}


/*------------------------------------------------------------------------
 * eth_ntoh  -  Convert Ethernet type field to host byte order
 *------------------------------------------------------------------------
 */
void    eth_ntoh(
          struct netpacket *pktptr
        )
{
        pktptr->net_ethtype = ntohs(pktptr->net_ethtype);
}

/*------------------------------------------------------------------------
 * getport  -  Retrieve a random port number 
 *------------------------------------------------------------------------
 */
uint16  getport()
{
        netportseed = 1103515245 * netportseed + 12345;
        return 50000 + ((uint16)((netportseed >> 16)) % 15535);
}