Subversion Repositories amber

/*----------------------------------------------------------------
//                                                              //
//  boot-loader-ethmac.c                                        //
//                                                              //
//  This file is part of the Amber project                      //
//  http://www.opencores.org/project,amber                      //
//                                                              //
//  Description                                                 //
//  The main functions for the boot loader application. This    //
//  application is embedded in the FPGA's SRAM and is used      //
//  to load larger applications into the DDR3 memory on         //
//  the development board.                                      //
//                                                              //
//  Author(s):                                                  //
//      - Conor Santifort, csantifort.amber@gmail.com           //
//                                                              //
//////////////////////////////////////////////////////////////////
//                                                              //
// Copyright (C) 2011 Authors and OPENCORES.ORG                 //
//                                                              //
// This source file may be used and distributed without         //
// restriction provided that this copyright statement is not    //
// removed from the file and that any derivative work contains  //
// the original copyright notice and the associated disclaimer. //
//                                                              //
// This source file is free software; you can redistribute it   //
// and/or modify it under the terms of the GNU Lesser General   //
// Public License as published by the Free Software Foundation; //
// either version 2.1 of the License, or (at your option) any   //
// later version.                                               //
//                                                              //
// This source 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 Lesser General Public License for more //
// details.                                                     //
//                                                              //
// You should have received a copy of the GNU Lesser General    //
// Public License along with this source; if not, download it   //
// from http://www.opencores.org/lgpl.shtml                     //
//                                                              //
----------------------------------------------------------------*/
 
 
#include "address_map.h"
#include "line-buffer.h"
#include "timer.h"
#include "utilities.h"
#include "packet.h"
#include "udp.h"
 
 
int         udp_checksum_errors_g = 0;
 
 
void parse_udp_packet(char * buf, packet_t* rx_packet)
{
    unsigned int udp_src_port    = buf[0]<<8|buf[1];
    unsigned int udp_dst_port    = buf[2]<<8|buf[3];
    unsigned int udp_len         = buf[4]<<8|buf[5];
 
    unsigned short prot_udp=17;
    unsigned short word16;
    unsigned long  sum = 0;
    unsigned int   checksum;
    int mode_offset;
    int binary_mode;
    int i;
 
 
    for (i=0;i<4;i=i+2){
            word16 =((rx_packet->src_ip[i]<<8)&0xFF00)+(rx_packet->src_ip[i+1]&0xFF);
            sum=sum+word16;
    }
    for (i=0;i<4;i=i+2){
            word16 =((rx_packet->dst_ip[i]<<8)&0xFF00)+(rx_packet->dst_ip[i+1]&0xFF);
            sum=sum+word16;
    }
    // the protocol number and the length of the TCP packet
    sum = sum + prot_udp + udp_len;
 
    checksum = header_checksum16(buf, udp_len, sum);
 
    if (checksum)
        udp_checksum_errors_g++;
 
 
     /* TFTP */
    if (udp_dst_port == 69 && !checksum)
        parse_tftp_packet(buf, rx_packet, udp_len-12, udp_src_port, udp_dst_port);
 
}
 
 
 
void udp_reply(packet_t* rx_packet, int udp_src_port, int udp_dst_port, int block, int reply_type)
{
    char buf[96];
    unsigned short checksum;
    unsigned short prot_udp=17;
    unsigned short udp_len;
    unsigned short word16;
    unsigned long  sum = 0;
    int i;
 
    /* udp header */
    buf[34] = (udp_src_port & 0xff00)>>8;
    buf[35] =  udp_src_port & 0xff;
    buf[36] = (udp_dst_port & 0xff00)>>8;
    buf[37] =  udp_dst_port & 0xff;
 
    if (reply_type == UDP_ACK)
        udp_len = 8+4;
    else /* error */
        udp_len = 8+2+2+14;
 
 
    buf[38] = (udp_len      & 0xff00)>>8;
    buf[39] =  udp_len      & 0xff;
 
    buf[40] = 0;  // checksum
    buf[41] = 0;  // checksum
 
    // -------------------------------------
    // tftf payload
    // -------------------------------------
    // Opcode
    buf[42] = 0;
    buf[43] = reply_type & 0xff;  // Acknowledgment
 
    if (reply_type == UDP_ACK) {
        // block
        buf[44] = (block & 0xff00)>>8;
        buf[45] =  block & 0xff;
        }
    else {/* error */
        // Error Code
        buf[44] = 0;
        buf[45] = 0;
        // 46 to 59
        strncpy(&buf[46], "Not supported", 14);
        }
 
 
    // -------------------------------------
    // UDP Checksum calculation
    // -------------------------------------
    for (i=0;i<4;i=i+2){
            word16 =((rx_packet->src_ip[i]<<8)&0xFF00)+(rx_packet->src_ip[i+1]&0xFF);
            sum=sum+word16;
    }
    for (i=0;i<4;i=i+2){
            word16 =((rx_packet->dst_ip[i]<<8)&0xFF00)+(rx_packet->dst_ip[i+1]&0xFF);
            sum=sum+word16;
    }
    // the protocol number and the length of the TCP packet
    sum = sum + prot_udp + udp_len;
 
    checksum = header_checksum16(&buf[34], udp_len, sum);
    buf[40] = (checksum & 0xff00)>>8;  // checksum
    buf[41] =  checksum & 0xff;        // checksum
 
    ip_header(&buf[14], (ip_t*) rx_packet->src_ip, 20+udp_len, 17); /* 20 byes of tcp  options, bytes 14 to 33, ip_proto = 17, UDP */
    ethernet_header(buf, (mac_t*) rx_packet->src_mac, 0x0800);  /*bytes 0 to 13*/
 
    ethmac_tx_packet(buf, 34+udp_len);  // packet length in bytes
}