net_ipv4_tftp.c

em86xx 完整启动程序,支持网络下载与串通下载

/*****************************************
 Copyright (c) 2002-2004
 Sigma Designs, Inc. All Rights Reserved
 Proprietary and Confidential
 *****************************************/

/* This file is part of the boot loader */

/*
 * net_ipv4_tftp.c
 *
 * TFTP client 
 * Based on RFC 1350 "The TFTP Protocol (Revision 2)"
 * Based on RFC 1782 "TFTP Option Extension"
 *
 * Written by Ho Lee 11/20/2002
 */

#include "config.h"
#include "util.h"
#include "vsprintf.h"
#include "uart.h"
#include "timer.h"
#include "net.h"
#include "net_ipv4.h"

static const char *blkstr = "blksize";

/* 
    TFTP file transfer example (from RFC 1782)

    Read Request

      client                                           server
      -------------------------------------------------------
      |1|foofile|0|octet|0|blksize|0|1432|0|  -->               RRQ
                                    <--  |6|blksize|0|1432|0|   OACK
      |4|0|  -->                                                ACK
                             <--  |3|1| 1432 octets of data |   DATA
      |4|1|  -->                                                ACK
                             <--  |3|2| 1432 octets of data |   DATA
      |4|2|  -->                                                ACK
                             <--  |3|3|<1432 octets of data |   DATA
      |4|3|  -->                                                ACK
*/

int tftp_parsepacket(struct sk_buff *skb)
{
    skb->tftp = (struct tftphdr *) ((char *) skb->udp + sizeof(struct udphdr));
    skb->tftp->opcode = ntohs(skb->tftp->opcode);

    switch (skb->tftp->opcode) {
    case TFTPOP_DATA :
        skb->tftp->u.data.block = ntohs(skb->tftp->u.data.block);
        break;
    case TFTPOP_ACK :
        skb->tftp->u.ack.block = ntohs(skb->tftp->u.ack.block);
        break;
    case TFTPOP_ERROR :
        skb->tftp->u.err.errcode = ntohs(skb->tftp->u.err.errcode);
        break;
    }

    return 0;
}

void tftp_dump_packet(struct sk_buff *skb, int need_parsing)
{
    uart_printf("TFTP : \n");
}

int ipv4_tftp(in_addr_t ipaddr, char *filename, unsigned int addr, unsigned int *datalen)
{
    tftpip_t packet;
    int len, nretry;
    int nloop = 0, nloop2 = 0;
    struct sk_buff *skb = NULL;
    unsigned char *dataptr;
    unsigned int iport = ipv4_alloc_port();
    unsigned int blksize = TFTP_DEF_PACKET;
    unsigned int last_block = 0;
   
    dataptr = (unsigned char *) addr;
    *datalen = 0;

    // send RRQ
    packet.tftp.opcode = htons(TFTPOP_RRQ);
    len = sizeof packet.tftp.opcode;
    len += sprintf((char *) packet.tftp.u.rrq, "%s%coctet%c%s%c%d", 
        filename, 0, 0, blkstr, 0, TFTP_MAX_PACKET);
    len += 1;

    for (nretry = 1; nretry <= MAX_TFTP_RETRIES; ++nretry) {
        uart_printf("Getting (%s)...\n", filename);
        udp_transmit(ipaddr, iport, IPPORT_TFTP, len, &packet, 0);
        if ((skb = udp_receive(ipaddr, 0, iport, TIMEOUT)) != NULL)
            break;

        if (nretry == MAX_TFTP_RETRIES) {
            uart_puts("Timeout. Connection failed.\n");
            return TFTPRET_NETWORKERR;
        } else {
            uart_puts("Timeout. Retrying...\n");
        }
    }

    while (skb) {
        tftp_parsepacket(skb);

        switch (skb->tftp->opcode) {
        case TFTPOP_RRQ : 
        case TFTPOP_WRQ : 
        case TFTPOP_ACK :
            // invalid op code for client
            // just ignore them
            break;
        case TFTPOP_DATA :
            // print progress
            if ((nloop++ & 0x3f) == 0) {
                if ((nloop2++ & 0x3f) == 0) {
                    if (nloop2 == 1)
                        uart_puts("Receiving");
                    else
                        uart_puts("\n            ");
                }
                uart_putc('.');
            }
            
	    /* Save the last block# so if ack is lost we won't copy the
               same packet more than once */
            if (last_block != skb->tftp->u.data.block) {
            	// Append to data buffer
            	len = skb->udpdata_len - 4;
            	memcpy(dataptr, skb->tftp->u.data.data, len);
            	dataptr += len;
            	*datalen += len;
                last_block = skb->tftp->u.data.block;
	    }

            // reply ACK
            packet.tftp.opcode = htons(TFTPOP_ACK);
            packet.tftp.u.ack.block = htons(skb->tftp->u.data.block);
            udp_transmit(ipaddr, iport, skb->udp->src, 4, &packet, 0);

            if (len < blksize) {
                uart_puts("\n");
                //uart_printf("Received %d (0x%x) bytes\n", *datalen, *datalen);
                return 0;
            }
            break;
        case TFTPOP_ERROR :
            switch (skb->tftp->u.err.errcode) {
            case TFTPERR_FILENOTFOUND :
                uart_puts("File not found\n");
                return TFTPRET_FILENOTFOUND;
            case TFTPERR_ACCESSDENIED :
                uart_puts("Access denied\n");
                return TFTPRET_ACCESSDENIED;
            default :
                uart_printf("TFTP error %d : %s\n", 
                    skb->tftp->u.err.errcode, skb->tftp->u.err.errmsg);
                return TFTPRET_OTHER;
            }
            break;
        case TFTPOP_OACK :
            // reply with ACK
	    if (strcmp(skb->tftp->u.oack.data, blkstr) == 0) {
		blksize = atoi(&(skb->tftp->u.oack.data[strlen(blkstr) + 1]));
		uart_printf("Block size set to %d.\n", blksize);
	    }
            packet.tftp.opcode = htons(TFTPOP_ACK);
            packet.tftp.u.ack.block = 0;
            udp_transmit(ipaddr, iport, skb->udp->src, 4, &packet, 0);
            break;
        }

        skb_free(skb);

        for (nretry = 1; nretry <= MAX_TFTP_RETRIES; ++nretry) {
            if ((skb = udp_receive(ipaddr, 0, iport, TIMEOUT)) != NULL)
                break;
            if (nretry == MAX_TFTP_RETRIES) {
                uart_puts("Timeout. Transfer failed.\n");
                return TFTPRET_NETWORKERR;
            }
        }
    }
    
    return 0;
}