net_ipv4_tftp.c

bootloader源代码

/*****************************************
 Copyright (c) 2001-2002 
 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 2002/11/20
 */

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

/* 
	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)
{
	PrintFormat("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();
   
	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%cblksize%c%d", 
		filename, 0, 0, 0, TFTP_MAX_PACKET);
	len += 1;

	for (nretry = 1; nretry <= MAX_TFTP_RETRIES; ++nretry) {
		PrintUart("Connecting...\r\n", -1);
		udp_transmit(ipaddr, iport, IPPORT_TFTP, len, &packet);
		if ((skb = udp_receive(ipaddr, 0, iport, TIMEOUT)) != NULL)
			break;

		if (nretry == MAX_TFTP_RETRIES) {
			PrintUart("Timeout. Connection failed.\r\n", -1);
			return TFTPRET_NETWORKERR;
		} else {
			PrintUart("Timeout. Retrying...\r\n", -1);
		}
	}

	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)
						PrintUart("Receiving : ", -1);
					else
						PrintUart("\r\n            ", -1);
				}
				PrintChar('.');
			}
			
			// Append to data buffer
			len = skb->udpdata_len - 4;
			PrintFormat("Received len=%d bytes\n", len);
			memcpy(dataptr, skb->tftp->u.data.data, len);
			dataptr += len;
			*datalen += len;

			// 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);

			if (len < TFTP_MAX_PACKET) {
				PrintUart("\r\n", -1);
				PrintFormat("Received Total=%d (0x%x) bytes\n", *datalen, *datalen);
				return 0;
			}
			break;
		case TFTPOP_ERROR :
			switch (skb->tftp->u.err.errcode) {
			case TFTPERR_FILENOTFOUND :
				PrintUart("File not found\r\n", -1);
				return TFTPRET_FILENOTFOUND;
			case TFTPERR_ACCESSDENIED :
				PrintUart("Access denied\r\n", -1);
				return TFTPRET_ACCESSDENIED;
			default :
				PrintFormat("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
			packet.tftp.opcode = htons(TFTPOP_ACK);
			packet.tftp.u.ack.block = 0;
			udp_transmit(ipaddr, iport, skb->udp->src, 4, &packet);
			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) {
				PrintUart("Timeout. Transfer failed.\r\n", -1);
				return TFTPRET_NETWORKERR;
			}
		}
	}
	
	return 0;
}