bootp.c

ARM的bootloader代码.rar

    *e++ = 3;		/* Router Option */
    *cnt += 1;
#endif
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_DNS)
    *e++ = 6;		/* DNS Server(s) */
    *cnt += 1;
#endif
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_HOSTNAME)
    *e++ = 12;		/* Hostname */
    *cnt += 1;
#endif
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_BOOTFILESIZE)
    *e++ = 13;		/* Boot File Size */
    *cnt += 1;
#endif
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_BOOTPATH)
    *e++ = 17;		/* Boot path */
    *cnt += 1;
#endif
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_NISDOMAIN)
    *e++ = 40;		/* NIS Domain name request */
    *cnt += 1;
#endif

    *e++ = 255;		/* End of the list */

    return e - start ;
}

#else	/* CFG_CMD_DHCP */
/*
 *	Warning: no field size check - change CONFIG_BOOTP_MASK at your own risk!
 */
static int BootpExtended (u8 *e)
{
    u8 *start = e ;

    *e++ =  99;		/* RFC1048 Magic Cookie */
    *e++ = 130;
    *e++ =  83;
    *e++ =  99;

#if (CONFIG_COMMANDS & CFG_CMD_DHCP)
    *e++ = 53;		/* DHCP Message Type */
    *e++ = 1;
    *e++ = DHCP_DISCOVER;

    *e++ = 57;		/* Maximum DHCP Message Size */
    *e++ = 2;
    *e++ = (576-312+OPT_SIZE) >> 16;
    *e++ = (576-312+OPT_SIZE) & 0xff;
#endif	/* CFG_CMD_DHCP */

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_SUBNETMASK)
    *e++ =  1;		/* Subnet mask request */
    *e++ =  4;
     e  +=  4;
#endif

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_GATEWAY)
    *e++ =  3;		/* Default gateway request */
    *e++ =  4;
     e  +=  4;
#endif

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_DNS)
    *e++ =  6;		/* Domain Name Server */
    *e++ =  4;
     e  +=  4;
#endif

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_HOSTNAME)
    *e++ = 12;		/* Host name request */
    *e++ = 32;
     e  += 32;
#endif

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_BOOTFILESIZE)
    *e++ = 13;		/* Boot file size */
    *e++ =  2;
     e  +=  2;
#endif

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_BOOTPATH)
    *e++ = 17;		/* Boot path */
    *e++ = 32;
     e  += 32;
#endif

#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_NISDOMAIN)
    *e++ = 40;		/* NIS Domain name request */
    *e++ = 32;
     e  += 32;
#endif

    *e++ = 255;		/* End of the list */

    return e - start ;
}
#endif	/* CFG_CMD_DHCP */

void
BootpRequest (void)
{
	volatile uchar *pkt, *iphdr;
	Bootp_t *bp;
	int ext_len, pktlen, iplen;

#if (CONFIG_COMMANDS & CFG_CMD_DHCP)
	dhcp_state = INIT;
#endif

	printf("BOOTP broadcast %d\n", ++BootpTry);
	pkt = NetTxPacket;
	memset ((void*)pkt, 0, PKTSIZE);

	NetSetEther(pkt, NetBcastAddr, PROT_IP);
	pkt += ETHER_HDR_SIZE;

	/*
	 * Next line results in incorrect packet size being transmitted, resulting
	 * in errors in some DHCP servers, reporting missing bytes.  Size must be
	 * set in packet header after extension length has been determined.
	 * C. Hallinan, DS4.COM, Inc.
	 */
	/* NetSetIP(pkt, 0xffffffffL, PORT_BOOTPS, PORT_BOOTPC, sizeof (Bootp_t)); */
	iphdr = pkt;	/* We need this later for NetSetIP() */
	pkt += IP_HDR_SIZE;

	bp = (Bootp_t *)pkt;
	bp->bp_op = OP_BOOTREQUEST;
	bp->bp_htype = HWT_ETHER;
	bp->bp_hlen = HWL_ETHER;
	bp->bp_hops = 0;
	bp->bp_secs = SWAP16( get_timer(0) / CFG_HZ);
	NetWriteIP((vuchar*)&bp->bp_ciaddr, 0);
	NetWriteIP((vuchar*)&bp->bp_yiaddr, 0);
	NetWriteIP((vuchar*)&bp->bp_siaddr, 0);
	NetWriteIP((vuchar*)&bp->bp_giaddr, 0);
	NetCopyEther(bp->bp_chaddr, NetOurEther);
	copy_filename (bp->bp_file, BootFile, sizeof(bp->bp_file));

	/* Request additional information from the BOOTP/DHCP server */
#if (CONFIG_COMMANDS & CFG_CMD_DHCP)
	ext_len = DhcpExtended(bp->bp_vend, DHCP_DISCOVER, 0, 0);
#else
	ext_len = BootpExtended(bp->bp_vend);
#endif	/* CFG_CMD_DHCP */

	/*
	 *	Bootp ID is the lower 4 bytes of our ethernet address
	 *	plus the current time in HZ.
	 */
	BootpID = ((ulong)NetOurEther[2] << 24)
		| ((ulong)NetOurEther[3] << 16)
		| ((ulong)NetOurEther[4] << 8)
		| (ulong)NetOurEther[5];
	BootpID += get_timer(0);
	memcpy(&bp->bp_id, &BootpID, sizeof(bp->bp_id));

	/*
	 * Calculate proper packet lengths taking into account the
	 * variable size of the options field
	 */
	pktlen = BOOTP_SIZE - sizeof(bp->bp_vend) + ext_len;
	iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + ext_len;
	NetSetIP(iphdr, 0xffffffffL, PORT_BOOTPS, PORT_BOOTPC, iplen);
	NetSetTimeout(SELECT_TIMEOUT * CFG_HZ, BootpTimeout);

#if (CONFIG_COMMANDS & CFG_CMD_DHCP)
	dhcp_state = SELECTING;
	NetSetHandler(DhcpHandler);
#else
	NetSetHandler(BootpHandler);
#endif	/* CFG_CMD_DHCP */
	NetSendPacket(NetTxPacket, pktlen);
}

#if (CONFIG_COMMANDS & CFG_CMD_DHCP)
void DhcpOptionsProcess(char *popt)
{
	char *end = popt + BOOTP_HDR_SIZE;
	int oplen, size;

	while ( popt < end && *popt != 0xff ) {
		oplen = *(popt + 1);
		switch(*popt) {
			case  1:
				NetOurSubnetMask = *(IPaddr_t *)(popt + 2);
				break;
			case  3:
				NetOurGatewayIP = *(IPaddr_t *)(popt + 2);
				break;
			case  6:
				NetOurDNSIP = *(IPaddr_t *)(popt +2);
				break;
			case 12:
				size = truncate_sz ("Host Name",
						    sizeof(NetOurHostName),
						    oplen);
				memcpy(&NetOurHostName, popt+2, size);
				NetOurHostName[size] = 0 ;
				break;
			case 15:		/* Ignore Domain Name Option */
				break;
			case 17:
				size = truncate_sz ("Root Path",
						    sizeof(NetOurRootPath),
						    oplen);
				memcpy(&NetOurRootPath, popt+2, size);
				NetOurRootPath[size] = 0 ;
				break;
			case 51:
				dhcp_leasetime = *(unsigned int *)(popt + 2);
				break;
			case 53:		/* Ignore Message Type Option */
				break;
			case 54:
				NetServerIP = *(IPaddr_t *)(popt+2);
				break;
			case 58:		/* Ignore Renewal Time Option */
				break;
			case 59:		/* Ignore Rebinding Time Option */
				break;
			default:
				printf("*** Unhandled DHCP Option in OFFER/ACK: %d\n",
					*popt);
				break;
		}
		popt += oplen + 2;	/* Process next option */
	}
}

static int DhcpMessageType(unsigned char *popt)
{
	ulong vendmagic;
	memcpy(&vendmagic, popt, 4);
	if (SWAP32(vendmagic) != BOOTP_VENDOR_MAGIC)
		return -1;

	popt += 4;
	while ( *popt != 0xff ) {
		if ( *popt == 53 )	/* DHCP Message Type */
			return *(popt + 2);
		popt += *(popt + 1) + 2;	/* Scan through all options */
	}
	return -1;
}

void DhcpSendRequestPkt(Bootp_t *bp_offer)
{
	volatile uchar *pkt, *iphdr;
	Bootp_t *bp;
	int pktlen, iplen, extlen;

	debug ("DhcpSendRequestPkt: Sending DHCPREQUEST\n");
	pkt = NetTxPacket;
	memset ((void*)pkt, 0, PKTSIZE);

	NetSetEther(pkt, NetBcastAddr, PROT_IP);
	pkt += ETHER_HDR_SIZE;

	iphdr = pkt;		/* We'll need this later to set proper pkt size */
	pkt += IP_HDR_SIZE;

	bp = (Bootp_t *)pkt;
	bp->bp_op = OP_BOOTREQUEST;
	bp->bp_htype = HWT_ETHER;
	bp->bp_hlen = HWL_ETHER;
	bp->bp_hops = 0;
	bp->bp_secs = SWAP16( get_timer(0) / CFG_HZ);
	NetCopyIP((vuchar*)&bp->bp_ciaddr, (vuchar*)&bp_offer->bp_ciaddr);
	NetCopyIP((vuchar*)&bp->bp_yiaddr, (vuchar*)&bp_offer->bp_yiaddr);
	NetCopyIP((vuchar*)&bp->bp_siaddr, (vuchar*)&bp_offer->bp_siaddr);
	NetCopyIP((vuchar*)&bp->bp_giaddr, (vuchar*)&bp_offer->bp_giaddr);
	NetCopyEther(bp->bp_chaddr, NetOurEther);

	/*
	 * ID is the id of the OFFER packet
	 */

	memcpy(bp->bp_id, bp_offer->bp_id, sizeof(bp->bp_id);

	/*
	 * Copy options from OFFER packet if present
	 */
	extlen = DhcpExtended(bp->bp_vend, DHCP_REQUEST, NetServerIP, bp->bp_yiaddr);

	pktlen = BOOTP_SIZE - sizeof(bp->bp_vend) + extlen;
	iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + extlen;
	NetSetIP(iphdr, 0xffffffffL, PORT_BOOTPS, PORT_BOOTPC, iplen);

	debug ("Transmitting DHCPREQUEST packet: len = %d\n", pktlen);
	NetSendPacket(NetTxPacket, pktlen);
}

/*
 *	Handle DHCP received packets.
 */
static void
DhcpHandler(uchar * pkt, unsigned dest, unsigned src, unsigned len)
{
	Bootp_t *bp = (Bootp_t *)pkt;

	debug ("DHCPHandler: got packet: (src=%d, dst=%d, len=%d) state: %d\n",
		src, dest, len, dhcp_state);

	if (BootpCheckPkt(pkt, dest, src, len))	/* Filter out pkts we don't want */
		return;

	debug ("DHCPHandler: got DHCP packet: (src=%d, dst=%d, len=%d) state: %d\n",
		src, dest, len, dhcp_state);

	switch (dhcp_state) {
	case SELECTING:
		/*
		 * Wait an appropriate time for any potential DHCPOFFER packets
		 * to arrive.  Then select one, and generate DHCPREQUEST response.
		 * If filename is in format we recognize, assume it is a valid
		 * OFFER from a server we want.
		 */
		debug ("DHCP: state=SELECTING bp_file: \"%s\"\n", bp->bp_file);
#ifdef CFG_BOOTFILE_PREFIX
		if (strncmp(bp->bp_file,
			    CFG_BOOTFILE_PREFIX,
			    strlen(CFG_BOOTFILE_PREFIX)) == 0 ) {
#endif	/* CFG_BOOTFILE_PREFIX */

			debug ("TRANSITIONING TO REQUESTING STATE\n");
			dhcp_state = REQUESTING;
#if 0
			if ((*(uint *)bp->bp_vend) == BOOTP_VENDOR_MAGIC)
				DhcpOptionsProcess(&bp->bp_vend[4]);

#endif
			BootpCopyNetParams(bp);	/* Store net params from reply */

			NetSetTimeout(TIMEOUT * CFG_HZ, BootpTimeout);
			DhcpSendRequestPkt(bp);
#ifdef CFG_BOOTFILE_PREFIX
		}
#endif	/* CFG_BOOTFILE_PREFIX */

		return;
		break;
	case REQUESTING:
		debug ("DHCP State: REQUESTING\n");

		if ( DhcpMessageType(bp->bp_vend) == DHCP_ACK ) {
			if ((*(uint *)bp->bp_vend) == BOOTP_VENDOR_MAGIC)
				DhcpOptionsProcess(&bp->bp_vend[4]);
			BootpCopyNetParams(bp);	/* Store net params from reply */
			dhcp_state = BOUND;
			printf("DHCP client bound to address ");
			print_IPaddr(NetOurIP);
			printf("\n");
			/* Send ARP request to get TFTP server ethernet address.
			 * This automagically starts TFTP, too.
			 */
			ArpRequest();
			return;
		}
		break;
	default:
		printf("DHCP: INVALID STATE\n");
		break;
	}

}

void DhcpRequest(void)
{
	BootpRequest();
}
#endif	/* CFG_CMD_DHCP */

#endif /* CFG_CMD_NET */