bootp.c

关于s3c2440之bootloader的源代码

	if ((x = dhcp_vendorex_prep (e)))
		return x - start;
#endif

	*e++ = 55;		/* Parameter Request List */
	 cnt = e++;		/* Pointer to count of requested items */
	*cnt = 0;
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_SUBNETMASK)
	*e++  = 1;		/* Subnet Mask */
	*cnt += 1;
#endif
#if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_GATEWAY)
	*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 */

	/* Pad to minimal length */
#ifdef	CONFIG_DHCP_MIN_EXT_LEN
	while ((e - start) <= CONFIG_DHCP_MIN_EXT_LEN)
		*e++ = 0;
#endif

	return e - start;
}

#else	/* CONFIG_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;

#ifdef CONFIG_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 /* CONFIG_CMD_DHCP */

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

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

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

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

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

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

#ifdef (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	/* CONFIG_CMD_DHCP */

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

#ifdef CONFIG_CMD_DHCP
	dhcp_state = INIT;
#endif

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

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

	/*
	 * 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 = htons(get_timer(0) / CFG_HZ);
	NetWriteIP(&bp->bp_ciaddr, 0);
	NetWriteIP(&bp->bp_yiaddr, 0);
	NetWriteIP(&bp->bp_siaddr, 0);
	NetWriteIP(&bp->bp_giaddr, 0);
	memcpy (bp->bp_chaddr, NetOurEther, 6);
	copy_filename (bp->bp_file, BootFile, sizeof(bp->bp_file));

	/* Request additional information from the BOOTP/DHCP server */
#ifdef CONFIG_CMD_DHCP
	ext_len = DhcpExtended(bp->bp_vend, DHCP_DISCOVER, 0, 0);
#else
	ext_len = BootpExtended(bp->bp_vend);
#endif	/* CONFIG_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);
	BootpID	 = htonl(BootpID);
	NetCopyLong(&bp->bp_id, &BootpID);

	/*
	 * 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);

#ifdef CONFIG_CMD_DHCP
	dhcp_state = SELECTING;
	NetSetHandler(DhcpHandler);
#else
	NetSetHandler(BootpHandler);
#endif	/* CONFIG_CMD_DHCP */
	NetSendPacket(NetTxPacket, pktlen);
}

#ifdef  CONFIG_CMD_DHCP
static void DhcpOptionsProcess (uchar * popt)
{
	uchar *end = popt + BOOTP_HDR_SIZE;
	int oplen, size;

	while (popt < end && *popt != 0xff) {
		oplen = *(popt + 1);
		switch (*popt) {
		case 1:
			NetCopyIP (&NetOurSubnetMask, (popt + 2));
			break;
		case 3:
			NetCopyIP (&NetOurGatewayIP, (popt + 2));
			break;
		case 6:
			NetCopyIP (&NetOurDNSIP, (popt + 2));
#ifdef (CONFIG_BOOTP_MASK & CONFIG_BOOTP_DNS2)
			if (*(popt + 1) > 4) {
				NetCopyIP (&NetOurDNS2IP, (popt + 2 + 4));
			}
#endif
			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:
			NetCopyLong (&dhcp_leasetime, (ulong *) (popt + 2));
			break;
		case 53:	/* Ignore Message Type Option */
			break;
		case 54:
			NetCopyIP (&NetDHCPServerIP, (popt + 2));
			break;
		case 58:	/* Ignore Renewal Time Option */
			break;
		case 59:	/* Ignore Rebinding Time Option */
			break;
		default:
#ifdef (CONFIG_BOOTP_MASK & CONFIG_BOOTP_VENDOREX)
			if (dhcp_vendorex_proc (popt))
				break;
#endif
			printk ("*** Unhandled DHCP Option in OFFER/ACK: %d\n", *popt);
			break;
		}
		popt += oplen + 2;	/* Process next option */
	}
}

static int DhcpMessageType(unsigned char *popt)
{
	if (NetReadLong((ulong*)popt) != htonl(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;
}

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

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

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

	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 = htons(get_timer(0) / CFG_HZ);
	NetCopyIP(&bp->bp_ciaddr, &bp_offer->bp_ciaddr); /* both in network byte order */
	NetCopyIP(&bp->bp_yiaddr, &bp_offer->bp_yiaddr);
	NetCopyIP(&bp->bp_siaddr, &bp_offer->bp_siaddr);
	NetCopyIP(&bp->bp_giaddr, &bp_offer->bp_giaddr);
	memcpy (bp->bp_chaddr, NetOurEther, 6);

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

	NetCopyLong(&bp->bp_id, &bp_offer->bp_id);

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

	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 (NetReadLong((ulong*)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
				DhcpOptionsProcess(&bp->bp_vend[4]);

			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 ) {
			char *s;

			if (NetReadLong((ulong*)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
				DhcpOptionsProcess(&bp->bp_vend[4]);
			BootpCopyNetParams(bp); /* Store net params from reply */
			dhcp_state = BOUND;
			printk("DHCP client bound to address ");
			print_IPaddr(NetOurIP);
			printk("\n");

			/* Obey the 'autoload' setting */
			TftpStart();
			return;
		}
		break;
	default:
		printk("DHCP: INVALID STATE\n");
		break;
	}

}

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