net.c

		return ip; /* not a fragment */
	return NULL;
}
#endif

/**
 * Receive an ICMP packet. We deal with REDIRECT and PING here, and silently
 * drop others.
 *
 * @parma ip	IP packet containing the ICMP
 */
static void receive_icmp(IP_t *ip, int len, IPaddr_t src_ip, Ethernet_t *et)
{
	ICMP_t *icmph = (ICMP_t *)&ip->udp_src;

	switch (icmph->type) {
	case ICMP_REDIRECT:
		if (icmph->code != ICMP_REDIR_HOST)
			return;
		printf(" ICMP Host Redirect to %pI4 ",
			&icmph->un.gateway);
		break;
#if defined(CONFIG_CMD_PING)
	case ICMP_ECHO_REPLY:
		/*
			* IP header OK.  Pass the packet to the
			* current handler.
			*/
		/*
		 * XXX point to ip packet - should this use
		 * packet_icmp_handler?
		 */
		(*packetHandler)((uchar *)ip, 0, src_ip, 0, 0);
		break;
	case ICMP_ECHO_REQUEST:
		debug("Got ICMP ECHO REQUEST, return %d bytes\n",
			ETHER_HDR_SIZE + len);

		memcpy(&et->et_dest[0], &et->et_src[0], 6);
		memcpy(&et->et_src[0], NetOurEther, 6);

		ip->ip_sum = 0;
		ip->ip_off = 0;
		NetCopyIP((void *)&ip->ip_dst, &ip->ip_src);
		NetCopyIP((void *)&ip->ip_src, &NetOurIP);
		ip->ip_sum = ~NetCksum((uchar *)ip,
					IP_HDR_SIZE_NO_UDP >> 1);

		icmph->type = ICMP_ECHO_REPLY;
		icmph->checksum = 0;
		icmph->checksum = ~NetCksum((uchar *)icmph,
			(len - IP_HDR_SIZE_NO_UDP) >> 1);
		(void) eth_send((uchar *)et,
				ETHER_HDR_SIZE + len);
		break;
#endif
	default:
#ifdef CONFIG_CMD_TFTPPUT
		if (packet_icmp_handler)
			packet_icmp_handler(icmph->type, icmph->code,
				ntohs(ip->udp_dst), src_ip, ntohs(ip->udp_src),
				icmph->un.data, ntohs(ip->udp_len));
#endif
		break;
	}
}

void
NetReceive(uchar *inpkt, int len)
{
	Ethernet_t *et;
	IP_t	*ip;
	ARP_t	*arp;
	IPaddr_t tmp;
	IPaddr_t src_ip;
	int	x;
	uchar *pkt;
#if defined(CONFIG_CMD_CDP)
	int iscdp;
#endif
	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;

	debug("packet received\n");

	NetRxPacket = inpkt;
	NetRxPacketLen = len;
	et = (Ethernet_t *)inpkt;

	/* too small packet? */
	if (len < ETHER_HDR_SIZE)
		return;

#ifdef CONFIG_API
	if (push_packet) {
		(*push_packet)(inpkt, len);
		return;
	}
#endif

#if defined(CONFIG_CMD_CDP)
	/* keep track if packet is CDP */
	iscdp = memcmp(et->et_dest, NetCDPAddr, 6) == 0;
#endif

	myvlanid = ntohs(NetOurVLAN);
	if (myvlanid == (ushort)-1)
		myvlanid = VLAN_NONE;
	mynvlanid = ntohs(NetOurNativeVLAN);
	if (mynvlanid == (ushort)-1)
		mynvlanid = VLAN_NONE;

	x = ntohs(et->et_protlen);

	debug("packet received\n");

	if (x < 1514) {
		/*
		 *	Got a 802 packet.  Check the other protocol field.
		 */
		x = ntohs(et->et_prot);

		ip = (IP_t *)(inpkt + E802_HDR_SIZE);
		len -= E802_HDR_SIZE;

	} else if (x != PROT_VLAN) {	/* normal packet */
		ip = (IP_t *)(inpkt + ETHER_HDR_SIZE);
		len -= ETHER_HDR_SIZE;

	} else {			/* VLAN packet */
		VLAN_Ethernet_t *vet = (VLAN_Ethernet_t *)et;

		debug("VLAN packet received\n");

		/* too small packet? */
		if (len < VLAN_ETHER_HDR_SIZE)
			return;

		/* if no VLAN active */
		if ((ntohs(NetOurVLAN) & VLAN_IDMASK) == VLAN_NONE
#if defined(CONFIG_CMD_CDP)
				&& iscdp == 0
#endif
				)
			return;

		cti = ntohs(vet->vet_tag);
		vlanid = cti & VLAN_IDMASK;
		x = ntohs(vet->vet_type);

		ip = (IP_t *)(inpkt + VLAN_ETHER_HDR_SIZE);
		len -= VLAN_ETHER_HDR_SIZE;
	}

	debug("Receive from protocol 0x%x\n", x);

#if defined(CONFIG_CMD_CDP)
	if (iscdp) {
		CDPHandler((uchar *)ip, len);
		return;
	}
#endif

	if ((myvlanid & VLAN_IDMASK) != VLAN_NONE) {
		if (vlanid == VLAN_NONE)
			vlanid = (mynvlanid & VLAN_IDMASK);
		/* not matched? */
		if (vlanid != (myvlanid & VLAN_IDMASK))
			return;
	}

	switch (x) {

	case PROT_ARP:
		/*
		 * We have to deal with two types of ARP packets:
		 * - REQUEST packets will be answered by sending  our
		 *   IP address - if we know it.
		 * - REPLY packates are expected only after we asked
		 *   for the TFTP server's or the gateway's ethernet
		 *   address; so if we receive such a packet, we set
		 *   the server ethernet address
		 */
		debug("Got ARP\n");

		arp = (ARP_t *)ip;
		if (len < ARP_HDR_SIZE) {
			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
			return;
		}
		if (ntohs(arp->ar_hrd) != ARP_ETHER)
			return;
		if (ntohs(arp->ar_pro) != PROT_IP)
			return;
		if (arp->ar_hln != 6)
			return;
		if (arp->ar_pln != 4)
			return;

		if (NetOurIP == 0)
			return;

		if (NetReadIP(&arp->ar_data[16]) != NetOurIP)
			return;

		switch (ntohs(arp->ar_op)) {
		case ARPOP_REQUEST:
			/* reply with our IP address */
			debug("Got ARP REQUEST, return our IP\n");
			pkt = (uchar *)et;
			pkt += NetSetEther(pkt, et->et_src, PROT_ARP);
			arp->ar_op = htons(ARPOP_REPLY);
			memcpy(&arp->ar_data[10], &arp->ar_data[0], 6);
			NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]);
			memcpy(&arp->ar_data[0], NetOurEther, 6);
			NetCopyIP(&arp->ar_data[6], &NetOurIP);
			(void) eth_send((uchar *)et,
					(pkt - (uchar *)et) + ARP_HDR_SIZE);
			return;

		case ARPOP_REPLY:		/* arp reply */
			/* are we waiting for a reply */
			if (!NetArpWaitPacketIP || !NetArpWaitPacketMAC)
				break;

#ifdef CONFIG_KEEP_SERVERADDR
			if (NetServerIP == NetArpWaitPacketIP) {
				char buf[20];
				sprintf(buf, "%pM", arp->ar_data);
				setenv("serveraddr", buf);
			}
#endif

			debug("Got ARP REPLY, set server/gtwy eth addr (%pM)\n",
				arp->ar_data);

			tmp = NetReadIP(&arp->ar_data[6]);

			/* matched waiting packet's address */
			if (tmp == NetArpWaitReplyIP) {
				debug("Got it\n");

				/* save address for later use */
				memcpy(NetArpWaitPacketMAC,
				       &arp->ar_data[0], 6);

#ifdef CONFIG_NETCONSOLE
				(*packetHandler)(0, 0, 0, 0, 0);
#endif
				/* modify header, and transmit it */
				memcpy(((Ethernet_t *)NetArpWaitTxPacket)->
					et_dest, NetArpWaitPacketMAC, 6);
				(void) eth_send(NetArpWaitTxPacket,
						NetArpWaitTxPacketSize);

				/* no arp request pending now */
				NetArpWaitPacketIP = 0;
				NetArpWaitTxPacketSize = 0;
				NetArpWaitPacketMAC = NULL;

			}
			return;
		default:
			debug("Unexpected ARP opcode 0x%x\n",
			      ntohs(arp->ar_op));
			return;
		}
		break;

#ifdef CONFIG_CMD_RARP
	case PROT_RARP:
		debug("Got RARP\n");
		arp = (ARP_t *)ip;
		if (len < ARP_HDR_SIZE) {
			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
			return;
		}

		if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
			(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
			(ntohs(arp->ar_pro) != PROT_IP)     ||
			(arp->ar_hln != 6) || (arp->ar_pln != 4)) {

			puts("invalid RARP header\n");
		} else {
			NetCopyIP(&NetOurIP, &arp->ar_data[16]);
			if (NetServerIP == 0)
				NetCopyIP(&NetServerIP, &arp->ar_data[6]);
			memcpy(NetServerEther, &arp->ar_data[0], 6);

			(*packetHandler)(0, 0, 0, 0, 0);
		}
		break;
#endif
	case PROT_IP:
		debug("Got IP\n");
		/* Before we start poking the header, make sure it is there */
		if (len < IP_HDR_SIZE) {
			debug("len bad %d < %lu\n", len, (ulong)IP_HDR_SIZE);
			return;
		}
		/* Check the packet length */
		if (len < ntohs(ip->ip_len)) {
			printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
			return;
		}
		len = ntohs(ip->ip_len);
		debug("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);

		/* Can't deal with anything except IPv4 */
		if ((ip->ip_hl_v & 0xf0) != 0x40)
			return;
		/* Can't deal with IP options (headers != 20 bytes) */
		if ((ip->ip_hl_v & 0x0f) > 0x05)
			return;
		/* Check the Checksum of the header */
		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
			puts("checksum bad\n");
			return;
		}
		/* If it is not for us, ignore it */
		tmp = NetReadIP(&ip->ip_dst);
		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
#ifdef CONFIG_MCAST_TFTP
			if (Mcast_addr != tmp)
#endif
				return;
		}
		/* Read source IP address for later use */
		src_ip = NetReadIP(&ip->ip_src);
		/*
		 * The function returns the unchanged packet if it's not
		 * a fragment, and either the complete packet or NULL if
		 * it is a fragment (if !CONFIG_IP_DEFRAG, it returns NULL)
		 */
		ip = NetDefragment(ip, &len);
		if (!ip)
			return;
		/*
		 * watch for ICMP host redirects
		 *
		 * There is no real handler code (yet). We just watch
		 * for ICMP host redirect messages. In case anybody
		 * sees these messages: please contact me
		 * (wd@denx.de), or - even better - send me the
		 * necessary fixes :-)
		 *
		 * Note: in all cases where I have seen this so far
		 * it was a problem with the router configuration,
		 * for instance when a router was configured in the
		 * BOOTP reply, but the TFTP server was on the same
		 * subnet. So this is probably a warning that your
		 * configuration might be wrong. But I'm not really
		 * sure if there aren't any other situations.
		 *
		 * Simon Glass <sjg@chromium.org>: We get an ICMP when
		 * we send a tftp packet to a dead connection, or when
		 * there is no server at the other end.
		 */
		if (ip->ip_p == IPPROTO_ICMP) {
			receive_icmp(ip, len, src_ip, et);
			return;
		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
			return;
		}

#ifdef CONFIG_UDP_CHECKSUM
		if (ip->udp_xsum != 0) {
			ulong   xsum;
			ushort *sumptr;
			ushort  sumlen;

			xsum  = ip->ip_p;
			xsum += (ntohs(ip->udp_len));
			xsum += (ntohl(ip->ip_src) >> 16) & 0x0000ffff;
			xsum += (ntohl(ip->ip_src) >>  0) & 0x0000ffff;
			xsum += (ntohl(ip->ip_dst) >> 16) & 0x0000ffff;
			xsum += (ntohl(ip->ip_dst) >>  0) & 0x0000ffff;

			sumlen = ntohs(ip->udp_len);
			sumptr = (ushort *) &(ip->udp_src);

			while (sumlen > 1) {
				ushort sumdata;

				sumdata = *sumptr++;
				xsum += ntohs(sumdata);
				sumlen -= 2;
			}
			if (sumlen > 0) {
				ushort sumdata;

				sumdata = *(unsigned char *) sumptr;
				sumdata = (sumdata << 8) & 0xff00;
				xsum += sumdata;
			}
			while ((xsum >> 16) != 0) {
				xsum = (xsum & 0x0000ffff) +
				       ((xsum >> 16) & 0x0000ffff);
			}
			if ((xsum != 0x00000000) && (xsum != 0x0000ffff)) {
				printf(" UDP wrong checksum %08lx %08x\n",
					xsum, ntohs(ip->udp_xsum));
				return;
			}
		}
#endif


#ifdef CONFIG_NETCONSOLE
		nc_input_packet((uchar *)ip + IP_HDR_SIZE,
						ntohs(ip->udp_dst),
						ntohs(ip->udp_src),
						ntohs(ip->udp_len) - 8);
#endif
		/*
		 *	IP header OK.  Pass the packet to the current handler.
		 */
		(*packetHandler)((uchar *)ip + IP_HDR_SIZE,
						ntohs(ip->udp_dst),
						src_ip,
						ntohs(ip->udp_src),
						ntohs(ip->udp_len) - 8);
		break;
	}
}


/**********************************************************************/

static int net_check_prereq(enum proto_t protocol)
{
	switch (protocol) {
		/* Fall through */
#if defined(CONFIG_CMD_PING)
	case PING:
		if (NetPingIP == 0) {
			puts("*** ERROR: ping address not given\n");
			return 1;
		}
		goto common;
#endif
#if defined(CONFIG_CMD_SNTP)
	case SNTP:
		if (NetNtpServerIP == 0) {
			puts("*** ERROR: NTP server address not given\n");
			return 1;
		}
		goto common;
#endif
#if defined(CONFIG_CMD_DNS)
	case DNS:
		if (NetOurDNSIP == 0) {
			puts("*** ERROR: DNS server address not given\n");
			return 1;
		}
		goto common;
#endif
#if defined(CONFIG_CMD_NFS)
	case NFS:
#endif
	case TFTPGET:
	case TFTPPUT:
		if (NetServerIP == 0) {
			puts("*** ERROR: `serverip' not set\n");
			return 1;
		}
#if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
	defined(CONFIG_CMD_DNS)
common:
#endif
		/* Fall through */

	case NETCONS:
	case TFTPSRV:
		if (NetOurIP == 0) {
			puts("*** ERROR: `ipaddr' not set\n");
			return 1;
		}
		/* Fall through */

#ifdef CONFIG_CMD_RARP
	case RARP:
#endif
	case BOOTP:
	case CDP:
	case DHCP:
		if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
			int num = eth_get_dev_index();

			switch (num) {
			case -1:
				puts("*** ERROR: No ethernet found.\n");
				return 1;
			case 0:
				puts("*** ERROR: `ethaddr' not set\n");
				break;
			default:
				printf("*** ERROR: `eth%daddr' not set\n",
					num);
				break;
			}

			NetStartAgain();
			return 2;
		}
		/* Fall through */
	default:
		return 0;
	}
	return 0;		/* OK */
}
/**********************************************************************/

int
NetCksumOk(uchar *ptr, int len)
{
	return !((NetCksum(ptr, len) + 1) & 0xfffe);
}


unsigned
NetCksum(uchar *ptr, int len)
{
	ulong	xsum;
	ushort *p = (ushort *)ptr;

	xsum = 0;
	while (len-- > 0)
		xsum += *p++;
	xsum = (xsum & 0xffff) + (xsum >> 16);
	xsum = (xsum & 0xffff) + (xsum >> 16);
	return xsum & 0xffff;
}

int
NetEthHdrSize(void)
{
	ushort myvlanid;

	myvlanid = ntohs(NetOurVLAN);
	if (myvlanid == (ushort)-1)
		myvlanid = VLAN_NONE;

	return ((myvlanid & VLAN_IDMASK) == VLAN_NONE) ? ETHER_HDR_SIZE :
		VLAN_ETHER_HDR_SIZE;
}

int
NetSetEther(uchar *xet, uchar * addr, uint prot)
{
	Ethernet_t *et = (Ethernet_t *)xet;
	ushort myvlanid;

	myvlanid = ntohs(NetOurVLAN);
	if (myvlanid == (ushort)-1)
		myvlanid = VLAN_NONE;

	memcpy(et->et_dest, addr, 6);
	memcpy(et->et_src, NetOurEther, 6);
	if ((myvlanid & VLAN_IDMASK) == VLAN_NONE) {
		et->et_protlen = htons(prot);
		return ETHER_HDR_SIZE;
	} else {
		VLAN_Ethernet_t *vet = (VLAN_Ethernet_t *)xet;

		vet->vet_vlan_type = htons(PROT_VLAN);
		vet->vet_tag = htons((0 << 5) | (myvlanid & VLAN_IDMASK));
		vet->vet_type = htons(prot);
		return VLAN_ETHER_HDR_SIZE;
	}
}

void
NetSetIP(uchar *xip, IPaddr_t dest, int dport, int sport, int len)
{
	IP_t *ip = (IP_t *)xip;

	/*
	 *	If the data is an odd number of bytes, zero the
	 *	byte after the last byte so that the checksum
	 *	will work.
	 */
	if (len & 1)
		xip[IP_HDR_SIZE + len] = 0;

	/*
	 *	Construct an IP and UDP header.
	 *	(need to set no fragment bit - XXX)
	 */
	/* IP_HDR_SIZE / 4 (not including UDP) */
	ip->ip_hl_v  = 0x45;
	ip->ip_tos   = 0;
	ip->ip_len   = htons(IP_HDR_SIZE + len);
	ip->ip_id    = htons(NetIPID++);
	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
	ip->ip_ttl   = 255;
	ip->ip_p     = 17;		/* UDP */
	ip->ip_sum   = 0;
	/* already in network byte order */
	NetCopyIP((void *)&ip->ip_src, &NetOurIP);
	/* - "" - */
	NetCopyIP((void *)&ip->ip_dst, &dest);
	ip->udp_src  = htons(sport);
	ip->udp_dst  = htons(dport);
	ip->udp_len  = htons(8 + len);
	ip->udp_xsum = 0;
	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
}

void copy_filename(char *dst, const char *src, int size)
{
	if (*src && (*src == '"')) {
		++src;
		--size;
	}

	while ((--size > 0) && *src && (*src != '"'))
		*dst++ = *src++;
	*dst = '\0';
}

#if	defined(CONFIG_CMD_NFS)		|| \
	defined(CONFIG_CMD_SNTP)	|| \
	defined(CONFIG_CMD_DNS)
/*
 * make port a little random (1024-17407)
 * This keeps the math somewhat trivial to compute, and seems to work with
 * all supported protocols/clients/servers
 */
unsigned int random_port(void)
{
	return 1024 + (get_timer(0) % 0x4000);
}
#endif

void ip_to_string(IPaddr_t x, char *s)
{
	x = ntohl(x);
	sprintf(s, "%d.%d.%d.%d",
		(int) ((x >> 24) & 0xff),
		(int) ((x >> 16) & 0xff),
		(int) ((x >> 8) & 0xff), (int) ((x >> 0) & 0xff)
	);
}

void VLAN_to_string(ushort x, char *s)
{
	x = ntohs(x);

	if (x == (ushort)-1)
		x = VLAN_NONE;

	if (x == VLAN_NONE)
		strcpy(s, "none");
	else
		sprintf(s, "%d", x & VLAN_IDMASK);
}

ushort string_to_VLAN(const char *s)
{
	ushort id;

	if (s == NULL)
		return htons(VLAN_NONE);

	if (*s < '0' || *s > '9')
		id = VLAN_NONE;
	else
		id = (ushort)simple_strtoul(s, NULL, 10);

	return htons(id);
}

ushort getenv_VLAN(char *var)
{
	return string_to_VLAN(getenv(var));
}