예제 #1
0
파일: flow.c 프로젝트: TCSOpenVSwitch/ovs
/**
 * key_extract - extracts a flow key from an Ethernet frame.
 * @skb: sk_buff that contains the frame, with skb->data pointing to the
 * Ethernet header
 * @key: output flow key
 *
 * The caller must ensure that skb->len >= ETH_HLEN.
 *
 * Returns 0 if successful, otherwise a negative errno value.
 *
 * Initializes @skb header pointers as follows:
 *
 *    - skb->mac_header: the Ethernet header.
 *
 *    - skb->network_header: just past the Ethernet header, or just past the
 *      VLAN header, to the first byte of the Ethernet payload.
 *
 *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
 *      on output, then just past the IP header, if one is present and
 *      of a correct length, otherwise the same as skb->network_header.
 *      For other key->eth.type values it is left untouched.
 */
static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
{
	int error;
	struct ethhdr *eth;

	/* Flags are always used as part of stats */
	key->tp.flags = 0;

	skb_reset_mac_header(skb);

	/* Link layer.  We are guaranteed to have at least the 14 byte Ethernet
	 * header in the linear data area.
	 */
	eth = eth_hdr(skb);
	ether_addr_copy(key->eth.src, eth->h_source);
	ether_addr_copy(key->eth.dst, eth->h_dest);

	__skb_pull(skb, 2 * ETH_ALEN);
	/* We are going to push all headers that we pull, so no need to
	 * update skb->csum here.
	 */

	key->eth.tci = 0;
	if (vlan_tx_tag_present(skb))
		key->eth.tci = htons(vlan_get_tci(skb));
	else if (eth->h_proto == htons(ETH_P_8021Q))
		if (unlikely(parse_vlan(skb, key)))
			return -ENOMEM;

	key->eth.type = parse_ethertype(skb);
	if (unlikely(key->eth.type == htons(0)))
		return -ENOMEM;

	skb_reset_network_header(skb);
	skb_reset_mac_len(skb);
	__skb_push(skb, skb->data - skb_mac_header(skb));

	/* Network layer. */
	if (key->eth.type == htons(ETH_P_IP)) {
		struct iphdr *nh;
		__be16 offset;

		error = check_iphdr(skb);
		if (unlikely(error)) {
			memset(&key->ip, 0, sizeof(key->ip));
			memset(&key->ipv4, 0, sizeof(key->ipv4));
			if (error == -EINVAL) {
				skb->transport_header = skb->network_header;
				error = 0;
			}
			return error;
		}

		nh = ip_hdr(skb);
		key->ipv4.addr.src = nh->saddr;
		key->ipv4.addr.dst = nh->daddr;

		key->ip.proto = nh->protocol;
		key->ip.tos = nh->tos;
		key->ip.ttl = nh->ttl;

		offset = nh->frag_off & htons(IP_OFFSET);
		if (offset) {
			key->ip.frag = OVS_FRAG_TYPE_LATER;
			return 0;
		}
		if (nh->frag_off & htons(IP_MF) ||
			skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			key->ip.frag = OVS_FRAG_TYPE_FIRST;
		else
			key->ip.frag = OVS_FRAG_TYPE_NONE;

		/* Transport layer. */
		if (key->ip.proto == IPPROTO_TCP) {
			if (tcphdr_ok(skb)) {
				struct tcphdr *tcp = tcp_hdr(skb);
				key->tp.src = tcp->source;
				key->tp.dst = tcp->dest;
				key->tp.flags = TCP_FLAGS_BE16(tcp);
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}

		} else if (key->ip.proto == IPPROTO_UDP) {
			if (udphdr_ok(skb)) {
				struct udphdr *udp = udp_hdr(skb);
				key->tp.src = udp->source;
				key->tp.dst = udp->dest;
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		} else if (key->ip.proto == IPPROTO_SCTP) {
			if (sctphdr_ok(skb)) {
				struct sctphdr *sctp = sctp_hdr(skb);
				key->tp.src = sctp->source;
				key->tp.dst = sctp->dest;
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		} else if (key->ip.proto == IPPROTO_ICMP) {
			if (icmphdr_ok(skb)) {
				struct icmphdr *icmp = icmp_hdr(skb);
				/* The ICMP type and code fields use the 16-bit
				 * transport port fields, so we need to store
				 * them in 16-bit network byte order.
				 */
				key->tp.src = htons(icmp->type);
				key->tp.dst = htons(icmp->code);
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		}

	} else if (key->eth.type == htons(ETH_P_ARP) ||
		   key->eth.type == htons(ETH_P_RARP)) {
		struct arp_eth_header *arp;
		bool arp_available = arphdr_ok(skb);

		arp = (struct arp_eth_header *)skb_network_header(skb);

		if (arp_available &&
		    arp->ar_hrd == htons(ARPHRD_ETHER) &&
		    arp->ar_pro == htons(ETH_P_IP) &&
		    arp->ar_hln == ETH_ALEN &&
		    arp->ar_pln == 4) {

			/* We only match on the lower 8 bits of the opcode. */
			if (ntohs(arp->ar_op) <= 0xff)
				key->ip.proto = ntohs(arp->ar_op);
			else
				key->ip.proto = 0;

			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
		} else {
			memset(&key->ip, 0, sizeof(key->ip));
			memset(&key->ipv4, 0, sizeof(key->ipv4));
		}
	} else if (eth_p_mpls(key->eth.type)) {
		size_t stack_len = MPLS_HLEN;

		/* In the presence of an MPLS label stack the end of the L2
		 * header and the beginning of the L3 header differ.
		 *
		 * Advance network_header to the beginning of the L3
		 * header. mac_len corresponds to the end of the L2 header.
		 */
		while (1) {
			__be32 lse;

			error = check_header(skb, skb->mac_len + stack_len);
			if (unlikely(error))
				return 0;

			memcpy(&lse, skb_network_header(skb), MPLS_HLEN);

			if (stack_len == MPLS_HLEN)
				memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN);

			skb_set_network_header(skb, skb->mac_len + stack_len);
			if (lse & htonl(MPLS_LS_S_MASK))
				break;

			stack_len += MPLS_HLEN;
		}
	} else if (key->eth.type == htons(ETH_P_IPV6)) {
		int nh_len;             /* IPv6 Header + Extensions */

		nh_len = parse_ipv6hdr(skb, key);
		if (unlikely(nh_len < 0)) {
			memset(&key->ip, 0, sizeof(key->ip));
			memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
			if (nh_len == -EINVAL) {
				skb->transport_header = skb->network_header;
				error = 0;
			} else {
				error = nh_len;
			}
			return error;
		}

		if (key->ip.frag == OVS_FRAG_TYPE_LATER)
			return 0;
		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			key->ip.frag = OVS_FRAG_TYPE_FIRST;

		/* Transport layer. */
		if (key->ip.proto == NEXTHDR_TCP) {
			if (tcphdr_ok(skb)) {
				struct tcphdr *tcp = tcp_hdr(skb);
				key->tp.src = tcp->source;
				key->tp.dst = tcp->dest;
				key->tp.flags = TCP_FLAGS_BE16(tcp);
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		} else if (key->ip.proto == NEXTHDR_UDP) {
			if (udphdr_ok(skb)) {
				struct udphdr *udp = udp_hdr(skb);
				key->tp.src = udp->source;
				key->tp.dst = udp->dest;
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		} else if (key->ip.proto == NEXTHDR_SCTP) {
			if (sctphdr_ok(skb)) {
				struct sctphdr *sctp = sctp_hdr(skb);
				key->tp.src = sctp->source;
				key->tp.dst = sctp->dest;
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		} else if (key->ip.proto == NEXTHDR_ICMP) {
			if (icmp6hdr_ok(skb)) {
				error = parse_icmpv6(skb, key, nh_len);
				if (error)
					return error;
			} else {
				memset(&key->tp, 0, sizeof(key->tp));
			}
		}
	}
	return 0;
}
예제 #2
0
파일: flow.c 프로젝트: IDM350/linux
/**
 * ovs_flow_extract - extracts a flow key from an Ethernet frame.
 * @skb: sk_buff that contains the frame, with skb->data pointing to the
 * Ethernet header
 * @in_port: port number on which @skb was received.
 * @key: output flow key
 *
 * The caller must ensure that skb->len >= ETH_HLEN.
 *
 * Returns 0 if successful, otherwise a negative errno value.
 *
 * Initializes @skb header pointers as follows:
 *
 *    - skb->mac_header: the Ethernet header.
 *
 *    - skb->network_header: just past the Ethernet header, or just past the
 *      VLAN header, to the first byte of the Ethernet payload.
 *
 *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
 *      on output, then just past the IP header, if one is present and
 *      of a correct length, otherwise the same as skb->network_header.
 *      For other key->eth.type values it is left untouched.
 */
int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
{
	int error;
	struct ethhdr *eth;

	memset(key, 0, sizeof(*key));

	key->phy.priority = skb->priority;
	if (OVS_CB(skb)->tun_key)
		memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key));
	key->phy.in_port = in_port;
	key->phy.skb_mark = skb->mark;

	skb_reset_mac_header(skb);

	/* Link layer.  We are guaranteed to have at least the 14 byte Ethernet
	 * header in the linear data area.
	 */
	eth = eth_hdr(skb);
	memcpy(key->eth.src, eth->h_source, ETH_ALEN);
	memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);

	__skb_pull(skb, 2 * ETH_ALEN);
	/* We are going to push all headers that we pull, so no need to
	 * update skb->csum here.
	 */

	if (vlan_tx_tag_present(skb))
		key->eth.tci = htons(skb->vlan_tci);
	else if (eth->h_proto == htons(ETH_P_8021Q))
		if (unlikely(parse_vlan(skb, key)))
			return -ENOMEM;

	key->eth.type = parse_ethertype(skb);
	if (unlikely(key->eth.type == htons(0)))
		return -ENOMEM;

	skb_reset_network_header(skb);
	__skb_push(skb, skb->data - skb_mac_header(skb));

	/* Network layer. */
	if (key->eth.type == htons(ETH_P_IP)) {
		struct iphdr *nh;
		__be16 offset;

		error = check_iphdr(skb);
		if (unlikely(error)) {
			if (error == -EINVAL) {
				skb->transport_header = skb->network_header;
				error = 0;
			}
			return error;
		}

		nh = ip_hdr(skb);
		key->ipv4.addr.src = nh->saddr;
		key->ipv4.addr.dst = nh->daddr;

		key->ip.proto = nh->protocol;
		key->ip.tos = nh->tos;
		key->ip.ttl = nh->ttl;

		offset = nh->frag_off & htons(IP_OFFSET);
		if (offset) {
			key->ip.frag = OVS_FRAG_TYPE_LATER;
			return 0;
		}
		if (nh->frag_off & htons(IP_MF) ||
			 skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			key->ip.frag = OVS_FRAG_TYPE_FIRST;

		/* Transport layer. */
		if (key->ip.proto == IPPROTO_TCP) {
			if (tcphdr_ok(skb)) {
				struct tcphdr *tcp = tcp_hdr(skb);
				key->ipv4.tp.src = tcp->source;
				key->ipv4.tp.dst = tcp->dest;
				key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp);
			}
		} else if (key->ip.proto == IPPROTO_UDP) {
			if (udphdr_ok(skb)) {
				struct udphdr *udp = udp_hdr(skb);
				key->ipv4.tp.src = udp->source;
				key->ipv4.tp.dst = udp->dest;
			}
		} else if (key->ip.proto == IPPROTO_SCTP) {
			if (sctphdr_ok(skb)) {
				struct sctphdr *sctp = sctp_hdr(skb);
				key->ipv4.tp.src = sctp->source;
				key->ipv4.tp.dst = sctp->dest;
			}
		} else if (key->ip.proto == IPPROTO_ICMP) {
			if (icmphdr_ok(skb)) {
				struct icmphdr *icmp = icmp_hdr(skb);
				/* The ICMP type and code fields use the 16-bit
				 * transport port fields, so we need to store
				 * them in 16-bit network byte order. */
				key->ipv4.tp.src = htons(icmp->type);
				key->ipv4.tp.dst = htons(icmp->code);
			}
		}

	} else if ((key->eth.type == htons(ETH_P_ARP) ||
		   key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) {
		struct arp_eth_header *arp;

		arp = (struct arp_eth_header *)skb_network_header(skb);

		if (arp->ar_hrd == htons(ARPHRD_ETHER)
				&& arp->ar_pro == htons(ETH_P_IP)
				&& arp->ar_hln == ETH_ALEN
				&& arp->ar_pln == 4) {

			/* We only match on the lower 8 bits of the opcode. */
			if (ntohs(arp->ar_op) <= 0xff)
				key->ip.proto = ntohs(arp->ar_op);
			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
			memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN);
			memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN);
		}
	} else if (key->eth.type == htons(ETH_P_IPV6)) {
		int nh_len;             /* IPv6 Header + Extensions */

		nh_len = parse_ipv6hdr(skb, key);
		if (unlikely(nh_len < 0)) {
			if (nh_len == -EINVAL) {
				skb->transport_header = skb->network_header;
				error = 0;
			} else {
				error = nh_len;
			}
			return error;
		}

		if (key->ip.frag == OVS_FRAG_TYPE_LATER)
			return 0;
		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			key->ip.frag = OVS_FRAG_TYPE_FIRST;

		/* Transport layer. */
		if (key->ip.proto == NEXTHDR_TCP) {
			if (tcphdr_ok(skb)) {
				struct tcphdr *tcp = tcp_hdr(skb);
				key->ipv6.tp.src = tcp->source;
				key->ipv6.tp.dst = tcp->dest;
				key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp);
			}
		} else if (key->ip.proto == NEXTHDR_UDP) {
			if (udphdr_ok(skb)) {
				struct udphdr *udp = udp_hdr(skb);
				key->ipv6.tp.src = udp->source;
				key->ipv6.tp.dst = udp->dest;
			}
		} else if (key->ip.proto == NEXTHDR_SCTP) {
			if (sctphdr_ok(skb)) {
				struct sctphdr *sctp = sctp_hdr(skb);
				key->ipv6.tp.src = sctp->source;
				key->ipv6.tp.dst = sctp->dest;
			}
		} else if (key->ip.proto == NEXTHDR_ICMP) {
			if (icmp6hdr_ok(skb)) {
				error = parse_icmpv6(skb, key, nh_len);
				if (error)
					return error;
			}
		}
	}

	return 0;
}