openvswitch: add ipv6 'set' action

This patch adds ipv6 set action functionality. It allows to change
traffic class, flow label, hop-limit, ipv6 source and destination
address fields.

Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

net/openvswitch/actions.c

@@ -28,6 +28,7 @@
 #include <linux/if_arp.h>
 #include <linux/if_vlan.h>
 #include <net/ip.h>
+#include <net/ipv6.h>
 #include <net/checksum.h>
 #include <net/dsfield.h>
 
@@ -162,6 +163,53 @@ static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 	*addr = new_addr;
 }
 
+static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
+				 __be32 addr[4], const __be32 new_addr[4])
+{
+	int transport_len = skb->len - skb_transport_offset(skb);
+
+	if (l4_proto == IPPROTO_TCP) {
+		if (likely(transport_len >= sizeof(struct tcphdr)))
+			inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
+						  addr, new_addr, 1);
+	} else if (l4_proto == IPPROTO_UDP) {
+		if (likely(transport_len >= sizeof(struct udphdr))) {
+			struct udphdr *uh = udp_hdr(skb);
+
+			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+				inet_proto_csum_replace16(&uh->check, skb,
+							  addr, new_addr, 1);
+				if (!uh->check)
+					uh->check = CSUM_MANGLED_0;
+			}
+		}
+	}
+}
+
+static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
+			  __be32 addr[4], const __be32 new_addr[4],
+			  bool recalculate_csum)
+{
+	if (recalculate_csum)
+		update_ipv6_checksum(skb, l4_proto, addr, new_addr);
+
+	skb->rxhash = 0;
+	memcpy(addr, new_addr, sizeof(__be32[4]));
+}
+
+static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
+{
+	nh->priority = tc >> 4;
+	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
+}
+
+static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
+{
+	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
+	nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
+	nh->flow_lbl[2] = fl & 0x000000FF;
+}
+
 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
 {
 	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
@@ -195,6 +243,47 @@ static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
 	return 0;
 }
 
+static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
+{
+	struct ipv6hdr *nh;
+	int err;
+	__be32 *saddr;
+	__be32 *daddr;
+
+	err = make_writable(skb, skb_network_offset(skb) +
+			    sizeof(struct ipv6hdr));
+	if (unlikely(err))
+		return err;
+
+	nh = ipv6_hdr(skb);
+	saddr = (__be32 *)&nh->saddr;
+	daddr = (__be32 *)&nh->daddr;
+
+	if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
+		set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
+			      ipv6_key->ipv6_src, true);
+
+	if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
+		unsigned int offset = 0;
+		int flags = IP6_FH_F_SKIP_RH;
+		bool recalc_csum = true;
+
+		if (ipv6_ext_hdr(nh->nexthdr))
+			recalc_csum = ipv6_find_hdr(skb, &offset,
+						    NEXTHDR_ROUTING, NULL,
+						    &flags) != NEXTHDR_ROUTING;
+
+		set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
+			      ipv6_key->ipv6_dst, recalc_csum);
+	}
+
+	set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
+	set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
+	nh->hop_limit = ipv6_key->ipv6_hlimit;
+
+	return 0;
+}
+
 /* Must follow make_writable() since that can move the skb data. */
 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 			 __be16 new_port, __sum16 *check)
@@ -347,6 +436,10 @@ static int execute_set_action(struct sk_buff *skb,
 		err = set_ipv4(skb, nla_data(nested_attr));
 		break;
 
+	case OVS_KEY_ATTR_IPV6:
+		err = set_ipv6(skb, nla_data(nested_attr));
+		break;
+
 	case OVS_KEY_ATTR_TCP:
 		err = set_tcp(skb, nla_data(nested_attr));
 		break;

net/openvswitch/datapath.c

@@ -479,6 +479,7 @@ static int validate_set(const struct nlattr *a,
 
 	switch (key_type) {
 	const struct ovs_key_ipv4 *ipv4_key;
+	const struct ovs_key_ipv6 *ipv6_key;
 
 	case OVS_KEY_ATTR_PRIORITY:
 	case OVS_KEY_ATTR_ETHERNET:
@@ -500,6 +501,25 @@ static int validate_set(const struct nlattr *a,
 
 		break;
 
+	case OVS_KEY_ATTR_IPV6:
+		if (flow_key->eth.type != htons(ETH_P_IPV6))
+			return -EINVAL;
+
+		if (!flow_key->ip.proto)
+			return -EINVAL;
+
+		ipv6_key = nla_data(ovs_key);
+		if (ipv6_key->ipv6_proto != flow_key->ip.proto)
+			return -EINVAL;
+
+		if (ipv6_key->ipv6_frag != flow_key->ip.frag)
+			return -EINVAL;
+
+		if (ntohl(ipv6_key->ipv6_label) & 0xFFF00000)
+			return -EINVAL;
+
+		break;
+
 	case OVS_KEY_ATTR_TCP:
 		if (flow_key->ip.proto != IPPROTO_TCP)
 			return -EINVAL;