ila: Add struct definitions and helpers

Add structures for identifiers, locators, and an ila address which
is composed of a locator and identifier and in6_addr can be cast to
it. This includes a three bit type field and enums for the types defined
in ILA I-D.

In ILA lwt don't allow user to set a translation for a non-ILA
address (type of identifier is zero meaning it is an IID). This also
requires that the destination prefix is at least 65 bytes (64
bit locator and first byte of identifier).

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 13 deletions

diff --git a/net/ipv6/ila/ila_lwt.c b/net/ipv6/ila/ila_lwt.c
index 9db3621b2126..de7f6d76e928 100644
--- a/net/ipv6/ila/ila_lwt.c
+++ b/net/ipv6/ila/ila_lwt.c
@@ -26,7 +26,7 @@ static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto drop;
 
-	update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));
+	ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));
 
 	return dst->lwtstate->orig_output(net, sk, skb);
 
@@ -42,7 +42,7 @@ static int ila_input(struct sk_buff *skb)
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto drop;
 
-	update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));
+	ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate));
 
 	return dst->lwtstate->orig_input(skb);
 
@@ -64,11 +64,26 @@ static int ila_build_state(struct net_device *dev, struct nlattr *nla,
 	size_t encap_len = sizeof(*p);
 	struct lwtunnel_state *newts;
 	const struct fib6_config *cfg6 = cfg;
+	struct ila_addr *iaddr;
 	int ret;
 
 	if (family != AF_INET6)
 		return -EINVAL;
 
+	if (cfg6->fc_dst_len < sizeof(struct ila_locator) + 1) {
+		/* Need to have full locator and at least type field
+		 * included in destination
+		 */
+		return -EINVAL;
+	}
+
+	iaddr = (struct ila_addr *)&cfg6->fc_dst;
+
+	if (!ila_addr_is_ila(iaddr)) {
+		/* Don't allow setting a translation for a non-ILA address */
+		return -EINVAL;
+	}
+
 	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla,
 			       ila_nl_policy);
 	if (ret < 0)
@@ -84,16 +99,14 @@ static int ila_build_state(struct net_device *dev, struct nlattr *nla,
 	newts->len = encap_len;
 	p = ila_params_lwtunnel(newts);
 
-	p->locator = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
+	p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
 
-	if (cfg6->fc_dst_len > sizeof(__be64)) {
-		/* Precompute checksum difference for translation since we
-		 * know both the old locator and the new one.
-		 */
-		p->locator_match = *(__be64 *)&cfg6->fc_dst;
-		p->csum_diff = compute_csum_diff8(
-			(__be32 *)&p->locator_match, (__be32 *)&p->locator);
-	}
+	/* Precompute checksum difference for translation since we
+	 * know both the old locator and the new one.
+	 */
+	p->locator_match = iaddr->loc;
+	p->csum_diff = compute_csum_diff8(
+		(__be32 *)&p->locator_match, (__be32 *)&p->locator);
 
 	newts->type = LWTUNNEL_ENCAP_ILA;
 	newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
@@ -109,7 +122,7 @@ static int ila_fill_encap_info(struct sk_buff *skb,
 {
 	struct ila_params *p = ila_params_lwtunnel(lwtstate);
 
-	if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator,
+	if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
 			      ILA_ATTR_PAD))
 		goto nla_put_failure;
 
@@ -130,7 +143,7 @@ static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
 	struct ila_params *a_p = ila_params_lwtunnel(a);
 	struct ila_params *b_p = ila_params_lwtunnel(b);
 
-	return (a_p->locator != b_p->locator);
+	return (a_p->locator.v64 != b_p->locator.v64);
 }
 
 static const struct lwtunnel_encap_ops ila_encap_ops = {