1 files changed, 76 insertions, 5 deletions

diff --git a/net/ipv6/ila/ila_common.c b/net/ipv6/ila/ila_common.c
index 30613050e4ca..0e94042d1289 100644
--- a/net/ipv6/ila/ila_common.c
+++ b/net/ipv6/ila/ila_common.c
@@ -15,20 +15,52 @@
 
 static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p)
 {
-	if (*(__be64 *)&ip6h->daddr == p->locator_match)
+	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
+
+	if (p->locator_match.v64)
 		return p->csum_diff;
 	else
-		return compute_csum_diff8((__be32 *)&ip6h->daddr,
+		return compute_csum_diff8((__be32 *)&iaddr->loc,
+					  (__be32 *)&p->locator);
+}
+
+static void ila_csum_do_neutral(struct ila_addr *iaddr,
+				struct ila_params *p)
+{
+	__sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
+	__wsum diff, fval;
+
+	/* Check if checksum adjust value has been cached */
+	if (p->locator_match.v64) {
+		diff = p->csum_diff;
+	} else {
+		diff = compute_csum_diff8((__be32 *)iaddr,
 					  (__be32 *)&p->locator);
+	}
+
+	fval = (__force __wsum)(ila_csum_neutral_set(iaddr->ident) ?
+			~CSUM_NEUTRAL_FLAG : CSUM_NEUTRAL_FLAG);
+
+	diff = csum_add(diff, fval);
+
+	*adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust)));
+
+	/* Flip the csum-neutral bit. Either we are doing a SIR->ILA
+	 * translation with ILA_CSUM_NEUTRAL_MAP as the csum_method
+	 * and the C-bit is not set, or we are doing an ILA-SIR
+	 * tranlsation and the C-bit is set.
+	 */
+	iaddr->ident.csum_neutral ^= 1;
 }
 
-void update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
+static void ila_csum_adjust_transport(struct sk_buff *skb,
+				      struct ila_params *p)
 {
 	__wsum diff;
 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
 	size_t nhoff = sizeof(struct ipv6hdr);
 
-	/* First update checksum */
 	switch (ip6h->nexthdr) {
 	case NEXTHDR_TCP:
 		if (likely(pskb_may_pull(skb, nhoff + sizeof(struct tcphdr)))) {
@@ -68,7 +100,46 @@ void update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
 	}
 
 	/* Now change destination address */
-	*(__be64 *)&ip6h->daddr = p->locator;
+	iaddr->loc = p->locator;
+}
+
+void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
+{
+	struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
+
+	/* First deal with the transport checksum */
+	if (ila_csum_neutral_set(iaddr->ident)) {
+		/* C-bit is set in the locator indicating that this
+		 * is a locator being translated to a SIR address.
+		 * Perform (receiver) checksum-neutral translation.
+		 */
+		ila_csum_do_neutral(iaddr, p);
+	} else {
+		switch (p->csum_mode) {
+		case ILA_CSUM_ADJUST_TRANSPORT:
+			ila_csum_adjust_transport(skb, p);
+			break;
+		case ILA_CSUM_NEUTRAL_MAP:
+			ila_csum_do_neutral(iaddr, p);
+			break;
+		case ILA_CSUM_NO_ACTION:
+			break;
+		}
+	}
+
+	/* Now change destination address */
+	iaddr->loc = p->locator;
+}
+
+void ila_init_saved_csum(struct ila_params *p)
+{
+	if (!p->locator_match.v64)
+		return;
+
+	p->csum_diff = compute_csum_diff8(
+				(__be32 *)&p->locator_match,
+				(__be32 *)&p->locator);
 }
 
 static int __init ila_init(void)