IPVS: Extend protocol DNAT/SNAT and state handlers

Extend protocol DNAT/SNAT and state handlers to work with IPv6. Also
change/introduce new checksumming helper functions for this.

Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 63 insertions, 19 deletions

diff --git a/net/ipv4/ipvs/ip_vs_proto_udp.c b/net/ipv4/ipvs/ip_vs_proto_udp.c
index d3a1b1f2d10..6cca0ad8e32 100644
--- a/net/ipv4/ipvs/ip_vs_proto_udp.c
+++ b/net/ipv4/ipvs/ip_vs_proto_udp.c
@@ -120,13 +120,23 @@ udp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
 
 
 static inline void
-udp_fast_csum_update(struct udphdr *uhdr, __be32 oldip, __be32 newip,
+udp_fast_csum_update(int af, struct udphdr *uhdr,
+		     const union nf_inet_addr *oldip,
+		     const union nf_inet_addr *newip,
 		     __be16 oldport, __be16 newport)
 {
-	uhdr->check =
-		csum_fold(ip_vs_check_diff4(oldip, newip,
-				 ip_vs_check_diff2(oldport, newport,
-					~csum_unfold(uhdr->check))));
+#ifdef CONFIG_IP_VS_IPV6
+	if (af == AF_INET6)
+		uhdr->check =
+			csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
+					 ip_vs_check_diff2(oldport, newport,
+						~csum_unfold(uhdr->check))));
+	else
+#endif
+		uhdr->check =
+			csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
+					 ip_vs_check_diff2(oldport, newport,
+						~csum_unfold(uhdr->check))));
 	if (!uhdr->check)
 		uhdr->check = CSUM_MANGLED_0;
 }
@@ -136,7 +146,14 @@ udp_snat_handler(struct sk_buff *skb,
 		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
 	struct udphdr *udph;
-	const unsigned int udphoff = ip_hdrlen(skb);
+	unsigned int udphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+	if (cp->af == AF_INET6)
+		udphoff = sizeof(struct ipv6hdr);
+	else
+#endif
+		udphoff = ip_hdrlen(skb);
 
 	/* csum_check requires unshared skb */
 	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
@@ -144,7 +161,7 @@ udp_snat_handler(struct sk_buff *skb,
 
 	if (unlikely(cp->app != NULL)) {
 		/* Some checks before mangling */
-		if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
+		if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
 			return 0;
 
 		/*
@@ -154,7 +171,7 @@ udp_snat_handler(struct sk_buff *skb,
 			return 0;
 	}
 
-	udph = (void *)ip_hdr(skb) + udphoff;
+	udph = (void *)skb_network_header(skb) + udphoff;
 	udph->source = cp->vport;
 
 	/*
@@ -162,7 +179,7 @@ udp_snat_handler(struct sk_buff *skb,
 	 */
 	if (!cp->app && (udph->check != 0)) {
 		/* Only port and addr are changed, do fast csum update */
-		udp_fast_csum_update(udph, cp->daddr.ip, cp->vaddr.ip,
+		udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
 				     cp->dport, cp->vport);
 		if (skb->ip_summed == CHECKSUM_COMPLETE)
 			skb->ip_summed = CHECKSUM_NONE;
@@ -170,9 +187,19 @@ udp_snat_handler(struct sk_buff *skb,
 		/* full checksum calculation */
 		udph->check = 0;
 		skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
-		udph->check = csum_tcpudp_magic(cp->vaddr.ip, cp->caddr.ip,
-						skb->len - udphoff,
-						cp->protocol, skb->csum);
+#ifdef CONFIG_IP_VS_IPV6
+		if (cp->af == AF_INET6)
+			udph->check = csum_ipv6_magic(&cp->vaddr.in6,
+						      &cp->caddr.in6,
+						      skb->len - udphoff,
+						      cp->protocol, skb->csum);
+		else
+#endif
+			udph->check = csum_tcpudp_magic(cp->vaddr.ip,
+							cp->caddr.ip,
+							skb->len - udphoff,
+							cp->protocol,
+							skb->csum);
 		if (udph->check == 0)
 			udph->check = CSUM_MANGLED_0;
 		IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
@@ -188,7 +215,14 @@ udp_dnat_handler(struct sk_buff *skb,
 		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
 	struct udphdr *udph;
-	unsigned int udphoff = ip_hdrlen(skb);
+	unsigned int udphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+	if (cp->af == AF_INET6)
+		udphoff = sizeof(struct ipv6hdr);
+	else
+#endif
+		udphoff = ip_hdrlen(skb);
 
 	/* csum_check requires unshared skb */
 	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
@@ -196,7 +230,7 @@ udp_dnat_handler(struct sk_buff *skb,
 
 	if (unlikely(cp->app != NULL)) {
 		/* Some checks before mangling */
-		if (pp->csum_check && !pp->csum_check(AF_INET, skb, pp))
+		if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
 			return 0;
 
 		/*
@@ -207,7 +241,7 @@ udp_dnat_handler(struct sk_buff *skb,
 			return 0;
 	}
 
-	udph = (void *)ip_hdr(skb) + udphoff;
+	udph = (void *)skb_network_header(skb) + udphoff;
 	udph->dest = cp->dport;
 
 	/*
@@ -215,7 +249,7 @@ udp_dnat_handler(struct sk_buff *skb,
 	 */
 	if (!cp->app && (udph->check != 0)) {
 		/* Only port and addr are changed, do fast csum update */
-		udp_fast_csum_update(udph, cp->vaddr.ip, cp->daddr.ip,
+		udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
 				     cp->vport, cp->dport);
 		if (skb->ip_summed == CHECKSUM_COMPLETE)
 			skb->ip_summed = CHECKSUM_NONE;
@@ -223,9 +257,19 @@ udp_dnat_handler(struct sk_buff *skb,
 		/* full checksum calculation */
 		udph->check = 0;
 		skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
-		udph->check = csum_tcpudp_magic(cp->caddr.ip, cp->daddr.ip,
-						skb->len - udphoff,
-						cp->protocol, skb->csum);
+#ifdef CONFIG_IP_VS_IPV6
+		if (cp->af == AF_INET6)
+			udph->check = csum_ipv6_magic(&cp->caddr.in6,
+						      &cp->daddr.in6,
+						      skb->len - udphoff,
+						      cp->protocol, skb->csum);
+		else
+#endif
+			udph->check = csum_tcpudp_magic(cp->caddr.ip,
+							cp->daddr.ip,
+							skb->len - udphoff,
+							cp->protocol,
+							skb->csum);
 		if (udph->check == 0)
 			udph->check = CSUM_MANGLED_0;
 		skb->ip_summed = CHECKSUM_UNNECESSARY;