Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 26461905 authored by Jarno Rajahalme's avatar Jarno Rajahalme Committed by Pablo Neira Ayuso
Browse files

netfilter: Allow calling into nat helper without skb_dst. 



NAT checksum recalculation code assumes existence of skb_dst, which
becomes a problem for a later patch in the series ("openvswitch:
Interface with NAT.").  Simplify this by removing the check on
skb_dst, as the checksum will be dealt with later in the stack.

Suggested-by: default avatarPravin Shelar <pshelar@nicira.com>
Signed-off-by: default avatarJarno Rajahalme <jarno@ovn.org>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent bfa3f9d7

net/ipv4/netfilter/nf_nat_l3proto_ipv4.c

+8 −22
Original line number Diff line number Diff line
@@ -127,29 +127,15 @@ static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, 
				    u8 proto, void *data, __sum16 *check,

				    int datalen, int oldlen)

{

	if (skb->ip_summed != CHECKSUM_PARTIAL) {

		const struct iphdr *iph = ip_hdr(skb);

	struct rtable *rt = skb_rtable(skb);



	if (skb->ip_summed != CHECKSUM_PARTIAL) {

		if (!(rt->rt_flags & RTCF_LOCAL) &&

		    (!skb->dev || skb->dev->features &

		     (NETIF_F_IP_CSUM | NETIF_F_HW_CSUM))) {

		skb->ip_summed = CHECKSUM_PARTIAL;

			skb->csum_start = skb_headroom(skb) +

					  skb_network_offset(skb) +

		skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) +

			ip_hdrlen(skb);

		skb->csum_offset = (void *)check - data;

			*check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,

						    datalen, proto, 0);

		} else {

			*check = 0;

			*check = csum_tcpudp_magic(iph->saddr, iph->daddr,

						   datalen, proto,

						   csum_partial(data, datalen,

								0));

			if (proto == IPPROTO_UDP && !*check)

				*check = CSUM_MANGLED_0;

		}

		*check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen,

					    proto, 0);

	} else

		inet_proto_csum_replace2(check, skb,

					 htons(oldlen), htons(datalen), true);

net/ipv6/netfilter/nf_nat_l3proto_ipv6.c

+8 −22
Original line number Diff line number Diff line
@@ -131,29 +131,15 @@ static void nf_nat_ipv6_csum_recalc(struct sk_buff *skb, 
				    u8 proto, void *data, __sum16 *check,

				    int datalen, int oldlen)

{

	if (skb->ip_summed != CHECKSUM_PARTIAL) {

		const struct ipv6hdr *ipv6h = ipv6_hdr(skb);

	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);



	if (skb->ip_summed != CHECKSUM_PARTIAL) {

		if (!(rt->rt6i_flags & RTF_LOCAL) &&

		    (!skb->dev || skb->dev->features &

		     (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))) {

		skb->ip_summed = CHECKSUM_PARTIAL;

			skb->csum_start = skb_headroom(skb) +

					  skb_network_offset(skb) +

		skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) +

			(data - (void *)skb->data);

		skb->csum_offset = (void *)check - data;

		*check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,

					  datalen, proto, 0);

		} else {

			*check = 0;

			*check = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,

						 datalen, proto,

						 csum_partial(data, datalen,

							      0));

			if (proto == IPPROTO_UDP && !*check)

				*check = CSUM_MANGLED_0;

		}

	} else

		inet_proto_csum_replace2(check, skb,

					 htons(oldlen), htons(datalen), true);