xfrm: remove decode_session indirection from afinfo_policy

No external dependencies, might as well handle this directly.
xfrm_afinfo_policy is now 40 bytes on x86_64.

Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Steffen Klassert <[email protected]>

Author: Florian Westphal

include/net/xfrm.h

@@ -326,9 +326,6 @@ struct xfrm_policy_afinfo {
 					     xfrm_address_t *saddr,
 					     xfrm_address_t *daddr,
 					     u32 mark);
-	void			(*decode_session)(struct sk_buff *skb,
-						  struct flowi *fl,
-						  int reverse);
 	int			(*fill_dst)(struct xfrm_dst *xdst,
 					    struct net_device *dev,
 					    const struct flowi *fl);

net/ipv4/xfrm4_policy.c

@@ -12,7 +12,6 @@
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/inetdevice.h>
-#include <linux/if_tunnel.h>
 #include <net/dst.h>
 #include <net/xfrm.h>
 #include <net/ip.h>
@@ -96,118 +95,6 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
 	return 0;
 }
 
-static void
-_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
-{
-	const struct iphdr *iph = ip_hdr(skb);
-	u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
-	struct flowi4 *fl4 = &fl->u.ip4;
-	int oif = 0;
-
-	if (skb_dst(skb))
-		oif = skb_dst(skb)->dev->ifindex;
-
-	memset(fl4, 0, sizeof(struct flowi4));
-	fl4->flowi4_mark = skb->mark;
-	fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
-
-	if (!ip_is_fragment(iph)) {
-		switch (iph->protocol) {
-		case IPPROTO_UDP:
-		case IPPROTO_UDPLITE:
-		case IPPROTO_TCP:
-		case IPPROTO_SCTP:
-		case IPPROTO_DCCP:
-			if (xprth + 4 < skb->data ||
-			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
-				__be16 *ports;
-
-				xprth = skb_network_header(skb) + iph->ihl * 4;
-				ports = (__be16 *)xprth;
-
-				fl4->fl4_sport = ports[!!reverse];
-				fl4->fl4_dport = ports[!reverse];
-			}
-			break;
-
-		case IPPROTO_ICMP:
-			if (xprth + 2 < skb->data ||
-			    pskb_may_pull(skb, xprth + 2 - skb->data)) {
-				u8 *icmp;
-
-				xprth = skb_network_header(skb) + iph->ihl * 4;
-				icmp = xprth;
-
-				fl4->fl4_icmp_type = icmp[0];
-				fl4->fl4_icmp_code = icmp[1];
-			}
-			break;
-
-		case IPPROTO_ESP:
-			if (xprth + 4 < skb->data ||
-			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
-				__be32 *ehdr;
-
-				xprth = skb_network_header(skb) + iph->ihl * 4;
-				ehdr = (__be32 *)xprth;
-
-				fl4->fl4_ipsec_spi = ehdr[0];
-			}
-			break;
-
-		case IPPROTO_AH:
-			if (xprth + 8 < skb->data ||
-			    pskb_may_pull(skb, xprth + 8 - skb->data)) {
-				__be32 *ah_hdr;
-
-				xprth = skb_network_header(skb) + iph->ihl * 4;
-				ah_hdr = (__be32 *)xprth;
-
-				fl4->fl4_ipsec_spi = ah_hdr[1];
-			}
-			break;
-
-		case IPPROTO_COMP:
-			if (xprth + 4 < skb->data ||
-			    pskb_may_pull(skb, xprth + 4 - skb->data)) {
-				__be16 *ipcomp_hdr;
-
-				xprth = skb_network_header(skb) + iph->ihl * 4;
-				ipcomp_hdr = (__be16 *)xprth;
-
-				fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
-			}
-			break;
-
-		case IPPROTO_GRE:
-			if (xprth + 12 < skb->data ||
-			    pskb_may_pull(skb, xprth + 12 - skb->data)) {
-				__be16 *greflags;
-				__be32 *gre_hdr;
-
-				xprth = skb_network_header(skb) + iph->ihl * 4;
-				greflags = (__be16 *)xprth;
-				gre_hdr = (__be32 *)xprth;
-
-				if (greflags[0] & GRE_KEY) {
-					if (greflags[0] & GRE_CSUM)
-						gre_hdr++;
-					fl4->fl4_gre_key = gre_hdr[1];
-				}
-			}
-			break;
-
-		default:
-			fl4->fl4_ipsec_spi = 0;
-			break;
-		}
-	}
-	fl4->flowi4_proto = iph->protocol;
-	fl4->daddr = reverse ? iph->saddr : iph->daddr;
-	fl4->saddr = reverse ? iph->daddr : iph->saddr;
-	fl4->flowi4_tos = iph->tos;
-}
-
 static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk,
 			      struct sk_buff *skb, u32 mtu)
 {
@@ -260,7 +147,6 @@ static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
 	.dst_ops =		&xfrm4_dst_ops_template,
 	.dst_lookup =		xfrm4_dst_lookup,
 	.get_saddr =		xfrm4_get_saddr,
-	.decode_session =	_decode_session4,
 	.fill_dst =		xfrm4_fill_dst,
 	.blackhole_route =	ipv4_blackhole_route,
 };

net/ipv6/xfrm6_policy.c

@@ -22,9 +22,6 @@
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
 #include <net/l3mdev.h>
-#if IS_ENABLED(CONFIG_IPV6_MIP6)
-#include <net/mip6.h>
-#endif
 
 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
 					  const xfrm_address_t *saddr,
@@ -100,108 +97,6 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
 	return 0;
 }
 
-static inline void
-_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
-{
-	struct flowi6 *fl6 = &fl->u.ip6;
-	int onlyproto = 0;
-	const struct ipv6hdr *hdr = ipv6_hdr(skb);
-	u32 offset = sizeof(*hdr);
-	struct ipv6_opt_hdr *exthdr;
-	const unsigned char *nh = skb_network_header(skb);
-	u16 nhoff = IP6CB(skb)->nhoff;
-	int oif = 0;
-	u8 nexthdr;
-
-	if (!nhoff)
-		nhoff = offsetof(struct ipv6hdr, nexthdr);
-
-	nexthdr = nh[nhoff];
-
-	if (skb_dst(skb))
-		oif = skb_dst(skb)->dev->ifindex;
-
-	memset(fl6, 0, sizeof(struct flowi6));
-	fl6->flowi6_mark = skb->mark;
-	fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
-
-	fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
-	fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
-
-	while (nh + offset + sizeof(*exthdr) < skb->data ||
-	       pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
-		nh = skb_network_header(skb);
-		exthdr = (struct ipv6_opt_hdr *)(nh + offset);
-
-		switch (nexthdr) {
-		case NEXTHDR_FRAGMENT:
-			onlyproto = 1;
-			/* fall through */
-		case NEXTHDR_ROUTING:
-		case NEXTHDR_HOP:
-		case NEXTHDR_DEST:
-			offset += ipv6_optlen(exthdr);
-			nexthdr = exthdr->nexthdr;
-			exthdr = (struct ipv6_opt_hdr *)(nh + offset);
-			break;
-
-		case IPPROTO_UDP:
-		case IPPROTO_UDPLITE:
-		case IPPROTO_TCP:
-		case IPPROTO_SCTP:
-		case IPPROTO_DCCP:
-			if (!onlyproto && (nh + offset + 4 < skb->data ||
-			     pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
-				__be16 *ports;
-
-				nh = skb_network_header(skb);
-				ports = (__be16 *)(nh + offset);
-				fl6->fl6_sport = ports[!!reverse];
-				fl6->fl6_dport = ports[!reverse];
-			}
-			fl6->flowi6_proto = nexthdr;
-			return;
-
-		case IPPROTO_ICMPV6:
-			if (!onlyproto && (nh + offset + 2 < skb->data ||
-			    pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
-				u8 *icmp;
-
-				nh = skb_network_header(skb);
-				icmp = (u8 *)(nh + offset);
-				fl6->fl6_icmp_type = icmp[0];
-				fl6->fl6_icmp_code = icmp[1];
-			}
-			fl6->flowi6_proto = nexthdr;
-			return;
-
-#if IS_ENABLED(CONFIG_IPV6_MIP6)
-		case IPPROTO_MH:
-			offset += ipv6_optlen(exthdr);
-			if (!onlyproto && (nh + offset + 3 < skb->data ||
-			    pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
-				struct ip6_mh *mh;
-
-				nh = skb_network_header(skb);
-				mh = (struct ip6_mh *)(nh + offset);
-				fl6->fl6_mh_type = mh->ip6mh_type;
-			}
-			fl6->flowi6_proto = nexthdr;
-			return;
-#endif
-
-		/* XXX Why are there these headers? */
-		case IPPROTO_AH:
-		case IPPROTO_ESP:
-		case IPPROTO_COMP:
-		default:
-			fl6->fl6_ipsec_spi = 0;
-			fl6->flowi6_proto = nexthdr;
-			return;
-		}
-	}
-}
-
 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
 			      struct sk_buff *skb, u32 mtu)
 {
@@ -273,7 +168,6 @@ static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
 	.dst_ops =		&xfrm6_dst_ops_template,
 	.dst_lookup =		xfrm6_dst_lookup,
 	.get_saddr =		xfrm6_get_saddr,
-	.decode_session =	_decode_session6,
 	.fill_dst =		xfrm6_fill_dst,
 	.blackhole_route =	ip6_blackhole_route,
 };