[PATCH ipsec,v2 2/2] xfrm: respect ip protocols rules criteria when performing dst lookups

[Eyal Birger <eyal.birger@gmail.com>]

The series in the "fixes" tag added the ability to consider L4 attributes
in routing rules.

The dst lookup in the xfrm code was not adapted to this change, thus
routing behavior that relies on L4 information is not respected, which
is relevant for UDP encapsulated IPsec traffic.

Pass the ip protocol information when performing dst lookups.

Fixes: a25724b05af0 ("Merge branch 'fib_rules-support-sport-dport-and-proto-match'")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
---
 include/net/xfrm.h      |  2 ++
 net/ipv4/xfrm4_policy.c |  2 ++
 net/ipv6/xfrm6_policy.c |  3 +++
 net/xfrm/xfrm_policy.c  | 14 ++++++++++++++
 4 files changed, 21 insertions(+)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 0f49f70dfd14..2a98d14b036f 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -356,6 +356,8 @@ struct xfrm_dst_lookup_params {
 	xfrm_address_t *saddr;
 	xfrm_address_t *daddr;
 	u32 mark;
+	__u8 ipproto;
+	union flowi_uli uli;
 };
 
 struct net_device;
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index ac1a28ef0c56..7e1c2faed1ff 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -30,6 +30,8 @@ static struct dst_entry *__xfrm4_dst_lookup(struct flowi4 *fl4,
 	fl4->flowi4_mark = params->mark;
 	if (params->saddr)
 		fl4->saddr = params->saddr->a4;
+	fl4->flowi4_proto = params->ipproto;
+	fl4->uli = params->uli;
 
 	rt = __ip_route_output_key(params->net, fl4);
 	if (!IS_ERR(rt))
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index fc3f5eec6898..1f19b6f14484 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -37,6 +37,9 @@ static struct dst_entry *xfrm6_dst_lookup(const struct xfrm_dst_lookup_params *p
 	if (params->saddr)
 		memcpy(&fl6.saddr, params->saddr, sizeof(fl6.saddr));
 
+	fl6.flowi4_proto = params->ipproto;
+	fl6.uli = params->uli;
+
 	dst = ip6_route_output(params->net, NULL, &fl6);
 
 	err = dst->error;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 1025b5b3a1dd..731fd02d787b 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -312,6 +312,20 @@ static inline struct dst_entry *xfrm_dst_lookup(struct xfrm_state *x,
 	params.tos = tos;
 	params.oif = oif;
 	params.mark = mark;
+	if (x->encap) {
+		switch (x->encap->encap_type) {
+		case UDP_ENCAP_ESPINUDP:
+			params.ipproto = IPPROTO_UDP;
+			params.uli.ports.sport = x->encap->encap_sport;
+			params.uli.ports.dport = x->encap->encap_dport;
+			break;
+		case TCP_ENCAP_ESPINTCP:
+			params.ipproto = IPPROTO_TCP;
+			params.uli.ports.sport = x->encap->encap_sport;
+			params.uli.ports.dport = x->encap->encap_dport;
+			break;
+		}
+	}
 
 	dst = __xfrm_dst_lookup(family, &params);
 
-- 
2.34.1