xfrm: respect ip protocols rules criteria when performing dst lookups

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

The dst lookup on the outer packet of encapsulated traffic in the xfrm
code was not adapted to this change, thus routing behavior that relies
on L4 information is not respected.

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 <[e-mail]>
Tested-by: Antony Antony <[e-mail]>
Signed-off-by: Steffen Klassert <[e-mail]>

include/net/xfrm.h

···
 	xfrm_address_t *saddr;
 	xfrm_address_t *daddr;
 	u32 mark;
+	__u8 ipproto;
+	union flowi_uli uli;
 };
 
 struct net_device;

net/ipv4/xfrm4_policy.c

···
 	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))

net/ipv6/xfrm6_policy.c

···
 	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;

net/xfrm/xfrm_policy.c

···
 	params.tos = tos;
 	params.oif = oif;
 	params.mark = mark;
+	params.ipproto = x->id.proto;
+	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);