[PATCH ipsec-next 5/7] esp4: prepare esp_input_done2 for non-UDP encapsulation

[Sabrina Dubroca]

For espintcp encapsulation, we will need to get the source port from the
TCP header instead of UDP. Introduce a variable to hold the port.

Co-developed-by: Herbert Xu <herb...@gondor.apana.org.au>
Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
Signed-off-by: Sabrina Dubroca <s...@queasysnail.net>
---
 net/ipv4/esp4.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 5c967764041f..c5d826642229 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -601,6 +601,18 @@ int esp_input_done2(struct sk_buff *skb, int err)
        if (x->encap) {
                struct xfrm_encap_tmpl *encap = x->encap;
                struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
+               __be16 source;
+
+               switch (x->encap->encap_type) {
+               case UDP_ENCAP_ESPINUDP:
+               case UDP_ENCAP_ESPINUDP_NON_IKE:
+                       source = uh->source;
+                       break;
+               default:
+                       WARN_ON_ONCE(1);
+                       err = -EINVAL;
+                       goto out;
+               }
 
                /*
                 * 1) if the NAT-T peer's IP or port changed then
@@ -609,11 +621,11 @@ int esp_input_done2(struct sk_buff *skb, int err)
                 *    SRC ports.
                 */
                if (iph->saddr != x->props.saddr.a4 ||
-                   uh->source != encap->encap_sport) {
+                   source != encap->encap_sport) {
                        xfrm_address_t ipaddr;
 
                        ipaddr.a4 = iph->saddr;
-                       km_new_mapping(x, &ipaddr, uh->source);
+                       km_new_mapping(x, &ipaddr, source);
 
                        /* XXX: perhaps add an extra
                         * policy check here, to see
-- 
2.22.0