[PATCH v2 net-next 5/6] fou: Support flow dissection

[Tom Herbert]

Populate offload flow_dissect callabck appropriately for fou and gue.

Signed-off-by: Tom Herbert <t...@quantonium.net>
---
 net/ipv4/fou.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 1540db65241a..a831dd49fb28 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -282,6 +282,20 @@ static int fou_gro_complete(struct sock *sk, struct 
sk_buff *skb,
        return err;
 }
 
+static enum flow_dissect_ret fou_flow_dissect(struct sock *sk,
+                       const struct sk_buff *skb,
+                       struct flow_dissector_key_control *key_control,
+                       struct flow_dissector *flow_dissector,
+                       void *target_container, void *data,
+                       __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+                       int *p_hlen, unsigned int flags)
+{
+       *p_ip_proto = fou_from_sock(sk)->protocol;
+       *p_nhoff += sizeof(struct udphdr);
+
+       return FLOW_DISSECT_RET_IPPROTO_AGAIN;
+}
+
 static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
                                      struct guehdr *guehdr, void *data,
                                      size_t hdrlen, struct gro_remcsum *grc,
@@ -500,6 +514,53 @@ static int gue_gro_complete(struct sock *sk, struct 
sk_buff *skb, int nhoff)
        return err;
 }
 
+static enum flow_dissect_ret gue_flow_dissect(struct sock *sk,
+                       const struct sk_buff *skb,
+                       struct flow_dissector_key_control *key_control,
+                       struct flow_dissector *flow_dissector,
+                       void *target_container, void *data,
+                       __be16 *p_proto, u8 *p_ip_proto, int *p_nhoff,
+                       int *p_hlen, unsigned int flags)
+{
+       struct guehdr *guehdr, _guehdr;
+
+       guehdr = __skb_header_pointer(skb, *p_nhoff + sizeof(struct udphdr),
+                                     sizeof(_guehdr), data, *p_hlen, &_guehdr);
+       if (!guehdr)
+               return FLOW_DISSECT_RET_OUT_BAD;
+
+       switch (guehdr->version) {
+       case 0:
+               if (unlikely(guehdr->control))
+                       return FLOW_DISSECT_RET_CONTINUE;
+
+               *p_ip_proto = guehdr->proto_ctype;
+               *p_nhoff += sizeof(struct udphdr) +
+                   sizeof(*guehdr) + (guehdr->hlen << 2);
+
+               break;
+       case 1:
+               switch (((struct iphdr *)guehdr)->version) {
+               case 4:
+                       *p_ip_proto = IPPROTO_IPIP;
+                       break;
+               case 6:
+                       *p_ip_proto = IPPROTO_IPV6;
+                       break;
+               default:
+                       return FLOW_DISSECT_RET_CONTINUE;
+               }
+
+               *p_nhoff += sizeof(struct udphdr);
+
+               break;
+       default:
+               return FLOW_DISSECT_RET_CONTINUE;
+       }
+
+       return FLOW_DISSECT_RET_IPPROTO_AGAIN;
+}
+
 static int fou_add_to_port_list(struct net *net, struct fou *fou)
 {
        struct fou_net *fn = net_generic(net, fou_net_id);
@@ -570,12 +631,14 @@ static int fou_create(struct net *net, struct fou_cfg 
*cfg,
                tunnel_cfg.encap_rcv = fou_udp_recv;
                tunnel_cfg.gro_receive = fou_gro_receive;
                tunnel_cfg.gro_complete = fou_gro_complete;
+               tunnel_cfg.flow_dissect = fou_flow_dissect;
                fou->protocol = cfg->protocol;
                break;
        case FOU_ENCAP_GUE:
                tunnel_cfg.encap_rcv = gue_udp_recv;
                tunnel_cfg.gro_receive = gue_gro_receive;
                tunnel_cfg.gro_complete = gue_gro_complete;
+               tunnel_cfg.flow_dissect = gue_flow_dissect;
                break;
        default:
                err = -EINVAL;
-- 
2.11.0