netlink-socket: Reduce nl_sock_recv() from 2 (or more) system calls to 1.

[sliver-openvswitch.git] / datapath / tunnel.c

diff --git a/datapath/tunnel.c b/datapath/tunnel.c
index 3263223..c2439f0 100644 (file)
--- a/datapath/tunnel.c
+++ b/datapath/tunnel.c
@@ -450,9 +450,13 @@ void tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos)
        secpath_reset(skb);
 
        ecn_decapsulate(skb, tos);
-       compute_ip_summed(skb, false);
        vlan_set_tci(skb, 0);
 
+       if (unlikely(compute_ip_summed(skb, false))) {
+               kfree_skb(skb);
+               return;
+       }
+
        vport_receive(vport, skb);
 }
 
@@ -718,7 +722,11 @@ bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutab
            (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION))
                OVS_CB(nskb)->tun_id = flow_key;
 
-       compute_ip_summed(nskb, false);
+       if (unlikely(compute_ip_summed(nskb, false))) {
+               kfree_skb(nskb);
+               return false;
+       }
+
        vport_receive(vport, nskb);
 
        return true;
@@ -960,7 +968,7 @@ static struct tnl_cache *build_cache(struct vport *vport,
                err = flow_extract(skb, dst_vport->port_no, &flow_key,
                                   &flow_key_len, &is_frag);
 
-               kfree_skb(skb);
+               consume_skb(skb);
                if (err || is_frag)
                        goto done;
 
@@ -1027,27 +1035,6 @@ static struct rtable *find_route(struct vport *vport,
        }
 }
 
-static struct sk_buff *check_headroom(struct sk_buff *skb, int headroom)
-{
-       if (skb_headroom(skb) < headroom || skb_header_cloned(skb)) {
-               struct sk_buff *nskb = skb_realloc_headroom(skb, headroom + 16);
-               if (unlikely(!nskb)) {
-                       kfree_skb(skb);
-                       return ERR_PTR(-ENOMEM);
-               }
-
-               set_skb_csum_bits(skb, nskb);
-
-               if (skb->sk)
-                       skb_set_owner_w(nskb, skb->sk);
-
-               kfree_skb(skb);
-               return nskb;
-       }
-
-       return skb;
-}
-
 static inline bool need_linearize(const struct sk_buff *skb)
 {
        int i;
@@ -1074,34 +1061,35 @@ static struct sk_buff *handle_offloads(struct sk_buff *skb,
        int min_headroom;
        int err;
 
-       forward_ip_summed(skb);
-
-       err = vswitch_skb_checksum_setup(skb);
-       if (unlikely(err))
-               goto error_free;
-
        min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
                        + mutable->tunnel_hlen
                        + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
 
-       skb = check_headroom(skb, min_headroom);
-       if (IS_ERR(skb)) {
-               err = PTR_ERR(skb);
-               goto error;
+       if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
+               int head_delta = SKB_DATA_ALIGN(min_headroom -
+                                               skb_headroom(skb) +
+                                               16);
+               err = pskb_expand_head(skb, max_t(int, head_delta, 0),
+                                       0, GFP_ATOMIC);
+               if (unlikely(err))
+                       goto error_free;
        }
 
+       forward_ip_summed(skb, true);
+
        if (skb_is_gso(skb)) {
                struct sk_buff *nskb;
 
                nskb = skb_gso_segment(skb, 0);
-               kfree_skb(skb);
                if (IS_ERR(nskb)) {
+                       kfree_skb(skb);
                        err = PTR_ERR(nskb);
                        goto error;
                }
 
+               consume_skb(skb);
                skb = nskb;
-       } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+       } else if (get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
                /* Pages aren't locked and could change at any time.
                 * If this happens after we compute the checksum, the
                 * checksum will be wrong.  We linearize now to avoid
@@ -1116,8 +1104,9 @@ static struct sk_buff *handle_offloads(struct sk_buff *skb,
                err = skb_checksum_help(skb);
                if (unlikely(err))
                        goto error_free;
-       } else if (skb->ip_summed == CHECKSUM_COMPLETE)
-               skb->ip_summed = CHECKSUM_NONE;
+       }
+
+       set_ip_summed(skb, OVS_CSUM_NONE);
 
        return skb;
 
@@ -1312,8 +1301,12 @@ int tnl_send(struct vport *vport, struct sk_buff *skb)
                        ip_send_check(iph);
 
                        if (cache_vport) {
+                               if (unlikely(compute_ip_summed(skb, true))) {
+                                       kfree_skb(skb);
+                                       goto next;
+                               }
+
                                OVS_CB(skb)->flow = cache->flow;
-                               compute_ip_summed(skb, true);
                                vport_receive(cache_vport, skb);
                                sent_len += orig_len;
                        } else {