net: sched: act_csum: Fix csum calc for tagged packets

[ Upstream commit 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 ]

The csum calculation is different for IPv4/6. For VLAN packets,
tc_skb_protocol returns the VLAN protocol rather than the packet's one
(e.g. IPv4/6), so csum is not calculated. Furthermore, VLAN may not be
stripped so csum is not calculated in this case too. Calculate the
csum for those cases.

Fixes: d8b9605d2697 ("net: sched: fix skb->protocol use in case of accelerated vlan path")
Signed-off-by: Eli Britstein <elibr@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index 1e26944..9ecbf8e 100644 (file)
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -560,8 +560,11 @@ static int tcf_csum_act(struct sk_buff *skb, const struct tc_action *a,
                        struct tcf_result *res)
 {
        struct tcf_csum *p = to_tcf_csum(a);
+       bool orig_vlan_tag_present = false;
+       unsigned int vlan_hdr_count = 0;
        struct tcf_csum_params *params;
        u32 update_flags;
+       __be16 protocol;
        int action;
 
        params = rcu_dereference_bh(p->params);
@@ -574,7 +577,9 @@ static int tcf_csum_act(struct sk_buff *skb, const struct tc_action *a,
                goto drop;
 
        update_flags = params->update_flags;
-       switch (tc_skb_protocol(skb)) {
+       protocol = tc_skb_protocol(skb);
+again:
+       switch (protocol) {
        case cpu_to_be16(ETH_P_IP):
                if (!tcf_csum_ipv4(skb, update_flags))
                        goto drop;
@@ -583,13 +588,35 @@ static int tcf_csum_act(struct sk_buff *skb, const struct tc_action *a,
                if (!tcf_csum_ipv6(skb, update_flags))
                        goto drop;
                break;
+       case cpu_to_be16(ETH_P_8021AD): /* fall through */
+       case cpu_to_be16(ETH_P_8021Q):
+               if (skb_vlan_tag_present(skb) && !orig_vlan_tag_present) {
+                       protocol = skb->protocol;
+                       orig_vlan_tag_present = true;
+               } else {
+                       struct vlan_hdr *vlan = (struct vlan_hdr *)skb->data;
+
+                       protocol = vlan->h_vlan_encapsulated_proto;
+                       skb_pull(skb, VLAN_HLEN);
+                       skb_reset_network_header(skb);
+                       vlan_hdr_count++;
+               }
+               goto again;
+       }
+
+out:
+       /* Restore the skb for the pulled VLAN tags */
+       while (vlan_hdr_count--) {
+               skb_push(skb, VLAN_HLEN);
+               skb_reset_network_header(skb);
        }
 
        return action;
 
 drop:
        qstats_drop_inc(this_cpu_ptr(p->common.cpu_qstats));
-       return TC_ACT_SHOT;
+       action = TC_ACT_SHOT;
+       goto out;
 }
 
 static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,