[PATCH AUTOSEL 4.19 227/671] net: sched: act_csum: Fix csum calc for tagged packets
From: Sasha Levin <sashal@kernel.org>
Date: 2020-01-16 17:02:34
Also in:
lkml, stable
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Eli Britstein <redacted>
[ 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 <redacted>
Signed-off-by: Jiri Pirko <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sched/act_csum.c | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index 1e269441065a..9ecbf8edcf39 100644
--- 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,
--
2.20.1