[PATCH v2 net-next] Enhanced skb_mpls_pop to update ethertype of the packet in all the cases when an ethernet header is present is the packet.
From: Martin Varghese <hidden>
Date: 2019-11-23 10:35:14
From: Martin Varghese <redacted>
The skb_mpls_pop was not updating ethertype of an ethernet packet if the
packet was originally received from a non ARPHRD_ETHER device.
In the below OVS data path flow, since the device corresponding to port 7
is an l3 device (ARPHRD_NONE) the skb_mpls_pop function does not update
the ethertype of the packet even though the previous push_eth action had
added an ethernet header to the packet.
recirc_id(0),in_port(7),eth_type(0x8847),
mpls(label=12/0xfffff,tc=0/0,ttl=0/0x0,bos=1/1),
actions:push_eth(src=00:00:00:00:00:00,dst=00:00:00:00:00:00),
pop_mpls(eth_type=0x800),4
Signed-off-by: Martin Varghese <redacted>
---
Changes in v2:
- check for dev type removed while updating ethertype
in function skb_mpls_pop.
- key->mac_proto is checked in function pop_mpls to pass
ethernt flag to skb_mpls_pop.
- dev type is checked in function tcf_mpls_act to pass
ethernet flag to skb_mpls_pop.
include/linux/skbuff.h | 3 ++-
net/core/skbuff.c | 7 ++++---
net/openvswitch/actions.c | 4 +++-
net/sched/act_mpls.c | 4 +++-
4 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index dfe02b6..70204b9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -3530,7 +3530,8 @@ int skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, int mac_len); -int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len); +int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, + bool ethernet); int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse); int skb_mpls_dec_ttl(struct sk_buff *skb); struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 867e61d..988eefb 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -5529,12 +5529,13 @@ int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, * @skb: buffer * @next_proto: ethertype of header after popped MPLS header * @mac_len: length of the MAC header - * + * @ethernet: flag to indicate if ethernet header is present in packet * Expects skb->data at mac header. * * Returns 0 on success, -errno otherwise. */ -int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len) +int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, + bool ethernet) { int err;
@@ -5553,7 +5554,7 @@ int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len) skb_reset_mac_header(skb); skb_set_network_header(skb, mac_len); - if (skb->dev && skb->dev->type == ARPHRD_ETHER) { + if (ethernet) { struct ethhdr *hdr; /* use mpls_hdr() to get ethertype to account for VLANs. */
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 12936c1..264c3c0 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c@@ -179,7 +179,9 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key, { int err; - err = skb_mpls_pop(skb, ethertype, skb->mac_len); + err = skb_mpls_pop(skb, ethertype, skb->mac_len, + (key->mac_proto & ~SW_FLOW_KEY_INVALID) + == MAC_PROTO_ETHERNET); if (err) return err;
diff --git a/net/sched/act_mpls.c b/net/sched/act_mpls.c
index 4d8c822..f919f95 100644
--- a/net/sched/act_mpls.c
+++ b/net/sched/act_mpls.c@@ -13,6 +13,7 @@ #include <net/pkt_sched.h> #include <net/pkt_cls.h> #include <net/tc_act/tc_mpls.h> +#include <linux/if_arp.h> static unsigned int mpls_net_id; static struct tc_action_ops act_mpls_ops;
@@ -76,7 +77,8 @@ static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a, switch (p->tcfm_action) { case TCA_MPLS_ACT_POP: - if (skb_mpls_pop(skb, p->tcfm_proto, mac_len)) + if (skb_mpls_pop(skb, p->tcfm_proto, mac_len, + (skb->dev && skb->dev->type == ARPHRD_ETHER))) goto drop; break; case TCA_MPLS_ACT_PUSH:
--
1.8.3.1