net: core: move pop MPLS functionality from OvS to core helper

Open vSwitch provides code to pop an MPLS header to a packet. In
preparation for supporting this in TC, move the pop code to an skb helper
that can be reused.

Remove the, now unused, update_ethertype static function from OvS.

Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Hurley 2019-07-07 15:01:55 +01:00 committed by David S. Miller
parent 8822e270d6
commit ed246cee09
3 changed files with 45 additions and 35 deletions

View File

@ -3448,6 +3448,7 @@ int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
int skb_vlan_pop(struct sk_buff *skb);
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 skb_mpls_pop(struct sk_buff *skb, __be16 next_proto);
struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
gfp_t gfp);

View File

@ -5489,6 +5489,48 @@ int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto)
}
EXPORT_SYMBOL_GPL(skb_mpls_push);
/**
* skb_mpls_pop() - pop the outermost MPLS header
*
* @skb: buffer
* @next_proto: ethertype of header after popped MPLS header
*
* Expects skb->data at mac header.
*
* Returns 0 on success, -errno otherwise.
*/
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto)
{
int err;
if (unlikely(!eth_p_mpls(skb->protocol)))
return -EINVAL;
err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
if (unlikely(err))
return err;
skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);
memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
skb->mac_len);
__skb_pull(skb, MPLS_HLEN);
skb_reset_mac_header(skb);
skb_set_network_header(skb, skb->mac_len);
if (skb->dev && skb->dev->type == ARPHRD_ETHER) {
struct ethhdr *hdr;
/* use mpls_hdr() to get ethertype to account for VLANs. */
hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
skb_mod_eth_type(skb, hdr, next_proto);
}
skb->protocol = next_proto;
return 0;
}
EXPORT_SYMBOL_GPL(skb_mpls_pop);
/**
* alloc_skb_with_frags - allocate skb with page frags
*

View File

@ -160,18 +160,6 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *attr, int len);
static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr,
__be16 ethertype)
{
if (skb->ip_summed == CHECKSUM_COMPLETE) {
__be16 diff[] = { ~(hdr->h_proto), ethertype };
skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum);
}
hdr->h_proto = ethertype;
}
static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
const struct ovs_action_push_mpls *mpls)
{
@ -190,31 +178,10 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
{
int err;
err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
if (unlikely(err))
err = skb_mpls_pop(skb, ethertype);
if (err)
return err;
skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);
memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
skb->mac_len);
__skb_pull(skb, MPLS_HLEN);
skb_reset_mac_header(skb);
skb_set_network_header(skb, skb->mac_len);
if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET) {
struct ethhdr *hdr;
/* mpls_hdr() is used to locate the ethertype field correctly in the
* presence of VLAN tags.
*/
hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
update_ethertype(skb, hdr, ethertype);
}
if (eth_p_mpls(skb->protocol))
skb->protocol = ethertype;
invalidate_flow_key(key);
return 0;
}