[PATCH RFC bpf-next 42/52] net, xdp: shortcut skb->dev in bpf_prog_run_generic_xdp()

Alexander Lobakin
2022-06-28T19:53:33Z

It's being used 3 times and more to come. Fetch it onto the stack
to reduce jumping back and forth.

Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
net/bpf/dev.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/bpf/dev.c b/net/bpf/dev.c
index cc43f73929f3..350ebdc783a0 100644
--- a/net/bpf/dev.c
+++ b/net/bpf/dev.c
@@ -31,6 +31,7 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
void *orig_data, *orig_data_end, *hard_start;
+ struct net_device *dev = skb->dev;
struct netdev_rx_queue *rxqueue;
bool orig_bcast, orig_host;
u32 mac_len, frame_sz;
@@ -57,7 +58,7 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
orig_data_end = xdp->data_end;
orig_data = xdp->data;
eth = (struct ethhdr *)xdp->data;
- orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
+ orig_host = ether_addr_equal_64bits(eth->h_dest, dev->dev_addr);
orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
orig_eth_type = eth->h_proto;

@@ -86,11 +87,11 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
eth = (struct ethhdr *)xdp->data;
if ((orig_eth_type != eth->h_proto) ||
(orig_host != ether_addr_equal_64bits(eth->h_dest,
- skb->dev->dev_addr)) ||
+ dev->dev_addr)) ||
(orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
__skb_push(skb, ETH_HLEN);
skb->pkt_type = PACKET_HOST;
- skb->protocol = eth_type_trans(skb, skb->dev);
+ skb->protocol = eth_type_trans(skb, dev);
}

/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
--
2.36.1