net: core: Split out code to run generic XDP prog

This helper can later be utilized in code that runs cpumap and devmap
programs in generic redirect mode and adjust skb based on changes made
to xdp_buff.

When returning XDP_REDIRECT/XDP_TX, it invokes __skb_push, so whenever a
generic redirect path invokes devmap/cpumap prog if set, it must
__skb_pull again as we expect mac header to be pulled.

It also drops the skb_reset_mac_len call after do_xdp_generic, as the
mac_header and network_header are advanced by the same offset, so the
difference (mac_len) remains constant.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210702111825.491065-2-memxor@gmail.com
This commit is contained in:
Kumar Kartikeya Dwivedi
2021-07-02 16:48:21 +05:30
committed by Alexei Starovoitov
parent a080cdccc9
commit fe21cb91ae
2 changed files with 55 additions and 31 deletions

View File

@@ -3984,6 +3984,8 @@ static inline void dev_consume_skb_any(struct sk_buff *skb)
__dev_kfree_skb_any(skb, SKB_REASON_CONSUMED);
}
u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog);
void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog);
int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb);
int netif_rx(struct sk_buff *skb);