Daniel Borkmann b4ab314149 bpf: Add redirect_neigh helper as redirect drop-in ... Add a redirect_neigh() helper as redirect() drop-in replacement for the xmit side. Main idea for the helper is to be very similar in semantics to the latter just that the skb gets injected into the neighboring subsystem in order to let the stack do the work it knows best anyway to populate the L2 addresses of the packet and then hand over to dev_queue_xmit() as redirect() does. This solves two bigger items: i) skbs don't need to go up to the stack on the host facing veth ingress side for traffic egressing the container to achieve the same for populating L2 which also has the huge advantage that ii) the skb->sk won't get orphaned in ip_rcv_core() when entering the IP routing layer on the host stack. Given that skb->sk neither gets orphaned when crossing the netns as per 9c4c325252 ("skbuff: preserve sock reference when scrubbing the skb.") the helper can then push the skbs directly to the phys device where FQ scheduler can do its work and TCP stack gets proper backpressure given we hold on to skb->sk as long as skb is still residing in queues. With the helper used in BPF data path to then push the skb to the phys device, I observed a stable/consistent TCP_STREAM improvement on veth devices for traffic going container -> host -> host -> container from ~10Gbps to ~15Gbps for a single stream in my test environment. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: David Ahern <dsahern@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/bpf/f207de81629e1724899b73b8112e0013be782d35.1601477936.git.daniel@iogearbox.net		2020-09-30 11:50:35 -07:00
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asm	tools: Add missing stdio.h include to asm/bug.h header	2019-09-25 09:51:44 -03:00
asm-generic	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36	2019-05-24 17:27:11 +02:00
linux	btf: Add BTF_ID_LIST_SINGLE macro	2020-09-21 15:00:40 -07:00
nolibc	tool headers nolibc: add RISCV support	2019-05-08 15:48:43 +02:00
tools	tools: bpf: fix license for a compat header file	2018-09-19 23:49:58 +02:00
trace/events	tools/lib/lockdep: Remove private kernel headers	2017-06-05 09:28:14 +02:00
uapi	bpf: Add redirect_neigh helper as redirect drop-in	2020-09-30 11:50:35 -07:00
vdso	tools headers: Synchronize linux/bits.h with the kernel sources	2020-04-14 11:40:05 -03:00