bpf: allow option for setting bpf_l4_csum_replace from scratch
authorDaniel Borkmann <daniel@iogearbox.net>
Tue, 24 Jan 2017 00:06:28 +0000 (01:06 +0100)
committerDavid S. Miller <davem@davemloft.net>
Tue, 24 Jan 2017 19:46:06 +0000 (14:46 -0500)
commitd1b662adcdb87944b7f6f7bd2f95cbb1404dbf18
treece847a4583aff07f03b6218180915d066949d403
parent2492d3b867043f6880708d095a7a5d65debcfc32
bpf: allow option for setting bpf_l4_csum_replace from scratch

When programs need to calculate the csum from scratch for small UDP
packets and use bpf_l4_csum_replace() to feed the result from helpers
like bpf_csum_diff(), then we need a flag besides BPF_F_MARK_MANGLED_0
that would ignore the case of current csum being 0, and which would
still allow for the helper to set the csum and transform when needed
to CSUM_MANGLED_0.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/uapi/linux/bpf.h
net/core/filter.c