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| author | Daniel Borkmann <daniel@iogearbox.net> | 2015-03-19 19:38:27 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-20 20:24:26 +0100 |
| commit | 0b8c707ddf37171413fe67350263e5b6ffeedf7c (patch) | |
| tree | e2f6a1849cc78ec2cc41846718ad3076e84de0cd /lib/rhashtable.c | |
| parent | ipv6: invert join/leave anycast rtnl/socket locking order (diff) | |
| download | linux-0b8c707ddf37171413fe67350263e5b6ffeedf7c.tar.xz linux-0b8c707ddf37171413fe67350263e5b6ffeedf7c.zip | |
ebpf, filter: do not convert skb->protocol to host endianess during runtime
Commit c24973957975 ("bpf: allow BPF programs access 'protocol' and 'vlan_tci'
fields") has added support for accessing protocol, vlan_present and vlan_tci
into the skb offset map.
As referenced in the below discussion, accessing skb->protocol from an eBPF
program should be converted without handling endianess.
The reason for this is that an eBPF program could simply do a check more
naturally, by f.e. testing skb->protocol == htons(ETH_P_IP), where the LLVM
compiler resolves htons() against a constant automatically during compilation
time, as opposed to an otherwise needed run time conversion.
After all, the way of programming both from a user perspective differs quite
a lot, i.e. bpf_asm ["ld proto"] versus a C subset/LLVM.
Reference: https://patchwork.ozlabs.org/patch/450819/
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions