diff options
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/bpf.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index a396b516a2b2..cffea1826a1f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1571,8 +1571,11 @@ union bpf_attr { * but this is only implemented for native XDP (with driver * support) as of this writing). * - * All values for *flags* are reserved for future usage, and must - * be left at zero. + * The lower two bits of *flags* are used as the return code if + * the map lookup fails. This is so that the return value can be + * one of the XDP program return codes up to XDP_TX, as chosen by + * the caller. Any higher bits in the *flags* argument must be + * unset. * * When used to redirect packets to net devices, this helper * provides a high performance increase over **bpf_redirect**\ (). |