Re: [PATCH] bpf: synchronize bpf uapi header with tools

[Taeung Song]

Hi Quentin,

On 07/19/2018 11:01 PM, Quentin Monnet wrote:
> Hi Taeung,
>
> 2018-07-19 21:53 UTC+0900 ~ Taeung Song <treeze.taeung@xxxxxxxxx>
> > To pick the change in:
> >
> >    4c79579b44b1 ("bpf: Change bpf_fib_lookup to return lookup status")
> >
> > This bpftool build warning occurs:
> >
> >    Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'
> >
> > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Cc: David Ahern <dsahern@xxxxxxxxx>
> > Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
> > ---
> >   tools/include/uapi/linux/bpf.h | 28 +++++++++++++++++++++++-----
> >   1 file changed, 23 insertions(+), 5 deletions(-)
> >
> > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> > index 59b19b6a40d7..b7db3261c62d 100644
> > --- a/tools/include/uapi/linux/bpf.h
> > +++ b/tools/include/uapi/linux/bpf.h
> > @@ -1857,7 +1857,8 @@ union bpf_attr {
> >    *		is resolved), the nexthop address is returned in ipv4_dst
> >    *		or ipv6_dst based on family, smac is set to mac address of
> >    *		egress device, dmac is set to nexthop mac address, rt_metric
> > - *		is set to metric from route (IPv4/IPv6 only).
> > + *		is set to metric from route (IPv4/IPv6 only), and ifindex
> > + *		is set to the device index of the nexthop from the FIB lookup.
> >    *
> >    *             *plen* argument is the size of the passed in struct.
> >    *             *flags* argument can be a combination of one or more of the
> > @@ -1873,9 +1874,10 @@ union bpf_attr {
> >    *             *ctx* is either **struct xdp_md** for XDP programs or
> >    *             **struct sk_buff** tc cls_act programs.
> >    *     Return
> > - *             Egress device index on success, 0 if packet needs to continue
> > - *             up the stack for further processing or a negative error in case
> > - *             of failure.
> > + *		* < 0 if any input argument is invalid
> > + *		*   0 on success (packet is forwarded, nexthop neighbor exists)
> > + *		* > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
> > + *		*     packet is not forwarded or needs assist from full stack
> >    *
> >    * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags)
> >    *	Description
> > @@ -2612,6 +2614,18 @@ struct bpf_raw_tracepoint_args {
> >   #define BPF_FIB_LOOKUP_DIRECT  BIT(0)
> >   #define BPF_FIB_LOOKUP_OUTPUT  BIT(1)
> >   
> > +enum {
> > +	BPF_FIB_LKUP_RET_SUCCESS,      /* lookup successful */
> > +	BPF_FIB_LKUP_RET_BLACKHOLE,    /* dest is blackholed; can be dropped */
> > +	BPF_FIB_LKUP_RET_UNREACHABLE,  /* dest is unreachable; can be dropped */
> > +	BPF_FIB_LKUP_RET_PROHIBIT,     /* dest not allowed; can be dropped */
> > +	BPF_FIB_LKUP_RET_NOT_FWDED,    /* packet is not forwarded */
> > +	BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */
> > +	BPF_FIB_LKUP_RET_UNSUPP_LWT,   /* fwd requires encapsulation */
> > +	BPF_FIB_LKUP_RET_NO_NEIGH,     /* no neighbor entry for nh */
> > +	BPF_FIB_LKUP_RET_FRAG_NEEDED,  /* fragmentation required to fwd */
> > +};
> > +
> >   struct bpf_fib_lookup {
> >   	/* input:  network family for lookup (AF_INET, AF_INET6)
> >   	 * output: network family of egress nexthop
> > @@ -2625,7 +2639,11 @@ struct bpf_fib_lookup {
> >   
> >   	/* total length of packet from network header - used for MTU check */
> >   	__u16	tot_len;
> > -	__u32	ifindex;  /* L3 device index for lookup */
> > +
> > +	/* input: L3 device index for lookup
> > +	 * output: device index from FIB lookup
> > +	 */
> > +	__u32	ifindex;
> >   
> >   	union {
> >   		/* inputs to lookup */
>
> This has been updated in the bpf-next tree already, see commit
> 9b8ca3795199 ("tools: bpf: synchronise BPF UAPI header with tools").
>
> Best regards,
> Quentin

OK ! Thanks.

--
Thanks,
Taeung