Subject: Re: [PATCH bpf-next 5/6] libbpf: Add bpf_get_link_xdp_info() function to get more XDP information

From: Toke Høiland-Jørgensen <[email-masked]>
Date: Fri, 08 Nov 2019 21:04:11 +0100

Song Liu <[email-masked]> writes:

>> On Nov 7, 2019, at 8:52 AM, Toke Høiland-Jørgensen <[email-masked]> wrote:
>> 
>> From: Toke Høiland-Jørgensen <[email-masked]>
>> 
>> Currently, libbpf only provides a function to get a single ID for the XDP
>> program attached to the interface. However, it can be useful to get the
>> full set of program IDs attached, along with the attachment mode, in one
>> go. Add a new getter function to support this, using an extendible
>> structure to carry the information. Express the old bpf_get_link_id()
>> function in terms of the new function.
>> 
>> Signed-off-by: Toke Høiland-Jørgensen <[email-masked]>
>> ---
>> tools/lib/bpf/libbpf.h   |   10 ++++++
>> tools/lib/bpf/libbpf.map |    1 +
>> tools/lib/bpf/netlink.c  |   78 ++++++++++++++++++++++++++++++----------------
>> 3 files changed, 62 insertions(+), 27 deletions(-)
>> 
>> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
>> index 6ddc0419337b..f0947cc949d2 100644
>> --- a/tools/lib/bpf/libbpf.h
>> +++ b/tools/lib/bpf/libbpf.h
>> @@ -427,8 +427,18 @@ LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
>> LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
>> 			     struct bpf_object **pobj, int *prog_fd);
>> 
>> +struct xdp_link_info {
>> +	__u32 prog_id;
>> +	__u32 drv_prog_id;
>> +	__u32 hw_prog_id;
>> +	__u32 skb_prog_id;
>> +	__u8 attach_mode;
>> +};
>> +
>> LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
>> LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
>> +LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
>> +				     size_t info_size, __u32 flags);
>> 
>> struct perf_buffer;
>> 
>> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
>> index 86173cbb159d..45f229af2766 100644
>> --- a/tools/lib/bpf/libbpf.map
>> +++ b/tools/lib/bpf/libbpf.map
>> @@ -202,4 +202,5 @@ LIBBPF_0.0.6 {
>> 		bpf_program__get_type;
>> 		bpf_program__is_tracing;
>> 		bpf_program__set_tracing;
>> +		bpf_get_link_xdp_info;
>
> Please keep these entries in alphabetic order.

Huh, I could have sworn I already did that; will fix and re-send.

> Just found I added most out-of-order entries. :(
>
> Other than this
>
> Acked-by: Song Liu <[email-masked]>

Thanks for your review (of the whole series).