On 01/25/2018 01:05 AM, Eric Leblond wrote:
> Most of the code is taken from set_link_xdp_fd() in bpf_load.c and
> slightly modified to be library compliant.
>
> Signed-off-by: Eric Leblond <e...@regit.org>
> Acked-by: Alexei Starovoitov <a...@kernel.org>
> ---
> tools/lib/bpf/bpf.c | 127
> +++++++++++++++++++++++++++++++++++++++++++++++++
> tools/lib/bpf/libbpf.c | 2 +
> tools/lib/bpf/libbpf.h | 4 ++
> 3 files changed, 133 insertions(+)
>
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index 5128677e4117..749a447ec9ed 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -25,6 +25,17 @@
> #include <asm/unistd.h>
> #include <linux/bpf.h>
> #include "bpf.h"
> +#include "libbpf.h"
> +#include "nlattr.h"
> +#include <uapi/linux/rtnetlink.h>
Doesn't libbpf pull in already -I$(srctree)/tools/include/uapi? Seems the
other headers don't need 'uapi/' path prefix.
> +#include <sys/socket.h>
> +#include <errno.h>
> +
> +#ifndef IFLA_XDP_MAX
> +#define IFLA_XDP 43
> +#define IFLA_XDP_FD 1
> +#define IFLA_XDP_FLAGS 3
> +#endif
Hm, given we pull in tools/include/uapi/linux/netlink.h, shouldn't we also
get include/uapi/linux/if_link.h dependency in here, so above ifdef workaround
can be avoided?
> /*
> * When building perf, unistd.h is overridden. __NR_bpf is
> @@ -46,7 +57,9 @@
> # endif
> #endif
>
> +#ifndef min
> #define min(x, y) ((x) < (y) ? (x) : (y))
> +#endif
>
> static inline __u64 ptr_to_u64(const void *ptr)
> {
> @@ -413,3 +426,117 @@ int bpf_obj_get_info_by_fd(int prog_fd, void *info,
> __u32 *info_len)
>
> return err;
> }
> +
> +int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
> +{
> + struct sockaddr_nl sa;
> + int sock, seq = 0, len, ret = -1;
> + char buf[4096];
> + struct nlattr *nla, *nla_xdp;
> + struct {
[...]
