Re: [PATCH net-next] libbpf: add function to setup XDP

From: Toshiaki Makita
Date: Sun Dec 10 2017 - 21:25:29 EST


On 2017/12/09 23:43, 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 <eric@xxxxxxxxx>
...
> +int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
...
> + for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
> + nh = NLMSG_NEXT(nh, len)) {
> + if (nh->nlmsg_pid != getpid()) {

Generally nlmsg_pid should not be compared with process id.
See man netlink and
https://github.com/iovisor/bcc/pull/1275/commits/69ce96a54c55960c8de3392061254c97b6306a6d

> + ret = -LIBBPF_ERRNO__WRNGPID;
> + goto cleanup;
> + }

--
Toshiaki Makita