libbpf: Remove getsockopt() check for XDP_OPTIONS

The xsk_socket__create() function fails and returns an error if it cannot
get the XDP_OPTIONS through getsockopt(). However, support for XDP_OPTIONS
was not added until kernel 5.3, so this means that creating XSK sockets
always fails on older kernels.

Since the option is just used to set the zero-copy flag in the xsk struct,
and that flag is not really used for anything yet, just remove the
getsockopt() call until a proper use for it is introduced.

Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index 842c4fd558592183a6ce0a007acfa68ebbcf7237..24fa313524fb216fa9390725c99fc4d0766c1564 100644 (file)
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -65,7 +65,6 @@ struct xsk_socket {
        int xsks_map_fd;
        __u32 queue_id;
        char ifname[IFNAMSIZ];
-       bool zc;
 };
 
 struct xsk_nl_info {
@@ -491,7 +490,6 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
        void *rx_map = NULL, *tx_map = NULL;
        struct sockaddr_xdp sxdp = {};
        struct xdp_mmap_offsets off;
-       struct xdp_options opts;
        struct xsk_socket *xsk;
        socklen_t optlen;
        int err;
@@ -611,15 +609,6 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
 
        xsk->prog_fd = -1;
 
-       optlen = sizeof(opts);
-       err = getsockopt(xsk->fd, SOL_XDP, XDP_OPTIONS, &opts, &optlen);
-       if (err) {
-               err = -errno;
-               goto out_mmap_tx;
-       }
-
-       xsk->zc = opts.flags & XDP_OPTIONS_ZEROCOPY;
-
        if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
                err = xsk_setup_xdp_prog(xsk);
                if (err)