[PATCH bpf-next v4 04/17] libbpf: Support getsockopt XDP_OPTIONS

[Maxim Mikityanskiy]

Query XDP_OPTIONS in libbpf to determine if the zero-copy mode is active
or not.

Signed-off-by: Maxim Mikityanskiy <maxi...@mellanox.com>
Reviewed-by: Tariq Toukan <tar...@mellanox.com>
Acked-by: Saeed Mahameed <sae...@mellanox.com>
---
 tools/lib/bpf/xsk.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index 7ef6293b4fd7..bf15a80a37c2 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -65,6 +65,7 @@ struct xsk_socket {
        int xsks_map_fd;
        __u32 queue_id;
        char ifname[IFNAMSIZ];
+       bool zc;
 };
 
 struct xsk_nl_info {
@@ -480,6 +481,7 @@ 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;
@@ -597,6 +599,16 @@ 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)
-- 
2.19.1