linux/samples/bpf/xdpsock_kern.c
Magnus Karlsson b4b8faa1de samples/bpf: sample application and documentation for AF_XDP sockets
This is a sample application for AF_XDP sockets. The application
supports three different modes of operation: rxdrop, txonly and l2fwd.

To show-case a simple round-robin load-balancing between a set of
sockets in an xskmap, set the RR_LB compile time define option to 1 in
"xdpsock.h".

v2: The entries variable was calculated twice in {umem,xq}_nb_avail.

Co-authored-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-03 15:55:25 -07:00

57 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#define KBUILD_MODNAME "foo"
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
#include "xdpsock.h"
struct bpf_map_def SEC("maps") qidconf_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};
struct bpf_map_def SEC("maps") xsks_map = {
.type = BPF_MAP_TYPE_XSKMAP,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 4,
};
struct bpf_map_def SEC("maps") rr_map = {
.type = BPF_MAP_TYPE_PERCPU_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(unsigned int),
.max_entries = 1,
};
SEC("xdp_sock")
int xdp_sock_prog(struct xdp_md *ctx)
{
int *qidconf, key = 0, idx;
unsigned int *rr;
qidconf = bpf_map_lookup_elem(&qidconf_map, &key);
if (!qidconf)
return XDP_ABORTED;
if (*qidconf != ctx->rx_queue_index)
return XDP_PASS;
#if RR_LB /* NB! RR_LB is configured in xdpsock.h */
rr = bpf_map_lookup_elem(&rr_map, &key);
if (!rr)
return XDP_ABORTED;
*rr = (*rr + 1) & (MAX_SOCKS - 1);
idx = *rr;
#else
idx = 0;
#endif
return bpf_redirect_map(&xsks_map, idx, 0);
}
char _license[] SEC("license") = "GPL";