samples/bpf/xdpsock_kern.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define KBUILD_MODNAME "foo"
   3 #include <uapi/linux/bpf.h>
   4 #include "bpf_helpers.h"
   5
   6 #include "xdpsock.h"
   7
   8 struct bpf_map_def SEC("maps") qidconf_map = {
   9         .type           = BPF_MAP_TYPE_ARRAY,
  10         .key_size       = sizeof(int),
  11         .value_size     = sizeof(int),
  12         .max_entries    = 1,
  13 };
  14
  15 struct bpf_map_def SEC("maps") xsks_map = {
  16         .type = BPF_MAP_TYPE_XSKMAP,
  17         .key_size = sizeof(int),
  18         .value_size = sizeof(int),
  19         .max_entries = MAX_SOCKS,
  20 };
  21
  22 struct bpf_map_def SEC("maps") rr_map = {
  23         .type = BPF_MAP_TYPE_PERCPU_ARRAY,
  24         .key_size = sizeof(int),
  25         .value_size = sizeof(unsigned int),
  26         .max_entries = 1,
  27 };
  28
  29 SEC("xdp_sock")
  30 int xdp_sock_prog(struct xdp_md *ctx)
  31 {
  32         int *qidconf, key = 0, idx;
  33         unsigned int *rr;
  34
  35         qidconf = bpf_map_lookup_elem(&qidconf_map, &key);
  36         if (!qidconf)
  37                 return XDP_ABORTED;
  38
  39         if (*qidconf != ctx->rx_queue_index)
  40                 return XDP_PASS;
  41
  42 #if RR_LB /* NB! RR_LB is configured in xdpsock.h */
  43         rr = bpf_map_lookup_elem(&rr_map, &key);
  44         if (!rr)
  45                 return XDP_ABORTED;
  46
  47         *rr = (*rr + 1) & (MAX_SOCKS - 1);
  48         idx = *rr;
  49 #else
  50         idx = 0;
  51 #endif
  52
  53         return bpf_redirect_map(&xsks_map, idx, 0);
  54 }
  55
  56 char _license[] SEC("license") = "GPL";