xref: /OK3568_Linux_fs/kernel/samples/bpf/xdpsock_kern.c (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/bpf.h>
3*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
4*4882a593Smuzhiyun #include "xdpsock.h"
5*4882a593Smuzhiyun 
6*4882a593Smuzhiyun /* This XDP program is only needed for the XDP_SHARED_UMEM mode.
7*4882a593Smuzhiyun  * If you do not use this mode, libbpf can supply an XDP program for you.
8*4882a593Smuzhiyun  */
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun struct {
11*4882a593Smuzhiyun 	__uint(type, BPF_MAP_TYPE_XSKMAP);
12*4882a593Smuzhiyun 	__uint(max_entries, MAX_SOCKS);
13*4882a593Smuzhiyun 	__uint(key_size, sizeof(int));
14*4882a593Smuzhiyun 	__uint(value_size, sizeof(int));
15*4882a593Smuzhiyun } xsks_map SEC(".maps");
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun static unsigned int rr;
18*4882a593Smuzhiyun 
xdp_sock_prog(struct xdp_md * ctx)19*4882a593Smuzhiyun SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun 	rr = (rr + 1) & (MAX_SOCKS - 1);
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun 	return bpf_redirect_map(&xsks_map, rr, XDP_DROP);
24*4882a593Smuzhiyun }
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