test_xdp_pull_data.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3#include "vmlinux.h"
 4#include <bpf/bpf_helpers.h>
 5
 6int xdpf_sz;
 7int sinfo_sz;
 8int data_len;
 9int pull_len;
10
11#define XDP_PACKET_HEADROOM 256
12
13SEC("xdp.frags")
14int xdp_find_sizes(struct xdp_md *ctx)
15{
16	xdpf_sz = sizeof(struct xdp_frame);
17	sinfo_sz = __PAGE_SIZE - XDP_PACKET_HEADROOM -
18		   (ctx->data_end - ctx->data);
19
20	return XDP_PASS;
21}
22
23SEC("xdp.frags")
24int xdp_pull_data_prog(struct xdp_md *ctx)
25{
26	__u8 *data_end = (void *)(long)ctx->data_end;
27	__u8 *data = (void *)(long)ctx->data;
28	__u8 *val_p;
29	int err;
30
31	if (data_len != data_end - data)
32		return XDP_DROP;
33
34	err = bpf_xdp_pull_data(ctx, pull_len);
35	if (err)
36		return XDP_DROP;
37
38	val_p = (void *)(long)ctx->data + 1024;
39	if (val_p + 1 > (void *)(long)ctx->data_end)
40		return XDP_DROP;
41
42	if (*val_p != 0xbb)
43		return XDP_DROP;
44
45	return XDP_PASS;
46}
47
48char _license[] SEC("license") = "GPL";