tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/bpf.h>
3#include <bpf/bpf_helpers.h>
4
5SEC("xdp")
6int _xdp_adjust_tail_grow(struct xdp_md *xdp)
7{
8 int data_len = bpf_xdp_get_buff_len(xdp);
9 int offset = 0;
10 /* SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) */
11#if defined(__TARGET_ARCH_s390)
12 int tailroom = 512;
13#elif defined(__TARGET_ARCH_powerpc)
14 int tailroom = 384;
15#else
16 int tailroom = 320;
17#endif
18
19 /* Data length determine test case */
20
21 if (data_len == 54) { /* sizeof(pkt_v4) */
22 offset = 4096; /* test too large offset */
23 } else if (data_len == 74) { /* sizeof(pkt_v6) */
24 offset = 40;
25 } else if (data_len == 64) {
26 offset = 128;
27 } else if (data_len == 128) {
28 /* Max tail grow 3520 */
29 offset = 4096 - 256 - tailroom - data_len;
30 } else if (data_len == 9000) {
31 offset = 10;
32 } else if (data_len == 9001) {
33 offset = 4096;
34 } else {
35 return XDP_ABORTED; /* No matching test */
36 }
37
38 if (bpf_xdp_adjust_tail(xdp, offset))
39 return XDP_DROP;
40 return XDP_TX;
41}
42
43char _license[] SEC("license") = "GPL";