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1// SPDX-License-Identifier: GPL-2.02#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#else14 int tailroom = 320;15#endif16 17 /* Data length determine test case */18 19 if (data_len == 54) { /* sizeof(pkt_v4) */20 offset = 4096; /* test too large offset */21 } else if (data_len == 74) { /* sizeof(pkt_v6) */22 offset = 40;23 } else if (data_len == 64) {24 offset = 128;25 } else if (data_len == 128) {26 /* Max tail grow 3520 */27 offset = 4096 - 256 - tailroom - data_len;28 } else if (data_len == 9000) {29 offset = 10;30 } else if (data_len == 9001) {31 offset = 4096;32 } else {33 return XDP_ABORTED; /* No matching test */34 }35 36 if (bpf_xdp_adjust_tail(xdp, offset))37 return XDP_DROP;38 return XDP_TX;39}40 41char _license[] SEC("license") = "GPL";42