1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright Amazon.com Inc. or its affiliates */ 3 #include <linux/types.h> 4 #include <linux/bpf.h> 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_tracing.h> 7 8 #define BUFF_SZ 512 9 10 /* Will be updated by benchmark before program loading */ 11 char to_buff[BUFF_SZ]; 12 const volatile unsigned int to_buff_len = 0; 13 char from_buff[BUFF_SZ]; 14 const volatile unsigned int from_buff_len = 0; 15 unsigned short seed = 0; 16 17 short result; 18 19 char _license[] SEC("license") = "GPL"; 20 21 SEC("tc") 22 int compute_checksum(void *ctx) 23 { 24 int to_len_half = to_buff_len / 2; 25 int from_len_half = from_buff_len / 2; 26 short result2; 27 28 /* Calculate checksum in one go */ 29 result2 = bpf_csum_diff((void *)from_buff, from_buff_len, 30 (void *)to_buff, to_buff_len, seed); 31 32 /* Calculate checksum by concatenating bpf_csum_diff()*/ 33 result = bpf_csum_diff((void *)from_buff, from_buff_len - from_len_half, 34 (void *)to_buff, to_buff_len - to_len_half, seed); 35 36 result = bpf_csum_diff((void *)from_buff + (from_buff_len - from_len_half), from_len_half, 37 (void *)to_buff + (to_buff_len - to_len_half), to_len_half, result); 38 39 result = (result == result2) ? result : 0; 40 41 return 0; 42 } 43