1*00c1f3dcSPuranjay Mohan // SPDX-License-Identifier: GPL-2.0 2*00c1f3dcSPuranjay Mohan /* Copyright Amazon.com Inc. or its affiliates */ 3*00c1f3dcSPuranjay Mohan #include <linux/types.h> 4*00c1f3dcSPuranjay Mohan #include <linux/bpf.h> 5*00c1f3dcSPuranjay Mohan #include <bpf/bpf_helpers.h> 6*00c1f3dcSPuranjay Mohan #include <bpf/bpf_tracing.h> 7*00c1f3dcSPuranjay Mohan 8*00c1f3dcSPuranjay Mohan #define BUFF_SZ 512 9*00c1f3dcSPuranjay Mohan 10*00c1f3dcSPuranjay Mohan /* Will be updated by benchmark before program loading */ 11*00c1f3dcSPuranjay Mohan char to_buff[BUFF_SZ]; 12*00c1f3dcSPuranjay Mohan const volatile unsigned int to_buff_len = 0; 13*00c1f3dcSPuranjay Mohan char from_buff[BUFF_SZ]; 14*00c1f3dcSPuranjay Mohan const volatile unsigned int from_buff_len = 0; 15*00c1f3dcSPuranjay Mohan unsigned short seed = 0; 16*00c1f3dcSPuranjay Mohan 17*00c1f3dcSPuranjay Mohan short result; 18*00c1f3dcSPuranjay Mohan 19*00c1f3dcSPuranjay Mohan char _license[] SEC("license") = "GPL"; 20*00c1f3dcSPuranjay Mohan 21*00c1f3dcSPuranjay Mohan SEC("tc") 22*00c1f3dcSPuranjay Mohan int compute_checksum(void *ctx) 23*00c1f3dcSPuranjay Mohan { 24*00c1f3dcSPuranjay Mohan int to_len_half = to_buff_len / 2; 25*00c1f3dcSPuranjay Mohan int from_len_half = from_buff_len / 2; 26*00c1f3dcSPuranjay Mohan short result2; 27*00c1f3dcSPuranjay Mohan 28*00c1f3dcSPuranjay Mohan /* Calculate checksum in one go */ 29*00c1f3dcSPuranjay Mohan result2 = bpf_csum_diff((void *)from_buff, from_buff_len, 30*00c1f3dcSPuranjay Mohan (void *)to_buff, to_buff_len, seed); 31*00c1f3dcSPuranjay Mohan 32*00c1f3dcSPuranjay Mohan /* Calculate checksum by concatenating bpf_csum_diff()*/ 33*00c1f3dcSPuranjay Mohan result = bpf_csum_diff((void *)from_buff, from_buff_len - from_len_half, 34*00c1f3dcSPuranjay Mohan (void *)to_buff, to_buff_len - to_len_half, seed); 35*00c1f3dcSPuranjay Mohan 36*00c1f3dcSPuranjay Mohan result = bpf_csum_diff((void *)from_buff + (from_buff_len - from_len_half), from_len_half, 37*00c1f3dcSPuranjay Mohan (void *)to_buff + (to_buff_len - to_len_half), to_len_half, result); 38*00c1f3dcSPuranjay Mohan 39*00c1f3dcSPuranjay Mohan result = (result == result2) ? result : 0; 40*00c1f3dcSPuranjay Mohan 41*00c1f3dcSPuranjay Mohan return 0; 42*00c1f3dcSPuranjay Mohan } 43