1 // SPDX-License-Identifier: GPL-2.0 2 #include "vmlinux.h" 3 #include <bpf/bpf_helpers.h> 4 #include <bpf/bpf_tracing.h> 5 #include <bpf/bpf_core_read.h> 6 #include "bpf_misc.h" 7 8 static struct sockaddr_in old; 9 10 SEC("ksyscall/connect") 11 int BPF_KSYSCALL(handle_sys_connect, int fd, struct sockaddr_in *uservaddr, int addrlen) 12 { 13 struct sockaddr_in new; 14 15 bpf_probe_read_user(&old, sizeof(old), uservaddr); 16 __builtin_memset(&new, 0xab, sizeof(new)); 17 bpf_probe_write_user(uservaddr, &new, sizeof(new)); 18 19 return 0; 20 } 21 22 char _license[] SEC("license") = "GPL"; 23