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 8static struct sockaddr_in old; 9 10static int handle_sys_connect_common(struct sockaddr_in *uservaddr) 11{ 12 struct sockaddr_in new; 13 14 bpf_probe_read_user(&old, sizeof(old), uservaddr); 15 __builtin_memset(&new, 0xab, sizeof(new)); 16 bpf_probe_write_user(uservaddr, &new, sizeof(new)); 17 18 return 0; 19} 20 21SEC("ksyscall/connect") 22int BPF_KSYSCALL(handle_sys_connect, int fd, struct sockaddr_in *uservaddr, 23 int addrlen) 24{ 25 return handle_sys_connect_common(uservaddr); 26} 27 28#if defined(bpf_target_s390) 29#ifndef SYS_CONNECT 30#define SYS_CONNECT 3 31#endif 32 33SEC("ksyscall/socketcall") 34int BPF_KSYSCALL(handle_sys_socketcall, int call, unsigned long *args) 35{ 36 if (call == SYS_CONNECT) { 37 struct sockaddr_in *uservaddr; 38 39 bpf_probe_read_user(&uservaddr, sizeof(uservaddr), &args[1]); 40 return handle_sys_connect_common(uservaddr); 41 } 42 43 return 0; 44} 45#endif 46 47char _license[] SEC("license") = "GPL"; 48