// SPDX-License-Identifier: GPL-2.0 #include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <bpf/bpf_core_read.h> #include "bpf_misc.h" static struct sockaddr_in old; static int handle_sys_connect_common(struct sockaddr_in *uservaddr) { struct sockaddr_in new; bpf_probe_read_user(&old, sizeof(old), uservaddr); __builtin_memset(&new, 0xab, sizeof(new)); bpf_probe_write_user(uservaddr, &new, sizeof(new)); return 0; } SEC("ksyscall/connect") int BPF_KSYSCALL(handle_sys_connect, int fd, struct sockaddr_in *uservaddr, int addrlen) { return handle_sys_connect_common(uservaddr); } #if defined(bpf_target_s390) #ifndef SYS_CONNECT #define SYS_CONNECT 3 #endif SEC("ksyscall/socketcall") int BPF_KSYSCALL(handle_sys_socketcall, int call, unsigned long *args) { if (call == SYS_CONNECT) { struct sockaddr_in *uservaddr; bpf_probe_read_user(&uservaddr, sizeof(uservaddr), &args[1]); return handle_sys_connect_common(uservaddr); } return 0; } #endif char _license[] SEC("license") = "GPL";