1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/ptrace.h> 4 #include <linux/bpf.h> 5 6 #include <netinet/in.h> 7 8 #include "bpf_helpers.h" 9 #include "bpf_tracing.h" 10 11 static struct sockaddr_in old; 12 13 SEC("kprobe/__sys_connect") handle_sys_connect(struct pt_regs * ctx)14int handle_sys_connect(struct pt_regs *ctx) 15 { 16 void *ptr = (void *)PT_REGS_PARM2(ctx); 17 struct sockaddr_in new; 18 19 bpf_probe_read_user(&old, sizeof(old), ptr); 20 __builtin_memset(&new, 0xab, sizeof(new)); 21 bpf_probe_write_user(ptr, &new, sizeof(new)); 22 23 return 0; 24 } 25 26 char _license[] SEC("license") = "GPL"; 27