1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2023, SUSE. */ 3 4 #include "vmlinux.h" 5 #include <bpf/bpf_tracing.h> 6 #include "bpf_tracing_net.h" 7 8 char _license[] SEC("license") = "GPL"; 9 int pid; 10 11 SEC("fmod_ret/update_socket_protocol") 12 int BPF_PROG(mptcpify, int family, int type, int protocol) 13 { 14 if (bpf_get_current_pid_tgid() >> 32 != pid) 15 return protocol; 16 17 if ((family == AF_INET || family == AF_INET6) && 18 type == SOCK_STREAM && 19 (!protocol || protocol == IPPROTO_TCP)) { 20 return IPPROTO_MPTCP; 21 } 22 23 return protocol; 24 } 25