1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (c) 2020 Isovalent, Inc. 3 #include "vmlinux.h" 4 #include <bpf/bpf_helpers.h> 5 6 struct { 7 __uint(type, BPF_MAP_TYPE_SOCKMAP); 8 __uint(max_entries, 2); 9 __type(key, __u32); 10 __type(value, __u64); 11 } sock_map SEC(".maps"); 12 13 struct { 14 __uint(type, BPF_MAP_TYPE_SOCKHASH); 15 __uint(max_entries, 2); 16 __type(key, __u32); 17 __type(value, __u64); 18 } sock_hash SEC(".maps"); 19 20 struct { 21 __uint(type, BPF_MAP_TYPE_SK_STORAGE); 22 __uint(map_flags, BPF_F_NO_PREALLOC); 23 __type(key, __u32); 24 __type(value, __u64); 25 } socket_storage SEC(".maps"); 26 27 SEC("sk_msg") 28 int prog_msg_verdict(struct sk_msg_md *msg) 29 { 30 struct task_struct *task = (struct task_struct *)bpf_get_current_task(); 31 int verdict = SK_PASS; 32 __u32 pid, tpid; 33 __u64 *sk_stg; 34 35 pid = bpf_get_current_pid_tgid() >> 32; 36 sk_stg = bpf_sk_storage_get(&socket_storage, msg->sk, 0, BPF_SK_STORAGE_GET_F_CREATE); 37 if (!sk_stg) 38 return SK_DROP; 39 *sk_stg = pid; 40 bpf_probe_read_kernel(&tpid , sizeof(tpid), &task->tgid); 41 if (pid != tpid) 42 verdict = SK_DROP; 43 bpf_sk_storage_delete(&socket_storage, (void *)msg->sk); 44 return verdict; 45 } 46 47 char _license[] SEC("license") = "GPL"; 48