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| // SPDX-License-Identifier: GPL-2.0
| // Copyright (c) 2020 Isovalent, Inc.
| #include "vmlinux.h"
| #include <bpf/bpf_helpers.h>
|
| struct {
| __uint(type, BPF_MAP_TYPE_SOCKMAP);
| __uint(max_entries, 2);
| __type(key, __u32);
| __type(value, __u64);
| } sock_map SEC(".maps");
|
| struct {
| __uint(type, BPF_MAP_TYPE_SOCKHASH);
| __uint(max_entries, 2);
| __type(key, __u32);
| __type(value, __u64);
| } sock_hash SEC(".maps");
|
| struct {
| __uint(type, BPF_MAP_TYPE_SK_STORAGE);
| __uint(map_flags, BPF_F_NO_PREALLOC);
| __type(key, __u32);
| __type(value, __u64);
| } socket_storage SEC(".maps");
|
| SEC("sk_msg")
| int prog_msg_verdict(struct sk_msg_md *msg)
| {
| struct task_struct *task = (struct task_struct *)bpf_get_current_task();
| int verdict = SK_PASS;
| __u32 pid, tpid;
| __u64 *sk_stg;
|
| pid = bpf_get_current_pid_tgid() >> 32;
| sk_stg = bpf_sk_storage_get(&socket_storage, msg->sk, 0, BPF_SK_STORAGE_GET_F_CREATE);
| if (!sk_stg)
| return SK_DROP;
| *sk_stg = pid;
| bpf_probe_read_kernel(&tpid , sizeof(tpid), &task->tgid);
| if (pid != tpid)
| verdict = SK_DROP;
| bpf_sk_storage_delete(&socket_storage, (void *)msg->sk);
| return verdict;
| }
|
| char _license[] SEC("license") = "GPL";
|
|
