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