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