tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3
4#include "vmlinux.h"
5
6#include <string.h>
7#include <bpf/bpf_helpers.h>
8#include <bpf/bpf_core_read.h>
9#include "bpf_kfuncs.h"
10
11__u8 SERVUN_REWRITE_ADDRESS[] = "\0bpf_cgroup_unix_test_rewrite";
12
13SEC("cgroup/getpeername_unix")
14int getpeername_unix_prog(struct bpf_sock_addr *ctx)
15{
16 struct bpf_sock_addr_kern *sa_kern = bpf_cast_to_kern_ctx(ctx);
17 struct sockaddr_un *sa_kern_unaddr;
18 __u32 unaddrlen = offsetof(struct sockaddr_un, sun_path) +
19 sizeof(SERVUN_REWRITE_ADDRESS) - 1;
20 int ret;
21
22 ret = bpf_sock_addr_set_sun_path(sa_kern, SERVUN_REWRITE_ADDRESS,
23 sizeof(SERVUN_REWRITE_ADDRESS) - 1);
24 if (ret)
25 return 1;
26
27 if (sa_kern->uaddrlen != unaddrlen)
28 return 1;
29
30 sa_kern_unaddr = bpf_rdonly_cast(sa_kern->uaddr,
31 bpf_core_type_id_kernel(struct sockaddr_un));
32 if (memcmp(sa_kern_unaddr->sun_path, SERVUN_REWRITE_ADDRESS,
33 sizeof(SERVUN_REWRITE_ADDRESS) - 1) != 0)
34 return 1;
35
36 return 1;
37}
38
39char _license[] SEC("license") = "GPL";