40 lines
1 KiB
C
40 lines
1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
|
|
|
|
#include "vmlinux.h"
|
|
|
|
#include <string.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_core_read.h>
|
|
#include "bpf_kfuncs.h"
|
|
|
|
__u8 SERVUN_REWRITE_ADDRESS[] = "\0bpf_cgroup_unix_test_rewrite";
|
|
|
|
SEC("cgroup/sendmsg_unix")
|
|
int sendmsg_unix_prog(struct bpf_sock_addr *ctx)
|
|
{
|
|
struct bpf_sock_addr_kern *sa_kern = bpf_cast_to_kern_ctx(ctx);
|
|
struct sockaddr_un *sa_kern_unaddr;
|
|
__u32 unaddrlen = offsetof(struct sockaddr_un, sun_path) +
|
|
sizeof(SERVUN_REWRITE_ADDRESS) - 1;
|
|
int ret;
|
|
|
|
/* Rewrite destination. */
|
|
ret = bpf_sock_addr_set_sun_path(sa_kern, SERVUN_REWRITE_ADDRESS,
|
|
sizeof(SERVUN_REWRITE_ADDRESS) - 1);
|
|
if (ret)
|
|
return 0;
|
|
|
|
if (sa_kern->uaddrlen != unaddrlen)
|
|
return 0;
|
|
|
|
sa_kern_unaddr = bpf_rdonly_cast(sa_kern->uaddr,
|
|
bpf_core_type_id_kernel(struct sockaddr_un));
|
|
if (memcmp(sa_kern_unaddr->sun_path, SERVUN_REWRITE_ADDRESS,
|
|
sizeof(SERVUN_REWRITE_ADDRESS) - 1) != 0)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|