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1// SPDX-License-Identifier: GPL-2.02/* 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/sendmsg_unix")14int sendmsg_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 /* Rewrite destination. */23 ret = bpf_sock_addr_set_sun_path(sa_kern, SERVUN_REWRITE_ADDRESS,24 sizeof(SERVUN_REWRITE_ADDRESS) - 1);25 if (ret)26 return 0;27 28 if (sa_kern->uaddrlen != unaddrlen)29 return 0;30 31 sa_kern_unaddr = bpf_core_cast(sa_kern->uaddr, struct sockaddr_un);32 if (memcmp(sa_kern_unaddr->sun_path, SERVUN_REWRITE_ADDRESS,33 sizeof(SERVUN_REWRITE_ADDRESS) - 1) != 0)34 return 0;35 36 return 1;37}38 39SEC("cgroup/sendmsg_unix")40int sendmsg_unix_deny_prog(struct bpf_sock_addr *ctx)41{42 return 0;43}44 45char _license[] SEC("license") = "GPL";46