// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH * * Author: Roberto Sassu <roberto.sassu@huawei.com> */ #include "vmlinux.h" #include <errno.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> char _license[] SEC("license") = "GPL"; __u32 monitored_pid; __u32 key_serial; __u32 key_id; __u64 flags; extern struct bpf_key *bpf_lookup_user_key(__u32 serial, __u64 flags) __ksym; extern struct bpf_key *bpf_lookup_system_key(__u64 id) __ksym; extern void bpf_key_put(struct bpf_key *key) __ksym; SEC("lsm.s/bpf") int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size) { struct bpf_key *bkey; __u32 pid; pid = bpf_get_current_pid_tgid() >> 32; if (pid != monitored_pid) return 0; if (key_serial) bkey = bpf_lookup_user_key(key_serial, flags); else bkey = bpf_lookup_system_key(key_id); if (!bkey) return -ENOENT; bpf_key_put(bkey); return 0; }