LXR linux/tools/testing/selftests/bpf/progs/ima.c

   1// SPDX-License-Identifier: GPL-2.0
   2
   3/*
   4 * Copyright 2020 Google LLC.
   5 */
   6
   7#include "vmlinux.h"
   8#include <errno.h>
   9#include <bpf/bpf_helpers.h>
  10#include <bpf/bpf_tracing.h>
  11
  12u32 monitored_pid = 0;
  13
  14struct {
  15        __uint(type, BPF_MAP_TYPE_RINGBUF);
  16        __uint(max_entries, 1 << 12);
  17} ringbuf SEC(".maps");
  18
  19char _license[] SEC("license") = "GPL";
  20
  21SEC("lsm.s/bprm_committed_creds")
  22void BPF_PROG(ima, struct linux_binprm *bprm)
  23{
  24        u64 ima_hash = 0;
  25        u64 *sample;
  26        int ret;
  27        u32 pid;
  28
  29        pid = bpf_get_current_pid_tgid() >> 32;
  30        if (pid == monitored_pid) {
  31                ret = bpf_ima_inode_hash(bprm->file->f_inode, &ima_hash,
  32                                         sizeof(ima_hash));
  33                if (ret < 0 || ima_hash == 0)
  34                        return;
  35
  36                sample = bpf_ringbuf_reserve(&ringbuf, sizeof(u64), 0);
  37                if (!sample)
  38                        return;
  39
  40                *sample = ima_hash;
  41                bpf_ringbuf_submit(sample, 0);
  42        }
  43
  44        return;
  45}
  46