1 /*
2 * Copyright (C) 2021 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 use anyhow::{anyhow, bail, Result};
18 use nix::sys::stat::FileStat;
19 use std::fs::File;
20 use std::os::unix::fs::FileTypeExt;
21 use std::os::unix::io::AsRawFd;
22 use std::path::Path;
23 use std::thread;
24 use std::time::{Duration, Instant};
25
26 /// Returns when the file exists on the given `path` or timeout (1s) occurs.
wait_for_path<P: AsRef<Path>>(path: P) -> Result<()>27 pub fn wait_for_path<P: AsRef<Path>>(path: P) -> Result<()> {
28 const TIMEOUT: Duration = Duration::from_secs(1);
29 const INTERVAL: Duration = Duration::from_millis(10);
30 let begin = Instant::now();
31 while !path.as_ref().exists() {
32 if begin.elapsed() > TIMEOUT {
33 bail!("{:?} not found. TIMEOUT.", path.as_ref());
34 }
35 thread::sleep(INTERVAL);
36 }
37 Ok(())
38 }
39
40 /// Returns hexadecimal reprentation of a given byte array.
hexstring_from(s: &[u8]) -> String41 pub fn hexstring_from(s: &[u8]) -> String {
42 s.iter().map(|byte| format!("{:02x}", byte)).reduce(|i, j| i + &j).unwrap_or_default()
43 }
44
45 /// Parses a hexadecimal string into a byte array
parse_hexstring(s: &str) -> Result<Vec<u8>>46 pub fn parse_hexstring(s: &str) -> Result<Vec<u8>> {
47 let len = s.len();
48 if len % 2 != 0 {
49 bail!("length {} is not even", len)
50 } else {
51 (0..len)
52 .step_by(2)
53 .map(|i| u8::from_str_radix(&s[i..i + 2], 16).map_err(|e| anyhow!(e)))
54 .collect()
55 }
56 }
57
58 /// fstat that accepts a path rather than FD
fstat(p: &Path) -> Result<FileStat>59 pub fn fstat(p: &Path) -> Result<FileStat> {
60 let f = File::open(p)?;
61 Ok(nix::sys::stat::fstat(f.as_raw_fd())?)
62 }
63
64 // From include/uapi/linux/fs.h
65 const BLK: u8 = 0x12;
66 const BLKGETSIZE64: u8 = 114;
67 nix::ioctl_read!(_blkgetsize64, BLK, BLKGETSIZE64, libc::size_t);
68
69 /// Gets the size of a block device
blkgetsize64(p: &Path) -> Result<u64>70 pub fn blkgetsize64(p: &Path) -> Result<u64> {
71 let f = File::open(p)?;
72 if !f.metadata()?.file_type().is_block_device() {
73 bail!("{:?} is not a block device", p);
74 }
75 let mut size: usize = 0;
76 // SAFETY: kernel copies the return value out to `size`. The file is kept open until the end of
77 // this function.
78 unsafe { _blkgetsize64(f.as_raw_fd(), &mut size) }?;
79 Ok(size as u64)
80 }
81