pico_download/
lib.rs

1#![forbid(unsafe_code)]
2
3//! Downloads Pico Technology oscilloscope drivers.
4//!
5//! This is a sub crate that you probably don't want to use directly. Try the top level
6//! [`pico-sdk`](https://crates.io/crates/pico-sdk) crate which exposes everything from here.
7//!
8//! This helper crate allows the distribution of software that can communicate with every Pico oscilloscope
9//! without the need to ship every driver binary.
10//!
11//! Supported platforms:
12//!  - Windows (32 or 64 bit)
13//!  - macOS (64 bit)
14//!  - Linux (64 bit or ARM for Raspberry Pi)
15//!
16//! All binaries are stored in Amazon AWS S3 storage and can be browsed [here](https://pico-drivers.s3.eu-west-2.amazonaws.com/).
17//!
18//! Some of these binaries have been modified using `install_name_tool` or `rpath` after download from the
19//! Pico website which allows them to be loaded dynamically from non-standard paths. Pico singing certificates remain.
20//!
21//! File hashes are validated after download to ensure the hosted files have not been tampered with.
22//! These hashes are generated using the `generate-hashes` example.
23//!
24//! `download_drivers_to_cache()` downloads the passed drivers and their dependencies and `cache_resolution()`
25//! returns a `Resolution` that can be used to resolve the downloaded binaries.
26//!
27//! `let enumerator = DeviceEnumerator::with_resolution(cache_resolution());`
28
29use hashes::get_expected_driver_hash;
30use http_req::request;
31use paths::get_cache_dir;
32use pico_common::Driver;
33use pico_driver::Resolution;
34use ring::digest::{Context, Digest, SHA256};
35use std::{fs, io::Read, path::Path};
36use thiserror::Error;
37
38mod hashes;
39mod paths;
40
41#[derive(Error, Debug)]
42pub enum DriverDownloadError {
43    #[error("IO Error: {0}")]
44    IoError(#[from] std::io::Error),
45
46    #[error("HTTP request Error: {0}")]
47    HttpRequestError(#[from] http_req::error::Error),
48
49    #[error("HTTP response Error: {0}")]
50    HttpResponseError(http_req::response::StatusCode),
51
52    #[error("Invalid driver hash")]
53    HashMismatch,
54}
55
56/// Gets a `Resolution` that points to the download cache location
57pub fn cache_resolution() -> Resolution {
58    Resolution::Custom(get_cache_dir())
59}
60
61/// Downloads the requested drivers and any dependencies to the supplied path.
62pub fn download_drivers<P: AsRef<Path>>(
63    drivers: &[Driver],
64    path: P,
65) -> Result<(), DriverDownloadError> {
66    let driver_dir = path.as_ref().to_path_buf();
67
68    let required_files = [drivers, &Driver::get_dependencies_for_platform()].concat();
69
70    fs::create_dir_all(&driver_dir)?;
71
72    for driver in required_files {
73        let file_path = driver_dir.join(&driver.get_binary_name());
74
75        if file_path.exists() {
76            match driver {
77                Driver::PicoIPP | Driver::IOMP5 => {
78                    continue;
79                }
80                _ => {
81                    fs::remove_file(&file_path)?;
82                }
83            }
84        }
85
86        download_driver(driver, &driver_dir)?;
87    }
88
89    Ok(())
90}
91
92/// Downloads the requested drivers and any dependencies to the cache location.
93///
94/// Drivers downloaded using this function can be loaded using the `Resolution`
95/// returned from `cache_resolution()`.
96///
97/// `DeviceEnumerator::with_resolution(cache_resolution())`
98pub fn download_drivers_to_cache(drivers: &[Driver]) -> Result<(), DriverDownloadError> {
99    download_drivers(drivers, get_cache_dir())
100}
101
102fn sha256_digest_for_file<P: AsRef<Path>>(path: P) -> Result<Digest, DriverDownloadError> {
103    let mut src_file = fs::File::open(&path)?;
104
105    let mut context = Context::new(&SHA256);
106    let mut buffer = [0; 1024];
107
108    loop {
109        let count = src_file.read(&mut buffer)?;
110        if count == 0 {
111            break;
112        }
113        context.update(&buffer[..count]);
114    }
115
116    Ok(context.finish())
117}
118
119fn download_driver(driver: Driver, dst_dir: &Path) -> Result<(), DriverDownloadError> {
120    let name = driver.get_binary_name();
121
122    let url = format!(
123        "https://pico-drivers.s3.eu-west-2.amazonaws.com/{}/{}/{}",
124        std::env::consts::OS,
125        std::env::consts::ARCH,
126        name
127    );
128
129    let dst_temp_path = dst_dir.join(name.to_string() + ".temp");
130
131    let mut dst_file = fs::File::create(&dst_temp_path)?;
132    let response = request::get(url, &mut dst_file)?;
133
134    if response.status_code().is_success() {
135        let computed_hash = format!("{:?}", sha256_digest_for_file(&dst_temp_path)?);
136
137        let expected_hash = get_expected_driver_hash(driver);
138
139        if computed_hash == expected_hash {
140            let dst_path = dst_dir.join(name);
141            fs::copy(&dst_temp_path, dst_path)?;
142            fs::remove_file(dst_temp_path)?;
143
144            Ok(())
145        } else {
146            Err(DriverDownloadError::HashMismatch)
147        }
148    } else {
149        Err(DriverDownloadError::HttpResponseError(
150            response.status_code(),
151        ))
152    }
153}
pico_download/lib.rs

pico_download/
lib.rs
