Add NAR parser

This commit is contained in:
Eelco Dolstra 2019-09-18 00:31:51 +02:00
parent 6317f0f7a0
commit 7f08975050
6 changed files with 160 additions and 3 deletions

1
nix-rust/Cargo.lock generated
View file

@ -666,6 +666,7 @@ name = "nix-rust"
version = "0.1.0" version = "0.1.0"
dependencies = [ dependencies = [
"assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)", "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
"byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
"futures-preview 0.3.0-alpha.18 (registry+https://github.com/rust-lang/crates.io-index)", "futures-preview 0.3.0-alpha.18 (registry+https://github.com/rust-lang/crates.io-index)",
"hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)", "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
"http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)", "http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",

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@ -17,8 +17,9 @@ reqwest = { version = "0.9", default-features = false, features = ["rustls-tls"]
http = "0.1" http = "0.1"
tokio = { version = "0.1", default-features = false } tokio = { version = "0.1", default-features = false }
lazy_static = "1.4" lazy_static = "1.4"
byteorder = "1.3"
[dev-dependencies] [dev-dependencies]
hex = "0.3" hex = "0.3"
assert_matches = "1.3" assert_matches = "1.3"
proptest = "0.9" proptest = "0.9"

View file

@ -1,4 +1,8 @@
use super::{foreign::{self, CBox}, error, util, store}; use super::{
error,
foreign::{self, CBox},
util,
};
#[no_mangle] #[no_mangle]
pub extern "C" fn unpack_tarfile( pub extern "C" fn unpack_tarfile(
@ -10,7 +14,8 @@ pub extern "C" fn unpack_tarfile(
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_test() { pub extern "C" fn rust_test() {
use crate::store::Store; /*
use crate::store::{self, Store};
use futures::future::{FutureExt, TryFutureExt}; use futures::future::{FutureExt, TryFutureExt};
use std::path::Path; use std::path::Path;
@ -39,4 +44,9 @@ pub extern "C" fn rust_test() {
}; };
tokio::run(fut.boxed().compat()); tokio::run(fut.boxed().compat());
*/
let file = std::fs::File::open("test.nar").unwrap();
crate::nar::parse(&mut std::io::BufReader::new(file)).unwrap();
} }

View file

@ -8,6 +8,15 @@ pub enum Error {
BadBase32, BadBase32,
StorePathNameTooLong, StorePathNameTooLong,
BadStorePathName, BadStorePathName,
NarSizeFieldTooBig,
BadNarString,
BadNarPadding,
BadNarVersionMagic,
MissingNarOpenTag,
MissingNarCloseTag,
MissingNarField,
BadNarField(String),
BadExecutableField,
IOError(std::io::Error), IOError(std::io::Error),
HttpError(reqwest::Error), HttpError(reqwest::Error),
Misc(String), Misc(String),
@ -37,6 +46,15 @@ impl fmt::Display for Error {
write!(f, "store path name is longer than 211 characters") write!(f, "store path name is longer than 211 characters")
} }
Error::BadStorePathName => write!(f, "store path name contains forbidden character"), Error::BadStorePathName => write!(f, "store path name contains forbidden character"),
Error::NarSizeFieldTooBig => write!(f, "size field in NAR is too big"),
Error::BadNarString => write!(f, "NAR string is not valid UTF-8"),
Error::BadNarPadding => write!(f, "NAR padding is not zero"),
Error::BadNarVersionMagic => write!(f, "unsupported NAR version"),
Error::MissingNarOpenTag => write!(f, "NAR open tag is missing"),
Error::MissingNarCloseTag => write!(f, "NAR close tag is missing"),
Error::MissingNarField => write!(f, "expected NAR field is missing"),
Error::BadNarField(s) => write!(f, "unrecognized NAR field '{}'", s),
Error::BadExecutableField => write!(f, "bad 'executable' field in NAR"),
Error::IOError(err) => write!(f, "I/O error: {}", err), Error::IOError(err) => write!(f, "I/O error: {}", err),
Error::HttpError(err) => write!(f, "HTTP error: {}", err), Error::HttpError(err) => write!(f, "HTTP error: {}", err),
Error::Foreign(_) => write!(f, "<C++ exception>"), // FIXME Error::Foreign(_) => write!(f, "<C++ exception>"), // FIXME

View file

@ -14,6 +14,7 @@ extern crate proptest;
mod c; mod c;
mod error; mod error;
mod foreign; mod foreign;
mod nar;
mod store; mod store;
mod util; mod util;

126
nix-rust/src/nar.rs Normal file
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@ -0,0 +1,126 @@
use crate::Error;
use byteorder::{LittleEndian, ReadBytesExt};
use std::convert::TryFrom;
use std::io::Read;
pub fn parse<R: Read>(input: &mut R) -> Result<(), Error> {
if String::read(input)? != NAR_VERSION_MAGIC {
return Err(Error::BadNarVersionMagic);
}
parse_file(input)
}
const NAR_VERSION_MAGIC: &str = "nix-archive-1";
fn parse_file<R: Read>(input: &mut R) -> Result<(), Error> {
if String::read(input)? != "(" {
return Err(Error::MissingNarOpenTag);
}
if String::read(input)? != "type" {
return Err(Error::MissingNarField);
}
match String::read(input)?.as_ref() {
"regular" => {
let mut executable = false;
let mut tag = String::read(input)?;
if tag == "executable" {
executable = true;
if String::read(input)? != "" {
return Err(Error::BadExecutableField);
}
tag = String::read(input)?;
}
if tag != "contents" {
return Err(Error::MissingNarField);
}
let contents = Vec::<u8>::read(input)?;
if String::read(input)? != ")" {
return Err(Error::MissingNarCloseTag);
}
}
"directory" => loop {
match String::read(input)?.as_ref() {
"entry" => {
if String::read(input)? != "(" {
return Err(Error::MissingNarOpenTag);
}
if String::read(input)? != "name" {
return Err(Error::MissingNarField);
}
let name = String::read(input)?;
if String::read(input)? != "node" {
return Err(Error::MissingNarField);
}
parse_file(input)?;
let tag = String::read(input)?;
if tag != ")" {
return Err(Error::MissingNarCloseTag);
}
}
")" => break,
s => return Err(Error::BadNarField(s.into())),
}
},
"symlink" => {
if String::read(input)? != "target" {
return Err(Error::MissingNarField);
}
let target = String::read(input)?;
if String::read(input)? != ")" {
return Err(Error::MissingNarCloseTag);
}
}
s => return Err(Error::BadNarField(s.into())),
}
Ok(())
}
trait Deserialize: Sized {
fn read<R: Read>(input: &mut R) -> Result<Self, Error>;
}
impl Deserialize for String {
fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
let buf = Deserialize::read(input)?;
Ok(String::from_utf8(buf).map_err(|_| Error::BadNarString)?)
}
}
impl Deserialize for Vec<u8> {
fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
let n: usize = Deserialize::read(input)?;
let mut buf = vec![0; n];
input.read_exact(&mut buf)?;
skip_padding(input, n)?;
Ok(buf)
}
}
fn skip_padding<R: Read>(input: &mut R, len: usize) -> Result<(), Error> {
if len % 8 != 0 {
let mut buf = [0; 8];
let buf = &mut buf[0..8 - (len % 8)];
input.read_exact(buf)?;
if !buf.iter().all(|b| *b == 0) {
return Err(Error::BadNarPadding);
}
}
Ok(())
}
impl Deserialize for u64 {
fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
Ok(input.read_u64::<LittleEndian>()?)
}
}
impl Deserialize for usize {
fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
let n: u64 = Deserialize::read(input)?;
Ok(usize::try_from(n).map_err(|_| Error::NarSizeFieldTooBig)?)
}
}