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#![warn(missing_docs)]
extern crate byteorder;
extern crate bytes;
extern crate compress;
extern crate failure;
use std::fmt;
use std::io::{self, Cursor, Read};
use bytes::{Buf, Bytes};
use compress::zlib;
use failure::Fail;
struct Header {
pub directory_name: String,
pub file_name: String,
pub uncompressed_size: i32,
pub file_count: i32,
}
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum Unreal4FileType {
Minidump,
Log,
Config,
Context,
Unknown,
}
impl Unreal4FileType {
pub fn name(self) -> &'static str {
match self {
Unreal4FileType::Minidump => "minidump",
Unreal4FileType::Log => "log",
Unreal4FileType::Config => "config",
Unreal4FileType::Context => "context",
Unreal4FileType::Unknown => "unknown",
}
}
}
impl fmt::Display for Unreal4FileType {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.name())
}
}
#[derive(Clone, Debug)]
pub struct Unreal4CrashFile {
pub index: usize,
pub file_name: String,
pub offset: usize,
pub len: usize,
}
impl Unreal4CrashFile {
pub fn ty(&self) -> Unreal4FileType {
match self.file_name.as_str() {
"UE4Minidump.dmp" => Unreal4FileType::Minidump,
"CrashReportClient.ini" => Unreal4FileType::Config,
"CrashContext.runtime-xml" => Unreal4FileType::Context,
name => {
if name.ends_with(".log") {
Unreal4FileType::Log
} else {
Unreal4FileType::Unknown
}
}
}
}
}
#[derive(Fail, Debug)]
pub enum Unreal4Error {
#[fail(display = "unknown bytes format")]
UnknownBytesFormat,
#[fail(display = "empty crash")]
Empty,
#[fail(display = "out of bounds")]
OutOfBounds,
#[fail(display = "bad compression")]
BadCompression(io::Error),
}
#[derive(Debug)]
pub struct Unreal4Crash {
bytes: Bytes,
files: Vec<Unreal4CrashFile>,
}
impl Unreal4Crash {
pub fn from_slice(bytes: &[u8]) -> Result<Unreal4Crash, Unreal4Error> {
if bytes.is_empty() {
return Err(Unreal4Error::Empty);
}
let mut zlib_decoder = zlib::Decoder::new(bytes);
let mut decompressed = Vec::new();
zlib_decoder
.read_to_end(&mut decompressed)
.map_err(Unreal4Error::BadCompression)?;
let decompressed = Bytes::from(decompressed);
let file_meta = get_files_from_slice(&decompressed)?;
Ok(Unreal4Crash {
bytes: decompressed,
files: file_meta,
})
}
pub fn files(&self) -> impl Iterator<Item = &Unreal4CrashFile> {
self.files.iter()
}
pub fn file_count(&self) -> usize {
self.files.len() as usize
}
pub fn file_by_index(&self, index: usize) -> Option<&Unreal4CrashFile> {
self.files().find(|f| f.index == index)
}
pub fn file_contents_by_index(&self, index: usize) -> Result<Option<&[u8]>, Unreal4Error> {
match self.file_by_index(index) {
Some(f) => Ok(Some(self.get_file_contents(f)?)),
None => Ok(None),
}
}
pub fn get_minidump_slice(&self) -> Result<Option<&[u8]>, Unreal4Error> {
let minidump = match self.files().find(|f| f.ty() == Unreal4FileType::Minidump) {
Some(m) => m,
None => return Ok(None),
};
Ok(Some(self.get_file_contents(minidump)?))
}
pub fn get_file_contents(&self, file_meta: &Unreal4CrashFile) -> Result<&[u8], Unreal4Error> {
let end = file_meta
.offset
.checked_add(file_meta.len)
.ok_or(Unreal4Error::OutOfBounds)?;
self.bytes
.get(file_meta.offset..end)
.ok_or(Unreal4Error::OutOfBounds)
}
}
fn read_ansi_string(buffer: &mut Cursor<&[u8]>) -> String {
let size = buffer.get_u32_le() as usize;
let dir_name = String::from_utf8_lossy(&Buf::bytes(&buffer)[..size]).into_owned();
buffer.advance(size);
dir_name.trim_end_matches('\0').into()
}
fn read_header(cursor: &mut Cursor<&[u8]>) -> Header {
Header {
directory_name: read_ansi_string(cursor),
file_name: read_ansi_string(cursor),
uncompressed_size: cursor.get_i32_le(),
file_count: cursor.get_i32_le(),
}
}
fn get_files_from_slice(bytes: &Bytes) -> Result<Vec<Unreal4CrashFile>, Unreal4Error> {
let mut rv = vec![];
let file_count = Cursor::new(
&bytes
.get(bytes.len() - 4..)
.ok_or(Unreal4Error::OutOfBounds)?,
).get_i32_le();
let mut cursor = Cursor::new(&bytes[..]);
read_header(&mut cursor);
for _ in 0..file_count {
let meta = Unreal4CrashFile {
index: cursor.get_i32_le() as usize,
file_name: read_ansi_string(&mut cursor),
len: cursor.get_i32_le() as usize,
offset: cursor.position() as usize,
};
cursor.advance(meta.len);
rv.push(meta);
}
Ok(rv)
}
#[test]
fn test_from_slice_empty_buffer() {
let crash = &[];
let result = Unreal4Crash::from_slice(crash);
assert!(match result.expect_err("empty crash") {
Unreal4Error::Empty => true,
_ => false,
})
}
#[test]
fn test_from_slice_invalid_input() {
let crash = &[0u8; 1];
let result = Unreal4Crash::from_slice(crash);
let err = match result.expect_err("empty crash") {
Unreal4Error::BadCompression(b) => b.to_string(),
_ => panic!(),
};
assert_eq!("unexpected EOF", err)
}