From b28326198cdd45191530b974bc3409f50f66e187 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Fri, 22 Sep 2023 01:39:21 -0700
Subject: [PATCH] Use crates for cpio code

---
 native/src/Cargo.lock      |  2 ++
 native/src/boot/Cargo.toml |  2 ++
 native/src/boot/cpio.rs    | 55 +++++++++++++++++++++-----------------
 3 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/native/src/Cargo.lock b/native/src/Cargo.lock
index 79b81f325..e0f5ad7b5 100644
--- a/native/src/Cargo.lock
+++ b/native/src/Cargo.lock
@@ -462,12 +462,14 @@ version = "0.0.0"
 dependencies = [
  "argh",
  "base",
+ "bytemuck",
  "byteorder",
  "cxx",
  "cxx-gen",
  "der",
  "digest",
  "fdt",
+ "num-traits",
  "p256",
  "p384",
  "pb-rs",
diff --git a/native/src/boot/Cargo.toml b/native/src/boot/Cargo.toml
index 5034c6c65..79807f067 100644
--- a/native/src/boot/Cargo.toml
+++ b/native/src/boot/Cargo.toml
@@ -27,3 +27,5 @@ rsa = { workspace = true, features = ["sha2"] }
 x509-cert = { workspace = true }
 der = { workspace = true, features = ["derive"] }
 fdt = { workspace = true }
+bytemuck = { workspace = true, features = ["derive", "min_const_generics"] }
+num-traits = { workspace = true }
diff --git a/native/src/boot/cpio.rs b/native/src/boot/cpio.rs
index 5a830d9f5..7f8d25580 100644
--- a/native/src/boot/cpio.rs
+++ b/native/src/boot/cpio.rs
@@ -1,7 +1,6 @@
 #![allow(clippy::useless_conversion)]
 
 use std::collections::BTreeMap;
-use std::ffi::CStr;
 use std::fmt::{Display, Formatter};
 use std::fs::{metadata, read, DirBuilder, File};
 use std::io::Write;
@@ -9,8 +8,11 @@ use std::mem::size_of;
 use std::os::unix::fs::{symlink, DirBuilderExt, FileTypeExt, MetadataExt};
 use std::path::Path;
 use std::process::exit;
+use std::str;
 
 use argh::FromArgs;
+use bytemuck::{from_bytes, Pod, Zeroable};
+use num_traits::cast::AsPrimitive;
 use size::{Base, Size, Style};
 
 use base::libc::{
@@ -183,6 +185,7 @@ Supported commands:
     )
 }
 
+#[derive(Copy, Clone, Pod, Zeroable)]
 #[repr(C, packed)]
 struct CpioHeader {
     magic: [u8; 6],
@@ -223,17 +226,17 @@ impl Cpio {
 
     fn load_from_data(data: &[u8]) -> LoggedResult<Self> {
         let mut cpio = Cpio::new();
-        let mut pos = 0usize;
+        let mut pos = 0_usize;
         while pos < data.len() {
-            let hdr = unsafe { &*(data.as_ptr().add(pos) as *const CpioHeader) };
+            let hdr_sz = size_of::<CpioHeader>();
+            let hdr = from_bytes::<CpioHeader>(&data[pos..(pos + hdr_sz)]);
             if &hdr.magic != b"070701" {
                 return Err(log_err!("invalid cpio magic"));
             }
-            pos += size_of::<CpioHeader>();
-            let name = CStr::from_bytes_until_nul(&data[pos..])?
-                .to_str()?
-                .to_string();
-            pos += x8u::<usize>(&hdr.namesize)?;
+            pos += hdr_sz;
+            let name_sz = x8u(&hdr.namesize)? as usize;
+            let name = Utf8CStr::from_bytes(&data[pos..(pos + name_sz)])?.to_string();
+            pos += name_sz;
             pos = align_4(pos);
             if name == "." || name == ".." {
                 continue;
@@ -245,16 +248,16 @@ impl Cpio {
                 }
                 continue;
             }
-            let file_size = x8u::<usize>(&hdr.filesize)?;
+            let file_sz = x8u(&hdr.filesize)? as usize;
             let entry = Box::new(CpioEntry {
-                mode: x8u(&hdr.mode)?,
-                uid: x8u(&hdr.uid)?,
-                gid: x8u(&hdr.gid)?,
-                rdevmajor: x8u(&hdr.rdevmajor)?,
-                rdevminor: x8u(&hdr.rdevminor)?,
-                data: data[pos..pos + file_size].to_vec(),
+                mode: x8u(&hdr.mode)?.as_(),
+                uid: x8u(&hdr.uid)?.as_(),
+                gid: x8u(&hdr.gid)?.as_(),
+                rdevmajor: x8u(&hdr.rdevmajor)?.as_(),
+                rdevminor: x8u(&hdr.rdevminor)?.as_(),
+                data: data[pos..(pos + file_sz)].to_vec(),
             });
-            pos += file_size;
+            pos += file_sz;
             cpio.entries.insert(name, entry);
             pos = align_4(pos);
         }
@@ -352,7 +355,7 @@ impl Cpio {
                 file.write_all(&entry.data)?;
             }
             S_IFLNK => {
-                symlink(Path::new(&std::str::from_utf8(entry.data.as_slice())?), out)?;
+                symlink(Path::new(&str::from_utf8(entry.data.as_slice())?), out)?;
             }
             S_IFBLK | S_IFCHR => {
                 let dev = makedev(entry.rdevmajor.try_into()?, entry.rdevminor.try_into()?);
@@ -600,15 +603,14 @@ pub fn cpio_commands(argc: i32, argv: *const *const c_char) -> bool {
         .is_ok()
 }
 
-fn x8u<U: TryFrom<u32>>(x: &[u8; 8]) -> LoggedResult<U> {
+fn x8u(x: &[u8; 8]) -> LoggedResult<u32> {
     // parse hex
     let mut ret = 0u32;
-    for i in x {
-        let c = *i as char;
-        let v = c.to_digit(16).ok_or_else(|| log_err!("bad cpio header"))?;
-        ret = ret * 16 + v;
+    let s = str::from_utf8(x).log_with_msg(|w| w.write_str("bad cpio header"))?;
+    for c in s.chars() {
+        ret = ret * 16 + c.to_digit(16).ok_or_else(|| log_err!("bad cpio header"))?;
     }
-    ret.try_into().map_err(|_| log_err!("bad cpio header"))
+    Ok(ret)
 }
 
 #[inline(always)]
@@ -618,8 +620,11 @@ fn align_4(x: usize) -> usize {
 
 #[inline(always)]
 fn norm_path(path: &str) -> String {
-    let path = path.strip_prefix('/').unwrap_or(path);
-    path.strip_suffix('/').unwrap_or(path).to_string()
+    path.strip_prefix('/')
+        .unwrap_or(path)
+        .strip_suffix('/')
+        .unwrap_or(path)
+        .to_string()
 }
 
 fn parse_mode(s: &str) -> Result<mode_t, String> {