forked from brl/citadel-tools
ImageHeader refactored to be thread safe and shareable
This commit is contained in:
parent
025d7f3aa4
commit
533ed4b8be
@ -1,14 +1,14 @@
|
||||
use std::cell::RefCell;
|
||||
use std::fs::{File,OpenOptions};
|
||||
use std::io::{Read, Write};
|
||||
use std::path::Path;
|
||||
|
||||
use failure::ResultExt;
|
||||
|
||||
use toml;
|
||||
|
||||
use crate::blockdev::AlignedBuffer;
|
||||
use crate::{BlockDev,Result,public_key_for_channel,PublicKey};
|
||||
use std::sync::{Arc, Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard};
|
||||
use std::sync::atomic::{Ordering,AtomicIsize};
|
||||
use std::os::unix::fs::MetadataExt;
|
||||
|
||||
/// Expected magic value in header
|
||||
const MAGIC: &[u8] = b"SGOS";
|
||||
@ -58,9 +58,74 @@ fn is_valid_status_code(code: u8) -> bool {
|
||||
/// signature : ed25519 signature over the bytes of the metainfo field
|
||||
///
|
||||
|
||||
#[derive(Clone)]
|
||||
pub struct ImageHeader(RefCell<Vec<u8>>);
|
||||
pub struct ImageHeader {
|
||||
buffer: RwLock<HeaderBytes>,
|
||||
metainfo: Mutex<Option<Arc<MetaInfo>>>,
|
||||
timestamp: AtomicIsize,
|
||||
}
|
||||
|
||||
struct HeaderBytes([u8; ImageHeader::HEADER_SIZE]);
|
||||
|
||||
impl HeaderBytes {
|
||||
|
||||
fn create_empty() -> RwLock<Self> {
|
||||
let mut buffer = HeaderBytes::new();
|
||||
buffer.clear();
|
||||
RwLock::new(buffer)
|
||||
}
|
||||
|
||||
fn create_from_slice(slice: &[u8]) -> RwLock<Self> {
|
||||
assert_eq!(slice.len(), ImageHeader::HEADER_SIZE);
|
||||
let mut buffer = HeaderBytes::new();
|
||||
buffer.0.copy_from_slice(slice);
|
||||
RwLock::new(buffer)
|
||||
}
|
||||
|
||||
fn new() -> Self {
|
||||
HeaderBytes([0u8; ImageHeader::HEADER_SIZE])
|
||||
}
|
||||
|
||||
fn clear(&mut self) {
|
||||
for b in &mut self.0[..] {
|
||||
*b = 0;
|
||||
}
|
||||
self.write_bytes(0, MAGIC);
|
||||
}
|
||||
|
||||
fn read_u8(&self, idx: usize) -> u8 {
|
||||
self.0[idx]
|
||||
}
|
||||
|
||||
fn write_u8(&mut self, idx: usize, val: u8) {
|
||||
self.0[idx] = val;
|
||||
}
|
||||
|
||||
fn read_u16(&self, idx: usize) -> u16 {
|
||||
let hi = self.read_u8(idx) as u16;
|
||||
let lo = self.read_u8(idx + 1) as u16;
|
||||
(hi << 8) | lo
|
||||
}
|
||||
|
||||
fn write_u16(&mut self, idx: usize, val: u16) {
|
||||
let hi = (val >> 8) as u8;
|
||||
let lo = val as u8;
|
||||
self.write_u8(idx, hi);
|
||||
self.write_u8(idx + 1, lo);
|
||||
}
|
||||
|
||||
fn set_metainfo_len(&mut self, len: usize) {
|
||||
self.write_u16(6, len as u16);
|
||||
}
|
||||
|
||||
fn write_bytes(&mut self, offset: usize, data: &[u8]) {
|
||||
self.0[offset..offset + data.len()].copy_from_slice(data)
|
||||
}
|
||||
|
||||
fn read_bytes(&self, offset: usize, len: usize) -> Vec<u8> {
|
||||
Vec::from(&self.0[offset..offset + len])
|
||||
}
|
||||
|
||||
}
|
||||
const CODE_TO_LABEL: [&str; 7] = [
|
||||
"Invalid",
|
||||
"New",
|
||||
@ -88,22 +153,69 @@ impl ImageHeader {
|
||||
pub const HEADER_SIZE: usize = 4096;
|
||||
|
||||
pub fn new() -> ImageHeader {
|
||||
let v = vec![0u8; ImageHeader::HEADER_SIZE];
|
||||
let header = ImageHeader(RefCell::new(v));
|
||||
header.write_bytes(0, MAGIC);
|
||||
header
|
||||
let metainfo = Mutex::new(None);
|
||||
let buffer = HeaderBytes::create_empty();
|
||||
let timestamp = AtomicIsize::new(0);
|
||||
ImageHeader { buffer, metainfo, timestamp }
|
||||
}
|
||||
|
||||
/// Reload header if file has changed on disk
|
||||
pub fn reload_if_stale<P: AsRef<Path>>(&self, path: P) -> Result<bool> {
|
||||
let path = path.as_ref();
|
||||
let reload = self.is_stale(path)?;
|
||||
if reload {
|
||||
self.reload_file(path)?;
|
||||
}
|
||||
Ok(reload)
|
||||
}
|
||||
|
||||
fn is_stale(&self, path: &Path) -> Result<bool> {
|
||||
let (_,ts) = Self::file_metadata(path)?;
|
||||
let stale = self.timestamp.swap(ts, Ordering::SeqCst) != ts;
|
||||
Ok(stale)
|
||||
}
|
||||
|
||||
fn reload_file(&self, path: &Path) -> Result<()> {
|
||||
let header = Self::from_file(path)?;
|
||||
let header_lock = header.metainfo.lock().unwrap();
|
||||
let mut lock = self.metainfo.lock().unwrap();
|
||||
self.bytes_mut().0.copy_from_slice(&header.bytes().0);
|
||||
*lock = (*header_lock).clone();
|
||||
Ok(())
|
||||
}
|
||||
|
||||
pub fn from_file<P: AsRef<Path>>(path: P) -> Result<ImageHeader> {
|
||||
// XXX check file size is at least HEADER_SIZE
|
||||
let mut f = File::open(path.as_ref())?;
|
||||
ImageHeader::from_reader(&mut f)
|
||||
let path = path.as_ref();
|
||||
let (size,ts) = Self::file_metadata(path)?;
|
||||
if size < Self::HEADER_SIZE {
|
||||
bail!("Cannot load image header because {} has a size of {}", path.display(), size);
|
||||
}
|
||||
let mut f = File::open(path)?;
|
||||
let mut header = ImageHeader::from_reader(&mut f)?;
|
||||
*header.timestamp.get_mut() = ts;
|
||||
Ok(header)
|
||||
}
|
||||
|
||||
// returns tuple of (size,mtime)
|
||||
fn file_metadata(path: &Path) -> Result<(usize, isize)> {
|
||||
let metadata = path.metadata()?;
|
||||
Ok((metadata.len() as usize, metadata.mtime() as isize))
|
||||
}
|
||||
|
||||
pub fn from_reader<R: Read>(r: &mut R) -> Result<ImageHeader> {
|
||||
let mut v = vec![0u8; ImageHeader::HEADER_SIZE];
|
||||
r.read_exact(&mut v)?;
|
||||
Ok(ImageHeader(RefCell::new(v)))
|
||||
Self::from_slice(&v)
|
||||
}
|
||||
|
||||
fn from_slice(slice: &[u8]) -> Result<ImageHeader> {
|
||||
assert_eq!(slice.len(), ImageHeader::HEADER_SIZE);
|
||||
let buffer = HeaderBytes::create_from_slice(slice);
|
||||
let metainfo = Mutex::new(None);
|
||||
let timestamp = AtomicIsize::new(0);
|
||||
let header = ImageHeader { buffer, metainfo, timestamp };
|
||||
header.load_metainfo_if_magic_valid()?;
|
||||
Ok(header)
|
||||
}
|
||||
|
||||
pub fn from_partition<P: AsRef<Path>>(path: P) -> Result<ImageHeader> {
|
||||
@ -117,8 +229,7 @@ impl ImageHeader {
|
||||
);
|
||||
let mut buffer = AlignedBuffer::new(ImageHeader::HEADER_SIZE);
|
||||
dev.read_sectors(nsectors - 8, buffer.as_mut())?;
|
||||
let header = ImageHeader(RefCell::new(buffer.as_ref().into()));
|
||||
Ok(header)
|
||||
Self::from_slice(buffer.as_ref())
|
||||
}
|
||||
|
||||
pub fn write_partition<P: AsRef<Path>>(&self, path: P) -> Result<()> {
|
||||
@ -130,24 +241,53 @@ impl ImageHeader {
|
||||
path.as_ref().display(),
|
||||
nsectors
|
||||
);
|
||||
let buffer = AlignedBuffer::from_slice(&self.0.borrow());
|
||||
let lock = self.bytes();
|
||||
let buffer = AlignedBuffer::from_slice(&lock.0);
|
||||
dev.write_sectors(nsectors - 8, buffer.as_ref())?;
|
||||
Ok(())
|
||||
}
|
||||
|
||||
pub fn metainfo(&self) -> Result<MetaInfo> {
|
||||
let mlen = self.metainfo_len();
|
||||
if mlen == 0 || mlen > MAX_METAINFO_LEN {
|
||||
bail!("Invalid metainfo-len field: {}", mlen);
|
||||
|
||||
fn bytes(&self) -> RwLockReadGuard<HeaderBytes> {
|
||||
self.buffer.read().unwrap()
|
||||
}
|
||||
let mbytes = self.metainfo_bytes();
|
||||
let mut metainfo = MetaInfo::new(mbytes);
|
||||
metainfo.parse_toml()?;
|
||||
Ok(metainfo)
|
||||
|
||||
fn bytes_mut(&self) -> RwLockWriteGuard<HeaderBytes> {
|
||||
self.buffer.write().unwrap()
|
||||
}
|
||||
|
||||
fn with_bytes<F,R>(&self, f: F) -> R
|
||||
where F: FnOnce(&HeaderBytes) -> R
|
||||
{
|
||||
f(&self.bytes())
|
||||
}
|
||||
|
||||
fn with_bytes_mut<F,R>(&self, f: F) -> R
|
||||
where F: FnOnce(&mut HeaderBytes) -> R
|
||||
{
|
||||
f(&mut self.bytes_mut())
|
||||
}
|
||||
|
||||
fn load_metainfo_if_magic_valid(&self) -> Result<()> {
|
||||
if !self.is_magic_valid() {
|
||||
return Ok(())
|
||||
}
|
||||
|
||||
let mut lock = self.metainfo.lock().unwrap();
|
||||
let mb = self.metainfo_bytes();
|
||||
let metainfo = MetaInfo::parse_bytes(&mb)
|
||||
.ok_or(format_err!("ImageHeader has invalid metainfo"))?;
|
||||
*lock = Some(Arc::new(metainfo));
|
||||
Ok(())
|
||||
}
|
||||
|
||||
pub fn metainfo(&self) -> Arc<MetaInfo> {
|
||||
let lock = self.metainfo.lock().unwrap();
|
||||
lock.as_ref().expect("Header has no metainfo set").clone()
|
||||
}
|
||||
|
||||
pub fn is_magic_valid(&self) -> bool {
|
||||
self.read_bytes(0, 4) == MAGIC
|
||||
self.with_bytes(|bs| bs.read_bytes(0,4) == MAGIC)
|
||||
}
|
||||
|
||||
pub fn status(&self) -> u8 {
|
||||
@ -196,13 +336,18 @@ impl ImageHeader {
|
||||
self.read_u16(6) as usize
|
||||
}
|
||||
|
||||
pub fn set_metainfo_len(&self, len: usize) {
|
||||
self.write_u16(6, len as u16);
|
||||
}
|
||||
pub fn set_metainfo_bytes(&self, bytes: &[u8]) -> Result<()> {
|
||||
let metainfo = MetaInfo::parse_bytes(bytes)
|
||||
.ok_or(format_err!("Could not parse metainfo bytes as valid metainfo document"))?;
|
||||
|
||||
pub fn set_metainfo_bytes(&self, bytes: &[u8]) {
|
||||
self.set_metainfo_len(bytes.len());
|
||||
self.write_bytes(8, bytes);
|
||||
let mut lock = self.metainfo.lock().unwrap();
|
||||
self.with_bytes_mut(|bs| {
|
||||
bs.0.iter_mut().skip(8).for_each(|b| *b = 0);
|
||||
bs.set_metainfo_len(bytes.len());
|
||||
bs.write_bytes(8,bytes);
|
||||
});
|
||||
*lock = Some(Arc::new(metainfo));
|
||||
Ok(())
|
||||
}
|
||||
|
||||
pub fn metainfo_bytes(&self) -> Vec<u8> {
|
||||
@ -211,6 +356,10 @@ impl ImageHeader {
|
||||
self.read_bytes(METAINFO_OFFSET, mlen)
|
||||
}
|
||||
|
||||
pub fn has_signature(&self) -> bool {
|
||||
self.signature().iter().any(|b| *b != 0)
|
||||
}
|
||||
|
||||
pub fn signature(&self) -> Vec<u8> {
|
||||
let mlen = self.metainfo_len();
|
||||
assert!(mlen > 0 && mlen < MAX_METAINFO_LEN);
|
||||
@ -232,8 +381,7 @@ impl ImageHeader {
|
||||
}
|
||||
|
||||
pub fn public_key(&self) -> Result<Option<PublicKey>> {
|
||||
let metainfo = self.metainfo()?;
|
||||
public_key_for_channel(metainfo.channel())
|
||||
public_key_for_channel(self.metainfo().channel())
|
||||
}
|
||||
|
||||
pub fn verify_signature(&self, pubkey: PublicKey) -> bool {
|
||||
@ -241,7 +389,7 @@ impl ImageHeader {
|
||||
}
|
||||
|
||||
pub fn write_header<W: Write>(&self, mut writer: W) -> Result<()> {
|
||||
writer.write_all(&self.0.borrow())?;
|
||||
self.with_bytes(|bs| writer.write_all(&bs.0))?;
|
||||
Ok(())
|
||||
}
|
||||
|
||||
@ -249,52 +397,30 @@ impl ImageHeader {
|
||||
self.write_header(OpenOptions::new().write(true).open(path.as_ref())?)
|
||||
}
|
||||
|
||||
pub fn clear(&self) {
|
||||
for b in &mut self.0.borrow_mut()[..] {
|
||||
*b = 0;
|
||||
}
|
||||
self.write_bytes(0, MAGIC);
|
||||
}
|
||||
|
||||
fn read_u8(&self, idx: usize) -> u8 {
|
||||
self.0.borrow()[idx]
|
||||
}
|
||||
|
||||
fn read_u16(&self, idx: usize) -> u16 {
|
||||
let hi = self.read_u8(idx) as u16;
|
||||
let lo = self.read_u8(idx + 1) as u16;
|
||||
(hi << 8) | lo
|
||||
self.with_bytes(|bs| bs.read_u8(idx))
|
||||
}
|
||||
|
||||
fn write_u8(&self, idx: usize, val: u8) {
|
||||
self.0.borrow_mut()[idx] = val;
|
||||
self.with_bytes_mut(|bs| bs.write_u8(idx, val))
|
||||
}
|
||||
|
||||
fn write_u16(&self, idx: usize, val: u16) {
|
||||
let hi = (val >> 8) as u8;
|
||||
let lo = val as u8;
|
||||
self.write_u8(idx, hi);
|
||||
self.write_u8(idx + 1, lo);
|
||||
fn read_u16(&self, idx: usize) -> u16 {
|
||||
self.with_bytes(|bs| bs.read_u16(idx))
|
||||
}
|
||||
|
||||
fn write_bytes(&self, offset: usize, data: &[u8]) {
|
||||
self.0.borrow_mut()[offset..offset + data.len()].copy_from_slice(data)
|
||||
self.with_bytes_mut(|bs| bs.write_bytes(offset, data))
|
||||
}
|
||||
|
||||
fn read_bytes(&self, offset: usize, len: usize) -> Vec<u8> {
|
||||
Vec::from(&self.0.borrow()[offset..offset + len])
|
||||
self.with_bytes(|bs| bs.read_bytes(offset, len))
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Clone)]
|
||||
pub struct MetaInfo {
|
||||
bytes: Vec<u8>,
|
||||
is_parsed: bool,
|
||||
toml: Option<MetaInfoToml>,
|
||||
}
|
||||
|
||||
#[derive(Deserialize, Serialize, Clone)]
|
||||
struct MetaInfoToml {
|
||||
#[derive(Deserialize, Serialize, Clone, Default)]
|
||||
pub struct MetaInfo {
|
||||
#[serde(rename = "image-type")]
|
||||
image_type: String,
|
||||
|
||||
@ -333,64 +459,68 @@ struct MetaInfoToml {
|
||||
}
|
||||
|
||||
impl MetaInfo {
|
||||
fn new(bytes: Vec<u8>) -> MetaInfo {
|
||||
MetaInfo {
|
||||
bytes,
|
||||
is_parsed: false,
|
||||
toml: None,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn parse_toml(&mut self) -> Result<()> {
|
||||
if !self.is_parsed {
|
||||
self.is_parsed = true;
|
||||
let toml =
|
||||
toml::from_slice::<MetaInfoToml>(&self.bytes).context("parsing header metainfo")?;
|
||||
self.toml = Some(toml);
|
||||
}
|
||||
Ok(())
|
||||
}
|
||||
|
||||
fn toml(&self) -> &MetaInfoToml {
|
||||
self.toml.as_ref().unwrap()
|
||||
fn parse_bytes(bytes: &[u8]) -> Option<MetaInfo> {
|
||||
toml::from_slice::<MetaInfo>(bytes).ok()
|
||||
}
|
||||
|
||||
pub fn image_type(&self) -> &str {
|
||||
self.toml().image_type.as_str()
|
||||
self.image_type.as_str()
|
||||
}
|
||||
|
||||
pub fn channel(&self) -> &str {
|
||||
self.toml().channel.as_str()
|
||||
self.channel.as_str()
|
||||
}
|
||||
|
||||
pub fn kernel_version(&self) -> Option<&str> { self.toml().kernel_version.as_ref().map(|s| s.as_str()) }
|
||||
fn str_ref(arg: &Option<String>) -> Option<&str> {
|
||||
match arg {
|
||||
Some(ref s) => Some(s.as_str()),
|
||||
None => None,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn kernel_id(&self) -> Option<&str> { self.toml().kernel_id.as_ref().map(|s| s.as_str()) }
|
||||
pub fn kernel_version(&self) -> Option<&str> {
|
||||
Self::str_ref(&self.kernel_version)
|
||||
}
|
||||
|
||||
pub fn realmfs_name(&self) -> Option<&str> { self.toml().realmfs_name.as_ref().map(|s| s.as_str()) }
|
||||
pub fn realmfs_owner(&self) -> Option<&str> { self.toml().realmfs_owner.as_ref().map(|s| s.as_str()) }
|
||||
pub fn kernel_id(&self) -> Option<&str> {
|
||||
Self::str_ref(&self.kernel_id)
|
||||
}
|
||||
|
||||
pub fn realmfs_name(&self) -> Option<&str> {
|
||||
Self::str_ref(&self.realmfs_name)
|
||||
}
|
||||
|
||||
pub fn realmfs_owner(&self) -> Option<&str> {
|
||||
Self::str_ref(&self.realmfs_owner)
|
||||
}
|
||||
|
||||
pub fn version(&self) -> u32 {
|
||||
self.toml().version
|
||||
self.version
|
||||
}
|
||||
|
||||
pub fn timestamp(&self) -> &str {
|
||||
&self.toml().timestamp
|
||||
&self.timestamp
|
||||
}
|
||||
|
||||
pub fn nblocks(&self) -> usize {
|
||||
self.toml().nblocks as usize
|
||||
self.nblocks as usize
|
||||
}
|
||||
|
||||
pub fn shasum(&self) -> &str {
|
||||
&self.toml().shasum
|
||||
&self.shasum
|
||||
}
|
||||
|
||||
pub fn verity_root(&self) -> &str {
|
||||
&self.toml().verity_root
|
||||
&self.verity_root
|
||||
}
|
||||
|
||||
pub fn verity_salt(&self) -> &str {
|
||||
&self.toml().verity_salt
|
||||
&self.verity_salt
|
||||
}
|
||||
|
||||
pub fn verity_tag(&self) -> String {
|
||||
self.verity_root().chars().take(8).collect()
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user