3 files changed, 173 insertions, 20 deletions

diff --git a/src/structured_values/index_allocation.rs b/src/structured_values/index_allocation.rs
new file mode 100644
index 0000000..24d9e27
--- /dev/null
+++ b/src/structured_values/index_allocation.rs
@@ -0,0 +1,111 @@
+// Copyright 2021 Colin Finck <colin@reactos.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+use crate::attribute_value::NtfsAttributeValue;
+use crate::error::Result;
+use crate::index_record::NtfsIndexRecord;
+use crate::structured_values::index_root::NtfsIndexRoot;
+use crate::structured_values::NewNtfsStructuredValue;
+use crate::traits::NtfsReadSeek;
+use binread::io::{Read, Seek, SeekFrom};
+use core::iter::FusedIterator;
+
+#[derive(Clone, Debug)]
+pub struct NtfsIndexAllocation<'n> {
+    value: NtfsAttributeValue<'n>,
+}
+
+impl<'n> NtfsIndexAllocation<'n> {
+    pub fn iter(&self, index_root: &NtfsIndexRoot) -> NtfsIndexRecords<'n> {
+        let index_record_size = index_root.index_record_size();
+        NtfsIndexRecords::new(self.value.clone(), index_record_size)
+    }
+}
+
+impl<'n> NewNtfsStructuredValue<'n> for NtfsIndexAllocation<'n> {
+    fn new<T>(_fs: &mut T, value: NtfsAttributeValue<'n>, _length: u64) -> Result<Self>
+    where
+        T: Read + Seek,
+    {
+        Ok(Self { value })
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct NtfsIndexRecords<'n> {
+    value: NtfsAttributeValue<'n>,
+    index_record_size: u32,
+}
+
+impl<'n> NtfsIndexRecords<'n> {
+    fn new(value: NtfsAttributeValue<'n>, index_record_size: u32) -> Self {
+        Self {
+            value,
+            index_record_size,
+        }
+    }
+
+    pub fn attach<'a, T>(self, fs: &'a mut T) -> NtfsIndexRecordsAttached<'n, 'a, T>
+    where
+        T: Read + Seek,
+    {
+        NtfsIndexRecordsAttached::new(fs, self)
+    }
+
+    pub fn next<T>(&mut self, fs: &mut T) -> Option<Result<NtfsIndexRecord<'n>>>
+    where
+        T: Read + Seek,
+    {
+        if self.value.stream_position() >= self.value.len() {
+            return None;
+        }
+
+        // Get the current record.
+        let record = iter_try!(NtfsIndexRecord::new(
+            fs,
+            self.value.clone(),
+            self.index_record_size
+        ));
+
+        // Advance our iterator to the next record.
+        iter_try!(self
+            .value
+            .seek(fs, SeekFrom::Current(self.index_record_size as i64)));
+
+        Some(Ok(record))
+    }
+}
+
+pub struct NtfsIndexRecordsAttached<'n, 'a, T>
+where
+    T: Read + Seek,
+{
+    fs: &'a mut T,
+    index_records: NtfsIndexRecords<'n>,
+}
+
+impl<'n, 'a, T> NtfsIndexRecordsAttached<'n, 'a, T>
+where
+    T: Read + Seek,
+{
+    fn new(fs: &'a mut T, index_records: NtfsIndexRecords<'n>) -> Self {
+        Self { fs, index_records }
+    }
+
+    pub fn detach(self) -> NtfsIndexRecords<'n> {
+        self.index_records
+    }
+}
+
+impl<'n, 'a, T> Iterator for NtfsIndexRecordsAttached<'n, 'a, T>
+where
+    T: Read + Seek,
+{
+    type Item = Result<NtfsIndexRecord<'n>>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.index_records.next(self.fs)
+    }
+}
+
+impl<'n, 'a, T> FusedIterator for NtfsIndexRecordsAttached<'n, 'a, T> where T: Read + Seek {}
diff --git a/src/structured_values/index_root.rs b/src/structured_values/index_root.rs
index 26c7115..5a97cda 100644
--- a/src/structured_values/index_root.rs
+++ b/src/structured_values/index_root.rs
@@ -4,34 +4,67 @@
 use crate::attribute::NtfsAttributeType;
 use crate::attribute_value::NtfsAttributeValue;
 use crate::error::{NtfsError, Result};
+use crate::index_entry::NtfsIndexEntries;
+use crate::index_record::{IndexNodeHeader, INDEX_NODE_HEADER_SIZE};
 use crate::structured_values::NewNtfsStructuredValue;
-use binread::io::{Read, Seek};
+use crate::traits::NtfsReadSeek;
+use binread::io::{Read, Seek, SeekFrom};
 use binread::{BinRead, BinReaderExt};
 
 /// Size of all [`IndexRootHeader`] fields plus some reserved bytes.
-const INDEX_ROOT_HEADER_SIZE: u64 = 32;
-
-#[derive(BinRead, Clone, Debug)]
-struct IndexHeader {
-    entries_offset: u32,
-    index_size: u32,
-    allocated_size: u32,
-    flags: u8,
-}
+const INDEX_ROOT_HEADER_SIZE: u64 = 16;
 
 #[derive(BinRead, Clone, Debug)]
 struct IndexRootHeader {
     ty: u32,
     collation_rule: u32,
-    index_block_size: u32,
-    clusters_per_index_block: i8,
-    reserved: [u8; 3],
-    index: IndexHeader,
+    index_record_size: u32,
+    clusters_per_index_record: i8,
 }
 
 #[derive(Clone, Debug)]
-pub struct NtfsIndexRoot {
-    header: IndexRootHeader,
+pub struct NtfsIndexRoot<'n> {
+    value: NtfsAttributeValue<'n>,
+    index_root_header: IndexRootHeader,
+    index_node_header: IndexNodeHeader,
+}
+
+const LARGE_INDEX_FLAG: u8 = 0x01;
+
+impl<'n> NtfsIndexRoot<'n> {
+    pub fn index_allocated_size(&self) -> u32 {
+        self.index_node_header.allocated_size
+    }
+
+    pub fn entries<K, T>(&self, fs: &mut T) -> Result<NtfsIndexEntries<'n, K>>
+    where
+        K: NewNtfsStructuredValue<'n>,
+        T: Read + Seek,
+    {
+        let offset = self.value.stream_position() + INDEX_ROOT_HEADER_SIZE as u64;
+        let start = offset + self.index_node_header.entries_offset as u64;
+        let end = offset + self.index_used_size() as u64;
+
+        let mut value = self.value.clone();
+        value.seek(fs, SeekFrom::Start(start))?;
+
+        Ok(NtfsIndexEntries::new(value, end))
+    }
+
+    pub fn index_record_size(&self) -> u32 {
+        self.index_root_header.index_record_size
+    }
+
+    pub fn index_used_size(&self) -> u32 {
+        self.index_node_header.index_size
+    }
+
+    /// Returns whether the index belonging to this Index Root is large enough
+    /// to need an extra Index Allocation attribute.
+    /// Otherwise, the entire index information is stored in this Index Root.
+    pub fn is_large_index(&self) -> bool {
+        (self.index_node_header.flags & LARGE_INDEX_FLAG) != 0
+    }
 }
 
 impl<'n> NewNtfsStructuredValue<'n> for NtfsIndexRoot<'n> {
@@ -39,7 +72,7 @@ impl<'n> NewNtfsStructuredValue<'n> for NtfsIndexRoot<'n> {
     where
         T: Read + Seek,
     {
-        if value.len() < INDEX_ROOT_HEADER_SIZE {
+        if value.len() < INDEX_ROOT_HEADER_SIZE + INDEX_NODE_HEADER_SIZE {
             return Err(NtfsError::InvalidStructuredValueSize {
                 position: value.data_position().unwrap(),
                 ty: NtfsAttributeType::IndexRoot,
@@ -49,8 +82,14 @@ impl<'n> NewNtfsStructuredValue<'n> for NtfsIndexRoot<'n> {
         }
 
         let mut value_attached = value.clone().attach(fs);
-        let header = value_attached.read_le::<IndexRootHeader>()?;
+        let index_root_header = value_attached.read_le::<IndexRootHeader>()?;
+        value_attached.seek(SeekFrom::Start(INDEX_ROOT_HEADER_SIZE))?;
+        let index_node_header = value_attached.read_le::<IndexNodeHeader>()?;
 
-        Ok(Self { header })
+        Ok(Self {
+            value,
+            index_root_header,
+            index_node_header,
+        })
     }
 }
diff --git a/src/structured_values/mod.rs b/src/structured_values/mod.rs
index 9fb743d..b61f24b 100644
--- a/src/structured_values/mod.rs
+++ b/src/structured_values/mod.rs
@@ -3,6 +3,7 @@
 
 mod attribute_list;
 mod file_name;
+mod index_allocation;
 mod index_root;
 mod object_id;
 mod security_descriptor;
@@ -12,6 +13,7 @@ mod volume_name;
 
 pub use attribute_list::*;
 pub use file_name::*;
+pub use index_allocation::*;
 pub use index_root::*;
 pub use object_id::*;
 pub use security_descriptor::*;
@@ -49,7 +51,8 @@ pub enum NtfsStructuredValue<'n> {
     ObjectId(NtfsObjectId),
     VolumeInformation(NtfsVolumeInformation),
     VolumeName(NtfsVolumeName<'n>),
-    IndexRoot(NtfsIndexRoot),
+    IndexRoot(NtfsIndexRoot<'n>),
+    IndexAllocation(NtfsIndexAllocation<'n>),
 }
 
 pub trait NewNtfsStructuredValue<'n>: Sized {