Further work on inode decoding

inode.zig

@@ -1,3 +1,5 @@
+const std = @import("std");
+
 pub const InodeRef = packed struct {
     _: u16,
     block_start: u32,
@@ -52,14 +54,14 @@ const file = @import("inode_types/file.zig");
 const sym = @import("inode_types/sym.zig");
 const misc = @import("inode_types/misc.zig");
 
-const Inode = struct {
+pub const Inode = struct {
     header: InodeHeader,
     data: InodeData,
 };
 
 const io = @import("std").io;
 
-pub fn readInode(rdr: io.AnyReader, block_size: u64) !Inode {
+pub fn readInode(rdr: io.AnyReader, block_size: u64, alloc: std.heap.Allocator) !Inode {
     const hdr = try rdr.readStruct(InodeHeader);
     const data: InodeData = undefined;
     switch (hdr.inode_type) {
@@ -67,19 +69,19 @@ pub fn readInode(rdr: io.AnyReader, block_size: u64) !Inode {
             .dir = dir.readDirInode(rdr),
         },
         .ext_dir => data = .{
-            .ext_dir = try dir.readExtDirInode(rdr),
+            .ext_dir = try dir.readExtDirInode(rdr, alloc),
         },
         .file => data = .{
-            .file = try file.readFileInode(rdr, block_size),
+            .file = try file.readFileInode(rdr, block_size, alloc),
         },
         .ext_file => data = .{
-            .ext_file = try file.readExtFileInode(rdr, block_size),
+            .ext_file = try file.readExtFileInode(rdr, block_size, alloc),
         },
         .symlink => data = .{
-            .block_device = try misc.readSymlinkInode(rdr),
+            .block_device = try misc.readSymlinkInode(rdr, alloc),
         },
         .ext_symlink => data = .{
-            .ext_symlink = try sym.readExtSymlinkInode(rdr),
+            .ext_symlink = try sym.readExtSymlinkInode(rdr, alloc),
         },
     }
     return Inode{

inode_types/dir.zig

@@ -20,17 +20,15 @@ pub const DirIndex = struct {
     name: []const u8,
 };
 
-fn readDirIndex(rdr: io.AnyReader) !DirIndex {
+fn readDirIndex(rdr: io.AnyReader, alloc: std.heap.Allocator) !DirIndex {
     const out = DirIndex{
         .dir_header_offset = try rdr.readInt(u32, std.builtin.Endian.little),
         .dir_table_offset = try rdr.readInt(u32, std.builtin.Endian.little),
         .name_size = try rdr.readInt(u32, std.builtin.Endian.little),
         .name = undefined,
     };
-    const buf = try std.heap.page_allocator.alloc(u8, out.name_size);
-    defer std.heap.page_allocator.free(buf);
-    try rdr.read(buf);
-    out.name = buf[0..];
+    out.name = try alloc.alloc(u8, out.name_size);
+    try rdr.read(out.name);
     return out;
 }
 
@@ -45,7 +43,7 @@ pub const ExtDirInode = struct {
     indexes: []const DirIndex,
 };
 
-pub fn readExtDirInode(rdr: io.AnyReader) !ExtDirInode {
+pub fn readExtDirInode(rdr: io.AnyReader, alloc: std.heap.Allocator) !ExtDirInode {
     const out = ExtDirInode{
         .hard_links = rdr.readInt(u32, std.builtin.Endian.little),
         .dir_table_size = rdr.readInt(u32, std.builtin.Endian.little),
@@ -56,10 +54,12 @@ pub fn readExtDirInode(rdr: io.AnyReader) !ExtDirInode {
         .xattr_index = rdr.readInt(u32, std.builtin.Endian.little),
         .indexes = undefined,
     };
-    out.indexes = []const DirIndex{undefined} ** out.dir_index_count;
+    const tmp = std.ArrayList(DirIndex).init(alloc);
+    try tmp.resize(out.dir_index_count);
     const i: u16 = 0;
     while (i < out.dir_index_count) : (i += 1) {
-        out.indexes[i] = try readDirIndex(rdr);
+        tmp.items[i] = try readDirIndex(rdr, alloc);
     }
+    out.indexes = tmp.items;
     return out;
 }

inode_types/file.zig

@@ -8,7 +8,7 @@ pub const FileInode = struct {
     block_sizes: []const u32,
 };
 
-pub fn readFileInode(rdr: std.io.AnyReader, block_size: u32) !FileInode {
+pub fn readFileInode(rdr: std.io.AnyReader, block_size: u32, alloc: std.heap.Allocator) !FileInode {
     const out = FileInode{
         .start = try rdr.readInt(u32, std.builtin.Endian.little),
         .frag_index = try rdr.readInt(u32, std.builtin.Endian.little),
@@ -17,9 +17,11 @@ pub fn readFileInode(rdr: std.io.AnyReader, block_size: u32) !FileInode {
         .block_sizes = undefined,
     };
     var block_num = out.size / block_size;
-    if (out.frag_index != 0xFFFFFFFF and out.size % block_size != 0) {
+    if (out.frag_index != 0xFFFFFFFF) {
         block_num += 1;
     }
+    out.block_sizes = try alloc.alloc(u32, block_num);
+    try rdr.read(std.mem.asBytes(&out.block_sizes));
     return out;
 }
 
@@ -34,7 +36,7 @@ pub const ExtFileInode = struct {
     block_sizes: []const u32,
 };
 
-pub fn readExtFileInode(rdr: std.io.AnyReader, block_size: u32) !ExtFileInode {
+pub fn readExtFileInode(rdr: std.io.AnyReader, block_size: u32, alloc: std.heap.Allocator) !ExtFileInode {
     const out = ExtFileInode{
         .start = try rdr.readInt(u64, std.builtin.Endian.little),
         .size = try rdr.readInt(u64, std.builtin.Endian.little),
@@ -49,6 +51,7 @@ pub fn readExtFileInode(rdr: std.io.AnyReader, block_size: u32) !ExtFileInode {
     if (out.frag_index != 0xFFFFFFFF and out.size % block_size != 0) {
         block_num += 1;
     }
-    //TODO: stuff
+    out.block_sizes = try alloc.alloc(u32, block_num);
+    try rdr.read(std.mem.asBytes(&out.block_sizes));
     return out;
 }

inode_types/sym.zig

@@ -7,13 +7,14 @@ pub const SymlinkInode = struct {
     path: []const u8,
 };
 
-pub fn readSymlinkInode(rdr: io.AnyReader) !SymlinkInode {
+pub fn readSymlinkInode(rdr: io.AnyReader, alloc: std.heap.Allocator) !SymlinkInode {
     const out = SymlinkInode{
         .hard_links = try rdr.readInt(u32, std.builtin.Endian.little),
         .target_size = try rdr.readInt(u32, std.builtin.Endian.little),
         .path = undefined,
     };
-    out.path = (try rdr.readBoundedBytes(out.target_size + 1)).constSlice();
+    out.path = try alloc.alloc(u8, out.target_size + 1);
+    try rdr.read(out.path);
     return out;
 }
 
@@ -24,14 +25,15 @@ pub const ExtSymlinkInode = struct {
     xattr_index: u32,
 };
 
-pub fn readExtSymlinkInode(rdr: io.AnyReader) !SymlinkInode {
+pub fn readExtSymlinkInode(rdr: io.AnyReader, alloc: std.heap.Allocator) !SymlinkInode {
     const out = ExtSymlinkInode{
         .hard_links = try rdr.readInt(u32, std.builtin.Endian.little),
         .target_size = try rdr.readInt(u32, std.builtin.Endian.little),
         .path = undefined,
         .xattr_index = undefined,
     };
-    out.path = (try rdr.readBoundedBytes(out.target_size + 1)).constSlice();
+    out.path = try alloc.alloc(u8, out.target_size + 1);
+    try rdr.read(out.path);
     out.xattr_index = try rdr.readInt(u32, std.builtin.Endian.little);
     return out;
 }

squashfs.zig

@@ -1,17 +1,32 @@
 const std = @import("std");
-const io = std.io;
+const fs = std.fs;
+
 const Superblock = @import("superblock.zig").Superblock;
+const Inode = @import("inode.zig").Inode;
 
 pub const Reader = struct {
     super: Superblock,
-    rdr: io.AnyReader,
+    rdr: fs.File,
+    root: Inode,
+    alloc: std.heap.GeneralPurposeAllocator(.{}),
+
+    pub fn close(self: Reader) void {
+        self.rdr.close();
+        self.alloc.deinit();
+    }
 };
 
-pub fn newReader(rdr: io.AnyReader) !Reader {
-    const super = try rdr.readStruct(Superblock);
+pub fn newReader(filename: []const u8) !Reader {
+    const file = try std.fs.cwd().openFile(filename, .{});
+    errdefer file.close();
+    const alloc = std.heap.GeneralPurposeAllocator(.{});
+    errdefer alloc.deinit();
+    const super = try file.reader().readStruct(Superblock);
     try super.valid();
+
     return Reader{
         .super = super,
-        .rdr = rdr,
+        .rdr = file,
+        .alloc = alloc,
     };
-}
+}

test_squashfs.zig

@@ -5,11 +5,6 @@ const squashfs = @import("squashfs.zig");
 const testFileName = "testing/LinuxPATest.sfs";
 
 test "open test file" {
-    const testFile = try std.fs.cwd().openFile(
-        testFileName,
-        .{},
-    );
-    defer testFile.close();
-    const reader = try squashfs.newReader(testFile.reader().any());
-    _ = reader;
+    const reader = try squashfs.newReader(testFileName);
+    defer reader.close();
 }