Belac/zig-squashfs
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Inode parsing works!

Browse Source
This commit is contained in:
Caleb Gardner
2025-05-14 05:16:12 -05:00
parent 3684a958a0
commit b0c71c59f8
5 changed files with 64 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files
inode.zig
+4 -4
View File
@@ -1,9 +1,9 @@
const std = @import("std");
pub const InodeRef = packed struct {
_: u16,
block_start: u32,
offset: u16,
block_start: u32,
_: u16,
};
pub const InodeType = enum(u16) {
@@ -67,10 +67,10 @@ pub fn readInode(rdr: io.AnyReader, block_size: u32, alloc: std.mem.Allocator) !
.header = hdr,
.data = switch (hdr.inode_type) {
.dir => .{
.dir = try dir.readDirInode(rdr),
.dir = try .init(rdr),
},
.ext_dir => .{
.ext_dir = try dir.readExtDirInode(rdr, alloc),
.ext_dir = try .init(rdr, alloc),
},
.file => .{
.file = try file.readFileInode(rdr, block_size, alloc),
inode_types/dir.zig
+36 -36
View File
@@ -7,30 +7,30 @@ pub const DirInode = packed struct {
dir_table_size: u16,
dir_block_offset: u16,
parent_inode_num: u32,
};
pub fn readDirInode(rdr: io.AnyReader) !DirInode {
return try rdr.readStruct(DirInode);
}
pub fn init(rdr: io.AnyReader) !DirInode {
return try rdr.readStruct(DirInode);
}
};
pub const DirIndex = struct {
dir_header_offset: u32,
dir_table_offset: u32,
name_size: u32,
name: []u8,
};
fn readDirIndex(rdr: io.AnyReader, alloc: std.mem.Allocator) !DirIndex {
var 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,
};
out.name = try alloc.alloc(u8, out.name_size);
_ = try rdr.readAll(out.name);
return out;
}
pub fn init(rdr: io.AnyReader, alloc: std.mem.Allocator) !DirIndex {
var 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,
};
out.name = try alloc.alloc(u8, out.name_size);
_ = try rdr.readAll(out.name);
return out;
}
};
pub const ExtDirInode = struct {
hard_links: u32,
@@ -41,25 +41,25 @@ pub const ExtDirInode = struct {
dir_block_offset: u16,
xattr_index: u32,
indexes: []DirIndex,
};
pub fn readExtDirInode(rdr: io.AnyReader, alloc: std.mem.Allocator) !ExtDirInode {
var out = ExtDirInode{
.hard_links = try rdr.readInt(u32, std.builtin.Endian.little),
.dir_table_size = try rdr.readInt(u32, std.builtin.Endian.little),
.dir_block_start = try rdr.readInt(u32, std.builtin.Endian.little),
.parent_inode_num = try rdr.readInt(u32, std.builtin.Endian.little),
.dir_index_count = try rdr.readInt(u16, std.builtin.Endian.little),
.dir_block_offset = try rdr.readInt(u16, std.builtin.Endian.little),
.xattr_index = try rdr.readInt(u32, std.builtin.Endian.little),
.indexes = undefined,
};
var tmp = std.ArrayList(DirIndex).init(alloc);
try tmp.resize(out.dir_index_count);
var i: u16 = 0;
while (i < out.dir_index_count) : (i += 1) {
tmp.items[i] = try readDirIndex(rdr, alloc);
pub fn init(rdr: io.AnyReader, alloc: std.mem.Allocator) !ExtDirInode {
var out = ExtDirInode{
.hard_links = try rdr.readInt(u32, std.builtin.Endian.little),
.dir_table_size = try rdr.readInt(u32, std.builtin.Endian.little),
.dir_block_start = try rdr.readInt(u32, std.builtin.Endian.little),
.parent_inode_num = try rdr.readInt(u32, std.builtin.Endian.little),
.dir_index_count = try rdr.readInt(u16, std.builtin.Endian.little),
.dir_block_offset = try rdr.readInt(u16, std.builtin.Endian.little),
.xattr_index = try rdr.readInt(u32, std.builtin.Endian.little),
.indexes = undefined,
};
var tmp = std.ArrayList(DirIndex).init(alloc);
try tmp.resize(out.dir_index_count);
var i: u16 = 0;
while (i < out.dir_index_count) : (i += 1) {
tmp.items[i] = try .init(rdr, alloc);
}
out.indexes = tmp.items;
return out;
}
out.indexes = tmp.items;
return out;
}
};
metadata_reader.zig
+15 -3
View File
@@ -4,8 +4,8 @@ const io = std.io;
const CompressionType = @import("decompress.zig").CompressionType;
const MetadataHeader = packed struct {
not_compressed: bool,
size: u15,
not_compressed: bool,
};
pub const MetadataReader = struct {
@@ -14,6 +14,7 @@ pub const MetadataReader = struct {
decomp: CompressionType,
curBlock: []u8,
curOffset: u16,
free: bool = false,
pub fn init(decomp: CompressionType, rdr: io.AnyReader, alloc: std.mem.Allocator) !MetadataReader {
var out: MetadataReader = .{
@@ -26,12 +27,25 @@ pub const MetadataReader = struct {
try out.readNextBlock();
return out;
}
pub fn deinit(self: *MetadataReader) void {
self.alloc.free(self.curBlock);
}
pub fn any(self: *MetadataReader) io.AnyReader {
return .{
.context = @ptrCast(self),
.readFn = readOpaque,
};
}
pub fn skip(self: *MetadataReader, offset: u16) !void {
var to_skip = offset;
var cur_left = self.curBlock.len - self.curOffset;
while (to_skip > cur_left) {
to_skip -= @intCast(cur_left);
try self.readNextBlock();
cur_left = self.curBlock.len;
}
self.curOffset = to_skip;
}
fn readNextBlock(self: *MetadataReader) !void {
if (self.curBlock.len != 0) {
@@ -52,12 +66,10 @@ pub const MetadataReader = struct {
var cur_read: usize = 0;
var to_read: usize = 0;
while (cur_read < bytes.len) {
std.debug.print("hello there!, {}\n", .{cur_read});
if (self.curOffset + 1 == self.curBlock.len) {
try self.readNextBlock();
}
to_read = @min(bytes.len - cur_read, self.curBlock.len - self.curOffset);
std.debug.print("{} {} {}\n", .{ cur_read, to_read, self.curOffset });
std.mem.copyForwards(u8, bytes[cur_read..], self.curBlock[self.curOffset .. self.curOffset + to_read]);
self.curOffset += @truncate(to_read);
cur_read += to_read;
squashfs.zig
+6 -4
View File
@@ -9,23 +9,25 @@ pub const Reader = struct {
super: Superblock,
rdr: fs.File,
root: inode.Inode,
alloc: std.heap.GeneralPurposeAllocator(.{}),
alloc: std.heap.ArenaAllocator,
pub fn close(self: *Reader) void {
pub fn deinit(self: *Reader) void {
self.rdr.close();
_ = self.alloc.deinit();
self.alloc.deinit();
}
};
pub fn newReader(filename: []const u8) !Reader {
const file = try std.fs.cwd().openFile(filename, .{});
errdefer file.close();
var alloc: std.heap.GeneralPurposeAllocator(.{}) = .init;
var alloc: std.heap.ArenaAllocator = .init(std.heap.page_allocator);
errdefer _ = alloc.deinit();
const super = try file.reader().readStruct(Superblock);
try super.valid();
try file.seekTo(super.inode_table + super.root_inode.block_start);
var root_reader: MetadataReader = try .init(super.comp, file.reader().any(), alloc.allocator());
defer root_reader.deinit();
try root_reader.skip(super.root_inode.offset);
const root_inode = try inode.readInode(root_reader.any(), super.block_size, alloc.allocator());
return Reader{
.super = super,
test_squashfs.zig
+3 -1
View File
@@ -1,10 +1,12 @@
const std = @import("std");
const debug = std.debug;
const squashfs = @import("squashfs.zig");
const print = std.debug.print;
const testFileName = "testing/LinuxPATest.sfs";
test "open test file" {
var reader = try squashfs.newReader(testFileName);
defer reader.close();
defer reader.deinit();
print("{}\n", .{reader.root});
}