zig-squashfs/inode.zig

const std = @import("std");

pub const InodeRef = packed struct {
    offset: u16,
    block_start: u32,
    _: u16,
};

pub const InodeType = enum(u16) {
    dir = 1,
    file,
    symlink,
    block_device,
    char_device,
    fifo,
    socket,
    ext_dir,
    ext_file,
    ext_symlink,
    ext_block_device,
    ext_char_device,
    ext_fifo,
    ext_socket,
};

pub const InodeHeader = packed struct {
    inode_type: InodeType,
    perm: u16,
    uid_index: u16,
    gid_index: u16,
    mod_time: u32,
    inode_num: u32,
};

pub const InodeData = union(enum) {
    dir: dir.DirInode,
    file: file.FileInode,
    symlink: sym.SymlinkInode,
    block_device: misc.DeviceInode,
    char_device: misc.DeviceInode,
    fifo: misc.IPCInode,
    socket: misc.IPCInode,
    ext_dir: dir.ExtDirInode,
    ext_file: file.ExtFileInode,
    ext_symlink: sym.ExtSymlinkInode,
    ext_block_device: misc.ExtDeviceInode,
    ext_char_device: misc.ExtDeviceInode,
    ext_fifo: misc.ExtIPCInode,
    ext_socket: misc.ExtIPCInode,
};

const dir = @import("inode_types/dir.zig");
const file = @import("inode_types/file.zig");
const sym = @import("inode_types/sym.zig");
const misc = @import("inode_types/misc.zig");

pub const Inode = struct {
    header: InodeHeader,
    data: InodeData,
};

const io = @import("std").io;

pub fn readInode(rdr: io.AnyReader, block_size: u32, alloc: std.mem.Allocator) !Inode {
    const hdr = try rdr.readStruct(InodeHeader);
    return Inode{
        .header = hdr,
        .data = switch (hdr.inode_type) {
            .dir => .{
                .dir = try .init(rdr),
            },
            .ext_dir => .{
                .ext_dir = try .init(rdr, alloc),
            },
            .file => .{
                .file = try .init(rdr, block_size, alloc),
            },
            .ext_file => .{
                .ext_file = try .init(rdr, block_size, alloc),
            },
            .symlink => .{
                .symlink = try .init(rdr, alloc),
            },
            .ext_symlink => .{
                .ext_symlink = try .init(rdr, alloc),
            },
            .block_device => .{
                .block_device = try rdr.readStruct(misc.DeviceInode),
            },
            .ext_block_device => .{
                .ext_block_device = try rdr.readStruct(misc.ExtDeviceInode),
            },
            .char_device => .{
                .char_device = try rdr.readStruct(misc.DeviceInode),
            },
            .ext_char_device => .{
                .ext_char_device = try rdr.readStruct(misc.ExtDeviceInode),
            },
            .fifo => .{
                .fifo = try rdr.readStruct(misc.IPCInode),
            },
            .ext_fifo => .{
                .ext_fifo = try rdr.readStruct(misc.ExtIPCInode),
            },
            .socket => .{
                .socket = try rdr.readStruct(misc.IPCInode),
            },
            .ext_socket => .{
                .ext_socket = try rdr.readStruct(misc.ExtIPCInode),
            },
        },
    };
}