@@ -1,3 +1,7 @@
pub const Domains = struct {
strings: std.ArrayListUnmanaged(u8),
};
pub const Message = struct {
header: Header,
question: ?[]Question = null,
@@ -38,11 +42,11 @@ pub const Message = struct {
return .{
.id = id,
.qr = 0x80 & hbits != 0,
.opcode = 0,
.opcode = @truncate((0x70 & hbits) >> 3),
.aa = 0x4 & hbits != 0,
.tc = 0x2 & hbits != 0,
.rd = 0x1 & hbits != 0,
.ra = 0x8 & hbits != 0,
.ra = 0x80 & lbits != 0,
.rcode = @enumFromInt(0xf & (lbits)),
.qdcount = @byteSwap(@as(u16, @bitCast(bytes[4..6].*))),
.ancount = @byteSwap(@as(u16, @bitCast(bytes[6..8].*))),
@@ -82,6 +86,42 @@ pub const Message = struct {
try w.writeInt(u16, @intFromEnum(q.qtype), .big);
try w.writeInt(u16, @intFromEnum(q.class), .big);
}
pub fn fromBytes(a: Allocator, bytes: []const u8) !Question {
const end = indexOfScalar(u8, bytes, 0) orelse return error.InvalidQuestion;
if (bytes.len < end + 4) return error.InvalidQuestion;
const qtype: Type = @enumFromInt(@byteSwap(@as(u16, bytes[end + 1 .. end + 3].*)));
const class: Class = @enumFromInt(@byteSwap(@as(u16, bytes[end + 3 .. end + 5].*)));
var idx: usize = 0;
var count: usize = 0;
sw: switch (bytes[idx]) {
0...63 => |b| {
count += 1;
idx += b + 1;
if (idx >= bytes.len) return error.InvalidLabel;
continue :sw bytes[idx];
},
192...255 => |b| {
count += 1;
idx += 2;
if (idx >= bytes.len) return error.InvalidLabel;
const offset: u16 = b & 0b111111 << 8 | bytes[idx - 1];
if (offset >= bytes.len) return error.InvalidLabel;
count += 1;
continue :sw bytes[idx];
},
else => return error.InvalidLabel,
}
const labels = try a.alloc(Label, count);
return .{
.name = labels,
.qtype = qtype,
.class = class,
};
}
};
pub const Resource = struct {
@@ -308,3 +348,4 @@ test "fuzz example" {
const std = @import("std");
const log = std.log;
const Allocator = std.mem.Allocator;
const indexOfScalar = std.mem.indexOfScalar;