1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
const is_debug = builtin.mode == .Debug;
const base64Enc = std.base64.Base64Encoder.init(std.base64.standard_alphabet_chars, '=');
const base64Dec = std.base64.Base64Decoder.init(std.base64.standard_alphabet_chars, '=');
const SaprusPacketType = enum(u16) {
relay = 0x003C,
file_transfer = 0x8888,
connection = 0x00E9,
_,
};
const SaprusConnectionOptions = packed struct(u8) {
opt1: bool = false,
opt2: bool = false,
opt3: bool = false,
opt4: bool = false,
opt5: bool = false,
opt6: bool = false,
opt7: bool = false,
opt8: bool = false,
};
const SaprusError = error{
NotImplementedSaprusType,
UnknownSaprusType,
};
const SaprusMessage = union(SaprusPacketType) {
const Relay = struct {
const Header = packed struct {
dest: @Vector(4, u8),
};
header: Header,
payload: []const u8,
};
const Connection = struct {
const Header = packed struct {
src_port: u16,
dest_port: u16,
seq_num: u32 = 0,
msg_id: u32 = 0,
reserved: u8 = 0,
options: SaprusConnectionOptions = .{},
};
header: Header,
payload: []const u8,
};
relay: Relay,
file_transfer: void, // unimplemented
connection: Connection,
fn deinit(self: SaprusMessage, allocator: Allocator) void {
switch (self) {
.relay => |r| allocator.free(r.payload),
.connection => |c| allocator.free(c.payload),
else => unreachable,
}
}
fn toBytes(self: SaprusMessage, allocator: Allocator) ![]u8 {
var buf = std.ArrayList(u8).init(allocator);
const w = buf.writer();
try w.writeInt(u16, @intFromEnum(self), .big);
switch (self) {
.relay => |r| try toBytesAux(Relay.Header, r.header, r.payload, w, allocator),
.connection => |c| try toBytesAux(Connection.Header, c.header, c.payload, w, allocator),
.file_transfer => return SaprusError.NotImplementedSaprusType,
}
return buf.toOwnedSlice();
}
fn fromBytes(bytes: []const u8, allocator: Allocator) !SaprusMessage {
var s = std.io.fixedBufferStream(bytes);
const r = s.reader();
switch (@as(SaprusPacketType, @enumFromInt(try r.readInt(u16, .big)))) {
.relay => return fromBytesAux(.relay, Relay.Header, r, allocator),
.connection => return fromBytesAux(.connection, Connection.Header, r, allocator),
.file_transfer => return SaprusError.NotImplementedSaprusType,
else => return SaprusError.UnknownSaprusType,
}
}
};
inline fn toBytesAux(
Header: type,
header: Header,
payload: []const u8,
w: std.ArrayList(u8).Writer,
allocator: Allocator,
) !void {
const payload_list = try encodeToList(payload, allocator);
defer payload_list.deinit();
try w.writeStructEndian(header, .big);
try w.writeInt(u16, @intCast(payload_list.items.len), .big);
try w.writeAll(payload_list.items);
}
inline fn fromBytesAux(
packet: SaprusPacketType,
Header: type,
r: StringReader,
allocator: Allocator,
) !SaprusMessage {
const header = try r.readStructEndian(Header, .big);
const len = try r.readInt(u16, .big);
const payload = try decodeFromReader(r, len, allocator);
return @unionInit(SaprusMessage, @tagName(packet), .{
.header = header,
.payload = payload,
});
}
pub fn main() !void {
var dba: ?DebugAllocator = if (comptime is_debug) DebugAllocator.init else null;
defer if (dba) |*d| {
_ = d.deinit();
};
var gpa = if (dba) |*d| d.allocator() else std.heap.smp_allocator;
const msg = SaprusMessage{
.relay = .{
.header = .{ .dest = .{ 255, 255, 255, 255 } },
.payload = "Hello darkness my old friend",
},
};
const msg_bytes = try msg.toBytes(gpa);
defer gpa.free(msg_bytes);
try network.init();
defer network.deinit();
var sock = try network.Socket.create(.ipv4, .udp);
defer sock.close();
try sock.setBroadcast(true);
// Bind to 0.0.0.0:0
const bind_addr = network.EndPoint{
.address = network.Address{ .ipv4 = network.Address.IPv4.any },
.port = 0,
};
const dest_addr = network.EndPoint{
.address = network.Address{ .ipv4 = network.Address.IPv4.broadcast },
.port = 8888,
};
try sock.bind(bind_addr);
_ = try sock.sendTo(dest_addr, msg_bytes);
}
fn encodeToList(buf: []const u8, allocator: Allocator) !std.ArrayList(u8) {
var b64_buf = std.ArrayList(u8).init(allocator);
const buf_w = b64_buf.writer();
try base64Enc.encodeWriter(buf_w, buf);
return b64_buf;
}
fn decodeFromReader(reader: StringReader, len: u16, allocator: Allocator) ![]const u8 {
var b64_buf = std.ArrayList(u8).init(allocator);
defer b64_buf.deinit();
try reader.readAllArrayList(&b64_buf, len);
const payload = try allocator.alloc(u8, try base64Dec.calcSizeForSlice(b64_buf.items));
try base64Dec.decode(payload, b64_buf.items);
return payload;
}
const builtin = @import("builtin");
const std = @import("std");
const Allocator = std.mem.Allocator;
const DebugAllocator = std.heap.DebugAllocator(.{});
const StringReader = std.io.FixedBufferStream([]const u8).Reader;
const network = @import("network");
test "Round trip Relay toBytes and fromBytes" {
const gpa = std.testing.allocator;
const msg = SaprusMessage{
.relay = .{
.header = .{ .dest = .{ 255, 255, 255, 255 } },
.payload = "Hello darkness my old friend",
},
};
const to_bytes = try msg.toBytes(gpa);
defer gpa.free(to_bytes);
const from_bytes = try SaprusMessage.fromBytes(to_bytes, gpa);
defer from_bytes.deinit(gpa);
try std.testing.expectEqualDeep(msg, from_bytes);
}
test "Round trip Connection toBytes and fromBytes" {
const gpa = std.testing.allocator;
const msg = SaprusMessage{
.connection = .{
.header = .{
.src_port = 0,
.dest_port = 0,
},
.payload = "Hello darkness my old friend",
},
};
const to_bytes = try msg.toBytes(gpa);
defer gpa.free(to_bytes);
const from_bytes = try SaprusMessage.fromBytes(to_bytes, gpa);
defer from_bytes.deinit(gpa);
try std.testing.expectEqualDeep(msg, from_bytes);
}
|
