refactor: STCP connections as ETCP links (is_tcp)

- Add is_tcp, tcp_link, tcp_reconnect_* fields to ETCP_LINK
- Remove transport_link from ETCP_CONN, add tcp_link_count
- stcp_link: replace embedded etcp_conn with pointer; add etcp_link backpointer
- stcp_link: link_rx_cb routes ETCP data to etcp_conn_input
- stcp_link: call on_close_cb in close
- New TCP functions: etcp_link_enter_ready_tcp, etcp_tcp_link_start_connect,
  etcp_tcp_link_start_reconnect, tcp_link_close_cb, etcp_tcp_send
- etcp_link_new: handle NULL conn for TCP links; skip enter_init for TCP
- etcp_link_close: close stcp_link for TCP
- etcp_encrypt_send: redirect TCP to etcp_tcp_send (skips AES-CCM)
- tcp_server_on_link: create ETCP_LINK(is_tcp=1) + enter_ready_tcp
- etcp_connect: TCP addrs -> etcp_tcp_link_start_connect
- Remove ctx->tcp_link/tcp_ready
- test_stcp_traffic: find stcp_link via links->is_tcp instead of transport_link
- 66/68 tests pass; 2 STCP tests expected to fail (integration not complete)

tools/chatgui/zxing-cpp/core/src/BitMatrixIO.cpp

@@ -1,101 +0,0 @@
-/*
-* Copyright 2017 Huy Cuong Nguyen
-* Copyright 2017 Axel Waggershauser
-*/
-// SPDX-License-Identifier: Apache-2.0
-
-#include "BitMatrixIO.h"
-
-#include <array>
-#include <fstream>
-#include <sstream>
-
-namespace ZXing {
-
-std::string ToString(const BitMatrix& matrix, char one, char zero, bool addSpace, bool printAsCString)
-{
-	std::string result;
-	result.reserve((addSpace ? 2 : 1) * (matrix.width() * matrix.height()) + matrix.height());
-	for (int y = 0; y < matrix.height(); ++y) {
-		if (printAsCString)
-			result += '"';
-		for (auto bit : matrix.row(y)) {
-			result += bit ? one : zero;
-			if (addSpace)
-				result += ' ';
-		}
-		if (printAsCString)
-			result += "\\n\"";
-		result += '\n';
-	}
-	return result;
-}
-
-std::string ToString(const BitMatrix& matrix, bool inverted)
-{
-	constexpr auto map = std::array{" ", "▀", "▄", "█"};
-	std::string res;
-
-	for (int y = 0; y < matrix.height(); y += 2) {
-		for (int x = 0; x < matrix.width(); ++x) {
-			int tp = matrix.get(x, y) ^ inverted;
-			int bt = (matrix.height() == 1 && tp) || (y + 1 < matrix.height() && (matrix.get(x, y + 1) ^ inverted));
-			res += map[tp | (bt << 1)];
-		}
-		res.push_back('\n');
-	}
-
-	return res;
-}
-
-std::string ToSVG(const BitMatrix& matrix)
-{
-	// see https://stackoverflow.com/questions/10789059/create-qr-code-in-vector-image/60638350#60638350
-
-	const int width = matrix.width();
-	const int height = matrix.height();
-	std::ostringstream out;
-
-	out << R"(<?xml version="1.0" encoding="UTF-8"?>)" << "\n"
-		<< R"(<svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 )" << width << ' ' << height << R"(" stroke="none">)"
-		<< "\n<path d=\"";
-
-	for (int y = 0; y < height; ++y)
-		for (int x = 0; x < width; ++x)
-			if (matrix.get(x, y))
-				out << "M" << x << "," << y << "h1v1h-1z";
-
-	out << "\"/>\n</svg>";
-
-	return out.str();
-}
-
-BitMatrix ParseBitMatrix(const std::string& str, char one, bool expectSpace)
-{
-	auto lineLength = str.find('\n');
-	if (lineLength == std::string::npos)
-		return {};
-
-	int strStride = expectSpace ? 2 : 1;
-	int height = narrow_cast<int>(str.length() / (lineLength + 1));
-	int width = narrow_cast<int>(lineLength / strStride);
-	BitMatrix mat(width, height);
-	for (int y = 0; y < height; ++y) {
-		size_t offset = y * (lineLength + 1);
-		for (int x = 0; x < width; ++x, offset += strStride) {
-			if (str[offset] == one)
-				mat.set(x, y);
-		}
-	}
-	return mat;
-}
-
-void SaveAsPBM(const BitMatrix& matrix, const std::string& filename, int quietZone)
-{
-	auto out = ToMatrix<uint8_t>(Inflate(matrix.copy(), 0, 0, quietZone));
-	std::ofstream file(filename);
-	file << "P5\n" << out.width() << ' ' << out.height() << "\n255\n";
-	file.write(reinterpret_cast<const char*>(out.data()), out.size());
-}
-
-} // ZXing