/** * libdatachannel client example * Copyright (c) 2019-2020 Paul-Louis Ageneau * Copyright (c) 2019 Murat Dogan * Copyright (c) 2020 Will Munn * Copyright (c) 2020 Nico Chatzi * Copyright (c) 2020 Lara Mackey * Copyright (c) 2020 Erik Cota-Robles * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ #include "rtc/rtc.hpp" #include "parse_cl.h" #include #include #include #include #include #include #include #include #include #include using namespace std::chrono_literals; using std::shared_ptr; using std::weak_ptr; template weak_ptr make_weak_ptr(shared_ptr ptr) { return ptr; } using nlohmann::json; std::string localId; std::unordered_map> peerConnectionMap; std::unordered_map> dataChannelMap; shared_ptr createPeerConnection(const rtc::Configuration &config, weak_ptr wws, std::string id); std::string randomId(size_t length); int main(int argc, char **argv) try { Cmdline params(argc, argv); rtc::InitLogger(rtc::LogLevel::Info); rtc::Configuration config; std::string stunServer = ""; if (params.noStun()) { std::cout << "No STUN server is configured. Only local hosts and public IP addresses supported." << std::endl; } else { if (params.stunServer().substr(0, 5).compare("stun:") != 0) { stunServer = "stun:"; } stunServer += params.stunServer() + ":" + std::to_string(params.stunPort()); std::cout << "STUN server is " << stunServer << std::endl; config.iceServers.emplace_back(stunServer); } if (params.udpMux()) { std::cout << "ICE UDP mux enabled" << std::endl; config.enableIceUdpMux = true; } localId = randomId(4); std::cout << "The local ID is " << localId << std::endl; auto ws = std::make_shared(); std::promise wsPromise; auto wsFuture = wsPromise.get_future(); ws->onOpen([&wsPromise]() { std::cout << "WebSocket connected, signaling ready" << std::endl; wsPromise.set_value(); }); ws->onError([&wsPromise](std::string s) { std::cout << "WebSocket error" << std::endl; wsPromise.set_exception(std::make_exception_ptr(std::runtime_error(s))); }); ws->onClosed([]() { std::cout << "WebSocket closed" << std::endl; }); ws->onMessage([&config, wws = make_weak_ptr(ws)](auto data) { // data holds either std::string or rtc::binary if (!std::holds_alternative(data)) return; json message = json::parse(std::get(data)); auto it = message.find("id"); if (it == message.end()) return; auto id = it->get(); it = message.find("type"); if (it == message.end()) return; auto type = it->get(); shared_ptr pc; if (auto jt = peerConnectionMap.find(id); jt != peerConnectionMap.end()) { pc = jt->second; } else if (type == "offer") { std::cout << "Answering to " + id << std::endl; pc = createPeerConnection(config, wws, id); } else { return; } if (type == "offer" || type == "answer") { auto sdp = message["description"].get(); pc->setRemoteDescription(rtc::Description(sdp, type)); } else if (type == "candidate") { auto sdp = message["candidate"].get(); auto mid = message["mid"].get(); pc->addRemoteCandidate(rtc::Candidate(sdp, mid)); } }); const std::string wsPrefix = params.webSocketServer().find("://") == std::string::npos ? "ws://" : ""; const std::string url = wsPrefix + params.webSocketServer() + ":" + std::to_string(params.webSocketPort()) + "/" + localId; std::cout << "WebSocket URL is " << url << std::endl; ws->open(url); std::cout << "Waiting for signaling to be connected..." << std::endl; wsFuture.get(); while (true) { std::string id; std::cout << "Enter a remote ID to send an offer:" << std::endl; std::cin >> id; std::cin.ignore(); if (id.empty()) break; if (id == localId) { std::cout << "Invalid remote ID (This is the local ID)" << std::endl; continue; } std::cout << "Offering to " + id << std::endl; auto pc = createPeerConnection(config, ws, id); // We are the offerer, so create a data channel to initiate the process const std::string label = "test"; std::cout << "Creating DataChannel with label \"" << label << "\"" << std::endl; auto dc = pc->createDataChannel(label); dc->onOpen([id, wdc = make_weak_ptr(dc)]() { std::cout << "DataChannel from " << id << " open" << std::endl; if (auto dc = wdc.lock()) dc->send("Hello from " + localId); }); dc->onClosed([id]() { std::cout << "DataChannel from " << id << " closed" << std::endl; }); dc->onMessage([id, wdc = make_weak_ptr(dc)](auto data) { // data holds either std::string or rtc::binary if (std::holds_alternative(data)) std::cout << "Message from " << id << " received: " << std::get(data) << std::endl; else std::cout << "Binary message from " << id << " received, size=" << std::get(data).size() << std::endl; }); dataChannelMap.emplace(id, dc); } std::cout << "Cleaning up..." << std::endl; dataChannelMap.clear(); peerConnectionMap.clear(); return 0; } catch (const std::exception &e) { std::cout << "Error: " << e.what() << std::endl; dataChannelMap.clear(); peerConnectionMap.clear(); return -1; } // Create and setup a PeerConnection shared_ptr createPeerConnection(const rtc::Configuration &config, weak_ptr wws, std::string id) { auto pc = std::make_shared(config); pc->onStateChange( [](rtc::PeerConnection::State state) { std::cout << "State: " << state << std::endl; }); pc->onGatheringStateChange([](rtc::PeerConnection::GatheringState state) { std::cout << "Gathering State: " << state << std::endl; }); pc->onLocalDescription([wws, id](rtc::Description description) { json message = {{"id", id}, {"type", description.typeString()}, {"description", std::string(description)}}; if (auto ws = wws.lock()) ws->send(message.dump()); }); pc->onLocalCandidate([wws, id](rtc::Candidate candidate) { json message = {{"id", id}, {"type", "candidate"}, {"candidate", std::string(candidate)}, {"mid", candidate.mid()}}; if (auto ws = wws.lock()) ws->send(message.dump()); }); pc->onDataChannel([id](shared_ptr dc) { std::cout << "DataChannel from " << id << " received with label \"" << dc->label() << "\"" << std::endl; dc->onOpen([wdc = make_weak_ptr(dc)]() { if (auto dc = wdc.lock()) dc->send("Hello from " + localId); }); dc->onClosed([id]() { std::cout << "DataChannel from " << id << " closed" << std::endl; }); dc->onMessage([id](auto data) { // data holds either std::string or rtc::binary if (std::holds_alternative(data)) std::cout << "Message from " << id << " received: " << std::get(data) << std::endl; else std::cout << "Binary message from " << id << " received, size=" << std::get(data).size() << std::endl; }); dataChannelMap.emplace(id, dc); }); peerConnectionMap.emplace(id, pc); return pc; }; // Helper function to generate a random ID std::string randomId(size_t length) { using std::chrono::high_resolution_clock; static thread_local std::mt19937 rng( static_cast(high_resolution_clock::now().time_since_epoch().count())); static const std::string characters( "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"); std::string id(length, '0'); std::uniform_int_distribution uniform(0, int(characters.size() - 1)); std::generate(id.begin(), id.end(), [&]() { return characters.at(uniform(rng)); }); return id; }