| /* |
| * Copyright 2017 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #include "pc/ice_server_parsing.h" |
| |
| #include <stddef.h> |
| |
| #include <algorithm> |
| #include <cctype> // For std::isdigit. |
| #include <memory> |
| #include <string> |
| |
| #include "p2p/base/port_interface.h" |
| #include "rtc_base/arraysize.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/ip_address.h" |
| #include "rtc_base/logging.h" |
| #include "rtc_base/socket_address.h" |
| #include "rtc_base/string_encode.h" |
| |
| namespace webrtc { |
| |
| // Number of tokens must be preset when TURN uri has transport param. |
| static const size_t kTurnTransportTokensNum = 2; |
| // The default stun port. |
| static const int kDefaultStunPort = 3478; |
| static const int kDefaultStunTlsPort = 5349; |
| static const char kTransport[] = "transport"; |
| |
| // Allowed characters in hostname per RFC 3986 Appendix A "reg-name" |
| static const char kRegNameCharacters[] = |
| "abcdefghijklmnopqrstuvwxyz" |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZ" |
| "0123456789" |
| "-._~" // unreserved |
| "%" // pct-encoded |
| "!$&'()*+,;="; // sub-delims |
| |
| // NOTE: Must be in the same order as the ServiceType enum. |
| static const char* kValidIceServiceTypes[] = {"stun", "stuns", "turn", "turns"}; |
| |
| // NOTE: A loop below assumes that the first value of this enum is 0 and all |
| // other values are incremental. |
| enum ServiceType { |
| STUN = 0, // Indicates a STUN server. |
| STUNS, // Indicates a STUN server used with a TLS session. |
| TURN, // Indicates a TURN server |
| TURNS, // Indicates a TURN server used with a TLS session. |
| INVALID, // Unknown. |
| }; |
| static_assert(INVALID == arraysize(kValidIceServiceTypes), |
| "kValidIceServiceTypes must have as many strings as ServiceType " |
| "has values."); |
| |
| // `in_str` should follow of RFC 7064/7065 syntax, but with an optional |
| // "?transport=" already stripped. I.e., |
| // stunURI = scheme ":" host [ ":" port ] |
| // scheme = "stun" / "stuns" / "turn" / "turns" |
| // host = IP-literal / IPv4address / reg-name |
| // port = *DIGIT |
| static bool GetServiceTypeAndHostnameFromUri(const std::string& in_str, |
| ServiceType* service_type, |
| std::string* hostname) { |
| const std::string::size_type colonpos = in_str.find(':'); |
| if (colonpos == std::string::npos) { |
| RTC_LOG(LS_WARNING) << "Missing ':' in ICE URI: " << in_str; |
| return false; |
| } |
| if ((colonpos + 1) == in_str.length()) { |
| RTC_LOG(LS_WARNING) << "Empty hostname in ICE URI: " << in_str; |
| return false; |
| } |
| *service_type = INVALID; |
| for (size_t i = 0; i < arraysize(kValidIceServiceTypes); ++i) { |
| if (in_str.compare(0, colonpos, kValidIceServiceTypes[i]) == 0) { |
| *service_type = static_cast<ServiceType>(i); |
| break; |
| } |
| } |
| if (*service_type == INVALID) { |
| return false; |
| } |
| *hostname = in_str.substr(colonpos + 1, std::string::npos); |
| return true; |
| } |
| |
| static bool ParsePort(const std::string& in_str, int* port) { |
| // Make sure port only contains digits. FromString doesn't check this. |
| for (const char& c : in_str) { |
| if (!std::isdigit(c)) { |
| return false; |
| } |
| } |
| return rtc::FromString(in_str, port); |
| } |
| |
| // This method parses IPv6 and IPv4 literal strings, along with hostnames in |
| // standard hostname:port format. |
| // Consider following formats as correct. |
| // `hostname:port`, |[IPV6 address]:port|, |IPv4 address|:port, |
| // `hostname`, |[IPv6 address]|, |IPv4 address|. |
| static bool ParseHostnameAndPortFromString(const std::string& in_str, |
| std::string* host, |
| int* port) { |
| RTC_DCHECK(host->empty()); |
| if (in_str.at(0) == '[') { |
| // IP_literal syntax |
| std::string::size_type closebracket = in_str.rfind(']'); |
| if (closebracket != std::string::npos) { |
| std::string::size_type colonpos = in_str.find(':', closebracket); |
| if (std::string::npos != colonpos) { |
| if (!ParsePort(in_str.substr(closebracket + 2, std::string::npos), |
| port)) { |
| return false; |
| } |
| } |
| *host = in_str.substr(1, closebracket - 1); |
| } else { |
| return false; |
| } |
| } else { |
| // IPv4address or reg-name syntax |
| std::string::size_type colonpos = in_str.find(':'); |
| if (std::string::npos != colonpos) { |
| if (!ParsePort(in_str.substr(colonpos + 1, std::string::npos), port)) { |
| return false; |
| } |
| *host = in_str.substr(0, colonpos); |
| } else { |
| *host = in_str; |
| } |
| // RFC 3986 section 3.2.2 and Appendix A - "reg-name" syntax |
| if (host->find_first_not_of(kRegNameCharacters) != std::string::npos) { |
| return false; |
| } |
| } |
| return !host->empty(); |
| } |
| |
| // Adds a STUN or TURN server to the appropriate list, |
| // by parsing `url` and using the username/password in `server`. |
| static RTCErrorType ParseIceServerUrl( |
| const PeerConnectionInterface::IceServer& server, |
| const std::string& url, |
| cricket::ServerAddresses* stun_servers, |
| std::vector<cricket::RelayServerConfig>* turn_servers) { |
| // RFC 7064 |
| // stunURI = scheme ":" host [ ":" port ] |
| // scheme = "stun" / "stuns" |
| |
| // RFC 7065 |
| // turnURI = scheme ":" host [ ":" port ] |
| // [ "?transport=" transport ] |
| // scheme = "turn" / "turns" |
| // transport = "udp" / "tcp" / transport-ext |
| // transport-ext = 1*unreserved |
| |
| // RFC 3986 |
| // host = IP-literal / IPv4address / reg-name |
| // port = *DIGIT |
| |
| RTC_DCHECK(stun_servers != nullptr); |
| RTC_DCHECK(turn_servers != nullptr); |
| std::vector<std::string> tokens; |
| cricket::ProtocolType turn_transport_type = cricket::PROTO_UDP; |
| RTC_DCHECK(!url.empty()); |
| rtc::split(url, '?', &tokens); |
| std::string uri_without_transport = tokens[0]; |
| // Let's look into transport= param, if it exists. |
| if (tokens.size() == kTurnTransportTokensNum) { // ?transport= is present. |
| std::string uri_transport_param = tokens[1]; |
| rtc::split(uri_transport_param, '=', &tokens); |
| if (tokens[0] != kTransport) { |
| RTC_LOG(LS_WARNING) << "Invalid transport parameter key."; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| if (tokens.size() < 2) { |
| RTC_LOG(LS_WARNING) << "Transport parameter missing value."; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| if (!cricket::StringToProto(tokens[1].c_str(), &turn_transport_type) || |
| (turn_transport_type != cricket::PROTO_UDP && |
| turn_transport_type != cricket::PROTO_TCP)) { |
| RTC_LOG(LS_WARNING) << "Transport parameter should always be udp or tcp."; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| } |
| |
| std::string hoststring; |
| ServiceType service_type; |
| if (!GetServiceTypeAndHostnameFromUri(uri_without_transport, &service_type, |
| &hoststring)) { |
| RTC_LOG(LS_WARNING) << "Invalid transport parameter in ICE URI: " << url; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| |
| // GetServiceTypeAndHostnameFromUri should never give an empty hoststring |
| RTC_DCHECK(!hoststring.empty()); |
| |
| int port = kDefaultStunPort; |
| if (service_type == TURNS) { |
| port = kDefaultStunTlsPort; |
| turn_transport_type = cricket::PROTO_TLS; |
| } |
| |
| if (hoststring.find('@') != std::string::npos) { |
| RTC_LOG(LS_WARNING) << "Invalid url: " << uri_without_transport; |
| RTC_LOG(LS_WARNING) |
| << "Note that user-info@ in turn:-urls is long-deprecated."; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| std::string address; |
| if (!ParseHostnameAndPortFromString(hoststring, &address, &port)) { |
| RTC_LOG(LS_WARNING) << "Invalid hostname format: " << uri_without_transport; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| |
| if (port <= 0 || port > 0xffff) { |
| RTC_LOG(LS_WARNING) << "Invalid port: " << port; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| |
| switch (service_type) { |
| case STUN: |
| case STUNS: |
| stun_servers->insert(rtc::SocketAddress(address, port)); |
| break; |
| case TURN: |
| case TURNS: { |
| if (server.username.empty() || server.password.empty()) { |
| // The WebRTC spec requires throwing an InvalidAccessError when username |
| // or credential are ommitted; this is the native equivalent. |
| RTC_LOG(LS_WARNING) << "TURN server with empty username or password"; |
| return RTCErrorType::INVALID_PARAMETER; |
| } |
| // If the hostname field is not empty, then the server address must be |
| // the resolved IP for that host, the hostname is needed later for TLS |
| // handshake (SNI and Certificate verification). |
| const std::string& hostname = |
| server.hostname.empty() ? address : server.hostname; |
| rtc::SocketAddress socket_address(hostname, port); |
| if (!server.hostname.empty()) { |
| rtc::IPAddress ip; |
| if (!IPFromString(address, &ip)) { |
| // When hostname is set, the server address must be a |
| // resolved ip address. |
| RTC_LOG(LS_WARNING) |
| << "IceServer has hostname field set, but URI does not " |
| "contain an IP address."; |
| return RTCErrorType::INVALID_PARAMETER; |
| } |
| socket_address.SetResolvedIP(ip); |
| } |
| cricket::RelayServerConfig config = |
| cricket::RelayServerConfig(socket_address, server.username, |
| server.password, turn_transport_type); |
| if (server.tls_cert_policy == |
| PeerConnectionInterface::kTlsCertPolicyInsecureNoCheck) { |
| config.tls_cert_policy = |
| cricket::TlsCertPolicy::TLS_CERT_POLICY_INSECURE_NO_CHECK; |
| } |
| config.tls_alpn_protocols = server.tls_alpn_protocols; |
| config.tls_elliptic_curves = server.tls_elliptic_curves; |
| |
| turn_servers->push_back(config); |
| break; |
| } |
| default: |
| // We shouldn't get to this point with an invalid service_type, we should |
| // have returned an error already. |
| RTC_DCHECK_NOTREACHED() << "Unexpected service type"; |
| return RTCErrorType::INTERNAL_ERROR; |
| } |
| return RTCErrorType::NONE; |
| } |
| |
| RTCErrorType ParseIceServers( |
| const PeerConnectionInterface::IceServers& servers, |
| cricket::ServerAddresses* stun_servers, |
| std::vector<cricket::RelayServerConfig>* turn_servers) { |
| for (const PeerConnectionInterface::IceServer& server : servers) { |
| if (!server.urls.empty()) { |
| for (const std::string& url : server.urls) { |
| if (url.empty()) { |
| RTC_LOG(LS_WARNING) << "Empty uri."; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| RTCErrorType err = |
| ParseIceServerUrl(server, url, stun_servers, turn_servers); |
| if (err != RTCErrorType::NONE) { |
| return err; |
| } |
| } |
| } else if (!server.uri.empty()) { |
| // Fallback to old .uri if new .urls isn't present. |
| RTCErrorType err = |
| ParseIceServerUrl(server, server.uri, stun_servers, turn_servers); |
| if (err != RTCErrorType::NONE) { |
| return err; |
| } |
| } else { |
| RTC_LOG(LS_WARNING) << "Empty uri."; |
| return RTCErrorType::SYNTAX_ERROR; |
| } |
| } |
| // Candidates must have unique priorities, so that connectivity checks |
| // are performed in a well-defined order. |
| int priority = static_cast<int>(turn_servers->size() - 1); |
| for (cricket::RelayServerConfig& turn_server : *turn_servers) { |
| // First in the list gets highest priority. |
| turn_server.priority = priority--; |
| } |
| return RTCErrorType::NONE; |
| } |
| |
| } // namespace webrtc |
