| /* |
| * 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 "api/candidate.h" |
| |
| #include <algorithm> // IWYU pragma: keep |
| #include <cstdint> |
| #include <string> |
| |
| #include "absl/strings/string_view.h" |
| #include "p2p/base/p2p_constants.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/crc32.h" |
| #include "rtc_base/crypto_random.h" |
| #include "rtc_base/ip_address.h" |
| #include "rtc_base/network_constants.h" |
| #include "rtc_base/socket_address.h" |
| #include "rtc_base/string_encode.h" |
| #include "rtc_base/strings/string_builder.h" |
| |
| using webrtc::IceCandidateType; |
| |
| namespace webrtc { |
| absl::string_view IceCandidateTypeToString(IceCandidateType type) { |
| switch (type) { |
| case IceCandidateType::kHost: |
| return "host"; |
| case IceCandidateType::kSrflx: |
| return "srflx"; |
| case IceCandidateType::kPrflx: |
| return "prflx"; |
| case IceCandidateType::kRelay: |
| return "relay"; |
| } |
| } |
| } // namespace webrtc |
| |
| namespace cricket { |
| |
| Candidate::Candidate() |
| : id_(rtc::CreateRandomString(8)), |
| component_(ICE_CANDIDATE_COMPONENT_DEFAULT), |
| priority_(0), |
| network_type_(rtc::ADAPTER_TYPE_UNKNOWN), |
| underlying_type_for_vpn_(rtc::ADAPTER_TYPE_UNKNOWN), |
| generation_(0), |
| network_id_(0), |
| network_cost_(0) {} |
| |
| Candidate::Candidate(int component, |
| absl::string_view protocol, |
| const rtc::SocketAddress& address, |
| uint32_t priority, |
| absl::string_view username, |
| absl::string_view password, |
| webrtc::IceCandidateType type, |
| uint32_t generation, |
| absl::string_view foundation, |
| uint16_t network_id /*= 0*/, |
| uint16_t network_cost /*= 0*/) |
| : id_(rtc::CreateRandomString(8)), |
| component_(component), |
| protocol_(protocol), |
| address_(address), |
| priority_(priority), |
| username_(username), |
| password_(password), |
| type_(type), |
| network_type_(rtc::ADAPTER_TYPE_UNKNOWN), |
| underlying_type_for_vpn_(rtc::ADAPTER_TYPE_UNKNOWN), |
| generation_(generation), |
| foundation_(foundation), |
| network_id_(network_id), |
| network_cost_(network_cost) {} |
| |
| Candidate::Candidate(const Candidate&) = default; |
| |
| Candidate::~Candidate() = default; |
| |
| void Candidate::generate_id() { |
| id_ = rtc::CreateRandomString(8); |
| } |
| |
| bool Candidate::is_local() const { |
| return type_ == IceCandidateType::kHost; |
| } |
| bool Candidate::is_stun() const { |
| return type_ == IceCandidateType::kSrflx; |
| } |
| bool Candidate::is_prflx() const { |
| return type_ == IceCandidateType::kPrflx; |
| } |
| bool Candidate::is_relay() const { |
| return type_ == IceCandidateType::kRelay; |
| } |
| |
| absl::string_view Candidate::type_name() const { |
| return webrtc::IceCandidateTypeToString(type_); |
| } |
| |
| bool Candidate::IsEquivalent(const Candidate& c) const { |
| // We ignore the network name, since that is just debug information, and |
| // the priority and the network cost, since they should be the same if the |
| // rest are. |
| return (component_ == c.component_) && (protocol_ == c.protocol_) && |
| (address_ == c.address_) && (username_ == c.username_) && |
| (password_ == c.password_) && (type_ == c.type_) && |
| (generation_ == c.generation_) && (foundation_ == c.foundation_) && |
| (related_address_ == c.related_address_) && |
| (network_id_ == c.network_id_); |
| } |
| |
| bool Candidate::MatchesForRemoval(const Candidate& c) const { |
| return component_ == c.component_ && protocol_ == c.protocol_ && |
| address_ == c.address_; |
| } |
| |
| std::string Candidate::ToStringInternal(bool sensitive) const { |
| rtc::StringBuilder ost; |
| std::string address = |
| sensitive ? address_.ToSensitiveString() : address_.ToString(); |
| std::string related_address = sensitive ? related_address_.ToSensitiveString() |
| : related_address_.ToString(); |
| ost << "Cand[" << transport_name_ << ":" << foundation_ << ":" << component_ |
| << ":" << protocol_ << ":" << priority_ << ":" << address << ":" |
| << type_name() << ":" << related_address << ":" << username_ << ":" |
| << password_ << ":" << network_id_ << ":" << network_cost_ << ":" |
| << generation_ << "]"; |
| return ost.Release(); |
| } |
| |
| uint32_t Candidate::GetPriority(uint32_t type_preference, |
| int network_adapter_preference, |
| int relay_preference, |
| bool adjust_local_preference) const { |
| // RFC 5245 - 4.1.2.1. |
| // priority = (2^24)*(type preference) + |
| // (2^8)*(local preference) + |
| // (2^0)*(256 - component ID) |
| |
| // `local_preference` length is 2 bytes, 0-65535 inclusive. |
| // In our implemenation we will partion local_preference into |
| // 0 1 |
| // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // | NIC Pref | Addr Pref | |
| // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| // NIC Type - Type of the network adapter e.g. 3G/Wifi/Wired. |
| // Addr Pref - Address preference value as per RFC 3484. |
| // local preference = (NIC Type << 8 | Addr_Pref) + relay preference. |
| // The relay preference is based on the number of TURN servers, the |
| // first TURN server gets the highest preference. |
| int addr_pref = IPAddressPrecedence(address_.ipaddr()); |
| int local_preference = |
| ((network_adapter_preference << 8) | addr_pref) + relay_preference; |
| |
| // Ensure that the added relay preference will not result in a relay candidate |
| // whose STUN priority attribute has a higher priority than a server-reflexive |
| // candidate. |
| // The STUN priority attribute is calculated as |
| // (peer-reflexive type preference) << 24 | (priority & 0x00FFFFFF) |
| // as described in |
| // https://www.rfc-editor.org/rfc/rfc5245#section-7.1.2.1 |
| // To satisfy that condition, add kMaxTurnServers to the local preference. |
| // This can not overflow the field width since the highest "NIC pref" |
| // assigned is kHighestNetworkPreference = 127 |
| RTC_DCHECK_LT(local_preference + kMaxTurnServers, 0x10000); |
| if (adjust_local_preference && relay_protocol_.empty()) { |
| local_preference += kMaxTurnServers; |
| } |
| |
| return (type_preference << 24) | (local_preference << 8) | (256 - component_); |
| } |
| |
| bool Candidate::operator==(const Candidate& o) const { |
| return id_ == o.id_ && component_ == o.component_ && |
| protocol_ == o.protocol_ && relay_protocol_ == o.relay_protocol_ && |
| address_ == o.address_ && priority_ == o.priority_ && |
| username_ == o.username_ && password_ == o.password_ && |
| type_ == o.type_ && network_name_ == o.network_name_ && |
| network_type_ == o.network_type_ && generation_ == o.generation_ && |
| foundation_ == o.foundation_ && |
| related_address_ == o.related_address_ && tcptype_ == o.tcptype_ && |
| transport_name_ == o.transport_name_ && network_id_ == o.network_id_; |
| } |
| |
| bool Candidate::operator!=(const Candidate& o) const { |
| return !(*this == o); |
| } |
| |
| Candidate Candidate::ToSanitizedCopy(bool use_hostname_address, |
| bool filter_related_address) const { |
| Candidate copy(*this); |
| if (use_hostname_address) { |
| rtc::IPAddress ip; |
| if (address().hostname().empty()) { |
| // IP needs to be redacted, but no hostname available. |
| rtc::SocketAddress redacted_addr("redacted-ip.invalid", address().port()); |
| copy.set_address(redacted_addr); |
| } else if (IPFromString(address().hostname(), &ip)) { |
| // The hostname is an IP literal, and needs to be redacted too. |
| rtc::SocketAddress redacted_addr("redacted-literal.invalid", |
| address().port()); |
| copy.set_address(redacted_addr); |
| } else { |
| rtc::SocketAddress hostname_only_addr(address().hostname(), |
| address().port()); |
| copy.set_address(hostname_only_addr); |
| } |
| } |
| if (filter_related_address) { |
| copy.set_related_address( |
| rtc::EmptySocketAddressWithFamily(copy.address().family())); |
| } |
| return copy; |
| } |
| |
| void Candidate::ComputeFoundation(const rtc::SocketAddress& base_address, |
| uint64_t tie_breaker) { |
| // https://www.rfc-editor.org/rfc/rfc5245#section-4.1.1.3 |
| // The foundation is an identifier, scoped within a session. Two candidates |
| // MUST have the same foundation ID when all of the following are true: |
| // |
| // o they are of the same type. |
| // o their bases have the same IP address (the ports can be different). |
| // o for reflexive and relayed candidates, the STUN or TURN servers used to |
| // obtain them have the same IP address. |
| // o they were obtained using the same transport protocol (TCP, UDP, etc.). |
| // |
| // Similarly, two candidates MUST have different foundations if their |
| // types are different, their bases have different IP addresses, the STUN or |
| // TURN servers used to obtain them have different IP addresses, or their |
| // transport protocols are different. |
| |
| rtc::StringBuilder sb; |
| sb << type_name() << base_address.ipaddr().ToString() << protocol_ |
| << relay_protocol_; |
| |
| // https://www.rfc-editor.org/rfc/rfc5245#section-5.2 |
| // [...] it is possible for both agents to mistakenly believe they are |
| // controlled or controlling. To resolve this, each agent MUST select a random |
| // number, called the tie-breaker, uniformly distributed between 0 and (2**64) |
| // - 1 (that is, a 64-bit positive integer). This number is used in |
| // connectivity checks to detect and repair this case [...] |
| sb << rtc::ToString(tie_breaker); |
| foundation_ = rtc::ToString(rtc::ComputeCrc32(sb.Release())); |
| } |
| |
| void Candidate::ComputePrflxFoundation() { |
| RTC_DCHECK(is_prflx()); |
| RTC_DCHECK(!id_.empty()); |
| foundation_ = rtc::ToString(rtc::ComputeCrc32(id_)); |
| } |
| |
| void Candidate::Assign(std::string& s, absl::string_view view) { |
| // Assigning via a temporary object, like s = std::string(view), results in |
| // binary size bloat. To avoid that, extract pointer and size from the |
| // string view, and use std::string::assign method. |
| s.assign(view.data(), view.size()); |
| } |
| |
| } // namespace cricket |
