blob: dd02281c93042a47d5785d26723a33ce7d3cc3ac [file] [log] [blame] [edit]
/*
* Copyright 2004 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 "rtc_base/virtual_socket_server.h"
#include <errno.h>
#include <math.h>
#include <map>
#include <memory>
#include <vector>
#include "absl/algorithm/container.h"
#include "api/sequence_checker.h"
#include "api/units/time_delta.h"
#include "rtc_base/checks.h"
#include "rtc_base/event.h"
#include "rtc_base/fake_clock.h"
#include "rtc_base/logging.h"
#include "rtc_base/physical_socket_server.h"
#include "rtc_base/socket_address_pair.h"
#include "rtc_base/thread.h"
#include "rtc_base/time_utils.h"
namespace rtc {
using ::webrtc::MutexLock;
using ::webrtc::TaskQueueBase;
using ::webrtc::TimeDelta;
#if defined(WEBRTC_WIN)
const in_addr kInitialNextIPv4 = {{{0x01, 0, 0, 0}}};
#else
// This value is entirely arbitrary, hence the lack of concern about endianness.
const in_addr kInitialNextIPv4 = {0x01000000};
#endif
// Starts at ::2 so as to not cause confusion with ::1.
const in6_addr kInitialNextIPv6 = {
{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2}}};
const uint16_t kFirstEphemeralPort = 49152;
const uint16_t kLastEphemeralPort = 65535;
const uint16_t kEphemeralPortCount =
kLastEphemeralPort - kFirstEphemeralPort + 1;
const uint32_t kDefaultNetworkCapacity = 64 * 1024;
const uint32_t kDefaultTcpBufferSize = 32 * 1024;
const uint32_t UDP_HEADER_SIZE = 28; // IP + UDP headers
const uint32_t TCP_HEADER_SIZE = 40; // IP + TCP headers
const uint32_t TCP_MSS = 1400; // Maximum segment size
// Note: The current algorithm doesn't work for sample sizes smaller than this.
const int NUM_SAMPLES = 1000;
// Packets are passed between sockets as messages. We copy the data just like
// the kernel does.
class Packet {
public:
Packet(const char* data, size_t size, const SocketAddress& from)
: size_(size), consumed_(0), from_(from) {
RTC_DCHECK(nullptr != data);
data_ = new char[size_];
memcpy(data_, data, size_);
}
~Packet() { delete[] data_; }
const char* data() const { return data_ + consumed_; }
size_t size() const { return size_ - consumed_; }
const SocketAddress& from() const { return from_; }
// Remove the first size bytes from the data.
void Consume(size_t size) {
RTC_DCHECK(size + consumed_ < size_);
consumed_ += size;
}
private:
char* data_;
size_t size_, consumed_;
SocketAddress from_;
};
VirtualSocket::VirtualSocket(VirtualSocketServer* server, int family, int type)
: server_(server),
type_(type),
state_(CS_CLOSED),
error_(0),
network_size_(0),
recv_buffer_size_(0),
bound_(false),
was_any_(false) {
RTC_DCHECK((type_ == SOCK_DGRAM) || (type_ == SOCK_STREAM));
server->SignalReadyToSend.connect(this,
&VirtualSocket::OnSocketServerReadyToSend);
}
VirtualSocket::~VirtualSocket() {
Close();
}
SocketAddress VirtualSocket::GetLocalAddress() const {
return local_addr_;
}
SocketAddress VirtualSocket::GetRemoteAddress() const {
return remote_addr_;
}
void VirtualSocket::SetLocalAddress(const SocketAddress& addr) {
local_addr_ = addr;
}
int VirtualSocket::Bind(const SocketAddress& addr) {
if (!local_addr_.IsNil()) {
error_ = EINVAL;
return -1;
}
local_addr_ = server_->AssignBindAddress(addr);
int result = server_->Bind(this, local_addr_);
if (result != 0) {
local_addr_.Clear();
error_ = EADDRINUSE;
} else {
bound_ = true;
was_any_ = addr.IsAnyIP();
}
return result;
}
int VirtualSocket::Connect(const SocketAddress& addr) {
return InitiateConnect(addr, true);
}
VirtualSocket::SafetyBlock::SafetyBlock(VirtualSocket* socket)
: socket_(*socket) {}
VirtualSocket::SafetyBlock::~SafetyBlock() {
// Ensure `SetNotAlive` was called and there is nothing left to cleanup.
RTC_DCHECK(!alive_);
RTC_DCHECK(posted_connects_.empty());
RTC_DCHECK(recv_buffer_.empty());
RTC_DCHECK(!listen_queue_.has_value());
}
void VirtualSocket::SafetyBlock::SetNotAlive() {
VirtualSocketServer* const server = socket_.server_;
const SocketAddress& local_addr = socket_.local_addr_;
MutexLock lock(&mutex_);
// Cancel pending sockets
if (listen_queue_.has_value()) {
for (const SocketAddress& remote_addr : *listen_queue_) {
server->Disconnect(remote_addr);
}
listen_queue_ = std::nullopt;
}
// Cancel potential connects
for (const SocketAddress& remote_addr : posted_connects_) {
// Lookup remote side.
VirtualSocket* lookup_socket =
server->LookupConnection(local_addr, remote_addr);
if (lookup_socket) {
// Server socket, remote side is a socket retreived by accept. Accepted
// sockets are not bound so we will not find it by looking in the
// bindings table.
server->Disconnect(lookup_socket);
server->RemoveConnection(local_addr, remote_addr);
} else {
server->Disconnect(remote_addr);
}
}
posted_connects_.clear();
recv_buffer_.clear();
alive_ = false;
}
void VirtualSocket::SafetyBlock::PostSignalReadEvent() {
if (pending_read_signal_event_) {
// Avoid posting multiple times.
return;
}
pending_read_signal_event_ = true;
rtc::scoped_refptr<SafetyBlock> safety(this);
socket_.server_->msg_queue_->PostTask(
[safety = std::move(safety)] { safety->MaybeSignalReadEvent(); });
}
void VirtualSocket::SafetyBlock::MaybeSignalReadEvent() {
{
MutexLock lock(&mutex_);
pending_read_signal_event_ = false;
if (!alive_ || recv_buffer_.empty()) {
return;
}
}
socket_.SignalReadEvent(&socket_);
}
int VirtualSocket::Close() {
if (!local_addr_.IsNil() && bound_) {
// Remove from the binding table.
server_->Unbind(local_addr_, this);
bound_ = false;
}
// Disconnect stream sockets
if (state_ == CS_CONNECTED && type_ == SOCK_STREAM) {
server_->Disconnect(local_addr_, remote_addr_);
}
safety_->SetNotAlive();
state_ = CS_CLOSED;
local_addr_.Clear();
remote_addr_.Clear();
return 0;
}
int VirtualSocket::Send(const void* pv, size_t cb) {
if (CS_CONNECTED != state_) {
error_ = ENOTCONN;
return -1;
}
if (SOCK_DGRAM == type_) {
return SendUdp(pv, cb, remote_addr_);
} else {
return SendTcp(pv, cb);
}
}
int VirtualSocket::SendTo(const void* pv,
size_t cb,
const SocketAddress& addr) {
if (SOCK_DGRAM == type_) {
return SendUdp(pv, cb, addr);
} else {
if (CS_CONNECTED != state_) {
error_ = ENOTCONN;
return -1;
}
return SendTcp(pv, cb);
}
}
int VirtualSocket::Recv(void* pv, size_t cb, int64_t* timestamp) {
SocketAddress addr;
return RecvFrom(pv, cb, &addr, timestamp);
}
int VirtualSocket::RecvFrom(void* pv,
size_t cb,
SocketAddress* paddr,
int64_t* timestamp) {
if (timestamp) {
*timestamp = -1;
}
int data_read = safety_->RecvFrom(pv, cb, *paddr);
if (data_read < 0) {
error_ = EAGAIN;
return -1;
}
if (type_ == SOCK_STREAM) {
bool was_full = (recv_buffer_size_ == server_->recv_buffer_capacity());
recv_buffer_size_ -= data_read;
if (was_full) {
server_->SendTcp(remote_addr_);
}
}
return data_read;
}
int VirtualSocket::SafetyBlock::RecvFrom(void* buffer,
size_t size,
SocketAddress& addr) {
MutexLock lock(&mutex_);
// If we don't have a packet, then either error or wait for one to arrive.
if (recv_buffer_.empty()) {
return -1;
}
// Return the packet at the front of the queue.
Packet& packet = *recv_buffer_.front();
size_t data_read = std::min(size, packet.size());
memcpy(buffer, packet.data(), data_read);
addr = packet.from();
if (data_read < packet.size()) {
packet.Consume(data_read);
} else {
recv_buffer_.pop_front();
}
// To behave like a real socket, SignalReadEvent should fire if there's still
// data buffered.
if (!recv_buffer_.empty()) {
PostSignalReadEvent();
}
return data_read;
}
int VirtualSocket::Listen(int backlog) {
RTC_DCHECK(SOCK_STREAM == type_);
RTC_DCHECK(CS_CLOSED == state_);
if (local_addr_.IsNil()) {
error_ = EINVAL;
return -1;
}
safety_->Listen();
state_ = CS_CONNECTING;
return 0;
}
void VirtualSocket::SafetyBlock::Listen() {
MutexLock lock(&mutex_);
RTC_DCHECK(!listen_queue_.has_value());
listen_queue_.emplace();
}
VirtualSocket* VirtualSocket::Accept(SocketAddress* paddr) {
SafetyBlock::AcceptResult result = safety_->Accept();
if (result.error != 0) {
error_ = result.error;
return nullptr;
}
if (paddr) {
*paddr = result.remote_addr;
}
return result.socket.release();
}
VirtualSocket::SafetyBlock::AcceptResult VirtualSocket::SafetyBlock::Accept() {
AcceptResult result;
MutexLock lock(&mutex_);
RTC_DCHECK(alive_);
if (!listen_queue_.has_value()) {
result.error = EINVAL;
return result;
}
while (!listen_queue_->empty()) {
auto socket = std::make_unique<VirtualSocket>(socket_.server_, AF_INET,
socket_.type_);
// Set the new local address to the same as this server socket.
socket->SetLocalAddress(socket_.local_addr_);
// Sockets made from a socket that 'was Any' need to inherit that.
socket->set_was_any(socket_.was_any());
SocketAddress remote_addr = listen_queue_->front();
listen_queue_->pop_front();
if (socket->InitiateConnect(remote_addr, false) != 0) {
continue;
}
socket->CompleteConnect(remote_addr);
result.socket = std::move(socket);
result.remote_addr = remote_addr;
return result;
}
result.error = EWOULDBLOCK;
return result;
}
int VirtualSocket::GetError() const {
return error_;
}
void VirtualSocket::SetError(int error) {
error_ = error;
}
Socket::ConnState VirtualSocket::GetState() const {
return state_;
}
int VirtualSocket::GetOption(Option opt, int* value) {
OptionsMap::const_iterator it = options_map_.find(opt);
if (it == options_map_.end()) {
return -1;
}
*value = it->second;
return 0; // 0 is success to emulate getsockopt()
}
int VirtualSocket::SetOption(Option opt, int value) {
options_map_[opt] = value;
return 0; // 0 is success to emulate setsockopt()
}
void VirtualSocket::PostPacket(TimeDelta delay,
std::unique_ptr<Packet> packet) {
rtc::scoped_refptr<SafetyBlock> safety = safety_;
VirtualSocket* socket = this;
server_->msg_queue_->PostDelayedTask(
[safety = std::move(safety), socket,
packet = std::move(packet)]() mutable {
if (safety->AddPacket(std::move(packet))) {
socket->SignalReadEvent(socket);
}
},
delay);
}
bool VirtualSocket::SafetyBlock::AddPacket(std::unique_ptr<Packet> packet) {
MutexLock lock(&mutex_);
if (alive_) {
recv_buffer_.push_back(std::move(packet));
}
return alive_;
}
void VirtualSocket::PostConnect(TimeDelta delay,
const SocketAddress& remote_addr) {
safety_->PostConnect(delay, remote_addr);
}
void VirtualSocket::SafetyBlock::PostConnect(TimeDelta delay,
const SocketAddress& remote_addr) {
rtc::scoped_refptr<SafetyBlock> safety(this);
MutexLock lock(&mutex_);
RTC_DCHECK(alive_);
// Save addresses of the pending connects to allow propertly disconnect them
// if socket closes before delayed task below runs.
// `posted_connects_` is an std::list, thus its iterators are valid while the
// element is in the list. It can be removed either in the `Connect` just
// below or by calling SetNotAlive function, thus inside `Connect` `it` should
// be valid when alive_ == true.
auto it = posted_connects_.insert(posted_connects_.end(), remote_addr);
auto task = [safety = std::move(safety), it] {
switch (safety->Connect(it)) {
case Signal::kNone:
break;
case Signal::kReadEvent:
safety->socket_.SignalReadEvent(&safety->socket_);
break;
case Signal::kConnectEvent:
safety->socket_.SignalConnectEvent(&safety->socket_);
break;
}
};
socket_.server_->msg_queue_->PostDelayedTask(std::move(task), delay);
}
VirtualSocket::SafetyBlock::Signal VirtualSocket::SafetyBlock::Connect(
VirtualSocket::SafetyBlock::PostedConnects::iterator remote_addr_it) {
MutexLock lock(&mutex_);
if (!alive_) {
return Signal::kNone;
}
RTC_DCHECK(!posted_connects_.empty());
SocketAddress remote_addr = *remote_addr_it;
posted_connects_.erase(remote_addr_it);
if (listen_queue_.has_value()) {
listen_queue_->push_back(remote_addr);
return Signal::kReadEvent;
}
if (socket_.type_ == SOCK_STREAM && socket_.state_ == CS_CONNECTING) {
socket_.CompleteConnect(remote_addr);
return Signal::kConnectEvent;
}
RTC_LOG(LS_VERBOSE) << "Socket at " << socket_.local_addr_.ToString()
<< " is not listening";
socket_.server_->Disconnect(remote_addr);
return Signal::kNone;
}
bool VirtualSocket::SafetyBlock::IsAlive() {
MutexLock lock(&mutex_);
return alive_;
}
void VirtualSocket::PostDisconnect(TimeDelta delay) {
// Posted task may outlive this. Use different name for `this` inside the task
// to avoid accidental unsafe `this->safety_` instead of safe `safety`
VirtualSocket* socket = this;
rtc::scoped_refptr<SafetyBlock> safety = safety_;
auto task = [safety = std::move(safety), socket] {
if (!safety->IsAlive()) {
return;
}
RTC_DCHECK_EQ(socket->type_, SOCK_STREAM);
if (socket->state_ == CS_CLOSED) {
return;
}
int error_to_signal = (socket->state_ == CS_CONNECTING) ? ECONNREFUSED : 0;
socket->state_ = CS_CLOSED;
socket->remote_addr_.Clear();
socket->SignalCloseEvent(socket, error_to_signal);
};
server_->msg_queue_->PostDelayedTask(std::move(task), delay);
}
int VirtualSocket::InitiateConnect(const SocketAddress& addr, bool use_delay) {
if (!remote_addr_.IsNil()) {
error_ = (CS_CONNECTED == state_) ? EISCONN : EINPROGRESS;
return -1;
}
if (local_addr_.IsNil()) {
// If there's no local address set, grab a random one in the correct AF.
int result = 0;
if (addr.ipaddr().family() == AF_INET) {
result = Bind(SocketAddress("0.0.0.0", 0));
} else if (addr.ipaddr().family() == AF_INET6) {
result = Bind(SocketAddress("::", 0));
}
if (result != 0) {
return result;
}
}
if (type_ == SOCK_DGRAM) {
remote_addr_ = addr;
state_ = CS_CONNECTED;
} else {
int result = server_->Connect(this, addr, use_delay);
if (result != 0) {
error_ = EHOSTUNREACH;
return -1;
}
state_ = CS_CONNECTING;
}
return 0;
}
void VirtualSocket::CompleteConnect(const SocketAddress& addr) {
RTC_DCHECK(CS_CONNECTING == state_);
remote_addr_ = addr;
state_ = CS_CONNECTED;
server_->AddConnection(remote_addr_, local_addr_, this);
}
int VirtualSocket::SendUdp(const void* pv,
size_t cb,
const SocketAddress& addr) {
// If we have not been assigned a local port, then get one.
if (local_addr_.IsNil()) {
local_addr_ = server_->AssignBindAddress(
EmptySocketAddressWithFamily(addr.ipaddr().family()));
int result = server_->Bind(this, local_addr_);
if (result != 0) {
local_addr_.Clear();
error_ = EADDRINUSE;
return result;
}
}
// Send the data in a message to the appropriate socket.
return server_->SendUdp(this, static_cast<const char*>(pv), cb, addr);
}
int VirtualSocket::SendTcp(const void* pv, size_t cb) {
size_t capacity = server_->send_buffer_capacity() - send_buffer_.size();
if (0 == capacity) {
ready_to_send_ = false;
error_ = EWOULDBLOCK;
return -1;
}
size_t consumed = std::min(cb, capacity);
const char* cpv = static_cast<const char*>(pv);
send_buffer_.insert(send_buffer_.end(), cpv, cpv + consumed);
server_->SendTcp(this);
return static_cast<int>(consumed);
}
void VirtualSocket::OnSocketServerReadyToSend() {
if (ready_to_send_) {
// This socket didn't encounter EWOULDBLOCK, so there's nothing to do.
return;
}
if (type_ == SOCK_DGRAM) {
ready_to_send_ = true;
SignalWriteEvent(this);
} else {
RTC_DCHECK(type_ == SOCK_STREAM);
// This will attempt to empty the full send buffer, and will fire
// SignalWriteEvent if successful.
server_->SendTcp(this);
}
}
void VirtualSocket::SetToBlocked() {
ready_to_send_ = false;
error_ = EWOULDBLOCK;
}
void VirtualSocket::UpdateRecv(size_t data_size) {
recv_buffer_size_ += data_size;
}
void VirtualSocket::UpdateSend(size_t data_size) {
size_t new_buffer_size = send_buffer_.size() - data_size;
// Avoid undefined access beyond the last element of the vector.
// This only happens when new_buffer_size is 0.
if (data_size < send_buffer_.size()) {
// memmove is required for potentially overlapping source/destination.
memmove(&send_buffer_[0], &send_buffer_[data_size], new_buffer_size);
}
send_buffer_.resize(new_buffer_size);
}
void VirtualSocket::MaybeSignalWriteEvent(size_t capacity) {
if (!ready_to_send_ && (send_buffer_.size() < capacity)) {
ready_to_send_ = true;
SignalWriteEvent(this);
}
}
uint32_t VirtualSocket::AddPacket(int64_t cur_time, size_t packet_size) {
network_size_ += packet_size;
uint32_t send_delay =
server_->SendDelay(static_cast<uint32_t>(network_size_));
NetworkEntry entry;
entry.size = packet_size;
entry.done_time = cur_time + send_delay;
network_.push_back(entry);
return send_delay;
}
int64_t VirtualSocket::UpdateOrderedDelivery(int64_t ts) {
// Ensure that new packets arrive after previous ones
ts = std::max(ts, last_delivery_time_);
// A socket should not have both ordered and unordered delivery, so its last
// delivery time only needs to be updated when it has ordered delivery.
last_delivery_time_ = ts;
return ts;
}
size_t VirtualSocket::PurgeNetworkPackets(int64_t cur_time) {
while (!network_.empty() && (network_.front().done_time <= cur_time)) {
RTC_DCHECK(network_size_ >= network_.front().size);
network_size_ -= network_.front().size;
network_.pop_front();
}
return network_size_;
}
VirtualSocketServer::VirtualSocketServer() : VirtualSocketServer(nullptr) {}
VirtualSocketServer::VirtualSocketServer(ThreadProcessingFakeClock* fake_clock)
: fake_clock_(fake_clock),
msg_queue_(nullptr),
stop_on_idle_(false),
next_ipv4_(kInitialNextIPv4),
next_ipv6_(kInitialNextIPv6),
next_port_(kFirstEphemeralPort),
bindings_(new AddressMap()),
connections_(new ConnectionMap()),
bandwidth_(0),
network_capacity_(kDefaultNetworkCapacity),
send_buffer_capacity_(kDefaultTcpBufferSize),
recv_buffer_capacity_(kDefaultTcpBufferSize),
delay_mean_(0),
delay_stddev_(0),
delay_samples_(NUM_SAMPLES),
drop_prob_(0.0) {
UpdateDelayDistribution();
}
VirtualSocketServer::~VirtualSocketServer() {
delete bindings_;
delete connections_;
}
IPAddress VirtualSocketServer::GetNextIP(int family) {
if (family == AF_INET) {
IPAddress next_ip(next_ipv4_);
next_ipv4_.s_addr = HostToNetwork32(NetworkToHost32(next_ipv4_.s_addr) + 1);
return next_ip;
} else if (family == AF_INET6) {
IPAddress next_ip(next_ipv6_);
uint32_t* as_ints = reinterpret_cast<uint32_t*>(&next_ipv6_.s6_addr);
as_ints[3] += 1;
return next_ip;
}
return IPAddress();
}
uint16_t VirtualSocketServer::GetNextPort() {
uint16_t port = next_port_;
if (next_port_ < kLastEphemeralPort) {
++next_port_;
} else {
next_port_ = kFirstEphemeralPort;
}
return port;
}
void VirtualSocketServer::SetSendingBlocked(bool blocked) {
{
webrtc::MutexLock lock(&mutex_);
if (blocked == sending_blocked_) {
// Unchanged; nothing to do.
return;
}
sending_blocked_ = blocked;
}
if (!blocked) {
// Sending was blocked, but is now unblocked. This signal gives sockets a
// chance to fire SignalWriteEvent, and for TCP, send buffered data.
SignalReadyToSend();
}
}
VirtualSocket* VirtualSocketServer::CreateSocket(int family, int type) {
return new VirtualSocket(this, family, type);
}
void VirtualSocketServer::SetMessageQueue(Thread* msg_queue) {
msg_queue_ = msg_queue;
}
bool VirtualSocketServer::Wait(webrtc::TimeDelta max_wait_duration,
bool process_io) {
RTC_DCHECK_RUN_ON(msg_queue_);
if (stop_on_idle_ && Thread::Current()->empty()) {
return false;
}
// Note: we don't need to do anything with `process_io` since we don't have
// any real I/O. Received packets come in the form of queued messages, so
// Thread will ensure WakeUp is called if another thread sends a
// packet.
wakeup_.Wait(max_wait_duration);
return true;
}
void VirtualSocketServer::WakeUp() {
wakeup_.Set();
}
void VirtualSocketServer::SetAlternativeLocalAddress(
const rtc::IPAddress& address,
const rtc::IPAddress& alternative) {
alternative_address_mapping_[address] = alternative;
}
bool VirtualSocketServer::ProcessMessagesUntilIdle() {
RTC_DCHECK_RUN_ON(msg_queue_);
stop_on_idle_ = true;
while (!msg_queue_->empty()) {
if (fake_clock_) {
// If using a fake clock, advance it in millisecond increments until the
// queue is empty.
fake_clock_->AdvanceTime(webrtc::TimeDelta::Millis(1));
} else {
// Otherwise, run a normal message loop.
msg_queue_->ProcessMessages(Thread::kForever);
}
}
stop_on_idle_ = false;
return !msg_queue_->IsQuitting();
}
void VirtualSocketServer::SetNextPortForTesting(uint16_t port) {
next_port_ = port;
}
bool VirtualSocketServer::CloseTcpConnections(
const SocketAddress& addr_local,
const SocketAddress& addr_remote) {
VirtualSocket* socket = LookupConnection(addr_local, addr_remote);
if (!socket) {
return false;
}
// Signal the close event on the local connection first.
socket->SignalCloseEvent(socket, 0);
// Trigger the remote connection's close event.
socket->Close();
return true;
}
int VirtualSocketServer::Bind(VirtualSocket* socket,
const SocketAddress& addr) {
RTC_DCHECK(nullptr != socket);
// Address must be completely specified at this point
RTC_DCHECK(!IPIsUnspec(addr.ipaddr()));
RTC_DCHECK(addr.port() != 0);
// Normalize the address (turns v6-mapped addresses into v4-addresses).
SocketAddress normalized(addr.ipaddr().Normalized(), addr.port());
AddressMap::value_type entry(normalized, socket);
return bindings_->insert(entry).second ? 0 : -1;
}
SocketAddress VirtualSocketServer::AssignBindAddress(
const SocketAddress& app_addr) {
RTC_DCHECK(!IPIsUnspec(app_addr.ipaddr()));
// Normalize the IP.
SocketAddress addr;
addr.SetIP(app_addr.ipaddr().Normalized());
// If the IP appears in `alternative_address_mapping_`, meaning the test has
// configured sockets bound to this IP to actually use another IP, replace
// the IP here.
auto alternative = alternative_address_mapping_.find(addr.ipaddr());
if (alternative != alternative_address_mapping_.end()) {
addr.SetIP(alternative->second);
}
if (app_addr.port() != 0) {
addr.SetPort(app_addr.port());
} else {
// Assign a port.
for (int i = 0; i < kEphemeralPortCount; ++i) {
addr.SetPort(GetNextPort());
if (bindings_->find(addr) == bindings_->end()) {
break;
}
}
}
return addr;
}
VirtualSocket* VirtualSocketServer::LookupBinding(const SocketAddress& addr) {
SocketAddress normalized(addr.ipaddr().Normalized(), addr.port());
AddressMap::iterator it = bindings_->find(normalized);
if (it != bindings_->end()) {
return it->second;
}
IPAddress default_ip = GetDefaultSourceAddress(addr.ipaddr().family());
if (!IPIsUnspec(default_ip) && addr.ipaddr() == default_ip) {
// If we can't find a binding for the packet which is sent to the interface
// corresponding to the default route, it should match a binding with the
// correct port to the any address.
SocketAddress sock_addr =
EmptySocketAddressWithFamily(addr.ipaddr().family());
sock_addr.SetPort(addr.port());
return LookupBinding(sock_addr);
}
return nullptr;
}
int VirtualSocketServer::Unbind(const SocketAddress& addr,
VirtualSocket* socket) {
SocketAddress normalized(addr.ipaddr().Normalized(), addr.port());
RTC_DCHECK((*bindings_)[normalized] == socket);
bindings_->erase(bindings_->find(normalized));
return 0;
}
void VirtualSocketServer::AddConnection(const SocketAddress& local,
const SocketAddress& remote,
VirtualSocket* remote_socket) {
// Add this socket pair to our routing table. This will allow
// multiple clients to connect to the same server address.
SocketAddress local_normalized(local.ipaddr().Normalized(), local.port());
SocketAddress remote_normalized(remote.ipaddr().Normalized(), remote.port());
SocketAddressPair address_pair(local_normalized, remote_normalized);
connections_->insert(std::pair<SocketAddressPair, VirtualSocket*>(
address_pair, remote_socket));
}
VirtualSocket* VirtualSocketServer::LookupConnection(
const SocketAddress& local,
const SocketAddress& remote) {
SocketAddress local_normalized(local.ipaddr().Normalized(), local.port());
SocketAddress remote_normalized(remote.ipaddr().Normalized(), remote.port());
SocketAddressPair address_pair(local_normalized, remote_normalized);
ConnectionMap::iterator it = connections_->find(address_pair);
return (connections_->end() != it) ? it->second : nullptr;
}
void VirtualSocketServer::RemoveConnection(const SocketAddress& local,
const SocketAddress& remote) {
SocketAddress local_normalized(local.ipaddr().Normalized(), local.port());
SocketAddress remote_normalized(remote.ipaddr().Normalized(), remote.port());
SocketAddressPair address_pair(local_normalized, remote_normalized);
connections_->erase(address_pair);
}
static double Random() {
return static_cast<double>(rand()) / RAND_MAX;
}
int VirtualSocketServer::Connect(VirtualSocket* socket,
const SocketAddress& remote_addr,
bool use_delay) {
RTC_DCHECK(msg_queue_);
TimeDelta delay = TimeDelta::Millis(use_delay ? GetTransitDelay(socket) : 0);
VirtualSocket* remote = LookupBinding(remote_addr);
if (!CanInteractWith(socket, remote)) {
RTC_LOG(LS_INFO) << "Address family mismatch between "
<< socket->GetLocalAddress().ToString() << " and "
<< remote_addr.ToString();
return -1;
}
if (remote != nullptr) {
remote->PostConnect(delay, socket->GetLocalAddress());
} else {
RTC_LOG(LS_INFO) << "No one listening at " << remote_addr.ToString();
socket->PostDisconnect(delay);
}
return 0;
}
bool VirtualSocketServer::Disconnect(VirtualSocket* socket) {
if (!socket || !msg_queue_)
return false;
// If we simulate packets being delayed, we should simulate the
// equivalent of a FIN being delayed as well.
socket->PostDisconnect(TimeDelta::Millis(GetTransitDelay(socket)));
return true;
}
bool VirtualSocketServer::Disconnect(const SocketAddress& addr) {
return Disconnect(LookupBinding(addr));
}
bool VirtualSocketServer::Disconnect(const SocketAddress& local_addr,
const SocketAddress& remote_addr) {
// Disconnect remote socket, check if it is a child of a server socket.
VirtualSocket* socket = LookupConnection(local_addr, remote_addr);
if (!socket) {
// Not a server socket child, then see if it is bound.
// TODO(tbd): If this is indeed a server socket that has no
// children this will cause the server socket to be
// closed. This might lead to unexpected results, how to fix this?
socket = LookupBinding(remote_addr);
}
Disconnect(socket);
// Remove mapping for both directions.
RemoveConnection(remote_addr, local_addr);
RemoveConnection(local_addr, remote_addr);
return socket != nullptr;
}
int VirtualSocketServer::SendUdp(VirtualSocket* socket,
const char* data,
size_t data_size,
const SocketAddress& remote_addr) {
{
webrtc::MutexLock lock(&mutex_);
++sent_packets_;
if (sending_blocked_) {
socket->SetToBlocked();
return -1;
}
// See if we want to drop this packet.
if (data_size > max_udp_payload_) {
RTC_LOG(LS_VERBOSE) << "Dropping too large UDP payload of size "
<< data_size << ", UDP payload limit is "
<< max_udp_payload_;
// Return as if send was successful; packet disappears.
return data_size;
}
if (Random() < drop_prob_) {
RTC_LOG(LS_VERBOSE) << "Dropping packet: bad luck";
return static_cast<int>(data_size);
}
}
VirtualSocket* recipient = LookupBinding(remote_addr);
if (!recipient) {
// Make a fake recipient for address family checking.
std::unique_ptr<VirtualSocket> dummy_socket(
CreateSocket(AF_INET, SOCK_DGRAM));
dummy_socket->SetLocalAddress(remote_addr);
if (!CanInteractWith(socket, dummy_socket.get())) {
RTC_LOG(LS_VERBOSE) << "Incompatible address families: "
<< socket->GetLocalAddress().ToString() << " and "
<< remote_addr.ToString();
return -1;
}
RTC_LOG(LS_VERBOSE) << "No one listening at " << remote_addr.ToString();
return static_cast<int>(data_size);
}
if (!CanInteractWith(socket, recipient)) {
RTC_LOG(LS_VERBOSE) << "Incompatible address families: "
<< socket->GetLocalAddress().ToString() << " and "
<< remote_addr.ToString();
return -1;
}
{
int64_t cur_time = TimeMillis();
size_t network_size = socket->PurgeNetworkPackets(cur_time);
// Determine whether we have enough bandwidth to accept this packet. To do
// this, we need to update the send queue. Once we know it's current size,
// we know whether we can fit this packet.
//
// NOTE: There are better algorithms for maintaining such a queue (such as
// "Derivative Random Drop"); however, this algorithm is a more accurate
// simulation of what a normal network would do.
{
webrtc::MutexLock lock(&mutex_);
size_t packet_size = data_size + UDP_HEADER_SIZE;
if (network_size + packet_size > network_capacity_) {
RTC_LOG(LS_VERBOSE) << "Dropping packet: network capacity exceeded";
return static_cast<int>(data_size);
}
}
AddPacketToNetwork(socket, recipient, cur_time, data, data_size,
UDP_HEADER_SIZE, false);
return static_cast<int>(data_size);
}
}
void VirtualSocketServer::SendTcp(VirtualSocket* socket) {
{
webrtc::MutexLock lock(&mutex_);
++sent_packets_;
if (sending_blocked_) {
// Eventually the socket's buffer will fill and VirtualSocket::SendTcp
// will set EWOULDBLOCK.
return;
}
}
// TCP can't send more data than will fill up the receiver's buffer.
// We track the data that is in the buffer plus data in flight using the
// recipient's recv_buffer_size_. Anything beyond that must be stored in the
// sender's buffer. We will trigger the buffered data to be sent when data
// is read from the recv_buffer.
// Lookup the local/remote pair in the connections table.
VirtualSocket* recipient =
LookupConnection(socket->GetLocalAddress(), socket->GetRemoteAddress());
if (!recipient) {
RTC_LOG(LS_VERBOSE) << "Sending data to no one.";
return;
}
int64_t cur_time = TimeMillis();
socket->PurgeNetworkPackets(cur_time);
while (true) {
size_t available = recv_buffer_capacity() - recipient->recv_buffer_size();
size_t max_data_size =
std::min<size_t>(available, TCP_MSS - TCP_HEADER_SIZE);
size_t data_size = std::min(socket->send_buffer_size(), max_data_size);
if (0 == data_size)
break;
AddPacketToNetwork(socket, recipient, cur_time, socket->send_buffer_data(),
data_size, TCP_HEADER_SIZE, true);
recipient->UpdateRecv(data_size);
socket->UpdateSend(data_size);
}
socket->MaybeSignalWriteEvent(send_buffer_capacity());
}
void VirtualSocketServer::SendTcp(const SocketAddress& addr) {
VirtualSocket* sender = LookupBinding(addr);
RTC_DCHECK(nullptr != sender);
SendTcp(sender);
}
void VirtualSocketServer::AddPacketToNetwork(VirtualSocket* sender,
VirtualSocket* recipient,
int64_t cur_time,
const char* data,
size_t data_size,
size_t header_size,
bool ordered) {
RTC_DCHECK(msg_queue_);
uint32_t send_delay = sender->AddPacket(cur_time, data_size + header_size);
// Find the delay for crossing the many virtual hops of the network.
uint32_t transit_delay = GetTransitDelay(sender);
// When the incoming packet is from a binding of the any address, translate it
// to the default route here such that the recipient will see the default
// route.
SocketAddress sender_addr = sender->GetLocalAddress();
IPAddress default_ip = GetDefaultSourceAddress(sender_addr.ipaddr().family());
if (sender_addr.IsAnyIP() && !IPIsUnspec(default_ip)) {
sender_addr.SetIP(default_ip);
}
int64_t ts = cur_time + send_delay + transit_delay;
if (ordered) {
ts = sender->UpdateOrderedDelivery(ts);
}
recipient->PostPacket(TimeDelta::Millis(ts - cur_time),
std::make_unique<Packet>(data, data_size, sender_addr));
}
uint32_t VirtualSocketServer::SendDelay(uint32_t size) {
webrtc::MutexLock lock(&mutex_);
if (bandwidth_ == 0)
return 0;
else
return 1000 * size / bandwidth_;
}
#if 0
void PrintFunction(std::vector<std::pair<double, double> >* f) {
return;
double sum = 0;
for (uint32_t i = 0; i < f->size(); ++i) {
std::cout << (*f)[i].first << '\t' << (*f)[i].second << std::endl;
sum += (*f)[i].second;
}
if (!f->empty()) {
const double mean = sum / f->size();
double sum_sq_dev = 0;
for (uint32_t i = 0; i < f->size(); ++i) {
double dev = (*f)[i].second - mean;
sum_sq_dev += dev * dev;
}
std::cout << "Mean = " << mean << " StdDev = "
<< sqrt(sum_sq_dev / f->size()) << std::endl;
}
}
#endif // <unused>
void VirtualSocketServer::UpdateDelayDistribution() {
webrtc::MutexLock lock(&mutex_);
delay_dist_ = CreateDistribution(delay_mean_, delay_stddev_, delay_samples_);
}
static double PI = 4 * atan(1.0);
static double Normal(double x, double mean, double stddev) {
double a = (x - mean) * (x - mean) / (2 * stddev * stddev);
return exp(-a) / (stddev * sqrt(2 * PI));
}
#if 0 // static unused gives a warning
static double Pareto(double x, double min, double k) {
if (x < min)
return 0;
else
return k * std::pow(min, k) / std::pow(x, k+1);
}
#endif
std::unique_ptr<VirtualSocketServer::Function>
VirtualSocketServer::CreateDistribution(uint32_t mean,
uint32_t stddev,
uint32_t samples) {
auto f = std::make_unique<Function>();
if (0 == stddev) {
f->push_back(Point(mean, 1.0));
} else {
double start = 0;
if (mean >= 4 * static_cast<double>(stddev))
start = mean - 4 * static_cast<double>(stddev);
double end = mean + 4 * static_cast<double>(stddev);
for (uint32_t i = 0; i < samples; i++) {
double x = start + (end - start) * i / (samples - 1);
double y = Normal(x, mean, stddev);
f->push_back(Point(x, y));
}
}
return Resample(Invert(Accumulate(std::move(f))), 0, 1, samples);
}
uint32_t VirtualSocketServer::GetTransitDelay(Socket* socket) {
// Use the delay based on the address if it is set.
auto iter = delay_by_ip_.find(socket->GetLocalAddress().ipaddr());
if (iter != delay_by_ip_.end()) {
return static_cast<uint32_t>(iter->second);
}
// Otherwise, use the delay from the distribution distribution.
size_t index = rand() % delay_dist_->size();
double delay = (*delay_dist_)[index].second;
// RTC_LOG_F(LS_INFO) << "random[" << index << "] = " << delay;
return static_cast<uint32_t>(delay);
}
struct FunctionDomainCmp {
bool operator()(const VirtualSocketServer::Point& p1,
const VirtualSocketServer::Point& p2) {
return p1.first < p2.first;
}
bool operator()(double v1, const VirtualSocketServer::Point& p2) {
return v1 < p2.first;
}
bool operator()(const VirtualSocketServer::Point& p1, double v2) {
return p1.first < v2;
}
};
std::unique_ptr<VirtualSocketServer::Function> VirtualSocketServer::Accumulate(
std::unique_ptr<Function> f) {
RTC_DCHECK(f->size() >= 1);
double v = 0;
for (Function::size_type i = 0; i < f->size() - 1; ++i) {
double dx = (*f)[i + 1].first - (*f)[i].first;
double avgy = ((*f)[i + 1].second + (*f)[i].second) / 2;
(*f)[i].second = v;
v = v + dx * avgy;
}
(*f)[f->size() - 1].second = v;
return f;
}
std::unique_ptr<VirtualSocketServer::Function> VirtualSocketServer::Invert(
std::unique_ptr<Function> f) {
for (Function::size_type i = 0; i < f->size(); ++i)
std::swap((*f)[i].first, (*f)[i].second);
absl::c_sort(*f, FunctionDomainCmp());
return f;
}
std::unique_ptr<VirtualSocketServer::Function> VirtualSocketServer::Resample(
std::unique_ptr<Function> f,
double x1,
double x2,
uint32_t samples) {
auto g = std::make_unique<Function>();
for (size_t i = 0; i < samples; i++) {
double x = x1 + (x2 - x1) * i / (samples - 1);
double y = Evaluate(f.get(), x);
g->push_back(Point(x, y));
}
return g;
}
double VirtualSocketServer::Evaluate(const Function* f, double x) {
Function::const_iterator iter =
absl::c_lower_bound(*f, x, FunctionDomainCmp());
if (iter == f->begin()) {
return (*f)[0].second;
} else if (iter == f->end()) {
RTC_DCHECK(f->size() >= 1);
return (*f)[f->size() - 1].second;
} else if (iter->first == x) {
return iter->second;
} else {
double x1 = (iter - 1)->first;
double y1 = (iter - 1)->second;
double x2 = iter->first;
double y2 = iter->second;
return y1 + (y2 - y1) * (x - x1) / (x2 - x1);
}
}
bool VirtualSocketServer::CanInteractWith(VirtualSocket* local,
VirtualSocket* remote) {
if (!local || !remote) {
return false;
}
IPAddress local_ip = local->GetLocalAddress().ipaddr();
IPAddress remote_ip = remote->GetLocalAddress().ipaddr();
IPAddress local_normalized = local_ip.Normalized();
IPAddress remote_normalized = remote_ip.Normalized();
// Check if the addresses are the same family after Normalization (turns
// mapped IPv6 address into IPv4 addresses).
// This will stop unmapped V6 addresses from talking to mapped V6 addresses.
if (local_normalized.family() == remote_normalized.family()) {
return true;
}
// If ip1 is IPv4 and ip2 is :: and ip2 is not IPV6_V6ONLY.
int remote_v6_only = 0;
remote->GetOption(Socket::OPT_IPV6_V6ONLY, &remote_v6_only);
if (local_ip.family() == AF_INET && !remote_v6_only && IPIsAny(remote_ip)) {
return true;
}
// Same check, backwards.
int local_v6_only = 0;
local->GetOption(Socket::OPT_IPV6_V6ONLY, &local_v6_only);
if (remote_ip.family() == AF_INET && !local_v6_only && IPIsAny(local_ip)) {
return true;
}
// Check to see if either socket was explicitly bound to IPv6-any.
// These sockets can talk with anyone.
if (local_ip.family() == AF_INET6 && local->was_any()) {
return true;
}
if (remote_ip.family() == AF_INET6 && remote->was_any()) {
return true;
}
return false;
}
IPAddress VirtualSocketServer::GetDefaultSourceAddress(int family) {
if (family == AF_INET) {
return default_source_address_v4_;
}
if (family == AF_INET6) {
return default_source_address_v6_;
}
return IPAddress();
}
void VirtualSocketServer::SetDefaultSourceAddress(const IPAddress& from_addr) {
RTC_DCHECK(!IPIsAny(from_addr));
if (from_addr.family() == AF_INET) {
default_source_address_v4_ = from_addr;
} else if (from_addr.family() == AF_INET6) {
default_source_address_v6_ = from_addr;
}
}
void VirtualSocketServer::set_bandwidth(uint32_t bandwidth) {
webrtc::MutexLock lock(&mutex_);
bandwidth_ = bandwidth;
}
void VirtualSocketServer::set_network_capacity(uint32_t capacity) {
webrtc::MutexLock lock(&mutex_);
network_capacity_ = capacity;
}
uint32_t VirtualSocketServer::send_buffer_capacity() const {
webrtc::MutexLock lock(&mutex_);
return send_buffer_capacity_;
}
void VirtualSocketServer::set_send_buffer_capacity(uint32_t capacity) {
webrtc::MutexLock lock(&mutex_);
send_buffer_capacity_ = capacity;
}
uint32_t VirtualSocketServer::recv_buffer_capacity() const {
webrtc::MutexLock lock(&mutex_);
return recv_buffer_capacity_;
}
void VirtualSocketServer::set_recv_buffer_capacity(uint32_t capacity) {
webrtc::MutexLock lock(&mutex_);
recv_buffer_capacity_ = capacity;
}
void VirtualSocketServer::set_delay_mean(uint32_t delay_mean) {
webrtc::MutexLock lock(&mutex_);
delay_mean_ = delay_mean;
}
void VirtualSocketServer::set_delay_stddev(uint32_t delay_stddev) {
webrtc::MutexLock lock(&mutex_);
delay_stddev_ = delay_stddev;
}
void VirtualSocketServer::set_delay_samples(uint32_t delay_samples) {
webrtc::MutexLock lock(&mutex_);
delay_samples_ = delay_samples;
}
void VirtualSocketServer::set_drop_probability(double drop_prob) {
RTC_DCHECK_GE(drop_prob, 0.0);
RTC_DCHECK_LE(drop_prob, 1.0);
webrtc::MutexLock lock(&mutex_);
drop_prob_ = drop_prob;
}
void VirtualSocketServer::set_max_udp_payload(size_t payload_size) {
webrtc::MutexLock lock(&mutex_);
max_udp_payload_ = payload_size;
}
uint32_t VirtualSocketServer::sent_packets() const {
webrtc::MutexLock lock(&mutex_);
return sent_packets_;
}
} // namespace rtc