net/socket/websocket_endpoint_lock_manager.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/socket/websocket_endpoint_lock_manager.h"
   6
   7 #include <utility>
   8
   9 #include "base/bind.h"
  10 #include "base/logging.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "net/base/net_errors.h"
  13 #include "net/log/net_log.h"
  14
  15 namespace net {
  16
  17 namespace {
  18
  19 // This delay prevents DoS attacks.
  20 // TODO(ricea): Replace this with randomised truncated exponential backoff.
  21 // See crbug.com/377613.
  22 const int kUnlockDelayInMs = 10;
  23
  24 }  // namespace
  25
  26 WebSocketEndpointLockManager::Waiter::~Waiter() {
  27   if (next()) {
  28     DCHECK(previous());
  29     RemoveFromList();
  30   }
  31 }
  32
  33 WebSocketEndpointLockManager* WebSocketEndpointLockManager::GetInstance() {
  34   return Singleton<WebSocketEndpointLockManager>::get();
  35 }
  36
  37 int WebSocketEndpointLockManager::LockEndpoint(const IPEndPoint& endpoint,
  38                                                Waiter* waiter) {
  39   LockInfoMap::value_type insert_value(endpoint, LockInfo());
  40   std::pair<LockInfoMap::iterator, bool> rv =
  41       lock_info_map_.insert(insert_value);
  42   LockInfo& lock_info_in_map = rv.first->second;
  43   if (rv.second) {
  44     DVLOG(3) << "Locking endpoint " << endpoint.ToString();
  45     lock_info_in_map.queue.reset(new LockInfo::WaiterQueue);
  46     return OK;
  47   }
  48   DVLOG(3) << "Waiting for endpoint " << endpoint.ToString();
  49   lock_info_in_map.queue->Append(waiter);
  50   return ERR_IO_PENDING;
  51 }
  52
  53 void WebSocketEndpointLockManager::RememberSocket(StreamSocket* socket,
  54                                                   const IPEndPoint& endpoint) {
  55   LockInfoMap::iterator lock_info_it = lock_info_map_.find(endpoint);
  56   CHECK(lock_info_it != lock_info_map_.end());
  57   bool inserted =
  58       socket_lock_info_map_.insert(SocketLockInfoMap::value_type(
  59                                        socket, lock_info_it)).second;
  60   DCHECK(inserted);
  61   DCHECK(!lock_info_it->second.socket);
  62   lock_info_it->second.socket = socket;
  63   DVLOG(3) << "Remembered (StreamSocket*)" << socket << " for "
  64            << endpoint.ToString() << " (" << socket_lock_info_map_.size()
  65            << " socket(s) remembered)";
  66 }
  67
  68 void WebSocketEndpointLockManager::UnlockSocket(StreamSocket* socket) {
  69   SocketLockInfoMap::iterator socket_it = socket_lock_info_map_.find(socket);
  70   if (socket_it == socket_lock_info_map_.end())
  71     return;
  72
  73   LockInfoMap::iterator lock_info_it = socket_it->second;
  74
  75   DVLOG(3) << "Unlocking (StreamSocket*)" << socket << " for "
  76            << lock_info_it->first.ToString() << " ("
  77            << socket_lock_info_map_.size() << " socket(s) left)";
  78   socket_lock_info_map_.erase(socket_it);
  79   DCHECK_EQ(socket, lock_info_it->second.socket);
  80   lock_info_it->second.socket = NULL;
  81   UnlockEndpointAfterDelay(lock_info_it->first);
  82 }
  83
  84 void WebSocketEndpointLockManager::UnlockEndpoint(const IPEndPoint& endpoint) {
  85   LockInfoMap::iterator lock_info_it = lock_info_map_.find(endpoint);
  86   if (lock_info_it == lock_info_map_.end())
  87     return;
  88   if (lock_info_it->second.socket)
  89     EraseSocket(lock_info_it);
  90   UnlockEndpointAfterDelay(endpoint);
  91 }
  92
  93 bool WebSocketEndpointLockManager::IsEmpty() const {
  94   return lock_info_map_.empty() && socket_lock_info_map_.empty();
  95 }
  96
  97 base::TimeDelta WebSocketEndpointLockManager::SetUnlockDelayForTesting(
  98     base::TimeDelta new_delay) {
  99   base::TimeDelta old_delay = unlock_delay_;
 100   unlock_delay_ = new_delay;
 101   return old_delay;
 102 }
 103
 104 WebSocketEndpointLockManager::LockInfo::LockInfo() : socket(NULL) {}
 105 WebSocketEndpointLockManager::LockInfo::~LockInfo() {
 106   DCHECK(!socket);
 107 }
 108
 109 WebSocketEndpointLockManager::LockInfo::LockInfo(const LockInfo& rhs)
 110     : socket(rhs.socket) {
 111   DCHECK(!rhs.queue);
 112 }
 113
 114 WebSocketEndpointLockManager::WebSocketEndpointLockManager()
 115     : unlock_delay_(base::TimeDelta::FromMilliseconds(kUnlockDelayInMs)),
 116       pending_unlock_count_(0),
 117       weak_factory_(this) {
 118 }
 119
 120 WebSocketEndpointLockManager::~WebSocketEndpointLockManager() {
 121   DCHECK_EQ(lock_info_map_.size(), pending_unlock_count_);
 122   DCHECK(socket_lock_info_map_.empty());
 123 }
 124
 125 void WebSocketEndpointLockManager::UnlockEndpointAfterDelay(
 126     const IPEndPoint& endpoint) {
 127   DVLOG(3) << "Delaying " << unlock_delay_.InMilliseconds()
 128            << "ms before unlocking endpoint " << endpoint.ToString();
 129   ++pending_unlock_count_;
 130   base::MessageLoop::current()->PostDelayedTask(
 131       FROM_HERE,
 132       base::Bind(&WebSocketEndpointLockManager::DelayedUnlockEndpoint,
 133                  weak_factory_.GetWeakPtr(), endpoint),
 134       unlock_delay_);
 135 }
 136
 137 void WebSocketEndpointLockManager::DelayedUnlockEndpoint(
 138     const IPEndPoint& endpoint) {
 139   LockInfoMap::iterator lock_info_it = lock_info_map_.find(endpoint);
 140   DCHECK_GT(pending_unlock_count_, 0U);
 141   --pending_unlock_count_;
 142   if (lock_info_it == lock_info_map_.end())
 143     return;
 144   DCHECK(!lock_info_it->second.socket);
 145   LockInfo::WaiterQueue* queue = lock_info_it->second.queue.get();
 146   DCHECK(queue);
 147   if (queue->empty()) {
 148     DVLOG(3) << "Unlocking endpoint " << lock_info_it->first.ToString();
 149     lock_info_map_.erase(lock_info_it);
 150     return;
 151   }
 152
 153   DVLOG(3) << "Unlocking endpoint " << lock_info_it->first.ToString()
 154            << " and activating next waiter";
 155   Waiter* next_job = queue->head()->value();
 156   next_job->RemoveFromList();
 157   next_job->GotEndpointLock();
 158 }
 159
 160 void WebSocketEndpointLockManager::EraseSocket(
 161     LockInfoMap::iterator lock_info_it) {
 162   DVLOG(3) << "Removing (StreamSocket*)" << lock_info_it->second.socket
 163            << " for " << lock_info_it->first.ToString() << " ("
 164            << socket_lock_info_map_.size() << " socket(s) left)";
 165   size_t erased = socket_lock_info_map_.erase(lock_info_it->second.socket);
 166   DCHECK_EQ(1U, erased);
 167   lock_info_it->second.socket = NULL;
 168 }
 169
 170 }  // namespace net