| // Copyright (c) 2012 The Chromium OS Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "shill/config80211.h" |
| |
| #include <ctype.h> |
| #include <netlink/msg.h> |
| |
| #include <map> |
| #include <sstream> |
| #include <string> |
| |
| #include <base/memory/weak_ptr.h> |
| #include <base/stl_util.h> |
| |
| #include "shill/error.h" |
| #include "shill/io_handler.h" |
| #include "shill/logging.h" |
| #include "shill/nl80211_message.h" |
| #include "shill/nl80211_socket.h" |
| #include "shill/scope_logger.h" |
| |
| using base::Bind; |
| using base::LazyInstance; |
| using std::list; |
| using std::string; |
| |
| namespace shill { |
| |
| namespace { |
| LazyInstance<Config80211> g_config80211 = LAZY_INSTANCE_INITIALIZER; |
| } // namespace |
| |
| Config80211::EventTypeStrings *Config80211::event_types_ = NULL; |
| |
| Config80211::Config80211() |
| : wifi_state_(kWifiDown), |
| dispatcher_(NULL), |
| weak_ptr_factory_(this), |
| dispatcher_callback_(Bind(&Config80211::OnRawNlMessageReceived, |
| weak_ptr_factory_.GetWeakPtr())), |
| sock_(NULL) { |
| } |
| |
| Config80211::~Config80211() { |
| // Since Config80211 is a singleton, it should be safe to delete a static |
| // member. |
| delete event_types_; |
| event_types_ = NULL; |
| } |
| |
| Config80211 *Config80211::GetInstance() { |
| return g_config80211.Pointer(); |
| } |
| |
| void Config80211::Reset(bool full) { |
| wifi_state_ = kWifiDown; |
| subscribed_events_.clear(); |
| ClearBroadcastHandlers(); |
| if (full) { |
| dispatcher_ = NULL; |
| delete sock_; |
| sock_ = NULL; |
| } |
| } |
| |
| bool Config80211::Init(EventDispatcher *dispatcher) { |
| if (!sock_) { |
| sock_ = new Nl80211Socket; |
| if (!sock_) { |
| LOG(ERROR) << "No memory"; |
| return false; |
| } |
| |
| if (!sock_->Init()) { |
| return false; |
| } |
| // Don't make libnl do the sequence checking (because it'll not like |
| // the broadcast messages for which we'll eventually ask). We'll do all the |
| // sequence checking we need. |
| sock_->DisableSequenceChecking(); |
| } |
| |
| if (!event_types_) { |
| event_types_ = new EventTypeStrings; |
| (*event_types_)[Config80211::kEventTypeConfig] = "config"; |
| (*event_types_)[Config80211::kEventTypeScan] = "scan"; |
| (*event_types_)[Config80211::kEventTypeRegulatory] = "regulatory"; |
| (*event_types_)[Config80211::kEventTypeMlme] = "mlme"; |
| } |
| |
| dispatcher_ = dispatcher; |
| return true; |
| } |
| |
| bool Config80211::AddBroadcastHandler(const NetlinkMessageHandler &handler) { |
| list<NetlinkMessageHandler>::iterator i; |
| if (FindBroadcastHandler(handler)) { |
| LOG(WARNING) << "Trying to re-add a handler"; |
| return false; // Should only be one copy in the list. |
| } |
| if (handler.is_null()) { |
| LOG(WARNING) << "Trying to add a NULL handler"; |
| return false; |
| } |
| // And add the handler to the list. |
| SLOG(WiFi, 3) << "Config80211::" << __func__ << " - adding handler"; |
| broadcast_handlers_.push_back(handler); |
| return true; |
| } |
| |
| bool Config80211::RemoveBroadcastHandler( |
| const NetlinkMessageHandler &handler) { |
| list<NetlinkMessageHandler>::iterator i; |
| for (i = broadcast_handlers_.begin(); i != broadcast_handlers_.end(); ++i) { |
| if ((*i).Equals(handler)) { |
| broadcast_handlers_.erase(i); |
| // Should only be one copy in the list so we don't have to continue |
| // looking for another one. |
| return true; |
| } |
| } |
| LOG(WARNING) << "NetlinkMessageHandler not found."; |
| return false; |
| } |
| |
| bool Config80211::FindBroadcastHandler(const NetlinkMessageHandler &handler) |
| const { |
| list<NetlinkMessageHandler>::const_iterator i; |
| for (i = broadcast_handlers_.begin(); i != broadcast_handlers_.end(); ++i) { |
| if ((*i).Equals(handler)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void Config80211::ClearBroadcastHandlers() { |
| broadcast_handlers_.clear(); |
| } |
| |
| bool Config80211::SendMessage(NetlinkMessage *message, |
| const NetlinkMessageHandler &handler) { |
| if (!message) { |
| LOG(ERROR) << "Message is NULL."; |
| return false; |
| } |
| |
| ByteString message_string = message->Encode(this->GetSequenceNumber(), |
| sock_->family_id()); |
| |
| SLOG(WiFi, 6) << "NL Message " << message->sequence_number() |
| << " Sending ===>"; |
| message->Print(6); |
| |
| if (!sock_->SendMessage(message_string)) { |
| LOG(ERROR) << "Failed to send Netlink message."; |
| return false; |
| } |
| if (handler.is_null()) { |
| LOG(INFO) << "Handler for message was null."; |
| return true; |
| } |
| if (ContainsKey(message_handlers_, message->sequence_number())) { |
| LOG(ERROR) << "Sent message, but already had a handler for this message?"; |
| return false; |
| } |
| message_handlers_[message->sequence_number()] = handler; |
| LOG(INFO) << "Sent Netlink message with sequence number: " |
| << message->sequence_number(); |
| return true; |
| } |
| |
| bool Config80211::RemoveMessageHandler(const NetlinkMessage &message) { |
| if (!ContainsKey(message_handlers_, message.sequence_number())) { |
| return false; |
| } |
| message_handlers_.erase(message.sequence_number()); |
| return true; |
| } |
| |
| // static |
| bool Config80211::GetEventTypeString(EventType type, string *value) { |
| if (!value) { |
| LOG(ERROR) << "NULL |value|"; |
| return false; |
| } |
| if (!event_types_) { |
| LOG(ERROR) << "NULL |event_types_|"; |
| return false; |
| } |
| |
| EventTypeStrings::iterator match = (*event_types_).find(type); |
| if (match == (*event_types_).end()) { |
| LOG(ERROR) << "Event type " << type << " not found"; |
| return false; |
| } |
| *value = match->second; |
| return true; |
| } |
| |
| void Config80211::SetWifiState(WifiState new_state) { |
| if (wifi_state_ == new_state) { |
| return; |
| } |
| |
| if (!sock_) { |
| LOG(ERROR) << "Config80211::Init needs to be called before this"; |
| return; |
| } |
| |
| if (new_state == kWifiUp) { |
| // Install ourselves in the shill mainloop so we receive messages on the |
| // nl80211 socket. |
| if (dispatcher_) { |
| dispatcher_handler_.reset(dispatcher_->CreateInputHandler( |
| GetFd(), |
| dispatcher_callback_, |
| Bind(&Config80211::OnReadError, weak_ptr_factory_.GetWeakPtr()))); |
| } |
| |
| // If we're newly-up, subscribe to all the event types that have been |
| // requested. |
| SubscribedEvents::const_iterator i; |
| for (i = subscribed_events_.begin(); i != subscribed_events_.end(); ++i) { |
| ActuallySubscribeToEvents(*i); |
| } |
| } |
| wifi_state_ = new_state; |
| } |
| |
| uint32_t Config80211::GetSequenceNumber() { |
| return sock_ ? |
| sock_->GetSequenceNumber() : NetlinkMessage::kBroadcastSequenceNumber; |
| } |
| |
| bool Config80211::SubscribeToEvents(EventType type) { |
| bool it_worked = true; |
| if (!ContainsKey(subscribed_events_, type)) { |
| if (wifi_state_ == kWifiUp) { |
| it_worked = ActuallySubscribeToEvents(type); |
| } |
| // |subscribed_events_| is a list of events to which we want to subscribe |
| // when wifi comes up (including when it comes _back_ up after it goes |
| // down sometime in the future). |
| subscribed_events_.insert(type); |
| } |
| return it_worked; |
| } |
| |
| bool Config80211::ActuallySubscribeToEvents(EventType type) { |
| string group_name; |
| |
| if (!GetEventTypeString(type, &group_name)) { |
| return false; |
| } |
| if (!sock_->AddGroupMembership(group_name)) { |
| return false; |
| } |
| return true; |
| } |
| |
| void Config80211::OnRawNlMessageReceived(InputData *data) { |
| if (!data) { |
| LOG(ERROR) << __func__ << "() called with null header."; |
| return; |
| } |
| unsigned char *buf = data->buf; |
| unsigned char *end = buf + data->len; |
| while (buf < end) { |
| nlmsghdr *msg = reinterpret_cast<nlmsghdr *>(buf); |
| // Discard the message if there're not enough bytes to a) tell the code how |
| // much space is in the message (i.e., to access nlmsg_len) or b) to hold |
| // the entire message. The odd calculation is there to keep the code from |
| // potentially calculating an illegal address (causes a segfault on some |
| // architectures). |
| size_t bytes_left = end - buf; |
| if (((bytes_left < (offsetof(nlmsghdr, nlmsg_len) + |
| sizeof(msg->nlmsg_len))) || |
| (bytes_left < msg->nlmsg_len))) { |
| LOG(ERROR) << "Discarding incomplete message."; |
| return; |
| } |
| OnNlMessageReceived(msg); |
| buf += msg->nlmsg_len; |
| } |
| } |
| |
| void Config80211::OnNlMessageReceived(nlmsghdr *msg) { |
| if (!msg) { |
| LOG(ERROR) << __func__ << "() called with null header."; |
| return; |
| } |
| const uint32 sequence_number = msg->nlmsg_seq; |
| scoped_ptr<NetlinkMessage> message(NetlinkMessageFactory::CreateMessage(msg)); |
| if (message == NULL) { |
| SLOG(WiFi, 3) << "NL Message " << sequence_number << " <==="; |
| SLOG(WiFi, 3) << __func__ << "(msg:NULL)"; |
| return; // Skip current message, continue parsing buffer. |
| } |
| SLOG(WiFi, 3) << "NL Message " << sequence_number |
| << " Received (" << msg->nlmsg_len << " bytes) <==="; |
| message->Print(6); |
| NetlinkMessage::PrintBytes(8, reinterpret_cast<const unsigned char *>(msg), |
| msg->nlmsg_len); |
| |
| // Call (then erase) any message-specific handler. |
| // TODO(wdg): Support multi-part messages; don't delete handler until last |
| // part appears. |
| if (ContainsKey(message_handlers_, sequence_number)) { |
| SLOG(WiFi, 3) << "found message-specific handler"; |
| if (message_handlers_[sequence_number].is_null()) { |
| LOG(ERROR) << "NetlinkMessageHandler exists but is NULL for ID " |
| << sequence_number; |
| } else { |
| message_handlers_[sequence_number].Run(*message); |
| } |
| message_handlers_.erase(sequence_number); |
| } else { |
| list<NetlinkMessageHandler>::const_iterator i = |
| broadcast_handlers_.begin(); |
| while (i != broadcast_handlers_.end()) { |
| SLOG(WiFi, 3) << __func__ << " - calling broadcast handler"; |
| i->Run(*message); |
| ++i; |
| } |
| } |
| } |
| |
| void Config80211::OnReadError(const Error &error) { |
| // TODO(wdg): When config80211 is used for scan, et al., this should either be |
| // LOG(FATAL) or the code should properly deal with errors, e.g., dropped |
| // messages due to the socket buffer being full. |
| LOG(ERROR) << "Config80211's netlink Socket read returns error: " |
| << error.message(); |
| } |
| |
| |
| } // namespace shill. |