| // 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/netlink_manager.h" |
| |
| #include <netlink/netlink.h> |
| #include <sys/select.h> |
| #include <sys/time.h> |
| #include <map> |
| |
| #include <base/memory/weak_ptr.h> |
| #include <base/stl_util.h> |
| |
| #include "shill/attribute_list.h" |
| #include "shill/error.h" |
| #include "shill/event_dispatcher.h" |
| #include "shill/generic_netlink_message.h" |
| #include "shill/io_handler.h" |
| #include "shill/logging.h" |
| #include "shill/netlink_message.h" |
| #include "shill/netlink_socket.h" |
| #include "shill/scope_logger.h" |
| #include "shill/shill_time.h" |
| |
| using base::Bind; |
| using base::LazyInstance; |
| using std::list; |
| using std::map; |
| using std::string; |
| |
| namespace shill { |
| |
| namespace { |
| LazyInstance<NetlinkManager> g_netlink_manager = LAZY_INSTANCE_INITIALIZER; |
| } // namespace |
| |
| const char NetlinkManager::kEventTypeConfig[] = "config"; |
| const char NetlinkManager::kEventTypeScan[] = "scan"; |
| const char NetlinkManager::kEventTypeRegulatory[] = "regulatory"; |
| const char NetlinkManager::kEventTypeMlme[] = "mlme"; |
| const long NetlinkManager::kMaximumNewFamilyWaitSeconds = 1; |
| const long NetlinkManager::kMaximumNewFamilyWaitMicroSeconds = 0; |
| |
| NetlinkManager::MessageType::MessageType() : |
| family_id(NetlinkMessage::kIllegalMessageType) {} |
| |
| NetlinkManager::NetlinkManager() |
| : dispatcher_(NULL), |
| weak_ptr_factory_(this), |
| dispatcher_callback_(Bind(&NetlinkManager::OnRawNlMessageReceived, |
| weak_ptr_factory_.GetWeakPtr())), |
| sock_(NULL) {} |
| |
| NetlinkManager *NetlinkManager::GetInstance() { |
| return g_netlink_manager.Pointer(); |
| } |
| |
| void NetlinkManager::Reset(bool full) { |
| ClearBroadcastHandlers(); |
| message_types_.clear(); |
| if (full) { |
| dispatcher_ = NULL; |
| delete sock_; |
| sock_ = NULL; |
| } |
| } |
| |
| void NetlinkManager::OnNewFamilyMessage(const NetlinkMessage &raw_message) { |
| uint16_t family_id; |
| string family_name; |
| |
| if (raw_message.message_type() == ErrorAckMessage::kMessageType) { |
| const ErrorAckMessage *error_ack_message = |
| reinterpret_cast<const ErrorAckMessage *>(&raw_message); |
| if (error_ack_message->error()) { |
| LOG(ERROR) << __func__ << ": Message (seq: " |
| << raw_message.sequence_number() << ") failed: " |
| << error_ack_message->ToString(); |
| } else { |
| SLOG(WiFi, 6) << __func__ << ": Message (seq: " |
| << raw_message.sequence_number() << ") ACKed"; |
| } |
| return; |
| } |
| |
| if (raw_message.message_type() != ControlNetlinkMessage::kMessageType) { |
| LOG(ERROR) << "Received unexpected message type: " |
| << raw_message.message_type(); |
| return; |
| } |
| |
| const ControlNetlinkMessage *message = |
| reinterpret_cast<const ControlNetlinkMessage *>(&raw_message); |
| |
| if (!message->const_attributes()->GetU16AttributeValue(CTRL_ATTR_FAMILY_ID, |
| &family_id)) { |
| LOG(ERROR) << __func__ << ": Couldn't get family_id attribute"; |
| return; |
| } |
| |
| if (!message->const_attributes()->GetStringAttributeValue( |
| CTRL_ATTR_FAMILY_NAME, &family_name)) { |
| LOG(ERROR) << __func__ << ": Couldn't get family_name attribute"; |
| return; |
| } |
| |
| SLOG(WiFi, 3) << "Socket family '" << family_name << "' has id=" << family_id; |
| |
| // Extract the available multicast groups from the message. |
| AttributeListConstRefPtr multicast_groups; |
| if (message->const_attributes()->ConstGetNestedAttributeList( |
| CTRL_ATTR_MCAST_GROUPS, &multicast_groups)) { |
| AttributeListConstRefPtr current_group; |
| |
| for (int i = 1; |
| multicast_groups->ConstGetNestedAttributeList(i, ¤t_group); |
| ++i) { |
| string group_name; |
| uint32_t group_id; |
| if (!current_group->GetStringAttributeValue(CTRL_ATTR_MCAST_GRP_NAME, |
| &group_name)) { |
| LOG(WARNING) << "Expected CTRL_ATTR_MCAST_GRP_NAME, found none"; |
| continue; |
| } |
| if (!current_group->GetU32AttributeValue(CTRL_ATTR_MCAST_GRP_ID, |
| &group_id)) { |
| LOG(WARNING) << "Expected CTRL_ATTR_MCAST_GRP_ID, found none"; |
| continue; |
| } |
| SLOG(WiFi, 3) << " Adding group '" << group_name << "' = " << group_id; |
| message_types_[family_name].groups[group_name] = group_id; |
| } |
| } |
| |
| message_types_[family_name].family_id = family_id; |
| } |
| |
| bool NetlinkManager::Init() { |
| // Install message factory for control class of messages, which has |
| // statically-known message type. |
| message_factory_.AddFactoryMethod( |
| ControlNetlinkMessage::kMessageType, |
| Bind(&ControlNetlinkMessage::CreateMessage)); |
| if (!sock_) { |
| sock_ = new NetlinkSocket; |
| if (!sock_) { |
| LOG(ERROR) << "No memory"; |
| return false; |
| } |
| |
| if (!sock_->Init()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void NetlinkManager::Start(EventDispatcher *dispatcher) { |
| dispatcher_ = dispatcher; |
| CHECK(dispatcher_); |
| // Install ourselves in the shill mainloop so we receive messages on the |
| // netlink socket. |
| dispatcher_handler_.reset(dispatcher_->CreateInputHandler( |
| file_descriptor(), |
| dispatcher_callback_, |
| Bind(&NetlinkManager::OnReadError, weak_ptr_factory_.GetWeakPtr()))); |
| } |
| |
| int NetlinkManager::file_descriptor() const { |
| return (sock_ ? sock_->file_descriptor() : -1); |
| } |
| |
| uint16_t NetlinkManager::GetFamily(string name, |
| const NetlinkMessageFactory::FactoryMethod &message_factory) { |
| MessageType &message_type = message_types_[name]; |
| if (message_type.family_id != NetlinkMessage::kIllegalMessageType) { |
| return message_type.family_id; |
| } |
| if (!sock_) { |
| LOG(FATAL) << "Must call |Init| before this method."; |
| return false; |
| } |
| |
| GetFamilyMessage msg; |
| if (!msg.attributes()->CreateStringAttribute(CTRL_ATTR_FAMILY_NAME, |
| "CTRL_ATTR_FAMILY_NAME")) { |
| LOG(ERROR) << "Couldn't create string attribute"; |
| return false; |
| } |
| if (!msg.attributes()->SetStringAttributeValue(CTRL_ATTR_FAMILY_NAME, name)) { |
| LOG(ERROR) << "Couldn't set string attribute"; |
| return false; |
| } |
| SendMessage(&msg, Bind(&NetlinkManager::OnNewFamilyMessage, |
| weak_ptr_factory_.GetWeakPtr())); |
| |
| // Wait for a response. The code absolutely needs family_ids for its |
| // message types so we do a synchronous wait. It's OK to do this because |
| // a) libnl does a synchronous wait (so there's prior art), b) waiting |
| // asynchronously would add significant and unnecessary complexity to the |
| // code that deals with pending messages that could, potentially, be waiting |
| // for a message type, and c) it really doesn't take very long for the |
| // GETFAMILY / NEWFAMILY transaction to transpire (this transaction was timed |
| // over 20 times and found a maximum duration of 11.1 microseconds and an |
| // average of 4.0 microseconds). |
| struct timeval start_time, now, end_time; |
| struct timeval maximum_wait_duration = {kMaximumNewFamilyWaitSeconds, |
| kMaximumNewFamilyWaitMicroSeconds}; |
| Time *time = Time::GetInstance(); |
| time->GetTimeMonotonic(&start_time); |
| now = start_time; |
| timeradd(&start_time, &maximum_wait_duration, &end_time); |
| |
| do { |
| // Wait with timeout for a message from the netlink socket. |
| fd_set read_fds; |
| FD_ZERO(&read_fds); |
| FD_SET(file_descriptor(), &read_fds); |
| struct timeval wait_duration; |
| timersub(&end_time, &now, &wait_duration); |
| int result = select(file_descriptor() + 1, &read_fds, NULL, NULL, |
| &wait_duration); |
| if (result < 0) { |
| PLOG(ERROR) << "Select failed"; |
| return NetlinkMessage::kIllegalMessageType; |
| } |
| if (result == 0) { |
| LOG(WARNING) << "Timed out waiting for family_id for family '" |
| << name << "'."; |
| return NetlinkMessage::kIllegalMessageType; |
| } |
| |
| // Read and process any messages. |
| ByteString received; |
| sock_->RecvMessage(&received); |
| InputData input_data(received.GetData(), received.GetLength()); |
| OnRawNlMessageReceived(&input_data); |
| if (message_type.family_id != NetlinkMessage::kIllegalMessageType) { |
| uint16_t family_id = message_type.family_id; |
| if (family_id != NetlinkMessage::kIllegalMessageType) { |
| message_factory_.AddFactoryMethod(family_id, message_factory); |
| } |
| time->GetTimeMonotonic(&now); |
| timersub(&now, &start_time, &wait_duration); |
| SLOG(WiFi, 5) << "Found id " << message_type.family_id |
| << " for name '" << name << "' in " |
| << wait_duration.tv_sec << " sec, " |
| << wait_duration.tv_usec << " usec."; |
| return message_type.family_id; |
| } |
| time->GetTimeMonotonic(&now); |
| } while (timercmp(&now, &end_time, <)); |
| |
| LOG(ERROR) << "Timed out waiting for family_id for family '" << name << "'."; |
| return NetlinkMessage::kIllegalMessageType; |
| } |
| |
| bool NetlinkManager::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) << "NetlinkManager::" << __func__ << " - adding handler"; |
| broadcast_handlers_.push_back(handler); |
| return true; |
| } |
| |
| bool NetlinkManager::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 NetlinkManager::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 NetlinkManager::ClearBroadcastHandlers() { |
| broadcast_handlers_.clear(); |
| } |
| |
| bool NetlinkManager::SendMessage(NetlinkMessage *message, |
| const NetlinkMessageHandler &handler) { |
| if (!message) { |
| LOG(ERROR) << "Message is NULL."; |
| return false; |
| } |
| |
| ByteString message_string = message->Encode(this->GetSequenceNumber()); |
| |
| if (handler.is_null()) { |
| SLOG(WiFi, 3) << "Handler for message was null."; |
| } else if (ContainsKey(message_handlers_, message->sequence_number())) { |
| LOG(ERROR) << "A handler already existed for sequence: " |
| << message->sequence_number(); |
| return false; |
| } else { |
| message_handlers_[message->sequence_number()] = handler; |
| } |
| |
| SLOG(WiFi, 5) << "NL Message " << message->sequence_number() |
| << " Sending (" << message_string.GetLength() |
| << " bytes) ===>"; |
| message->Print(6, 7); |
| NetlinkMessage::PrintBytes(8, message_string.GetConstData(), |
| message_string.GetLength()); |
| |
| if (!sock_->SendMessage(message_string)) { |
| LOG(ERROR) << "Failed to send Netlink message."; |
| return false; |
| } |
| return true; |
| } |
| |
| bool NetlinkManager::RemoveMessageHandler(const NetlinkMessage &message) { |
| if (!ContainsKey(message_handlers_, message.sequence_number())) { |
| return false; |
| } |
| message_handlers_.erase(message.sequence_number()); |
| return true; |
| } |
| |
| uint32_t NetlinkManager::GetSequenceNumber() { |
| return sock_ ? |
| sock_->GetSequenceNumber() : NetlinkMessage::kBroadcastSequenceNumber; |
| } |
| |
| bool NetlinkManager::SubscribeToEvents(const string &family_id, |
| const string &group_name) { |
| if (!ContainsKey(message_types_, family_id)) { |
| LOG(ERROR) << "Family '" << family_id << "' doesn't exist"; |
| return false; |
| } |
| |
| if (!ContainsKey(message_types_[family_id].groups, group_name)) { |
| LOG(ERROR) << "Group '" << group_name << "' doesn't exist in family '" |
| << family_id << "'"; |
| return false; |
| } |
| |
| uint32_t group_id = message_types_[family_id].groups[group_name]; |
| if (!sock_) { |
| LOG(FATAL) << "Need to call |Init| first."; |
| } |
| return sock_->SubscribeToEvents(group_id); |
| } |
| |
| void NetlinkManager::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 NetlinkManager::OnNlMessageReceived(nlmsghdr *msg) { |
| if (!msg) { |
| LOG(ERROR) << __func__ << "() called with null header."; |
| return; |
| } |
| const uint32 sequence_number = msg->nlmsg_seq; |
| scoped_ptr<NetlinkMessage> message(message_factory_.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, 5) << "NL Message " << sequence_number |
| << " Received (" << msg->nlmsg_len << " bytes) <==="; |
| message->Print(6, 7); |
| NetlinkMessage::PrintBytes(8, reinterpret_cast<const unsigned char *>(msg), |
| msg->nlmsg_len); |
| |
| // Call (then erase) any message-specific handler. |
| if (ContainsKey(message_handlers_, sequence_number)) { |
| SLOG(WiFi, 6) << "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); |
| } |
| |
| if (message->message_type() == ErrorAckMessage::kMessageType) { |
| const ErrorAckMessage *error_ack_message = |
| reinterpret_cast<const ErrorAckMessage *>(message.get()); |
| if (error_ack_message->error()) { |
| SLOG(WiFi, 3) << "Removing callback"; |
| message_handlers_.erase(sequence_number); |
| } else { |
| SLOG(WiFi, 3) << "ACK message -- not removing callback"; |
| } |
| } else if ((message->flags() & NLM_F_MULTI) && |
| (message->message_type() != NLMSG_DONE)) { |
| SLOG(WiFi, 6) << "Multi-part message -- not removing callback"; |
| } else { |
| SLOG(WiFi, 6) << "Removing callback"; |
| message_handlers_.erase(sequence_number); |
| } |
| } else { |
| list<NetlinkMessageHandler>::const_iterator i = |
| broadcast_handlers_.begin(); |
| while (i != broadcast_handlers_.end()) { |
| SLOG(WiFi, 6) << __func__ << " - calling broadcast handler"; |
| i->Run(*message); |
| ++i; |
| } |
| } |
| } |
| |
| void NetlinkManager::OnReadError(const Error &error) { |
| // TODO(wdg): When netlink_manager 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) << "NetlinkManager's netlink Socket read returns error: " |
| << error.message(); |
| } |
| |
| |
| } // namespace shill. |