Peter M. Groen / FlashMQ

Commit ce161b1f6b133d707c01707a7abfe5c5d57f7232

Authored by Wiebe Cazemier
1 parent 3d565018

Incoming and outgoing max packet size

Inline Side-by-side
Showing 5 changed files with 46 additions and 16 deletions
client.cpp
  View file @ce161b1
... ... @@ -31,7 +31,8 @@ Client::Client(int fd, std::shared_ptr<ThreadData> threadData, SSL *ssl, bool we
31 31 fd(fd),
32 32 fuzzMode(fuzzMode),
33 33 initialBufferSize(settings->clientInitialBufferSize), // The client is constructed in the main thread, so we need to use its settings copy
34   - maxPacketSize(settings->maxPacketSize), // Same as initialBufferSize comment.
  34 + maxOutgoingPacketSize(settings->maxPacketSize), // Same as initialBufferSize comment.
  35 + maxIncomingPacketSize(settings->maxPacketSize),
35 36 ioWrapper(ssl, websocket, initialBufferSize, this),
36 37 readbuf(initialBufferSize),
37 38 writebuf(initialBufferSize),
... ... @@ -141,7 +142,7 @@ bool Client::readFdIntoBuffer()
141 142 // Make sure we either always have enough space for a next call of this method, or stop reading the fd.
142 143 if (readbuf.freeSpace() == 0)
143 144 {
144   - if (readbuf.getSize() * 2 < maxPacketSize)
  145 + if (readbuf.getSize() * 2 < this->maxIncomingPacketSize)
145 146 {
146 147 readbuf.doubleSize();
147 148 }
... ... @@ -181,18 +182,27 @@ void Client::writeText(const std::string &amp;text)
181 182  
182 183 int Client::writeMqttPacket(const MqttPacket &packet)
183 184 {
  185 + const size_t packetSize = packet.getSizeIncludingNonPresentHeader();
  186 +
  187 + // "Where a Packet is too large to send, the Server MUST discard it without sending it and then behave as if it had completed
  188 + // sending that Application Message [MQTT-3.1.2-25]."
  189 + if (packetSize > this->maxOutgoingPacketSize)
  190 + {
  191 + return 0;
  192 + }
  193 +
184 194 std::lock_guard<std::mutex> locker(writeBufMutex);
185 195  
186 196 // We have to allow big packets, yet don't allow a slow loris subscriber to grow huge write buffers. This
187 197 // could be enhanced a lot, but it's a start.
188   - const uint32_t growBufMaxTo = std::min<int>(packet.getSizeIncludingNonPresentHeader() * 1000, maxPacketSize);
  198 + const uint32_t growBufMaxTo = std::min<int>(packetSize * 1000, this->maxOutgoingPacketSize);
189 199  
190 200 // Grow as far as we can. We have to make room for one MQTT packet.
191   - writebuf.ensureFreeSpace(packet.getSizeIncludingNonPresentHeader(), growBufMaxTo);
  201 + writebuf.ensureFreeSpace(packetSize, growBufMaxTo);
192 202  
193 203 // And drop a publish when it doesn't fit, even after resizing. This means we do allow pings. And
194 204 // QoS packet are queued and limited elsewhere.
195   - if (packet.packetType == PacketType::PUBLISH && packet.getQos() == 0 && packet.getSizeIncludingNonPresentHeader() > writebuf.freeSpace())
  205 + if (packet.packetType == PacketType::PUBLISH && packet.getQos() == 0 && packetSize > writebuf.freeSpace())
196 206 {
197 207 return 0;
198 208 }
... ... @@ -371,6 +381,16 @@ const std::string &amp;Client::getTopicAlias(const uint16_t id)
371 381 return this->incomingTopicAliases[id];
372 382 }
373 383  
  384 +/**
  385 + * @brief We use this for doing the checks on client traffic, as opposed to using settings.maxPacketSize, because the latter than change on config reload,
  386 + * possibly resulting in exceeding what the other side uses as maximum.
  387 + * @return
  388 + */
  389 +uint32_t Client::getMaxIncomingPacketSize() const
  390 +{
  391 + return this->maxIncomingPacketSize;
  392 +}
  393 +
374 394 #ifndef NDEBUG
375 395 /**
376 396 * @brief IoWrapper::setFakeUpgraded().
... ... @@ -462,14 +482,14 @@ void Client::setClientProperties(ProtocolVersion protocolVersion, const std::str
462 482  
463 483  
464 484 void Client::setClientProperties(ProtocolVersion protocolVersion, const std::string &clientId, const std::string username, bool connectPacketSeen, uint16_t keepalive,
465   - uint32_t maxPacketSize, uint16_t maxOutgoingTopicAliasValue)
  485 + uint32_t maxOutgoingPacketSize, uint16_t maxOutgoingTopicAliasValue)
466 486 {
467 487 this->protocolVersion = protocolVersion;
468 488 this->clientid = clientId;
469 489 this->username = username;
470 490 this->connectPacketSeen = connectPacketSeen;
471 491 this->keepalive = keepalive;
472   - this->maxPacketSize = maxPacketSize;
  492 + this->maxOutgoingPacketSize = maxOutgoingPacketSize;
473 493 this->maxOutgoingTopicAliasValue = maxOutgoingTopicAliasValue;
474 494 }
475 495  
... ...
client.h
  View file @ce161b1
... ... @@ -52,7 +52,9 @@ class Client
52 52 ProtocolVersion protocolVersion = ProtocolVersion::None;
53 53  
54 54 const size_t initialBufferSize = 0;
55   - uint32_t maxPacketSize = 0;
  55 + uint32_t maxOutgoingPacketSize;
  56 + const uint32_t maxIncomingPacketSize;
  57 +
56 58 uint16_t maxOutgoingTopicAliasValue = 0;
57 59  
58 60 IoWrapper ioWrapper;
... ... @@ -111,7 +113,7 @@ public:
111 113 void bufferToMqttPackets(std::vector<MqttPacket> &packetQueueIn, std::shared_ptr<Client> &sender);
112 114 void setClientProperties(ProtocolVersion protocolVersion, const std::string &clientId, const std::string username, bool connectPacketSeen, uint16_t keepalive);
113 115 void setClientProperties(ProtocolVersion protocolVersion, const std::string &clientId, const std::string username, bool connectPacketSeen, uint16_t keepalive,
114   - uint32_t maxPacketSize, uint16_t maxOutgoingTopicAliasValue);
  116 + uint32_t maxOutgoingPacketSize, uint16_t maxOutgoingTopicAliasValue);
115 117 void setWill(const std::string &topic, const std::string &payload, bool retain, char qos);
116 118 void setWill(Publish &&willPublish);
117 119 void clearWill();
... ... @@ -145,6 +147,8 @@ public:
145 147 void setTopicAlias(const uint16_t alias_id, const std::string &topic);
146 148 const std::string &getTopicAlias(const uint16_t id);
147 149  
  150 + uint32_t getMaxIncomingPacketSize() const;
  151 +
148 152 #ifndef NDEBUG
149 153 void setFakeUpgraded();
150 154 #endif
... ...
configfileparser.h
  View file @ce161b1
... ... @@ -30,8 +30,6 @@ License along with FlashMQ. If not, see &lt;https://www.gnu.org/licenses/&gt;.
30 30 #include "listener.h"
31 31 #include "settings.h"
32 32  
33   -#define ABSOLUTE_MAX_PACKET_SIZE 268435461 // 256 MB + 5
34   -
35 33 enum class ConfigParseLevel
36 34 {
37 35 Root,
... ...
mqttpacket.cpp
  View file @ce161b1
... ... @@ -31,6 +31,12 @@ MqttPacket::MqttPacket(CirBuf &amp;buf, size_t packet_len, size_t fixed_header_lengt
31 31 sender(sender)
32 32 {
33 33 assert(packet_len > 0);
  34 +
  35 + if (packet_len > sender->getMaxIncomingPacketSize())
  36 + {
  37 + throw ProtocolError("Incoming packet size exceeded. TODO: DISCONNECT WITH CODE 0x95");
  38 + }
  39 +
34 40 buf.read(bites.data(), packet_len);
35 41  
36 42 protocolVersion = sender->getProtocolVersion();
... ... @@ -338,7 +344,7 @@ void MqttPacket::handleConnect()
338 344  
339 345 uint16_t max_qos_packets = settings.maxQosMsgPendingPerClient;
340 346 uint32_t session_expire = settings.expireSessionsAfterSeconds > 0 ? settings.expireSessionsAfterSeconds : std::numeric_limits<uint32_t>::max();
341   - uint32_t max_packet_size = settings.maxPacketSize;
  347 + uint32_t max_outgoing_packet_size = settings.maxPacketSize;
342 348 uint16_t max_outgoing_topic_aliases = 0; // Default MUST BE 0, meaning server won't initiate aliases
343 349 bool request_response_information = false;
344 350 bool request_problem_information = false;
... ... @@ -361,7 +367,7 @@ void MqttPacket::handleConnect()
361 367 max_qos_packets = std::min<int16_t>(readTwoBytesToUInt16(), max_qos_packets);
362 368 break;
363 369 case Mqtt5Properties::MaximumPacketSize:
364   - max_packet_size = std::min<uint32_t>(readFourBytesToUint32(), max_packet_size);
  370 + max_outgoing_packet_size = std::min<uint32_t>(readFourBytesToUint32(), max_outgoing_packet_size);
365 371 break;
366 372 case Mqtt5Properties::TopicAliasMaximum:
367 373 max_outgoing_topic_aliases = std::min<uint16_t>(readTwoBytesToUInt16(), settings.maxOutgoingTopicAliasValue);
... ... @@ -535,7 +541,7 @@ void MqttPacket::handleConnect()
535 541 clientIdGenerated = true;
536 542 }
537 543  
538   - sender->setClientProperties(protocolVersion, client_id, username, true, keep_alive, max_packet_size, max_outgoing_topic_aliases);
  544 + sender->setClientProperties(protocolVersion, client_id, username, true, keep_alive, max_outgoing_packet_size, max_outgoing_topic_aliases);
539 545  
540 546 if (will_flag)
541 547 sender->setWill(std::move(willpublish));
... ... @@ -573,7 +579,7 @@ void MqttPacket::handleConnect()
573 579 connAck.propertyBuilder->writeSessionExpiry(session_expire);
574 580 connAck.propertyBuilder->writeReceiveMax(max_qos_packets);
575 581 connAck.propertyBuilder->writeRetainAvailable(1);
576   - connAck.propertyBuilder->writeMaxPacketSize(max_packet_size);
  582 + connAck.propertyBuilder->writeMaxPacketSize(sender->getMaxIncomingPacketSize());
577 583 if (clientIdGenerated)
578 584 connAck.propertyBuilder->writeAssignedClientId(client_id);
579 585 connAck.propertyBuilder->writeMaxTopicAliases(settings.maxIncomingTopicAliasValue);
... ...
settings.h
  View file @ce161b1
... ... @@ -24,6 +24,8 @@ License along with FlashMQ. If not, see &lt;https://www.gnu.org/licenses/&gt;.
24 24 #include "mosquittoauthoptcompatwrap.h"
25 25 #include "listener.h"
26 26  
  27 +#define ABSOLUTE_MAX_PACKET_SIZE 268435461 // 256 MB + 5
  28 +
27 29 class Settings
28 30 {
29 31 friend class ConfigFileParser;
... ... @@ -41,7 +43,7 @@ public:
41 43 bool authPluginSerializeInit = false;
42 44 bool authPluginSerializeAuthChecks = false;
43 45 int clientInitialBufferSize = 1024; // Must be power of 2
44   - int maxPacketSize = 268435461; // 256 MB + 5
  46 + int maxPacketSize = ABSOLUTE_MAX_PACKET_SIZE;
45 47 uint16_t maxIncomingTopicAliasValue = 65535;
46 48 uint16_t maxOutgoingTopicAliasValue = 65535;
47 49 #ifdef TESTING
... ...