http, i2pcontrol: use thread-safe snapshots for session/tunnel lists

daemon/HTTPServer.cpp

@@ -440,7 +440,7 @@ namespace http {
 	{
 		std::string webroot; i2p::config::GetOption("http.webroot", webroot);
 		s << "<b>" << tr("Local Destinations") << ":</b><br>\r\n<div class=\"list\">\r\n";
-		for (auto& it: i2p::client::context.GetDestinations ())
+		for (auto& it: i2p::client::context.GetDestinationsList ())
 		{
 			auto ident = it.second->GetIdentHash ();
 			s << "<div class=\"listitem\"><a href=\"" << webroot << "?page=" << HTTP_PAGE_LOCAL_DESTINATION << "&b32=" << ident.ToBase32 () << "\">";
@@ -449,10 +449,11 @@ namespace http {
 		s << "</div>\r\n<br>\r\n";
 
 		auto i2cpServer = i2p::client::context.GetI2CPServer ();
-		if (i2cpServer && !(i2cpServer->GetSessions ().empty ()))
+		auto i2cpSessions = i2cpServer ? i2cpServer->GetSessionsList () : std::vector<std::pair<uint16_t, std::shared_ptr<i2p::client::I2CPSession> > > ();
+		if (!i2cpSessions.empty ())
 		{
 			s << "<br><b>I2CP "<< tr("Local Destinations") << ":</b><br>\r\n<div class=\"list\">\r\n";
-			for (auto& it: i2cpServer->GetSessions ())
+			for (auto& it: i2cpSessions)
 			{
 				auto dest = it.second->GetDestination ();
 				if (dest)
@@ -523,15 +524,15 @@ namespace http {
 			  << "<th>" << tr("Type") << "</th>"
 			  << "<th>" << tr("EncType") << "</th>"
 			  << "</tr></thead>\r\n<tbody class=\"tableitem\">";
-			for(auto& it: dest->GetLeaseSets ())
+			for(auto& it: dest->GetLeaseSetsList ())
 			{
 				s << "<tr>"
-				  << "<td>" << it.first.ToBase32 () << "</td>"
+				  << "<td>" << it->GetIdentHash ().ToBase32 () << "</td>"
 				  << "<td><a class=\"button\" href=\"" << webroot << "?cmd=" << HTTP_COMMAND_EXPIRELEASE<< "&b32=" << dest->GetIdentHash ().ToBase32 ()
-				  << "&lease=" << it.first.ToBase32 () << "&token=" << token << "\" title=\"" << tr("Expire LeaseSet") << "\"> &#10008; </a></td>"
-				  << "<td>" << (int)it.second->GetStoreType () << "</td>";
-				if (!it.second->IsIncompatibleCrypto ())
-					s << "<td>" << (int)it.second->GetEncryptionType () <<"</td>";
+				  << "&lease=" << it->GetIdentHash ().ToBase32 () << "&token=" << token << "\" title=\"" << tr("Expire LeaseSet") << "\"> &#10008; </a></td>"
+				  << "<td>" << (int)it->GetStoreType () << "</td>";
+				if (!it->IsIncompatibleCrypto ())
+					s << "<td>" << (int)it->GetEncryptionType () <<"</td>";
 				else
 					s << "<td>n/a</td>";
 				s << "</tr>\r\n";
@@ -545,7 +546,7 @@ namespace http {
 		if (pool)
 		{
 			s << "<b>" << tr("Inbound tunnels") << ":</b><br>\r\n<div class=\"list\">\r\n";
-			for (auto & it : pool->GetInboundTunnels ()) {
+			for (auto & it : pool->GetInboundTunnelsList ()) {
 				s << "<div class=\"listitem\">";
 				// for each tunnel hop if not zero-hop
 				if (it->GetNumHops ())
@@ -567,7 +568,7 @@ namespace http {
 			}
 			s << "</div>\r\n<br>\r\n";
 			s << "<b>" << tr("Outbound tunnels") << ":</b><br>\r\n<div class=\"list\">\r\n";
-			for (auto & it : pool->GetOutboundTunnels ()) {
+			for (auto & it : pool->GetOutboundTunnelsList ()) {
 				s << "<div class=\"listitem\">";
 				s << it->GetTunnelID () << ":me &#8658;";
 				// for each tunnel hop if not zero-hop
@@ -593,9 +594,10 @@ namespace http {
 
 		s << "<b>" << tr("Tags") << "</b><br>\r\n"
 		  << tr("Incoming") << ": <i>" << dest->GetNumIncomingTags () << "</i><br>\r\n";
-		if (!dest->GetSessions ().empty ()) {
+		auto sessionsList = dest->GetSessionsList ();
+		if (!sessionsList.empty ()) {
 			std::stringstream tmp_s; uint32_t out_tags = 0;
-			for (const auto& it: dest->GetSessions ()) {
+			for (const auto& it: sessionsList) {
 				tmp_s << "<tr><td>" << i2p::client::context.GetAddressBook ().ToAddress(it.first) << "</td><td>" << it.second->GetNumOutgoingTags () << "</td></tr>\r\n";
 				out_tags += it.second->GetNumOutgoingTags ();
 			}
@@ -612,11 +614,12 @@ namespace http {
 		auto numECIESx25519Tags = dest->GetNumIncomingECIESx25519Tags ();
 		if (numECIESx25519Tags > 0) {
 			s << "<b>ECIESx25519</b><br>\r\n" << tr("Incoming Tags") << ": <i>" << numECIESx25519Tags << "</i><br>\r\n";
-			if (!dest->GetECIESx25519Sessions ().empty ())
+			auto eciesSessionsList = dest->GetECIESx25519SessionsList ().get ();
+			if (!eciesSessionsList.empty ())
 			{
 				std::stringstream tmp_s; uint32_t ecies_sessions = 0;
-				for (const auto& it: dest->GetECIESx25519Sessions ()) {
-					tmp_s << "<tr><td>" << i2p::client::context.GetAddressBook ().ToAddress(it.second->GetDestination ()) << "</td><td>" << it.second->GetState () << "</td></tr>\r\n";
+				for (const auto& it: eciesSessionsList) {
+					tmp_s << "<tr><td>" << i2p::client::context.GetAddressBook ().ToAddress(it->GetDestination ()) << "</td><td>" << it->GetState () << "</td></tr>\r\n";
 					ecies_sessions++;
 				}
 				s << "<div class='slide'><label for='slide-ecies-sessions'>" << tr("Tags sessions") << ": <i>" << ecies_sessions << "</i></label>\r\n"
@@ -696,9 +699,9 @@ namespace http {
 		if (i2cpServer)
 		{
 			s << "<b>I2CP " << tr("Local Destination") << ":</b><br>\r\n<br>\r\n";
-			auto it = i2cpServer->GetSessions ().find (std::stoi (id));
-			if (it != i2cpServer->GetSessions ().end ())
-				ShowLeaseSetDestination (s, it->second->GetDestination (), 0);
+			auto session = i2cpServer->FindSessionByID ((uint16_t)std::stoi (id));
+			if (session)
+				ShowLeaseSetDestination (s, session->GetDestination (), 0);
 			else
 				ShowError(s, tr("I2CP session not found"));
 		}
@@ -776,7 +779,7 @@ namespace http {
 		auto ExplPool = i2p::tunnel::tunnels.GetExploratoryPool ();
 
 		s << "<b>" << tr("Inbound tunnels") << ":</b><br>\r\n<div class=\"list\">\r\n";
-		for (auto & it : i2p::tunnel::tunnels.GetInboundTunnels ()) {
+		for (auto & it : i2p::tunnel::tunnels.GetInboundTunnelsList ()) {
 			s << "<div class=\"listitem\">";
 			if (it->GetNumHops ())
 			{
@@ -797,7 +800,7 @@ namespace http {
 		}
 		s << "</div>\r\n<br>\r\n";
 		s << "<b>" << tr("Outbound tunnels") << ":</b><br>\r\n<div class=\"list\">\r\n";
-		for (auto & it : i2p::tunnel::tunnels.GetOutboundTunnels ()) {
+		for (auto & it : i2p::tunnel::tunnels.GetOutboundTunnelsList ()) {
 			s << "<div class=\"listitem\">";
 			s << it->GetTunnelID () << ":me &#8658;";
 			// for each tunnel hop if not zero-hop
@@ -899,7 +902,7 @@ namespace http {
 			s << "<table>\r\n";
 			s << "<thead><tr><th>&#8658;</th><th>ID</th><th>&#8658;</th><th>" << tr("Amount") << "</th><th>" << tr("Next") << "</th></tr></thead>\r\n";
 			s << "<tbody class=\"tableitem\">\r\n";
-			for (const auto& it: i2p::tunnel::tunnels.GetTransitTunnels ())
+			for (const auto& it: i2p::tunnel::tunnels.GetTransitTunnelsList ())
 			{
 				s << "<tr class=\"tcell_center\">";
 				if (std::dynamic_pointer_cast<i2p::tunnel::TransitTunnelGateway>(it))
@@ -1033,10 +1036,11 @@ namespace http {
 			return;
 		}
 
-		if (sam->GetSessions ().size ())
+		auto samSessions = sam->GetSessionsList ();
+		if (samSessions.size ())
 		{
 			s << "<b>" << tr("SAM sessions") << ":</b><br>\r\n<div class=\"list\">\r\n";
-			for (auto& it: sam->GetSessions ())
+			for (auto& it: samSessions)
 			{
 				auto& name = it.second->GetLocalDestination ()->GetNickname ();
 				auto sam_id = i2p::data::ByteStreamToBase64 ((const uint8_t *)it.first.data (), it.first.length ()); // base64, becuase session name might be UTF-8

daemon/I2PControlHandlers.cpp

@@ -235,7 +235,7 @@ namespace client
 
 	void I2PControlHandlers::TunnelsParticipatingHandler (std::ostringstream& results)
 	{
-		int transit = i2p::tunnel::tunnels.GetTransitTunnels ().size ();
+		int transit = i2p::tunnel::tunnels.CountTransitTunnels ();
 		InsertParam (results, "i2p.router.net.tunnels.participating", transit);
 	}
 
@@ -468,7 +468,7 @@ namespace client
 		{
 			pt.put("enabled", true);
 			boost::property_tree::ptree sam_sessions;
-			for (auto& it: sam->GetSessions ())
+			for (auto& it: sam->GetSessionsList ())
 			{
 				boost::property_tree::ptree sam_session, sam_session_sockets;
 				auto& name = it.second->GetLocalDestination ()->GetNickname ();

libi2pd/Destination.cpp

@@ -671,7 +671,7 @@ namespace client
 		auto inbound = m_Pool->GetNextInboundTunnel (nullptr, floodfill->GetCompatibleTransports (true));
 		if (!outbound || !inbound)
 		{
-			if (!m_Pool->GetInboundTunnels ().empty () && !m_Pool->GetOutboundTunnels ().empty ())
+			if (m_Pool->HasInboundTunnels () && m_Pool->HasOutboundTunnels ())
 			{
 				LogPrint (eLogInfo, "Destination: No compatible tunnels with ", floodfill->GetIdentHash ().ToBase64 (), ". Trying another floodfill");
 				m_ExcludedFloodfills.insert (floodfill->GetIdentHash ());

libi2pd/Destination.h

@@ -19,6 +19,7 @@
 #include <unordered_set>
 #include <string>
 #include <functional>
+#include <future>
 #include <boost/asio.hpp>
 #include "Identity.h"
 #include "TunnelPool.h"
@@ -141,7 +142,7 @@ namespace client
 			LeaseSetDestination (boost::asio::io_context& service, bool isPublic, const i2p::util::Mapping * params = nullptr);
 			~LeaseSetDestination ();
 			const std::string& GetNickname () const { return m_Nickname; };
-			auto& GetService () { return m_Service; };
+			auto& GetService () const { return m_Service; };
 
 			virtual void Start ();
 			virtual void Stop ();
@@ -150,7 +151,7 @@ namespace client
 			virtual bool Reconfigure(const i2p::util::Mapping& i2cpOpts);
 
 			std::shared_ptr<i2p::tunnel::TunnelPool> GetTunnelPool () { return m_Pool; };
-			bool IsReady () const { return m_LeaseSet && !m_LeaseSet->IsExpired () && m_Pool->GetOutboundTunnels ().size () > 0; };
+			bool IsReady () const { return m_LeaseSet && !m_LeaseSet->IsExpired () && m_Pool->HasOutboundTunnels (); };
 			std::shared_ptr<i2p::data::LeaseSet> FindLeaseSet (const i2p::data::IdentHash& ident);
 			bool RequestDestination (const i2p::data::IdentHash& dest, RequestComplete requestComplete = nullptr);
 			bool RequestDestinationWithEncryptedLeaseSet (std::shared_ptr<const i2p::data::BlindedPublicKey> dest, RequestComplete requestComplete = nullptr);
@@ -234,8 +235,7 @@ namespace client
 		public:
 
 			// for HTTP only
-			int GetNumRemoteLeaseSets () const { return m_RemoteLeaseSets.size (); };
-			const decltype(m_RemoteLeaseSets)& GetLeaseSets () const { return m_RemoteLeaseSets; };
+			int GetNumRemoteLeaseSets () const { std::lock_guard<std::mutex> lock(m_RemoteLeaseSetsMutex); return m_RemoteLeaseSets.size (); };
 			// copy for other threads, unlike GetLeaseSets which hands out the container itself
 			std::vector<std::shared_ptr<i2p::data::LeaseSet> > GetLeaseSetsList () const
 			{
@@ -248,6 +248,11 @@ namespace client
 			}
 			bool IsEncryptedLeaseSet () const { return m_LeaseSetType == i2p::data::NETDB_STORE_TYPE_ENCRYPTED_LEASESET2; };
 			bool IsPerClientAuth () const { return m_AuthType > 0; };
+			std::future<std::vector<i2p::garlic::ECIESX25519AEADRatchetSessionPtr> > GetECIESx25519SessionsList () const
+			{
+				return boost::asio::post (GetService (),
+					boost::asio::use_future ([this]() { return GetECIESx25519SessionsListSync (); }));
+			}
 	};
 
 	class ClientDestination: public LeaseSetDestination

libi2pd/Garlic.h

@@ -12,6 +12,8 @@
 #include <inttypes.h>
 #include <unordered_map>
 #include <list>
+#include <vector>
+#include <utility>
 #include <string>
 #include <thread>
 #include <mutex>
@@ -319,7 +321,7 @@ namespace garlic
 			bool m_IsIdling;
 			// outgoing sessions
 			int m_NumTags;
-			std::mutex m_SessionsMutex;
+			mutable std::mutex m_SessionsMutex;
 			std::unordered_map<i2p::data::IdentHash, ElGamalAESSessionPtr> m_Sessions;
 			std::unordered_map<i2p::data::Tag<32>, ECIESX25519AEADRatchetSessionPtr> m_ECIESx25519Sessions; // static key -> session
 			uint8_t * m_PayloadBuffer; // for ECIESX25519AEADRatchet
@@ -341,8 +343,23 @@ namespace garlic
 			// for HTTP only
 			size_t GetNumIncomingTags () const { return m_Tags.size (); }
 			size_t GetNumIncomingECIESx25519Tags () const { return m_ECIESx25519Tags.size (); }
-			const decltype(m_Sessions)& GetSessions () const { return m_Sessions; };
-			const decltype(m_ECIESx25519Sessions)& GetECIESx25519Sessions () const { return m_ECIESx25519Sessions; }
+			// thread-safe snapshots, safe to iterate without holding any lock
+			std::vector<std::pair<i2p::data::IdentHash, ElGamalAESSessionPtr> > GetSessionsList () const
+			{
+				std::unique_lock<std::mutex> l(m_SessionsMutex);
+				return std::vector<std::pair<i2p::data::IdentHash, ElGamalAESSessionPtr> > (m_Sessions.begin (), m_Sessions.end ());
+			}
+
+		protected:
+
+			std::vector<ECIESX25519AEADRatchetSessionPtr> GetECIESx25519SessionsListSync () const
+			{
+				std::vector<ECIESX25519AEADRatchetSessionPtr> sessions;
+				sessions.reserve (m_ECIESx25519Sessions.size ());
+				for (const auto& it: m_ECIESx25519Sessions)
+					sessions.push_back (it.second);
+				return sessions;
+			}
 	};
 
 	void CleanUpTagsFiles ();

libi2pd/TransitTunnel.cpp

@@ -222,6 +222,7 @@ namespace tunnel
 			m_Thread->join ();
 			m_Thread = nullptr;
 		}
+		std::lock_guard<std::mutex> l(m_TransitTunnelsMutex);
 		m_TransitTunnels.clear ();
 	}
 
@@ -636,7 +637,10 @@ namespace tunnel
 	bool TransitTunnels::AddTransitTunnel (std::shared_ptr<TransitTunnel> tunnel)
 	{
 		if (tunnels.AddTunnel (tunnel))
+		{
+			std::lock_guard<std::mutex> l(m_TransitTunnelsMutex);
 			m_TransitTunnels.push_back (tunnel);
+		}
 		else
 		{
 			LogPrint (eLogError, "TransitTunnel: Tunnel with id ", tunnel->GetTunnelID (), " already exists");
@@ -647,6 +651,7 @@ namespace tunnel
 
 	void TransitTunnels::ManageTransitTunnels (uint64_t ts)
 	{
+		std::lock_guard<std::mutex> l(m_TransitTunnelsMutex);
 		for (auto it = m_TransitTunnels.begin (); it != m_TransitTunnels.end ();)
 		{
 			auto tunnel = *it;
@@ -670,7 +675,7 @@ namespace tunnel
 	{
 		int timeout = 0;
 		uint32_t ts = i2p::util::GetSecondsSinceEpoch ();
-		// TODO: possible race condition with I2PControl
+		std::lock_guard<std::mutex> l(m_TransitTunnelsMutex);
 		for (const auto& it : m_TransitTunnels)
 		{
 			int t = it->GetCreationTime () + TUNNEL_EXPIRATION_TIMEOUT - ts;

libi2pd/TransitTunnel.h

@@ -11,6 +11,7 @@
 
 #include <inttypes.h>
 #include <list>
+#include <vector>
 #include <mutex>
 #include <memory>
 #include "Crypto.h"
@@ -137,7 +138,7 @@ namespace tunnel
 			void Stop ();
 			void PostTransitTunnelBuildMsg  (std::shared_ptr<I2NPMessage>&& msg);
 
-			size_t GetNumTransitTunnels () const { return m_TransitTunnels.size (); }
+			size_t GetNumTransitTunnels () const { std::lock_guard<std::mutex> l(m_TransitTunnelsMutex); return m_TransitTunnels.size (); }
 			int GetTransitTunnelsExpirationTimeout ();
 
 		private:
@@ -155,14 +156,19 @@ namespace tunnel
 
 			volatile bool m_IsRunning;
 			std::unique_ptr<std::thread> m_Thread;
+			mutable std::mutex m_TransitTunnelsMutex;
 			std::list<std::shared_ptr<TransitTunnel> > m_TransitTunnels;
 			i2p::util::Queue<std::shared_ptr<I2NPMessage> > m_TunnelBuildMsgQueue;
 			std::mt19937 m_Rng;
 
 		public:
 
-			// for HTTP only
-			const auto& GetTransitTunnels () const { return m_TransitTunnels; };
+			// for HTTP and I2PControl; thread-safe snapshot, safe to iterate without holding any lock
+			std::vector<std::shared_ptr<TransitTunnel> > GetTransitTunnelsList () const
+			{
+				std::lock_guard<std::mutex> l(m_TransitTunnelsMutex);
+				return std::vector<std::shared_ptr<TransitTunnel> > (m_TransitTunnels.begin (), m_TransitTunnels.end ());
+			}
 			size_t GetTunnelBuildMsgQueueSize () const { return m_TunnelBuildMsgQueue.GetSize (); };
 	};
 }