rpc: Add listen address to incoming connections in `getpeerinfo`

This adds the listening address on which incoming connections were received to the
CNode and CNodeStats structures.

The address is reported in `getpeerinfo`.

This can be useful for distinguishing connections received on different listening ports
(e.g. when using a different listening port for Tor hidden service connections)
or different networks.

5 files changed, 46 insertions, 13 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 378ac99d66..14ac5618eb 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -340,6 +340,22 @@ bool CConnman::CheckIncomingNonce(uint64_t nonce)
     return true;
 }
 
+/** Get the bind address for a socket as CAddress */
+static CAddress GetBindAddress(SOCKET sock)
+{
+    CAddress addr_bind;
+    struct sockaddr_storage sockaddr_bind;
+    socklen_t sockaddr_bind_len = sizeof(sockaddr_bind);
+    if (sock != INVALID_SOCKET) {
+        if (!getsockname(sock, (struct sockaddr*)&sockaddr_bind, &sockaddr_bind_len)) {
+            addr_bind.SetSockAddr((const struct sockaddr*)&sockaddr_bind);
+        } else {
+            LogPrint(BCLog::NET, "Warning: getsockname failed\n");
+        }
+    }
+    return addr_bind;
+}
+
 CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure)
 {
     if (pszDest == NULL) {
@@ -393,7 +409,8 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         // Add node
         NodeId id = GetNewNodeId();
         uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
-        CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, pszDest ? pszDest : "", false);
+        CAddress addr_bind = GetBindAddress(hSocket);
+        CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, addr_bind, pszDest ? pszDest : "", false);
         pnode->nServicesExpected = ServiceFlags(addrConnect.nServices & nRelevantServices);
         pnode->AddRef();
 
@@ -635,6 +652,7 @@ void CNode::copyStats(CNodeStats &stats)
     stats.nodeid = this->GetId();
     X(nServices);
     X(addr);
+    X(addrBind);
     {
         LOCK(cs_filter);
         X(fRelayTxes);
@@ -1036,9 +1054,11 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
     int nInbound = 0;
     int nMaxInbound = nMaxConnections - (nMaxOutbound + nMaxFeeler);
 
-    if (hSocket != INVALID_SOCKET)
-        if (!addr.SetSockAddr((const struct sockaddr*)&sockaddr))
+    if (hSocket != INVALID_SOCKET) {
+        if (!addr.SetSockAddr((const struct sockaddr*)&sockaddr)) {
             LogPrintf("Warning: Unknown socket family\n");
+        }
+    }
 
     bool whitelisted = hListenSocket.whitelisted || IsWhitelistedRange(addr);
     {
@@ -1092,8 +1112,9 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
 
     NodeId id = GetNewNodeId();
     uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
+    CAddress addr_bind = GetBindAddress(hSocket);
 
-    CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addr, CalculateKeyedNetGroup(addr), nonce, "", true);
+    CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addr, CalculateKeyedNetGroup(addr), nonce, addr_bind, "", true);
     pnode->AddRef();
     pnode->fWhitelisted = whitelisted;
     GetNodeSignals().InitializeNode(pnode, *this);
@@ -2639,9 +2660,10 @@ int CConnman::GetBestHeight() const
 unsigned int CConnman::GetReceiveFloodSize() const { return nReceiveFloodSize; }
 unsigned int CConnman::GetSendBufferSize() const{ return nSendBufferMaxSize; }
 
-CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const std::string& addrNameIn, bool fInboundIn) :
+CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress &addrBindIn, const std::string& addrNameIn, bool fInboundIn) :
     nTimeConnected(GetSystemTimeInSeconds()),
     addr(addrIn),
+    addrBind(addrBindIn),
     fInbound(fInboundIn),
     nKeyedNetGroup(nKeyedNetGroupIn),
     addrKnown(5000, 0.001),
diff --git a/src/net.h b/src/net.h
index 00d04e9914..b89c13a90d 100644
--- a/src/net.h
+++ b/src/net.h
@@ -504,8 +504,12 @@ public:
     double dPingTime;
     double dPingWait;
     double dMinPing;
+    // Our address, as reported by the peer
     std::string addrLocal;
+    // Address of this peer
     CAddress addr;
+    // Bind address of our side of the connection
+    CAddress addrBind;
 };
 
 
@@ -586,7 +590,10 @@ public:
     std::atomic<int64_t> nLastRecv;
     const int64_t nTimeConnected;
     std::atomic<int64_t> nTimeOffset;
+    // Address of this peer
     const CAddress addr;
+    // Bind address of our side of the connection
+    const CAddress addrBind;
     std::atomic<int> nVersion;
     // strSubVer is whatever byte array we read from the wire. However, this field is intended
     // to be printed out, displayed to humans in various forms and so on. So we sanitize it and
@@ -676,7 +683,7 @@ public:
     CAmount lastSentFeeFilter;
     int64_t nextSendTimeFeeFilter;
 
-    CNode(NodeId id, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const std::string &addrNameIn = "", bool fInboundIn = false);
+    CNode(NodeId id, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress &addrBindIn, const std::string &addrNameIn = "", bool fInboundIn = false);
     ~CNode();
 
 private:
@@ -695,6 +702,7 @@ private:
     mutable CCriticalSection cs_addrName;
     std::string addrName;
 
+    // Our address, as reported by the peer
     CService addrLocal;
     mutable CCriticalSection cs_addrLocal;
 public:
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index cde5ae723b..10bf99eb38 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -76,7 +76,8 @@ UniValue getpeerinfo(const JSONRPCRequest& request)
             "  {\n"
             "    \"id\": n,                   (numeric) Peer index\n"
             "    \"addr\":\"host:port\",      (string) The ip address and port of the peer\n"
-            "    \"addrlocal\":\"ip:port\",   (string) local address\n"
+            "    \"addrbind\":\"ip:port\",    (string) Bind address of the connection to the peer\n"
+            "    \"addrlocal\":\"ip:port\",   (string) Local address as reported by the peer\n"
             "    \"services\":\"xxxxxxxxxxxxxxxx\",   (string) The services offered\n"
             "    \"relaytxes\":true|false,    (boolean) Whether peer has asked us to relay transactions to it\n"
             "    \"lastsend\": ttt,           (numeric) The time in seconds since epoch (Jan 1 1970 GMT) of the last send\n"
@@ -133,6 +134,8 @@ UniValue getpeerinfo(const JSONRPCRequest& request)
         obj.push_back(Pair("addr", stats.addrName));
         if (!(stats.addrLocal.empty()))
             obj.push_back(Pair("addrlocal", stats.addrLocal));
+        if (stats.addrBind.IsValid())
+            obj.push_back(Pair("addrbind", stats.addrBind.ToString()));
         obj.push_back(Pair("services", strprintf("%016x", stats.nServices)));
         obj.push_back(Pair("relaytxes", stats.fRelayTxes));
         obj.push_back(Pair("lastsend", stats.nLastSend));
diff --git a/src/test/DoS_tests.cpp b/src/test/DoS_tests.cpp
index c62e6ae838..e6b45a3b5e 100644
--- a/src/test/DoS_tests.cpp
+++ b/src/test/DoS_tests.cpp
@@ -51,7 +51,7 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
 
     connman->ClearBanned();
     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
-    CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 0, 0, "", true);
+    CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 0, 0, CAddress(), "", true);
     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
     GetNodeSignals().InitializeNode(&dummyNode1, *connman);
     dummyNode1.nVersion = 1;
@@ -62,7 +62,7 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
     BOOST_CHECK(!connman->IsBanned(ip(0xa0b0c001|0x0000ff00))); // Different IP, not banned
 
     CAddress addr2(ip(0xa0b0c002), NODE_NONE);
-    CNode dummyNode2(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr2, 1, 1, "", true);
+    CNode dummyNode2(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr2, 1, 1, CAddress(), "", true);
     dummyNode2.SetSendVersion(PROTOCOL_VERSION);
     GetNodeSignals().InitializeNode(&dummyNode2, *connman);
     dummyNode2.nVersion = 1;
@@ -83,7 +83,7 @@ BOOST_AUTO_TEST_CASE(DoS_banscore)
     connman->ClearBanned();
     ForceSetArg("-banscore", "111"); // because 11 is my favorite number
     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
-    CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 3, 1, "", true);
+    CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 3, 1, CAddress(), "", true);
     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
     GetNodeSignals().InitializeNode(&dummyNode1, *connman);
     dummyNode1.nVersion = 1;
@@ -109,7 +109,7 @@ BOOST_AUTO_TEST_CASE(DoS_bantime)
     SetMockTime(nStartTime); // Overrides future calls to GetTime()
 
     CAddress addr(ip(0xa0b0c001), NODE_NONE);
-    CNode dummyNode(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr, 4, 4, "", true);
+    CNode dummyNode(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr, 4, 4, CAddress(), "", true);
     dummyNode.SetSendVersion(PROTOCOL_VERSION);
     GetNodeSignals().InitializeNode(&dummyNode, *connman);
     dummyNode.nVersion = 1;
diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
index 0c7f3e5e23..66354699b2 100644
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -175,12 +175,12 @@ BOOST_AUTO_TEST_CASE(cnode_simple_test)
     bool fInboundIn = false;
 
     // Test that fFeeler is false by default.
-    std::unique_ptr<CNode> pnode1(new CNode(id++, NODE_NETWORK, height, hSocket, addr, 0, 0, pszDest, fInboundIn));
+    std::unique_ptr<CNode> pnode1(new CNode(id++, NODE_NETWORK, height, hSocket, addr, 0, 0, CAddress(), pszDest, fInboundIn));
     BOOST_CHECK(pnode1->fInbound == false);
     BOOST_CHECK(pnode1->fFeeler == false);
 
     fInboundIn = true;
-    std::unique_ptr<CNode> pnode2(new CNode(id++, NODE_NETWORK, height, hSocket, addr, 1, 1, pszDest, fInboundIn));
+    std::unique_ptr<CNode> pnode2(new CNode(id++, NODE_NETWORK, height, hSocket, addr, 1, 1, CAddress(), pszDest, fInboundIn));
     BOOST_CHECK(pnode2->fInbound == true);
     BOOST_CHECK(pnode2->fFeeler == false);
 }