Replace non-threadsafe strerror

Log the name of the error as well as the error code if a network problem
happens. This makes network troubleshooting more convenient.

Use thread-safe strerror_r and the WIN32 equivalent FormatMessage.

4 files changed, 53 insertions, 16 deletions

diff --git a/configure.ac b/configure.ac
index 6a8afe6e44..3a8d33a5a0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -303,6 +303,8 @@ INCLUDES="$INCLUDES $PTHREAD_CFLAGS"
 # they also need to be passed down to any subprojects. Pull the results out of
 # the cache and add them to CPPFLAGS.
 AC_SYS_LARGEFILE
+# detect POSIX or GNU variant of strerror_r
+AC_FUNC_STRERROR_R
 
 if test x$ac_cv_sys_file_offset_bits != x &&
    test x$ac_cv_sys_file_offset_bits != xno &&
diff --git a/src/net.cpp b/src/net.cpp
index 6bde1e7999..4cbd26a563 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -178,7 +178,7 @@ bool RecvLine(SOCKET hSocket, string& strLine)
             {
                 // socket error
                 int nErr = WSAGetLastError();
-                LogPrint("net", "recv failed: %d\n", nErr);
+                LogPrint("net", "recv failed: %s\n", NetworkErrorString(nErr));
                 return false;
             }
         }
@@ -489,10 +489,10 @@ CNode* ConnectNode(CAddress addrConnect, const char *pszDest)
 #ifdef WIN32
         u_long nOne = 1;
         if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR)
-            LogPrintf("ConnectSocket() : ioctlsocket non-blocking setting failed, error %d\n", WSAGetLastError());
+            LogPrintf("ConnectSocket() : ioctlsocket non-blocking setting failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 #else
         if (fcntl(hSocket, F_SETFL, O_NONBLOCK) == SOCKET_ERROR)
-            LogPrintf("ConnectSocket() : fcntl non-blocking setting failed, error %d\n", errno);
+            LogPrintf("ConnectSocket() : fcntl non-blocking setting failed, error %s\n", NetworkErrorString(errno));
 #endif
 
         // Add node
@@ -736,7 +736,7 @@ void SocketSendData(CNode *pnode)
                 int nErr = WSAGetLastError();
                 if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS)
                 {
-                    LogPrintf("socket send error %d\n", nErr);
+                    LogPrintf("socket send error %s\n", NetworkErrorString(nErr));
                     pnode->CloseSocketDisconnect();
                 }
             }
@@ -896,7 +896,7 @@ void ThreadSocketHandler()
             if (have_fds)
             {
                 int nErr = WSAGetLastError();
-                LogPrintf("socket select error %d\n", nErr);
+                LogPrintf("socket select error %s\n", NetworkErrorString(nErr));
                 for (unsigned int i = 0; i <= hSocketMax; i++)
                     FD_SET(i, &fdsetRecv);
             }
@@ -933,7 +933,7 @@ void ThreadSocketHandler()
             {
                 int nErr = WSAGetLastError();
                 if (nErr != WSAEWOULDBLOCK)
-                    LogPrintf("socket error accept failed: %d\n", nErr);
+                    LogPrintf("socket error accept failed: %s\n", NetworkErrorString(nErr));
             }
             else if (nInbound >= nMaxConnections - MAX_OUTBOUND_CONNECTIONS)
             {
@@ -1007,7 +1007,7 @@ void ThreadSocketHandler()
                             if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS)
                             {
                                 if (!pnode->fDisconnect)
-                                    LogPrintf("socket recv error %d\n", nErr);
+                                    LogPrintf("socket recv error %s\n", NetworkErrorString(nErr));
                                 pnode->CloseSocketDisconnect();
                             }
                         }
@@ -1585,7 +1585,7 @@ bool BindListenPort(const CService &addrBind, string& strError)
     SOCKET hListenSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
     if (hListenSocket == INVALID_SOCKET)
     {
-        strError = strprintf("Error: Couldn't open socket for incoming connections (socket returned error %d)", WSAGetLastError());
+        strError = strprintf("Error: Couldn't open socket for incoming connections (socket returned error %s)", NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }
@@ -1609,7 +1609,7 @@ bool BindListenPort(const CService &addrBind, string& strError)
     if (fcntl(hListenSocket, F_SETFL, O_NONBLOCK) == SOCKET_ERROR)
 #endif
     {
-        strError = strprintf("Error: Couldn't set properties on socket for incoming connections (error %d)", WSAGetLastError());
+        strError = strprintf("Error: Couldn't set properties on socket for incoming connections (error %s)", NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }
@@ -1638,7 +1638,7 @@ bool BindListenPort(const CService &addrBind, string& strError)
         if (nErr == WSAEADDRINUSE)
             strError = strprintf(_("Unable to bind to %s on this computer. Bitcoin Core is probably already running."), addrBind.ToString());
         else
-            strError = strprintf(_("Unable to bind to %s on this computer (bind returned error %d, %s)"), addrBind.ToString(), nErr, strerror(nErr));
+            strError = strprintf(_("Unable to bind to %s on this computer (bind returned error %s)"), addrBind.ToString(), NetworkErrorString(nErr));
         LogPrintf("%s\n", strError);
         return false;
     }
@@ -1647,7 +1647,7 @@ bool BindListenPort(const CService &addrBind, string& strError)
     // Listen for incoming connections
     if (listen(hListenSocket, SOMAXCONN) == SOCKET_ERROR)
     {
-        strError = strprintf(_("Error: Listening for incoming connections failed (listen returned error %d)"), WSAGetLastError());
+        strError = strprintf(_("Error: Listening for incoming connections failed (listen returned error %s)"), NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }
@@ -1785,7 +1785,7 @@ public:
         BOOST_FOREACH(SOCKET hListenSocket, vhListenSocket)
             if (hListenSocket != INVALID_SOCKET)
                 if (closesocket(hListenSocket) == SOCKET_ERROR)
-                    LogPrintf("closesocket(hListenSocket) failed with error %d\n", WSAGetLastError());
+                    LogPrintf("closesocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError()));
 
         // clean up some globals (to help leak detection)
         BOOST_FOREACH(CNode *pnode, vNodes)
diff --git a/src/netbase.cpp b/src/netbase.cpp
index 82a681281d..e24a0a195c 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -361,7 +361,7 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe
             }
             if (nRet == SOCKET_ERROR)
             {
-                LogPrintf("select() for %s failed: %i\n", addrConnect.ToString(), WSAGetLastError());
+                LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
                 closesocket(hSocket);
                 return false;
             }
@@ -372,13 +372,13 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe
             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
 #endif
             {
-                LogPrintf("getsockopt() for %s failed: %i\n", addrConnect.ToString(), WSAGetLastError());
+                LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
                 closesocket(hSocket);
                 return false;
             }
             if (nRet != 0)
             {
-                LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), strerror(nRet));
+                LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
                 closesocket(hSocket);
                 return false;
             }
@@ -389,7 +389,7 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe
         else
 #endif
         {
-            LogPrintf("connect() to %s failed: %i\n", addrConnect.ToString(), WSAGetLastError());
+            LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
             closesocket(hSocket);
             return false;
         }
@@ -1237,3 +1237,36 @@ bool operator!=(const CSubNet& a, const CSubNet& b)
 {
     return !(a==b);
 }
+
+#ifdef WIN32
+std::string NetworkErrorString(int err)
+{
+    char buf[256];
+    buf[0] = 0;
+    if(FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
+            NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+            buf, sizeof(buf), NULL))
+    {
+        return strprintf("%s (%d)", buf, err);
+    }
+    else
+    {
+        return strprintf("Unknown error (%d)", err);
+    }
+}
+#else
+std::string NetworkErrorString(int err)
+{
+    char buf[256];
+    const char *s = buf;
+    buf[0] = 0;
+    /* Too bad there are two incompatible implementations of the
+     * thread-safe strerror. */
+#ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
+    s = strerror_r(err, buf, sizeof(buf));
+#else /* POSIX variant always returns message in buffer */
+    (void) strerror_r(err, buf, sizeof(buf));
+#endif
+    return strprintf("%s (%d)", s, err);
+}
+#endif
diff --git a/src/netbase.h b/src/netbase.h
index 118f866d6c..5fd8be4aca 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -179,5 +179,7 @@ bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault =
 bool LookupNumeric(const char *pszName, CService& addr, int portDefault = 0);
 bool ConnectSocket(const CService &addr, SOCKET& hSocketRet, int nTimeout = nConnectTimeout);
 bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault = 0, int nTimeout = nConnectTimeout);
+/** Return readable error string for a network error code */
+std::string NetworkErrorString(int err);
 
 #endif