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.

1 files changed, 37 insertions, 4 deletions

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