net: add SetSocketNonBlocking() as OS independent wrapper

Author: Philip Kaufmann

src/net.cpp

@@ -501,14 +501,8 @@ CNode* ConnectNode(CAddress addrConnect, const char *pszDest)
         addrman.Attempt(addrConnect);
 
         // Set to non-blocking
-#ifdef WIN32
-        u_long nOne = 1;
-        if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR)
-            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 %s\n", NetworkErrorString(errno));
-#endif
+        if (!SetSocketNonBlocking(hSocket, true))
+            LogPrintf("ConnectNode: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 
         // Add node
         CNode* pnode = new CNode(hSocket, addrConnect, pszDest ? pszDest : "", false);
@@ -1642,14 +1636,9 @@ bool BindListenPort(const CService &addrBind, string& strError, bool fWhiteliste
     setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (void*)&nOne, sizeof(int));
 #endif
 
-#ifdef WIN32
     // Set to non-blocking, incoming connections will also inherit this
-    if (ioctlsocket(hListenSocket, FIONBIO, (u_long*)&nOne) == SOCKET_ERROR)
-#else
-    if (fcntl(hListenSocket, F_SETFL, O_NONBLOCK) == SOCKET_ERROR)
-#endif
-    {
-        strError = strprintf("Error: Couldn't set properties on socket for incoming connections (error %s)", NetworkErrorString(WSAGetLastError()));
+    if (!SetSocketNonBlocking(hListenSocket, true)) {
+        strError = strprintf("BindListenPort: Setting listening socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }

src/netbase.cpp

@@ -7,17 +7,17 @@
 #include "bitcoin-config.h"
 #endif
 
-#ifdef HAVE_GETADDRINFO_A
-#include <netdb.h>
-#endif
-
 #include "netbase.h"
 
 #include "hash.h"
 #include "sync.h"
 #include "uint256.h"
 #include "util.h"
 
+#ifdef HAVE_GETADDRINFO_A
+#include <netdb.h>
+#endif
+
 #ifndef WIN32
 #if HAVE_INET_PTON
 #include <arpa/inet.h>
@@ -331,22 +331,15 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe
     SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
     if (hSocket == INVALID_SOCKET)
         return false;
+
 #ifdef SO_NOSIGPIPE
     int set = 1;
     setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
 #endif
 
-#ifdef WIN32
-    u_long fNonblock = 1;
-    if (ioctlsocket(hSocket, FIONBIO, &fNonblock) == SOCKET_ERROR)
-#else
-    int fFlags = fcntl(hSocket, F_GETFL, 0);
-    if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == -1)
-#endif
-    {
-        CloseSocket(hSocket);
-        return false;
-    }
+    // Set to non-blocking
+    if (!SetSocketNonBlocking(hSocket, true))
+        return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 
     if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
     {
@@ -404,20 +397,10 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe
         }
     }
 
-    // this isn't even strictly necessary
-    // CNode::ConnectNode immediately turns the socket back to non-blocking
-    // but we'll turn it back to blocking just in case
-#ifdef WIN32
-    fNonblock = 0;
-    if (ioctlsocket(hSocket, FIONBIO, &fNonblock) == SOCKET_ERROR)
-#else
-    fFlags = fcntl(hSocket, F_GETFL, 0);
-    if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR)
-#endif
-    {
-        CloseSocket(hSocket);
-        return false;
-    }
+    // This is required when using SOCKS5 proxy!
+    // CNode::ConnectNode turns the socket back to non-blocking.
+    if (!SetSocketNonBlocking(hSocket, false))
+        return error("ConnectSocketDirectly: Setting socket to blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 
     hSocketRet = hSocket;
     return true;
@@ -1271,3 +1254,32 @@ bool CloseSocket(SOCKET& hSocket)
     hSocket = INVALID_SOCKET;
     return ret != SOCKET_ERROR;
 }
+
+bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking)
+{
+    if (fNonBlocking) {
+#ifdef WIN32
+        u_long nOne = 1;
+        if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
+#else
+        int fFlags = fcntl(hSocket, F_GETFL, 0);
+        if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
+#endif
+            CloseSocket(hSocket);
+            return false;
+        }
+    } else {
+#ifdef WIN32
+        u_long nZero = 0;
+        if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) {
+#else
+        int fFlags = fcntl(hSocket, F_GETFL, 0);
+        if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) {
+#endif
+            CloseSocket(hSocket);
+            return false;
+        }
+    }
+
+    return true;
+}

src/netbase.h

@@ -180,5 +180,7 @@ bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest
 std::string NetworkErrorString(int err);
 /** Close socket and set hSocket to INVALID_SOCKET */
 bool CloseSocket(SOCKET& hSocket);
+/** Disable or enable blocking-mode for a socket */
+bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking);
 
 #endif