1 files changed, 77 insertions, 0 deletions

diff --git a/src/platform/w32functions.c b/src/platform/w32functions.c
index a0b35dec..34c5d73d 100644
--- a/src/platform/w32functions.c
+++ b/src/platform/w32functions.c
@@ -541,3 +541,80 @@ void MHD_W32_set_last_winsock_error_(int errnum)
     break;
     }
 }
+
+/**
+ * Create pair of mutually connected TCP/IP sockets on loopback address
+ * @param sockets_pair array to receive resulted sockets
+ * @return zero on success, -1 otherwise
+ */
+int MHD_W32_pair_of_sockets_(SOCKET sockets_pair[2])
+{
+  int i;
+  if (!sockets_pair)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+#define PAIRMAXTRYIES 800
+  for (i = 0; i < PAIRMAXTRYIES; i++)
+    {
+      struct sockaddr_in listen_addr;
+      SOCKET listen_s;
+      static const int c_addinlen = sizeof(struct sockaddr_in); /* help compiler to optimize */
+      int addr_len = c_addinlen;
+      int opt = 1;
+
+      listen_s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+      if (INVALID_SOCKET == listen_s)
+        break; /* can't create even single socket */
+
+      listen_addr.sin_family = AF_INET;
+      listen_addr.sin_port = htons(0);
+      listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+      if (0 == bind(listen_s, (struct sockaddr*) &listen_addr, c_addinlen)
+          && 0 == listen(listen_s, 1)
+          && 0 == getsockname(listen_s, (struct sockaddr*) &listen_addr,
+                  &addr_len))
+        {
+          SOCKET client_s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+          if (INVALID_SOCKET != client_s)
+            {
+              if (0 == ioctlsocket(client_s, FIONBIO, (u_long*) &opt)
+                  && (0 == connect(client_s, (struct sockaddr*) &listen_addr, c_addinlen)
+                      || WSAGetLastError() == WSAEWOULDBLOCK))
+                {
+                  struct sockaddr_in accepted_from_addr;
+                  addr_len = c_addinlen;
+                  SOCKET server_s = accept(listen_s,
+                      (struct sockaddr*) &accepted_from_addr, &addr_len);
+                  if (INVALID_SOCKET != server_s)
+                    {
+                      struct sockaddr_in client_addr;
+                      addr_len = c_addinlen;
+                      opt = 0;
+                      if (0 == getsockname(client_s, (struct sockaddr*) &client_addr, &addr_len)
+                          && accepted_from_addr.sin_family == client_addr.sin_family
+                          && accepted_from_addr.sin_port == client_addr.sin_port
+                          && accepted_from_addr.sin_addr.s_addr == client_addr.sin_addr.s_addr
+                          && 0 == ioctlsocket(client_s, FIONBIO, (u_long*) &opt)
+                          && 0 == ioctlsocket(server_s, FIONBIO, (u_long*) &opt))
+                        {
+                          closesocket(listen_s);
+                          sockets_pair[0] = client_s;
+                          sockets_pair[1] = server_s;
+                          return 0;
+                        }
+                      closesocket(server_s);
+                    }
+                }
+              closesocket(client_s);
+            }
+        }
+      closesocket(listen_s);
+    }
+
+  sockets_pair[0] = INVALID_SOCKET;
+  sockets_pair[1] = INVALID_SOCKET;
+  return -1;
+}