[newlib-cygwin] Cygwin: socket: move socket creation inside fhandler_socket class

Corinna Vinschen corinna@sourceware.org
Wed Feb 14 21:22:00 GMT 2018


https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=913c6ca2c1467893bb0c3b7598cccdb02ca9f598

commit 913c6ca2c1467893bb0c3b7598cccdb02ca9f598
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Wed Feb 14 22:21:58 2018 +0100

    Cygwin: socket: move socket creation inside fhandler_socket class
    
    Add fhandler_socket::socket method
    Add fhandler_socket::set_socket_handle method, basically duplicating
    what fdsock is doing.  This is the first step in getting rid of fdsock.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/fhandler.h         |   5 ++
 winsup/cygwin/fhandler_socket.cc | 117 +++++++++++++++++++++++++++++++++++++++
 winsup/cygwin/net.cc             |  90 +++++++++++++++---------------
 3 files changed, 166 insertions(+), 46 deletions(-)

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 9d2b263..e1659db 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -556,6 +556,10 @@ class fhandler_socket: public fhandler_base
       {}
   } status;
 
+#ifdef __INSIDE_CYGWIN_NET__
+  int set_socket_handle (SOCKET sock);
+#endif
+
  public:
   fhandler_socket ();
   ~fhandler_socket ();
@@ -576,6 +580,7 @@ class fhandler_socket: public fhandler_base
   IMPLEMENT_STATUS_FLAG (conn_state, connect_state)
   IMPLEMENT_STATUS_FLAG (bool, no_getpeereid)
 
+  int socket (int af, int type, int protocol, int flags);
   int bind (const struct sockaddr *name, int namelen);
   int connect (const struct sockaddr *name, int namelen);
   int listen (int backlog);
diff --git a/winsup/cygwin/fhandler_socket.cc b/winsup/cygwin/fhandler_socket.cc
index 2d043bd..a30b495 100644
--- a/winsup/cygwin/fhandler_socket.cc
+++ b/winsup/cygwin/fhandler_socket.cc
@@ -262,6 +262,120 @@ fhandler_socket::open (int flags, mode_t mode)
   return 0;
 }
 
+int
+fhandler_socket::set_socket_handle (SOCKET sock)
+{
+  DWORD flags;
+  bool lsp_fixup = false;
+
+  /* Usually sockets are inheritable IFS objects.  Unfortunately some virus
+     scanners or other network-oriented software replace normal sockets
+     with their own kind, which is running through a filter driver called
+     "layered service provider" (LSP) which, fortunately, are deprecated.
+
+     LSP sockets are not kernel objects.  They are typically not marked as
+     inheritable, nor are they IFS handles.  They are in fact not inheritable
+     to child processes, and it does not help to mark them inheritable via
+     SetHandleInformation.  Subsequent socket calls in the child process fail
+     with error 10038, WSAENOTSOCK.
+
+     There's a neat way to workaround these annoying LSP sockets.  WSAIoctl
+     allows to fetch the underlying base socket, which is a normal, inheritable
+     IFS handle.  So we fetch the base socket, duplicate it, and close the
+     original socket.  Now we have a standard IFS socket which (hopefully)
+     works as expected.
+
+     If that doesn't work for some reason, mark the sockets for duplication
+     via WSADuplicateSocket/WSASocket.  This requires to start the child
+     process in SUSPENDED state so we only do this if really necessary. */
+  if (!GetHandleInformation ((HANDLE) sock, &flags)
+      || !(flags & HANDLE_FLAG_INHERIT))
+    {
+      int ret;
+      SOCKET base_sock;
+      DWORD bret;
+
+      lsp_fixup = true;
+      debug_printf ("LSP handle: %p", sock);
+      ret = WSAIoctl (sock, SIO_BASE_HANDLE, NULL, 0, (void *) &base_sock,
+                      sizeof (base_sock), &bret, NULL, NULL);
+      if (ret)
+        debug_printf ("WSAIoctl: %u", WSAGetLastError ());
+      else if (base_sock != sock)
+        {
+          if (GetHandleInformation ((HANDLE) base_sock, &flags)
+              && (flags & HANDLE_FLAG_INHERIT))
+            {
+              if (!DuplicateHandle (GetCurrentProcess (), (HANDLE) base_sock,
+                                    GetCurrentProcess (), (PHANDLE) &base_sock,
+                                    0, TRUE, DUPLICATE_SAME_ACCESS))
+                debug_printf ("DuplicateHandle failed, %E");
+              else
+                {
+                  closesocket (sock);
+                  sock = base_sock;
+                  lsp_fixup = false;
+                }
+            }
+        }
+    }
+  set_io_handle ((HANDLE) sock);
+  if (!init_events ())
+    {
+      closesocket (sock);
+      return -1;
+    }
+  if (lsp_fixup)
+    init_fixup_before ();
+  set_flags (O_RDWR | O_BINARY);
+  set_unique_id ();
+  if (get_socket_type () == SOCK_DGRAM)
+    {
+      /* Workaround the problem that a missing listener on a UDP socket
+	 in a call to sendto will result in select/WSAEnumNetworkEvents
+	 reporting that the socket has pending data and a subsequent call
+	 to recvfrom will return -1 with error set to WSAECONNRESET.
+
+	 This problem is a regression introduced in Windows 2000.
+	 Instead of fixing the problem, a new socket IOCTL code has
+	 been added, see http://support.microsoft.com/kb/263823 */
+      BOOL cr = FALSE;
+      DWORD blen;
+      if (WSAIoctl (sock, SIO_UDP_CONNRESET, &cr, sizeof cr, NULL, 0,
+		    &blen, NULL, NULL) == SOCKET_ERROR)
+	debug_printf ("Reset SIO_UDP_CONNRESET: WinSock error %u",
+		      WSAGetLastError ());
+    }
+#ifdef __x86_64__
+  rmem () = 212992;
+  wmem () = 212992;
+#else
+  rmem () = 64512;
+  wmem () = 64512;
+#endif
+  return 0;
+}
+
+int
+fhandler_socket::socket (int af, int type, int protocol, int flags)
+{
+  SOCKET sock;
+
+  sock = ::socket (af == AF_LOCAL ? AF_INET : af, type, protocol);
+  if (sock == INVALID_SOCKET)
+    {
+      set_winsock_errno ();
+      return -1;
+    }
+  set_addr_family (af);
+  set_socket_type (type);
+  if (flags & SOCK_NONBLOCK)
+    set_nonblocking (true);
+  if (flags & SOCK_CLOEXEC)
+    set_close_on_exec (true);
+  return set_socket_handle (sock);
+}
+
 void
 fhandler_socket::af_local_set_sockpair_cred ()
 {
@@ -635,6 +749,9 @@ fhandler_socket::init_events ()
     }
 
   /* sock type not yet set here. */
+  /* FIXME: as soon as we switch to socket method, we're good to use
+     get_socket_type (). */
+
   if (pc.dev == FH_UDP || pc.dev == FH_DGRAM)
     wsock_events->events = FD_WRITE;
   return true;
diff --git a/winsup/cygwin/net.cc b/winsup/cygwin/net.cc
index c7bd736..8497d59 100644
--- a/winsup/cygwin/net.cc
+++ b/winsup/cygwin/net.cc
@@ -655,67 +655,65 @@ extern "C" int
 cygwin_socket (int af, int type, int protocol)
 {
   int res = -1;
-  SOCKET soc = 0;
+  const device *dev;
+  fhandler_socket *fh;
 
   int flags = type & _SOCK_FLAG_MASK;
   type &= ~_SOCK_FLAG_MASK;
 
   debug_printf ("socket (%d, %d (flags %y), %d)", af, type, flags, protocol);
 
-  if ((flags & ~(SOCK_NONBLOCK | SOCK_CLOEXEC)) != 0)
+  switch (af)
     {
-      set_errno (EINVAL);
+    case AF_LOCAL:
+      if (type != SOCK_STREAM && type != SOCK_DGRAM)
+        {
+          set_errno (EINVAL);
+          goto done;
+        }
+      if (protocol != 0)
+        {
+          set_errno (EPROTONOSUPPORT);
+          goto done;
+        }
+      dev = type == SOCK_STREAM ? stream_dev : dgram_dev;
+      break;
+    case AF_INET:
+    case AF_INET6:
+      if (type != SOCK_STREAM && type != SOCK_DGRAM && type != SOCK_RAW)
+        {
+          set_errno (EINVAL);
+          goto done;
+        }
+      dev = type == SOCK_STREAM ? tcp_dev : udp_dev;
+      break;
+    default:
+      set_errno (EAFNOSUPPORT);
       goto done;
     }
 
-  soc = socket (af == AF_LOCAL ? AF_INET : af, type,
-		af == AF_LOCAL ? 0 : protocol);
-
-  if (soc == INVALID_SOCKET)
+  if ((flags & ~(SOCK_NONBLOCK | SOCK_CLOEXEC)) != 0)
     {
-      set_winsock_errno ();
+      set_errno (EINVAL);
       goto done;
     }
 
-  const device *dev;
-
-  if (af == AF_LOCAL)
-    dev = type == SOCK_STREAM ? stream_dev : dgram_dev;
-  else
-    dev = type == SOCK_STREAM ? tcp_dev : udp_dev;
+    {
+      cygheap_fdnew fd;
 
-  {
-    cygheap_fdnew fd;
-    if (fd < 0 || !fdsock (fd, dev, soc))
-      closesocket (soc);
-    else
-      {
-	((fhandler_socket *) fd)->set_addr_family (af);
-	((fhandler_socket *) fd)->set_socket_type (type);
-	if (flags & SOCK_NONBLOCK)
-	  ((fhandler_socket *) fd)->set_nonblocking (true);
-	if (flags & SOCK_CLOEXEC)
-	  ((fhandler_socket *) fd)->set_close_on_exec (true);
-	if (type == SOCK_DGRAM)
-	  {
-	    /* Workaround the problem that a missing listener on a UDP socket
-	       in a call to sendto will result in select/WSAEnumNetworkEvents
-	       reporting that the socket has pending data and a subsequent call
-	       to recvfrom will return -1 with error set to WSAECONNRESET.
-
-	       This problem is a regression introduced in Windows 2000.
-	       Instead of fixing the problem, a new socket IOCTL code has
-	       been added, see http://support.microsoft.com/kb/263823 */
-	    BOOL cr = FALSE;
-	    DWORD blen;
-	    if (WSAIoctl (soc, SIO_UDP_CONNRESET, &cr, sizeof cr, NULL, 0,
-			  &blen, NULL, NULL) == SOCKET_ERROR)
-	      debug_printf ("Reset SIO_UDP_CONNRESET: WinSock error %u",
-			    WSAGetLastError ());
-	  }
-	res = fd;
-      }
-  }
+      if (fd < 0)
+	goto done;
+      fh = (fhandler_socket *) build_fh_dev (*dev);
+      if (fh && fh->socket (af, type, protocol, flags) == 0)
+	{
+	  fd = fh;
+	  if (fd <= 2)
+	    set_std_handle (fd);
+	  res = fd;
+	}
+      else
+        fd.release ();
+    }
 
 done:
   syscall_printf ("%R = socket(%d, %d (flags %y), %d)",



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