* fhandler_socket.cc (get_inet_addr): Only test the file for being a

	socket after opening it.  Retry if opening failed with sharing
	violation.  Explain why we do this.
	(fhandler_socket::bind): Create file with no sharing allowed.

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 2e3321a..305660f 100644 (file)
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,10 @@
+2010-04-13  Corinna Vinschen  <corinna@vinschen.de>
+
+       * fhandler_socket.cc (get_inet_addr): Only test the file for being a
+       socket after opening it.  Retry if opening failed with sharing
+       violation.  Explain why we do this.
+       (fhandler_socket::bind): Create file with no sharing allowed.
+
 2010-04-13  John Bowman  <bowman@math.ualberta.ca>
 
        * cygheap.cc (cwcsdup): Fix allocation size to accommodate sizeof WCHAR.

diff --git a/winsup/cygwin/fhandler_socket.cc b/winsup/cygwin/fhandler_socket.cc
index 66ba3e9..82be0ca 100644 (file)
--- a/winsup/cygwin/fhandler_socket.cc
+++ b/winsup/cygwin/fhandler_socket.cc
@@ -38,6 +38,7 @@
 #include "cygtls.h"
 #include "cygwin/in6.h"
 #include "ntdll.h"
+#include "miscfuncs.h"
 
 #define ASYNC_MASK (FD_READ|FD_WRITE|FD_OOB|FD_ACCEPT|FD_CONNECT)
 #define EVENT_MASK (FD_READ|FD_WRITE|FD_OOB|FD_ACCEPT|FD_CONNECT|FD_CLOSE)
@@ -94,21 +95,33 @@ get_inet_addr (const struct sockaddr *in, int inlen,
          set_errno (ENOENT);
          return 0;
        }
-      if (!pc.issocket ())
-       {
-         set_errno (EBADF);
-         return 0;
-       }
-      status = NtOpenFile (&fh, GENERIC_READ | SYNCHRONIZE,
-                          pc.get_object_attr (attr, sec_none_nih), &io,
-                          FILE_SHARE_VALID_FLAGS,
-                          FILE_SYNCHRONOUS_IO_NONALERT
-                          | FILE_OPEN_FOR_BACKUP_INTENT);
-      if (!NT_SUCCESS (status))
+      /* Do NOT test for the file being a socket file here.  The socket file
+        creation is not an atomic operation, so there is a chance that socket
+        files which are just in the process of being created are recognized
+        as non-socket files.  To work around this problem we now create the
+        file with all sharing disabled.  If the below NtOpenFile fails
+        with STATUS_SHARING_VIOLATION we know that the file already exists,
+        but the creating process isn't finished yet.  So we yield and try
+        again, until we can either open the file successfully, or some error
+        other than STATUS_SHARING_VIOLATION occurs.
+        Since we now don't know if the file is actually a socket file, we
+        perform this check here explicitely. */
+      pc.get_object_attr (attr, sec_none_nih);
+      do
        {
-         __seterrno_from_nt_status (status);
-         return 0;
+         status = NtOpenFile (&fh, GENERIC_READ | SYNCHRONIZE, &attr, &io,
+                              FILE_SHARE_VALID_FLAGS,
+                              FILE_SYNCHRONOUS_IO_NONALERT
+                              | FILE_OPEN_FOR_BACKUP_INTENT);
+         if (status == STATUS_SHARING_VIOLATION)
+           yield ();
+         else if (!NT_SUCCESS (status))
+           {
+             __seterrno_from_nt_status (status);
+             return 0;
+           }
        }
+      while (status == STATUS_SHARING_VIOLATION);
       int ret = 0;
       char buf[128];
       memset (buf, 0, sizeof buf);
@@ -119,6 +132,11 @@ get_inet_addr (const struct sockaddr *in, int inlen,
          struct sockaddr_in sin;
          char ctype;
          sin.sin_family = AF_INET;
+         if (strncmp (buf, SOCKET_COOKIE, strlen (SOCKET_COOKIE)))
+           {
+             set_errno (EBADF);
+             return 0;
+           }
          sscanf (buf + strlen (SOCKET_COOKIE), "%hu %c %08x-%08x-%08x-%08x",
                  &sin.sin_port,
                  &ctype,
@@ -972,7 +990,7 @@ fhandler_socket::bind (const struct sockaddr *name, int namelen)
 
       status = NtCreateFile (&fh, DELETE | FILE_GENERIC_WRITE,
                             pc.get_object_attr (attr, sa), &io, NULL, fattr,
-                            FILE_SHARE_VALID_FLAGS, FILE_CREATE,
+                            0, FILE_CREATE,
                             FILE_NON_DIRECTORY_FILE
                             | FILE_SYNCHRONOUS_IO_NONALERT
                             | FILE_OPEN_FOR_BACKUP_INTENT,