Simplify atomicity of socket creation in bind.

diff --git a/ChangeLog b/ChangeLog
index 6261ed4..8d1eef4 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2014-08-27  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+       Simplify atomicity of socket creation in bind.
+
+       * sysdeps/mach/hurd/bind.c (__bind): Use dir_lookup(node, "") instead of
+       looking up the name after linking the file.
+
 2014-08-27  Allan McRae  <allan@archlinux.org>
 
        * sysdeps/i386/fpu/libm-test-ulps: Update ULPs.

diff --git a/sysdeps/mach/hurd/bind.c b/sysdeps/mach/hurd/bind.c
index 17ef22a..9bd668c 100644 (file)
--- a/sysdeps/mach/hurd/bind.c
+++ b/sysdeps/mach/hurd/bind.c
@@ -39,7 +39,7 @@ __bind  (int fd, __CONST_SOCKADDR_ARG addrarg, socklen_t len)
     {
       /* For the local domain, we must create a node in the filesystem
         using the ifsock translator and then fetch the address from it.  */
-      file_t dir, node;
+      file_t dir, node, ifsock;
       char name[len - offsetof (struct sockaddr_un, sun_path) + 1], *n;
 
       strncpy (name, addr->sun_path, sizeof name - 1);
@@ -63,36 +63,32 @@ __bind  (int fd, __CONST_SOCKADDR_ARG addrarg, socklen_t len)
                                       MACH_MSG_TYPE_COPY_SEND);
          if (! err)
            {
-             /* Link the node, now a socket, into the target directory.  */
-             err = __dir_link (dir, node, n, 1);
-             if (err == EEXIST)
+             enum retry_type doretry;
+             char retryname[1024];
+             /* Get a port to the ifsock translator.  */
+             err = __dir_lookup (node, "", 0, 0, &doretry, retryname, &ifsock);
+             if (! err && (doretry != FS_RETRY_NORMAL || retryname[0] != '\0'))
                err = EADDRINUSE;
            }
-         __mach_port_deallocate (__mach_task_self (), node);
          if (! err)
            {
-             /* Get a port to the ifsock translator.  */
-             file_t ifsock = __file_name_lookup_under (dir, n, 0, 0);
-             if (ifsock == MACH_PORT_NULL)
+             /* Get the address port.  */
+             err = __ifsock_getsockaddr (ifsock, &aport);
+             if (err == MIG_BAD_ID || err == EOPNOTSUPP)
+               err = EGRATUITOUS;
+             if (! err)
                {
-                 err = errno;
-                 /* If we failed, get rid of the node we created.  */
-                 __dir_unlink (dir, n);
-               }
-             else
-               {
-                 /* Get the address port.  */
-                 err = __ifsock_getsockaddr (ifsock, &aport);
-                 if (err == MIG_BAD_ID || err == EOPNOTSUPP)
-                   /* We are not talking to /hurd/ifsock.  Probably
-                      someone came in after we linked our node, unlinked
-                      it, and replaced it with a different node, before we
-                      did our lookup.  Treat it as if our link had failed
-                      with EEXIST.  */
+                 /* Link the node, now a socket with proper mode, into the
+                    target directory.  */
+                 err = __dir_link (dir, node, n, 1);
+                 if (err == EEXIST)
                    err = EADDRINUSE;
+                 if (err)
+                   __mach_port_deallocate (__mach_task_self (), aport);
                }
              __mach_port_deallocate (__mach_task_self (), ifsock);
            }
+         __mach_port_deallocate (__mach_task_self (), node);
        }
       __mach_port_deallocate (__mach_task_self (), dir);