Re: [PATCH,Hurd] bind() fails when umask is 0777

[Samuel Thibault]

Roland McGrath, le Tue 26 Aug 2014 14:26:15 -0700, a écrit :
> I assume you mean umask is 0666 or more, such that (0600 & ~umask) is 0.

Oops, sure, yes :)

> The fix to use dir_lookup of "" to invoke the active translator seems
> correct and orthogonal to the umask issue. [...] Can you send a fix
> for just that issue separately first?

Yes, here it is.

Samuel

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.

---
 bind.c |   48 +++++++++++++++++++++++++-----------------------
 1 file changed, 25 insertions(+), 23 deletions(-)

--- a/sysdeps/mach/hurd/bind.c
+++ b/sysdeps/mach/hurd/bind.c
@@ -40,7 +40,7 @@ __bind  (int fd, __CONST_SOCKADDR_ARG ad
       char *name = _hurd_sun_path_dupa (addr, 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 *n;
 
       dir = __file_name_split (name, &n);
@@ -61,36 +61,38 @@ __bind  (int fd, __CONST_SOCKADDR_ARG ad
                                       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)
-               err = EADDRINUSE;
+             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)
+               if (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)
-               {
-                 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.  */
+               err = EADDRINUSE;
+             if (! err)
                {
-                 /* 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);