Hi,
First of all, I think the title of the patch is wrong. The relevant bit
is that this patch has the initial implementation for loading
server-provided ioctl handlers. The fact that they are reloaded each
time, is something that would normally be mentioned in the commit
message; but certainly not in the title.
On Wed, Aug 26, 2009 at 04:42:32PM +0200, Carl Fredrik Hammar wrote:
> * hurd/hurdioctl.c (_hurd_dummy_ioctl_handler): New function.
> * hurd/hurd/ioctl.h (_hurd_dummy_ioctl_handler): Likewise.
> * hurd/fd-ioctl-call.c: New file.
> * hurd/hurd/fd.h: Update copyright years.
Don't mention this in the changelog.
> (_hurd_fd_call_ioctl_handler): New function declaration.
> * hurd/Makefile: Update copyright years.
> (user-interfaces): Add `ioctl_handler'.
> (dtable): Add `fd-ioctl-call'.
> * sysdeps/mach/hurd/ioctl.c: Update copyright years.
> (__ioctl): Call fd ioctl handler.
> ---
> hurd/Makefile | 7 ++-
> hurd/fd-ioctl-call.c | 90
> +++++++++++++++++++++++++++++++++++++++++++++
> hurd/hurd/fd.h | 6 ++-
> hurd/hurd/ioctl.h | 5 ++
> hurd/hurdioctl.c | 9 ++++-
> sysdeps/mach/hurd/ioctl.c | 12 +++++-
> 6 files changed, 123 insertions(+), 6 deletions(-)
> create mode 100644 hurd/fd-ioctl-call.c
>
> diff --git a/hurd/Makefile b/hurd/Makefile
> index ff6b7cb..4ad5128 100644
> --- a/hurd/Makefile
> +++ b/hurd/Makefile
> @@ -1,4 +1,4 @@
> -# Copyright (C) 1991,92,93,94,95,96,97,98,99,2001,2002,2004,2006
> +# Copyright (C) 1991,92,93,94,95,96,97,98,99,2001,2002,2004,2006,2009
> # Free Software Foundation, Inc.
> # This file is part of the GNU C Library.
>
> @@ -40,7 +40,7 @@ user-interfaces := $(addprefix hurd/,\
> msg msg_reply msg_request \
> exec exec_startup crash interrupt \
> fs fsys io term tioctl socket ifsock \
> - login password pfinet \
> + login password pfinet ioctl_handler \
> )
> server-interfaces := hurd/msg faultexc
>
> @@ -67,7 +67,8 @@ sig = hurdsig hurdfault siginfo hurd-raise preempt-sig \
> thread-self thread-cancel intr-msg catch-signal
> dtable = dtable port2fd new-fd alloc-fd intern-fd \
> getdport openport \
> - fd-close fd-read fd-write hurdioctl ctty-input ctty-output
> + fd-close fd-read fd-write hurdioctl ctty-input ctty-output \
> + fd-ioctl-call
> inlines = $(inline-headers:%.h=%-inlines)
> distribute = hurdstartup.h hurdfault.h hurdhost.h sysvshm.h \
> faultexc.defs intr-rpc.defs intr-rpc.h intr-msg.h Notes
> diff --git a/hurd/fd-ioctl-call.c b/hurd/fd-ioctl-call.c
> new file mode 100644
> index 0000000..c5a41e8
> --- /dev/null
> +++ b/hurd/fd-ioctl-call.c
> @@ -0,0 +1,90 @@
> +/* Call descriptors ioctl handler.
> + Copyright (C) 2009 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, write to the Free
> + Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
> + Boston, MA 02110-1301, USA. */
> +
> +#include <hurd.h>
> +#include <hurd/fd.h>
> +#include <hurd/ioctl.h>
> +#include <hurd/ioctl_handler.h>
> +#include <dlfcn.h>
> +#include <stdio.h>
> +#include <unistd.h>
> +
> +
> +/* Get PORT's ioctl handler module and load it, returning the linker map
> + in MAP as returned by `dlopen'. */
> +
> +static error_t
> +load_ioctl_handler (io_t port, void **map)
> +{
> + io_t handler;
> + error_t err;
> +
> + err = __ioctl_handler_get (port, &handler);
> + if (!err)
> + {
> + int fd = _hurd_intern_fd (handler, 0, 1); /* Consumes HANDLER. */
> + if (fd == -1)
> + err = errno;
> + else
> + {
> + char *name;
> + err = __asprintf (&name, "/dev/fd/%d", fd);
> + if (err == -1)
> + err = errno;
> + else
> + {
> + *map = __libc_dlopen (name);
> + free (name);
> + err = 0;
> + }
> + __close (fd);
> + }
> + }
> +
> + return err;
> +}
> +
> +
> +/* Call D's ioctl handler, loading it from the underlying port if
> + necessary. Arguments are the same as ioctl handlers. */
> +
> +int
> +_hurd_fd_call_ioctl_handler (int fd, int request, void *arg)
> +{
> + ioctl_handler_t ioctl_handler;
> + void *ioctl_handler_map;
> + int result;
> + error_t err;
> +
> + /* Avoid spurious "may be used uninitialized" warning. */
> + ioctl_handler_map = NULL;
> +
> + err = HURD_DPORT_USE (fd, load_ioctl_handler (port, &ioctl_handler_map));
> + if (!err && ioctl_handler_map)
> + ioctl_handler = __libc_dlsym (ioctl_handler_map, "hurd_ioctl_handler");
The "hurd_" prefix is not very descriptive IMHO.
> + if (err || !ioctl_handler_map || !ioctl_handler)
> + ioctl_handler = _hurd_dummy_ioctl_handler;
> +
> + result = (*ioctl_handler) (fd, request, arg);
Using a dummy handler here seems overkill...
> +
> + if (ioctl_handler_map)
> + __libc_dlclose (ioctl_handler_map);
> +
> + return result;
> +}
> diff --git a/hurd/hurd/fd.h b/hurd/hurd/fd.h
> index 2a981f4..6ea9ad6 100644
> --- a/hurd/hurd/fd.h
> +++ b/hurd/hurd/fd.h
> @@ -1,6 +1,6 @@
> /* File descriptors.
> Copyright (C) 1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2006,2007
> - Free Software Foundation, Inc.
> + 2009 Free Software Foundation, Inc.
> This file is part of the GNU C Library.
>
> The GNU C Library is free software; you can redistribute it and/or
> @@ -291,5 +291,9 @@ extern file_t __directory_name_split_at (int fd, const
> char *directory_name,
> char **name);
>
>
> +/* Call D's ioctl handler, loading it from the underlying port if
> + necessary. Arguments are the same as ioctl handlers. */
> +extern int _hurd_fd_call_ioctl_handler (int fd, int request, void *arg);
> +
>
> #endif /* hurd/fd.h */
> diff --git a/hurd/hurd/ioctl.h b/hurd/hurd/ioctl.h
> index e5ab3dc..f932fa1 100644
> --- a/hurd/hurd/ioctl.h
> +++ b/hurd/hurd/ioctl.h
> @@ -74,4 +74,9 @@ extern int hurd_register_ioctl_handler (int first_request,
> int last_request,
> ioctl_handler_t _hurd_lookup_ioctl_handler (int request);
>
>
> +/* A dummy handler that always fails. */
> +
> +int _hurd_dummy_ioctl_handler (int fd, int request, void *arg);
> +
> +
> #endif /* hurd/ioctl.h */
> diff --git a/hurd/hurdioctl.c b/hurd/hurdioctl.c
> index 13a1a78..0b91ee1 100644
> --- a/hurd/hurdioctl.c
> +++ b/hurd/hurdioctl.c
> @@ -1,5 +1,5 @@
> /* ioctl commands which must be done in the C library.
> - Copyright (C) 1994,95,96,97,99,2001,02 Free Software Foundation, Inc.
> + Copyright (C) 1994,95,96,97,99,2001,02,09 Free Software Foundation, Inc.
> This file is part of the GNU C Library.
>
> The GNU C Library is free software; you can redistribute it and/or
> @@ -50,6 +50,13 @@ _hurd_lookup_ioctl_handler (int request)
> return NULL;
> }
>
> +/* A dummy handler that always fails. */
> +int
> +_hurd_dummy_ioctl_handler (int fd, int request, void *arg)
> +{
> + return __hurd_fail (ENOTTY);
> +}
> +
> #include <fcntl.h>
>
> /* Find out how many bytes may be read from FD without blocking. */
> diff --git a/sysdeps/mach/hurd/ioctl.c b/sysdeps/mach/hurd/ioctl.c
> index 769eb68..736ad8e 100644
> --- a/sysdeps/mach/hurd/ioctl.c
> +++ b/sysdeps/mach/hurd/ioctl.c
> @@ -1,4 +1,4 @@
> -/* Copyright (C) 1992,93,94,95,96,97,99,2000,2002,2005
> +/* Copyright (C) 1992,93,94,95,96,97,99,2000,2002,2005,2009
> Free Software Foundation, Inc.
> This file is part of the GNU C Library.
>
> @@ -220,6 +220,16 @@ __ioctl (int fd, unsigned long int request, ...)
> }
>
> {
> + int save = errno;
> + int result = _hurd_fd_call_ioctl_handler (fd, request, arg);
> + if (result != -1 || errno != ENOTTY)
> + return result;
> +
> + /* The handler doesn't grok this one. Try linked handlers. */
> + errno = save;
> + }
I think you should add a comment to this code block.
-antrik-
