[PATCH v4] netfilter: ebtables: CONFIG_COMPAT support

[Florian Westphal <fw@strlen.de>]

Version 4 of the ebtables CONFIG_COMPAT patch set.

Changes since v3:
- reformat to get rid of overly long lines.

One long line remains (a BUG_ON() ), fixing this would make this much
more ugly, so I'd rather remove the BUG_ON if that one line is still a
problem.

Changes since v2:
- remove last use of MEMPRINT macro
- remove BUGPRINT line instead of adding compat argument to copy_counters_to_user

First patches are preparation patches to reduce copy & paste in later
patches.  Patch 4 is the main CONFIG_COMPAT hunk, next ones
handles those ebtables binaries specifically built for 64 bit kernel
(i.e. pad in userspace).
Last two patches add CONFIG_COMPAT support to the targets/matches that
need special handling (maybe I missed some, though).

Tested on x86_64 with x86 userland by comparing output of 32 and 64 bit ebtables binaries.

Changes since v1 were:
- also move handling of ebt counter set/getsockopt handling to helper functions to avoid
copy & pasting the same code in the COMPAT handlers.
- add missing length check to compat_do_ebt_get_ctl().
- add a patch to handle "userspace-side-padding" in some ebtables 32bit userspace binaries.
- add "const *" qualifiers to the compat_from/to user functions.

The following changes since commit 3e5e524ffb5fcf2447eb5dd9f8e54ad22dd9baa7:
  Florian Westphal (1):
        netfilter: CONFIG_COMPAT: allow delta to exceed 32767

are available in the git repository at:

  git://git.breakpoint.cc/fw/nf-next-2.6.git ebt_config_compat_v4

Florian Westphal (7):
      netfilter: ebtables: split do_replace into two functions
      netfilter: ebtables: split copy_everything_to_user into two functions
      netfilter: ebtables: split update_counters into two functions
      netfilter: ebtables: add CONFIG_COMPAT support
      netfilter: ebtables: try native set/getsockopt handlers, too
      netfilter: ebt_limit: add CONFIG_COMPAT support
      netfilter: ebtables: mark: add CONFIG_COMPAT support

 net/bridge/netfilter/ebt_limit.c  |   16 +
 net/bridge/netfilter/ebt_mark.c   |   31 +
 net/bridge/netfilter/ebt_mark_m.c |   37 ++
 net/bridge/netfilter/ebtables.c   | 1159 +++++++++++++++++++++++++++++++++----
 4 files changed, 1124 insertions(+), 119 deletions(-)