[PATCH net-next 0/6] ipv4,ipv6: convert the getsockopt switches to sockopt_t

This series continues the migration to sockopt_t, as described in [1].
do_ip_getsockopt() and do_ipv6_getsockopt() are the last two switches
still taking a sockptr_t pair, and everything they forward to now takes
a sockopt_t, so convert them both.

Patch 1 first rejects a negative optlen on ipv6, which do_ip_getsockopt()
already does. len is an int, but every consumer compares it unsigned, so
-1 reads as a huge value and each site clamps to its own reply size. The
conversion cannot carry that.

MCAST_MSFILTER has to move before the switches above it. It is the last
option with the quirk sockopt_expand_out() was added for [2]: optlen only
covers the fixed part, and the real reply size comes from the gf_numsrc
field inside it. Patches 2 and 3 convert it on both families.

Patches 4 and 5 convert the switches themselves. Each wrapper keeps its
__user prototype and builds the sockopt_t with sockopt_init_user(), so
the proto layer is untouched. Patch 6 grows the selftest an ip and an
ipv6 fixture, pinning the returned length and errno.

Link: https://lore.kernel.org/all/20260401-getsockopt-v2-0-611df6771aff@debian.org/ (local) [1]
Link: https://lore.kernel.org/all/20260914-getsockopt_phase6-v2-0-e48befc9602e@debian.org/ (local) [2]

To: David Ahern <dsahern@kernel.org>
To: Ido Schimmel <idosch@nvidia.com>
To: David S. Miller <davem@davemloft.net>
To: Eric Dumazet <edumazet@google.com>
To: Jakub Kicinski <kuba@kernel.org>
To: Paolo Abeni <pabeni@redhat.com>
To: Simon Horman <horms@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>
To: Daniel Borkmann <daniel@iogearbox.net>
To: Andrii Nakryiko <andrii@kernel.org>
To: Eduard Zingerman <eddyz87@gmail.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: Martin KaFai Lau <martin.lau@linux.dev>
To: Song Liu <song@kernel.org>
To: Yonghong Song <yonghong.song@linux.dev>
To: Jiri Olsa <jolsa@kernel.org>
To: Emil Tsalapatis <emil@etsalapatis.com>
To: Ihor Solodrai <ihor.solodrai@linux.dev>
To: John Fastabend <john.fastabend@gmail.com>
To: Stanislav Fomichev <sdf@fomichev.me>
To: Shuah Khan <shuah@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
To: Stanislav Fomichev <sdf@fomichev.me>
Cc: david.laight.linux@gmail.com

Signed-off-by: Breno Leitao <leitao@debian.org>
---
Breno Leitao (6):
      ipv6: reject a negative optlen in do_ipv6_getsockopt()
      ipv6: mcast: convert ip6_mc_msfget() to sockopt_t
      ipv4: igmp: convert ip_mc_gsfget() to sockopt_t
      ipv4: convert do_ip_getsockopt() to sockopt_t
      ipv6: convert do_ipv6_getsockopt() to sockopt_t
      selftests: net: getsockopt_iter: cover ip and ipv6

 include/linux/igmp.h                          |   2 +-
 include/linux/mroute.h                        |   4 +-
 include/linux/mroute6.h                       |   5 +-
 include/net/ip.h                              |   3 +-
 include/net/ipv6.h                            |   4 +-
 net/core/filter.c                             |  36 ++-
 net/ipv4/igmp.c                               |  23 +-
 net/ipv4/ip_sockglue.c                        | 118 +++++-----
 net/ipv4/ipmr.c                               |  11 +-
 net/ipv6/ip6mr.c                              |  13 +-
 net/ipv6/ipv6_sockglue.c                      | 111 +++++-----
 net/ipv6/mcast.c                              |  19 +-
 tools/testing/selftests/net/getsockopt_iter.c | 302 ++++++++++++++++++++++++++
 13 files changed, 494 insertions(+), 157 deletions(-)
---
base-commit: 42a9fb3382fc2573e92f41d203b095d9a372cfc9
change-id: 20260924-sockopt_expand_out_v2-ee4bc7ba4cea

Best regards,
--  
Breno Leitao [off-list ref]