[PATCH net-next v5 0/2] report TCP MD5 signing keys and addresses

Ivan Delalande
2017-08-31T16:59:40Z

Allow userspace to retrieve MD5 signature keys and addresses configured
on TCP sockets through inet_diag.

Thanks to Eric Dumazet and Stephen Hemminger for their useful
explanations and feedback.

v5: - memset the whole netlink payload after it has been nla_reserve-d
in tcp_diag_put_md5sig (a third memset had to be added for
tcpm_key so we might as well have just one for entire region).
- move the nla_total_size call from inet_sk_attr_size to the
idiag_get_aux_size defined by protocols as they could add multiple
netlink attributes,
- add check for net_admin in tcp_diag_get_aux_size.

v4: - add new struct tcp_diag_md5sig to report the data instead of
tcp_md5sig to avoid wasting 112 bytes on every tcpm_addr,
- memset tcpm_addr on IPv4 addresses to avoid leaks,
- style fix in inet_diag_dump_one_icsk.

v3: - rename inet_diag_*md5sig in tcp_diag.c to tcp_diag_* for
consistency,
- don't lock the socket in tcp_diag_put_md5sig,
- add checks on md5sig_count in tcp_diag_put_md5sig to not create
the netlink attribute if the list is empty, and to avoid overflows
or memory leaks if the list has changed in the meantime.

v2: - move changes to tcp_diag.c and extend inet_diag_handler to allow
protocols to provide additional data on INET_DIAG_INFO,
- lock socket before calling tcp_diag_put_md5sig.

I also have a patch for iproute2/ss to test this change, making it print
this new attribute. I'm planning to polish and send it if this series
gets applied.

Ivan Delalande (2):
inet_diag: allow protocols to provide additional data
tcp_diag: report TCP MD5 signing keys and addresses

include/linux/inet_diag.h | 7 +++
include/uapi/linux/inet_diag.h | 1 +
include/uapi/linux/tcp.h | 9 ++++
net/ipv4/inet_diag.c | 22 +++++++--
net/ipv4/tcp_diag.c | 109 ++++++++++++++++++++++++++++++++++++++---
5 files changed, 138 insertions(+), 10 deletions(-)

--
2.14.1