mbox series

[v2,net-next,0/5] ipv6: Rework infrastructure for TLV options in extension headers

Message ID 1548699775-3015-1-git-send-email-tom@quantonium.net
Headers show
Series ipv6: Rework infrastructure for TLV options in extension headers | expand

Message

Tom Herbert Jan. 28, 2019, 6:22 p.m. UTC 
This patch set implements an infrastructure to allow fine grained
control over IPv6 Destination and Hop-by-Hop TLV options. This
includes being able to registers handlers for receiving options as
well as a set of parameters that sets permissions for who may send a
TLV option and the preferred format of a list of options.

The goal of the patch is to enable broader use cases of IPv6 options,
including those for which non-privileged users can send options. In
order to curtail misuse of options in such cases, a number of
requirements on how the option may be sent and formatted is
enforced.

Particular features are:

- A single TLV paramters table containing the information about each
  TLV is defined. Lookups are simple offset accesses to the table
  based on TLV type. Both receiving and sending properties of TLVs
  are maintained in the table.
- Allow registration/deregistration of receive handlers for specific
  TLVs.
- Describe the properties of sending different TLVs in a TLV parameter
  table. The parameter table can be managed via netlink.
- Allow non-privileged users to send TLVs for which they have been
  granted permission.
- Provide a deep validation of TLVs and TLV lists to enforce specific
  limits and permission in order to thwart misuse of TLVs.
- Define a canonical format for sending TLVs that includes a
  preferred order, option alignment, minimal padding between TLVs.
- Allow individual TLVs to be added or set in txoptions list on a
  socket.

Tested: Write and read different TLVs on a socket via setsockopt
and getsockopt. Flow is add individual TLV, read back options,
set read option on new socket as a list. Verify options are
properly sent and received. Used a modified ip command in iproute2
to test managing the TLV parameter via netlink.

v2:
   - Change the TLV parameters table to be an array of u8s as
     opposed to pointers. Each entry gives the offset into
     a second array of TLV parameters structures. This reduces
     the memory footprint needed for the table but still allows
     O(1) lookups on TLV type.


Tom Herbert (5):
  exthdrs: Create exthdrs_options.c
  exthdrs: Registration of TLV handlers and parameters
  ip6tlvs: Add netlink interface
  ip6tlvs: Validation of TX Destination and Hop-by-Hop options
  ip6tlvs: API to set and remove individual TLVs from DO or HBH EH

 include/net/ipv6.h         |   82 ++
 include/uapi/linux/in6.h   |   58 ++
 net/ipv6/Makefile          |    2 +-
 net/ipv6/datagram.c        |   27 +-
 net/ipv6/exthdrs.c         |  389 +---------
 net/ipv6/exthdrs_options.c | 1798 ++++++++++++++++++++++++++++++++++++++++++++
 net/ipv6/ipv6_sockglue.c   |  110 ++-
 7 files changed, 2089 insertions(+), 377 deletions(-)
 create mode 100644 net/ipv6/exthdrs_options.c