[PATCH RFC net-next 0/9] net: Add address attribute to control metric of prefix route

[dsahern@kernel.org]

From: David Ahern <dsahern@gmail.com>

For use cases such as VRR (Virtual Router Redundancy) interface managers
want efficient control over the order of prefix routes when multiple
interfaces have addresses with overlapping/duplicate subnets.

Currently, if two interfaces have addresses in the same subnet, the order
of the prefix route entries is determined by the order in which the
addresses are assigned or the links brought up. Any actions like cycling
an interface up and down changes that order. This set adds a new attribute
for addresses to allow a user to specify the metric of the prefix route
associated with an address giving interface managers better and more
efficient control of the order of prefix routes.

Patches 1-5 refactor IPv6 address add functions to pass an ifa6_config
struct. The functions currently have a long list of arguments and adding
the metric just makes it worse. Because of the overall diff size in
moving the arguments to a struct, the change is done in changes to make
it easier to review starting with the bottom function and pushing the
struct up to callers in each successive patch.

Patch 6 introduces the new attribute.

Patches 7 and 8 add support for the new attribute to IPv4 and IPv6
addresses.

Patch 9 adds a set of test cases.

David Ahern (9):
  net/ipv6: Introduce ifa6_config struct
  net/ipv6: Convert ipv6_add_addr to struct ifa6_config
  net/ipv6: Remove temp variables in ipv6_create_tempaddr
  net/ipv6: Pass ifa6_config struct to inet6_addr_add
  net/ipv6: Pass ifa6_config struct to inet6_addr_modify
  net: Add IFA_RT_PRIORITY address attribute
  net/ipv4: Add support for specifying metric of connected routes
  net/ipv6: Add support for specifying metric of connected routes
  selftests: fib_tests: Add prefix route tests with metric

 include/linux/inetdevice.h               |   1 +
 include/net/addrconf.h                   |  13 ++
 include/net/if_inet6.h                   |   1 +
 include/net/route.h                      |   1 +
 include/uapi/linux/if_addr.h             |   1 +
 net/ipv4/devinet.c                       |  14 ++
 net/ipv4/fib_frontend.c                  |  56 ++++-
 net/ipv6/addrconf.c                      | 360 +++++++++++++++++++------------
 tools/testing/selftests/net/fib_tests.sh | 181 +++++++++++++++-
 9 files changed, 475 insertions(+), 153 deletions(-)
 mode change 100755 => 100644 tools/testing/selftests/net/fib_tests.sh

-- 
2.11.0