linux-stable/include
David Ahern 0ae8133586 net: ipv6: Allow shorthand delete of all nexthops in multipath route
IPv4 allows multipath routes to be deleted using just the prefix and
length. For example:
    $ ip ro ls vrf red
    unreachable default metric 8192
    1.1.1.0/24
        nexthop via 10.100.1.254  dev eth1 weight 1
        nexthop via 10.11.200.2  dev eth11.200 weight 1
    10.11.200.0/24 dev eth11.200 proto kernel scope link src 10.11.200.3
    10.100.1.0/24 dev eth1 proto kernel scope link src 10.100.1.3

    $ ip ro del 1.1.1.0/24 vrf red

    $ ip ro ls vrf red
    unreachable default metric 8192
    10.11.200.0/24 dev eth11.200 proto kernel scope link src 10.11.200.3
    10.100.1.0/24 dev eth1 proto kernel scope link src 10.100.1.3

The same notation does not work with IPv6 because of how multipath routes
are implemented for IPv6. For IPv6 only the first nexthop of a multipath
route is deleted if the request contains only a prefix and length. This
leads to unnecessary complexity in userspace dealing with IPv6 multipath
routes.

This patch allows all nexthops to be deleted without specifying each one
in the delete request. Internally, this is done by walking the sibling
list of the route matching the specifications given (prefix, length,
metric, protocol, etc).

    $  ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    2001:db8:200::/120 via 2001:db8:1::2 dev eth1 metric 1024  pref medium
    2001:db8:200::/120 via 2001:db8:2::2 dev eth2 metric 1024  pref medium
    ...

    $ ip -6 ro del vrf red 2001:db8:200::/120

    $ ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    ...

Because IPv6 allows individual nexthops to be deleted without deleting
the entire route, the ip6_route_multipath_del and non-multipath code
path (ip6_route_del) have to be discriminated so that all nexthops are
only deleted for the latter case. This is done by making the existing
fc_type in fib6_config a u16 and then adding a new u16 field with
fc_delete_all_nh as the first bit.

Suggested-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-04 19:58:14 -05:00
..
acpi More ACPI updates for v4.10-rc1 2016-12-22 10:19:32 -08:00
asm-generic asm-prototypes: Clear any CPP defines before declaring the functions 2017-01-05 12:57:42 +01:00
clocksource
crypto
drm Merge tag 'drm-misc-fixes-2017-01-23' of git://anongit.freedesktop.org/git/drm-misc into drm-fixes 2017-01-27 10:16:56 +10:00
dt-bindings dt-bindings: mfd: Remove TPS65217 interrupts 2016-12-27 10:06:00 -08:00
keys
kvm KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systems 2017-01-13 11:19:25 +00:00
linux net: remove support for per driver ndo_busy_poll() 2017-02-03 17:28:29 -05:00
math-emu
media
memory
misc
net net: ipv6: Allow shorthand delete of all nexthops in multipath route 2017-02-04 19:58:14 -05:00
pcmcia
ras
rdma RDMA/core: Add the function ib_mtu_int_to_enum 2017-01-24 15:34:22 -05:00
rxrpc
scsi Merge remote-tracking branch 'mkp-scsi/fixes' into fixes 2017-01-17 17:32:54 -05:00
soc ARCv2: MCIP: update the BCR per current changes 2017-01-24 11:05:59 -08:00
sound Merge remote-tracking branches 'asoc/fix/arizona', 'asoc/fix/dpcm', 'asoc/fix/dwc', 'asoc/fix/fsl-ssi' and 'asoc/fix/hdmi-codec' into asoc-linus 2017-01-10 10:47:50 +00:00
target target: add XCOPY target/segment desc sense codes 2017-01-10 08:40:32 -08:00
trace trace: rename trace_print_hex_seq arg and add kdoc 2017-02-03 15:50:18 -05:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2017-02-03 16:58:20 -05:00
video
xen
Kbuild