The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/496f396f9178b2830a60e3f667321f7eae5c482c

commit 496f396f9178b2830a60e3f667321f7eae5c482c
Author: Kevin Cernekee <cernekee@chromium.org>
Date: Sun Jul 03 21:24:48 2016

Handle duplicate IPv6 default routes

After shill adjusts a default IPv6 route to use a metric other than 1024,
the kernel will re-create a duplicate route with a metric of 1024 the
next time it receives a Router Advertisement.  Ignore these redundant
routes when shill is trying to adjust the metric, by choosing the
default route with the lowest (most preferred) metric.

BUG= chromium:625229 
TEST=run `ip -6 route list` while hot plugging / unplugging a USB
     ethernet adapter

Change-Id: I9a775cc2435ba4cb1b7a235cfc8753b5a171df1d
Reviewed-on: https://chromium-review.googlesource.com/358143
Commit-Ready: Kevin Cernekee <cernekee@chromium.org>
Tested-by: Kevin Cernekee <cernekee@chromium.org>
Reviewed-by: Eric Caruso <ejcaruso@chromium.org>
Reviewed-by: Kirtika Ruchandani <kirtika@google.com>

[modify] https://crrev.com/496f396f9178b2830a60e3f667321f7eae5c482c/routing_table.cc
[modify] https://crrev.com/496f396f9178b2830a60e3f667321f7eae5c482c/routing_table_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b

commit 6bbd442d269e108eedf9e762bd5fa2fe18a05a4b
Author: Kevin Cernekee <cernekee@chromium.org>
Date: Sun Jul 03 18:40:01 2016

Track the IPv6 default gateway on each connection

shill currently does not look at the default gateway created by the
kernel's stateless autoconfiguration mechanism.  This leads to several
issues:

1) The IPConfig Gateway property is left blank even when a gateway
has been configured.

2) Since ONC in Chrome promises that its own gateway field will be
populated whenever an IP address is present, this leads to an ONC spec
violation that may confuse clients that use ONC APIs.

3) The kernel always seems to assign a metric of IP6_RT_PRIO_USER (1024)
to all IPv6 default routes, rather than honoring the technology/service
preference order.  This can cause IPv6 traffic to be inadvertently
routed through a non-default service.

4) When ARC sets up forwarding rules through netfilter, it explicitly
whitelists the interface associated with the default service.  If
the kernel picks a default route on a different interface, all IPv6
traffic from the container will be dropped even though the containerized
OS believes it has a usable IPv6 address with global scope.

BUG= chromium:625229 
TEST=`FEATURES=test emerge-link shill`
TEST=`ip -6 route list` with multiple interfaces connected, and verify
     that the metric on each default route matches with IPv4

Change-Id: Ie900529c3895d5e8f0c4d1b148d9f7401559db85
Reviewed-on: https://chromium-review.googlesource.com/358139
Commit-Ready: Kevin Cernekee <cernekee@chromium.org>
Tested-by: Kevin Cernekee <cernekee@chromium.org>
Reviewed-by: Kirtika Ruchandani <kirtika@google.com>

[modify] https://crrev.com/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b/routing_table_unittest.cc
[modify] https://crrev.com/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b/connection.cc
[modify] https://crrev.com/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b/connection.h
[modify] https://crrev.com/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b/device.cc
[modify] https://crrev.com/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b/device.h
[modify] https://crrev.com/6bbd442d269e108eedf9e762bd5fa2fe18a05a4b/routing_table.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/d9064490e6d3729499bb78aa9f3d1c034c8ef57e

commit d9064490e6d3729499bb78aa9f3d1c034c8ef57e
Author: Kevin Cernekee <cernekee@chromium.org>
Date: Tue Jul 05 02:28:49 2016

Allow duplicate routes with different metrics

When a new route shows up, RouteMsgHandler() currently scans the list of
known routes for matches.  If a matching route with a different metric
is found, the old entry is replaced by the new entry.

But on IPv6 it is normal for the kernel to add duplicate default routes
with different metrics in response to RA messages received off the LAN.
So shill needs to track the duplicate routes so that it knows which
entries to have the kernel delete when the service sort order changes.

BUG= chromium:625229 
TEST=`FEATURES=test emerge-link shill`

Change-Id: I22cd572d891e800b41d3ff9b7a9e441fd3d5e3cc
Reviewed-on: https://chromium-review.googlesource.com/358172
Commit-Ready: Kevin Cernekee <cernekee@chromium.org>
Tested-by: Kevin Cernekee <cernekee@chromium.org>
Reviewed-by: Eric Caruso <ejcaruso@chromium.org>
Reviewed-by: Kirtika Ruchandani <kirtika@google.com>

[modify] https://crrev.com/d9064490e6d3729499bb78aa9f3d1c034c8ef57e/routing_table.cc
[modify] https://crrev.com/d9064490e6d3729499bb78aa9f3d1c034c8ef57e/routing_table_unittest.cc

Your change meets the bar and is auto-approved for M53 (branch: 2785)

The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8

commit a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8
Author: Kevin Cernekee <cernekee@chromium.org>
Date: Sun Jul 03 18:40:01 2016

Track the IPv6 default gateway on each connection

shill currently does not look at the default gateway created by the
kernel's stateless autoconfiguration mechanism.  This leads to several
issues:

1) The IPConfig Gateway property is left blank even when a gateway
has been configured.

2) Since ONC in Chrome promises that its own gateway field will be
populated whenever an IP address is present, this leads to an ONC spec
violation that may confuse clients that use ONC APIs.

3) The kernel always seems to assign a metric of IP6_RT_PRIO_USER (1024)
to all IPv6 default routes, rather than honoring the technology/service
preference order.  This can cause IPv6 traffic to be inadvertently
routed through a non-default service.

4) When ARC sets up forwarding rules through netfilter, it explicitly
whitelists the interface associated with the default service.  If
the kernel picks a default route on a different interface, all IPv6
traffic from the container will be dropped even though the containerized
OS believes it has a usable IPv6 address with global scope.

BUG= chromium:625229 
TEST=`FEATURES=test emerge-link shill`
TEST=`ip -6 route list` with multiple interfaces connected, and verify
     that the metric on each default route matches with IPv4

Change-Id: Ie900529c3895d5e8f0c4d1b148d9f7401559db85
Previous-Reviewed-on: https://chromium-review.googlesource.com/358139
(cherry picked from commit 4f08cef232578bcd9ff332f428d9389b943a2807)

[modify] https://crrev.com/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8/routing_table_unittest.cc
[modify] https://crrev.com/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8/connection.cc
[modify] https://crrev.com/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8/connection.h
[modify] https://crrev.com/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8/device.cc
[modify] https://crrev.com/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8/device.h
[modify] https://crrev.com/a2cde3cdbd9c12ca6ede7fb48c75d7a451ac02e8/routing_table.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/7d0fd1db8ad32a0956971da25393f359a0b1752c

commit 7d0fd1db8ad32a0956971da25393f359a0b1752c
Author: Kevin Cernekee <cernekee@chromium.org>
Date: Tue Jul 05 02:28:49 2016

Allow duplicate routes with different metrics

When a new route shows up, RouteMsgHandler() currently scans the list of
known routes for matches.  If a matching route with a different metric
is found, the old entry is replaced by the new entry.

But on IPv6 it is normal for the kernel to add duplicate default routes
with different metrics in response to RA messages received off the LAN.
So shill needs to track the duplicate routes so that it knows which
entries to have the kernel delete when the service sort order changes.

BUG= chromium:625229 
TEST=`FEATURES=test emerge-link shill`

Change-Id: I22cd572d891e800b41d3ff9b7a9e441fd3d5e3cc
Previous-Reviewed-on: https://chromium-review.googlesource.com/358172
(cherry picked from commit 8607bebf6c445ecd1dd0e6e447dee94334d1417f)

[modify] https://crrev.com/7d0fd1db8ad32a0956971da25393f359a0b1752c/routing_table.cc
[modify] https://crrev.com/7d0fd1db8ad32a0956971da25393f359a0b1752c/routing_table_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/ffc6e8657330c28a742cfbf3b904f1b33fa04cbf

commit ffc6e8657330c28a742cfbf3b904f1b33fa04cbf
Author: Kevin Cernekee <cernekee@chromium.org>
Date: Sun Jul 03 21:24:48 2016

Handle duplicate IPv6 default routes

After shill adjusts a default IPv6 route to use a metric other than 1024,
the kernel will re-create a duplicate route with a metric of 1024 the
next time it receives a Router Advertisement.  Ignore these redundant
routes when shill is trying to adjust the metric, by choosing the
default route with the lowest (most preferred) metric.

BUG= chromium:625229 
TEST=run `ip -6 route list` while hot plugging / unplugging a USB
     ethernet adapter

Change-Id: I9a775cc2435ba4cb1b7a235cfc8753b5a171df1d
Previous-Reviewed-on: https://chromium-review.googlesource.com/358143
(cherry picked from commit f568d8ba08c2679ec8196ca724f80ecf861f0206)

[modify] https://crrev.com/ffc6e8657330c28a742cfbf3b904f1b33fa04cbf/routing_table.cc
[modify] https://crrev.com/ffc6e8657330c28a742cfbf3b904f1b33fa04cbf/routing_table_unittest.cc

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I was able to see link local address in default gateway entry after running the following command 
dbus-send --system --dest=org.chromium.flimflam --print-reply /ipconfig/eth0_1_ip org.chromium.flimflam.IPConfig.GetProperties

dict entry(
         string "Gateway"
         variant             string "fe80::21c:b0ff:feb6:9140"
      )

ip -6 route list

2620:0:1000:1305::/64 dev eth0  proto kernel  metric 256  expires 2591957sec
fe80::/64 dev eth0  proto kernel  metric 256
default via fe80::21c:b0ff:feb6:9140 dev eth0  metric 1
default via fe80::21c:b0ff:feb6:9140 dev eth0  proto ra  metric 1024  expires 1757sec

ELM 8685.0.0