Re: [Regression?] fib_rules: Added NLM_F_EXCL support to fib_nl_newrule breaks Android userspace

From: John Stultz <john.stultz@linaro.org>
To: Lorenzo Colitti <lorenzo@google.com>
Cc: David Ahern <dsa@cumulusnetworks.com>,
	David Miller <davem@davemloft.net>,
	Mateusz Bajorski <mateusz.bajorski@nokia.com>,
	lkml <linux-kernel@vger.kernel.org>,
	Guodong Xu <guodong.xu@linaro.org>,
	Dmitry Shmidt <dimitrysh@google.com>,
	Chih-Hung Hsieh <chh@google.com>,
	Eric Caruso <ejcaruso@google.com>
Subject: Re: [Regression?] fib_rules: Added NLM_F_EXCL support to fib_nl_newrule breaks Android userspace
Date: Tue, 2 Aug 2016 09:37:27 -0700	[thread overview]
Message-ID: <CALAqxLVpnJef7_-pqj8EJhk2aM3YTCmEFc693kG7tNq5OjS79g@mail.gmail.com> (raw)
In-Reply-To: <CAKD1Yr06yV+P7_WwaF+CXuzD9xHEHQYereL-1Ax0_8hLDTSMOQ@mail.gmail.com>

On Sun, Jul 31, 2016 at 6:42 PM, Lorenzo Colitti <lorenzo@google.com> wrote:
> On Sat, Jul 30, 2016 at 1:57 AM, John Stultz <john.stultz@linaro.org> wrote:
>>
>> With the patch reverted, and the system working,  I see:
>>
>> # ip rule ls
>> 0:      from all lookup local
>> 10000:  from all fwmark 0xc0000/0xd0000 lookup legacy_system
>> 13000:  from all fwmark 0x10063/0x1ffff lookup local_network
>> 13000:  from all fwmark 0x10065/0x1ffff lookup wlan0
>> 14000:  from all oif wlan0 lookup wlan0
>> 14000:  from all oif wlan0 lookup wlan0
>> 15000:  from all fwmark 0x0/0x10000 lookup legacy_system
>> 16000:  from all fwmark 0x0/0x10000 lookup legacy_network
>> 17000:  from all fwmark 0x0/0x10000 lookup local_network
>> 19000:  from all fwmark 0x64/0x1ffff lookup wlan0
>> 19000:  from all fwmark 0x65/0x1ffff lookup wlan0
>> 22000:  from all fwmark 0x0/0xffff lookup wlan0
>> 32000:  from all unreachable
>
>
> This is not correct, you're missing "uidrange 0-0" qualifiers on some
> of the rules.
>
> Does the kernel pass the networking unit tests at
> https://source.android.com/devices/tech/config/kernel_network_tests.html
> ? If not, the Android network stack will not work correctly.

So I looked into getting the tests above to run (had to get a UML fix
for recent kernels).

Against vanilla v4.7 (plus that one UML fix), all the tests pass.

Against linus/master (plus that one UML fix), I see 7 failures, which
all look very similar:

Traceback (most recent call last):
  File "./multinetwork_test.py", line 28, in <module>
    import multinetwork_base
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/multinetwork_base.py",
line 84, in <module>
    HAVE_UID_ROUTING = HaveUidRouting()
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/multinetwork_base.py",
line 78, in HaveUidRouting
    iproute.IPRoute().UidRangeRule(6, False, 1000, 2000, 100, 10000)
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/iproute.py",
line 380, in UidRangeRule
    return self._Rule(version, is_add, RTN_UNICAST, table, nlattr, priority)
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/iproute.py",
line 348, in _Rule
    self._SendNlRequest(command, rtmsg)
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/iproute.py",
line 318, in _SendNlRequest
    super(IPRoute, self)._SendNlRequest(command, data, flags)
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/netlink.py",
line 183, in _SendNlRequest
    self._ExpectAck()
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/netlink.py",
line 170, in _ExpectAck
    self._ParseAck(response)
  File "/host/home/jstultz/projects/android/hikey/kernel/tests/net/test/netlink.py",
line 164, in _ParseAck
    raise IOError(error, os.strerror(-error))
IOError: [Errno -2] No such file or directory

Interestingly, reverting 153380ec4b9b ("fib_rules: Added NLM_F_EXCL
support to fib_nl_newrule"), does not seem to fix it, and I get the
same errors.

thanks
-john