linux-toradex.git/net/ipv6, branch v4.6-rc7

ipv6/ila: fix nlsize calculation for lwtunnel

2016-05-03T20:21:33+00:00

The handler 'ila_fill_encap_info' adds one attribute: ILA_ATTR_LOCATOR.

Fixes: 65d7ab8de582 ("net: Identifier Locator Addressing module")
CC: Tom Herbert 
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

net: ipv6: Delete host routes on an ifdown

2016-04-26T15:48:26+00:00

It was a simple idea -- save IPv6 configured addresses on a link down
so that IPv6 behaves similar to IPv4. As always the devil is in the
details and the IPv6 stack as too many behavioral differences from IPv4
making the simple idea more complicated than it needs to be.

The current implementation for keeping IPv6 addresses can panic or spit
out a warning in one of many paths:

1. IPv6 route gets an IPv4 route as its 'next' which causes a panic in
   rt6_fill_node while handling a route dump request.

2. rt->dst.obsolete is set to DST_OBSOLETE_DEAD hitting the WARN_ON in
   fib6_del

3. Panic in fib6_purge_rt because rt6i_ref count is not 1.

The root cause of all these is references related to the host route for
an address that is retained.

So, this patch deletes the host route every time the ifdown loop runs.
Since the host route is deleted and will be re-generated an up there is
no longer a need for the l3mdev fix up. On the 'admin up' side move
addrconf_permanent_addr into the NETDEV_UP event handling so that it
runs only once versus on UP and CHANGE events.

All of the current panics and warnings appear to be related to
addresses on the loopback device, but given the catastrophic nature when
a bug is triggered this patch takes the conservative approach and evicts
all host routes rather than trying to determine when it can be re-used
and when it can not. That can be a later optimizaton if desired.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

Revert "ipv6: Revert optional address flusing on ifdown."

2016-04-26T15:47:41+00:00

This reverts commit 841645b5f2dfceac69b78fcd0c9050868d41ea61.

Ok, this puts the feature back.  I've decided to apply David A.'s
bug fix and run with that rather than make everyone wait another
whole release for this feature.

Signed-off-by: David S. Miller

ipv6: Revert optional address flusing on ifdown.

2016-04-25T19:33:55+00:00

This reverts the following three commits:

70af921db6f8835f4b11c65731116560adb00c14
799977d9aafbf0ca0b9c39b04cbfb16db71302c9
f1705ec197e705b79ea40fe7a2cc5acfa1d3bfac

The feature was ill conceived, has terrible semantics, and has added
nothing but regressions to the already fragile ipv6 stack.

Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional")
Signed-off-by: David S. Miller

ipv6: udp: Do a route lookup and update during release_cb

2016-04-14T20:29:53+00:00

This patch adds a release_cb for UDPv6.  It does a route lookup
and updates sk->sk_dst_cache if it is needed.  It picks up the
left-over job from ip6_sk_update_pmtu() if the sk was owned
by user during the pmtu update.

It takes a rcu_read_lock to protect the __sk_dst_get() operations
because another thread may do ip6_dst_store() without taking the
sk lock (e.g. sendmsg).

Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception")
Signed-off-by: Martin KaFai Lau 
Reported-by: Wei Wang 
Cc: Cong Wang 
Cc: Eric Dumazet 
Cc: Wei Wang 
Signed-off-by: David S. Miller

ipv6: datagram: Update dst cache of a connected datagram sk during pmtu update

2016-04-14T20:29:51+00:00

There is a case in connected UDP socket such that
getsockopt(IPV6_MTU) will return a stale MTU value. The reproducible
sequence could be the following:
1. Create a connected UDP socket
2. Send some datagrams out
3. Receive a ICMPV6_PKT_TOOBIG
4. No new outgoing datagrams to trigger the sk_dst_check()
   logic to update the sk->sk_dst_cache.
5. getsockopt(IPV6_MTU) returns the mtu from the invalid
   sk->sk_dst_cache instead of the newly created RTF_CACHE clone.

This patch updates the sk->sk_dst_cache for a connected datagram sk
during pmtu-update code path.

Note that the sk->sk_v6_daddr is used to do the route lookup
instead of skb->data (i.e. iph).  It is because a UDP socket can become
connected after sending out some datagrams in un-connected state.  or
It can be connected multiple times to different destinations.  Hence,
iph may not be related to where sk is currently connected to.

It is done under '!sock_owned_by_user(sk)' condition because
the user may make another ip6_datagram_connect()  (i.e changing
the sk->sk_v6_daddr) while dst lookup is happening in the pmtu-update
code path.

For the sock_owned_by_user(sk) == true case, the next patch will
introduce a release_cb() which will update the sk->sk_dst_cache.

Test:

Server (Connected UDP Socket):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Route Details:
[root@arch-fb-vm1 ~]# ip -6 r show | egrep '2fac'
2fac::/64 dev eth0  proto kernel  metric 256  pref medium
2fac:face::/64 via 2fac::face dev eth0  metric 1024  pref medium

A simple python code to create a connected UDP socket:

import socket
import errno

HOST = '2fac::1'
PORT = 8080

s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
s.bind((HOST, PORT))
s.connect(('2fac:face::face', 53))
print("connected")
while True:
    try:
	data = s.recv(1024)
    except socket.error as se:
	if se.errno == errno.EMSGSIZE:
		pmtu = s.getsockopt(41, 24)
		print("PMTU:%d" % pmtu)
		break
s.close()

Python program output after getting a ICMPV6_PKT_TOOBIG:
[root@arch-fb-vm1 ~]# python2 ~/devshare/kernel/tasks/fib6/udp-connect-53-8080.py
connected
PMTU:1300

Cache routes after recieving TOOBIG:
[root@arch-fb-vm1 ~]# ip -6 r show table cache
2fac:face::face via 2fac::face dev eth0  metric 0
    cache  expires 463sec mtu 1300 pref medium

Client (Send the ICMPV6_PKT_TOOBIG):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
scapy is used to generate the TOOBIG message.  Here is the scapy script I have
used:

>>> p=Ether(src='da:75:4d:36:ac:32', dst='52:54:00:12:34:66', type=0x86dd)/IPv6(src='2fac::face', dst='2fac::1')/ICMPv6PacketTooBig(mtu=1300)/IPv6(src='2fac::
1',dst='2fac:face::face', nh='UDP')/UDP(sport=8080,dport=53)
>>> sendp(p, iface='qemubr0')

Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception")
Signed-off-by: Martin KaFai Lau 
Reported-by: Wei Wang 
Cc: Cong Wang 
Cc: Eric Dumazet 
Cc: Wei Wang 
Signed-off-by: David S. Miller

ipv6: datagram: Refactor dst lookup and update codes to a new function

2016-04-14T20:29:50+00:00

This patch moves the route lookup and update codes for connected
datagram sk to a newly created function ip6_datagram_dst_update()

It will be reused during the pmtu update in the later patch.

Signed-off-by: Martin KaFai Lau 
Cc: Cong Wang 
Cc: Eric Dumazet 
Cc: Wei Wang 
Signed-off-by: David S. Miller

ipv6: datagram: Refactor flowi6 init codes to a new function

2016-04-14T20:29:49+00:00

Move flowi6 init codes for connected datagram sk to a newly created
function ip6_datagram_flow_key_init().

Notes:
1. fl6_flowlabel is used instead of fl6.flowlabel in __ip6_datagram_connect
2. ipv6_addr_is_multicast(&fl6->daddr) is used instead of
   (addr_type & IPV6_ADDR_MULTICAST) in ip6_datagram_flow_key_init()

This new function will be reused during pmtu update in the later patch.

Signed-off-by: Martin KaFai Lau 
Cc: Cong Wang 
Cc: Eric Dumazet 
Cc: Wei Wang 
Signed-off-by: David S. Miller

net: ipv6: Do not keep linklocal and loopback addresses

2016-04-14T02:58:37+00:00

f1705ec197e7 added the option to retain user configured addresses on an
admin down. A comment to one of the later revisions suggested using the
IFA_F_PERMANENT flag rather than adding a user_managed boolean to the
ifaddr struct. A side effect of this change is that link local and
loopback addresses are also retained which is not part of the objective
of f1705ec197e7. Add check to drop those addresses.

Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: vrf: Fix dev refcnt leak due to IPv6 prefix route

2016-04-11T19:56:20+00:00

ifupdown2 found a kernel bug with IPv6 routes and movement from the main
table to the VRF table. Sequence of events:

Create the interface and add addresses:
    ip link add dev eth4.105 link eth4 type vlan id 105
    ip addr add dev eth4.105 8.105.105.10/24
    ip -6 addr add dev eth4.105 2008:105:105::10/64

At this point IPv6 has inserted a prefix route in the main table even
though the interface is 'down'. From there the VRF device is created:
    ip link add dev vrf105 type vrf table 105
    ip addr add dev vrf105 9.9.105.10/32
    ip -6 addr add dev vrf105 2000:9:105::10/128
    ip link set vrf105 up

Then the interface is enslaved, while still in the 'down' state:
    ip link set dev eth4.105 master vrf105

Since the device is down the VRF driver cycling the device does not
send the NETDEV_UP and NETDEV_DOWN but rather the NETDEV_CHANGE event
which does not flush the routes inserted prior.

When the link is brought up
    ip link set dev eth4.105 up

the prefix route is added in the VRF table, but does not remove
the route from the main table.

Fix by handling the NETDEV_CHANGEUPPER event similar what was implemented
for IPv4 in 7f49e7a38b77 ("net: Flush local routes when device changes vrf
association")

Fixes: 35402e3136634 ("net: Add IPv6 support to VRF device")

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller