When we add a new IPv6 address, we should also join corresponding solicited-node
multicast address, unless the interface has IFF_NOARP flag, as function
addrconf_join_solict() did. But if we remove IFF_NOARP flag later, we do
not do dad and add the mcast address. So we will drop corresponding neighbour
discovery message that came from other nodes.

A typical example is after creating a ipvlan with mode l3, setting up an ipv6
address and changing the mode to l2. Then we will not be able to ping this
address as the interface doesn't join related solicited-node mcast address.

Fix it by re-doing dad when interface changed IFF_NOARP flag. Then we will add
corresponding mcast group and check if there is a duplicate address on the
network.

Reported-by: Jianlin Shi <jishi@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Preethi reported that PMTU discovery for UDP/raw applications is not
working in the presence of VRF when the socket is not bound to a device.
The problem is that ip6_sk_update_pmtu does not consider the L3 domain
of the skb device if the socket is not bound. Update the function to
set oif to the L3 master device if relevant.

Fixes: ca254490c8df ("net: Add VRF support to IPv6 stack")
Reported-by: Preethi Ramachandra <preethir@juniper.net>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These is no need to hold dst before calling rt6_remove_exception_rt().
The call to dst_hold_safe() in ip6_link_failure() was for ip6_del_rt(),
which has been removed in Commit 93531c674315 ("net/ipv6: separate
handling of FIB entries from dst based routes"). Otherwise, it will
cause a dst leak.

This patch is to simply remove the dst_hold_safe() call before calling
rt6_remove_exception_rt() and also do the same in ip6_del_cached_rt().
It's safe, because the removal of the exception that holds its dst's
refcnt is protected by rt6_exception_lock.

Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes")
Fixes: 23fb93a4d3f1 ("net/ipv6: Cleanup exception and cache route handling")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains the first batch of Netfilter fixes for
your net tree:

1) Fix splat with IPv6 defragmenting locally generated fragments,
   from Florian Westphal.

2) Fix Incorrect check for missing attribute in nft_osf.

3) Missing INT_MIN & INT_MAX definition for netfilter bridge uapi
   header, from Jiri Slaby.

4) Revert map lookup in nft_numgen, this is already possible with
   the existing infrastructure without this extension.

5) Fix wrong listing of set reference counter, make counter
   synchronous again, from Stefano Brivio.

6) Fix CIDR 0 in hash:net,port,net, from Eric Westbrook.

7) Fix allocation failure with large set, use kvcalloc().
   From Andrey Ryabinin.

8) No need to disable BH when fetch ip set comment, patch from
   Jozsef Kadlecsik.

9) Sanity check for valid sysfs entry in xt_IDLETIMER, from
   Taehee Yoo.

10) Fix suspicious rcu usage via ip_set() macro at netlink dump,
    from Jozsef Kadlecsik.

11) Fix setting default timeout via nfnetlink_cttimeout, this
    comes with preparation patch to add nf_{tcp,udp,...}_pernet()
    helper.

12) Allow ebtables table nat to be of filter type via nft_compat.
    From Florian Westphal.

13) Incorrect calculation of next bucket in early_drop, do no bump
    hash value, update bucket counter instead. From Vasily Khoruzhick.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Make sure we call fib6_dump_end() if it happens that skb->len
is zero. rtnl_dump_all() can reset cb->args on the next loop
iteration there.

Fixes: 08e814c9e8eb ("net/ipv6: Bail early if user only wants cloned entries")
Fixes: ae677bbb4441 ("net: Don't return invalid table id error when dumping all families")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the anycast.c init and cleanup functions which were inadvertently
added inside the CONFIG_PROC_FS definition.

Fixes: 2384d02520ff ("net/ipv6: Add anycast addresses to a global hashtable")
Signed-off-by: Jeff Barnhill <0xeffeff@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

icmp6_send() function is expensive on systems with a large number of
interfaces. Every time it’s called, it has to verify that the source
address does not correspond to an existing anycast address by looping
through every device and every anycast address on the device.  This can
result in significant delays for a CPU when there are a large number of
neighbors and ND timers are frequently timing out and calling
neigh_invalidate().

Add anycast addresses to a global hashtable to allow quick searching for
matching anycast addresses.  This is based on inet6_addr_lst in addrconf.c.

Signed-off-by: Jeff Barnhill <0xeffeff@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Traceroute executed in a vrf succeeds if no device is given or if the
vrf is given as the device, but fails if the interface is given as the
device. This is for default UDP probes, it succeeds for TCP SYN or ICMP
ECHO probes. As the skb bound dev is the interface and the sk dev is
the vrf, sk lookup fails for ICMP_DEST_UNREACH and ICMP_TIME_EXCEEDED
messages. The solution is for the secondary dev to be passed so that
the interface is available for the device match to succeed, in the same
way as is already done for non-error cases.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit a61bbcf28a8c ("[NET]: Store skb->timestamp as offset to a base
timestamp") introduces a neighbour control buffer and zeroes it out in
ndisc_rcv(), as ndisc_recv_ns() uses it.

Commit f2776ff04722 ("[IPV6]: Fix address/interface handling in UDP and
DCCP, according to the scoping architecture.") introduces the usage of the
IPv6 control buffer in protocol error handlers (e.g. inet6_iif() in
present-day __udp6_lib_err()).

Now, with commit b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate
redirect, instead of rt6_redirect()."), we call protocol error handlers
from ndisc_redirect_rcv(), after the control buffer is already stolen and
some parts are already zeroed out. This implies that inet6_iif() on this
path will always return zero.

This gives unexpected results on UDP socket lookup in __udp6_lib_err(), as
we might actually need to match sockets for a given interface.

Instead of always claiming the control buffer in ndisc_rcv(), do that only
when needed.

Fixes: b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect().")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

The cleanup path will put the target net when netnsid is set.  So we must
reset netnsid if the input is invalid.

Fixes: d7e38611b81e ("net/ipv4: Put target net when address dump fails due to bad attributes")
Fixes: 242afaa6968c ("net/ipv6: Put target net when address dump fails due to bad attributes")
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>