This patch implements an ILA tanslation table. This table can be
configured with identifier to locator mappings, and can be be queried
to resolve a mapping. Queries can be parameterized based on interface,
direction (incoming or outoing), and matching locator.  The table is
implemented using rhashtable and is configured via netlink (through
"ip ila .." in iproute).

The table may be used as alternative means to do do ILA tanslations
other than the lw tunnels
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Create ila directory in preparation for supporting other hooks in the
kernel than LWT for doing ILA. This includes:
  - Moving ila.c to ila/ila_lwt.c
  - Splitting out some common functions into ila_common.c
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These netif flags are unnecessary convolutions. It is more
straightforward to just use NETIF_F_HW_CSUM, NETIF_F_IP_CSUM,
and NETIF_F_IPV6_CSUM directly.

This patch also:
    - Cleans up can_checksum_protocol
    - Simplifies netdev_intersect_features
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes ARPHRD_IEEE802154 from addrconf handling. In the
earlier days of 802.15.4 6LoWPAN, the interface type was ARPHRD_IEEE802154
which introduced several issues, because 802.15.4 interfaces used the
same type.

Since commit 965e613d ("ieee802154: 6lowpan: fix ARPHRD to
ARPHRD_6LOWPAN") we use ARPHRD_6LOWPAN for 6LoWPAN interfaces. This
patch will remove ARPHRD_IEEE802154 which is currently deadcode, because
ARPHRD_IEEE802154 doesn't reach the minimum 1280 MTU of IPv6.

Also we use 6LoWPAN EUI64 specific defines instead using link-layer
constanst from 802.15.4 link-layer header.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

An interface changing type may not have IPv6 addresses. Don't
call the address configuration type change in this case.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Setting a value bigger than 255 resulted in using only the lower eight
bits of that value as it is assigned to the u8 header field. To avoid
this unexpected result, reject such values.

Setting a value of zero is technically possible, but hosts receiving
such a packet have to treat it like hop_limit was set to one, according
to RFC2460. Therefore I don't see a use-case for that.

Setting a route's hop_limit to zero in iproute2 means to use the sysctl
default, which is not the case here: Setting e.g.
net.conf.eth0.hop_limit=0 will not make the kernel use
net.conf.all.hop_limit for outgoing packets on eth0. To avoid these
kinds of confusion, reject zero.
Signed-off-by: NPhil Sutter <phil@nwl.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While testing the np->opt RCU conversion, I found that UDP/IPv6 was
using a mixture of xchg() and sk_dst_lock to protect concurrent changes
to sk->sk_dst_cache, leading to possible corruptions and crashes.

ip6_sk_dst_lookup_flow() uses sk_dst_check() anyway, so the simplest
way to fix the mess is to remove sk_dst_lock completely, as we did for
IPv4.

__ip6_dst_store() and ip6_dst_store() share same implementation.

sk_setup_caps() being called with socket lock being held or not,
we have to use sk_dst_set() instead of __sk_dst_set()

Note that I had to move the "np->dst_cookie = rt6_get_cookie(rt);"
in ip6_dst_store() before the sk_setup_caps(sk, dst) call.

This is because ip6_dst_store() can be called from process context,
without any lock held.

As soon as the dst is installed in sk->sk_dst_cache, dst can be freed
from another cpu doing a concurrent ip6_dst_store()

Doing the dst dereference before doing the install is needed to make
sure no use after free would trigger.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If tcp_send_ack() can not allocate skb, we properly handle this
and setup a timer to try later.

Use __GFP_NOWARN to avoid polluting syslog in the case host is
under memory pressure, so that pertinent messages are not lost under
a flood of useless information.

sk_gfp_atomic() can use its gfp_mask argument (all callers currently
were using GFP_ATOMIC before this patch)

We rename sk_gfp_atomic() to sk_gfp_mask() to clearly express this
function now takes into account its second argument (gfp_mask)

Note that when tcp_transmit_skb() is called with clone_it set to false,
we do not attempt memory allocations, so can pass a 0 gfp_mask, which
most compilers can emit faster than a non zero or constant value.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch addresses multiple problems :

UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions
while socket is not locked : Other threads can change np->opt
concurrently. Dmitry posted a syzkaller
(http://github.com/google/syzkaller) program desmonstrating
use-after-free.

Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock()
and dccp_v6_request_recv_sock() also need to use RCU protection
to dereference np->opt once (before calling ipv6_dup_options())

This patch adds full RCU protection to np->opt
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit ab450605.

In IPv6, we cannot inherit the dst of the original dst. ndisc packets
are IPv6 packets and may take another route than the original packet.

This patch breaks the following scenario: a packet comes from eth0 and
is forwarded through vxlan1. The encapsulated packet triggers an NS
which cannot be sent because of the wrong route.

CC: Jiri Benc <jbenc@redhat.com>
CC: Thomas Graf <tgraf@suug.ch>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It looks like many files are including mroute.h unnecessarily, so remove
the include. Most importantly remove it from ipv6.

CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Steffen Klassert <steffen.klassert@secunet.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since (at least) commit b17a7c17 ("[NET]: Do sysfs registration as
part of register_netdevice."), netdev_run_todo() deals only with
unregistration, so we don't need to do the rtnl_unlock/lock cycle to
finish registration when failing pimreg or dvmrp device creation. In
fact that opens a race condition where someone can delete the device
while rtnl is unlocked because it's fully registered. The problem gets
worse when netlink support is introduced as there are more points of entry
that can cause it and it also makes reusing that code correctly impossible.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a fragmented multicast packet is received on an ethernet device which
has an active macvlan on top of it, each fragment is duplicated and
received both on the underlying device and the macvlan. If some
fragments for macvlan are processed before the whole packet for the
underlying device is reassembled, the "overlapping fragments" test in
ip6_frag_queue() discards the whole fragment queue.

To resolve this, add device ifindex to the search key and require it to
match reassembling multicast packets and packets to link-local
addresses.

Note: similar patch has been already submitted by Yoshifuji Hideaki in

  http://patchwork.ozlabs.org/patch/220979/

but got lost and forgotten for some reason.
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to ipv4, when destroying an mrt table the static mfc entries and
the static devices are kept, which leads to devices that can never be
destroyed (because of refcnt taken) and leaked memory. Make sure that
everything is cleaned up on netns destruction.

Fixes: 8229efda ("netns: ip6mr: enable namespace support in ipv6 multicast forwarding code")
CC: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add tracepoint to show fib6 table lookups and result.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the commit cdf3464e ("ipv6: Fix dst_entry refcnt bugs in ip6_tunnel")
introduced percpu storage for ip6_tunnel dst cache, but while clearing
such cache it used raw_cpu_ptr to walk the per cpu entries, so cached
dst on non current cpu are not actually reset.

This patch replaces raw_cpu_ptr with per_cpu_ptr, properly cleaning
such storage.

Fixes: cdf3464e ("ipv6: Fix dst_entry refcnt bugs in ip6_tunnel")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the OUTMCAST stat is double incremented, getting bumped once in the mcast code
itself, and again in the common ip output path.  Remove the mcast bump, as its
not needed

Validated by the reporter, with good results
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Reported-by: NClaus Jensen <claus.jensen@microsemi.com>
CC: Claus Jensen <claus.jensen@microsemi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some functions access TCP sockets without holding a lock and
might output non consistent data, depending on compiler and or
architecture.

tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...

Introduce sk_state_load() and sk_state_store() to fix the issues,
and more clearly document where this lack of locking is happening.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All DST_NOCACHE rt6_info used to have rt->dst.from set to
its parent.

After commit 8e3d5be7 ("ipv6: Avoid double dst_free"),
DST_NOCACHE is also set to rt6_info which does not have
a parent (i.e. rt->dst.from is NULL).

This patch catches the rt->dst.from == NULL case.

Fixes: 8e3d5be7 ("ipv6: Avoid double dst_free")
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the expires of the DST_NOCACHE rt can be set during
the ip6_rt_update_pmtu(), we also need to consider the expires
value when doing ip6_dst_check().

This patches creates __rt6_check_expired() to only
check the expire value (if one exists) of the current rt.

In rt6_dst_from_check(), it adds __rt6_check_expired() as
one of the condition check.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The original bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=1272571

The setup has a IPv4 GRE tunnel running in a IPSec.  The bug
happens when ndisc starts sending router solicitation at the gre
interface.  The simplified oops stack is like:

__lock_acquire+0x1b2/0x1c30
lock_acquire+0xb9/0x140
_raw_write_lock_bh+0x3f/0x50
__ip6_ins_rt+0x2e/0x60
ip6_ins_rt+0x49/0x50
~~~~~~~~
__ip6_rt_update_pmtu.part.54+0x145/0x250
ip6_rt_update_pmtu+0x2e/0x40
~~~~~~~~
ip_tunnel_xmit+0x1f1/0xf40
__gre_xmit+0x7a/0x90
ipgre_xmit+0x15a/0x220
dev_hard_start_xmit+0x2bd/0x480
__dev_queue_xmit+0x696/0x730
dev_queue_xmit+0x10/0x20
neigh_direct_output+0x11/0x20
ip6_finish_output2+0x21f/0x770
ip6_finish_output+0xa7/0x1d0
ip6_output+0x56/0x190
~~~~~~~~
ndisc_send_skb+0x1d9/0x400
ndisc_send_rs+0x88/0xc0
~~~~~~~~

The rt passed to ip6_rt_update_pmtu() is created by
icmp6_dst_alloc() and it is not managed by the fib6 tree,
so its rt6i_table == NULL.  When __ip6_rt_update_pmtu() creates
a RTF_CACHE clone, the newly created clone also has rt6i_table == NULL
and it causes the ip6_ins_rt() oops.

During pmtu update, we only want to create a RTF_CACHE clone
from a rt which is currently managed (or owned) by the
fib6 tree.  It means either rt->rt6i_node != NULL or
rt is a RTF_PCPU clone.

It is worth to note that rt6i_table may not be NULL even it is
not (yet) managed by the fib6 tree (e.g. addrconf_dst_alloc()).
Hence, rt6i_node is a better check instead of rt6i_table.

Fixes: 45e4fd26 ("ipv6: Only create RTF_CACHE routes after encountering pmtu")
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Reported-by: NChris Siebenmann <cks-rhbugzilla@cs.toronto.edu>
Cc: Chris Siebenmann <cks-rhbugzilla@cs.toronto.edu>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I mistakenly took wrong request sock pointer when calling tcp_move_syn()

@req_unhash is either a copy of @req, or a NULL value for
FastOpen connexions (as we do not expect to unhash the temporary
request sock from ehash table)

Fixes: 805c4bc0 ("tcp: fix req->saved_syn race")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Ying Cai <ycai@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For the reasons explained in commit ce105008 ("tcp/dccp: fix
ireq->pktopts race"), we need to make sure we do not access
req->saved_syn unless we own the request sock.

This fixes races for listeners using TCP_SAVE_SYN option.

Fixes: e994b2f0 ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f1 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NYing Cai <ycai@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In ipv6_add_dev, when addrconf_sysctl_register fails, we do not clean up
the dev_snmp6 entry that we have already registered for this device.
Call snmp6_unregister_dev in this case.

Fixes: a317a2f1 ("ipv6: fail early when creating netdev named all or default")
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both tunnel6_protocol and tunnel46_protocol share the same error
handler, tunnel6_err(), which traverses through tunnel6_handlers list.
For ipip6 tunnels, we need to traverse tunnel46_handlers as we do e.g.
in tunnel46_rcv(). Current code can generate an ICMPv6 error message
with an IPv4 packet embedded in it.

Fixes: 73d605d1 ("[IPSEC]: changing API of xfrm6_tunnel_register")
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sit0 device allocates its percpu storage twice :
- One time in ipip6_tunnel_init()
- One time in ipip6_fb_tunnel_init()

Thus we leak 48 bytes per possible cpu per network namespace dismantle.

ipip6_fb_tunnel_init() can be much simpler and does not
return an error, and should be called after register_netdev()

Note that ipip6_tunnel_clone_6rd() also needs to be called
after register_netdev() (calling ipip6_tunnel_init())

Fixes: ebe084aa ("sit: Use ipip6_tunnel_init as the ndo_init function.")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes following problems :

1) percpu_counter_init() can return an error, therefore
  init_frag_mem_limit() must propagate this error so that
  inet_frags_init_net() can do the same up to its callers.

2) If ip[46]_frags_ns_ctl_register() fail, we must unwind
   properly and free the percpu_counter.

Without this fix, we leave freed object in percpu_counters
global list (if CONFIG_HOTPLUG_CPU) leading to crashes.

This bug was detected by KASAN and syzkaller tool
(http://github.com/google/syzkaller)

Fixes: 6d7b857d ("net: use lib/percpu_counter API for fragmentation mem accounting")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are other error values besides ip6_null_entry that can be returned by
ip6_route_redirect(): fib6_rule_action() can also result in
ip6_blk_hole_entry and ip6_prohibit_entry if such ip rules are installed.

Only checking for ip6_null_entry in rt6_do_redirect() causes ip6_ins_rt()
to be called with rt->rt6i_table == NULL in these cases, making the kernel
crash.
Signed-off-by: NMatthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv6 request sockets store a pointer to skb containing the SYN packet
to be able to transfer it to full blown socket when 3WHS is done
(ireq->pktopts -> np->pktoptions)

As explained in commit 5e0724d0 ("tcp/dccp: fix hashdance race for
passive sessions"), we must transfer the skb only if we won the
hashdance race, if multiple cpus receive the 'ack' packet completing
3WHS at the same time.

Fixes: e994b2f0 ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f1 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CHECKSUM_PARTIAL skbs should never arrive in ip_fragment. If we get one
of those warn about them once and handle them gracefully by recalculating
the checksum.

Fixes: commit 32dce968 ("ipv6: Allow for partial checksums on non-ufo packets")
See-also: commit 72e843bb ("ipv6: ip6_fragment() should check CHECKSUM_PARTIAL")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We cannot reliable calculate packet size on MSG_MORE corked sockets
and thus cannot decide if they are going to be fragmented later on,
so better not use CHECKSUM_PARTIAL in the first place.

The IPv6 code also intended to protect and not use CHECKSUM_PARTIAL in
the existence of IPv6 extension headers, but the condition was wrong. Fix
it up, too. Also the condition to check whether the packet fits into
one fragment was wrong and has been corrected.

Fixes: commit 32dce968 ("ipv6: Allow for partial checksums on non-ufo packets")
See-also: commit 72e843bb ("ipv6: ip6_fragment() should check CHECKSUM_PARTIAL")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change makes it so that we reinitialize the interface if the MTU is
increased back above IPV6_MIN_MTU and the interface is up.

Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Raw sockets with hdrincl enabled can insert ipv6 extension headers
right into the data stream. In case we need to fragment those packets,
we reparse the options header to find the place where we can insert
the fragment header. If the extension headers exceed the link's MTU we
actually cannot make progress in such a case.

Instead of ending up in broken arithmetic or rounding towards 0 and
entering an endless loop in ip6_fragment, just prevent those cases by
aborting early and signal -EMSGSIZE to user space.

This is the second version of the patch which doesn't use the
overflow_usub function, which got reverted for now.
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Linus dislikes these changes. To not hold up the net-merge let's revert
it for now and fix the bug like Linus suggested.

This reverts commit ec3661b4, reversing
changes made to c80dbe04.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is needed in openvswitch to fix an skb leak in the next patch.
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Messages like "icmp6_send: no reply to icmp error" are close
to useless. Adding source and destination addresses to provide
some more clue.
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Multiple cpus can process duplicates of incoming ACK messages
matching a SYN_RECV request socket. This is a rare event under
normal operations, but definitely can happen.

Only one must win the race, otherwise corruption would occur.

To fix this without adding new atomic ops, we use logic in
inet_ehash_nolisten() to detect the request was present in the same
ehash bucket where we try to insert the new child.

If request socket was not found, we have to undo the child creation.

This actually removes a spin_lock()/spin_unlock() pair in
reqsk_queue_unlink() for the fast path.

Fixes: e994b2f0 ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f1 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Raw sockets with hdrincl enabled can insert ipv6 extension headers
right into the data stream. In case we need to fragment those packets,
we reparse the options header to find the place where we can insert
the fragment header. If the extension headers exceed the link's MTU we
actually cannot make progress in such a case.

Instead of ending up in broken arithmetic or rounding towards 0 and
entering an endless loop in ip6_fragment, just prevent those cases by
aborting early and signal -EMSGSIZE to user space.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The error condition -EAGAIN, which is signaled by throw routes, tells
the rules framework to walk on searching for next matches. If the walk
ends and we stop walking the rules with the result of a throw route we
have to translate the error conditions to -ENETUNREACH.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

741a11d9 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set")
adds the RT6_LOOKUP_F_IFACE flag to make device index mismatch fatal if
oif is given. Hajime reported that this change breaks the Mobile IPv6
use case that wants to force the message through one interface yet use
the source address from another interface. Handle this case by only
adding the flag if oif is set and saddr is not set.

Fixes: 741a11d9 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set")
Cc: Hajime Tazaki <thehajime@gmail.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>