Make IPv4 consistent with IPv6 and return an extack message that the
ONLINK flag requires a nexthop device.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before using nla_get_u32(), better make sure the attribute
is of the proper size.

Code recently was changed, but bug has been there from beginning
of git.

BUG: KMSAN: uninit-value in rtnetlink_put_metrics+0x553/0x960 net/core/rtnetlink.c:746
CPU: 1 PID: 14139 Comm: syz-executor6 Not tainted 4.17.0-rc5+ #103
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686
 rtnetlink_put_metrics+0x553/0x960 net/core/rtnetlink.c:746
 fib_dump_info+0xc42/0x2190 net/ipv4/fib_semantics.c:1361
 rtmsg_fib+0x65f/0x8c0 net/ipv4/fib_semantics.c:419
 fib_table_insert+0x2314/0x2b50 net/ipv4/fib_trie.c:1287
 inet_rtm_newroute+0x210/0x340 net/ipv4/fib_frontend.c:779
 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646
 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117
 __sys_sendmsg net/socket.c:2155 [inline]
 __do_sys_sendmsg net/socket.c:2164 [inline]
 __se_sys_sendmsg net/socket.c:2162 [inline]
 __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a09
RSP: 002b:00007faae5fd8c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007faae5fd96d4 RCX: 0000000000455a09
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000005d0 R14: 00000000006fdc20 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:294 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:685
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:529
 fib_convert_metrics net/ipv4/fib_semantics.c:1056 [inline]
 fib_create_info+0x2d46/0x9dc0 net/ipv4/fib_semantics.c:1150
 fib_table_insert+0x3e4/0x2b50 net/ipv4/fib_trie.c:1146
 inet_rtm_newroute+0x210/0x340 net/ipv4/fib_frontend.c:779
 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646
 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117
 __sys_sendmsg net/socket.c:2155 [inline]
 __do_sys_sendmsg net/socket.c:2164 [inline]
 __se_sys_sendmsg net/socket.c:2162 [inline]
 __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
 netlink_sendmsg+0x76e/0x1350 net/netlink/af_netlink.c:1876
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117
 __sys_sendmsg net/socket.c:2155 [inline]
 __do_sys_sendmsg net/socket.c:2164 [inline]
 __se_sys_sendmsg net/socket.c:2162 [inline]
 __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: a919525a ("net: Move fib_convert_metrics to metrics file")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move logic of fib_convert_metrics into ip_metrics_convert. This allows
the code that converts netlink attributes into metrics struct to be
re-used in a later patch by IPv6.

This is mostly a code move with the following changes to variable names:
  - fi->fib_net becomes net
  - fc_mx and fc_mx_len are passed as inputs pulled from fib_config
  - metrics array is passed as an input from fi->fib_metrics->metrics
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prior to this patch, when one packet is hashed into path [1]
(hash <= nh_upper_bound) and it's neigh is dead, it will try
path [2]. However, if path [2]'s neigh is alive but it's
hash > nh_upper_bound, it will not return this alive path.
This packet will never be sent even if path [2] is alive.

 3.3.3.1/24:
  nexthop via 1.1.1.254 dev eth1 weight 1 <--[1] (dead neigh)
  nexthop via 2.2.2.254 dev eth2 weight 1 <--[2]

With sysctl_fib_multipath_use_neigh set is supposed to find an
available path respecting to the l3/l4 hash. But if there is
no available route with this hash, it should at least return
an alive route even with other hash.

This patch is to fix it by processing fib_multipath_use_neigh
earlier than the hash check, so that it will at least return
an alive route if there is when fib_multipath_use_neigh is
enabled. It's also compatible with before when there are alive
routes with the l3/l4 hash.

Fixes: a6db4494 ("net: ipv4: Consider failed nexthops in multipath routes")
Reported-by: NJianlin Shi <jishi@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_multipath_hash only needs net struct to check a sysctl. Make it
clear by passing net instead of fib_info. In the end this allows
alignment between the ipv4 and ipv6 versions.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dissect flow in fwd path if fib rules require it. Controlled by
a flag to avoid penatly for the common case. Flag is set when fib
rules with sport, dport and proto match that require flow dissect
are installed. Also passes the dissected hash keys to the multipath
hash function when applicable to avoid dissecting the flow again.
icmp packets will continue to use inner header for hash
calculations (Thanks to Nikolay Aleksandrov for some review here).
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ran simple script to find/remove trailing whitespace and blank lines
at EOF because that kind of stuff git whines about and editors leave
behind.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In fib_nh_match(), if output interface or gateway are passed in
the FIB configuration, we don't have to check next hops of
multipath routes to conclude whether we have a match or not.

However, we might still have routes with different realms
matching the same output interface and gateway configuration,
and this needs to cause the match to fail. Otherwise the first
route inserted in the FIB will match, regardless of the realms:

 # ip route add 1.1.1.1 dev eth0 table 1234 realms 1/2
 # ip route append 1.1.1.1 dev eth0 table 1234 realms 3/4
 # ip route list table 1234
 1.1.1.1 dev eth0 scope link realms 1/2
 1.1.1.1 dev eth0 scope link realms 3/4
 # ip route del 1.1.1.1 dev ens3 table 1234 realms 3/4
 # ip route list table 1234
 1.1.1.1 dev ens3 scope link realms 3/4

whereas route with realms 3/4 should have been deleted instead.

Explicitly check for fc_flow passed in the FIB configuration
(this comes from RTA_FLOW extracted by rtm_to_fib_config()) and
fail matching if it differs from nh_tclassid.

The handling of RTA_FLOW for multipath routes later in
fib_nh_match() is still needed, as we can have multiple RTA_FLOW
attributes that need to be matched against the tclassid of each
next hop.

v2: Check that fc_flow is set before discarding the match, so
    that the user can still select the first matching rule by
    not specifying any realm, as suggested by David Ahern.
Reported-by: NJianlin Shi <jishi@redhat.com>
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do not export fib_multipath_hash or fib_select_path; both are only used
by core ipv4 code.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If flow oif is set and it is not an l3mdev, then fib_select_path
can jump to the source address check.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The recently added fib_metrics_match() causes a regression for routes
with both RTAX_FEATURES and RTAX_CC_ALGO if the latter has
TCP_CONG_NEEDS_ECN flag set:

| # ip link add d0 type dummy
| # ip link set d0 up
| # ip route add 172.29.29.0/24 dev d0 features ecn congctl dctcp
| # ip route del 172.29.29.0/24 dev d0 features ecn congctl dctcp
| RTNETLINK answers: No such process

During route insertion, fib_convert_metrics() detects that the given CC
algo requires ECN and hence sets DST_FEATURE_ECN_CA bit in
RTAX_FEATURES.

During route deletion though, fib_metrics_match() compares stored
RTAX_FEATURES value with that from userspace (which obviously has no
knowledge about DST_FEATURE_ECN_CA) and fails.

Fixes: 5f9ae3d9 ("ipv4: do metrics match when looking up and deleting a route")
Signed-off-by: NPhil Sutter <phil@nwl.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make default TCP default congestion control to a per namespace
value. This changes default congestion control to a pointer to congestion ops
(rather than implicit as first element of available lsit).

The congestion control setting of new namespaces is inherited
from the current setting of the root namespace.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported yet another regression added with DOIT_UNLOCKED.
When nexthop is marked as dead, fib_dump_info uses __in_dev_get_rtnl():

./include/linux/inetdevice.h:230 suspicious rcu_dereference_protected() usage!
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor2/23859:
 #0:  (rcu_read_lock){....}, at: [<ffffffff840283f0>]
inet_rtm_getroute+0xaa0/0x2d70 net/ipv4/route.c:2738
[..]
  lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4665
  __in_dev_get_rtnl include/linux/inetdevice.h:230 [inline]
  fib_dump_info+0x1136/0x13d0 net/ipv4/fib_semantics.c:1377
  inet_rtm_getroute+0xf97/0x2d70 net/ipv4/route.c:2785
..

This isn't safe anymore, callers either hold RTNL mutex or rcu read lock,
so these spots must use rcu_dereference_rtnl() or plain rcu_derefence()
(plus unconditional rcu read lock).

This does the latter.

Fixes: 394f51ab ("ipv4: route: set ipv4 RTM_GETROUTE to not use rtnl")
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_check_nh does not use the fib_info arg; remove t.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_weight in fib_info is set but not used. Remove it and the
helpers for setting it.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now when ipv4 route inserts a fib_info, it memcmp fib_metrics.
It means ipv4 route identifies one route also with metrics.

But when removing a route, it tries to find the route without
caring about the metrics. It will cause that the route with
right metrics can't be removed.

Thomas noticed this issue when doing the testing:

1. add:
   # ip route append 192.168.7.0/24 dev v window 1000
   # ip route append 192.168.7.0/24 dev v window 1001
   # ip route append 192.168.7.0/24 dev v window 1002
   # ip route append 192.168.7.0/24 dev v window 1003
2. delete:
   # ip route delete 192.168.7.0/24 dev v window 1002
3. show:
     192.168.7.0/24 proto boot scope link window 1001
     192.168.7.0/24 proto boot scope link window 1002
     192.168.7.0/24 proto boot scope link window 1003

The one with window 1002 wasn't deleted but the first one was.

This patch is to do metrics match when looking up and deleting
one route.
Reported-by: NThomas Haller <thaller@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If fi->fib_metrics could not be allocated in fib_create_info()
we attempt to dereference a NULL pointer in free_fib_info_rcu() :

    m = fi->fib_metrics;
    if (m != &dst_default_metrics && atomic_dec_and_test(&m->refcnt))
            kfree(m);

Before my recent patch, we used to call kfree(NULL) and nothing wrong
happened.

Instead of using RCU to defer freeing while we are under memory stress,
it seems better to take immediate action.

This was reported by syzkaller team.

Fixes: 3fb07daf ("ipv4: add reference counting to metrics")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The FIB notification chain is currently soley used by IPv4 code.
However, we're going to introduce IPv6 FIB offload support, which
requires these notification as well.

As explained in commit c3852ef7 ("ipv4: fib: Replay events when
registering FIB notifier"), upon registration to the chain, the callee
receives a full dump of the FIB tables and rules by traversing all the
net namespaces. The integrity of the dump is ensured by a per-namespace
sequence counter that is incremented whenever a change to the tables or
rules occurs.

In order to allow more address families to use the chain, each family is
expected to register its fib_notifier_ops in its pernet init. These
operations allow the common code to read the family's sequence counter
as well as dump its tables and rules in the given net namespace.

Additionally, a 'family' parameter is added to sent notifications, so
that listeners could distinguish between the different families.

Implement the common code that allows listeners to register to the chain
and for address families to register their fib_notifier_ops. Subsequent
patches will implement these operations in IPv6.

In the future, ipmr and ip6mr will be extended to provide these
notifications as well.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're going to have capable drivers indicate route offload using the
nexthop flags, but for non-multipath routes these flags aren't dumped to
user space.

Instead, set the offload indication in the route message flags.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Michał reported a NULL pointer deref during fib_sync_down_dev() when
unregistering a netdevice. The problem is that we don't check for
'in_dev' being NULL, which can happen in very specific cases.

Usually routes are flushed upon NETDEV_DOWN sent in either the netdev or
the inetaddr notification chains. However, if an interface isn't
configured with any IP address, then it's possible for host routes to be
flushed following NETDEV_UNREGISTER, after NULLing dev->ip_ptr in
inetdev_destroy().

To reproduce:
$ ip link add type dummy
$ ip route add local 1.1.1.0/24 dev dummy0
$ ip link del dev dummy0

Fix this by checking for the presence of 'in_dev' before referencing it.

Fixes: 982acb97 ("ipv4: fib: Notify about nexthop status changes")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv4 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv4 dst and remove the calls
to dst_free().
At this point, all dst created in ipv4 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In IPv4 routing code, fib_nh and fib_nh_exception can hold pointers
to struct rtable but they never increment dst->__refcnt.
This leads to the need of the dst garbage collector because when user
is done with this dst and calls dst_release(), it can only decrement
dst->__refcnt and can not free the dst even it sees dst->__refcnt
drops from 1 to 0 (unless DST_NOCACHE flag is set) because the routing
code might still hold reference to it.
And when the routing code tries to delete a route, it has to put the
dst to the gc_list if dst->__refcnt is not yet 0 and have a gc thread
running periodically to check on dst->__refcnt and finally to free dst
when refcnt becomes 0.

This patch increments dst->__refcnt when
fib_nh/fib_nh_exception holds reference to this dst and properly release
the dst when fib_nh/fib_nh_exception has been updated with a new dst.

This patch is a preparation in order to fully get rid of dst gc later.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass extack arg down to lwtunnel_build_state and the build_state callbacks.
Add messages for failures in lwtunnel_build_state, and add the extarg to
nla_parse where possible in the build_state callbacks.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrey Konovalov reported crashes in ipv4_mtu()

I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :

1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &

2) At the same time run following loop :
while :
do
 ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done

Cong Wang attempted to add back rt->fi in commit
82486aa6 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.

Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)

I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.

Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.

Fixes: 2860583f ("ipv4: Kill rt->fi")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add messages for non-obvious errors (e.g, no need to add text for malloc
failures or ENODEV failures). This mostly covers the annoying EINVAL errors
Some message strings violate the 80-columns but searchable strings need to
trump that rule.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Plumb extack argument down to route add functions.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for ECMP hash policy choice via a new sysctl
called fib_multipath_hash_policy and also adds support for L4 hashes.
The current values for fib_multipath_hash_policy are:
 0 - layer 3 (default)
 1 - layer 4
If there's an skb hash already set and it matches the chosen policy then it
will be used instead of being calculated (currently only for L4).
In L3 mode we always calculate the hash due to the ICMP error special
case, the flow dissector's field consistentification should handle the
address order thus we can remove the address reversals.
If the skb is provided we always use it for the hash calculation,
otherwise we fallback to fl4, that is if skb is NULL fl4 has to be set.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a multipath route is hit the kernel doesn't consider nexthops that
are DEAD or LINKDOWN when IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN is set.
Devices that offload multipath routes need to be made aware of nexthop
status changes. Otherwise, the device will keep forwarding packets to
non-functional nexthops.

Add the FIB_EVENT_NH_{ADD,DEL} events to the fib notification chain,
which notify capable devices when they should add or delete a nexthop
from their tables.

Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
Cc: David Ahern <dsa@cumulusnetworks.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NAndy Gospodarek <gospo@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Nothing about lwt state requires a device reference, so remove the
input argument.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Handle failure in lwtunnel_fill_encap adding attributes to skb.

Fixes: 571e7226 ("ipv4: support for fib route lwtunnel encap attributes")
Fixes: 19e42e45 ("ipv6: support for fib route lwtunnel encap attributes")
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_select_path does not call fib_select_multipath if oif is set in the
flow struct. For VRF use cases oif is always set, so multipath route
selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif
check similar to what is done in fib_table_lookup.

Add saddr and proto to the flow struct for the fib lookup done by the
VRF driver to better match hash computation for a flow.

Fixes: 613d09b3 ("net: Use VRF device index for lookups on TX")
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_select_default has a single caller within the same file.
Make it static.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.
Requested-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The FIB notification chain is going to be converted to an atomic chain,
which means switchdev drivers will have to offload FIB entries in
deferred work, as hardware operations entail sleeping.

However, while the work is queued fib info might be freed, so a
reference must be taken. To release the reference (and potentially free
the fib info) fib_info_put() will be called, which in turn calls
free_fib_info().

Export free_fib_info() so that modules will be able to invoke
fib_info_put().
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When deleting an IP address from an interface, there is a clean-up of
routes which refer to this local address. However, there was no check to
see that the VRF matched. This meant that deletion wasn't confined to
the VRF it should have been.

To solve this, a new field has been added to fib_info to hold a table
id. When removing fib entries corresponding to a local ip address, this
table id is also used in the comparison.

The table id is populated when the fib_info is created. This was already
done in some places, but not in ip_rt_ioctl(). This has now been fixed.

Fixes: 021dd3b8 ("net: Add routes to the table associated with the device")
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Tested-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NMark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes following sparse errors :

net/ipv4/fib_semantics.c:1579:61: warning: incorrect type in argument 2
(different base types)
net/ipv4/fib_semantics.c:1579:61:    expected unsigned int [unsigned]
[usertype] key
net/ipv4/fib_semantics.c:1579:61:    got restricted __be32 const
[usertype] nh_gw

Fixes: a6db4494 ("net: ipv4: Consider failed nexthops in multipath routes")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Vegard Nossum is reporting for a crash in fib_dump_info
when nh_dev = NULL and fib_nhs == 1:

Pid: 50, comm: netlink.exe Not tainted 4.7.0-rc5+
RIP: 0033:[<00000000602b3d18>]
RSP: 0000000062623890  EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000006261b800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000024 RDI: 000000006245ba00
RBP: 00000000626238f0 R08: 000000000000029c R09: 0000000000000000
R10: 0000000062468038 R11: 000000006245ba00 R12: 000000006245ba00
R13: 00000000625f96c0 R14: 00000000601e16f0 R15: 0000000000000000
Kernel panic - not syncing: Kernel mode fault at addr 0x2e0, ip 0x602b3d18
CPU: 0 PID: 50 Comm: netlink.exe Not tainted 4.7.0-rc5+ #581
Stack:
 626238f0 960226a02 00000400 000000fe
 62623910 600afca7 62623970 62623a48
 62468038 00000018 00000000 00000000
Call Trace:
 [<602b3e93>] rtmsg_fib+0xd3/0x190
 [<602b6680>] fib_table_insert+0x260/0x500
 [<602b0e5d>] inet_rtm_newroute+0x4d/0x60
 [<60250def>] rtnetlink_rcv_msg+0x8f/0x270
 [<60267079>] netlink_rcv_skb+0xc9/0xe0
 [<60250d4b>] rtnetlink_rcv+0x3b/0x50
 [<60265400>] netlink_unicast+0x1a0/0x2c0
 [<60265e47>] netlink_sendmsg+0x3f7/0x470
 [<6021dc9a>] sock_sendmsg+0x3a/0x90
 [<6021e0d0>] ___sys_sendmsg+0x300/0x360
 [<6021fa64>] __sys_sendmsg+0x54/0xa0
 [<6021fac0>] SyS_sendmsg+0x10/0x20
 [<6001ea68>] handle_syscall+0x88/0x90
 [<600295fd>] userspace+0x3fd/0x500
 [<6001ac55>] fork_handler+0x85/0x90

$ addr2line -e vmlinux -i 0x602b3d18
include/linux/inetdevice.h:222
net/ipv4/fib_semantics.c:1264

Problem happens when RTNH_F_LINKDOWN is provided from user space
when creating routes that do not use the flag, catched with
netlink fuzzer.

Currently, the kernel allows user space to set both flags
to nh_flags and fib_flags but this is not intentional, the
assumption was that they are not set. Fix this by rejecting
both flags with EINVAL.
Reported-by: NVegard Nossum <vegard.nossum@oracle.com>
Fixes: 0eeb075f ("net: ipv4 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Cc: Andy Gospodarek <gospo@cumulusnetworks.com>
Cc: Dinesh Dutt <ddutt@cumulusnetworks.com>
Cc: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: NAndy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>