Currently, parameters such as oif and source address are not taken into
account during fibmatch lookup. Example (IPv4 for reference) before
patch:
$ ip -4 route show
192.0.2.0/24 dev dummy0 proto kernel scope link src 192.0.2.1
198.51.100.0/24 dev dummy1 proto kernel scope link src 198.51.100.1
$ ip -6 route show
2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium
2001:db8:2::/64 dev dummy1 proto kernel metric 256 pref medium
fe80::/64 dev dummy0 proto kernel metric 256 pref medium
fe80::/64 dev dummy1 proto kernel metric 256 pref medium
$ ip -4 route get fibmatch 192.0.2.2 oif dummy0
192.0.2.0/24 dev dummy0 proto kernel scope link src 192.0.2.1
$ ip -4 route get fibmatch 192.0.2.2 oif dummy1
RTNETLINK answers: No route to host
$ ip -6 route get fibmatch 2001:db8:1::2 oif dummy0
2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium
$ ip -6 route get fibmatch 2001:db8:1::2 oif dummy1
2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium
After:
$ ip -6 route get fibmatch 2001:db8:1::2 oif dummy0
2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium
$ ip -6 route get fibmatch 2001:db8:1::2 oif dummy1
RTNETLINK answers: Network is unreachable
The problem stems from the fact that the necessary route lookup flags
are not set based on these parameters.
Instead of duplicating the same logic for fibmatch, we can simply
resolve the original route from its copy and dump it instead.
Fixes: 18c3a61c42 ("net: ipv6: RTM_GETROUTE: return matched fib result when requested")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One example of when an ICMPv6 packet is required to be looped back is
when a host acts as both a Multicast Listener and a Multicast Router.
A Multicast Router will listen on address ff02::16 for MLDv2 messages.
Currently, MLDv2 messages originating from a Multicast Listener running
on the same host as the Multicast Router are not being delivered to the
Multicast Router. This is due to dst.input being assigned the default
value of dst_discard.
This results in the packet being looped back but discarded before being
delivered to the Multicast Router.
This patch sets dst.input to ip6_input to ensure a looped back packet
is delivered to the Multicast Router.
Signed-off-by: Brendan McGrath <redmcg@redmandi.dyndns.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Florian reported a breakage with anycast routes due to commit
4832c30d54 ("net: ipv6: put host and anycast routes on device with
address"). Prior to this commit anycast routes were added against the
loopback device causing repetitive route entries with no insight into
why they existed. e.g.:
$ ip -6 ro ls table local type anycast
anycast 2001:db8:1:: dev lo proto kernel metric 0 pref medium
anycast 2001:db8:2:: dev lo proto kernel metric 0 pref medium
anycast fe80:: dev lo proto kernel metric 0 pref medium
anycast fe80:: dev lo proto kernel metric 0 pref medium
The point of commit 4832c30d54 is to add the routes using the device
with the address which is causing the route to be added. e.g.,:
$ ip -6 ro ls table local type anycast
anycast 2001:db8:1:: dev eth1 proto kernel metric 0 pref medium
anycast 2001:db8:2:: dev eth2 proto kernel metric 0 pref medium
anycast fe80:: dev eth2 proto kernel metric 0 pref medium
anycast fe80:: dev eth1 proto kernel metric 0 pref medium
For traffic to work as it did before, the dst device needs to be switched
to the loopback when the copy is created similar to local routes.
Fixes: 4832c30d54 ("net: ipv6: put host and anycast routes on device with address")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the 'ignore_routes_with_linkdown' sysctl is set, we should not
consider linkdown nexthops during route lookup.
While the code correctly verifies that the initially selected route
('match') has a carrier, it does not perform the same check in the
subsequent multipath selection, resulting in a potential packet loss.
In case the chosen route does not have a carrier and the sysctl is set,
choose the initially selected route.
Fixes: 35103d1117 ("net: ipv6 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David 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: Stephen Hemminger <sthemmin@microsoft.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cached routes should only be created by the system when receiving pmtu
discovery or ip redirect msg. Users should not be allowed to create
cached routes.
Furthermore, after the patch series to move cached routes into exception
table, user added cached routes will trigger the following warning in
fib6_add():
WARNING: CPU: 0 PID: 2985 at net/ipv6/ip6_fib.c:1137
fib6_add+0x20d9/0x2c10 net/ipv6/ip6_fib.c:1137
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 2985 Comm: syzkaller320388 Not tainted 4.14.0-rc3+ #74
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:52
panic+0x1e4/0x417 kernel/panic.c:181
__warn+0x1c4/0x1d9 kernel/panic.c:542
report_bug+0x211/0x2d0 lib/bug.c:183
fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:fib6_add+0x20d9/0x2c10 net/ipv6/ip6_fib.c:1137
RSP: 0018:ffff8801cf09f6a0 EFLAGS: 00010297
RAX: ffff8801ce45e340 RBX: 1ffff10039e13eec RCX: ffff8801d749c814
RDX: 0000000000000000 RSI: ffff8801d749c700 RDI: ffff8801d749c780
RBP: ffff8801cf09fa08 R08: 0000000000000000 R09: ffff8801cf09f360
R10: ffff8801cf09f2d8 R11: 1ffff10039c8befb R12: 0000000000000001
R13: dffffc0000000000 R14: ffff8801d749c700 R15: ffffffff860655c0
__ip6_ins_rt+0x6c/0x90 net/ipv6/route.c:1011
ip6_route_add+0x148/0x1a0 net/ipv6/route.c:2782
ipv6_route_ioctl+0x4d5/0x690 net/ipv6/route.c:3291
inet6_ioctl+0xef/0x1e0 net/ipv6/af_inet6.c:521
sock_do_ioctl+0x65/0xb0 net/socket.c:961
sock_ioctl+0x2c2/0x440 net/socket.c:1058
vfs_ioctl fs/ioctl.c:45 [inline]
do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685
SYSC_ioctl fs/ioctl.c:700 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
entry_SYSCALL_64_fastpath+0x1f/0xbe
So we fix this by failing the attemp to add cached routes from userspace
with returning EINVAL error.
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In rt6_select(), fn->leaf could be pointing to net->ipv6.ip6_null_entry.
In this case, we should directly return instead of trying to carry on
with the rest of the process.
If not, we could crash at:
spin_lock_bh(&leaf->rt6i_table->rt6_lock);
because net->ipv6.ip6_null_entry does not have rt6i_table set.
Syzkaller recently reported following issue on net-next:
Use struct sctp_sack_info instead
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
sctp: [Deprecated]: syz-executor4 (pid 26496) Use of struct sctp_assoc_value in delayed_ack socket option.
Use struct sctp_sack_info instead
CPU: 1 PID: 26523 Comm: syz-executor6 Not tainted 4.14.0-rc4+ #85
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d147e3c0 task.stack: ffff8801a4328000
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
RIP: 0010:do_raw_spin_lock+0x23/0x1e0 kernel/locking/spinlock_debug.c:112
RSP: 0018:ffff8801a432ed70 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 000000000000001c
RBP: ffff8801a432ed90 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8482b279 R12: ffff8801ce2ff3a0
sctp: [Deprecated]: syz-executor1 (pid 26546) Use of int in maxseg socket option.
Use struct sctp_assoc_value instead
R13: dffffc0000000000 R14: ffff8801d971e000 R15: ffff8801ce2ff0d8
FS: 00007f56e82f5700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001ddbc22000 CR3: 00000001a4a04000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
_raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:321 [inline]
rt6_select net/ipv6/route.c:786 [inline]
ip6_pol_route+0x1be3/0x3bd0 net/ipv6/route.c:1650
sctp: [Deprecated]: syz-executor1 (pid 26576) Use of int in maxseg socket option.
Use struct sctp_assoc_value instead
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.
ip6_pol_route_output+0x4c/0x60 net/ipv6/route.c:1843
fib6_rule_lookup+0x9e/0x2a0 net/ipv6/ip6_fib.c:309
ip6_route_output_flags+0x1f1/0x2b0 net/ipv6/route.c:1871
ip6_route_output include/net/ip6_route.h:80 [inline]
ip6_dst_lookup_tail+0x4ea/0x970 net/ipv6/ip6_output.c:953
ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1076
sctp_v6_get_dst+0x675/0x1c30 net/sctp/ipv6.c:274
sctp_transport_route+0xa8/0x430 net/sctp/transport.c:287
sctp_assoc_add_peer+0x4fe/0x1100 net/sctp/associola.c:656
__sctp_connect+0x251/0xc80 net/sctp/socket.c:1187
sctp_connect+0xb4/0xf0 net/sctp/socket.c:4209
inet_dgram_connect+0x16b/0x1f0 net/ipv4/af_inet.c:541
SYSC_connect+0x20a/0x480 net/socket.c:1642
SyS_connect+0x24/0x30 net/socket.c:1623
entry_SYSCALL_64_fastpath+0x1f/0xbe
Fixes: 66f5d6ce53 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The perf traces for ipv6 routing code show a relevant cost around
trace_fib6_table_lookup(), even if no trace is enabled. This is
due to the fib6_table de-referencing currently performed by the
caller.
Let's the tracing code pay this overhead, passing to the trace
helper the table pointer. This gives small but measurable
performance improvement under UDP flood.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit 2b760fcf5c ("ipv6: hook up exception table to store
dst cache") partially reverted the commit 1e2ea8ad37 ("ipv6: set
dst.obsolete when a cached route has expired").
As a result, RTF_CACHE dst referenced outside the fib tree will
not be removed until the next sernum change; dst_check() does not
fail on aged-out dst, and dst->__refcnt can't decrease: the aged
out dst will stay valid for a potentially unlimited time after the
timeout expiration.
This change explicitly removes RTF_CACHE dst from the fib tree when
aged out. The rt6_remove_exception() logic will then obsolete the
dst and other entities will drop the related reference on next
dst_check().
pMTU exceptions are not aged-out, and are removed from the exception
table only when the - usually considerably longer - ip6_rt_mtu_expires
timeout expires.
v1 -> v2:
- do not touch dst.obsolete in rt6_remove_exception(), not needed
v2 -> v3:
- take care of pMTU exceptions, too
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the commit 2b760fcf5c ("ipv6: hook up exception table
to store dst cache"), the fib6 gc is not started after the
creation of a RTF_CACHE via a redirect or pmtu update, since
fib6_add() isn't invoked anymore for such dsts.
We need the fib6 gc to run periodically to clean the RTF_CACHE,
or the dst will stay there forever.
Fix it by explicitly calling fib6_force_start_gc() on successful
exception creation. gc_args->more accounting will ensure that
the gc timer will run for whatever time needed to properly
clean the table.
v2 -> v3:
- clarified the commit message
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The use of the | operator always leads to true which looks rather
suspect to me. Fix this by using & instead to just check the
RTF_CACHE entry bit.
Detected by CoverityScan, CID#1457734, #1457747 ("Wrong operator used")
Fixes: 35732d01fe ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently rt6_ex is being dereferenced before it is null checked
hence there is a possible null dereference bug. Fix this by only
dereferencing rt6_ex after it has been null checked.
Detected by CoverityScan, CID#1457749 ("Dereference before null check")
Fixes: 81eb8447da ("ipv6: take care of rt6_stats")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
per cpu allocations are already zeroed, no need to clear them again.
Fixes: d52d3997f8 ("ipv6: Create percpu rt6_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A recent patch removed the dst_free() on the allocated
dst_entry in ipv6_blackhole_route(). The dst_free() marked
the dst_entry as dead and added it to the gc list. I.e. it
was setup for a one time usage. As a result we may now have
a blackhole route cached at a socket on some IPsec scenarios.
This makes the connection unusable.
Fix this by marking the dst_entry directly at allocation time
as 'dead', so it is used only once.
Fixes: 587fea7411 ("ipv6: mark DST_NOGC and remove the operation of dst_free()")
Reported-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ido reported following splat and provided a patch.
[ 122.221814] BUG: using smp_processor_id() in preemptible [00000000] code: sshd/2672
[ 122.221845] caller is debug_smp_processor_id+0x17/0x20
[ 122.221866] CPU: 0 PID: 2672 Comm: sshd Not tainted 4.14.0-rc3-idosch-next-custom #639
[ 122.221880] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[ 122.221893] Call Trace:
[ 122.221919] dump_stack+0xb1/0x10c
[ 122.221946] ? _atomic_dec_and_lock+0x124/0x124
[ 122.221974] ? ___ratelimit+0xfe/0x240
[ 122.222020] check_preemption_disabled+0x173/0x1b0
[ 122.222060] debug_smp_processor_id+0x17/0x20
[ 122.222083] ip6_pol_route+0x1482/0x24a0
...
I believe we can simplify this code path a bit, since we no longer
hold a read_lock and need to release it to avoid a dead lock.
By disabling BH, we make sure we'll prevent code re-entry and
rt6_get_pcpu_route()/rt6_make_pcpu_route() run on the same cpu.
Fixes: 66f5d6ce53 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Reported-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, most of the rt6_stats are not hooked up correctly. As the
last part of this patch series, hook up all existing rt6_stats and add
one new stat fib_rt_uncache to indicate the number of routes in the
uncached list.
For details of the stats, please refer to the comments added in
include/net/ip6_fib.h.
Note: fib_rt_alloc and fib_rt_uncache are not guaranteed to be modified
under a lock. So atomic_t is used for them.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With all the preparation work before, we are now ready to replace rwlock
with rcu and spinlock in fib6_table.
That means now all fib6_node in fib6_table are protected by rcu. And
when freeing fib6_node, call_rcu() is used to wait for the rcu grace
period before releasing the memory.
When accessing fib6_node, corresponding rcu APIs need to be used.
And all previous sessions protected by the write lock will now be
protected by the spin lock per table.
All previous sessions protected by read lock will now be protected by
rcu_read_lock().
A couple of things to note here:
1. As part of the work of replacing rwlock with rcu, the linked list of
fn->leaf now has to be rcu protected as well. So both fn->leaf and
rt->dst.rt6_next are now __rcu tagged and corresponding rcu APIs are
used when manipulating them.
2. For fn->rr_ptr, first of all, it also needs to be rcu protected now
and is tagged with __rcu and rcu APIs are used in corresponding places.
Secondly, fn->rr_ptr is changed in rt6_select() which is a reader
thread. This makes the issue a bit complicated. We think a valid
solution for it is to let rt6_select() grab the tb6_lock if it decides
to change it. As it is not in the normal operation and only happens when
there is no valid neighbor cache for the route, we think the performance
impact should be low.
3. fib6_walk_continue() has to be called with tb6_lock held even in the
route dumping related functions, e.g. inet6_dump_fib(),
fib6_tables_dump() and ipv6_route_seq_ops. It is because
fib6_walk_continue() makes modifications to the walker structure, and so
are fib6_repair_tree() and fib6_del_route(). In order to do proper
syncing between them, we need to let fib6_walk_continue() hold the lock.
We may be able to do further improvement on the way we do the tree walk
to get rid of the need for holding the spin lock. But not for now.
4. When fib6_del_route() removes a route from the tree, we no longer
mark rt->dst.rt6_next to NULL to make simultaneous reader be able to
further traverse the list with rcu. However, rt->dst.rt6_next is only
valid within this same rcu period. No one should access it later.
5. All the operation of atomic_inc(rt->rt6i_ref) is changed to be
performed before we publish this route (either by linking it to fn->leaf
or insert it in the list pointed by fn->leaf) just to be safe because as
soon as we publish the route, some read thread will be able to access it.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After rwlock is replaced with rcu and spinlock, fib6_lookup() could
potentially return an intermediate node if other thread is doing
fib6_del() on a route which is the only route on the node so that
fib6_repair_tree() will be called on this node and potentially assigns
fn->leaf to the its child's fn->leaf.
In order to detect this situation in rt6_select(), we have to check if
fn->fn_bit is consistent with the key length stored in the route. And
depending on if the fn is in the subtree or not, the key is either
rt->rt6i_dst or rt->rt6i_src.
If any inconsistency is found, that means the node no longer holds valid
routes in it. So net->ipv6.ip6_null_entry is returned.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If rwlock is replaced with rcu and spinlock, it is possible that the
reader thread will see fn->leaf as NULL in the following scenarios:
1. fib6_add() is in progress and we have already inserted a new node but
not yet inserted the route.
2. fib6_del_route() is in progress and we have already set fn->leaf to
NULL but not yet freed the node because of rcu grace period.
This patch makes sure all the reader threads check fn->leaf first before
using it. And together with later patch to grab rcu_read_lock() and
rcu_dereference() fn->leaf, it makes sure reader threads are safe when
accessing fn->leaf.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With rwlock, it is safe to call dst_hold() in the read thread because
read thread is guaranteed to be separated from write thread.
However, after we replace rwlock with rcu, it is no longer safe to use
dst_hold(). A dst might already have been deleted but is waiting for the
rcu grace period to pass before freeing the memory when a read thread is
trying to do dst_hold(). This could potentially cause double free issue.
So this commit replaces all dst_hold() with dst_hold_safe() in all read
thread to avoid this double free issue.
And in order to make the code more compact, a new function ip6_hold_safe()
is introduced. It calls dst_hold_safe() first, and if that fails, it will
either fall back to hold and return net->ipv6.ip6_null_entry or set rt to
NULL according to the caller's need.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After rwlock is replaced with rcu and spinlock, ip6_pol_route() will be
called with only rcu held. That means rt6 route deletion could happen
simultaneously with rt6_make_pcpu_rt(). This could potentially cause
memory leak if rt6_release() is called right before rt6_make_pcpu_rt()
on the same route.
This patch grabs rt->rt6i_ref safely before calling rt6_make_pcpu_rt()
to make sure rt6_release() will not get triggered while
rt6_make_pcpu_rt() is in progress. And rt6_release() is called after
rt6_make_pcpu_rt() is finished.
Note: As we are incrementing rt->rt6i_ref in ip6_pol_route(), there is a
very slim chance that fib6_purge_rt() will be triggered unnecessarily
when deleting a route if ip6_pol_route() running on another thread picks
this route as well and tries to make pcpu cache for it.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit makes use of the exception hash table implementation to
store dst caches created by pmtu discovery and ip redirect into the hash
table under the rt_info and no longer inserts these routes into fib6
tree.
This makes the fib6 tree only contain static configured routes and could
now be protected by rcu instead of a rw lock.
With this change, in the route lookup related functions, after finding
the rt6_info with the longest prefix, we also need to search for the
exception table before doing backtracking.
In the route delete function, if the route being deleted is not a dst
cache, deletion of this route also need to flush the whole hash table
under it. If it is a dst cache, then only delete the cached dst in the
hash table.
Note: for fib6_walk_continue() function, w->root now is always pointing
to a root node considering that fib6_prune_clones() is removed from the
code. So we add a WARN_ON() msg to make sure w->root always points to a
root node and also removed the update of w->root in fib6_repair_tree().
This is a prerequisite for later patch because we don't need to make
w->root as rcu protected when replacing rwlock with RCU.
Also, we remove all prune related variables as it is no longer used.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fib6_locate() is used to find the fib6_node according to the passed in
prefix address key. It currently tries to find the fib6_node with the
exact match of the passed in key. However, when we move cached routes
into the exception table, fib6_locate() will fail to find the fib6_node
for it as the cached routes will be stored in the exception table under
the fib6_node with the longest prefix match of the cache's dst addr key.
This commit adds a new parameter to let the caller specify if it needs
exact match or longest prefix match.
Right now, all callers still does exact match when calling
fib6_locate(). It will be changed in later commit where exception table
is hooked up to store cached routes.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If all dst cache entries are stored in the exception table under the
main route, we have to go through them during fib6_age() when doing
garbage collecting.
Introduce a new function rt6_age_exception() which goes through all dst
entries in the exception table and remove those entries that are expired.
This function is called in fib6_age() so that all dst caches are also
garbage collected.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we move all cached dst into the exception table under the main route,
current rt6_clean_tohost() will no longer be able to access them.
This commit makes fib6_clean_tohost() to also go through all cached
routes in exception table and removes cached gateway routes to the
passed in gateway.
This is a preparation in order to move all cached routes into the
exception table.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we move all cached dst into the exception table under the main route,
current rt6_mtu_change() will no longer be able to access them.
This commit makes rt6_mtu_change_route() function to also go through all
cached routes in the exception table under the main route and do proper
updates on the mtu.
This is a preparation in order to move all cached routes into the
exception table.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After we move cached dst entries into the exception table under its
parent route, current fib6_remove_prefsrc() no longer can access them.
This commit makes fib6_remove_prefsrc() also go through all routes
in the exception table to remove the pref src.
This is a preparation patch in order to move all cached dst into the
exception table.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a hash table into struct rt6_info in order to store dst caches
created by pmtu discovery and ip redirect in ipv6 routing code.
APIs to add dst cache, delete dst cache, find dst cache and update
dst cache in the hash table are implemented and will be used in later
commits.
This is a preparation work to move all cache routes into the exception
table instead of getting inserted into the fib6 tree.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now it doesn't check for the cached route expiration in ipv6's
dst_ops->check(), because it trusts dst_gc that would clean the
cached route up when it's expired.
The problem is in dst_gc, it would clean the cached route only
when it's refcount is 1. If some other module (like xfrm) keeps
holding it and the module only release it when dst_ops->check()
fails.
But without checking for the cached route expiration, .check()
may always return true. Meanwhile, without releasing the cached
route, dst_gc couldn't del it. It will cause this cached route
never to expire.
This patch is to set dst.obsolete with DST_OBSOLETE_KILL in .gc
when it's expired, and check obsolete != DST_OBSOLETE_FORCE_CHK
in .check.
Note that this is even needed when ipv6 dst_gc timer is removed
one day. It would set dst.obsolete in .redirect and .update_pmtu
instead, and check for cached route expiration when getting it,
just like what ipv4 route does.
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit c5cff8561d adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
net/ipv6/route.c:1394:30: error: incompatible types in comparison
expression (different address spaces)
./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
expression (different address spaces)
This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.
Fixes: c5cff8561d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rt_cookie might be used uninitialized, fix this by
initializing it.
Fixes: c5cff8561d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow our callers to influence the choice of ECMP link by honoring the
hash passed together with the flow info. This allows for special
treatment of ICMP errors which we would like to route over the same path
as the IPv6 datagram that triggered the error.
Also go through rt6_multipath_hash(), in the usual case when we aren't
dealing with an ICMP error, so that there is one central place where
multipath hash is computed.
Signed-off-by: Jakub Sitnicki <jkbs@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 644d0e6569 ("ipv6 Use get_hash_from_flowi6 for rt6 hash") has
turned rt6_info_hash_nhsfn() into a one-liner, so it no longer makes
sense to keep it around. Also remove the accompanying comment that has
become outdated.
Signed-off-by: Jakub Sitnicki <jkbs@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When forwarding or sending out an ICMPv6 error, look at the embedded
packet that triggered the error and compute a flow hash over its
headers.
This let's us route the ICMP error together with the flow it belongs to
when multipath (ECMP) routing is in use, which in turn makes Path MTU
Discovery work in ECMP load-balanced or anycast setups (RFC 7690).
Granted, end-hosts behind the ECMP router (aka servers) need to reflect
the IPv6 Flow Label for PMTUD to work.
The code is organized to be in parallel with ipv4 stack:
ip_multipath_l3_keys -> ip6_multipath_l3_keys
fib_multipath_hash -> rt6_multipath_hash
Signed-off-by: Jakub Sitnicki <jkbs@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().
Note: there is no "Fixes" tag because this bug was there in a very
early stage.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One nagging difference between ipv4 and ipv6 is host routes for ipv6
addresses are installed using the loopback device or VRF / L3 Master
device. e.g.,
2001:db8:1::/120 dev veth0 proto kernel metric 256 pref medium
local 2001:db8:1::1 dev lo table local proto kernel metric 0 pref medium
Using the loopback device is convenient -- necessary for local tx, but
has some nasty side effects, most notably setting the 'lo' device down
causes all host routes for all local IPv6 address to be removed from the
FIB and completely breaks IPv6 networking across all interfaces.
This patch puts FIB entries for IPv6 routes against the device. This
simplifies the routes in the FIB, for example by making dst->dev and
rt6i_idev->dev the same (a future patch can look at removing the device
reference taken for rt6i_idev for FIB entries).
When copies are made on FIB lookups, the cloned route has dst->dev
set to loopback (or the L3 master device). This is needed for the
local Tx of packets to local addresses.
With fib entries allocated against the real network device, the addrconf
code that reinserts host routes on admin up of 'lo' is no longer needed.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adding a lock around one of the assignments prevents gcc from
tracking the state of the local 'fibmatch' variable, so it can no
longer prove that 'dst' is always initialized, leading to a bogus
warning:
net/ipv6/route.c: In function 'inet6_rtm_getroute':
net/ipv6/route.c:3659:2: error: 'dst' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This moves the other assignment into the same lock to shut up the
warning.
Fixes: 121622dba8 ("ipv6: route: make rtm_getroute not assume rtnl is locked")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
__dev_get_by_index assumes RTNL is held, use _rcu version instead.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv6 routes currently lack nexthop flags as in IPv4. This has several
implications.
In the forwarding path, it requires us to check the carrier state of the
nexthop device and potentially ignore a linkdown route, instead of
checking for RTNH_F_LINKDOWN.
It also requires capable drivers to use the user facing IPv6-specific
route flags to provide offload indication, instead of using the nexthop
flags as in IPv4.
Add nexthop flags to IPv6 routes in the 40 bytes hole and use it to
provide offload indication instead of the RTF_OFFLOAD flag, which is
removed while it's still not part of any official kernel release.
In the near future we would like to use the field for the
RTNH_F_{LINKDOWN,DEAD} flags, but this change is more involved and might
not be ready in time for the current cycle.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a dst is created by addrconf_dst_alloc() for a host route or an
anycast route, dst->dev points to loopback dev while rt6->rt6i_idev
points to a real device.
When the real device goes down, the current cleanup code only checks for
dst->dev and assumes rt6->rt6i_idev->dev is the same. This causes the
refcount leak on the real device in the above situation.
This patch makes sure to always release the refcount taken on
rt6->rt6i_idev during dst_dev_put().
Fixes: 587fea7411 ("ipv6: mark DST_NOGC and remove the operation of
dst_free()")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change allows us to later indicate to rtnetlink core that certain
doit functions should be called without acquiring rtnl_mutex.
This change should have no effect, we simply replace the last (now
unused) calcit argument with the new flag.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The UDP offload conflict is dealt with by simply taking what is
in net-next where we have removed all of the UFO handling code
entirely.
The TCP conflict was a case of local variables in a function
being removed from both net and net-next.
In netvsc we had an assignment right next to where a missing
set of u64 stats sync object inits were added.
Signed-off-by: David S. Miller <davem@davemloft.net>
If the user hasn't installed any custom rules, don't go through the
whole FIB rules layer. This is pretty similar to f4530fa574 (ipv4:
Avoid overhead when no custom FIB rules are installed).
Using a micro-benchmark module [1], timing ip6_route_output() with
get_cycles(), with 40,000 routes in the main routing table, before this
patch:
min=606 max=12911 count=627 average=1959 95th=4903 90th=3747 50th=1602 mad=821
table=254 avgdepth=21.8 maxdepth=39
value │ ┊ count
600 │▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ 199
880 │▒▒▒░░░░░░░░░░░░░░░░ 43
1160 │▒▒▒░░░░░░░░░░░░░░░░░░░░ 48
1440 │▒▒▒░░░░░░░░░░░░░░░░░░░░░░░ 43
1720 │▒▒▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░ 59
2000 │▒▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 50
2280 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 26
2560 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 31
2840 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 28
3120 │▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 17
3400 │▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 17
3680 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 8
3960 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 11
4240 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 6
4520 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 6
4800 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 9
After:
min=544 max=11687 count=627 average=1776 95th=4546 90th=3585 50th=1227 mad=565
table=254 avgdepth=21.8 maxdepth=39
value │ ┊ count
540 │▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ 201
800 │▒▒▒▒▒░░░░░░░░░░░░░░░░ 63
1060 │▒▒▒▒▒░░░░░░░░░░░░░░░░░░░░░ 68
1320 │▒▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░ 39
1580 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 32
1840 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 32
2100 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 34
2360 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 33
2620 │▒▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 26
2880 │▒░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 22
3140 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 9
3400 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 8
3660 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 9
3920 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 8
4180 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 8
4440 │░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 8
At the frequency of the host during the bench (~ 3.7 GHz), this is
about a 100 ns difference on the median value.
A next step would be to collapse local and main tables, as in
0ddcf43d5d (ipv4: FIB Local/MAIN table collapse).
[1]: https://github.com/vincentbernat/network-lab/blob/master/lab-routes-ipv6/kbench_mod.c
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow user space applications to see which routes are offloaded and
which aren't by setting the RTNH_F_OFFLOAD flag when dumping them.
To be consistent with IPv4, offload indication is provided on a
per-nexthop basis.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit c2ed1880fd ("net: ipv6: check route protocol when
deleting routes"), ipv6 route checks rt protocol when trying to
remove a rt entry.
It introduced a side effect causing 'ip -6 route flush cache' not
to work well. When flushing caches with iproute, all route caches
get dumped from kernel then removed one by one by sending DELROUTE
requests to kernel for each cache.
The thing is iproute sends the request with the cache whose proto
is set with RTPROT_REDIRECT by rt6_fill_node() when kernel dumps
it. But in kernel the rt_cache protocol is still 0, which causes
the cache not to be matched and removed.
So the real reason is rt6i_protocol in the route is not set when
it is allocated. As David Ahern's suggestion, this patch is to
set rt6i_protocol properly in the route when it is installed and
remove the codes setting rtm_protocol according to rt6i_flags in
rt6_fill_node.
This is also an improvement to keep rt6i_protocol consistent with
rtm_protocol.
Fixes: c2ed1880fd ("net: ipv6: check route protocol when deleting routes")
Reported-by: Jianlin Shi <jishi@redhat.com>
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ido Schimmel