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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib6_add() logic currently calls fib6_add_1() to figure out what node
should be used for the newly added route and then call
fib6_add_rt2node() to insert the route to the node.
And during the call of fib6_add_1(), fn_sernum is updated for all nodes
that share the same prefix as the new route.
This does not have issue in the current code because reader thread will
not be able to access the tree while writer thread is inserting new
route to it. However, it is not the case once we transition to use RCU.
Reader thread could potentially see the new fn_sernum before the new
route is inserted. As a result, reader thread's route lookup will return
a stale route with the new fn_sernum.

In order to solve this issue, we remove all the update of fn_sernum in
fib6_add_1(), and instead, introduce a new function that updates fn_sernum
for all related nodes and call this functions once the route is
successfully inserted to the tree.
Also, smp_wmb() is used after a route is successfully inserted into the
fib tree and right before the updated of fn->sernum. And smp_rmb() is
used right after fn->sernum is accessed in rt6_get_cookie_safe(). This
is to guarantee that when the reader thread sees the new fn->sernum, the
new route is already inserted in the tree in memory.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After rwlock is replaced with rcu and spinlock, route lookup can happen
simultanously with route deletion.
This patch removes the call to free_percpu(rt->rt6i_pcpu) from
rt6_release() to avoid the race condition between rt6_release() and
rt6_get_pcpu_route(). And as free_percpu(rt->rt6i_pcpu) is already
called in ip6_dst_destroy() after the rcu grace period, it is safe to do
this change.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid 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: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function takes a route as input and tries to update the sernum in
the fib6_node this route is associated with. It will be used in later
commit when adding a cached route into the exception table under that
route.
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of zeroing out bnxt_tc.c with a #ifdef foo, instead don't compile
the file when the option is not enabled. Now make and the preprocessor do
not have to waste time compiling a no-op.
Signed-off-by: NJonathan Toppins <jtoppins@redhat.com>
Acked-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: implement rb-tree based retransmit queue

This patch series implement RB-tree based retransmit queue for TCP,
to better match modern BDP.

Tested:

 On receiver :
 netem on ingress : delay 150ms 200us loss 1
 GRO disabled to force stress and SACK storms.

for f in `seq 1 10`
do
 ./netperf -H lpaa6 -l30 -- -K bbr -o THROUGHPUT|tail -1
done | awk '{print $0} {sum += $0} END {printf "%7u\n",sum}'

Before patch :

323.87  351.48  339.59  338.62  306.72
204.07  304.93  291.88  202.47  176.88
->   2840

After patch:

1700.83 2207.98 2070.17 1544.26 2114.76
2124.89 1693.14 1080.91 2216.82 1299.94
->  18053

Average of 1805 Mbits istead of 284 Mbits.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using a linear list to store all skbs in write queue has been okay
for quite a while : O(N) is not too bad when N < 500.

Things get messy when N is the order of 100,000 : Modern TCP stacks
want 10Gbit+ of throughput even with 200 ms RTT flows.

40 ns per cache line miss means a full scan can use 4 ms,
blowing away CPU caches.

SACK processing often can use various hints to avoid parsing
whole retransmit queue. But with high packet losses and/or high
reordering, hints no longer work.

Sender has to process thousands of unfriendly SACK, accumulating
a huge socket backlog, burning a cpu and massively dropping packets.

Using an rb-tree for retransmit queue has been avoided for years
because it added complexity and overhead, but now is the time
to be more resistant and say no to quadratic behavior.

1) RTX queue is no longer part of the write queue : already sent skbs
are stored in one rb-tree.

2) Since reaching the head of write queue no longer needs
sk->sk_send_head, we added an union of sk_send_head and tcp_rtx_queue

Tested:

 On receiver :
 netem on ingress : delay 150ms 200us loss 1
 GRO disabled to force stress and SACK storms.

for f in `seq 1 10`
do
 ./netperf -H lpaa6 -l30 -- -K bbr -o THROUGHPUT|tail -1
done | awk '{print $0} {sum += $0} END {printf "%7u\n",sum}'

Before patch :

323.87
351.48
339.59
338.62
306.72
204.07
304.93
291.88
202.47
176.88
   2840

After patch:

1700.83
2207.98
2070.17
1544.26
2114.76
2124.89
1693.14
1080.91
2216.82
1299.94
  18053
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No need to recompute previous skb, as it will be a bit more
expensive when rtx queue is converted to RB tree.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With upcoming rb-tree implementation, the checks will trigger
more often, and this is expected.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It will be a bit more expensive to get the head of rtx queue
once rtx queue is converted to an rb-tree.

We can avoid this extra cost in case tp->lost_skb_hint is set.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_write_queue_tail() call can be factorized.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the upcoming rtx rbtree will add some extra code,
it is time to not inline this fat function anymore.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Geeralize private netem_rb_to_skb()

TCP rtx queue will soon be converted to rb-tree,
so we will need skb_rbtree_walk() helpers.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
40GbE Intel Wired LAN Driver Updates 2017-10-06

This series contains updates to i40e and i40evf only.

Rami fixes a typo in the code comments.

Mitch adds an ethtool private flag to control source pruning to resolve an
issue where our default behavior is to enable source pruning which breaks ARP
monitoring in channel bonding.  Fixes a couple of register definitions, which
were incorrect.

Jake fixes an issue with multiple logical CPUs per core (simultaneous
multithreading - SMT) and how we set an affinity hint based on the v_idx of
that q_vector, which is an incremental value and might lead to multiple
offline CPUs being assigned to a q_vector.  Instead, we should only assign
hints for CPUs which are online, so look to use cpumask_local_spread().
Also fixed a VF VLAN tag stripping issue, where the flag created to change
this feature was seen as unchangeable.  Lastly, organized and re-numbered
the feature flags.

Alan re-enables PTP L4 for XL710 devices with firmware version 6.0 or
greater, now that the previous bug in the older firmware is fixed.
Implements the PCI error handlers for reset_prepare() and reset_done() to
allow us to handle function level resets.

Alice cleans up code that was added to the incorrect function during a
merge.

Filip adds a change to display an error message when a module is inserted
that does not meet the thermal requirements, Talking Heads "Burning Down
the House" comes to mind.  Also fixed a flow director filter issue where
a variable was not being cleared which stores the filter number to be
removed from the list when the firmware refused to add the requested
filter.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simon Wunderlich says:

====================
This cleanup patchset includes the following patches:

 - bump version strings, by Simon Wunderlich

 - Cleanup patches to make checkpatch happy, by Sven Eckelmann (3 patches)
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use pci_ari_enabled() from the PCI core instead of the identical local copy
bnx2x_ari_enabled().  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer says:

====================
Improve xdp_monitor samples/bpf

Here are some improvements to the xdp_monitor tool currently located
under samples/bpf/.  Once the tools library libbpf become more feature
complete, xdp_monitor should be converted to use it, and be moved into
tools/bpf/xdp/ or tools/xdp/.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Other concurrent running programs, like perf or the XDP program what
needed to be monitored, might take up part of the max locked memory
limit.  Thus, the xdp_monitor tool have to set the RLIMIT_MEMLOCK to
RLIM_INFINITY, as it cannot determine a more sane limit.

Using the man exit(3) specified EXIT_FAILURE return exit code, and
correct other users too.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also monitor the tracepoint xdp_exception.  This tracepoint is usually
invoked by the drivers.  Programs themselves can activate this by
returning XDP_ABORTED, which will drop the packet but also trigger the
tracepoint.  This is useful for distinguishing intentional (XDP_DROP)
vs. ebpf-program error cases that cased a drop (XDP_ABORTED).

Drivers also use this tracepoint for reporting on XDP actions that are
unknown to the specific driver.  This can help the user to detect if a
driver e.g. doesn't implement XDP_REDIRECT yet.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The first 8 bytes of the tracepoint context struct are not accessible
by the bpf code.  This is a choice that dates back to the original
inclusion of this code.

See explaination in:
 commit 98b5c2c6 ("perf, bpf: allow bpf programs attach to tracepoints")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simon Horman says:

====================
nfp: extend match and action for flower offload

Pieter says:

This series extends flower offload match and action capabilities. It
specifically adds offload capabilities for matching on MPLS, TTL, TOS
and flow label. Furthermore offload capabilities for action have been
expanded to include set ethernet, ipv4, ipv6, tcp and udp headers.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously we did not have offloading support for set TCP/UDP actions. This
patch enables TC flower offload of set TCP/UDP sport and dport actions.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously we did not have offloading support for set IPv6 actions. This
patch enables TC flower offload of set IPv6 src and dst address actions.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously we did not have offloading support for set IPv4 actions. This
patch enables TC flower offload of set IPv4 src and dst address actions.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously we did not have offloading support for set ethernet actions.
This patch enables TC flower offload of set ethernet actions.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously matching on IPv6 ttl and tos fields were not offloaded. This
patch enables offloading IPv6 ttl and tos as match fields.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously matching on IPv4 ttl and tos fields were not offloaded. This
patch enables offloading IPv4 ttl and tos as match fields.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously MPLS match offloading was not supported. This patch enables
MPLS match offloading support for label, bos and tc fields.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit cc71b7b0 ("net/ipv6: remove unused err variable on
icmpv6_push_pending_frames") exposed icmpv6_push_pending_frames
return value not being used.

Remove now unnecessary int err declarations and uses.

Miscellanea:

o Remove unnecessary goto and out: labels
o Realign arguments
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that we've reduced the number of flags, organize similar flags
together and re-number them accordingly.

Since we don't yet have more than 32 flags, we'll use a u32 for both the
hw_features and flag field. Should we gain more flags in the future, we
may need to convert to a u64 or separate flags out into two fields.

One alternative approach considered, but not implemented here, was to
use an enumeration for the flag variables, and create a macro
I40E_FLAG() which used string concatenation to generate BIT_ULL values.
This has the advantage of making the actual bit values compile-time
dynamic so that we do not need to worry about matching the order to the
bit value. However, this does produce a high level of code churn, and
makes it more difficult to read a dumped flags value when debugging.

Change-ID: I8653fff69453cd547d6fe98d29dfa9d8710387d1
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Reviewed-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>