A function in kernel/bpf/syscall.c which got a bug fix in 'net'
was moved to kernel/bpf/verifier.c in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is to fix the replay attack issue for strreset asoc requests.
When a duplicated strreset asoc request is received, reply it with bad
seqno if it's seqno < asoc->strreset_inseq - 2, and reply it with the
result saved in asoc if it's seqno >= asoc->strreset_inseq - 2.
But note that if the result saved in asoc is performed, the sender's next
tsn and receiver's next tsn for the response chunk should be set. It's
safe to get them from asoc. Because if it's changed, which means the peer
has received the response already, the new response with wrong tsn won't
be accepted by peer.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is to fix the replay attack issue for strreset and addstrm in
requests.
When a duplicated strreset in or addstrm in request is received, reply it
with bad seqno if it's seqno < asoc->strreset_inseq - 2, and reply it with
the result saved in asoc if it's seqno >= asoc->strreset_inseq - 2.
For strreset in or addstrm in request, if the receiver side processes it
successfully, a strreset out or addstrm out request(as a response for that
request) will be sent back to peer. reconf_time will retransmit the out
request even if it's lost.
So when receiving a duplicated strreset in or addstrm in request and it's
result was performed, it shouldn't reply this request, but drop it instead.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now sctp stream reconf will process a request again even if it's seqno is
less than asoc->strreset_inseq.
If one request has been done successfully and some data chunks have been
accepted and then a duplicated strreset out request comes, the streamin's
ssn will be cleared. It will cause that stream will never receive chunks
any more because of unsynchronized ssn. It allows a replay attack.
A similar issue also exists when processing addstrm out requests. It will
cause more extra streams being added.
This patch is to fix it by saving the last 2 results into asoc. When a
duplicated strreset out or addstrm out request is received, reply it with
bad seqno if it's seqno < asoc->strreset_inseq - 2, and reply it with the
result saved in asoc if it's seqno >= asoc->strreset_inseq - 2.
Note that it saves last 2 results instead of only last 1 result, because
two requests can be sent together in one chunk.
And note that when receiving a duplicated request, the receiver side will
still reply it even if the peer has received the response. It's safe, As
the response will be dropped by the peer.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse
for doit functions that call it directly.
This is the first step to using extended error reporting in rtnetlink.
>From here individual subsystems can be updated to set netlink_ext_ack as
needed.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 07b26c9454 ("gso: Support partial splitting at the frag_list
pointer") assumes that all SKBs in a frag_list (except maybe the last
one) contain the same amount of GSO payload.
This assumption is not always correct, resulting in the following
warning message in the log:
skb_segment: too many frags
For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
one frag, and some with 2 frags.
After GRO, the frag_list SKBs end up having different amounts of payload.
If this frag_list SKB is then forwarded, the aforementioned assumption
is violated.
Validate the assumption, and fall back to software GSO if it not true.
Fixes: 07b26c9454 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now when processing strreset out responses, it gets outreq->list_of_streams
only when result is performed. But if result is not performed, str_p will
be NULL. It will cause panic in sctp_ulpevent_make_stream_reset_event if
nums is not 0.
This patch is to fix it by getting outreq->list_of_streams earlier, and
also to improve some codes for the strreset inreq process.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
BPF helper functions get_socket_cookie and get_socket_uid can be
used for network traffic classifications, among others. Expose
them also to programs of type BPF_PROG_TYPE_CGROUP_SKB. As of
commit 8f917bba00 ("bpf: pass sk to helper functions") the
required skb->sk function is available at both cgroup bpf ingress
and egress hooks. With these two new helper, cg_skb_func_proto is
effectively the same as sk_filter_func_proto.
Change since V1:
Instead of add the helper to cg_skb_func_proto, redirect the
cg_skb_func_proto to sk_filter_func_proto since all helper function
in sk_filter_func_proto are applicable to cg_skb_func_proto now.
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
We lack a saddr check for ::1. This causes security issues e.g. with acls
permitting connections from ::1 because of assumption that these originate
from local machine.
Assuming a source address of ::1 is local seems reasonable.
RFC4291 doesn't allow such a source address either, so drop such packets.
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Johan Hedberg says:
====================
pull request: bluetooth-next 2017-04-14
Here's the main batch of Bluetooth & 802.15.4 patches for the 4.12
kernel.
- Many fixes to 6LoWPAN, in particular for BLE
- New CA8210 IEEE 802.15.4 device driver (accounting for most of the
lines of code added in this pull request)
- Added Nokia Bluetooth (UART) HCI driver
- Some serdev & TTY changes that are dependencies for the Nokia
driver (with acks from relevant maintainers and an agreement that
these come through the bluetooth tree)
- Support for new Intel Bluetooth device
- Various other minor cleanups/fixes here and there
Please let me know if there are any issues pulling. Thanks.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Recently we added support for SW fdbs to take over HW ones, but that
results in changing a user-visible fdb flag thus we need to send a
notification, also it's consistent with how HW takes over SW entries.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct kcm_clone only contains fd, and kcm_clone() only
writes this struct, so there is no need to copy it from user.
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since 3.12 it has been possible to configure the default queuing
discipline via sysctl. This patch adds ability to configure the
default queue discipline in kernel configuration. This is useful for
environments where configuring the value from userspace is difficult
to manage.
The default is still the same as before (pfifo_fast) and it is
possible to change after kernel init with sysctl. This is similar
to how TCP congestion control works.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MTU overhead calculation in L2TP device set-up
merged via commit b784e7ebfc
needs to be adjusted to lock the tunnel socket while
referencing the sub-data structures to derive the
socket's IP overhead.
Reported-by: Guillaume Nault <g.nault@alphalink.fr>
Tested-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: R. Parameswaran <rparames@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Syzkaller reported a use-after-free in ip_recv_error at line
info->ipi_ifindex = skb->dev->ifindex;
This function is called on dequeue from the error queue, at which
point the device pointer may no longer be valid.
Save ifindex on enqueue in __skb_complete_tx_timestamp, when the
pointer is valid or NULL. Store it in temporary storage skb->cb.
It is safe to reference skb->dev here, as called from device drivers
or dev_queue_xmit. The exception is when called from tcp_ack_tstamp;
in that case it is NULL and ifindex is set to 0 (invalid).
Do not return a pktinfo cmsg if ifindex is 0. This maintains the
current behavior of not returning a cmsg if skb->dev was NULL.
On dequeue, the ipv4 path will cast from sock_exterr_skb to
in_pktinfo. Both have ifindex as their first element, so no explicit
conversion is needed. This is by design, introduced in commit
0b922b7a82 ("net: original ingress device index in PKTINFO"). For
ipv6 ip6_datagram_support_cmsg converts to in6_pktinfo.
Fixes: 829ae9d611 ("net-timestamp: allow reading recv cmsg on errqueue with origin tstamp")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to commit 87e9f03159
("ipv4: fix a potential deadlock in mcast getsockopt() path"),
there is a deadlock scenario for IP_ROUTER_ALERT too:
CPU0 CPU1
---- ----
lock(rtnl_mutex);
lock(sk_lock-AF_INET);
lock(rtnl_mutex);
lock(sk_lock-AF_INET);
Fix this by always locking RTNL first on all setsockopt() paths.
Note, after this patch ip_ra_lock is no longer needed either.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ndisc_notify is the ipv6 equivalent to arp_notify. When arp_notify is
set to 1, gratuitous arp requests are sent when the device is brought up.
The same is expected when ndisc_notify is set to 1 (per ndisc_notify in
Documentation/networking/ip-sysctl.txt). The NA is not sent on NETDEV_UP
event; add it.
Fixes: 5cb04436ee ("ipv6: add knob to send unsolicited ND on link-layer address change")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch moves as is the legacy DSA code from dsa.c to legacy.c,
except the few shared symbols which remain in dsa.c.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts were simply overlapping changes. In the net/ipv4/route.c
case the code had simply moved around a little bit and the same fix
was made in both 'net' and 'net-next'.
In the net/sched/sch_generic.c case a fix in 'net' happened at
the same time that a new argument was added to qdisc_hash_add().
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for your net tree,
they are:
1) Missing TCP header sanity check in TCPMSS target, from Eric Dumazet.
2) Incorrect event message type for related conntracks created via
ctnetlink, from Liping Zhang.
3) Fix incorrect rcu locking when handling helpers from ctnetlink,
from Gao feng.
4) Fix missing rcu locking when updating helper, from Liping Zhang.
5) Fix missing read_lock_bh when iterating over list of device addresses
from TPROXY and redirect, also from Liping.
6) Fix crash when trying to dump expectations from conntrack with no
helper via ctnetlink, from Liping.
7) Missing RCU protection to expecation list update given ctnetlink
iterates over the list under rcu read lock side, from Liping too.
8) Don't dump autogenerated seed in nft_hash to userspace, this is
very confusing to the user, again from Liping.
9) Fix wrong conntrack netns module refcount in ipt_CLUSTERIP,
from Gao feng.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Current codes invoke wrongly nf_ct_netns_get in the destroy routine,
it should use nf_ct_netns_put, not nf_ct_netns_get.
It could cause some modules could not be unloaded.
Fixes: ecb2421b5d ("netfilter: add and use nf_ct_netns_get/put")
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This can prevent the nft utility from printing out the auto generated
seed to the user, which is unnecessary and confusing.
Fixes: cb1b69b0b1 ("netfilter: nf_tables: add hash expression")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we have extended error reporting and a new message format for
netlink ACK messages, also extend this to be able to return arbitrary
cookie data on success.
This will allow, for example, nl80211 to not send an extra message for
cookies identifying newly created objects, but return those directly
in the ACK message.
The cookie data size is currently limited to 20 bytes (since Jamal
talked about using SHA1 for identifiers.)
Thanks to Jamal Hadi Salim for bringing up this idea during the
discussions.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass the extended ACK reporting struct down from generic netlink to
the families, using the existing struct genl_info for simplicity.
Also add support to set the extended ACK information from generic
netlink users.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the base infrastructure and UAPI for netlink extended ACK
reporting. All "manual" calls to netlink_ack() pass NULL for now and
thus don't get extended ACK reporting.
Big thanks goes to Pablo Neira Ayuso for not only bringing up the
whole topic at netconf (again) but also coming up with the nlattr
passing trick and various other ideas.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1. Don't get the metric RTAX_ADVMSS of dst.
There are two reasons.
1) Its caller dst_metric_advmss has already invoke dst_metric_advmss
before invoke default_advmss.
2) The ipv4_default_advmss is used to get the default mss, it should
not try to get the metric like ip6_default_advmss.
2. Use sizeof(tcphdr)+sizeof(iphdr) instead of literal 40.
3. Define one new macro IPV4_MAX_PMTU instead of 65535 according to
RFC 2675, section 5.1.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NETDEV_CHANGEUPPER is an internal event; do not generate userspace
notifications.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CHANGELOWERSTATE is an internal event; do not generate userspace
notifications.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
PRECHANGEUPPER is an internal event; do not generate userspace
notifications.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changing the master device for a link generates many messages; the one
generated for POST_TYPE_CHANGE is redundant:
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue master br1 state UNKNOWN group default
link/ether 02:02:02:02:02:03 brd ff:ff:ff:ff:ff:ff
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue master br1 state UNKNOWN group default
link/ether 02:02:02:02:02:03 brd ff:ff:ff:ff:ff:ff
Remove POST_TYPE_CHANGE from the list of notifiers that generate
notifications.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changing hardware address generates redundant messages:
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
link/ether 02:02:02:02:02:02 brd ff:ff:ff:ff:ff:ff
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
link/ether 02:02:02:02:02:02 brd ff:ff:ff:ff:ff:ff
Do not send a notification for the CHANGEADDR notifier.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NETDEV_UDP_TUNNEL_PUSH_INFO is an internal notifier; nothing userspace
can do so don't generate a netlink notification.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changing MTU on a link currently causes 3 messages to be sent to userspace:
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1490 qdisc noqueue state UNKNOWN group default
link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff
[LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff
Remove the messages sent for PRE_CHANGE_MTU and CHANGE_MTU netdev events.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IPv6 stack needs to send and receive Neighbor Discovery
messages. Remove the IFF_POINTOPOINT flag.
Signed-off-by: Patrik Flykt <patrik.flykt@linux.intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Reviewed-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Make netdev queue packets if we run out of credits.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Consolidate code sending data to LE CoC channels and adds proper
accounting of packets sent, the remaining credits and how many packets
are queued.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Rely on netif_wake_queue and netif_stop_queue to flow control when
transmit resources are unavailable.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since l2cap_chan_send will now queue the packets there is no point in
checking the credits anymore.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There is no point in setting IFF_NO_QUEUE should already have taken
care of setting it if tx_queue_len is not set, in fact this may
actually disable queue for interfaces that require it and do set
tx_queue_len.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Just keep queueing them into TX queue since the caller might just have
to do the same and there is no impact in adding another packet to the
TX queue even if there aren't any credits to transmit them.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This makes should make it more clear why a packet is being dropped.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
During chan_recv_cb there is already a peer lookup which can be passed
to recv_pkt directly instead of the channel.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
A status field in the skb_cb struct was storing a channel status
based on channel suspend/resume events. This stored status was
then used to return EAGAIN if there were packet sending issues
in snd_pkt().
The issue is that the skb has been freed by the time the callback
to 6lowpan's suspend/resume was called. So, this generates a
"use after free" issue that was noticed while running kernel tests
with KASAN debug enabled.
Let's eliminate the status field entirely as we can use the channel
tx_credits to indicate whether we should return EAGAIN when handling
packets.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When adding 6lowpan devices very rapidly we sometimes see a crash:
[23122.306615] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.0-43-arm64 #1 Debian 4.9.9.linaro.43-1
[23122.315400] Hardware name: HiKey Development Board (DT)
[23122.320623] task: ffff800075443080 task.stack: ffff800075484000
[23122.326551] PC is at expire_timers+0x70/0x150
[23122.330907] LR is at run_timer_softirq+0xa0/0x1a0
[23122.335616] pc : [<ffff000008142dd8>] lr : [<ffff000008142f58>] pstate: 600001c5
This was due to add_peer_chan() unconditionally initializing the
lowpan_btle_dev->notify_peers delayed work structure, even if the
lowpan_btle_dev passed into add_peer_chan() had previously been
initialized.
Normally, this would go unnoticed as the delayed work timer is set for
100 msec, however when calling add_peer_chan() faster than 100 msec it
clears out a previously queued delay work causing the crash above.
To fix this, let add_peer_chan() know when a new lowpan_btle_dev is passed
in so that it only performs the delay work initialization when needed.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The data from peer->chan->dst is not being copied to peer_addr, the
current code just updates the pointer and not the contents of what
it points to. Fix this with the intended assignment.
Detected by CoverityScan, CID#1422111 ("Parse warning
(PW.PARAM_SET_BUT_NOT_USED)")
Fixes: fb6f2f606ce8 ("6lowpan: Fix IID format for Bluetooth")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Use the initial connection interval recommended in Bluetooth
Specification v4.2 (30ms - 50ms).
Signed-off-by: Jonas Holmberg <jonashg@axis.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
