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In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.
With commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.
This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.
Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.
This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.
We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.
For IPv6, adds saddr into the hash as well, but not nexthdr.
If I ping the patched target, we can see ID are now hard to predict.
21:57:11.008086 IP (...)
A > target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
target > A: ICMP echo reply, seq 1, length 64
21:57:12.013133 IP (...)
A > target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
target > A: ICMP echo reply, seq 2, length 64
21:57:13.016580 IP (...)
A > target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
target > A: ICMP echo reply, seq 3, length 64
[1] TCP sessions uses a per flow ID generator not changed by this patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jeffrey Knockel <jeffk@cs.unm.edu>
Reported-by: Jedidiah R. Crandall <crandall@cs.unm.edu>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Hannes Frederic Sowa <hannes@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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As per comment from David Miller, we try to make the buffer reassembly
function more resilient to user errors than it is today.
- We check that the "*buf" parameter always is set, since this is
mandatory input.
- We ensure that *buf->next always is set to NULL before linking in
the buffer, instead of relying of the caller to have done this.
- We ensure that the "tail" pointer in the head buffer's control
block is initialized to NULL when the first fragment arrives.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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ndm_type means L3 address type, in neighbour proxy and vxlan, it's RTN_UNICAST.
NDA_DST is for netlink TLV type, hence it's not right value in this context.
Signed-off-by: Jun Zhao <mypopydev@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
John W. Linville says:
====================
pull request: wireless-next 2014-07-25
Please pull this batch of updates intended for the 3.17 stream!
For the mac80211 bits, Johannes says:
"We have a lot of TDLS patches, among them a fix that should make hwsim
tests happy again. The rest, this time, is mostly small fixes."
For the Bluetooth bits, Gustavo says:
"Some more patches for 3.17. The most important change here is the move of
the 6lowpan code to net/6lowpan. It has been agreed with Davem that this
change will go through the bluetooth tree. The rest are mostly clean up and
fixes."
and,
"Here follows some more patches for 3.17. These are mostly fixes to what
we've sent to you before for next merge window."
For the iwlwifi bits, Emmanuel says:
"I have the usual amount of BT Coex stuff. Arik continues to work
on TDLS and Ariej contributes a few things for HS2.0. I added a few
more things to the firmware debugging infrastructure. Eran fixes a
small bug - pretty normal content."
And for the Atheros bits, Kalle says:
"For ath6kl me and Jessica added support for ar6004 hw3.0, our latest
version of ar6004.
For ath10k Janusz added a printout so that it's easier to check what
ath10k kconfig options are enabled. He also added a debugfs file to
configure maximum amsdu and ampdu values. Also we had few fixes as
usual."
On top of that is the usual large batch of various driver updates --
brcmfmac, mwifiex, the TI drivers, and wil6210 all get some action.
Rafał has also been very busy with b43 and related updates.
Also, I pulled the wireless tree into this in order to resolve a
merge conflict...
P.S. The change to fs/compat_ioctl.c reflects a name change in a
Bluetooth header file...
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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If we have entries in the whitelist we shouldn't disable page scanning
when disabling connectable mode. This patch adds the necessary check to
the Set Connectable command handler.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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This patch fixes a typo in the hci_cc_write_scan_enable() function where
we want to clear the HCI_PSCAN flag if the SCAN_PAGE bit of the HCI
command parameter was not set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This patch makes init_net's high_thresh limit to be the maximum for all
namespaces, thus introducing a global memory limit threshold equal to the
sum of the individual high_thresh limits which are capped.
It also introduces some sane minimums for low_thresh as it shouldn't be
able to drop below 0 (or > high_thresh in the unsigned case), and
overall low_thresh should not ever be above high_thresh, so we make the
following relations for a namespace:
init_net:
high_thresh - max(not capped), min(init_net low_thresh)
low_thresh - max(init_net high_thresh), min (0)
all other namespaces:
high_thresh = max(init_net high_thresh), min(namespace's low_thresh)
low_thresh = max(namespace's high_thresh), min(0)
The major issue with having low_thresh > high_thresh is that we'll
schedule eviction but never evict anything and thus rely only on the
timers.
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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rehash is rare operation, don't force readers to take
the read-side rwlock.
Instead, we only have to detect the (rare) case where
the secret was altered while we are trying to insert
a new inetfrag queue into the table.
If it was changed, drop the bucket lock and recompute
the hash to get the 'new' chain bucket that we have to
insert into.
Joint work with Nikolay Aleksandrov.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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merge functionality into the eviction workqueue.
Instead of rebuilding every n seconds, take advantage of the upper
hash chain length limit.
If we hit it, mark table for rebuild and schedule workqueue.
To prevent frequent rebuilds when we're completely overloaded,
don't rebuild more than once every 5 seconds.
ipfrag_secret_interval sysctl is now obsolete and has been marked as
deprecated, it still can be changed so scripts won't be broken but it
won't have any effect. A comment is left above each unused secret_timer
variable to avoid confusion.
Joint work with Nikolay Aleksandrov.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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no longer used.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The 'nqueues' counter is protected by the lru list lock,
once thats removed this needs to be converted to atomic
counter. Given this isn't used for anything except for
reporting it to userspace via /proc, just remove it.
We still report the memory currently used by fragment
reassembly queues.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When the high_thresh limit is reached we try to toss the 'oldest'
incomplete fragment queues until memory limits are below the low_thresh
value. This happens in softirq/packet processing context.
This has two drawbacks:
1) processors might evict a queue that was about to be completed
by another cpu, because they will compete wrt. resource usage and
resource reclaim.
2) LRU list maintenance is expensive.
But when constantly overloaded, even the 'least recently used' element is
recent, so removing 'lru' queue first is not 'fairer' than removing any
other fragment queue.
This moves eviction out of the fast path:
When the low threshold is reached, a work queue is scheduled
which then iterates over the table and removes the queues that exceed
the memory limits of the namespace. It sets a new flag called
INET_FRAG_EVICTED on the evicted queues so the proper counters will get
incremented when the queue is forcefully expired.
When the high threshold is reached, no more fragment queues are
created until we're below the limit again.
The LRU list is now unused and will be removed in a followup patch.
Joint work with Nikolay Aleksandrov.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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First step to move eviction handling into a work queue.
We lose two spots that accounted evicted fragments in MIB counters.
Accounting will be restored since the upcoming work-queue evictor
invokes the frag queue timer callbacks instead.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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hide actual hash size from individual users: The _find
function will now fold the given hash value into the required range.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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With the Bluetooth 4.1 specification the Simultaneous LE and BR/EDR
controller option has been deprecated. It shall be set to zero and
ignored otherwise.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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Expose the default values for minimum and maximum LE advertising
interval via debugfs for testing purposes.
Signed-off-by: Georg Lukas <georg@op-co.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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Store the default values for minimum and maximum advertising interval
with all the other controller defaults. These vaules are sent to the
adapter whenever advertising is (re)enabled.
Signed-off-by: Georg Lukas <georg@op-co.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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Devices using resolvable private addresses are required to provide
an identity resolving key. These devices can not be found using
the current controller white list support. This means if the kernel
knows about any devices with an identity resolving key, the white
list filtering must be disabled.
However so far the kernel kept identity resolving keys around even
for devices that are not using resolvable private addresses. The
notification to userspace clearly hints to not store the key and
so it is best to just remove the key from the kernel as well at
that point.
With this it easy now to detect when using the white list is
possible or when kernel side resolving of addresses is required.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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The Bluetooth controller can use a white list filter when scanning
to avoid waking up the host for devices that are of no interest.
Devices marked as reporting, direct connection (incoming) or general
connection are now added to the controller white list. The update of
the white list happens just before enabling passive scanning.
In case the white list is full and can not hold all devices, the
white list is not used and the filter policy set to accept all
advertisements.
Using the white list for scanning allows for power saving with
controllers that do not handle the duplicate filtering correctly.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless
Conflicts:
net/mac80211/cfg.c
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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If led-always-blink is set, then between switch led OFF and ON
is almost zero time. So blink is invisible. This use oneshot led trigger
with fixed time 50ms witch is enough to see blink.
Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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The ulog targets were recently killed. A few references to the Kconfig
macros CONFIG_IP_NF_TARGET_ULOG and CONFIG_BRIDGE_EBT_ULOG were left
untouched. Kill these too.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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The function led_trigger_register() will only return -EEXIST when
error arises.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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In this file, function names are otherwise used as pointers without &.
A simplified version of the Coccinelle semantic patch that makes this
change is as follows:
// <smpl>
@r@
identifier f;
@@
f(...) { ... }
@@
identifier r.f;
@@
- &f
+ f
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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After 11878b40e[net-timestamp: SOCK_RAW and PING timestamping], this comment
becomes obsolete since the codes check not only UDP socket, but also RAW sock;
and the codes are clear, not need the comments
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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"net" is normally for struct net*, pointer to struct net_device
should be named to either "dev" or "ndev" etc.
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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eBPF is used by socket filtering, seccomp and soon by tracing and
exposed to userspace, therefore 'sock_filter_int' name is not accurate.
Rename it to 'bpf_insn'
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In this file, function names are otherwise used as pointers without &.
A simplified version of the Coccinelle semantic patch that makes this
change is as follows:
// <smpl>
@r@
identifier f;
@@
f(...) { ... }
@@
identifier r.f;
@@
- &f
+ f
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In this file, function names are otherwise used as pointers without &.
A simplified version of the Coccinelle semantic patch that makes this
change is as follows:
// <smpl>
@r@
identifier f;
@@
f(...) { ... }
@@
identifier r.f;
@@
- &f
+ f
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In this file, function names are otherwise used as pointers without &.
A simplified version of the Coccinelle semantic patch that makes this
change is as follows:
// <smpl>
@r@
identifier f;
@@
f(...) { ... }
@@
identifier r.f;
@@
- &f
+ f
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless
John W. Linville says:
====================
pull request: wireless 2014-07-24
Please pull this batch of fixes intended for the 3.16 stream...
For the mac80211 fixes, Johannes says:
"I have two fixes: one for tracing that fixes a long-standing NULL
pointer dereference, and one for a mac80211 issue that causes iwlmvm to
send invalid frames during authentication/association."
and,
"One more fix - for a bug in the newly introduced code that obtains rate
control information for stations."
For the iwlwifi fixes, Emmanuel says:
"It includes a merge damage fix. This region has been changed in -next
and -fixes quite a few times and apparently, I failed to handle it
properly, so here the fix. Along with that I have a fix from Eliad
to properly handle overlapping BSS in AP mode."
On top of that, Felix provides and ath9k fix for Tx stalls that happen
after an aggregation session failure.
Please let me know if there are problems! There are some changes
here that will cause merge conflicts in -next. Once you merge this
I can pull it into wireless-next and resolve those issues.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pablo Neira Ayuso says:
====================
Via Simon Horman, I received the following one-liner for your net tree:
1) Fix crash when exiting from netns that uses IPVS and conntrack,
from Julian Anastasov via Simon Horman.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fix a bug where skb_clone() NULL check is missing in sample action
implementation.
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
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The sample action is rather generic, allowing arbitrary actions to be
executed based on a probability. However its use, within the Open
vSwitch
code-base is limited: only a single user-space action is ever nested.
A consequence of the current implementation of sample actions is that
depending on weather the sample action executed (due to its probability)
any side-effects of nested actions may or may not be present before
executing subsequent actions. This has the potential to complicate
verification of valid actions by the (kernel) datapath. And indeed
adding support for push and pop MPLS actions inside sample actions
is one case where such case.
In order to allow all supported actions to be continue to be nested
inside sample actions without the potential need for complex
verification code this patch changes the implementation of the sample
action in the kernel datapath so that sample actions are more like
a function call and any side effects of nested actions are not
present when executing subsequent actions.
With the above in mind the motivation for this change is twofold:
* To contain side-effects the sample action in the hope of making it
easier to deal with in the future and;
* To avoid some rather complex verification code introduced in the MPLS
datapath patch.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
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In queue_userspace_packet(), the ovs_nla_put_flow return value is
not checked. This is fine as long as key_attr_size() returns the
correct value. In case it does not, the current code may corrupt buffer
memory. Add a run time assertion catch this case to avoid silent
failure.
Reported-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
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xt_hashlimit cannot be used with large hash tables, because garbage
collector is run from a timer. If table is really big, its possible
to hold cpu for more than 500 msec, which is unacceptable.
Switch to a work queue, and use proper scheduling points to remove
latencies spikes.
Later, we also could switch to a smoother garbage collection done
at lookup time, one bucket at a time...
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Following patch enables all available tunnel GSO features for OVS
bridge device so that ovs can use hardware offloads available to
underling device.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>
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In order to allow handlers directly read upcalls from datapath,
we need to support per-handler netlink socket for each vport in
datapath. This commit makes this happen. Also, it is guaranteed
to be backward compatible with previous branch.
Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:
====================
pull request (net): ipsec 2014-07-23
Just two fixes this time, both are stable candidates.
1) Fix the dst_entry refcount on socket policy usage.
2) Fix a wrong SPI check that prevents AH SAs from getting
installed, dependent on the SPI. From Tobias Brunner.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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BPF is used in several kernel components. This split creates logical boundary
between generic eBPF core and the rest
kernel/bpf/core.c: eBPF interpreter
net/core/filter.c: classic->eBPF converter, classic verifiers, socket filters
This patch only moves functions.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently, although IP_MULTICAST_ALL and IP_MSFILTER ioctl calls succeed on
raw sockets, there is no code to implement the functionality on received
packets; it is only implemented for UDP sockets. The raw(7) man page states:
"In addition, all ip(7) IPPROTO_IP socket options valid for datagram sockets
are supported", which implies these ioctls should work on raw sockets.
To fix this, add a call to ip_mc_sf_allow on raw sockets.
This should not break any existing code, since the current position of
not calling ip_mc_sf_filter makes it behave as if neither the IP_MULTICAST_ALL
nor the IP_MSFILTER ioctl had been called. Adding the call to ip_mc_sf_allow
will therefore maintain the current behaviour so long as IP_MULTICAST_ALL and
IP_MSFILTER ioctls are not called. Any code that currently is calling
IP_MULTICAST_ALL or IP_MSFILTER ioctls on raw sockets presumably is wanting
the filter to be applied, although no filtering will currently be occurring.
Signed-off-by: Quentin Armitage <quentin@armitage.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When adding remote devices to the kernel using the Add Device management
command, these devices are explicitly allowed to connect. This kind of
incoming connections are possible even when the controller itself is
not connectable.
For BR/EDR this distinction is pretty simple since there is only one
type of incoming connections. With LE this is not that simple anymore
since there are ADV_IND and ADV_DIRECT_IND advertising events.
The ADV_DIRECT_IND advertising events are send for incoming (slave
initiated) connections only. And this is the only thing the kernel
should allow when adding devices using action 0x01. This meaning
of incoming connections is coming from BR/EDR and needs to be
mapped to LE the same way.
Supporting the auto-connection of devices using ADV_IND advertising
events is an important feature as well. However it does not map to
incoming connections. So introduce a new action 0x02 that allows
the kernel to connect to devices using ADV_DIRECT_IND and in addition
ADV_IND advertising reports.
This difference is represented by the new HCI_AUTO_CONN_DIRECT value
for only connecting to ADV_DIRECT_IND. For connection to ADV_IND and
ADV_DIRECT_IND the old value HCI_AUTO_CONN_ALWAYS is used.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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Unconditionally connecting to devices sending ADV_DIRECT_IND when
the controller is in CONNECTABLE mode is a feature that is not
fully working. The background scanning trigger for this has been
removed, but the statement allowing it to happen in case some
other part triggers is still present. So remove that code part
as well to avoid unwanted connections.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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It hasn't been used since commit 0fd7bac(net: relax rcvbuf limits).
Signed-off-by: Sorin Dumitru <sorin@returnze.ro>
Signed-off-by: David S. Miller <davem@davemloft.net>
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If the Bluetooth controller supports Get MWS Transport Layer
Configuration command, then issue it during initialization.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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If the Bluetooth controller supports Read Local Supported Codecs
command, then issue it during initialization so that the list of
codecs is known.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
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Jason reported an oops caused by SCTP on his ARM machine with
SCTP authentication enabled:
Internal error: Oops: 17 [#1] ARM
CPU: 0 PID: 104 Comm: sctp-test Not tainted 3.13.0-68744-g3632f30c9b20-dirty #1
task: c6eefa40 ti: c6f52000 task.ti: c6f52000
PC is at sctp_auth_calculate_hmac+0xc4/0x10c
LR is at sg_init_table+0x20/0x38
pc : [<c024bb80>] lr : [<c00f32dc>] psr: 40000013
sp : c6f538e8 ip : 00000000 fp : c6f53924
r10: c6f50d80 r9 : 00000000 r8 : 00010000
r7 : 00000000 r6 : c7be4000 r5 : 00000000 r4 : c6f56254
r3 : c00c8170 r2 : 00000001 r1 : 00000008 r0 : c6f1e660
Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 0005397f Table: 06f28000 DAC: 00000015
Process sctp-test (pid: 104, stack limit = 0xc6f521c0)
Stack: (0xc6f538e8 to 0xc6f54000)
[...]
Backtrace:
[<c024babc>] (sctp_auth_calculate_hmac+0x0/0x10c) from [<c0249af8>] (sctp_packet_transmit+0x33c/0x5c8)
[<c02497bc>] (sctp_packet_transmit+0x0/0x5c8) from [<c023e96c>] (sctp_outq_flush+0x7fc/0x844)
[<c023e170>] (sctp_outq_flush+0x0/0x844) from [<c023ef78>] (sctp_outq_uncork+0x24/0x28)
[<c023ef54>] (sctp_outq_uncork+0x0/0x28) from [<c0234364>] (sctp_side_effects+0x1134/0x1220)
[<c0233230>] (sctp_side_effects+0x0/0x1220) from [<c02330b0>] (sctp_do_sm+0xac/0xd4)
[<c0233004>] (sctp_do_sm+0x0/0xd4) from [<c023675c>] (sctp_assoc_bh_rcv+0x118/0x160)
[<c0236644>] (sctp_assoc_bh_rcv+0x0/0x160) from [<c023d5bc>] (sctp_inq_push+0x6c/0x74)
[<c023d550>] (sctp_inq_push+0x0/0x74) from [<c024a6b0>] (sctp_rcv+0x7d8/0x888)
While we already had various kind of bugs in that area
ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to verify if
we/peer is AUTH capable") and b14878ccb7fa ("net: sctp: cache
auth_enable per endpoint"), this one is a bit of a different
kind.
Giving a bit more background on why SCTP authentication is
needed can be found in RFC4895:
SCTP uses 32-bit verification tags to protect itself against
blind attackers. These values are not changed during the
lifetime of an SCTP association.
Looking at new SCTP extensions, there is the need to have a
method of proving that an SCTP chunk(s) was really sent by
the original peer that started the association and not by a
malicious attacker.
To cause this bug, we're triggering an INIT collision between
peers; normal SCTP handshake where both sides intent to
authenticate packets contains RANDOM; CHUNKS; HMAC-ALGO
parameters that are being negotiated among peers:
---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
<------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] ---------
-------------------- COOKIE-ECHO -------------------->
<-------------------- COOKIE-ACK ---------------------
RFC4895 says that each endpoint therefore knows its own random
number and the peer's random number *after* the association
has been established. The local and peer's random number along
with the shared key are then part of the secret used for
calculating the HMAC in the AUTH chunk.
Now, in our scenario, we have 2 threads with 1 non-blocking
SEQ_PACKET socket each, setting up common shared SCTP_AUTH_KEY
and SCTP_AUTH_ACTIVE_KEY properly, and each of them calling
sctp_bindx(3), listen(2) and connect(2) against each other,
thus the handshake looks similar to this, e.g.:
---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
<------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] ---------
<--------- INIT[RANDOM; CHUNKS; HMAC-ALGO] -----------
-------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] -------->
...
Since such collisions can also happen with verification tags,
the RFC4895 for AUTH rather vaguely says under section 6.1:
In case of INIT collision, the rules governing the handling
of this Random Number follow the same pattern as those for
the Verification Tag, as explained in Section 5.2.4 of
RFC 2960 [5]. Therefore, each endpoint knows its own Random
Number and the peer's Random Number after the association
has been established.
In RFC2960, section 5.2.4, we're eventually hitting Action B:
B) In this case, both sides may be attempting to start an
association at about the same time but the peer endpoint
started its INIT after responding to the local endpoint's
INIT. Thus it may have picked a new Verification Tag not
being aware of the previous Tag it had sent this endpoint.
The endpoint should stay in or enter the ESTABLISHED
state but it MUST update its peer's Verification Tag from
the State Cookie, stop any init or cookie timers that may
running and send a COOKIE ACK.
In other words, the handling of the Random parameter is the
same as behavior for the Verification Tag as described in
Action B of section 5.2.4.
Looking at the code, we exactly hit the sctp_sf_do_dupcook_b()
case which triggers an SCTP_CMD_UPDATE_ASSOC command to the
side effect interpreter, and in fact it properly copies over
peer_{random, hmacs, chunks} parameters from the newly created
association to update the existing one.
Also, the old asoc_shared_key is being released and based on
the new params, sctp_auth_asoc_init_active_key() updated.
However, the issue observed in this case is that the previous
asoc->peer.auth_capable was 0, and has *not* been updated, so
that instead of creating a new secret, we're doing an early
return from the function sctp_auth_asoc_init_active_key()
leaving asoc->asoc_shared_key as NULL. However, we now have to
authenticate chunks from the updated chunk list (e.g. COOKIE-ACK).
That in fact causes the server side when responding with ...
<------------------ AUTH; COOKIE-ACK -----------------
... to trigger a NULL pointer dereference, since in
sctp_packet_transmit(), it discovers that an AUTH chunk is
being queued for xmit, and thus it calls sctp_auth_calculate_hmac().
Since the asoc->active_key_id is still inherited from the
endpoint, and the same as encoded into the chunk, it uses
asoc->asoc_shared_key, which is still NULL, as an asoc_key
and dereferences it in ...
crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len)
... causing an oops. All this happens because sctp_make_cookie_ack()
called with the *new* association has the peer.auth_capable=1
and therefore marks the chunk with auth=1 after checking
sctp_auth_send_cid(), but it is *actually* sent later on over
the then *updated* association's transport that didn't initialize
its shared key due to peer.auth_capable=0. Since control chunks
in that case are not sent by the temporary association which
are scheduled for deletion, they are issued for xmit via
SCTP_CMD_REPLY in the interpreter with the context of the
*updated* association. peer.auth_capable was 0 in the updated
association (which went from COOKIE_WAIT into ESTABLISHED state),
since all previous processing that performed sctp_process_init()
was being done on temporary associations, that we eventually
throw away each time.
The correct fix is to update to the new peer.auth_capable
value as well in the collision case via sctp_assoc_update(),
so that in case the collision migrated from 0 -> 1,
sctp_auth_asoc_init_active_key() can properly recalculate
the secret. This therefore fixes the observed server panic.
Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing")
Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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