The original version of the candidate selection for DAT attempted to
compare both candidate and max_orig_node to identify which has the smaller
MAC address. This comparison is required as tie-break when a hash collision
happened.
But the used function returned 0 when the function was not equal and a
non-zero value when it was equal. As result, the actually selected
node was dependent on the order of entries in the orig_hash and not
actually on the mac addresses. The last originator in the hash collision
would always win.
To have a proper ordering, it must diff the actual MAC address bytes and
reject the candidate when the diff is not smaller than 0.
Cc: stable@vger.kernel.org
Fixes: 785ea11441 ("batman-adv: Distributed ARP Table - create DHT helper functions")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Before the access to struct batadv_tvlv_mcast_tracker's num_dests, it is
attempted to check whether enough space is actually in the network header.
But instead of using offsetofend() to check for the whole size (2) which
must be accessible, offsetof() of is called. The latter is always returning
0. The comparison with the network header length will always return that
enough data is available - even when only 1 or 0 bytes are accessible.
Instead of using offsetofend(), use the more common check for the whole
header.
Cc: stable@vger.kernel.org
Fixes: 07afe1ba28 ("batman-adv: mcast: implement multicast packet reception and forwarding")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
If the skb has a frag_list, it must be linearized before it can be split
using skb_split(). But when this step failed, it must not only free the skb
but also take care of the reference to the already found primary_if.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: a063f2fba3 ("batman-adv: Don't skb_split skbuffs with frag_list")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The caller of batadv_frag_send_packet() assume that the skb provided to the
function are always consumed. But the pre-check for an empty payload or the
zero fragment size returned an error without any further actions.
A failed pre-check must use the same error handling code as the rest of the
function.
Cc: stable@vger.kernel.org
Fixes: ee75ed8887 ("batman-adv: Fragment and send skbs larger than mtu")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
A TT unicast TVLV contains the number of VLANs stored in it. This number is
an u16 and gets multiplied by the size of the struct
batadv_tvlv_tt_vlan_data (8 bytes). The size can therefore overflow the u16
used to store the tt_vlan_len. All additional safety checks to prevent
out-of-bounds access of the TVLV buffer are invalid due to this overflow.
Using size_t prevents this overflow and ensures that the safety checks
compare against the actual buffer requirements.
Cc: stable@vger.kernel.org
Fixes: 7ea7b4a142 ("batman-adv: make the TT CRC logic VLAN specific")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_send_tt_request() allocates a tt_req_node when none exists for the
destination originator node. This should prevent that a multiple TT
requests are send at the same time to an originator.
But if allocation of the send buffer failed, this request must be cleaned
up again. But indicator for such a failure is "ret == false". But the
actual implementation is checking for "ret == true".
The check must be inverted to not loose the information about the TT
request directly after it was attempted to be sent out. This should avoid
potential request storms.
Cc: stable@vger.kernel.org
Fixes: 335fbe0f5d ("batman-adv: tvlv - convert tt query packet to use tvlv unicast packets")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When an mesh interface is registered, it creates an untagged struct
batadv_meshif_vlan on top of it via the NETDEV_REGISTER notifier. But in
this process, another receiver of this notification can veto the
registration. The netdev registration will be aborted because of this veto.
The register_netdevice() call will try to clean up the net_device using
unregister_netdevice_queue() - which only uses the .priv_destructor to
free private resources. In this situation, .dellink will not be called.
The cleanup of the untagged batadv_meshif_vlan must thefore be done in the
destructor to avoid a leak of this object.
Cc: stable@vger.kernel.org
Fixes: 5d2c05b213 ("batman-adv: add per VLAN interface attribute framework")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The batadv_skb_set_priority() receives an SKB with the inner ethernet
header at position "offset". When it tries to extract the IPv4 and IPv6
header, it needs to skip the ethernet header to get access to the IP
header.
But for VLAN header, it performs the access with the struct vlan_ethhdr.
This struct contains both both the ethernet header and the VLAN header. It
is therefore incorrect to skip over the whole vlan_ethhdr size to get
access to the vlan_ethhdr.
Cc: stable@vger.kernel.org
Fixes: c54f38c9aa ("batman-adv: set skb priority according to content")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
As documented in commit 8bd67ebb50 ("net: bridge: xmit: make sure we have
at least eth header len bytes"), it is possible by for a local user with
eBPF TC hook access to attach a tc filter which truncates the packet and
redirects to an batadv interface. But the code assumes that at least
ETH_HLEN bytes are available and thus might read outside of the available
buffer.
The batadv_interface_tx() must therefore always check itself if enough data
is available for the ethernet header and don't rely on min_header_len.
Cc: stable@vger.kernel.org
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_get_vid() accesses the proto field of the ethernet header, it
is not checking if the data itself is accessible. The caller is responsible
for it. But in contrast to other call sites, batadv_dat_get_vid() and its
caller didn't make sure this is true. This could have caused an
out-of-bounds access.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: be1db4f661 ("batman-adv: make the Distributed ARP Table vlan aware")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The pskb_may_pull() called by batadv_bla_is_backbone_gw() could reallocate
the buffer behind the skb. Variables which were pointing to the old buffer
need to be reassigned to avoid an use-after-free.
Cc: stable@vger.kernel.org
Fixes: 9e794b6bf4 ("batman-adv: drop unicast packets from other backbone gw")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
Cc: stable@vger.kernel.org
Fixes: b61ec31c85 ("batman-adv: Snoop DHCPACKs for DAT")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
Cc: stable@vger.kernel.org
Fixes: 6c413b1c22 ("batman-adv: send every DHCP packet as bat-unicast")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
This was done correctly for the ethernet header but missed for the
unicast_packet pointer.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: c018ad3de6 ("batman-adv: add the VLAN ID attribute to the TT entry")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
pskb_may_pull() in batadv_interface_rx() could reallocate the buffer behind
the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
This was done correctly for the VLAN header but missed for the ethernet
header which is later used for the TT and AP isolation handling.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Fixes: c78296665c ("batman-adv: Check skb size before using encapsulated ETH+VLAN header")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
TVLV handlers can have the flag BATADV_TVLV_HANDLER_OGM_CIFNOTFND set to
signal that the OGM handler should be called (with NULL for data) when the
specific TVLV container was not found in the OGM. This is used by:
* DAT
* GW
* Multicast (OGM + Tracker)
The state whether the handler was executed was stored in the struct
batadv_tvlv_handler. But the TVLV processing is started without any lock.
Multiple parallel contexts processing TVLVs would therefore overwrite each
others BATADV_TVLV_HANDLER_OGM_CALLED flag in the shared
batadv_tvlv_handler.
Drop the shared BATADV_TVLV_HANDLER_OGM_CALLED flag and instead determine,
per TVLV buffer, whether a matching container was present by scanning the
packet's buffer.
Cc: stable@kernel.org
Fixes: ef26157747 ("batman-adv: tvlv - basic infrastructure")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The fields of an aggregated OGM(v2) are accessed assuming (at least) 2-byte
alignment, so a following OGM must start at an even offset. As the header
length is even, an odd tvlv_len would misalign it and trigger unaligned
accesses on strict-alignment architectures.
Such a misaligned TVLV/OGM/OGMv2 is not created by a normal participant in
the mesh. Therefore, reject such malformed packets.
Cc: stable@kernel.org
Fixes: ef26157747 ("batman-adv: tvlv - basic infrastructure")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The local hash of DAT entries is supposed to be VLAN (VID) aware. But
the adding to the hash and the search in the hash were not checking the VID
information of the hash entries. The entries would therefore only be
correctly separated when batadv_hash_dat() didn't select the same buckets
for different VIDs.
Cc: stable@kernel.org
Fixes: be1db4f661 ("batman-adv: make the Distributed ARP Table vlan aware")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tt_check_roam_count() is supposed to track roaming of a TT entry.
But TT entries are for a MAC + VID. The VID was completely missed and thus
leads to incorrect detection of ROAM counts when a client MAC exists in
multiple VLANs.
Cc: stable@kernel.org
Fixes: c018ad3de6 ("batman-adv: add the VLAN ID attribute to the TT entry")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tt_local_event() merges/cancels events for the same client which
would conflict or be duplicates. The matching of the queued events only
compares the MAC address - the VLAN ID stored in each event is ignored.
If a MAC would now appear on multiple VID, the two ADD change events (for
VID 1 and VID 2) would be merged to a single vid event. The remote can
therefore not calculate the correct TT table and desync. A full translation
table exchange is required to recover from this state.
A check of VID is therefore necessary to avoid such wrong merges/cancels.
Cc: stable@kernel.org
Fixes: c018ad3de6 ("batman-adv: add the VLAN ID attribute to the TT entry")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
If the size of the packets would change during the transmission, it could
happen that some retries of packets are overlapping. In this case, precise
comparisons of sequence numbers by the receiver would be wrong. It is then
necessary to check if the start sequence number to the end sequence number
("seqno + length") would contain a new range.
If this is the case then this is enough to accept this packet. In all other
cases, the packet still has to be dropped (and not acked).
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When last_recv is updated to store the last receive sequence number, it is
assuming that nothing is modifying in parallel while:
* check for outdated packets is done
* out of order check is performed (and packets are stored in out-of-order
queue)
* the out-of-order queue was searched for closed gaps
* sequence number for next ack is calculated
Nothing of that was actually protected. It could therefore happen that the
last_recv was updated multiple times in parallel and the final sequence
number was calculated with deltas which had no connection to the sequence
number they were added to.
Lock this whole region with the same lock which was already used to protect
the unacked (out-of-order) list.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The last_recv_time field for batadv_tp_receiver tracks the jiffies value of
the most recent activity and is used to detect timeouts. These accesses are
not consistently protected by a lock, so READ_ONCE/WRITE_ONCE must be used
to prevent data races caused by compiler optimizations.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When the unacked_list is unbound, an attacker could send messages with
small lengths and appropriated seqno + gaps to force the receiver to
allocate more and more unacked_list entries. And the end either causing an
out-of-memory situation or increase the management overhead for the (large)
list that significant portions of CPU cycles are wasted in searching
through the list.
When limiting the list to a specific number, it is important to still
correctly add a new entry to the list. But if the list became larger than
the limit, the last entry of the list (with the highest seqno) must be
dropped to still allow the earlier seqnos to finish and therefore to
continue the process. Otherwise, the process might get stuck with too high
seqnos which are not handled by batadv_tp_ack_unordered().
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When an interface gets disabled, the worker is correctly disabled by
batadv_hardif_disable_interface() -> ... -> batadv_v_ogm_iface_disable().
In this process, the skb aggr_list is also freed.
But batadv_v_ogm_send_meshif() can still queue new skbs (via
batadv_v_ogm_queue_on_if()) to the aggr_list. This will only stop after all
cores can no longer find the RCU protected list of hard interfaces. These
queued skbs will never be freed or consumed by batadv_v_ogm_aggr_work.
The batadv_v_ogm_iface_disable() function must block
batadv_v_ogm_queue_on_if() to avoid leak of skbs.
Cc: stable@kernel.org
Fixes: f89255a02f ("batman-adv: BATMAN_V: introduce per hard-iface OGMv2 queues")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Packets with a TTL are using it to limit the amount of time this packet can
be forwarded. But for batadv_frag_packet, the TTL was always only reduced
but it was never evaluated. It could even underflow without any effect.
Check the TTL in batadv_frag_skb_fwd() before attempting to prepare it for
forwarding. This keeps it in sync with the not fragmented unicast packet.
Cc: stable@kernel.org
Fixes: 610bfc6bc9 ("batman-adv: Receive fragmented packets and merge")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Before batman-adv is allowed to write to an skb, it either has to have its
own copy of the skb or use skb_cow() to ensure that the data part is not
shared. But batadv_frag_skb_fwd() modifies the TTL even when it is shared.
Adding a skb_cow() right before this operation avoids this and can at the
same time prepare it for the modifications required to forward the
fragment.
Cc: stable@kernel.org
Fixes: 610bfc6bc9 ("batman-adv: Receive fragmented packets and merge")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The broadcast and multicast packets can be received at the same time by the
local system and forwarded to other nodes. Both are simply decrementing the
TTL at the beginning of the receive path - independent of chosen paths
(receive/forward). But such a modification of the data conflicts with the
hw csum. This is not a problem when the packet is directly forwarded but
can cause errors in the local receive path.
Such a problem can then trigger a "hw csum failure". The receiver path must
therefore ensure that the csum is fixed for each modification of the
payload before batadv_interface_rx() is reached.
Since all batman-adv packet types with a ttl have it as u8 at offset 2, a
helper can be used for all of them. But it is only used at the moment for
batadv_bcast_packet and batadv_mcast_packet because they are the only ones
which deliver the packet locally but unconditionally modify the TTL.
Cc: stable@kernel.org
Fixes: 3f69339068 ("batman-adv: bcast: queue per interface, if needed")
Fixes: 07afe1ba28 ("batman-adv: mcast: implement multicast packet reception and forwarding")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Before batman-adv is allowed to write to an skb, it either has to have its
own copy of the skb or used skb_cow() to ensure that the data part is not
shared.
The old implementation used a shared queue and created copies before
attempting to write to it. But with the new implementation, the broadcast
packet is already modified when it gets received. Potentially writing to
shared buffers in this process.
Adding a skb_cow() right before this operation avoids this and can at the
same time prepare it for the modifications required to rebroadcast the
packet.
Cc: stable@kernel.org
Fixes: 3f69339068 ("batman-adv: bcast: queue per interface, if needed")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The batadv_hardif_cnt() was previously checking if there is an
batadv_hard_iface->mesh_iface which is has the same mesh_iface. And since
batadv_hardif_disable_interface() was resetting the
batadv_hard_iface->mesh_iface after this check, it had to verify whether
*1* interface was still part of the mesh_iface before it started the
gateway deselection.
But after batadv_hardif_cnt() is now checking the lower interfaces of
mesh_iface and batadv_hardif_disable_interface() already removed the
interface via netdev_upper_dev_unlink() earlier in this function, the check
must now make sure that *0* interfaces can be found by batadv_hardif_cnt()
before selected gateway must be deselected. Otherwise the deselection would
already happen one batadv_hard_iface too early.
Because a 0 hardif count from batadv_hardif_cnt() is equal to an empty
list, it is possible to replace the counting with a simple list_empty().
Cc: stable@kernel.org
Fixes: 7dc284702b ("batman-adv: store hard_iface as iflink private data")
Reviewed-by: Nora Schiffer <neocturne@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Various minor errors were gathered over the time in batman-adv's kernel-doc
comments. Get rid of many of them before they are copied (again) to new
functions.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
All receive handlers in batman-adv are consuming the skbuff independent of
the result of the handler. The "(without freeing the skb) on failure" is
therefore not corrrect anymore for the current implementation.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The bridge-loop-avoidance code was changed recently to avoid inconsistent
state and race condition problems. The kernel-doc addded in these commits
(and related code) has various minor deficits which are now resolved.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The tp_meter codebase was recently refactored:
* throughput meter sender and receiver variables were split into
two different structures
* the congestion control variables were extracted in a separate structure
But the kernel-doc was not updated everywhere to reflect these changes.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The original kernel documentation for the batadv_wifi_* functions contained
copy+paste errors. Correct them to make it easier understandable.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
It doesn't seem to be obvious how the entries from the
batadv_wifi_net_devices rhashtable are getting removed before the actual
rhashtable is destroyed. Document the idea behind the process and which
steps are involved.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The batadv_wifi_net_device_insert() is called with ASSERT_RTNL() held, but
not inside a spinlock or another context which prevents "might_sleep"
functions. To relax the requirements for the allocator, use GFP_KERNEL.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
During the initialization of the batadv_wifi_net_device_state, it is enough
to write the wifi_flags once before the batadv_wifi_net_device_state is
added to the batadv_wifi_net_devices rhashtable.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
With commit 86898fa6b8 ("workqueue: Implement disable/enable for
(delayed) work items"), work queues gained the ability to permanently
disallow re-queuing of work items. This is particularly important during
object teardown, where a work item must not be re-armed after shutdown
begins.
Convert all cancel_work_sync() and cancel_delayed_work_sync() call sites to
their disable_* equivalents to clarify the intent to prevent re-arming
after teardown.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The last_recv_time is the most important indicator for a receiver session
to figure out whether a session timed out or not. But this information was
only initialized after the session was added to the tp_receiver_list and
after the timer was started.
In the worst case, the timer (function) could have tried to access this
information before the actual initialization was reached. Like rest of the
variables of the tp_meter receiver session, this field has to be filled out
before any other (parallel running) context has the chance to access it.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tt_local_add() tries to retrieve the wifi flags of an interface to
mark the TT entry as wifi client for the AP isolation feature. In the past,
it was necessary to look up the batadv_hard_iface because the wifi_flags
were stored inside this struct. But with the batadv_wifi_net_devices
rhashtable, it is preferred to directly retrieve the wifi_flags instead of
the indirect route via batadv_hard_iface - which at the end only provides
the net_device (which we used to find the batadv_hard_iface).
This will also be essential when the global batadv_hardif_list is removed
and each lookup via batadv_hardif_get_by_netdev() will require the RTNL
lock.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The batadv_tt_prepare_tvlv_local_data() and
batadv_tt_prepare_tvlv_global_data() functions are supposed to work the
same - just with different sources for the TT entries. But both handled the
return values completely different. The global variant only made sure that
the *tt_len parameter was set to 0 and didn't care about the actual return
value of the function.
The local function never made sure that the *tt_len value was set to some
value when the operation failed. The callers were handling these
differences and made sure that they didn't access the incorrectly
initialized variable.
Sync both function as good as possible to avoid problems with new code
which might not be aware of these differences in the behavior.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_v_elp_start_timer() enqeues a delayed work. The time when it starts
is randomly chosen between (elp_interval - BATADV_JITTER) and
(elp_interval + BATADV_JITTER). The configured elp_interval must therefore
be larger or equal to BATADV_JITTER to avoid that it causes an underflow of
the unsigned integer. If this would happen, then a "fast" ELP interval
would turn into a "day long" delay.
At the same time, it must not be larger than the maximum value the variable
can store.
Cc: stable@kernel.org
Fixes: a108008290 ("batman-adv: Add elp_interval hardif genl configuration")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The lasttime field for claim, backbone_gw, and loopdetect tracks the
jiffies value of the most recent activity and is used to detect timeouts.
These accesses are not consistently protected by a lock, so
READ_ONCE/WRITE_ONCE must be used to prevent data races caused by compiler
optimizations.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Congestion control variables in batadv_tp_sender were scattered across the
struct without clear grouping, making it difficult to reason about which
fields require cwnd_lock (now "cc_lock") protection. These should be
combined in a structure to make it more easily visible which variable
should be read/modified with the cc_lock held.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Some variables used atomic_t for concurrent access while others relied on
cwnd_lock, leading to an inconsistent locking model. This can be simplified
by:
* keeping all congestion control decisions inside the cc_lock
* variables which can be accessed without a lock must use
READ_ONCE/WRITE_ONE
This is only possible, by extracting the congestion control logic from
batadv_tp_recv_ack() into a new helper batadv_tp_handle_ack(). Its
decisions are returned as a batadv_tp_ack_reaction enum value and then
applied by the caller. This separates the algorithm (deciding what to do)
from the mechanism (actually doing it).
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The monolithic batadv_tp_vars struct holds fields for both sender and
receiver roles, distinguished only by a runtime enum role. This makes it
easy to accidentally access a field intended for the opposite role, since
neither the compiler nor the type system provide any guard against such
mistakes. The role check also adds unnecessary branching in several code
paths.
Introduce batadv_tp_vars_common to hold fields shared across both roles,
then derive two separate types (sender/receiver) from it. The functions can
operate on them without any ambiguity about the available fields. This also
reduces the memory footprint of receiver sessions, which no longer carry
the substantial sender-only fields.
Care must be taken to prevent concurrent TP sessions between the same two
peers in opposite directions, since sender and receiver sessions are now
tracked in separate lists and a lookup in one list no longer detects a
session in the other.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When the receiver variables (aka "session") are initialized, then they are
added to the list of sessions before the timer is set up. A RCU protected
reader could therefore find the entry and run mod_setup before
batadv_tp_init_recv() finished the timer initialization.
The same is true for batadv_tp_start(), which must first initialize the
finish_work and the test_length to avoid a similar problem.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The recover variable and the last_sent sequence number are initialized on
purpose as a really high value which will wrap-around after the first 2000
bytes. The fast recovery precondition must therefore not use simple integer
comparisons but use helpers which are aware of the sequence number
wrap-arounds.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The fast recovery precondition checks if the recover (initialized to
BATADV_TP_FIRST_SEQ) is bigger than the received ack. But since recover is
only updated when this check is successful, it will never enter the fast
recovery mode.
According to RFC6582 Section 3.2 step 2, the check should actually be
different:
> When the third duplicate ACK is received, the TCP sender first
> checks the value of recover to see if the Cumulative
> Acknowledgment field covers more than recover
The precondition must therefore check if recover is smaller than the
received ack - basically swapping the operands of the current check.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
