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>
The cwnd is always MSS <= cwnd <= 0x20000000. But the calculation in
batadv_tp_update_cwnd() assumes unsigned 32 bit arithmetics.
((mss * 8) ** 2) / (cwnd * 8)
In case cwnd is actually 0x20000000, it will be shifted by 3 bit to the
left end up at 0x100000000 or U32_MAX + 1. It will therefore wrap around
and be 0 - resulting in:
((mss * 8) ** 2) / 0
This is of course invalid and cannot be calculated. The calculation should
must be simplified to avoid this overflow:
(mss ** 2) * 8 / cwnd
It will keep the precision enhancement from the scaling (by 8) but avoid
the overflow in the divisor.
In theory, there could still be an overflow in the dividend. It is at the
moment fixed to BATADV_TP_PLEN in batadv_tp_recv_ack() - so it is not an
imminent problem. But allowing it to use the whole u32 bit range, would
mean that it can still use up to 67 bits. To keep this calculation safe for
32 bit arithmetic, mss must never use more than floor((32 - 3) / 2) bits -
or in other words: must never be larger than 16383.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
In batadv_tp_avail(), win_left is calculated with 32-bit unsigned
arithmetic: win_left = win_limit - tp_vars->last_sent;
During Fast Recovery, cwnd is inflated and last_sent advances rapidly. When
Fast Recovery ends, cwnd drops abruptly back to ss_threshold. If the newly
shrunk win_limit is less than last_sent, the unsigned subtraction will
underflow, wrapping to a massive positive value. Instead of returning that
the window is full (unavailable), it returns that the sender can continue
sending.
To handle this situation, it must be checked whether the windows end
sequence number (win_limit) has to be compared with the last sent sequence
number. If it would be before the last sent sequence number, then more acks
are needed before the transmission can be started again.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_tp_update_cwnd() is called, dec_cwnd is increased. But dec_cwnd
is only initialixed (to 0) when a duplicate Ack was received or when cwnd
is below the ss_threshold.
Just initialize the cwnd during the initialization to avoid any potential
access of uninitialized data.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When an ack with a sequence number equal to the last_acked is received, the
dup_acks counter is increased to decide whether fast retransmit should be
performed. Only when the sequence numbers are not equal, the dup_acks is
set to the initial value (0).
But if the initial packet would have the sequence number
BATADV_TP_FIRST_SEQ, dup_acks would not be initialized and atomic_inc would
operate on an undefined starting value. It is therefore required to have it
explicitly initialized during the start of the sender session.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_tp_handle_out_of_order inserts a new entry in the list of
unacked (out of order) packets, it searches from the entry with the newest
sequence number towards oldest sequence number. If an entry is found which
is older than the newly entry, the new entry has to be added after the
found one to keep the ascending order.
But for this operation list_add_tail() was used. But this function adds an
entry _before_ another one. As result, the list would contain a lot of
swapped sequence numbers. The consumer of this list
(batadv_tp_ack_unordered()) would then fail to correctly ack packets.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The orig_node member of struct batadv_neigh_node is no longer used in
B.A.T.M.A.N. IV. But batadv_neigh_node_create() is still storing it.
Only batadv_v_ogm_route_update() uses it to check if we route toward
it - not needing the data stored in the batadv_orig_node object itself,
but merely a pointer to identify the originator.
The field cannot hold a proper reference because that would create a
reference cycle, so it must never be dereferenced. Rename it to
orig_node_id and mark it __private to make any future attempt to
dereference it immediately noticeable.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Both OGMv1 (on the primary interface) and OGM2 unconditionally reallocated
their packet buffer on every transmission cycle, regardless of whether the
required size had changed. This meant a kfree/kmalloc pair even when the
TVLV payload size was identical to the previous send.
Introduce struct batadv_ogm_buf to encapsulate the OGM packet buffer
together with its current length, allocated capacity, and fixed header
length. This consolidates the separate buf/len arguments that were
previously threaded through each call site.
In batadv_tvlv_realloc_packet_buff(), the capacity is rounded up to the
next power of two so that small growth or shrinkage in TVLV data does not
trigger a reallocation. When kmalloc fails but the existing buffer is large
enough to hold the new data, the oversized buffer is reused rather than
returning an error.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The commit 6043a632dd06 ("batman-adv: reject oversized global TT response
buffers") introduced an open-coded check to ensure that the allocated
buffer size can be stored in a u16. The check_add_overflow() helper can
perform the addition and overflow check in one step, so use that instead.
Acked-by: Antonio Quartulli <antonio@mandelbit.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The last TT version number of an meshif is only accessed as plain
loads/stores and does not require full atomic_t semantics. Convert to an
native integer and replace its users with READ_ONCE()/WRITE_ONCE() to avoid
load/store tearing.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The maximum packet size of an meshif is only accessed as plain loads/stores
and does not require full atomic_t semantics. Convert to a native integer
and replace its users with READ_ONCE()/WRITE_ONCE() to avoid load/store
tearing.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The mesh state is only accessed as plain loads/stores and does not require
full atomic_t semantics. Convert to an enum and replace its users with
READ_ONCE()/WRITE_ONCE() to avoid load/store tearing.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The vlan configuration values are only accessed as plain loads/stores and
do not require full atomic_t semantics. Convert these fields to native
integer types and replace their users with READ_ONCE()/WRITE_ONCE() to
avoid load/store tearing.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The hardif configuration values are only accessed as plain loads/stores and
do not require full atomic_t semantics. Convert these fields to native
integer types and replace their users with READ_ONCE()/WRITE_ONCE() to
avoid load/store tearing.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The meshif configuration values are only accessed as plain loads/stores and
do not require full atomic_t semantics. Convert these fields to native
integer types and replace their users with READ_ONCE()/WRITE_ONCE() to
avoid load/store tearing.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Previously, wifi_flags were stored directly in batadv_hard_iface, which is
created for every network interface on the system (including those never
attached to a mesh interface). This wastes memory and complicates the
long-term goal of lazily allocating batadv_hard_iface only for interfaces
that actually join a mesh.
The problem is that several batman-adv features need wifi detection for
net_devices (and their underlying devices) regardless of whether a
batadv_hard_iface exists for them:
* B.A.T.M.A.N. IV TQ hop penalty calculation
* B.A.T.M.A.N. V ELP probing / throughput estimation
* AP isolation
To decouple wifi detection from batadv_hard_iface lifetime, introduce a
global rhashtable (batadv_wifi_net_devices) mapping net_device pointers to
batadv_wifi_net_device_state objects. Only net_devices that are actually
detected as (indirect) wifi interfaces occupy an entry, keeping the common
(non-wifi) case allocation-free.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_gw_election() only needs to test whether gw.reselect was set and
clear it afterwards. Replace the batadv_atomic_dec_not_zero()
[atomic_add_unless(..., -1, 0)] call with atomic_xchg(..., 0) to simplify
the logic and make the intent more explicit.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Some of the recent fixes required features from new header files. There is
currently no build problem because transitive includes take care of it. But
the batman-adv source code tries to avoid the dependency to
transitive/implicite includes because it has no control over them and they
might get removed at some point.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Bumping the version number on the first pull request after each merge
window was deemed inappropriate for an in-tree component. The version
number carries little meaningful information in the context of the Linux
kernel release model, where stable and distribution might all carry
slightly different patches (without any change to the batman-adv version).
Instead, expose a UTS_RELEASE-based string to consumers of the netlink and
ethtool interfaces. To avoid recompilation for each (re)generate of
generated/utsrelease.h, init_utsname()->release is used in code which can
dynamically retrieve the version string. The MODULE_VERSION is moved to a
separate file because it doesn't support dynamic retrieval of the version
string (but constant "at compile time" string) and it is required for the
/sys/module/batman_adv/version. The latter is unfortunately still required
by userspace tools.
Link: https://lore.kernel.org/r/20210203163302.13e8a2a7@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com
Link: https://lore.kernel.org/r/YnfjtpuAaH+Zkf9S@unreal
Link: https://lore.kernel.org/r/Y9faTA0rNSXg%2FsLD@nanopsycho
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Without rtnl_lock held, a hardif might be retrieved as primary interface of
a meshif, but then (while operating on this interface) getting decoupled
from the mesh interface. In this case, the meshif still exists but the
pointer from the primary hardif to the meshif is set to NULL.
The mesh_iface must be checked first to be non-NULL before continuing to
send an ARP request using meshif.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Reported-by: Ido Schimmel <idosch@nvidia.com>
Reported-by: syzbot+9fdcc9f05a98a540b816@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9fdcc9f05a98a540b816
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The bla.num_requests is increased when no request_sent was in progress. And
it is decremented in various places (announcement was received, backbone is
purged, periodic work). But the check if the request_sent is actually set
to a specific state and the atomic_dec/_inc are not safe because they are
not atomic (TOCTOU) and multiple such code portions can run concurrently.
At the same time, it is necessary to modify request_sent (state) and
bla.num_requests atomically. Otherwise batadv_bla_send_request() might set
request_sent to 1 and is interrupted. batadv_handle_announce() can then
set request_sent back to 0 and decrement num_requests before
batadv_bla_send_request() incremented it.
The two operations must therefore be locked. And since state (request_sent)
and wait_periods are only accessed inside this lock, they can be converted
to simpler datatypes. And to avoid that the bla.num_requests is touched by
a parallel running context with a valid backbone_gw reference after
batadv_bla_purge_backbone_gw() ran, a third state "stopped" is required to
correctly signal that a backbone_gw is in the state of being cleaned up.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
but fails to properly handle their associated report_work:
- If report_work is running, the purge must wait for it to finish before
freeing the backbone_gw, otherwise the worker may access freed memory
(e.g. bat_priv).
- If report_work is pending, the purge must cancel it and release the
reference held for that pending work item.
The previous implementation called hlist_for_each_entry_safe() inside a
spin_lock_bh() section, but cancel_work_sync() may sleep and therefore
cannot be called from within a spinlock-protected region.
Restructure the loop to handle one entry per spinlock critical section:
acquire the lock, find the next entry to purge, remove it from the hash
list, then release the lock before calling cancel_work_sync() and
dropping the hash_entry reference. Repeat until no more entries require
purging.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Reviewed-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_iv_ogm_schedule_buff() fails to allocate and queue a forward
packet for OGM transmission, the work item that drives periodic OGM
scheduling is never re-armed. This silently halts transmission of the
node's own OGMs on the affected interface — only OGMs from other peers
continue to be aggregated and forwarded.
Fix this by tracking whether batadv_iv_ogm_queue_add() (and transitively
batadv_iv_ogm_aggregate_new()) successfully scheduled a forward packet.
When scheduling fails, batadv_iv_ogm_schedule_buff() falls back to queuing
a dedicated recovery work item (reschedule_work) that fires after one
originator interval and calls batadv_iv_ogm_schedule() again.
Cc: stable@kernel.org
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_mcast_purge_orig() removes entries from RCU-protected hlists but
does not wait for an RCU grace period before returning. Concurrent RCU
readers may still accesses references to those entries at the point of
removal. RCU-protected readers trying to operate on entries like
orig->mcast_want_all_ipv6_node will then access already freed memory.
Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(),
just before the call_rcu() invocation. This ensures RCU readers that were
active at purge time have drained before the orig_node memory is reclaimed.
Cc: stable@kernel.org
Fixes: ab49886e3d ("batman-adv: Add IPv4 link-local/IPv6-ll-all-nodes multicast support")
Acked-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Session lookups in tp_list matched only on destination address (and
optionally session ID), leaving role validation to the caller. If two
sessions with the same other_end coexisted (one as sender, one as receiver)
a lookup could silently return the wrong one, causing the caller's role to
bail out early, potentially skipping necessary cleanup.
Move the role check into the lookup functions themselves so the correct
entry is always returned, or none at all. Since batadv_tp_start()
legitimately needs to detect any active session to a destination regardless
of role, introduce a dedicated helper for that case rather than bending the
existing lookup semantics.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tp_sender_shutdown() previously used two separate variables to track
session state: sending (an atomic flag indicating whether the session was
active) and reason (a plain enum storing the stop reason). This introduced
a race window between the two writes: after sending was cleared to 0,
batadv_tp_send() could observe the stopped state and call
batadv_tp_sender_end() before reason was written, causing the wrong stop
reason to be reported to the caller.
Fix this by consolidating both variables into a single atomic send_result,
which holds 0 while the session is running and the stop reason once it
ends.
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tvlv_container_ogm_append() builds a TVLV packet section from
the tvlv.container_list. The total size of this section is computed by
batadv_tvlv_container_list_size(), which sums the sizes of all registered
containers.
The return type and accumulator in batadv_tvlv_container_list_size() were
u16. If the accumulated size exceeds U16_MAX, the value wraps around,
causing the subsequent allocation in batadv_tvlv_container_ogm_append()
to be undersized. The memcpy-style copy that follows would then write
beyond the end of the allocated buffer, corrupting kernel memory.
Fix this by widening the return type of batadv_tvlv_container_list_size()
to size_t. In batadv_tvlv_container_ogm_append(), check the computed length
against U16_MAX before proceeding, and bail out as if the allocation had
failed when the limit is exceeded.
Cc: stable@kernel.org
Fixes: ef26157747 ("batman-adv: tvlv - basic infrastructure")
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Reviewed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tvlv_container_ogm_append() could fail in two ways: a memory
allocation failure when resizing the packet buffer, or the tvlv data
exceeding U16_MAX bytes. In both cases the function previously returned the
old (now stale) tvlv_value_len rather than signalling an error, causing the
OGM/OGM2 send path to transmit a packet whose TVLV length field no longer
matched the actual buffer contents. And because it also didn't fill in the
new TVLV data, sending either uninitialized or corrupted data on the wire.
All errors in batadv_tvlv_container_ogm_append() must be forwarded to the
caller. And the caller must abort the send of the OGM2. For B.A.T.M.A.N.
IV, it is currently not allowed to abort the send. The non-TVLV part of the
OGM must be queued up instead.
Cc: stable@kernel.org
Fixes: ef26157747 ("batman-adv: tvlv - basic infrastructure")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When a batadv_hard_iface is disabled, its mesh_iface pointer is set to
NULL. However, batadv_v_ogm_send_meshif() may still dispatch OGMs via
batadv_v_ogm_queue_on_if() for interfaces that have since lost their
mesh_iface association. This results in a NULL pointer dereference when
batadv_v_ogm_queue_on_if() unconditionally calls netdev_priv() on the
now NULL hard_iface->mesh_iface to retrieve the batadv_priv.
It is necessary to ensure that the batadv_v_ogm_queue_on_if() checks that
it is using the same mesh_iface for which batadv_v_ogm_send_meshif() was
called.
Cc: stable@kernel.org
Fixes: 0da0035942 ("batman-adv: OGMv2 - add basic infrastructure")
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Reviewed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The kernel-doc comment for batadv_skb_is_frag() contained two errors:
* the function description referred to "gain a unicast packet" instead
of "contains unicast fragment".
* the Return section omitted "merged" from "newly skb", leaving the
description grammatically incorrect and inconsistent with the
function description.
Fixes: bc62216dc8 ("batman-adv: frag: disallow unicast fragment in fragment")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_tp_sender_cleanup() was calling timer_delete_sync() followed by
timer_delete() to guard against the timer handler re-arming itself between
the two calls. This double-deletion hack relied on the sending status being
set to 0 to suppress re-arming.
Replace both calls with a single timer_shutdown_sync(). This function both
waits for any running timer callback to complete (like timer_delete_sync())
and permanently disarms the timer so it cannot be re-armed afterwards,
making re-arming prevention unconditional and self-documenting.
The re-arming property is also required because otherwise:
1. context 0 (batadv_tp_recv_ack()) checks in
batadv_tp_reset_sender_timer() if sending is still 1 -> it is
2. context 1 changes in batadv_tp_sender_shutdown() sending to 0 and in
this process forces the kthread to stop timer in
batadv_tp_sender_cleanup()
3. context 0 continues in batadv_tp_reset_sender_timer() and rearms the
timer -> but the reference for it is already gone
Cc: stable@kernel.org
Fixes: 33a3bb4a33 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Sven Eckelmann