can: isotp: support dynamic flow control parameters

The ISO15765-2 standard supports to take the PDUs communication parameters
blocksize (BS) and Separation Time minimum (STmin) either from the firs

can: isotp: support dynamic flow control parameters

The ISO15765-2 standard supports to take the PDUs communication parameters
blocksize (BS) and Separation Time minimum (STmin) either from the first
received flow control (FC) "static" or from every received FC "dynamic".

Add a new CAN_ISOTP_DYN_FC_PARMS flag to support dynamic FC parameters.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20231208165729.3011-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: isotp_sendmsg(): fix TX state detection and wait behavior

With patch [1], isotp_poll was updated to also queue the poller in the
so->wait queue, which is used for send state changes. Sin

can: isotp: isotp_sendmsg(): fix TX state detection and wait behavior

With patch [1], isotp_poll was updated to also queue the poller in the
so->wait queue, which is used for send state changes. Since the queue
now also contains polling tasks that are not interested in sending, the
queue fill state can no longer be used as an indication of send
readiness. As a consequence, nonblocking writes can lead to a race and
lock-up of the socket if there is a second task polling the socket in
parallel.

With this patch, isotp_sendmsg does not consult wq_has_sleepers but
instead tries to atomically set so->tx.state and waits on so->wait if it
is unable to do so. This behavior is in alignment with isotp_poll, which
also checks so->tx.state to determine send readiness.

V2:
- Revert direct exit to goto err_event_drop

[1] https://lore.kernel.org/all/20230331125511.372783-1-michal.sojka@cvut.cz

Reported-by: Maxime Jayat <maxime.jayat@mobile-devices.fr>
Closes: https://lore.kernel.org/linux-can/11328958-453f-447f-9af8-3b5824dfb041@munic.io/
Signed-off-by: Lukas Magel <lukas.magel@posteo.net>
Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: 79e19fa79cb5 ("can: isotp: isotp_ops: fix poll() to not report false EPOLLOUT events")
Link: https://github.com/pylessard/python-udsoncan/issues/178#issuecomment-1743786590
Link: https://lore.kernel.org/all/20230827092205.7908-1-lukas.magel@posteo.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: fix support for transmission of SF without flow control

The original implementation had a very simple handling for single frame
transmissions as it just sent the single frame without a t

can: isotp: fix support for transmission of SF without flow control

The original implementation had a very simple handling for single frame
transmissions as it just sent the single frame without a timeout handling.

With the new echo frame handling the echo frame was also introduced for
single frames but the former exception ('simple without timers') has been
maintained by accident. This leads to a 1 second timeout when closing the
socket and to an -ECOMM error when CAN_ISOTP_WAIT_TX_DONE is selected.

As the echo handling is always active (also for single frames) remove the
wrong extra condition for single frames.

Fixes: 9f39d36530e5 ("can: isotp: add support for transmission without flow control")
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20230821144547.6658-2-socketcan@hartkopp.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)

Remove ->sendpage() and ->sendpage_locked(). sendmsg() with
MSG_SPLICE_PAGES should be used instead. This allows multiple pages an

sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)

Remove ->sendpage() and ->sendpage_locked(). sendmsg() with
MSG_SPLICE_PAGES should be used instead. This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

can: isotp: isotp_sendmsg(): fix return error fix on TX path

With commit d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return
error on FC timeout on TX path") the missing correct return value in
t

can: isotp: isotp_sendmsg(): fix return error fix on TX path

With commit d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return
error on FC timeout on TX path") the missing correct return value in
the case of a protocol error was introduced.

But the way the error value has been read and sent to the user space
does not follow the common scheme to clear the error after reading
which is provided by the sock_error() function. This leads to an error
report at the following write() attempt although everything should be
working.

Fixes: d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return error on FC timeout on TX path")
Reported-by: Carsten Schmidt <carsten.schmidt-achim@t-online.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230607072708.38809-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag

The control message provided by isotp support MSG_CMSG_COMPAT but
blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user
space on 64

can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag

The control message provided by isotp support MSG_CMSG_COMPAT but
blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user
space on 64 bit kernels.

Link: https://github.com/hartkopp/can-isotp/issues/59
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when reading from socket")
Link: https://lore.kernel.org/20230505110308.81087-2-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: fix race between isotp_sendsmg() and isotp_release()

As discussed with Dae R. Jeong and Hillf Danton here [1] the sendmsg()
function in isotp.c might get into a race condition when resto

can: isotp: fix race between isotp_sendsmg() and isotp_release()

As discussed with Dae R. Jeong and Hillf Danton here [1] the sendmsg()
function in isotp.c might get into a race condition when restoring the
former tx.state from the old_state.

Remove the old_state concept and implement proper locking for the
ISOTP_IDLE transitions in isotp_sendmsg(), inspired by a
simplification idea from Hillf Danton.

Introduce a new tx.state ISOTP_SHUTDOWN and use the same locking
mechanism from isotp_release() which resolves a potential race between
isotp_sendsmg() and isotp_release().

[1] https://lore.kernel.org/linux-can/ZB%2F93xJxq%2FBUqAgG@dragonet

v1: https://lore.kernel.org/all/20230331102114.15164-1-socketcan@hartkopp.net
v2: https://lore.kernel.org/all/20230331123600.3550-1-socketcan@hartkopp.net
take care of signal interrupts for wait_event_interruptible() in
isotp_release()
v3: https://lore.kernel.org/all/20230331130654.9886-1-socketcan@hartkopp.net
take care of signal interrupts for wait_event_interruptible() in
isotp_sendmsg() in the wait_tx_done case
v4: https://lore.kernel.org/all/20230331131935.21465-1-socketcan@hartkopp.net
take care of signal interrupts for wait_event_interruptible() in
isotp_sendmsg() in ALL cases

Cc: Dae R. Jeong <threeearcat@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: 4f027cba8216 ("can: isotp: split tx timer into transmission and timeout")
Link: https://lore.kernel.org/all/20230331131935.21465-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
[mkl: rephrase commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: isotp_ops: fix poll() to not report false EPOLLOUT events

When using select()/poll()/epoll() with a non-blocking ISOTP socket to
wait for when non-blocking write is possible, a false EPO

can: isotp: isotp_ops: fix poll() to not report false EPOLLOUT events

When using select()/poll()/epoll() with a non-blocking ISOTP socket to
wait for when non-blocking write is possible, a false EPOLLOUT event
is sometimes returned. This can happen at least after sending a
message which must be split to multiple CAN frames.

The reason is that isotp_sendmsg() returns -EAGAIN when tx.state is
not equal to ISOTP_IDLE and this behavior is not reflected in
datagram_poll(), which is used in isotp_ops.

This is fixed by introducing ISOTP-specific poll function, which
suppresses the EPOLLOUT events in that case.

v2: https://lore.kernel.org/all/20230302092812.320643-1-michal.sojka@cvut.cz
v1: https://lore.kernel.org/all/20230224010659.48420-1-michal.sojka@cvut.cz
https://lore.kernel.org/all/b53a04a2-ba1f-3858-84c1-d3eb3301ae15@hartkopp.net

Signed-off-by: Michal Sojka <michal.sojka@cvut.cz>
Reported-by: Jakub Jira <jirajak2@fel.cvut.cz>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20230331125511.372783-1-michal.sojka@cvut.cz
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: isotp_recvmsg(): use sock_recv_cmsgs() to get SOCK_RXQ_OVFL infos

isotp.c was still using sock_recv_timestamp() which does not provide
control messages to detect dropped PDUs in the rece

can: isotp: isotp_recvmsg(): use sock_recv_cmsgs() to get SOCK_RXQ_OVFL infos

isotp.c was still using sock_recv_timestamp() which does not provide
control messages to detect dropped PDUs in the receive path.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230330170248.62342-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: add module parameter for maximum pdu size

With ISO 15765-2:2016 the PDU size is not limited to 2^12 - 1 (4095)
bytes but can be represented as a 32 bit unsigned integer value which
allow

can: isotp: add module parameter for maximum pdu size

With ISO 15765-2:2016 the PDU size is not limited to 2^12 - 1 (4095)
bytes but can be represented as a 32 bit unsigned integer value which
allows 2^32 - 1 bytes (~4GB). The use-cases like automotive unified
diagnostic services (UDS) and flashing of ECUs still use the small
static buffers which are provided at socket creation time.

When a use-case requires to transfer PDUs up to 1025 kByte the maximum
PDU size can now be extended by setting the module parameter
max_pdu_size. The extended size buffers are only allocated on a
per-socket/connection base when needed at run-time.

changes since v2: https://lore.kernel.org/all/20230313172510.3851-1-socketcan@hartkopp.net
- use ARRAY_SIZE() to reference DEFAULT_MAX_PDU_SIZE only at one place

changes since v1: https://lore.kernel.org/all/20230311143446.3183-1-socketcan@hartkopp.net
- limit the minimum 'max_pdu_size' to 4095 to maintain the classic
behavior before ISO 15765-2:2016

Link: https://github.com/raspberrypi/linux/issues/5371
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230326115911.15094-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: check CAN address family in isotp_bind()

Add missing check to block non-AF_CAN binds.

Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instea

can: isotp: check CAN address family in isotp_bind()

Add missing check to block non-AF_CAN binds.

Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instead of AF_CAN (0x1D) in the address family
field:

bind$xdp(r2, &(0x7f0000000540)={0x2c, 0x0, r4, 0x0, r2}, 0x10)
^^^^
This has no funtional impact but the userspace should be notified about
the wrong address family field content.

Link: https://syzkaller.appspot.com/text?tag=CrashLog&x=11ff9d8c480000
Reported-by: syzbot+5aed6c3aaba661f5b917@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230104201844.13168-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: split tx timer into transmission and timeout

The timer for the transmission of isotp PDUs formerly had two functions:
1. send two consecutive frames with a given time gap
2. monitor the

can: isotp: split tx timer into transmission and timeout

The timer for the transmission of isotp PDUs formerly had two functions:
1. send two consecutive frames with a given time gap
2. monitor the timeouts for flow control frames and the echo frames

This led to larger txstate checks and potentially to a problem discovered
by syzbot which enabled the panic_on_warn feature while testing.

The former 'txtimer' function is split into 'txfrtimer' and 'txtimer'
to handle the two above functionalities with separate timer callbacks.

The two simplified timers now run in one-shot mode and make the state
transitions (especially with isotp_rcv_echo) better understandable.

Fixes: 866337865f37 ("can: isotp: fix tx state handling for echo tx processing")
Reported-by: syzbot+5aed6c3aaba661f5b917@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # >= v6.0
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230104145701.2422-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: handle wait_event_interruptible() return values

When wait_event_interruptible() has been interrupted by a signal the
tx.state value might not be ISOTP_IDLE. Force the state machines
into

can: isotp: handle wait_event_interruptible() return values

When wait_event_interruptible() has been interrupted by a signal the
tx.state value might not be ISOTP_IDLE. Force the state machines
into idle state to inhibit the timer handlers to continue working.

Fixes: 866337865f37 ("can: isotp: fix tx state handling for echo tx processing")
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230112192347.1944-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: fix tx state handling for echo tx processing

In commit 4b7fe92c0690 ("can: isotp: add local echo tx processing for
consecutive frames") the data flow for consecutive frames (CF) has been

can: isotp: fix tx state handling for echo tx processing

In commit 4b7fe92c0690 ("can: isotp: add local echo tx processing for
consecutive frames") the data flow for consecutive frames (CF) has been
reworked to improve the reliability of long data transfers.

This rework did not touch the transmission and the tx state changes of
single frame (SF) transfers which likely led to the WARN in the
isotp_tx_timer_handler() catching a wrong tx state. This patch makes use
of the improved frame processing for SF frames and sets the ISOTP_SENDING
state in isotp_sendmsg() within the cmpxchg() condition handling.

A review of the state machine and the timer handling additionally revealed
a missing echo timeout handling in the case of the burst mode in
isotp_rcv_echo() and removes a potential timer configuration uncertainty
in isotp_rcv_fc() when the receiver requests consecutive frames.

Fixes: 4b7fe92c0690 ("can: isotp: add local echo tx processing for consecutive frames")
Link: https://lore.kernel.org/linux-can/CAO4mrfe3dG7cMP1V5FLUkw7s+50c9vichigUMQwsxX4M=45QEw@mail.gmail.com/T/#u
Reported-by: Wei Chen <harperchen1110@gmail.com>
Cc: stable@vger.kernel.org # v6.0
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20221104142551.16924-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: skb: unify skb CAN frame identification helpers

Replace open coded checks for sk_buffs containing Classical CAN and
CAN FD frame structures as a preparation for CAN XL support.

With the added

can: skb: unify skb CAN frame identification helpers

Replace open coded checks for sk_buffs containing Classical CAN and
CAN FD frame structures as a preparation for CAN XL support.

With the added length check the unintended processing of CAN XL frames
having the CANXL_XLF bit set can be suppressed even when the skb->len
fits to non CAN XL frames.

The CAN_RAW socket needs a rework to use these helpers. Therefore the
use of these helpers is postponed to the CAN_RAW CAN XL integration.

The J1939 protocol gets a check for Classical CAN frames too.

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: isotp_bind(): do not validate unused address information

With commit 2aa39889c463 ("can: isotp: isotp_bind(): return -EINVAL on
incorrect CAN ID formatting") the bind() syscall returns -

can: isotp: isotp_bind(): do not validate unused address information

With commit 2aa39889c463 ("can: isotp: isotp_bind(): return -EINVAL on
incorrect CAN ID formatting") the bind() syscall returns -EINVAL when
the given CAN ID needed to be sanitized. But in the case of an unconfirmed
broadcast mode the rx CAN ID is not needed and may be uninitialized from
the caller - which is ok.

This patch makes sure the result of an inproper CAN ID format is only
provided when the address information is needed.

Link: https://lore.kernel.org/all/20220517145653.2556-1-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: isotp_bind(): return -EINVAL on incorrect CAN ID formatting

Commit 3ea566422cbd ("can: isotp: sanitize CAN ID checks in
isotp_bind()") checks the given CAN ID address information by
sani

can: isotp: isotp_bind(): return -EINVAL on incorrect CAN ID formatting

Commit 3ea566422cbd ("can: isotp: sanitize CAN ID checks in
isotp_bind()") checks the given CAN ID address information by
sanitizing the input values.

This check (silently) removes obsolete bits by masking the given CAN
IDs.

Derek Will suggested to give a feedback to the application programmer
when the 'sanitizing' was actually needed which means the programmer
provided CAN ID content in a wrong format (e.g. SFF CAN IDs with a CAN
ID > 0x7FF).

Link: https://lore.kernel.org/all/20220515181633.76671-1-socketcan@hartkopp.net
Suggested-by: Derek Will <derekrobertwill@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: add support for transmission without flow control

Usually the ISO 15765-2 protocol is a point-to-point protocol to transfer
segmented PDUs to a dedicated receiver. This receiver sends a

can: isotp: add support for transmission without flow control

Usually the ISO 15765-2 protocol is a point-to-point protocol to transfer
segmented PDUs to a dedicated receiver. This receiver sends a flow control
message to specify protocol options and timings (e.g. block size / STmin).

The so called functional addressing communication allows a 1:N
communication but is limited to a single frame length.

This new CAN_ISOTP_CF_BROADCAST allows an unconfirmed 1:N communication
with PDU length that would not fit into a single frame. This feature is
not covered by the ISO 15765-2 standard.

Link: https://lore.kernel.org/all/20220507115558.19065-1-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: remove re-binding of bound socket

As a carry over from the CAN_RAW socket (which allows to change the CAN
interface while mantaining the filter setup) the re-binding of the
CAN_ISOTP soc

can: isotp: remove re-binding of bound socket

As a carry over from the CAN_RAW socket (which allows to change the CAN
interface while mantaining the filter setup) the re-binding of the
CAN_ISOTP socket needs to take care about CAN ID address information and
subscriptions. It turned out that this feature is so limited (e.g. the
sockopts remain fix) that it finally has never been needed/used.

In opposite to the stateless CAN_RAW socket the switching of the CAN ID
subscriptions might additionally lead to an interrupted ongoing PDU
reception. So better remove this unneeded complexity.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20220422082337.1676-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: stop timeout monitoring when no first frame was sent

The first attempt to fix a the 'impossible' WARN_ON_ONCE(1) in
isotp_tx_timer_handler() focussed on the identical CAN IDs created by

can: isotp: stop timeout monitoring when no first frame was sent

The first attempt to fix a the 'impossible' WARN_ON_ONCE(1) in
isotp_tx_timer_handler() focussed on the identical CAN IDs created by
the syzbot reproducer and lead to upstream fix/commit 3ea566422cbd
("can: isotp: sanitize CAN ID checks in isotp_bind()"). But this did
not catch the root cause of the wrong tx.state in the tx_timer handler.

In the isotp 'first frame' case a timeout monitoring needs to be started
before the 'first frame' is send. But when this sending failed the timeout
monitoring for this specific frame has to be disabled too.

Otherwise the tx_timer is fired with the 'warn me' tx.state of ISOTP_IDLE.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20220405175112.2682-1-socketcan@hartkopp.net
Reported-by: syzbot+2339c27f5c66c652843e@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

net: remove noblock parameter from skb_recv_datagram()

skb_recv_datagram() has two parameters 'flags' and 'noblock' that are
merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0

net: remove noblock parameter from skb_recv_datagram()

skb_recv_datagram() has two parameters 'flags' and 'noblock' that are
merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)'

As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags'
into 'flags' and 'noblock' with finally obsolete bit operations like this:

skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc);

And this is not even done consistently with the 'flags' parameter.

This patch removes the obsolete and costly splitting into two parameters
and only performs bit operations when really needed on the caller side.

One missing conversion thankfully reported by kernel test robot. I missed
to enable kunit tests to build the mctp code.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

can: isotp: restore accidentally removed MSG_PEEK feature

In commit 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when
reading from socket") a new check for recvmsg flags has been
introduced tha

can: isotp: restore accidentally removed MSG_PEEK feature

In commit 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when
reading from socket") a new check for recvmsg flags has been
introduced that only checked for the flags that are handled in
isotp_recvmsg() itself.

This accidentally removed the MSG_PEEK feature flag which is processed
later in the call chain in __skb_try_recv_from_queue().

Add MSG_PEEK to the set of valid flags to restore the feature.

Fixes: 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when reading from socket")
Link: https://github.com/linux-can/can-utils/issues/347#issuecomment-1079554254
Link: https://lore.kernel.org/all/20220328113611.3691-1-socketcan@hartkopp.net
Reported-by: Derek Will <derekrobertwill@gmail.com>
Suggested-by: Derek Will <derekrobertwill@gmail.com>
Tested-by: Derek Will <derekrobertwill@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: support MSG_TRUNC flag when reading from socket

When providing the MSG_TRUNC flag via recvmsg() syscall the return value
provides the real length of the packet or datagram, even when it

can: isotp: support MSG_TRUNC flag when reading from socket

When providing the MSG_TRUNC flag via recvmsg() syscall the return value
provides the real length of the packet or datagram, even when it was longer
than the passed buffer.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://github.com/linux-can/can-utils/issues/347#issuecomment-1065932671
Link: https://lore.kernel.org/all/20220316164258.54155-3-socketcan@hartkopp.net
Suggested-by: Derek Will <derekrobertwill@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: return -EADDRNOTAVAIL when reading from unbound socket

When reading from an unbound can-isotp socket the syscall blocked
indefinitely. As unbound sockets (without given CAN address infor

can: isotp: return -EADDRNOTAVAIL when reading from unbound socket

When reading from an unbound can-isotp socket the syscall blocked
indefinitely. As unbound sockets (without given CAN address information)
do not make sense anyway we directly return -EADDRNOTAVAIL on read()
analogue to the known behavior from sendmsg().

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://github.com/linux-can/can-utils/issues/349
Link: https://lore.kernel.org/all/20220316164258.54155-2-socketcan@hartkopp.net
Suggested-by: Derek Will <derekrobertwill@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: isotp: sanitize CAN ID checks in isotp_bind()

Syzbot created an environment that lead to a state machine status that
can not be reached with a compliant CAN ID address configuration.
The provid

can: isotp: sanitize CAN ID checks in isotp_bind()

Syzbot created an environment that lead to a state machine status that
can not be reached with a compliant CAN ID address configuration.
The provided address information consisted of CAN ID 0x6000001 and 0xC28001
which both boil down to 11 bit CAN IDs 0x001 in sending and receiving.

Sanitize the SFF/EFF CAN ID values before performing the address checks.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20220316164258.54155-1-socketcan@hartkopp.net
Reported-by: syzbot+2339c27f5c66c652843e@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...