linux/net/lapb, branch v5.11

net: lapb: Copy the skb before sending a packet

2021-02-02T16:40:48Z

When sending a packet, we will prepend it with an LAPB header. This modifies the shared parts of a cloned skb, so we should copy the skb rather than just clone it, before we prepend the header. In "Documentation/networking/driver.rst" (the 2nd point), it states that drivers shouldn't modify the shared parts of a cloned skb when transmitting. The "dev_queue_xmit_nit" function in "net/core/dev.c", which is called when an skb is being sent, clones the skb and sents the clone to AF_PACKET sockets. Because the LAPB drivers first remove a 1-byte pseudo-header before handing over the skb to us, if we don't copy the skb before prepending the LAPB header, the first byte of the packets received on AF_PACKET sockets can be corrupted. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xie He Acked-by: Martin Schiller Link: https://lore.kernel.org/r/20210201055706.415842-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski

net: lapb: Add locking to the lapb module

2021-01-27T01:53:45Z

In the lapb module, the timers may run concurrently with other code in this module, and there is currently no locking to prevent the code from racing on "struct lapb_cb". This patch adds locking to prevent racing. 1. Add "spinlock_t lock" to "struct lapb_cb"; Add "spin_lock_bh" and "spin_unlock_bh" to APIs, timer functions and notifier functions. 2. Add "bool t1timer_stop, t2timer_stop" to "struct lapb_cb" to make us able to ask running timers to abort; Modify "lapb_stop_t1timer" and "lapb_stop_t2timer" to make them able to abort running timers; Modify "lapb_t2timer_expiry" and "lapb_t1timer_expiry" to make them abort after they are stopped by "lapb_stop_t1timer", "lapb_stop_t2timer", and "lapb_start_t1timer", "lapb_start_t2timer". 3. Let lapb_unregister wait for other API functions and running timers to stop. 4. The lapb_device_event function calls lapb_disconnect_request. In order to avoid trying to hold the lock twice, add a new function named "__lapb_disconnect_request" which assumes the lock is held, and make it called by lapb_disconnect_request and lapb_device_event. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: Martin Schiller Signed-off-by: Xie He Link: https://lore.kernel.org/r/20210126040939.69995-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski

net: lapb: Decrease the refcount of "struct lapb_cb" in lapb_device_event

2021-01-04T21:42:41Z

In lapb_device_event, lapb_devtostruct is called to get a reference to an object of "struct lapb_cb". lapb_devtostruct increases the refcount of the object and returns a pointer to it. However, we didn't decrease the refcount after we finished using the pointer. This patch fixes this problem. Fixes: a4989fa91110 ("net/lapb: support netdev events") Cc: Martin Schiller Signed-off-by: Xie He Link: https://lore.kernel.org/r/20201231174331.64539-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski

net/lapb: fix t1 timer handling for LAPB_STATE_0

2020-11-28T01:22:51Z

1. DTE interface changes immediately to LAPB_STATE_1 and start sending SABM(E). 2. DCE interface sends N2-times DM and changes to LAPB_STATE_1 afterwards if there is no response in the meantime. Signed-off-by: Martin Schiller Signed-off-by: Jakub Kicinski

net/lapb: support netdev events

2020-11-28T01:22:51Z

This patch allows layer2 (LAPB) to react to netdev events itself and avoids the detour via layer3 (X.25). 1. Establish layer2 on NETDEV_UP events, if the carrier is already up. 2. Call lapb_disconnect_request() on NETDEV_GOING_DOWN events to signal the peer that the connection will go down. (Only when the carrier is up.) 3. When a NETDEV_DOWN event occur, clear all queues, enter state LAPB_STATE_0 and stop all timers. 4. The NETDEV_CHANGE event makes it possible to handle carrier loss and detection. In case of Carrier Loss, clear all queues, enter state LAPB_STATE_0 and stop all timers. In case of Carrier Detection, we start timer t1 on a DCE interface, and on a DTE interface we change to state LAPB_STATE_1 and start sending SABM(E). Signed-off-by: Martin Schiller Acked-by: Xie He Signed-off-by: Jakub Kicinski

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21Z

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada

docs: networking: convert lapb-module.txt to ReST

2020-04-30T19:56:35Z

- add SPDX header; - adjust title markup; - mark code blocks and literals as such; - mark tables as such; - adjust identation, whitespaces and blank lines; - add to networking/index.rst. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-18T03:20:36Z

Honestly all the conflicts were simple overlapping changes, nothing really interesting to report. Signed-off-by: David S. Miller

lapb: fixed leak of control-blocks.

2019-06-17T03:44:20Z

lapb_register calls lapb_create_cb, which initializes the control- block's ref-count to one, and __lapb_insert_cb, which increments it when adding the new block to the list of blocks. lapb_unregister calls __lapb_remove_cb, which decrements the ref-count when removing control-block from the list of blocks, and calls lapb_put itself to decrement the ref-count before returning. However, lapb_unregister also calls __lapb_devtostruct to look up the right control-block for the given net_device, and __lapb_devtostruct also bumps the ref-count, which means that when lapb_unregister returns the ref-count is still 1 and the control-block is leaked. Call lapb_put after __lapb_devtostruct to fix leak. Reported-by: syzbot+afb980676c836b4a0afa@syzkaller.appspotmail.com Signed-off-by: Jeremy Sowden Signed-off-by: David S. Miller

lapb: moved export of lapb_register.

2019-06-16T21:25:01Z

The EXPORT_SYMBOL for lapb_register was next to a different function. Moved it to the right place. Signed-off-by: Jeremy Sowden Signed-off-by: David S. Miller