Bluetooth: Provide L2CAP ops callback for memcpy_fromiovec
The highly optimized TX path for L2CAP channels and its fragmentation
within the HCI ACL packets requires to copy data from user provided
IO vectors and also kernel provided memory buffers.
This patch allows channel clients to provide a memcpy_fromiovec callback
to keep this optimized behavior, but adapt it to kernel vs user memory
for the TX path. For all kernel internal L2CAP channels, a default
implementation is provided that can be referenced.
In case of A2MP, this fixes a long-standing issue with wrongly accessing
kernel memory as user memory.
This patch originally by Marcel Holtmann.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 55215eb..bf72886 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1313,6 +1313,13 @@
return skb;
}
+static int l2cap_sock_memcpy_fromiovec_cb(struct l2cap_chan *chan,
+ unsigned char *kdata,
+ struct iovec *iov, int len)
+{
+ return memcpy_fromiovec(kdata, iov, len);
+}
+
static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
{
struct sock *sk = chan->data;
@@ -1379,19 +1386,20 @@
}
static const struct l2cap_ops l2cap_chan_ops = {
- .name = "L2CAP Socket Interface",
- .new_connection = l2cap_sock_new_connection_cb,
- .recv = l2cap_sock_recv_cb,
- .close = l2cap_sock_close_cb,
- .teardown = l2cap_sock_teardown_cb,
- .state_change = l2cap_sock_state_change_cb,
- .ready = l2cap_sock_ready_cb,
- .defer = l2cap_sock_defer_cb,
- .resume = l2cap_sock_resume_cb,
- .suspend = l2cap_sock_suspend_cb,
- .set_shutdown = l2cap_sock_set_shutdown_cb,
- .get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
- .alloc_skb = l2cap_sock_alloc_skb_cb,
+ .name = "L2CAP Socket Interface",
+ .new_connection = l2cap_sock_new_connection_cb,
+ .recv = l2cap_sock_recv_cb,
+ .close = l2cap_sock_close_cb,
+ .teardown = l2cap_sock_teardown_cb,
+ .state_change = l2cap_sock_state_change_cb,
+ .ready = l2cap_sock_ready_cb,
+ .defer = l2cap_sock_defer_cb,
+ .resume = l2cap_sock_resume_cb,
+ .suspend = l2cap_sock_suspend_cb,
+ .set_shutdown = l2cap_sock_set_shutdown_cb,
+ .get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
+ .alloc_skb = l2cap_sock_alloc_skb_cb,
+ .memcpy_fromiovec = l2cap_sock_memcpy_fromiovec_cb,
};
static void l2cap_sock_destruct(struct sock *sk)