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-rw-r--r--net/can/raw.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/net/can/raw.c b/net/can/raw.c
index 63ffdb0f3a23..0c8d537b59b8 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -74,6 +74,11 @@ MODULE_ALIAS("can-proto-1");
* storing the single filter in dfilter, to avoid using dynamic memory.
*/
+struct uniqframe {
+ ktime_t tstamp;
+ const struct sk_buff *skb;
+};
+
struct raw_sock {
struct sock sk;
int bound;
@@ -86,6 +91,7 @@ struct raw_sock {
struct can_filter dfilter; /* default/single filter */
struct can_filter *filter; /* pointer to filter(s) */
can_err_mask_t err_mask;
+ struct uniqframe __percpu *uniq;
};
/*
@@ -123,6 +129,15 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
if (!ro->fd_frames && oskb->len != CAN_MTU)
return;
+ /* eliminate multiple filter matches for the same skb */
+ if (this_cpu_ptr(ro->uniq)->skb == oskb &&
+ ktime_equal(this_cpu_ptr(ro->uniq)->tstamp, oskb->tstamp)) {
+ return;
+ } else {
+ this_cpu_ptr(ro->uniq)->skb = oskb;
+ this_cpu_ptr(ro->uniq)->tstamp = oskb->tstamp;
+ }
+
/* clone the given skb to be able to enqueue it into the rcv queue */
skb = skb_clone(oskb, GFP_ATOMIC);
if (!skb)
@@ -297,6 +312,11 @@ static int raw_init(struct sock *sk)
ro->recv_own_msgs = 0;
ro->fd_frames = 0;
+ /* alloc_percpu provides zero'ed memory */
+ ro->uniq = alloc_percpu(struct uniqframe);
+ if (unlikely(!ro->uniq))
+ return -ENOMEM;
+
/* set notifier */
ro->notifier.notifier_call = raw_notifier;
@@ -339,6 +359,7 @@ static int raw_release(struct socket *sock)
ro->ifindex = 0;
ro->bound = 0;
ro->count = 0;
+ free_percpu(ro->uniq);
sock_orphan(sk);
sock->sk = NULL;