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can: omit unneeded skb_clone() calls 

The AF_CAN core delivered always cloned sk_buffs to the AF_CAN
protocols, although this was _only_ needed by the can-raw protocol.
With this (additionally documented) change, the AF_CAN core calls the
callback functions of the registered AF_CAN protocols with the original
(uncloned) sk_buff pointer and let's the can-raw protocol do the
skb_clone() itself which omits all unneeded skb_clone() calls for other
AF_CAN protocols.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Oliver Hartkopp 2009-01-06 11:07:54 -08:00 committed by David S. Miller
parent 98658bc9dc
commit 1fa17d4ba4
4 changed files with 22 additions and 22 deletions
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2
include/linux/can/core.h
View File

@ -19,7 +19,7 @@
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#define CAN_VERSION "20081130"
#define CAN_VERSION "20090105"
/* increment this number each time you change some user-space interface */
#define CAN_ABI_VERSION "8"

15
net/can/af_can.c
View File

@ -414,6 +414,12 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
* The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
* filter for error frames (CAN_ERR_FLAG bit set in mask).
*
* The provided pointer to the sk_buff is guaranteed to be valid as long as
* the callback function is running. The callback function must *not* free
* the given sk_buff while processing it's task. When the given sk_buff is
* needed after the end of the callback function it must be cloned inside
* the callback function with skb_clone().
*
* Return:
* 0 on success
* -ENOMEM on missing cache mem to create subscription entry
@ -569,13 +575,8 @@ EXPORT_SYMBOL(can_rx_unregister);
static inline void deliver(struct sk_buff *skb, struct receiver *r)
{
struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
if (clone) {
clone->sk = skb->sk;
r->func(clone, r->data);
r->matches++;
}
r->func(skb, r->data);
r->matches++;
}
static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)

12
net/can/bcm.c
View File

@ -633,7 +633,7 @@ static void bcm_rx_handler(struct sk_buff *skb, void *data)
hrtimer_cancel(&op->timer);
if (op->can_id != rxframe->can_id)
goto rx_freeskb;
return;
/* save rx timestamp */
op->rx_stamp = skb->tstamp;
@ -645,19 +645,19 @@ static void bcm_rx_handler(struct sk_buff *skb, void *data)
if (op->flags & RX_RTR_FRAME) {
/* send reply for RTR-request (placed in op->frames[0]) */
bcm_can_tx(op);
goto rx_freeskb;
return;
}
if (op->flags & RX_FILTER_ID) {
/* the easiest case */
bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
goto rx_freeskb_starttimer;
goto rx_starttimer;
}
if (op->nframes == 1) {
/* simple compare with index 0 */
bcm_rx_cmp_to_index(op, 0, rxframe);
goto rx_freeskb_starttimer;
goto rx_starttimer;
}
if (op->nframes > 1) {
@ -678,10 +678,8 @@ static void bcm_rx_handler(struct sk_buff *skb, void *data)
}
}
rx_freeskb_starttimer:
rx_starttimer:
bcm_rx_starttimer(op);
rx_freeskb:
kfree_skb(skb);
}
/*

15
net/can/raw.c
View File

@ -99,13 +99,14 @@ static void raw_rcv(struct sk_buff *skb, void *data)
struct raw_sock *ro = raw_sk(sk);
struct sockaddr_can *addr;
if (!ro->recv_own_msgs) {
/* check the received tx sock reference */
if (skb->sk == sk) {
kfree_skb(skb);
return;
}
}
/* check the received tx sock reference */
if (!ro->recv_own_msgs && skb->sk == sk)
return;
/* clone the given skb to be able to enqueue it into the rcv queue */
skb = skb_clone(skb, GFP_ATOMIC);
if (!skb)
return;
/*
* Put the datagram to the queue so that raw_recvmsg() can