diff options
| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2013-01-17 18:43:39 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2013-01-26 16:59:01 +0100 |
| commit | 156c2bb9f88065c8da78814f98fde665a5cbb527 (patch) | |
| tree | ecd77a89c19ed0e1d420568f85769d7289ac3a37 /net/can/raw.c | |
| parent | e2d5f2c7d66224c1a401ed1f797e467c02c025b8 (diff) | |
can: add private data space for CAN sk_buffs
The struct can_skb_priv is used to transport additional information along
with the stored struct can(fd)_frame that can not be contained in existing
struct sk_buff elements.
can_skb_priv is located in the skb headroom, which does not touch the existing
CAN sk_buff usage with skb->data and skb->len, so that even out-of-tree
CAN drivers can be used without changes.
Btw. out-of-tree CAN drivers without can_skb_priv in the sk_buff headroom
would not support features based on can_skb_priv.
The can_skb_priv->ifindex contains the first interface where the CAN frame
appeared on the local host. Unfortunately skb->skb_iif can not be used as this
value is overwritten in every netif_receive_skb() call.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can/raw.c')
| -rw-r--r-- | net/can/raw.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/can/raw.c b/net/can/raw.c index 5b0e3e330d97..5d860e8dcc52 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -50,6 +50,7 @@ #include <linux/skbuff.h> #include <linux/can.h> #include <linux/can/core.h> +#include <linux/can/skb.h> #include <linux/can/raw.h> #include <net/sock.h> #include <net/net_namespace.h> @@ -699,11 +700,14 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock, if (!dev) return -ENXIO; - skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, - &err); + skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), + msg->msg_flags & MSG_DONTWAIT, &err); if (!skb) goto put_dev; + skb_reserve(skb, sizeof(struct can_skb_priv)); + ((struct can_skb_priv *)(skb->head))->ifindex = dev->ifindex; + err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); if (err < 0) goto free_skb; |