From 156c2bb9f88065c8da78814f98fde665a5cbb527 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Thu, 17 Jan 2013 18:43:39 +0100 Subject: 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 Signed-off-by: Marc Kleine-Budde --- net/can/raw.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/can/raw.c') 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 #include #include +#include #include #include #include @@ -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; -- cgit v1.2.3