From 445409602c09219767c06497c0dc2285eac244ed Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 26 Nov 2009 06:07:08 +0000 Subject: [PATCH] veth: move loopback logic to common location The veth driver contains code to forward an skb from the start_xmit function of one network device into the receive path of another device. Moving that code into a common location lets us reuse the code for direct forwarding of data between macvlan ports, and possibly in other drivers. Signed-off-by: Arnd Bergmann Acked-by: Patrick McHardy Signed-off-by: David S. Miller --- drivers/net/veth.c | 17 +++-------------- include/linux/netdevice.h | 2 ++ net/core/dev.c | 40 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 45 insertions(+), 14 deletions(-) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 2d657f2314cb..6c4b5a2d7877 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -155,8 +155,6 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) struct veth_net_stats *stats, *rcv_stats; int length, cpu; - skb_orphan(skb); - priv = netdev_priv(dev); rcv = priv->peer; rcv_priv = netdev_priv(rcv); @@ -168,20 +166,12 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) if (!(rcv->flags & IFF_UP)) goto tx_drop; - if (skb->len > (rcv->mtu + MTU_PAD)) - goto rx_drop; - - skb->tstamp.tv64 = 0; - skb->pkt_type = PACKET_HOST; - skb->protocol = eth_type_trans(skb, rcv); if (dev->features & NETIF_F_NO_CSUM) skb->ip_summed = rcv_priv->ip_summed; - skb->mark = 0; - secpath_reset(skb); - nf_reset(skb); - - length = skb->len; + length = skb->len + ETH_HLEN; + if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS) + goto rx_drop; stats->tx_bytes += length; stats->tx_packets++; @@ -189,7 +179,6 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) rcv_stats->rx_bytes += length; rcv_stats->rx_packets++; - netif_rx(skb); return NETDEV_TX_OK; tx_drop: diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 97873e31661c..9428793775a0 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1562,6 +1562,8 @@ extern int dev_set_mac_address(struct net_device *, extern int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, struct netdev_queue *txq); +extern int dev_forward_skb(struct net_device *dev, + struct sk_buff *skb); extern int netdev_budget; diff --git a/net/core/dev.c b/net/core/dev.c index e65af6041415..7775e8b48deb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -105,6 +105,7 @@ #include #include #include +#include #include #include #include @@ -1419,6 +1420,45 @@ static inline void net_timestamp(struct sk_buff *skb) skb->tstamp.tv64 = 0; } +/** + * dev_forward_skb - loopback an skb to another netif + * + * @dev: destination network device + * @skb: buffer to forward + * + * return values: + * NET_RX_SUCCESS (no congestion) + * NET_RX_DROP (packet was dropped) + * + * dev_forward_skb can be used for injecting an skb from the + * start_xmit function of one device into the receive queue + * of another device. + * + * The receiving device may be in another namespace, so + * we have to clear all information in the skb that could + * impact namespace isolation. + */ +int dev_forward_skb(struct net_device *dev, struct sk_buff *skb) +{ + skb_orphan(skb); + + if (!(dev->flags & IFF_UP)) + return NET_RX_DROP; + + if (skb->len > (dev->mtu + dev->hard_header_len)) + return NET_RX_DROP; + + skb_dst_drop(skb); + skb->tstamp.tv64 = 0; + skb->pkt_type = PACKET_HOST; + skb->protocol = eth_type_trans(skb, dev); + skb->mark = 0; + secpath_reset(skb); + nf_reset(skb); + return netif_rx(skb); +} +EXPORT_SYMBOL_GPL(dev_forward_skb); + /* * Support routine. Sends outgoing frames to any network * taps currently in use. -- 2.30.2