Commit 8a4eb573 authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller
Browse files

net: introduce rx_handler results and logic around that 



This patch allows rx_handlers to better signalize what to do next to
it's caller. That makes skb->deliver_no_wcard no longer needed.

kernel-doc for rx_handler_result is taken from Nicolas' patch.

Signed-off-by: default avatarJiri Pirko <jpirko@redhat.com>
Reviewed-by: default avatarNicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2d7011ca

drivers/net/bonding/bond_main.c

+12 −10
Original line number Diff line number Diff line
@@ -1480,20 +1480,23 @@ static bool bond_should_deliver_exact_match(struct sk_buff *skb, 
	return false;

}



static struct sk_buff *bond_handle_frame(struct sk_buff *skb)

static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb)

{

	struct sk_buff *skb = *pskb;

	struct slave *slave;

	struct net_device *bond_dev;

	struct bonding *bond;



	skb = skb_share_check(skb, GFP_ATOMIC);

	if (unlikely(!skb))

		return NULL;



	slave = bond_slave_get_rcu(skb->dev);

	bond_dev = ACCESS_ONCE(slave->dev->master);

	if (unlikely(!bond_dev))

		return skb;

		return RX_HANDLER_PASS;



	skb = skb_share_check(skb, GFP_ATOMIC);

	if (unlikely(!skb))

		return RX_HANDLER_CONSUMED;



	*pskb = skb;



	bond = netdev_priv(bond_dev);
@@ -1501,8 +1504,7 @@ static struct sk_buff *bond_handle_frame(struct sk_buff *skb) 
		slave->dev->last_rx = jiffies;



	if (bond_should_deliver_exact_match(skb, slave, bond)) {

		skb->deliver_no_wcard = 1;

		return skb;

		return RX_HANDLER_EXACT;

	}



	skb->dev = bond_dev;
@@ -1514,12 +1516,12 @@ static struct sk_buff *bond_handle_frame(struct sk_buff *skb) 
		if (unlikely(skb_cow_head(skb,

					  skb->data - skb_mac_header(skb)))) {

			kfree_skb(skb);

			return NULL;

			return RX_HANDLER_CONSUMED;

		}

		memcpy(eth_hdr(skb)->h_dest, bond_dev->dev_addr, ETH_ALEN);

	}



	return skb;

	return RX_HANDLER_ANOTHER;

}



/* enslave device <slave> to bond device <master> */

drivers/net/macvlan.c

+6 −5
Original line number Diff line number Diff line
@@ -152,9 +152,10 @@ static void macvlan_broadcast(struct sk_buff *skb, 
}



/* called under rcu_read_lock() from netif_receive_skb */

static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)

static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)

{

	struct macvlan_port *port;

	struct sk_buff *skb = *pskb;

	const struct ethhdr *eth = eth_hdr(skb);

	const struct macvlan_dev *vlan;

	const struct macvlan_dev *src;
@@ -184,7 +185,7 @@ static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb) 
			 */

			macvlan_broadcast(skb, port, src->dev,

					  MACVLAN_MODE_VEPA);

		return skb;

		return RX_HANDLER_PASS;

	}



	if (port->passthru)
@@ -192,12 +193,12 @@ static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb) 
	else

		vlan = macvlan_hash_lookup(port, eth->h_dest);

	if (vlan == NULL)

		return skb;

		return RX_HANDLER_PASS;



	dev = vlan->dev;

	if (unlikely(!(dev->flags & IFF_UP))) {

		kfree_skb(skb);

		return NULL;

		return RX_HANDLER_CONSUMED;

	}

	len = skb->len + ETH_HLEN;

	skb = skb_share_check(skb, GFP_ATOMIC);
@@ -211,7 +212,7 @@ static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb) 


out:

	macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, 0);

	return NULL;

	return RX_HANDLER_CONSUMED;

}



static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)

include/linux/netdevice.h

+49 −1
Original line number Diff line number Diff line
@@ -390,7 +390,55 @@ enum gro_result { 
};

typedef enum gro_result gro_result_t;



typedef struct sk_buff *rx_handler_func_t(struct sk_buff *skb);

/*

 * enum rx_handler_result - Possible return values for rx_handlers.

 * @RX_HANDLER_CONSUMED: skb was consumed by rx_handler, do not process it

 * further.

 * @RX_HANDLER_ANOTHER: Do another round in receive path. This is indicated in

 * case skb->dev was changed by rx_handler.

 * @RX_HANDLER_EXACT: Force exact delivery, no wildcard.

 * @RX_HANDLER_PASS: Do nothing, passe the skb as if no rx_handler was called.

 *

 * rx_handlers are functions called from inside __netif_receive_skb(), to do

 * special processing of the skb, prior to delivery to protocol handlers.

 *

 * Currently, a net_device can only have a single rx_handler registered. Trying

 * to register a second rx_handler will return -EBUSY.

 *

 * To register a rx_handler on a net_device, use netdev_rx_handler_register().

 * To unregister a rx_handler on a net_device, use

 * netdev_rx_handler_unregister().

 *

 * Upon return, rx_handler is expected to tell __netif_receive_skb() what to

 * do with the skb.

 *

 * If the rx_handler consumed to skb in some way, it should return

 * RX_HANDLER_CONSUMED. This is appropriate when the rx_handler arranged for

 * the skb to be delivered in some other ways.

 *

 * If the rx_handler changed skb->dev, to divert the skb to another

 * net_device, it should return RX_HANDLER_ANOTHER. The rx_handler for the

 * new device will be called if it exists.

 *

 * If the rx_handler consider the skb should be ignored, it should return

 * RX_HANDLER_EXACT. The skb will only be delivered to protocol handlers that

 * are registred on exact device (ptype->dev == skb->dev).

 *

 * If the rx_handler didn't changed skb->dev, but want the skb to be normally

 * delivered, it should return RX_HANDLER_PASS.

 *

 * A device without a registered rx_handler will behave as if rx_handler

 * returned RX_HANDLER_PASS.

 */



enum rx_handler_result {

	RX_HANDLER_CONSUMED,

	RX_HANDLER_ANOTHER,

	RX_HANDLER_EXACT,

	RX_HANDLER_PASS,

};

typedef enum rx_handler_result rx_handler_result_t;

typedef rx_handler_result_t rx_handler_func_t(struct sk_buff **pskb);



extern void __napi_schedule(struct napi_struct *n);

include/linux/skbuff.h

+1 −4
Original line number Diff line number Diff line
@@ -388,10 +388,7 @@ struct sk_buff { 
	kmemcheck_bitfield_begin(flags2);

	__u16			queue_mapping:16;

#ifdef CONFIG_IPV6_NDISC_NODETYPE

	__u8			ndisc_nodetype:2,

				deliver_no_wcard:1;

#else

	__u8			deliver_no_wcard:1;

	__u8			ndisc_nodetype:2;

#endif

	__u8			ooo_okay:1;

	kmemcheck_bitfield_end(flags2);

net/bridge/br_input.c

+15 −10
Original line number Diff line number Diff line
@@ -139,21 +139,22 @@ static inline int is_link_local(const unsigned char *dest) 
 * Return NULL if skb is handled

 * note: already called with rcu_read_lock

 */

struct sk_buff *br_handle_frame(struct sk_buff *skb)

rx_handler_result_t br_handle_frame(struct sk_buff **pskb)

{

	struct net_bridge_port *p;

	struct sk_buff *skb = *pskb;

	const unsigned char *dest = eth_hdr(skb)->h_dest;

	br_should_route_hook_t *rhook;



	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))

		return skb;

		return RX_HANDLER_PASS;



	if (!is_valid_ether_addr(eth_hdr(skb)->h_source))

		goto drop;



	skb = skb_share_check(skb, GFP_ATOMIC);

	if (!skb)

		return NULL;

		return RX_HANDLER_CONSUMED;



	p = br_port_get_rcu(skb->dev);
@@ -167,10 +168,12 @@ struct sk_buff *br_handle_frame(struct sk_buff *skb) 
			goto forward;



		if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,

			    NULL, br_handle_local_finish))

			return NULL;	/* frame consumed by filter */

		else

			return skb;	/* continue processing */

			    NULL, br_handle_local_finish)) {

			return RX_HANDLER_CONSUMED; /* consumed by filter */

		} else {

			*pskb = skb;

			return RX_HANDLER_PASS;	/* continue processing */

		}

	}



forward:
@@ -178,8 +181,10 @@ struct sk_buff *br_handle_frame(struct sk_buff *skb) 
	case BR_STATE_FORWARDING:

		rhook = rcu_dereference(br_should_route_hook);

		if (rhook) {

			if ((*rhook)(skb))

				return skb;

			if ((*rhook)(skb)) {

				*pskb = skb;

				return RX_HANDLER_PASS;

			}

			dest = eth_hdr(skb)->h_dest;

		}

		/* fall through */
@@ -194,5 +199,5 @@ struct sk_buff *br_handle_frame(struct sk_buff *skb) 
drop:

		kfree_skb(skb);

	}

	return NULL;

	return RX_HANDLER_CONSUMED;

}