![Jesse Gross](/assets/img/avatar_default.png)
Currently each driver that is capable of vlan hardware acceleration must be aware of the vlan groups that are configured and then pass the stripped tag to a specialized receive function. This is different from other types of hardware offload in that it places a significant amount of knowledge in the driver itself rather keeping it in the networking core. This makes vlan offloading function more similarly to other forms of offloading (such as checksum offloading or TSO) by doing the following: * On receive, stripped vlans are passed directly to the network core, without attempting to check for vlan groups or reconstructing the header if no group * vlans are made less special by folding the logic into the main receive routines * On transmit, the device layer will add the vlan header in software if the hardware doesn't support it, instead of spreading that logic out in upper layers, such as bonding. There are a number of advantages to this: * Fixes all bugs with drivers incorrectly dropping vlan headers at once. * Avoids having to disable VLAN acceleration when in promiscuous mode (good for bridging since it always puts devices in promiscuous mode). * Keeps VLAN tag separate until given to ultimate consumer, which avoids needing to do header reconstruction as in tg3 unless absolutely necessary. * Consolidates common code in core networking. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
91 lines
2.3 KiB
C
91 lines
2.3 KiB
C
#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/if_vlan.h>
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#include <linux/netpoll.h>
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#include "vlan.h"
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bool vlan_hwaccel_do_receive(struct sk_buff **skbp)
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{
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struct sk_buff *skb = *skbp;
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u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
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struct net_device *vlan_dev;
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struct vlan_rx_stats *rx_stats;
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vlan_dev = vlan_find_dev(skb->dev, vlan_id);
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if (!vlan_dev) {
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if (vlan_id)
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skb->pkt_type = PACKET_OTHERHOST;
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return false;
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}
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skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
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if (unlikely(!skb))
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return false;
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skb->dev = vlan_dev;
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skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
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skb->vlan_tci = 0;
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rx_stats = this_cpu_ptr(vlan_dev_info(vlan_dev)->vlan_rx_stats);
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u64_stats_update_begin(&rx_stats->syncp);
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rx_stats->rx_packets++;
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rx_stats->rx_bytes += skb->len;
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switch (skb->pkt_type) {
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case PACKET_BROADCAST:
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break;
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case PACKET_MULTICAST:
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rx_stats->rx_multicast++;
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break;
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case PACKET_OTHERHOST:
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/* Our lower layer thinks this is not local, let's make sure.
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* This allows the VLAN to have a different MAC than the
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* underlying device, and still route correctly. */
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if (!compare_ether_addr(eth_hdr(skb)->h_dest,
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vlan_dev->dev_addr))
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skb->pkt_type = PACKET_HOST;
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break;
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}
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u64_stats_update_end(&rx_stats->syncp);
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return true;
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}
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struct net_device *vlan_dev_real_dev(const struct net_device *dev)
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{
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return vlan_dev_info(dev)->real_dev;
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}
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EXPORT_SYMBOL(vlan_dev_real_dev);
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u16 vlan_dev_vlan_id(const struct net_device *dev)
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{
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return vlan_dev_info(dev)->vlan_id;
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}
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EXPORT_SYMBOL(vlan_dev_vlan_id);
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/* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
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int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
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u16 vlan_tci, int polling)
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{
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__vlan_hwaccel_put_tag(skb, vlan_tci);
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return polling ? netif_receive_skb(skb) : netif_rx(skb);
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}
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EXPORT_SYMBOL(__vlan_hwaccel_rx);
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gro_result_t vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
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unsigned int vlan_tci, struct sk_buff *skb)
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{
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__vlan_hwaccel_put_tag(skb, vlan_tci);
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return napi_gro_receive(napi, skb);
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}
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EXPORT_SYMBOL(vlan_gro_receive);
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gro_result_t vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
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unsigned int vlan_tci)
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{
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__vlan_hwaccel_put_tag(napi->skb, vlan_tci);
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return napi_gro_frags(napi);
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}
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EXPORT_SYMBOL(vlan_gro_frags);
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