net/8021q/vlan_core.c

   1 #include <linux/skbuff.h>
   2 #include <linux/netdevice.h>
   3 #include <linux/if_vlan.h>
   4 #include <linux/netpoll.h>
   5 #include "vlan.h"
   6
   7 bool vlan_do_receive(struct sk_buff **skbp)
   8 {
   9         struct sk_buff *skb = *skbp;
  10         u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
  11         struct net_device *vlan_dev;
  12         struct vlan_pcpu_stats *rx_stats;
  13
  14         vlan_dev = vlan_find_dev(skb->dev, vlan_id);
  15         if (!vlan_dev) {
  16                 if (vlan_id)
  17                         skb->pkt_type = PACKET_OTHERHOST;
  18                 return false;
  19         }
  20
  21         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  22         if (unlikely(!skb))
  23                 return false;
  24
  25         skb->dev = vlan_dev;
  26         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
  27         skb->vlan_tci = 0;
  28
  29         rx_stats = this_cpu_ptr(vlan_dev_info(vlan_dev)->vlan_pcpu_stats);
  30
  31         u64_stats_update_begin(&rx_stats->syncp);
  32         rx_stats->rx_packets++;
  33         rx_stats->rx_bytes += skb->len;
  34
  35         switch (skb->pkt_type) {
  36         case PACKET_BROADCAST:
  37                 break;
  38         case PACKET_MULTICAST:
  39                 rx_stats->rx_multicast++;
  40                 break;
  41         case PACKET_OTHERHOST:
  42                 /* Our lower layer thinks this is not local, let's make sure.
  43                  * This allows the VLAN to have a different MAC than the
  44                  * underlying device, and still route correctly. */
  45                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
  46                                         vlan_dev->dev_addr))
  47                         skb->pkt_type = PACKET_HOST;
  48                 break;
  49         }
  50         u64_stats_update_end(&rx_stats->syncp);
  51
  52         return true;
  53 }
  54
  55 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  56 {
  57         return vlan_dev_info(dev)->real_dev;
  58 }
  59 EXPORT_SYMBOL(vlan_dev_real_dev);
  60
  61 u16 vlan_dev_vlan_id(const struct net_device *dev)
  62 {
  63         return vlan_dev_info(dev)->vlan_id;
  64 }
  65 EXPORT_SYMBOL(vlan_dev_vlan_id);
  66
  67 /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
  68 int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
  69                       u16 vlan_tci, int polling)
  70 {
  71         __vlan_hwaccel_put_tag(skb, vlan_tci);
  72         return polling ? netif_receive_skb(skb) : netif_rx(skb);
  73 }
  74 EXPORT_SYMBOL(__vlan_hwaccel_rx);
  75
  76 gro_result_t vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
  77                               unsigned int vlan_tci, struct sk_buff *skb)
  78 {
  79         __vlan_hwaccel_put_tag(skb, vlan_tci);
  80         return napi_gro_receive(napi, skb);
  81 }
  82 EXPORT_SYMBOL(vlan_gro_receive);
  83
  84 gro_result_t vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
  85                             unsigned int vlan_tci)
  86 {
  87         __vlan_hwaccel_put_tag(napi->skb, vlan_tci);
  88         return napi_gro_frags(napi);
  89 }
  90 EXPORT_SYMBOL(vlan_gro_frags);
  91
  92 static struct sk_buff *vlan_check_reorder_header(struct sk_buff *skb)
  93 {
  94         if (vlan_dev_info(skb->dev)->flags & VLAN_FLAG_REORDER_HDR) {
  95                 if (skb_cow(skb, skb_headroom(skb)) < 0)
  96                         skb = NULL;
  97                 if (skb) {
  98                         /* Lifted from Gleb's VLAN code... */
  99                         memmove(skb->data - ETH_HLEN,
 100                                 skb->data - VLAN_ETH_HLEN, 12);
 101                         skb->mac_header += VLAN_HLEN;
 102                 }
 103         }
 104         return skb;
 105 }
 106
 107 static void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr)
 108 {
 109         __be16 proto;
 110         unsigned char *rawp;
 111
 112         /*
 113          * Was a VLAN packet, grab the encapsulated protocol, which the layer
 114          * three protocols care about.
 115          */
 116
 117         proto = vhdr->h_vlan_encapsulated_proto;
 118         if (ntohs(proto) >= 1536) {
 119                 skb->protocol = proto;
 120                 return;
 121         }
 122
 123         rawp = skb->data;
 124         if (*(unsigned short *) rawp == 0xFFFF)
 125                 /*
 126                  * This is a magic hack to spot IPX packets. Older Novell
 127                  * breaks the protocol design and runs IPX over 802.3 without
 128                  * an 802.2 LLC layer. We look for FFFF which isn't a used
 129                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
 130                  * but does for the rest.
 131                  */
 132                 skb->protocol = htons(ETH_P_802_3);
 133         else
 134                 /*
 135                  * Real 802.2 LLC
 136                  */
 137                 skb->protocol = htons(ETH_P_802_2);
 138 }
 139
 140 struct sk_buff *vlan_untag(struct sk_buff *skb)
 141 {
 142         struct vlan_hdr *vhdr;
 143         u16 vlan_tci;
 144
 145         if (unlikely(vlan_tx_tag_present(skb))) {
 146                 /* vlan_tci is already set-up so leave this for another time */
 147                 return skb;
 148         }
 149
 150         skb = skb_share_check(skb, GFP_ATOMIC);
 151         if (unlikely(!skb))
 152                 goto err_free;
 153
 154         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 155                 goto err_free;
 156
 157         vhdr = (struct vlan_hdr *) skb->data;
 158         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 159         __vlan_hwaccel_put_tag(skb, vlan_tci);
 160
 161         skb_pull_rcsum(skb, VLAN_HLEN);
 162         vlan_set_encap_proto(skb, vhdr);
 163
 164         skb = vlan_check_reorder_header(skb);
 165         if (unlikely(!skb))
 166                 goto err_free;
 167
 168         return skb;
 169
 170 err_free:
 171         kfree_skb(skb);
 172         return NULL;
 173 }