Pileus Git - ~andy/linux/blob - 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 <linux/export.h>
   6 #include "vlan.h"
   7
   8 bool vlan_do_receive(struct sk_buff **skbp)
   9 {
  10         struct sk_buff *skb = *skbp;
  11         u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
  12         struct net_device *vlan_dev;
  13         struct vlan_pcpu_stats *rx_stats;
  14
  15         vlan_dev = vlan_find_dev(skb->dev, vlan_id);
  16         if (!vlan_dev) {
  17                 if (vlan_id)
  18                         skb->pkt_type = PACKET_OTHERHOST;
  19                 return false;
  20         }
  21
  22         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  23         if (unlikely(!skb))
  24                 return false;
  25
  26         skb->dev = vlan_dev;
  27         if (skb->pkt_type == PACKET_OTHERHOST) {
  28                 /* Our lower layer thinks this is not local, let's make sure.
  29                  * This allows the VLAN to have a different MAC than the
  30                  * underlying device, and still route correctly. */
  31                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
  32                                         vlan_dev->dev_addr))
  33                         skb->pkt_type = PACKET_HOST;
  34         }
  35
  36         if (!(vlan_dev_info(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
  37                 unsigned int offset = skb->data - skb_mac_header(skb);
  38
  39                 /*
  40                  * vlan_insert_tag expect skb->data pointing to mac header.
  41                  * So change skb->data before calling it and change back to
  42                  * original position later
  43                  */
  44                 skb_push(skb, offset);
  45                 skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
  46                 if (!skb)
  47                         return false;
  48                 skb_pull(skb, offset + VLAN_HLEN);
  49                 skb_reset_mac_len(skb);
  50         }
  51
  52         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
  53         skb->vlan_tci = 0;
  54
  55         rx_stats = this_cpu_ptr(vlan_dev_info(vlan_dev)->vlan_pcpu_stats);
  56
  57         u64_stats_update_begin(&rx_stats->syncp);
  58         rx_stats->rx_packets++;
  59         rx_stats->rx_bytes += skb->len;
  60         if (skb->pkt_type == PACKET_MULTICAST)
  61                 rx_stats->rx_multicast++;
  62         u64_stats_update_end(&rx_stats->syncp);
  63
  64         return true;
  65 }
  66
  67 /* Must be invoked with rcu_read_lock or with RTNL. */
  68 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  69                                         u16 vlan_id)
  70 {
  71         struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);
  72
  73         if (grp) {
  74                 return vlan_group_get_device(grp, vlan_id);
  75         } else {
  76                 /*
  77                  * Bonding slaves do not have grp assigned to themselves.
  78                  * Grp is assigned to bonding master instead.
  79                  */
  80                 if (netif_is_bond_slave(real_dev))
  81                         return __vlan_find_dev_deep(real_dev->master, vlan_id);
  82         }
  83
  84         return NULL;
  85 }
  86 EXPORT_SYMBOL(__vlan_find_dev_deep);
  87
  88 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  89 {
  90         return vlan_dev_info(dev)->real_dev;
  91 }
  92 EXPORT_SYMBOL(vlan_dev_real_dev);
  93
  94 u16 vlan_dev_vlan_id(const struct net_device *dev)
  95 {
  96         return vlan_dev_info(dev)->vlan_id;
  97 }
  98 EXPORT_SYMBOL(vlan_dev_vlan_id);
  99
 100 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 101 {
 102         if (skb_cow(skb, skb_headroom(skb)) < 0)
 103                 return NULL;
 104         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 105         skb->mac_header += VLAN_HLEN;
 106         skb_reset_mac_len(skb);
 107         return skb;
 108 }
 109
 110 static void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr)
 111 {
 112         __be16 proto;
 113         unsigned char *rawp;
 114
 115         /*
 116          * Was a VLAN packet, grab the encapsulated protocol, which the layer
 117          * three protocols care about.
 118          */
 119
 120         proto = vhdr->h_vlan_encapsulated_proto;
 121         if (ntohs(proto) >= 1536) {
 122                 skb->protocol = proto;
 123                 return;
 124         }
 125
 126         rawp = skb->data;
 127         if (*(unsigned short *) rawp == 0xFFFF)
 128                 /*
 129                  * This is a magic hack to spot IPX packets. Older Novell
 130                  * breaks the protocol design and runs IPX over 802.3 without
 131                  * an 802.2 LLC layer. We look for FFFF which isn't a used
 132                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
 133                  * but does for the rest.
 134                  */
 135                 skb->protocol = htons(ETH_P_802_3);
 136         else
 137                 /*
 138                  * Real 802.2 LLC
 139                  */
 140                 skb->protocol = htons(ETH_P_802_2);
 141 }
 142
 143 struct sk_buff *vlan_untag(struct sk_buff *skb)
 144 {
 145         struct vlan_hdr *vhdr;
 146         u16 vlan_tci;
 147
 148         if (unlikely(vlan_tx_tag_present(skb))) {
 149                 /* vlan_tci is already set-up so leave this for another time */
 150                 return skb;
 151         }
 152
 153         skb = skb_share_check(skb, GFP_ATOMIC);
 154         if (unlikely(!skb))
 155                 goto err_free;
 156
 157         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 158                 goto err_free;
 159
 160         vhdr = (struct vlan_hdr *) skb->data;
 161         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 162         __vlan_hwaccel_put_tag(skb, vlan_tci);
 163
 164         skb_pull_rcsum(skb, VLAN_HLEN);
 165         vlan_set_encap_proto(skb, vhdr);
 166
 167         skb = vlan_reorder_header(skb);
 168         if (unlikely(!skb))
 169                 goto err_free;
 170
 171         skb_reset_network_header(skb);
 172         skb_reset_transport_header(skb);
 173         return skb;
 174
 175 err_free:
 176         kfree_skb(skb);
 177         return NULL;
 178 }