datapath/linux/compat/netdevice.c

   1 #include <linux/netdevice.h>
   2 #include <linux/if_vlan.h>
   3
   4 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
   5 #ifndef HAVE_CAN_CHECKSUM_PROTOCOL
   6 static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
   7 {
   8         return  ((features & NETIF_F_GEN_CSUM) ||
   9                 ((features & NETIF_F_V4_CSUM) &&
  10                                 protocol == htons(ETH_P_IP)) ||
  11                 ((features & NETIF_F_V6_CSUM) &&
  12                                 protocol == htons(ETH_P_IPV6)) ||
  13                 ((features & NETIF_F_FCOE_CRC) &&
  14                                 protocol == htons(ETH_P_FCOE)));
  15 }
  16 #endif
  17
  18 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
  19 {
  20 #ifdef CONFIG_HIGHMEM
  21         int i;
  22
  23         if (dev->features & NETIF_F_HIGHDMA)
  24                 return 0;
  25
  26         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
  27                 if (PageHighMem(skb_shinfo(skb)->frags[i].page))
  28                         return 1;
  29
  30 #endif
  31         return 0;
  32 }
  33
  34 static netdev_features_t harmonize_features(struct sk_buff *skb,
  35                                             __be16 protocol,
  36                                             netdev_features_t features)
  37 {
  38         if (!can_checksum_protocol(features, protocol)) {
  39                 features &= ~NETIF_F_ALL_CSUM;
  40                 features &= ~NETIF_F_SG;
  41         } else if (illegal_highdma(skb->dev, skb)) {
  42                 features &= ~NETIF_F_SG;
  43         }
  44
  45         return features;
  46 }
  47
  48 netdev_features_t rpl_netif_skb_features(struct sk_buff *skb)
  49 {
  50         unsigned long vlan_features = skb->dev->vlan_features;
  51
  52         __be16 protocol = skb->protocol;
  53         netdev_features_t features = skb->dev->features;
  54
  55         if (protocol == htons(ETH_P_8021Q)) {
  56                 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
  57                 protocol = veh->h_vlan_encapsulated_proto;
  58         } else if (!vlan_tx_tag_present(skb)) {
  59                 return harmonize_features(skb, protocol, features);
  60         }
  61
  62         features &= (vlan_features | NETIF_F_HW_VLAN_TX);
  63
  64         if (protocol != htons(ETH_P_8021Q)) {
  65                 return harmonize_features(skb, protocol, features);
  66         } else {
  67                 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
  68                         NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
  69                 return harmonize_features(skb, protocol, features);
  70         }
  71 }
  72
  73 struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb,
  74                                     netdev_features_t features)
  75 {
  76         int vlan_depth = ETH_HLEN;
  77         __be16 type = skb->protocol;
  78         __be16 skb_proto;
  79         struct sk_buff *skb_gso;
  80
  81         while (type == htons(ETH_P_8021Q)) {
  82                 struct vlan_hdr *vh;
  83
  84                 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
  85                         return ERR_PTR(-EINVAL);
  86
  87                 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
  88                 type = vh->h_vlan_encapsulated_proto;
  89                 vlan_depth += VLAN_HLEN;
  90         }
  91
  92         /* this hack needed to get regular skb_gso_segment() */
  93 #undef skb_gso_segment
  94         skb_proto = skb->protocol;
  95         skb->protocol = type;
  96
  97         skb_gso = skb_gso_segment(skb, features);
  98         skb->protocol = skb_proto;
  99         return skb_gso;
 100 }
 101 #endif  /* kernel version < 2.6.38 */