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(unsigned long 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 u32 harmonize_features(struct sk_buff *skb, __be16 protocol, u32 features)
  35 {
  36         if (!can_checksum_protocol(features, protocol)) {
  37                 features &= ~NETIF_F_ALL_CSUM;
  38                 features &= ~NETIF_F_SG;
  39         } else if (illegal_highdma(skb->dev, skb)) {
  40                 features &= ~NETIF_F_SG;
  41         }
  42
  43         return features;
  44 }
  45
  46 u32 rpl_netif_skb_features(struct sk_buff *skb)
  47 {
  48 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,26)
  49         unsigned long vlan_features = 0;
  50 #else
  51         unsigned long vlan_features = skb->dev->vlan_features;
  52 #endif /* kernel version < 2.6.26 */
  53
  54         __be16 protocol = skb->protocol;
  55         u32 features = skb->dev->features;
  56
  57         if (protocol == htons(ETH_P_8021Q)) {
  58                 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
  59                 protocol = veh->h_vlan_encapsulated_proto;
  60         } else if (!vlan_tx_tag_present(skb)) {
  61                 return harmonize_features(skb, protocol, features);
  62         }
  63
  64         features &= (vlan_features | NETIF_F_HW_VLAN_TX);
  65
  66         if (protocol != htons(ETH_P_8021Q)) {
  67                 return harmonize_features(skb, protocol, features);
  68         } else {
  69                 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
  70                         NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
  71                 return harmonize_features(skb, protocol, features);
  72         }
  73 }
  74
  75 struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb, u32 features)
  76 {
  77         int vlan_depth = ETH_HLEN;
  78         __be16 type = skb->protocol;
  79         __be16 skb_proto;
  80         struct sk_buff *skb_gso;
  81
  82         while (type == htons(ETH_P_8021Q)) {
  83                 struct vlan_hdr *vh;
  84
  85                 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
  86                         return ERR_PTR(-EINVAL);
  87
  88                 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
  89                 type = vh->h_vlan_encapsulated_proto;
  90                 vlan_depth += VLAN_HLEN;
  91         }
  92
  93         /* this hack needed to get regular skb_gso_segment() */
  94 #undef skb_gso_segment
  95         skb_proto = skb->protocol;
  96         skb->protocol = type;
  97
  98         skb_gso = skb_gso_segment(skb, features);
  99         skb->protocol = skb_proto;
 100         return skb_gso;
 101 }
 102 #endif  /* kernel version < 2.6.38 */