datapath/linux/compat/netdevice.c

   1 #include <linux/netdevice.h>
   2 #include <linux/if_vlan.h>
   3
   4 #ifdef HAVE_RHEL_OVS_HOOK
   5 int nr_bridges = 0;
   6 #endif
   7
   8 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
   9 #ifndef HAVE_CAN_CHECKSUM_PROTOCOL
  10 static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
  11 {
  12         return  ((features & NETIF_F_GEN_CSUM) ||
  13                 ((features & NETIF_F_V4_CSUM) &&
  14                                 protocol == htons(ETH_P_IP)) ||
  15                 ((features & NETIF_F_V6_CSUM) &&
  16                                 protocol == htons(ETH_P_IPV6)) ||
  17                 ((features & NETIF_F_FCOE_CRC) &&
  18                                 protocol == htons(ETH_P_FCOE)));
  19 }
  20 #endif
  21
  22 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
  23 {
  24 #ifdef CONFIG_HIGHMEM
  25         int i;
  26
  27         if (dev->features & NETIF_F_HIGHDMA)
  28                 return 0;
  29
  30         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
  31                 if (PageHighMem(skb_shinfo(skb)->frags[i].page))
  32                         return 1;
  33
  34 #endif
  35         return 0;
  36 }
  37
  38 static netdev_features_t harmonize_features(struct sk_buff *skb,
  39                                             __be16 protocol,
  40                                             netdev_features_t features)
  41 {
  42         if (!can_checksum_protocol(features, protocol)) {
  43                 features &= ~NETIF_F_ALL_CSUM;
  44                 features &= ~NETIF_F_SG;
  45         } else if (illegal_highdma(skb->dev, skb)) {
  46                 features &= ~NETIF_F_SG;
  47         }
  48
  49         return features;
  50 }
  51
  52 netdev_features_t rpl_netif_skb_features(struct sk_buff *skb)
  53 {
  54         unsigned long vlan_features = skb->dev->vlan_features;
  55
  56         __be16 protocol = skb->protocol;
  57         netdev_features_t features = skb->dev->features;
  58
  59         if (protocol == htons(ETH_P_8021Q)) {
  60                 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
  61                 protocol = veh->h_vlan_encapsulated_proto;
  62         } else if (!vlan_tx_tag_present(skb)) {
  63                 return harmonize_features(skb, protocol, features);
  64         }
  65
  66         features &= (vlan_features | NETIF_F_HW_VLAN_TX);
  67
  68         if (protocol != htons(ETH_P_8021Q)) {
  69                 return harmonize_features(skb, protocol, features);
  70         } else {
  71                 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
  72                         NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
  73                 return harmonize_features(skb, protocol, features);
  74         }
  75 }
  76
  77 struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb,
  78                                     netdev_features_t features)
  79 {
  80         int vlan_depth = ETH_HLEN;
  81         __be16 type = skb->protocol;
  82         __be16 skb_proto;
  83         struct sk_buff *skb_gso;
  84
  85         while (type == htons(ETH_P_8021Q)) {
  86                 struct vlan_hdr *vh;
  87
  88                 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
  89                         return ERR_PTR(-EINVAL);
  90
  91                 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
  92                 type = vh->h_vlan_encapsulated_proto;
  93                 vlan_depth += VLAN_HLEN;
  94         }
  95
  96         /* this hack needed to get regular skb_gso_segment() */
  97 #undef skb_gso_segment
  98         skb_proto = skb->protocol;
  99         skb->protocol = type;
 100
 101         skb_gso = skb_gso_segment(skb, features);
 102         skb->protocol = skb_proto;
 103         return skb_gso;
 104 }
 105 #endif  /* kernel version < 2.6.38 */