datapath/linux/compat/netdevice.c

   1 #include <linux/netdevice.h>
   2 #include <linux/if_vlan.h>
   3 #include <net/mpls.h>
   4
   5 #include "gso.h"
   6
   7 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
   8 #ifndef HAVE_CAN_CHECKSUM_PROTOCOL
   9 static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
  10 {
  11         return  ((features & NETIF_F_GEN_CSUM) ||
  12                 ((features & NETIF_F_V4_CSUM) &&
  13                                 protocol == htons(ETH_P_IP)) ||
  14                 ((features & NETIF_F_V6_CSUM) &&
  15                                 protocol == htons(ETH_P_IPV6)) ||
  16                 ((features & NETIF_F_FCOE_CRC) &&
  17                                 protocol == htons(ETH_P_FCOE)));
  18 }
  19 #endif
  20
  21 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
  22 {
  23 #ifdef CONFIG_HIGHMEM
  24         int i;
  25
  26         if (dev->features & NETIF_F_HIGHDMA)
  27                 return 0;
  28
  29         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
  30                 if (PageHighMem(skb_shinfo(skb)->frags[i].page))
  31                         return 1;
  32
  33 #endif
  34         return 0;
  35 }
  36
  37 static netdev_features_t harmonize_features(struct sk_buff *skb,
  38                                             __be16 protocol,
  39                                             netdev_features_t features)
  40 {
  41         if (!can_checksum_protocol(features, protocol)) {
  42                 features &= ~NETIF_F_ALL_CSUM;
  43                 features &= ~NETIF_F_SG;
  44         } else if (illegal_highdma(skb->dev, skb)) {
  45                 features &= ~NETIF_F_SG;
  46         }
  47
  48         return features;
  49 }
  50
  51 netdev_features_t rpl_netif_skb_features(struct sk_buff *skb)
  52 {
  53         unsigned long vlan_features = skb->dev->vlan_features;
  54
  55         __be16 protocol = skb->protocol;
  56         netdev_features_t features = skb->dev->features;
  57
  58         if (protocol == htons(ETH_P_8021Q)) {
  59                 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
  60                 protocol = veh->h_vlan_encapsulated_proto;
  61         } else if (!skb_vlan_tag_present(skb)) {
  62                 return harmonize_features(skb, protocol, features);
  63         }
  64
  65         features &= (vlan_features | NETIF_F_HW_VLAN_TX);
  66
  67         if (protocol != htons(ETH_P_8021Q)) {
  68                 return harmonize_features(skb, protocol, features);
  69         } else {
  70                 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
  71                         NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
  72                 return harmonize_features(skb, protocol, features);
  73         }
  74 }
  75 EXPORT_SYMBOL_GPL(rpl_netif_skb_features);
  76 #endif  /* kernel version < 2.6.38 */
  77
  78 #ifdef OVS_USE_COMPAT_GSO_SEGMENTATION
  79 struct sk_buff *rpl__skb_gso_segment(struct sk_buff *skb,
  80                                     netdev_features_t features,
  81                                     bool tx_path)
  82 {
  83         int vlan_depth = ETH_HLEN;
  84         __be16 type = skb->protocol;
  85         __be16 skb_proto;
  86         struct sk_buff *skb_gso;
  87
  88         while (type == htons(ETH_P_8021Q)) {
  89                 struct vlan_hdr *vh;
  90
  91                 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
  92                         return ERR_PTR(-EINVAL);
  93
  94                 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
  95                 type = vh->h_vlan_encapsulated_proto;
  96                 vlan_depth += VLAN_HLEN;
  97         }
  98
  99         if (eth_p_mpls(type))
 100                 type = ovs_skb_get_inner_protocol(skb);
 101
 102         /* this hack needed to get regular skb_gso_segment() */
 103         skb_proto = skb->protocol;
 104         skb->protocol = type;
 105
 106 #ifdef HAVE___SKB_GSO_SEGMENT
 107 #undef __skb_gso_segment
 108         skb_gso = __skb_gso_segment(skb, features, tx_path);
 109 #else
 110 #undef skb_gso_segment
 111         skb_gso = skb_gso_segment(skb, features);
 112 #endif
 113
 114         skb->protocol = skb_proto;
 115         return skb_gso;
 116 }
 117 EXPORT_SYMBOL_GPL(rpl__skb_gso_segment);
 118
 119 #endif  /* OVS_USE_COMPAT_GSO_SEGMENTATION */