include/net/dst_metadata.h

   1 #ifndef __NET_DST_METADATA_H
   2 #define __NET_DST_METADATA_H 1
   3
   4 #include <linux/skbuff.h>
   5 #include <net/ip_tunnels.h>
   6 #include <net/dst.h>
   7
   8 struct metadata_dst {
   9         struct dst_entry                dst;
  10         union {
  11                 struct ip_tunnel_info   tun_info;
  12         } u;
  13 };
  14
  15 static inline struct metadata_dst *skb_metadata_dst(struct sk_buff *skb)
  16 {
  17         struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
  18
  19         if (md_dst && md_dst->dst.flags & DST_METADATA)
  20                 return md_dst;
  21
  22         return NULL;
  23 }
  24
  25 static inline struct ip_tunnel_info *skb_tunnel_info(struct sk_buff *skb)
  26 {
  27         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  28         struct dst_entry *dst;
  29
  30         if (md_dst)
  31                 return &md_dst->u.tun_info;
  32
  33         dst = skb_dst(skb);
  34         if (dst && dst->lwtstate)
  35                 return lwt_tun_info(dst->lwtstate);
  36
  37         return NULL;
  38 }
  39
  40 static inline bool skb_valid_dst(const struct sk_buff *skb)
  41 {
  42         struct dst_entry *dst = skb_dst(skb);
  43
  44         return dst && !(dst->flags & DST_METADATA);
  45 }
  46
  47 struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
  48 struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);
  49
  50 static inline struct metadata_dst *tun_rx_dst(int md_size)
  51 {
  52         struct metadata_dst *tun_dst;
  53
  54         tun_dst = metadata_dst_alloc(md_size, GFP_ATOMIC);
  55         if (!tun_dst)
  56                 return NULL;
  57
  58         tun_dst->u.tun_info.options_len = 0;
  59         tun_dst->u.tun_info.mode = 0;
  60         return tun_dst;
  61 }
  62
  63 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
  64 {
  65         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  66         int md_size = md_dst->u.tun_info.options_len;
  67         struct metadata_dst *new_md;
  68
  69         if (!md_dst)
  70                 return ERR_PTR(-EINVAL);
  71
  72         new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
  73         if (!new_md)
  74                 return ERR_PTR(-ENOMEM);
  75
  76         memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
  77                sizeof(struct ip_tunnel_info) + md_size);
  78         skb_dst_drop(skb);
  79         dst_hold(&new_md->dst);
  80         skb_dst_set(skb, &new_md->dst);
  81         return new_md;
  82 }
  83
  84 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
  85 {
  86         struct metadata_dst *dst;
  87
  88         dst = tun_dst_unclone(skb);
  89         if (IS_ERR(dst))
  90                 return NULL;
  91
  92         return &dst->u.tun_info;
  93 }
  94
  95 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
  96                                                  __be16 flags,
  97                                                  __be64 tunnel_id,
  98                                                  int md_size)
  99 {
 100         const struct iphdr *iph = ip_hdr(skb);
 101         struct metadata_dst *tun_dst;
 102
 103         tun_dst = tun_rx_dst(md_size);
 104         if (!tun_dst)
 105                 return NULL;
 106
 107         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 108                            iph->saddr, iph->daddr, iph->tos, iph->ttl,
 109                            0, 0, tunnel_id, flags);
 110         return tun_dst;
 111 }
 112
 113 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 114                                                  __be16 flags,
 115                                                  __be64 tunnel_id,
 116                                                  int md_size)
 117 {
 118         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 119         struct metadata_dst *tun_dst;
 120         struct ip_tunnel_info *info;
 121
 122         tun_dst = tun_rx_dst(md_size);
 123         if (!tun_dst)
 124                 return NULL;
 125
 126         info = &tun_dst->u.tun_info;
 127         info->mode = IP_TUNNEL_INFO_IPV6;
 128         info->key.tun_flags = flags;
 129         info->key.tun_id = tunnel_id;
 130         info->key.tp_src = 0;
 131         info->key.tp_dst = 0;
 132
 133         info->key.u.ipv6.src = ip6h->saddr;
 134         info->key.u.ipv6.dst = ip6h->daddr;
 135         info->key.tos = ipv6_get_dsfield(ip6h);
 136         info->key.ttl = ip6h->hop_limit;
 137         return tun_dst;
 138 }
 139
 140 #endif /* __NET_DST_METADATA_H */