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;
  67         struct metadata_dst *new_md;
  68
  69         if (!md_dst)
  70                 return ERR_PTR(-EINVAL);
  71
  72         md_size = md_dst->u.tun_info.options_len;
  73         new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
  74         if (!new_md)
  75                 return ERR_PTR(-ENOMEM);
  76
  77         memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
  78                sizeof(struct ip_tunnel_info) + md_size);
  79         skb_dst_drop(skb);
  80         dst_hold(&new_md->dst);
  81         skb_dst_set(skb, &new_md->dst);
  82         return new_md;
  83 }
  84
  85 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
  86 {
  87         struct metadata_dst *dst;
  88
  89         dst = tun_dst_unclone(skb);
  90         if (IS_ERR(dst))
  91                 return NULL;
  92
  93         return &dst->u.tun_info;
  94 }
  95
  96 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
  97                                                  __be16 flags,
  98                                                  __be64 tunnel_id,
  99                                                  int md_size)
 100 {
 101         const struct iphdr *iph = ip_hdr(skb);
 102         struct metadata_dst *tun_dst;
 103
 104         tun_dst = tun_rx_dst(md_size);
 105         if (!tun_dst)
 106                 return NULL;
 107
 108         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 109                            iph->saddr, iph->daddr, iph->tos, iph->ttl,
 110                            0, 0, tunnel_id, flags);
 111         return tun_dst;
 112 }
 113
 114 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 115                                                  __be16 flags,
 116                                                  __be64 tunnel_id,
 117                                                  int md_size)
 118 {
 119         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 120         struct metadata_dst *tun_dst;
 121         struct ip_tunnel_info *info;
 122
 123         tun_dst = tun_rx_dst(md_size);
 124         if (!tun_dst)
 125                 return NULL;
 126
 127         info = &tun_dst->u.tun_info;
 128         info->mode = IP_TUNNEL_INFO_IPV6;
 129         info->key.tun_flags = flags;
 130         info->key.tun_id = tunnel_id;
 131         info->key.tp_src = 0;
 132         info->key.tp_dst = 0;
 133
 134         info->key.u.ipv6.src = ip6h->saddr;
 135         info->key.u.ipv6.dst = ip6h->daddr;
 136         info->key.tos = ipv6_get_dsfield(ip6h);
 137         info->key.ttl = ip6h->hop_limit;
 138         return tun_dst;
 139 }
 140
 141 #endif /* __NET_DST_METADATA_H */