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 static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
  48                                        const struct sk_buff *skb_b)
  49 {
  50         const struct metadata_dst *a, *b;
  51
  52         if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
  53                 return 0;
  54
  55         a = (const struct metadata_dst *) skb_dst(skb_a);
  56         b = (const struct metadata_dst *) skb_dst(skb_b);
  57
  58         if (!a != !b || a->u.tun_info.options_len != b->u.tun_info.options_len)
  59                 return 1;
  60
  61         return memcmp(&a->u.tun_info, &b->u.tun_info,
  62                       sizeof(a->u.tun_info) + a->u.tun_info.options_len);
  63 }
  64
  65 struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
  66 struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);
  67
  68 static inline struct metadata_dst *tun_rx_dst(int md_size)
  69 {
  70         struct metadata_dst *tun_dst;
  71
  72         tun_dst = metadata_dst_alloc(md_size, GFP_ATOMIC);
  73         if (!tun_dst)
  74                 return NULL;
  75
  76         tun_dst->u.tun_info.options_len = 0;
  77         tun_dst->u.tun_info.mode = 0;
  78         return tun_dst;
  79 }
  80
  81 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
  82 {
  83         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  84         int md_size;
  85         struct metadata_dst *new_md;
  86
  87         if (!md_dst)
  88                 return ERR_PTR(-EINVAL);
  89
  90         md_size = md_dst->u.tun_info.options_len;
  91         new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
  92         if (!new_md)
  93                 return ERR_PTR(-ENOMEM);
  94
  95         memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
  96                sizeof(struct ip_tunnel_info) + md_size);
  97         skb_dst_drop(skb);
  98         dst_hold(&new_md->dst);
  99         skb_dst_set(skb, &new_md->dst);
 100         return new_md;
 101 }
 102
 103 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
 104 {
 105         struct metadata_dst *dst;
 106
 107         dst = tun_dst_unclone(skb);
 108         if (IS_ERR(dst))
 109                 return NULL;
 110
 111         return &dst->u.tun_info;
 112 }
 113
 114 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
 115                                                  __be16 flags,
 116                                                  __be64 tunnel_id,
 117                                                  int md_size)
 118 {
 119         const struct iphdr *iph = ip_hdr(skb);
 120         struct metadata_dst *tun_dst;
 121
 122         tun_dst = tun_rx_dst(md_size);
 123         if (!tun_dst)
 124                 return NULL;
 125
 126         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 127                            iph->saddr, iph->daddr, iph->tos, iph->ttl,
 128                            0, 0, tunnel_id, flags);
 129         return tun_dst;
 130 }
 131
 132 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 133                                                  __be16 flags,
 134                                                  __be64 tunnel_id,
 135                                                  int md_size)
 136 {
 137         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 138         struct metadata_dst *tun_dst;
 139         struct ip_tunnel_info *info;
 140
 141         tun_dst = tun_rx_dst(md_size);
 142         if (!tun_dst)
 143                 return NULL;
 144
 145         info = &tun_dst->u.tun_info;
 146         info->mode = IP_TUNNEL_INFO_IPV6;
 147         info->key.tun_flags = flags;
 148         info->key.tun_id = tunnel_id;
 149         info->key.tp_src = 0;
 150         info->key.tp_dst = 0;
 151
 152         info->key.u.ipv6.src = ip6h->saddr;
 153         info->key.u.ipv6.dst = ip6h->daddr;
 154         info->key.tos = ipv6_get_dsfield(ip6h);
 155         info->key.ttl = ip6h->hop_limit;
 156         return tun_dst;
 157 }
 158
 159 #endif /* __NET_DST_METADATA_H */