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 void metadata_dst_free(struct metadata_dst *);
  66 struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
  67 struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);
  68
  69 static inline struct metadata_dst *tun_rx_dst(int md_size)
  70 {
  71         struct metadata_dst *tun_dst;
  72
  73         tun_dst = metadata_dst_alloc(md_size, GFP_ATOMIC);
  74         if (!tun_dst)
  75                 return NULL;
  76
  77         tun_dst->u.tun_info.options_len = 0;
  78         tun_dst->u.tun_info.mode = 0;
  79         return tun_dst;
  80 }
  81
  82 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
  83 {
  84         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  85         int md_size;
  86         struct metadata_dst *new_md;
  87
  88         if (!md_dst)
  89                 return ERR_PTR(-EINVAL);
  90
  91         md_size = md_dst->u.tun_info.options_len;
  92         new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
  93         if (!new_md)
  94                 return ERR_PTR(-ENOMEM);
  95
  96         memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
  97                sizeof(struct ip_tunnel_info) + md_size);
  98         skb_dst_drop(skb);
  99         dst_hold(&new_md->dst);
 100         skb_dst_set(skb, &new_md->dst);
 101         return new_md;
 102 }
 103
 104 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
 105 {
 106         struct metadata_dst *dst;
 107
 108         dst = tun_dst_unclone(skb);
 109         if (IS_ERR(dst))
 110                 return NULL;
 111
 112         return &dst->u.tun_info;
 113 }
 114
 115 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
 116                                                  __be16 flags,
 117                                                  __be64 tunnel_id,
 118                                                  int md_size)
 119 {
 120         const struct iphdr *iph = ip_hdr(skb);
 121         struct metadata_dst *tun_dst;
 122
 123         tun_dst = tun_rx_dst(md_size);
 124         if (!tun_dst)
 125                 return NULL;
 126
 127         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 128                            iph->saddr, iph->daddr, iph->tos, iph->ttl,
 129                            0, 0, 0, tunnel_id, flags);
 130         return tun_dst;
 131 }
 132
 133 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 134                                                  __be16 flags,
 135                                                  __be64 tunnel_id,
 136                                                  int md_size)
 137 {
 138         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 139         struct metadata_dst *tun_dst;
 140         struct ip_tunnel_info *info;
 141
 142         tun_dst = tun_rx_dst(md_size);
 143         if (!tun_dst)
 144                 return NULL;
 145
 146         info = &tun_dst->u.tun_info;
 147         info->mode = IP_TUNNEL_INFO_IPV6;
 148         info->key.tun_flags = flags;
 149         info->key.tun_id = tunnel_id;
 150         info->key.tp_src = 0;
 151         info->key.tp_dst = 0;
 152
 153         info->key.u.ipv6.src = ip6h->saddr;
 154         info->key.u.ipv6.dst = ip6h->daddr;
 155
 156         info->key.tos = ipv6_get_dsfield(ip6h);
 157         info->key.ttl = ip6h->hop_limit;
 158         info->key.label = ip6_flowlabel(ip6h);
 159
 160         return tun_dst;
 161 }
 162
 163 #endif /* __NET_DST_METADATA_H */