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_set_dst(__be32 saddr,
 116                                                     __be32 daddr,
 117                                                     __u8 tos, __u8 ttl,
 118                                                     __be16 tp_dst,
 119                                                     __be16 flags,
 120                                                     __be64 tunnel_id,
 121                                                     int md_size)
 122 {
 123         struct metadata_dst *tun_dst;
 124
 125         tun_dst = tun_rx_dst(md_size);
 126         if (!tun_dst)
 127                 return NULL;
 128
 129         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 130                            saddr, daddr, tos, ttl,
 131                            0, 0, tp_dst, tunnel_id, flags);
 132         return tun_dst;
 133 }
 134
 135 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
 136                                                  __be16 flags,
 137                                                  __be64 tunnel_id,
 138                                                  int md_size)
 139 {
 140         const struct iphdr *iph = ip_hdr(skb);
 141
 142         return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
 143                                 0, flags, tunnel_id, md_size);
 144 }
 145
 146 static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
 147                                                       const struct in6_addr *daddr,
 148                                                       __u8 tos, __u8 ttl,
 149                                                       __be16 tp_dst,
 150                                                       __be32 label,
 151                                                       __be16 flags,
 152                                                       __be64 tunnel_id,
 153                                                       int md_size)
 154 {
 155         struct metadata_dst *tun_dst;
 156         struct ip_tunnel_info *info;
 157
 158         tun_dst = tun_rx_dst(md_size);
 159         if (!tun_dst)
 160                 return NULL;
 161
 162         info = &tun_dst->u.tun_info;
 163         info->mode = IP_TUNNEL_INFO_IPV6;
 164         info->key.tun_flags = flags;
 165         info->key.tun_id = tunnel_id;
 166         info->key.tp_src = 0;
 167         info->key.tp_dst = tp_dst;
 168
 169         info->key.u.ipv6.src = *saddr;
 170         info->key.u.ipv6.dst = *daddr;
 171
 172         info->key.tos = tos;
 173         info->key.ttl = ttl;
 174         info->key.label = label;
 175
 176         return tun_dst;
 177 }
 178
 179 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 180                                                    __be16 flags,
 181                                                    __be64 tunnel_id,
 182                                                    int md_size)
 183 {
 184         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 185
 186         return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
 187                                   ipv6_get_dsfield(ip6h), ip6h->hop_limit,
 188                                   0, ip6_flowlabel(ip6h), flags, tunnel_id,
 189                                   md_size);
 190 }
 191 #endif /* __NET_DST_METADATA_H */