include/net/dst_metadata.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __NET_DST_METADATA_H
   3 #define __NET_DST_METADATA_H 1
   4
   5 #include <linux/skbuff.h>
   6 #include <net/ip_tunnels.h>
   7 #include <net/macsec.h>
   8 #include <net/dst.h>
   9
  10 enum metadata_type {
  11         METADATA_IP_TUNNEL,
  12         METADATA_HW_PORT_MUX,
  13         METADATA_MACSEC,
  14         METADATA_XFRM,
  15 };
  16
  17 struct hw_port_info {
  18         struct net_device *lower_dev;
  19         u32 port_id;
  20 };
  21
  22 struct macsec_info {
  23         sci_t sci;
  24 };
  25
  26 struct xfrm_md_info {
  27         u32 if_id;
  28         int link;
  29         struct dst_entry *dst_orig;
  30 };
  31
  32 struct metadata_dst {
  33         struct dst_entry                dst;
  34         enum metadata_type              type;
  35         union {
  36                 struct ip_tunnel_info   tun_info;
  37                 struct hw_port_info     port_info;
  38                 struct macsec_info      macsec_info;
  39                 struct xfrm_md_info     xfrm_info;
  40         } u;
  41 };
  42
  43 static inline struct metadata_dst *skb_metadata_dst(const struct sk_buff *skb)
  44 {
  45         struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
  46
  47         if (md_dst && md_dst->dst.flags & DST_METADATA)
  48                 return md_dst;
  49
  50         return NULL;
  51 }
  52
  53 static inline struct ip_tunnel_info *
  54 skb_tunnel_info(const struct sk_buff *skb)
  55 {
  56         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  57         struct dst_entry *dst;
  58
  59         if (md_dst && md_dst->type == METADATA_IP_TUNNEL)
  60                 return &md_dst->u.tun_info;
  61
  62         dst = skb_dst(skb);
  63         if (dst && dst->lwtstate &&
  64             (dst->lwtstate->type == LWTUNNEL_ENCAP_IP ||
  65              dst->lwtstate->type == LWTUNNEL_ENCAP_IP6))
  66                 return lwt_tun_info(dst->lwtstate);
  67
  68         return NULL;
  69 }
  70
  71 static inline struct xfrm_md_info *lwt_xfrm_info(struct lwtunnel_state *lwt)
  72 {
  73         return (struct xfrm_md_info *)lwt->data;
  74 }
  75
  76 static inline struct xfrm_md_info *skb_xfrm_md_info(const struct sk_buff *skb)
  77 {
  78         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  79         struct dst_entry *dst;
  80
  81         if (md_dst && md_dst->type == METADATA_XFRM)
  82                 return &md_dst->u.xfrm_info;
  83
  84         dst = skb_dst(skb);
  85         if (dst && dst->lwtstate &&
  86             dst->lwtstate->type == LWTUNNEL_ENCAP_XFRM)
  87                 return lwt_xfrm_info(dst->lwtstate);
  88
  89         return NULL;
  90 }
  91
  92 static inline bool skb_valid_dst(const struct sk_buff *skb)
  93 {
  94         struct dst_entry *dst = skb_dst(skb);
  95
  96         return dst && !(dst->flags & DST_METADATA);
  97 }
  98
  99 static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
 100                                        const struct sk_buff *skb_b)
 101 {
 102         const struct metadata_dst *a, *b;
 103
 104         if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
 105                 return 0;
 106
 107         a = (const struct metadata_dst *) skb_dst(skb_a);
 108         b = (const struct metadata_dst *) skb_dst(skb_b);
 109
 110         if (!a != !b || a->type != b->type)
 111                 return 1;
 112
 113         switch (a->type) {
 114         case METADATA_HW_PORT_MUX:
 115                 return memcmp(&a->u.port_info, &b->u.port_info,
 116                               sizeof(a->u.port_info));
 117         case METADATA_IP_TUNNEL:
 118                 return memcmp(&a->u.tun_info, &b->u.tun_info,
 119                               sizeof(a->u.tun_info) +
 120                                          a->u.tun_info.options_len);
 121         case METADATA_MACSEC:
 122                 return memcmp(&a->u.macsec_info, &b->u.macsec_info,
 123                               sizeof(a->u.macsec_info));
 124         case METADATA_XFRM:
 125                 return memcmp(&a->u.xfrm_info, &b->u.xfrm_info,
 126                               sizeof(a->u.xfrm_info));
 127         default:
 128                 return 1;
 129         }
 130 }
 131
 132 void metadata_dst_free(struct metadata_dst *);
 133 struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
 134                                         gfp_t flags);
 135 void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
 136 struct metadata_dst __percpu *
 137 metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
 138
 139 static inline struct metadata_dst *tun_rx_dst(int md_size)
 140 {
 141         struct metadata_dst *tun_dst;
 142
 143         tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
 144         if (!tun_dst)
 145                 return NULL;
 146
 147         tun_dst->u.tun_info.options_len = 0;
 148         tun_dst->u.tun_info.mode = 0;
 149         return tun_dst;
 150 }
 151
 152 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
 153 {
 154         struct metadata_dst *md_dst = skb_metadata_dst(skb);
 155         int md_size;
 156         struct metadata_dst *new_md;
 157
 158         if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
 159                 return ERR_PTR(-EINVAL);
 160
 161         md_size = md_dst->u.tun_info.options_len;
 162         new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
 163         if (!new_md)
 164                 return ERR_PTR(-ENOMEM);
 165
 166         unsafe_memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
 167                       sizeof(struct ip_tunnel_info) + md_size,
 168                       /* metadata_dst_alloc() reserves room (md_size bytes) for
 169                        * options right after the ip_tunnel_info struct.
 170                        */);
 171 #ifdef CONFIG_DST_CACHE
 172         /* Unclone the dst cache if there is one */
 173         if (new_md->u.tun_info.dst_cache.cache) {
 174                 int ret;
 175
 176                 ret = dst_cache_init(&new_md->u.tun_info.dst_cache, GFP_ATOMIC);
 177                 if (ret) {
 178                         metadata_dst_free(new_md);
 179                         return ERR_PTR(ret);
 180                 }
 181         }
 182 #endif
 183
 184         skb_dst_drop(skb);
 185         skb_dst_set(skb, &new_md->dst);
 186         return new_md;
 187 }
 188
 189 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
 190 {
 191         struct metadata_dst *dst;
 192
 193         dst = tun_dst_unclone(skb);
 194         if (IS_ERR(dst))
 195                 return NULL;
 196
 197         return &dst->u.tun_info;
 198 }
 199
 200 static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
 201                                                     __be32 daddr,
 202                                                     __u8 tos, __u8 ttl,
 203                                                     __be16 tp_dst,
 204                                                     const unsigned long *flags,
 205                                                     __be64 tunnel_id,
 206                                                     int md_size)
 207 {
 208         struct metadata_dst *tun_dst;
 209
 210         tun_dst = tun_rx_dst(md_size);
 211         if (!tun_dst)
 212                 return NULL;
 213
 214         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 215                            saddr, daddr, tos, ttl,
 216                            0, 0, tp_dst, tunnel_id, flags);
 217         return tun_dst;
 218 }
 219
 220 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
 221                                                  const unsigned long *flags,
 222                                                  __be64 tunnel_id,
 223                                                  int md_size)
 224 {
 225         const struct iphdr *iph = ip_hdr(skb);
 226
 227         return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
 228                                 0, flags, tunnel_id, md_size);
 229 }
 230
 231 static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
 232                                                       const struct in6_addr *daddr,
 233                                                       __u8 tos, __u8 ttl,
 234                                                       __be16 tp_dst,
 235                                                       __be32 label,
 236                                                       const unsigned long *flags,
 237                                                       __be64 tunnel_id,
 238                                                       int md_size)
 239 {
 240         struct metadata_dst *tun_dst;
 241         struct ip_tunnel_info *info;
 242
 243         tun_dst = tun_rx_dst(md_size);
 244         if (!tun_dst)
 245                 return NULL;
 246
 247         info = &tun_dst->u.tun_info;
 248         info->mode = IP_TUNNEL_INFO_IPV6;
 249         ip_tunnel_flags_copy(info->key.tun_flags, flags);
 250         info->key.tun_id = tunnel_id;
 251         info->key.tp_src = 0;
 252         info->key.tp_dst = tp_dst;
 253
 254         info->key.u.ipv6.src = *saddr;
 255         info->key.u.ipv6.dst = *daddr;
 256
 257         info->key.tos = tos;
 258         info->key.ttl = ttl;
 259         info->key.label = label;
 260
 261         return tun_dst;
 262 }
 263
 264 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 265                                                    const unsigned long *flags,
 266                                                    __be64 tunnel_id,
 267                                                    int md_size)
 268 {
 269         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 270
 271         return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
 272                                   ipv6_get_dsfield(ip6h), ip6h->hop_limit,
 273                                   0, ip6_flowlabel(ip6h), flags, tunnel_id,
 274                                   md_size);
 275 }
 276 #endif /* __NET_DST_METADATA_H */