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/dst.h>
   8
   9 enum metadata_type {
  10         METADATA_IP_TUNNEL,
  11         METADATA_HW_PORT_MUX,
  12 };
  13
  14 struct hw_port_info {
  15         struct net_device *lower_dev;
  16         u32 port_id;
  17 };
  18
  19 struct metadata_dst {
  20         struct dst_entry                dst;
  21         enum metadata_type              type;
  22         union {
  23                 struct ip_tunnel_info   tun_info;
  24                 struct hw_port_info     port_info;
  25         } u;
  26 };
  27
  28 static inline struct metadata_dst *skb_metadata_dst(const struct sk_buff *skb)
  29 {
  30         struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
  31
  32         if (md_dst && md_dst->dst.flags & DST_METADATA)
  33                 return md_dst;
  34
  35         return NULL;
  36 }
  37
  38 static inline struct ip_tunnel_info *
  39 skb_tunnel_info(const struct sk_buff *skb)
  40 {
  41         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  42         struct dst_entry *dst;
  43
  44         if (md_dst && md_dst->type == METADATA_IP_TUNNEL)
  45                 return &md_dst->u.tun_info;
  46
  47         dst = skb_dst(skb);
  48         if (dst && dst->lwtstate)
  49                 return lwt_tun_info(dst->lwtstate);
  50
  51         return NULL;
  52 }
  53
  54 static inline bool skb_valid_dst(const struct sk_buff *skb)
  55 {
  56         struct dst_entry *dst = skb_dst(skb);
  57
  58         return dst && !(dst->flags & DST_METADATA);
  59 }
  60
  61 static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
  62                                        const struct sk_buff *skb_b)
  63 {
  64         const struct metadata_dst *a, *b;
  65
  66         if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
  67                 return 0;
  68
  69         a = (const struct metadata_dst *) skb_dst(skb_a);
  70         b = (const struct metadata_dst *) skb_dst(skb_b);
  71
  72         if (!a != !b || a->type != b->type)
  73                 return 1;
  74
  75         switch (a->type) {
  76         case METADATA_HW_PORT_MUX:
  77                 return memcmp(&a->u.port_info, &b->u.port_info,
  78                               sizeof(a->u.port_info));
  79         case METADATA_IP_TUNNEL:
  80                 return memcmp(&a->u.tun_info, &b->u.tun_info,
  81                               sizeof(a->u.tun_info) +
  82                                          a->u.tun_info.options_len);
  83         default:
  84                 return 1;
  85         }
  86 }
  87
  88 void metadata_dst_free(struct metadata_dst *);
  89 struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
  90                                         gfp_t flags);
  91 void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
  92 struct metadata_dst __percpu *
  93 metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
  94
  95 static inline struct metadata_dst *tun_rx_dst(int md_size)
  96 {
  97         struct metadata_dst *tun_dst;
  98
  99         tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
 100         if (!tun_dst)
 101                 return NULL;
 102
 103         tun_dst->u.tun_info.options_len = 0;
 104         tun_dst->u.tun_info.mode = 0;
 105         return tun_dst;
 106 }
 107
 108 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
 109 {
 110         struct metadata_dst *md_dst = skb_metadata_dst(skb);
 111         int md_size;
 112         struct metadata_dst *new_md;
 113
 114         if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
 115                 return ERR_PTR(-EINVAL);
 116
 117         md_size = md_dst->u.tun_info.options_len;
 118         new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
 119         if (!new_md)
 120                 return ERR_PTR(-ENOMEM);
 121
 122         memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
 123                sizeof(struct ip_tunnel_info) + md_size);
 124         skb_dst_drop(skb);
 125         dst_hold(&new_md->dst);
 126         skb_dst_set(skb, &new_md->dst);
 127         return new_md;
 128 }
 129
 130 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
 131 {
 132         struct metadata_dst *dst;
 133
 134         dst = tun_dst_unclone(skb);
 135         if (IS_ERR(dst))
 136                 return NULL;
 137
 138         return &dst->u.tun_info;
 139 }
 140
 141 static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
 142                                                     __be32 daddr,
 143                                                     __u8 tos, __u8 ttl,
 144                                                     __be16 tp_dst,
 145                                                     __be16 flags,
 146                                                     __be64 tunnel_id,
 147                                                     int md_size)
 148 {
 149         struct metadata_dst *tun_dst;
 150
 151         tun_dst = tun_rx_dst(md_size);
 152         if (!tun_dst)
 153                 return NULL;
 154
 155         ip_tunnel_key_init(&tun_dst->u.tun_info.key,
 156                            saddr, daddr, tos, ttl,
 157                            0, 0, tp_dst, tunnel_id, flags);
 158         return tun_dst;
 159 }
 160
 161 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
 162                                                  __be16 flags,
 163                                                  __be64 tunnel_id,
 164                                                  int md_size)
 165 {
 166         const struct iphdr *iph = ip_hdr(skb);
 167
 168         return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
 169                                 0, flags, tunnel_id, md_size);
 170 }
 171
 172 static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
 173                                                       const struct in6_addr *daddr,
 174                                                       __u8 tos, __u8 ttl,
 175                                                       __be16 tp_dst,
 176                                                       __be32 label,
 177                                                       __be16 flags,
 178                                                       __be64 tunnel_id,
 179                                                       int md_size)
 180 {
 181         struct metadata_dst *tun_dst;
 182         struct ip_tunnel_info *info;
 183
 184         tun_dst = tun_rx_dst(md_size);
 185         if (!tun_dst)
 186                 return NULL;
 187
 188         info = &tun_dst->u.tun_info;
 189         info->mode = IP_TUNNEL_INFO_IPV6;
 190         info->key.tun_flags = flags;
 191         info->key.tun_id = tunnel_id;
 192         info->key.tp_src = 0;
 193         info->key.tp_dst = tp_dst;
 194
 195         info->key.u.ipv6.src = *saddr;
 196         info->key.u.ipv6.dst = *daddr;
 197
 198         info->key.tos = tos;
 199         info->key.ttl = ttl;
 200         info->key.label = label;
 201
 202         return tun_dst;
 203 }
 204
 205 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
 206                                                    __be16 flags,
 207                                                    __be64 tunnel_id,
 208                                                    int md_size)
 209 {
 210         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 211
 212         return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
 213                                   ipv6_get_dsfield(ip6h), ip6h->hop_limit,
 214                                   0, ip6_flowlabel(ip6h), flags, tunnel_id,
 215                                   md_size);
 216 }
 217 #endif /* __NET_DST_METADATA_H */