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