linux/include/net/dst_metadata.h
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   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
   9enum metadata_type {
  10        METADATA_IP_TUNNEL,
  11        METADATA_HW_PORT_MUX,
  12};
  13
  14struct hw_port_info {
  15        struct net_device *lower_dev;
  16        u32 port_id;
  17};
  18
  19struct 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
  28static 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
  38static inline struct ip_tunnel_info *
  39skb_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
  54static 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
  61static 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
  88void metadata_dst_free(struct metadata_dst *);
  89struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
  90                                        gfp_t flags);
  91void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
  92struct metadata_dst __percpu *
  93metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
  94
  95static 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
 108static 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
 130static 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
 141static 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
 161static 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
 172static 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
 205static 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 */
 218