net/bridge/br_vlan_tunnel.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Bridge per vlan tunnel port dst_metadata handling code
   4  *
   5  *      Authors:
   6  *      Roopa Prabhu            <roopa@cumulusnetworks.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/rtnetlink.h>
  12 #include <linux/slab.h>
  13 #include <net/switchdev.h>
  14 #include <net/dst_metadata.h>
  15
  16 #include "br_private.h"
  17 #include "br_private_tunnel.h"
  18
  19 static inline int br_vlan_tunid_cmp(struct rhashtable_compare_arg *arg,
  20                                     const void *ptr)
  21 {
  22         const struct net_bridge_vlan *vle = ptr;
  23         __be64 tunid = *(__be64 *)arg->key;
  24
  25         return vle->tinfo.tunnel_id != tunid;
  26 }
  27
  28 static const struct rhashtable_params br_vlan_tunnel_rht_params = {
  29         .head_offset = offsetof(struct net_bridge_vlan, tnode),
  30         .key_offset = offsetof(struct net_bridge_vlan, tinfo.tunnel_id),
  31         .key_len = sizeof(__be64),
  32         .nelem_hint = 3,
  33         .obj_cmpfn = br_vlan_tunid_cmp,
  34         .automatic_shrinking = true,
  35 };
  36
  37 static struct net_bridge_vlan *br_vlan_tunnel_lookup(struct rhashtable *tbl,
  38                                                      __be64 tunnel_id)
  39 {
  40         return rhashtable_lookup_fast(tbl, &tunnel_id,
  41                                       br_vlan_tunnel_rht_params);
  42 }
  43
  44 static void vlan_tunnel_info_release(struct net_bridge_vlan *vlan)
  45 {
  46         struct metadata_dst *tdst = rtnl_dereference(vlan->tinfo.tunnel_dst);
  47
  48         WRITE_ONCE(vlan->tinfo.tunnel_id, 0);
  49         RCU_INIT_POINTER(vlan->tinfo.tunnel_dst, NULL);
  50         dst_release(&tdst->dst);
  51 }
  52
  53 void vlan_tunnel_info_del(struct net_bridge_vlan_group *vg,
  54                           struct net_bridge_vlan *vlan)
  55 {
  56         if (!rcu_access_pointer(vlan->tinfo.tunnel_dst))
  57                 return;
  58         rhashtable_remove_fast(&vg->tunnel_hash, &vlan->tnode,
  59                                br_vlan_tunnel_rht_params);
  60         vlan_tunnel_info_release(vlan);
  61 }
  62
  63 static int __vlan_tunnel_info_add(struct net_bridge_vlan_group *vg,
  64                                   struct net_bridge_vlan *vlan, u32 tun_id)
  65 {
  66         struct metadata_dst *metadata = rtnl_dereference(vlan->tinfo.tunnel_dst);
  67         __be64 key = key32_to_tunnel_id(cpu_to_be32(tun_id));
  68         int err;
  69
  70         if (metadata)
  71                 return -EEXIST;
  72
  73         metadata = __ip_tun_set_dst(0, 0, 0, 0, 0, TUNNEL_KEY,
  74                                     key, 0);
  75         if (!metadata)
  76                 return -EINVAL;
  77
  78         metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_BRIDGE;
  79         rcu_assign_pointer(vlan->tinfo.tunnel_dst, metadata);
  80         WRITE_ONCE(vlan->tinfo.tunnel_id, key);
  81
  82         err = rhashtable_lookup_insert_fast(&vg->tunnel_hash, &vlan->tnode,
  83                                             br_vlan_tunnel_rht_params);
  84         if (err)
  85                 goto out;
  86
  87         return 0;
  88 out:
  89         vlan_tunnel_info_release(vlan);
  90
  91         return err;
  92 }
  93
  94 /* Must be protected by RTNL.
  95  * Must be called with vid in range from 1 to 4094 inclusive.
  96  */
  97 int nbp_vlan_tunnel_info_add(const struct net_bridge_port *port, u16 vid,
  98                              u32 tun_id)
  99 {
 100         struct net_bridge_vlan_group *vg;
 101         struct net_bridge_vlan *vlan;
 102
 103         ASSERT_RTNL();
 104
 105         vg = nbp_vlan_group(port);
 106         vlan = br_vlan_find(vg, vid);
 107         if (!vlan)
 108                 return -EINVAL;
 109
 110         return __vlan_tunnel_info_add(vg, vlan, tun_id);
 111 }
 112
 113 /* Must be protected by RTNL.
 114  * Must be called with vid in range from 1 to 4094 inclusive.
 115  */
 116 int nbp_vlan_tunnel_info_delete(const struct net_bridge_port *port, u16 vid)
 117 {
 118         struct net_bridge_vlan_group *vg;
 119         struct net_bridge_vlan *v;
 120
 121         ASSERT_RTNL();
 122
 123         vg = nbp_vlan_group(port);
 124         v = br_vlan_find(vg, vid);
 125         if (!v)
 126                 return -ENOENT;
 127
 128         vlan_tunnel_info_del(vg, v);
 129
 130         return 0;
 131 }
 132
 133 static void __vlan_tunnel_info_flush(struct net_bridge_vlan_group *vg)
 134 {
 135         struct net_bridge_vlan *vlan, *tmp;
 136
 137         list_for_each_entry_safe(vlan, tmp, &vg->vlan_list, vlist)
 138                 vlan_tunnel_info_del(vg, vlan);
 139 }
 140
 141 void nbp_vlan_tunnel_info_flush(struct net_bridge_port *port)
 142 {
 143         struct net_bridge_vlan_group *vg;
 144
 145         ASSERT_RTNL();
 146
 147         vg = nbp_vlan_group(port);
 148         __vlan_tunnel_info_flush(vg);
 149 }
 150
 151 int vlan_tunnel_init(struct net_bridge_vlan_group *vg)
 152 {
 153         return rhashtable_init(&vg->tunnel_hash, &br_vlan_tunnel_rht_params);
 154 }
 155
 156 void vlan_tunnel_deinit(struct net_bridge_vlan_group *vg)
 157 {
 158         rhashtable_destroy(&vg->tunnel_hash);
 159 }
 160
 161 int br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
 162                                   struct net_bridge_port *p,
 163                                   struct net_bridge_vlan_group *vg)
 164 {
 165         struct ip_tunnel_info *tinfo = skb_tunnel_info(skb);
 166         struct net_bridge_vlan *vlan;
 167
 168         if (!vg || !tinfo)
 169                 return 0;
 170
 171         /* if already tagged, ignore */
 172         if (skb_vlan_tagged(skb))
 173                 return 0;
 174
 175         /* lookup vid, given tunnel id */
 176         vlan = br_vlan_tunnel_lookup(&vg->tunnel_hash, tinfo->key.tun_id);
 177         if (!vlan)
 178                 return 0;
 179
 180         skb_dst_drop(skb);
 181
 182         __vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
 183
 184         return 0;
 185 }
 186
 187 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
 188                                  struct net_bridge_vlan *vlan)
 189 {
 190         struct metadata_dst *tunnel_dst;
 191         __be64 tunnel_id;
 192         int err;
 193
 194         if (!vlan)
 195                 return 0;
 196
 197         tunnel_id = READ_ONCE(vlan->tinfo.tunnel_id);
 198         if (!tunnel_id || unlikely(!skb_vlan_tag_present(skb)))
 199                 return 0;
 200
 201         skb_dst_drop(skb);
 202         err = skb_vlan_pop(skb);
 203         if (err)
 204                 return err;
 205
 206         tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
 207         if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
 208                 skb_dst_set(skb, &tunnel_dst->dst);
 209
 210         return 0;
 211 }