net/bridge/br_vlan_tunnel.c

   1 /*
   2  *      Bridge per vlan tunnel port dst_metadata handling code
   3  *
   4  *      Authors:
   5  *      Roopa Prabhu            <roopa@cumulusnetworks.com>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/rtnetlink.h>
  16 #include <linux/slab.h>
  17 #include <net/switchdev.h>
  18 #include <net/dst_metadata.h>
  19
  20 #include "br_private.h"
  21 #include "br_private_tunnel.h"
  22
  23 static inline int br_vlan_tunid_cmp(struct rhashtable_compare_arg *arg,
  24                                     const void *ptr)
  25 {
  26         const struct net_bridge_vlan *vle = ptr;
  27         __be64 tunid = *(__be64 *)arg->key;
  28
  29         return vle->tinfo.tunnel_id != tunid;
  30 }
  31
  32 static const struct rhashtable_params br_vlan_tunnel_rht_params = {
  33         .head_offset = offsetof(struct net_bridge_vlan, tnode),
  34         .key_offset = offsetof(struct net_bridge_vlan, tinfo.tunnel_id),
  35         .key_len = sizeof(__be64),
  36         .nelem_hint = 3,
  37         .locks_mul = 1,
  38         .obj_cmpfn = br_vlan_tunid_cmp,
  39         .automatic_shrinking = true,
  40 };
  41
  42 static struct net_bridge_vlan *br_vlan_tunnel_lookup(struct rhashtable *tbl,
  43                                                      u64 tunnel_id)
  44 {
  45         return rhashtable_lookup_fast(tbl, &tunnel_id,
  46                                       br_vlan_tunnel_rht_params);
  47 }
  48
  49 static void vlan_tunnel_info_release(struct net_bridge_vlan *vlan)
  50 {
  51         struct metadata_dst *tdst = rtnl_dereference(vlan->tinfo.tunnel_dst);
  52
  53         WRITE_ONCE(vlan->tinfo.tunnel_id, 0);
  54         RCU_INIT_POINTER(vlan->tinfo.tunnel_dst, NULL);
  55         dst_release(&tdst->dst);
  56 }
  57
  58 void vlan_tunnel_info_del(struct net_bridge_vlan_group *vg,
  59                           struct net_bridge_vlan *vlan)
  60 {
  61         if (!rcu_access_pointer(vlan->tinfo.tunnel_dst))
  62                 return;
  63         rhashtable_remove_fast(&vg->tunnel_hash, &vlan->tnode,
  64                                br_vlan_tunnel_rht_params);
  65         vlan_tunnel_info_release(vlan);
  66 }
  67
  68 static int __vlan_tunnel_info_add(struct net_bridge_vlan_group *vg,
  69                                   struct net_bridge_vlan *vlan, u32 tun_id)
  70 {
  71         struct metadata_dst *metadata = rtnl_dereference(vlan->tinfo.tunnel_dst);
  72         __be64 key = key32_to_tunnel_id(cpu_to_be32(tun_id));
  73         int err;
  74
  75         if (metadata)
  76                 return -EEXIST;
  77
  78         metadata = __ip_tun_set_dst(0, 0, 0, 0, 0, TUNNEL_KEY,
  79                                     key, 0);
  80         if (!metadata)
  81                 return -EINVAL;
  82
  83         metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_BRIDGE;
  84         rcu_assign_pointer(vlan->tinfo.tunnel_dst, metadata);
  85         WRITE_ONCE(vlan->tinfo.tunnel_id, key);
  86
  87         err = rhashtable_lookup_insert_fast(&vg->tunnel_hash, &vlan->tnode,
  88                                             br_vlan_tunnel_rht_params);
  89         if (err)
  90                 goto out;
  91
  92         return 0;
  93 out:
  94         vlan_tunnel_info_release(vlan);
  95
  96         return err;
  97 }
  98
  99 /* Must be protected by RTNL.
 100  * Must be called with vid in range from 1 to 4094 inclusive.
 101  */
 102 int nbp_vlan_tunnel_info_add(struct net_bridge_port *port, u16 vid, u32 tun_id)
 103 {
 104         struct net_bridge_vlan_group *vg;
 105         struct net_bridge_vlan *vlan;
 106
 107         ASSERT_RTNL();
 108
 109         vg = nbp_vlan_group(port);
 110         vlan = br_vlan_find(vg, vid);
 111         if (!vlan)
 112                 return -EINVAL;
 113
 114         return __vlan_tunnel_info_add(vg, vlan, tun_id);
 115 }
 116
 117 /* Must be protected by RTNL.
 118  * Must be called with vid in range from 1 to 4094 inclusive.
 119  */
 120 int nbp_vlan_tunnel_info_delete(struct net_bridge_port *port, u16 vid)
 121 {
 122         struct net_bridge_vlan_group *vg;
 123         struct net_bridge_vlan *v;
 124
 125         ASSERT_RTNL();
 126
 127         vg = nbp_vlan_group(port);
 128         v = br_vlan_find(vg, vid);
 129         if (!v)
 130                 return -ENOENT;
 131
 132         vlan_tunnel_info_del(vg, v);
 133
 134         return 0;
 135 }
 136
 137 static void __vlan_tunnel_info_flush(struct net_bridge_vlan_group *vg)
 138 {
 139         struct net_bridge_vlan *vlan, *tmp;
 140
 141         list_for_each_entry_safe(vlan, tmp, &vg->vlan_list, vlist)
 142                 vlan_tunnel_info_del(vg, vlan);
 143 }
 144
 145 void nbp_vlan_tunnel_info_flush(struct net_bridge_port *port)
 146 {
 147         struct net_bridge_vlan_group *vg;
 148
 149         ASSERT_RTNL();
 150
 151         vg = nbp_vlan_group(port);
 152         __vlan_tunnel_info_flush(vg);
 153 }
 154
 155 int vlan_tunnel_init(struct net_bridge_vlan_group *vg)
 156 {
 157         return rhashtable_init(&vg->tunnel_hash, &br_vlan_tunnel_rht_params);
 158 }
 159
 160 void vlan_tunnel_deinit(struct net_bridge_vlan_group *vg)
 161 {
 162         rhashtable_destroy(&vg->tunnel_hash);
 163 }
 164
 165 int br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
 166                                   struct net_bridge_port *p,
 167                                   struct net_bridge_vlan_group *vg)
 168 {
 169         struct ip_tunnel_info *tinfo = skb_tunnel_info(skb);
 170         struct net_bridge_vlan *vlan;
 171
 172         if (!vg || !tinfo)
 173                 return 0;
 174
 175         /* if already tagged, ignore */
 176         if (skb_vlan_tagged(skb))
 177                 return 0;
 178
 179         /* lookup vid, given tunnel id */
 180         vlan = br_vlan_tunnel_lookup(&vg->tunnel_hash, tinfo->key.tun_id);
 181         if (!vlan)
 182                 return 0;
 183
 184         skb_dst_drop(skb);
 185
 186         __vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
 187
 188         return 0;
 189 }
 190
 191 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
 192                                  struct net_bridge_vlan *vlan)
 193 {
 194         struct metadata_dst *tunnel_dst;
 195         __be64 tunnel_id;
 196         int err;
 197
 198         if (!vlan)
 199                 return 0;
 200
 201         tunnel_id = READ_ONCE(vlan->tinfo.tunnel_id);
 202         if (!tunnel_id || unlikely(!skb_vlan_tag_present(skb)))
 203                 return 0;
 204
 205         skb_dst_drop(skb);
 206         err = skb_vlan_pop(skb);
 207         if (err)
 208                 return err;
 209
 210         tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
 211         if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
 212                 skb_dst_set(skb, &tunnel_dst->dst);
 213
 214         return 0;
 215 }