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         IP_TUNNEL_DECLARE_FLAGS(flags) = { };
  69         int err;
  70
  71         if (metadata)
  72                 return -EEXIST;
  73
  74         __set_bit(IP_TUNNEL_KEY_BIT, flags);
  75         metadata = __ip_tun_set_dst(0, 0, 0, 0, 0, flags, key, 0);
  76         if (!metadata)
  77                 return -EINVAL;
  78
  79         metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_BRIDGE;
  80         rcu_assign_pointer(vlan->tinfo.tunnel_dst, metadata);
  81         WRITE_ONCE(vlan->tinfo.tunnel_id, key);
  82
  83         err = rhashtable_lookup_insert_fast(&vg->tunnel_hash, &vlan->tnode,
  84                                             br_vlan_tunnel_rht_params);
  85         if (err)
  86                 goto out;
  87
  88         return 0;
  89 out:
  90         vlan_tunnel_info_release(vlan);
  91
  92         return err;
  93 }
  94
  95 /* Must be protected by RTNL.
  96  * Must be called with vid in range from 1 to 4094 inclusive.
  97  */
  98 int nbp_vlan_tunnel_info_add(const struct net_bridge_port *port, u16 vid,
  99                              u32 tun_id)
 100 {
 101         struct net_bridge_vlan_group *vg;
 102         struct net_bridge_vlan *vlan;
 103
 104         ASSERT_RTNL();
 105
 106         vg = nbp_vlan_group(port);
 107         vlan = br_vlan_find(vg, vid);
 108         if (!vlan)
 109                 return -EINVAL;
 110
 111         return __vlan_tunnel_info_add(vg, vlan, tun_id);
 112 }
 113
 114 /* Must be protected by RTNL.
 115  * Must be called with vid in range from 1 to 4094 inclusive.
 116  */
 117 int nbp_vlan_tunnel_info_delete(const struct net_bridge_port *port, u16 vid)
 118 {
 119         struct net_bridge_vlan_group *vg;
 120         struct net_bridge_vlan *v;
 121
 122         ASSERT_RTNL();
 123
 124         vg = nbp_vlan_group(port);
 125         v = br_vlan_find(vg, vid);
 126         if (!v)
 127                 return -ENOENT;
 128
 129         vlan_tunnel_info_del(vg, v);
 130
 131         return 0;
 132 }
 133
 134 static void __vlan_tunnel_info_flush(struct net_bridge_vlan_group *vg)
 135 {
 136         struct net_bridge_vlan *vlan, *tmp;
 137
 138         list_for_each_entry_safe(vlan, tmp, &vg->vlan_list, vlist)
 139                 vlan_tunnel_info_del(vg, vlan);
 140 }
 141
 142 void nbp_vlan_tunnel_info_flush(struct net_bridge_port *port)
 143 {
 144         struct net_bridge_vlan_group *vg;
 145
 146         ASSERT_RTNL();
 147
 148         vg = nbp_vlan_group(port);
 149         __vlan_tunnel_info_flush(vg);
 150 }
 151
 152 int vlan_tunnel_init(struct net_bridge_vlan_group *vg)
 153 {
 154         return rhashtable_init(&vg->tunnel_hash, &br_vlan_tunnel_rht_params);
 155 }
 156
 157 void vlan_tunnel_deinit(struct net_bridge_vlan_group *vg)
 158 {
 159         rhashtable_destroy(&vg->tunnel_hash);
 160 }
 161
 162 void br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
 163                                    struct net_bridge_port *p,
 164                                    struct net_bridge_vlan_group *vg)
 165 {
 166         struct ip_tunnel_info *tinfo = skb_tunnel_info(skb);
 167         struct net_bridge_vlan *vlan;
 168
 169         if (!vg || !tinfo)
 170                 return;
 171
 172         /* if already tagged, ignore */
 173         if (skb_vlan_tagged(skb))
 174                 return;
 175
 176         /* lookup vid, given tunnel id */
 177         vlan = br_vlan_tunnel_lookup(&vg->tunnel_hash, tinfo->key.tun_id);
 178         if (!vlan)
 179                 return;
 180
 181         skb_dst_drop(skb);
 182
 183         __vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
 184 }
 185
 186 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
 187                                  struct net_bridge_vlan *vlan)
 188 {
 189         IP_TUNNEL_DECLARE_FLAGS(flags) = { };
 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         if (BR_INPUT_SKB_CB(skb)->backup_nhid) {
 207                 __set_bit(IP_TUNNEL_KEY_BIT, flags);
 208                 tunnel_dst = __ip_tun_set_dst(0, 0, 0, 0, 0, flags,
 209                                               tunnel_id, 0);
 210                 if (!tunnel_dst)
 211                         return -ENOMEM;
 212
 213                 tunnel_dst->u.tun_info.mode |= IP_TUNNEL_INFO_TX |
 214                                                IP_TUNNEL_INFO_BRIDGE;
 215                 tunnel_dst->u.tun_info.key.nhid =
 216                         BR_INPUT_SKB_CB(skb)->backup_nhid;
 217                 skb_dst_set(skb, &tunnel_dst->dst);
 218
 219                 return 0;
 220         }
 221
 222         tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
 223         if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
 224                 skb_dst_set(skb, &tunnel_dst->dst);
 225
 226         return 0;
 227 }