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                                                      u64 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(struct net_bridge_port *port, u16 vid, u32 tun_id)
  98 {
  99         struct net_bridge_vlan_group *vg;
 100         struct net_bridge_vlan *vlan;
 101
 102         ASSERT_RTNL();
 103
 104         vg = nbp_vlan_group(port);
 105         vlan = br_vlan_find(vg, vid);
 106         if (!vlan)
 107                 return -EINVAL;
 108
 109         return __vlan_tunnel_info_add(vg, vlan, tun_id);
 110 }
 111
 112 /* Must be protected by RTNL.
 113  * Must be called with vid in range from 1 to 4094 inclusive.
 114  */
 115 int nbp_vlan_tunnel_info_delete(struct net_bridge_port *port, u16 vid)
 116 {
 117         struct net_bridge_vlan_group *vg;
 118         struct net_bridge_vlan *v;
 119
 120         ASSERT_RTNL();
 121
 122         vg = nbp_vlan_group(port);
 123         v = br_vlan_find(vg, vid);
 124         if (!v)
 125                 return -ENOENT;
 126
 127         vlan_tunnel_info_del(vg, v);
 128
 129         return 0;
 130 }
 131
 132 static void __vlan_tunnel_info_flush(struct net_bridge_vlan_group *vg)
 133 {
 134         struct net_bridge_vlan *vlan, *tmp;
 135
 136         list_for_each_entry_safe(vlan, tmp, &vg->vlan_list, vlist)
 137                 vlan_tunnel_info_del(vg, vlan);
 138 }
 139
 140 void nbp_vlan_tunnel_info_flush(struct net_bridge_port *port)
 141 {
 142         struct net_bridge_vlan_group *vg;
 143
 144         ASSERT_RTNL();
 145
 146         vg = nbp_vlan_group(port);
 147         __vlan_tunnel_info_flush(vg);
 148 }
 149
 150 int vlan_tunnel_init(struct net_bridge_vlan_group *vg)
 151 {
 152         return rhashtable_init(&vg->tunnel_hash, &br_vlan_tunnel_rht_params);
 153 }
 154
 155 void vlan_tunnel_deinit(struct net_bridge_vlan_group *vg)
 156 {
 157         rhashtable_destroy(&vg->tunnel_hash);
 158 }
 159
 160 int br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
 161                                   struct net_bridge_port *p,
 162                                   struct net_bridge_vlan_group *vg)
 163 {
 164         struct ip_tunnel_info *tinfo = skb_tunnel_info(skb);
 165         struct net_bridge_vlan *vlan;
 166
 167         if (!vg || !tinfo)
 168                 return 0;
 169
 170         /* if already tagged, ignore */
 171         if (skb_vlan_tagged(skb))
 172                 return 0;
 173
 174         /* lookup vid, given tunnel id */
 175         vlan = br_vlan_tunnel_lookup(&vg->tunnel_hash, tinfo->key.tun_id);
 176         if (!vlan)
 177                 return 0;
 178
 179         skb_dst_drop(skb);
 180
 181         __vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
 182
 183         return 0;
 184 }
 185
 186 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
 187                                  struct net_bridge_vlan *vlan)
 188 {
 189         struct metadata_dst *tunnel_dst;
 190         __be64 tunnel_id;
 191         int err;
 192
 193         if (!vlan)
 194                 return 0;
 195
 196         tunnel_id = READ_ONCE(vlan->tinfo.tunnel_id);
 197         if (!tunnel_id || unlikely(!skb_vlan_tag_present(skb)))
 198                 return 0;
 199
 200         skb_dst_drop(skb);
 201         err = skb_vlan_pop(skb);
 202         if (err)
 203                 return err;
 204
 205         tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
 206         if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
 207                 skb_dst_set(skb, &tunnel_dst->dst);
 208
 209         return 0;
 210 }