xref: /linux/net/bridge/br_vlan_tunnel.c (revision f9aec1648df09d55436a0e3a94acff1df507751f)
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 void 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;
170 
171 	/* if already tagged, ignore */
172 	if (skb_vlan_tagged(skb))
173 		return;
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;
179 
180 	skb_dst_drop(skb);
181 
182 	__vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
183 }
184 
185 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
186 				 struct net_bridge_vlan *vlan)
187 {
188 	struct metadata_dst *tunnel_dst;
189 	__be64 tunnel_id;
190 	int err;
191 
192 	if (!vlan)
193 		return 0;
194 
195 	tunnel_id = READ_ONCE(vlan->tinfo.tunnel_id);
196 	if (!tunnel_id || unlikely(!skb_vlan_tag_present(skb)))
197 		return 0;
198 
199 	skb_dst_drop(skb);
200 	err = skb_vlan_pop(skb);
201 	if (err)
202 		return err;
203 
204 	tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
205 	if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
206 		skb_dst_set(skb, &tunnel_dst->dst);
207 
208 	return 0;
209 }
210