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
19static 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
28static 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
37static 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
44static 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
53void 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
63static 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;
88out:
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 */
97int 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 */
116int 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
133static 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
141void 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
151int vlan_tunnel_init(struct net_bridge_vlan_group *vg)
152{
153	return rhashtable_init(&vg->tunnel_hash, &br_vlan_tunnel_rht_params);
154}
155
156void vlan_tunnel_deinit(struct net_bridge_vlan_group *vg)
157{
158	rhashtable_destroy(&vg->tunnel_hash);
159}
160
161void 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
185int 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	if (BR_INPUT_SKB_CB(skb)->backup_nhid) {
205		tunnel_dst = __ip_tun_set_dst(0, 0, 0, 0, 0, TUNNEL_KEY,
206					      tunnel_id, 0);
207		if (!tunnel_dst)
208			return -ENOMEM;
209
210		tunnel_dst->u.tun_info.mode |= IP_TUNNEL_INFO_TX |
211					       IP_TUNNEL_INFO_BRIDGE;
212		tunnel_dst->u.tun_info.key.nhid =
213			BR_INPUT_SKB_CB(skb)->backup_nhid;
214		skb_dst_set(skb, &tunnel_dst->dst);
215
216		return 0;
217	}
218
219	tunnel_dst = rcu_dereference(vlan->tinfo.tunnel_dst);
220	if (tunnel_dst && dst_hold_safe(&tunnel_dst->dst))
221		skb_dst_set(skb, &tunnel_dst->dst);
222
223	return 0;
224}
225