1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Bridge Multiple Spanning Tree Support
4 *
5 * Authors:
6 * Tobias Waldekranz <tobias@waldekranz.com>
7 */
8
9 #include <linux/kernel.h>
10 #include <net/switchdev.h>
11
12 #include "br_private.h"
13
14 DEFINE_STATIC_KEY_FALSE(br_mst_used);
15
br_mst_enabled(const struct net_device * dev)16 bool br_mst_enabled(const struct net_device *dev)
17 {
18 if (!netif_is_bridge_master(dev))
19 return false;
20
21 return br_opt_get(netdev_priv(dev), BROPT_MST_ENABLED);
22 }
23 EXPORT_SYMBOL_GPL(br_mst_enabled);
24
br_mst_get_info(const struct net_device * dev,u16 msti,unsigned long * vids)25 int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids)
26 {
27 const struct net_bridge_vlan_group *vg;
28 const struct net_bridge_vlan *v;
29 const struct net_bridge *br;
30
31 ASSERT_RTNL();
32
33 if (!netif_is_bridge_master(dev))
34 return -EINVAL;
35
36 br = netdev_priv(dev);
37 if (!br_opt_get(br, BROPT_MST_ENABLED))
38 return -EINVAL;
39
40 vg = br_vlan_group(br);
41
42 list_for_each_entry(v, &vg->vlan_list, vlist) {
43 if (v->msti == msti)
44 __set_bit(v->vid, vids);
45 }
46
47 return 0;
48 }
49 EXPORT_SYMBOL_GPL(br_mst_get_info);
50
br_mst_get_state(const struct net_device * dev,u16 msti,u8 * state)51 int br_mst_get_state(const struct net_device *dev, u16 msti, u8 *state)
52 {
53 const struct net_bridge_port *p = NULL;
54 const struct net_bridge_vlan_group *vg;
55 const struct net_bridge_vlan *v;
56
57 ASSERT_RTNL();
58
59 p = br_port_get_check_rtnl(dev);
60 if (!p || !br_opt_get(p->br, BROPT_MST_ENABLED))
61 return -EINVAL;
62
63 vg = nbp_vlan_group(p);
64
65 list_for_each_entry(v, &vg->vlan_list, vlist) {
66 if (v->brvlan->msti == msti) {
67 *state = v->state;
68 return 0;
69 }
70 }
71
72 return -ENOENT;
73 }
74 EXPORT_SYMBOL_GPL(br_mst_get_state);
75
br_mst_vlan_set_state(struct net_bridge_vlan_group * vg,struct net_bridge_vlan * v,u8 state)76 static void br_mst_vlan_set_state(struct net_bridge_vlan_group *vg,
77 struct net_bridge_vlan *v,
78 u8 state)
79 {
80 if (br_vlan_get_state(v) == state)
81 return;
82
83 br_vlan_set_state(v, state);
84
85 if (v->vid == vg->pvid)
86 br_vlan_set_pvid_state(vg, state);
87 }
88
br_mst_set_state(struct net_bridge_port * p,u16 msti,u8 state,struct netlink_ext_ack * extack)89 int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state,
90 struct netlink_ext_ack *extack)
91 {
92 struct switchdev_attr attr = {
93 .id = SWITCHDEV_ATTR_ID_PORT_MST_STATE,
94 .orig_dev = p->dev,
95 .u.mst_state = {
96 .msti = msti,
97 .state = state,
98 },
99 };
100 struct net_bridge_vlan_group *vg;
101 struct net_bridge_vlan *v;
102 int err = 0;
103
104 rcu_read_lock();
105 vg = nbp_vlan_group_rcu(p);
106 if (!vg)
107 goto out;
108
109 /* MSTI 0 (CST) state changes are notified via the regular
110 * SWITCHDEV_ATTR_ID_PORT_STP_STATE.
111 */
112 if (msti) {
113 err = switchdev_port_attr_set(p->dev, &attr, extack);
114 if (err && err != -EOPNOTSUPP)
115 goto out;
116 }
117
118 err = 0;
119 list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
120 if (v->brvlan->msti != msti)
121 continue;
122
123 br_mst_vlan_set_state(vg, v, state);
124 }
125
126 out:
127 rcu_read_unlock();
128 return err;
129 }
130
br_mst_vlan_sync_state(struct net_bridge_vlan * pv,u16 msti)131 static void br_mst_vlan_sync_state(struct net_bridge_vlan *pv, u16 msti)
132 {
133 struct net_bridge_vlan_group *vg = nbp_vlan_group(pv->port);
134 struct net_bridge_vlan *v;
135
136 list_for_each_entry(v, &vg->vlan_list, vlist) {
137 /* If this port already has a defined state in this
138 * MSTI (through some other VLAN membership), inherit
139 * it.
140 */
141 if (v != pv && v->brvlan->msti == msti) {
142 br_mst_vlan_set_state(vg, pv, v->state);
143 return;
144 }
145 }
146
147 /* Otherwise, start out in a new MSTI with all ports disabled. */
148 return br_mst_vlan_set_state(vg, pv, BR_STATE_DISABLED);
149 }
150
br_mst_vlan_set_msti(struct net_bridge_vlan * mv,u16 msti)151 int br_mst_vlan_set_msti(struct net_bridge_vlan *mv, u16 msti)
152 {
153 struct switchdev_attr attr = {
154 .id = SWITCHDEV_ATTR_ID_VLAN_MSTI,
155 .orig_dev = mv->br->dev,
156 .u.vlan_msti = {
157 .vid = mv->vid,
158 .msti = msti,
159 },
160 };
161 struct net_bridge_vlan_group *vg;
162 struct net_bridge_vlan *pv;
163 struct net_bridge_port *p;
164 int err;
165
166 if (mv->msti == msti)
167 return 0;
168
169 err = switchdev_port_attr_set(mv->br->dev, &attr, NULL);
170 if (err && err != -EOPNOTSUPP)
171 return err;
172
173 mv->msti = msti;
174
175 list_for_each_entry(p, &mv->br->port_list, list) {
176 vg = nbp_vlan_group(p);
177
178 pv = br_vlan_find(vg, mv->vid);
179 if (pv)
180 br_mst_vlan_sync_state(pv, msti);
181 }
182
183 return 0;
184 }
185
br_mst_vlan_init_state(struct net_bridge_vlan * v)186 void br_mst_vlan_init_state(struct net_bridge_vlan *v)
187 {
188 /* VLANs always start out in MSTI 0 (CST) */
189 v->msti = 0;
190
191 if (br_vlan_is_master(v))
192 v->state = BR_STATE_FORWARDING;
193 else
194 v->state = v->port->state;
195 }
196
br_mst_set_enabled(struct net_bridge * br,bool on,struct netlink_ext_ack * extack)197 int br_mst_set_enabled(struct net_bridge *br, bool on,
198 struct netlink_ext_ack *extack)
199 {
200 struct switchdev_attr attr = {
201 .id = SWITCHDEV_ATTR_ID_BRIDGE_MST,
202 .orig_dev = br->dev,
203 .u.mst = on,
204 };
205 struct net_bridge_vlan_group *vg;
206 struct net_bridge_port *p;
207 int err;
208
209 list_for_each_entry(p, &br->port_list, list) {
210 vg = nbp_vlan_group(p);
211
212 if (!vg->num_vlans)
213 continue;
214
215 NL_SET_ERR_MSG(extack,
216 "MST mode can't be changed while VLANs exist");
217 return -EBUSY;
218 }
219
220 if (br_opt_get(br, BROPT_MST_ENABLED) == on)
221 return 0;
222
223 err = switchdev_port_attr_set(br->dev, &attr, extack);
224 if (err && err != -EOPNOTSUPP)
225 return err;
226
227 if (on)
228 static_branch_enable(&br_mst_used);
229 else
230 static_branch_disable(&br_mst_used);
231
232 br_opt_toggle(br, BROPT_MST_ENABLED, on);
233 return 0;
234 }
235
br_mst_info_size(const struct net_bridge_vlan_group * vg)236 size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
237 {
238 DECLARE_BITMAP(seen, VLAN_N_VID) = { 0 };
239 const struct net_bridge_vlan *v;
240 size_t sz;
241
242 /* IFLA_BRIDGE_MST */
243 sz = nla_total_size(0);
244
245 list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
246 if (test_bit(v->brvlan->msti, seen))
247 continue;
248
249 /* IFLA_BRIDGE_MST_ENTRY */
250 sz += nla_total_size(0) +
251 /* IFLA_BRIDGE_MST_ENTRY_MSTI */
252 nla_total_size(sizeof(u16)) +
253 /* IFLA_BRIDGE_MST_ENTRY_STATE */
254 nla_total_size(sizeof(u8));
255
256 __set_bit(v->brvlan->msti, seen);
257 }
258
259 return sz;
260 }
261
br_mst_fill_info(struct sk_buff * skb,const struct net_bridge_vlan_group * vg)262 int br_mst_fill_info(struct sk_buff *skb,
263 const struct net_bridge_vlan_group *vg)
264 {
265 DECLARE_BITMAP(seen, VLAN_N_VID) = { 0 };
266 const struct net_bridge_vlan *v;
267 struct nlattr *nest;
268 int err = 0;
269
270 list_for_each_entry(v, &vg->vlan_list, vlist) {
271 if (test_bit(v->brvlan->msti, seen))
272 continue;
273
274 nest = nla_nest_start_noflag(skb, IFLA_BRIDGE_MST_ENTRY);
275 if (!nest ||
276 nla_put_u16(skb, IFLA_BRIDGE_MST_ENTRY_MSTI, v->brvlan->msti) ||
277 nla_put_u8(skb, IFLA_BRIDGE_MST_ENTRY_STATE, v->state)) {
278 err = -EMSGSIZE;
279 break;
280 }
281 nla_nest_end(skb, nest);
282
283 __set_bit(v->brvlan->msti, seen);
284 }
285
286 return err;
287 }
288
289 static const struct nla_policy br_mst_nl_policy[IFLA_BRIDGE_MST_ENTRY_MAX + 1] = {
290 [IFLA_BRIDGE_MST_ENTRY_MSTI] = NLA_POLICY_RANGE(NLA_U16,
291 1, /* 0 reserved for CST */
292 VLAN_N_VID - 1),
293 [IFLA_BRIDGE_MST_ENTRY_STATE] = NLA_POLICY_RANGE(NLA_U8,
294 BR_STATE_DISABLED,
295 BR_STATE_BLOCKING),
296 };
297
br_mst_process_one(struct net_bridge_port * p,const struct nlattr * attr,struct netlink_ext_ack * extack)298 static int br_mst_process_one(struct net_bridge_port *p,
299 const struct nlattr *attr,
300 struct netlink_ext_ack *extack)
301 {
302 struct nlattr *tb[IFLA_BRIDGE_MST_ENTRY_MAX + 1];
303 u16 msti;
304 u8 state;
305 int err;
306
307 err = nla_parse_nested(tb, IFLA_BRIDGE_MST_ENTRY_MAX, attr,
308 br_mst_nl_policy, extack);
309 if (err)
310 return err;
311
312 if (!tb[IFLA_BRIDGE_MST_ENTRY_MSTI]) {
313 NL_SET_ERR_MSG_MOD(extack, "MSTI not specified");
314 return -EINVAL;
315 }
316
317 if (!tb[IFLA_BRIDGE_MST_ENTRY_STATE]) {
318 NL_SET_ERR_MSG_MOD(extack, "State not specified");
319 return -EINVAL;
320 }
321
322 msti = nla_get_u16(tb[IFLA_BRIDGE_MST_ENTRY_MSTI]);
323 state = nla_get_u8(tb[IFLA_BRIDGE_MST_ENTRY_STATE]);
324
325 return br_mst_set_state(p, msti, state, extack);
326 }
327
br_mst_process(struct net_bridge_port * p,const struct nlattr * mst_attr,struct netlink_ext_ack * extack)328 int br_mst_process(struct net_bridge_port *p, const struct nlattr *mst_attr,
329 struct netlink_ext_ack *extack)
330 {
331 struct nlattr *attr;
332 int err, msts = 0;
333 int rem;
334
335 if (!br_opt_get(p->br, BROPT_MST_ENABLED)) {
336 NL_SET_ERR_MSG_MOD(extack, "Can't modify MST state when MST is disabled");
337 return -EBUSY;
338 }
339
340 nla_for_each_nested(attr, mst_attr, rem) {
341 switch (nla_type(attr)) {
342 case IFLA_BRIDGE_MST_ENTRY:
343 err = br_mst_process_one(p, attr, extack);
344 break;
345 default:
346 continue;
347 }
348
349 msts++;
350 if (err)
351 break;
352 }
353
354 if (!msts) {
355 NL_SET_ERR_MSG_MOD(extack, "Found no MST entries to process");
356 err = -EINVAL;
357 }
358
359 return err;
360 }
361