1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	Sysfs attributes of bridge ports
4 *	Linux ethernet bridge
5 *
6 *	Authors:
7 *	Stephen Hemminger		<shemminger@osdl.org>
8 */
9
10#include <linux/capability.h>
11#include <linux/kernel.h>
12#include <linux/netdevice.h>
13#include <linux/if_bridge.h>
14#include <linux/rtnetlink.h>
15#include <linux/spinlock.h>
16#include <linux/sched/signal.h>
17
18#include "br_private.h"
19
20/* IMPORTANT: new bridge port options must be added with netlink support only
21 *            please do not add new sysfs entries
22 */
23
24struct brport_attribute {
25	struct attribute	attr;
26	ssize_t (*show)(struct net_bridge_port *, char *);
27	int (*store)(struct net_bridge_port *, unsigned long);
28	int (*store_raw)(struct net_bridge_port *, char *);
29};
30
31#define BRPORT_ATTR_RAW(_name, _mode, _show, _store)			\
32const struct brport_attribute brport_attr_##_name = {			\
33	.attr		= {.name = __stringify(_name),			\
34			   .mode = _mode },				\
35	.show		= _show,					\
36	.store_raw	= _store,					\
37};
38
39#define BRPORT_ATTR(_name, _mode, _show, _store)		\
40const struct brport_attribute brport_attr_##_name = { 	        \
41	.attr = {.name = __stringify(_name), 			\
42		 .mode = _mode },				\
43	.show	= _show,					\
44	.store	= _store,					\
45};
46
47#define BRPORT_ATTR_FLAG(_name, _mask)				\
48static ssize_t show_##_name(struct net_bridge_port *p, char *buf) \
49{								\
50	return sprintf(buf, "%d\n", !!(p->flags & _mask));	\
51}								\
52static int store_##_name(struct net_bridge_port *p, unsigned long v) \
53{								\
54	return store_flag(p, v, _mask);				\
55}								\
56static BRPORT_ATTR(_name, 0644,					\
57		   show_##_name, store_##_name)
58
59static int store_flag(struct net_bridge_port *p, unsigned long v,
60		      unsigned long mask)
61{
62	struct netlink_ext_ack extack = {0};
63	unsigned long flags = p->flags;
64	int err;
65
66	if (v)
67		flags |= mask;
68	else
69		flags &= ~mask;
70
71	if (flags != p->flags) {
72		err = br_switchdev_set_port_flag(p, flags, mask, &extack);
73		if (err) {
74			netdev_err(p->dev, "%s\n", extack._msg);
75			return err;
76		}
77
78		p->flags = flags;
79		br_port_flags_change(p, mask);
80	}
81	return 0;
82}
83
84static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
85{
86	return sprintf(buf, "%d\n", p->path_cost);
87}
88
89static BRPORT_ATTR(path_cost, 0644,
90		   show_path_cost, br_stp_set_path_cost);
91
92static ssize_t show_priority(struct net_bridge_port *p, char *buf)
93{
94	return sprintf(buf, "%d\n", p->priority);
95}
96
97static BRPORT_ATTR(priority, 0644,
98			 show_priority, br_stp_set_port_priority);
99
100static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
101{
102	return br_show_bridge_id(buf, &p->designated_root);
103}
104static BRPORT_ATTR(designated_root, 0444, show_designated_root, NULL);
105
106static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
107{
108	return br_show_bridge_id(buf, &p->designated_bridge);
109}
110static BRPORT_ATTR(designated_bridge, 0444, show_designated_bridge, NULL);
111
112static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
113{
114	return sprintf(buf, "%d\n", p->designated_port);
115}
116static BRPORT_ATTR(designated_port, 0444, show_designated_port, NULL);
117
118static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
119{
120	return sprintf(buf, "%d\n", p->designated_cost);
121}
122static BRPORT_ATTR(designated_cost, 0444, show_designated_cost, NULL);
123
124static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
125{
126	return sprintf(buf, "0x%x\n", p->port_id);
127}
128static BRPORT_ATTR(port_id, 0444, show_port_id, NULL);
129
130static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
131{
132	return sprintf(buf, "0x%x\n", p->port_no);
133}
134
135static BRPORT_ATTR(port_no, 0444, show_port_no, NULL);
136
137static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
138{
139	return sprintf(buf, "%d\n", p->topology_change_ack);
140}
141static BRPORT_ATTR(change_ack, 0444, show_change_ack, NULL);
142
143static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
144{
145	return sprintf(buf, "%d\n", p->config_pending);
146}
147static BRPORT_ATTR(config_pending, 0444, show_config_pending, NULL);
148
149static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
150{
151	return sprintf(buf, "%d\n", p->state);
152}
153static BRPORT_ATTR(state, 0444, show_port_state, NULL);
154
155static ssize_t show_message_age_timer(struct net_bridge_port *p,
156					    char *buf)
157{
158	return sprintf(buf, "%ld\n", br_timer_value(&p->message_age_timer));
159}
160static BRPORT_ATTR(message_age_timer, 0444, show_message_age_timer, NULL);
161
162static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
163					    char *buf)
164{
165	return sprintf(buf, "%ld\n", br_timer_value(&p->forward_delay_timer));
166}
167static BRPORT_ATTR(forward_delay_timer, 0444, show_forward_delay_timer, NULL);
168
169static ssize_t show_hold_timer(struct net_bridge_port *p,
170					    char *buf)
171{
172	return sprintf(buf, "%ld\n", br_timer_value(&p->hold_timer));
173}
174static BRPORT_ATTR(hold_timer, 0444, show_hold_timer, NULL);
175
176static int store_flush(struct net_bridge_port *p, unsigned long v)
177{
178	br_fdb_delete_by_port(p->br, p, 0, 0); // Don't delete local entry
179	return 0;
180}
181static BRPORT_ATTR(flush, 0200, NULL, store_flush);
182
183static ssize_t show_group_fwd_mask(struct net_bridge_port *p, char *buf)
184{
185	return sprintf(buf, "%#x\n", p->group_fwd_mask);
186}
187
188static int store_group_fwd_mask(struct net_bridge_port *p,
189				unsigned long v)
190{
191	if (v & BR_GROUPFWD_MACPAUSE)
192		return -EINVAL;
193	p->group_fwd_mask = v;
194
195	return 0;
196}
197static BRPORT_ATTR(group_fwd_mask, 0644, show_group_fwd_mask,
198		   store_group_fwd_mask);
199
200static ssize_t show_backup_port(struct net_bridge_port *p, char *buf)
201{
202	struct net_bridge_port *backup_p;
203	int ret = 0;
204
205	rcu_read_lock();
206	backup_p = rcu_dereference(p->backup_port);
207	if (backup_p)
208		ret = sprintf(buf, "%s\n", backup_p->dev->name);
209	rcu_read_unlock();
210
211	return ret;
212}
213
214static int store_backup_port(struct net_bridge_port *p, char *buf)
215{
216	struct net_device *backup_dev = NULL;
217	char *nl = strchr(buf, '\n');
218
219	if (nl)
220		*nl = '\0';
221
222	if (strlen(buf) > 0) {
223		backup_dev = __dev_get_by_name(dev_net(p->dev), buf);
224		if (!backup_dev)
225			return -ENOENT;
226	}
227
228	return nbp_backup_change(p, backup_dev);
229}
230static BRPORT_ATTR_RAW(backup_port, 0644, show_backup_port, store_backup_port);
231
232BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE);
233BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD);
234BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK);
235BRPORT_ATTR_FLAG(learning, BR_LEARNING);
236BRPORT_ATTR_FLAG(unicast_flood, BR_FLOOD);
237BRPORT_ATTR_FLAG(proxyarp, BR_PROXYARP);
238BRPORT_ATTR_FLAG(proxyarp_wifi, BR_PROXYARP_WIFI);
239BRPORT_ATTR_FLAG(multicast_flood, BR_MCAST_FLOOD);
240BRPORT_ATTR_FLAG(broadcast_flood, BR_BCAST_FLOOD);
241BRPORT_ATTR_FLAG(neigh_suppress, BR_NEIGH_SUPPRESS);
242BRPORT_ATTR_FLAG(isolated, BR_ISOLATED);
243
244#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
245static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
246{
247	return sprintf(buf, "%d\n", p->multicast_ctx.multicast_router);
248}
249
250static int store_multicast_router(struct net_bridge_port *p,
251				      unsigned long v)
252{
253	return br_multicast_set_port_router(&p->multicast_ctx, v);
254}
255static BRPORT_ATTR(multicast_router, 0644, show_multicast_router,
256		   store_multicast_router);
257
258BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
259BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UNICAST);
260#endif
261
262static const struct brport_attribute *brport_attrs[] = {
263	&brport_attr_path_cost,
264	&brport_attr_priority,
265	&brport_attr_port_id,
266	&brport_attr_port_no,
267	&brport_attr_designated_root,
268	&brport_attr_designated_bridge,
269	&brport_attr_designated_port,
270	&brport_attr_designated_cost,
271	&brport_attr_state,
272	&brport_attr_change_ack,
273	&brport_attr_config_pending,
274	&brport_attr_message_age_timer,
275	&brport_attr_forward_delay_timer,
276	&brport_attr_hold_timer,
277	&brport_attr_flush,
278	&brport_attr_hairpin_mode,
279	&brport_attr_bpdu_guard,
280	&brport_attr_root_block,
281	&brport_attr_learning,
282	&brport_attr_unicast_flood,
283#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
284	&brport_attr_multicast_router,
285	&brport_attr_multicast_fast_leave,
286	&brport_attr_multicast_to_unicast,
287#endif
288	&brport_attr_proxyarp,
289	&brport_attr_proxyarp_wifi,
290	&brport_attr_multicast_flood,
291	&brport_attr_broadcast_flood,
292	&brport_attr_group_fwd_mask,
293	&brport_attr_neigh_suppress,
294	&brport_attr_isolated,
295	&brport_attr_backup_port,
296	NULL
297};
298
299#define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
300
301static ssize_t brport_show(struct kobject *kobj,
302			   struct attribute *attr, char *buf)
303{
304	struct brport_attribute *brport_attr = to_brport_attr(attr);
305	struct net_bridge_port *p = kobj_to_brport(kobj);
306
307	if (!brport_attr->show)
308		return -EINVAL;
309
310	return brport_attr->show(p, buf);
311}
312
313static ssize_t brport_store(struct kobject *kobj,
314			    struct attribute *attr,
315			    const char *buf, size_t count)
316{
317	struct brport_attribute *brport_attr = to_brport_attr(attr);
318	struct net_bridge_port *p = kobj_to_brport(kobj);
319	ssize_t ret = -EINVAL;
320	unsigned long val;
321	char *endp;
322
323	if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
324		return -EPERM;
325
326	if (!rtnl_trylock())
327		return restart_syscall();
328
329	if (brport_attr->store_raw) {
330		char *buf_copy;
331
332		buf_copy = kstrndup(buf, count, GFP_KERNEL);
333		if (!buf_copy) {
334			ret = -ENOMEM;
335			goto out_unlock;
336		}
337		spin_lock_bh(&p->br->lock);
338		ret = brport_attr->store_raw(p, buf_copy);
339		spin_unlock_bh(&p->br->lock);
340		kfree(buf_copy);
341	} else if (brport_attr->store) {
342		val = simple_strtoul(buf, &endp, 0);
343		if (endp == buf)
344			goto out_unlock;
345		spin_lock_bh(&p->br->lock);
346		ret = brport_attr->store(p, val);
347		spin_unlock_bh(&p->br->lock);
348	}
349
350	if (!ret) {
351		br_ifinfo_notify(RTM_NEWLINK, NULL, p);
352		ret = count;
353	}
354out_unlock:
355	rtnl_unlock();
356
357	return ret;
358}
359
360const struct sysfs_ops brport_sysfs_ops = {
361	.show = brport_show,
362	.store = brport_store,
363};
364
365/*
366 * Add sysfs entries to ethernet device added to a bridge.
367 * Creates a brport subdirectory with bridge attributes.
368 * Puts symlink in bridge's brif subdirectory
369 */
370int br_sysfs_addif(struct net_bridge_port *p)
371{
372	struct net_bridge *br = p->br;
373	const struct brport_attribute **a;
374	int err;
375
376	err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,
377				SYSFS_BRIDGE_PORT_LINK);
378	if (err)
379		return err;
380
381	for (a = brport_attrs; *a; ++a) {
382		err = sysfs_create_file(&p->kobj, &((*a)->attr));
383		if (err)
384			return err;
385	}
386
387	strscpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
388	return sysfs_create_link(br->ifobj, &p->kobj, p->sysfs_name);
389}
390
391/* Rename bridge's brif symlink */
392int br_sysfs_renameif(struct net_bridge_port *p)
393{
394	struct net_bridge *br = p->br;
395	int err;
396
397	/* If a rename fails, the rollback will cause another
398	 * rename call with the existing name.
399	 */
400	if (!strncmp(p->sysfs_name, p->dev->name, IFNAMSIZ))
401		return 0;
402
403	err = sysfs_rename_link(br->ifobj, &p->kobj,
404				p->sysfs_name, p->dev->name);
405	if (err)
406		netdev_notice(br->dev, "unable to rename link %s to %s",
407			      p->sysfs_name, p->dev->name);
408	else
409		strscpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
410
411	return err;
412}
413