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