xref: /openbmc/linux/net/bridge/br_netlink.c (revision 840ef8b7cc584a23c4f9d05352f4dbaf8e56e5ab)
1 /*
2  *	Bridge netlink control interface
3  *
4  *	Authors:
5  *	Stephen Hemminger		<shemminger@osdl.org>
6  *
7  *	This program is free software; you can redistribute it and/or
8  *	modify it under the terms of the GNU General Public License
9  *	as published by the Free Software Foundation; either version
10  *	2 of the License, or (at your option) any later version.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/etherdevice.h>
16 #include <net/rtnetlink.h>
17 #include <net/net_namespace.h>
18 #include <net/sock.h>
19 #include <uapi/linux/if_bridge.h>
20 
21 #include "br_private.h"
22 #include "br_private_stp.h"
23 
24 static inline size_t br_port_info_size(void)
25 {
26 	return nla_total_size(1)	/* IFLA_BRPORT_STATE  */
27 		+ nla_total_size(2)	/* IFLA_BRPORT_PRIORITY */
28 		+ nla_total_size(4)	/* IFLA_BRPORT_COST */
29 		+ nla_total_size(1)	/* IFLA_BRPORT_MODE */
30 		+ nla_total_size(1)	/* IFLA_BRPORT_GUARD */
31 		+ nla_total_size(1)	/* IFLA_BRPORT_PROTECT */
32 		+ 0;
33 }
34 
35 static inline size_t br_nlmsg_size(void)
36 {
37 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
38 		+ nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
39 		+ nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
40 		+ nla_total_size(4) /* IFLA_MASTER */
41 		+ nla_total_size(4) /* IFLA_MTU */
42 		+ nla_total_size(4) /* IFLA_LINK */
43 		+ nla_total_size(1) /* IFLA_OPERSTATE */
44 		+ nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
45 }
46 
47 static int br_port_fill_attrs(struct sk_buff *skb,
48 			      const struct net_bridge_port *p)
49 {
50 	u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
51 
52 	if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
53 	    nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
54 	    nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
55 	    nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
56 	    nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
57 	    nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
58 	    nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)))
59 		return -EMSGSIZE;
60 
61 	return 0;
62 }
63 
64 /*
65  * Create one netlink message for one interface
66  * Contains port and master info as well as carrier and bridge state.
67  */
68 static int br_fill_ifinfo(struct sk_buff *skb,
69 			  const struct net_bridge_port *port,
70 			  u32 pid, u32 seq, int event, unsigned int flags,
71 			  u32 filter_mask, const struct net_device *dev)
72 {
73 	const struct net_bridge *br;
74 	struct ifinfomsg *hdr;
75 	struct nlmsghdr *nlh;
76 	u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
77 
78 	if (port)
79 		br = port->br;
80 	else
81 		br = netdev_priv(dev);
82 
83 	br_debug(br, "br_fill_info event %d port %s master %s\n",
84 		     event, dev->name, br->dev->name);
85 
86 	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
87 	if (nlh == NULL)
88 		return -EMSGSIZE;
89 
90 	hdr = nlmsg_data(nlh);
91 	hdr->ifi_family = AF_BRIDGE;
92 	hdr->__ifi_pad = 0;
93 	hdr->ifi_type = dev->type;
94 	hdr->ifi_index = dev->ifindex;
95 	hdr->ifi_flags = dev_get_flags(dev);
96 	hdr->ifi_change = 0;
97 
98 	if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
99 	    nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
100 	    nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
101 	    nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
102 	    (dev->addr_len &&
103 	     nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
104 	    (dev->ifindex != dev->iflink &&
105 	     nla_put_u32(skb, IFLA_LINK, dev->iflink)))
106 		goto nla_put_failure;
107 
108 	if (event == RTM_NEWLINK && port) {
109 		struct nlattr *nest
110 			= nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
111 
112 		if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
113 			goto nla_put_failure;
114 		nla_nest_end(skb, nest);
115 	}
116 
117 	/* Check if  the VID information is requested */
118 	if (filter_mask & RTEXT_FILTER_BRVLAN) {
119 		struct nlattr *af;
120 		const struct net_port_vlans *pv;
121 		struct bridge_vlan_info vinfo;
122 		u16 vid;
123 		u16 pvid;
124 
125 		if (port)
126 			pv = nbp_get_vlan_info(port);
127 		else
128 			pv = br_get_vlan_info(br);
129 
130 		if (!pv || bitmap_empty(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN))
131 			goto done;
132 
133 		af = nla_nest_start(skb, IFLA_AF_SPEC);
134 		if (!af)
135 			goto nla_put_failure;
136 
137 		pvid = br_get_pvid(pv);
138 		for (vid = find_first_bit(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN);
139 		     vid < BR_VLAN_BITMAP_LEN;
140 		     vid = find_next_bit(pv->vlan_bitmap,
141 					 BR_VLAN_BITMAP_LEN, vid+1)) {
142 			vinfo.vid = vid;
143 			vinfo.flags = 0;
144 			if (vid == pvid)
145 				vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
146 
147 			if (test_bit(vid, pv->untagged_bitmap))
148 				vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
149 
150 			if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
151 				    sizeof(vinfo), &vinfo))
152 				goto nla_put_failure;
153 		}
154 
155 		nla_nest_end(skb, af);
156 	}
157 
158 done:
159 	return nlmsg_end(skb, nlh);
160 
161 nla_put_failure:
162 	nlmsg_cancel(skb, nlh);
163 	return -EMSGSIZE;
164 }
165 
166 /*
167  * Notify listeners of a change in port information
168  */
169 void br_ifinfo_notify(int event, struct net_bridge_port *port)
170 {
171 	struct net *net;
172 	struct sk_buff *skb;
173 	int err = -ENOBUFS;
174 
175 	if (!port)
176 		return;
177 
178 	net = dev_net(port->dev);
179 	br_debug(port->br, "port %u(%s) event %d\n",
180 		 (unsigned int)port->port_no, port->dev->name, event);
181 
182 	skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
183 	if (skb == NULL)
184 		goto errout;
185 
186 	err = br_fill_ifinfo(skb, port, 0, 0, event, 0, 0, port->dev);
187 	if (err < 0) {
188 		/* -EMSGSIZE implies BUG in br_nlmsg_size() */
189 		WARN_ON(err == -EMSGSIZE);
190 		kfree_skb(skb);
191 		goto errout;
192 	}
193 	rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
194 	return;
195 errout:
196 	if (err < 0)
197 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
198 }
199 
200 
201 /*
202  * Dump information about all ports, in response to GETLINK
203  */
204 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
205 	       struct net_device *dev, u32 filter_mask)
206 {
207 	int err = 0;
208 	struct net_bridge_port *port = br_port_get_rcu(dev);
209 
210 	/* not a bridge port and  */
211 	if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
212 		goto out;
213 
214 	err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
215 			     filter_mask, dev);
216 out:
217 	return err;
218 }
219 
220 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
221 	[IFLA_BRIDGE_FLAGS]	= { .type = NLA_U16 },
222 	[IFLA_BRIDGE_MODE]	= { .type = NLA_U16 },
223 	[IFLA_BRIDGE_VLAN_INFO]	= { .type = NLA_BINARY,
224 				    .len = sizeof(struct bridge_vlan_info), },
225 };
226 
227 static int br_afspec(struct net_bridge *br,
228 		     struct net_bridge_port *p,
229 		     struct nlattr *af_spec,
230 		     int cmd)
231 {
232 	struct nlattr *tb[IFLA_BRIDGE_MAX+1];
233 	int err = 0;
234 
235 	err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
236 	if (err)
237 		return err;
238 
239 	if (tb[IFLA_BRIDGE_VLAN_INFO]) {
240 		struct bridge_vlan_info *vinfo;
241 
242 		vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
243 
244 		if (vinfo->vid >= VLAN_N_VID)
245 			return -EINVAL;
246 
247 		switch (cmd) {
248 		case RTM_SETLINK:
249 			if (p) {
250 				err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
251 				if (err)
252 					break;
253 
254 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
255 					err = br_vlan_add(p->br, vinfo->vid,
256 							  vinfo->flags);
257 			} else
258 				err = br_vlan_add(br, vinfo->vid, vinfo->flags);
259 
260 			if (err)
261 				break;
262 
263 			break;
264 
265 		case RTM_DELLINK:
266 			if (p) {
267 				nbp_vlan_delete(p, vinfo->vid);
268 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
269 					br_vlan_delete(p->br, vinfo->vid);
270 			} else
271 				br_vlan_delete(br, vinfo->vid);
272 			break;
273 		}
274 	}
275 
276 	return err;
277 }
278 
279 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
280 	[IFLA_BRPORT_STATE]	= { .type = NLA_U8 },
281 	[IFLA_BRPORT_COST]	= { .type = NLA_U32 },
282 	[IFLA_BRPORT_PRIORITY]	= { .type = NLA_U16 },
283 	[IFLA_BRPORT_MODE]	= { .type = NLA_U8 },
284 	[IFLA_BRPORT_GUARD]	= { .type = NLA_U8 },
285 	[IFLA_BRPORT_PROTECT]	= { .type = NLA_U8 },
286 };
287 
288 /* Change the state of the port and notify spanning tree */
289 static int br_set_port_state(struct net_bridge_port *p, u8 state)
290 {
291 	if (state > BR_STATE_BLOCKING)
292 		return -EINVAL;
293 
294 	/* if kernel STP is running, don't allow changes */
295 	if (p->br->stp_enabled == BR_KERNEL_STP)
296 		return -EBUSY;
297 
298 	/* if device is not up, change is not allowed
299 	 * if link is not present, only allowable state is disabled
300 	 */
301 	if (!netif_running(p->dev) ||
302 	    (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
303 		return -ENETDOWN;
304 
305 	p->state = state;
306 	br_log_state(p);
307 	br_port_state_selection(p->br);
308 	return 0;
309 }
310 
311 /* Set/clear or port flags based on attribute */
312 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
313 			   int attrtype, unsigned long mask)
314 {
315 	if (tb[attrtype]) {
316 		u8 flag = nla_get_u8(tb[attrtype]);
317 		if (flag)
318 			p->flags |= mask;
319 		else
320 			p->flags &= ~mask;
321 	}
322 }
323 
324 /* Process bridge protocol info on port */
325 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
326 {
327 	int err;
328 
329 	br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
330 	br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
331 	br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
332 
333 	if (tb[IFLA_BRPORT_COST]) {
334 		err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
335 		if (err)
336 			return err;
337 	}
338 
339 	if (tb[IFLA_BRPORT_PRIORITY]) {
340 		err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
341 		if (err)
342 			return err;
343 	}
344 
345 	if (tb[IFLA_BRPORT_STATE]) {
346 		err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
347 		if (err)
348 			return err;
349 	}
350 	return 0;
351 }
352 
353 /* Change state and parameters on port. */
354 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
355 {
356 	struct ifinfomsg *ifm;
357 	struct nlattr *protinfo;
358 	struct nlattr *afspec;
359 	struct net_bridge_port *p;
360 	struct nlattr *tb[IFLA_BRPORT_MAX + 1];
361 	int err;
362 
363 	ifm = nlmsg_data(nlh);
364 
365 	protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
366 	afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
367 	if (!protinfo && !afspec)
368 		return 0;
369 
370 	p = br_port_get_rtnl(dev);
371 	/* We want to accept dev as bridge itself if the AF_SPEC
372 	 * is set to see if someone is setting vlan info on the brigde
373 	 */
374 	if (!p && ((dev->priv_flags & IFF_EBRIDGE) && !afspec))
375 		return -EINVAL;
376 
377 	if (p && protinfo) {
378 		if (protinfo->nla_type & NLA_F_NESTED) {
379 			err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
380 					       protinfo, ifla_brport_policy);
381 			if (err)
382 				return err;
383 
384 			spin_lock_bh(&p->br->lock);
385 			err = br_setport(p, tb);
386 			spin_unlock_bh(&p->br->lock);
387 		} else {
388 			/* Binary compatability with old RSTP */
389 			if (nla_len(protinfo) < sizeof(u8))
390 				return -EINVAL;
391 
392 			spin_lock_bh(&p->br->lock);
393 			err = br_set_port_state(p, nla_get_u8(protinfo));
394 			spin_unlock_bh(&p->br->lock);
395 		}
396 		if (err)
397 			goto out;
398 	}
399 
400 	if (afspec) {
401 		err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
402 				afspec, RTM_SETLINK);
403 	}
404 
405 	if (err == 0)
406 		br_ifinfo_notify(RTM_NEWLINK, p);
407 
408 out:
409 	return err;
410 }
411 
412 /* Delete port information */
413 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
414 {
415 	struct ifinfomsg *ifm;
416 	struct nlattr *afspec;
417 	struct net_bridge_port *p;
418 	int err;
419 
420 	ifm = nlmsg_data(nlh);
421 
422 	afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
423 	if (!afspec)
424 		return 0;
425 
426 	p = br_port_get_rtnl(dev);
427 	/* We want to accept dev as bridge itself as well */
428 	if (!p && !(dev->priv_flags & IFF_EBRIDGE))
429 		return -EINVAL;
430 
431 	err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
432 			afspec, RTM_DELLINK);
433 
434 	return err;
435 }
436 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
437 {
438 	if (tb[IFLA_ADDRESS]) {
439 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
440 			return -EINVAL;
441 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
442 			return -EADDRNOTAVAIL;
443 	}
444 
445 	return 0;
446 }
447 
448 static size_t br_get_link_af_size(const struct net_device *dev)
449 {
450 	struct net_port_vlans *pv;
451 
452 	if (br_port_exists(dev))
453 		pv = nbp_get_vlan_info(br_port_get_rcu(dev));
454 	else if (dev->priv_flags & IFF_EBRIDGE)
455 		pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
456 	else
457 		return 0;
458 
459 	if (!pv)
460 		return 0;
461 
462 	/* Each VLAN is returned in bridge_vlan_info along with flags */
463 	return pv->num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
464 }
465 
466 static struct rtnl_af_ops br_af_ops = {
467 	.family			= AF_BRIDGE,
468 	.get_link_af_size	= br_get_link_af_size,
469 };
470 
471 struct rtnl_link_ops br_link_ops __read_mostly = {
472 	.kind		= "bridge",
473 	.priv_size	= sizeof(struct net_bridge),
474 	.setup		= br_dev_setup,
475 	.validate	= br_validate,
476 	.dellink	= br_dev_delete,
477 };
478 
479 int __init br_netlink_init(void)
480 {
481 	int err;
482 
483 	br_mdb_init();
484 	err = rtnl_af_register(&br_af_ops);
485 	if (err)
486 		goto out;
487 
488 	err = rtnl_link_register(&br_link_ops);
489 	if (err)
490 		goto out_af;
491 
492 	return 0;
493 
494 out_af:
495 	rtnl_af_unregister(&br_af_ops);
496 out:
497 	br_mdb_uninit();
498 	return err;
499 }
500 
501 void __exit br_netlink_fini(void)
502 {
503 	br_mdb_uninit();
504 	rtnl_af_unregister(&br_af_ops);
505 	rtnl_link_unregister(&br_link_ops);
506 }
507