xref: /linux/net/bridge/br_netlink.c (revision c5aec4c76af1a2d89ee2f2d4d5463b2ad2d85de5)
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 		+ nla_total_size(1)	/* IFLA_BRPORT_FAST_LEAVE */
33 		+ nla_total_size(1)	/* IFLA_BRPORT_LEARNING */
34 		+ nla_total_size(1)	/* IFLA_BRPORT_UNICAST_FLOOD */
35 		+ 0;
36 }
37 
38 static inline size_t br_nlmsg_size(void)
39 {
40 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
41 		+ nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
42 		+ nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
43 		+ nla_total_size(4) /* IFLA_MASTER */
44 		+ nla_total_size(4) /* IFLA_MTU */
45 		+ nla_total_size(4) /* IFLA_LINK */
46 		+ nla_total_size(1) /* IFLA_OPERSTATE */
47 		+ nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
48 }
49 
50 static int br_port_fill_attrs(struct sk_buff *skb,
51 			      const struct net_bridge_port *p)
52 {
53 	u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
54 
55 	if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
56 	    nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
57 	    nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
58 	    nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
59 	    nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
60 	    nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
61 	    nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)) ||
62 	    nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(p->flags & BR_LEARNING)) ||
63 	    nla_put_u8(skb, IFLA_BRPORT_UNICAST_FLOOD, !!(p->flags & BR_FLOOD)))
64 		return -EMSGSIZE;
65 
66 	return 0;
67 }
68 
69 /*
70  * Create one netlink message for one interface
71  * Contains port and master info as well as carrier and bridge state.
72  */
73 static int br_fill_ifinfo(struct sk_buff *skb,
74 			  const struct net_bridge_port *port,
75 			  u32 pid, u32 seq, int event, unsigned int flags,
76 			  u32 filter_mask, const struct net_device *dev)
77 {
78 	const struct net_bridge *br;
79 	struct ifinfomsg *hdr;
80 	struct nlmsghdr *nlh;
81 	u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
82 
83 	if (port)
84 		br = port->br;
85 	else
86 		br = netdev_priv(dev);
87 
88 	br_debug(br, "br_fill_info event %d port %s master %s\n",
89 		     event, dev->name, br->dev->name);
90 
91 	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
92 	if (nlh == NULL)
93 		return -EMSGSIZE;
94 
95 	hdr = nlmsg_data(nlh);
96 	hdr->ifi_family = AF_BRIDGE;
97 	hdr->__ifi_pad = 0;
98 	hdr->ifi_type = dev->type;
99 	hdr->ifi_index = dev->ifindex;
100 	hdr->ifi_flags = dev_get_flags(dev);
101 	hdr->ifi_change = 0;
102 
103 	if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
104 	    nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
105 	    nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
106 	    nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
107 	    (dev->addr_len &&
108 	     nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
109 	    (dev->ifindex != dev->iflink &&
110 	     nla_put_u32(skb, IFLA_LINK, dev->iflink)))
111 		goto nla_put_failure;
112 
113 	if (event == RTM_NEWLINK && port) {
114 		struct nlattr *nest
115 			= nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
116 
117 		if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
118 			goto nla_put_failure;
119 		nla_nest_end(skb, nest);
120 	}
121 
122 	/* Check if  the VID information is requested */
123 	if (filter_mask & RTEXT_FILTER_BRVLAN) {
124 		struct nlattr *af;
125 		const struct net_port_vlans *pv;
126 		struct bridge_vlan_info vinfo;
127 		u16 vid;
128 		u16 pvid;
129 
130 		if (port)
131 			pv = nbp_get_vlan_info(port);
132 		else
133 			pv = br_get_vlan_info(br);
134 
135 		if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID))
136 			goto done;
137 
138 		af = nla_nest_start(skb, IFLA_AF_SPEC);
139 		if (!af)
140 			goto nla_put_failure;
141 
142 		pvid = br_get_pvid(pv);
143 		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
144 			vinfo.vid = vid;
145 			vinfo.flags = 0;
146 			if (vid == pvid)
147 				vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
148 
149 			if (test_bit(vid, pv->untagged_bitmap))
150 				vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
151 
152 			if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
153 				    sizeof(vinfo), &vinfo))
154 				goto nla_put_failure;
155 		}
156 
157 		nla_nest_end(skb, af);
158 	}
159 
160 done:
161 	return nlmsg_end(skb, nlh);
162 
163 nla_put_failure:
164 	nlmsg_cancel(skb, nlh);
165 	return -EMSGSIZE;
166 }
167 
168 /*
169  * Notify listeners of a change in port information
170  */
171 void br_ifinfo_notify(int event, struct net_bridge_port *port)
172 {
173 	struct net *net;
174 	struct sk_buff *skb;
175 	int err = -ENOBUFS;
176 
177 	if (!port)
178 		return;
179 
180 	net = dev_net(port->dev);
181 	br_debug(port->br, "port %u(%s) event %d\n",
182 		 (unsigned int)port->port_no, port->dev->name, event);
183 
184 	skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
185 	if (skb == NULL)
186 		goto errout;
187 
188 	err = br_fill_ifinfo(skb, port, 0, 0, event, 0, 0, port->dev);
189 	if (err < 0) {
190 		/* -EMSGSIZE implies BUG in br_nlmsg_size() */
191 		WARN_ON(err == -EMSGSIZE);
192 		kfree_skb(skb);
193 		goto errout;
194 	}
195 	rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
196 	return;
197 errout:
198 	rtnl_set_sk_err(net, RTNLGRP_LINK, err);
199 }
200 
201 
202 /*
203  * Dump information about all ports, in response to GETLINK
204  */
205 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
206 	       struct net_device *dev, u32 filter_mask)
207 {
208 	int err = 0;
209 	struct net_bridge_port *port = br_port_get_rtnl(dev);
210 
211 	/* not a bridge port and  */
212 	if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
213 		goto out;
214 
215 	err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
216 			     filter_mask, dev);
217 out:
218 	return err;
219 }
220 
221 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
222 	[IFLA_BRIDGE_FLAGS]	= { .type = NLA_U16 },
223 	[IFLA_BRIDGE_MODE]	= { .type = NLA_U16 },
224 	[IFLA_BRIDGE_VLAN_INFO]	= { .type = NLA_BINARY,
225 				    .len = sizeof(struct bridge_vlan_info), },
226 };
227 
228 static int br_afspec(struct net_bridge *br,
229 		     struct net_bridge_port *p,
230 		     struct nlattr *af_spec,
231 		     int cmd)
232 {
233 	struct nlattr *tb[IFLA_BRIDGE_MAX+1];
234 	int err = 0;
235 
236 	err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
237 	if (err)
238 		return err;
239 
240 	if (tb[IFLA_BRIDGE_VLAN_INFO]) {
241 		struct bridge_vlan_info *vinfo;
242 
243 		vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
244 
245 		if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
246 			return -EINVAL;
247 
248 		switch (cmd) {
249 		case RTM_SETLINK:
250 			if (p) {
251 				err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
252 				if (err)
253 					break;
254 
255 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
256 					err = br_vlan_add(p->br, vinfo->vid,
257 							  vinfo->flags);
258 			} else
259 				err = br_vlan_add(br, vinfo->vid, vinfo->flags);
260 
261 			if (err)
262 				break;
263 
264 			break;
265 
266 		case RTM_DELLINK:
267 			if (p) {
268 				nbp_vlan_delete(p, vinfo->vid);
269 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
270 					br_vlan_delete(p->br, vinfo->vid);
271 			} else
272 				br_vlan_delete(br, vinfo->vid);
273 			break;
274 		}
275 	}
276 
277 	return err;
278 }
279 
280 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
281 	[IFLA_BRPORT_STATE]	= { .type = NLA_U8 },
282 	[IFLA_BRPORT_COST]	= { .type = NLA_U32 },
283 	[IFLA_BRPORT_PRIORITY]	= { .type = NLA_U16 },
284 	[IFLA_BRPORT_MODE]	= { .type = NLA_U8 },
285 	[IFLA_BRPORT_GUARD]	= { .type = NLA_U8 },
286 	[IFLA_BRPORT_PROTECT]	= { .type = NLA_U8 },
287 	[IFLA_BRPORT_LEARNING]	= { .type = NLA_U8 },
288 	[IFLA_BRPORT_UNICAST_FLOOD] = { .type = NLA_U8 },
289 };
290 
291 /* Change the state of the port and notify spanning tree */
292 static int br_set_port_state(struct net_bridge_port *p, u8 state)
293 {
294 	if (state > BR_STATE_BLOCKING)
295 		return -EINVAL;
296 
297 	/* if kernel STP is running, don't allow changes */
298 	if (p->br->stp_enabled == BR_KERNEL_STP)
299 		return -EBUSY;
300 
301 	/* if device is not up, change is not allowed
302 	 * if link is not present, only allowable state is disabled
303 	 */
304 	if (!netif_running(p->dev) ||
305 	    (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
306 		return -ENETDOWN;
307 
308 	p->state = state;
309 	br_log_state(p);
310 	br_port_state_selection(p->br);
311 	return 0;
312 }
313 
314 /* Set/clear or port flags based on attribute */
315 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
316 			   int attrtype, unsigned long mask)
317 {
318 	if (tb[attrtype]) {
319 		u8 flag = nla_get_u8(tb[attrtype]);
320 		if (flag)
321 			p->flags |= mask;
322 		else
323 			p->flags &= ~mask;
324 	}
325 }
326 
327 /* Process bridge protocol info on port */
328 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
329 {
330 	int err;
331 
332 	br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
333 	br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
334 	br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
335 	br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
336 	br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
337 	br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
338 
339 	if (tb[IFLA_BRPORT_COST]) {
340 		err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
341 		if (err)
342 			return err;
343 	}
344 
345 	if (tb[IFLA_BRPORT_PRIORITY]) {
346 		err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
347 		if (err)
348 			return err;
349 	}
350 
351 	if (tb[IFLA_BRPORT_STATE]) {
352 		err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
353 		if (err)
354 			return err;
355 	}
356 	return 0;
357 }
358 
359 /* Change state and parameters on port. */
360 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
361 {
362 	struct nlattr *protinfo;
363 	struct nlattr *afspec;
364 	struct net_bridge_port *p;
365 	struct nlattr *tb[IFLA_BRPORT_MAX + 1];
366 	int err = 0;
367 
368 	protinfo = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_PROTINFO);
369 	afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
370 	if (!protinfo && !afspec)
371 		return 0;
372 
373 	p = br_port_get_rtnl(dev);
374 	/* We want to accept dev as bridge itself if the AF_SPEC
375 	 * is set to see if someone is setting vlan info on the bridge
376 	 */
377 	if (!p && !afspec)
378 		return -EINVAL;
379 
380 	if (p && protinfo) {
381 		if (protinfo->nla_type & NLA_F_NESTED) {
382 			err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
383 					       protinfo, ifla_brport_policy);
384 			if (err)
385 				return err;
386 
387 			spin_lock_bh(&p->br->lock);
388 			err = br_setport(p, tb);
389 			spin_unlock_bh(&p->br->lock);
390 		} else {
391 			/* Binary compatibility with old RSTP */
392 			if (nla_len(protinfo) < sizeof(u8))
393 				return -EINVAL;
394 
395 			spin_lock_bh(&p->br->lock);
396 			err = br_set_port_state(p, nla_get_u8(protinfo));
397 			spin_unlock_bh(&p->br->lock);
398 		}
399 		if (err)
400 			goto out;
401 	}
402 
403 	if (afspec) {
404 		err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
405 				afspec, RTM_SETLINK);
406 	}
407 
408 	if (err == 0)
409 		br_ifinfo_notify(RTM_NEWLINK, p);
410 
411 out:
412 	return err;
413 }
414 
415 /* Delete port information */
416 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
417 {
418 	struct nlattr *afspec;
419 	struct net_bridge_port *p;
420 	int err;
421 
422 	afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), 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 int br_dev_newlink(struct net *src_net, struct net_device *dev,
449 			  struct nlattr *tb[], struct nlattr *data[])
450 {
451 	struct net_bridge *br = netdev_priv(dev);
452 
453 	if (tb[IFLA_ADDRESS]) {
454 		spin_lock_bh(&br->lock);
455 		br_stp_change_bridge_id(br, nla_data(tb[IFLA_ADDRESS]));
456 		spin_unlock_bh(&br->lock);
457 	}
458 
459 	return register_netdevice(dev);
460 }
461 
462 static size_t br_get_link_af_size(const struct net_device *dev)
463 {
464 	struct net_port_vlans *pv;
465 
466 	if (br_port_exists(dev))
467 		pv = nbp_get_vlan_info(br_port_get_rtnl(dev));
468 	else if (dev->priv_flags & IFF_EBRIDGE)
469 		pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
470 	else
471 		return 0;
472 
473 	if (!pv)
474 		return 0;
475 
476 	/* Each VLAN is returned in bridge_vlan_info along with flags */
477 	return pv->num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
478 }
479 
480 static struct rtnl_af_ops br_af_ops = {
481 	.family			= AF_BRIDGE,
482 	.get_link_af_size	= br_get_link_af_size,
483 };
484 
485 struct rtnl_link_ops br_link_ops __read_mostly = {
486 	.kind		= "bridge",
487 	.priv_size	= sizeof(struct net_bridge),
488 	.setup		= br_dev_setup,
489 	.validate	= br_validate,
490 	.newlink	= br_dev_newlink,
491 	.dellink	= br_dev_delete,
492 };
493 
494 int __init br_netlink_init(void)
495 {
496 	int err;
497 
498 	br_mdb_init();
499 	rtnl_af_register(&br_af_ops);
500 
501 	err = rtnl_link_register(&br_link_ops);
502 	if (err)
503 		goto out_af;
504 
505 	return 0;
506 
507 out_af:
508 	rtnl_af_unregister(&br_af_ops);
509 	br_mdb_uninit();
510 	return err;
511 }
512 
513 void __exit br_netlink_fini(void)
514 {
515 	br_mdb_uninit();
516 	rtnl_af_unregister(&br_af_ops);
517 	rtnl_link_unregister(&br_link_ops);
518 }
519