xref: /openbmc/linux/net/bridge/br_netlink.c (revision bc000245)
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 	if (err < 0)
199 		rtnl_set_sk_err(net, RTNLGRP_LINK, err);
200 }
201 
202 
203 /*
204  * Dump information about all ports, in response to GETLINK
205  */
206 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
207 	       struct net_device *dev, u32 filter_mask)
208 {
209 	int err = 0;
210 	struct net_bridge_port *port = br_port_get_rtnl(dev);
211 
212 	/* not a bridge port and  */
213 	if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
214 		goto out;
215 
216 	err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
217 			     filter_mask, dev);
218 out:
219 	return err;
220 }
221 
222 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
223 	[IFLA_BRIDGE_FLAGS]	= { .type = NLA_U16 },
224 	[IFLA_BRIDGE_MODE]	= { .type = NLA_U16 },
225 	[IFLA_BRIDGE_VLAN_INFO]	= { .type = NLA_BINARY,
226 				    .len = sizeof(struct bridge_vlan_info), },
227 };
228 
229 static int br_afspec(struct net_bridge *br,
230 		     struct net_bridge_port *p,
231 		     struct nlattr *af_spec,
232 		     int cmd)
233 {
234 	struct nlattr *tb[IFLA_BRIDGE_MAX+1];
235 	int err = 0;
236 
237 	err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
238 	if (err)
239 		return err;
240 
241 	if (tb[IFLA_BRIDGE_VLAN_INFO]) {
242 		struct bridge_vlan_info *vinfo;
243 
244 		vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
245 
246 		if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
247 			return -EINVAL;
248 
249 		switch (cmd) {
250 		case RTM_SETLINK:
251 			if (p) {
252 				err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
253 				if (err)
254 					break;
255 
256 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
257 					err = br_vlan_add(p->br, vinfo->vid,
258 							  vinfo->flags);
259 			} else
260 				err = br_vlan_add(br, vinfo->vid, vinfo->flags);
261 
262 			if (err)
263 				break;
264 
265 			break;
266 
267 		case RTM_DELLINK:
268 			if (p) {
269 				nbp_vlan_delete(p, vinfo->vid);
270 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
271 					br_vlan_delete(p->br, vinfo->vid);
272 			} else
273 				br_vlan_delete(br, vinfo->vid);
274 			break;
275 		}
276 	}
277 
278 	return err;
279 }
280 
281 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
282 	[IFLA_BRPORT_STATE]	= { .type = NLA_U8 },
283 	[IFLA_BRPORT_COST]	= { .type = NLA_U32 },
284 	[IFLA_BRPORT_PRIORITY]	= { .type = NLA_U16 },
285 	[IFLA_BRPORT_MODE]	= { .type = NLA_U8 },
286 	[IFLA_BRPORT_GUARD]	= { .type = NLA_U8 },
287 	[IFLA_BRPORT_PROTECT]	= { .type = NLA_U8 },
288 	[IFLA_BRPORT_LEARNING]	= { .type = NLA_U8 },
289 	[IFLA_BRPORT_UNICAST_FLOOD] = { .type = NLA_U8 },
290 };
291 
292 /* Change the state of the port and notify spanning tree */
293 static int br_set_port_state(struct net_bridge_port *p, u8 state)
294 {
295 	if (state > BR_STATE_BLOCKING)
296 		return -EINVAL;
297 
298 	/* if kernel STP is running, don't allow changes */
299 	if (p->br->stp_enabled == BR_KERNEL_STP)
300 		return -EBUSY;
301 
302 	/* if device is not up, change is not allowed
303 	 * if link is not present, only allowable state is disabled
304 	 */
305 	if (!netif_running(p->dev) ||
306 	    (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
307 		return -ENETDOWN;
308 
309 	p->state = state;
310 	br_log_state(p);
311 	br_port_state_selection(p->br);
312 	return 0;
313 }
314 
315 /* Set/clear or port flags based on attribute */
316 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
317 			   int attrtype, unsigned long mask)
318 {
319 	if (tb[attrtype]) {
320 		u8 flag = nla_get_u8(tb[attrtype]);
321 		if (flag)
322 			p->flags |= mask;
323 		else
324 			p->flags &= ~mask;
325 	}
326 }
327 
328 /* Process bridge protocol info on port */
329 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
330 {
331 	int err;
332 
333 	br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
334 	br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
335 	br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
336 	br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
337 	br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
338 	br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
339 
340 	if (tb[IFLA_BRPORT_COST]) {
341 		err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
342 		if (err)
343 			return err;
344 	}
345 
346 	if (tb[IFLA_BRPORT_PRIORITY]) {
347 		err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
348 		if (err)
349 			return err;
350 	}
351 
352 	if (tb[IFLA_BRPORT_STATE]) {
353 		err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
354 		if (err)
355 			return err;
356 	}
357 	return 0;
358 }
359 
360 /* Change state and parameters on port. */
361 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
362 {
363 	struct nlattr *protinfo;
364 	struct nlattr *afspec;
365 	struct net_bridge_port *p;
366 	struct nlattr *tb[IFLA_BRPORT_MAX + 1];
367 	int err = 0;
368 
369 	protinfo = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_PROTINFO);
370 	afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
371 	if (!protinfo && !afspec)
372 		return 0;
373 
374 	p = br_port_get_rtnl(dev);
375 	/* We want to accept dev as bridge itself if the AF_SPEC
376 	 * is set to see if someone is setting vlan info on the brigde
377 	 */
378 	if (!p && !afspec)
379 		return -EINVAL;
380 
381 	if (p && protinfo) {
382 		if (protinfo->nla_type & NLA_F_NESTED) {
383 			err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
384 					       protinfo, ifla_brport_policy);
385 			if (err)
386 				return err;
387 
388 			spin_lock_bh(&p->br->lock);
389 			err = br_setport(p, tb);
390 			spin_unlock_bh(&p->br->lock);
391 		} else {
392 			/* Binary compatability with old RSTP */
393 			if (nla_len(protinfo) < sizeof(u8))
394 				return -EINVAL;
395 
396 			spin_lock_bh(&p->br->lock);
397 			err = br_set_port_state(p, nla_get_u8(protinfo));
398 			spin_unlock_bh(&p->br->lock);
399 		}
400 		if (err)
401 			goto out;
402 	}
403 
404 	if (afspec) {
405 		err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
406 				afspec, RTM_SETLINK);
407 	}
408 
409 	if (err == 0)
410 		br_ifinfo_notify(RTM_NEWLINK, p);
411 
412 out:
413 	return err;
414 }
415 
416 /* Delete port information */
417 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
418 {
419 	struct nlattr *afspec;
420 	struct net_bridge_port *p;
421 	int err;
422 
423 	afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
424 	if (!afspec)
425 		return 0;
426 
427 	p = br_port_get_rtnl(dev);
428 	/* We want to accept dev as bridge itself as well */
429 	if (!p && !(dev->priv_flags & IFF_EBRIDGE))
430 		return -EINVAL;
431 
432 	err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
433 			afspec, RTM_DELLINK);
434 
435 	return err;
436 }
437 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
438 {
439 	if (tb[IFLA_ADDRESS]) {
440 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
441 			return -EINVAL;
442 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
443 			return -EADDRNOTAVAIL;
444 	}
445 
446 	return 0;
447 }
448 
449 static size_t br_get_link_af_size(const struct net_device *dev)
450 {
451 	struct net_port_vlans *pv;
452 
453 	if (br_port_exists(dev))
454 		pv = nbp_get_vlan_info(br_port_get_rtnl(dev));
455 	else if (dev->priv_flags & IFF_EBRIDGE)
456 		pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
457 	else
458 		return 0;
459 
460 	if (!pv)
461 		return 0;
462 
463 	/* Each VLAN is returned in bridge_vlan_info along with flags */
464 	return pv->num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
465 }
466 
467 static struct rtnl_af_ops br_af_ops = {
468 	.family			= AF_BRIDGE,
469 	.get_link_af_size	= br_get_link_af_size,
470 };
471 
472 struct rtnl_link_ops br_link_ops __read_mostly = {
473 	.kind		= "bridge",
474 	.priv_size	= sizeof(struct net_bridge),
475 	.setup		= br_dev_setup,
476 	.validate	= br_validate,
477 	.dellink	= br_dev_delete,
478 };
479 
480 int __init br_netlink_init(void)
481 {
482 	int err;
483 
484 	br_mdb_init();
485 	err = rtnl_af_register(&br_af_ops);
486 	if (err)
487 		goto out;
488 
489 	err = rtnl_link_register(&br_link_ops);
490 	if (err)
491 		goto out_af;
492 
493 	return 0;
494 
495 out_af:
496 	rtnl_af_unregister(&br_af_ops);
497 out:
498 	br_mdb_uninit();
499 	return err;
500 }
501 
502 void __exit br_netlink_fini(void)
503 {
504 	br_mdb_uninit();
505 	rtnl_af_unregister(&br_af_ops);
506 	rtnl_link_unregister(&br_link_ops);
507 }
508