xref: /openbmc/linux/net/ipv4/ipmr_base.c (revision a17922de)
1 /* Linux multicast routing support
2  * Common logic shared by IPv4 [ipmr] and IPv6 [ip6mr] implementation
3  */
4 
5 #include <linux/rhashtable.h>
6 #include <linux/mroute_base.h>
7 
8 /* Sets everything common except 'dev', since that is done under locking */
9 void vif_device_init(struct vif_device *v,
10 		     struct net_device *dev,
11 		     unsigned long rate_limit,
12 		     unsigned char threshold,
13 		     unsigned short flags,
14 		     unsigned short get_iflink_mask)
15 {
16 	v->dev = NULL;
17 	v->bytes_in = 0;
18 	v->bytes_out = 0;
19 	v->pkt_in = 0;
20 	v->pkt_out = 0;
21 	v->rate_limit = rate_limit;
22 	v->flags = flags;
23 	v->threshold = threshold;
24 	if (v->flags & get_iflink_mask)
25 		v->link = dev_get_iflink(dev);
26 	else
27 		v->link = dev->ifindex;
28 }
29 EXPORT_SYMBOL(vif_device_init);
30 
31 struct mr_table *
32 mr_table_alloc(struct net *net, u32 id,
33 	       struct mr_table_ops *ops,
34 	       void (*expire_func)(struct timer_list *t),
35 	       void (*table_set)(struct mr_table *mrt,
36 				 struct net *net))
37 {
38 	struct mr_table *mrt;
39 	int err;
40 
41 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
42 	if (!mrt)
43 		return ERR_PTR(-ENOMEM);
44 	mrt->id = id;
45 	write_pnet(&mrt->net, net);
46 
47 	mrt->ops = *ops;
48 	err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
49 	if (err) {
50 		kfree(mrt);
51 		return ERR_PTR(err);
52 	}
53 	INIT_LIST_HEAD(&mrt->mfc_cache_list);
54 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
55 
56 	timer_setup(&mrt->ipmr_expire_timer, expire_func, 0);
57 
58 	mrt->mroute_reg_vif_num = -1;
59 	table_set(mrt, net);
60 	return mrt;
61 }
62 EXPORT_SYMBOL(mr_table_alloc);
63 
64 void *mr_mfc_find_parent(struct mr_table *mrt, void *hasharg, int parent)
65 {
66 	struct rhlist_head *tmp, *list;
67 	struct mr_mfc *c;
68 
69 	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
70 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
71 		if (parent == -1 || parent == c->mfc_parent)
72 			return c;
73 
74 	return NULL;
75 }
76 EXPORT_SYMBOL(mr_mfc_find_parent);
77 
78 void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi)
79 {
80 	struct rhlist_head *tmp, *list;
81 	struct mr_mfc *c;
82 
83 	list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any,
84 			       *mrt->ops.rht_params);
85 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
86 		if (c->mfc_un.res.ttls[vifi] < 255)
87 			return c;
88 
89 	return NULL;
90 }
91 EXPORT_SYMBOL(mr_mfc_find_any_parent);
92 
93 void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg)
94 {
95 	struct rhlist_head *tmp, *list;
96 	struct mr_mfc *c, *proxy;
97 
98 	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
99 	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
100 		if (c->mfc_un.res.ttls[vifi] < 255)
101 			return c;
102 
103 		/* It's ok if the vifi is part of the static tree */
104 		proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent);
105 		if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
106 			return c;
107 	}
108 
109 	return mr_mfc_find_any_parent(mrt, vifi);
110 }
111 EXPORT_SYMBOL(mr_mfc_find_any);
112 
113 #ifdef CONFIG_PROC_FS
114 void *mr_vif_seq_idx(struct net *net, struct mr_vif_iter *iter, loff_t pos)
115 {
116 	struct mr_table *mrt = iter->mrt;
117 
118 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
119 		if (!VIF_EXISTS(mrt, iter->ct))
120 			continue;
121 		if (pos-- == 0)
122 			return &mrt->vif_table[iter->ct];
123 	}
124 	return NULL;
125 }
126 EXPORT_SYMBOL(mr_vif_seq_idx);
127 
128 void *mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
129 {
130 	struct mr_vif_iter *iter = seq->private;
131 	struct net *net = seq_file_net(seq);
132 	struct mr_table *mrt = iter->mrt;
133 
134 	++*pos;
135 	if (v == SEQ_START_TOKEN)
136 		return mr_vif_seq_idx(net, iter, 0);
137 
138 	while (++iter->ct < mrt->maxvif) {
139 		if (!VIF_EXISTS(mrt, iter->ct))
140 			continue;
141 		return &mrt->vif_table[iter->ct];
142 	}
143 	return NULL;
144 }
145 EXPORT_SYMBOL(mr_vif_seq_next);
146 
147 void *mr_mfc_seq_idx(struct net *net,
148 		     struct mr_mfc_iter *it, loff_t pos)
149 {
150 	struct mr_table *mrt = it->mrt;
151 	struct mr_mfc *mfc;
152 
153 	rcu_read_lock();
154 	it->cache = &mrt->mfc_cache_list;
155 	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
156 		if (pos-- == 0)
157 			return mfc;
158 	rcu_read_unlock();
159 
160 	spin_lock_bh(it->lock);
161 	it->cache = &mrt->mfc_unres_queue;
162 	list_for_each_entry(mfc, it->cache, list)
163 		if (pos-- == 0)
164 			return mfc;
165 	spin_unlock_bh(it->lock);
166 
167 	it->cache = NULL;
168 	return NULL;
169 }
170 EXPORT_SYMBOL(mr_mfc_seq_idx);
171 
172 void *mr_mfc_seq_next(struct seq_file *seq, void *v,
173 		      loff_t *pos)
174 {
175 	struct mr_mfc_iter *it = seq->private;
176 	struct net *net = seq_file_net(seq);
177 	struct mr_table *mrt = it->mrt;
178 	struct mr_mfc *c = v;
179 
180 	++*pos;
181 
182 	if (v == SEQ_START_TOKEN)
183 		return mr_mfc_seq_idx(net, seq->private, 0);
184 
185 	if (c->list.next != it->cache)
186 		return list_entry(c->list.next, struct mr_mfc, list);
187 
188 	if (it->cache == &mrt->mfc_unres_queue)
189 		goto end_of_list;
190 
191 	/* exhausted cache_array, show unresolved */
192 	rcu_read_unlock();
193 	it->cache = &mrt->mfc_unres_queue;
194 
195 	spin_lock_bh(it->lock);
196 	if (!list_empty(it->cache))
197 		return list_first_entry(it->cache, struct mr_mfc, list);
198 
199 end_of_list:
200 	spin_unlock_bh(it->lock);
201 	it->cache = NULL;
202 
203 	return NULL;
204 }
205 EXPORT_SYMBOL(mr_mfc_seq_next);
206 #endif
207 
208 int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
209 		   struct mr_mfc *c, struct rtmsg *rtm)
210 {
211 	struct rta_mfc_stats mfcs;
212 	struct nlattr *mp_attr;
213 	struct rtnexthop *nhp;
214 	unsigned long lastuse;
215 	int ct;
216 
217 	/* If cache is unresolved, don't try to parse IIF and OIF */
218 	if (c->mfc_parent >= MAXVIFS) {
219 		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
220 		return -ENOENT;
221 	}
222 
223 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
224 	    nla_put_u32(skb, RTA_IIF,
225 			mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
226 		return -EMSGSIZE;
227 
228 	if (c->mfc_flags & MFC_OFFLOAD)
229 		rtm->rtm_flags |= RTNH_F_OFFLOAD;
230 
231 	mp_attr = nla_nest_start(skb, RTA_MULTIPATH);
232 	if (!mp_attr)
233 		return -EMSGSIZE;
234 
235 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
236 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
237 			struct vif_device *vif;
238 
239 			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
240 			if (!nhp) {
241 				nla_nest_cancel(skb, mp_attr);
242 				return -EMSGSIZE;
243 			}
244 
245 			nhp->rtnh_flags = 0;
246 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
247 			vif = &mrt->vif_table[ct];
248 			nhp->rtnh_ifindex = vif->dev->ifindex;
249 			nhp->rtnh_len = sizeof(*nhp);
250 		}
251 	}
252 
253 	nla_nest_end(skb, mp_attr);
254 
255 	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
256 	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
257 
258 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
259 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
260 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
261 	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
262 	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
263 			      RTA_PAD))
264 		return -EMSGSIZE;
265 
266 	rtm->rtm_type = RTN_MULTICAST;
267 	return 1;
268 }
269 EXPORT_SYMBOL(mr_fill_mroute);
270 
271 int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
272 		     struct mr_table *(*iter)(struct net *net,
273 					      struct mr_table *mrt),
274 		     int (*fill)(struct mr_table *mrt,
275 				 struct sk_buff *skb,
276 				 u32 portid, u32 seq, struct mr_mfc *c,
277 				 int cmd, int flags),
278 		     spinlock_t *lock)
279 {
280 	unsigned int t = 0, e = 0, s_t = cb->args[0], s_e = cb->args[1];
281 	struct net *net = sock_net(skb->sk);
282 	struct mr_table *mrt;
283 	struct mr_mfc *mfc;
284 
285 	rcu_read_lock();
286 	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
287 		if (t < s_t)
288 			goto next_table;
289 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
290 			if (e < s_e)
291 				goto next_entry;
292 			if (fill(mrt, skb, NETLINK_CB(cb->skb).portid,
293 				 cb->nlh->nlmsg_seq, mfc,
294 				 RTM_NEWROUTE, NLM_F_MULTI) < 0)
295 				goto done;
296 next_entry:
297 			e++;
298 		}
299 		e = 0;
300 		s_e = 0;
301 
302 		spin_lock_bh(lock);
303 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
304 			if (e < s_e)
305 				goto next_entry2;
306 			if (fill(mrt, skb, NETLINK_CB(cb->skb).portid,
307 				 cb->nlh->nlmsg_seq, mfc,
308 				 RTM_NEWROUTE, NLM_F_MULTI) < 0) {
309 				spin_unlock_bh(lock);
310 				goto done;
311 			}
312 next_entry2:
313 			e++;
314 		}
315 		spin_unlock_bh(lock);
316 		e = 0;
317 		s_e = 0;
318 next_table:
319 		t++;
320 	}
321 done:
322 	rcu_read_unlock();
323 
324 	cb->args[1] = e;
325 	cb->args[0] = t;
326 
327 	return skb->len;
328 }
329 EXPORT_SYMBOL(mr_rtm_dumproute);
330 
331 int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
332 	    int (*rules_dump)(struct net *net,
333 			      struct notifier_block *nb),
334 	    struct mr_table *(*mr_iter)(struct net *net,
335 					struct mr_table *mrt),
336 	    rwlock_t *mrt_lock)
337 {
338 	struct mr_table *mrt;
339 	int err;
340 
341 	err = rules_dump(net, nb);
342 	if (err)
343 		return err;
344 
345 	for (mrt = mr_iter(net, NULL); mrt; mrt = mr_iter(net, mrt)) {
346 		struct vif_device *v = &mrt->vif_table[0];
347 		struct mr_mfc *mfc;
348 		int vifi;
349 
350 		/* Notifiy on table VIF entries */
351 		read_lock(mrt_lock);
352 		for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
353 			if (!v->dev)
354 				continue;
355 
356 			mr_call_vif_notifier(nb, net, family,
357 					     FIB_EVENT_VIF_ADD,
358 					     v, vifi, mrt->id);
359 		}
360 		read_unlock(mrt_lock);
361 
362 		/* Notify on table MFC entries */
363 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
364 			mr_call_mfc_notifier(nb, net, family,
365 					     FIB_EVENT_ENTRY_ADD,
366 					     mfc, mrt->id);
367 	}
368 
369 	return 0;
370 }
371 EXPORT_SYMBOL(mr_dump);
372