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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DECnet       An implementation of the DECnet protocol suite for the LINUX
4  *              operating system.  DECnet is implemented using the  BSD Socket
5  *              interface as the means of communication with the user level.
6  *
7  *              DECnet Routing Forwarding Information Base (Glue/Info List)
8  *
9  * Author:      Steve Whitehouse <SteveW@ACM.org>
10  *
11  *
12  * Changes:
13  *              Alexey Kuznetsov : SMP locking changes
14  *              Steve Whitehouse : Rewrote it... Well to be more correct, I
15  *                                 copied most of it from the ipv4 fib code.
16  *              Steve Whitehouse : Updated it in style and fixed a few bugs
17  *                                 which were fixed in the ipv4 code since
18  *                                 this code was copied from it.
19  *
20  */
21 #include <linux/string.h>
22 #include <linux/net.h>
23 #include <linux/socket.h>
24 #include <linux/slab.h>
25 #include <linux/sockios.h>
26 #include <linux/init.h>
27 #include <linux/skbuff.h>
28 #include <linux/netlink.h>
29 #include <linux/rtnetlink.h>
30 #include <linux/proc_fs.h>
31 #include <linux/netdevice.h>
32 #include <linux/timer.h>
33 #include <linux/spinlock.h>
34 #include <linux/atomic.h>
35 #include <linux/uaccess.h>
36 #include <net/neighbour.h>
37 #include <net/dst.h>
38 #include <net/flow.h>
39 #include <net/fib_rules.h>
40 #include <net/dn.h>
41 #include <net/dn_route.h>
42 #include <net/dn_fib.h>
43 #include <net/dn_neigh.h>
44 #include <net/dn_dev.h>
45 #include <net/rtnh.h>
46 
47 #define RT_MIN_TABLE 1
48 
49 #define for_fib_info() { struct dn_fib_info *fi;\
50 	for(fi = dn_fib_info_list; fi; fi = fi->fib_next)
51 #define endfor_fib_info() }
52 
53 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
54 	for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
55 
56 #define change_nexthops(fi) { int nhsel; struct dn_fib_nh *nh;\
57 	for(nhsel = 0, nh = (struct dn_fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
58 
59 #define endfor_nexthops(fi) }
60 
61 static DEFINE_SPINLOCK(dn_fib_multipath_lock);
62 static struct dn_fib_info *dn_fib_info_list;
63 static DEFINE_SPINLOCK(dn_fib_info_lock);
64 
65 static struct
66 {
67 	int error;
68 	u8 scope;
69 } dn_fib_props[RTN_MAX+1] = {
70 	[RTN_UNSPEC] =      { .error = 0,       .scope = RT_SCOPE_NOWHERE },
71 	[RTN_UNICAST] =     { .error = 0,       .scope = RT_SCOPE_UNIVERSE },
72 	[RTN_LOCAL] =       { .error = 0,       .scope = RT_SCOPE_HOST },
73 	[RTN_BROADCAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
74 	[RTN_ANYCAST] =     { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
75 	[RTN_MULTICAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
76 	[RTN_BLACKHOLE] =   { .error = -EINVAL, .scope = RT_SCOPE_UNIVERSE },
77 	[RTN_UNREACHABLE] = { .error = -EHOSTUNREACH, .scope = RT_SCOPE_UNIVERSE },
78 	[RTN_PROHIBIT] =    { .error = -EACCES, .scope = RT_SCOPE_UNIVERSE },
79 	[RTN_THROW] =       { .error = -EAGAIN, .scope = RT_SCOPE_UNIVERSE },
80 	[RTN_NAT] =         { .error = 0,       .scope = RT_SCOPE_NOWHERE },
81 	[RTN_XRESOLVE] =    { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
82 };
83 
84 static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force);
85 static int dn_fib_sync_up(struct net_device *dev);
86 
dn_fib_free_info(struct dn_fib_info * fi)87 void dn_fib_free_info(struct dn_fib_info *fi)
88 {
89 	if (fi->fib_dead == 0) {
90 		printk(KERN_DEBUG "DECnet: BUG! Attempt to free alive dn_fib_info\n");
91 		return;
92 	}
93 
94 	change_nexthops(fi) {
95 		if (nh->nh_dev)
96 			dev_put(nh->nh_dev);
97 		nh->nh_dev = NULL;
98 	} endfor_nexthops(fi);
99 	kfree(fi);
100 }
101 
dn_fib_release_info(struct dn_fib_info * fi)102 void dn_fib_release_info(struct dn_fib_info *fi)
103 {
104 	spin_lock(&dn_fib_info_lock);
105 	if (fi && --fi->fib_treeref == 0) {
106 		if (fi->fib_next)
107 			fi->fib_next->fib_prev = fi->fib_prev;
108 		if (fi->fib_prev)
109 			fi->fib_prev->fib_next = fi->fib_next;
110 		if (fi == dn_fib_info_list)
111 			dn_fib_info_list = fi->fib_next;
112 		fi->fib_dead = 1;
113 		dn_fib_info_put(fi);
114 	}
115 	spin_unlock(&dn_fib_info_lock);
116 }
117 
dn_fib_nh_comp(const struct dn_fib_info * fi,const struct dn_fib_info * ofi)118 static inline int dn_fib_nh_comp(const struct dn_fib_info *fi, const struct dn_fib_info *ofi)
119 {
120 	const struct dn_fib_nh *onh = ofi->fib_nh;
121 
122 	for_nexthops(fi) {
123 		if (nh->nh_oif != onh->nh_oif ||
124 			nh->nh_gw != onh->nh_gw ||
125 			nh->nh_scope != onh->nh_scope ||
126 			nh->nh_weight != onh->nh_weight ||
127 			((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
128 				return -1;
129 		onh++;
130 	} endfor_nexthops(fi);
131 	return 0;
132 }
133 
dn_fib_find_info(const struct dn_fib_info * nfi)134 static inline struct dn_fib_info *dn_fib_find_info(const struct dn_fib_info *nfi)
135 {
136 	for_fib_info() {
137 		if (fi->fib_nhs != nfi->fib_nhs)
138 			continue;
139 		if (nfi->fib_protocol == fi->fib_protocol &&
140 			nfi->fib_prefsrc == fi->fib_prefsrc &&
141 			nfi->fib_priority == fi->fib_priority &&
142 			memcmp(nfi->fib_metrics, fi->fib_metrics, sizeof(fi->fib_metrics)) == 0 &&
143 			((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
144 			(nfi->fib_nhs == 0 || dn_fib_nh_comp(fi, nfi) == 0))
145 				return fi;
146 	} endfor_fib_info();
147 	return NULL;
148 }
149 
dn_fib_count_nhs(const struct nlattr * attr)150 static int dn_fib_count_nhs(const struct nlattr *attr)
151 {
152 	struct rtnexthop *nhp = nla_data(attr);
153 	int nhs = 0, nhlen = nla_len(attr);
154 
155 	while (rtnh_ok(nhp, nhlen)) {
156 		nhs++;
157 		nhp = rtnh_next(nhp, &nhlen);
158 	}
159 
160 	/* leftover implies invalid nexthop configuration, discard it */
161 	return nhlen > 0 ? 0 : nhs;
162 }
163 
dn_fib_get_nhs(struct dn_fib_info * fi,const struct nlattr * attr,const struct rtmsg * r)164 static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct nlattr *attr,
165 			  const struct rtmsg *r)
166 {
167 	struct rtnexthop *nhp = nla_data(attr);
168 	int nhlen = nla_len(attr);
169 
170 	change_nexthops(fi) {
171 		int attrlen;
172 
173 		if (!rtnh_ok(nhp, nhlen))
174 			return -EINVAL;
175 
176 		nh->nh_flags  = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
177 		nh->nh_oif    = nhp->rtnh_ifindex;
178 		nh->nh_weight = nhp->rtnh_hops + 1;
179 
180 		attrlen = rtnh_attrlen(nhp);
181 		if (attrlen > 0) {
182 			struct nlattr *gw_attr;
183 
184 			gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
185 			nh->nh_gw = gw_attr ? nla_get_le16(gw_attr) : 0;
186 		}
187 
188 		nhp = rtnh_next(nhp, &nhlen);
189 	} endfor_nexthops(fi);
190 
191 	return 0;
192 }
193 
194 
dn_fib_check_nh(const struct rtmsg * r,struct dn_fib_info * fi,struct dn_fib_nh * nh)195 static int dn_fib_check_nh(const struct rtmsg *r, struct dn_fib_info *fi, struct dn_fib_nh *nh)
196 {
197 	int err;
198 
199 	if (nh->nh_gw) {
200 		struct flowidn fld;
201 		struct dn_fib_res res;
202 
203 		if (nh->nh_flags&RTNH_F_ONLINK) {
204 			struct net_device *dev;
205 
206 			if (r->rtm_scope >= RT_SCOPE_LINK)
207 				return -EINVAL;
208 			if (dnet_addr_type(nh->nh_gw) != RTN_UNICAST)
209 				return -EINVAL;
210 			if ((dev = __dev_get_by_index(&init_net, nh->nh_oif)) == NULL)
211 				return -ENODEV;
212 			if (!(dev->flags&IFF_UP))
213 				return -ENETDOWN;
214 			nh->nh_dev = dev;
215 			dev_hold(dev);
216 			nh->nh_scope = RT_SCOPE_LINK;
217 			return 0;
218 		}
219 
220 		memset(&fld, 0, sizeof(fld));
221 		fld.daddr = nh->nh_gw;
222 		fld.flowidn_oif = nh->nh_oif;
223 		fld.flowidn_scope = r->rtm_scope + 1;
224 
225 		if (fld.flowidn_scope < RT_SCOPE_LINK)
226 			fld.flowidn_scope = RT_SCOPE_LINK;
227 
228 		if ((err = dn_fib_lookup(&fld, &res)) != 0)
229 			return err;
230 
231 		err = -EINVAL;
232 		if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
233 			goto out;
234 		nh->nh_scope = res.scope;
235 		nh->nh_oif = DN_FIB_RES_OIF(res);
236 		nh->nh_dev = DN_FIB_RES_DEV(res);
237 		if (nh->nh_dev == NULL)
238 			goto out;
239 		dev_hold(nh->nh_dev);
240 		err = -ENETDOWN;
241 		if (!(nh->nh_dev->flags & IFF_UP))
242 			goto out;
243 		err = 0;
244 out:
245 		dn_fib_res_put(&res);
246 		return err;
247 	} else {
248 		struct net_device *dev;
249 
250 		if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
251 			return -EINVAL;
252 
253 		dev = __dev_get_by_index(&init_net, nh->nh_oif);
254 		if (dev == NULL || dev->dn_ptr == NULL)
255 			return -ENODEV;
256 		if (!(dev->flags&IFF_UP))
257 			return -ENETDOWN;
258 		nh->nh_dev = dev;
259 		dev_hold(nh->nh_dev);
260 		nh->nh_scope = RT_SCOPE_HOST;
261 	}
262 
263 	return 0;
264 }
265 
266 
dn_fib_create_info(const struct rtmsg * r,struct nlattr * attrs[],const struct nlmsghdr * nlh,int * errp)267 struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *attrs[],
268 				       const struct nlmsghdr *nlh, int *errp)
269 {
270 	int err;
271 	struct dn_fib_info *fi = NULL;
272 	struct dn_fib_info *ofi;
273 	int nhs = 1;
274 
275 	if (r->rtm_type > RTN_MAX)
276 		goto err_inval;
277 
278 	if (dn_fib_props[r->rtm_type].scope > r->rtm_scope)
279 		goto err_inval;
280 
281 	if (attrs[RTA_MULTIPATH] &&
282 	    (nhs = dn_fib_count_nhs(attrs[RTA_MULTIPATH])) == 0)
283 		goto err_inval;
284 
285 	fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL);
286 	err = -ENOBUFS;
287 	if (fi == NULL)
288 		goto failure;
289 
290 	fi->fib_protocol = r->rtm_protocol;
291 	fi->fib_nhs = nhs;
292 	fi->fib_flags = r->rtm_flags;
293 
294 	if (attrs[RTA_PRIORITY])
295 		fi->fib_priority = nla_get_u32(attrs[RTA_PRIORITY]);
296 
297 	if (attrs[RTA_METRICS]) {
298 		struct nlattr *attr;
299 		int rem;
300 
301 		nla_for_each_nested(attr, attrs[RTA_METRICS], rem) {
302 			int type = nla_type(attr);
303 
304 			if (type) {
305 				if (type > RTAX_MAX || type == RTAX_CC_ALGO ||
306 				    nla_len(attr) < 4)
307 					goto err_inval;
308 
309 				fi->fib_metrics[type-1] = nla_get_u32(attr);
310 			}
311 		}
312 	}
313 
314 	if (attrs[RTA_PREFSRC])
315 		fi->fib_prefsrc = nla_get_le16(attrs[RTA_PREFSRC]);
316 
317 	if (attrs[RTA_MULTIPATH]) {
318 		if ((err = dn_fib_get_nhs(fi, attrs[RTA_MULTIPATH], r)) != 0)
319 			goto failure;
320 
321 		if (attrs[RTA_OIF] &&
322 		    fi->fib_nh->nh_oif != nla_get_u32(attrs[RTA_OIF]))
323 			goto err_inval;
324 
325 		if (attrs[RTA_GATEWAY] &&
326 		    fi->fib_nh->nh_gw != nla_get_le16(attrs[RTA_GATEWAY]))
327 			goto err_inval;
328 	} else {
329 		struct dn_fib_nh *nh = fi->fib_nh;
330 
331 		if (attrs[RTA_OIF])
332 			nh->nh_oif = nla_get_u32(attrs[RTA_OIF]);
333 
334 		if (attrs[RTA_GATEWAY])
335 			nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
336 
337 		nh->nh_flags = r->rtm_flags;
338 		nh->nh_weight = 1;
339 	}
340 
341 	if (r->rtm_type == RTN_NAT) {
342 		if (!attrs[RTA_GATEWAY] || nhs != 1 || attrs[RTA_OIF])
343 			goto err_inval;
344 
345 		fi->fib_nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
346 		goto link_it;
347 	}
348 
349 	if (dn_fib_props[r->rtm_type].error) {
350 		if (attrs[RTA_GATEWAY] || attrs[RTA_OIF] || attrs[RTA_MULTIPATH])
351 			goto err_inval;
352 
353 		goto link_it;
354 	}
355 
356 	if (r->rtm_scope > RT_SCOPE_HOST)
357 		goto err_inval;
358 
359 	if (r->rtm_scope == RT_SCOPE_HOST) {
360 		struct dn_fib_nh *nh = fi->fib_nh;
361 
362 		/* Local address is added */
363 		if (nhs != 1 || nh->nh_gw)
364 			goto err_inval;
365 		nh->nh_scope = RT_SCOPE_NOWHERE;
366 		nh->nh_dev = dev_get_by_index(&init_net, fi->fib_nh->nh_oif);
367 		err = -ENODEV;
368 		if (nh->nh_dev == NULL)
369 			goto failure;
370 	} else {
371 		change_nexthops(fi) {
372 			if ((err = dn_fib_check_nh(r, fi, nh)) != 0)
373 				goto failure;
374 		} endfor_nexthops(fi)
375 	}
376 
377 	if (fi->fib_prefsrc) {
378 		if (r->rtm_type != RTN_LOCAL || !attrs[RTA_DST] ||
379 		    fi->fib_prefsrc != nla_get_le16(attrs[RTA_DST]))
380 			if (dnet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
381 				goto err_inval;
382 	}
383 
384 link_it:
385 	if ((ofi = dn_fib_find_info(fi)) != NULL) {
386 		fi->fib_dead = 1;
387 		dn_fib_free_info(fi);
388 		ofi->fib_treeref++;
389 		return ofi;
390 	}
391 
392 	fi->fib_treeref++;
393 	refcount_set(&fi->fib_clntref, 1);
394 	spin_lock(&dn_fib_info_lock);
395 	fi->fib_next = dn_fib_info_list;
396 	fi->fib_prev = NULL;
397 	if (dn_fib_info_list)
398 		dn_fib_info_list->fib_prev = fi;
399 	dn_fib_info_list = fi;
400 	spin_unlock(&dn_fib_info_lock);
401 	return fi;
402 
403 err_inval:
404 	err = -EINVAL;
405 
406 failure:
407 	*errp = err;
408 	if (fi) {
409 		fi->fib_dead = 1;
410 		dn_fib_free_info(fi);
411 	}
412 
413 	return NULL;
414 }
415 
dn_fib_semantic_match(int type,struct dn_fib_info * fi,const struct flowidn * fld,struct dn_fib_res * res)416 int dn_fib_semantic_match(int type, struct dn_fib_info *fi, const struct flowidn *fld, struct dn_fib_res *res)
417 {
418 	int err = dn_fib_props[type].error;
419 
420 	if (err == 0) {
421 		if (fi->fib_flags & RTNH_F_DEAD)
422 			return 1;
423 
424 		res->fi = fi;
425 
426 		switch (type) {
427 		case RTN_NAT:
428 			DN_FIB_RES_RESET(*res);
429 			refcount_inc(&fi->fib_clntref);
430 			return 0;
431 		case RTN_UNICAST:
432 		case RTN_LOCAL:
433 			for_nexthops(fi) {
434 				if (nh->nh_flags & RTNH_F_DEAD)
435 					continue;
436 				if (!fld->flowidn_oif ||
437 				    fld->flowidn_oif == nh->nh_oif)
438 					break;
439 			}
440 			if (nhsel < fi->fib_nhs) {
441 				res->nh_sel = nhsel;
442 				refcount_inc(&fi->fib_clntref);
443 				return 0;
444 			}
445 			endfor_nexthops(fi);
446 			res->fi = NULL;
447 			return 1;
448 		default:
449 			net_err_ratelimited("DECnet: impossible routing event : dn_fib_semantic_match type=%d\n",
450 					    type);
451 			res->fi = NULL;
452 			return -EINVAL;
453 		}
454 	}
455 	return err;
456 }
457 
dn_fib_select_multipath(const struct flowidn * fld,struct dn_fib_res * res)458 void dn_fib_select_multipath(const struct flowidn *fld, struct dn_fib_res *res)
459 {
460 	struct dn_fib_info *fi = res->fi;
461 	int w;
462 
463 	spin_lock_bh(&dn_fib_multipath_lock);
464 	if (fi->fib_power <= 0) {
465 		int power = 0;
466 		change_nexthops(fi) {
467 			if (!(nh->nh_flags&RTNH_F_DEAD)) {
468 				power += nh->nh_weight;
469 				nh->nh_power = nh->nh_weight;
470 			}
471 		} endfor_nexthops(fi);
472 		fi->fib_power = power;
473 		if (power < 0) {
474 			spin_unlock_bh(&dn_fib_multipath_lock);
475 			res->nh_sel = 0;
476 			return;
477 		}
478 	}
479 
480 	w = jiffies % fi->fib_power;
481 
482 	change_nexthops(fi) {
483 		if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
484 			if ((w -= nh->nh_power) <= 0) {
485 				nh->nh_power--;
486 				fi->fib_power--;
487 				res->nh_sel = nhsel;
488 				spin_unlock_bh(&dn_fib_multipath_lock);
489 				return;
490 			}
491 		}
492 	} endfor_nexthops(fi);
493 	res->nh_sel = 0;
494 	spin_unlock_bh(&dn_fib_multipath_lock);
495 }
496 
rtm_get_table(struct nlattr * attrs[],u8 table)497 static inline u32 rtm_get_table(struct nlattr *attrs[], u8 table)
498 {
499 	if (attrs[RTA_TABLE])
500 		table = nla_get_u32(attrs[RTA_TABLE]);
501 
502 	return table;
503 }
504 
dn_fib_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)505 static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
506 			       struct netlink_ext_ack *extack)
507 {
508 	struct net *net = sock_net(skb->sk);
509 	struct dn_fib_table *tb;
510 	struct rtmsg *r = nlmsg_data(nlh);
511 	struct nlattr *attrs[RTA_MAX+1];
512 	int err;
513 
514 	if (!netlink_capable(skb, CAP_NET_ADMIN))
515 		return -EPERM;
516 
517 	if (!net_eq(net, &init_net))
518 		return -EINVAL;
519 
520 	err = nlmsg_parse_deprecated(nlh, sizeof(*r), attrs, RTA_MAX,
521 				     rtm_dn_policy, extack);
522 	if (err < 0)
523 		return err;
524 
525 	tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 0);
526 	if (!tb)
527 		return -ESRCH;
528 
529 	return tb->delete(tb, r, attrs, nlh, &NETLINK_CB(skb));
530 }
531 
dn_fib_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)532 static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
533 			       struct netlink_ext_ack *extack)
534 {
535 	struct net *net = sock_net(skb->sk);
536 	struct dn_fib_table *tb;
537 	struct rtmsg *r = nlmsg_data(nlh);
538 	struct nlattr *attrs[RTA_MAX+1];
539 	int err;
540 
541 	if (!netlink_capable(skb, CAP_NET_ADMIN))
542 		return -EPERM;
543 
544 	if (!net_eq(net, &init_net))
545 		return -EINVAL;
546 
547 	err = nlmsg_parse_deprecated(nlh, sizeof(*r), attrs, RTA_MAX,
548 				     rtm_dn_policy, extack);
549 	if (err < 0)
550 		return err;
551 
552 	tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 1);
553 	if (!tb)
554 		return -ENOBUFS;
555 
556 	return tb->insert(tb, r, attrs, nlh, &NETLINK_CB(skb));
557 }
558 
fib_magic(int cmd,int type,__le16 dst,int dst_len,struct dn_ifaddr * ifa)559 static void fib_magic(int cmd, int type, __le16 dst, int dst_len, struct dn_ifaddr *ifa)
560 {
561 	struct dn_fib_table *tb;
562 	struct {
563 		struct nlmsghdr nlh;
564 		struct rtmsg rtm;
565 	} req;
566 	struct {
567 		struct nlattr hdr;
568 		__le16 dst;
569 	} dst_attr = {
570 		.dst = dst,
571 	};
572 	struct {
573 		struct nlattr hdr;
574 		__le16 prefsrc;
575 	} prefsrc_attr = {
576 		.prefsrc = ifa->ifa_local,
577 	};
578 	struct {
579 		struct nlattr hdr;
580 		u32 oif;
581 	} oif_attr = {
582 		.oif = ifa->ifa_dev->dev->ifindex,
583 	};
584 	struct nlattr *attrs[RTA_MAX+1] = {
585 		[RTA_DST] = (struct nlattr *) &dst_attr,
586 		[RTA_PREFSRC] = (struct nlattr * ) &prefsrc_attr,
587 		[RTA_OIF] = (struct nlattr *) &oif_attr,
588 	};
589 
590 	memset(&req.rtm, 0, sizeof(req.rtm));
591 
592 	if (type == RTN_UNICAST)
593 		tb = dn_fib_get_table(RT_MIN_TABLE, 1);
594 	else
595 		tb = dn_fib_get_table(RT_TABLE_LOCAL, 1);
596 
597 	if (tb == NULL)
598 		return;
599 
600 	req.nlh.nlmsg_len = sizeof(req);
601 	req.nlh.nlmsg_type = cmd;
602 	req.nlh.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_APPEND;
603 	req.nlh.nlmsg_pid = 0;
604 	req.nlh.nlmsg_seq = 0;
605 
606 	req.rtm.rtm_dst_len = dst_len;
607 	req.rtm.rtm_table = tb->n;
608 	req.rtm.rtm_protocol = RTPROT_KERNEL;
609 	req.rtm.rtm_scope = (type != RTN_LOCAL ? RT_SCOPE_LINK : RT_SCOPE_HOST);
610 	req.rtm.rtm_type = type;
611 
612 	if (cmd == RTM_NEWROUTE)
613 		tb->insert(tb, &req.rtm, attrs, &req.nlh, NULL);
614 	else
615 		tb->delete(tb, &req.rtm, attrs, &req.nlh, NULL);
616 }
617 
dn_fib_add_ifaddr(struct dn_ifaddr * ifa)618 static void dn_fib_add_ifaddr(struct dn_ifaddr *ifa)
619 {
620 
621 	fib_magic(RTM_NEWROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
622 
623 #if 0
624 	if (!(dev->flags&IFF_UP))
625 		return;
626 	/* In the future, we will want to add default routes here */
627 
628 #endif
629 }
630 
dn_fib_del_ifaddr(struct dn_ifaddr * ifa)631 static void dn_fib_del_ifaddr(struct dn_ifaddr *ifa)
632 {
633 	int found_it = 0;
634 	struct net_device *dev;
635 	struct dn_dev *dn_db;
636 	struct dn_ifaddr *ifa2;
637 
638 	ASSERT_RTNL();
639 
640 	/* Scan device list */
641 	rcu_read_lock();
642 	for_each_netdev_rcu(&init_net, dev) {
643 		dn_db = rcu_dereference(dev->dn_ptr);
644 		if (dn_db == NULL)
645 			continue;
646 		for (ifa2 = rcu_dereference(dn_db->ifa_list);
647 		     ifa2 != NULL;
648 		     ifa2 = rcu_dereference(ifa2->ifa_next)) {
649 			if (ifa2->ifa_local == ifa->ifa_local) {
650 				found_it = 1;
651 				break;
652 			}
653 		}
654 	}
655 	rcu_read_unlock();
656 
657 	if (found_it == 0) {
658 		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
659 
660 		if (dnet_addr_type(ifa->ifa_local) != RTN_LOCAL) {
661 			if (dn_fib_sync_down(ifa->ifa_local, NULL, 0))
662 				dn_fib_flush();
663 		}
664 	}
665 }
666 
dn_fib_disable_addr(struct net_device * dev,int force)667 static void dn_fib_disable_addr(struct net_device *dev, int force)
668 {
669 	if (dn_fib_sync_down(0, dev, force))
670 		dn_fib_flush();
671 	dn_rt_cache_flush(0);
672 	neigh_ifdown(&dn_neigh_table, dev);
673 }
674 
dn_fib_dnaddr_event(struct notifier_block * this,unsigned long event,void * ptr)675 static int dn_fib_dnaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
676 {
677 	struct dn_ifaddr *ifa = (struct dn_ifaddr *)ptr;
678 
679 	switch (event) {
680 	case NETDEV_UP:
681 		dn_fib_add_ifaddr(ifa);
682 		dn_fib_sync_up(ifa->ifa_dev->dev);
683 		dn_rt_cache_flush(-1);
684 		break;
685 	case NETDEV_DOWN:
686 		dn_fib_del_ifaddr(ifa);
687 		if (ifa->ifa_dev && ifa->ifa_dev->ifa_list == NULL) {
688 			dn_fib_disable_addr(ifa->ifa_dev->dev, 1);
689 		} else {
690 			dn_rt_cache_flush(-1);
691 		}
692 		break;
693 	}
694 	return NOTIFY_DONE;
695 }
696 
dn_fib_sync_down(__le16 local,struct net_device * dev,int force)697 static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force)
698 {
699 	int ret = 0;
700 	int scope = RT_SCOPE_NOWHERE;
701 
702 	if (force)
703 		scope = -1;
704 
705 	for_fib_info() {
706 		/*
707 		 * This makes no sense for DECnet.... we will almost
708 		 * certainly have more than one local address the same
709 		 * over all our interfaces. It needs thinking about
710 		 * some more.
711 		 */
712 		if (local && fi->fib_prefsrc == local) {
713 			fi->fib_flags |= RTNH_F_DEAD;
714 			ret++;
715 		} else if (dev && fi->fib_nhs) {
716 			int dead = 0;
717 
718 			change_nexthops(fi) {
719 				if (nh->nh_flags&RTNH_F_DEAD)
720 					dead++;
721 				else if (nh->nh_dev == dev &&
722 						nh->nh_scope != scope) {
723 					spin_lock_bh(&dn_fib_multipath_lock);
724 					nh->nh_flags |= RTNH_F_DEAD;
725 					fi->fib_power -= nh->nh_power;
726 					nh->nh_power = 0;
727 					spin_unlock_bh(&dn_fib_multipath_lock);
728 					dead++;
729 				}
730 			} endfor_nexthops(fi)
731 			if (dead == fi->fib_nhs) {
732 				fi->fib_flags |= RTNH_F_DEAD;
733 				ret++;
734 			}
735 		}
736 	} endfor_fib_info();
737 	return ret;
738 }
739 
740 
dn_fib_sync_up(struct net_device * dev)741 static int dn_fib_sync_up(struct net_device *dev)
742 {
743 	int ret = 0;
744 
745 	if (!(dev->flags&IFF_UP))
746 		return 0;
747 
748 	for_fib_info() {
749 		int alive = 0;
750 
751 		change_nexthops(fi) {
752 			if (!(nh->nh_flags&RTNH_F_DEAD)) {
753 				alive++;
754 				continue;
755 			}
756 			if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
757 				continue;
758 			if (nh->nh_dev != dev || dev->dn_ptr == NULL)
759 				continue;
760 			alive++;
761 			spin_lock_bh(&dn_fib_multipath_lock);
762 			nh->nh_power = 0;
763 			nh->nh_flags &= ~RTNH_F_DEAD;
764 			spin_unlock_bh(&dn_fib_multipath_lock);
765 		} endfor_nexthops(fi);
766 
767 		if (alive > 0) {
768 			fi->fib_flags &= ~RTNH_F_DEAD;
769 			ret++;
770 		}
771 	} endfor_fib_info();
772 	return ret;
773 }
774 
775 static struct notifier_block dn_fib_dnaddr_notifier = {
776 	.notifier_call = dn_fib_dnaddr_event,
777 };
778 
dn_fib_cleanup(void)779 void __exit dn_fib_cleanup(void)
780 {
781 	dn_fib_table_cleanup();
782 	dn_fib_rules_cleanup();
783 
784 	unregister_dnaddr_notifier(&dn_fib_dnaddr_notifier);
785 }
786 
787 
dn_fib_init(void)788 void __init dn_fib_init(void)
789 {
790 	dn_fib_table_init();
791 	dn_fib_rules_init();
792 
793 	register_dnaddr_notifier(&dn_fib_dnaddr_notifier);
794 
795 	rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_NEWROUTE,
796 			     dn_fib_rtm_newroute, NULL, 0);
797 	rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_DELROUTE,
798 			     dn_fib_rtm_delroute, NULL, 0);
799 }
800