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