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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 (Routing Tables)
7  *
8  * Author:      Steve Whitehouse <SteveW@ACM.org>
9  *              Mostly copied from the IPv4 routing code
10  *
11  *
12  * Changes:
13  *
14  */
15 #include <linux/string.h>
16 #include <linux/net.h>
17 #include <linux/socket.h>
18 #include <linux/slab.h>
19 #include <linux/sockios.h>
20 #include <linux/init.h>
21 #include <linux/skbuff.h>
22 #include <linux/rtnetlink.h>
23 #include <linux/proc_fs.h>
24 #include <linux/netdevice.h>
25 #include <linux/timer.h>
26 #include <linux/spinlock.h>
27 #include <linux/atomic.h>
28 #include <asm/uaccess.h>
29 #include <linux/route.h> /* RTF_xxx */
30 #include <net/neighbour.h>
31 #include <net/netlink.h>
32 #include <net/tcp.h>
33 #include <net/dst.h>
34 #include <net/flow.h>
35 #include <net/fib_rules.h>
36 #include <net/dn.h>
37 #include <net/dn_route.h>
38 #include <net/dn_fib.h>
39 #include <net/dn_neigh.h>
40 #include <net/dn_dev.h>
41 
42 struct dn_zone
43 {
44 	struct dn_zone		*dz_next;
45 	struct dn_fib_node 	**dz_hash;
46 	int			dz_nent;
47 	int			dz_divisor;
48 	u32			dz_hashmask;
49 #define DZ_HASHMASK(dz)	((dz)->dz_hashmask)
50 	int			dz_order;
51 	__le16			dz_mask;
52 #define DZ_MASK(dz)	((dz)->dz_mask)
53 };
54 
55 struct dn_hash
56 {
57 	struct dn_zone	*dh_zones[17];
58 	struct dn_zone	*dh_zone_list;
59 };
60 
61 #define dz_key_0(key)		((key).datum = 0)
62 
63 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
64 	for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
65 
66 #define endfor_nexthops(fi) }
67 
68 #define DN_MAX_DIVISOR 1024
69 #define DN_S_ZOMBIE 1
70 #define DN_S_ACCESSED 2
71 
72 #define DN_FIB_SCAN(f, fp) \
73 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
74 
75 #define DN_FIB_SCAN_KEY(f, fp, key) \
76 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
77 
78 #define RT_TABLE_MIN 1
79 #define DN_FIB_TABLE_HASHSZ 256
80 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
81 static DEFINE_RWLOCK(dn_fib_tables_lock);
82 
83 static struct kmem_cache *dn_hash_kmem __read_mostly;
84 static int dn_fib_hash_zombies;
85 
dn_hash(dn_fib_key_t key,struct dn_zone * dz)86 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
87 {
88 	u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
89 	h ^= (h >> 10);
90 	h ^= (h >> 6);
91 	h &= DZ_HASHMASK(dz);
92 	return *(dn_fib_idx_t *)&h;
93 }
94 
dz_key(__le16 dst,struct dn_zone * dz)95 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
96 {
97 	dn_fib_key_t k;
98 	k.datum = dst & DZ_MASK(dz);
99 	return k;
100 }
101 
dn_chain_p(dn_fib_key_t key,struct dn_zone * dz)102 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
103 {
104 	return &dz->dz_hash[dn_hash(key, dz).datum];
105 }
106 
dz_chain(dn_fib_key_t key,struct dn_zone * dz)107 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
108 {
109 	return dz->dz_hash[dn_hash(key, dz).datum];
110 }
111 
dn_key_eq(dn_fib_key_t a,dn_fib_key_t b)112 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
113 {
114 	return a.datum == b.datum;
115 }
116 
dn_key_leq(dn_fib_key_t a,dn_fib_key_t b)117 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
118 {
119 	return a.datum <= b.datum;
120 }
121 
dn_rebuild_zone(struct dn_zone * dz,struct dn_fib_node ** old_ht,int old_divisor)122 static inline void dn_rebuild_zone(struct dn_zone *dz,
123 				   struct dn_fib_node **old_ht,
124 				   int old_divisor)
125 {
126 	struct dn_fib_node *f, **fp, *next;
127 	int i;
128 
129 	for(i = 0; i < old_divisor; i++) {
130 		for(f = old_ht[i]; f; f = next) {
131 			next = f->fn_next;
132 			for(fp = dn_chain_p(f->fn_key, dz);
133 				*fp && dn_key_leq((*fp)->fn_key, f->fn_key);
134 				fp = &(*fp)->fn_next)
135 				/* NOTHING */;
136 			f->fn_next = *fp;
137 			*fp = f;
138 		}
139 	}
140 }
141 
dn_rehash_zone(struct dn_zone * dz)142 static void dn_rehash_zone(struct dn_zone *dz)
143 {
144 	struct dn_fib_node **ht, **old_ht;
145 	int old_divisor, new_divisor;
146 	u32 new_hashmask;
147 
148 	old_divisor = dz->dz_divisor;
149 
150 	switch (old_divisor) {
151 	case 16:
152 		new_divisor = 256;
153 		new_hashmask = 0xFF;
154 		break;
155 	default:
156 		printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
157 		       old_divisor);
158 	case 256:
159 		new_divisor = 1024;
160 		new_hashmask = 0x3FF;
161 		break;
162 	}
163 
164 	ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
165 	if (ht == NULL)
166 		return;
167 
168 	write_lock_bh(&dn_fib_tables_lock);
169 	old_ht = dz->dz_hash;
170 	dz->dz_hash = ht;
171 	dz->dz_hashmask = new_hashmask;
172 	dz->dz_divisor = new_divisor;
173 	dn_rebuild_zone(dz, old_ht, old_divisor);
174 	write_unlock_bh(&dn_fib_tables_lock);
175 	kfree(old_ht);
176 }
177 
dn_free_node(struct dn_fib_node * f)178 static void dn_free_node(struct dn_fib_node *f)
179 {
180 	dn_fib_release_info(DN_FIB_INFO(f));
181 	kmem_cache_free(dn_hash_kmem, f);
182 }
183 
184 
dn_new_zone(struct dn_hash * table,int z)185 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
186 {
187 	int i;
188 	struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
189 	if (!dz)
190 		return NULL;
191 
192 	if (z) {
193 		dz->dz_divisor = 16;
194 		dz->dz_hashmask = 0x0F;
195 	} else {
196 		dz->dz_divisor = 1;
197 		dz->dz_hashmask = 0;
198 	}
199 
200 	dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
201 	if (!dz->dz_hash) {
202 		kfree(dz);
203 		return NULL;
204 	}
205 
206 	dz->dz_order = z;
207 	dz->dz_mask = dnet_make_mask(z);
208 
209 	for(i = z + 1; i <= 16; i++)
210 		if (table->dh_zones[i])
211 			break;
212 
213 	write_lock_bh(&dn_fib_tables_lock);
214 	if (i>16) {
215 		dz->dz_next = table->dh_zone_list;
216 		table->dh_zone_list = dz;
217 	} else {
218 		dz->dz_next = table->dh_zones[i]->dz_next;
219 		table->dh_zones[i]->dz_next = dz;
220 	}
221 	table->dh_zones[z] = dz;
222 	write_unlock_bh(&dn_fib_tables_lock);
223 	return dz;
224 }
225 
226 
dn_fib_nh_match(struct rtmsg * r,struct nlmsghdr * nlh,struct nlattr * attrs[],struct dn_fib_info * fi)227 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
228 {
229 	struct rtnexthop *nhp;
230 	int nhlen;
231 
232 	if (attrs[RTA_PRIORITY] &&
233 	    nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
234 		return 1;
235 
236 	if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
237 		if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
238 		    (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
239 			return 0;
240 		return 1;
241 	}
242 
243 	if (!attrs[RTA_MULTIPATH])
244 		return 0;
245 
246 	nhp = nla_data(attrs[RTA_MULTIPATH]);
247 	nhlen = nla_len(attrs[RTA_MULTIPATH]);
248 
249 	for_nexthops(fi) {
250 		int attrlen = nhlen - sizeof(struct rtnexthop);
251 		__le16 gw;
252 
253 		if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
254 			return -EINVAL;
255 		if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
256 			return 1;
257 		if (attrlen) {
258 			struct nlattr *gw_attr;
259 
260 			gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
261 			gw = gw_attr ? nla_get_le16(gw_attr) : 0;
262 
263 			if (gw && gw != nh->nh_gw)
264 				return 1;
265 		}
266 		nhp = RTNH_NEXT(nhp);
267 	} endfor_nexthops(fi);
268 
269 	return 0;
270 }
271 
dn_fib_nlmsg_size(struct dn_fib_info * fi)272 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
273 {
274 	size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
275 			 + nla_total_size(4) /* RTA_TABLE */
276 			 + nla_total_size(2) /* RTA_DST */
277 			 + nla_total_size(4) /* RTA_PRIORITY */
278 			 + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
279 
280 	/* space for nested metrics */
281 	payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
282 
283 	if (fi->fib_nhs) {
284 		/* Also handles the special case fib_nhs == 1 */
285 
286 		/* each nexthop is packed in an attribute */
287 		size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
288 
289 		/* may contain a gateway attribute */
290 		nhsize += nla_total_size(4);
291 
292 		/* all nexthops are packed in a nested attribute */
293 		payload += nla_total_size(fi->fib_nhs * nhsize);
294 	}
295 
296 	return payload;
297 }
298 
dn_fib_dump_info(struct sk_buff * skb,u32 portid,u32 seq,int event,u32 tb_id,u8 type,u8 scope,void * dst,int dst_len,struct dn_fib_info * fi,unsigned int flags)299 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
300 			u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
301 			struct dn_fib_info *fi, unsigned int flags)
302 {
303 	struct rtmsg *rtm;
304 	struct nlmsghdr *nlh;
305 
306 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
307 	if (!nlh)
308 		return -EMSGSIZE;
309 
310 	rtm = nlmsg_data(nlh);
311 	rtm->rtm_family = AF_DECnet;
312 	rtm->rtm_dst_len = dst_len;
313 	rtm->rtm_src_len = 0;
314 	rtm->rtm_tos = 0;
315 	rtm->rtm_table = tb_id;
316 	rtm->rtm_flags = fi->fib_flags;
317 	rtm->rtm_scope = scope;
318 	rtm->rtm_type  = type;
319 	rtm->rtm_protocol = fi->fib_protocol;
320 
321 	if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
322 		goto errout;
323 
324 	if (rtm->rtm_dst_len &&
325 	    nla_put(skb, RTA_DST, 2, dst) < 0)
326 		goto errout;
327 
328 	if (fi->fib_priority &&
329 	    nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
330 		goto errout;
331 
332 	if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
333 		goto errout;
334 
335 	if (fi->fib_nhs == 1) {
336 		if (fi->fib_nh->nh_gw &&
337 		    nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
338 			goto errout;
339 
340 		if (fi->fib_nh->nh_oif &&
341 		    nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
342 			goto errout;
343 	}
344 
345 	if (fi->fib_nhs > 1) {
346 		struct rtnexthop *nhp;
347 		struct nlattr *mp_head;
348 
349 		if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
350 			goto errout;
351 
352 		for_nexthops(fi) {
353 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
354 				goto errout;
355 
356 			nhp->rtnh_flags = nh->nh_flags & 0xFF;
357 			nhp->rtnh_hops = nh->nh_weight - 1;
358 			nhp->rtnh_ifindex = nh->nh_oif;
359 
360 			if (nh->nh_gw &&
361 			    nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
362 				goto errout;
363 
364 			nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
365 		} endfor_nexthops(fi);
366 
367 		nla_nest_end(skb, mp_head);
368 	}
369 
370 	nlmsg_end(skb, nlh);
371 	return 0;
372 
373 errout:
374 	nlmsg_cancel(skb, nlh);
375 	return -EMSGSIZE;
376 }
377 
378 
dn_rtmsg_fib(int event,struct dn_fib_node * f,int z,u32 tb_id,struct nlmsghdr * nlh,struct netlink_skb_parms * req)379 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
380 			struct nlmsghdr *nlh, struct netlink_skb_parms *req)
381 {
382 	struct sk_buff *skb;
383 	u32 portid = req ? req->portid : 0;
384 	int err = -ENOBUFS;
385 
386 	skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
387 	if (skb == NULL)
388 		goto errout;
389 
390 	err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
391 			       f->fn_type, f->fn_scope, &f->fn_key, z,
392 			       DN_FIB_INFO(f), 0);
393 	if (err < 0) {
394 		/* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
395 		WARN_ON(err == -EMSGSIZE);
396 		kfree_skb(skb);
397 		goto errout;
398 	}
399 	rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
400 	return;
401 errout:
402 	if (err < 0)
403 		rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
404 }
405 
dn_hash_dump_bucket(struct sk_buff * skb,struct netlink_callback * cb,struct dn_fib_table * tb,struct dn_zone * dz,struct dn_fib_node * f)406 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
407 				struct netlink_callback *cb,
408 				struct dn_fib_table *tb,
409 				struct dn_zone *dz,
410 				struct dn_fib_node *f)
411 {
412 	int i, s_i;
413 
414 	s_i = cb->args[4];
415 	for(i = 0; f; i++, f = f->fn_next) {
416 		if (i < s_i)
417 			continue;
418 		if (f->fn_state & DN_S_ZOMBIE)
419 			continue;
420 		if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
421 				cb->nlh->nlmsg_seq,
422 				RTM_NEWROUTE,
423 				tb->n,
424 				(f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
425 				f->fn_scope, &f->fn_key, dz->dz_order,
426 				f->fn_info, NLM_F_MULTI) < 0) {
427 			cb->args[4] = i;
428 			return -1;
429 		}
430 	}
431 	cb->args[4] = i;
432 	return skb->len;
433 }
434 
dn_hash_dump_zone(struct sk_buff * skb,struct netlink_callback * cb,struct dn_fib_table * tb,struct dn_zone * dz)435 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
436 				struct netlink_callback *cb,
437 				struct dn_fib_table *tb,
438 				struct dn_zone *dz)
439 {
440 	int h, s_h;
441 
442 	s_h = cb->args[3];
443 	for(h = 0; h < dz->dz_divisor; h++) {
444 		if (h < s_h)
445 			continue;
446 		if (h > s_h)
447 			memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
448 		if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
449 			continue;
450 		if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
451 			cb->args[3] = h;
452 			return -1;
453 		}
454 	}
455 	cb->args[3] = h;
456 	return skb->len;
457 }
458 
dn_fib_table_dump(struct dn_fib_table * tb,struct sk_buff * skb,struct netlink_callback * cb)459 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
460 				struct netlink_callback *cb)
461 {
462 	int m, s_m;
463 	struct dn_zone *dz;
464 	struct dn_hash *table = (struct dn_hash *)tb->data;
465 
466 	s_m = cb->args[2];
467 	read_lock(&dn_fib_tables_lock);
468 	for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
469 		if (m < s_m)
470 			continue;
471 		if (m > s_m)
472 			memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
473 
474 		if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
475 			cb->args[2] = m;
476 			read_unlock(&dn_fib_tables_lock);
477 			return -1;
478 		}
479 	}
480 	read_unlock(&dn_fib_tables_lock);
481 	cb->args[2] = m;
482 
483 	return skb->len;
484 }
485 
dn_fib_dump(struct sk_buff * skb,struct netlink_callback * cb)486 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
487 {
488 	struct net *net = sock_net(skb->sk);
489 	unsigned int h, s_h;
490 	unsigned int e = 0, s_e;
491 	struct dn_fib_table *tb;
492 	int dumped = 0;
493 
494 	if (!net_eq(net, &init_net))
495 		return 0;
496 
497 	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
498 		((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
499 			return dn_cache_dump(skb, cb);
500 
501 	s_h = cb->args[0];
502 	s_e = cb->args[1];
503 
504 	for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
505 		e = 0;
506 		hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
507 			if (e < s_e)
508 				goto next;
509 			if (dumped)
510 				memset(&cb->args[2], 0, sizeof(cb->args) -
511 						 2 * sizeof(cb->args[0]));
512 			if (tb->dump(tb, skb, cb) < 0)
513 				goto out;
514 			dumped = 1;
515 next:
516 			e++;
517 		}
518 	}
519 out:
520 	cb->args[1] = e;
521 	cb->args[0] = h;
522 
523 	return skb->len;
524 }
525 
dn_fib_table_insert(struct dn_fib_table * tb,struct rtmsg * r,struct nlattr * attrs[],struct nlmsghdr * n,struct netlink_skb_parms * req)526 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
527 			       struct nlmsghdr *n, struct netlink_skb_parms *req)
528 {
529 	struct dn_hash *table = (struct dn_hash *)tb->data;
530 	struct dn_fib_node *new_f, *f, **fp, **del_fp;
531 	struct dn_zone *dz;
532 	struct dn_fib_info *fi;
533 	int z = r->rtm_dst_len;
534 	int type = r->rtm_type;
535 	dn_fib_key_t key;
536 	int err;
537 
538 	if (z > 16)
539 		return -EINVAL;
540 
541 	dz = table->dh_zones[z];
542 	if (!dz && !(dz = dn_new_zone(table, z)))
543 		return -ENOBUFS;
544 
545 	dz_key_0(key);
546 	if (attrs[RTA_DST]) {
547 		__le16 dst = nla_get_le16(attrs[RTA_DST]);
548 		if (dst & ~DZ_MASK(dz))
549 			return -EINVAL;
550 		key = dz_key(dst, dz);
551 	}
552 
553 	if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
554 		return err;
555 
556 	if (dz->dz_nent > (dz->dz_divisor << 2) &&
557 			dz->dz_divisor > DN_MAX_DIVISOR &&
558 			(z==16 || (1<<z) > dz->dz_divisor))
559 		dn_rehash_zone(dz);
560 
561 	fp = dn_chain_p(key, dz);
562 
563 	DN_FIB_SCAN(f, fp) {
564 		if (dn_key_leq(key, f->fn_key))
565 			break;
566 	}
567 
568 	del_fp = NULL;
569 
570 	if (f && (f->fn_state & DN_S_ZOMBIE) &&
571 			dn_key_eq(f->fn_key, key)) {
572 		del_fp = fp;
573 		fp = &f->fn_next;
574 		f = *fp;
575 		goto create;
576 	}
577 
578 	DN_FIB_SCAN_KEY(f, fp, key) {
579 		if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
580 			break;
581 	}
582 
583 	if (f && dn_key_eq(f->fn_key, key) &&
584 			fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
585 		struct dn_fib_node **ins_fp;
586 
587 		err = -EEXIST;
588 		if (n->nlmsg_flags & NLM_F_EXCL)
589 			goto out;
590 
591 		if (n->nlmsg_flags & NLM_F_REPLACE) {
592 			del_fp = fp;
593 			fp = &f->fn_next;
594 			f = *fp;
595 			goto replace;
596 		}
597 
598 		ins_fp = fp;
599 		err = -EEXIST;
600 
601 		DN_FIB_SCAN_KEY(f, fp, key) {
602 			if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
603 				break;
604 			if (f->fn_type == type &&
605 			    f->fn_scope == r->rtm_scope &&
606 			    DN_FIB_INFO(f) == fi)
607 				goto out;
608 		}
609 
610 		if (!(n->nlmsg_flags & NLM_F_APPEND)) {
611 			fp = ins_fp;
612 			f = *fp;
613 		}
614 	}
615 
616 create:
617 	err = -ENOENT;
618 	if (!(n->nlmsg_flags & NLM_F_CREATE))
619 		goto out;
620 
621 replace:
622 	err = -ENOBUFS;
623 	new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
624 	if (new_f == NULL)
625 		goto out;
626 
627 	new_f->fn_key = key;
628 	new_f->fn_type = type;
629 	new_f->fn_scope = r->rtm_scope;
630 	DN_FIB_INFO(new_f) = fi;
631 
632 	new_f->fn_next = f;
633 	write_lock_bh(&dn_fib_tables_lock);
634 	*fp = new_f;
635 	write_unlock_bh(&dn_fib_tables_lock);
636 	dz->dz_nent++;
637 
638 	if (del_fp) {
639 		f = *del_fp;
640 		write_lock_bh(&dn_fib_tables_lock);
641 		*del_fp = f->fn_next;
642 		write_unlock_bh(&dn_fib_tables_lock);
643 
644 		if (!(f->fn_state & DN_S_ZOMBIE))
645 			dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
646 		if (f->fn_state & DN_S_ACCESSED)
647 			dn_rt_cache_flush(-1);
648 		dn_free_node(f);
649 		dz->dz_nent--;
650 	} else {
651 		dn_rt_cache_flush(-1);
652 	}
653 
654 	dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
655 
656 	return 0;
657 out:
658 	dn_fib_release_info(fi);
659 	return err;
660 }
661 
662 
dn_fib_table_delete(struct dn_fib_table * tb,struct rtmsg * r,struct nlattr * attrs[],struct nlmsghdr * n,struct netlink_skb_parms * req)663 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
664 			       struct nlmsghdr *n, struct netlink_skb_parms *req)
665 {
666 	struct dn_hash *table = (struct dn_hash*)tb->data;
667 	struct dn_fib_node **fp, **del_fp, *f;
668 	int z = r->rtm_dst_len;
669 	struct dn_zone *dz;
670 	dn_fib_key_t key;
671 	int matched;
672 
673 
674 	if (z > 16)
675 		return -EINVAL;
676 
677 	if ((dz = table->dh_zones[z]) == NULL)
678 		return -ESRCH;
679 
680 	dz_key_0(key);
681 	if (attrs[RTA_DST]) {
682 		__le16 dst = nla_get_le16(attrs[RTA_DST]);
683 		if (dst & ~DZ_MASK(dz))
684 			return -EINVAL;
685 		key = dz_key(dst, dz);
686 	}
687 
688 	fp = dn_chain_p(key, dz);
689 
690 	DN_FIB_SCAN(f, fp) {
691 		if (dn_key_eq(f->fn_key, key))
692 			break;
693 		if (dn_key_leq(key, f->fn_key))
694 			return -ESRCH;
695 	}
696 
697 	matched = 0;
698 	del_fp = NULL;
699 	DN_FIB_SCAN_KEY(f, fp, key) {
700 		struct dn_fib_info *fi = DN_FIB_INFO(f);
701 
702 		if (f->fn_state & DN_S_ZOMBIE)
703 			return -ESRCH;
704 
705 		matched++;
706 
707 		if (del_fp == NULL &&
708 				(!r->rtm_type || f->fn_type == r->rtm_type) &&
709 				(r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
710 				(!r->rtm_protocol ||
711 					fi->fib_protocol == r->rtm_protocol) &&
712 				dn_fib_nh_match(r, n, attrs, fi) == 0)
713 			del_fp = fp;
714 	}
715 
716 	if (del_fp) {
717 		f = *del_fp;
718 		dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
719 
720 		if (matched != 1) {
721 			write_lock_bh(&dn_fib_tables_lock);
722 			*del_fp = f->fn_next;
723 			write_unlock_bh(&dn_fib_tables_lock);
724 
725 			if (f->fn_state & DN_S_ACCESSED)
726 				dn_rt_cache_flush(-1);
727 			dn_free_node(f);
728 			dz->dz_nent--;
729 		} else {
730 			f->fn_state |= DN_S_ZOMBIE;
731 			if (f->fn_state & DN_S_ACCESSED) {
732 				f->fn_state &= ~DN_S_ACCESSED;
733 				dn_rt_cache_flush(-1);
734 			}
735 			if (++dn_fib_hash_zombies > 128)
736 				dn_fib_flush();
737 		}
738 
739 		return 0;
740 	}
741 
742 	return -ESRCH;
743 }
744 
dn_flush_list(struct dn_fib_node ** fp,int z,struct dn_hash * table)745 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
746 {
747 	int found = 0;
748 	struct dn_fib_node *f;
749 
750 	while((f = *fp) != NULL) {
751 		struct dn_fib_info *fi = DN_FIB_INFO(f);
752 
753 		if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
754 			write_lock_bh(&dn_fib_tables_lock);
755 			*fp = f->fn_next;
756 			write_unlock_bh(&dn_fib_tables_lock);
757 
758 			dn_free_node(f);
759 			found++;
760 			continue;
761 		}
762 		fp = &f->fn_next;
763 	}
764 
765 	return found;
766 }
767 
dn_fib_table_flush(struct dn_fib_table * tb)768 static int dn_fib_table_flush(struct dn_fib_table *tb)
769 {
770 	struct dn_hash *table = (struct dn_hash *)tb->data;
771 	struct dn_zone *dz;
772 	int found = 0;
773 
774 	dn_fib_hash_zombies = 0;
775 	for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
776 		int i;
777 		int tmp = 0;
778 		for(i = dz->dz_divisor-1; i >= 0; i--)
779 			tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
780 		dz->dz_nent -= tmp;
781 		found += tmp;
782 	}
783 
784 	return found;
785 }
786 
dn_fib_table_lookup(struct dn_fib_table * tb,const struct flowidn * flp,struct dn_fib_res * res)787 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
788 {
789 	int err;
790 	struct dn_zone *dz;
791 	struct dn_hash *t = (struct dn_hash *)tb->data;
792 
793 	read_lock(&dn_fib_tables_lock);
794 	for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
795 		struct dn_fib_node *f;
796 		dn_fib_key_t k = dz_key(flp->daddr, dz);
797 
798 		for(f = dz_chain(k, dz); f; f = f->fn_next) {
799 			if (!dn_key_eq(k, f->fn_key)) {
800 				if (dn_key_leq(k, f->fn_key))
801 					break;
802 				else
803 					continue;
804 			}
805 
806 			f->fn_state |= DN_S_ACCESSED;
807 
808 			if (f->fn_state&DN_S_ZOMBIE)
809 				continue;
810 
811 			if (f->fn_scope < flp->flowidn_scope)
812 				continue;
813 
814 			err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
815 
816 			if (err == 0) {
817 				res->type = f->fn_type;
818 				res->scope = f->fn_scope;
819 				res->prefixlen = dz->dz_order;
820 				goto out;
821 			}
822 			if (err < 0)
823 				goto out;
824 		}
825 	}
826 	err = 1;
827 out:
828 	read_unlock(&dn_fib_tables_lock);
829 	return err;
830 }
831 
832 
dn_fib_get_table(u32 n,int create)833 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
834 {
835 	struct dn_fib_table *t;
836 	unsigned int h;
837 
838 	if (n < RT_TABLE_MIN)
839 		return NULL;
840 
841 	if (n > RT_TABLE_MAX)
842 		return NULL;
843 
844 	h = n & (DN_FIB_TABLE_HASHSZ - 1);
845 	rcu_read_lock();
846 	hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
847 		if (t->n == n) {
848 			rcu_read_unlock();
849 			return t;
850 		}
851 	}
852 	rcu_read_unlock();
853 
854 	if (!create)
855 		return NULL;
856 
857 	if (in_interrupt()) {
858 		net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
859 		return NULL;
860 	}
861 
862 	t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
863 		    GFP_KERNEL);
864 	if (t == NULL)
865 		return NULL;
866 
867 	t->n = n;
868 	t->insert = dn_fib_table_insert;
869 	t->delete = dn_fib_table_delete;
870 	t->lookup = dn_fib_table_lookup;
871 	t->flush  = dn_fib_table_flush;
872 	t->dump = dn_fib_table_dump;
873 	hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
874 
875 	return t;
876 }
877 
dn_fib_empty_table(void)878 struct dn_fib_table *dn_fib_empty_table(void)
879 {
880 	u32 id;
881 
882 	for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
883 		if (dn_fib_get_table(id, 0) == NULL)
884 			return dn_fib_get_table(id, 1);
885 	return NULL;
886 }
887 
dn_fib_flush(void)888 void dn_fib_flush(void)
889 {
890 	int flushed = 0;
891 	struct dn_fib_table *tb;
892 	unsigned int h;
893 
894 	for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
895 		hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
896 			flushed += tb->flush(tb);
897 	}
898 
899 	if (flushed)
900 		dn_rt_cache_flush(-1);
901 }
902 
dn_fib_table_init(void)903 void __init dn_fib_table_init(void)
904 {
905 	dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
906 					sizeof(struct dn_fib_info),
907 					0, SLAB_HWCACHE_ALIGN,
908 					NULL);
909 }
910 
dn_fib_table_cleanup(void)911 void __exit dn_fib_table_cleanup(void)
912 {
913 	struct dn_fib_table *t;
914 	struct hlist_node *next;
915 	unsigned int h;
916 
917 	write_lock(&dn_fib_tables_lock);
918 	for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
919 		hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
920 					  hlist) {
921 			hlist_del(&t->hlist);
922 			kfree(t);
923 		}
924 	}
925 	write_unlock(&dn_fib_tables_lock);
926 }
927