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 (Routing Tables)
8 *
9 * Author: Steve Whitehouse <SteveW@ACM.org>
10 * Mostly copied from the IPv4 routing code
11 *
12 *
13 * Changes:
14 *
15 */
16 #include <linux/string.h>
17 #include <linux/net.h>
18 #include <linux/socket.h>
19 #include <linux/slab.h>
20 #include <linux/sockios.h>
21 #include <linux/init.h>
22 #include <linux/skbuff.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/proc_fs.h>
25 #include <linux/netdevice.h>
26 #include <linux/timer.h>
27 #include <linux/spinlock.h>
28 #include <linux/atomic.h>
29 #include <linux/uaccess.h>
30 #include <linux/route.h> /* RTF_xxx */
31 #include <net/neighbour.h>
32 #include <net/netlink.h>
33 #include <net/tcp.h>
34 #include <net/dst.h>
35 #include <net/flow.h>
36 #include <net/fib_rules.h>
37 #include <net/dn.h>
38 #include <net/dn_route.h>
39 #include <net/dn_fib.h>
40 #include <net/dn_neigh.h>
41 #include <net/dn_dev.h>
42
43 struct dn_zone
44 {
45 struct dn_zone *dz_next;
46 struct dn_fib_node **dz_hash;
47 int dz_nent;
48 int dz_divisor;
49 u32 dz_hashmask;
50 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
51 int dz_order;
52 __le16 dz_mask;
53 #define DZ_MASK(dz) ((dz)->dz_mask)
54 };
55
56 struct dn_hash
57 {
58 struct dn_zone *dh_zones[17];
59 struct dn_zone *dh_zone_list;
60 };
61
62 #define dz_key_0(key) ((key).datum = 0)
63
64 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
65 for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
66
67 #define endfor_nexthops(fi) }
68
69 #define DN_MAX_DIVISOR 1024
70 #define DN_S_ZOMBIE 1
71 #define DN_S_ACCESSED 2
72
73 #define DN_FIB_SCAN(f, fp) \
74 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
75
76 #define DN_FIB_SCAN_KEY(f, fp, key) \
77 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
78
79 #define RT_TABLE_MIN 1
80 #define DN_FIB_TABLE_HASHSZ 256
81 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
82 static DEFINE_RWLOCK(dn_fib_tables_lock);
83
84 static struct kmem_cache *dn_hash_kmem __read_mostly;
85 static int dn_fib_hash_zombies;
86
dn_hash(dn_fib_key_t key,struct dn_zone * dz)87 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
88 {
89 u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
90 h ^= (h >> 10);
91 h ^= (h >> 6);
92 h &= DZ_HASHMASK(dz);
93 return *(dn_fib_idx_t *)&h;
94 }
95
dz_key(__le16 dst,struct dn_zone * dz)96 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
97 {
98 dn_fib_key_t k;
99 k.datum = dst & DZ_MASK(dz);
100 return k;
101 }
102
dn_chain_p(dn_fib_key_t key,struct dn_zone * dz)103 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
104 {
105 return &dz->dz_hash[dn_hash(key, dz).datum];
106 }
107
dz_chain(dn_fib_key_t key,struct dn_zone * dz)108 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
109 {
110 return dz->dz_hash[dn_hash(key, dz).datum];
111 }
112
dn_key_eq(dn_fib_key_t a,dn_fib_key_t b)113 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
114 {
115 return a.datum == b.datum;
116 }
117
dn_key_leq(dn_fib_key_t a,dn_fib_key_t b)118 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
119 {
120 return a.datum <= b.datum;
121 }
122
dn_rebuild_zone(struct dn_zone * dz,struct dn_fib_node ** old_ht,int old_divisor)123 static inline void dn_rebuild_zone(struct dn_zone *dz,
124 struct dn_fib_node **old_ht,
125 int old_divisor)
126 {
127 struct dn_fib_node *f, **fp, *next;
128 int i;
129
130 for(i = 0; i < old_divisor; i++) {
131 for(f = old_ht[i]; f; f = next) {
132 next = f->fn_next;
133 for(fp = dn_chain_p(f->fn_key, dz);
134 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
135 fp = &(*fp)->fn_next)
136 /* NOTHING */;
137 f->fn_next = *fp;
138 *fp = f;
139 }
140 }
141 }
142
dn_rehash_zone(struct dn_zone * dz)143 static void dn_rehash_zone(struct dn_zone *dz)
144 {
145 struct dn_fib_node **ht, **old_ht;
146 int old_divisor, new_divisor;
147 u32 new_hashmask;
148
149 old_divisor = dz->dz_divisor;
150
151 switch (old_divisor) {
152 case 16:
153 new_divisor = 256;
154 new_hashmask = 0xFF;
155 break;
156 default:
157 printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
158 old_divisor);
159 /* fall through */
160 case 256:
161 new_divisor = 1024;
162 new_hashmask = 0x3FF;
163 break;
164 }
165
166 ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
167 if (ht == NULL)
168 return;
169
170 write_lock_bh(&dn_fib_tables_lock);
171 old_ht = dz->dz_hash;
172 dz->dz_hash = ht;
173 dz->dz_hashmask = new_hashmask;
174 dz->dz_divisor = new_divisor;
175 dn_rebuild_zone(dz, old_ht, old_divisor);
176 write_unlock_bh(&dn_fib_tables_lock);
177 kfree(old_ht);
178 }
179
dn_free_node(struct dn_fib_node * f)180 static void dn_free_node(struct dn_fib_node *f)
181 {
182 dn_fib_release_info(DN_FIB_INFO(f));
183 kmem_cache_free(dn_hash_kmem, f);
184 }
185
186
dn_new_zone(struct dn_hash * table,int z)187 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
188 {
189 int i;
190 struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
191 if (!dz)
192 return NULL;
193
194 if (z) {
195 dz->dz_divisor = 16;
196 dz->dz_hashmask = 0x0F;
197 } else {
198 dz->dz_divisor = 1;
199 dz->dz_hashmask = 0;
200 }
201
202 dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
203 if (!dz->dz_hash) {
204 kfree(dz);
205 return NULL;
206 }
207
208 dz->dz_order = z;
209 dz->dz_mask = dnet_make_mask(z);
210
211 for(i = z + 1; i <= 16; i++)
212 if (table->dh_zones[i])
213 break;
214
215 write_lock_bh(&dn_fib_tables_lock);
216 if (i>16) {
217 dz->dz_next = table->dh_zone_list;
218 table->dh_zone_list = dz;
219 } else {
220 dz->dz_next = table->dh_zones[i]->dz_next;
221 table->dh_zones[i]->dz_next = dz;
222 }
223 table->dh_zones[z] = dz;
224 write_unlock_bh(&dn_fib_tables_lock);
225 return dz;
226 }
227
228
dn_fib_nh_match(struct rtmsg * r,struct nlmsghdr * nlh,struct nlattr * attrs[],struct dn_fib_info * fi)229 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
230 {
231 struct rtnexthop *nhp;
232 int nhlen;
233
234 if (attrs[RTA_PRIORITY] &&
235 nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
236 return 1;
237
238 if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
239 if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
240 (!attrs[RTA_GATEWAY] || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
241 return 0;
242 return 1;
243 }
244
245 if (!attrs[RTA_MULTIPATH])
246 return 0;
247
248 nhp = nla_data(attrs[RTA_MULTIPATH]);
249 nhlen = nla_len(attrs[RTA_MULTIPATH]);
250
251 for_nexthops(fi) {
252 int attrlen = nhlen - sizeof(struct rtnexthop);
253 __le16 gw;
254
255 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
256 return -EINVAL;
257 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
258 return 1;
259 if (attrlen) {
260 struct nlattr *gw_attr;
261
262 gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
263 gw = gw_attr ? nla_get_le16(gw_attr) : 0;
264
265 if (gw && gw != nh->nh_gw)
266 return 1;
267 }
268 nhp = RTNH_NEXT(nhp);
269 } endfor_nexthops(fi);
270
271 return 0;
272 }
273
dn_fib_nlmsg_size(struct dn_fib_info * fi)274 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
275 {
276 size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
277 + nla_total_size(4) /* RTA_TABLE */
278 + nla_total_size(2) /* RTA_DST */
279 + nla_total_size(4) /* RTA_PRIORITY */
280 + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
281
282 /* space for nested metrics */
283 payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
284
285 if (fi->fib_nhs) {
286 /* Also handles the special case fib_nhs == 1 */
287
288 /* each nexthop is packed in an attribute */
289 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
290
291 /* may contain a gateway attribute */
292 nhsize += nla_total_size(4);
293
294 /* all nexthops are packed in a nested attribute */
295 payload += nla_total_size(fi->fib_nhs * nhsize);
296 }
297
298 return payload;
299 }
300
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)301 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
302 u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
303 struct dn_fib_info *fi, unsigned int flags)
304 {
305 struct rtmsg *rtm;
306 struct nlmsghdr *nlh;
307
308 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
309 if (!nlh)
310 return -EMSGSIZE;
311
312 rtm = nlmsg_data(nlh);
313 rtm->rtm_family = AF_DECnet;
314 rtm->rtm_dst_len = dst_len;
315 rtm->rtm_src_len = 0;
316 rtm->rtm_tos = 0;
317 rtm->rtm_table = tb_id;
318 rtm->rtm_flags = fi->fib_flags;
319 rtm->rtm_scope = scope;
320 rtm->rtm_type = type;
321 rtm->rtm_protocol = fi->fib_protocol;
322
323 if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
324 goto errout;
325
326 if (rtm->rtm_dst_len &&
327 nla_put(skb, RTA_DST, 2, dst) < 0)
328 goto errout;
329
330 if (fi->fib_priority &&
331 nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
332 goto errout;
333
334 if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
335 goto errout;
336
337 if (fi->fib_nhs == 1) {
338 if (fi->fib_nh->nh_gw &&
339 nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
340 goto errout;
341
342 if (fi->fib_nh->nh_oif &&
343 nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
344 goto errout;
345 }
346
347 if (fi->fib_nhs > 1) {
348 struct rtnexthop *nhp;
349 struct nlattr *mp_head;
350
351 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
352 goto errout;
353
354 for_nexthops(fi) {
355 if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
356 goto errout;
357
358 nhp->rtnh_flags = nh->nh_flags & 0xFF;
359 nhp->rtnh_hops = nh->nh_weight - 1;
360 nhp->rtnh_ifindex = nh->nh_oif;
361
362 if (nh->nh_gw &&
363 nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
364 goto errout;
365
366 nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
367 } endfor_nexthops(fi);
368
369 nla_nest_end(skb, mp_head);
370 }
371
372 nlmsg_end(skb, nlh);
373 return 0;
374
375 errout:
376 nlmsg_cancel(skb, nlh);
377 return -EMSGSIZE;
378 }
379
380
dn_rtmsg_fib(int event,struct dn_fib_node * f,int z,u32 tb_id,struct nlmsghdr * nlh,struct netlink_skb_parms * req)381 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
382 struct nlmsghdr *nlh, struct netlink_skb_parms *req)
383 {
384 struct sk_buff *skb;
385 u32 portid = req ? req->portid : 0;
386 int err = -ENOBUFS;
387
388 skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
389 if (skb == NULL)
390 goto errout;
391
392 err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
393 f->fn_type, f->fn_scope, &f->fn_key, z,
394 DN_FIB_INFO(f), 0);
395 if (err < 0) {
396 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
397 WARN_ON(err == -EMSGSIZE);
398 kfree_skb(skb);
399 goto errout;
400 }
401 rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
402 return;
403 errout:
404 if (err < 0)
405 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
406 }
407
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)408 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
409 struct netlink_callback *cb,
410 struct dn_fib_table *tb,
411 struct dn_zone *dz,
412 struct dn_fib_node *f)
413 {
414 int i, s_i;
415
416 s_i = cb->args[4];
417 for(i = 0; f; i++, f = f->fn_next) {
418 if (i < s_i)
419 continue;
420 if (f->fn_state & DN_S_ZOMBIE)
421 continue;
422 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
423 cb->nlh->nlmsg_seq,
424 RTM_NEWROUTE,
425 tb->n,
426 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
427 f->fn_scope, &f->fn_key, dz->dz_order,
428 f->fn_info, NLM_F_MULTI) < 0) {
429 cb->args[4] = i;
430 return -1;
431 }
432 }
433 cb->args[4] = i;
434 return skb->len;
435 }
436
dn_hash_dump_zone(struct sk_buff * skb,struct netlink_callback * cb,struct dn_fib_table * tb,struct dn_zone * dz)437 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
438 struct netlink_callback *cb,
439 struct dn_fib_table *tb,
440 struct dn_zone *dz)
441 {
442 int h, s_h;
443
444 s_h = cb->args[3];
445 for(h = 0; h < dz->dz_divisor; h++) {
446 if (h < s_h)
447 continue;
448 if (h > s_h)
449 memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
450 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
451 continue;
452 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
453 cb->args[3] = h;
454 return -1;
455 }
456 }
457 cb->args[3] = h;
458 return skb->len;
459 }
460
dn_fib_table_dump(struct dn_fib_table * tb,struct sk_buff * skb,struct netlink_callback * cb)461 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
462 struct netlink_callback *cb)
463 {
464 int m, s_m;
465 struct dn_zone *dz;
466 struct dn_hash *table = (struct dn_hash *)tb->data;
467
468 s_m = cb->args[2];
469 read_lock(&dn_fib_tables_lock);
470 for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
471 if (m < s_m)
472 continue;
473 if (m > s_m)
474 memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
475
476 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
477 cb->args[2] = m;
478 read_unlock(&dn_fib_tables_lock);
479 return -1;
480 }
481 }
482 read_unlock(&dn_fib_tables_lock);
483 cb->args[2] = m;
484
485 return skb->len;
486 }
487
dn_fib_dump(struct sk_buff * skb,struct netlink_callback * cb)488 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
489 {
490 struct net *net = sock_net(skb->sk);
491 unsigned int h, s_h;
492 unsigned int e = 0, s_e;
493 struct dn_fib_table *tb;
494 int dumped = 0;
495
496 if (!net_eq(net, &init_net))
497 return 0;
498
499 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
500 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
501 return dn_cache_dump(skb, cb);
502
503 s_h = cb->args[0];
504 s_e = cb->args[1];
505
506 for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
507 e = 0;
508 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
509 if (e < s_e)
510 goto next;
511 if (dumped)
512 memset(&cb->args[2], 0, sizeof(cb->args) -
513 2 * sizeof(cb->args[0]));
514 if (tb->dump(tb, skb, cb) < 0)
515 goto out;
516 dumped = 1;
517 next:
518 e++;
519 }
520 }
521 out:
522 cb->args[1] = e;
523 cb->args[0] = h;
524
525 return skb->len;
526 }
527
dn_fib_table_insert(struct dn_fib_table * tb,struct rtmsg * r,struct nlattr * attrs[],struct nlmsghdr * n,struct netlink_skb_parms * req)528 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
529 struct nlmsghdr *n, struct netlink_skb_parms *req)
530 {
531 struct dn_hash *table = (struct dn_hash *)tb->data;
532 struct dn_fib_node *new_f, *f, **fp, **del_fp;
533 struct dn_zone *dz;
534 struct dn_fib_info *fi;
535 int z = r->rtm_dst_len;
536 int type = r->rtm_type;
537 dn_fib_key_t key;
538 int err;
539
540 if (z > 16)
541 return -EINVAL;
542
543 dz = table->dh_zones[z];
544 if (!dz && !(dz = dn_new_zone(table, z)))
545 return -ENOBUFS;
546
547 dz_key_0(key);
548 if (attrs[RTA_DST]) {
549 __le16 dst = nla_get_le16(attrs[RTA_DST]);
550 if (dst & ~DZ_MASK(dz))
551 return -EINVAL;
552 key = dz_key(dst, dz);
553 }
554
555 if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
556 return err;
557
558 if (dz->dz_nent > (dz->dz_divisor << 2) &&
559 dz->dz_divisor > DN_MAX_DIVISOR &&
560 (z==16 || (1<<z) > dz->dz_divisor))
561 dn_rehash_zone(dz);
562
563 fp = dn_chain_p(key, dz);
564
565 DN_FIB_SCAN(f, fp) {
566 if (dn_key_leq(key, f->fn_key))
567 break;
568 }
569
570 del_fp = NULL;
571
572 if (f && (f->fn_state & DN_S_ZOMBIE) &&
573 dn_key_eq(f->fn_key, key)) {
574 del_fp = fp;
575 fp = &f->fn_next;
576 f = *fp;
577 goto create;
578 }
579
580 DN_FIB_SCAN_KEY(f, fp, key) {
581 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
582 break;
583 }
584
585 if (f && dn_key_eq(f->fn_key, key) &&
586 fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
587 struct dn_fib_node **ins_fp;
588
589 err = -EEXIST;
590 if (n->nlmsg_flags & NLM_F_EXCL)
591 goto out;
592
593 if (n->nlmsg_flags & NLM_F_REPLACE) {
594 del_fp = fp;
595 fp = &f->fn_next;
596 f = *fp;
597 goto replace;
598 }
599
600 ins_fp = fp;
601 err = -EEXIST;
602
603 DN_FIB_SCAN_KEY(f, fp, key) {
604 if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
605 break;
606 if (f->fn_type == type &&
607 f->fn_scope == r->rtm_scope &&
608 DN_FIB_INFO(f) == fi)
609 goto out;
610 }
611
612 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
613 fp = ins_fp;
614 f = *fp;
615 }
616 }
617
618 create:
619 err = -ENOENT;
620 if (!(n->nlmsg_flags & NLM_F_CREATE))
621 goto out;
622
623 replace:
624 err = -ENOBUFS;
625 new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
626 if (new_f == NULL)
627 goto out;
628
629 new_f->fn_key = key;
630 new_f->fn_type = type;
631 new_f->fn_scope = r->rtm_scope;
632 DN_FIB_INFO(new_f) = fi;
633
634 new_f->fn_next = f;
635 write_lock_bh(&dn_fib_tables_lock);
636 *fp = new_f;
637 write_unlock_bh(&dn_fib_tables_lock);
638 dz->dz_nent++;
639
640 if (del_fp) {
641 f = *del_fp;
642 write_lock_bh(&dn_fib_tables_lock);
643 *del_fp = f->fn_next;
644 write_unlock_bh(&dn_fib_tables_lock);
645
646 if (!(f->fn_state & DN_S_ZOMBIE))
647 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
648 if (f->fn_state & DN_S_ACCESSED)
649 dn_rt_cache_flush(-1);
650 dn_free_node(f);
651 dz->dz_nent--;
652 } else {
653 dn_rt_cache_flush(-1);
654 }
655
656 dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
657
658 return 0;
659 out:
660 dn_fib_release_info(fi);
661 return err;
662 }
663
664
dn_fib_table_delete(struct dn_fib_table * tb,struct rtmsg * r,struct nlattr * attrs[],struct nlmsghdr * n,struct netlink_skb_parms * req)665 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
666 struct nlmsghdr *n, struct netlink_skb_parms *req)
667 {
668 struct dn_hash *table = (struct dn_hash*)tb->data;
669 struct dn_fib_node **fp, **del_fp, *f;
670 int z = r->rtm_dst_len;
671 struct dn_zone *dz;
672 dn_fib_key_t key;
673 int matched;
674
675
676 if (z > 16)
677 return -EINVAL;
678
679 if ((dz = table->dh_zones[z]) == NULL)
680 return -ESRCH;
681
682 dz_key_0(key);
683 if (attrs[RTA_DST]) {
684 __le16 dst = nla_get_le16(attrs[RTA_DST]);
685 if (dst & ~DZ_MASK(dz))
686 return -EINVAL;
687 key = dz_key(dst, dz);
688 }
689
690 fp = dn_chain_p(key, dz);
691
692 DN_FIB_SCAN(f, fp) {
693 if (dn_key_eq(f->fn_key, key))
694 break;
695 if (dn_key_leq(key, f->fn_key))
696 return -ESRCH;
697 }
698
699 matched = 0;
700 del_fp = NULL;
701 DN_FIB_SCAN_KEY(f, fp, key) {
702 struct dn_fib_info *fi = DN_FIB_INFO(f);
703
704 if (f->fn_state & DN_S_ZOMBIE)
705 return -ESRCH;
706
707 matched++;
708
709 if (del_fp == NULL &&
710 (!r->rtm_type || f->fn_type == r->rtm_type) &&
711 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
712 (!r->rtm_protocol ||
713 fi->fib_protocol == r->rtm_protocol) &&
714 dn_fib_nh_match(r, n, attrs, fi) == 0)
715 del_fp = fp;
716 }
717
718 if (del_fp) {
719 f = *del_fp;
720 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
721
722 if (matched != 1) {
723 write_lock_bh(&dn_fib_tables_lock);
724 *del_fp = f->fn_next;
725 write_unlock_bh(&dn_fib_tables_lock);
726
727 if (f->fn_state & DN_S_ACCESSED)
728 dn_rt_cache_flush(-1);
729 dn_free_node(f);
730 dz->dz_nent--;
731 } else {
732 f->fn_state |= DN_S_ZOMBIE;
733 if (f->fn_state & DN_S_ACCESSED) {
734 f->fn_state &= ~DN_S_ACCESSED;
735 dn_rt_cache_flush(-1);
736 }
737 if (++dn_fib_hash_zombies > 128)
738 dn_fib_flush();
739 }
740
741 return 0;
742 }
743
744 return -ESRCH;
745 }
746
dn_flush_list(struct dn_fib_node ** fp,int z,struct dn_hash * table)747 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
748 {
749 int found = 0;
750 struct dn_fib_node *f;
751
752 while((f = *fp) != NULL) {
753 struct dn_fib_info *fi = DN_FIB_INFO(f);
754
755 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
756 write_lock_bh(&dn_fib_tables_lock);
757 *fp = f->fn_next;
758 write_unlock_bh(&dn_fib_tables_lock);
759
760 dn_free_node(f);
761 found++;
762 continue;
763 }
764 fp = &f->fn_next;
765 }
766
767 return found;
768 }
769
dn_fib_table_flush(struct dn_fib_table * tb)770 static int dn_fib_table_flush(struct dn_fib_table *tb)
771 {
772 struct dn_hash *table = (struct dn_hash *)tb->data;
773 struct dn_zone *dz;
774 int found = 0;
775
776 dn_fib_hash_zombies = 0;
777 for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
778 int i;
779 int tmp = 0;
780 for(i = dz->dz_divisor-1; i >= 0; i--)
781 tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
782 dz->dz_nent -= tmp;
783 found += tmp;
784 }
785
786 return found;
787 }
788
dn_fib_table_lookup(struct dn_fib_table * tb,const struct flowidn * flp,struct dn_fib_res * res)789 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
790 {
791 int err;
792 struct dn_zone *dz;
793 struct dn_hash *t = (struct dn_hash *)tb->data;
794
795 read_lock(&dn_fib_tables_lock);
796 for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
797 struct dn_fib_node *f;
798 dn_fib_key_t k = dz_key(flp->daddr, dz);
799
800 for(f = dz_chain(k, dz); f; f = f->fn_next) {
801 if (!dn_key_eq(k, f->fn_key)) {
802 if (dn_key_leq(k, f->fn_key))
803 break;
804 else
805 continue;
806 }
807
808 f->fn_state |= DN_S_ACCESSED;
809
810 if (f->fn_state&DN_S_ZOMBIE)
811 continue;
812
813 if (f->fn_scope < flp->flowidn_scope)
814 continue;
815
816 err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
817
818 if (err == 0) {
819 res->type = f->fn_type;
820 res->scope = f->fn_scope;
821 res->prefixlen = dz->dz_order;
822 goto out;
823 }
824 if (err < 0)
825 goto out;
826 }
827 }
828 err = 1;
829 out:
830 read_unlock(&dn_fib_tables_lock);
831 return err;
832 }
833
834
dn_fib_get_table(u32 n,int create)835 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
836 {
837 struct dn_fib_table *t;
838 unsigned int h;
839
840 if (n < RT_TABLE_MIN)
841 return NULL;
842
843 if (n > RT_TABLE_MAX)
844 return NULL;
845
846 h = n & (DN_FIB_TABLE_HASHSZ - 1);
847 rcu_read_lock();
848 hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
849 if (t->n == n) {
850 rcu_read_unlock();
851 return t;
852 }
853 }
854 rcu_read_unlock();
855
856 if (!create)
857 return NULL;
858
859 if (in_interrupt()) {
860 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
861 return NULL;
862 }
863
864 t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
865 GFP_KERNEL);
866 if (t == NULL)
867 return NULL;
868
869 t->n = n;
870 t->insert = dn_fib_table_insert;
871 t->delete = dn_fib_table_delete;
872 t->lookup = dn_fib_table_lookup;
873 t->flush = dn_fib_table_flush;
874 t->dump = dn_fib_table_dump;
875 hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
876
877 return t;
878 }
879
dn_fib_empty_table(void)880 struct dn_fib_table *dn_fib_empty_table(void)
881 {
882 u32 id;
883
884 for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
885 if (dn_fib_get_table(id, 0) == NULL)
886 return dn_fib_get_table(id, 1);
887 return NULL;
888 }
889
dn_fib_flush(void)890 void dn_fib_flush(void)
891 {
892 int flushed = 0;
893 struct dn_fib_table *tb;
894 unsigned int h;
895
896 for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
897 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
898 flushed += tb->flush(tb);
899 }
900
901 if (flushed)
902 dn_rt_cache_flush(-1);
903 }
904
dn_fib_table_init(void)905 void __init dn_fib_table_init(void)
906 {
907 dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
908 sizeof(struct dn_fib_info),
909 0, SLAB_HWCACHE_ALIGN,
910 NULL);
911 }
912
dn_fib_table_cleanup(void)913 void __exit dn_fib_table_cleanup(void)
914 {
915 struct dn_fib_table *t;
916 struct hlist_node *next;
917 unsigned int h;
918
919 write_lock(&dn_fib_tables_lock);
920 for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
921 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
922 hlist) {
923 hlist_del(&t->hlist);
924 kfree(t);
925 }
926 }
927 write_unlock(&dn_fib_tables_lock);
928 }
929
