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.
6
* DECnet Routing Forwarding Information Base (Routing Tables)
8
* Author: Steve Whitehouse <SteveW@ACM.org>
9
* Mostly copied from the IPv4 routing code
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/netlink.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 <asm/uaccess.h>
30
#include <linux/route.h> /* RTF_xxx */
31
#include <net/neighbour.h>
32
#include <net/netlink.h>
35
#include <net/fib_rules.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>
44
struct dn_zone *dz_next;
45
struct dn_fib_node **dz_hash;
49
#define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
52
#define DZ_MASK(dz) ((dz)->dz_mask)
57
struct dn_zone *dh_zones[17];
58
struct dn_zone *dh_zone_list;
61
#define dz_key_0(key) ((key).datum = 0)
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++)
66
#define endfor_nexthops(fi) }
68
#define DN_MAX_DIVISOR 1024
70
#define DN_S_ACCESSED 2
72
#define DN_FIB_SCAN(f, fp) \
73
for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
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)
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);
83
static struct kmem_cache *dn_hash_kmem __read_mostly;
84
static int dn_fib_hash_zombies;
86
static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
88
u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
92
return *(dn_fib_idx_t *)&h;
95
static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
98
k.datum = dst & DZ_MASK(dz);
102
static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
104
return &dz->dz_hash[dn_hash(key, dz).datum];
107
static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
109
return dz->dz_hash[dn_hash(key, dz).datum];
112
static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
114
return a.datum == b.datum;
117
static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
119
return a.datum <= b.datum;
122
static inline void dn_rebuild_zone(struct dn_zone *dz,
123
struct dn_fib_node **old_ht,
126
struct dn_fib_node *f, **fp, *next;
129
for(i = 0; i < old_divisor; i++) {
130
for(f = old_ht[i]; f; f = 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)
142
static void dn_rehash_zone(struct dn_zone *dz)
144
struct dn_fib_node **ht, **old_ht;
145
int old_divisor, new_divisor;
148
old_divisor = dz->dz_divisor;
150
switch (old_divisor) {
156
printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
160
new_hashmask = 0x3FF;
164
ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
168
write_lock_bh(&dn_fib_tables_lock);
169
old_ht = dz->dz_hash;
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);
178
static void dn_free_node(struct dn_fib_node *f)
180
dn_fib_release_info(DN_FIB_INFO(f));
181
kmem_cache_free(dn_hash_kmem, f);
185
static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
188
struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
194
dz->dz_hashmask = 0x0F;
200
dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
207
dz->dz_mask = dnet_make_mask(z);
209
for(i = z + 1; i <= 16; i++)
210
if (table->dh_zones[i])
213
write_lock_bh(&dn_fib_tables_lock);
215
dz->dz_next = table->dh_zone_list;
216
table->dh_zone_list = dz;
218
dz->dz_next = table->dh_zones[i]->dz_next;
219
table->dh_zones[i]->dz_next = dz;
221
table->dh_zones[z] = dz;
222
write_unlock_bh(&dn_fib_tables_lock);
227
static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
229
struct rtnexthop *nhp;
232
if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
235
if (rta->rta_oif || rta->rta_gw) {
236
if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
237
(!rta->rta_gw || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
242
if (rta->rta_mp == NULL)
245
nhp = RTA_DATA(rta->rta_mp);
246
nhlen = RTA_PAYLOAD(rta->rta_mp);
249
int attrlen = nhlen - sizeof(struct rtnexthop);
252
if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
254
if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
257
gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
259
if (gw && gw != nh->nh_gw)
262
nhp = RTNH_NEXT(nhp);
263
} endfor_nexthops(fi);
268
static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
270
size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
271
+ nla_total_size(4) /* RTA_TABLE */
272
+ nla_total_size(2) /* RTA_DST */
273
+ nla_total_size(4); /* RTA_PRIORITY */
275
/* space for nested metrics */
276
payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
279
/* Also handles the special case fib_nhs == 1 */
281
/* each nexthop is packed in an attribute */
282
size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
284
/* may contain a gateway attribute */
285
nhsize += nla_total_size(4);
287
/* all nexthops are packed in a nested attribute */
288
payload += nla_total_size(fi->fib_nhs * nhsize);
294
static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
295
u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
296
struct dn_fib_info *fi, unsigned int flags)
299
struct nlmsghdr *nlh;
300
unsigned char *b = skb_tail_pointer(skb);
302
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
303
rtm = NLMSG_DATA(nlh);
304
rtm->rtm_family = AF_DECnet;
305
rtm->rtm_dst_len = dst_len;
306
rtm->rtm_src_len = 0;
308
rtm->rtm_table = tb_id;
309
RTA_PUT_U32(skb, RTA_TABLE, tb_id);
310
rtm->rtm_flags = fi->fib_flags;
311
rtm->rtm_scope = scope;
312
rtm->rtm_type = type;
313
if (rtm->rtm_dst_len)
314
RTA_PUT(skb, RTA_DST, 2, dst);
315
rtm->rtm_protocol = fi->fib_protocol;
316
if (fi->fib_priority)
317
RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
318
if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
320
if (fi->fib_nhs == 1) {
321
if (fi->fib_nh->nh_gw)
322
RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
323
if (fi->fib_nh->nh_oif)
324
RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
326
if (fi->fib_nhs > 1) {
327
struct rtnexthop *nhp;
328
struct rtattr *mp_head;
329
if (skb_tailroom(skb) <= RTA_SPACE(0))
331
mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
334
if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
336
nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
337
nhp->rtnh_flags = nh->nh_flags & 0xFF;
338
nhp->rtnh_hops = nh->nh_weight - 1;
339
nhp->rtnh_ifindex = nh->nh_oif;
341
RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
342
nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
343
} endfor_nexthops(fi);
344
mp_head->rta_type = RTA_MULTIPATH;
345
mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
348
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
359
static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
360
struct nlmsghdr *nlh, struct netlink_skb_parms *req)
363
u32 pid = req ? req->pid : 0;
366
skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
370
err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
371
f->fn_type, f->fn_scope, &f->fn_key, z,
374
/* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
375
WARN_ON(err == -EMSGSIZE);
379
rtnl_notify(skb, &init_net, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
383
rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
386
static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
387
struct netlink_callback *cb,
388
struct dn_fib_table *tb,
390
struct dn_fib_node *f)
395
for(i = 0; f; i++, f = f->fn_next) {
398
if (f->fn_state & DN_S_ZOMBIE)
400
if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
404
(f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
405
f->fn_scope, &f->fn_key, dz->dz_order,
406
f->fn_info, NLM_F_MULTI) < 0) {
415
static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
416
struct netlink_callback *cb,
417
struct dn_fib_table *tb,
423
for(h = 0; h < dz->dz_divisor; h++) {
427
memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
428
if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
430
if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
439
static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
440
struct netlink_callback *cb)
444
struct dn_hash *table = (struct dn_hash *)tb->data;
447
read_lock(&dn_fib_tables_lock);
448
for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
452
memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
454
if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
456
read_unlock(&dn_fib_tables_lock);
460
read_unlock(&dn_fib_tables_lock);
466
int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
468
struct net *net = sock_net(skb->sk);
470
unsigned int e = 0, s_e;
471
struct dn_fib_table *tb;
472
struct hlist_node *node;
475
if (!net_eq(net, &init_net))
478
if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
479
((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
480
return dn_cache_dump(skb, cb);
485
for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
487
hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
491
memset(&cb->args[2], 0, sizeof(cb->args) -
492
2 * sizeof(cb->args[0]));
493
if (tb->dump(tb, skb, cb) < 0)
507
static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
509
struct dn_hash *table = (struct dn_hash *)tb->data;
510
struct dn_fib_node *new_f, *f, **fp, **del_fp;
512
struct dn_fib_info *fi;
513
int z = r->rtm_dst_len;
514
int type = r->rtm_type;
521
dz = table->dh_zones[z];
522
if (!dz && !(dz = dn_new_zone(table, z)))
528
memcpy(&dst, rta->rta_dst, 2);
529
if (dst & ~DZ_MASK(dz))
531
key = dz_key(dst, dz);
534
if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
537
if (dz->dz_nent > (dz->dz_divisor << 2) &&
538
dz->dz_divisor > DN_MAX_DIVISOR &&
539
(z==16 || (1<<z) > dz->dz_divisor))
542
fp = dn_chain_p(key, dz);
545
if (dn_key_leq(key, f->fn_key))
551
if (f && (f->fn_state & DN_S_ZOMBIE) &&
552
dn_key_eq(f->fn_key, key)) {
559
DN_FIB_SCAN_KEY(f, fp, key) {
560
if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
564
if (f && dn_key_eq(f->fn_key, key) &&
565
fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
566
struct dn_fib_node **ins_fp;
569
if (n->nlmsg_flags & NLM_F_EXCL)
572
if (n->nlmsg_flags & NLM_F_REPLACE) {
582
DN_FIB_SCAN_KEY(f, fp, key) {
583
if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
585
if (f->fn_type == type &&
586
f->fn_scope == r->rtm_scope &&
587
DN_FIB_INFO(f) == fi)
591
if (!(n->nlmsg_flags & NLM_F_APPEND)) {
599
if (!(n->nlmsg_flags & NLM_F_CREATE))
604
new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
609
new_f->fn_type = type;
610
new_f->fn_scope = r->rtm_scope;
611
DN_FIB_INFO(new_f) = fi;
614
write_lock_bh(&dn_fib_tables_lock);
616
write_unlock_bh(&dn_fib_tables_lock);
621
write_lock_bh(&dn_fib_tables_lock);
622
*del_fp = f->fn_next;
623
write_unlock_bh(&dn_fib_tables_lock);
625
if (!(f->fn_state & DN_S_ZOMBIE))
626
dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
627
if (f->fn_state & DN_S_ACCESSED)
628
dn_rt_cache_flush(-1);
632
dn_rt_cache_flush(-1);
635
dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
639
dn_fib_release_info(fi);
644
static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
646
struct dn_hash *table = (struct dn_hash*)tb->data;
647
struct dn_fib_node **fp, **del_fp, *f;
648
int z = r->rtm_dst_len;
657
if ((dz = table->dh_zones[z]) == NULL)
663
memcpy(&dst, rta->rta_dst, 2);
664
if (dst & ~DZ_MASK(dz))
666
key = dz_key(dst, dz);
669
fp = dn_chain_p(key, dz);
672
if (dn_key_eq(f->fn_key, key))
674
if (dn_key_leq(key, f->fn_key))
680
DN_FIB_SCAN_KEY(f, fp, key) {
681
struct dn_fib_info *fi = DN_FIB_INFO(f);
683
if (f->fn_state & DN_S_ZOMBIE)
688
if (del_fp == NULL &&
689
(!r->rtm_type || f->fn_type == r->rtm_type) &&
690
(r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
692
fi->fib_protocol == r->rtm_protocol) &&
693
dn_fib_nh_match(r, n, rta, fi) == 0)
699
dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
702
write_lock_bh(&dn_fib_tables_lock);
703
*del_fp = f->fn_next;
704
write_unlock_bh(&dn_fib_tables_lock);
706
if (f->fn_state & DN_S_ACCESSED)
707
dn_rt_cache_flush(-1);
711
f->fn_state |= DN_S_ZOMBIE;
712
if (f->fn_state & DN_S_ACCESSED) {
713
f->fn_state &= ~DN_S_ACCESSED;
714
dn_rt_cache_flush(-1);
716
if (++dn_fib_hash_zombies > 128)
726
static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
729
struct dn_fib_node *f;
731
while((f = *fp) != NULL) {
732
struct dn_fib_info *fi = DN_FIB_INFO(f);
734
if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
735
write_lock_bh(&dn_fib_tables_lock);
737
write_unlock_bh(&dn_fib_tables_lock);
749
static int dn_fib_table_flush(struct dn_fib_table *tb)
751
struct dn_hash *table = (struct dn_hash *)tb->data;
755
dn_fib_hash_zombies = 0;
756
for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
759
for(i = dz->dz_divisor-1; i >= 0; i--)
760
tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
768
static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
772
struct dn_hash *t = (struct dn_hash *)tb->data;
774
read_lock(&dn_fib_tables_lock);
775
for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
776
struct dn_fib_node *f;
777
dn_fib_key_t k = dz_key(flp->daddr, dz);
779
for(f = dz_chain(k, dz); f; f = f->fn_next) {
780
if (!dn_key_eq(k, f->fn_key)) {
781
if (dn_key_leq(k, f->fn_key))
787
f->fn_state |= DN_S_ACCESSED;
789
if (f->fn_state&DN_S_ZOMBIE)
792
if (f->fn_scope < flp->flowidn_scope)
795
err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
798
res->type = f->fn_type;
799
res->scope = f->fn_scope;
800
res->prefixlen = dz->dz_order;
809
read_unlock(&dn_fib_tables_lock);
814
struct dn_fib_table *dn_fib_get_table(u32 n, int create)
816
struct dn_fib_table *t;
817
struct hlist_node *node;
820
if (n < RT_TABLE_MIN)
823
if (n > RT_TABLE_MAX)
826
h = n & (DN_FIB_TABLE_HASHSZ - 1);
828
hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
839
if (in_interrupt() && net_ratelimit()) {
840
printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
844
t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
850
t->insert = dn_fib_table_insert;
851
t->delete = dn_fib_table_delete;
852
t->lookup = dn_fib_table_lookup;
853
t->flush = dn_fib_table_flush;
854
t->dump = dn_fib_table_dump;
855
hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
860
struct dn_fib_table *dn_fib_empty_table(void)
864
for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
865
if (dn_fib_get_table(id, 0) == NULL)
866
return dn_fib_get_table(id, 1);
870
void dn_fib_flush(void)
873
struct dn_fib_table *tb;
874
struct hlist_node *node;
877
for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
878
hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
879
flushed += tb->flush(tb);
883
dn_rt_cache_flush(-1);
886
void __init dn_fib_table_init(void)
888
dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
889
sizeof(struct dn_fib_info),
890
0, SLAB_HWCACHE_ALIGN,
894
void __exit dn_fib_table_cleanup(void)
896
struct dn_fib_table *t;
897
struct hlist_node *node, *next;
900
write_lock(&dn_fib_tables_lock);
901
for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
902
hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
904
hlist_del(&t->hlist);
908
write_unlock(&dn_fib_tables_lock);