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YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +09001/*
2 * IPv6 Address Label subsystem
3 * for the IPv6 "Default" Source Address Selection
4 *
5 * Copyright (C)2007 USAGI/WIDE Project
6 */
7/*
8 * Author:
9 * YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
10 */
11
12#include <linux/kernel.h>
13#include <linux/list.h>
14#include <linux/rcupdate.h>
15#include <linux/in6.h>
16#include <net/addrconf.h>
17#include <linux/if_addrlabel.h>
18#include <linux/netlink.h>
19#include <linux/rtnetlink.h>
20
21#if 0
22#define ADDRLABEL(x...) printk(x)
23#else
24#define ADDRLABEL(x...) do { ; } while(0)
25#endif
26
27/*
28 * Policy Table
29 */
30struct ip6addrlbl_entry
31{
32 struct in6_addr prefix;
33 int prefixlen;
34 int ifindex;
35 int addrtype;
36 u32 label;
37 struct hlist_node list;
38 atomic_t refcnt;
39 struct rcu_head rcu;
40};
41
42static struct ip6addrlbl_table
43{
44 struct hlist_head head;
45 spinlock_t lock;
46 u32 seq;
47} ip6addrlbl_table;
48
49/*
50 * Default policy table (RFC3484 + extensions)
51 *
52 * prefix addr_type label
53 * -------------------------------------------------------------------------
54 * ::1/128 LOOPBACK 0
55 * ::/0 N/A 1
56 * 2002::/16 N/A 2
57 * ::/96 COMPATv4 3
58 * ::ffff:0:0/96 V4MAPPED 4
59 * fc00::/7 N/A 5 ULA (RFC 4193)
60 * 2001::/32 N/A 6 Teredo (RFC 4380)
Juha-Matti Tapio5fe47b82008-02-28 20:55:02 -080061 * 2001:10::/28 N/A 7 ORCHID (RFC 4843)
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +090062 *
63 * Note: 0xffffffff is used if we do not have any policies.
64 */
65
66#define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
67
68static const __initdata struct ip6addrlbl_init_table
69{
70 const struct in6_addr *prefix;
71 int prefixlen;
72 u32 label;
73} ip6addrlbl_init_table[] = {
74 { /* ::/0 */
75 .prefix = &in6addr_any,
76 .label = 1,
77 },{ /* fc00::/7 */
78 .prefix = &(struct in6_addr){{{ 0xfc }}},
79 .prefixlen = 7,
80 .label = 5,
81 },{ /* 2002::/16 */
82 .prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
83 .prefixlen = 16,
84 .label = 2,
85 },{ /* 2001::/32 */
86 .prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
87 .prefixlen = 32,
88 .label = 6,
Juha-Matti Tapio5fe47b82008-02-28 20:55:02 -080089 },{ /* 2001:10::/28 */
90 .prefix = &(struct in6_addr){{{ 0x20, 0x01, 0x00, 0x10 }}},
91 .prefixlen = 28,
92 .label = 7,
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +090093 },{ /* ::ffff:0:0 */
94 .prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
95 .prefixlen = 96,
96 .label = 4,
97 },{ /* ::/96 */
98 .prefix = &in6addr_any,
99 .prefixlen = 96,
100 .label = 3,
101 },{ /* ::1/128 */
102 .prefix = &in6addr_loopback,
103 .prefixlen = 128,
104 .label = 0,
105 }
106};
107
108/* Object management */
109static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
110{
111 kfree(p);
112}
113
YOSHIFUJI Hideaki85040bc2008-01-28 15:46:02 -0800114static void ip6addrlbl_free_rcu(struct rcu_head *h)
115{
116 ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
117}
118
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900119static inline int ip6addrlbl_hold(struct ip6addrlbl_entry *p)
120{
121 return atomic_inc_not_zero(&p->refcnt);
122}
123
124static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
125{
126 if (atomic_dec_and_test(&p->refcnt))
YOSHIFUJI Hideaki85040bc2008-01-28 15:46:02 -0800127 call_rcu(&p->rcu, ip6addrlbl_free_rcu);
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900128}
129
130/* Find label */
131static int __ip6addrlbl_match(struct ip6addrlbl_entry *p,
132 const struct in6_addr *addr,
133 int addrtype, int ifindex)
134{
135 if (p->ifindex && p->ifindex != ifindex)
136 return 0;
137 if (p->addrtype && p->addrtype != addrtype)
138 return 0;
139 if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
140 return 0;
141 return 1;
142}
143
144static struct ip6addrlbl_entry *__ipv6_addr_label(const struct in6_addr *addr,
145 int type, int ifindex)
146{
147 struct hlist_node *pos;
148 struct ip6addrlbl_entry *p;
149 hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
150 if (__ip6addrlbl_match(p, addr, type, ifindex))
151 return p;
152 }
153 return NULL;
154}
155
156u32 ipv6_addr_label(const struct in6_addr *addr, int type, int ifindex)
157{
158 u32 label;
159 struct ip6addrlbl_entry *p;
160
161 type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
162
163 rcu_read_lock();
164 p = __ipv6_addr_label(addr, type, ifindex);
165 label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
166 rcu_read_unlock();
167
168 ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
169 __FUNCTION__,
170 NIP6(*addr), type, ifindex,
171 label);
172
173 return label;
174}
175
176/* allocate one entry */
YOSHIFUJI Hideaki40fee362008-01-22 17:12:50 +0900177static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
178 int prefixlen, int ifindex,
179 u32 label)
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900180{
181 struct ip6addrlbl_entry *newp;
182 int addrtype;
183
184 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
185 __FUNCTION__,
186 NIP6(*prefix), prefixlen,
187 ifindex,
188 (unsigned int)label);
189
190 addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
191
192 switch (addrtype) {
193 case IPV6_ADDR_MAPPED:
194 if (prefixlen > 96)
195 return ERR_PTR(-EINVAL);
196 if (prefixlen < 96)
197 addrtype = 0;
198 break;
199 case IPV6_ADDR_COMPATv4:
200 if (prefixlen != 96)
201 addrtype = 0;
202 break;
203 case IPV6_ADDR_LOOPBACK:
204 if (prefixlen != 128)
205 addrtype = 0;
206 break;
207 }
208
209 newp = kmalloc(sizeof(*newp), GFP_KERNEL);
210 if (!newp)
211 return ERR_PTR(-ENOMEM);
212
213 ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
214 newp->prefixlen = prefixlen;
215 newp->ifindex = ifindex;
216 newp->addrtype = addrtype;
217 newp->label = label;
218 INIT_HLIST_NODE(&newp->list);
219 atomic_set(&newp->refcnt, 1);
220 return newp;
221}
222
223/* add a label */
YOSHIFUJI Hideaki40fee362008-01-22 17:12:50 +0900224static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900225{
226 int ret = 0;
227
228 ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
229 __FUNCTION__,
230 newp, replace);
231
232 if (hlist_empty(&ip6addrlbl_table.head)) {
233 hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
234 } else {
235 struct hlist_node *pos, *n;
236 struct ip6addrlbl_entry *p = NULL;
237 hlist_for_each_entry_safe(p, pos, n,
238 &ip6addrlbl_table.head, list) {
239 if (p->prefixlen == newp->prefixlen &&
240 p->ifindex == newp->ifindex &&
241 ipv6_addr_equal(&p->prefix, &newp->prefix)) {
242 if (!replace) {
243 ret = -EEXIST;
244 goto out;
245 }
246 hlist_replace_rcu(&p->list, &newp->list);
247 ip6addrlbl_put(p);
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900248 goto out;
249 } else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
250 (p->prefixlen < newp->prefixlen)) {
251 hlist_add_before_rcu(&newp->list, &p->list);
252 goto out;
253 }
254 }
255 hlist_add_after_rcu(&p->list, &newp->list);
256 }
257out:
258 if (!ret)
259 ip6addrlbl_table.seq++;
260 return ret;
261}
262
263/* add a label */
YOSHIFUJI Hideaki40fee362008-01-22 17:12:50 +0900264static int ip6addrlbl_add(const struct in6_addr *prefix, int prefixlen,
265 int ifindex, u32 label, int replace)
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900266{
267 struct ip6addrlbl_entry *newp;
268 int ret = 0;
269
270 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
271 __FUNCTION__,
272 NIP6(*prefix), prefixlen,
273 ifindex,
274 (unsigned int)label,
275 replace);
276
277 newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
278 if (IS_ERR(newp))
279 return PTR_ERR(newp);
280 spin_lock(&ip6addrlbl_table.lock);
281 ret = __ip6addrlbl_add(newp, replace);
282 spin_unlock(&ip6addrlbl_table.lock);
283 if (ret)
284 ip6addrlbl_free(newp);
285 return ret;
286}
287
288/* remove a label */
YOSHIFUJI Hideaki40fee362008-01-22 17:12:50 +0900289static int __ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
290 int ifindex)
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900291{
292 struct ip6addrlbl_entry *p = NULL;
293 struct hlist_node *pos, *n;
294 int ret = -ESRCH;
295
296 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
297 __FUNCTION__,
298 NIP6(*prefix), prefixlen,
299 ifindex);
300
301 hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
302 if (p->prefixlen == prefixlen &&
303 p->ifindex == ifindex &&
304 ipv6_addr_equal(&p->prefix, prefix)) {
305 hlist_del_rcu(&p->list);
306 ip6addrlbl_put(p);
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900307 ret = 0;
308 break;
309 }
310 }
311 return ret;
312}
313
YOSHIFUJI Hideaki40fee362008-01-22 17:12:50 +0900314static int ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
315 int ifindex)
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900316{
317 struct in6_addr prefix_buf;
318 int ret;
319
320 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
321 __FUNCTION__,
322 NIP6(*prefix), prefixlen,
323 ifindex);
324
325 ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
326 spin_lock(&ip6addrlbl_table.lock);
327 ret = __ip6addrlbl_del(&prefix_buf, prefixlen, ifindex);
328 spin_unlock(&ip6addrlbl_table.lock);
329 return ret;
330}
331
332/* add default label */
333static __init int ip6addrlbl_init(void)
334{
335 int err = 0;
336 int i;
337
338 ADDRLABEL(KERN_DEBUG "%s()\n", __FUNCTION__);
339
340 for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
341 int ret = ip6addrlbl_add(ip6addrlbl_init_table[i].prefix,
342 ip6addrlbl_init_table[i].prefixlen,
343 0,
344 ip6addrlbl_init_table[i].label, 0);
345 /* XXX: should we free all rules when we catch an error? */
346 if (ret && (!err || err != -ENOMEM))
347 err = ret;
348 }
349 return err;
350}
351
352int __init ipv6_addr_label_init(void)
353{
354 spin_lock_init(&ip6addrlbl_table.lock);
355
356 return ip6addrlbl_init();
357}
358
359static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
360 [IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
361 [IFAL_LABEL] = { .len = sizeof(u32), },
362};
363
364static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
365 void *arg)
366{
Denis V. Lunevb8542722007-12-01 00:21:31 +1100367 struct net *net = skb->sk->sk_net;
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900368 struct ifaddrlblmsg *ifal;
369 struct nlattr *tb[IFAL_MAX+1];
370 struct in6_addr *pfx;
371 u32 label;
372 int err = 0;
373
Denis V. Lunevb8542722007-12-01 00:21:31 +1100374 if (net != &init_net)
375 return 0;
376
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900377 err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
378 if (err < 0)
379 return err;
380
381 ifal = nlmsg_data(nlh);
382
383 if (ifal->ifal_family != AF_INET6 ||
384 ifal->ifal_prefixlen > 128)
385 return -EINVAL;
386
387 if (ifal->ifal_index &&
388 !__dev_get_by_index(&init_net, ifal->ifal_index))
389 return -EINVAL;
390
391 if (!tb[IFAL_ADDRESS])
392 return -EINVAL;
393
394 pfx = nla_data(tb[IFAL_ADDRESS]);
395 if (!pfx)
396 return -EINVAL;
397
398 if (!tb[IFAL_LABEL])
399 return -EINVAL;
400 label = nla_get_u32(tb[IFAL_LABEL]);
401 if (label == IPV6_ADDR_LABEL_DEFAULT)
402 return -EINVAL;
403
404 switch(nlh->nlmsg_type) {
405 case RTM_NEWADDRLABEL:
406 err = ip6addrlbl_add(pfx, ifal->ifal_prefixlen,
407 ifal->ifal_index, label,
408 nlh->nlmsg_flags & NLM_F_REPLACE);
409 break;
410 case RTM_DELADDRLABEL:
411 err = ip6addrlbl_del(pfx, ifal->ifal_prefixlen,
412 ifal->ifal_index);
413 break;
414 default:
415 err = -EOPNOTSUPP;
416 }
417 return err;
418}
419
420static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
421 int prefixlen, int ifindex, u32 lseq)
422{
423 struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
424 ifal->ifal_family = AF_INET6;
425 ifal->ifal_prefixlen = prefixlen;
426 ifal->ifal_flags = 0;
427 ifal->ifal_index = ifindex;
428 ifal->ifal_seq = lseq;
429};
430
431static int ip6addrlbl_fill(struct sk_buff *skb,
432 struct ip6addrlbl_entry *p,
433 u32 lseq,
434 u32 pid, u32 seq, int event,
435 unsigned int flags)
436{
437 struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
438 sizeof(struct ifaddrlblmsg), flags);
439 if (!nlh)
440 return -EMSGSIZE;
441
442 ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
443
444 if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 ||
445 nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
446 nlmsg_cancel(skb, nlh);
447 return -EMSGSIZE;
448 }
449
450 return nlmsg_end(skb, nlh);
451}
452
453static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
454{
Denis V. Lunevb8542722007-12-01 00:21:31 +1100455 struct net *net = skb->sk->sk_net;
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900456 struct ip6addrlbl_entry *p;
457 struct hlist_node *pos;
458 int idx = 0, s_idx = cb->args[0];
459 int err;
460
Denis V. Lunevb8542722007-12-01 00:21:31 +1100461 if (net != &init_net)
462 return 0;
463
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900464 rcu_read_lock();
465 hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
466 if (idx >= s_idx) {
467 if ((err = ip6addrlbl_fill(skb, p,
468 ip6addrlbl_table.seq,
469 NETLINK_CB(cb->skb).pid,
470 cb->nlh->nlmsg_seq,
471 RTM_NEWADDRLABEL,
472 NLM_F_MULTI)) <= 0)
473 break;
474 }
475 idx++;
476 }
477 rcu_read_unlock();
478 cb->args[0] = idx;
479 return skb->len;
480}
481
482static inline int ip6addrlbl_msgsize(void)
483{
484 return (NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
485 + nla_total_size(16) /* IFAL_ADDRESS */
486 + nla_total_size(4) /* IFAL_LABEL */
487 );
488}
489
490static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr* nlh,
491 void *arg)
492{
Denis V. Lunevb8542722007-12-01 00:21:31 +1100493 struct net *net = in_skb->sk->sk_net;
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900494 struct ifaddrlblmsg *ifal;
495 struct nlattr *tb[IFAL_MAX+1];
496 struct in6_addr *addr;
497 u32 lseq;
498 int err = 0;
499 struct ip6addrlbl_entry *p;
500 struct sk_buff *skb;
501
Denis V. Lunevb8542722007-12-01 00:21:31 +1100502 if (net != &init_net)
503 return 0;
504
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900505 err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
506 if (err < 0)
507 return err;
508
509 ifal = nlmsg_data(nlh);
510
511 if (ifal->ifal_family != AF_INET6 ||
512 ifal->ifal_prefixlen != 128)
513 return -EINVAL;
514
515 if (ifal->ifal_index &&
516 !__dev_get_by_index(&init_net, ifal->ifal_index))
517 return -EINVAL;
518
519 if (!tb[IFAL_ADDRESS])
520 return -EINVAL;
521
522 addr = nla_data(tb[IFAL_ADDRESS]);
523 if (!addr)
524 return -EINVAL;
525
526 rcu_read_lock();
527 p = __ipv6_addr_label(addr, ipv6_addr_type(addr), ifal->ifal_index);
528 if (p && ip6addrlbl_hold(p))
529 p = NULL;
530 lseq = ip6addrlbl_table.seq;
531 rcu_read_unlock();
532
533 if (!p) {
534 err = -ESRCH;
535 goto out;
536 }
537
538 if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
539 ip6addrlbl_put(p);
540 return -ENOBUFS;
541 }
542
543 err = ip6addrlbl_fill(skb, p, lseq,
544 NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
545 RTM_NEWADDRLABEL, 0);
546
547 ip6addrlbl_put(p);
548
549 if (err < 0) {
550 WARN_ON(err == -EMSGSIZE);
551 kfree_skb(skb);
552 goto out;
553 }
554
Denis V. Lunev97c53ca2007-11-19 22:26:51 -0800555 err = rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
YOSHIFUJI Hideaki2a8cc6c2007-11-14 15:56:23 +0900556out:
557 return err;
558}
559
560void __init ipv6_addr_label_rtnl_register(void)
561{
562 __rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
563 __rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
564 __rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
565}
566