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authorYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>2007-11-14 01:56:23 -0500
committerDavid S. Miller <davem@davemloft.net>2008-01-28 17:53:58 -0500
commit2a8cc6c89039e0530a3335954253b76ed0f9339a (patch)
treedf7c77496032025bf73d0ee60441e0cc2724ed29 /net/ipv6/addrlabel.c
parent303065a8545bf7524550bd9564afb48e8a685a2d (diff)
[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.
Policy table is implemented as an RCU linear list since we do not expect large list nor frequent updates. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/addrlabel.c')
-rw-r--r--net/ipv6/addrlabel.c551
1 files changed, 551 insertions, 0 deletions
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
new file mode 100644
index 000000000000..204d4d66834c
--- /dev/null
+++ b/net/ipv6/addrlabel.c
@@ -0,0 +1,551 @@
1/*
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)
61 *
62 * Note: 0xffffffff is used if we do not have any policies.
63 */
64
65#define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
66
67static const __initdata struct ip6addrlbl_init_table
68{
69 const struct in6_addr *prefix;
70 int prefixlen;
71 u32 label;
72} ip6addrlbl_init_table[] = {
73 { /* ::/0 */
74 .prefix = &in6addr_any,
75 .label = 1,
76 },{ /* fc00::/7 */
77 .prefix = &(struct in6_addr){{{ 0xfc }}},
78 .prefixlen = 7,
79 .label = 5,
80 },{ /* 2002::/16 */
81 .prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
82 .prefixlen = 16,
83 .label = 2,
84 },{ /* 2001::/32 */
85 .prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
86 .prefixlen = 32,
87 .label = 6,
88 },{ /* ::ffff:0:0 */
89 .prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
90 .prefixlen = 96,
91 .label = 4,
92 },{ /* ::/96 */
93 .prefix = &in6addr_any,
94 .prefixlen = 96,
95 .label = 3,
96 },{ /* ::1/128 */
97 .prefix = &in6addr_loopback,
98 .prefixlen = 128,
99 .label = 0,
100 }
101};
102
103/* Object management */
104static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
105{
106 kfree(p);
107}
108
109static inline int ip6addrlbl_hold(struct ip6addrlbl_entry *p)
110{
111 return atomic_inc_not_zero(&p->refcnt);
112}
113
114static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
115{
116 if (atomic_dec_and_test(&p->refcnt))
117 ip6addrlbl_free(p);
118}
119
120static void ip6addrlbl_free_rcu(struct rcu_head *h)
121{
122 ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
123}
124
125/* Find label */
126static int __ip6addrlbl_match(struct ip6addrlbl_entry *p,
127 const struct in6_addr *addr,
128 int addrtype, int ifindex)
129{
130 if (p->ifindex && p->ifindex != ifindex)
131 return 0;
132 if (p->addrtype && p->addrtype != addrtype)
133 return 0;
134 if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
135 return 0;
136 return 1;
137}
138
139static struct ip6addrlbl_entry *__ipv6_addr_label(const struct in6_addr *addr,
140 int type, int ifindex)
141{
142 struct hlist_node *pos;
143 struct ip6addrlbl_entry *p;
144 hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
145 if (__ip6addrlbl_match(p, addr, type, ifindex))
146 return p;
147 }
148 return NULL;
149}
150
151u32 ipv6_addr_label(const struct in6_addr *addr, int type, int ifindex)
152{
153 u32 label;
154 struct ip6addrlbl_entry *p;
155
156 type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
157
158 rcu_read_lock();
159 p = __ipv6_addr_label(addr, type, ifindex);
160 label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
161 rcu_read_unlock();
162
163 ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
164 __FUNCTION__,
165 NIP6(*addr), type, ifindex,
166 label);
167
168 return label;
169}
170
171/* allocate one entry */
172struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
173 int prefixlen, int ifindex,
174 u32 label)
175{
176 struct ip6addrlbl_entry *newp;
177 int addrtype;
178
179 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
180 __FUNCTION__,
181 NIP6(*prefix), prefixlen,
182 ifindex,
183 (unsigned int)label);
184
185 addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
186
187 switch (addrtype) {
188 case IPV6_ADDR_MAPPED:
189 if (prefixlen > 96)
190 return ERR_PTR(-EINVAL);
191 if (prefixlen < 96)
192 addrtype = 0;
193 break;
194 case IPV6_ADDR_COMPATv4:
195 if (prefixlen != 96)
196 addrtype = 0;
197 break;
198 case IPV6_ADDR_LOOPBACK:
199 if (prefixlen != 128)
200 addrtype = 0;
201 break;
202 }
203
204 newp = kmalloc(sizeof(*newp), GFP_KERNEL);
205 if (!newp)
206 return ERR_PTR(-ENOMEM);
207
208 ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
209 newp->prefixlen = prefixlen;
210 newp->ifindex = ifindex;
211 newp->addrtype = addrtype;
212 newp->label = label;
213 INIT_HLIST_NODE(&newp->list);
214 atomic_set(&newp->refcnt, 1);
215 return newp;
216}
217
218/* add a label */
219int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
220{
221 int ret = 0;
222
223 ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
224 __FUNCTION__,
225 newp, replace);
226
227 if (hlist_empty(&ip6addrlbl_table.head)) {
228 hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
229 } else {
230 struct hlist_node *pos, *n;
231 struct ip6addrlbl_entry *p = NULL;
232 hlist_for_each_entry_safe(p, pos, n,
233 &ip6addrlbl_table.head, list) {
234 if (p->prefixlen == newp->prefixlen &&
235 p->ifindex == newp->ifindex &&
236 ipv6_addr_equal(&p->prefix, &newp->prefix)) {
237 if (!replace) {
238 ret = -EEXIST;
239 goto out;
240 }
241 hlist_replace_rcu(&p->list, &newp->list);
242 ip6addrlbl_put(p);
243 call_rcu(&p->rcu, ip6addrlbl_free_rcu);
244 goto out;
245 } else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
246 (p->prefixlen < newp->prefixlen)) {
247 hlist_add_before_rcu(&newp->list, &p->list);
248 goto out;
249 }
250 }
251 hlist_add_after_rcu(&p->list, &newp->list);
252 }
253out:
254 if (!ret)
255 ip6addrlbl_table.seq++;
256 return ret;
257}
258
259/* add a label */
260int ip6addrlbl_add(const struct in6_addr *prefix, int prefixlen,
261 int ifindex, u32 label, int replace)
262{
263 struct ip6addrlbl_entry *newp;
264 int ret = 0;
265
266 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
267 __FUNCTION__,
268 NIP6(*prefix), prefixlen,
269 ifindex,
270 (unsigned int)label,
271 replace);
272
273 newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
274 if (IS_ERR(newp))
275 return PTR_ERR(newp);
276 spin_lock(&ip6addrlbl_table.lock);
277 ret = __ip6addrlbl_add(newp, replace);
278 spin_unlock(&ip6addrlbl_table.lock);
279 if (ret)
280 ip6addrlbl_free(newp);
281 return ret;
282}
283
284/* remove a label */
285int __ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
286 int ifindex)
287{
288 struct ip6addrlbl_entry *p = NULL;
289 struct hlist_node *pos, *n;
290 int ret = -ESRCH;
291
292 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
293 __FUNCTION__,
294 NIP6(*prefix), prefixlen,
295 ifindex);
296
297 hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
298 if (p->prefixlen == prefixlen &&
299 p->ifindex == ifindex &&
300 ipv6_addr_equal(&p->prefix, prefix)) {
301 hlist_del_rcu(&p->list);
302 ip6addrlbl_put(p);
303 call_rcu(&p->rcu, ip6addrlbl_free_rcu);
304 ret = 0;
305 break;
306 }
307 }
308 return ret;
309}
310
311int ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
312 int ifindex)
313{
314 struct in6_addr prefix_buf;
315 int ret;
316
317 ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
318 __FUNCTION__,
319 NIP6(*prefix), prefixlen,
320 ifindex);
321
322 ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
323 spin_lock(&ip6addrlbl_table.lock);
324 ret = __ip6addrlbl_del(&prefix_buf, prefixlen, ifindex);
325 spin_unlock(&ip6addrlbl_table.lock);
326 return ret;
327}
328
329/* add default label */
330static __init int ip6addrlbl_init(void)
331{
332 int err = 0;
333 int i;
334
335 ADDRLABEL(KERN_DEBUG "%s()\n", __FUNCTION__);
336
337 for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
338 int ret = ip6addrlbl_add(ip6addrlbl_init_table[i].prefix,
339 ip6addrlbl_init_table[i].prefixlen,
340 0,
341 ip6addrlbl_init_table[i].label, 0);
342 /* XXX: should we free all rules when we catch an error? */
343 if (ret && (!err || err != -ENOMEM))
344 err = ret;
345 }
346 return err;
347}
348
349int __init ipv6_addr_label_init(void)
350{
351 spin_lock_init(&ip6addrlbl_table.lock);
352
353 return ip6addrlbl_init();
354}
355
356static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
357 [IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
358 [IFAL_LABEL] = { .len = sizeof(u32), },
359};
360
361static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
362 void *arg)
363{
364 struct ifaddrlblmsg *ifal;
365 struct nlattr *tb[IFAL_MAX+1];
366 struct in6_addr *pfx;
367 u32 label;
368 int err = 0;
369
370 err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
371 if (err < 0)
372 return err;
373
374 ifal = nlmsg_data(nlh);
375
376 if (ifal->ifal_family != AF_INET6 ||
377 ifal->ifal_prefixlen > 128)
378 return -EINVAL;
379
380 if (ifal->ifal_index &&
381 !__dev_get_by_index(&init_net, ifal->ifal_index))
382 return -EINVAL;
383
384 if (!tb[IFAL_ADDRESS])
385 return -EINVAL;
386
387 pfx = nla_data(tb[IFAL_ADDRESS]);
388 if (!pfx)
389 return -EINVAL;
390
391 if (!tb[IFAL_LABEL])
392 return -EINVAL;
393 label = nla_get_u32(tb[IFAL_LABEL]);
394 if (label == IPV6_ADDR_LABEL_DEFAULT)
395 return -EINVAL;
396
397 switch(nlh->nlmsg_type) {
398 case RTM_NEWADDRLABEL:
399 err = ip6addrlbl_add(pfx, ifal->ifal_prefixlen,
400 ifal->ifal_index, label,
401 nlh->nlmsg_flags & NLM_F_REPLACE);
402 break;
403 case RTM_DELADDRLABEL:
404 err = ip6addrlbl_del(pfx, ifal->ifal_prefixlen,
405 ifal->ifal_index);
406 break;
407 default:
408 err = -EOPNOTSUPP;
409 }
410 return err;
411}
412
413static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
414 int prefixlen, int ifindex, u32 lseq)
415{
416 struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
417 ifal->ifal_family = AF_INET6;
418 ifal->ifal_prefixlen = prefixlen;
419 ifal->ifal_flags = 0;
420 ifal->ifal_index = ifindex;
421 ifal->ifal_seq = lseq;
422};
423
424static int ip6addrlbl_fill(struct sk_buff *skb,
425 struct ip6addrlbl_entry *p,
426 u32 lseq,
427 u32 pid, u32 seq, int event,
428 unsigned int flags)
429{
430 struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
431 sizeof(struct ifaddrlblmsg), flags);
432 if (!nlh)
433 return -EMSGSIZE;
434
435 ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
436
437 if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 ||
438 nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
439 nlmsg_cancel(skb, nlh);
440 return -EMSGSIZE;
441 }
442
443 return nlmsg_end(skb, nlh);
444}
445
446static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
447{
448 struct ip6addrlbl_entry *p;
449 struct hlist_node *pos;
450 int idx = 0, s_idx = cb->args[0];
451 int err;
452
453 rcu_read_lock();
454 hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
455 if (idx >= s_idx) {
456 if ((err = ip6addrlbl_fill(skb, p,
457 ip6addrlbl_table.seq,
458 NETLINK_CB(cb->skb).pid,
459 cb->nlh->nlmsg_seq,
460 RTM_NEWADDRLABEL,
461 NLM_F_MULTI)) <= 0)
462 break;
463 }
464 idx++;
465 }
466 rcu_read_unlock();
467 cb->args[0] = idx;
468 return skb->len;
469}
470
471static inline int ip6addrlbl_msgsize(void)
472{
473 return (NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
474 + nla_total_size(16) /* IFAL_ADDRESS */
475 + nla_total_size(4) /* IFAL_LABEL */
476 );
477}
478
479static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr* nlh,
480 void *arg)
481{
482 struct ifaddrlblmsg *ifal;
483 struct nlattr *tb[IFAL_MAX+1];
484 struct in6_addr *addr;
485 u32 lseq;
486 int err = 0;
487 struct ip6addrlbl_entry *p;
488 struct sk_buff *skb;
489
490 err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
491 if (err < 0)
492 return err;
493
494 ifal = nlmsg_data(nlh);
495
496 if (ifal->ifal_family != AF_INET6 ||
497 ifal->ifal_prefixlen != 128)
498 return -EINVAL;
499
500 if (ifal->ifal_index &&
501 !__dev_get_by_index(&init_net, ifal->ifal_index))
502 return -EINVAL;
503
504 if (!tb[IFAL_ADDRESS])
505 return -EINVAL;
506
507 addr = nla_data(tb[IFAL_ADDRESS]);
508 if (!addr)
509 return -EINVAL;
510
511 rcu_read_lock();
512 p = __ipv6_addr_label(addr, ipv6_addr_type(addr), ifal->ifal_index);
513 if (p && ip6addrlbl_hold(p))
514 p = NULL;
515 lseq = ip6addrlbl_table.seq;
516 rcu_read_unlock();
517
518 if (!p) {
519 err = -ESRCH;
520 goto out;
521 }
522
523 if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
524 ip6addrlbl_put(p);
525 return -ENOBUFS;
526 }
527
528 err = ip6addrlbl_fill(skb, p, lseq,
529 NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
530 RTM_NEWADDRLABEL, 0);
531
532 ip6addrlbl_put(p);
533
534 if (err < 0) {
535 WARN_ON(err == -EMSGSIZE);
536 kfree_skb(skb);
537 goto out;
538 }
539
540 err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
541out:
542 return err;
543}
544
545void __init ipv6_addr_label_rtnl_register(void)
546{
547 __rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
548 __rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
549 __rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
550}
551
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