Commit | Line | Data |
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2c8d7ca0 NT |
1 | /* |
2 | * Copyright (C)2003-2006 Helsinki University of Technology | |
3 | * Copyright (C)2003-2006 USAGI/WIDE Project | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | /* | |
20 | * Authors: | |
21 | * Noriaki TAKAMIYA @USAGI | |
22 | * Masahide NAKAMURA @USAGI | |
23 | */ | |
24 | ||
25 | #include <linux/config.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/skbuff.h> | |
70182ed2 | 28 | #include <linux/time.h> |
2c8d7ca0 | 29 | #include <linux/ipv6.h> |
7be96f76 MN |
30 | #include <linux/icmpv6.h> |
31 | #include <net/sock.h> | |
2c8d7ca0 | 32 | #include <net/ipv6.h> |
7be96f76 | 33 | #include <net/ip6_checksum.h> |
2c8d7ca0 NT |
34 | #include <net/xfrm.h> |
35 | #include <net/mip6.h> | |
36 | ||
37 | static xfrm_address_t *mip6_xfrm_addr(struct xfrm_state *x, xfrm_address_t *addr) | |
38 | { | |
39 | return x->coaddr; | |
40 | } | |
41 | ||
3d126890 NT |
42 | static inline unsigned int calc_padlen(unsigned int len, unsigned int n) |
43 | { | |
44 | return (n - len + 16) & 0x7; | |
45 | } | |
46 | ||
47 | static inline void *mip6_padn(__u8 *data, __u8 padlen) | |
48 | { | |
49 | if (!data) | |
50 | return NULL; | |
51 | if (padlen == 1) { | |
52 | data[0] = MIP6_OPT_PAD_1; | |
53 | } else if (padlen > 1) { | |
54 | data[0] = MIP6_OPT_PAD_N; | |
55 | data[1] = padlen - 2; | |
56 | if (padlen > 2) | |
57 | memset(data+2, 0, data[1]); | |
58 | } | |
59 | return data + padlen; | |
60 | } | |
61 | ||
7be96f76 MN |
62 | static inline void mip6_param_prob(struct sk_buff *skb, int code, int pos) |
63 | { | |
64 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev); | |
65 | } | |
66 | ||
67 | static int mip6_mh_len(int type) | |
68 | { | |
69 | int len = 0; | |
70 | ||
71 | switch (type) { | |
72 | case IP6_MH_TYPE_BRR: | |
73 | len = 0; | |
74 | break; | |
75 | case IP6_MH_TYPE_HOTI: | |
76 | case IP6_MH_TYPE_COTI: | |
77 | case IP6_MH_TYPE_BU: | |
78 | case IP6_MH_TYPE_BACK: | |
79 | len = 1; | |
80 | break; | |
81 | case IP6_MH_TYPE_HOT: | |
82 | case IP6_MH_TYPE_COT: | |
83 | case IP6_MH_TYPE_BERROR: | |
84 | len = 2; | |
85 | break; | |
86 | } | |
87 | return len; | |
88 | } | |
89 | ||
90 | int mip6_mh_filter(struct sock *sk, struct sk_buff *skb) | |
91 | { | |
92 | struct ip6_mh *mh; | |
93 | int mhlen; | |
94 | ||
95 | if (!pskb_may_pull(skb, (skb->h.raw - skb->data) + 8) || | |
96 | !pskb_may_pull(skb, (skb->h.raw - skb->data) + ((skb->h.raw[1] + 1) << 3))) | |
97 | return -1; | |
98 | ||
99 | mh = (struct ip6_mh *)skb->h.raw; | |
100 | ||
101 | if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) { | |
102 | LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n", | |
103 | mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type)); | |
104 | mip6_param_prob(skb, 0, (&mh->ip6mh_hdrlen) - skb->nh.raw); | |
105 | return -1; | |
106 | } | |
107 | mhlen = (mh->ip6mh_hdrlen + 1) << 3; | |
108 | ||
109 | if (skb->ip_summed == CHECKSUM_COMPLETE) { | |
110 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
111 | if (csum_ipv6_magic(&skb->nh.ipv6h->saddr, | |
112 | &skb->nh.ipv6h->daddr, | |
113 | mhlen, IPPROTO_MH, | |
114 | skb->csum)) { | |
115 | LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH hw checksum failed\n"); | |
116 | skb->ip_summed = CHECKSUM_NONE; | |
117 | } | |
118 | } | |
119 | if (skb->ip_summed == CHECKSUM_NONE) { | |
120 | if (csum_ipv6_magic(&skb->nh.ipv6h->saddr, | |
121 | &skb->nh.ipv6h->daddr, | |
122 | mhlen, IPPROTO_MH, | |
123 | skb_checksum(skb, 0, mhlen, 0))) { | |
124 | LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH checksum failed [%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x > %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]\n", | |
125 | NIP6(skb->nh.ipv6h->saddr), | |
126 | NIP6(skb->nh.ipv6h->daddr)); | |
127 | return -1; | |
128 | } | |
129 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
130 | } | |
131 | ||
132 | if (mh->ip6mh_proto != IPPROTO_NONE) { | |
133 | LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n", | |
134 | mh->ip6mh_proto); | |
135 | mip6_param_prob(skb, 0, (&mh->ip6mh_proto) - skb->nh.raw); | |
136 | return -1; | |
137 | } | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
70182ed2 MN |
142 | struct mip6_report_rate_limiter { |
143 | spinlock_t lock; | |
144 | struct timeval stamp; | |
145 | int iif; | |
146 | struct in6_addr src; | |
147 | struct in6_addr dst; | |
148 | }; | |
149 | ||
150 | static struct mip6_report_rate_limiter mip6_report_rl = { | |
151 | .lock = SPIN_LOCK_UNLOCKED | |
152 | }; | |
153 | ||
3d126890 NT |
154 | static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb) |
155 | { | |
156 | struct ipv6hdr *iph = skb->nh.ipv6h; | |
157 | struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data; | |
158 | ||
159 | if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) && | |
160 | !ipv6_addr_any((struct in6_addr *)x->coaddr)) | |
161 | return -ENOENT; | |
162 | ||
163 | return destopt->nexthdr; | |
164 | } | |
165 | ||
166 | /* Destination Option Header is inserted. | |
167 | * IP Header's src address is replaced with Home Address Option in | |
168 | * Destination Option Header. | |
169 | */ | |
170 | static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb) | |
171 | { | |
172 | struct ipv6hdr *iph; | |
173 | struct ipv6_destopt_hdr *dstopt; | |
174 | struct ipv6_destopt_hao *hao; | |
175 | u8 nexthdr; | |
176 | int len; | |
177 | ||
178 | iph = (struct ipv6hdr *)skb->data; | |
179 | iph->payload_len = htons(skb->len - sizeof(*iph)); | |
180 | ||
181 | nexthdr = *skb->nh.raw; | |
182 | *skb->nh.raw = IPPROTO_DSTOPTS; | |
183 | ||
184 | dstopt = (struct ipv6_destopt_hdr *)skb->h.raw; | |
185 | dstopt->nexthdr = nexthdr; | |
186 | ||
187 | hao = mip6_padn((char *)(dstopt + 1), | |
188 | calc_padlen(sizeof(*dstopt), 6)); | |
189 | ||
190 | hao->type = IPV6_TLV_HAO; | |
191 | hao->length = sizeof(*hao) - 2; | |
192 | BUG_TRAP(hao->length == 16); | |
193 | ||
194 | len = ((char *)hao - (char *)dstopt) + sizeof(*hao); | |
195 | ||
196 | memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr)); | |
197 | memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr)); | |
198 | ||
199 | BUG_TRAP(len == x->props.header_len); | |
200 | dstopt->hdrlen = (x->props.header_len >> 3) - 1; | |
201 | ||
202 | return 0; | |
203 | } | |
204 | ||
70182ed2 MN |
205 | static inline int mip6_report_rl_allow(struct timeval *stamp, |
206 | struct in6_addr *dst, | |
207 | struct in6_addr *src, int iif) | |
208 | { | |
209 | int allow = 0; | |
210 | ||
211 | spin_lock_bh(&mip6_report_rl.lock); | |
212 | if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec || | |
213 | mip6_report_rl.stamp.tv_usec != stamp->tv_usec || | |
214 | mip6_report_rl.iif != iif || | |
215 | !ipv6_addr_equal(&mip6_report_rl.src, src) || | |
216 | !ipv6_addr_equal(&mip6_report_rl.dst, dst)) { | |
217 | mip6_report_rl.stamp.tv_sec = stamp->tv_sec; | |
218 | mip6_report_rl.stamp.tv_usec = stamp->tv_usec; | |
219 | mip6_report_rl.iif = iif; | |
220 | ipv6_addr_copy(&mip6_report_rl.src, src); | |
221 | ipv6_addr_copy(&mip6_report_rl.dst, dst); | |
222 | allow = 1; | |
223 | } | |
224 | spin_unlock_bh(&mip6_report_rl.lock); | |
225 | return allow; | |
226 | } | |
227 | ||
228 | static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct flowi *fl) | |
229 | { | |
230 | struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb; | |
231 | struct ipv6_destopt_hao *hao = NULL; | |
232 | struct xfrm_selector sel; | |
233 | int offset; | |
234 | struct timeval stamp; | |
235 | int err = 0; | |
236 | ||
237 | if (likely(opt->dsthao)) { | |
238 | offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
239 | if (likely(offset >= 0)) | |
240 | hao = (struct ipv6_destopt_hao *)(skb->nh.raw + offset); | |
241 | } | |
242 | ||
243 | skb_get_timestamp(skb, &stamp); | |
244 | ||
245 | if (!mip6_report_rl_allow(&stamp, &skb->nh.ipv6h->daddr, | |
246 | hao ? &hao->addr : &skb->nh.ipv6h->saddr, | |
247 | opt->iif)) | |
248 | goto out; | |
249 | ||
250 | memset(&sel, 0, sizeof(sel)); | |
251 | memcpy(&sel.daddr, (xfrm_address_t *)&skb->nh.ipv6h->daddr, | |
252 | sizeof(sel.daddr)); | |
253 | sel.prefixlen_d = 128; | |
254 | memcpy(&sel.saddr, (xfrm_address_t *)&skb->nh.ipv6h->saddr, | |
255 | sizeof(sel.saddr)); | |
256 | sel.prefixlen_s = 128; | |
257 | sel.family = AF_INET6; | |
258 | sel.proto = fl->proto; | |
259 | sel.dport = xfrm_flowi_dport(fl); | |
260 | if (sel.dport) | |
261 | sel.dport_mask = ~((__u16)0); | |
262 | sel.sport = xfrm_flowi_sport(fl); | |
263 | if (sel.sport) | |
264 | sel.sport_mask = ~((__u16)0); | |
265 | sel.ifindex = fl->oif; | |
266 | ||
267 | err = km_report(IPPROTO_DSTOPTS, &sel, | |
268 | (hao ? (xfrm_address_t *)&hao->addr : NULL)); | |
269 | ||
270 | out: | |
271 | return err; | |
272 | } | |
273 | ||
3d126890 NT |
274 | static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb, |
275 | u8 **nexthdr) | |
276 | { | |
277 | u16 offset = sizeof(struct ipv6hdr); | |
278 | struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1); | |
279 | unsigned int packet_len = skb->tail - skb->nh.raw; | |
280 | int found_rhdr = 0; | |
281 | ||
282 | *nexthdr = &skb->nh.ipv6h->nexthdr; | |
283 | ||
284 | while (offset + 1 <= packet_len) { | |
285 | ||
286 | switch (**nexthdr) { | |
287 | case NEXTHDR_HOP: | |
288 | break; | |
289 | case NEXTHDR_ROUTING: | |
290 | found_rhdr = 1; | |
291 | break; | |
292 | case NEXTHDR_DEST: | |
293 | /* | |
294 | * HAO MUST NOT appear more than once. | |
295 | * XXX: It is better to try to find by the end of | |
296 | * XXX: packet if HAO exists. | |
297 | */ | |
298 | if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) { | |
299 | LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n"); | |
300 | return offset; | |
301 | } | |
302 | ||
303 | if (found_rhdr) | |
304 | return offset; | |
305 | ||
306 | break; | |
307 | default: | |
308 | return offset; | |
309 | } | |
310 | ||
311 | offset += ipv6_optlen(exthdr); | |
312 | *nexthdr = &exthdr->nexthdr; | |
313 | exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); | |
314 | } | |
315 | ||
316 | return offset; | |
317 | } | |
318 | ||
319 | static int mip6_destopt_init_state(struct xfrm_state *x) | |
320 | { | |
321 | if (x->id.spi) { | |
322 | printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__, | |
323 | x->id.spi); | |
324 | return -EINVAL; | |
325 | } | |
326 | if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) { | |
327 | printk(KERN_INFO "%s: state's mode is not %u: %u\n", | |
328 | __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode); | |
329 | return -EINVAL; | |
330 | } | |
331 | ||
332 | x->props.header_len = sizeof(struct ipv6_destopt_hdr) + | |
333 | calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) + | |
334 | sizeof(struct ipv6_destopt_hao); | |
335 | BUG_TRAP(x->props.header_len == 24); | |
336 | ||
337 | return 0; | |
338 | } | |
339 | ||
340 | /* | |
341 | * Do nothing about destroying since it has no specific operation for | |
342 | * destination options header unlike IPsec protocols. | |
343 | */ | |
344 | static void mip6_destopt_destroy(struct xfrm_state *x) | |
345 | { | |
346 | } | |
347 | ||
348 | static struct xfrm_type mip6_destopt_type = | |
349 | { | |
350 | .description = "MIP6DESTOPT", | |
351 | .owner = THIS_MODULE, | |
352 | .proto = IPPROTO_DSTOPTS, | |
353 | .flags = XFRM_TYPE_NON_FRAGMENT, | |
354 | .init_state = mip6_destopt_init_state, | |
355 | .destructor = mip6_destopt_destroy, | |
356 | .input = mip6_destopt_input, | |
357 | .output = mip6_destopt_output, | |
70182ed2 | 358 | .reject = mip6_destopt_reject, |
3d126890 NT |
359 | .hdr_offset = mip6_destopt_offset, |
360 | .local_addr = mip6_xfrm_addr, | |
361 | }; | |
362 | ||
2c8d7ca0 NT |
363 | static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb) |
364 | { | |
365 | struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data; | |
366 | ||
367 | if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) && | |
368 | !ipv6_addr_any((struct in6_addr *)x->coaddr)) | |
369 | return -ENOENT; | |
370 | ||
371 | return rt2->rt_hdr.nexthdr; | |
372 | } | |
373 | ||
374 | /* Routing Header type 2 is inserted. | |
375 | * IP Header's dst address is replaced with Routing Header's Home Address. | |
376 | */ | |
377 | static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb) | |
378 | { | |
379 | struct ipv6hdr *iph; | |
380 | struct rt2_hdr *rt2; | |
381 | u8 nexthdr; | |
382 | ||
383 | iph = (struct ipv6hdr *)skb->data; | |
384 | iph->payload_len = htons(skb->len - sizeof(*iph)); | |
385 | ||
386 | nexthdr = *skb->nh.raw; | |
387 | *skb->nh.raw = IPPROTO_ROUTING; | |
388 | ||
389 | rt2 = (struct rt2_hdr *)skb->h.raw; | |
390 | rt2->rt_hdr.nexthdr = nexthdr; | |
391 | rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1; | |
392 | rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2; | |
393 | rt2->rt_hdr.segments_left = 1; | |
394 | memset(&rt2->reserved, 0, sizeof(rt2->reserved)); | |
395 | ||
396 | BUG_TRAP(rt2->rt_hdr.hdrlen == 2); | |
397 | ||
398 | memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr)); | |
399 | memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr)); | |
400 | ||
401 | return 0; | |
402 | } | |
403 | ||
404 | static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb, | |
405 | u8 **nexthdr) | |
406 | { | |
407 | u16 offset = sizeof(struct ipv6hdr); | |
408 | struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1); | |
409 | unsigned int packet_len = skb->tail - skb->nh.raw; | |
410 | int found_rhdr = 0; | |
411 | ||
412 | *nexthdr = &skb->nh.ipv6h->nexthdr; | |
413 | ||
414 | while (offset + 1 <= packet_len) { | |
415 | ||
416 | switch (**nexthdr) { | |
417 | case NEXTHDR_HOP: | |
418 | break; | |
419 | case NEXTHDR_ROUTING: | |
420 | if (offset + 3 <= packet_len) { | |
421 | struct ipv6_rt_hdr *rt; | |
422 | rt = (struct ipv6_rt_hdr *)(skb->nh.raw + offset); | |
423 | if (rt->type != 0) | |
424 | return offset; | |
425 | } | |
426 | found_rhdr = 1; | |
427 | break; | |
428 | case NEXTHDR_DEST: | |
429 | if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) | |
430 | return offset; | |
431 | ||
432 | if (found_rhdr) | |
433 | return offset; | |
434 | ||
435 | break; | |
436 | default: | |
437 | return offset; | |
438 | } | |
439 | ||
440 | offset += ipv6_optlen(exthdr); | |
441 | *nexthdr = &exthdr->nexthdr; | |
442 | exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); | |
443 | } | |
444 | ||
445 | return offset; | |
446 | } | |
447 | ||
448 | static int mip6_rthdr_init_state(struct xfrm_state *x) | |
449 | { | |
450 | if (x->id.spi) { | |
451 | printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__, | |
452 | x->id.spi); | |
453 | return -EINVAL; | |
454 | } | |
455 | if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) { | |
456 | printk(KERN_INFO "%s: state's mode is not %u: %u\n", | |
457 | __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode); | |
458 | return -EINVAL; | |
459 | } | |
460 | ||
461 | x->props.header_len = sizeof(struct rt2_hdr); | |
462 | ||
463 | return 0; | |
464 | } | |
465 | ||
466 | /* | |
467 | * Do nothing about destroying since it has no specific operation for routing | |
468 | * header type 2 unlike IPsec protocols. | |
469 | */ | |
470 | static void mip6_rthdr_destroy(struct xfrm_state *x) | |
471 | { | |
472 | } | |
473 | ||
474 | static struct xfrm_type mip6_rthdr_type = | |
475 | { | |
476 | .description = "MIP6RT", | |
477 | .owner = THIS_MODULE, | |
478 | .proto = IPPROTO_ROUTING, | |
479 | .flags = XFRM_TYPE_NON_FRAGMENT, | |
480 | .init_state = mip6_rthdr_init_state, | |
481 | .destructor = mip6_rthdr_destroy, | |
482 | .input = mip6_rthdr_input, | |
483 | .output = mip6_rthdr_output, | |
484 | .hdr_offset = mip6_rthdr_offset, | |
485 | .remote_addr = mip6_xfrm_addr, | |
486 | }; | |
487 | ||
488 | int __init mip6_init(void) | |
489 | { | |
490 | printk(KERN_INFO "Mobile IPv6\n"); | |
491 | ||
3d126890 NT |
492 | if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) { |
493 | printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__); | |
494 | goto mip6_destopt_xfrm_fail; | |
495 | } | |
2c8d7ca0 NT |
496 | if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) { |
497 | printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__); | |
498 | goto mip6_rthdr_xfrm_fail; | |
499 | } | |
500 | return 0; | |
501 | ||
502 | mip6_rthdr_xfrm_fail: | |
3d126890 NT |
503 | xfrm_unregister_type(&mip6_destopt_type, AF_INET6); |
504 | mip6_destopt_xfrm_fail: | |
2c8d7ca0 NT |
505 | return -EAGAIN; |
506 | } | |
507 | ||
508 | void __exit mip6_fini(void) | |
509 | { | |
510 | if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0) | |
511 | printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__); | |
3d126890 NT |
512 | if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0) |
513 | printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__); | |
2c8d7ca0 | 514 | } |