1 /*
2 * Copyright (c) 2018-2020 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /*
30 * Copyright (c) 2001 Daniel Hartmeier
31 * Copyright (c) 2002 - 2013 Henning Brauer
32 * NAT64 - Copyright (c) 2010 Viagenie Inc. (http://www.viagenie.ca)
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 *
39 * - Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * - Redistributions in binary form must reproduce the above
42 * copyright notice, this list of conditions and the following
43 * disclaimer in the documentation and/or other materials provided
44 * with the distribution.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
47 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
48 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
49 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
50 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
51 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
52 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
53 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
54 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
56 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
57 * POSSIBILITY OF SUCH DAMAGE.
58 *
59 * Effort sponsored in part by the Defense Advanced Research Projects
60 * Agency (DARPA) and Air Force Research Laboratory, Air Force
61 * Materiel Command, USAF, under agreement number F30602-01-2-0537.
62 *
63 */
64 #include <sys/param.h>
65 #include <sys/types.h>
66 #include <sys/mbuf.h>
67
68 #include <net/if.h>
69 #include <net/if_types.h>
70 #include <net/dlil.h>
71 #include <net/nat464_utils.h>
72 #include <net/nwk_wq.h>
73
74 #include <netinet/in.h>
75 #include <netinet/in_var.h>
76 #include <netinet/in_systm.h>
77 #include <netinet/ip.h>
78 #include <netinet/ip6.h>
79 #include <netinet/ip_var.h>
80 #include <netinet/ip_icmp.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/icmp_var.h>
83 #include <netinet/icmp6.h>
84 #include <netinet/tcp.h>
85 #include <netinet/udp.h>
86 #include <netinet/udp_var.h>
87 #include <os/log.h>
88
89 int clat_debug = 0;
90
91 os_log_t nat_log_handle;
92
93 static void
94 nat464_addr_cksum_fixup(uint16_t *, struct nat464_addr *, struct nat464_addr *,
95 protocol_family_t, protocol_family_t, uint8_t, boolean_t);
96
97 /* Synthesize ipv6 from ipv4 */
98 int
nat464_synthesize_ipv6(ifnet_t ifp,const struct in_addr * addrv4,struct in6_addr * addr)99 nat464_synthesize_ipv6(ifnet_t ifp, const struct in_addr *addrv4, struct in6_addr *addr)
100 {
101 static const struct in6_addr well_known_prefix = {
102 .__u6_addr.__u6_addr8 = {0x00, 0x64, 0xff, 0x9b, 0x00, 0x00,
103 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
104 0x00, 0x00, 0x00, 0x00},
105 };
106
107 struct ipv6_prefix nat64prefixes[NAT64_MAX_NUM_PREFIXES];
108 int error = 0, i = 0;
109 /* Below call is not optimized as it creates a copy of prefixes */
110 if ((error = ifnet_get_nat64prefix(ifp, nat64prefixes)) != 0) {
111 return error;
112 }
113
114 for (i = 0; i < NAT64_MAX_NUM_PREFIXES; i++) {
115 if (nat64prefixes[i].prefix_len != 0) {
116 break;
117 }
118 }
119
120 VERIFY(i < NAT64_MAX_NUM_PREFIXES);
121
122 struct in6_addr prefix = nat64prefixes[i].ipv6_prefix;
123 int prefix_len = nat64prefixes[i].prefix_len;
124
125 char *ptrv4 = __DECONST(char *, addrv4);
126 char *ptr = __DECONST(char *, addr);
127
128 if (IN_ZERONET(ntohl(addrv4->s_addr)) || // 0.0.0.0/8 Source hosts on local network
129 IN_LOOPBACK(ntohl(addrv4->s_addr)) || // 127.0.0.0/8 Loopback
130 IN_LINKLOCAL(ntohl(addrv4->s_addr)) || // 169.254.0.0/16 Link Local
131 IN_DS_LITE(ntohl(addrv4->s_addr)) || // 192.0.0.0/29 DS-Lite
132 IN_6TO4_RELAY_ANYCAST(ntohl(addrv4->s_addr)) || // 192.88.99.0/24 6to4 Relay Anycast
133 IN_MULTICAST(ntohl(addrv4->s_addr)) || // 224.0.0.0/4 Multicast
134 INADDR_BROADCAST == addrv4->s_addr) { // 255.255.255.255/32 Limited Broadcast
135 return -1;
136 }
137
138 /* Check for the well-known prefix */
139 if (prefix_len == NAT64_PREFIX_LEN_96 &&
140 IN6_ARE_ADDR_EQUAL(&prefix, &well_known_prefix)) { // https://tools.ietf.org/html/rfc6052#section-3.1
141 if (IN_PRIVATE(ntohl(addrv4->s_addr)) || // 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16 Private-Use
142 IN_SHARED_ADDRESS_SPACE(ntohl(addrv4->s_addr))) { // 100.64.0.0/10 Shared Address Space
143 return -1;
144 }
145 }
146
147 memcpy(ptr, (char *)&prefix, prefix_len);
148
149 switch (prefix_len) {
150 case NAT64_PREFIX_LEN_96:
151 memcpy(ptr + 12, ptrv4, 4);
152 break;
153 case NAT64_PREFIX_LEN_64:
154 memcpy(ptr + 9, ptrv4, 4);
155 break;
156 case NAT64_PREFIX_LEN_56:
157 memcpy(ptr + 7, ptrv4, 1);
158 memcpy(ptr + 9, ptrv4 + 1, 3);
159 break;
160 case NAT64_PREFIX_LEN_48:
161 memcpy(ptr + 6, ptrv4, 2);
162 memcpy(ptr + 9, ptrv4 + 2, 2);
163 break;
164 case NAT64_PREFIX_LEN_40:
165 memcpy(ptr + 5, ptrv4, 3);
166 memcpy(ptr + 9, ptrv4 + 3, 1);
167 break;
168 case NAT64_PREFIX_LEN_32:
169 memcpy(ptr + 4, ptrv4, 4);
170 break;
171 default:
172 panic("NAT64-prefix len is wrong: %u", prefix_len);
173 }
174
175 if (clat_debug) {
176 char buf[MAX_IPv6_STR_LEN];
177 clat_log2((LOG_DEBUG, "%s synthesized %s\n", __func__,
178 inet_ntop(AF_INET6, (void *)addr, buf, sizeof(buf))));
179 }
180
181 return error;
182 }
183
184 /* Synthesize ipv4 from ipv6 */
185 int
nat464_synthesize_ipv4(ifnet_t ifp,const struct in6_addr * addr,struct in_addr * addrv4)186 nat464_synthesize_ipv4(ifnet_t ifp, const struct in6_addr *addr, struct in_addr *addrv4)
187 {
188 struct ipv6_prefix nat64prefixes[NAT64_MAX_NUM_PREFIXES];
189 int error = 0, i = 0;
190
191 /* Below call is not optimized as it creates a copy of prefixes */
192 if ((error = ifnet_get_nat64prefix(ifp, nat64prefixes)) != 0) {
193 return error;
194 }
195
196 for (i = 0; i < NAT64_MAX_NUM_PREFIXES; i++) {
197 if (nat64prefixes[i].prefix_len != 0) {
198 break;
199 }
200 }
201
202 VERIFY(i < NAT64_MAX_NUM_PREFIXES);
203
204 struct in6_addr prefix = nat64prefixes[i].ipv6_prefix;
205 int prefix_len = nat64prefixes[i].prefix_len;
206
207 char *ptrv4 = __DECONST(void *, addrv4);
208 char *ptr = __DECONST(void *, addr);
209
210 if (memcmp(addr, &prefix, prefix_len) != 0) {
211 return -1;
212 }
213
214 switch (prefix_len) {
215 case NAT64_PREFIX_LEN_96:
216 memcpy(ptrv4, ptr + 12, 4);
217 break;
218 case NAT64_PREFIX_LEN_64:
219 memcpy(ptrv4, ptr + 9, 4);
220 break;
221 case NAT64_PREFIX_LEN_56:
222 memcpy(ptrv4, ptr + 7, 1);
223 memcpy(ptrv4 + 1, ptr + 9, 3);
224 break;
225 case NAT64_PREFIX_LEN_48:
226 memcpy(ptrv4, ptr + 6, 2);
227 memcpy(ptrv4 + 2, ptr + 9, 2);
228 break;
229 case NAT64_PREFIX_LEN_40:
230 memcpy(ptrv4, ptr + 5, 3);
231 memcpy(ptrv4 + 3, ptr + 9, 1);
232 break;
233 case NAT64_PREFIX_LEN_32:
234 memcpy(ptrv4, ptr + 4, 4);
235 break;
236 default:
237 panic("NAT64-prefix len is wrong: %u",
238 prefix_len);
239 }
240
241 if (clat_debug) {
242 char buf[MAX_IPv4_STR_LEN];
243 clat_log2((LOG_DEBUG, "%s desynthesized to %s\n", __func__,
244 inet_ntop(AF_INET, (void *)addrv4, buf, sizeof(buf))));
245 }
246 return error;
247 }
248
249 #define PTR_IP(field) ((int32_t)offsetof(struct ip, field))
250 #define PTR_IP6(field) ((int32_t)offsetof(struct ip6_hdr, field))
251
252 /*
253 * Translate the ICMP header
254 */
255 int
nat464_translate_icmp(int naf,void * arg)256 nat464_translate_icmp(int naf, void *arg)
257 {
258 struct icmp *icmp4;
259 struct icmp6_hdr *icmp6;
260 uint32_t mtu;
261 int32_t ptr = -1;
262 uint8_t type;
263 uint8_t code;
264
265 switch (naf) {
266 case AF_INET:
267 icmp6 = arg;
268 type = icmp6->icmp6_type;
269 code = icmp6->icmp6_code;
270 mtu = ntohl(icmp6->icmp6_mtu);
271
272 switch (type) {
273 case ICMP6_ECHO_REQUEST:
274 type = ICMP_ECHO;
275 break;
276 case ICMP6_ECHO_REPLY:
277 type = ICMP_ECHOREPLY;
278 break;
279 case ICMP6_DST_UNREACH:
280 type = ICMP_UNREACH;
281 switch (code) {
282 case ICMP6_DST_UNREACH_NOROUTE:
283 case ICMP6_DST_UNREACH_BEYONDSCOPE:
284 case ICMP6_DST_UNREACH_ADDR:
285 code = ICMP_UNREACH_HOST;
286 break;
287 case ICMP6_DST_UNREACH_ADMIN:
288 code = ICMP_UNREACH_HOST_PROHIB;
289 break;
290 case ICMP6_DST_UNREACH_NOPORT:
291 code = ICMP_UNREACH_PORT;
292 break;
293 default:
294 return -1;
295 }
296 break;
297 case ICMP6_PACKET_TOO_BIG:
298 type = ICMP_UNREACH;
299 code = ICMP_UNREACH_NEEDFRAG;
300 mtu -= 20;
301 break;
302 case ICMP6_TIME_EXCEEDED:
303 type = ICMP_TIMXCEED;
304 break;
305 case ICMP6_PARAM_PROB:
306 switch (code) {
307 case ICMP6_PARAMPROB_HEADER:
308 type = ICMP_PARAMPROB;
309 code = ICMP_PARAMPROB_ERRATPTR;
310 ptr = ntohl(icmp6->icmp6_pptr);
311
312 if (ptr == PTR_IP6(ip6_vfc)) {
313 ; /* preserve */
314 } else if (ptr == PTR_IP6(ip6_vfc) + 1) {
315 ptr = PTR_IP(ip_tos);
316 } else if (ptr == PTR_IP6(ip6_plen) ||
317 ptr == PTR_IP6(ip6_plen) + 1) {
318 ptr = PTR_IP(ip_len);
319 } else if (ptr == PTR_IP6(ip6_nxt)) {
320 ptr = PTR_IP(ip_p);
321 } else if (ptr == PTR_IP6(ip6_hlim)) {
322 ptr = PTR_IP(ip_ttl);
323 } else if (ptr >= PTR_IP6(ip6_src) &&
324 ptr < PTR_IP6(ip6_dst)) {
325 ptr = PTR_IP(ip_src);
326 } else if (ptr >= PTR_IP6(ip6_dst) &&
327 ptr < (int32_t)sizeof(struct ip6_hdr)) {
328 ptr = PTR_IP(ip_dst);
329 } else {
330 return -1;
331 }
332 break;
333 case ICMP6_PARAMPROB_NEXTHEADER:
334 type = ICMP_UNREACH;
335 code = ICMP_UNREACH_PROTOCOL;
336 break;
337 default:
338 return -1;
339 }
340 break;
341 default:
342 return -1;
343 }
344 icmp6->icmp6_type = type;
345 icmp6->icmp6_code = code;
346 /* aligns well with a icmpv4 nextmtu */
347 icmp6->icmp6_mtu = htonl(mtu);
348 /* icmpv4 pptr is a one most significant byte */
349 if (ptr >= 0) {
350 icmp6->icmp6_pptr = htonl(ptr << 24);
351 }
352 break;
353
354 case AF_INET6:
355 icmp4 = arg;
356 type = icmp4->icmp_type;
357 code = icmp4->icmp_code;
358 mtu = ntohs(icmp4->icmp_nextmtu);
359
360 switch (type) {
361 case ICMP_ECHO:
362 type = ICMP6_ECHO_REQUEST;
363 break;
364 case ICMP_ECHOREPLY:
365 type = ICMP6_ECHO_REPLY;
366 break;
367 case ICMP_UNREACH:
368 type = ICMP6_DST_UNREACH;
369 switch (code) {
370 case ICMP_UNREACH_NET:
371 case ICMP_UNREACH_HOST:
372 case ICMP_UNREACH_NET_UNKNOWN:
373 case ICMP_UNREACH_HOST_UNKNOWN:
374 case ICMP_UNREACH_ISOLATED:
375 case ICMP_UNREACH_TOSNET:
376 case ICMP_UNREACH_TOSHOST:
377 code = ICMP6_DST_UNREACH_NOROUTE;
378 break;
379 case ICMP_UNREACH_PORT:
380 code = ICMP6_DST_UNREACH_NOPORT;
381 break;
382 case ICMP_UNREACH_NET_PROHIB:
383 case ICMP_UNREACH_HOST_PROHIB:
384 case ICMP_UNREACH_FILTER_PROHIB:
385 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
386 code = ICMP6_DST_UNREACH_ADMIN;
387 break;
388 case ICMP_UNREACH_PROTOCOL:
389 type = ICMP6_PARAM_PROB;
390 code = ICMP6_PARAMPROB_NEXTHEADER;
391 ptr = offsetof(struct ip6_hdr, ip6_nxt);
392 break;
393 case ICMP_UNREACH_NEEDFRAG:
394 type = ICMP6_PACKET_TOO_BIG;
395 code = 0;
396 /*
397 * Make sure we don't overflow adjusting for
398 * translation overhead.
399 * If we do, just work with a lower mtu as is.
400 */
401 if (mtu <= (UINT16_MAX - CLAT46_HDR_EXPANSION_OVERHD)) {
402 mtu += CLAT46_HDR_EXPANSION_OVERHD;
403 }
404 break;
405 default:
406 return -1;
407 }
408 break;
409 case ICMP_TIMXCEED:
410 type = ICMP6_TIME_EXCEEDED;
411 break;
412 case ICMP_PARAMPROB:
413 type = ICMP6_PARAM_PROB;
414 switch (code) {
415 case ICMP_PARAMPROB_ERRATPTR:
416 code = ICMP6_PARAMPROB_HEADER;
417 break;
418 case ICMP_PARAMPROB_LENGTH:
419 code = ICMP6_PARAMPROB_HEADER;
420 break;
421 default:
422 return -1;
423 }
424
425 ptr = icmp4->icmp_pptr;
426 if (ptr == 0 || ptr == PTR_IP(ip_tos)) {
427 ; /* preserve */
428 } else if (ptr == PTR_IP(ip_len) ||
429 ptr == PTR_IP(ip_len) + 1) {
430 ptr = PTR_IP6(ip6_plen);
431 } else if (ptr == PTR_IP(ip_ttl)) {
432 ptr = PTR_IP6(ip6_hlim);
433 } else if (ptr == PTR_IP(ip_p)) {
434 ptr = PTR_IP6(ip6_nxt);
435 } else if (ptr >= PTR_IP(ip_src) &&
436 ptr < PTR_IP(ip_dst)) {
437 ptr = PTR_IP6(ip6_src);
438 } else if (ptr >= PTR_IP(ip_dst) &&
439 ptr < (int32_t)sizeof(struct ip)) {
440 ptr = PTR_IP6(ip6_dst);
441 } else {
442 return -1;
443 }
444 break;
445 default:
446 return -1;
447 }
448 icmp4->icmp_type = type;
449 icmp4->icmp_code = code;
450 icmp4->icmp_nextmtu = htons((uint16_t)mtu);
451
452 if (ptr >= 0) {
453 icmp4->icmp_void = htonl(ptr);
454 }
455 break;
456 }
457
458 return 0;
459 }
460
461 /*
462 * @brief This routine is called to perform address family translation on the
463 * inner IP header (that may come as payload) of an ICMP(v4/v6) error
464 * response.
465 *
466 * @param pbuf Pointer to packet buffer
467 * @param off Points to end of ICMP header
468 * @param tot_len Pointer to total length of the outer IP header
469 * @param off2 Points to end of inner IP header
470 * @param proto2 Inner IP proto field
471 * @param ttl2 Inner IP ttl field
472 * @param tot_len2 Inner IP total length
473 * @param src Pointer to the generic v4/v6 src address
474 * @param dst Pointer to the generic v4/v6 dst address
475 * @param af Old protocol family
476 * @param naf New protocol family
477 *
478 * @return -1 on error and 0 on success
479 */
480 int
nat464_translate_icmp_ip(pbuf_t * pbuf,uint16_t off,uint16_t * tot_len,uint16_t * off2,uint8_t proto2,uint8_t ttl2,uint16_t tot_len2,struct nat464_addr * src,struct nat464_addr * dst,protocol_family_t af,protocol_family_t naf)481 nat464_translate_icmp_ip(pbuf_t *pbuf, uint16_t off, uint16_t *tot_len, uint16_t *off2,
482 uint8_t proto2, uint8_t ttl2, uint16_t tot_len2, struct nat464_addr *src,
483 struct nat464_addr *dst, protocol_family_t af, protocol_family_t naf)
484 {
485 struct ip *ip4 = NULL;
486 struct ip6_hdr *ip6 = NULL;
487 void *hdr = NULL;
488 int hlen = 0, olen = 0;
489 uint64_t ipid_salt = (uint64_t)pbuf_get_packet_buffer_address(pbuf);
490
491 if (af == naf || (af != AF_INET && af != AF_INET6) ||
492 (naf != AF_INET && naf != AF_INET6)) {
493 return -1;
494 }
495
496 /* old header */
497 olen = *off2 - off;
498 /* new header */
499 hlen = naf == PF_INET ? sizeof(*ip4) : sizeof(*ip6);
500
501 /* Modify the pbuf to accommodate the new header */
502 hdr = pbuf_resize_segment(pbuf, off, olen, hlen);
503 if (hdr == NULL) {
504 return -1;
505 }
506
507 /* translate inner ip/ip6 header */
508 switch (naf) {
509 case AF_INET:
510 ip4 = hdr;
511 bzero(ip4, sizeof(*ip4));
512 ip4->ip_v = IPVERSION;
513 ip4->ip_hl = sizeof(*ip4) >> 2;
514 ip4->ip_len = htons((uint16_t)(sizeof(*ip4) + tot_len2 - olen));
515 ip4->ip_id = rfc6864 ? 0 : htons(ip_randomid(ipid_salt));
516 ip4->ip_off = htons(IP_DF);
517 ip4->ip_ttl = ttl2;
518 if (proto2 == IPPROTO_ICMPV6) {
519 ip4->ip_p = IPPROTO_ICMP;
520 } else {
521 ip4->ip_p = proto2;
522 }
523 ip4->ip_src = src->natv4addr;
524 ip4->ip_dst = dst->natv4addr;
525 ip4->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, ip4->ip_hl << 2);
526
527 if (clat_debug) {
528 char buf[MAX_IPv4_STR_LEN];
529 clat_log2((LOG_DEBUG, "%s translated to IPv4 (inner) "
530 "ip_len: %#x ip_p: %d ip_sum: %#x ip_src: %s ip_dst: %s \n",
531 __func__, ntohs(ip4->ip_len), ip4->ip_p, ntohs(ip4->ip_sum),
532 inet_ntop(AF_INET, (void *)&ip4->ip_src, buf, sizeof(buf)),
533 inet_ntop(AF_INET, (void *)&ip4->ip_dst, buf, sizeof(buf))));
534 }
535 break;
536 case AF_INET6:
537 ip6 = hdr;
538 bzero(ip6, sizeof(*ip6));
539 ip6->ip6_vfc = IPV6_VERSION;
540 ip6->ip6_plen = htons((uint16_t)(tot_len2 - olen));
541 if (proto2 == IPPROTO_ICMP) {
542 ip6->ip6_nxt = IPPROTO_ICMPV6;
543 } else {
544 ip6->ip6_nxt = proto2;
545 }
546 if (!ttl2 || ttl2 > IPV6_DEFHLIM) {
547 ip6->ip6_hlim = IPV6_DEFHLIM;
548 } else {
549 ip6->ip6_hlim = ttl2;
550 }
551 ip6->ip6_src = src->natv6addr;
552 ip6->ip6_dst = dst->natv6addr;
553
554 if (clat_debug) {
555 char buf2[MAX_IPv6_STR_LEN];
556 clat_log2((LOG_DEBUG, "%s translated to IPv6 (inner) "
557 "ip6_plen: %#x ip6_nxt: %d ip6_src: %s ip6_dst: %s \n",
558 __func__, ntohs(ip6->ip6_plen), ip6->ip6_nxt,
559 inet_ntop(AF_INET6, (void *)&ip6->ip6_src, buf2, sizeof(buf2)),
560 inet_ntop(AF_INET6, (void *)&ip6->ip6_dst, buf2, sizeof(buf2))));
561 }
562 break;
563 }
564
565 /* adjust payload offset and total packet length */
566 *off2 += hlen - olen;
567 *tot_len += hlen - olen;
568
569 return 0;
570 }
571 /*
572 * @brief The function inserts IPv6 fragmentation header
573 * and populates it with the passed parameters.
574 *
575 * @param pbuf Pointer to the packet buffer
576 * @param ip_id IP identifier (in network byte order)
577 * @param frag_offset Fragment offset (in network byte order)
578 * @param is_last_frag Boolean indicating if the fragment header is for
579 * last fragment or not.
580 *
581 * @return -1 on error and 0 on success.
582 */
583 int
nat464_insert_frag46(pbuf_t * pbuf,uint16_t ip_id_val,uint16_t frag_offset,boolean_t is_last_frag)584 nat464_insert_frag46(pbuf_t *pbuf, uint16_t ip_id_val, uint16_t frag_offset,
585 boolean_t is_last_frag)
586 {
587 struct ip6_frag *p_ip6_frag = NULL;
588 struct ip6_hdr *p_ip6h = NULL;
589
590 /* Insert IPv6 fragmentation header */
591 if (pbuf_resize_segment(pbuf, sizeof(struct ip6_hdr), 0,
592 sizeof(struct ip6_frag)) == NULL) {
593 return -1;
594 }
595
596 p_ip6h = mtod(pbuf->pb_mbuf, struct ip6_hdr *);
597 p_ip6_frag = (struct ip6_frag *)pbuf_contig_segment(pbuf,
598 sizeof(struct ip6_hdr), sizeof(struct ip6_frag));
599
600 if (p_ip6_frag == NULL) {
601 return -1;
602 }
603
604 /* Populate IPv6 fragmentation header */
605 p_ip6_frag->ip6f_nxt = p_ip6h->ip6_nxt;
606 p_ip6_frag->ip6f_reserved = 0;
607 p_ip6_frag->ip6f_offlg = (uint16_t)(frag_offset << 3);
608 if (!is_last_frag) {
609 p_ip6_frag->ip6f_offlg |= 0x1;
610 }
611 p_ip6_frag->ip6f_offlg = htons(p_ip6_frag->ip6f_offlg);
612 p_ip6_frag->ip6f_ident = ip_id_val;
613
614 /* Update IPv6 header */
615 p_ip6h->ip6_nxt = IPPROTO_FRAGMENT;
616 p_ip6h->ip6_plen = htons(ntohs(p_ip6h->ip6_plen) +
617 sizeof(struct ip6_frag));
618
619 return 0;
620 }
621
622 int
nat464_translate_64(pbuf_t * pbuf,int off,uint8_t tos,uint8_t * proto,uint8_t ttl,struct in_addr src_v4,struct in_addr dst_v4,uint64_t tot_len,boolean_t * p_is_first_frag)623 nat464_translate_64(pbuf_t *pbuf, int off, uint8_t tos,
624 uint8_t *proto, uint8_t ttl, struct in_addr src_v4,
625 struct in_addr dst_v4, uint64_t tot_len, boolean_t *p_is_first_frag)
626 {
627 struct ip *ip4;
628 struct ip6_frag *p_frag6 = NULL;
629 struct ip6_frag frag6 = {};
630 boolean_t is_frag = FALSE;
631 uint16_t ip_frag_off = 0;
632
633 /*
634 * ip_input asserts for rcvif to be not NULL
635 * That may not be true for two corner cases
636 * 1. If for some reason a local app sends DNS
637 * AAAA query to local host
638 * 2. If IPv6 stack in kernel internally generates a
639 * message destined for a synthesized IPv6 end-point.
640 */
641 if (pbuf->pb_ifp == NULL) {
642 return NT_DROP;
643 }
644
645 if (*proto == IPPROTO_FRAGMENT) {
646 p_frag6 = (struct ip6_frag *)pbuf_contig_segment(pbuf,
647 sizeof(struct ip6_hdr), sizeof(struct ip6_frag));
648 if (p_frag6 == NULL) {
649 ip6stat.ip6s_clat464_in_64frag_transfail_drop++;
650 return NT_DROP;
651 }
652
653 frag6 = *p_frag6;
654 p_frag6 = NULL;
655 *proto = frag6.ip6f_nxt;
656 off += sizeof(struct ip6_frag);
657 is_frag = TRUE;
658 ip_frag_off = (ntohs(frag6.ip6f_offlg & IP6F_OFF_MASK)) >> 3;
659 if (ip_frag_off != 0) {
660 *p_is_first_frag = FALSE;
661 }
662 }
663
664 ip4 = (struct ip *)pbuf_resize_segment(pbuf, 0, off, sizeof(*ip4));
665 if (ip4 == NULL) {
666 return NT_DROP;
667 }
668 ip4->ip_v = 4;
669 ip4->ip_hl = 5;
670 ip4->ip_tos = tos;
671 ip4->ip_len = htons((uint16_t)(sizeof(*ip4) + (tot_len - off)));
672 ip4->ip_id = 0;
673 ip4->ip_off = 0;
674 ip4->ip_ttl = ttl;
675 ip4->ip_p = *proto;
676 ip4->ip_sum = 0;
677 ip4->ip_src = src_v4;
678 ip4->ip_dst = dst_v4;
679 if (is_frag) {
680 /*
681 * https://tools.ietf.org/html/rfc7915#section-5.1.1
682 * Identification: Copied from the low-order 16 bits in the
683 * Identification field in the Fragment Header.
684 */
685 ip4->ip_id = ntohl(frag6.ip6f_ident) & 0xffff;
686 ip4->ip_id = htons(ip4->ip_id);
687 if (frag6.ip6f_offlg & IP6F_MORE_FRAG) {
688 ip_frag_off |= IP_MF;
689 }
690 ip4->ip_off = htons(ip_frag_off);
691 } else {
692 ip4->ip_off |= htons(IP_DF);
693 }
694
695 /*
696 * Defer calculating ip_sum for ICMPv6 as we do it
697 * later in Protocol translation
698 */
699 if (*proto != IPPROTO_ICMPV6) {
700 ip4->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, ip4->ip_hl << 2);
701 }
702
703 if (clat_debug) {
704 char buf1[MAX_IPv4_STR_LEN], buf2[MAX_IPv4_STR_LEN];
705 clat_log2((LOG_DEBUG, "%s translated to IPv4 ip_len: %#x "
706 "ip_p: %d ip_sum: %#x ip_src: %s ip_dst: %s \n", __func__,
707 ntohs(ip4->ip_len), ip4->ip_p, ntohs(ip4->ip_sum),
708 inet_ntop(AF_INET, (void *)&ip4->ip_src, buf1, sizeof(buf1)),
709 inet_ntop(AF_INET, (void *)&ip4->ip_dst, buf2, sizeof(buf2))));
710 }
711 return NT_NAT64;
712 }
713 /*
714 * @brief The routine translates the IPv4 header to IPv6 header.
715 *
716 * @param pbuf Pointer to the generic packet buffer
717 * @param off Offset to the end of IP header
718 * @param tos Type of service
719 * @param proto Protocol running over IP
720 * @param ttl Time to live
721 * @param src_v6 Source IPv6 address
722 * @param dst_v6 Destination IPv6 address
723 * @param tot_len Total payload length
724 *
725 * @return NT_NAT64 if IP header translation is successful, else error
726 */
727 int
nat464_translate_46(pbuf_t * pbuf,uint16_t off,uint8_t tos,uint8_t proto,uint8_t ttl,struct in6_addr src_v6,struct in6_addr dst_v6,uint16_t tot_len)728 nat464_translate_46(pbuf_t *pbuf, uint16_t off, uint8_t tos,
729 uint8_t proto, uint8_t ttl, struct in6_addr src_v6,
730 struct in6_addr dst_v6, uint16_t tot_len)
731 {
732 struct ip6_hdr *ip6;
733
734 if (pbuf->pb_ifp == NULL) {
735 return NT_DROP;
736 }
737
738 /*
739 * Trim the buffer from head of size equal to to off (which is equal to
740 * the size of IP header and prepend IPv6 header length to the buffer
741 */
742 ip6 = (struct ip6_hdr *)pbuf_resize_segment(pbuf, 0, off, sizeof(*ip6));
743 if (ip6 == NULL) {
744 return NT_DROP;
745 }
746 ip6->ip6_flow = htonl((6 << 28) | (tos << 20));
747 ip6->ip6_plen = htons(tot_len - off);
748 ip6->ip6_nxt = proto;
749 ip6->ip6_hlim = ttl;
750 ip6->ip6_src = src_v6;
751 ip6->ip6_dst = dst_v6;
752
753 if (clat_debug) {
754 char buf1[MAX_IPv6_STR_LEN], buf2[MAX_IPv6_STR_LEN];
755 clat_log2((LOG_DEBUG, "%s translated to IPv6 ip6_plen: %#x "
756 " ip6_nxt: %d ip6_src: %s ip6_dst: %s \n", __func__,
757 ntohs(ip6->ip6_plen), ip6->ip6_nxt,
758 inet_ntop(AF_INET6, (void *)&ip6->ip6_src, buf1, sizeof(buf1)),
759 inet_ntop(AF_INET6, (void *)&ip6->ip6_dst, buf2, sizeof(buf2))));
760 }
761 return NT_NAT64;
762 }
763
764 /* Handle the next protocol checksum */
765 /*
766 * @brief This routine translates the Proto running over IP and updates the checksum
767 * for IP header translation. It also updates pbuf checksum flags and related fields.
768 *
769 * @param pbuf Pointer to protocol buffer
770 * @param nsrc New source address
771 * @param ndst New destination address
772 * @param af Old family
773 * @param naf New family
774 *
775 * @return void
776 */
777 int
nat464_translate_proto(pbuf_t * pbuf,struct nat464_addr * osrc,struct nat464_addr * odst,uint8_t oproto,protocol_family_t af,protocol_family_t naf,int direction,boolean_t only_csum)778 nat464_translate_proto(pbuf_t *pbuf, struct nat464_addr *osrc,
779 struct nat464_addr *odst, uint8_t oproto, protocol_family_t af,
780 protocol_family_t naf, int direction, boolean_t only_csum)
781 {
782 struct ip *iph = NULL;
783 struct ip6_hdr *ip6h = NULL;
784 uint16_t hlen = 0, plen = 0;
785 uint16_t tot_len = 0;
786 void *nsrc = NULL, *ndst = NULL;
787 uint8_t *proto = 0;
788 uint16_t *psum = NULL;
789 boolean_t do_ones_complement = FALSE;
790
791 /* For now these routines only support 464 translations */
792 VERIFY(af != naf);
793 VERIFY(af == PF_INET || af == PF_INET6);
794
795 /*
796 * For now out must be for v4 to v6 translation
797 * and in must be for v6 to v4 translation.
798 */
799 switch (naf) {
800 case PF_INET: {
801 iph = pbuf->pb_data;
802 hlen = (uint16_t)(iph->ip_hl << 2);
803 plen = ntohs(iph->ip_len) - hlen;
804 tot_len = ntohs(iph->ip_len);
805 nsrc = &iph->ip_src;
806 ndst = &iph->ip_dst;
807 proto = &iph->ip_p;
808 break;
809 }
810 case PF_INET6: {
811 ip6h = pbuf->pb_data;
812 hlen = (uint16_t)sizeof(*ip6h);
813 plen = ntohs(ip6h->ip6_plen);
814 tot_len = hlen + plen;
815 nsrc = &ip6h->ip6_src;
816 ndst = &ip6h->ip6_dst;
817 proto = &ip6h->ip6_nxt;
818 break;
819 }
820 default:
821 return NT_DROP; /* We should never come here */
822 }
823
824 if (*proto != oproto) {
825 return NT_DROP;
826 }
827
828 /*
829 * We may want to manipulate csum flags in some cases
830 * and not act on the protocol header as it may not
831 * carry protocol checksums.
832 * For example, fragments other than the first one would
833 * not carry protocol headers.
834 */
835 if (only_csum) {
836 /*
837 * Only translate ICMP proto in the header
838 * and adjust checksums
839 */
840 if (*proto == IPPROTO_ICMP) {
841 if (naf != PF_INET6) {
842 return NT_DROP;
843 }
844
845 *proto = IPPROTO_ICMPV6;
846 } else if (*proto == IPPROTO_ICMPV6) {
847 if (naf != PF_INET) {
848 return NT_DROP;
849 }
850
851 *proto = IPPROTO_ICMP;
852 /* Recalculate IP checksum as proto field has changed */
853 iph->ip_sum = 0;
854 iph->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, hlen);
855 }
856 goto done;
857 }
858
859 switch (*proto) {
860 case IPPROTO_UDP: {
861 struct udphdr *uh = (struct udphdr *)pbuf_contig_segment(pbuf, hlen,
862 sizeof(*uh));
863
864 if (uh == NULL) {
865 return NT_DROP;
866 }
867
868 if (!(*pbuf->pb_csum_flags & (CSUM_UDP | CSUM_PARTIAL)) &&
869 uh->uh_sum == 0 && af == PF_INET && naf == PF_INET6) {
870 uh->uh_sum = pbuf_inet6_cksum(pbuf, IPPROTO_UDP,
871 hlen, ntohs(ip6h->ip6_plen));
872 if (uh->uh_sum == 0) {
873 uh->uh_sum = 0xffff;
874 }
875 goto done;
876 }
877
878 psum = &uh->uh_sum;
879 break;
880 }
881 case IPPROTO_TCP: {
882 struct tcphdr *th = (struct tcphdr *)pbuf_contig_segment(pbuf, hlen,
883 sizeof(*th));
884
885 if (th == NULL) {
886 return NT_DROP;
887 }
888
889 psum = &th->th_sum;
890 break;
891 }
892 }
893
894 /*
895 * Translate the protocol header, update IP header if needed,
896 * calculate checksums and update the checksum flags.
897 */
898 switch (*proto) {
899 case IPPROTO_UDP:
900 /* Fall through */
901 case IPPROTO_TCP:
902 {
903 /*
904 * If it is a locally generated and has CSUM flags set
905 * for TCP and UDP it means we have pseudo header checksum
906 * that has not yet been one's complemented.
907 */
908 if (direction == NT_OUT &&
909 (*pbuf->pb_csum_flags & CSUM_DELAY_DATA)) {
910 do_ones_complement = TRUE;
911 }
912
913 nat464_addr_cksum_fixup(psum, osrc, (struct nat464_addr *)nsrc,
914 af, naf, (*proto == IPPROTO_UDP) ? 1 : 0, do_ones_complement);
915 nat464_addr_cksum_fixup(psum, odst, (struct nat464_addr *)ndst,
916 af, naf, (*proto == IPPROTO_UDP) ? 1 : 0, do_ones_complement);
917
918 break;
919 }
920 case IPPROTO_ICMP: {
921 if (naf != PF_INET6) { /* allow only v6 as naf for ICMP */
922 return NT_DROP;
923 }
924
925 struct icmp *icmph = NULL;
926 struct icmp6_hdr *icmp6h = NULL;
927 uint16_t ip2off = 0, hlen2 = 0, tot_len2 = 0;
928
929 icmph = (struct icmp*) pbuf_contig_segment(pbuf, hlen,
930 ICMP_MINLEN);
931 if (icmph == NULL) {
932 return NT_DROP;
933 }
934
935 /* Translate the ICMP header */
936 if (nat464_translate_icmp(PF_INET6, icmph) != 0) {
937 return NT_DROP;
938 }
939
940 *proto = IPPROTO_ICMPV6;
941 icmp6h = (struct icmp6_hdr *)(uintptr_t)icmph;
942 pbuf_copy_back(pbuf, hlen, sizeof(struct icmp6_hdr),
943 icmp6h);
944
945 /*Translate the inner IP header only for error messages */
946 if (ICMP6_ERRORTYPE(icmp6h->icmp6_type)) {
947 ip2off = (uint16_t)(hlen + sizeof(*icmp6h));
948 struct ip *iph2 = NULL;
949 iph2 = (struct ip*) pbuf_contig_segment(pbuf, ip2off,
950 sizeof(*iph2));
951 if (iph2 == NULL) {
952 return NT_DROP;
953 }
954
955 hlen2 = (uint16_t)(ip2off + (iph2->ip_hl << 2));
956 tot_len2 = ntohs(iph2->ip_len);
957
958 /* Destination in outer IP should be Source in inner IP */
959 VERIFY(IN_ARE_ADDR_EQUAL(&odst->natv4addr, &iph2->ip_src));
960 if (nat464_translate_icmp_ip(pbuf, ip2off, &tot_len,
961 &hlen2, iph2->ip_p, iph2->ip_ttl, tot_len2,
962 (struct nat464_addr *)ndst, (struct nat464_addr *)nsrc,
963 PF_INET, PF_INET6) != 0) {
964 return NT_DROP;
965 }
966 /* Update total length/payload length for outer header */
967 switch (naf) {
968 case PF_INET:
969 iph->ip_len = htons(tot_len);
970 break;
971 case PF_INET6:
972 ip6h->ip6_plen = htons(tot_len - hlen);
973 break;
974 }
975 iph2 = NULL;
976 }
977
978 icmp6h->icmp6_cksum = 0;
979 icmp6h->icmp6_cksum = pbuf_inet6_cksum(pbuf, IPPROTO_ICMPV6, hlen,
980 ntohs(ip6h->ip6_plen));
981
982 clat_log2((LOG_DEBUG, "%s translated to ICMPV6 type: %d "
983 "code: %d checksum: %#x \n", __func__, icmp6h->icmp6_type,
984 icmp6h->icmp6_code, icmp6h->icmp6_cksum));
985
986 icmph = NULL;
987 icmp6h = NULL;
988 break;
989 }
990 case IPPROTO_ICMPV6:
991 { if (naf != PF_INET) { /* allow only v4 as naf for ICMPV6 */
992 return NT_DROP;
993 }
994
995 struct icmp6_hdr *icmp6h = NULL;
996 struct icmp *icmph = NULL;
997 uint16_t ip2off = 0, hlen2 = 0, tot_len2 = 0;
998
999 icmp6h = (struct icmp6_hdr*) pbuf_contig_segment(pbuf, hlen,
1000 sizeof(*icmp6h));
1001 if (icmp6h == NULL) {
1002 return NT_DROP;
1003 }
1004
1005 /* Translate the ICMP header */
1006 if (nat464_translate_icmp(PF_INET, icmp6h) != 0) {
1007 return NT_DROP;
1008 }
1009
1010 *proto = IPPROTO_ICMP;
1011 icmph = (struct icmp *)(uintptr_t)icmp6h;
1012 pbuf_copy_back(pbuf, hlen, ICMP_MINLEN,
1013 icmph);
1014
1015 /*Translate the inner IP header only for error messages */
1016 if (ICMP_ERRORTYPE(icmph->icmp_type)) {
1017 ip2off = hlen + ICMP_MINLEN;
1018 struct ip6_hdr *iph2 = NULL;
1019 iph2 = (struct ip6_hdr*) pbuf_contig_segment(pbuf, ip2off,
1020 sizeof(*iph2));
1021 if (iph2 == NULL) {
1022 return NT_DROP;
1023 }
1024
1025 /* hlen2 points to end of inner IP header from the beginning */
1026 hlen2 = ip2off + sizeof(struct ip6_hdr);
1027 tot_len2 = ntohs(iph2->ip6_plen) + sizeof(struct ip6_hdr);
1028
1029 if (nat464_translate_icmp_ip(pbuf, ip2off, &tot_len,
1030 &hlen2, iph2->ip6_nxt, iph2->ip6_hlim, tot_len2,
1031 (struct nat464_addr *)ndst, (struct nat464_addr *)nsrc,
1032 PF_INET6, PF_INET) != 0) {
1033 return NT_DROP;
1034 }
1035
1036 /* Update total length for outer header */
1037 switch (naf) {
1038 case PF_INET:
1039 iph->ip_len = htons(tot_len);
1040 break;
1041 case PF_INET6:
1042 ip6h->ip6_plen = htons(tot_len - hlen);
1043 break;
1044 }
1045 iph2 = NULL;
1046 }
1047 /* Recalculate IP checksum as some IP fields might have changed */
1048 iph->ip_sum = 0;
1049 iph->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, iph->ip_hl << 2);
1050 icmph->icmp_cksum = 0;
1051 icmph->icmp_cksum = pbuf_inet_cksum(pbuf, 0, hlen,
1052 ntohs(iph->ip_len) - hlen);
1053
1054 clat_log2((LOG_DEBUG, "%s translated to ICMP type: %d "
1055 "code: %d checksum: %#x \n", __func__, icmph->icmp_type,
1056 icmph->icmp_code, icmph->icmp_cksum));
1057
1058 icmp6h = NULL;
1059 icmph = NULL;
1060 break;}
1061
1062 /*
1063 * https://tools.ietf.org/html/rfc7915#section-5.1.1
1064 * If the Next Header field of the Fragment Header is an
1065 * extension header (except ESP, but including the Authentication
1066 * Header (AH)), then the packet SHOULD be dropped and logged.
1067 */
1068 case IPPROTO_HOPOPTS:
1069 case IPPROTO_ROUTING:
1070 case IPPROTO_DSTOPTS:
1071 case IPPROTO_AH:
1072 return NT_DROP;
1073
1074 case IPPROTO_FRAGMENT:
1075 /*
1076 * The fragment header is appended after or removed before
1077 * calling into this routine.
1078 */
1079 VERIFY(FALSE);
1080 case IPPROTO_ESP:
1081 break;
1082
1083 default:
1084 return NT_DROP;
1085 }
1086
1087 done:
1088 /* Update checksum flags and offsets based on direction */
1089 if (direction == NT_OUT) {
1090 if ((*pbuf->pb_csum_flags & (CSUM_DATA_VALID | CSUM_PARTIAL)) ==
1091 (CSUM_DATA_VALID | CSUM_PARTIAL)) {
1092 (pbuf->pb_mbuf)->m_pkthdr.csum_tx_start += CLAT46_HDR_EXPANSION_OVERHD;
1093 (pbuf->pb_mbuf)->m_pkthdr.csum_tx_stuff += CLAT46_HDR_EXPANSION_OVERHD;
1094 }
1095
1096 if (*pbuf->pb_csum_flags & CSUM_TCP) {
1097 *pbuf->pb_csum_flags |= CSUM_TCPIPV6;
1098 }
1099 if (*pbuf->pb_csum_flags & CSUM_UDP) {
1100 *pbuf->pb_csum_flags |= CSUM_UDPIPV6;
1101 }
1102 if (*pbuf->pb_csum_flags & CSUM_FRAGMENT) {
1103 *pbuf->pb_csum_flags |= CSUM_FRAGMENT_IPV6;
1104 }
1105
1106 /* Clear IPv4 checksum flags */
1107 *pbuf->pb_csum_flags &= ~(CSUM_IP | CSUM_IP_FRAGS | CSUM_DELAY_DATA | CSUM_FRAGMENT);
1108 /*
1109 * If the packet requires TCP segmentation due to TSO offload,
1110 * then change the checksum flag to indicate that an IPv6
1111 * TCP segmentation is needed now.
1112 */
1113 if (*pbuf->pb_csum_flags & CSUM_TSO_IPV4) {
1114 *pbuf->pb_csum_flags &= ~CSUM_TSO_IPV4;
1115 *pbuf->pb_csum_flags |= CSUM_TSO_IPV6;
1116 }
1117 } else if (direction == NT_IN) {
1118 /* XXX On input just reset csum flags */
1119 *pbuf->pb_csum_flags = 0; /* Reset all flags for now */
1120 #if 0
1121 /* Update csum flags and offsets for rx */
1122 if (*pbuf->pb_csum_flags & CSUM_PARTIAL) {
1123 (pbuf->pb_mbuf)->m_pkthdr.csum_rx_start -= CLAT46_HDR_EXPANSION_OVERHD;
1124 }
1125 #endif
1126 }
1127 return NT_NAT64;
1128 }
1129
1130 /* Fix the proto checksum for address change */
1131 static void
nat464_addr_cksum_fixup(uint16_t * pc,struct nat464_addr * ao,struct nat464_addr * an,protocol_family_t af,protocol_family_t naf,uint8_t u,boolean_t do_ones_complement)1132 nat464_addr_cksum_fixup(uint16_t *pc, struct nat464_addr *ao, struct nat464_addr *an,
1133 protocol_family_t af, protocol_family_t naf, uint8_t u, boolean_t do_ones_complement)
1134 {
1135 /* Currently we only support v4 to v6 and vice versa */
1136 VERIFY(af != naf);
1137
1138 switch (af) {
1139 case PF_INET:
1140 switch (naf) {
1141 case PF_INET6:
1142 if (do_ones_complement) {
1143 *pc = ~nat464_cksum_fixup(nat464_cksum_fixup(
1144 nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(
1145 nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(~*pc,
1146 ao->nataddr16[0], an->nataddr16[0], u),
1147 ao->nataddr16[1], an->nataddr16[1], u),
1148 0, an->nataddr16[2], u),
1149 0, an->nataddr16[3], u),
1150 0, an->nataddr16[4], u),
1151 0, an->nataddr16[5], u),
1152 0, an->nataddr16[6], u),
1153 0, an->nataddr16[7], u);
1154 } else {
1155 *pc = nat464_cksum_fixup(nat464_cksum_fixup(
1156 nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(
1157 nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(*pc,
1158 ao->nataddr16[0], an->nataddr16[0], u),
1159 ao->nataddr16[1], an->nataddr16[1], u),
1160 0, an->nataddr16[2], u),
1161 0, an->nataddr16[3], u),
1162 0, an->nataddr16[4], u),
1163 0, an->nataddr16[5], u),
1164 0, an->nataddr16[6], u),
1165 0, an->nataddr16[7], u);
1166 }
1167 break;
1168 }
1169 break;
1170 case PF_INET6:
1171 /*
1172 * XXX For NAT464 this only applies to the incoming path.
1173 * The checksum therefore is already ones complemented.
1174 * Therefore we just perform normal fixup.
1175 */
1176 switch (naf) {
1177 case PF_INET:
1178 *pc = nat464_cksum_fixup(nat464_cksum_fixup(
1179 nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(
1180 nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(*pc,
1181 ao->nataddr16[0], an->nataddr16[0], u),
1182 ao->nataddr16[1], an->nataddr16[1], u),
1183 ao->nataddr16[2], 0, u),
1184 ao->nataddr16[3], 0, u),
1185 ao->nataddr16[4], 0, u),
1186 ao->nataddr16[5], 0, u),
1187 ao->nataddr16[6], 0, u),
1188 ao->nataddr16[7], 0, u);
1189 break;
1190 }
1191 break;
1192 }
1193 }
1194
1195 uint16_t
nat464_cksum_fixup(uint16_t cksum,uint16_t old,uint16_t new,uint8_t udp)1196 nat464_cksum_fixup(uint16_t cksum, uint16_t old, uint16_t new, uint8_t udp)
1197 {
1198 uint32_t l;
1199
1200 if (udp && !cksum) {
1201 return 0;
1202 }
1203 l = cksum + old - new;
1204 l = (l >> 16) + (l & 0xffff);
1205 l = l & 0xffff;
1206 if (udp && !l) {
1207 return 0xffff;
1208 }
1209 return (uint16_t)l;
1210 }
1211
1212 /* CLAT46 event handlers */
1213 void
in6_clat46_eventhdlr_callback(struct eventhandler_entry_arg arg0 __unused,in6_clat46_evhdlr_code_t in6_clat46_ev_code,pid_t epid,uuid_t euuid)1214 in6_clat46_eventhdlr_callback(struct eventhandler_entry_arg arg0 __unused,
1215 in6_clat46_evhdlr_code_t in6_clat46_ev_code, pid_t epid, uuid_t euuid)
1216 {
1217 struct kev_msg ev_msg;
1218 struct kev_netevent_clat46_data clat46_event_data;
1219
1220 bzero(&ev_msg, sizeof(ev_msg));
1221 bzero(&clat46_event_data, sizeof(clat46_event_data));
1222
1223 ev_msg.vendor_code = KEV_VENDOR_APPLE;
1224 ev_msg.kev_class = KEV_NETWORK_CLASS;
1225 ev_msg.kev_subclass = KEV_NETEVENT_SUBCLASS;
1226 ev_msg.event_code = KEV_NETEVENT_CLAT46_EVENT;
1227
1228 bzero(&clat46_event_data, sizeof(clat46_event_data));
1229 clat46_event_data.clat46_event_code = in6_clat46_ev_code;
1230 clat46_event_data.epid = epid;
1231 uuid_copy(clat46_event_data.euuid, euuid);
1232
1233 ev_msg.dv[0].data_ptr = &clat46_event_data;
1234 ev_msg.dv[0].data_length = sizeof(clat46_event_data);
1235
1236 kev_post_msg(&ev_msg);
1237 }
1238
1239 struct in6_clat46_event_nwk_wq_entry {
1240 struct nwk_wq_entry nwk_wqe;
1241 struct kev_netevent_clat46_data in6_clat46_ev_arg;
1242 };
1243
1244 static void
in6_clat46_event_callback(struct nwk_wq_entry * nwk_item)1245 in6_clat46_event_callback(struct nwk_wq_entry *nwk_item)
1246 {
1247 struct in6_clat46_event_nwk_wq_entry *p_ev;
1248
1249 p_ev = __container_of(nwk_item,
1250 struct in6_clat46_event_nwk_wq_entry, nwk_wqe);
1251
1252 EVENTHANDLER_INVOKE(&in6_clat46_evhdlr_ctxt, in6_clat46_event,
1253 p_ev->in6_clat46_ev_arg.clat46_event_code, p_ev->in6_clat46_ev_arg.epid,
1254 p_ev->in6_clat46_ev_arg.euuid);
1255
1256 kfree_type(struct in6_clat46_event_nwk_wq_entry, p_ev);
1257 }
1258
1259 void
in6_clat46_event_enqueue_nwk_wq_entry(in6_clat46_evhdlr_code_t in6_clat46_event_code,pid_t epid,uuid_t euuid)1260 in6_clat46_event_enqueue_nwk_wq_entry(in6_clat46_evhdlr_code_t in6_clat46_event_code,
1261 pid_t epid, uuid_t euuid)
1262 {
1263 struct in6_clat46_event_nwk_wq_entry *p_ev = NULL;
1264
1265 p_ev = kalloc_type(struct in6_clat46_event_nwk_wq_entry,
1266 Z_WAITOK | Z_ZERO | Z_NOFAIL);
1267
1268 p_ev->nwk_wqe.func = in6_clat46_event_callback;
1269 p_ev->in6_clat46_ev_arg.clat46_event_code = in6_clat46_event_code;
1270 p_ev->in6_clat46_ev_arg.epid = epid;
1271 uuid_copy(p_ev->in6_clat46_ev_arg.euuid, euuid);
1272
1273 nwk_wq_enqueue(&p_ev->nwk_wqe);
1274 }
1275