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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 | |
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\n", 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 | |
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\n", | |
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 | |
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 | |
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 | ||
490 | if (af == naf || (af != AF_INET && af != AF_INET6) || | |
491 | (naf != AF_INET && naf != AF_INET6)) { | |
492 | return -1; | |
493 | } | |
494 | ||
495 | /* old header */ | |
496 | olen = *off2 - off; | |
497 | /* new header */ | |
498 | hlen = naf == PF_INET ? sizeof(*ip4) : sizeof(*ip6); | |
499 | ||
500 | /* Modify the pbuf to accommodate the new header */ | |
501 | hdr = pbuf_resize_segment(pbuf, off, olen, hlen); | |
502 | if (hdr == NULL) { | |
503 | return -1; | |
504 | } | |
505 | ||
506 | /* translate inner ip/ip6 header */ | |
507 | switch (naf) { | |
508 | case AF_INET: | |
509 | ip4 = hdr; | |
510 | bzero(ip4, sizeof(*ip4)); | |
511 | ip4->ip_v = IPVERSION; | |
512 | ip4->ip_hl = sizeof(*ip4) >> 2; | |
513 | ip4->ip_len = htons((uint16_t)(sizeof(*ip4) + tot_len2 - olen)); | |
514 | ip4->ip_id = rfc6864 ? 0 : htons(ip_randomid()); | |
515 | ip4->ip_off = htons(IP_DF); | |
516 | ip4->ip_ttl = ttl2; | |
517 | if (proto2 == IPPROTO_ICMPV6) { | |
518 | ip4->ip_p = IPPROTO_ICMP; | |
519 | } else { | |
520 | ip4->ip_p = proto2; | |
521 | } | |
522 | ip4->ip_src = src->natv4addr; | |
523 | ip4->ip_dst = dst->natv4addr; | |
524 | ip4->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, ip4->ip_hl << 2); | |
525 | ||
526 | if (clat_debug) { | |
527 | char buf[MAX_IPv4_STR_LEN]; | |
528 | clat_log2((LOG_DEBUG, "%s translated to IPv4 (inner) " | |
529 | "ip_len: %#x ip_p: %d ip_sum: %#x ip_src: %s ip_dst: %s \n", | |
530 | __func__, ntohs(ip4->ip_len), ip4->ip_p, ntohs(ip4->ip_sum), | |
531 | inet_ntop(AF_INET, (void *)&ip4->ip_src, buf, sizeof(buf)), | |
532 | inet_ntop(AF_INET, (void *)&ip4->ip_dst, buf, sizeof(buf)))); | |
533 | } | |
534 | break; | |
535 | case AF_INET6: | |
536 | ip6 = hdr; | |
537 | bzero(ip6, sizeof(*ip6)); | |
538 | ip6->ip6_vfc = IPV6_VERSION; | |
539 | ip6->ip6_plen = htons((uint16_t)(tot_len2 - olen)); | |
540 | if (proto2 == IPPROTO_ICMP) { | |
541 | ip6->ip6_nxt = IPPROTO_ICMPV6; | |
542 | } else { | |
543 | ip6->ip6_nxt = proto2; | |
544 | } | |
545 | if (!ttl2 || ttl2 > IPV6_DEFHLIM) { | |
546 | ip6->ip6_hlim = IPV6_DEFHLIM; | |
547 | } else { | |
548 | ip6->ip6_hlim = ttl2; | |
549 | } | |
550 | ip6->ip6_src = src->natv6addr; | |
551 | ip6->ip6_dst = dst->natv6addr; | |
552 | ||
553 | if (clat_debug) { | |
554 | char buf2[MAX_IPv6_STR_LEN]; | |
555 | clat_log2((LOG_DEBUG, "%s translated to IPv6 (inner) " | |
556 | "ip6_plen: %#x ip6_nxt: %d ip6_src: %s ip6_dst: %s \n", | |
557 | __func__, ntohs(ip6->ip6_plen), ip6->ip6_nxt, | |
558 | inet_ntop(AF_INET6, (void *)&ip6->ip6_src, buf2, sizeof(buf2)), | |
559 | inet_ntop(AF_INET6, (void *)&ip6->ip6_dst, buf2, sizeof(buf2)))); | |
560 | } | |
561 | break; | |
562 | } | |
563 | ||
564 | /* adjust payload offset and total packet length */ | |
565 | *off2 += hlen - olen; | |
566 | *tot_len += hlen - olen; | |
567 | ||
568 | return 0; | |
569 | } | |
570 | /* | |
571 | * @brief The function inserts IPv6 fragmentation header | |
572 | * and populates it with the passed parameters. | |
573 | * | |
574 | * @param pbuf Pointer to the packet buffer | |
575 | * @param ip_id IP identifier (in network byte order) | |
576 | * @param frag_offset Fragment offset (in network byte order) | |
577 | * @param is_last_frag Boolean indicating if the fragment header is for | |
578 | * last fragment or not. | |
579 | * | |
580 | * @return -1 on error and 0 on success. | |
581 | */ | |
582 | int | |
583 | nat464_insert_frag46(pbuf_t *pbuf, uint16_t ip_id_val, uint16_t frag_offset, | |
584 | boolean_t is_last_frag) | |
585 | { | |
586 | struct ip6_frag *p_ip6_frag = NULL; | |
587 | struct ip6_hdr *p_ip6h = NULL; | |
588 | ||
589 | /* Insert IPv6 fragmentation header */ | |
590 | if (pbuf_resize_segment(pbuf, sizeof(struct ip6_hdr), 0, | |
591 | sizeof(struct ip6_frag)) == NULL) { | |
592 | return -1; | |
593 | } | |
594 | ||
595 | p_ip6h = mtod(pbuf->pb_mbuf, struct ip6_hdr *); | |
596 | p_ip6_frag = (struct ip6_frag *)pbuf_contig_segment(pbuf, | |
597 | sizeof(struct ip6_hdr), sizeof(struct ip6_frag)); | |
598 | ||
599 | if (p_ip6_frag == NULL) { | |
600 | return -1; | |
601 | } | |
602 | ||
603 | /* Populate IPv6 fragmentation header */ | |
604 | p_ip6_frag->ip6f_nxt = p_ip6h->ip6_nxt; | |
605 | p_ip6_frag->ip6f_reserved = 0; | |
606 | p_ip6_frag->ip6f_offlg = (uint16_t)(frag_offset << 3); | |
607 | if (!is_last_frag) { | |
608 | p_ip6_frag->ip6f_offlg |= 0x1; | |
609 | } | |
610 | p_ip6_frag->ip6f_offlg = htons(p_ip6_frag->ip6f_offlg); | |
611 | p_ip6_frag->ip6f_ident = ip_id_val; | |
612 | ||
613 | /* Update IPv6 header */ | |
614 | p_ip6h->ip6_nxt = IPPROTO_FRAGMENT; | |
615 | p_ip6h->ip6_plen = htons(ntohs(p_ip6h->ip6_plen) + | |
616 | sizeof(struct ip6_frag)); | |
617 | ||
618 | return 0; | |
619 | } | |
620 | ||
621 | int | |
622 | nat464_translate_64(pbuf_t *pbuf, int off, uint8_t tos, | |
623 | uint8_t *proto, uint8_t ttl, struct in_addr src_v4, | |
624 | struct in_addr dst_v4, uint64_t tot_len, boolean_t *p_is_first_frag) | |
625 | { | |
626 | struct ip *ip4; | |
627 | struct ip6_frag *p_frag6 = NULL; | |
628 | struct ip6_frag frag6 = {}; | |
629 | boolean_t is_frag = FALSE; | |
630 | uint16_t ip_frag_off = 0; | |
631 | ||
632 | /* | |
633 | * ip_input asserts for rcvif to be not NULL | |
634 | * That may not be true for two corner cases | |
635 | * 1. If for some reason a local app sends DNS | |
636 | * AAAA query to local host | |
637 | * 2. If IPv6 stack in kernel internally generates a | |
638 | * message destined for a synthesized IPv6 end-point. | |
639 | */ | |
640 | if (pbuf->pb_ifp == NULL) { | |
641 | return NT_DROP; | |
642 | } | |
643 | ||
644 | if (*proto == IPPROTO_FRAGMENT) { | |
645 | p_frag6 = (struct ip6_frag *)pbuf_contig_segment(pbuf, | |
646 | sizeof(struct ip6_hdr), sizeof(struct ip6_frag)); | |
647 | if (p_frag6 == NULL) { | |
648 | ip6stat.ip6s_clat464_in_64frag_transfail_drop++; | |
649 | return NT_DROP; | |
650 | } | |
651 | ||
652 | frag6 = *p_frag6; | |
653 | p_frag6 = NULL; | |
654 | *proto = frag6.ip6f_nxt; | |
655 | off += sizeof(struct ip6_frag); | |
656 | is_frag = TRUE; | |
657 | ip_frag_off = (ntohs(frag6.ip6f_offlg & IP6F_OFF_MASK)) >> 3; | |
658 | if (ip_frag_off != 0) { | |
659 | *p_is_first_frag = FALSE; | |
660 | } | |
661 | } | |
662 | ||
663 | ip4 = (struct ip *)pbuf_resize_segment(pbuf, 0, off, sizeof(*ip4)); | |
664 | if (ip4 == NULL) { | |
665 | return NT_DROP; | |
666 | } | |
667 | ip4->ip_v = 4; | |
668 | ip4->ip_hl = 5; | |
669 | ip4->ip_tos = tos; | |
670 | ip4->ip_len = htons((uint16_t)(sizeof(*ip4) + (tot_len - off))); | |
671 | ip4->ip_id = 0; | |
672 | ip4->ip_off = 0; | |
673 | ip4->ip_ttl = ttl; | |
674 | ip4->ip_p = *proto; | |
675 | ip4->ip_sum = 0; | |
676 | ip4->ip_src = src_v4; | |
677 | ip4->ip_dst = dst_v4; | |
678 | if (is_frag) { | |
679 | /* | |
680 | * https://tools.ietf.org/html/rfc7915#section-5.1.1 | |
681 | * Identification: Copied from the low-order 16 bits in the | |
682 | * Identification field in the Fragment Header. | |
683 | */ | |
684 | ip4->ip_id = ntohl(frag6.ip6f_ident) & 0xffff; | |
685 | ip4->ip_id = htons(ip4->ip_id); | |
686 | if (frag6.ip6f_offlg & IP6F_MORE_FRAG) { | |
687 | ip_frag_off |= IP_MF; | |
688 | } | |
689 | ip4->ip_off = htons(ip_frag_off); | |
690 | } else { | |
691 | ip4->ip_off |= htons(IP_DF); | |
692 | } | |
693 | ||
694 | /* | |
695 | * Defer calculating ip_sum for ICMPv6 as we do it | |
696 | * later in Protocol translation | |
697 | */ | |
698 | if (*proto != IPPROTO_ICMPV6) { | |
699 | ip4->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, ip4->ip_hl << 2); | |
700 | } | |
701 | ||
702 | if (clat_debug) { | |
703 | char buf1[MAX_IPv4_STR_LEN], buf2[MAX_IPv4_STR_LEN]; | |
704 | clat_log2((LOG_DEBUG, "%s translated to IPv4 ip_len: %#x " | |
705 | "ip_p: %d ip_sum: %#x ip_src: %s ip_dst: %s \n", __func__, | |
706 | ntohs(ip4->ip_len), ip4->ip_p, ntohs(ip4->ip_sum), | |
707 | inet_ntop(AF_INET, (void *)&ip4->ip_src, buf1, sizeof(buf1)), | |
708 | inet_ntop(AF_INET, (void *)&ip4->ip_dst, buf2, sizeof(buf2)))); | |
709 | } | |
710 | return NT_NAT64; | |
711 | } | |
712 | /* | |
713 | * @brief The routine translates the IPv4 header to IPv6 header. | |
714 | * | |
715 | * @param pbuf Pointer to the generic packet buffer | |
716 | * @param off Offset to the end of IP header | |
717 | * @param tos Type of service | |
718 | * @param proto Protocol running over IP | |
719 | * @param ttl Time to live | |
720 | * @param src_v6 Source IPv6 address | |
721 | * @param dst_v6 Destination IPv6 address | |
722 | * @param tot_len Total payload length | |
723 | * | |
724 | * @return NT_NAT64 if IP header translation is successful, else error | |
725 | */ | |
726 | int | |
727 | nat464_translate_46(pbuf_t *pbuf, uint16_t off, uint8_t tos, | |
728 | uint8_t proto, uint8_t ttl, struct in6_addr src_v6, | |
729 | struct in6_addr dst_v6, uint16_t tot_len) | |
730 | { | |
731 | struct ip6_hdr *ip6; | |
732 | ||
733 | if (pbuf->pb_ifp == NULL) { | |
734 | return NT_DROP; | |
735 | } | |
736 | ||
737 | /* | |
738 | * Trim the buffer from head of size equal to to off (which is equal to | |
739 | * the size of IP header and prepend IPv6 header length to the buffer | |
740 | */ | |
741 | ip6 = (struct ip6_hdr *)pbuf_resize_segment(pbuf, 0, off, sizeof(*ip6)); | |
742 | if (ip6 == NULL) { | |
743 | return NT_DROP; | |
744 | } | |
745 | ip6->ip6_flow = htonl((6 << 28) | (tos << 20)); | |
746 | ip6->ip6_plen = htons(tot_len - off); | |
747 | ip6->ip6_nxt = proto; | |
748 | ip6->ip6_hlim = ttl; | |
749 | ip6->ip6_src = src_v6; | |
750 | ip6->ip6_dst = dst_v6; | |
751 | ||
752 | if (clat_debug) { | |
753 | char buf1[MAX_IPv6_STR_LEN], buf2[MAX_IPv6_STR_LEN]; | |
754 | clat_log2((LOG_DEBUG, "%s translated to IPv6 ip6_plen: %#x " | |
755 | " ip6_nxt: %d ip6_src: %s ip6_dst: %s \n", __func__, | |
756 | ntohs(ip6->ip6_plen), ip6->ip6_nxt, | |
757 | inet_ntop(AF_INET6, (void *)&ip6->ip6_src, buf1, sizeof(buf1)), | |
758 | inet_ntop(AF_INET6, (void *)&ip6->ip6_dst, buf2, sizeof(buf2)))); | |
759 | } | |
760 | return NT_NAT64; | |
761 | } | |
762 | ||
763 | /* Handle the next protocol checksum */ | |
764 | /* | |
765 | * @brief This routine translates the Proto running over IP and updates the checksum | |
766 | * for IP header translation. It also updates pbuf checksum flags and related fields. | |
767 | * | |
768 | * @param pbuf Pointer to protocol buffer | |
769 | * @param nsrc New source address | |
770 | * @param ndst New destination address | |
771 | * @param af Old family | |
772 | * @param naf New family | |
773 | * | |
774 | * @return void | |
775 | */ | |
776 | int | |
777 | nat464_translate_proto(pbuf_t *pbuf, struct nat464_addr *osrc, | |
778 | struct nat464_addr *odst, uint8_t oproto, protocol_family_t af, | |
779 | protocol_family_t naf, int direction, boolean_t only_csum) | |
780 | { | |
781 | struct ip *iph = NULL; | |
782 | struct ip6_hdr *ip6h = NULL; | |
783 | uint16_t hlen = 0, plen = 0; | |
784 | uint16_t tot_len = 0; | |
785 | void *nsrc = NULL, *ndst = NULL; | |
786 | uint8_t *proto = 0; | |
787 | uint16_t *psum = NULL; | |
788 | boolean_t do_ones_complement = FALSE; | |
789 | ||
790 | /* For now these routines only support 464 translations */ | |
791 | VERIFY(af != naf); | |
792 | VERIFY(af == PF_INET || af == PF_INET6); | |
793 | ||
794 | /* | |
795 | * For now out must be for v4 to v6 translation | |
796 | * and in must be for v6 to v4 translation. | |
797 | */ | |
798 | switch (naf) { | |
799 | case PF_INET: { | |
800 | iph = pbuf->pb_data; | |
801 | hlen = (uint16_t)(iph->ip_hl << 2); | |
802 | plen = ntohs(iph->ip_len) - hlen; | |
803 | tot_len = ntohs(iph->ip_len); | |
804 | nsrc = &iph->ip_src; | |
805 | ndst = &iph->ip_dst; | |
806 | proto = &iph->ip_p; | |
807 | break; | |
808 | } | |
809 | case PF_INET6: { | |
810 | ip6h = pbuf->pb_data; | |
811 | hlen = (uint16_t)sizeof(*ip6h); | |
812 | plen = ntohs(ip6h->ip6_plen); | |
813 | tot_len = hlen + plen; | |
814 | nsrc = &ip6h->ip6_src; | |
815 | ndst = &ip6h->ip6_dst; | |
816 | proto = &ip6h->ip6_nxt; | |
817 | break; | |
818 | } | |
819 | default: | |
820 | return NT_DROP; /* We should never come here */ | |
821 | } | |
822 | ||
823 | if (*proto != oproto) { | |
824 | return NT_DROP; | |
825 | } | |
826 | ||
827 | /* | |
828 | * We may want to manipulate csum flags in some cases | |
829 | * and not act on the protocol header as it may not | |
830 | * carry protocol checksums. | |
831 | * For example, fragments other than the first one would | |
832 | * not carry protocol headers. | |
833 | */ | |
834 | if (only_csum) { | |
835 | /* | |
836 | * Only translate ICMP proto in the header | |
837 | * and adjust checksums | |
838 | */ | |
839 | if (*proto == IPPROTO_ICMP) { | |
840 | if (naf != PF_INET6) { | |
841 | return NT_DROP; | |
842 | } | |
843 | ||
844 | *proto = IPPROTO_ICMPV6; | |
845 | } else if (*proto == IPPROTO_ICMPV6) { | |
846 | if (naf != PF_INET) { | |
847 | return NT_DROP; | |
848 | } | |
849 | ||
850 | *proto = IPPROTO_ICMP; | |
851 | /* Recalculate IP checksum as proto field has changed */ | |
852 | iph->ip_sum = 0; | |
853 | iph->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, hlen); | |
854 | } | |
855 | goto done; | |
856 | } | |
857 | ||
858 | switch (*proto) { | |
859 | case IPPROTO_UDP: { | |
860 | struct udphdr *uh = (struct udphdr *)pbuf_contig_segment(pbuf, hlen, | |
861 | sizeof(*uh)); | |
862 | ||
863 | if (uh == NULL) { | |
864 | return NT_DROP; | |
865 | } | |
866 | ||
867 | if (!(*pbuf->pb_csum_flags & (CSUM_UDP | CSUM_PARTIAL)) && | |
868 | uh->uh_sum == 0 && af == PF_INET && naf == PF_INET6) { | |
869 | uh->uh_sum = pbuf_inet6_cksum(pbuf, IPPROTO_UDP, | |
870 | hlen, ntohs(ip6h->ip6_plen)); | |
871 | if (uh->uh_sum == 0) { | |
872 | uh->uh_sum = 0xffff; | |
873 | } | |
874 | goto done; | |
875 | } | |
876 | ||
877 | psum = &uh->uh_sum; | |
878 | break; | |
879 | } | |
880 | case IPPROTO_TCP: { | |
881 | struct tcphdr *th = (struct tcphdr *)pbuf_contig_segment(pbuf, hlen, | |
882 | sizeof(*th)); | |
883 | ||
884 | if (th == NULL) { | |
885 | return NT_DROP; | |
886 | } | |
887 | ||
888 | psum = &th->th_sum; | |
889 | break; | |
890 | } | |
891 | } | |
892 | ||
893 | /* | |
894 | * Translate the protocol header, update IP header if needed, | |
895 | * calculate checksums and update the checksum flags. | |
896 | */ | |
897 | switch (*proto) { | |
898 | case IPPROTO_UDP: | |
899 | /* Fall through */ | |
900 | case IPPROTO_TCP: | |
901 | { | |
902 | /* | |
903 | * If it is a locally generated and has CSUM flags set | |
904 | * for TCP and UDP it means we have pseudo header checksum | |
905 | * that has not yet been one's complemented. | |
906 | */ | |
907 | if (direction == NT_OUT && | |
908 | (*pbuf->pb_csum_flags & CSUM_DELAY_DATA)) { | |
909 | do_ones_complement = TRUE; | |
910 | } | |
911 | ||
912 | nat464_addr_cksum_fixup(psum, osrc, (struct nat464_addr *)nsrc, | |
913 | af, naf, (*proto == IPPROTO_UDP) ? 1 : 0, do_ones_complement); | |
914 | nat464_addr_cksum_fixup(psum, odst, (struct nat464_addr *)ndst, | |
915 | af, naf, (*proto == IPPROTO_UDP) ? 1 : 0, do_ones_complement); | |
916 | ||
917 | break; | |
918 | } | |
919 | case IPPROTO_ICMP: { | |
920 | if (naf != PF_INET6) { /* allow only v6 as naf for ICMP */ | |
921 | return NT_DROP; | |
922 | } | |
923 | ||
924 | struct icmp *icmph = NULL; | |
925 | struct icmp6_hdr *icmp6h = NULL; | |
926 | uint16_t ip2off = 0, hlen2 = 0, tot_len2 = 0; | |
927 | ||
928 | icmph = (struct icmp*) pbuf_contig_segment(pbuf, hlen, | |
929 | ICMP_MINLEN); | |
930 | if (icmph == NULL) { | |
931 | return NT_DROP; | |
932 | } | |
933 | ||
934 | /* Translate the ICMP header */ | |
935 | if (nat464_translate_icmp(PF_INET6, icmph) != 0) { | |
936 | return NT_DROP; | |
937 | } | |
938 | ||
939 | *proto = IPPROTO_ICMPV6; | |
940 | icmp6h = (struct icmp6_hdr *)(uintptr_t)icmph; | |
941 | pbuf_copy_back(pbuf, hlen, sizeof(struct icmp6_hdr), | |
942 | icmp6h); | |
943 | ||
944 | /*Translate the inner IP header only for error messages */ | |
945 | if (ICMP6_ERRORTYPE(icmp6h->icmp6_type)) { | |
946 | ip2off = (uint16_t)(hlen + sizeof(*icmp6h)); | |
947 | struct ip *iph2 = NULL; | |
948 | iph2 = (struct ip*) pbuf_contig_segment(pbuf, ip2off, | |
949 | sizeof(*iph2)); | |
950 | if (iph2 == NULL) { | |
951 | return NT_DROP; | |
952 | } | |
953 | ||
954 | hlen2 = (uint16_t)(ip2off + (iph2->ip_hl << 2)); | |
955 | tot_len2 = ntohs(iph2->ip_len); | |
956 | ||
957 | /* Destination in outer IP should be Source in inner IP */ | |
958 | VERIFY(IN_ARE_ADDR_EQUAL(&odst->natv4addr, &iph2->ip_src)); | |
959 | if (nat464_translate_icmp_ip(pbuf, ip2off, &tot_len, | |
960 | &hlen2, iph2->ip_p, iph2->ip_ttl, tot_len2, | |
961 | (struct nat464_addr *)ndst, (struct nat464_addr *)nsrc, | |
962 | PF_INET, PF_INET6) != 0) { | |
963 | return NT_DROP; | |
964 | } | |
965 | /* Update total length/payload length for outer header */ | |
966 | switch (naf) { | |
967 | case PF_INET: | |
968 | iph->ip_len = htons(tot_len); | |
969 | break; | |
970 | case PF_INET6: | |
971 | ip6h->ip6_plen = htons(tot_len - hlen); | |
972 | break; | |
973 | } | |
974 | iph2 = NULL; | |
975 | } | |
976 | ||
977 | icmp6h->icmp6_cksum = 0; | |
978 | icmp6h->icmp6_cksum = pbuf_inet6_cksum(pbuf, IPPROTO_ICMPV6, hlen, | |
979 | ntohs(ip6h->ip6_plen)); | |
980 | ||
981 | clat_log2((LOG_DEBUG, "%s translated to ICMPV6 type: %d " | |
982 | "code: %d checksum: %#x \n", __func__, icmp6h->icmp6_type, | |
983 | icmp6h->icmp6_code, icmp6h->icmp6_cksum)); | |
984 | ||
985 | icmph = NULL; | |
986 | icmp6h = NULL; | |
987 | break; | |
988 | } | |
989 | case IPPROTO_ICMPV6: | |
990 | { if (naf != PF_INET) { /* allow only v4 as naf for ICMPV6 */ | |
991 | return NT_DROP; | |
992 | } | |
993 | ||
994 | struct icmp6_hdr *icmp6h = NULL; | |
995 | struct icmp *icmph = NULL; | |
996 | uint16_t ip2off = 0, hlen2 = 0, tot_len2 = 0; | |
997 | ||
998 | icmp6h = (struct icmp6_hdr*) pbuf_contig_segment(pbuf, hlen, | |
999 | sizeof(*icmp6h)); | |
1000 | if (icmp6h == NULL) { | |
1001 | return NT_DROP; | |
1002 | } | |
1003 | ||
1004 | /* Translate the ICMP header */ | |
1005 | if (nat464_translate_icmp(PF_INET, icmp6h) != 0) { | |
1006 | return NT_DROP; | |
1007 | } | |
1008 | ||
1009 | *proto = IPPROTO_ICMP; | |
1010 | icmph = (struct icmp *)(uintptr_t)icmp6h; | |
1011 | pbuf_copy_back(pbuf, hlen, ICMP_MINLEN, | |
1012 | icmph); | |
1013 | ||
1014 | /*Translate the inner IP header only for error messages */ | |
1015 | if (ICMP_ERRORTYPE(icmph->icmp_type)) { | |
1016 | ip2off = hlen + ICMP_MINLEN; | |
1017 | struct ip6_hdr *iph2 = NULL; | |
1018 | iph2 = (struct ip6_hdr*) pbuf_contig_segment(pbuf, ip2off, | |
1019 | sizeof(*iph2)); | |
1020 | if (iph2 == NULL) { | |
1021 | return NT_DROP; | |
1022 | } | |
1023 | ||
1024 | /* hlen2 points to end of inner IP header from the beginning */ | |
1025 | hlen2 = ip2off + sizeof(struct ip6_hdr); | |
1026 | tot_len2 = ntohs(iph2->ip6_plen) + sizeof(struct ip6_hdr); | |
1027 | ||
1028 | if (nat464_translate_icmp_ip(pbuf, ip2off, &tot_len, | |
1029 | &hlen2, iph2->ip6_nxt, iph2->ip6_hlim, tot_len2, | |
1030 | (struct nat464_addr *)ndst, (struct nat464_addr *)nsrc, | |
1031 | PF_INET6, PF_INET) != 0) { | |
1032 | return NT_DROP; | |
1033 | } | |
1034 | ||
1035 | /* Update total length for outer header */ | |
1036 | switch (naf) { | |
1037 | case PF_INET: | |
1038 | iph->ip_len = htons(tot_len); | |
1039 | break; | |
1040 | case PF_INET6: | |
1041 | ip6h->ip6_plen = htons(tot_len - hlen); | |
1042 | break; | |
1043 | } | |
1044 | iph2 = NULL; | |
1045 | } | |
1046 | /* Recalculate IP checksum as some IP fields might have changed */ | |
1047 | iph->ip_sum = 0; | |
1048 | iph->ip_sum = pbuf_inet_cksum(pbuf, 0, 0, iph->ip_hl << 2); | |
1049 | icmph->icmp_cksum = 0; | |
1050 | icmph->icmp_cksum = pbuf_inet_cksum(pbuf, 0, hlen, | |
1051 | ntohs(iph->ip_len) - hlen); | |
1052 | ||
1053 | clat_log2((LOG_DEBUG, "%s translated to ICMP type: %d " | |
1054 | "code: %d checksum: %#x \n", __func__, icmph->icmp_type, | |
1055 | icmph->icmp_code, icmph->icmp_cksum)); | |
1056 | ||
1057 | icmp6h = NULL; | |
1058 | icmph = NULL; | |
1059 | break;} | |
1060 | ||
1061 | /* | |
1062 | * https://tools.ietf.org/html/rfc7915#section-5.1.1 | |
1063 | * If the Next Header field of the Fragment Header is an | |
1064 | * extension header (except ESP, but including the Authentication | |
1065 | * Header (AH)), then the packet SHOULD be dropped and logged. | |
1066 | */ | |
1067 | case IPPROTO_HOPOPTS: | |
1068 | case IPPROTO_ROUTING: | |
1069 | case IPPROTO_DSTOPTS: | |
1070 | case IPPROTO_AH: | |
1071 | return NT_DROP; | |
1072 | ||
1073 | case IPPROTO_FRAGMENT: | |
1074 | /* | |
1075 | * The fragment header is appended after or removed before | |
1076 | * calling into this routine. | |
1077 | */ | |
1078 | VERIFY(FALSE); | |
1079 | case IPPROTO_ESP: | |
1080 | break; | |
1081 | ||
1082 | default: | |
1083 | return NT_DROP; | |
1084 | } | |
1085 | ||
1086 | done: | |
1087 | /* Update checksum flags and offsets based on direction */ | |
1088 | if (direction == NT_OUT) { | |
1089 | if ((*pbuf->pb_csum_flags & (CSUM_DATA_VALID | CSUM_PARTIAL)) == | |
1090 | (CSUM_DATA_VALID | CSUM_PARTIAL)) { | |
1091 | (pbuf->pb_mbuf)->m_pkthdr.csum_tx_start += CLAT46_HDR_EXPANSION_OVERHD; | |
1092 | (pbuf->pb_mbuf)->m_pkthdr.csum_tx_stuff += CLAT46_HDR_EXPANSION_OVERHD; | |
1093 | } | |
1094 | ||
1095 | if (*pbuf->pb_csum_flags & CSUM_TCP) { | |
1096 | *pbuf->pb_csum_flags |= CSUM_TCPIPV6; | |
1097 | } | |
1098 | if (*pbuf->pb_csum_flags & CSUM_UDP) { | |
1099 | *pbuf->pb_csum_flags |= CSUM_UDPIPV6; | |
1100 | } | |
1101 | if (*pbuf->pb_csum_flags & CSUM_FRAGMENT) { | |
1102 | *pbuf->pb_csum_flags |= CSUM_FRAGMENT_IPV6; | |
1103 | } | |
1104 | ||
1105 | /* Clear IPv4 checksum flags */ | |
1106 | *pbuf->pb_csum_flags &= ~(CSUM_IP | CSUM_IP_FRAGS | CSUM_DELAY_DATA | CSUM_FRAGMENT); | |
1107 | /* | |
1108 | * If the packet requires TCP segmentation due to TSO offload, | |
1109 | * then change the checksum flag to indicate that an IPv6 | |
1110 | * TCP segmentation is needed now. | |
1111 | */ | |
1112 | if (*pbuf->pb_csum_flags & CSUM_TSO_IPV4) { | |
1113 | *pbuf->pb_csum_flags &= ~CSUM_TSO_IPV4; | |
1114 | *pbuf->pb_csum_flags |= CSUM_TSO_IPV6; | |
1115 | } | |
1116 | } else if (direction == NT_IN) { | |
1117 | /* XXX On input just reset csum flags */ | |
1118 | *pbuf->pb_csum_flags = 0; /* Reset all flags for now */ | |
1119 | #if 0 | |
1120 | /* Update csum flags and offsets for rx */ | |
1121 | if (*pbuf->pb_csum_flags & CSUM_PARTIAL) { | |
1122 | (pbuf->pb_mbuf)->m_pkthdr.csum_rx_start -= CLAT46_HDR_EXPANSION_OVERHD; | |
1123 | } | |
1124 | #endif | |
1125 | } | |
1126 | return NT_NAT64; | |
1127 | } | |
1128 | ||
1129 | /* Fix the proto checksum for address change */ | |
1130 | static void | |
1131 | nat464_addr_cksum_fixup(uint16_t *pc, struct nat464_addr *ao, struct nat464_addr *an, | |
1132 | protocol_family_t af, protocol_family_t naf, uint8_t u, boolean_t do_ones_complement) | |
1133 | { | |
1134 | /* Currently we only support v4 to v6 and vice versa */ | |
1135 | VERIFY(af != naf); | |
1136 | ||
1137 | switch (af) { | |
1138 | case PF_INET: | |
1139 | switch (naf) { | |
1140 | case PF_INET6: | |
1141 | if (do_ones_complement) { | |
1142 | *pc = ~nat464_cksum_fixup(nat464_cksum_fixup( | |
1143 | nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup( | |
1144 | nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(~*pc, | |
1145 | ao->nataddr16[0], an->nataddr16[0], u), | |
1146 | ao->nataddr16[1], an->nataddr16[1], u), | |
1147 | 0, an->nataddr16[2], u), | |
1148 | 0, an->nataddr16[3], u), | |
1149 | 0, an->nataddr16[4], u), | |
1150 | 0, an->nataddr16[5], u), | |
1151 | 0, an->nataddr16[6], u), | |
1152 | 0, an->nataddr16[7], u); | |
1153 | } else { | |
1154 | *pc = nat464_cksum_fixup(nat464_cksum_fixup( | |
1155 | nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup( | |
1156 | nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(*pc, | |
1157 | ao->nataddr16[0], an->nataddr16[0], u), | |
1158 | ao->nataddr16[1], an->nataddr16[1], u), | |
1159 | 0, an->nataddr16[2], u), | |
1160 | 0, an->nataddr16[3], u), | |
1161 | 0, an->nataddr16[4], u), | |
1162 | 0, an->nataddr16[5], u), | |
1163 | 0, an->nataddr16[6], u), | |
1164 | 0, an->nataddr16[7], u); | |
1165 | } | |
1166 | break; | |
1167 | } | |
1168 | break; | |
1169 | case PF_INET6: | |
1170 | /* | |
1171 | * XXX For NAT464 this only applies to the incoming path. | |
1172 | * The checksum therefore is already ones complemented. | |
1173 | * Therefore we just perform normal fixup. | |
1174 | */ | |
1175 | switch (naf) { | |
1176 | case PF_INET: | |
1177 | *pc = nat464_cksum_fixup(nat464_cksum_fixup( | |
1178 | nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup( | |
1179 | nat464_cksum_fixup(nat464_cksum_fixup(nat464_cksum_fixup(*pc, | |
1180 | ao->nataddr16[0], an->nataddr16[0], u), | |
1181 | ao->nataddr16[1], an->nataddr16[1], u), | |
1182 | ao->nataddr16[2], 0, u), | |
1183 | ao->nataddr16[3], 0, u), | |
1184 | ao->nataddr16[4], 0, u), | |
1185 | ao->nataddr16[5], 0, u), | |
1186 | ao->nataddr16[6], 0, u), | |
1187 | ao->nataddr16[7], 0, u); | |
1188 | break; | |
1189 | } | |
1190 | break; | |
1191 | } | |
1192 | } | |
1193 | ||
1194 | uint16_t | |
1195 | nat464_cksum_fixup(uint16_t cksum, uint16_t old, uint16_t new, uint8_t udp) | |
1196 | { | |
1197 | uint32_t l; | |
1198 | ||
1199 | if (udp && !cksum) { | |
1200 | return 0; | |
1201 | } | |
1202 | l = cksum + old - new; | |
1203 | l = (l >> 16) + (l & 0xffff); | |
1204 | l = l & 0xffff; | |
1205 | if (udp && !l) { | |
1206 | return 0xffff; | |
1207 | } | |
1208 | return (uint16_t)l; | |
1209 | } | |
1210 | ||
1211 | /* CLAT46 event handlers */ | |
1212 | void | |
1213 | in6_clat46_eventhdlr_callback(struct eventhandler_entry_arg arg0 __unused, | |
1214 | in6_clat46_evhdlr_code_t in6_clat46_ev_code, pid_t epid, uuid_t euuid) | |
1215 | { | |
1216 | struct kev_msg ev_msg; | |
1217 | struct kev_netevent_clat46_data clat46_event_data; | |
1218 | ||
1219 | bzero(&ev_msg, sizeof(ev_msg)); | |
1220 | bzero(&clat46_event_data, sizeof(clat46_event_data)); | |
1221 | ||
1222 | ev_msg.vendor_code = KEV_VENDOR_APPLE; | |
1223 | ev_msg.kev_class = KEV_NETWORK_CLASS; | |
1224 | ev_msg.kev_subclass = KEV_NETEVENT_SUBCLASS; | |
1225 | ev_msg.event_code = KEV_NETEVENT_CLAT46_EVENT; | |
1226 | ||
1227 | bzero(&clat46_event_data, sizeof(clat46_event_data)); | |
1228 | clat46_event_data.clat46_event_code = in6_clat46_ev_code; | |
1229 | clat46_event_data.epid = epid; | |
1230 | uuid_copy(clat46_event_data.euuid, euuid); | |
1231 | ||
1232 | ev_msg.dv[0].data_ptr = &clat46_event_data; | |
1233 | ev_msg.dv[0].data_length = sizeof(clat46_event_data); | |
1234 | ||
1235 | kev_post_msg(&ev_msg); | |
1236 | } | |
1237 | ||
1238 | static void | |
1239 | in6_clat46_event_callback(void *arg) | |
1240 | { | |
1241 | struct kev_netevent_clat46_data *p_in6_clat46_ev = | |
1242 | (struct kev_netevent_clat46_data *)arg; | |
1243 | ||
1244 | EVENTHANDLER_INVOKE(&in6_clat46_evhdlr_ctxt, in6_clat46_event, | |
1245 | p_in6_clat46_ev->clat46_event_code, p_in6_clat46_ev->epid, | |
1246 | p_in6_clat46_ev->euuid); | |
1247 | } | |
1248 | ||
1249 | struct in6_clat46_event_nwk_wq_entry { | |
1250 | struct nwk_wq_entry nwk_wqe; | |
1251 | struct kev_netevent_clat46_data in6_clat46_ev_arg; | |
1252 | }; | |
1253 | ||
1254 | void | |
1255 | in6_clat46_event_enqueue_nwk_wq_entry(in6_clat46_evhdlr_code_t in6_clat46_event_code, | |
1256 | pid_t epid, uuid_t euuid) | |
1257 | { | |
1258 | struct in6_clat46_event_nwk_wq_entry *p_ev = NULL; | |
1259 | ||
1260 | MALLOC(p_ev, struct in6_clat46_event_nwk_wq_entry *, | |
1261 | sizeof(struct in6_clat46_event_nwk_wq_entry), | |
1262 | M_NWKWQ, M_WAITOK | M_ZERO); | |
1263 | ||
1264 | p_ev->nwk_wqe.func = in6_clat46_event_callback; | |
1265 | p_ev->nwk_wqe.is_arg_managed = TRUE; | |
1266 | p_ev->nwk_wqe.arg = &p_ev->in6_clat46_ev_arg; | |
1267 | ||
1268 | p_ev->in6_clat46_ev_arg.clat46_event_code = in6_clat46_event_code; | |
1269 | p_ev->in6_clat46_ev_arg.epid = epid; | |
1270 | uuid_copy(p_ev->in6_clat46_ev_arg.euuid, euuid); | |
1271 | ||
1272 | nwk_wq_enqueue((struct nwk_wq_entry*)p_ev); | |
1273 | } |