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1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ | |
2 | /*** | |
3 | Copyright © 2014-2015 Intel Corporation. All rights reserved. | |
4 | ***/ | |
5 | ||
6 | #include <netinet/in.h> | |
7 | ||
8 | #include "sd-dhcp6-client.h" | |
9 | #include "sd-dhcp6-option.h" | |
10 | ||
11 | #include "alloc-util.h" | |
12 | #include "dhcp6-internal.h" | |
13 | #include "dhcp6-option.h" | |
14 | #include "dhcp6-protocol.h" | |
15 | #include "dns-def.h" | |
16 | #include "dns-domain.h" | |
17 | #include "escape.h" | |
18 | #include "memory-util.h" | |
19 | #include "network-common.h" | |
20 | #include "ordered-set.h" | |
21 | #include "string-util.h" | |
22 | #include "strv.h" | |
23 | #include "unaligned.h" | |
24 | ||
25 | #define DHCP6_OPTION_IA_NA_LEN (sizeof(struct ia_na)) | |
26 | #define DHCP6_OPTION_IA_PD_LEN (sizeof(struct ia_pd)) | |
27 | #define DHCP6_OPTION_IA_TA_LEN (sizeof(struct ia_ta)) | |
28 | ||
29 | bool dhcp6_option_can_request(uint16_t option) { | |
30 | /* See Client ORO field in | |
31 | * https://www.iana.org/assignments/dhcpv6-parameters/dhcpv6-parameters.xhtml#dhcpv6-parameters-2 */ | |
32 | ||
33 | switch (option) { | |
34 | case SD_DHCP6_OPTION_CLIENTID: | |
35 | case SD_DHCP6_OPTION_SERVERID: | |
36 | case SD_DHCP6_OPTION_IA_NA: | |
37 | case SD_DHCP6_OPTION_IA_TA: | |
38 | case SD_DHCP6_OPTION_IAADDR: | |
39 | case SD_DHCP6_OPTION_ORO: | |
40 | case SD_DHCP6_OPTION_PREFERENCE: | |
41 | case SD_DHCP6_OPTION_ELAPSED_TIME: | |
42 | case SD_DHCP6_OPTION_RELAY_MSG: | |
43 | case SD_DHCP6_OPTION_AUTH: | |
44 | case SD_DHCP6_OPTION_UNICAST: | |
45 | case SD_DHCP6_OPTION_STATUS_CODE: | |
46 | case SD_DHCP6_OPTION_RAPID_COMMIT: | |
47 | case SD_DHCP6_OPTION_USER_CLASS: | |
48 | case SD_DHCP6_OPTION_VENDOR_CLASS: | |
49 | return false; | |
50 | case SD_DHCP6_OPTION_VENDOR_OPTS: | |
51 | return true; | |
52 | case SD_DHCP6_OPTION_INTERFACE_ID: | |
53 | case SD_DHCP6_OPTION_RECONF_MSG: | |
54 | case SD_DHCP6_OPTION_RECONF_ACCEPT: | |
55 | return false; | |
56 | case SD_DHCP6_OPTION_SIP_SERVER_DOMAIN_NAME: | |
57 | case SD_DHCP6_OPTION_SIP_SERVER_ADDRESS: | |
58 | case SD_DHCP6_OPTION_DNS_SERVER: | |
59 | case SD_DHCP6_OPTION_DOMAIN: | |
60 | return true; | |
61 | case SD_DHCP6_OPTION_IA_PD: | |
62 | case SD_DHCP6_OPTION_IA_PD_PREFIX: | |
63 | return false; | |
64 | case SD_DHCP6_OPTION_NIS_SERVER: | |
65 | case SD_DHCP6_OPTION_NISP_SERVER: | |
66 | case SD_DHCP6_OPTION_NIS_DOMAIN_NAME: | |
67 | case SD_DHCP6_OPTION_NISP_DOMAIN_NAME: | |
68 | case SD_DHCP6_OPTION_SNTP_SERVER: | |
69 | return true; | |
70 | case SD_DHCP6_OPTION_INFORMATION_REFRESH_TIME: | |
71 | return false; /* This is automatically set when sending INFORMATION_REQUEST message. */ | |
72 | case SD_DHCP6_OPTION_BCMCS_SERVER_D: | |
73 | case SD_DHCP6_OPTION_BCMCS_SERVER_A: | |
74 | case SD_DHCP6_OPTION_GEOCONF_CIVIC: | |
75 | return true; | |
76 | case SD_DHCP6_OPTION_REMOTE_ID: | |
77 | case SD_DHCP6_OPTION_SUBSCRIBER_ID: | |
78 | return false; | |
79 | case SD_DHCP6_OPTION_CLIENT_FQDN: | |
80 | case SD_DHCP6_OPTION_PANA_AGENT: | |
81 | case SD_DHCP6_OPTION_POSIX_TIMEZONE: | |
82 | case SD_DHCP6_OPTION_TZDB_TIMEZONE: | |
83 | return true; | |
84 | case SD_DHCP6_OPTION_ERO: | |
85 | case SD_DHCP6_OPTION_LQ_QUERY: | |
86 | case SD_DHCP6_OPTION_CLIENT_DATA: | |
87 | case SD_DHCP6_OPTION_CLT_TIME: | |
88 | case SD_DHCP6_OPTION_LQ_RELAY_DATA: | |
89 | case SD_DHCP6_OPTION_LQ_CLIENT_LINK: | |
90 | return false; | |
91 | case SD_DHCP6_OPTION_MIP6_HNIDF: | |
92 | case SD_DHCP6_OPTION_MIP6_VDINF: | |
93 | case SD_DHCP6_OPTION_V6_LOST: | |
94 | case SD_DHCP6_OPTION_CAPWAP_AC_V6: | |
95 | return true; | |
96 | case SD_DHCP6_OPTION_RELAY_ID: | |
97 | return false; | |
98 | case SD_DHCP6_OPTION_IPV6_ADDRESS_MOS: | |
99 | case SD_DHCP6_OPTION_IPV6_FQDN_MOS: | |
100 | case SD_DHCP6_OPTION_NTP_SERVER: | |
101 | case SD_DHCP6_OPTION_V6_ACCESS_DOMAIN: | |
102 | case SD_DHCP6_OPTION_SIP_UA_CS_LIST: | |
103 | case SD_DHCP6_OPTION_BOOTFILE_URL: | |
104 | case SD_DHCP6_OPTION_BOOTFILE_PARAM: | |
105 | return true; | |
106 | case SD_DHCP6_OPTION_CLIENT_ARCH_TYPE: | |
107 | return false; | |
108 | case SD_DHCP6_OPTION_NII: | |
109 | case SD_DHCP6_OPTION_GEOLOCATION: | |
110 | case SD_DHCP6_OPTION_AFTR_NAME: | |
111 | case SD_DHCP6_OPTION_ERP_LOCAL_DOMAIN_NAME: | |
112 | return true; | |
113 | case SD_DHCP6_OPTION_RSOO: | |
114 | return false; | |
115 | case SD_DHCP6_OPTION_PD_EXCLUDE: | |
116 | return true; | |
117 | case SD_DHCP6_OPTION_VSS: | |
118 | return false; | |
119 | case SD_DHCP6_OPTION_MIP6_IDINF: | |
120 | case SD_DHCP6_OPTION_MIP6_UDINF: | |
121 | case SD_DHCP6_OPTION_MIP6_HNP: | |
122 | case SD_DHCP6_OPTION_MIP6_HAA: | |
123 | case SD_DHCP6_OPTION_MIP6_HAF: | |
124 | case SD_DHCP6_OPTION_RDNSS_SELECTION: | |
125 | case SD_DHCP6_OPTION_KRB_PRINCIPAL_NAME: | |
126 | case SD_DHCP6_OPTION_KRB_REALM_NAME: | |
127 | case SD_DHCP6_OPTION_KRB_DEFAULT_REALM_NAME: | |
128 | case SD_DHCP6_OPTION_KRB_KDC: | |
129 | return true; | |
130 | case SD_DHCP6_OPTION_CLIENT_LINKLAYER_ADDR: | |
131 | case SD_DHCP6_OPTION_LINK_ADDRESS: | |
132 | case SD_DHCP6_OPTION_RADIUS: | |
133 | case SD_DHCP6_OPTION_SOL_MAX_RT: /* Automatically set when sending SOLICIT message. */ | |
134 | case SD_DHCP6_OPTION_INF_MAX_RT: /* Automatically set when sending INFORMATION_REQUEST message. */ | |
135 | return false; | |
136 | case SD_DHCP6_OPTION_ADDRSEL: | |
137 | case SD_DHCP6_OPTION_ADDRSEL_TABLE: | |
138 | case SD_DHCP6_OPTION_V6_PCP_SERVER: | |
139 | return true; | |
140 | case SD_DHCP6_OPTION_DHCPV4_MSG: | |
141 | return false; | |
142 | case SD_DHCP6_OPTION_DHCP4_O_DHCP6_SERVER: | |
143 | return true; | |
144 | case SD_DHCP6_OPTION_S46_RULE: | |
145 | return false; | |
146 | case SD_DHCP6_OPTION_S46_BR: | |
147 | return true; | |
148 | case SD_DHCP6_OPTION_S46_DMR: | |
149 | case SD_DHCP6_OPTION_S46_V4V6BIND: | |
150 | case SD_DHCP6_OPTION_S46_PORTPARAMS: | |
151 | return false; | |
152 | case SD_DHCP6_OPTION_S46_CONT_MAPE: | |
153 | case SD_DHCP6_OPTION_S46_CONT_MAPT: | |
154 | case SD_DHCP6_OPTION_S46_CONT_LW: | |
155 | case SD_DHCP6_OPTION_4RD: | |
156 | case SD_DHCP6_OPTION_4RD_MAP_RULE: | |
157 | case SD_DHCP6_OPTION_4RD_NON_MAP_RULE: | |
158 | return true; | |
159 | case SD_DHCP6_OPTION_LQ_BASE_TIME: | |
160 | case SD_DHCP6_OPTION_LQ_START_TIME: | |
161 | case SD_DHCP6_OPTION_LQ_END_TIME: | |
162 | return false; | |
163 | case SD_DHCP6_OPTION_CAPTIVE_PORTAL: | |
164 | case SD_DHCP6_OPTION_MPL_PARAMETERS: | |
165 | return true; | |
166 | case SD_DHCP6_OPTION_ANI_ATT: | |
167 | case SD_DHCP6_OPTION_ANI_NETWORK_NAME: | |
168 | case SD_DHCP6_OPTION_ANI_AP_NAME: | |
169 | case SD_DHCP6_OPTION_ANI_AP_BSSID: | |
170 | case SD_DHCP6_OPTION_ANI_OPERATOR_ID: | |
171 | case SD_DHCP6_OPTION_ANI_OPERATOR_REALM: | |
172 | return false; | |
173 | case SD_DHCP6_OPTION_S46_PRIORITY: | |
174 | return true; | |
175 | case SD_DHCP6_OPTION_MUD_URL_V6: | |
176 | return false; | |
177 | case SD_DHCP6_OPTION_V6_PREFIX64: | |
178 | return true; | |
179 | case SD_DHCP6_OPTION_F_BINDING_STATUS: | |
180 | case SD_DHCP6_OPTION_F_CONNECT_FLAGS: | |
181 | case SD_DHCP6_OPTION_F_DNS_REMOVAL_INFO: | |
182 | case SD_DHCP6_OPTION_F_DNS_HOST_NAME: | |
183 | case SD_DHCP6_OPTION_F_DNS_ZONE_NAME: | |
184 | case SD_DHCP6_OPTION_F_DNS_FLAGS: | |
185 | case SD_DHCP6_OPTION_F_EXPIRATION_TIME: | |
186 | case SD_DHCP6_OPTION_F_MAX_UNACKED_BNDUPD: | |
187 | case SD_DHCP6_OPTION_F_MCLT: | |
188 | case SD_DHCP6_OPTION_F_PARTNER_LIFETIME: | |
189 | case SD_DHCP6_OPTION_F_PARTNER_LIFETIME_SENT: | |
190 | case SD_DHCP6_OPTION_F_PARTNER_DOWN_TIME: | |
191 | case SD_DHCP6_OPTION_F_PARTNER_RAW_CLT_TIME: | |
192 | case SD_DHCP6_OPTION_F_PROTOCOL_VERSION: | |
193 | case SD_DHCP6_OPTION_F_KEEPALIVE_TIME: | |
194 | case SD_DHCP6_OPTION_F_RECONFIGURE_DATA: | |
195 | case SD_DHCP6_OPTION_F_RELATIONSHIP_NAME: | |
196 | case SD_DHCP6_OPTION_F_SERVER_FLAGS: | |
197 | case SD_DHCP6_OPTION_F_SERVER_STATE: | |
198 | case SD_DHCP6_OPTION_F_START_TIME_OF_STATE: | |
199 | case SD_DHCP6_OPTION_F_STATE_EXPIRATION_TIME: | |
200 | case SD_DHCP6_OPTION_RELAY_PORT: | |
201 | return false; | |
202 | case SD_DHCP6_OPTION_V6_SZTP_REDIRECT: | |
203 | case SD_DHCP6_OPTION_S46_BIND_IPV6_PREFIX: | |
204 | return true; | |
205 | case SD_DHCP6_OPTION_IA_LL: | |
206 | case SD_DHCP6_OPTION_LLADDR: | |
207 | case SD_DHCP6_OPTION_SLAP_QUAD: | |
208 | return false; | |
209 | case SD_DHCP6_OPTION_V6_DOTS_RI: | |
210 | case SD_DHCP6_OPTION_V6_DOTS_ADDRESS: | |
211 | case SD_DHCP6_OPTION_IPV6_ADDRESS_ANDSF: | |
212 | case SD_DHCP6_OPTION_V6_DNR: | |
213 | case SD_DHCP6_OPTION_REGISTERED_DOMAIN: | |
214 | case SD_DHCP6_OPTION_FORWARD_DIST_MANAGER: | |
215 | case SD_DHCP6_OPTION_REVERSE_DIST_MANAGER: | |
216 | case SD_DHCP6_OPTION_ADDR_REG_ENABLE: | |
217 | return true; | |
218 | default: | |
219 | return false; | |
220 | } | |
221 | } | |
222 | ||
223 | static int option_append_hdr(uint8_t **buf, size_t *offset, uint16_t optcode, size_t optlen) { | |
224 | assert(buf); | |
225 | assert(*buf); | |
226 | assert(offset); | |
227 | ||
228 | if (optlen > 0xffff) | |
229 | return -ENOBUFS; | |
230 | ||
231 | if (optlen + offsetof(DHCP6Option, data) > SIZE_MAX - *offset) | |
232 | return -ENOBUFS; | |
233 | ||
234 | if (!GREEDY_REALLOC(*buf, *offset + optlen + offsetof(DHCP6Option, data))) | |
235 | return -ENOMEM; | |
236 | ||
237 | unaligned_write_be16(*buf + *offset + offsetof(DHCP6Option, code), optcode); | |
238 | unaligned_write_be16(*buf + *offset + offsetof(DHCP6Option, len), optlen); | |
239 | ||
240 | *offset += offsetof(DHCP6Option, data); | |
241 | return 0; | |
242 | } | |
243 | ||
244 | int dhcp6_option_append( | |
245 | uint8_t **buf, | |
246 | size_t *offset, | |
247 | uint16_t code, | |
248 | size_t optlen, | |
249 | const void *optval) { | |
250 | ||
251 | int r; | |
252 | ||
253 | assert(optval || optlen == 0); | |
254 | ||
255 | r = option_append_hdr(buf, offset, code, optlen); | |
256 | if (r < 0) | |
257 | return r; | |
258 | ||
259 | memcpy_safe(*buf + *offset, optval, optlen); | |
260 | *offset += optlen; | |
261 | ||
262 | return 0; | |
263 | } | |
264 | ||
265 | int dhcp6_option_append_vendor_option(uint8_t **buf, size_t *offset, OrderedSet *vendor_options) { | |
266 | sd_dhcp6_option *options; | |
267 | int r; | |
268 | ||
269 | assert(buf); | |
270 | assert(*buf); | |
271 | assert(offset); | |
272 | ||
273 | ORDERED_SET_FOREACH(options, vendor_options) { | |
274 | _cleanup_free_ uint8_t *p = NULL; | |
275 | size_t total; | |
276 | ||
277 | total = 4 + 2 + 2 + options->length; | |
278 | ||
279 | p = malloc(total); | |
280 | if (!p) | |
281 | return -ENOMEM; | |
282 | ||
283 | unaligned_write_be32(p, options->enterprise_identifier); | |
284 | unaligned_write_be16(p + 4, options->option); | |
285 | unaligned_write_be16(p + 6, options->length); | |
286 | memcpy(p + 8, options->data, options->length); | |
287 | ||
288 | r = dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_VENDOR_OPTS, total, p); | |
289 | if (r < 0) | |
290 | return r; | |
291 | } | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static int option_append_ia_address(uint8_t **buf, size_t *offset, const struct iaaddr *address) { | |
297 | assert(buf); | |
298 | assert(*buf); | |
299 | assert(offset); | |
300 | assert(address); | |
301 | ||
302 | /* Do not append T1 and T2. */ | |
303 | const struct iaaddr a = { | |
304 | .address = address->address, | |
305 | }; | |
306 | ||
307 | return dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_IAADDR, sizeof(struct iaaddr), &a); | |
308 | } | |
309 | ||
310 | static int option_append_pd_prefix(uint8_t **buf, size_t *offset, const struct iapdprefix *prefix) { | |
311 | assert(buf); | |
312 | assert(*buf); | |
313 | assert(offset); | |
314 | assert(prefix); | |
315 | ||
316 | if (prefix->prefixlen == 0) | |
317 | return -EINVAL; | |
318 | ||
319 | /* Do not append T1 and T2. */ | |
320 | const struct iapdprefix p = { | |
321 | .prefixlen = prefix->prefixlen, | |
322 | .address = prefix->address, | |
323 | }; | |
324 | ||
325 | return dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_IA_PD_PREFIX, sizeof(struct iapdprefix), &p); | |
326 | } | |
327 | ||
328 | int dhcp6_option_append_ia(uint8_t **buf, size_t *offset, const DHCP6IA *ia) { | |
329 | _cleanup_free_ uint8_t *data = NULL; | |
330 | struct ia_header header; | |
331 | size_t len; | |
332 | int r; | |
333 | ||
334 | assert(buf); | |
335 | assert(*buf); | |
336 | assert(offset); | |
337 | assert(ia); | |
338 | ||
339 | /* client should not send set T1 and T2. See, RFC 8415, and issue #18090. */ | |
340 | ||
341 | switch (ia->type) { | |
342 | case SD_DHCP6_OPTION_IA_NA: | |
343 | case SD_DHCP6_OPTION_IA_PD: | |
344 | len = sizeof(struct ia_header); | |
345 | header = (struct ia_header) { | |
346 | .id = ia->header.id, | |
347 | }; | |
348 | break; | |
349 | ||
350 | case SD_DHCP6_OPTION_IA_TA: | |
351 | len = sizeof(header.id); /* IA_TA does not have lifetime. */ | |
352 | header = (struct ia_header) { | |
353 | .id = ia->header.id, | |
354 | }; | |
355 | break; | |
356 | ||
357 | default: | |
358 | assert_not_reached(); | |
359 | } | |
360 | ||
361 | if (!GREEDY_REALLOC(data, len)) | |
362 | return -ENOMEM; | |
363 | ||
364 | memcpy(data, &header, len); | |
365 | ||
366 | LIST_FOREACH(addresses, addr, ia->addresses) { | |
367 | if (ia->type == SD_DHCP6_OPTION_IA_PD) | |
368 | r = option_append_pd_prefix(&data, &len, &addr->iapdprefix); | |
369 | else | |
370 | r = option_append_ia_address(&data, &len, &addr->iaaddr); | |
371 | if (r < 0) | |
372 | return r; | |
373 | } | |
374 | ||
375 | return dhcp6_option_append(buf, offset, ia->type, len, data); | |
376 | } | |
377 | ||
378 | int dhcp6_option_append_fqdn(uint8_t **buf, size_t *offset, const char *fqdn) { | |
379 | uint8_t buffer[1 + DNS_WIRE_FORMAT_HOSTNAME_MAX]; | |
380 | int r; | |
381 | ||
382 | assert(buf); | |
383 | assert(*buf); | |
384 | assert(offset); | |
385 | ||
386 | if (isempty(fqdn)) | |
387 | return 0; | |
388 | ||
389 | buffer[0] = DHCP6_FQDN_FLAG_S; /* Request server to perform AAAA RR DNS updates */ | |
390 | ||
391 | /* Store domain name after flags field */ | |
392 | r = dns_name_to_wire_format(fqdn, buffer + 1, sizeof(buffer) - 1, false); | |
393 | if (r <= 0) | |
394 | return r; | |
395 | ||
396 | /* | |
397 | * According to RFC 4704, chapter 4.2 only add terminating zero-length | |
398 | * label in case a FQDN is provided. Since dns_name_to_wire_format | |
399 | * always adds terminating zero-length label remove if only a hostname | |
400 | * is provided. | |
401 | */ | |
402 | if (dns_name_is_single_label(fqdn)) | |
403 | r--; | |
404 | ||
405 | return dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_CLIENT_FQDN, 1 + r, buffer); | |
406 | } | |
407 | ||
408 | int dhcp6_option_append_user_class(uint8_t **buf, size_t *offset, char * const *user_class) { | |
409 | _cleanup_free_ uint8_t *p = NULL; | |
410 | size_t n = 0; | |
411 | ||
412 | assert(buf); | |
413 | assert(*buf); | |
414 | assert(offset); | |
415 | ||
416 | if (strv_isempty(user_class)) | |
417 | return 0; | |
418 | ||
419 | STRV_FOREACH(s, user_class) { | |
420 | size_t len = strlen(*s); | |
421 | ||
422 | if (len > UINT16_MAX || len == 0) | |
423 | return -EINVAL; | |
424 | ||
425 | if (!GREEDY_REALLOC(p, n + len + 2)) | |
426 | return -ENOMEM; | |
427 | ||
428 | unaligned_write_be16(p + n, len); | |
429 | memcpy(p + n + 2, *s, len); | |
430 | n += len + 2; | |
431 | } | |
432 | ||
433 | return dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_USER_CLASS, n, p); | |
434 | } | |
435 | ||
436 | int dhcp6_option_append_vendor_class(uint8_t **buf, size_t *offset, char * const *vendor_class) { | |
437 | _cleanup_free_ uint8_t *p = NULL; | |
438 | size_t n = 0; | |
439 | ||
440 | assert(buf); | |
441 | assert(*buf); | |
442 | assert(offset); | |
443 | ||
444 | if (strv_isempty(vendor_class)) | |
445 | return 0; | |
446 | ||
447 | if (!GREEDY_REALLOC(p, sizeof(be32_t))) | |
448 | return -ENOMEM; | |
449 | ||
450 | /* Enterprise Identifier */ | |
451 | unaligned_write_be32(p, SYSTEMD_PEN); | |
452 | n += sizeof(be32_t); | |
453 | ||
454 | STRV_FOREACH(s, vendor_class) { | |
455 | size_t len = strlen(*s); | |
456 | ||
457 | if (len > UINT16_MAX || len == 0) | |
458 | return -EINVAL; | |
459 | ||
460 | if (!GREEDY_REALLOC(p, n + len + 2)) | |
461 | return -ENOMEM; | |
462 | ||
463 | unaligned_write_be16(p + n, len); | |
464 | memcpy(p + n + 2, *s, len); | |
465 | n += len + 2; | |
466 | } | |
467 | ||
468 | return dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_VENDOR_CLASS, n, p); | |
469 | } | |
470 | ||
471 | int dhcp6_option_parse( | |
472 | const uint8_t *buf, | |
473 | size_t buflen, | |
474 | size_t *offset, | |
475 | uint16_t *ret_option_code, | |
476 | size_t *ret_option_data_len, | |
477 | const uint8_t **ret_option_data) { | |
478 | ||
479 | size_t len; | |
480 | ||
481 | assert(buf); | |
482 | assert(offset); | |
483 | assert(ret_option_code); | |
484 | assert(ret_option_data_len); | |
485 | assert(ret_option_data); | |
486 | ||
487 | if (buflen < offsetof(DHCP6Option, data)) | |
488 | return -EBADMSG; | |
489 | ||
490 | if (*offset > buflen - offsetof(DHCP6Option, data)) | |
491 | return -EBADMSG; | |
492 | ||
493 | len = unaligned_read_be16(buf + *offset + offsetof(DHCP6Option, len)); | |
494 | ||
495 | if (len > buflen - offsetof(DHCP6Option, data) - *offset) | |
496 | return -EBADMSG; | |
497 | ||
498 | *ret_option_code = unaligned_read_be16(buf + *offset + offsetof(DHCP6Option, code)); | |
499 | *ret_option_data_len = len; | |
500 | *ret_option_data = len == 0 ? NULL : buf + *offset + offsetof(DHCP6Option, data); | |
501 | *offset += offsetof(DHCP6Option, data) + len; | |
502 | ||
503 | return 0; | |
504 | } | |
505 | ||
506 | int dhcp6_option_parse_status(const uint8_t *data, size_t data_len, char **ret_status_message) { | |
507 | DHCP6Status status; | |
508 | ||
509 | assert(data || data_len == 0); | |
510 | ||
511 | if (data_len < sizeof(uint16_t)) | |
512 | return -EBADMSG; | |
513 | ||
514 | status = unaligned_read_be16(data); | |
515 | ||
516 | if (ret_status_message) { | |
517 | _cleanup_free_ char *msg = NULL; | |
518 | const char *s; | |
519 | ||
520 | /* The status message MUST NOT be null-terminated. See section 21.13 of RFC8415. | |
521 | * Let's escape unsafe characters for safety. */ | |
522 | msg = cescape_length((const char*) (data + sizeof(uint16_t)), data_len - sizeof(uint16_t)); | |
523 | if (!msg) | |
524 | return -ENOMEM; | |
525 | ||
526 | s = dhcp6_message_status_to_string(status); | |
527 | if (s && !strextend_with_separator(&msg, ": ", s)) | |
528 | return -ENOMEM; | |
529 | ||
530 | *ret_status_message = TAKE_PTR(msg); | |
531 | } | |
532 | ||
533 | return status; | |
534 | } | |
535 | ||
536 | /* parse a string from dhcp option field. *ret must be initialized */ | |
537 | int dhcp6_option_parse_string(const uint8_t *data, size_t data_len, char **ret) { | |
538 | _cleanup_free_ char *string = NULL; | |
539 | int r; | |
540 | ||
541 | assert(data || data_len == 0); | |
542 | assert(ret); | |
543 | ||
544 | if (data_len <= 0) { | |
545 | *ret = mfree(*ret); | |
546 | return 0; | |
547 | } | |
548 | ||
549 | r = make_cstring((const char *) data, data_len, MAKE_CSTRING_REFUSE_TRAILING_NUL, &string); | |
550 | if (r < 0) | |
551 | return r; | |
552 | ||
553 | return free_and_replace(*ret, string); | |
554 | } | |
555 | ||
556 | static int dhcp6_option_parse_ia_options(sd_dhcp6_client *client, const uint8_t *buf, size_t buflen) { | |
557 | int r; | |
558 | ||
559 | assert(buf || buflen == 0); | |
560 | ||
561 | for (size_t offset = 0; offset < buflen;) { | |
562 | const uint8_t *data; | |
563 | size_t data_len; | |
564 | uint16_t code; | |
565 | ||
566 | r = dhcp6_option_parse(buf, buflen, &offset, &code, &data_len, &data); | |
567 | if (r < 0) | |
568 | return r; | |
569 | ||
570 | switch (code) { | |
571 | case SD_DHCP6_OPTION_STATUS_CODE: { | |
572 | _cleanup_free_ char *msg = NULL; | |
573 | ||
574 | r = dhcp6_option_parse_status(data, data_len, &msg); | |
575 | if (r == -ENOMEM) | |
576 | return r; | |
577 | if (r > 0) | |
578 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
579 | "Received an IA address or PD prefix option with non-zero status%s%s", | |
580 | isempty(msg) ? "." : ": ", strempty(msg)); | |
581 | if (r < 0) | |
582 | /* Let's log but ignore the invalid status option. */ | |
583 | log_dhcp6_client_errno(client, r, | |
584 | "Received an IA address or PD prefix option with an invalid status sub option, ignoring: %m"); | |
585 | break; | |
586 | } | |
587 | default: | |
588 | log_dhcp6_client(client, "Received an unknown sub option %u in IA address or PD prefix, ignoring.", code); | |
589 | } | |
590 | } | |
591 | ||
592 | return 0; | |
593 | } | |
594 | ||
595 | static int dhcp6_option_parse_ia_address(sd_dhcp6_client *client, DHCP6IA *ia, const uint8_t *data, size_t len) { | |
596 | _cleanup_free_ DHCP6Address *a = NULL; | |
597 | usec_t lt_valid, lt_pref; | |
598 | int r; | |
599 | ||
600 | assert(ia); | |
601 | assert(data || len == 0); | |
602 | ||
603 | if (!IN_SET(ia->type, SD_DHCP6_OPTION_IA_NA, SD_DHCP6_OPTION_IA_TA)) | |
604 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
605 | "Received an IA address sub-option in an invalid option, ignoring."); | |
606 | ||
607 | if (len < sizeof(struct iaaddr)) | |
608 | return -EBADMSG; | |
609 | ||
610 | a = new(DHCP6Address, 1); | |
611 | if (!a) | |
612 | return -ENOMEM; | |
613 | ||
614 | memcpy(&a->iaaddr, data, sizeof(struct iaaddr)); | |
615 | ||
616 | lt_valid = be32_sec_to_usec(a->iaaddr.lifetime_valid, /* max_as_infinity = */ true); | |
617 | lt_pref = be32_sec_to_usec(a->iaaddr.lifetime_preferred, /* max_as_infinity = */ true); | |
618 | ||
619 | if (lt_valid == 0) | |
620 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
621 | "Received an IA address with zero valid lifetime, ignoring."); | |
622 | if (lt_pref > lt_valid) | |
623 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
624 | "Received an IA address with preferred lifetime %s " | |
625 | "larger than valid lifetime %s, ignoring.", | |
626 | FORMAT_TIMESPAN(lt_pref, USEC_PER_SEC), | |
627 | FORMAT_TIMESPAN(lt_valid, USEC_PER_SEC)); | |
628 | ||
629 | if (len > sizeof(struct iaaddr)) { | |
630 | r = dhcp6_option_parse_ia_options(client, data + sizeof(struct iaaddr), len - sizeof(struct iaaddr)); | |
631 | if (r < 0) | |
632 | return r; | |
633 | } | |
634 | ||
635 | LIST_PREPEND(addresses, ia->addresses, TAKE_PTR(a)); | |
636 | return 0; | |
637 | } | |
638 | ||
639 | static int dhcp6_option_parse_ia_pdprefix(sd_dhcp6_client *client, DHCP6IA *ia, const uint8_t *data, size_t len) { | |
640 | _cleanup_free_ DHCP6Address *a = NULL; | |
641 | usec_t lt_valid, lt_pref; | |
642 | int r; | |
643 | ||
644 | assert(ia); | |
645 | assert(data || len == 0); | |
646 | ||
647 | if (ia->type != SD_DHCP6_OPTION_IA_PD) | |
648 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
649 | "Received an PD prefix sub-option in an invalid option, ignoring"); | |
650 | ||
651 | if (len < sizeof(struct iapdprefix)) | |
652 | return -EBADMSG; | |
653 | ||
654 | a = new(DHCP6Address, 1); | |
655 | if (!a) | |
656 | return -ENOMEM; | |
657 | ||
658 | memcpy(&a->iapdprefix, data, sizeof(struct iapdprefix)); | |
659 | ||
660 | lt_valid = be32_sec_to_usec(a->iapdprefix.lifetime_valid, /* max_as_infinity = */ true); | |
661 | lt_pref = be32_sec_to_usec(a->iapdprefix.lifetime_preferred, /* max_as_infinity = */ true); | |
662 | ||
663 | if (lt_valid == 0) | |
664 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
665 | "Received a PD prefix with zero valid lifetime, ignoring."); | |
666 | if (lt_pref > lt_valid) | |
667 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
668 | "Received a PD prefix with preferred lifetime %s " | |
669 | "larger than valid lifetime %s, ignoring.", | |
670 | FORMAT_TIMESPAN(lt_pref, USEC_PER_SEC), | |
671 | FORMAT_TIMESPAN(lt_valid, USEC_PER_SEC)); | |
672 | ||
673 | if (len > sizeof(struct iapdprefix)) { | |
674 | r = dhcp6_option_parse_ia_options(client, data + sizeof(struct iapdprefix), len - sizeof(struct iapdprefix)); | |
675 | if (r < 0) | |
676 | return r; | |
677 | } | |
678 | ||
679 | LIST_PREPEND(addresses, ia->addresses, TAKE_PTR(a)); | |
680 | return 0; | |
681 | } | |
682 | ||
683 | int dhcp6_option_parse_ia( | |
684 | sd_dhcp6_client *client, | |
685 | be32_t iaid, | |
686 | uint16_t option_code, | |
687 | size_t option_data_len, | |
688 | const uint8_t *option_data, | |
689 | DHCP6IA **ret) { | |
690 | ||
691 | _cleanup_(dhcp6_ia_freep) DHCP6IA *ia = NULL; | |
692 | usec_t lt_t1, lt_t2; | |
693 | size_t header_len; | |
694 | int r; | |
695 | ||
696 | assert(IN_SET(option_code, SD_DHCP6_OPTION_IA_NA, SD_DHCP6_OPTION_IA_TA, SD_DHCP6_OPTION_IA_PD)); | |
697 | assert(option_data || option_data_len == 0); | |
698 | assert(ret); | |
699 | ||
700 | /* This will return the following: | |
701 | * -ENOMEM: memory allocation error, | |
702 | * -ENOANO: unmatching IAID, | |
703 | * -EINVAL: non-zero status code, or invalid lifetime, | |
704 | * -EBADMSG: invalid message format, | |
705 | * -ENODATA: no valid address or PD prefix, | |
706 | * 0: success. */ | |
707 | ||
708 | switch (option_code) { | |
709 | case SD_DHCP6_OPTION_IA_NA: | |
710 | case SD_DHCP6_OPTION_IA_PD: | |
711 | header_len = sizeof(struct ia_header); | |
712 | break; | |
713 | ||
714 | case SD_DHCP6_OPTION_IA_TA: | |
715 | header_len = sizeof(be32_t); /* IA_TA does not have lifetime. */ | |
716 | break; | |
717 | ||
718 | default: | |
719 | assert_not_reached(); | |
720 | } | |
721 | ||
722 | if (option_data_len < header_len) | |
723 | return -EBADMSG; | |
724 | ||
725 | ia = new(DHCP6IA, 1); | |
726 | if (!ia) | |
727 | return -ENOMEM; | |
728 | ||
729 | *ia = (DHCP6IA) { | |
730 | .type = option_code, | |
731 | }; | |
732 | memcpy(&ia->header, option_data, header_len); | |
733 | ||
734 | /* According to RFC8415, IAs which do not match the client's IAID should be ignored, | |
735 | * but not necessary to ignore or refuse the whole message. */ | |
736 | if (ia->header.id != iaid) | |
737 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(ENOANO), | |
738 | "Received an IA option with a different IAID " | |
739 | "from the one chosen by the client, ignoring."); | |
740 | ||
741 | /* It is not necessary to check if the lifetime_t2 is zero here, as in that case it will be updated later. */ | |
742 | lt_t1 = be32_sec_to_usec(ia->header.lifetime_t1, /* max_as_infinity = */ true); | |
743 | lt_t2 = be32_sec_to_usec(ia->header.lifetime_t2, /* max_as_infinity = */ true); | |
744 | ||
745 | if (lt_t1 > lt_t2) | |
746 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
747 | "Received an IA option with T1 %s > T2 %s, ignoring.", | |
748 | FORMAT_TIMESPAN(lt_t1, USEC_PER_SEC), | |
749 | FORMAT_TIMESPAN(lt_t2, USEC_PER_SEC)); | |
750 | if (lt_t1 == 0 && lt_t2 > 0) | |
751 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
752 | "Received an IA option with zero T1 and non-zero T2 (%s), ignoring.", | |
753 | FORMAT_TIMESPAN(lt_t2, USEC_PER_SEC)); | |
754 | ||
755 | for (size_t offset = header_len; offset < option_data_len;) { | |
756 | const uint8_t *subdata; | |
757 | size_t subdata_len; | |
758 | uint16_t subopt; | |
759 | ||
760 | r = dhcp6_option_parse(option_data, option_data_len, &offset, &subopt, &subdata_len, &subdata); | |
761 | if (r < 0) | |
762 | return r; | |
763 | ||
764 | switch (subopt) { | |
765 | case SD_DHCP6_OPTION_IAADDR: { | |
766 | r = dhcp6_option_parse_ia_address(client, ia, subdata, subdata_len); | |
767 | if (r == -ENOMEM) | |
768 | return r; | |
769 | ||
770 | /* Ignore non-critical errors in the sub-option. */ | |
771 | break; | |
772 | } | |
773 | case SD_DHCP6_OPTION_IA_PD_PREFIX: { | |
774 | r = dhcp6_option_parse_ia_pdprefix(client, ia, subdata, subdata_len); | |
775 | if (r == -ENOMEM) | |
776 | return r; | |
777 | ||
778 | /* Ignore non-critical errors in the sub-option. */ | |
779 | break; | |
780 | } | |
781 | case SD_DHCP6_OPTION_STATUS_CODE: { | |
782 | _cleanup_free_ char *msg = NULL; | |
783 | ||
784 | r = dhcp6_option_parse_status(subdata, subdata_len, &msg); | |
785 | if (r == -ENOMEM) | |
786 | return r; | |
787 | if (r > 0) | |
788 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), | |
789 | "Received an IA option with non-zero status%s%s", | |
790 | isempty(msg) ? "." : ": ", strempty(msg)); | |
791 | if (r < 0) | |
792 | log_dhcp6_client_errno(client, r, | |
793 | "Received an IA option with an invalid status sub option, ignoring: %m"); | |
794 | break; | |
795 | } | |
796 | default: | |
797 | log_dhcp6_client(client, "Received an IA option with an unknown sub-option %u, ignoring", subopt); | |
798 | } | |
799 | } | |
800 | ||
801 | if (!ia->addresses) | |
802 | return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(ENODATA), | |
803 | "Received an IA option without valid IA addresses or PD prefixes, ignoring."); | |
804 | ||
805 | *ret = TAKE_PTR(ia); | |
806 | return 0; | |
807 | } | |
808 | ||
809 | int dhcp6_option_parse_addresses( | |
810 | const uint8_t *optval, | |
811 | size_t optlen, | |
812 | struct in6_addr **addrs, | |
813 | size_t *count) { | |
814 | ||
815 | assert(optval || optlen == 0); | |
816 | assert(addrs); | |
817 | assert(count); | |
818 | ||
819 | if (optlen == 0 || optlen % sizeof(struct in6_addr) != 0) | |
820 | return -EBADMSG; | |
821 | ||
822 | if (!GREEDY_REALLOC(*addrs, *count + optlen / sizeof(struct in6_addr))) | |
823 | return -ENOMEM; | |
824 | ||
825 | memcpy(*addrs + *count, optval, optlen); | |
826 | *count += optlen / sizeof(struct in6_addr); | |
827 | ||
828 | return 0; | |
829 | } | |
830 | ||
831 | int dhcp6_option_parse_domainname(const uint8_t *optval, size_t optlen, char **ret) { | |
832 | _cleanup_free_ char *domain = NULL; | |
833 | int r; | |
834 | ||
835 | assert(optval || optlen == 0); | |
836 | assert(ret); | |
837 | ||
838 | r = dns_name_from_wire_format(&optval, &optlen, &domain); | |
839 | if (r < 0) | |
840 | return r; | |
841 | if (r == 0) | |
842 | return -ENODATA; | |
843 | if (optlen != 0) | |
844 | return -EINVAL; | |
845 | ||
846 | *ret = TAKE_PTR(domain); | |
847 | return 0; | |
848 | } | |
849 | ||
850 | int dhcp6_option_parse_domainname_list(const uint8_t *optval, size_t optlen, char ***ret) { | |
851 | _cleanup_strv_free_ char **names = NULL; | |
852 | int r; | |
853 | ||
854 | assert(optval || optlen == 0); | |
855 | assert(ret); | |
856 | ||
857 | if (optlen <= 1) | |
858 | return -ENODATA; | |
859 | if (optval[optlen - 1] != '\0') | |
860 | return -EINVAL; | |
861 | ||
862 | while (optlen > 0) { | |
863 | _cleanup_free_ char *name = NULL; | |
864 | ||
865 | r = dns_name_from_wire_format(&optval, &optlen, &name); | |
866 | if (r < 0) | |
867 | return r; | |
868 | if (dns_name_is_root(name)) /* root domain */ | |
869 | return -EBADMSG; | |
870 | ||
871 | r = strv_consume(&names, TAKE_PTR(name)); | |
872 | if (r < 0) | |
873 | return r; | |
874 | } | |
875 | ||
876 | *ret = TAKE_PTR(names); | |
877 | return 0; | |
878 | } | |
879 | ||
880 | static sd_dhcp6_option* dhcp6_option_free(sd_dhcp6_option *i) { | |
881 | if (!i) | |
882 | return NULL; | |
883 | ||
884 | free(i->data); | |
885 | return mfree(i); | |
886 | } | |
887 | ||
888 | int sd_dhcp6_option_new(uint16_t option, const void *data, size_t length, uint32_t enterprise_identifier, sd_dhcp6_option **ret) { | |
889 | assert_return(ret, -EINVAL); | |
890 | assert_return(length == 0 || data, -EINVAL); | |
891 | ||
892 | _cleanup_free_ void *q = memdup(data, length); | |
893 | if (!q) | |
894 | return -ENOMEM; | |
895 | ||
896 | sd_dhcp6_option *p = new(sd_dhcp6_option, 1); | |
897 | if (!p) | |
898 | return -ENOMEM; | |
899 | ||
900 | *p = (sd_dhcp6_option) { | |
901 | .n_ref = 1, | |
902 | .option = option, | |
903 | .enterprise_identifier = enterprise_identifier, | |
904 | .length = length, | |
905 | .data = TAKE_PTR(q), | |
906 | }; | |
907 | ||
908 | *ret = p; | |
909 | return 0; | |
910 | } | |
911 | ||
912 | DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp6_option, sd_dhcp6_option, dhcp6_option_free); | |
913 | DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR( | |
914 | dhcp6_option_hash_ops, | |
915 | void, | |
916 | trivial_hash_func, | |
917 | trivial_compare_func, | |
918 | sd_dhcp6_option, | |
919 | sd_dhcp6_option_unref); |