2 Unix SMB/CIFS implementation.
4 manipulate dns name structures
6 Copyright (C) 2010 Kai Blin <kai@samba.org>
8 Heavily based on nbtname.c which is:
10 Copyright (C) Andrew Tridgell 2005
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation; either version 3 of the License, or
15 (at your option) any later version.
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
22 You should have received a copy of the GNU General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>.
27 see rfc1002 for the detailed format of compressed names
31 #include "librpc/gen_ndr/ndr_dns.h"
32 #include "librpc/gen_ndr/ndr_misc.h"
33 #include "system/locale.h"
34 #include "lib/util/util_net.h"
36 /* don't allow an unlimited number of name components */
37 #define MAX_COMPONENTS 128
42 _PUBLIC_ void ndr_print_dns_string(struct ndr_print *ndr,
46 ndr_print_string(ndr, name, s);
50 pull one component of a dns_string
52 static enum ndr_err_code ndr_pull_component(struct ndr_pull *ndr,
58 unsigned int loops = 0;
60 if (*offset >= ndr->data_size) {
61 return ndr_pull_error(ndr, NDR_ERR_STRING,
62 "BAD DNS NAME component, bad offset");
64 len = ndr->data[*offset];
67 *max_offset = MAX(*max_offset, *offset);
69 return NDR_ERR_SUCCESS;
71 if ((len & 0xC0) == 0xC0) {
72 /* its a label pointer */
73 if (1 + *offset >= ndr->data_size) {
74 return ndr_pull_error(ndr, NDR_ERR_STRING,
75 "BAD DNS NAME component, " \
78 *max_offset = MAX(*max_offset, *offset + 2);
79 *offset = ((len&0x3F)<<8) | ndr->data[1 + *offset];
80 *max_offset = MAX(*max_offset, *offset);
84 if ((len & 0xC0) != 0) {
85 /* its a reserved length field */
86 return ndr_pull_error(ndr, NDR_ERR_STRING,
87 "BAD DNS NAME component, " \
88 "reserved lenght field: 0x%02x",
91 if (*offset + len + 2 > ndr->data_size) {
92 return ndr_pull_error(ndr, NDR_ERR_STRING,
93 "BAD DNS NAME component, "\
96 *component = (uint8_t*)talloc_strndup(ndr,
97 (const char *)&ndr->data[1 + *offset], len);
98 NDR_ERR_HAVE_NO_MEMORY(*component);
100 *max_offset = MAX(*max_offset, *offset);
101 return NDR_ERR_SUCCESS;
104 /* too many pointers */
105 return ndr_pull_error(ndr, NDR_ERR_STRING,
106 "BAD DNS NAME component, too many pointers");
110 pull a dns_string from the wire
112 _PUBLIC_ enum ndr_err_code ndr_pull_dns_string(struct ndr_pull *ndr,
116 uint32_t offset = ndr->offset;
117 uint32_t max_offset = offset;
118 unsigned num_components;
121 if (!(ndr_flags & NDR_SCALARS)) {
122 return NDR_ERR_SUCCESS;
125 name = talloc_strdup(ndr->current_mem_ctx, "");
127 /* break up name into a list of components */
128 for (num_components=0; num_components<MAX_COMPONENTS;
130 uint8_t *component = NULL;
131 NDR_CHECK(ndr_pull_component(ndr, &component, &offset,
133 if (component == NULL) break;
134 if (num_components > 0) {
135 name = talloc_asprintf_append_buffer(name, ".%s",
138 name = talloc_asprintf_append_buffer(name, "%s",
141 NDR_ERR_HAVE_NO_MEMORY(name);
143 if (num_components == MAX_COMPONENTS) {
144 return ndr_pull_error(ndr, NDR_ERR_STRING,
145 "BAD DNS NAME too many components");
149 ndr->offset = max_offset;
151 return NDR_ERR_SUCCESS;
155 push a dns string to the wire
157 _PUBLIC_ enum ndr_err_code ndr_push_dns_string(struct ndr_push *ndr,
161 if (!(ndr_flags & NDR_SCALARS)) {
162 return NDR_ERR_SUCCESS;
166 enum ndr_err_code ndr_err;
171 /* see if we have pushed the remaing string allready,
172 * if so we use a label pointer to this string
174 ndr_err = ndr_token_retrieve_cmp_fn(&ndr->dns_string_list, s,
176 (comparison_fn_t)strcmp,
178 if (NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
181 if (offset > 0x3FFF) {
182 return ndr_push_error(ndr, NDR_ERR_STRING,
183 "offset for dns string " \
185 "%u[%08X] > 0x00003FFF",
189 b[0] = 0xC0 | (offset>>8);
190 b[1] = (offset & 0xFF);
192 return ndr_push_bytes(ndr, b, 2);
195 complen = strcspn(s, ".");
197 /* we need to make sure the length fits into 6 bytes */
198 if (complen > 0x3F) {
199 return ndr_push_error(ndr, NDR_ERR_STRING,
200 "component length %u[%08X] > " \
206 compname = talloc_asprintf(ndr, "%c%*.*s",
207 (unsigned char)complen,
208 (unsigned char)complen,
209 (unsigned char)complen, s);
210 NDR_ERR_HAVE_NO_MEMORY(compname);
212 /* remember the current componemt + the rest of the string
213 * so it can be reused later
215 NDR_CHECK(ndr_token_store(ndr, &ndr->dns_string_list, s,
218 /* push just this component into the blob */
219 NDR_CHECK(ndr_push_bytes(ndr, (const uint8_t *)compname,
221 talloc_free(compname);
227 /* if we reach the end of the string and have pushed the last component
228 * without using a label pointer, we need to terminate the string
230 return ndr_push_bytes(ndr, (const uint8_t *)"", 1);
233 _PUBLIC_ enum ndr_err_code ndr_push_dns_res_rec(struct ndr_push *ndr,
235 const struct dns_res_rec *r)
237 uint32_t _flags_save_STRUCT = ndr->flags;
238 uint32_t _saved_offset1, _saved_offset2;
240 ndr_set_flags(&ndr->flags, LIBNDR_PRINT_ARRAY_HEX |
241 LIBNDR_FLAG_NOALIGN);
242 if (ndr_flags & NDR_SCALARS) {
243 NDR_CHECK(ndr_push_align(ndr, 4));
244 NDR_CHECK(ndr_push_dns_string(ndr, NDR_SCALARS, r->name));
245 NDR_CHECK(ndr_push_dns_qtype(ndr, NDR_SCALARS, r->rr_type));
246 NDR_CHECK(ndr_push_dns_qclass(ndr, NDR_SCALARS, r->rr_class));
247 NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, r->ttl));
248 _saved_offset1 = ndr->offset;
249 NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, 0));
251 NDR_CHECK(ndr_push_set_switch_value(ndr, &r->rdata,
253 NDR_CHECK(ndr_push_dns_rdata(ndr, NDR_SCALARS,
255 if (r->unexpected.length > 0) {
256 return ndr_push_error(ndr,
258 "Invalid...Unexpected " \
259 "blob lenght is too " \
263 if (r->unexpected.length > UINT16_MAX) {
264 return ndr_push_error(ndr, NDR_ERR_LENGTH,
265 "Unexpected blob lenght "\
269 NDR_CHECK(ndr_push_bytes(ndr, r->unexpected.data,
270 r->unexpected.length));
271 NDR_CHECK(ndr_push_trailer_align(ndr, 4));
272 length = ndr->offset - (_saved_offset1 + 2);
273 _saved_offset2 = ndr->offset;
274 ndr->offset = _saved_offset1;
275 NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, length));
276 ndr->offset = _saved_offset2;
278 if (ndr_flags & NDR_BUFFERS) {
279 NDR_CHECK(ndr_push_dns_rdata(ndr, NDR_BUFFERS,
282 ndr->flags = _flags_save_STRUCT;
283 return NDR_ERR_SUCCESS;
286 _PUBLIC_ enum ndr_err_code ndr_pull_dns_res_rec(struct ndr_pull *ndr,
288 struct dns_res_rec *r)
290 uint32_t _flags_save_STRUCT = ndr->flags;
291 uint32_t _saved_offset1;
292 uint32_t pad, length;
294 ndr_set_flags(&ndr->flags, LIBNDR_PRINT_ARRAY_HEX |
295 LIBNDR_FLAG_NOALIGN);
296 if (ndr_flags & NDR_SCALARS) {
297 NDR_CHECK(ndr_pull_align(ndr, 4));
298 NDR_CHECK(ndr_pull_dns_string(ndr, NDR_SCALARS, &r->name));
299 NDR_CHECK(ndr_pull_dns_qtype(ndr, NDR_SCALARS, &r->rr_type));
300 NDR_CHECK(ndr_pull_dns_qclass(ndr, NDR_SCALARS, &r->rr_class));
301 NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &r->ttl));
302 NDR_CHECK(ndr_pull_uint16(ndr, NDR_SCALARS, &r->length));
303 _saved_offset1 = ndr->offset;
305 NDR_CHECK(ndr_pull_set_switch_value(ndr, &r->rdata,
307 NDR_CHECK(ndr_pull_dns_rdata(ndr, NDR_SCALARS,
310 ZERO_STRUCT(r->rdata);
312 length = ndr->offset - _saved_offset1;
313 if (length > r->length) {
314 return ndr_pull_error(ndr, NDR_ERR_LENGTH, "TODO");
317 r->unexpected = data_blob_null;
318 pad = r->length - length;
320 NDR_PULL_NEED_BYTES(ndr, pad);
321 r->unexpected = data_blob_talloc(ndr->current_mem_ctx,
325 if (r->unexpected.data == NULL) {
326 return ndr_pull_error(ndr,
328 "Failed to allocate a " \
335 NDR_CHECK(ndr_pull_trailer_align(ndr, 4));
337 if (ndr_flags & NDR_BUFFERS) {
338 NDR_CHECK(ndr_pull_dns_rdata(ndr, NDR_BUFFERS, &r->rdata));
340 ndr->flags = _flags_save_STRUCT;
341 return NDR_ERR_SUCCESS;