LCOV - code coverage report
Current view: top level - librpc/ndr - ndr_dns.c (source / functions) Hit Total Coverage
Test: coverage report for master 2b515b7d Lines: 135 151 89.4 %
Date: 2024-02-28 12:06:22 Functions: 7 7 100.0 %

          Line data    Source code
       1             : /*
       2             :    Unix SMB/CIFS implementation.
       3             : 
       4             :    manipulate dns name structures
       5             : 
       6             :    Copyright (C) 2010 Kai Blin  <kai@samba.org>
       7             : 
       8             :    Heavily based on nbtname.c which is:
       9             : 
      10             :    Copyright (C) Andrew Tridgell 2005
      11             : 
      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.
      16             : 
      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.
      21             : 
      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/>.
      24             : */
      25             : 
      26             : /*
      27             :   see rfc1002 for the detailed format of compressed names
      28             : */
      29             : 
      30             : #include "includes.h"
      31             : #include "librpc/gen_ndr/ndr_dns.h"
      32             : #include "librpc/gen_ndr/ndr_misc.h"
      33             : #include "librpc/gen_ndr/ndr_dnsp.h"
      34             : #include "system/locale.h"
      35             : #include "lib/util/util_net.h"
      36             : #include "ndr_dns_utils.h"
      37             : 
      38             : /* don't allow an unlimited number of name components */
      39             : #define MAX_COMPONENTS 128
      40             : 
      41             : /**
      42             :   print a dns string
      43             : */
      44           6 : _PUBLIC_ void ndr_print_dns_string(struct ndr_print *ndr,
      45             :                                    const char *name,
      46             :                                    const char *s)
      47             : {
      48           6 :         ndr_print_string(ndr, name, s);
      49           6 : }
      50             : 
      51             : /*
      52             :   pull one component of a dns_string
      53             : */
      54      199345 : static enum ndr_err_code ndr_pull_component(struct ndr_pull *ndr,
      55             :                                             uint8_t **component,
      56             :                                             uint32_t *offset,
      57             :                                             uint32_t *max_offset)
      58             : {
      59         276 :         uint8_t len;
      60      199345 :         unsigned int loops = 0;
      61      219427 :         while (loops < 5) {
      62      219427 :                 if (*offset >= ndr->data_size) {
      63           0 :                         return ndr_pull_error(ndr, NDR_ERR_STRING,
      64             :                                         "BAD DNS NAME component, bad offset");
      65             :                 }
      66      219427 :                 len = ndr->data[*offset];
      67      219427 :                 if (len == 0) {
      68       34267 :                         *offset += 1;
      69       34267 :                         *max_offset = MAX(*max_offset, *offset);
      70       34267 :                         *component = NULL;
      71       34267 :                         return NDR_ERR_SUCCESS;
      72             :                 }
      73      185160 :                 if ((len & 0xC0) == 0xC0) {
      74             :                         /* its a label pointer */
      75       20082 :                         if (1 + *offset >= ndr->data_size) {
      76           0 :                                 return ndr_pull_error(ndr, NDR_ERR_STRING,
      77             :                                                 "BAD DNS NAME component, " \
      78             :                                                 "bad label offset");
      79             :                         }
      80       20082 :                         *max_offset = MAX(*max_offset, *offset + 2);
      81       20082 :                         *offset = ((len&0x3F)<<8) | ndr->data[1 + *offset];
      82       20082 :                         *max_offset = MAX(*max_offset, *offset);
      83       20082 :                         loops++;
      84       20082 :                         continue;
      85             :                 }
      86      165078 :                 if ((len & 0xC0) != 0) {
      87             :                         /* its a reserved length field */
      88           0 :                         return ndr_pull_error(ndr, NDR_ERR_STRING,
      89             :                                               "BAD DNS NAME component, " \
      90             :                                               "reserved length field: 0x%02"PRIx8,
      91             :                                               (len &0xC));
      92             :                 }
      93      165078 :                 if (*offset + len + 1 > ndr->data_size) {
      94           0 :                         return ndr_pull_error(ndr, NDR_ERR_STRING,
      95             :                                               "BAD DNS NAME component, "\
      96             :                                               "length too long");
      97             :                 }
      98      330156 :                 *component = (uint8_t*)talloc_strndup(ndr,
      99      165078 :                                 (const char *)&ndr->data[1 + *offset], len);
     100      165078 :                 NDR_ERR_HAVE_NO_MEMORY(*component);
     101      165078 :                 *offset += len + 1;
     102      165078 :                 *max_offset = MAX(*max_offset, *offset);
     103      165078 :                 return NDR_ERR_SUCCESS;
     104             :         }
     105             : 
     106             :         /* too many pointers */
     107           0 :         return ndr_pull_error(ndr, NDR_ERR_STRING,
     108             :                               "BAD DNS NAME component, too many pointers");
     109             : }
     110             : 
     111             : /**
     112             :   pull a dns_string from the wire
     113             : */
     114       34267 : _PUBLIC_ enum ndr_err_code ndr_pull_dns_string(struct ndr_pull *ndr,
     115             :                                                ndr_flags_type ndr_flags,
     116             :                                                const char **s)
     117             : {
     118       34267 :         uint32_t offset = ndr->offset;
     119       34267 :         uint32_t max_offset = offset;
     120           8 :         unsigned num_components;
     121           8 :         char *name;
     122             : 
     123       34267 :         if (!(ndr_flags & NDR_SCALARS)) {
     124           0 :                 return NDR_ERR_SUCCESS;
     125             :         }
     126             : 
     127       34267 :         name = talloc_strdup(ndr->current_mem_ctx, "");
     128             : 
     129             :         /* break up name into a list of components */
     130      199353 :         for (num_components=0; num_components<MAX_COMPONENTS;
     131      165078 :              num_components++) {
     132      199345 :                 uint8_t *component = NULL;
     133      199345 :                 NDR_CHECK(ndr_pull_component(ndr, &component, &offset,
     134             :                                              &max_offset));
     135      199345 :                 if (component == NULL) break;
     136      165078 :                 if (num_components > 0) {
     137      130847 :                         name = talloc_asprintf_append_buffer(name, ".%s",
     138             :                                                              component);
     139             :                 } else {
     140       34231 :                         name = talloc_asprintf_append_buffer(name, "%s",
     141             :                                                              component);
     142             :                 }
     143      165078 :                 NDR_ERR_HAVE_NO_MEMORY(name);
     144             :         }
     145       34267 :         if (num_components == MAX_COMPONENTS) {
     146           0 :                 return ndr_pull_error(ndr, NDR_ERR_STRING,
     147             :                                       "BAD DNS NAME too many components");
     148             :         }
     149             : 
     150       34267 :         (*s) = name;
     151       34267 :         ndr->offset = max_offset;
     152             : 
     153       34267 :         return NDR_ERR_SUCCESS;
     154             : }
     155             : 
     156             : /**
     157             :   push a dns string to the wire
     158             : */
     159       39293 : _PUBLIC_ enum ndr_err_code ndr_push_dns_string(struct ndr_push *ndr,
     160             :                                                ndr_flags_type ndr_flags,
     161             :                                                const char *s)
     162             : {
     163       39293 :         return ndr_push_dns_string_list(ndr,
     164             :                                         &ndr->dns_string_list,
     165             :                                         ndr_flags,
     166             :                                         s,
     167             :                                         false);
     168             : }
     169             : 
     170        1872 : _PUBLIC_ enum ndr_err_code ndr_pull_dns_txt_record(struct ndr_pull *ndr, ndr_flags_type ndr_flags, struct dns_txt_record *r)
     171             : {
     172        1872 :         NDR_PULL_CHECK_FLAGS(ndr, ndr_flags);
     173        1872 :         if (ndr_flags & NDR_SCALARS) {
     174           0 :                 enum ndr_err_code ndr_err;
     175        1872 :                 uint32_t data_size = ndr->data_size;
     176        1872 :                 uint32_t record_size = 0;
     177        1872 :                 ndr_err = ndr_token_retrieve(&ndr->array_size_list, r,
     178             :                                              &record_size);
     179        1872 :                 if (NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
     180        1872 :                         NDR_PULL_NEED_BYTES(ndr, record_size);
     181        1872 :                         ndr->data_size = ndr->offset + record_size;
     182             :                 }
     183        1872 :                 NDR_CHECK(ndr_pull_align(ndr, 1));
     184        1872 :                 NDR_CHECK(ndr_pull_dnsp_string_list(ndr, NDR_SCALARS, &r->txt));
     185        1872 :                 NDR_CHECK(ndr_pull_trailer_align(ndr, 1));
     186        1872 :                 ndr->data_size = data_size;
     187             :         }
     188        1872 :         if (ndr_flags & NDR_BUFFERS) {
     189           0 :         }
     190        1872 :         return NDR_ERR_SUCCESS;
     191             : }
     192             : 
     193       26212 : _PUBLIC_ enum ndr_err_code ndr_push_dns_res_rec(struct ndr_push *ndr,
     194             :                                                 ndr_flags_type ndr_flags,
     195             :                                                 const struct dns_res_rec *r)
     196             : {
     197       26212 :         libndr_flags _flags_save_STRUCT = ndr->flags;
     198           0 :         uint32_t _saved_offset1, _saved_offset2;
     199           0 :         uint16_t length;
     200       26212 :         ndr_set_flags(&ndr->flags, LIBNDR_PRINT_ARRAY_HEX |
     201             :                                    LIBNDR_FLAG_NOALIGN);
     202       26212 :         if (ndr_flags & NDR_SCALARS) {
     203       13140 :                 libndr_flags _flags_save_name = ndr->flags;
     204             : 
     205       13140 :                 NDR_CHECK(ndr_push_align(ndr, 4));
     206             : 
     207       13140 :                 switch (r->rr_type) {
     208         384 :                 case DNS_QTYPE_TKEY:
     209             :                 case DNS_QTYPE_TSIG:
     210         384 :                         ndr_set_flags(&ndr->flags, LIBNDR_FLAG_NO_COMPRESSION);
     211         384 :                         break;
     212       12756 :                 default:
     213       12756 :                         break;
     214             :                 }
     215       13140 :                 NDR_CHECK(ndr_push_dns_string(ndr, NDR_SCALARS, r->name));
     216       13140 :                 ndr->flags = _flags_save_name;
     217             : 
     218       13140 :                 NDR_CHECK(ndr_push_dns_qtype(ndr, NDR_SCALARS, r->rr_type));
     219       13140 :                 NDR_CHECK(ndr_push_dns_qclass(ndr, NDR_SCALARS, r->rr_class));
     220       13140 :                 NDR_CHECK(ndr_push_uint32(ndr, NDR_SCALARS, r->ttl));
     221       13140 :                 _saved_offset1 = ndr->offset;
     222       13140 :                 NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, 0));
     223       13140 :                 if (r->length > 0) {
     224           0 :                         uint32_t _saved_offset3;
     225             : 
     226       12940 :                         NDR_CHECK(ndr_push_set_switch_value(ndr, &r->rdata,
     227             :                                                             r->rr_type));
     228       12940 :                         _saved_offset3 = ndr->offset;
     229       12940 :                         NDR_CHECK(ndr_push_dns_rdata(ndr, NDR_SCALARS,
     230             :                                                      &r->rdata));
     231       12940 :                         if ((ndr->offset != _saved_offset3) &&
     232       12927 :                             (r->unexpected.length > 0)) {
     233             :                                 /*
     234             :                                  * ndr_push_dns_rdata pushed a known
     235             :                                  * record, but we have something
     236             :                                  * unexpected. That's invalid.
     237             :                                  */
     238           0 :                                 return ndr_push_error(ndr,
     239             :                                                       NDR_ERR_LENGTH,
     240             :                                                       "Invalid...Unexpected " \
     241             :                                                       "blob length is too " \
     242             :                                                       "large");
     243             :                         }
     244             :                 }
     245       13140 :                 if (r->unexpected.length > UINT16_MAX) {
     246           0 :                         return ndr_push_error(ndr, NDR_ERR_LENGTH,
     247             :                                               "Unexpected blob length "\
     248             :                                               "is too large");
     249             :                 }
     250             : 
     251       13140 :                 NDR_CHECK(ndr_push_bytes(ndr, r->unexpected.data,
     252             :                                          r->unexpected.length));
     253       13140 :                 NDR_CHECK(ndr_push_trailer_align(ndr, 4));
     254       13140 :                 length = ndr->offset - (_saved_offset1 + 2);
     255       13140 :                 _saved_offset2 = ndr->offset;
     256       13140 :                 ndr->offset = _saved_offset1;
     257       13140 :                 NDR_CHECK(ndr_push_uint16(ndr, NDR_SCALARS, length));
     258       13140 :                 ndr->offset = _saved_offset2;
     259             :         }
     260       26212 :         if (ndr_flags & NDR_BUFFERS) {
     261       13140 :                 NDR_CHECK(ndr_push_dns_rdata(ndr, NDR_BUFFERS,
     262             :                                              &r->rdata));
     263             :         }
     264       26212 :         ndr->flags = _flags_save_STRUCT;
     265       26212 :         return NDR_ERR_SUCCESS;
     266             : }
     267             : 
     268       22552 : _PUBLIC_ enum ndr_err_code ndr_pull_dns_res_rec(struct ndr_pull *ndr,
     269             :                                                 ndr_flags_type ndr_flags,
     270             :                                                 struct dns_res_rec *r)
     271             : {
     272       22552 :         libndr_flags _flags_save_STRUCT = ndr->flags;
     273           4 :         uint32_t _saved_offset1;
     274           4 :         uint32_t pad, length;
     275             : 
     276       22552 :         ndr_set_flags(&ndr->flags, LIBNDR_PRINT_ARRAY_HEX |
     277             :                                    LIBNDR_FLAG_NOALIGN);
     278       22552 :         if (ndr_flags & NDR_SCALARS) {
     279       11276 :                 NDR_CHECK(ndr_pull_align(ndr, 4));
     280       11276 :                 NDR_CHECK(ndr_pull_dns_string(ndr, NDR_SCALARS, &r->name));
     281       11276 :                 NDR_CHECK(ndr_pull_dns_qtype(ndr, NDR_SCALARS, &r->rr_type));
     282       11276 :                 NDR_CHECK(ndr_pull_dns_qclass(ndr, NDR_SCALARS, &r->rr_class));
     283       11276 :                 NDR_CHECK(ndr_pull_uint32(ndr, NDR_SCALARS, &r->ttl));
     284       11276 :                 NDR_CHECK(ndr_pull_uint16(ndr, NDR_SCALARS, &r->length));
     285       11276 :                 _saved_offset1 = ndr->offset;
     286       11276 :                 if (r->length > 0) {
     287       10997 :                         NDR_CHECK(ndr_token_store(ndr, &ndr->array_size_list,
     288             :                                                   &r->rdata,
     289             :                                                   r->length));
     290       10997 :                         NDR_CHECK(ndr_pull_set_switch_value(ndr, &r->rdata,
     291             :                                                             r->rr_type));
     292       10997 :                         NDR_CHECK(ndr_pull_dns_rdata(ndr, NDR_SCALARS,
     293             :                                                      &r->rdata));
     294             :                 } else {
     295         279 :                         ZERO_STRUCT(r->rdata);
     296             :                 }
     297       11276 :                 length = ndr->offset - _saved_offset1;
     298       11276 :                 if (length > r->length) {
     299           0 :                         return ndr_pull_error(ndr, NDR_ERR_LENGTH, "TODO");
     300             :                 }
     301             : 
     302       11276 :                 r->unexpected = data_blob_null;
     303       11276 :                 pad = r->length - length;
     304       11276 :                 if (pad > 0) {
     305           2 :                         NDR_PULL_NEED_BYTES(ndr, pad);
     306           2 :                         r->unexpected = data_blob_talloc(ndr->current_mem_ctx,
     307             :                                                          ndr->data +
     308             :                                                          ndr->offset,
     309             :                                                          pad);
     310           2 :                         if (r->unexpected.data == NULL) {
     311           0 :                                 return ndr_pull_error(ndr,
     312             :                                                       NDR_ERR_ALLOC,
     313             :                                                       "Failed to allocate a " \
     314             :                                                       "data blob");
     315             :                         }
     316           2 :                         ndr->offset += pad;
     317             :                 }
     318             : 
     319             : 
     320       11276 :                 NDR_CHECK(ndr_pull_trailer_align(ndr, 4));
     321             :         }
     322       22552 :         if (ndr_flags & NDR_BUFFERS) {
     323       11276 :                 NDR_CHECK(ndr_pull_dns_rdata(ndr, NDR_BUFFERS, &r->rdata));
     324             :         }
     325       22552 :         ndr->flags = _flags_save_STRUCT;
     326       22552 :         return NDR_ERR_SUCCESS;
     327             : }

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