Source/charon/encoding/payloads/sa_payload.c

   1 /**
   2  * @file sa_payload.c
   3  *
   4  * @brief Declaration of the class sa_payload_t.
   5  *
   6  * An object of this type represents an IKEv2 SA-Payload and contains proposal
   7  * substructures.
   8  *
   9  */
  10
  11 /*
  12  * Copyright (C) 2005 Jan Hutter, Martin Willi
  13  * Hochschule fuer Technik Rapperswil
  14  *
  15  * This program is free software; you can redistribute it and/or modify it
  16  * under the terms of the GNU General Public License as published by the
  17  * Free Software Foundation; either version 2 of the License, or (at your
  18  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  19  *
  20  * This program is distributed in the hope that it will be useful, but
  21  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  22  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  23  * for more details.
  24  */
  25
  26 /* offsetof macro */
  27 #include <stddef.h>
  28
  29 #include "sa_payload.h"
  30
  31 #include <encoding/payloads/encodings.h>
  32 #include <utils/allocator.h>
  33 #include <utils/linked_list.h>
  34
  35
  36 /**
  37  * Private data of an sa_payload_t' Object
  38  *
  39  */
  40 typedef struct private_sa_payload_s private_sa_payload_t;
  41
  42 struct private_sa_payload_s {
  43         /**
  44          * public sa_payload_t interface
  45          */
  46         sa_payload_t public;
  47
  48         /**
  49          * next payload type
  50          */
  51         u_int8_t  next_payload;
  52
  53         /**
  54          * Critical flag
  55          */
  56         bool critical;
  57
  58         /**
  59          * Length of this payload
  60          */
  61         u_int16_t payload_length;
  62
  63         /**
  64          * Proposals in this payload are stored in a linked_list_t
  65          */
  66         linked_list_t * proposals;
  67
  68         /**
  69          * @brief Computes the length of this payload.
  70          *
  71          * @param this  calling private_sa_payload_t object
  72          * @return
  73          *                              SUCCESS in any case
  74          */
  75         status_t (*compute_length) (private_sa_payload_t *this);
  76 };
  77
  78 /**
  79  * Encoding rules to parse or generate a IKEv2-SA Payload
  80  *
  81  * The defined offsets are the positions in a object of type
  82  * private_sa_payload_t.
  83  *
  84  */
  85 encoding_rule_t sa_payload_encodings[] = {
  86         /* 1 Byte next payload type, stored in the field next_payload */
  87         { U_INT_8,              offsetof(private_sa_payload_t, next_payload)                    },
  88         /* the critical bit */
  89         { FLAG,                 offsetof(private_sa_payload_t, critical)                                },
  90         /* 7 Bit reserved bits, nowhere stored */
  91         { RESERVED_BIT, 0                                                                                                               },
  92         { RESERVED_BIT, 0                                                                                                               },
  93         { RESERVED_BIT, 0                                                                                                               },
  94         { RESERVED_BIT, 0                                                                                                               },
  95         { RESERVED_BIT, 0                                                                                                               },
  96         { RESERVED_BIT, 0                                                                                                               },
  97         { RESERVED_BIT, 0                                                                                                               },
  98         /* Length of the whole SA payload*/
  99         { PAYLOAD_LENGTH,               offsetof(private_sa_payload_t, payload_length)  },
 100         /* Proposals are stored in a proposal substructure,
 101            offset points to a linked_list_t pointer */
 102         { PROPOSALS,            offsetof(private_sa_payload_t, proposals)                               }
 103 };
 104
 105 /*
 106                            1                   2                   3
 107        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 108       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 109       ! Next Payload  !C!  RESERVED   !         Payload Length        !
 110       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 111       !                                                               !
 112       ~                          <Proposals>                          ~
 113       !                                                               !
 114       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 115 */
 116
 117 /**
 118  * Implements payload_t's verify function.
 119  * See #payload_s.verify for description.
 120  */
 121 static status_t verify(private_sa_payload_t *this)
 122 {
 123         int proposal_number = 1;
 124         status_t status;
 125         linked_list_iterator_t *iterator;
 126         bool first = TRUE;
 127
 128         if (this->critical)
 129         {
 130                 /* critical bit set! */
 131                 return FAILED;
 132         }
 133
 134         /* check proposal numbering */
 135         status = this->proposals->create_iterator(this->proposals,&iterator,TRUE);
 136         if (status != SUCCESS)
 137         {
 138                 return status;
 139         }
 140
 141         while(iterator->has_next(iterator))
 142         {
 143                 proposal_substructure_t *current_proposal;
 144                 status = iterator->current(iterator,(void **)&current_proposal);
 145                 {
 146                         break;
 147                 }
 148                 if (current_proposal->get_proposal_number(current_proposal) > proposal_number)
 149                 {
 150                         if (first)
 151                         {
 152                                 /* first number must be 1 */
 153                                 status = FAILED;
 154                                 break;
 155                         }
 156
 157                         if (current_proposal->get_proposal_number(current_proposal) != (proposal_number + 1))
 158                         {
 159                                 /* must be only one more then previous proposal */
 160                                 status = FAILED;
 161                                 break;
 162                         }
 163                 }
 164                 else if (current_proposal->get_proposal_number(current_proposal) < proposal_number)
 165                 {
 166                         iterator->destroy(iterator);
 167                         /* must not be smaller then proceeding one */
 168                         status = FAILED;
 169                         break;
 170                 }
 171                 first = FALSE;
 172         }
 173
 174         iterator->destroy(iterator);
 175         return status;
 176 }
 177
 178
 179 /**
 180  * Implements payload_t's and sa_payload_t's destroy function.
 181  * See #payload_s.destroy or sa_payload_s.destroy for description.
 182  */
 183 static status_t destroy(private_sa_payload_t *this)
 184 {
 185         /* all proposals are getting destroyed */
 186         while (this->proposals->get_count(this->proposals) > 0)
 187         {
 188                 proposal_substructure_t *current_proposal;
 189                 if (this->proposals->remove_last(this->proposals,(void **)&current_proposal) != SUCCESS)
 190                 {
 191                         break;
 192                 }
 193                 current_proposal->destroy(current_proposal);
 194         }
 195         this->proposals->destroy(this->proposals);
 196
 197         allocator_free(this);
 198
 199         return SUCCESS;
 200 }
 201
 202 /**
 203  * Implements payload_t's get_encoding_rules function.
 204  * See #payload_s.get_encoding_rules for description.
 205  */
 206 static status_t get_encoding_rules(private_sa_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
 207 {
 208         *rules = sa_payload_encodings;
 209         *rule_count = sizeof(sa_payload_encodings) / sizeof(encoding_rule_t);
 210
 211         return SUCCESS;
 212 }
 213
 214 /**
 215  * Implements payload_t's get_type function.
 216  * See #payload_s.get_type for description.
 217  */
 218 static payload_type_t get_type(private_sa_payload_t *this)
 219 {
 220         return SECURITY_ASSOCIATION;
 221 }
 222
 223 /**
 224  * Implements payload_t's get_next_type function.
 225  * See #payload_s.get_next_type for description.
 226  */
 227 static payload_type_t get_next_type(private_sa_payload_t *this)
 228 {
 229         return (this->next_payload);
 230 }
 231
 232 /**
 233  * Implements payload_t's set_next_type function.
 234  * See #payload_s.set_next_type for description.
 235  */
 236 static status_t set_next_type(private_sa_payload_t *this,payload_type_t type)
 237 {
 238         this->next_payload = type;
 239         return SUCCESS;
 240 }
 241
 242 /**
 243  * Implements payload_t's get_length function.
 244  * See #payload_s.get_length for description.
 245  */
 246 static size_t get_length(private_sa_payload_t *this)
 247 {
 248         this->compute_length(this);
 249         return this->payload_length;
 250 }
 251
 252 /**
 253  * Implements sa_payload_t's create_proposal_substructure_iterator function.
 254  * See #sa_payload_s.create_proposal_substructure_iterator for description.
 255  */
 256 static status_t create_proposal_substructure_iterator (private_sa_payload_t *this,linked_list_iterator_t **iterator,bool forward)
 257 {
 258         return (this->proposals->create_iterator(this->proposals,iterator,forward));
 259 }
 260
 261 /**
 262  * Implements sa_payload_t's add_proposal_substructure function.
 263  * See #sa_payload_s.add_proposal_substructure for description.
 264  */
 265 static status_t add_proposal_substructure (private_sa_payload_t *this,proposal_substructure_t *proposal)
 266 {
 267         status_t status;
 268         status = this->proposals->insert_last(this->proposals,(void *) proposal);
 269         this->compute_length(this);
 270         return status;
 271 }
 272
 273 /**
 274  * Implements private_sa_payload_t's compute_length function.
 275  * See #private_sa_payload_s.compute_length for description.
 276  */
 277 static status_t compute_length (private_sa_payload_t *this)
 278 {
 279         linked_list_iterator_t *iterator;
 280         status_t status;
 281         size_t length = SA_PAYLOAD_HEADER_LENGTH;
 282         status = this->proposals->create_iterator(this->proposals,&iterator,TRUE);
 283         if (status != SUCCESS)
 284         {
 285                 return length;
 286         }
 287         while (iterator->has_next(iterator))
 288         {
 289                 payload_t *current_proposal;
 290                 iterator->current(iterator,(void **) &current_proposal);
 291                 length += current_proposal->get_length(current_proposal);
 292         }
 293         iterator->destroy(iterator);
 294
 295         this->payload_length = length;
 296
 297         return SUCCESS;
 298 }
 299
 300 /*
 301  * Described in header
 302  */
 303 sa_payload_t *sa_payload_create()
 304 {
 305         private_sa_payload_t *this = allocator_alloc_thing(private_sa_payload_t);
 306         if (this == NULL)
 307         {
 308                 return NULL;
 309         }
 310
 311         /* public interface */
 312         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 313         this->public.payload_interface.get_encoding_rules = (status_t (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 314         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 315         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 316         this->public.payload_interface.set_next_type = (status_t (*) (payload_t *,payload_type_t)) set_next_type;
 317         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 318         this->public.payload_interface.destroy = (status_t (*) (payload_t *))destroy;
 319
 320         /* public functions */
 321         this->public.create_proposal_substructure_iterator = (status_t (*) (sa_payload_t *,linked_list_iterator_t **,bool)) create_proposal_substructure_iterator;
 322         this->public.add_proposal_substructure = (status_t (*) (sa_payload_t *,proposal_substructure_t *)) add_proposal_substructure;
 323         this->public.destroy = (status_t (*) (sa_payload_t *)) destroy;
 324
 325         /* private functions */
 326         this->compute_length = compute_length;
 327
 328         /* set default values of the fields */
 329         this->critical = SA_PAYLOAD_CRITICAL_FLAG;
 330         this->next_payload = NO_PAYLOAD;
 331         this->payload_length = SA_PAYLOAD_HEADER_LENGTH;
 332
 333         this->proposals = linked_list_create();
 334
 335         if (this->proposals == NULL)
 336         {
 337                 allocator_free(this);
 338                 return NULL;
 339         }
 340         return (&(this->public));
 341 }
 342
 343