Source/charon/encoding/payloads/sa_payload.c

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