src/libcharon/encoding/payloads/delete_payload.c

   1 /*
   2  * Copyright (C) 2005-2010 Martin Willi
   3  * Copyright (C) 2010 revosec AG
   4  * Copyright (C) 2005 Jan Hutter
   5  * Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 #include <stddef.h>
  19
  20 #include "delete_payload.h"
  21
  22
  23 typedef struct private_delete_payload_t private_delete_payload_t;
  24
  25 /**
  26  * Private data of an delete_payload_t object.
  27  *
  28  */
  29 struct private_delete_payload_t {
  30         /**
  31          * Public delete_payload_t interface.
  32          */
  33         delete_payload_t public;
  34
  35         /**
  36          * Next payload type.
  37          */
  38         u_int8_t  next_payload;
  39
  40         /**
  41          * Critical flag.
  42          */
  43         bool critical;
  44
  45         /**
  46          * reserved bits
  47          */
  48         bool reserved[7];
  49
  50         /**
  51          * Length of this payload.
  52          */
  53         u_int16_t payload_length;
  54
  55         /**
  56          * Protocol ID.
  57          */
  58         u_int8_t protocol_id;
  59
  60         /**
  61          * SPI Size.
  62          */
  63         u_int8_t spi_size;
  64
  65         /**
  66          * Number of SPI's.
  67          */
  68         u_int16_t spi_count;
  69
  70         /**
  71          * The contained SPI's.
  72          */
  73         chunk_t spis;
  74 };
  75
  76 /**
  77  * Encoding rules to parse or generate a DELETE payload
  78  *
  79  * The defined offsets are the positions in a object of type
  80  * private_delete_payload_t.
  81  */
  82 static encoding_rule_t encodings[] = {
  83         /* 1 Byte next payload type, stored in the field next_payload */
  84         { U_INT_8,                      offsetof(private_delete_payload_t, next_payload)        },
  85         /* the critical bit */
  86         { FLAG,                         offsetof(private_delete_payload_t, critical)            },
  87         /* 7 Bit reserved bits */
  88         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[0])         },
  89         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[1])         },
  90         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[2])         },
  91         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[3])         },
  92         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[4])         },
  93         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[5])         },
  94         { RESERVED_BIT,         offsetof(private_delete_payload_t, reserved[6])         },
  95         /* Length of the whole payload*/
  96         { PAYLOAD_LENGTH,       offsetof(private_delete_payload_t, payload_length)      },
  97         { U_INT_8,                      offsetof(private_delete_payload_t, protocol_id)         },
  98         { U_INT_8,                      offsetof(private_delete_payload_t, spi_size)            },
  99         { U_INT_16,                     offsetof(private_delete_payload_t, spi_count)           },
 100         /* some delete data bytes, length is defined in PAYLOAD_LENGTH */
 101         { SPIS,                         offsetof(private_delete_payload_t, spis)                        }
 102 };
 103
 104 /*
 105                            1                   2                   3
 106        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
 107       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 108       ! Next Payload  !C!  RESERVED   !         Payload Length        !
 109       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 110       ! Protocol ID   !   SPI Size    !           # of SPIs           !
 111       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 112       !                                                               !
 113       ~               Security Parameter Index(es) (SPI)              ~
 114       !                                                               !
 115       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 116 */
 117
 118 METHOD(payload_t, verify, status_t,
 119         private_delete_payload_t *this)
 120 {
 121         switch (this->protocol_id)
 122         {
 123                 case PROTO_AH:
 124                 case PROTO_ESP:
 125                         if (this->spi_size != 4)
 126                         {
 127                                 return FAILED;
 128                         }
 129                         break;
 130                 case PROTO_IKE:
 131                 case 0:
 132                         /* IKE deletion has no spi assigned! */
 133                         if (this->spi_size != 0)
 134                         {
 135                                 return FAILED;
 136                         }
 137                         break;
 138                 default:
 139                         return FAILED;
 140         }
 141         if (this->spis.len != (this->spi_count * this->spi_size))
 142         {
 143                 return FAILED;
 144         }
 145         return SUCCESS;
 146 }
 147
 148 METHOD(payload_t, get_encoding_rules, int,
 149         private_delete_payload_t *this, encoding_rule_t **rules)
 150 {
 151         *rules = encodings;
 152         return countof(encodings);
 153 }
 154
 155 METHOD(payload_t, get_payload_type, payload_type_t,
 156         private_delete_payload_t *this)
 157 {
 158         return DELETE;
 159 }
 160
 161 METHOD(payload_t, get_next_type, payload_type_t,
 162         private_delete_payload_t *this)
 163 {
 164         return this->next_payload;
 165 }
 166
 167 METHOD(payload_t, set_next_type, void,
 168         private_delete_payload_t *this,payload_type_t type)
 169 {
 170         this->next_payload = type;
 171 }
 172
 173 METHOD(payload_t, get_length, size_t,
 174         private_delete_payload_t *this)
 175 {
 176         return this->payload_length;
 177 }
 178
 179 METHOD(delete_payload_t, get_protocol_id, protocol_id_t,
 180         private_delete_payload_t *this)
 181 {
 182         return this->protocol_id;
 183 }
 184
 185 METHOD(delete_payload_t, add_spi, void,
 186         private_delete_payload_t *this, u_int32_t spi)
 187 {
 188         switch (this->protocol_id)
 189         {
 190                 case PROTO_AH:
 191                 case PROTO_ESP:
 192                         this->spi_count++;
 193                         this->payload_length += sizeof(spi);
 194                         this->spis = chunk_cat("mc", this->spis, chunk_from_thing(spi));
 195                         break;
 196                 default:
 197                         break;
 198         }
 199 }
 200
 201 /**
 202  * SPI enumerator implementation
 203  */
 204 typedef struct {
 205         /** implements enumerator_t */
 206         enumerator_t public;
 207         /** remaining SPIs */
 208         chunk_t spis;
 209 } spi_enumerator_t;
 210
 211 METHOD(enumerator_t, spis_enumerate, bool,
 212         spi_enumerator_t *this, u_int32_t *spi)
 213 {
 214         if (this->spis.len >= sizeof(*spi))
 215         {
 216                 memcpy(spi, this->spis.ptr, sizeof(*spi));
 217                 this->spis = chunk_skip(this->spis, sizeof(*spi));
 218                 return TRUE;
 219         }
 220         return FALSE;
 221 }
 222
 223 METHOD(delete_payload_t, create_spi_enumerator, enumerator_t*,
 224         private_delete_payload_t *this)
 225 {
 226         spi_enumerator_t *e;
 227
 228         if (this->spi_size != sizeof(u_int32_t))
 229         {
 230                 return enumerator_create_empty();
 231         }
 232         INIT(e,
 233                 .public = {
 234                         .enumerate = (void*)_spis_enumerate,
 235                         .destroy = (void*)free,
 236                 },
 237                 .spis = this->spis,
 238         );
 239         return &e->public;
 240 }
 241
 242 METHOD2(payload_t, delete_payload_t, destroy, void,
 243         private_delete_payload_t *this)
 244 {
 245         free(this->spis.ptr);
 246         free(this);
 247 }
 248
 249 /*
 250  * Described in header
 251  */
 252 delete_payload_t *delete_payload_create(protocol_id_t protocol_id)
 253 {
 254         private_delete_payload_t *this;
 255
 256         INIT(this,
 257                 .public = {
 258                         .payload_interface = {
 259                                 .verify = _verify,
 260                                 .get_encoding_rules = _get_encoding_rules,
 261                                 .get_length = _get_length,
 262                                 .get_next_type = _get_next_type,
 263                                 .set_next_type = _set_next_type,
 264                                 .get_type = _get_payload_type,
 265                                 .destroy = _destroy,
 266                         },
 267                         .get_protocol_id = _get_protocol_id,
 268                         .add_spi = _add_spi,
 269                         .create_spi_enumerator = _create_spi_enumerator,
 270                         .destroy = _destroy,
 271                 },
 272                 .next_payload = NO_PAYLOAD,
 273                 .payload_length = DELETE_PAYLOAD_HEADER_LENGTH,
 274                 .protocol_id = protocol_id,
 275                 .spi_size = protocol_id == PROTO_AH || protocol_id == PROTO_ESP ? 4 : 0,
 276         );
 277         return &this->public;
 278 }