src/libcharon/encoding/payloads/encodings.h

   1 /*
   2  * Copyright (C) 2005-2006 Martin Willi
   3  * Copyright (C) 2005 Jan Hutter
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 /**
  18  * @defgroup encodings encodings
  19  * @{ @ingroup payloads
  20  */
  21
  22 #ifndef ENCODINGS_H_
  23 #define ENCODINGS_H_
  24
  25 typedef enum encoding_type_t encoding_type_t;
  26 typedef struct encoding_rule_t encoding_rule_t;
  27
  28 #include <library.h>
  29
  30 /**
  31  * All different kinds of encoding types.
  32  *
  33  * Each field of an IKEv2-Message (in header or payload)
  34  * which has to be parsed or generated differently has its own
  35  * type defined here.
  36  *
  37  * Header is parsed like a payload and gets its one payload_id
  38  * from PRIVATE USE space. Also the substructures
  39  * of specific payload types get their own payload_id
  40  * from PRIVATE_USE space. See IKEv2-Draft for more informations.
  41  */
  42 enum encoding_type_t {
  43
  44         /**
  45          * Representing a 4 Bit unsigned int value.
  46          *
  47          *
  48          * When generating it must be changed from host to network order.
  49          * The value is read from the associated data struct.
  50          * The current write position is moved 4 bit forward afterwards.
  51          *
  52          * When parsing it must be changed from network to host order.
  53          * The value is written to the associated data struct.
  54          * The current read pointer is moved 4 bit forward afterwards.
  55          */
  56         U_INT_4,
  57
  58         /**
  59          * Representing a 8 Bit unsigned int value.
  60          *
  61          *
  62          * When generating it must be changed from host to network order.
  63          * The value is read from the associated data struct.
  64          * The current write position is moved 8 bit forward afterwards.
  65          *
  66          * When parsing it must be changed from network to host order.
  67          * The value is written to the associated data struct.
  68          * The current read pointer is moved 8 bit forward afterwards.
  69          */
  70         U_INT_8,
  71
  72         /**
  73          * Representing a 16 Bit unsigned int value.
  74          *
  75          *
  76          * When generating it must be changed from host to network order.
  77          * The value is read from the associated data struct.
  78          * The current write position is moved 16 bit forward afterwards.
  79          *
  80          * When parsing it must be changed from network to host order.
  81          * The value is written to the associated data struct.
  82          * The current read pointer is moved 16 bit forward afterwards.
  83          */
  84         U_INT_16,
  85
  86         /**
  87          * Representing a 32 Bit unsigned int value.
  88          *
  89          * When generating it must be changed from host to network order.
  90          * The value is read from the associated data struct.
  91          * The current write position is moved 32 bit forward afterwards.
  92          *
  93          * When parsing it must be changed from network to host order.
  94          * The value is written to the associated data struct.
  95          * The current read pointer is moved 32 bit forward afterwards.
  96          */
  97         U_INT_32,
  98
  99         /**
 100          * represents a RESERVED_BIT used in FLAG-Bytes.
 101          *
 102          * When generating, the next bit is set to zero and the current write
 103          * position is moved one bit forward.
 104          * No value is read from the associated data struct.
 105          * The current write position is moved 1 bit forward afterwards.
 106          *
 107          * When parsing, the current read pointer is moved one bit forward.
 108          * No value is written to the associated data struct.
 109          * The current read pointer is moved 1 bit forward afterwards.
 110          */
 111         RESERVED_BIT,
 112
 113         /**
 114          * represents a RESERVED_BYTE.
 115          *
 116          * When generating, the next byte is set to zero and the current write
 117          * position is moved one byte forward.
 118          * No value is read from the associated data struct.
 119          * The current write position is moved 1 byte forward afterwards.
 120          *
 121          * When parsing, the current read pointer is moved one byte forward.
 122          * No value is written to the associated data struct.
 123          * The current read pointer is moved 1 byte forward afterwards.
 124          */
 125         RESERVED_BYTE,
 126
 127         /**
 128          * Representing a 1 Bit flag.
 129          *
 130          * When generation, the next bit is set to 1 if the associated value
 131          * in the data struct is TRUE, 0 otherwise. The current write position
 132          * is moved 1 bit forward afterwards.
 133          *
 134          * When parsing, the next bit is read and stored in the associated data
 135          * struct. 0 means FALSE, 1 means TRUE, The current read pointer
 136          * is moved 1 bit forward afterwards
 137          */
 138         FLAG,
 139
 140         /**
 141          * Representating a length field of a payload.
 142          *
 143          * When generating it must be changed from host to network order.
 144          * The value is read from the associated data struct.
 145          * The current write position is moved 16 bit forward afterwards.
 146          *
 147          * When parsing it must be changed from network to host order.
 148          * The value is written to the associated data struct.
 149          * The current read pointer is moved 16 bit forward afterwards.
 150          */
 151         PAYLOAD_LENGTH,
 152
 153         /**
 154          * Representating a length field of a header.
 155          *
 156          * When generating it must be changed from host to network order.
 157          * The value is read from the associated data struct.
 158          * The current write position is moved 32 bit forward afterwards.
 159          *
 160          * When parsing it must be changed from network to host order.
 161          * The value is written to the associated data struct.
 162          * The current read pointer is moved 32 bit forward afterwards.
 163          */
 164         HEADER_LENGTH,
 165
 166         /**
 167          * Representating a spi size field.
 168          *
 169          * When generating it must be changed from host to network order.
 170          * The value is read from the associated data struct.
 171          * The current write position is moved 8 bit forward afterwards.
 172          *
 173          * When parsing it must be changed from network to host order.
 174          * The value is written to the associated data struct.
 175          * The current read pointer is moved 8 bit forward afterwards.
 176          */
 177         SPI_SIZE,
 178
 179         /**
 180          * Representating a spi field.
 181          *
 182          * When generating the content of the chunkt pointing to
 183          * is written.
 184          *
 185          * When parsing SPI_SIZE bytes are read and written into the chunk pointing to.
 186          */
 187         SPI,
 188
 189         /**
 190          * Representing a 1 Bit flag specifying the format of a transform attribute.
 191          *
 192          * When generation, the next bit is set to 1 if the associated value
 193          * in the data struct is TRUE, 0 otherwise. The current write position
 194          * is moved 1 bit forward afterwards.
 195          *
 196          * When parsing, the next bit is read and stored in the associated data
 197          * struct. 0 means FALSE, 1 means TRUE, The current read pointer
 198          * is moved 1 bit forward afterwards.
 199          */
 200         ATTRIBUTE_FORMAT,
 201
 202         /**
 203          * Representing a 15 Bit unsigned int value used as attribute type
 204          * in an attribute transform.
 205          *
 206          *
 207          * When generating it must be changed from host to network order.
 208          * The value is read from the associated data struct.
 209          * The current write position is moved 15 bit forward afterwards.
 210          *
 211          * When parsing it must be changed from network to host order.
 212          * The value is written to the associated data struct.
 213          * The current read pointer is moved 15 bit forward afterwards.
 214          */
 215         ATTRIBUTE_TYPE,
 216
 217         /**
 218          * Depending on the field of type ATTRIBUTE_FORMAT
 219          * this field contains the length or the value of an transform attribute.
 220          * Its stored in a 16 unsigned integer field.
 221          *
 222          * When generating it must be changed from host to network order.
 223          * The value is read from the associated data struct.
 224          * The current write position is moved 16 bit forward afterwards.
 225          *
 226          * When parsing it must be changed from network to host order.
 227          * The value is written to the associated data struct.
 228          * The current read pointer is moved 16 bit forward afterwards.
 229          */
 230         ATTRIBUTE_LENGTH_OR_VALUE,
 231
 232         /**
 233          * This field contains the length or the value of an configuration attribute.
 234          * Its stored in a 16 unsigned integer field.
 235          *
 236          * When generating it must be changed from host to network order.
 237          * The value is read from the associated data struct.
 238          * The current write position is moved 16 bit forward afterwards.
 239          *
 240          * When parsing it must be changed from network to host order.
 241          * The value is written to the associated data struct.
 242          * The current read pointer is moved 16 bit forward afterwards.
 243          */
 244         CONFIGURATION_ATTRIBUTE_LENGTH,
 245
 246         /**
 247          * Depending on the field of type ATTRIBUTE_FORMAT
 248          * this field is available or missing and so parsed/generated
 249          * or not parsed/not generated.
 250          *
 251          * When generating the content of the chunkt pointing to
 252          * is written.
 253          *
 254          * When parsing SPI_SIZE bytes are read and written into the chunk pointing to.
 255          */
 256         ATTRIBUTE_VALUE,
 257
 258         /**
 259          * Representating a Traffic selector type field.
 260          *
 261          * When generating it must be changed from host to network order.
 262          * The value is read from the associated data struct.
 263          * The current write position is moved 16 bit forward afterwards.
 264          *
 265          * When parsing it must be changed from network to host order.
 266          * The value is written to the associated data struct.
 267          * The current read pointer is moved 16 bit forward afterwards.
 268          */
 269         TS_TYPE,
 270
 271         /**
 272          * Representating an address field in a traffic selector.
 273          *
 274          * Depending on the last field of type TS_TYPE
 275          * this field is either 4 or 16 byte long.
 276          *
 277          * When generating the content of the chunkt pointing to
 278          * is written.
 279          *
 280          * When parsing 4 or 16 bytes are read and written into the chunk pointing to.
 281          */
 282         ADDRESS,
 283
 284         /**
 285          * Representing a variable length byte field.
 286          */
 287         CHUNK_DATA,
 288
 289         /**
 290          * Representating an IKE_SPI field in an IKEv2 Header.
 291          *
 292          * When generating the value of the u_int64_t pointing to
 293          * is written (host and networ order is not changed).
 294          *
 295          * When parsing 8 bytes are read and written into the u_int64_t pointing to.
 296          */
 297         IKE_SPI,
 298
 299         /**
 300          * Reprensenting a field containing a set of wrapped payloads.
 301          *
 302          * This type is not used directly, but as an offset to the wrapped payloads.
 303          * The type of the wrapped payload is added to this encoding type.
 304          *
 305          * @note As payload types are added to this encoding type, it has
 306          * to be the last in encoding_type_t.
 307          */
 308         PAYLOAD_LIST = 1000 /* no comma, read above! */
 309 };
 310
 311 /**
 312  * enum name for encoding_type_t
 313  */
 314 extern enum_name_t *encoding_type_names;
 315
 316 /**
 317  * Rule how to en-/decode a payload field.
 318  *
 319  * An encoding rule is a mapping of a specific encoding type to
 320  * a location in the data struct where the current field is stored to
 321  * or read from.
 322  * This rules are used by parser and generator.
 323  */
 324 struct encoding_rule_t {
 325
 326         /**
 327          * Encoding type.
 328          */
 329         encoding_type_t type;
 330
 331         /**
 332          * Offset in the data struct.
 333          *
 334          * When parsing, data are written to this offset of the
 335          * data struct.
 336          *
 337          * When generating, data are read from this offset in the
 338          * data struct.
 339          */
 340         u_int32_t offset;
 341 };
 342
 343 #endif /** ENCODINGS_H_ @}*/