Use a generic encoding type for all variable length chunks
[strongswan.git] / 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 * Representating one or more proposal substructures.
191 *
192 * The offset points to a linked_list_t pointer.
193 *
194 * When generating the proposal_substructure_t objects are stored
195 * in the pointed linked_list.
196 *
197 * When parsing the parsed proposal_substructure_t objects have
198 * to be stored in the pointed linked_list.
199 */
200 PROPOSALS,
201
202 /**
203 * Same as PROPOSALS, but for IKEv1 in a SECURITY_ASSOCIATION_V1
204 */
205 PROPOSALS_V1,
206
207 /**
208 * Representating one or more transform substructures.
209 *
210 * The offset points to a linked_list_t pointer.
211 *
212 * When generating the transform_substructure_t objects are stored
213 * in the pointed linked_list.
214 *
215 * When parsing the parsed transform_substructure_t objects have
216 * to be stored in the pointed linked_list.
217 */
218 TRANSFORMS,
219
220 /**
221 * Same as TRANSFORMS, but for IKEv1 in a PROPOSAL_SUBSTRUCTURE_V1.
222 */
223 TRANSFORMS_V1,
224
225 /**
226 * Representating one or more Attributes of a transform substructure.
227 *
228 * The offset points to a linked_list_t pointer.
229 *
230 * When generating the transform_attribute_t objects are stored
231 * in the pointed linked_list.
232 *
233 * When parsing the parsed transform_attribute_t objects have
234 * to be stored in the pointed linked_list.
235 */
236 TRANSFORM_ATTRIBUTES,
237
238 /**
239 * Same as TRANSFORM_ATTRIBUTES, but for IKEv1 in TRANSFORMS_V1.
240 */
241 TRANSFORM_ATTRIBUTES_V1,
242
243 /**
244 * Representating one or more Attributes of a configuration payload.
245 *
246 * The offset points to a linked_list_t pointer.
247 *
248 * When generating the configuration_attribute_t objects are stored
249 * in the pointed linked_list.
250 *
251 * When parsing the parsed configuration_attribute_t objects have
252 * to be stored in the pointed linked_list.
253 */
254 CONFIGURATION_ATTRIBUTES,
255
256 /**
257 * Representing a 1 Bit flag specifying the format of a transform attribute.
258 *
259 * When generation, the next bit is set to 1 if the associated value
260 * in the data struct is TRUE, 0 otherwise. The current write position
261 * is moved 1 bit forward afterwards.
262 *
263 * When parsing, the next bit is read and stored in the associated data
264 * struct. 0 means FALSE, 1 means TRUE, The current read pointer
265 * is moved 1 bit forward afterwards.
266 */
267 ATTRIBUTE_FORMAT,
268
269 /**
270 * Representing a 15 Bit unsigned int value used as attribute type
271 * in an attribute transform.
272 *
273 *
274 * When generating it must be changed from host to network order.
275 * The value is read from the associated data struct.
276 * The current write position is moved 15 bit forward afterwards.
277 *
278 * When parsing it must be changed from network to host order.
279 * The value is written to the associated data struct.
280 * The current read pointer is moved 15 bit forward afterwards.
281 */
282 ATTRIBUTE_TYPE,
283
284 /**
285 * Depending on the field of type ATTRIBUTE_FORMAT
286 * this field contains the length or the value of an transform attribute.
287 * Its stored in a 16 unsigned integer field.
288 *
289 * When generating it must be changed from host to network order.
290 * The value is read from the associated data struct.
291 * The current write position is moved 16 bit forward afterwards.
292 *
293 * When parsing it must be changed from network to host order.
294 * The value is written to the associated data struct.
295 * The current read pointer is moved 16 bit forward afterwards.
296 */
297 ATTRIBUTE_LENGTH_OR_VALUE,
298
299 /**
300 * This field contains the length or the value of an configuration attribute.
301 * Its stored in a 16 unsigned integer field.
302 *
303 * When generating it must be changed from host to network order.
304 * The value is read from the associated data struct.
305 * The current write position is moved 16 bit forward afterwards.
306 *
307 * When parsing it must be changed from network to host order.
308 * The value is written to the associated data struct.
309 * The current read pointer is moved 16 bit forward afterwards.
310 */
311 CONFIGURATION_ATTRIBUTE_LENGTH,
312
313 /**
314 * Depending on the field of type ATTRIBUTE_FORMAT
315 * this field is available or missing and so parsed/generated
316 * or not parsed/not generated.
317 *
318 * When generating the content of the chunkt pointing to
319 * is written.
320 *
321 * When parsing SPI_SIZE bytes are read and written into the chunk pointing to.
322 */
323 ATTRIBUTE_VALUE,
324
325 /**
326 * Representating one or more Traffic selectors of a TS payload.
327 *
328 * The offset points to a linked_list_t pointer.
329 *
330 * When generating the traffic_selector_substructure_t objects are stored
331 * in the pointed linked_list.
332 *
333 * When parsing the parsed traffic_selector_substructure_t objects have
334 * to be stored in the pointed linked_list.
335 */
336 TRAFFIC_SELECTORS,
337
338 /**
339 * Representating a Traffic selector type field.
340 *
341 * When generating it must be changed from host to network order.
342 * The value is read from the associated data struct.
343 * The current write position is moved 16 bit forward afterwards.
344 *
345 * When parsing it must be changed from network to host order.
346 * The value is written to the associated data struct.
347 * The current read pointer is moved 16 bit forward afterwards.
348 */
349 TS_TYPE,
350
351 /**
352 * Representating an address field in a traffic selector.
353 *
354 * Depending on the last field of type TS_TYPE
355 * this field is either 4 or 16 byte long.
356 *
357 * When generating the content of the chunkt pointing to
358 * is written.
359 *
360 * When parsing 4 or 16 bytes are read and written into the chunk pointing to.
361 */
362 ADDRESS,
363
364 /**
365 * Representing a variable length byte field.
366 */
367 CHUNK_DATA,
368
369 /**
370 * Representating an IKE_SPI field in an IKEv2 Header.
371 *
372 * When generating the value of the u_int64_t pointing to
373 * is written (host and networ order is not changed).
374 *
375 * When parsing 8 bytes are read and written into the u_int64_t pointing to.
376 */
377 IKE_SPI,
378 };
379
380 /**
381 * enum name for encoding_type_t
382 */
383 extern enum_name_t *encoding_type_names;
384
385 /**
386 * Rule how to en-/decode a payload field.
387 *
388 * An encoding rule is a mapping of a specific encoding type to
389 * a location in the data struct where the current field is stored to
390 * or read from.
391 * This rules are used by parser and generator.
392 */
393 struct encoding_rule_t {
394
395 /**
396 * Encoding type.
397 */
398 encoding_type_t type;
399
400 /**
401 * Offset in the data struct.
402 *
403 * When parsing, data are written to this offset of the
404 * data struct.
405 *
406 * When generating, data are read from this offset in the
407 * data struct.
408 */
409 u_int32_t offset;
410 };
411
412 #endif /** ENCODINGS_H_ @}*/