message.h 12.1 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
/*
 * Copyright (C) 1999  Internet Software Consortium.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

18 19
#ifndef DNS_MESSAGE_H
#define DNS_MESSAGE_H 1
20 21 22 23 24 25

/***
 ***	Imports
 ***/

#include <isc/mem.h>
Michael Graff's avatar
Michael Graff committed
26
#include <isc/buffer.h>
27 28 29 30 31

#include <dns/types.h>
#include <dns/result.h>
#include <dns/name.h>
#include <dns/rdataset.h>
Michael Graff's avatar
Michael Graff committed
32
#include <dns/compress.h>
33 34 35 36

/*
 * How this beast works:
 *
37
 * When a dns message is received in a buffer, dns_message_fromwire() is called
38 39 40 41 42 43 44 45
 * on the memory region.  Various items are checked including the format
 * of the message (if counts are right, if counts consume the entire sections,
 * and if sections consume the entire message) and known pseudo-RRs in the
 * additional data section are analyzed and removed.
 *
 * TSIG checking is also done at this layer, and any DNSSEC information should
 * also be performed at this time.
 *
46
 * If dns_message_fromwire() returns DNS_R_MOREDATA additional
47 48
 * message packets are required.  This implies an EDNS message.
 *
49
 * When going from structure to wire, dns_message_towire() will return
Michael Graff's avatar
typo  
Michael Graff committed
50
 * DNS_R_MOREDATA if there is more data left in the output buffer that
51 52 53 54 55 56 57 58 59
 * could not be rendered into the exisiting buffer.
 *
 * XXX Needed:  ways to handle TSIG and DNSSEC, supply TSIG and DNSSEC
 * keys, set and retrieve EDNS information, add rdata to a section,
 * move rdata from one section to another, remove rdata, etc.
 */

ISC_LANG_BEGINDECLS

60 61 62 63 64
#define DNS_MESSAGEFLAG_QR		0x8000U
#define DNS_MESSAGEFLAG_AA		0x0400U
#define DNS_MESSAGEFLAG_TC		0x0200U
#define DNS_MESSAGEFLAG_RD		0x0100U
#define DNS_MESSAGEFLAG_RA		0x0080U
65

66 67 68
#define DNS_MESSAGE_OPCODE_MASK		0x7000U
#define DNS_MESSAGE_OPCODE_SHIFT	    11
#define DNS_MESSAGE_RCODE_MASK		0x000fU
69
#define DNS_MESSAGE_FLAG_MASK		0x8ff0U
70

Michael Graff's avatar
Michael Graff committed
71 72
#define DNS_MESSAGE_HEADER_LEN		    12 /* 6 u_int16_t's */

Michael Graff's avatar
Michael Graff committed
73 74 75 76
/*
 * Ordering here matters.  DNS_SECTION_ANY must be the lowest and negative,
 * and DNS_SECTION_MAX must be one greater than the last used section.
 */
Michael Graff's avatar
Michael Graff committed
77
typedef int dns_section_t;
Michael Graff's avatar
Michael Graff committed
78
#define DNS_SECTION_ANY			(-1)
Michael Graff's avatar
Michael Graff committed
79 80 81 82 83 84
#define DNS_SECTION_QUESTION		0
#define DNS_SECTION_ANSWER		1
#define DNS_SECTION_AUTHORITY		2
#define DNS_SECTION_ADDITIONAL		3
#define DNS_SECTION_OPT			4 /* pseudo-section */
#define DNS_SECTION_TSIG		5 /* pseudo-section */
Michael Graff's avatar
Michael Graff committed
85
#define DNS_SECTION_MAX			6
Michael Graff's avatar
Michael Graff committed
86 87

/*
Michael Graff's avatar
Michael Graff committed
88
 * These tell the message library how the created dns_message_t will be used.
Michael Graff's avatar
Michael Graff committed
89
 */
Michael Graff's avatar
Michael Graff committed
90 91 92 93
#define DNS_MESSAGE_INTENT_UNKNOWN	0 /* internal use only */
#define DNS_MESSAGE_INTENT_PARSE	1 /* parsing messages */
#define DNS_MESSAGE_INTENT_RENDER	2 /* rendering */

Michael Graff's avatar
Michael Graff committed
94 95
typedef struct dns_msgblock dns_msgblock_t;

96
typedef struct {
Michael Graff's avatar
Michael Graff committed
97
	unsigned int			magic;
98

Michael Graff's avatar
Michael Graff committed
99
	unsigned int			id;
Michael Graff's avatar
Michael Graff committed
100 101 102
	unsigned int			flags;
	unsigned int			rcode;
	unsigned int			opcode;
Michael Graff's avatar
Michael Graff committed
103
	dns_rdataclass_t		rdclass;
Michael Graff's avatar
Michael Graff committed
104

Michael Graff's avatar
Michael Graff committed
105
	/* 4 real, 2 pseudo */
Michael Graff's avatar
Michael Graff committed
106
	unsigned int			counts[DNS_SECTION_MAX];
Michael Graff's avatar
Michael Graff committed
107 108
	dns_namelist_t			sections[DNS_SECTION_MAX];
	dns_name_t		       *cursors[DNS_SECTION_MAX];
109

Michael Graff's avatar
Michael Graff committed
110
	int				state;
Michael Graff's avatar
Michael Graff committed
111
	unsigned int			from_to_wire : 2;
Michael Graff's avatar
Michael Graff committed
112
	unsigned int			reserved;
113

114
	isc_buffer_t		       *buffer;
Michael Graff's avatar
Michael Graff committed
115 116
	dns_compress_t			cctx;
	isc_boolean_t			need_cctx_cleanup;
117

Michael Graff's avatar
Michael Graff committed
118
	isc_mem_t		       *mctx;
Michael Graff's avatar
Michael Graff committed
119
	ISC_LIST(isc_dynbuffer_t)	scratchpad;
Michael Graff's avatar
Michael Graff committed
120 121
	ISC_LIST(dns_msgblock_t)	names;
	ISC_LIST(dns_msgblock_t)	rdatas;
Michael Graff's avatar
Michael Graff committed
122
	ISC_LIST(dns_msgblock_t)	rdatasets;
Michael Graff's avatar
Michael Graff committed
123
	ISC_LIST(dns_msgblock_t)	rdatalists;
Michael Graff's avatar
Michael Graff committed
124 125 126 127
	dns_name_t		       *nextname;
	dns_rdata_t		       *nextrdata;
	dns_rdataset_t		       *nextrdataset;
	dns_rdatalist_t		       *nextrdatalist;
Michael Graff's avatar
Michael Graff committed
128
} dns_message_t;
129

Michael Graff's avatar
Michael Graff committed
130
dns_result_t
Michael Graff's avatar
Michael Graff committed
131
dns_message_create(isc_mem_t *mctx, dns_message_t **msg, unsigned int intent);
132
/*
Michael Graff's avatar
Michael Graff committed
133
 * Initialize msg structure.  Must be called on a new (or reused) structure.
134
 *
Michael Graff's avatar
Michael Graff committed
135 136 137 138 139
 * This function will allocate some internal blocks of memory that are
 * exptected to be needed for parsing or rendering nearly any type of message.
 *
 * Requires:
 *	'mctx' be a valid memory context.
140
 *
Michael Graff's avatar
Michael Graff committed
141 142 143 144
 *	'msg' be non-null and '*msg' be NULL.
 *
 *	'intent' must be one of DNS_MESSAGE_INTENT_PARSE or
 *	DNS_MESSAGE_INTENT_RENDER.
Michael Graff's avatar
Michael Graff committed
145 146
 *
 * Ensures:
Michael Graff's avatar
Michael Graff committed
147
 *	The data in "*msg" is set to indicate an unused and empty msg
Michael Graff's avatar
Michael Graff committed
148 149 150
 *	structure.
 *
 * Returns:
151 152
 *	DNS_R_NOMEMORY		-- out of memory
 *	DNS_R_SUCCESS		-- success
153 154
 */

Michael Graff's avatar
Michael Graff committed
155 156 157 158 159 160 161 162 163 164 165 166 167 168 169
void
dns_message_reset(dns_message_t *msg);
/*
 * Reset a message structure to default state.  All internal lists are freed
 * or reset to a default state as well.  This is simply a more efficient
 * way to call dns_message_destroy() followed by dns_message_allocate(),
 * since it avoid many memory allocations.
 *
 * Requires:
 *
 *	'msg' be valid.
 *
 *	If any data loanouts (buffers, names, rdatas, etc) were requested,
 *	the caller must no longer use them after this call.
 */
Michael Graff's avatar
Michael Graff committed
170

Michael Graff's avatar
Michael Graff committed
171
void
Michael Graff's avatar
Michael Graff committed
172
dns_message_destroy(dns_message_t **msg);
Michael Graff's avatar
Michael Graff committed
173
/*
Michael Graff's avatar
Michael Graff committed
174 175 176 177 178 179 180
 * Destroy all state in the message.
 *
 * Requires:
 *
 *	'msg' be valid.
 *
 *	'msg' be "empty" with no message elements on the internal lists.
Michael Graff's avatar
Michael Graff committed
181 182
 *
 * Ensures:
Michael Graff's avatar
Michael Graff committed
183
 *	'msg' can be reused via re-initialization with dns_message_init()
Michael Graff's avatar
Michael Graff committed
184 185
 */

Michael Graff's avatar
Michael Graff committed
186
dns_result_t
Michael Graff's avatar
Michael Graff committed
187
dns_message_parse(dns_message_t *msg, isc_buffer_t *source);
Michael Graff's avatar
Michael Graff committed
188
/*
Michael Graff's avatar
Michael Graff committed
189 190 191 192 193 194 195
 * Parse raw wire data pointed to by "buffer" and bounded by "buflen" as a
 * DNS message.
 *
 * OPT records are detected and stored in the pseudo-section "opt".
 * TSIGs are detected and stored in the pseudo-section "tsig".  At detection
 * time, the TSIG is verified (XXX) and the message fails if the TSIG fails
 * to verify.
Michael Graff's avatar
Michael Graff committed
196 197 198 199 200 201 202 203 204 205 206 207 208 209
 *
 * If this is a multi-packet message (edns) and more data is required to
 * build the full message state, DNS_R_MOREDATA is returned.  In this case,
 * this function should be repeated with all input buffers until DNS_R_SUCCESS
 * (or an error) is returned.
 *
 * Requires:
 *	"msg" be valid.
 *
 *	"buffer" have "sane" contents.
 *
 * Ensures:
 *	The buffer's data format is correct.
 *
Michael Graff's avatar
Michael Graff committed
210 211
 *	The buffer's contents verify as correct regarding header bits, buffer
 * 	and rdata sizes, etc.
Michael Graff's avatar
Michael Graff committed
212 213 214
 *
 * Returns:
 *	DNS_R_SUCCESS		-- all is well
Michael Graff's avatar
Michael Graff committed
215
 *	DNS_R_NOMEMORY		-- no memory
Michael Graff's avatar
Michael Graff committed
216 217 218 219
 *	DNS_R_MOREDATA		-- more packets needed for complete message
 *	DNS_R_???		-- bad signature (XXX need more of these)
 */

Michael Graff's avatar
Michael Graff committed
220 221
dns_result_t
dns_message_renderbegin(dns_message_t *msg, isc_buffer_t *buffer);
Michael Graff's avatar
Michael Graff committed
222
/*
Michael Graff's avatar
Michael Graff committed
223 224
 * Begin rendering on a message.  Only one call can be made to this function
 * per message.
Michael Graff's avatar
Michael Graff committed
225 226
 *
 * Requires:
Michael Graff's avatar
Michael Graff committed
227 228
 *
 *	'msg' be valid.
229 230 231 232
 *
 *	buffer != NULL.
 *
 *	buffer is empty.
Michael Graff's avatar
Michael Graff committed
233 234 235
 */

dns_result_t
236 237 238 239 240 241 242 243 244 245 246 247 248 249 250
dns_message_renderchangebuffer(dns_message_t *msg, isc_buffer_t *buffer);
/*
 * Reset the buffer.  This can be used after growing the old buffer
 * on a DNS_R_NOSPACE return from most of the render functions.
 *
 * Requires:
 *
 *	'msg' be valid.
 *
 *	dns_message_renderbegin() was called.
 *
 *	buffer != NULL.
 *
 * Returns:
 *
251 252
 *	DNS_R_NOSPACE		-- new buffer is too small
 *	DNS_R_SUCCESS		-- all is well.
253 254 255 256
 */

dns_result_t
dns_message_renderreserve(dns_message_t *msg, unsigned int space);
Michael Graff's avatar
Michael Graff committed
257 258 259 260 261 262
/*
 * Reserve "space" bytes in the given buffer.
 *
 * Requires:
 *
 *	'msg' be valid.
Michael Graff's avatar
Michael Graff committed
263
 *
264 265
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
266
 * Returns:
Michael Graff's avatar
Michael Graff committed
267 268 269
 *
 *	DNS_R_SUCCESS		-- all is well.
 *	DNS_R_NOSPACE		-- not enough free space in the buffer.
Michael Graff's avatar
Michael Graff committed
270 271
 */

Michael Graff's avatar
Michael Graff committed
272 273 274 275 276 277 278 279 280
dns_result_t
dns_message_renderrelease(dns_message_t *msg, unsigned int space);
/*
 * Release "space" bytes in the given buffer that was previously reserved.
 *
 * Requires:
 *
 *	'msg' be valid.
 *
281 282
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
283 284 285 286 287 288
 * Returns:
 *
 *	DNS_R_SUCCESS		-- all is well.
 *	DNS_R_NOSPACE		-- trying to release more than was reserved.
 */

Michael Graff's avatar
Michael Graff committed
289
dns_result_t
290 291
dns_message_rendersection(dns_message_t *msg, dns_section_t section,
			  unsigned int priority, unsigned int flags);
Michael Graff's avatar
Michael Graff committed
292
/*
Michael Graff's avatar
Michael Graff committed
293 294
 * Render all names, rdatalists, etc from the given section at the
 * specified priority or higher.
Michael Graff's avatar
Michael Graff committed
295 296
 *
 * Requires:
Michael Graff's avatar
Michael Graff committed
297 298 299
 *	'msg' be valid.
 *
 *	'section' be a valid section.
Michael Graff's avatar
Michael Graff committed
300
 *
Michael Graff's avatar
Michael Graff committed
301 302
 *	'buffer' be non-NULL and be initialized to point to a valid memory
 *	block.
Michael Graff's avatar
Michael Graff committed
303
 *
304 305
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
306
 * Returns:
Michael Graff's avatar
Michael Graff committed
307 308 309 310 311 312
 *	DNS_R_SUCCESS		-- all records were written, and there are
 *				   no more records for this section.
 *	DNS_R_NOSPACE		-- Not enough room in the buffer to write
 *				   all records requested.
 *	DNS_R_MOREDATA		-- All requested records written, and there
 *				   are records remaining for this section.
Michael Graff's avatar
Michael Graff committed
313 314
 */

Michael Graff's avatar
Michael Graff committed
315
dns_result_t
316
dns_message_renderend(dns_message_t *msg);
Michael Graff's avatar
Michael Graff committed
317
/*
Michael Graff's avatar
Michael Graff committed
318 319 320 321 322 323 324 325
 * Finish rendering to the buffer.  Note that more data can be in the
 * 'msg' structure.  Destroying the structure will free this, or in a multi-
 * part EDNS1 message this data can be rendered to another buffer later.
 *
 * Requires:
 *
 *	'msg' be a valid message.
 *
326 327
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362
 * Returns:
 *
 *	DNS_R_SUCCESS		-- all is well.
 */
		      

dns_result_t
dns_message_firstname(dns_message_t *msg, dns_section_t section);
/*
 * Set internal per-section name pointer to the beginning of the section.
 *
 * Requires:
 *
 *   	'msg' be valid.
 *
 *	'section' be a valid section.
 *
 * Returns:
 *
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMORE		-- No names on given section.
 */

dns_result_t
dns_message_nextname(dns_message_t *msg, dns_section_t section);
/*
 * Sets the internal per-section name pointer to point to the next name
 * in that section.
 *
 * Requires:
 *
 *   	'msg' be valid.
 *
 *	'section' be a valid section.
 *
Michael Graff's avatar
Michael Graff committed
363 364 365
 *	dns_message_firstname() must have been called on this section,
 *	and the result was DNS_R_SUCCESS.
 *
Michael Graff's avatar
Michael Graff committed
366 367 368 369 370 371
 * Returns:
 *
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMORE		-- No names in given section.
 */

Michael Graff's avatar
Michael Graff committed
372
void
Michael Graff's avatar
Michael Graff committed
373 374 375 376 377 378 379 380 381 382 383 384 385 386
dns_message_currentname(dns_message_t *msg, dns_section_t section,
			dns_name_t **name);
/*
 * Sets 'name' to point to the name where the per-section internal name
 * pointer is currently set.
 *
 * Requires:
 *
 *	'msg' be valid.
 *
 *	'name' be non-NULL, and *name be NULL.
 *
 *	'section' be a valid section.
 *
Michael Graff's avatar
Michael Graff committed
387 388 389
 *	dns_message_firstname() must have been called on this section,
 *	and the result of it and any dns_message_nextname() calls was
 *	DNS_R_SUCCESS.
Michael Graff's avatar
Michael Graff committed
390 391
 */

Michael Graff's avatar
Michael Graff committed
392 393 394 395
dns_result_t
dns_message_findname(dns_message_t *msg, dns_section_t section,
		     dns_name_t *target, dns_rdatatype_t type,
		     dns_name_t **name, dns_rdataset_t **rdataset);
Michael Graff's avatar
Michael Graff committed
396
/*
Michael Graff's avatar
Michael Graff committed
397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422
 * Search for a name in the specified section.  If it is found, *name is
 * set to point to the name, and *rdataset is set to point to the found
 * rdataset (if type is specified as other than dns_rdatatype_any.)
 *
 * Requires:
 *	'msg' be valid.
 *
 *	'section' be a valid section.
 *
 *	If a pointer to the name is desired, 'name' should be non-NULL.
 *	If it is non-NULL, '*name' MUST be NULL.
 *
 *	If a type other than dns_datatype_any is searched for, 'rdataset'
 *	may be non-NULL, '*rdataset' be NULL, and will point at the found
 *	rdataset.
 *
 *	'target' be a valid name.
 *
 *	'type' be a valid type.
 *
 * Returns:
 *
 *	DNS_R_SUCCESS		-- all is well.
 *	DNS_R_NXDOMAIN		-- name does not exist in that section.
 *	DNS_R_NXRDATASET	-- The name does exist, but the desired
 *				   type does not.
Michael Graff's avatar
Michael Graff committed
423 424
 */

Michael Graff's avatar
Michael Graff committed
425 426 427 428
void
dns_message_movename(dns_message_t *msg, dns_name_t *name,
		     dns_section_t fromsection,
		     dns_section_t tosection);
Michael Graff's avatar
Michael Graff committed
429 430
/*
 * Move a name from one section to another.
Michael Graff's avatar
Michael Graff committed
431 432 433 434 435
 *
 * Requires:
 *
 *	'msg' be valid.
 *
Michael Graff's avatar
Michael Graff committed
436
 *	'name' must be in 'fromsection'.
Michael Graff's avatar
Michael Graff committed
437 438 439 440
 *
 *	'fromsection' must be a valid section.
 *
 *	'tosection' must be a valid section, and be renderable.
Michael Graff's avatar
Michael Graff committed
441 442
 *
 *	'fromsection' and 'tosection' cannot be the same section.
Michael Graff's avatar
Michael Graff committed
443 444
 */

Michael Graff's avatar
Michael Graff committed
445 446 447
void
dns_message_addname(dns_message_t *msg, dns_name_t *name,
		    dns_section_t section);
Michael Graff's avatar
Michael Graff committed
448 449 450
/*
 * Adds the name to the given section.
 *
Michael Graff's avatar
Michael Graff committed
451 452
 * Caller must ensure that the name does not already exist.  This condition
 * is NOT checked for by this function.
Michael Graff's avatar
Michael Graff committed
453 454 455 456 457 458 459 460
 *
 * Requires:
 *
 *	'msg' be valid, and be a renderable message.
 *
 *	'name' be a valid name.
 *
 *	'section' be a named section.
Michael Graff's avatar
Michael Graff committed
461
 */
462 463 464 465

ISC_LANG_ENDDECLS

#endif	/* DNS_DNS_H */