1 /*
2
3 silcpacket.h
4
5 Author: Pekka Riikonen <priikone@silcnet.org>
6
7 Copyright (C) 1997 - 2007 Pekka Riikonen
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; version 2 of the License.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 */
19
20 /****h* silccore/SILC Packet Engine Interface
21 *
22 * DESCRIPTION
23 *
24 * The SILC secure binary packet protocol interface, provides interface for
25 * sending and receiving SILC packets. The interface provides a packet
26 * engine, that can be used to receive packets from packet streams, and
27 * routines for sending all kinds of SILC packets.
28 *
29 * The packet engine and packet stream are thread safe. They can be safely
30 * used in multi threaded environment.
31 *
32 ***/
33
34 #ifndef SILCPACKET_H
35 #define SILCPACKET_H
36
37 /* Maximum packet length */
38 #define SILC_PACKET_MAX_LEN 0xffff
39
40 /* Maximum length of ID */
41 #define SILC_PACKET_MAX_ID_LEN 28
42
43 /****d* silccore/SilcPacketAPI/SilcPacketType
44 *
45 * NAME
46 *
47 * typedef SilcUInt8 SilcPacketType;
48 *
49 * DESCRIPTION
50 *
51 * SILC packet type definition and all the packet types.
52 *
53 * SOURCE
54 */
55 typedef SilcUInt8 SilcPacketType;
56
57 /* SILC Packet types. */
58 #define SILC_PACKET_DISCONNECT 1 /* Disconnection */
59 #define SILC_PACKET_SUCCESS 2 /* Success */
60 #define SILC_PACKET_FAILURE 3 /* Failure */
61 #define SILC_PACKET_REJECT 4 /* Rejected */
62 #define SILC_PACKET_NOTIFY 5 /* Notify message */
63 #define SILC_PACKET_ERROR 6 /* Error message */
64 #define SILC_PACKET_CHANNEL_MESSAGE 7 /* Message for channel */
65 #define SILC_PACKET_CHANNEL_KEY 8 /* Key of the channel */
66 #define SILC_PACKET_PRIVATE_MESSAGE 9 /* Private message */
67 #define SILC_PACKET_PRIVATE_MESSAGE_KEY 10 /* Private message key*/
68 #define SILC_PACKET_COMMAND 11 /* Command */
69 #define SILC_PACKET_COMMAND_REPLY 12 /* Reply to a command */
70 #define SILC_PACKET_KEY_EXCHANGE 13 /* Start of KE */
71 #define SILC_PACKET_KEY_EXCHANGE_1 14 /* KE1 */
72 #define SILC_PACKET_KEY_EXCHANGE_2 15 /* KE2 */
73 #define SILC_PACKET_CONNECTION_AUTH_REQUEST 16 /* Request of auth meth */
74 #define SILC_PACKET_CONNECTION_AUTH 17 /* Connectinon auth */
75 #define SILC_PACKET_NEW_ID 18 /* Sending new ID */
76 #define SILC_PACKET_NEW_CLIENT 19 /* Client registering */
77 #define SILC_PACKET_NEW_SERVER 20 /* Server registering */
78 #define SILC_PACKET_NEW_CHANNEL 21 /* Channel registering */
79 #define SILC_PACKET_REKEY 22 /* Re-key start */
80 #define SILC_PACKET_REKEY_DONE 23 /* Re-key done */
81 #define SILC_PACKET_HEARTBEAT 24 /* Heartbeat */
82 #define SILC_PACKET_KEY_AGREEMENT 25 /* Key Agreement request */
83 #define SILC_PACKET_RESUME_ROUTER 26 /* Backup router resume */
84 #define SILC_PACKET_FTP 27 /* File Transfer */
85 #define SILC_PACKET_RESUME_CLIENT 28 /* Client resume */
86 #define SILC_PACKET_ACK 29 /* Acknowledgement */
87
88 #define SILC_PACKET_PRIVATE 200 /* Private range start */
89 #define SILC_PACKET_MAX 255 /* RESERVED */
90
91 #define SILC_PACKET_NONE 0 /* RESERVED */
92 #define SILC_PACKET_ANY 0
93 /***/
94
95 /****d* silccore/SilcPacketAPI/SilcPacketFlags
96 *
97 * NAME
98 *
99 * typedef SilcUInt8 SilcPacketFlags;
100 *
101 * DESCRIPTION
102 *
103 * SILC packet flags type definition and all the packet flags.
104 *
105 * SOURCE
106 */
107 typedef SilcUInt8 SilcPacketFlags;
108
109 /* All defined packet flags */
110 #define SILC_PACKET_FLAG_NONE 0x00 /* No flags */
111 #define SILC_PACKET_FLAG_PRIVMSG_KEY 0x01 /* Private message key */
112 #define SILC_PACKET_FLAG_LIST 0x02 /* Packet is a list */
113 #define SILC_PACKET_FLAG_BROADCAST 0x04 /* Packet is a broadcast */
114 #define SILC_PACKET_FLAG_COMPRESSED 0x08 /* Payload is compressed */
115 #define SILC_PACKET_FLAG_ACK 0x10 /* Acknowledge packet */
116
117 /* Impelemntation specific flags */
118 #define SILC_PACKET_FLAG_LONG_PAD 0x20 /* Use maximum padding */
119 /***/
120
121 /****s* silccore/SilcPacketAPI/SilcPacketEngine
122 *
123 * NAME
124 *
125 * typedef struct SilcPacketEngineStruct *SilcPacketEngine;
126 *
127 * DESCRIPTION
128 *
129 * The packet engine context, allocated by silc_packet_engine_start.
130 * The engine is destroyed with silc_packet_engine_stop.
131 *
132 ***/
133 typedef struct SilcPacketEngineStruct *SilcPacketEngine;
134
135 /****s* silccore/SilcPacketAPI/SilcPacketStream
136 *
137 * NAME
138 *
139 * typedef struct SilcPacketStreamStruct *SilcPacketStream;
140 *
141 * DESCRIPTION
142 *
143 * The packet stream context, allocated by silc_packet_stream_create.
144 * The stream is destroyed with silc_packet_stream_destroy.
145 *
146 ***/
147 typedef struct SilcPacketStreamStruct *SilcPacketStream;
148
149 /****s* silccore/SilcPacketAPI/SilcPacket
150 *
151 * NAME
152 *
153 * typedef struct SilcPacketStruct *SilcPacket;
154 *
155 * DESCRIPTION
156 *
157 * The SilcPacket is returned by the packet engine in the SilcPacketReceive
158 * callback. The application can parse the data payload from the
159 * SilcPacket. Also packet type, flags, and sender and destination
160 * IDs are available. The application must free the packet with the
161 * silc_packet_free function if it takes it in for processing.
162 *
163 * The `buffer' field contains the parsed packet payload and the start
164 * of the data area will point to the start of the packet payload.
165 *
166 * The list pointer `next' can be used by the application to put the
167 * packet context in a list during processing, if needed.
168 *
169 * SOURCE
170 */
171 typedef struct SilcPacketStruct {
172 struct SilcPacketStruct *next; /* List pointer, application may set */
173 SilcPacketStream stream; /* Packet stream this packet is from */
174 SilcBufferStruct buffer; /* Packet data payload */
175 unsigned char *src_id; /* Source ID */
176 unsigned char *dst_id; /* Destination ID */
177 unsigned int src_id_len : 6; /* Source ID length */
178 unsigned int src_id_type : 2; /* Source ID type */
179 unsigned int dst_id_len : 6; /* Destination ID length */
180 unsigned int dst_id_type : 2; /* Destination ID type */
181 SilcPacketType type; /* Packet type */
182 SilcPacketFlags flags; /* Packet flags */
183 } *SilcPacket;
184 /***/
185
186 /****d* silcutil/SilcPacketAPI/SilcPacketError
187 *
188 * NAME
189 *
190 * typedef enum { ... } SilcPacketError
191 *
192 * DESCRIPTION
193 *
194 * Packet errors. This is returned in the error callback. If application
195 * needs the actual lower level stream error, it needs to retrieve it
196 * from the actual stream. It can retrieve the underlaying stream from
197 * the packet stream by calling silc_packet_stream_get_stream function.
198 *
199 * You may retrieve string version of the SilcPacketError by calling
200 * silc_packet_error_string.
201 *
202 * SOURCE
203 */
204 typedef enum {
205 SILC_PACKET_ERR_READ, /* Error while reading */
206 SILC_PACKET_ERR_WRITE, /* Error while writing */
207 SILC_PACKET_ERR_MAC_FAILED, /* Packet MAC check failed */
208 SILC_PACKET_ERR_DECRYPTION_FAILED, /* Packet decryption failed */
209 SILC_PACKET_ERR_UNKNOWN_SID, /* Unknown SID (with IV included) */
210 SILC_PACKET_ERR_MALFORMED, /* Packet is malformed */
211 SILC_PACKET_ERR_NO_MEMORY, /* System out of memory */
212 } SilcPacketError;
213 /***/
214
215 /****f* silccore/SilcPacketAPI/SilcPacketReceiveCb
216 *
217 * SYNOPSIS
218 *
219 * typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
220 * SilcPacketStream stream,
221 * SilcPacket packet,
222 * void *callback_context,
223 * void *stream_context);
224 *
225 * DESCRIPTION
226 *
227 * The packet receive callback is called by the packet engine when a new
228 * SILC Packet has arrived. The application must free the returned
229 * SilcPacket with silc_packet_free if it takes the packet in for
230 * processing. This callback is set in the SilcPacketCallbacks structure.
231 * The `callback_context' is the context set as argument in the
232 * silc_packet_engine_start function. The `stream_context' is stream
233 * specific context that was set by calling silc_packet_set_context.
234 *
235 * If the application takes the received packet `packet' into processing
236 * TRUE must be returned. If FALSE is returned the packet engine will
237 * pass the packet to other packet processor, if one has been linked
238 * to the stream with silc_packet_stream_link function. If no extra
239 * processor is linked the packet is dropped.
240 *
241 * EXAMPLE
242 *
243 * SilcBool
244 * silc_foo_packet_receive_cb(SilcPacketEngine engine,
245 * SilcPacketStream stream, SilcPacket packet,
246 * void *callback_context, void *stream_context)
247 * {
248 * Application ctx = callback_context;
249 *
250 * // If we're not up yet, let's not process the packet
251 * if (ctx->initialized == FALSE)
252 * return FALSE;
253 *
254 * // Process the incoming packet...
255 * ...
256 *
257 * // It's our packet now, no one else will get it
258 * return TRUE;
259 * }
260 *
261 ***/
262 typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
263 SilcPacketStream stream,
264 SilcPacket packet,
265 void *callback_context,
266 void *stream_context);
267
268 /****f* silccore/SilcPacketAPI/SilcPacketEosCb
269 *
270 * SYNOPSIS
271 *
272 * typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
273 * SilcPacketStream stream,
274 * void *callback_context,
275 * void *stream_context);
276 *
277 * DESCRIPTION
278 *
279 * The End Of Stream (EOS) callback, that is called by the packet engine
280 * when the underlaying stream has ended. No more data can be sent to
281 * the stream or read from it. The `stream' must be destroyed by
282 * calling the silc_packet_stream_destroy. This callback is set in the
283 * SilcPacketCallbacks structure.
284 *
285 ***/
286 typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
287 SilcPacketStream stream,
288 void *callback_context,
289 void *stream_context);
290
291 /****f* silccore/SilcPacketAPI/SilcPacketErrorCb
292 *
293 * SYNOPSIS
294 *
295 * typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
296 * SilcPacketStream stream,
297 * SilcPacketError error,
298 * void *callback_context,
299 * void *stream_context);
300 *
301 * DESCRIPTION
302 *
303 * The error callback that is called by the packet engine if an error
304 * occurs. The `error' will indicate the error. This callback is set
305 * in the SilcPacketCallbacks structure.
306 *
307 ***/
308 typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
309 SilcPacketStream stream,
310 SilcPacketError error,
311 void *callback_context,
312 void *stream_context);
313
314 /****s* silccore/SilcPacketAPI/SilcPacketCallbacks
315 *
316 * NAME
317 *
318 * typedef struct { ... } *SilcPacketCallbacks;
319 *
320 * DESCRIPTION
321 *
322 * This structure is sent as argument to the silc_packet_engine_start
323 * function to set the callback functions for the packet engine. The
324 * packet engine will call the callbacks when necessary. Application
325 * must always be provided for the packet engine.
326 *
327 * SOURCE
328 */
329 typedef struct {
330 SilcPacketReceiveCb packet_receive; /* Called when packet is received */
331 SilcPacketEosCb eos; /* Called on end of stream */
332 SilcPacketErrorCb error; /* Called on an error */
333 } SilcPacketCallbacks;
334 /***/
335
336 /* Prototypes */
337
338 /****f* silccore/SilcPacketAPI/silc_packet_engine_start
339 *
340 * SYNOPSIS
341 *
342 * SilcPacketEngine
343 * silc_packet_engine_start(SilcRng rng, SilcBool router,
344 * SilcPacketCallbacks *callbacks,
345 * void *callback_context);
346 *
347 * DESCRIPTION
348 *
349 * Create new packet engine for processing incoming and outgoing packets.
350 * If `router' is TRUE then the application is considered to be router
351 * server, and certain packets are handled differently. Client and normal
352 * server must set it to FALSE. The `callbacks' is a SilcPacketCallbacks
353 * structure provided by the caller which includes the callbacks that is
354 * called when for example packet is received, or end of stream is called.
355 *
356 * NOTES
357 *
358 * The packet engine is thread safe. You can use one packet engine in
359 * multi threaded application.
360 *
361 ***/
362 SilcPacketEngine
363 silc_packet_engine_start(SilcRng rng, SilcBool router,
364 SilcPacketCallbacks *callbacks,
365 void *callback_context);
366
367 /****f* silccore/SilcPacketAPI/silc_packet_engine_stop
368 *
369 * SYNOPSIS
370 *
371 * void silc_packet_engine_stop(SilcPacketEngine engine);
372 *
373 * DESCRIPTION
374 *
375 * Stop the packet engine. No new packets can be sent or received after
376 * calling this, and the `engine' will become invalid.
377 *
378 ***/
379 void silc_packet_engine_stop(SilcPacketEngine engine);
380
381 /****f* silccore/SilcPacketAPI/silc_packet_error_string
382 *
383 * SYNOPSIS
384 *
385 * const char *silc_packet_error_string(SilcPacketError error);
386 *
387 * DESCRIPTION
388 *
389 * Return the packet error as string.
390 *
391 ***/
392 const char *silc_packet_error_string(SilcPacketError error);
393
394 /****f* silccore/SilcPacketAPI/silc_packet_engine_get_streams
395 *
396 * SYNOPSIS
397 *
398 * SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
399 *
400 * DESCRIPTION
401 *
402 * Returns list of packet streams added to the packet engine. The caller
403 * must free the list with silc_packet_engine_free_streams_list.
404 *
405 * NOTES
406 *
407 * This function may also return disconnected and destroyed streams. The
408 * caller should use silc_packet_stream_is_valid to check if the stream
409 * is valid.
410 *
411 ***/
412 SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
413
414 /****f* silccore/SilcPacketAPI/silc_packet_engine_free_streams_list
415 *
416 * SYNOPSIS
417 *
418 * void silc_packet_engine_free_streams_list(SilcDList streams);
419 *
420 * DESCRIPTION
421 *
422 * Free's the streams list returned by silc_packet_engine_get_streams.
423 *
424 ***/
425 void silc_packet_engine_free_streams_list(SilcDList streams);
426
427 /****f* silccore/SilcPacketAPI/silc_packet_stream_create
428 *
429 * SYNOPSIS
430 *
431 * SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
432 * SilcSchedule schedule,
433 * SilcStream stream);
434 *
435 * DESCRIPTION
436 *
437 * Create new packet stream and use the `stream' as underlaying stream.
438 * Usually the `stream' would be a socket stream, but it can be any
439 * stream. After this function returns, packets can immediately be
440 * sent to and received from the stream.
441 *
442 * NOTES
443 *
444 * SilcPacketStream cannot be used with silc_stream_* routines (such as
445 * silc_stream_read and silc_stream_write) because of its special nature.
446 * Use the silc_packet_send and the silc_packet_send_ext to send packets.
447 * To read packets you will receive the packet receive callback from
448 * packet engine. Destroy the stream with silc_packet_stream_destroy.
449 *
450 * The SilcPacketStream is thread safe. Same context can be safely used
451 * in multi threaded environment.
452 *
453 ***/
454 SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
455 SilcSchedule schedule,
456 SilcStream stream);
457
458 /****f* silccore/SilcPacketAPI/silc_packet_stream_add_remote
459 *
460 * SYNOPSIS
461 *
462 * SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
463 * const char *remote_ip,
464 * SilcUInt16 remote_port,
465 * SilcPacket packet);
466 *
467 * DESCRIPTION
468 *
469 * This function is used to add remote receivers in packet stream `stream'
470 * that has UDP/IP socket stream as the underlaying stream. This function
471 * cannot be used with other type of streams. This returns new packet
472 * stream context that can be used to send to and receive packets from
473 * the specified remote IP and remote port, or NULL on error. The `stream'
474 * is the actual stream that is used to send and receive the data.
475 *
476 * When the parent `stream' receives packets from remote IP address
477 * and port that does not have its own remote packet stream, it returns
478 * the packet to the packet callback set for `stream'. The sender's
479 * IP address and port can then be retrieved by using the
480 * silc_packet_get_sender function and to create new packet stream by
481 * calling this function. After that, all packets from that IP address
482 * and port will be received by the new packet stream.
483 *
484 * If the `packet' is non-NULL it will be injected into the new packet
485 * stream as soon as the scheduler associated with `stream' schedules
486 * new tasks. It can be used to inject an incoming packet to the stream.
487 *
488 * This interface is for connectionless UDP streams. If it is possible
489 * to create connected stream it should be done for performance reasons.
490 *
491 * EXAMPLE
492 *
493 * // Create parent packet stream, it can receive packets from anywhere
494 * listener = silc_net_udp_connect("0.0.0.0", 500, NULL, 0, schedule);
495 * parent = silc_packet_stream_create(engine, schedule, listener);
496 *
497 * ...
498 * // Received a packet to the parent stream, get the sender information.
499 * silc_packet_get_sender(packet, &ip, &port);
500 *
501 * // Create new packet stream for this remote location.
502 * remote = silc_packet_stream_add_remote(parent, ip, port, packet);
503 *
504 ***/
505 SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
506 const char *remote_ip,
507 SilcUInt16 remote_port,
508 SilcPacket packet);
509
510 /****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
511 *
512 * SYNOPSIS
513 *
514 * void silc_packet_stream_destroy(SilcPacketStream stream);
515 *
516 * DESCRIPTION
517 *
518 * Destroy packet stream and the underlaying stream. This will also
519 * close and destroy the underlaying stream.
520 *
521 ***/
522 void silc_packet_stream_destroy(SilcPacketStream stream);
523
524 /****f* silccore/SilcPacketAPI/silc_packet_stream_is_valid
525 *
526 * SYNOPSIS
527 *
528 * SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
529 *
530 * DESCRIPTION
531 *
532 * Returns TRUE if the packet stream indicated by `stream' is valid and
533 * has not been disconnected or destroyed.
534 *
535 ***/
536 SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
537
538 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_router
539 *
540 * SYNOPSIS
541 *
542 * void silc_packet_stream_set_router(SilcPacketStream stream);
543 *
544 * DESCRIPTION
545 *
546 * When called sets the stream indicates by `stream' as SILC router
547 * connection stream. This causes that certain packets are handled
548 * differently. This must be called for router connection streams and
549 * must not be called for any other stream.
550 *
551 ***/
552 void silc_packet_stream_set_router(SilcPacketStream stream);
553
554 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_iv_included
555 *
556 * SYNOPSIS
557 *
558 * void silc_packet_stream_set_iv_included(SilcPacketStream stream);
559 *
560 * DESCRIPTION
561 *
562 * Sets an IV Included property for the stream indicated by `stream'.
563 * This means that the IV used in the encryption will be included in
564 * the resulted ciphertext. This makes it possible to send and receive
565 * packets on unreliable network transport protocol, such as UDP/IP.
566 * This must be called if the underlaying stream in the `stream' is UDP
567 * stream.
568 *
569 * When this is set to the stream the silc_packet_set_sid must be called
570 * to set new Security ID. The Security ID will be included with the IV
571 * in the ciphertext.
572 *
573 ***/
574 void silc_packet_stream_set_iv_included(SilcPacketStream stream);
575
576 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_stream
577 *
578 * SYNOPSIS
579 *
580 * void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
581 * SilcStream stream);
582 *
583 * DESCRIPTION
584 *
585 * This function may be used to change the underlaying stream in the
586 * packet stream indicated by `packet_stream'. Note that the old
587 * stream will not be used after calling this function. The caller is
588 * responsible destroying the old stream. The `stream' will use
589 * the same scheduler as the `packet_stream'.
590 *
591 ***/
592 void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
593 SilcStream stream);
594
595 /****f* silccore/SilcPacketAPI/silc_packet_stream_get_stream
596 *
597 * SYNOPSIS
598 *
599 * SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
600 *
601 * DESCRIPTION
602 *
603 * Returns the actual stream that is associated with the packet stream
604 * `stream'. The caller must not free the returned stream. The returned
605 * stream is the same pointer that was set for silc_packet_stream_create.
606 * This function could be used for example when an error callback is
607 * called by the packet engine to retrieve the actual lower level error
608 * from the stream.
609 *
610 ***/
611 SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
612
613 /****f* silccore/SilcPacketAPI/silc_packet_stream_link
614 *
615 * SYNOPSIS
616 *
617 * SilcBool silc_packet_stream_link(SilcPacketStream stream,
618 * SilcPacketCallbacks *callbacks,
619 * void *callback_context,
620 * int priority, ...);
621 *
622 * DESCRIPTION
623 *
624 * Links the packet processing callbacks indicated by `callbacks' into
625 * the packet stream indicated by `stream' with priority `priority' for
626 * the packet types given in the variable argument list. This function
627 * can be used to link to the packet stream for specific packet types
628 * and receive them in the specified callbacks. This way, a third party,
629 * for example some library may attach itself into the packet stream
630 * and receive and process certain packets. The variable argument
631 * list is ended with -1. To link to receive all packets use
632 * SILC_PACKET_ANY.
633 *
634 * The default packet processing callbacks given as argument to the
635 * silc_packet_engine_start has the priority 0. Any priority higher
636 * than 0 will then take precedence over the default callbacks. Any
637 * priority lower than 0 (negative value) will be processed after the
638 * default callbacks.
639 *
640 * Note that setting only the 'packet_receive' callback in the `callbacks'
641 * is required.
642 *
643 * EXAMPLE
644 *
645 * // Link to this packet stream, with high priority, for
646 * // SILC_PACKET_CONNECTION_AUTH and SILC_PACKET_CONNECTION_AUTH_REQUEST
647 * // packets. We don't care about other packets.
648 * silc_packet_stream_link(stream, our_callbacks, our_context,
649 * 1000000, SILC_PACKET_CONNECTION_AUTH,
650 * SILC_PACKET_CONNECTION_AUTH_REQUEST, -1);
651 *
652 ***/
653 SilcBool silc_packet_stream_link(SilcPacketStream stream,
654 SilcPacketCallbacks *callbacks,
655 void *callback_context,
656 int priority, ...);
657
658 /****f* silccore/SilcPacketAPI/silc_packet_stream_unlink
659 *
660 * SYNOPSIS
661 *
662 * void silc_packet_stream_unlink(SilcPacketStream stream,
663 * SilcPacketCallbacks *callbacks,
664 * void *callback_context);
665 *
666 * DESCRIPTION
667 *
668 * Unlinks the `callbacks' with `callback_context' from the packet stream
669 * indicated by `stream'. This function must be called for the callbacks
670 * that was linked to `stream' when they are not needed anymore.
671 *
672 ***/
673 void silc_packet_stream_unlink(SilcPacketStream stream,
674 SilcPacketCallbacks *callbacks,
675 void *callback_context);
676
677 /****f* silccore/SilcPacketAPI/SilcPacketWrapCoder
678 *
679 * SYNOPSIS
680 *
681 * typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
682 * SilcStreamStatus status,
683 * SilcBuffer buffer,
684 * void *context);
685 *
686 * DESCRIPTION
687 *
688 * The encoder/decoder callback for silc_packet_stream_wrap. If the
689 * `status' is SILC_STREAM_CAN_WRITE then additional data can be added
690 * to `buffer'. It is added before the data that is written with
691 * silc_stream_write. The silc_buffer_enlarge should be called to verify
692 * there is enough room in `buffer' before adding data to it. The `buffer'
693 * must not be freed.
694 *
695 * If the `status' is SILC_STREAM_CAN_READ then data from the `buffer'
696 * may be read before it is passed to readed when silc_stream_read is
697 * called. The `buffer' may be advanced also to hide data in it.
698 *
699 * This function returns FALSE in case of error.
700 *
701 ***/
702 typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
703 SilcStreamStatus status,
704 SilcBuffer buffer,
705 void *context);
706
707 /****f* silccore/SilcPacketAPI/silc_packet_stream_wrap
708 *
709 * SYNOPSIS
710 *
711 * SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
712 * SilcPacketType type,
713 * SilcPacketFlags flags,
714 * SilcBool blocking_mode,
715 * SilcPacketWrapCoder coder,
716 * void *context);
717 *
718 * DESCRIPTION
719 *
720 * Wraps the packet stream indicated by `stream' into a SilcStream for
721 * the packet type indicated by `type' with packet flags indicated by
722 * `flags'. The returned SilcStream can be used to read and write the
723 * specified SILC packets with the specified packet flags, by calling
724 * silc_stream_read and silc_stream_write, respectively. The returned
725 * stream can be destroyed by calling silc_stream_destroy. It does not
726 * destroy the wrapped packet stream.
727 *
728 * If the `blocking_mode' mode is TRUE then the silc_stream_read and
729 * silc_stream_write may block the calling process or thread until SILC
730 * packet is read or written. If it is FALSE the stream is in non-blocking
731 * mode and the calls never block. The returned stream is thread-safe and
732 * packets may be read and written in multi-threaded environment.
733 *
734 * In non-blocking mode the silc_stream_set_notifier must be called before
735 * the returned stream can be used to read packets. The stream status
736 * SILC_STREAM_CAN_READ will be returned to the notifier callback to
737 * indicate that a packet is ready for reading. Calling silc_stream_read
738 * once returns one complete SILC packet data payload (which is of type of
739 * `type').
740 *
741 * The `coder' is optional encoder/decoder callback which the packet engine
742 * will call if it is non-NULL. It can be used to encode additional data
743 * into each packet when silc_stream_write is called or decode data before
744 * it is passed to reader when silc_stream_read is called. The `context'
745 * is passed to `coder'.
746 *
747 * The returned SilcStream can be used as any normal stream and all
748 * SilcStream API functions may be used with the stream. This returns
749 * NULL on error.
750 *
751 ***/
752 SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
753 SilcPacketType type,
754 SilcPacketFlags flags,
755 SilcBool blocking_mode,
756 SilcPacketWrapCoder coder,
757 void *context);
758
759 /****f* silccore/SilcPacketAPI/silc_packet_stream_is_udp
760 *
761 * SYNOPSIS
762 *
763 * SilcBool silc_packet_stream_is_udp(SilcPacketStream stream);
764 *
765 * DESCRIPTION
766 *
767 * Returns TRUE if the packet stream indicated by `stream' is using
768 * UDP transport.
769 *
770 ***/
771 SilcBool silc_packet_stream_is_udp(SilcPacketStream stream);
772
773 /****f* silccore/SilcPacketAPI/silc_packet_get_sender
774 *
775 * SYNOPSIS
776 *
777 * SilcBool silc_packet_get_sender(SilcPacket packet,
778 * const char **sender_ip,
779 * SilcUInt16 *sender_port);
780 *
781 * DESCRIPTION
782 *
783 * Returns the packet sender's IP address and port from UDP packet
784 * indicated by `packet'. This can be called only from the packet
785 * callback to retrieve the information of the packet's sender. Returns
786 * FALSE if the information is not available.
787 *
788 ***/
789 SilcBool silc_packet_get_sender(SilcPacket packet,
790 const char **sender_ip,
791 SilcUInt16 *sender_port);
792
793 /****f* silccore/SilcPacketAPI/silc_packet_stream_ref
794 *
795 * SYNOPSIS
796 *
797 * void silc_packet_stream_ref(SilcPacketStream stream);
798 *
799 * DESCRIPTION
800 *
801 * Increase reference counter for the stream indicated by `stream'. This
802 * can be used to take a reference for the stream. To unreference the
803 * stream call silc_packet_stream_unref function.
804 *
805 ***/
806 void silc_packet_stream_ref(SilcPacketStream stream);
807
808 /****f* silccore/SilcPacketAPI/silc_packet_stream_unref
809 *
810 * SYNOPSIS
811 *
812 * void silc_packet_stream_unref(SilcPacketStream stream);
813 *
814 * DESCRIPTION
815 *
816 * Decrease reference counter for the stream indicated by `stream'. If
817 * the counter hits zero the stream will be destroyed automatically.
818 *
819 ***/
820 void silc_packet_stream_unref(SilcPacketStream stream);
821
822 /****f* silccore/SilcPacketAPI/silc_packet_get_engine
823 *
824 * SYNOPSIS
825 *
826 * SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
827 *
828 * DESCRIPTION
829 *
830 * Returns the packet engine from the `stream'.
831 *
832 ***/
833 SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
834
835 /****f* silccore/SilcPacketAPI/silc_packet_set_context
836 *
837 * SYNOPSIS
838 *
839 * void silc_packet_set_context(SilcPacketStream stream,
840 * void *stream_context);
841 *
842 * DESCRIPTION
843 *
844 * Sets a stream specific context to the stream. The context will
845 * be delivered to all callback functions, and it can be retrieved by
846 * calling silc_packet_get_context function as well. Note that this is
847 * separate packet stream specific context, and not the same as
848 * `callback_context' in silc_packet_engine_start. Both will be delivered
849 * to the callbacks, and this context as the `stream_context' argument.
850 *
851 ***/
852 void silc_packet_set_context(SilcPacketStream stream, void *stream_context);
853
854 /****f* silccore/SilcPacketAPI/silc_packet_get_context
855 *
856 * SYNOPSIS
857 *
858 * void *silc_packet_get_context(SilcPacketStream stream);
859 *
860 * DESCRIPTION
861 *
862 * Returns the current set application context, or NULL if none is set.
863 *
864 ***/
865 void *silc_packet_get_context(SilcPacketStream stream);
866
867 /****f* silccore/SilcPacketAPI/silc_packet_set_keys
868 *
869 * SYNOPSIS
870 *
871 * void silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
872 * SilcCipher receive_key, SilcHmac send_hmac,
873 * SilcHmac receive_hmac, SilcBool rekey);
874 *
875 * DESCRIPTION
876 *
877 * Set ciphers and HMACs to be used to encrypt sent packets, and decrypt
878 * received packets. This can be called multiple times to change the
879 * ciphers and HMACs.
880 *
881 * If the `rekey' is TRUE this function will send SILC_PACKET_REKEY_DONE
882 * to the `stream' and will set the new keys. If it is FALSE the keys
883 * are changed but the packet is not changed.
884 *
885 * When changing keys the old cipher and HMACs will be freed. If the keys
886 * are not set at all, packets will not be encrypted or decrypted.
887 *
888 ***/
889 SilcBool silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
890 SilcCipher receive_key, SilcHmac send_hmac,
891 SilcHmac receive_hmac, SilcBool rekey);
892
893 /****f* silccore/SilcPacketAPI/silc_packet_get_keys
894 *
895 * SYNOPSIS
896 *
897 * SilcBool silc_packet_get_keys(SilcPacketStream stream,
898 * SilcCipher *send_key,
899 * SilcCipher *receive_key,
900 * SilcHmac *send_hmac,
901 * SilcHmac *receive_hmac);
902 *
903 * DESCRIPTION
904 *
905 * Returns the pointers of current ciphers and HMACs from the `stream'.
906 * Returns FALSE if keys are not set.
907 *
908 ***/
909 SilcBool silc_packet_get_keys(SilcPacketStream stream,
910 SilcCipher *send_key, SilcCipher *receive_key,
911 SilcHmac *send_hmac, SilcHmac *receive_hmac);
912
913 /****f* silccore/SilcPacketAPI/silc_packet_set_ids
914 *
915 * SYNOPSIS
916 *
917 * SilcBool silc_packet_set_ids(SilcPacketStream stream,
918 * SilcIdType src_id_type, const void *src_id
919 * SilcIdType dst_id_type, const void *dst_id);
920 *
921 * DESCRIPTION
922 *
923 * Set the source ID and destination ID to be used when sending packets to
924 * this packet stream. The IDs to be used for a packet stream can be
925 * overridden when sending packets. However, if the IDs do not ever change
926 * for the packet stream it is recommended they are set using this function.
927 * In this case they can be omitted when sending packets to the stream.
928 * It is also possible to set only source or destination ID.
929 *
930 ***/
931 SilcBool silc_packet_set_ids(SilcPacketStream stream,
932 SilcIdType src_id_type, const void *src_id,
933 SilcIdType dst_id_type, const void *dst_id);
934
935 /****f* silccore/SilcPacketAPI/silc_packet_get_ids
936 *
937 * SYNOPSIS
938 *
939 * SilcBool silc_packet_get_ids(SilcPacketStream stream,
940 * SilcBool *src_id_set, SilcID *src_id,
941 * SilcBool *dst_id_set, SilcID *dst_id);
942 *
943 * DESCRIPTION
944 *
945 * Returns source and destination IDs from the packet stream. The
946 * `src_id_set' is set to TRUE if the source ID was returned. The
947 * `dst_id_set' is set to TRUE if the destination ID was returned.
948 *
949 ***/
950 SilcBool silc_packet_get_ids(SilcPacketStream stream,
951 SilcBool *src_id_set, SilcID *src_id,
952 SilcBool *dst_id_set, SilcID *dst_id);
953
954 /****f* silccore/SilcPacketAPI/silc_packet_set_sid
955 *
956 * SYNOPSIS
957 *
958 * SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
959 *
960 * DESCRIPTION
961 *
962 * Sets new Security ID to the packet stream indicated by `stream'. This
963 * is called only if the IV Included property was set to the stream
964 * by calling silc_packet_stream_set_iv_included. This function sets
965 * new Security ID to the stream which is then included in the ciphertext
966 * of a packet. The `sid' must be 0 when it is set for the very first
967 * time and must be increased by one after each rekey. This function must
968 * be called every time new keys are added to the stream after a rekey.
969 *
970 * If this function is called when the IV Included property has not been
971 * set to the stream the `sid' will be ignored. Returns FALSE if the
972 * IV Included has not been set, TRUE otherwise.
973 *
974 ***/
975 SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
976
977 /****f* silccore/SilcPacketAPI/silc_packet_send
978 *
979 * SYNOPSIS
980 *
981 * SilcBool silc_packet_send(SilcPacketStream stream,
982 * SilcPacketType type, SilcPacketFlags flags,
983 * const unsigned char *data,
984 * SilcUInt32 data_len);
985 *
986 * DESCRIPTION
987 *
988 * Send `data' of length of `data_len' to the packet stream indicated by
989 * `stream'. If ciphers and HMACs were set using silc_packet_set_keys
990 * the packet will be encrypted and MAC will be computed for it. If
991 * silc_packet_set_ids was used to set source and destination ID for the
992 * packet stream those IDs are used in the packet. If IDs have not been
993 * set and they need to be provided then silc_packet_send_ext function
994 * should be used. Otherwise, the packet will not have IDs set at all.
995 * Returns FALSE if packet could not be sent.
996 *
997 ***/
998 SilcBool silc_packet_send(SilcPacketStream stream,
999 SilcPacketType type, SilcPacketFlags flags,
1000 const unsigned char *data, SilcUInt32 data_len);
1001
1002 /****f* silccore/SilcPacketAPI/silc_packet_send_ext
1003 *
1004 * SYNOPSIS
1005 *
1006 * SilcBool
1007 * silc_packet_send_ext(SilcPacketStream stream,
1008 * SilcPacketType type, SilcPacketFlags flags,
1009 * SilcIdType src_id_type, void *srd_id,
1010 * SilcIdType dst_id_type, void *dst_id,
1011 * const unsigned char *data, SilcUInt32 data_len,
1012 * SilcCipher cipher, SilcHmac hmac);
1013 *
1014 * DESCRIPTION
1015 *
1016 * Same as silc_packet_send but with this function different sending
1017 * parameters can be sent as argument. This function can be used to
1018 * set specific IDs, cipher and HMAC to be used in packet sending,
1019 * instead of the ones saved in the `stream'. If any of the extra
1020 * pointers are NULL, default values set to the stream will apply.
1021 *
1022 ***/
1023 SilcBool silc_packet_send_ext(SilcPacketStream stream,
1024 SilcPacketType type, SilcPacketFlags flags,
1025 SilcIdType src_id_type, void *src_id,
1026 SilcIdType dst_id_type, void *dst_id,
1027 const unsigned char *data, SilcUInt32 data_len,
1028 SilcCipher cipher, SilcHmac hmac);
1029
1030 /****f* silccore/SilcPacketAPI/silc_packet_send_va
1031 *
1032 * SYNOPSIS
1033 *
1034 * SilcBool silc_packet_send_va(SilcPacketStream stream,
1035 * SilcPacketType type,
1036 * SilcPacketFlags flags, ...);
1037 *
1038 * DESCRIPTION
1039 *
1040 * Same as silc_packet_send but takes the data in as variable argument
1041 * formatted buffer (see silcbuffmt.h). The arguments must be ended
1042 * with SILC_STR_END. Returns FALSE if packet could not be sent or
1043 * the buffer could not be formatted.
1044 *
1045 * EXAMPLE
1046 *
1047 * // Send NEW_CLIENT packet
1048 * silc_packet_send_va(stream, SILC_PACKET_NEW_CLIENT, 0,
1049 *