5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 1997 - 2006 Pekka Riikonen
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.
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.
20 /****h* silccore/Packet Protocol Interface
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.
29 * The packet engine and packet stream are thread safe. They can be safely
30 * used in multi threaded environment.
37 /* XXX many of these could go to silcpacket_i.h */
39 /* Maximum packet length */
40 #define SILC_PACKET_MAX_LEN 0xffff
42 /* Maximum length of ID */
43 #define SILC_PACKET_MAX_ID_LEN 28
45 /****d* silccore/SilcPacketAPI/SilcPacketType
49 * typedef SilcUInt8 SilcPacketType;
53 * SILC packet type definition and all the packet types.
57 typedef SilcUInt8 SilcPacketType;
59 /* SILC Packet types. */
60 #define SILC_PACKET_DISCONNECT 1 /* Disconnection */
61 #define SILC_PACKET_SUCCESS 2 /* Success */
62 #define SILC_PACKET_FAILURE 3 /* Failure */
63 #define SILC_PACKET_REJECT 4 /* Rejected */
64 #define SILC_PACKET_NOTIFY 5 /* Notify message */
65 #define SILC_PACKET_ERROR 6 /* Error message */
66 #define SILC_PACKET_CHANNEL_MESSAGE 7 /* Message for channel */
67 #define SILC_PACKET_CHANNEL_KEY 8 /* Key of the channel */
68 #define SILC_PACKET_PRIVATE_MESSAGE 9 /* Private message */
69 #define SILC_PACKET_PRIVATE_MESSAGE_KEY 10 /* Private message key*/
70 #define SILC_PACKET_COMMAND 11 /* Command */
71 #define SILC_PACKET_COMMAND_REPLY 12 /* Reply to a command */
72 #define SILC_PACKET_KEY_EXCHANGE 13 /* Start of KE */
73 #define SILC_PACKET_KEY_EXCHANGE_1 14 /* KE1 */
74 #define SILC_PACKET_KEY_EXCHANGE_2 15 /* KE2 */
75 #define SILC_PACKET_CONNECTION_AUTH_REQUEST 16 /* Request of auth meth */
76 #define SILC_PACKET_CONNECTION_AUTH 17 /* Connectinon auth */
77 #define SILC_PACKET_NEW_ID 18 /* Sending new ID */
78 #define SILC_PACKET_NEW_CLIENT 19 /* Client registering */
79 #define SILC_PACKET_NEW_SERVER 20 /* Server registering */
80 #define SILC_PACKET_NEW_CHANNEL 21 /* Channel registering */
81 #define SILC_PACKET_REKEY 22 /* Re-key start */
82 #define SILC_PACKET_REKEY_DONE 23 /* Re-key done */
83 #define SILC_PACKET_HEARTBEAT 24 /* Heartbeat */
84 #define SILC_PACKET_KEY_AGREEMENT 25 /* Key Agreement request */
85 #define SILC_PACKET_RESUME_ROUTER 26 /* Backup router resume */
86 #define SILC_PACKET_FTP 27 /* File Transfer */
87 #define SILC_PACKET_RESUME_CLIENT 28 /* Client resume */
89 #define SILC_PACKET_PRIVATE 200 /* Private range start */
90 #define SILC_PACKET_MAX 255 /* RESERVED */
92 #define SILC_PACKET_NONE 0 /* RESERVED */
93 #define SILC_PACKET_ANY 0
96 /****d* silccore/SilcPacketAPI/SilcPacketFlags
100 * typedef SilcUInt8 SilcPacketFlags;
104 * SILC packet flags type definition and all the packet flags.
108 typedef SilcUInt8 SilcPacketFlags;
110 /* All defined packet flags */
111 #define SILC_PACKET_FLAG_NONE 0x00 /* No flags */
112 #define SILC_PACKET_FLAG_PRIVMSG_KEY 0x01 /* Private message key */
113 #define SILC_PACKET_FLAG_LIST 0x02 /* Packet is a list */
114 #define SILC_PACKET_FLAG_BROADCAST 0x04 /* Packet is a broadcast */
115 #define SILC_PACKET_FLAG_COMPRESSED 0x08 /* Payload is compressed */
117 /* Impelemntation specific flags */
118 #define SILC_PACKET_FLAG_LONG_PAD 0x10 /* Use maximum padding */
121 /****s* silccore/SilcPacketAPI/SilcPacketEngine
125 * typedef struct SilcPacketEngineStruct *SilcPacketEngine;
129 * The packet engine context, allocated by silc_packet_engine_start.
130 * The engine is destroyed with silc_packet_engine_stop.
133 typedef struct SilcPacketEngineStruct *SilcPacketEngine;
135 /****s* silccore/SilcPacketAPI/SilcPacketStream
139 * typedef struct SilcPacketStreamStruct *SilcPacketStream;
143 * The packet stream context, allocated by silc_packet_stream_create.
144 * The stream is destroyed with silc_packet_stream_destroy.
147 typedef struct SilcPacketStreamStruct *SilcPacketStream;
149 /****s* silccore/SilcPacketAPI/SilcPacket
153 * typedef struct SilcPacketStruct *SilcPacket;
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.
163 * The list pointer `next' can be used by the application to put the
164 * packet context in a list during processing, if needed.
168 typedef struct SilcPacketStruct {
169 struct SilcPacketStruct *next; /* List pointer, application may set */
170 SilcPacketStream stream; /* Packet stream this packet is from */
171 SilcBufferStruct buffer; /* Packet data payload */
172 unsigned char *src_id; /* Source ID */
173 unsigned char *dst_id; /* Destination ID */
174 unsigned int src_id_len : 6; /* Source ID length */
175 unsigned int src_id_type : 2; /* Source ID type */
176 unsigned int dst_id_len : 6; /* Destination ID length */
177 unsigned int dst_id_type : 2; /* Destination ID type */
178 SilcPacketType type; /* Packet type */
179 SilcPacketFlags flags; /* Packet flags */
183 /****d* silcutil/SilcPacketAPI/SilcPacketError
187 * typedef enum { ... } SilcPacketError
191 * Packet errors. This is returned in the error callback. If application
192 * needs the actual lower level stream error, it needs to retrieve it
193 * from the actual stream. It can retrieve the underlaying stream from
194 * the packet stream by calling silc_packet_stream_get_stream function.
199 SILC_PACKET_ERR_READ, /* Error while reading */
200 SILC_PACKET_ERR_WRITE, /* Error while writing */
201 SILC_PACKET_ERR_MAC_FAILED, /* Packet MAC check failed */
202 SILC_PACKET_ERR_DECRYPTION_FAILED, /* Packet decryption failed */
203 SILC_PACKET_ERR_UNKNOWN_SID, /* Unknown SID (with IV included) */
204 SILC_PACKET_ERR_MALFORMED, /* Packet is malformed */
205 SILC_PACKET_ERR_NO_MEMORY, /* System out of memory */
209 /****f* silccore/SilcPacketAPI/SilcPacketReceiveCb
213 * typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
214 * SilcPacketStream stream,
216 * void *callback_context,
217 * void *stream_context);
221 * The packet receive callback is called by the packet engine when a new
222 * SILC Packet has arrived. The application must free the returned
223 * SilcPacket with silc_packet_free if it takes the packet in for
224 * processing. This callback is set in the SilcPacketCallbacks structure.
225 * The `callback_context' is the context set as argument in the
226 * silc_packet_engine_start function. The `stream_context' is stream
227 * specific context that was set by calling silc_packet_set_context.
229 * If the application takes the received packet `packet' into processing
230 * TRUE must be returned. If FALSE is returned the packet engine will
231 * pass the packet to other packet processor, if one has been linked
232 * to the stream with silc_packet_stream_link function. If no extra
233 * processor is linked the packet is dropped.
238 * silc_foo_packet_receive_cb(SilcPacketEngine engine,
239 * SilcPacketStream stream, SilcPacket packet,
240 * void *callback_context, void *stream_context)
242 * Application ctx = callback_context;
244 * // If we're not up yet, let's not process the packet
245 * if (ctx->initialized == FALSE)
248 * // Process the incoming packet...
251 * // It's our packet now, no one else will get it
256 typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
257 SilcPacketStream stream,
259 void *callback_context,
260 void *stream_context);
262 /****f* silccore/SilcPacketAPI/SilcPacketEosCb
266 * typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
267 * SilcPacketStream stream,
268 * void *callback_context,
269 * void *stream_context);
273 * The End Of Stream (EOS) callback, that is called by the packet engine
274 * when the underlaying stream has ended. No more data can be sent to
275 * the stream or read from it. The `stream' must be destroyed by
276 * calling the silc_packet_stream_destroy. This callback is set in the
277 * SilcPacketCallbacks structure.
280 typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
281 SilcPacketStream stream,
282 void *callback_context,
283 void *stream_context);
285 /****f* silccore/SilcPacketAPI/SilcPacketErrorCb
289 * typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
290 * SilcPacketStream stream,
291 * SilcPacketError error,
292 * void *callback_context,
293 * void *stream_context);
297 * The error callback that is called by the packet engine if an error
298 * occurs. The `error' will indicate the error. This callback is set
299 * in the SilcPacketCallbacks structure.
302 typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
303 SilcPacketStream stream,
304 SilcPacketError error,
305 void *callback_context,
306 void *stream_context);
308 /****s* silccore/SilcPacketAPI/SilcPacketStream
312 * typedef struct SilcPacketStreamStruct *SilcPacketStream;
316 * This structure is sent as argument to the silc_packet_engine_start
317 * function to set the callback functions for the packet engine. The
318 * packet engine will call the callbacks when necessary. Application
319 * must always be provided for the packet engine.
324 SilcPacketReceiveCb packet_receive; /* Called when packet is received */
325 SilcPacketEosCb eos; /* Called on end of stream */
326 SilcPacketErrorCb error; /* Called on an error */
327 } SilcPacketCallbacks;
332 /****f* silccore/SilcPacketAPI/silc_packet_engine_start
337 * silc_packet_engine_start(SilcRng rng, SilcBool router,
338 * SilcPacketCallbacks *callbacks,
339 * void *callback_context);
343 * Create new packet engine for processing incoming and outgoing packets.
344 * If `router' is TRUE then the application is considered to be router
345 * server, and certain packets are handled differently. Client and normal
346 * server must set it to FALSE. The `callbacks' is a SilcPacketCallbacks
347 * structure provided by the caller which includes the callbacks that is
348 * called when for example packet is received, or end of stream is called.
352 * The packet engine is thread safe. You can use one packet engine in
353 * multi threaded application.
357 silc_packet_engine_start(SilcRng rng, SilcBool router,
358 SilcPacketCallbacks *callbacks,
359 void *callback_context);
361 /****f* silccore/SilcPacketAPI/silc_packet_engine_stop
365 * void silc_packet_engine_stop(SilcPacketEngine engine);
369 * Stop the packet engine. No new packets can be sent or received after
370 * calling this, and the `engine' will become invalid.
373 void silc_packet_engine_stop(SilcPacketEngine engine);
375 /****f* silccore/SilcPacketAPI/silc_packet_stream_create
379 * SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
380 * SilcSchedule schedule,
381 * SilcStream stream);
385 * Create new packet stream and use the `stream' as underlaying stream.
386 * Usually the `stream' would be a socket stream, but it can be any
387 * stream. After this function returns, packets can immediately be
388 * sent to or received from the stream.
392 * SilcPacketStream cannot be used with silc_stream_* routines (such as
393 * silc_stream_read and silc_stream_write) because of its special nature.
394 * Use the silc_packet_send and the silc_packet_send_ext to send packets.
395 * To read packets you will receive the packet receive callback from
396 * packet engine. Destroy the stream with silc_packet_stream_destroy.
398 * The SilcPacketStream is thread safe. Same context can be safely used
399 * in multi threaded environment.
402 SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
403 SilcSchedule schedule,
406 /****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
410 * void silc_packet_stream_destroy(SilcPacketStream stream);
414 * Destroy packet stream and the underlaying stream. This will also
415 * send end of stream to the underlaying stream.
418 void silc_packet_stream_destroy(SilcPacketStream stream);
420 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_router
424 * void silc_packet_stream_set_router(SilcPacketStream stream);
428 * When called sets the stream indicates by `stream' as SILC router
429 * connection stream. This causes that certain packets are handled
430 * differently. This must be called for router connection streams and
431 * must not be called for any other stream.
434 void silc_packet_stream_set_router(SilcPacketStream stream);
436 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_iv_included
440 * void silc_packet_stream_set_iv_included(SilcPacketStream stream);
444 * Sets an IV Included property for the stream indicated by `stream'.
445 * This means that the IV used in the encryption will be included in
446 * the resulted ciphertext. This makes it possible to send and receive
447 * packets on unreliable network transport protocol, such as UDP/IP.
448 * This must be called if the underlaying stream in the `stream' is UDP
451 * When this is set to the stream the silc_packet_set_sid must be called
452 * to set new Security ID. The Security ID will be included with the IV
456 void silc_packet_stream_set_iv_included(SilcPacketStream stream);
458 /****f* silccore/SilcPacketAPI/silc_packet_stream_get_stream
462 * SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
466 * Returns the actual stream that is associated with the packet stream
467 * `stream'. The caller must not free the returned stream. The returned
468 * stream is the same pointer that was set for silc_packet_stream_create.
469 * This function could be used for example when an error callback is
470 * called by the packet engine to retrieve the actual lower level error
474 SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
476 /****f* silccore/SilcPacketAPI/silc_packet_stream_link
480 * SilcBool silc_packet_stream_link(SilcPacketStream stream,
481 * SilcPacketCallbacks *callbacks,
482 * void *callback_context,
483 * int priority, ...);
487 * Links the packet processing callbacks indicated by `callbacks' into
488 * the packet stream indicated by `stream' with priority `priority' for
489 * the packet types given in the variable argument list. This function
490 * can be used to link to the packet stream for specific packet types
491 * and receive them in the specified callbacks. This way, a third party,
492 * for example some library may attach itself into the packet stream
493 * and receive and process certain packets. The variable argument
494 * list is ended with -1. To link to receive all packets use
497 * The default packet processing callbacks given as argument to the
498 * silc_packet_engine_start has the priority 0. Any priority higher
499 * than 0 will then take precedence over the default callbacks. Any
500 * priority lower than 0 (negative value) will be processed after the
503 * Note that setting only the 'packet_receive' callback in the `callbacks'
508 * // Link to this packet stream, with high priority, for
509 * // SILC_PACKET_CONNECTION_AUTH and SILC_PACKET_CONNECTION_AUTH_REQUEST
510 * // packets. We don't care about other packets.
511 * silc_packet_stream_link(stream, our_callbacks, our_context,
512 * 1000000, SILC_PACKET_CONNECTION_AUTH,
513 * SILC_PACKET_CONNECTION_AUTH_REQUEST, -1);
516 SilcBool silc_packet_stream_link(SilcPacketStream stream,
517 SilcPacketCallbacks *callbacks,
518 void *callback_context,
521 /****f* silccore/SilcPacketAPI/silc_packet_stream_unlink
525 * void silc_packet_stream_unlink(SilcPacketStream stream,
526 * SilcPacketCallbacks *callbacks,
527 * void *callback_context);
531 * Unlinks the `callbacks' with `callback_context' from the packet stream
532 * indicated by `stream'. This function must be called for the callbacks
533 * that was linked to `stream' when they are not needed anymore.
536 void silc_packet_stream_unlink(SilcPacketStream stream,
537 SilcPacketCallbacks *callbacks,
538 void *callback_context);
540 /****f* silccore/SilcPacketAPI/silc_packet_stream_ref
544 * void silc_packet_stream_ref(SilcPacketStream stream);
548 * Increase reference counter for the stream indicated by `stream'. This
549 * can be used to take a reference for the stream. To unreference the
550 * stream call silc_packet_stream_unref function.
553 void silc_packet_stream_ref(SilcPacketStream stream);
555 /****f* silccore/SilcPacketAPI/silc_packet_stream_unref
559 * void silc_packet_stream_unref(SilcPacketStream stream);
563 * Decrease reference counter for the stream indicated by `stream'. If
564 * the counter hits zero the stream will be destroyed automatically.
567 void silc_packet_stream_unref(SilcPacketStream stream);
569 /****f* silccore/SilcPacketAPI/silc_packet_get_engine
573 * SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
577 * Returns the packet engine from the `stream'.
580 SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
582 /****f* silccore/SilcPacketAPI/silc_packet_set_context
586 * void silc_packet_set_context(SilcPacketStream stream,
587 * void *stream_context);
591 * Sets a stream specific context to the stream. The context will
592 * be delivered to all callback functions, and it can be retrieved by
593 * calling silc_packet_get_context function as well. Note that this is
594 * separate packet stream specific context, and not the same as
595 * `callback_context' in silc_packet_engine_start. Both will be delivered
596 * to the callbacks, and this context as the `stream_context' argument.
599 void silc_packet_set_context(SilcPacketStream stream, void *stream_context);
601 /****f* silccore/SilcPacketAPI/silc_packet_get_context
605 * void *silc_packet_get_context(SilcPacketStream stream);
609 * Returns the current set application context, or NULL if none is set.
612 void *silc_packet_get_context(SilcPacketStream stream);
614 /****f* silccore/SilcPacketAPI/silc_packet_set_ciphers
618 * void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
619 * SilcCipher receive);
623 * Set ciphers to be used to encrypt sent packets, and decrypt received
624 * packets. This can be called multiple times to change the ciphers.
625 * In this case if old cipher is set it will be freed. If ciphers are
626 * not set packets will not be encrypted or decrypted.
629 void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
632 /****f* silccore/SilcPacketAPI/silc_packet_get_ciphers
636 * SilcBool silc_packet_get_ciphers(SilcPacketStream stream,
638 * SilcCipher *receive);
642 * Returns the pointers of current ciphers from the `stream'. Returns
643 * FALSE if ciphers are not set.
646 SilcBool silc_packet_get_ciphers(SilcPacketStream stream, SilcCipher *send,
647 SilcCipher *receive);
649 /****f* silccore/SilcPacketAPI/silc_packet_set_hmacs
653 * void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
658 * Set HMACs to be used to create MACs for sent packets and to check
659 * MAC for received packets. This can be called multiple times to change
660 * the HMACs. In this case if old HMAC is set it will be freed. If
661 * HMACs are not set MACs are not generated or verified for packets.
664 void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
667 /****f* silccore/SilcPacketAPI/silc_packet_get_hmacs
671 * SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
672 * SilcHmac *receive);
676 * Returns the pointers of current HMACs from the `stream'. Returns
677 * FALSE if HMACs are not set.
680 SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
683 /****f* silccore/SilcPacketAPI/silc_packet_set_ids
687 * SilcBool silc_packet_set_ids(SilcPacketStream stream,
688 * SilcIdType src_id_type, const void *src_id
689 * SilcIdType dst_id_type, const void *dst_id);
693 * Set the source ID and destinaion ID to be used when sending packets to
694 * this packet stream. The IDs to be used for a packet stream can be
695 * overridden when sending packets. However, if the IDs do not ever change
696 * for the packet stream it is recommended they are set using this function.
697 * In this case they can be omitted when sending packets to the stream.
698 * It is also possible to set only source or destination ID.
701 SilcBool silc_packet_set_ids(SilcPacketStream stream,
702 SilcIdType src_id_type, const void *src_id,
703 SilcIdType dst_id_type, const void *dst_id);
705 /****f* silccore/SilcPacketAPI/silc_packet_set_sid
709 * SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
713 * Sets new Security ID to the packet stream indicated by `stream'. This
714 * is called only if the IV Included property was set to the stream
715 * by calling silc_packet_stream_set_iv_included. This function sets
716 * new Security ID to the stream which is then included in the ciphertext
717 * of a packet. The `sid' must be 0 when it is set for the very first
718 * time and must be increased by one after each rekey. This function must
719 * be called every time new keys are added to the stream after a rekey.
721 * If this function is called when the IV Included property has not been
722 * set to the stream the `sid' will be ignored. Returns FALSE if the
723 * IV Included has not been set, TRUE otherwise.
726 SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
728 /****f* silccore/SilcPacketAPI/silc_packet_send
732 * SilcBool silc_packet_send(SilcPacketStream stream,
733 * SilcPacketType type, SilcPacketFlags flags,
734 * const unsigned char *data,
735 * SilcUInt32 data_len);
739 * Send `data' of length of `data_len' to the packet stream indicated by
740 * `stream'. If ciphers and HMACs were set using silc_packet_set_ciphers
741 * and silc_packet_set_hmacs the packet will be encrypted and MAC will be
742 * computed for it. If silc_packet_set_ids was used to set source and
743 * destination ID for the packet stream those IDs are used in the
744 * packet. If IDs have not been set and they need to be provided then
745 * silc_packet_send_ext function should be used. Otherwise, the packet
746 * will not have IDs set at all. Returns FALSE if packet could not be
750 SilcBool silc_packet_send(SilcPacketStream stream,
751 SilcPacketType type, SilcPacketFlags flags,
752 const unsigned char *data, SilcUInt32 data_len);
754 /****f* silccore/SilcPacketAPI/silc_packet_send_ext
759 * silc_packet_send_ext(SilcPacketStream stream,
760 * SilcPacketType type, SilcPacketFlags flags,
761 * SilcIdType src_id_type, void *srd_id,
762 * SilcIdType dst_id_type, void *dst_id,
763 * const unsigned char *data, SilcUInt32 data_len,
764 * SilcCipher cipher, SilcHmac hmac);
768 * Same as silc_packet_send but with this function different sending
769 * parameters can be sent as argument. This function can be used to
770 * set specific IDs, cipher and HMAC to be used in packet sending,
771 * instead of the ones saved in the `stream'. If any of the extra
772 * pointers are NULL, default values set to the stream will apply.
775 SilcBool silc_packet_send_ext(SilcPacketStream stream,
776 SilcPacketType type, SilcPacketFlags flags,
777 SilcIdType src_id_type, void *src_id,
778 SilcIdType dst_id_type, void *dst_id,
779 const unsigned char *data, SilcUInt32 data_len,
780 SilcCipher cipher, SilcHmac hmac);
782 /****f* silccore/SilcPacketAPI/silc_packet_wait
786 * void *silc_packet_wait_init(SilcPacketStream stream, ...);
790 * Initializes a packet waiter for the packet stream `stream' and
791 * for the variable argument list of packet types. The function
792 * silc_packet_wait can be used to block the thread until a packet
793 * has been received. This function is used to initialize the waiting
794 * and to give the list of packet types that caller wish to receive.
795 * The variable argument list must end with -1. To receive all
796 * packets use SILC_PACKET_ANY. Returns a context that must be given
797 * to the silc_packet_wait function as argument. Returns NULL on
798 * error. To uninitialize the waiting call silc_packet_wait_uninit.
802 * Note that packets may be available immediately after calling this
803 * function and they will be buffered, until silc_packet_wait is called.
809 * // Will wait for private message packets
810 * waiter = silc_packet_wait_init(stream,
811 * SILC_PACKET_PRIVATE_MESSAGE, -1);
815 void *silc_packet_wait_init(SilcPacketStream stream, ...);
817 /****f* silccore/SilcPacketAPI/silc_packet_wait
821 * void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
825 * Uninitializes the waiting context. This may be called also from
826 * another thread while other thread is waiting for packets. This will
827 * inform the waiting thread to stop waiting.
830 void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
832 /****f* silccore/SilcPacketAPI/silc_packet_wait
836 * int silc_packet_wait(void *waiter, int timeout,
837 * SilcPacket *return_packet)
841 * A special function that can be used to wait for a packet to arrive.
842 * This function will block the calling process or thread until either
843 * a packet is received into the `return_packet' pointer or the specified
844 * timeout value `timeout', which is in milliseconds, will expire. If
845 * the timeout is 0, no timeout exist. Before calling this function the
846 * silc_packet_wait_init must be called. The caller is responsible for
847 * freeing the returned packet with silc_packet_free.
849 * This function can be used for example from a thread that wants to
850 * block until SILC packet has been received.
852 * Returns 1 when packet was received, 0 if timeout occurred and -1 if
857 * static int foo_read_data(FooContext c)
863 * // Will wait for private message packets
864 * if (c->initialized == FALSE) {
865 * waiter = silc_packet_wait_init(stream,
866 * SILC_PACKET_PRIVATE_MESSAGE, -1);
867 * c->initialized = TRUE;
871 * // Wait here until private message packet is received
872 * if ((silc_packet_wait(waiter, 0, &packet)) < 0)
875 * ... process packet ...
881 int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet);
883 /****f* silccore/SilcPacketAPI/silc_packet_free
887 * void silc_packet_free(SilcPacket packet);
891 * This function is used to free the SilcPacket pointer that application
892 * receives in the SilcPacketReceive callback. Application must free
893 * the packet if it takes it in to processing.
896 void silc_packet_free(SilcPacket packet);
898 #endif /* SILCPACKET_H */