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_MALFORMED, /* Packet is malformed */
204 SILC_PACKET_ERR_NO_MEMORY, /* System out of memory */
208 /****f* silccore/SilcPacketAPI/SilcPacketReceiveCb
212 * typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
213 * SilcPacketStream stream,
215 * void *callback_context,
216 * void *stream_context);
220 * The packet receive callback is called by the packet engine when a new
221 * SILC Packet has arrived. The application must free the returned
222 * SilcPacket with silc_packet_free if it takes the packet in for
223 * processing. This callback is set in the SilcPacketCallbacks structure.
224 * The `callback_context' is the context set as argument in the
225 * silc_packet_engine_start function. The `stream_context' is stream
226 * specific context that was set by calling silc_packet_set_context.
228 * If the application takes the received packet `packet' into processing
229 * TRUE must be returned. If FALSE is returned the packet engine will
230 * pass the packet to other packet processor, if one has been linked
231 * to the stream with silc_packet_stream_link function. If no extra
232 * processor is linked the packet is dropped.
237 * silc_foo_packet_receive_cb(SilcPacketEngine engine,
238 * SilcPacketStream stream, SilcPacket packet,
239 * void *callback_context, void *stream_context)
241 * Application ctx = callback_context;
243 * // If we're not up yet, let's not process the packet
244 * if (ctx->initialized == FALSE)
247 * // Process the incoming packet...
250 * // It's our packet now, no one else will get it
255 typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
256 SilcPacketStream stream,
258 void *callback_context,
259 void *stream_context);
261 /****f* silccore/SilcPacketAPI/SilcPacketEosCb
265 * typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
266 * SilcPacketStream stream,
267 * void *callback_context,
268 * void *stream_context);
272 * The End Of Stream (EOS) callback, that is called by the packet engine
273 * when the underlaying stream has ended. No more data can be sent to
274 * the stream or read from it. The `stream' must be destroyed by
275 * calling the silc_packet_stream_destroy. This callback is set in the
276 * SilcPacketCallbacks structure.
279 typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
280 SilcPacketStream stream,
281 void *callback_context,
282 void *stream_context);
284 /****f* silccore/SilcPacketAPI/SilcPacketErrorCb
288 * typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
289 * SilcPacketStream stream,
290 * SilcPacketError error,
291 * void *callback_context,
292 * void *stream_context);
296 * The error callback that is called by the packet engine if an error
297 * occurs. The `error' will indicate the error. This callback is set
298 * in the SilcPacketCallbacks structure.
301 typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
302 SilcPacketStream stream,
303 SilcPacketError error,
304 void *callback_context,
305 void *stream_context);
307 /****s* silccore/SilcPacketAPI/SilcPacketStream
311 * typedef struct SilcPacketStreamStruct *SilcPacketStream;
315 * This structure is sent as argument to the silc_packet_engine_start
316 * function to set the callback functions for the packet engine. The
317 * packet engine will call the callbacks when necessary. Application
318 * must always be provided for the packet engine.
323 SilcPacketReceiveCb packet_receive; /* Called when packet is received */
324 SilcPacketEosCb eos; /* Called on end of stream */
325 SilcPacketErrorCb error; /* Called on an error */
326 } SilcPacketCallbacks;
331 /****f* silccore/SilcPacketAPI/silc_packet_engine_start
336 * silc_packet_engine_start(SilcRng rng, SilcBool router,
337 * SilcPacketCallbacks *callbacks,
338 * void *callback_context);
342 * Create new packet engine for processing incoming and outgoing packets.
343 * If `router' is TRUE then the application is considered to be router
344 * server, and certain packets are handled differently. Client and normal
345 * server must set it to FALSE. The `callbacks' is a SilcPacketCallbacks
346 * structure provided by the caller which includes the callbacks that is
347 * called when for example packet is received, or end of stream is called.
351 * The packet engine is thread safe. You can use one packet engine in
352 * multi threaded application.
356 silc_packet_engine_start(SilcRng rng, SilcBool router,
357 SilcPacketCallbacks *callbacks,
358 void *callback_context);
360 /****f* silccore/SilcPacketAPI/silc_packet_engine_stop
364 * void silc_packet_engine_stop(SilcPacketEngine engine);
368 * Stop the packet engine. No new packets can be sent or received after
369 * calling this, and the `engine' will become invalid.
372 void silc_packet_engine_stop(SilcPacketEngine engine);
374 /****f* silccore/SilcPacketAPI/silc_packet_stream_create
378 * SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
379 * SilcSchedule schedule,
380 * SilcStream stream);
384 * Create new packet stream and use the `stream' as underlaying stream.
385 * Usually the `stream' would be a socket stream, but it can be any
386 * stream. After this function returns, packets can immediately be
387 * sent to or received from the stream.
391 * SilcPacketStream cannot be used with silc_stream_* routines (such as
392 * silc_stream_read and silc_stream_write) because of its special nature.
393 * Use the silc_packet_send and the silc_packet_send_ext to send packets.
394 * To read packets you will receive the packet receive callback from
395 * packet engine. Destroy the stream with silc_packet_stream_destroy.
397 * The SilcPacketStream is thread safe. Same context can be safely used
398 * in multi threaded environment.
401 SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
402 SilcSchedule schedule,
405 /****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
409 * void silc_packet_stream_destroy(SilcPacketStream stream);
413 * Destroy packet stream and the underlaying stream. This will also
414 * send end of stream to the underlaying stream.
417 void silc_packet_stream_destroy(SilcPacketStream stream);
419 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_router
423 * void silc_packet_stream_set_router(SilcPacketStream stream);
427 * When called sets the stream indicates by `stream' as SILC router
428 * connection stream. This causes that certain packets are handled
429 * differently. This must be called for router connection streams and
430 * must not be called for any other stream.
433 void silc_packet_stream_set_router(SilcPacketStream stream);
435 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_iv_included
439 * void silc_packet_stream_set_iv_included(SilcPacketStream stream);
443 * Sets an IV Included property for the stream indicated by `stream'.
444 * This means that the IV used in the encryption will be included in
445 * the resulted ciphertext. This makes it possible to send and receive
446 * packets on unreliable network transport protocol, such as UDP/IP.
447 * This must be called if the underlaying stream in the `stream' is UDP
451 void silc_packet_stream_set_iv_included(SilcPacketStream stream);
453 /****f* silccore/SilcPacketAPI/silc_packet_stream_get_stream
457 * SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
461 * Returns the actual stream that is associated with the packet stream
462 * `stream'. The caller must not free the returned stream. The returned
463 * stream is the same pointer that was set for silc_packet_stream_create.
464 * This function could be used for example when an error callback is
465 * called by the packet engine to retrieve the actual lower level error
469 SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
471 /****f* silccore/SilcPacketAPI/silc_packet_stream_link
475 * SilcBool silc_packet_stream_link(SilcPacketStream stream,
476 * SilcPacketCallbacks *callbacks,
477 * void *callback_context,
478 * int priority, ...);
482 * Links the packet processing callbacks indicated by `callbacks' into
483 * the packet stream indicated by `stream' with priority `priority' for
484 * the packet types given in the variable argument list. This function
485 * can be used to link to the packet stream for specific packet types
486 * and receive them in the specified callbacks. This way, a third party,
487 * for example some library may attach itself into the packet stream
488 * and receive and process certain packets. The variable argument
489 * list is ended with -1. To link to receive all packets use
492 * The default packet processing callbacks given as argument to the
493 * silc_packet_engine_start has the priority 0. Any priority higher
494 * than 0 will then take precedence over the default callbacks. Any
495 * priority lower than 0 (negative value) will be processed after the
498 * Note that setting only the 'packet_receive' callback in the `callbacks'
503 * // Link to this packet stream, with high priority, for
504 * // SILC_PACKET_CONNECTION_AUTH and SILC_PACKET_CONNECTION_AUTH_REQUEST
505 * // packets. We don't care about other packets.
506 * silc_packet_stream_link(stream, our_callbacks, our_context,
507 * 1000000, SILC_PACKET_CONNECTION_AUTH,
508 * SILC_PACKET_CONNECTION_AUTH_REQUEST, -1);
511 SilcBool silc_packet_stream_link(SilcPacketStream stream,
512 SilcPacketCallbacks *callbacks,
513 void *callback_context,
516 /****f* silccore/SilcPacketAPI/silc_packet_stream_unlink
520 * void silc_packet_stream_unlink(SilcPacketStream stream,
521 * SilcPacketCallbacks *callbacks,
522 * void *callback_context);
526 * Unlinks the `callbacks' with `callback_context' from the packet stream
527 * indicated by `stream'. This function must be called for the callbacks
528 * that was linked to `stream' when they are not needed anymore.
531 void silc_packet_stream_unlink(SilcPacketStream stream,
532 SilcPacketCallbacks *callbacks,
533 void *callback_context);
535 /****f* silccore/SilcPacketAPI/silc_packet_stream_ref
539 * void silc_packet_stream_ref(SilcPacketStream stream);
543 * Increase reference counter for the stream indicated by `stream'. This
544 * can be used to take a reference for the stream. To unreference the
545 * stream call silc_packet_stream_unref function.
548 void silc_packet_stream_ref(SilcPacketStream stream);
550 /****f* silccore/SilcPacketAPI/silc_packet_stream_unref
554 * void silc_packet_stream_unref(SilcPacketStream stream);
558 * Decrease reference counter for the stream indicated by `stream'. If
559 * the counter hits zero the stream will be destroyed automatically.
562 void silc_packet_stream_unref(SilcPacketStream stream);
564 /****f* silccore/SilcPacketAPI/silc_packet_get_engine
568 * SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
572 * Returns the packet engine from the `stream'.
575 SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
577 /****f* silccore/SilcPacketAPI/silc_packet_set_context
581 * void silc_packet_set_context(SilcPacketStream stream,
582 * void *stream_context);
586 * Sets a stream specific context to the stream. The context will
587 * be delivered to all callback functions, and it can be retrieved by
588 * calling silc_packet_get_context function as well. Note that this is
589 * separate packet stream specific context, and not the same as
590 * `callback_context' in silc_packet_engine_start. Both will be delivered
591 * to the callbacks, and this context as the `stream_context' argument.
594 void silc_packet_set_context(SilcPacketStream stream, void *stream_context);
596 /****f* silccore/SilcPacketAPI/silc_packet_get_context
600 * void *silc_packet_get_context(SilcPacketStream stream);
604 * Returns the current set application context, or NULL if none is set.
607 void *silc_packet_get_context(SilcPacketStream stream);
609 /****f* silccore/SilcPacketAPI/silc_packet_set_ciphers
613 * void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
614 * SilcCipher receive);
618 * Set ciphers to be used to encrypt sent packets, and decrypt received
619 * packets. This can be called multiple times to change the ciphers.
620 * In this case if old cipher is set it will be freed. If ciphers are
621 * not set packets will not be encrypted or decrypted.
624 void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
627 /****f* silccore/SilcPacketAPI/silc_packet_get_ciphers
631 * SilcBool silc_packet_get_ciphers(SilcPacketStream stream,
633 * SilcCipher *receive);
637 * Returns the pointers of current ciphers from the `stream'. Returns
638 * FALSE if ciphers are not set.
641 SilcBool silc_packet_get_ciphers(SilcPacketStream stream, SilcCipher *send,
642 SilcCipher *receive);
644 /****f* silccore/SilcPacketAPI/silc_packet_set_hmacs
648 * void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
653 * Set HMACs to be used to create MACs for sent packets and to check
654 * MAC for received packets. This can be called multiple times to change
655 * the HMACs. In this case if old HMAC is set it will be freed. If
656 * HMACs are not set MACs are not generated or verified for packets.
659 void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
662 /****f* silccore/SilcPacketAPI/silc_packet_get_hmacs
666 * SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
667 * SilcHmac *receive);
671 * Returns the pointers of current HMACs from the `stream'. Returns
672 * FALSE if HMACs are not set.
675 SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
678 /****f* silccore/SilcPacketAPI/silc_packet_set_ids
682 * SilcBool silc_packet_set_ids(SilcPacketStream stream,
683 * SilcIdType src_id_type, const void *src_id
684 * SilcIdType dst_id_type, const void *dst_id);
688 * Set the source ID and destinaion ID to be used when sending packets to
689 * this packet stream. The IDs to be used for a packet stream can be
690 * overridden when sending packets. However, if the IDs do not ever change
691 * for the packet stream it is recommended they are set using this function.
692 * In this case they can be omitted when sending packets to the stream.
693 * It is also possible to set only source or destination ID.
696 SilcBool silc_packet_set_ids(SilcPacketStream stream,
697 SilcIdType src_id_type, const void *src_id,
698 SilcIdType dst_id_type, const void *dst_id);
700 /****f* silccore/SilcPacketAPI/silc_packet_send
704 * SilcBool silc_packet_send(SilcPacketStream stream,
705 * SilcPacketType type, SilcPacketFlags flags,
706 * const unsigned char *data,
707 * SilcUInt32 data_len);
711 * Send `data' of length of `data_len' to the packet stream indicated by
712 * `stream'. If ciphers and HMACs were set using silc_packet_set_ciphers
713 * and silc_packet_set_hmacs the packet will be encrypted and MAC will be
714 * computed for it. If silc_packet_set_ids was used to set source and
715 * destination ID for the packet stream those IDs are used in the
716 * packet. If IDs have not been set and they need to be provided then
717 * silc_packet_send_ext function should be used. Otherwise, the packet
718 * will not have IDs set at all. Returns FALSE if packet could not be
722 SilcBool silc_packet_send(SilcPacketStream stream,
723 SilcPacketType type, SilcPacketFlags flags,
724 const unsigned char *data, SilcUInt32 data_len);
726 /****f* silccore/SilcPacketAPI/silc_packet_send_ext
731 * silc_packet_send_ext(SilcPacketStream stream,
732 * SilcPacketType type, SilcPacketFlags flags,
733 * SilcIdType src_id_type, void *srd_id,
734 * SilcIdType dst_id_type, void *dst_id,
735 * const unsigned char *data, SilcUInt32 data_len,
736 * SilcCipher cipher, SilcHmac hmac);
740 * Same as silc_packet_send but with this function different sending
741 * parameters can be sent as argument. This function can be used to
742 * set specific IDs, cipher and HMAC to be used in packet sending,
743 * instead of the ones saved in the `stream'. If any of the extra
744 * pointers are NULL, default values set to the stream will apply.
747 SilcBool silc_packet_send_ext(SilcPacketStream stream,
748 SilcPacketType type, SilcPacketFlags flags,
749 SilcIdType src_id_type, void *src_id,
750 SilcIdType dst_id_type, void *dst_id,
751 const unsigned char *data, SilcUInt32 data_len,
752 SilcCipher cipher, SilcHmac hmac);
754 /****f* silccore/SilcPacketAPI/silc_packet_wait
758 * void *silc_packet_wait_init(SilcPacketStream stream, ...);
762 * Initializes a packet waiter for the packet stream `stream' and
763 * for the variable argument list of packet types. The function
764 * silc_packet_wait can be used to block the thread until a packet
765 * has been received. This function is used to initialize the waiting
766 * and to give the list of packet types that caller wish to receive.
767 * The variable argument list must end with -1. To receive all
768 * packets use SILC_PACKET_ANY. Returns a context that must be given
769 * to the silc_packet_wait function as argument. Returns NULL on
770 * error. To uninitialize the waiting call silc_packet_wait_uninit.
774 * Note that packets may be available immediately after calling this
775 * function and they will be buffered, until silc_packet_wait is called.
781 * // Will wait for private message packets
782 * waiter = silc_packet_wait_init(stream,
783 * SILC_PACKET_PRIVATE_MESSAGE, -1);
787 void *silc_packet_wait_init(SilcPacketStream stream, ...);
789 /****f* silccore/SilcPacketAPI/silc_packet_wait
793 * void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
797 * Uninitializes the waiting context. This may be called also from
798 * another thread while other thread is waiting for packets. This will
799 * inform the waiting thread to stop waiting.
802 void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
804 /****f* silccore/SilcPacketAPI/silc_packet_wait
808 * int silc_packet_wait(void *waiter, int timeout,
809 * SilcPacket *return_packet)
813 * A special function that can be used to wait for a packet to arrive.
814 * This function will block the calling process or thread until either
815 * a packet is received into the `return_packet' pointer or the specified
816 * timeout value `timeout', which is in milliseconds, will expire. If
817 * the timeout is 0, no timeout exist. Before calling this function the
818 * silc_packet_wait_init must be called. The caller is responsible for
819 * freeing the returned packet with silc_packet_free.
821 * This function can be used for example from a thread that wants to
822 * block until SILC packet has been received.
824 * Returns 1 when packet was received, 0 if timeout occurred and -1 if
829 * static int foo_read_data(FooContext c)
835 * // Will wait for private message packets
836 * if (c->initialized == FALSE) {
837 * waiter = silc_packet_wait_init(stream,
838 * SILC_PACKET_PRIVATE_MESSAGE, -1);
839 * c->initialized = TRUE;
843 * // Wait here until private message packet is received
844 * if ((silc_packet_wait(waiter, 0, &packet)) < 0)
847 * ... process packet ...
853 int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet);
855 /****f* silccore/SilcPacketAPI/silc_packet_free
859 * void silc_packet_free(SilcPacket packet);
863 * This function is used to free the SilcPacket pointer that application
864 * receives in the SilcPacketReceive callback. Application must free
865 * the packet if it takes it in to processing.
868 void silc_packet_free(SilcPacket packet);
870 #endif /* SILCPACKET_H */