5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 1997 - 2014 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/SILC Packet Engine 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 /* Maximum packet length */
38 #define SILC_PACKET_MAX_LEN 0xffff
40 /* Maximum length of ID */
41 #define SILC_PACKET_MAX_ID_LEN 28
43 /****d* silccore/SilcPacketAPI/SilcPacketType
47 * typedef SilcUInt8 SilcPacketType;
51 * SILC packet type definition and all the packet types.
55 typedef SilcUInt8 SilcPacketType;
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 */
88 #define SILC_PACKET_PRIVATE 200 /* Private range start */
89 #define SILC_PACKET_MAX 255 /* RESERVED */
91 #define SILC_PACKET_NONE 0 /* RESERVED */
92 #define SILC_PACKET_ANY 0
95 /****d* silccore/SilcPacketAPI/SilcPacketFlags
99 * typedef SilcUInt8 SilcPacketFlags;
103 * SILC packet flags type definition and all the packet flags.
107 typedef SilcUInt8 SilcPacketFlags;
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 */
117 /* Impelemntation specific flags */
118 #define SILC_PACKET_FLAG_LONG_PAD 0x20 /* 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 `buffer' field contains the parsed packet payload and the start
164 * of the data area will point to the start of the packet payload.
166 * The list pointer `next' can be used by the application to put the
167 * packet context in a list during processing, if needed.
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 */
186 /****d* silcutil/SilcPacketAPI/SilcPacketError
190 * typedef enum { ... } SilcPacketError
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.
199 * You may retrieve string version of the SilcPacketError by calling
200 * silc_packet_error_string.
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 */
215 /****f* silccore/SilcPacketAPI/SilcPacketReceiveCb
219 * typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
220 * SilcPacketStream stream,
222 * void *callback_context,
223 * void *stream_context);
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.
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.
244 * silc_foo_packet_receive_cb(SilcPacketEngine engine,
245 * SilcPacketStream stream, SilcPacket packet,
246 * void *callback_context, void *stream_context)
248 * Application ctx = callback_context;
250 * // If we're not up yet, let's not process the packet
251 * if (ctx->initialized == FALSE)
254 * // Process the incoming packet...
257 * // It's our packet now, no one else will get it
262 typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
263 SilcPacketStream stream,
265 void *callback_context,
266 void *stream_context);
268 /****f* silccore/SilcPacketAPI/SilcPacketEosCb
272 * typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
273 * SilcPacketStream stream,
274 * void *callback_context,
275 * void *stream_context);
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.
286 typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
287 SilcPacketStream stream,
288 void *callback_context,
289 void *stream_context);
291 /****f* silccore/SilcPacketAPI/SilcPacketErrorCb
295 * typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
296 * SilcPacketStream stream,
297 * SilcPacketError error,
298 * void *callback_context,
299 * void *stream_context);
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.
308 typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
309 SilcPacketStream stream,
310 SilcPacketError error,
311 void *callback_context,
312 void *stream_context);
314 /****s* silccore/SilcPacketAPI/SilcPacketCallbacks
318 * typedef struct { ... } *SilcPacketCallbacks;
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.
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;
338 /****f* silccore/SilcPacketAPI/silc_packet_engine_start
343 * silc_packet_engine_start(SilcRng rng, SilcBool router,
344 * SilcPacketCallbacks *callbacks,
345 * void *callback_context);
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.
358 * The packet engine is thread safe. You can use one packet engine in
359 * multi threaded application.
363 silc_packet_engine_start(SilcRng rng, SilcBool router,
364 const SilcPacketCallbacks *callbacks,
365 void *callback_context);
367 /****f* silccore/SilcPacketAPI/silc_packet_engine_stop
371 * void silc_packet_engine_stop(SilcPacketEngine engine);
375 * Stop the packet engine. No new packets can be sent or received after
376 * calling this, and the `engine' will become invalid.
379 void silc_packet_engine_stop(SilcPacketEngine engine);
381 /****f* silccore/SilcPacketAPI/silc_packet_error_string
385 * const char *silc_packet_error_string(SilcPacketError error);
389 * Return the packet error as string.
392 const char *silc_packet_error_string(SilcPacketError error);
394 /****f* silccore/SilcPacketAPI/silc_packet_engine_get_streams
398 * SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
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.
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
412 SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
414 /****f* silccore/SilcPacketAPI/silc_packet_engine_free_streams_list
418 * void silc_packet_engine_free_streams_list(SilcDList streams);
422 * Free's the streams list returned by silc_packet_engine_get_streams.
425 void silc_packet_engine_free_streams_list(SilcDList streams);
427 /****f* silccore/SilcPacketAPI/silc_packet_stream_create
431 * SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
432 * SilcSchedule schedule,
433 * SilcStream stream);
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.
442 * The `stream' will be owned by the packet stream and will be closed
443 * and destroyed when the packet stream is destroyed. If the packet
444 * stream creation fails the `stream' is left intact.
448 * SilcPacketStream cannot be used with silc_stream_* routines (such as
449 * silc_stream_read and silc_stream_write) because of its special nature.
450 * Use the silc_packet_send and the silc_packet_send_ext to send packets.
451 * To read packets you will receive the packet receive callback from
452 * packet engine. Destroy the stream with silc_packet_stream_destroy.
454 * The SilcPacketStream is thread safe. Same context can be safely used
455 * in multi threaded environment.
458 SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
459 SilcSchedule schedule,
462 /****f* silccore/SilcPacketAPI/silc_packet_stream_add_remote
466 * SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
467 * const char *remote_ip,
468 * SilcUInt16 remote_port,
469 * SilcPacket packet);
473 * This function is used to add remote receivers in packet stream `stream'
474 * that has UDP/IP socket stream as the underlaying stream. This function
475 * cannot be used with other type of streams. This returns new packet
476 * stream context that can be used to send to and receive packets from
477 * the specified remote IP and remote port, or NULL on error. The `stream'
478 * is the actual stream that is used to send and receive the data.
480 * When the parent `stream' receives packets from remote IP address
481 * and port that does not have its own remote packet stream, it returns
482 * the packet to the packet callback set for `stream'. The sender's
483 * IP address and port can then be retrieved by using the
484 * silc_packet_get_sender function and to create new packet stream by
485 * calling this function. After that, all packets from that IP address
486 * and port will be received by the new packet stream.
488 * If the `packet' is non-NULL it will be injected into the new packet
489 * stream as soon as the scheduler associated with `stream' schedules
490 * new tasks. It can be used to inject an incoming packet to the stream.
492 * This interface is for connectionless UDP streams. If it is possible
493 * to create connected stream it should be done for performance reasons.
497 * // Create parent packet stream, it can receive packets from anywhere
498 * listener = silc_net_udp_connect("0.0.0.0", 500, NULL, 0, schedule);
499 * parent = silc_packet_stream_create(engine, schedule, listener);
502 * // Received a packet to the parent stream, get the sender information.
503 * silc_packet_get_sender(packet, &ip, &port);
505 * // Create new packet stream for this remote location.
506 * remote = silc_packet_stream_add_remote(parent, ip, port, packet);
509 SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
510 const char *remote_ip,
511 SilcUInt16 remote_port,
514 /****f* silccore/SilcPacketAPI/silc_packet_stream_inject
518 * SilcBool silc_packet_stream_inject(SilcPacketStream stream,
519 * SilcPacket packet);
523 * This function can be used to inject the `packet' to the given
524 * packet `stream'. The packet will appear in the packet stream's
525 * packet handler(s). If this returns FALSE the packet was not
529 SilcBool silc_packet_stream_inject(SilcPacketStream stream,
532 /****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
536 * void silc_packet_stream_destroy(SilcPacketStream stream);
540 * Destroy packet stream and the underlaying stream. This will also
541 * close and destroy the underlaying stream.
544 void silc_packet_stream_destroy(SilcPacketStream stream);
546 /****f* silccore/SilcPacketAPI/silc_packet_stream_is_valid
550 * SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
554 * Returns TRUE if the packet stream indicated by `stream' is valid and
555 * has not been disconnected or destroyed.
558 SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
560 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_router
564 * void silc_packet_stream_set_router(SilcPacketStream stream);
568 * When called sets the stream indicates by `stream' as SILC router
569 * connection stream. This causes that certain packets are handled
570 * differently. This must be called for router connection streams and
571 * must not be called for any other stream.
574 void silc_packet_stream_set_router(SilcPacketStream stream);
576 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_iv_included
580 * void silc_packet_stream_set_iv_included(SilcPacketStream stream);
584 * Sets an IV Included property for the stream indicated by `stream'.
585 * This means that the IV used in the encryption will be included in
586 * the resulted ciphertext. This makes it possible to send and receive
587 * packets on unreliable network transport protocol, such as UDP/IP.
588 * This must be called if the underlaying stream in the `stream' is UDP
591 * When this is set to the stream the silc_packet_set_sid must be called
592 * to set new Security ID. The Security ID will be included with the IV
596 void silc_packet_stream_set_iv_included(SilcPacketStream stream);
598 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_stream
602 * void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
603 * SilcStream stream);
607 * This function may be used to change the underlaying stream in the
608 * packet stream indicated by `packet_stream'. Note that the old
609 * stream will not be used after calling this function. The caller is
610 * responsible destroying the old stream. The `stream' will use
611 * the same scheduler as the `packet_stream'.
614 void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
617 /****f* silccore/SilcPacketAPI/silc_packet_stream_get_stream
621 * SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
625 * Returns the actual stream that is associated with the packet stream
626 * `stream'. The caller must not free the returned stream. The returned
627 * stream is the same pointer that was set for silc_packet_stream_create.
628 * This function could be used for example when an error callback is
629 * called by the packet engine to retrieve the actual lower level error
633 SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
635 /****f* silccore/SilcPacketAPI/silc_packet_stream_link
639 * SilcBool silc_packet_stream_link(SilcPacketStream stream,
640 * SilcPacketCallbacks *callbacks,
641 * void *callback_context,
642 * int priority, ...);
646 * Links the packet processing callbacks indicated by `callbacks' into
647 * the packet stream indicated by `stream' with priority `priority' for
648 * the packet types given in the variable argument list. This function
649 * can be used to link to the packet stream for specific packet types
650 * and receive them in the specified callbacks. This way, a third party,
651 * for example some library may attach itself into the packet stream
652 * and receive and process certain packets. The variable argument
653 * list is ended with -1. To link to receive all packets use
656 * The default packet processing callbacks given as argument to the
657 * silc_packet_engine_start has the priority 0. Any priority higher
658 * than 0 will then take precedence over the default callbacks. Any
659 * priority lower than 0 (negative value) will be processed after the
662 * Note that setting only the 'packet_receive' callback in the `callbacks'
667 * // Link to this packet stream, with high priority, for
668 * // SILC_PACKET_CONNECTION_AUTH and SILC_PACKET_CONNECTION_AUTH_REQUEST
669 * // packets. We don't care about other packets.
670 * silc_packet_stream_link(stream, our_callbacks, our_context,
671 * 1000000, SILC_PACKET_CONNECTION_AUTH,
672 * SILC_PACKET_CONNECTION_AUTH_REQUEST, -1);
675 SilcBool silc_packet_stream_link(SilcPacketStream stream,
676 const SilcPacketCallbacks *callbacks,
677 void *callback_context,
680 /****f* silccore/SilcPacketAPI/silc_packet_stream_unlink
684 * void silc_packet_stream_unlink(SilcPacketStream stream,
685 * SilcPacketCallbacks *callbacks,
686 * void *callback_context);
690 * Unlinks the `callbacks' with `callback_context' from the packet stream
691 * indicated by `stream'. This function must be called for the callbacks
692 * that was linked to `stream' when they are not needed anymore.
695 void silc_packet_stream_unlink(SilcPacketStream stream,
696 const SilcPacketCallbacks *callbacks,
697 void *callback_context);
699 /****f* silccore/SilcPacketAPI/SilcPacketWrapCoder
703 * typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
704 * SilcStreamStatus status,
710 * The encoder/decoder callback for silc_packet_stream_wrap.
712 * If the `status' is SILC_STREAM_CAN_WRITE then additional data can
713 * be added to `buffer' which contains the data that is being written
714 * to the stream. There is at least 16 bytes of free space in head
715 * space of the buffer in case new headers need to be added.
716 * The silc_buffer_enlarge should be called to verify that there is
717 * enough room before adding data to it. The `buffer' must not be freed.
718 * If the return value is FALSE the encoding failed and the packet is
719 * not sent at all and the stream will receive error. Return TRUE if
720 * the encoding succeeded.
722 * If the `status' is SILC_STREAM_CAN_READ then data from the `buffer'
723 * may be read before it is passed to reader when silc_stream_read is
724 * called. The `buffer' may be advanced also to hide data in it. If
725 * return value is FALSE the decoding failed (or the packet is ignored)
726 * and the packet will not be processed by the wrapped packet stream.
727 * If there are other packet streams wanting the same packet, they will
728 * get it, and if not the packet will drop. Return TRUE if decoding
732 typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
733 SilcStreamStatus status,
737 /****f* silccore/SilcPacketAPI/silc_packet_stream_wrap
741 * SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
742 * SilcPacketType type,
743 * SilcPacketFlags flags,
744 * SilcBool blocking_mode,
745 * SilcIdType src_id_type, void *src_id,
746 * SilcIdType dst_id_type, void *dst_id,
747 * SilcPacketWrapCoder coder,
752 * Wraps the packet stream indicated by `stream' into a SilcStream for
753 * the packet type indicated by `type' with packet flags indicated by
754 * `flags'. The returned SilcStream can be used to read and write the
755 * specified SILC packets with the specified packet flags, by calling
756 * silc_stream_read and silc_stream_write, respectively. The returned
757 * stream can be destroyed by calling silc_stream_destroy. It does not
758 * destroy the wrapped packet stream.
760 * If the `blocking_mode' mode is TRUE then the silc_stream_read and
761 * silc_stream_write may block the calling process or thread until SILC
762 * packet is read or written. If it is FALSE the stream is in non-blocking
763 * mode and the calls never block. The returned stream is thread-safe and
764 * packets may be read and written in multi-threaded environment.
766 * In non-blocking mode the silc_stream_set_notifier must be called before
767 * the returned stream can be used to read packets. The stream status
768 * SILC_STREAM_CAN_READ will be returned to the notifier callback to
769 * indicate that a packet is ready for reading. Calling silc_stream_read
770 * once returns one complete SILC packet data payload (which is of type of
773 * If src_id and/or dst_id are set they will be used as the ids in the
774 * sent SILC packets. If the dst_id is set then the stream will receive
775 * packets only originating from that id.
777 * The `coder' is optional encoder/decoder callback which the packet engine
778 * will call if it is non-NULL. It can be used to encode additional data
779 * into each packet when silc_stream_write is called or decode data before
780 * it is passed to reader when silc_stream_read is called. The `context'
781 * is passed to `coder'.
783 * The returned SilcStream can be used as any normal stream and all
784 * SilcStream API functions may be used with the stream. This returns
788 SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
790 SilcPacketFlags flags,
791 SilcBool blocking_mode,
792 SilcIdType src_id_type, void *src_id,
793 SilcIdType dst_id_type, void *dst_id,
794 SilcPacketWrapCoder coder,
797 /****f* silccore/SilcPacketAPI/silc_packet_stream_is_udp
801 * SilcBool silc_packet_stream_is_udp(SilcPacketStream stream);
805 * Returns TRUE if the packet stream indicated by `stream' is using
809 SilcBool silc_packet_stream_is_udp(SilcPacketStream stream);
811 /****f* silccore/SilcPacketAPI/silc_packet_get_sender
815 * SilcBool silc_packet_get_sender(SilcPacket packet,
816 * const char **sender_ip,
817 * SilcUInt16 *sender_port);
821 * Returns the packet sender's IP address and port from UDP packet
822 * indicated by `packet'. This can be called only from the packet
823 * callback to retrieve the information of the packet's sender. Returns
824 * FALSE if the information is not available.
827 SilcBool silc_packet_get_sender(SilcPacket packet,
828 const char **sender_ip,
829 SilcUInt16 *sender_port);
831 /****f* silccore/SilcPacketAPI/silc_packet_stream_ref
835 * void silc_packet_stream_ref(SilcPacketStream stream);
839 * Increase reference counter for the stream indicated by `stream'. This
840 * can be used to take a reference for the stream. To unreference the
841 * stream call silc_packet_stream_unref function.
844 void silc_packet_stream_ref(SilcPacketStream stream);
846 /****f* silccore/SilcPacketAPI/silc_packet_stream_unref
850 * void silc_packet_stream_unref(SilcPacketStream stream);
854 * Decrease reference counter for the stream indicated by `stream'. If
855 * the counter hits zero the stream will be destroyed automatically.
858 void silc_packet_stream_unref(SilcPacketStream stream);
860 /****f* silccore/SilcPacketAPI/silc_packet_get_engine
864 * SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
868 * Returns the packet engine from the `stream'.
871 SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
873 /****f* silccore/SilcPacketAPI/silc_packet_set_context
877 * void silc_packet_set_context(SilcPacketStream stream,
878 * void *stream_context);
882 * Sets a stream specific context to the stream. The context will
883 * be delivered to all callback functions, and it can be retrieved by
884 * calling silc_packet_get_context function as well. Note that this is
885 * separate packet stream specific context, and not the same as
886 * `callback_context' in silc_packet_engine_start. Both will be delivered
887 * to the callbacks, and this context as the `stream_context' argument.
890 void silc_packet_set_context(SilcPacketStream stream, void *stream_context);
892 /****f* silccore/SilcPacketAPI/silc_packet_get_context
896 * void *silc_packet_get_context(SilcPacketStream stream);
900 * Returns the current set application context, or NULL if none is set.
903 void *silc_packet_get_context(SilcPacketStream stream);
905 /****f* silccore/SilcPacketAPI/silc_packet_set_keys
909 * void silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
910 * SilcCipher receive_key, SilcHmac send_hmac,
911 * SilcHmac receive_hmac, SilcBool rekey);
915 * Set ciphers and HMACs to be used to encrypt sent packets, and decrypt
916 * received packets. This can be called multiple times to change the
919 * If the `rekey' is TRUE this function will send SILC_PACKET_REKEY_DONE
920 * to the `stream' and will set the new keys. If it is FALSE the keys
921 * are changed but the packet is not changed.
923 * When changing keys the old cipher and HMACs will be freed. If the keys
924 * are not set at all, packets will not be encrypted or decrypted.
927 SilcBool silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
928 SilcCipher receive_key, SilcHmac send_hmac,
929 SilcHmac receive_hmac, SilcBool rekey);
931 /****f* silccore/SilcPacketAPI/silc_packet_get_keys
935 * SilcBool silc_packet_get_keys(SilcPacketStream stream,
936 * SilcCipher *send_key,
937 * SilcCipher *receive_key,
938 * SilcHmac *send_hmac,
939 * SilcHmac *receive_hmac);
943 * Returns the pointers of current ciphers and HMACs from the `stream'.
944 * Returns FALSE if keys are not set.
947 SilcBool silc_packet_get_keys(SilcPacketStream stream,
948 SilcCipher *send_key, SilcCipher *receive_key,
949 SilcHmac *send_hmac, SilcHmac *receive_hmac);
951 /****f* silccore/SilcPacketAPI/silc_packet_set_ids
955 * SilcBool silc_packet_set_ids(SilcPacketStream stream,
956 * SilcIdType src_id_type, const void *src_id
957 * SilcIdType dst_id_type, const void *dst_id);
961 * Set the source ID and destination ID to be used when sending packets to
962 * this packet stream. The IDs to be used for a packet stream can be
963 * overridden when sending packets. However, if the IDs do not ever change
964 * for the packet stream it is recommended they are set using this function.
965 * In this case they can be omitted when sending packets to the stream.
966 * It is also possible to set only source or destination ID.
969 SilcBool silc_packet_set_ids(SilcPacketStream stream,
970 SilcIdType src_id_type, const void *src_id,
971 SilcIdType dst_id_type, const void *dst_id);
973 /****f* silccore/SilcPacketAPI/silc_packet_get_ids
977 * SilcBool silc_packet_get_ids(SilcPacketStream stream,
978 * SilcBool *src_id_set, SilcID *src_id,
979 * SilcBool *dst_id_set, SilcID *dst_id);
983 * Returns source and destination IDs from the packet stream. The
984 * `src_id_set' is set to TRUE if the source ID was returned. The
985 * `dst_id_set' is set to TRUE if the destination ID was returned.
988 SilcBool silc_packet_get_ids(SilcPacketStream stream,
989 SilcBool *src_id_set, SilcID *src_id,
990 SilcBool *dst_id_set, SilcID *dst_id);
992 /****f* silccore/SilcPacketAPI/silc_packet_set_sid
996 * SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
1000 * Sets new Security ID to the packet stream indicated by `stream'. This
1001 * is called only if the IV Included property was set to the stream
1002 * by calling silc_packet_stream_set_iv_included. This function sets
1003 * new Security ID to the stream which is then included in the ciphertext
1004 * of a packet. The `sid' must be 0 when it is set for the very first
1005 * time and must be increased by one after each rekey. This function must
1006 * be called every time new keys are added to the stream after a rekey.
1008 * If this function is called when the IV Included property has not been
1009 * set to the stream the `sid' will be ignored. Returns FALSE if the
1010 * IV Included has not been set, TRUE otherwise.
1013 SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
1015 /****f* silccore/SilcPacketAPI/silc_packet_send
1019 * SilcBool silc_packet_send(SilcPacketStream stream,
1020 * SilcPacketType type, SilcPacketFlags flags,
1021 * const unsigned char *data,
1022 * SilcUInt32 data_len);
1026 * Send `data' of length of `data_len' to the packet stream indicated by
1027 * `stream'. If ciphers and HMACs were set using silc_packet_set_keys
1028 * the packet will be encrypted and MAC will be computed for it. If
1029 * silc_packet_set_ids was used to set source and destination ID for the
1030 * packet stream those IDs are used in the packet. If IDs have not been
1031 * set and they need to be provided then silc_packet_send_ext function
1032 * should be used. Otherwise, the packet will not have IDs set at all.
1033 * Returns FALSE if packet could not be sent.
1036 SilcBool silc_packet_send(SilcPacketStream stream,
1037 SilcPacketType type, SilcPacketFlags flags,
1038 const unsigned char *data, SilcUInt32 data_len);
1040 /****f* silccore/SilcPacketAPI/silc_packet_send_ext
1045 * silc_packet_send_ext(SilcPacketStream stream,
1046 * SilcPacketType type, SilcPacketFlags flags,
1047 * SilcIdType src_id_type, void *srd_id,
1048 * SilcIdType dst_id_type, void *dst_id,
1049 * const unsigned char *data, SilcUInt32 data_len,
1050 * SilcCipher cipher, SilcHmac hmac);
1054 * Same as silc_packet_send but with this function different sending
1055 * parameters can be sent as argument. This function can be used to
1056 * set specific IDs, cipher and HMAC to be used in packet sending,
1057 * instead of the ones saved in the `stream'. If any of the extra
1058 * pointers are NULL, default values set to the stream will apply.
1061 SilcBool silc_packet_send_ext(SilcPacketStream stream,
1062 SilcPacketType type, SilcPacketFlags flags,
1063 SilcIdType src_id_type, void *src_id,
1064 SilcIdType dst_id_type, void *dst_id,
1065 const unsigned char *data, SilcUInt32 data_len,
1066 SilcCipher cipher, SilcHmac hmac);
1068 /****f* silccore/SilcPacketAPI/silc_packet_send_va
1072 * SilcBool silc_packet_send_va(SilcPacketStream stream,
1073 * SilcPacketType type,
1074 * SilcPacketFlags flags, ...);
1078 * Same as silc_packet_send but takes the data in as variable argument
1079 * formatted buffer (see silcbuffmt.h). The arguments must be ended
1080 * with SILC_STR_END. Returns FALSE if packet could not be sent or
1081 * the buffer could not be formatted.
1085 * // Send NEW_CLIENT packet
1086 * silc_packet_send_va(stream, SILC_PACKET_NEW_CLIENT, 0,
1087 * SILC_STR_UI_SHORT(username_len),
1088 * SILC_STR_DATA(username, username_len),
1089 * SILC_STR_UI_SHORT(realname_len),
1090 * SILC_STR_DATA(realname, realname_len),
1094 SilcBool silc_packet_send_va(SilcPacketStream stream,
1095 SilcPacketType type, SilcPacketFlags flags, ...);
1097 /****f* silccore/SilcPacketAPI/silc_packet_send_va_ext
1102 * silc_packet_send_va_ext(SilcPacketStream stream,
1103 * SilcPacketType type, SilcPacketFlags flags,
1104 * SilcIdType src_id_type, void *srd_id,
1105 * SilcIdType dst_id_type, void *dst_id,
1106 * SilcCipher cipher, SilcHmac hmac, ...);
1110 * Same as silc_packet_send_va but with this function different sending
1111 * parameters can be sent as argument. This function can be used to
1112 * set specific IDs, cipher and HMAC to be used in packet sending,
1113 * instead of the ones saved in the `stream'. If any of the extra
1114 * pointers are NULL, default values set to the stream will apply.
1117 SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
1118 SilcPacketType type, SilcPacketFlags flags,
1119 SilcIdType src_id_type, void *src_id,
1120 SilcIdType dst_id_type, void *dst_id,
1121 SilcCipher cipher, SilcHmac hmac, ...);
1123 /****f* silccore/SilcPacketAPI/silc_packet_wait_init
1127 * void *silc_packet_wait_init(SilcPacketStream stream,
1128 * const SilcID *source_id, ...);
1132 * Initializes a packet waiter for the packet stream `stream' and
1133 * for the variable argument list of packet types. The function
1134 * silc_packet_wait can be used to block the thread until a packet
1135 * has been received.
1137 * This function is used to initialize the waiting and to give the list
1138 * of packet types that caller wish to receive. The variable argument
1139 * list must end with -1. To receive all packets use SILC_PACKET_ANY.
1140 * If the `source_id' is non-NULL then only packets of the specified
1141 * type from the specified `source_id' are received. If it is NULL
1142 * then the packet source is ignored.
1144 * Returns a context that must be given to the silc_packet_wait function
1145 * as argument. Returns NULL on error. To uninitialize the waiting
1146 * call silc_packet_wait_uninit.
1150 * Note that packets may be available immediately after calling this
1151 * function and they will be buffered, until silc_packet_wait is called.
1157 * // Will wait for private message packets
1158 * waiter = silc_packet_wait_init(stream, NULL,
1159 * SILC_PACKET_PRIVATE_MESSAGE, -1);
1162 void *silc_packet_wait_init(SilcPacketStream stream,
1163 const SilcID *source_id, ...);
1165 /****f* silccore/SilcPacketAPI/silc_packet_wait_uninit
1169 * void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
1173 * Uninitializes the waiting context. This may be called also from
1174 * another thread while other thread is waiting for packets. This will
1175 * inform the waiting thread to stop waiting.
1178 void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
1180 /****f* silccore/SilcPacketAPI/silc_packet_wait
1184 * int silc_packet_wait(void *waiter, int timeout,
1185 * SilcPacket *return_packet)
1189 * A special function that can be used to wait for a packet to arrive.
1190 * This function will block the calling process or thread until either
1191 * a packet is received into the `return_packet' pointer or the specified
1192 * timeout value `timeout', which is in milliseconds, will expire. If
1193 * the timeout is 0, no timeout exist. Before calling this function the
1194 * silc_packet_wait_init must be called. The caller is responsible for
1195 * freeing the returned packet with silc_packet_free.
1197 * This function can be used for example from a thread that wants to
1198 * block until SILC packet has been received.
1200 * Returns 1 when packet was received, 0 if timeout occurred and -1 if
1205 * static int foo_read_data(FooContext c)
1207 * SilcPacket packet;
1211 * // Will wait for private message packets
1212 * if (c->initialized == FALSE) {
1213 * waiter = silc_packet_wait_init(stream,
1214 * SILC_PACKET_PRIVATE_MESSAGE, -1);
1215 * c->initialized = TRUE;
1219 * // Wait here until private message packet is received
1220 * if ((silc_packet_wait(waiter, 0, &packet)) < 0)
1223 * ... process packet ...
1229 int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet);
1231 /****f* silccore/SilcPacketAPI/silc_packet_free
1235 * void silc_packet_free(SilcPacket packet);
1239 * This function is used to free the SilcPacket pointer that application
1240 * receives in the SilcPacketReceive callback. Application must free
1241 * the packet if it takes it in to processing.
1244 void silc_packet_free(SilcPacket packet);
1246 #endif /* SILCPACKET_H */