Packet streams: make packet handling callback pointers read only.
[silc.git] / lib / silccore / silcpacket.h
index fd4302303f50f10eaaac75cf8db1e72a4cd0f9ba..0caf10d8c21bc8b54c245e3311265b8b785e6e9a 100644 (file)
@@ -2,15 +2,14 @@
 
   silcpacket.h
 
-  Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+  Author: Pekka Riikonen <priikone@silcnet.org>
 
-  Copyright (C) 1997 - 2001 Pekka Riikonen
+  Copyright (C) 1997 - 2007 Pekka Riikonen
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-  
+  the Free Software Foundation; version 2 of the License.
+
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
 */
 
+/****h* silccore/SILC Packet Engine Interface
+ *
+ * DESCRIPTION
+ *
+ * The SILC secure binary packet protocol interface, provides interface for
+ * sending and receiving SILC packets.  The interface provides a packet
+ * engine, that can be used to receive packets from packet streams, and
+ * routines for sending all kinds of SILC packets.
+ *
+ * The packet engine and packet stream are thread safe.  They can be safely
+ * used in multi threaded environment.
+ *
+ ***/
+
 #ifndef SILCPACKET_H
 #define SILCPACKET_H
 
-/* Amount of bytes to be read from the socket connection at once. */
-#define SILC_PACKET_READ_SIZE 16384
+/* Maximum packet length */
+#define SILC_PACKET_MAX_LEN 0xffff
 
-/* Default byte size of the packet. This can be set larger if this
-   is not enough, we shall see. */
-#define SILC_PACKET_DEFAULT_SIZE 2048
+/* Maximum length of ID */
+#define SILC_PACKET_MAX_ID_LEN 28
 
-/* Header length without source and destination ID's. */
-#define SILC_PACKET_HEADER_LEN 8 + 2
+/****d* silccore/SilcPacketAPI/SilcPacketType
+ *
+ * NAME
+ *
+ *    typedef SilcUInt8 SilcPacketType;
+ *
+ * DESCRIPTION
+ *
+ *    SILC packet type definition and all the packet types.
+ *
+ * SOURCE
+ */
+typedef SilcUInt8 SilcPacketType;
 
-/* Minimum length of SILC Packet Header. This much is decrypted always
-   when packet is received to be able to get all the relevant data out
-   from the header. */
-#define SILC_PACKET_MIN_HEADER_LEN 16 + 2
+/* SILC Packet types. */
+#define SILC_PACKET_DISCONNECT          1       /* Disconnection */
+#define SILC_PACKET_SUCCESS             2       /* Success */
+#define SILC_PACKET_FAILURE             3       /* Failure */
+#define SILC_PACKET_REJECT              4       /* Rejected */
+#define SILC_PACKET_NOTIFY               5       /* Notify message */
+#define SILC_PACKET_ERROR                6       /* Error message */
+#define SILC_PACKET_CHANNEL_MESSAGE     7       /* Message for channel */
+#define SILC_PACKET_CHANNEL_KEY          8       /* Key of the channel */
+#define SILC_PACKET_PRIVATE_MESSAGE      9       /* Private message */
+#define SILC_PACKET_PRIVATE_MESSAGE_KEY  10      /* Private message key*/
+#define SILC_PACKET_COMMAND              11      /* Command */
+#define SILC_PACKET_COMMAND_REPLY        12      /* Reply to a command */
+#define SILC_PACKET_KEY_EXCHANGE         13      /* Start of KE */
+#define SILC_PACKET_KEY_EXCHANGE_1       14      /* KE1 */
+#define SILC_PACKET_KEY_EXCHANGE_2       15      /* KE2 */
+#define SILC_PACKET_CONNECTION_AUTH_REQUEST 16   /* Request of auth meth */
+#define SILC_PACKET_CONNECTION_AUTH      17      /* Connectinon auth */
+#define SILC_PACKET_NEW_ID               18      /* Sending new ID */
+#define SILC_PACKET_NEW_CLIENT           19      /* Client registering */
+#define SILC_PACKET_NEW_SERVER           20      /* Server registering */
+#define SILC_PACKET_NEW_CHANNEL          21      /* Channel registering */
+#define SILC_PACKET_REKEY                22      /* Re-key start */
+#define SILC_PACKET_REKEY_DONE           23      /* Re-key done */
+#define SILC_PACKET_HEARTBEAT            24      /* Heartbeat */
+#define SILC_PACKET_KEY_AGREEMENT        25      /* Key Agreement request */
+#define SILC_PACKET_RESUME_ROUTER        26      /* Backup router resume */
+#define SILC_PACKET_FTP                  27      /* File Transfer */
+#define SILC_PACKET_RESUME_CLIENT        28      /* Client resume */
+#define SILC_PACKET_ACK                  29      /* Acknowledgement */
 
-/* Maximum padding length */
-#define SILC_PACKET_MAX_PADLEN 16
+#define SILC_PACKET_PRIVATE              200     /* Private range start  */
+#define SILC_PACKET_MAX                  255     /* RESERVED */
 
-/* Minimum packet length */
-#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
+#define SILC_PACKET_NONE                0       /* RESERVED */
+#define SILC_PACKET_ANY                  0
+/***/
 
-/* Maximum length of ID */
-#define SILC_PACKET_MAX_ID_LEN 16
+/****d* silccore/SilcPacketAPI/SilcPacketFlags
+ *
+ * NAME
+ *
+ *    typedef SilcUInt8 SilcPacketFlags;
+ *
+ * DESCRIPTION
+ *
+ *    SILC packet flags type definition and all the packet flags.
+ *
+ * SOURCE
+ */
+typedef SilcUInt8 SilcPacketFlags;
 
-/* SILC packet type definition. For now, it is defined like this and I don't 
-   expect it to change in any near future. If one byte as a packet type is 
-   not enough we can, then, think something else. */
-typedef unsigned char SilcPacketType;
+/* All defined packet flags */
+#define SILC_PACKET_FLAG_NONE             0x00    /* No flags */
+#define SILC_PACKET_FLAG_PRIVMSG_KEY      0x01   /* Private message key */
+#define SILC_PACKET_FLAG_LIST             0x02   /* Packet is a list */
+#define SILC_PACKET_FLAG_BROADCAST        0x04   /* Packet is a broadcast */
+#define SILC_PACKET_FLAG_COMPRESSED       0x08    /* Payload is compressed */
+#define SILC_PACKET_FLAG_ACK              0x10    /* Acknowledge packet */
 
-/* SILC packet version type definition. */
-typedef unsigned char SilcPacketVersion;
+/* Impelemntation specific flags */
+#define SILC_PACKET_FLAG_LONG_PAD         0x20    /* Use maximum padding */
+/***/
 
-/* SILC packet flags type definition. */
-typedef unsigned char SilcPacketFlags;
+/****s* silccore/SilcPacketAPI/SilcPacketEngine
+ *
+ * NAME
+ *
+ *    typedef struct SilcPacketEngineStruct *SilcPacketEngine;
+ *
+ * DESCRIPTION
+ *
+ *    The packet engine context, allocated by silc_packet_engine_start.
+ *    The engine is destroyed with silc_packet_engine_stop.
+ *
+ ***/
+typedef struct SilcPacketEngineStruct *SilcPacketEngine;
 
-/* All defined packet flags */
-#define SILC_PACKET_FLAG_NONE             0x00
-#define SILC_PACKET_FLAG_PRIVMSG_KEY      0x01
-#define SILC_PACKET_FLAG_LIST             0x02
-#define SILC_PACKET_FLAG_BROADCAST        0x04
-#define SILC_PACKET_FLAG_TUNNELED         0x08
-/* Rest of flags still available
-#define SILC_PACKET_FLAG_XXX              0x10
-#define SILC_PACKET_FLAG_XXX              0x20
-#define SILC_PACKET_FLAG_XXX              0x40
-#define SILC_PACKET_FLAG_XXX              0x80
-*/
+/****s* silccore/SilcPacketAPI/SilcPacketStream
+ *
+ * NAME
+ *
+ *    typedef struct SilcPacketStreamStruct *SilcPacketStream;
+ *
+ * DESCRIPTION
+ *
+ *    The packet stream context, allocated by silc_packet_stream_create.
+ *    The stream is destroyed with silc_packet_stream_destroy.
+ *
+ ***/
+typedef struct SilcPacketStreamStruct *SilcPacketStream;
 
-/* 
-   SILC packet context. 
+/****s* silccore/SilcPacketAPI/SilcPacket
+ *
+ * NAME
+ *
+ *    typedef struct SilcPacketStruct *SilcPacket;
+ *
+ * DESCRIPTION
+ *
+ *    The SilcPacket is returned by the packet engine in the SilcPacketReceive
+ *    callback.  The application can parse the data payload from the
+ *    SilcPacket.  Also packet type, flags, and sender and destination
+ *    IDs are available.  The application must free the packet with the
+ *    silc_packet_free function if it takes it in for processing.
+ *
+ *    The `buffer' field contains the parsed packet payload and the start
+ *    of the data area will point to the start of the packet payload.
+ *
+ *    The list pointer `next' can be used by the application to put the
+ *    packet context in a list during processing, if needed.
+ *
+ * SOURCE
+ */
+typedef struct SilcPacketStruct {
+  struct SilcPacketStruct *next;     /* List pointer, application may set */
+  SilcPacketStream stream;          /* Packet stream this packet is from */
+  SilcBufferStruct buffer;          /* Packet data payload */
+  unsigned char *src_id;            /* Source ID */
+  unsigned char *dst_id;            /* Destination ID */
+  unsigned int src_id_len  : 6;             /* Source ID length */
+  unsigned int src_id_type : 2;             /* Source ID type */
+  unsigned int dst_id_len  : 6;             /* Destination ID length */
+  unsigned int dst_id_type : 2;             /* Destination ID type */
+  SilcPacketType type;              /* Packet type */
+  SilcPacketFlags flags;            /* Packet flags */
+} *SilcPacket;
+/***/
 
-   In packet sending this is filled and sent to silc_packet_assemble 
-   which then uses it to assemble new packet. In packet reception pointer 
-   to this context is sent to silc_packet_parse which parses the packet 
-   and returns the relevant information to this structure. On packet 
-   reception returned ID's are always the hash values of the ID's from 
-   the packet. 
+/****d* silcutil/SilcPacketAPI/SilcPacketError
+ *
+ * NAME
+ *
+ *    typedef enum { ... } SilcPacketError
+ *
+ * DESCRIPTION
+ *
+ *    Packet errors.  This is returned in the error callback.  If application
+ *    needs the actual lower level stream error, it needs to retrieve it
+ *    from the actual stream.  It can retrieve the underlaying stream from
+ *    the packet stream by calling silc_packet_stream_get_stream function.
+ *
+ *    You may retrieve string version of the SilcPacketError by calling
+ *    silc_packet_error_string.
+ *
+ * SOURCE
+ */
+typedef enum {
+  SILC_PACKET_ERR_READ,                         /* Error while reading */
+  SILC_PACKET_ERR_WRITE,                        /* Error while writing */
+  SILC_PACKET_ERR_MAC_FAILED,           /* Packet MAC check failed */
+  SILC_PACKET_ERR_DECRYPTION_FAILED,            /* Packet decryption failed */
+  SILC_PACKET_ERR_UNKNOWN_SID,          /* Unknown SID (with IV included) */
+  SILC_PACKET_ERR_MALFORMED,            /* Packet is malformed */
+  SILC_PACKET_ERR_NO_MEMORY,            /* System out of memory */
+} SilcPacketError;
+/***/
 
-   Short description of the fields following:
+/****f* silccore/SilcPacketAPI/SilcPacketReceiveCb
+ *
+ * SYNOPSIS
+ *
+ *    typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
+ *                                            SilcPacketStream stream,
+ *                                            SilcPacket packet,
+ *                                            void *callback_context,
+ *                                            void *stream_context);
+ *
+ * DESCRIPTION
+ *
+ *    The packet receive callback is called by the packet engine when a new
+ *    SILC Packet has arrived.  The application must free the returned
+ *    SilcPacket with silc_packet_free if it takes the packet in for
+ *    processing.  This callback is set in the SilcPacketCallbacks structure.
+ *    The `callback_context' is the context set as argument in the
+ *    silc_packet_engine_start function.  The `stream_context' is stream
+ *    specific context that was set by calling silc_packet_set_context.
+ *
+ *    If the application takes the received packet `packet' into processing
+ *    TRUE must be returned.  If FALSE is returned the packet engine will
+ *    pass the packet to other packet processor, if one has been linked
+ *    to the stream with silc_packet_stream_link function.  If no extra
+ *    processor is linked the packet is dropped.
+ *
+ * EXAMPLE
+ *
+ *    SilcBool
+ *    silc_foo_packet_receive_cb(SilcPacketEngine engine,
+ *                               SilcPacketStream stream, SilcPacket packet,
+ *                               void *callback_context, void *stream_context)
+ *    {
+ *      Application ctx = callback_context;
+ *
+ *      // If we're not up yet, let's not process the packet
+ *      if (ctx->initialized == FALSE)
+ *        return FALSE;
+ *
+ *      // Process the incoming packet...
+ *      ...
+ *
+ *      // It's our packet now, no one else will get it
+ *      return TRUE;
+ *    }
+ *
+ ***/
+typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
+                                       SilcPacketStream stream,
+                                       SilcPacket packet,
+                                       void *callback_context,
+                                       void *stream_context);
 
-   SilcBuffer buffer
+/****f* silccore/SilcPacketAPI/SilcPacketEosCb
+ *
+ * SYNOPSIS
+ *
+ *    typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
+ *                                    SilcPacketStream stream,
+ *                                    void *callback_context,
+ *                                    void *stream_context);
+ *
+ * DESCRIPTION
+ *
+ *    The End Of Stream (EOS) callback, that is called by the packet engine
+ *    when the underlaying stream has ended.  No more data can be sent to
+ *    the stream or read from it.  The `stream' must be destroyed by
+ *    calling the silc_packet_stream_destroy.  This callback is set in the
+ *    SilcPacketCallbacks structure.
+ *
+ ***/
+typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
+                               SilcPacketStream stream,
+                               void *callback_context,
+                               void *stream_context);
 
-       The data buffer.
+/****f* silccore/SilcPacketAPI/SilcPacketErrorCb
+ *
+ * SYNOPSIS
+ *
+ *    typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
+ *                                      SilcPacketStream stream,
+ *                                      SilcPacketError error,
+ *                                      void *callback_context,
+ *                                      void *stream_context);
+ *
+ * DESCRIPTION
+ *
+ *    The error callback that is called by the packet engine if an error
+ *    occurs.  The `error' will indicate the error.  This callback is set
+ *    in the SilcPacketCallbacks structure.
+ *
+ ***/
+typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
+                                 SilcPacketStream stream,
+                                 SilcPacketError error,
+                                 void *callback_context,
+                                 void *stream_context);
 
-   SilcPacketType type
+/****s* silccore/SilcPacketAPI/SilcPacketCallbacks
+ *
+ * NAME
+ *
+ *    typedef struct { ... } *SilcPacketCallbacks;
+ *
+ * DESCRIPTION
+ *
+ *    This structure is sent as argument to the silc_packet_engine_start
+ *    function to set the callback functions for the packet engine.  The
+ *    packet engine will call the callbacks when necessary.  Application
+ *    must always be provided for the packet engine.
+ *
+ * SOURCE
+ */
+typedef struct {
+  SilcPacketReceiveCb packet_receive;   /* Called when packet is received */
+  SilcPacketEosCb eos;                  /* Called on end of stream */
+  SilcPacketErrorCb error;              /* Called on an error */
+} SilcPacketCallbacks;
+/***/
 
-       Type of the packet. Types are defined below.
+/* Prototypes */
 
-   SilcPacketFlags flags
+/****f* silccore/SilcPacketAPI/silc_packet_engine_start
+ *
+ * SYNOPSIS
+ *
+ *    SilcPacketEngine
+ *    silc_packet_engine_start(SilcRng rng, SilcBool router,
+ *                             SilcPacketCallbacks *callbacks,
+ *                             void *callback_context);
+ *
+ * DESCRIPTION
+ *
+ *    Create new packet engine for processing incoming and outgoing packets.
+ *    If `router' is  TRUE then the application is considered to be router
+ *    server, and certain packets are handled differently.  Client and normal
+ *    server must set it to FALSE.  The `callbacks' is a SilcPacketCallbacks
+ *    structure provided by the caller which includes the callbacks that is
+ *    called when for example packet is received, or end of stream is called.
+ *
+ * NOTES
+ *
+ *    The packet engine is thread safe.  You can use one packet engine in
+ *    multi threaded application.
+ *
+ ***/
+SilcPacketEngine
+silc_packet_engine_start(SilcRng rng, SilcBool router,
+                        const SilcPacketCallbacks *callbacks,
+                        void *callback_context);
 
-       Packet flags. Flags are defined above.
+/****f* silccore/SilcPacketAPI/silc_packet_engine_stop
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_engine_stop(SilcPacketEngine engine);
+ *
+ * DESCRIPTION
+ *
+ *    Stop the packet engine.  No new packets can be sent or received after
+ *    calling this, and the `engine' will become invalid.
+ *
+ ***/
+void silc_packet_engine_stop(SilcPacketEngine engine);
 
-   unsigned char *src_id
-   unsigned short src_id_len
-   unsigned char src_id_type
+/****f* silccore/SilcPacketAPI/silc_packet_error_string
+ *
+ * SYNOPSIS
+ *
+ *    const char *silc_packet_error_string(SilcPacketError error);
+ *
+ * DESCRIPTION
+ *
+ *    Return the packet error as string.
+ *
+ ***/
+const char *silc_packet_error_string(SilcPacketError error);
 
-       Source ID, its length and type. On packet reception retuned ID's
-       are always the hash values of the ID's from the packet.
+/****f* silccore/SilcPacketAPI/silc_packet_engine_get_streams
+ *
+ * SYNOPSIS
+ *
+ *    SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
+ *
+ * DESCRIPTION
+ *
+ *    Returns list of packet streams added to the packet engine.  The caller
+ *    must free the list with silc_packet_engine_free_streams_list.
+ *
+ * NOTES
+ *
+ *    This function may also return disconnected and destroyed streams.  The
+ *    caller should use silc_packet_stream_is_valid to check if the stream
+ *    is valid.
+ *
+ ***/
+SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
 
-  unsigned char *dst_id;
-  unsigned short dst_id_len;
-  unsigned char src_id_type;
+/****f* silccore/SilcPacketAPI/silc_packet_engine_free_streams_list
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_engine_free_streams_list(SilcDList streams);
+ *
+ * DESCRIPTION
+ *
+ *    Free's the streams list returned by silc_packet_engine_get_streams.
+ *
+ ***/
+void silc_packet_engine_free_streams_list(SilcDList streams);
 
-       Destination ID, its length and type. On packet reception retuned
-       ID's are always the hash values of the ID's from the packet.
+/****f* silccore/SilcPacketAPI/silc_packet_stream_create
+ *
+ * SYNOPSIS
+ *
+ *    SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+ *                                               SilcSchedule schedule,
+ *                                               SilcStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Create new packet stream and use the `stream' as underlaying stream.
+ *    Usually the `stream' would be a socket stream, but it can be any
+ *    stream.  After this function returns, packets can immediately be
+ *    sent to and received from the stream.
+ *
+ * NOTES
+ *
+ *    SilcPacketStream cannot be used with silc_stream_* routines (such as
+ *    silc_stream_read and silc_stream_write) because of its special nature.
+ *    Use the silc_packet_send and the silc_packet_send_ext to send packets.
+ *    To read packets you will receive the packet receive callback from
+ *    packet engine.  Destroy the stream with silc_packet_stream_destroy.
+ *
+ *    The SilcPacketStream is thread safe.  Same context can be safely used
+ *    in multi threaded environment.
+ *
+ ***/
+SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+                                          SilcSchedule schedule,
+                                          SilcStream stream);
 
-   SilcHash hash
+/****f* silccore/SilcPacketAPI/silc_packet_stream_add_remote
+ *
+ * SYNOPSIS
+ *
+ *    SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
+ *                                                   const char *remote_ip,
+ *                                                   SilcUInt16 remote_port,
+ *                                                   SilcPacket packet);
+ *
+ * DESCRIPTION
+ *
+ *    This function is used to add remote receivers in packet stream `stream'
+ *    that has UDP/IP socket stream as the underlaying stream.  This function
+ *    cannot be used with other type of streams.  This returns new packet
+ *    stream context that can be used to send to and receive packets from
+ *    the specified remote IP and remote port, or NULL on error.  The `stream'
+ *    is the actual stream that is used to send and receive the data.
+ *
+ *    When the parent `stream' receives packets from remote IP address
+ *    and port that does not have its own remote packet stream, it returns
+ *    the packet to the packet callback set for `stream'.  The sender's
+ *    IP address and port can then be retrieved by using the
+ *    silc_packet_get_sender function and to create new packet stream by
+ *    calling this function.  After that, all packets from that IP address
+ *    and port will be received by the new packet stream.
+ *
+ *    If the `packet' is non-NULL it will be injected into the new packet
+ *    stream as soon as the scheduler associated with `stream' schedules
+ *    new tasks.  It can be used to inject an incoming packet to the stream.
+ *
+ *    This interface is for connectionless UDP streams.  If it is possible
+ *    to create connected stream it should be done for performance reasons.
+ *
+ * EXAMPLE
+ *
+ *    // Create parent packet stream, it can receive packets from anywhere
+ *    listener = silc_net_udp_connect("0.0.0.0", 500, NULL, 0, schedule);
+ *    parent = silc_packet_stream_create(engine, schedule, listener);
+ *
+ *    ...
+ *    // Received a packet to the parent stream, get the sender information.
+ *    silc_packet_get_sender(packet, &ip, &port);
+ *
+ *    // Create new packet stream for this remote location.
+ *    remote = silc_packet_stream_add_remote(parent, ip, port, packet);
+ *
+ ***/
+SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
+                                              const char *remote_ip,
+                                              SilcUInt16 remote_port,
+                                              SilcPacket packet);
 
-       Pointer to allocated hash object. This must be MD5 hash object.
-       This is used to calculate checksum of the packet.
+/****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_destroy(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Destroy packet stream and the underlaying stream.  This will also
+ *    close and destroy the underlaying stream.
+ *
+ ***/
+void silc_packet_stream_destroy(SilcPacketStream stream);
 
-*/
-typedef struct {
-  SilcBuffer buffer;
-  SilcPacketType type;
-  SilcPacketFlags flags;
+/****f* silccore/SilcPacketAPI/silc_packet_stream_is_valid
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Returns TRUE if the packet stream indicated by `stream' is valid and
+ *    has not been disconnected or destroyed.
+ *
+ ***/
+SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
 
-  unsigned char *src_id;
-  unsigned short src_id_len;
-  unsigned char src_id_type;
+/****f* silccore/SilcPacketAPI/silc_packet_stream_set_router
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_set_router(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    When called sets the stream indicates by `stream' as SILC router
+ *    connection stream.  This causes that certain packets are handled
+ *    differently.  This must be called for router connection streams and
+ *    must not be called for any other stream.
+ *
+ ***/
+void silc_packet_stream_set_router(SilcPacketStream stream);
 
-  unsigned char *dst_id;
-  unsigned short dst_id_len;
-  unsigned char dst_id_type;
+/****f* silccore/SilcPacketAPI/silc_packet_stream_set_iv_included
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_set_iv_included(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Sets an IV Included property for the stream indicated by `stream'.
+ *    This means that the IV used in the encryption will be included in
+ *    the resulted ciphertext.  This makes it possible to send and receive
+ *    packets on unreliable network transport protocol, such as UDP/IP.
+ *    This must be called if the underlaying stream in the `stream' is UDP
+ *    stream.
+ *
+ *    When this is set to the stream the silc_packet_set_sid must be called
+ *    to set new Security ID.  The Security ID will be included with the IV
+ *    in the ciphertext.
+ *
+ ***/
+void silc_packet_stream_set_iv_included(SilcPacketStream stream);
 
-  unsigned short truelen;
-  unsigned short padlen;
+/****f* silccore/SilcPacketAPI/silc_packet_stream_set_stream
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
+ *                                       SilcStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    This function may be used to change the underlaying stream in the
+ *    packet stream indicated by `packet_stream'.  Note that the old
+ *    stream will not be used after calling this function.  The caller is
+ *    responsible destroying the old stream.  The `stream' will use
+ *    the same scheduler as the `packet_stream'.
+ *
+ ***/
+void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
+                                  SilcStream stream);
 
-  /* Back pointers */
-  void *context;
-  SilcSocketConnection sock;
+/****f* silccore/SilcPacketAPI/silc_packet_stream_get_stream
+ *
+ * SYNOPSIS
+ *
+ *    SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Returns the actual stream that is associated with the packet stream
+ *    `stream'.  The caller must not free the returned stream.  The returned
+ *    stream is the same pointer that was set for silc_packet_stream_create.
+ *    This function could be used for example when an error callback is
+ *    called by the packet engine to retrieve the actual lower level error
+ *    from the stream.
+ *
+ ***/
+SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
 
-  /* Reference count for this context. The context is free'd only
-     after the reference count is zero. */
-  int users;
-} SilcPacketContext;
+/****f* silccore/SilcPacketAPI/silc_packet_stream_link
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_stream_link(SilcPacketStream stream,
+ *                                     SilcPacketCallbacks *callbacks,
+ *                                     void *callback_context,
+ *                                     int priority, ...);
+ *
+ * DESCRIPTION
+ *
+ *    Links the packet processing callbacks indicated by `callbacks' into
+ *    the packet stream indicated by `stream' with priority `priority' for
+ *    the packet types given in the variable argument list.  This function
+ *    can be used to link to the packet stream for specific packet types
+ *    and receive them in the specified callbacks.  This way, a third party,
+ *    for example some library may attach itself into the packet stream
+ *    and receive and process certain packets.  The variable argument
+ *    list is ended with -1.  To link to receive all packets use
+ *    SILC_PACKET_ANY.
+ *
+ *    The default packet processing callbacks given as argument to the
+ *    silc_packet_engine_start has the priority 0.  Any priority higher
+ *    than 0 will then take precedence over the default callbacks.  Any
+ *    priority lower than 0 (negative value) will be processed after the
+ *    default callbacks.
+ *
+ *    Note that setting only the 'packet_receive' callback in the `callbacks'
+ *    is required.
+ *
+ * EXAMPLE
+ *
+ *    // Link to this packet stream, with high priority, for
+ *    // SILC_PACKET_CONNECTION_AUTH and SILC_PACKET_CONNECTION_AUTH_REQUEST
+ *    // packets. We don't care about other packets.
+ *    silc_packet_stream_link(stream, our_callbacks, our_context,
+ *                            1000000, SILC_PACKET_CONNECTION_AUTH,
+ *                            SILC_PACKET_CONNECTION_AUTH_REQUEST, -1);
+ *
+ ***/
+SilcBool silc_packet_stream_link(SilcPacketStream stream,
+                                const SilcPacketCallbacks *callbacks,
+                                void *callback_context,
+                                int priority, ...);
 
-/* 
-   Silc Packet Parser context.
+/****f* silccore/SilcPacketAPI/silc_packet_stream_unlink
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_unlink(SilcPacketStream stream,
+ *                                   SilcPacketCallbacks *callbacks,
+ *                                   void *callback_context);
+ *
+ * DESCRIPTION
+ *
+ *    Unlinks the `callbacks' with `callback_context' from the packet stream
+ *    indicated by `stream'.  This function must be called for the callbacks
+ *    that was linked to `stream' when they are not needed anymore.
+ *
+ ***/
+void silc_packet_stream_unlink(SilcPacketStream stream,
+                              const SilcPacketCallbacks *callbacks,
+                              void *callback_context);
 
-   This context is used in packet reception when silc_packet_receive_process
-   function calls parser callback that performs the actual packet decryption
-   and parsing. This context is sent as argument to the parser function.
-   This context must be free'd by the parser callback function.
+/****f* silccore/SilcPacketAPI/SilcPacketWrapCoder
+ *
+ * SYNOPSIS
+ *
+ *    typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
+ *                                            SilcStreamStatus status,
+ *                                            SilcBuffer buffer,
+ *                                            void *context);
+ *
+ * DESCRIPTION
+ *
+ *    The encoder/decoder callback for silc_packet_stream_wrap.  If the
+ *    `status' is SILC_STREAM_CAN_WRITE then additional data can be added
+ *    to `buffer'.  It is added before the data that is written with
+ *    silc_stream_write.  The silc_buffer_enlarge should be called to verify
+ *    there is enough room in `buffer' before adding data to it.  The `buffer'
+ *    must not be freed.
+ *
+ *    If the `status' is SILC_STREAM_CAN_READ then data from the `buffer'
+ *    may be read before it is passed to readed when silc_stream_read is
+ *    called.  The `buffer' may be advanced also to hide data in it.
+ *
+ *    This function returns FALSE in case of error.
+ *
+ ***/
+typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
+                                       SilcStreamStatus status,
+                                       SilcBuffer buffer,
+                                       void *context);
 
-   Following description of the fields:
+/****f* silccore/SilcPacketAPI/silc_packet_stream_wrap
+ *
+ * SYNOPSIS
+ *
+ *    SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
+ *                                       SilcPacketType type,
+ *                                       SilcPacketFlags flags,
+ *                                       SilcBool blocking_mode,
+ *                                       SilcPacketWrapCoder coder,
+ *                                       void *context);
+ *
+ * DESCRIPTION
+ *
+ *    Wraps the packet stream indicated by `stream' into a SilcStream for
+ *    the packet type indicated by `type' with packet flags indicated by
+ *    `flags'.  The returned SilcStream can be used to read and write the
+ *    specified SILC packets with the specified packet flags, by calling
+ *    silc_stream_read and silc_stream_write, respectively.  The returned
+ *    stream can be destroyed by calling silc_stream_destroy.  It does not
+ *    destroy the wrapped packet stream.
+ *
+ *    If the `blocking_mode' mode is TRUE then the silc_stream_read and
+ *    silc_stream_write may block the calling process or thread until SILC
+ *    packet is read or written.  If it is FALSE the stream is in non-blocking
+ *    mode and the calls never block.  The returned stream is thread-safe and
+ *    packets may be read and written in multi-threaded environment.
+ *
+ *    In non-blocking mode the silc_stream_set_notifier must be called before
+ *    the returned stream can be used to read packets.  The stream status
+ *    SILC_STREAM_CAN_READ will be returned to the notifier callback to
+ *    indicate that a packet is ready for reading.  Calling silc_stream_read
+ *    once returns one complete SILC packet data payload (which is of type of
+ *    `type').
+ *
+ *    The `coder' is optional encoder/decoder callback which the packet engine
+ *    will call if it is non-NULL.  It can be used to encode additional data
+ *    into each packet when silc_stream_write is called or decode data before
+ *    it is passed to reader when silc_stream_read is called.  The `context'
+ *    is passed to `coder'.
+ *
+ *    The returned SilcStream can be used as any normal stream and all
+ *    SilcStream API functions may be used with the stream.  This returns
+ *    NULL on error.
+ *
+ ***/
+SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
+                                  SilcPacketType type,
+                                  SilcPacketFlags flags,
+                                  SilcBool blocking_mode,
+                                  SilcPacketWrapCoder coder,
+                                  void *context);
 
-   SilcPacketContext *packet
+/****f* silccore/SilcPacketAPI/silc_packet_stream_is_udp
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_stream_is_udp(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Returns TRUE if the packet stream indicated by `stream' is using
+ *    UDP transport.
+ *
+ ***/
+SilcBool silc_packet_stream_is_udp(SilcPacketStream stream);
 
-       The actual packet received from the network. In this phase the
-       context is not parsed, only the packet->buffer is allocated and
-       it includes the raw packet data, which is encrypted.
+/****f* silccore/SilcPacketAPI/silc_packet_get_sender
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_get_sender(SilcPacket packet,
+ *                                    const char **sender_ip,
+ *                                    SilcUInt16 *sender_port);
+ *
+ * DESCRIPTION
+ *
+ *    Returns the packet sender's IP address and port from UDP packet
+ *    indicated by `packet'.  This can be called only from the packet
+ *    callback to retrieve the information of the packet's sender.  Returns
+ *    FALSE if the information is not available.
+ *
+ ***/
+SilcBool silc_packet_get_sender(SilcPacket packet,
+                               const char **sender_ip,
+                               SilcUInt16 *sender_port);
 
-   SilcSocketConnection sock
+/****f* silccore/SilcPacketAPI/silc_packet_stream_ref
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_ref(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Increase reference counter for the stream indicated by `stream'.  This
+ *    can be used to take a reference for the stream.  To unreference the
+ *    stream call silc_packet_stream_unref function.
+ *
+ ***/
+void silc_packet_stream_ref(SilcPacketStream stream);
 
-       The associated connection.
+/****f* silccore/SilcPacketAPI/silc_packet_stream_unref
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_stream_unref(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Decrease reference counter for the stream indicated by `stream'.  If
+ *    the counter hits zero the stream will be destroyed automatically.
+ *
+ ***/
+void silc_packet_stream_unref(SilcPacketStream stream);
 
-   SilcCipher cipher
+/****f* silccore/SilcPacketAPI/silc_packet_get_engine
+ *
+ * SYNOPSIS
+ *
+ *    SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Returns the packet engine from the `stream'.
+ *
+ ***/
+SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
 
-       The cipher to be used in the decryption.
+/****f* silccore/SilcPacketAPI/silc_packet_set_context
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_set_context(SilcPacketStream stream,
+ *                                 void *stream_context);
+ *
+ * DESCRIPTION
+ *
+ *    Sets a stream specific context to the stream.  The context will
+ *    be delivered to all callback functions, and it can be retrieved by
+ *    calling silc_packet_get_context function as well.  Note that this is
+ *    separate packet stream specific context, and not the same as
+ *    `callback_context' in silc_packet_engine_start.  Both will be delivered
+ *    to the callbacks, and this context as the `stream_context' argument.
+ *
+ ***/
+void silc_packet_set_context(SilcPacketStream stream, void *stream_context);
 
-   SilcHmac hmac
+/****f* silccore/SilcPacketAPI/silc_packet_get_context
+ *
+ * SYNOPSIS
+ *
+ *    void *silc_packet_get_context(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Returns the current set application context, or NULL if none is set.
+ *
+ ***/
+void *silc_packet_get_context(SilcPacketStream stream);
 
-       The HMAC to be used in the decryption.
+/****f* silccore/SilcPacketAPI/silc_packet_set_keys
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
+ *                              SilcCipher receive_key, SilcHmac send_hmac,
+ *                              SilcHmac receive_hmac, SilcBool rekey);
+ *
+ * DESCRIPTION
+ *
+ *    Set ciphers and HMACs to be used to encrypt sent packets, and decrypt
+ *    received packets.  This can be called multiple times to change the
+ *    ciphers and HMACs.
+ *
+ *    If the `rekey' is TRUE this function will send SILC_PACKET_REKEY_DONE
+ *    to the `stream' and will set the new keys.  If it is FALSE the keys
+ *    are changed but the packet is not changed.
+ *
+ *    When changing keys the old cipher and HMACs will be freed.  If the keys
+ *    are not set at all, packets will not be encrypted or decrypted.
+ *
+ ***/
+SilcBool silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
+                              SilcCipher receive_key, SilcHmac send_hmac,
+                              SilcHmac receive_hmac, SilcBool rekey);
 
-   void *context
+/****f* silccore/SilcPacketAPI/silc_packet_get_keys
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_get_keys(SilcPacketStream stream,
+ *                                  SilcCipher *send_key,
+ *                                  SilcCipher *receive_key,
+ *                                  SilcHmac *send_hmac,
+ *                                  SilcHmac *receive_hmac);
+ *
+ * DESCRIPTION
+ *
+ *    Returns the pointers of current ciphers and HMACs from the `stream'.
+ *    Returns FALSE if keys are not set.
+ *
+ ***/
+SilcBool silc_packet_get_keys(SilcPacketStream stream,
+                             SilcCipher *send_key, SilcCipher *receive_key,
+                             SilcHmac *send_hmac, SilcHmac *receive_hmac);
 
-       User context that is sent to the silc_packet_receive_process
-       function. This usually includes application and connection specific
-       data.
+/****f* silccore/SilcPacketAPI/silc_packet_set_ids
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_set_ids(SilcPacketStream stream,
+ *                                 SilcIdType src_id_type, const void *src_id
+ *                                 SilcIdType dst_id_type, const void *dst_id);
+ *
+ * DESCRIPTION
+ *
+ *    Set the source ID and destination ID to be used when sending packets to
+ *    this packet stream.  The IDs to be used for a packet stream can be
+ *    overridden when sending packets.  However, if the IDs do not ever change
+ *    for the packet stream it is recommended they are set using this function.
+ *    In this case they can be omitted when sending packets to the stream.
+ *    It is also possible to set only source or destination ID.
+ *
+ ***/
+SilcBool silc_packet_set_ids(SilcPacketStream stream,
+                            SilcIdType src_id_type, const void *src_id,
+                            SilcIdType dst_id_type, const void *dst_id);
 
-*/
+/****f* silccore/SilcPacketAPI/silc_packet_get_ids
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_get_ids(SilcPacketStream stream,
+ *                                 SilcBool *src_id_set, SilcID *src_id,
+ *                                 SilcBool *dst_id_set, SilcID *dst_id);
+ *
+ * DESCRIPTION
+ *
+ *    Returns source and destination IDs from the packet stream.  The
+ *    `src_id_set' is set to TRUE if the source ID was returned.  The
+ *    `dst_id_set' is set to TRUE if the destination ID was returned.
+ *
+ ***/
+SilcBool silc_packet_get_ids(SilcPacketStream stream,
+                            SilcBool *src_id_set, SilcID *src_id,
+                            SilcBool *dst_id_set, SilcID *dst_id);
 
-typedef struct {
-  SilcPacketContext *packet;
-  SilcSocketConnection sock;
-  SilcCipher cipher;
-  SilcHmac hmac;
-  void *context;
-} SilcPacketParserContext;
+/****f* silccore/SilcPacketAPI/silc_packet_set_sid
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
+ *
+ * DESCRIPTION
+ *
+ *    Sets new Security ID to the packet stream indicated by `stream'.  This
+ *    is called only if the IV Included property was set to the stream
+ *    by calling silc_packet_stream_set_iv_included.  This function sets
+ *    new Security ID to the stream which is then included in the ciphertext
+ *    of a packet.  The `sid' must be 0 when it is set for the very first
+ *    time and must be increased by one after each rekey.  This function must
+ *    be called every time new keys are added to the stream after a rekey.
+ *
+ *    If this function is called when the IV Included property has not been
+ *    set to the stream the `sid' will be ignored.  Returns FALSE if the
+ *    IV Included has not been set, TRUE otherwise.
+ *
+ ***/
+SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid);
 
-/* The parser callback function. */
-typedef void (*SilcPacketParserCallback)(SilcPacketParserContext 
-                                        *parse_context);
+/****f* silccore/SilcPacketAPI/silc_packet_send
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_send(SilcPacketStream stream,
+ *                              SilcPacketType type, SilcPacketFlags flags,
+ *                              const unsigned char *data,
+ *                              SilcUInt32 data_len);
+ *
+ * DESCRIPTION
+ *
+ *    Send `data' of length of `data_len' to the packet stream indicated by
+ *    `stream'.  If ciphers and HMACs were set using silc_packet_set_keys
+ *    the packet will be encrypted and MAC will be computed for it.  If
+ *    silc_packet_set_ids was used to set source and destination ID for the
+ *    packet stream those IDs are used in the packet.  If IDs have not been
+ *    set and they need to be provided then silc_packet_send_ext function
+ *    should be used.  Otherwise, the packet will not have IDs set at all.
+ *    Returns FALSE if packet could not be sent.
+ *
+ ***/
+SilcBool silc_packet_send(SilcPacketStream stream,
+                         SilcPacketType type, SilcPacketFlags flags,
+                         const unsigned char *data, SilcUInt32 data_len);
 
+/****f* silccore/SilcPacketAPI/silc_packet_send_ext
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool
+ *    silc_packet_send_ext(SilcPacketStream stream,
+ *                         SilcPacketType type, SilcPacketFlags flags,
+ *                         SilcIdType src_id_type, void *srd_id,
+ *                         SilcIdType dst_id_type, void *dst_id,
+ *                         const unsigned char *data, SilcUInt32 data_len,
+ *                         SilcCipher cipher, SilcHmac hmac);
+ *
+ * DESCRIPTION
+ *
+ *    Same as silc_packet_send but with this function different sending
+ *    parameters can be sent as argument.  This function can be used to
+ *    set specific IDs, cipher and HMAC to be used in packet sending,
+ *    instead of the ones saved in the `stream'.  If any of the extra
+ *    pointers are NULL, default values set to the stream will apply.
+ *
+ ***/
+SilcBool silc_packet_send_ext(SilcPacketStream stream,
+                             SilcPacketType type, SilcPacketFlags flags,
+                             SilcIdType src_id_type, void *src_id,
+                             SilcIdType dst_id_type, void *dst_id,
+                             const unsigned char *data, SilcUInt32 data_len,
+                             SilcCipher cipher, SilcHmac hmac);
 
-/* SILC Packet types. */
-#define SILC_PACKET_NONE                0       /* NULL, never sent */
-#define SILC_PACKET_DISCONNECT          1       /* Disconnection */
-#define SILC_PACKET_SUCCESS             2       /* Success */
-#define SILC_PACKET_FAILURE             3       /* Failure */
-#define SILC_PACKET_REJECT              4       /* Rejected */
-#define SILC_PACKET_NOTIFY               5       /* Notify message */
-#define SILC_PACKET_ERROR                6       /* Error message */
-#define SILC_PACKET_CHANNEL_MESSAGE     7       /* Message for channel */
-#define SILC_PACKET_CHANNEL_KEY          8       /* Key of the channel */
-#define SILC_PACKET_PRIVATE_MESSAGE      9       /* Private message */
-#define SILC_PACKET_PRIVATE_MESSAGE_KEY  10      /* Private message key*/
-#define SILC_PACKET_COMMAND              11      /* Command */
-#define SILC_PACKET_COMMAND_REPLY        12      /* Reply to a command */
-#define SILC_PACKET_KEY_EXCHANGE         13      /* Start of KE */
-#define SILC_PACKET_KEY_EXCHANGE_1       14      /* KE1 */
-#define SILC_PACKET_KEY_EXCHANGE_2       15      /* KE2 */
-#define SILC_PACKET_CONNECTION_AUTH_REQUEST 16   /* Request of auth meth */
-#define SILC_PACKET_CONNECTION_AUTH      17      /* Connectinon auth */
-#define SILC_PACKET_NEW_ID               18      /* Sending new ID */
-#define SILC_PACKET_NEW_CLIENT           19      /* Client registering */
-#define SILC_PACKET_NEW_SERVER           20      /* Server registering */
-#define SILC_PACKET_NEW_CHANNEL          21      /* Channel registering */
-#define SILC_PACKET_REKEY                22      /* Re-key start */
-#define SILC_PACKET_REKEY_DONE           23      /* Re-key done */
-#define SILC_PACKET_HEARTBEAT            24      /* Heartbeat */
-#define SILC_PACKET_KEY_AGREEMENT        25      /* Key Agreement request */
+/****f* silccore/SilcPacketAPI/silc_packet_send_va
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_send_va(SilcPacketStream stream,
+ *                                 SilcPacketType type,
+ *                                 SilcPacketFlags flags, ...);
+ *
+ * DESCRIPTION
+ *
+ *    Same as silc_packet_send but takes the data in as variable argument
+ *    formatted buffer (see silcbuffmt.h).  The arguments must be ended
+ *    with SILC_STR_END.  Returns FALSE if packet could not be sent or
+ *    the buffer could not be formatted.
+ *
+ * EXAMPLE
+ *
+ *    // Send NEW_CLIENT packet
+ *    silc_packet_send_va(stream, SILC_PACKET_NEW_CLIENT, 0,
+ *                        SILC_STR_UI_SHORT(username_len),
+ *                        SILC_STR_DATA(username, username_len),
+ *                        SILC_STR_UI_SHORT(realname_len),
+ *                        SILC_STR_DATA(realname, realname_len),
+ *                        SILC_STR_END);
+ *
+ ***/
+SilcBool silc_packet_send_va(SilcPacketStream stream,
+                            SilcPacketType type, SilcPacketFlags flags, ...);
 
-#define SILC_PACKET_PRIVATE              200     /* Private range start  */
-#define SILC_PACKET_MAX                  255     /* RESERVED */
+/****f* silccore/SilcPacketAPI/silc_packet_send_va_ext
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool
+ *    silc_packet_send_va_ext(SilcPacketStream stream,
+ *                            SilcPacketType type, SilcPacketFlags flags,
+ *                            SilcIdType src_id_type, void *srd_id,
+ *                            SilcIdType dst_id_type, void *dst_id,
+ *                            SilcCipher cipher, SilcHmac hmac, ...);
+ *
+ * DESCRIPTION
+ *
+ *    Same as silc_packet_send_va but with this function different sending
+ *    parameters can be sent as argument.  This function can be used to
+ *    set specific IDs, cipher and HMAC to be used in packet sending,
+ *    instead of the ones saved in the `stream'.  If any of the extra
+ *    pointers are NULL, default values set to the stream will apply.
+ *
+ ***/
+SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
+                                SilcPacketType type, SilcPacketFlags flags,
+                                SilcIdType src_id_type, void *src_id,
+                                SilcIdType dst_id_type, void *dst_id,
+                                SilcCipher cipher, SilcHmac hmac, ...);
 
-/* Macros */
+/****f* silccore/SilcPacketAPI/silc_packet_wait_init
+ *
+ * SYNOPSIS
+ *
+ *    void *silc_packet_wait_init(SilcPacketStream stream,
+ *                                const SilcID *source_id, ...);
+ *
+ * DESCRIPTION
+ *
+ *    Initializes a packet waiter for the packet stream `stream' and
+ *    for the variable argument list of packet types.  The function
+ *    silc_packet_wait can be used to block the thread until a packet
+ *    has been received.
+ *
+ *    This function is used to initialize the waiting and to give the list
+ *    of packet types that caller wish to receive.  The variable argument
+ *    list must end with -1.  To receive all packets use SILC_PACKET_ANY.
+ *    If the `source_id' is non-NULL then only packets of the specified
+ *    type from the specified `source_id' are received.  If it is NULL
+ *    then the packet source is ignored.
+ *
+ *    Returns a context that must be given to the silc_packet_wait function
+ *    as argument.  Returns NULL on error.  To uninitialize the waiting
+ *    call silc_packet_wait_uninit.
+ *
+ * NOTES
+ *
+ *    Note that packets may be available immediately after calling this
+ *    function and they will be buffered, until silc_packet_wait is called.
+ *
+ * EXAMPLE
+ *
+ *    void *waiter;
+ *
+ *    // Will wait for private message packets
+ *    waiter = silc_packet_wait_init(stream, NULL,
+ *                                   SILC_PACKET_PRIVATE_MESSAGE, -1);
+ *
+ ***/
+void *silc_packet_wait_init(SilcPacketStream stream,
+                           const SilcID *source_id, ...);
 
-/* Returns true length of the packet and padded length of the packet */
-#define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_padlen)           \
-do {                                                                        \
-  SILC_GET16_MSB((__ret_truelen), (__packet)->data);                        \
-  (__ret_padlen) = (((__ret_truelen) - 2) +                                 \
-                   SILC_PACKET_MAX_PADLEN) & ~(SILC_PACKET_MAX_PADLEN - 1); \
-} while(0)
+/****f* silccore/SilcPacketAPI/silc_packet_wait_uninit
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Uninitializes the waiting context.  This may be called also from
+ *    another thread while other thread is waiting for packets.  This will
+ *    inform the waiting thread to stop waiting.
+ *
+ ***/
+void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream);
 
-/* Returns pad length of the packet */
-#define SILC_PACKET_PADLEN(__packetlen)                                         \
-  SILC_PACKET_MAX_PADLEN - ((__packetlen) - 2) % SILC_PACKET_MAX_PADLEN;
+/****f* silccore/SilcPacketAPI/silc_packet_wait
+ *
+ * SYNOPSIS
+ *
+ *    int silc_packet_wait(void *waiter, int timeout,
+ *                         SilcPacket *return_packet)
+ *
+ * DESCRIPTION
+ *
+ *    A special function that can be used to wait for a packet to arrive.
+ *    This function will block the calling process or thread until either
+ *    a packet is received into the `return_packet' pointer or the specified
+ *    timeout value `timeout', which is in milliseconds, will expire.  If
+ *    the timeout is 0, no timeout exist.  Before calling this function the
+ *    silc_packet_wait_init must be called.  The caller is responsible for
+ *    freeing the returned packet with silc_packet_free.
+ *
+ *    This function can be used for example from a thread that wants to
+ *    block until SILC packet has been received.
+ *
+ *    Returns 1 when packet was received, 0 if timeout occurred and -1 if
+ *    error occurred.
+ *
+ * EXAMPLE
+ *
+ *    static int foo_read_data(FooContext c)
+ *    {
+ *      SilcPacket packet;
+ *      void *waiter;
+ *      ...
+ *
+ *      // Will wait for private message packets
+ *      if (c->initialized == FALSE) {
+ *        waiter = silc_packet_wait_init(stream,
+ *                                       SILC_PACKET_PRIVATE_MESSAGE, -1);
+ *        c->initialized = TRUE;
+ *      }
+ *
+ *      ...
+ *      // Wait here until private message packet is received
+ *      if ((silc_packet_wait(waiter, 0, &packet)) < 0)
+ *        return -1;
+ *
+ *      ... process packet ...
+ *
+ *      return 1;
+ *    }
+ *
+ ***/
+int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet);
 
-/* Prototypes */
-int silc_packet_write(int sock, SilcBuffer src);
-int silc_packet_send(SilcSocketConnection sock, int force_send);
-void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, 
-                        SilcBuffer buffer, unsigned int len);
-void silc_packet_assemble(SilcPacketContext *ctx);
-void silc_packet_send_prepare(SilcSocketConnection sock,
-                             unsigned int header_len,
-                             unsigned int padlen,
-                             unsigned int data_len);
-int silc_packet_read(int sock, SilcBuffer dest);
-int silc_packet_receive(SilcSocketConnection sock);
-int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
-                       SilcBuffer buffer, SilcPacketContext *packet);
-void silc_packet_receive_process(SilcSocketConnection sock,
-                                SilcCipher cipher, SilcHmac hmac,
-                                SilcPacketParserCallback parser,
-                                void *context);
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
-SilcPacketContext *silc_packet_context_alloc();
-SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx);
-void silc_packet_context_free(SilcPacketContext *ctx);
-
-#endif
+/****f* silccore/SilcPacketAPI/silc_packet_free
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_free(SilcPacket packet);
+ *
+ * DESCRIPTION
+ *
+ *    This function is used to free the SilcPacket pointer that application
+ *    receives in the SilcPacketReceive callback.  Application must free
+ *    the packet if it takes it in to processing.
+ *
+ ***/
+void silc_packet_free(SilcPacket packet);
+
+#endif /* SILCPACKET_H */