/*
- silcpacket.h
+ silcpacket.h
Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2001 Pekka Riikonen
+ Copyright (C) 1997 - 2005 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
*/
-/****h* silccore/SilcPacketAPI
+/****h* silccore/Packet Protocol Interface
*
* DESCRIPTION
*
- * Implementation of the packet routines for sending and receiving
- * SILC Packets. These includes the data sending routines and data
- * reading routines, encrypting and decrypting routines, packet assembling
- * and packet parsing routines.
+ * 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
-/* Default byte size of the packet. */
-#define SILC_PACKET_DEFAULT_SIZE SILC_SOCKET_BUF_SIZE
-
-/* Header length without source and destination ID's. */
-#define SILC_PACKET_HEADER_LEN 10
-
-/* 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
-
-/* Maximum padding length */
-#define SILC_PACKET_MAX_PADLEN 128
-
-/* Default padding length */
-#define SILC_PACKET_DEFAULT_PADLEN 16
+/* XXX many of these could go to silcpacket_i.h */
-/* Minimum packet length */
-#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
+/* Maximum packet length */
+#define SILC_PACKET_MAX_LEN 0xffff
/* Maximum length of ID */
-#define SILC_PACKET_MAX_ID_LEN 16
+#define SILC_PACKET_MAX_ID_LEN 28
/****d* silccore/SilcPacketAPI/SilcPacketType
*
* NAME
- *
- * typedef unsigned char SilcPacketType;
+ *
+ * typedef SilcUInt8 SilcPacketType;
*
* DESCRIPTION
*
*
* SOURCE
*/
-typedef unsigned char SilcPacketType;
+typedef SilcUInt8 SilcPacketType;
/* 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_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_PRIVATE 200 /* Private range start */
#define SILC_PACKET_MAX 255 /* RESERVED */
-/***/
-/****d* silccore/SilcPacketAPI/SilcPacketVersion
- *
- * NAME
- *
- * typedef unsigned char SilcPacketVersion;
- *
- * DESCRIPTION
- *
- * SILC packet version type definition.
- *
- ***/
-typedef unsigned char SilcPacketVersion;
+#define SILC_PACKET_NONE 0 /* RESERVED */
+#define SILC_PACKET_ANY 0
+/***/
/****d* silccore/SilcPacketAPI/SilcPacketFlags
*
* NAME
- *
- * typedef unsigned char SilcPacketFlags;
+ *
+ * typedef SilcUInt8 SilcPacketFlags;
*
* DESCRIPTION
*
*
* SOURCE
*/
-typedef unsigned char SilcPacketFlags;
+typedef SilcUInt8 SilcPacketFlags;
/* 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 */
+
+/* Impelemntation specific flags */
+#define SILC_PACKET_FLAG_LONG_PAD 0x10 /* Use maximum padding */
/***/
-/* Rest of flags still available
-#define SILC_PACKET_FLAG_XXX 0x08
-#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/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;
-/****s* silccore/SilcPacketAPI/SilcPacketContext
+/****s* silccore/SilcPacketAPI/SilcPacketStream
*
* NAME
- *
- * typedef struct { ... } SilcPacketContext;
+ *
+ * typedef struct SilcPacketStreamStruct *SilcPacketStream;
*
* DESCRIPTION
*
- * 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.
+ * The packet stream context, allocated by silc_packet_stream_create.
+ * The stream is destroyed with silc_packet_stream_destroy.
*
- * Short description of the fields following:
+ ***/
+typedef struct SilcPacketStreamStruct *SilcPacketStream;
+
+/****s* silccore/SilcPacketAPI/SilcPacket
*
- * SilcBuffer buffer
+ * 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 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;
+/***/
+
+/****d* silcutil/SilcPacketAPI/SilcPacketError
*
- * The data buffer.
+ * NAME
*
- * SilcPacketType type
+ * typedef enum { ... } SilcPacketError
*
- * Type of the packet. Types are defined below.
+ * DESCRIPTION
*
- * SilcPacketFlags flags
+ * 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.
*
- * Packet flags. Flags are defined above.
+ * 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_MALFORMED, /* Packet is malformed */
+ SILC_PACKET_ERR_NO_MEMORY, /* System out of memory */
+} SilcPacketError;
+/***/
+
+/****f* silccore/SilcPacketAPI/SilcPacketReceiveCb
*
- * unsigned char *src_id
- * uint8 src_id_len
- * unsigned char src_id_type
+ * SYNOPSIS
*
- * Source ID, its length and type. On packet reception retuned ID's
- * are always the hash values of the ID's from the packet.
+ * typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
+ * SilcPacketStream stream,
+ * SilcPacket packet,
+ * void *callback_context,
+ * void *stream_context);
*
- * unsigned char *dst_id;
- * uint8 dst_id_len;
- * unsigned char src_id_type;
+ * DESCRIPTION
*
- * Destination ID, its length and type. On packet reception retuned
- * ID's are always the hash values of the ID's from the packet.
+ * 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.
*
- * uint16 truelen
- * uint8 padlen
+ * 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.
*
- * The true lenght of the packet and the padded length of the packet.
- * These may be set by the caller before calling any of the
- * silc_packet_* routines. If not provided the library will calculate
- * the values.
+ * EXAMPLE
*
- * int users;
+ * SilcBool
+ * silc_foo_packet_receive_cb(SilcPacketEngine engine,
+ * SilcPacketStream stream, SilcPacket packet,
+ * void *callback_context, void *stream_context)
+ * {
+ * Application ctx = callback_context;
*
- * Reference counter for this context. The context is freed only
- * after the reference counter hits zero. The counter is added
- * calling silc_packet_context_dup and decreased by calling the
- * silc_packet_context_free.
+ * // If we're not up yet, let's not process the packet
+ * if (ctx->initialized == FALSE)
+ * return FALSE;
*
- * uint32 sequence;
+ * // Process the incoming packet...
+ * ...
*
- * Packet sequence number.
+ * // It's our packet now, no one else will get it
+ * return TRUE;
+ * }
*
***/
-typedef struct {
- SilcBuffer buffer;
+typedef SilcBool (*SilcPacketReceiveCb)(SilcPacketEngine engine,
+ SilcPacketStream stream,
+ SilcPacket packet,
+ void *callback_context,
+ void *stream_context);
- uint16 truelen;
- SilcPacketFlags flags;
- SilcPacketType type;
- uint8 padlen;
+/****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);
- unsigned char *src_id;
- uint8 src_id_len;
- uint8 src_id_type;
+/****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);
- unsigned char *dst_id;
- uint8 dst_id_len;
- uint8 dst_id_type;
+/****s* silccore/SilcPacketAPI/SilcPacketStream
+ *
+ * NAME
+ *
+ * typedef struct SilcPacketStreamStruct *SilcPacketStream;
+ *
+ * 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;
+/***/
- int users;
- bool long_pad; /* Set to TRUE to use maximum padding
- in packet (up to 256 bytes). */
+/* Prototypes */
- uint32 sequence;
-} SilcPacketContext;
+/****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,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context);
-/****s* silccore/SilcPacketAPI/SilcPacketParserContext
+/****f* silccore/SilcPacketAPI/silc_packet_engine_stop
*
- * NAME
- *
- * typedef struct { ... } SilcPacketParserContext;
+ * SYNOPSIS
+ *
+ * void silc_packet_engine_stop(SilcPacketEngine engine);
*
* DESCRIPTION
*
- * This context is used in packet reception when the function
- * silc_packet_receive_process 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.
+ * Stop the packet engine. No new packets can be sent or received after
+ * calling this, and the `engine' will become invalid.
*
- * Following description of the fields:
+ ***/
+void silc_packet_engine_stop(SilcPacketEngine engine);
+
+/****f* silccore/SilcPacketAPI/silc_packet_stream_create
*
- * SilcPacketContext *packet
+ * SYNOPSIS
*
- * 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.
+ * SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+ * SilcSchedule schedule,
+ * SilcStream stream);
*
- * bool normal
+ * DESCRIPTION
*
- * Indicates whether the received packet is normal or special packet.
- * If special the parsing process is special also.
+ * 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 or received from the stream.
*
- * SilcSocketConnection sock
+ * NOTES
*
- * The associated connection.
+ * 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.
*
- * void *context
+ * If you need to send only one type of SILC packets, then it is possible
+ * to create SILC Packet Streamer with silc_packet_streamer_create, which
+ * can be used with silc_stream_read and silc_stream_write.
*
- * User context that is sent to the silc_packet_receive_process
- * function. This usually includes application and connection specific
- * data.
+ * The SilcPacketStream is thread safe. Same context can be safely used
+ * in multi threaded environment.
*
***/
-typedef struct {
- SilcPacketContext *packet;
- bool normal;
- SilcSocketConnection sock;
- void *context;
-} SilcPacketParserContext;
+SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+ SilcSchedule schedule,
+ SilcStream stream);
-/****f* silccore/SilcPacketAPI/SilcPacketParserCallback
+/****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
*
* SYNOPSIS
*
- * typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
- * *parse_context);
+ * void silc_packet_stream_destroy(SilcPacketStream stream);
*
* DESCRIPTION
*
- * This callback is given to the silc_packet_receive_process function.
- * The callback is called by the library every time a packet is
- * received from the network. After the packet has been decrypted
- * and at least partially parsed it is passed to the application
- * for further parsing using this callback and the SilcPacketParserContext
- * context. The application receiving the SilcPacketParserContext
- * must free it.
- *
- * This returns TRUE if the library should continue packet processing
- * (assuming there is more data to be processed), and FALSE if the
- * upper layer does not want the library to continue but to leave the
- * rest of the data is the packet queue untouched. Application may
- * want to do this for example if the cipher is not ready before
- * processing a certain packet. In this case the application wants
- * to recall the processing function with the correct cipher.
+ * Destroy packet stream and the underlaying stream. This will also
+ * send end of stream to the underlaying stream.
*
***/
-typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
- *parse_context, void *context);
+void silc_packet_stream_destroy(SilcPacketStream stream);
-/* Macros */
+/****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);
-/****d* silccore/SilcPacketAPI/SILC_PACKET_LENGTH
+/****f* silccore/SilcPacketAPI/silc_packet_streamer_create
*
- * NAME
- *
- * #define SILC_PACKET_LENGTH ...
+ * SYNOPSIS
+ *
+ * SilcStream silc_packet_streamer_create(SilcPacketStream stream,
+ * SilcPacketType packet_type,
+ * SilcPacketFlags packet_flags);
*
* DESCRIPTION
*
- * Returns true length of the packet. This is primarily used by the
- * libary in packet parsing phase but the application may use it as
- * well if needed.
+ * This function can be used to create a SILC Packet Streamer that will
+ * stream only one type of packet indicated by `packet_type' with packet
+ * flags `packet_flags'. This is special purpose function as usually
+ * multiple different types of packets need to be sent in application.
+ * There are cases however when creating streamer is simpler and more
+ * efficient. Cases such as file transfer stream or other data streams
+ * that only send and receive one type of packet. While it would be
+ * possible to use silc_packet_send function to send packets it is
+ * more efficient to create the SILC Packet Streamer and use the
+ * silc_stream_read and silc_stream_write functions.
*
- * SOURCE
- */
-#define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_paddedlen) \
-do { \
- SILC_GET16_MSB((__ret_truelen), (__packet)->data); \
- (__ret_paddedlen) = (__ret_truelen) + (__packet)->data[4]; \
-} while(0)
-/***/
+ * The encryption and decryption keys, and other information will be
+ * retrieved from the packet stream indicated by `stream', which must be
+ * created before creating the streamer.
+ *
+ * NOTES
+ *
+ * The packet type that is assocated with the packet stream `stream' will
+ * only be available through the returned SilcStream. That packet type
+ * will not be delivered to the packet callbacks. To return to the
+ * normal operation destroy the streamer silc_packet_streamer_destroy.
+ *
+ ***/
+SilcStream silc_packet_streamer_create(SilcPacketStream stream,
+ SilcPacketType packet_type,
+ SilcPacketFlags packet_flags);
-/****d* silccore/SilcPacketAPI/SILC_PACKET_PADLEN
+/****f* silccore/SilcPacketAPI/silc_packet_streamer_destroy
*
- * NAME
- *
- * #define SILC_PACKET_PADLEN ...
+ * SYNOPSIS
+ *
+ * void silc_packet_streamer_destroy(SilcStream stream);
*
* DESCRIPTION
*
- * Returns the length of the padding in the packet. This is used
- * by various library routines to determine needed padding length.
+ * Destroys the created packet streamer. Use this function only for
+ * stream created with silc_packet_streamer_create. The packet type
+ * that was associated with the streamer can be received in the packet
+ * callbacks after the streamer is destroyed.
*
- * SOURCE
- */
-#define SILC_PACKET_PADLEN(__packetlen, __blocklen) \
- SILC_PACKET_DEFAULT_PADLEN - (__packetlen) % \
- ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)
-/***/
+ ***/
+void silc_packet_streamer_destroy(SilcStream stream);
-/****d* silccore/SilcPacketAPI/SILC_PACKET_PADLEN_MAX
+/****f* silccore/SilcPacketAPI/silc_packet_stream_get_stream
*
- * NAME
- *
- * #define SILC_PACKET_PADLEN_MAX ...
+ * SYNOPSIS
+ *
+ * SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
*
* DESCRIPTION
*
- * Returns the length of the padding up to the maximum length, which
- * is 128 butes. This is used by various library routines to determine
- * needed padding length.
+ * 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.
*
- * SOURCE
- */
-#define SILC_PACKET_PADLEN_MAX(__packetlen) \
- SILC_PACKET_MAX_PADLEN - (__packetlen) % SILC_PACKET_MAX_PADLEN
-/***/
+ ***/
+SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
-/* Prototypes */
+/****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,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context,
+ int priority, ...);
-/****f* silccore/SilcPacketAPI/silc_packet_send
+/****f* silccore/SilcPacketAPI/silc_packet_stream_unlink
*
* SYNOPSIS
*
- * int silc_packet_send(SilcSocketConnection sock, bool force_send);
+ * void silc_packet_stream_unlink(SilcPacketStream stream,
+ * SilcPacketCallbacks *callbacks,
+ * void *callback_context);
*
* DESCRIPTION
*
- * Actually sends the packet. This flushes the connections outgoing data
- * buffer. If data is sent directly to the network this returns the bytes
- * written, if error occured this returns -1 and if the data could not
- * be written directly to the network at this time this returns -2, in
- * which case the data should be queued by the caller and sent at some
- * later time. If `force_send' is TRUE this attempts to write the data
- * directly to the network, if FALSE, this returns -2.
+ * 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.
*
***/
-int silc_packet_send(SilcSocketConnection sock, bool force_send);
+void silc_packet_stream_unlink(SilcPacketStream stream,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context);
-/****f* silccore/SilcPacketAPI/silc_packet_encrypt
+/****f* silccore/SilcPacketAPI/silc_packet_stream_ref
*
* SYNOPSIS
*
- * void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
- * SilcBuffer buffer, uint32 len);
+ * void silc_packet_stream_ref(SilcPacketStream stream);
*
* DESCRIPTION
*
- * Encrypts a packet. This also creates HMAC of the packet before
- * encryption and adds the HMAC at the end of the buffer. This assumes
- * that there is enough free space at the end of the buffer to add the
- * computed HMAC. This is the normal way of encrypting packets, if some
- * other process of HMAC computing and encryption is needed this function
- * cannot be used.
+ * 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_encrypt(SilcCipher cipher, SilcHmac hmac, uint32 sequence,
- SilcBuffer buffer, uint32 len);
+void silc_packet_stream_ref(SilcPacketStream stream);
-/****f* silccore/SilcPacketAPI/silc_packet_assemble
+/****f* silccore/SilcPacketAPI/silc_packet_stream_unref
*
* SYNOPSIS
*
- * void silc_packet_assemble(SilcPacketContext *ctx);
+ * void silc_packet_stream_unref(SilcPacketStream stream);
*
* DESCRIPTION
*
- * Assembles a new packet to be ready for send out. The buffer sent as
- * argument must include the data to be sent and it must not be encrypted.
- * The packet also must have enough free space so that the SILC header
- * and padding maybe added to the packet. The packet is encrypted after
- * this function has returned.
+ * Decrease reference counter for the stream indicated by `stream'. If
+ * the counter hits zero the stream will be destroyed automatically.
*
- * The buffer sent as argument should be something like following:
+ ***/
+void silc_packet_stream_unref(SilcPacketStream stream);
+
+/****f* silccore/SilcPacketAPI/silc_packet_get_engine
+ *
+ * SYNOPSIS
*
- * --------------------------------------------
- * | head | data | tail |
- * --------------------------------------------
- * ^ ^
- * 58 bytes x bytes
+ * SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
*
- * So that the SILC header and 1 - 16 bytes of padding can fit to
- * the buffer. After assembly the buffer might look like this:
+ * DESCRIPTION
*
- * --------------------------------------------
- * | data | |
- * --------------------------------------------
- * ^ ^
- * Start of assembled packet
+ * Returns the packet engine from the `stream'.
*
- * Packet construct is as follows (* = won't be encrypted):
+ ***/
+SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream);
+
+/****f* silccore/SilcPacketAPI/silc_packet_set_context
*
- * n bytes SILC Header
- * 2 bytes Payload length (*)
- * 1 byte Flags
- * 1 byte Packet type
- * 2 bytes Source ID Length
- * 2 bytes Destination ID Length
- * 1 byte Source ID Type
- * n bytes Source ID
- * 1 byte Destination ID Type
- * n bytes Destination ID
+ * SYNOPSIS
*
- * 1 - 16 bytes Padding
+ * void silc_packet_set_context(SilcPacketStream stream,
+ * void *stream_context);
*
- * n bytes Data payload
+ * DESCRIPTION
*
- * All fields in the packet will be authenticated by MAC. The MAC is
- * not computed here, it must be computed separately before encrypting
- * the packet.
+ * 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_assemble(SilcPacketContext *ctx, SilcCipher cipher);
+void silc_packet_set_context(SilcPacketStream stream, void *stream_context);
-/****f* silccore/SilcPacketAPI/silc_packet_send_prepare
+/****f* silccore/SilcPacketAPI/silc_packet_get_context
*
* SYNOPSIS
*
- * void silc_packet_send_prepare(SilcSocketConnection sock,
- * uint32 header_len,
- * uint32 padlen,
- * uint32 data_len);
+ * void *silc_packet_get_context(SilcPacketStream stream);
*
* DESCRIPTION
*
- * Prepare outgoing data buffer for packet sending. This moves the data
- * area so that new packet may be added into it. If needed this allocates
- * more space to the buffer. This handles directly the connection's
- * outgoing buffer in SilcSocketConnection object.
+ * Returns the current set application context, or NULL if none is set.
*
***/
-void silc_packet_send_prepare(SilcSocketConnection sock,
- uint32 header_len,
- uint32 padlen,
- uint32 data_len);
+void *silc_packet_get_context(SilcPacketStream stream);
-/****f* silccore/SilcPacketAPI/silc_packet_receive
+/****f* silccore/SilcPacketAPI/silc_packet_set_ciphers
*
* SYNOPSIS
*
- * int silc_packet_receive(SilcSocketConnection sock);
+ * void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
+ * SilcCipher receive);
*
* DESCRIPTION
*
- * Receives packet from network and reads the data into connection's
- * incoming data buffer. If the data was read directly this returns the
- * read bytes, if error occured this returns -1, if the data could not
- * be read directly at this time this returns -2 in which case the data
- * should be read again at some later time, or If EOF occured this returns
- * 0.
+ * Set ciphers to be used to encrypt sent packets, and decrypt received
+ * packets. This can be called multiple times to change the ciphers.
+ * In this case if old cipher is set it will be freed. If ciphers are
+ * not set packets will not be encrypted or decrypted.
*
***/
-int silc_packet_receive(SilcSocketConnection sock);
+void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
+ SilcCipher receive);
-/****f* silccore/SilcPacketAPI/silc_packet_receive_process
+/****f* silccore/SilcPacketAPI/silc_packet_get_ciphers
*
* SYNOPSIS
*
- * bool silc_packet_receive_process(SilcSocketConnection sock,
- * bool local_is_router,
- * SilcCipher cipher, SilcHmac hmac,
- * SilcPacketParserCallback parser,
- * void *parser_context);
+ * SilcBool silc_packet_get_ciphers(SilcPacketStream stream,
+ * SilcCipher *send,
+ * SilcCipher *receive);
*
* DESCRIPTION
*
- * Processes and decrypts the incoming data, and calls parser callback
- * for each received packet that will handle the actual packet parsing.
- * If more than one packet was received this calls the parser multiple
- * times. The parser callback will get context SilcPacketParserContext
- * that includes the packet and the `parser_context' sent to this
- * function.
+ * Returns the pointers of current ciphers from the `stream'. Returns
+ * FALSE if ciphers are not set.
*
- * The `local_is_router' indicates whether the caller is router server
- * in which case the receiving process of a certain packet types may
- * be special. Normal server and client must set it to FALSE. The
- * SilcPacketParserContext will indicate also whether the received
- * packet was normal or special packet.
+ ***/
+SilcBool silc_packet_get_ciphers(SilcPacketStream stream, SilcCipher *send,
+ SilcCipher *receive);
+
+/****f* silccore/SilcPacketAPI/silc_packet_set_hmacs
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
+ * SilcHmac receive);
+ *
+ * DESCRIPTION
+ *
+ * Set HMACs to be used to create MACs for sent packets and to check
+ * MAC for received packets. This can be called multiple times to change
+ * the HMACs. In this case if old HMAC is set it will be freed. If
+ * HMACs are not set MACs are not generated or verified for packets.
*
***/
-bool silc_packet_receive_process(SilcSocketConnection sock,
- bool local_is_router,
- SilcCipher cipher, SilcHmac hmac,
- uint32 sequence,
- SilcPacketParserCallback parser,
- void *parser_context);
+void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
+ SilcHmac receive);
-/****f* silccore/SilcPacketAPI/silc_packet_parse
+/****f* silccore/SilcPacketAPI/silc_packet_get_hmacs
*
* SYNOPSIS
*
- * SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
+ * SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
+ * SilcHmac *receive);
*
* DESCRIPTION
*
- * Parses the packet. This is called when a whole packet is ready to be
- * parsed. The buffer sent must be already decrypted before calling this
- * function. The len argument must be the true length of the packet. This
- * function returns the type of the packet. The data section of the
- * buffer is parsed, not head or tail sections.
+ * Returns the pointers of current HMACs from the `stream'. Returns
+ * FALSE if HMACs are not set.
*
***/
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx, SilcCipher cipher);
+SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
+ SilcHmac *receive);
-/****f* silccore/SilcPacketAPI/silc_packet_parse_special
+/****f* silccore/SilcPacketAPI/silc_packet_set_ids
*
* SYNOPSIS
*
- * SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
+ * SilcBool silc_packet_set_ids(SilcPacketStream stream,
+ * SilcIdType src_id_type, const void *src_id
+ * SilcIdType dst_id_type, const void *dst_id);
*
* DESCRIPTION
*
- * Perform special SILC Packet header parsing. This is required to some
- * packet types that have the data payload encrypted with different key
- * than the header area plus padding of the packet. Hence, this parses
- * the header in a way that it does not take the data area into account
- * and parses the header and padding area only.
+ * Set the source ID and destinaion 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.
*
***/
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx,
- SilcCipher cipher);
+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_context_alloc
+/****f* silccore/SilcPacketAPI/silc_packet_send
*
* SYNOPSIS
*
- * SilcPacketContext *silc_packet_context_alloc();
+ * SilcBool silc_packet_send(SilcPacketStream stream,
+ * SilcPacketType type, SilcPacketFlags flags,
+ * const unsigned char *data,
+ * SilcUInt32 data_len);
*
* DESCRIPTION
*
- * Allocates a packet context. Packet contexts are used when
- * packets are assembled and parsed. The context is freed by the
- * silc_packet_context_free function.
+ * Send `data' of length of `data_len' to the packet stream indicated by
+ * `stream'. If ciphers and HMACs were set using silc_packet_set_ciphers
+ * and silc_packet_set_hmacs 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.
*
***/
-SilcPacketContext *silc_packet_context_alloc(void);
+SilcBool silc_packet_send(SilcPacketStream stream,
+ SilcPacketType type, SilcPacketFlags flags,
+ const unsigned char *data, SilcUInt32 data_len);
-/****f* silccore/SilcPacketAPI/silc_packet_context_dup
+/****f* silccore/SilcPacketAPI/silc_packet_send_ext
*
* SYNOPSIS
*
- * SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx);
+ * 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
*
- * Duplicates the packet context. It actually does not duplicate
- * any data, instead a reference counter is increased.
+ * 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'.
*
***/
-SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx);
+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);
-/****f* silccore/SilcPacketAPI/silc_packet_context_free
+/****f* silccore/SilcPacketAPI/silc_packet_free
*
* SYNOPSIS
*
- * void silc_packet_context_free(SilcPacketContext *ctx);
+ * void silc_packet_free(SilcPacket packet);
*
* DESCRIPTION
*
- * Frees the packet context. The context is actually freed when the
- * reference counter hits zero.
+ * 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_context_free(SilcPacketContext *ctx);
+void silc_packet_free(SilcPacket packet);
-#endif
+#endif /* SILCPACKET_H */
projects / silc.git / blobdiff