silcpacket.h
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2000 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
- 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/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.
+ *
+ ***/
+
#ifndef SILCPACKET_H
#define SILCPACKET_H
-/* Amount of bytes to be read from the socket connection at once. */
-#define SILC_PACKET_READ_SIZE 16384
-
-/* 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
-
-/* Header length without source and destination ID's. */
-#define SILC_PACKET_HEADER_LEN 8 + 2
+/* XXX many of these could go to silcpacket_i.h */
-/* 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
-
-/* Maximum padding length */
-#define SILC_PACKET_MAX_PADLEN 16
-
-/* 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
-
-/* 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;
-
-/* SILC packet version type definition. */
-typedef unsigned char SilcPacketVersion;
-
-/* SILC packet flags type definition. */
-typedef unsigned char SilcPacketFlags;
-
-/* All defined packet flags */
-#define SILC_PACKET_FLAG_NONE 0x00
-#define SILC_PACKET_FLAG_PRIVMSG_KEY 0x01
-#define SILC_PACKET_FLAG_BROADCAST 0x02
-#define SILC_PACKET_FLAG_TUNNELED 0x04
-/* 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
-*/
-
-/*
- SILC packet context.
-
- 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.
-
- Short description of the fields following:
-
- SilcBuffer buffer
-
- The data buffer.
-
- SilcPacketType type
-
- Type of the packet. Types are defined below.
-
- SilcPacketFlags flags
-
- Packet flags. Flags are defined above.
-
- unsigned char *src_id
- unsigned short src_id_len
- unsigned char src_id_type
-
- Source ID, its length and type. On packet reception retuned ID's
- are always the hash values of the ID's from the packet.
-
- unsigned char *dst_id;
- unsigned short dst_id_len;
- unsigned char src_id_type;
-
- Destination ID, its length and type. On packet reception retuned
- ID's are always the hash values of the ID's from the packet.
-
- SilcHash hash
-
- Pointer to allocated hash object. This must be MD5 hash object.
- This is used to calculate checksum of the packet.
-
-*/
-typedef struct {
- SilcBuffer buffer;
- SilcPacketType type;
- SilcPacketFlags flags;
-
- unsigned char *src_id;
- unsigned short src_id_len;
- unsigned char src_id_type;
-
- unsigned char *dst_id;
- unsigned short dst_id_len;
- unsigned char dst_id_type;
-
- unsigned short truelen;
- unsigned short padlen;
-
- /* For padding generation */
- SilcRng rng;
-
- /* Back pointers */
- void *context;
- SilcSocketConnection sock;
-
- /* Reference count for this context. The context is free'd only
- after the reference count is zero. */
- int users;
-} SilcPacketContext;
-
-/*
- Silc Packet Parser 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.
-
- Following description of the fields:
-
- SilcPacketContext *packet
-
- 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.
-
- SilcSocketConnection sock
-
- The associated connection.
-
- SilcCipher cipher
-
- The cipher to be used in the decryption.
-
- SilcHmac hmac
-
- The HMAC to be used in the decryption.
-
- void *context
-
- User context that is sent to the silc_packet_receive_process
- function. This usually includes application and connection specific
- data.
-
-*/
-
-typedef struct {
- SilcPacketContext *packet;
- SilcSocketConnection sock;
- SilcCipher cipher;
- SilcHmac hmac;
- void *context;
-} SilcPacketParserContext;
-
-/* The parser callback function. */
-typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
- *parse_context);
-
+#define SILC_PACKET_MAX_ID_LEN 28
+
+/****d* silccore/SilcPacketAPI/SilcPacketType
+ *
+ * NAME
+ *
+ * typedef SilcUInt8 SilcPacketType;
+ *
+ * DESCRIPTION
+ *
+ * SILC packet type definition and all the packet types.
+ *
+ * SOURCE
+ */
+typedef SilcUInt8 SilcPacketType;
/* SILC Packet types. */
#define SILC_PACKET_NONE 0 /* NULL, never sent */
#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_ID_LIST 19 /* Sending list of them */
-#define SILC_PACKET_NEW_CLIENT 20 /* Registering client */
-#define SILC_PACKET_NEW_SERVER 21 /* Registering server */
-#define SILC_PACKET_NEW_CHANNEL 22 /* Registering channel */
-#define SILC_PACKET_NEW_CHANNEL_USER 23 /* "" user on channel */
-#define SILC_PACKET_NEW_CHANNEL_LIST 24 /* List of new channels */
-#define SILC_PACKET_NEW_CHANNEL_USER_LIST 25 /* List of users on "" */
-#define SILC_PACKET_REPLACE_ID 26 /* To replace old ID */
-#define SILC_PACKET_REMOVE_ID 27 /* To remove ID */
-#define SILC_PACKET_REMOVE_CHANNEL_USER 28 /* Remove user from channel */
-#define SILC_PACKET_REKEY 29
-#define SILC_PACKET_REKEY_DONE 30
-#define SILC_PACKET_SET_MODE 31 /* Set mode */
-/* #define SILC_PACKET_MAX 255 */
-
-/* Macros */
-
-/* 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)
-
-/* Returns pad length of the packet */
-#define SILC_PACKET_PADLEN(__packetlen) \
- SILC_PACKET_MAX_PADLEN - ((__packetlen) - 2) % SILC_PACKET_MAX_PADLEN;
+#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_PRIVATE 200 /* Private range start */
+#define SILC_PACKET_MAX 255 /* RESERVED */
+/***/
+
+/****d* silccore/SilcPacketAPI/SilcPacketFlags
+ *
+ * NAME
+ *
+ * typedef SilcUInt8 SilcPacketFlags;
+ *
+ * DESCRIPTION
+ *
+ * SILC packet flags type definition and all the packet flags.
+ *
+ * SOURCE
+ */
+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 */
+/***/
+
+/****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/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;
+
+/****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.
+ *
+ * SOURCE
+ */
+typedef struct SilcPacketStruct {
+ struct SilcPacketStruct *next;
+ 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
+ *
+ * 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.
+ *
+ * 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
+ *
+ * SYNOPSIS
+ *
+ * typedef void (*SilcPacketReceiveCb)(SilcPacketEngine engine,
+ * SilcPacketStream stream,
+ * SilcPacket packet,
+ * void *callback_context,
+ * void *app_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. This callback is set in the
+ * SilcPacketCallbacks structure.
+ *
+ ***/
+typedef void (*SilcPacketReceiveCb)(SilcPacketEngine engine,
+ SilcPacketStream stream,
+ SilcPacket packet,
+ void *callback_context,
+ void *app_context);
+
+/****f* silccore/SilcPacketAPI/SilcPacketEosCb
+ *
+ * SYNOPSIS
+ *
+ * typedef void (*SilcPacketEosCb)(SilcPacketEngine engine,
+ * SilcPacketStream stream,
+ * void *callback_context,
+ * void *app_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 *app_context);
+
+/****f* silccore/SilcPacketAPI/SilcPacketErrorCb
+ *
+ * SYNOPSIS
+ *
+ * typedef void (*SilcPacketErrorCb)(SilcPacketEngine engine,
+ * SilcPacketStream stream,
+ * SilcPacketError error,
+ * void *callback_context,
+ * void *app_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 *app_context);
+
+/****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;
+/***/
/* 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_engine_start
+ *
+ * SYNOPSIS
+ *
+ * SilcPacketEngine
+ * silc_packet_engine_start(SilcSchedule schedule, SilcRng rng, bool router,
+ * SilcPacketCallbacks *callbacks,
+ * void *callback_context);
+ *
+ * DESCRIPTION
+ *
+ * Create new packet engine for processing incoming and outgoing packets.
+ * If `rng' is non-NULL that RNG will be used to create necessary random
+ * numbers during packet processing. If NULL, Global RNG will be used.
+ * 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. Also the `schedule' and `rng' are
+ * thread safe. You can use one packet engine in multi threaded
+ * application.
+ *
+ ***/
+SilcPacketEngine
+silc_packet_engine_start(SilcSchedule schedule, SilcRng rng, bool router,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context);
+
+/****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);
+
+/****f* silccore/SilcPacketAPI/silc_packet_stream_create
+ *
+ * SYNOPSIS
+ *
+ * SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+ * 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 or 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.
+ *
+ * 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.
+ *
+ * The SilcPacketStream is not thread safe. If you share same stream
+ * with multiple threads concurrency control need to be employed. It
+ * is recommended to create new SilcPacketStream for every thread.
+ *
+ ***/
+SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+ SilcStream stream);
+
+/****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
+ * send end of stream to the underlaying stream.
+ *
+ ***/
+void silc_packet_stream_destroy(SilcPacketStream stream);
+
+/****f* silccore/SilcPacketAPI/silc_packet_streamer_create
+ *
+ * SYNOPSIS
+ *
+ * SilcStream silc_packet_streamer_create(SilcPacketStream stream,
+ * SilcPacketType packet_type,
+ * SilcPacketFlags packet_flags);
+ *
+ * DESCRIPTION
+ *
+ * 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.
+ *
+ * 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);
+
+/****f* silccore/SilcPacketAPI/silc_packet_streamer_destroy
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_streamer_destroy(SilcStream stream);
+ *
+ * DESCRIPTION
+ *
+ * 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.
+ *
+ ***/
+void silc_packet_streamer_destroy(SilcStream stream);
+
+/****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 couled 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);
+
+/****f* silccore/SilcPacketAPI/silc_packet_stream_callbacks
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_stream_callbacks(SilcPacketStream stream,
+ * SilcPacketCallbacks *callbacks,
+ * void *callback_context);
+ *
+ * DESCRIPTION
+ *
+ * This is optional function which can be used to set specific callbacks
+ * for the packet stream indicated by `stream'. If these are set then
+ * `callbacks' will be used instead of the ones set for the function
+ * silc_packet_engine_start. To reset the normal behaviour call this
+ * function again with `callbacks' as NULL. Note that the responsibility
+ * of handling end of stream, and error conditions moves to the layer
+ * calling this function since the original callbacks set in the
+ * silc_packet_engine_start will not be called.
+ *
+ ***/
+void silc_packet_stream_callbacks(SilcPacketStream stream,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context);
+
+/****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);
+
+/****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);
+
+/****f* silccore/SilcPacketAPI/silc_packet_set_context
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_set_context(SilcPacketStream stream, void *app_context);
+ *
+ * DESCRIPTION
+ *
+ * Set an application 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.
+ *
+ ***/
+void silc_packet_set_context(SilcPacketStream stream, void *app_context);
+
+/****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);
+
+/****f* silccore/SilcPacketAPI/silc_packet_set_ciphers
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
+ * SilcCipher receive);
+ *
+ * DESCRIPTION
+ *
+ * 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.
+ *
+ ***/
+void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
+ SilcCipher receive);
+
+/****f* silccore/SilcPacketAPI/silc_packet_get_ciphers
+ *
+ * SYNOPSIS
+ *
+ * bool silc_packet_get_ciphers(SilcPacketStream stream, SilcCipher *send,
+ * SilcCipher *receive);
+ *
+ * DESCRIPTION
+ *
+ * Returns the pointers of current ciphers from the `stream'. Returns
+ * FALSE if ciphers are not set.
+ *
+ ***/
+bool 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.
+ *
+ ***/
+void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
+ SilcHmac receive);
+
+/****f* silccore/SilcPacketAPI/silc_packet_get_hmacs
+ *
+ * SYNOPSIS
+ *
+ * bool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
+ * SilcHmac *receive);
+ *
+ * DESCRIPTION
+ *
+ * Returns the pointers of current HMACs from the `stream'. Returns
+ * FALSE if HMACs are not set.
+ *
+ ***/
+bool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
+ SilcHmac *receive);
+
+/****f* silccore/SilcPacketAPI/silc_packet_set_ids
+ *
+ * SYNOPSIS
+ *
+ * bool 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 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.
+ *
+ ***/
+bool 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_send
+ *
+ * SYNOPSIS
+ *
+ * bool 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_ciphers
+ * and silc_packet_set_hmacs the packet will be encrypted and MAC will be
+ * generated 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.
+ *
+ ***/
+bool silc_packet_send(SilcPacketStream stream,
+ SilcPacketType type, SilcPacketFlags flags,
+ const unsigned char *data, SilcUInt32 data_len);
+
+/****f* silccore/SilcPacketAPI/silc_packet_send_ext
+ *
+ * SYNOPSIS
+ *
+ * bool
+ * 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
+ *
+ * This function can be used to specificly set different parameters of
+ * the SILC packet to be sent to the stream indicated by `stream'. This
+ * function can be used to set specific IDs, cipher and HMAC to be used
+ * in packet creation. If `truelen' is provided that value is put to the
+ * SILC packet's truelen field, if it is zero the routine will calculate
+ * the truelen field for the packet. If `padlen' is provided that value
+ * will be the length of the padding for the packet, if zero the routine
+ * will calculate necessary amount of padding for the packet. This
+ * function can be used when specific ciphers, HMACs and IDs has not been
+ * set for the stream, or setting them for the stream is not suitable.
+ *
+ ***/
+bool 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_free
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_free(SilcPacketEngine engine, SilcPacket packet);
+ *
+ * DESCRIPTION
+ *
+ * This function is used to free the SilcPacket pointer that application
+ * receives in the SilcPacketReceive callback. Application must free
+ * the packet.
+ *
+ ***/
+void silc_packet_free(SilcPacketEngine engine, SilcPacket packet);
+
+#endif /* SILCPACKET_H */
projects / silc.git / blobdiff