silcpacket.h
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2000 Pekka Riikonen
+ Copyright (C) 1997 - 2006 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
+ *
+ * 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
-
-/* 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_DISCONNECT 1 /* Disconnection */
#define SILC_PACKET_SUCCESS 2 /* Success */
#define SILC_PACKET_FAILURE 3 /* Failure */
#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 */
+
+#define SILC_PACKET_NONE 0 /* RESERVED */
+#define SILC_PACKET_ANY 0
+/***/
+
+/****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 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;
+/***/
+
+/****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.
+ *
+ * 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;
+/***/
+
+/****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);
+
+/****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);
+
+/****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);
+
+/****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(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);
+
+/****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,
+ * 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 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.
+ *
+ * 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);
+
+/****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);
+
+/****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);
+
+/****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);
+
+/****f* silccore/SilcPacketAPI/silc_packet_stream_set_stream
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
+ * SilcStream stream,
+ * SilcSchedule schedule);
+ *
+ * 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.
+ *
+ ***/
+void silc_packet_stream_set_stream(SilcPacketStream packet_stream,
+ SilcStream stream,
+ SilcSchedule schedule);
+
+/****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);
+
+/****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_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,
+ 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_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);
+
+/****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);
+
+/****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
+ *
+ * SilcBool 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.
+ *
+ ***/
+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.
+ *
+ ***/
+void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
+ SilcHmac receive);
+
+/****f* silccore/SilcPacketAPI/silc_packet_get_hmacs
+ *
+ * SYNOPSIS
+ *
+ * SilcBool 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.
+ *
+ ***/
+SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
+ SilcHmac *receive);
+
+/****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 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.
+ *
+ ***/
+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_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);
+
+/****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_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.
+ *
+ ***/
+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);
+
+/****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, ...);
+
+/****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, ...);
+
+/****f* silccore/SilcPacketAPI/silc_packet_wait
+ *
+ * SYNOPSIS
+ *
+ * void *silc_packet_wait_init(SilcPacketStream stream, ...);
+ *
+ * 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. 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,
+ * SILC_PACKET_PRIVATE_MESSAGE, -1);
+ *
+ *
+ ***/
+void *silc_packet_wait_init(SilcPacketStream stream, ...);
+
+/****f* silccore/SilcPacketAPI/silc_packet_wait
+ *
+ * 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);
+
+/****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);
+
+/****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 */
projects / silc.git / blobdiff