/*
- silcpacket.h
+ silcpacket.h
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
Copyright (C) 1997 - 2001 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
+/* 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 8 + 2
+#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 + 2
+#define SILC_PACKET_MIN_HEADER_LEN 16
/* Maximum padding length */
-#define SILC_PACKET_MAX_PADLEN 16
+#define SILC_PACKET_MAX_PADLEN 128
+
+/* Default padding length */
+#define SILC_PACKET_DEFAULT_PADLEN 16
/* Minimum packet length */
#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
-/* 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_LIST 0x02
-#define SILC_PACKET_FLAG_BROADCAST 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
- uint16 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;
- uint16 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;
- uint16 src_id_len;
- unsigned char src_id_type;
-
- unsigned char *dst_id;
- uint16 dst_id_len;
- unsigned char dst_id_type;
-
- uint16 truelen;
- uint16 padlen;
-
- /* 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:
+/* Maximum packet length */
+#define SILC_PACKET_MAX_LEN 0xffff
- 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);
-
-/* The packet check callback in decryption phase */
-typedef int (*SilcPacketCheckDecrypt)(SilcPacketType packet_type,
- SilcBuffer buffer,
- SilcPacketContext *packet,
- void *context);
+/* Maximum length of ID */
+#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_REKEY_DONE 23 /* Re-key done */
#define SILC_PACKET_HEARTBEAT 24 /* Heartbeat */
#define SILC_PACKET_KEY_AGREEMENT 25 /* Key Agreement request */
-#define SILC_PACKET_CELL_ROUTERS 26 /* Cell routers backup */
+#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 SilcUInt8 SilcPacketVersion;
+ *
+ * DESCRIPTION
+ *
+ * SILC packet version type definition.
+ *
+ ***/
+typedef SilcUInt8 SilcPacketVersion;
+
+/****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 */
+/***/
+
+/* Rest of flags still available
+#define SILC_PACKET_FLAG_XXX 0x10
+#define SILC_PACKET_FLAG_XXX 0x20
+#define SILC_PACKET_FLAG_XXX 0x40
+#define SILC_PACKET_FLAG_XXX 0x80
+*/
+
+/****s* silccore/SilcPacketAPI/SilcPacketContext
+ *
+ * NAME
+ *
+ * typedef struct { ... } SilcPacketContext;
+ *
+ * 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.
+ *
+ * Short description of the fields following:
+ *
+ * SilcUInt16 truelen
+ *
+ * True length of the packet. This may be set by the caller before
+ * calling any of the silc_packet_* routines. If not provided the
+ * library will calculate the values.
+ *
+ * SilcPacketFlags flags
+ *
+ * Packet flags. Flags are defined above.
+ *
+ * SilcPacketType type
+ *
+ * Type of the packet. Types are defined below.
+ *
+ * unsigned char *src_id
+ * SilcUInt8 src_id_len
+ * SilcUInt8 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;
+ * SilcUInt8 dst_id_len;
+ * SilcUInt8 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.
+ *
+ * bool long_pad
+ *
+ * If set to TRUE the packet will include the maximum padding allowed
+ * in SILC packet, which is 128 bytes. If FALSE only the amount of
+ * padding needed will be applied.
+ *
+ * SilcUInt16 users;
+ *
+ * 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.
+ *
+ * SilcUInt8 padlen
+ *
+ * The padded length of the packet. This may be set by the caller
+ * before calling any of the silc_packet_* routines. If not provided
+ * the library will calculate the values.
+ *
+ * SilcUInt32 sequence;
+ *
+ * Packet sequence number. Set only when this context is a parsed
+ * packet.
+ *
+ * SilcBuffer buffer
+ *
+ * The actual packet data. Set only when this context is a parsed
+ * packet.
+ *
+ ***/
+typedef struct {
+ SilcUInt16 truelen;
+ SilcPacketFlags flags;
+ SilcPacketType type;
+
+ unsigned char *src_id;
+ unsigned char *dst_id;
+ unsigned int src_id_len : 5;
+ unsigned int src_id_type : 2;
+ unsigned int dst_id_len : 5;
+ unsigned int dst_id_type : 2;
+ unsigned int long_pad : 1; /* Set when maximum padding in packet */
+ unsigned int users : 9; /* Reference counter */
+ unsigned int padlen : 8;
+
+ SilcUInt32 sequence;
+ SilcBuffer buffer;
+} SilcPacketContext;
+
+/****s* silccore/SilcPacketAPI/SilcPacketParserContext
+ *
+ * NAME
+ *
+ * typedef struct { ... } SilcPacketParserContext;
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * bool normal
+ *
+ * Indicates whether the received packet is normal or special packet.
+ * If special the parsing process is special also.
+ *
+ * SilcSocketConnection sock
+ *
+ * The associated connection.
+ *
+ * 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;
+ bool normal;
+ SilcSocketConnection sock;
+ void *context;
+} SilcPacketParserContext;
+
+/****f* silccore/SilcPacketAPI/SilcPacketParserCallback
+ *
+ * SYNOPSIS
+ *
+ * typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
+ * *parse_context);
+ *
+ * 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.
+ *
+ ***/
+typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
+ *parse_context, void *context);
/* 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); \
+/****d* silccore/SilcPacketAPI/SILC_PACKET_LENGTH
+ *
+ * NAME
+ *
+ * #define SILC_PACKET_LENGTH ...
+ *
+ * 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.
+ *
+ * SOURCE
+ */
+#define SILC_PACKET_LENGTH(__packetdata, __ret_truelen, __ret_paddedlen) \
+do { \
+ SILC_GET16_MSB((__ret_truelen), (__packetdata)); \
+ (__ret_paddedlen) = (__ret_truelen) + (SilcUInt8)(__packetdata)[4]; \
} while(0)
-
-/* Returns pad length of the packet */
-#define SILC_PACKET_PADLEN(__packetlen) \
- SILC_PACKET_MAX_PADLEN - ((__packetlen) - 2) % SILC_PACKET_MAX_PADLEN;
+/***/
+
+/****d* silccore/SilcPacketAPI/SILC_PACKET_DATALEN
+ *
+ * NAME
+ *
+ * #define SILC_PACKET_DATALEN ...
+ *
+ * DESCRIPTION
+ *
+ * Calculates the data length with given header length. This macro
+ * can be used to check whether the data_len with header_len exceeds
+ * SILC_PACKET_MAX_LEN. If it does, this returns the new data_len
+ * so that the SILC_PACKET_MAX_LEN is not exceeded. If the data_len
+ * plus header_len fits SILC_PACKET_MAX_LEN the returned data length
+ * is the data_len given as argument. This macro can be used when
+ * assembling packet.
+ *
+ * SOURCE
+ */
+#define SILC_PACKET_DATALEN(data_len, header_len) \
+ ((data_len + header_len) > SILC_PACKET_MAX_LEN ? \
+ data_len - ((data_len + header_len) - SILC_PACKET_MAX_LEN) : data_len)
+/***/
+
+/****d* silccore/SilcPacketAPI/SILC_PACKET_PADLEN
+ *
+ * NAME
+ *
+ * #define SILC_PACKET_PADLEN ...
+ *
+ * DESCRIPTION
+ *
+ * Calculates the length of the padding in the packet. This is used
+ * by various library routines to determine needed padding length.
+ *
+ * SOURCE
+ */
+#define SILC_PACKET_PADLEN(__packetlen, __blocklen, __padlen) \
+do { \
+ __padlen = (SILC_PACKET_DEFAULT_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
+ if (__padlen < 8) \
+ __padlen += ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN); \
+} while(0)
+/***/
+
+/****d* silccore/SilcPacketAPI/SILC_PACKET_PADLEN_MAX
+ *
+ * NAME
+ *
+ * #define SILC_PACKET_PADLEN_MAX ...
+ *
+ * DESCRIPTION
+ *
+ * Returns the length of the padding up to the maximum length, which
+ * is 128 bytes. This is used by various library routines to determine
+ * needed padding length.
+ *
+ * SOURCE
+ */
+#define SILC_PACKET_PADLEN_MAX(__packetlen, __blocklen, __padlen) \
+do { \
+ __padlen = (SILC_PACKET_MAX_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
+} while(0)
+/***/
/* 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, uint32 len);
-void silc_packet_assemble(SilcPacketContext *ctx);
-void silc_packet_send_prepare(SilcSocketConnection sock,
- uint32 header_len,
- uint32 padlen,
- uint32 data_len);
-int silc_packet_read(int sock, SilcBuffer dest);
+
+/****f* silccore/SilcPacketAPI/silc_packet_send
+ *
+ * SYNOPSIS
+ *
+ * int silc_packet_send(SilcSocketConnection sock, bool force_send);
+ *
+ * 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.
+ *
+ ***/
+int silc_packet_send(SilcSocketConnection sock, bool force_send);
+
+/****f* silccore/SilcPacketAPI/silc_packet_encrypt
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
+ * SilcBuffer buffer, SilcUInt32 len);
+ *
+ * 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.
+ *
+ ***/
+void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, SilcUInt32 sequence,
+ SilcBuffer buffer, SilcUInt32 len);
+
+/****f* silccore/SilcPacketAPI/silc_packet_assemble
+ *
+ * SYNOPSIS
+ *
+ * bool silc_packet_assemble(SilcPacketContext *packet, SilcRng rng,
+ * SilcCipher cipher, SilcHmac hmac,
+ * SilcSocketConnection sock,
+ * const unsigned char *data, SilcUInt32 data_len,
+ * const SilcBuffer assembled_packet);
+ *
+ * DESCRIPTION
+ *
+ * Assembles new packet to be ready for encrypting and sending out.
+ * The `packet' is filled by caller to include the packet header specific
+ * values. This prepares the socket connection's `sock' outoing buffer
+ * for sending data, and returns the assembled packet to the
+ * `assembled_packet' pointer sent by the caller. The `assembled_packet'
+ * is a reference to the socket connection's outgoing buffer. The
+ * returned packet can be encrypted, and then sent to network by calling
+ * silc_packet_send function. The `assembled_packet' may be freely
+ * modified (like encrypted etc.) but it must not be freed, since it is
+ * reference from `sock' outgoing buffer, and it is const.
+ *
+ ***/
+bool silc_packet_assemble(SilcPacketContext *packet, SilcRng rng,
+ SilcCipher cipher, SilcHmac hmac,
+ SilcSocketConnection sock,
+ const unsigned char *data, SilcUInt32 data_len,
+ const SilcBuffer assembled_packet);
+
+/****f* silccore/SilcPacketAPI/silc_packet_send_prepare
+ *
+ * SYNOPSIS
+ *
+ * bool silc_packet_send_prepare(SilcSocketConnection sock,
+ * SilcUInt32 header_len,
+ * SilcUInt32 pad_len,
+ * SilcUInt32 data_len,
+ * SilcHmac hmac,
+ * const SilcBuffer packet);
+ *
+ * DESCRIPTION
+ *
+ * This function can be used to prepare the outgoing data buffer in
+ * the socket connection specified by `sock' for packet sending.
+ * This is used internally by packet sending routines, but application
+ * may call this if it doesn't call silc_packet_assemble function.
+ * If that function is called then application must not call this since
+ * that function calls this internally.
+ *
+ * This returns the prepared data area into the `packet' pointer provided
+ * caller, which can be used then to add data to it, and later encrypt
+ * it. The `packet' includes reference to the socket connection's
+ * outgoing buffer. The `packet' may be freely modified (like
+ * encrypted etc.) but it must not be freed, since it is reference from
+ * `sock' outgoing buffer, and it is const.
+ *
+ ***/
+bool silc_packet_send_prepare(SilcSocketConnection sock,
+ SilcUInt32 header_len,
+ SilcUInt32 pad_len,
+ SilcUInt32 data_len,
+ SilcHmac hmac,
+ const SilcBuffer packet);
+
+/****f* silccore/SilcPacketAPI/silc_packet_receive
+ *
+ * SYNOPSIS
+ *
+ * int silc_packet_receive(SilcSocketConnection sock);
+ *
+ * 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.
+ *
+ ***/
int silc_packet_receive(SilcSocketConnection sock);
-int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
- SilcBuffer buffer, SilcPacketContext *packet,
- SilcPacketCheckDecrypt check_packet,
- void *context);
-void silc_packet_receive_process(SilcSocketConnection sock,
+
+/****f* silccore/SilcPacketAPI/silc_packet_receive_process
+ *
+ * SYNOPSIS
+ *
+ * bool silc_packet_receive_process(SilcSocketConnection sock,
+ * bool local_is_router,
+ * SilcCipher cipher, SilcHmac hmac,
+ * SilcPacketParserCallback parser,
+ * void *parser_context);
+ *
+ * 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.
+ *
+ * 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.
+ *
+ ***/
+bool silc_packet_receive_process(SilcSocketConnection sock,
+ bool local_is_router,
SilcCipher cipher, SilcHmac hmac,
+ SilcUInt32 sequence,
SilcPacketParserCallback parser,
- void *context);
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
-SilcPacketContext *silc_packet_context_alloc();
+ void *parser_context);
+
+/****f* silccore/SilcPacketAPI/silc_packet_parse
+ *
+ * SYNOPSIS
+ *
+ * SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
+ *
+ * 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.
+ *
+ ***/
+SilcPacketType silc_packet_parse(SilcPacketContext *ctx, SilcCipher cipher);
+
+/****f* silccore/SilcPacketAPI/silc_packet_parse_special
+ *
+ * SYNOPSIS
+ *
+ * SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
+ *
+ * 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.
+ *
+ ***/
+SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx,
+ SilcCipher cipher);
+
+/****f* silccore/SilcPacketAPI/silc_packet_context_alloc
+ *
+ * SYNOPSIS
+ *
+ * SilcPacketContext *silc_packet_context_alloc();
+ *
+ * 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.
+ *
+ ***/
+SilcPacketContext *silc_packet_context_alloc(void);
+
+/****f* silccore/SilcPacketAPI/silc_packet_context_dup
+ *
+ * SYNOPSIS
+ *
+ * SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx);
+ *
+ * DESCRIPTION
+ *
+ * Duplicates the packet context. It actually does not duplicate
+ * any data, instead a reference counter is increased.
+ *
+ ***/
SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx);
+
+/****f* silccore/SilcPacketAPI/silc_packet_context_free
+ *
+ * SYNOPSIS
+ *
+ * void silc_packet_context_free(SilcPacketContext *ctx);
+ *
+ * DESCRIPTION
+ *
+ * Frees the packet context. The context is actually freed when the
+ * reference counter hits zero.
+ *
+ ***/
void silc_packet_context_free(SilcPacketContext *ctx);
#endif
projects / silc.git / blobdiff