*/
-/****h* silccore/SilcPacketAPI
+/****h* silccore/Packet Protocol Interface
*
* DESCRIPTION
*
/* Minimum packet length */
#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
+/* Maximum packet length */
+#define SILC_PACKET_MAX_LEN 0xffff
+
/* Maximum length of ID */
-#define SILC_PACKET_MAX_ID_LEN 16
+#define SILC_PACKET_MAX_ID_LEN 28
/****d* silccore/SilcPacketAPI/SilcPacketType
*
* NAME
*
- * typedef unsigned char SilcPacketType;
+ * typedef SilcUInt8 SilcPacketType;
*
* DESCRIPTION
*
*
* SOURCE
*/
-typedef unsigned char SilcPacketType;
+typedef SilcUInt8 SilcPacketType;
/* SILC Packet types. */
#define SILC_PACKET_NONE 0 /* NULL, never sent */
#define SILC_PACKET_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 */
*
* NAME
*
- * typedef unsigned char SilcPacketVersion;
+ * typedef SilcUInt8 SilcPacketVersion;
*
* DESCRIPTION
*
* SILC packet version type definition.
*
***/
-typedef unsigned char SilcPacketVersion;
+typedef SilcUInt8 SilcPacketVersion;
/****d* silccore/SilcPacketAPI/SilcPacketFlags
*
* NAME
*
- * typedef unsigned char SilcPacketFlags;
+ * typedef SilcUInt8 SilcPacketFlags;
*
* DESCRIPTION
*
*
* SOURCE
*/
-typedef unsigned char SilcPacketFlags;
+typedef SilcUInt8 SilcPacketFlags;
/* All defined packet flags */
#define SILC_PACKET_FLAG_NONE 0x00 /* No flags */
#define SILC_PACKET_FLAG_PRIVMSG_KEY 0x01 /* Private message key */
#define SILC_PACKET_FLAG_LIST 0x02 /* Packet is a list */
#define SILC_PACKET_FLAG_BROADCAST 0x04 /* Packet is a broadcast */
+#define SILC_PACKET_FLAG_COMPRESSED 0x08 /* Payload is compressed */
/***/
/* 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
*
* Short description of the fields following:
*
- * SilcBuffer buffer
- *
- * The data buffer.
+ * SilcUInt16 truelen
*
- * SilcPacketType type
- *
- * Type of the packet. Types are defined below.
+ * 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
- * uint16 src_id_len
- * unsigned char src_id_type
+ * 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;
- * uint16 dst_id_len;
- * unsigned char src_id_type;
+ * 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.
*
- * uint16 truelen
- * uint16 padlen
- *
- * The true lenght of the packet and the padded length of the packet.
- * These may be set by the caller before calling any of the
- * silc_packet_* routines. If not provided the library will calculate
- * the values.
+ * 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.
*
- * int users;
+ * 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.
*
- * uint32 sequence;
+ * SilcUInt8 padlen
*
- * Packet sequence number.
+ * 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 {
- SilcBuffer buffer;
-
- uint16 truelen;
+ SilcUInt16 truelen;
SilcPacketFlags flags;
SilcPacketType type;
- uint8 padlen;
unsigned char *src_id;
- uint8 src_id_len;
- uint8 src_id_type;
-
unsigned char *dst_id;
- uint8 dst_id_len;
- uint8 dst_id_type;
-
- int users;
- bool long_pad; /* Set to TRUE to use maximum padding
- in packet (up to 256 bytes). */
-
- uint32 sequence;
+ 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
*
* SYNOPSIS
*
- * typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
+ * typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
* *parse_context);
*
* DESCRIPTION
* 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 void (*SilcPacketParserCallback)(SilcPacketParserContext
+typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
*parse_context, void *context);
/* Macros */
*
* SOURCE
*/
-#define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_paddedlen) \
-do { \
- SILC_GET16_MSB((__ret_truelen), (__packet)->data); \
- (__ret_paddedlen) = (__ret_truelen) + (__packet)->data[4]; \
+#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)
/***/
+/****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
*
* DESCRIPTION
*
- * Returns the length of the padding in the packet. This is used
+ * 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) \
- SILC_PACKET_DEFAULT_PADLEN - (__packetlen) % \
- ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)
+#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
* DESCRIPTION
*
* Returns the length of the padding up to the maximum length, which
- * is 128 butes. This is used by various library routines to determine
+ * is 128 bytes. This is used by various library routines to determine
* needed padding length.
*
* SOURCE
*/
-#define SILC_PACKET_PADLEN_MAX(__packetlen) \
- SILC_PACKET_MAX_PADLEN - (__packetlen) % SILC_PACKET_MAX_PADLEN
+#define SILC_PACKET_PADLEN_MAX(__packetlen, __blocklen, __padlen) \
+do { \
+ __padlen = (SILC_PACKET_MAX_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
+} while(0)
/***/
/* Prototypes */
* SYNOPSIS
*
* void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
- * SilcBuffer buffer, uint32 len);
+ * SilcBuffer buffer, SilcUInt32 len);
*
* DESCRIPTION
*
* cannot be used.
*
***/
-void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, uint32 sequence,
- SilcBuffer buffer, uint32 len);
+void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, SilcUInt32 sequence,
+ SilcBuffer buffer, SilcUInt32 len);
/****f* silccore/SilcPacketAPI/silc_packet_assemble
*
* SYNOPSIS
*
- * void silc_packet_assemble(SilcPacketContext *ctx);
+ * 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 a new packet to be ready for send out. The buffer sent as
- * argument must include the data to be sent and it must not be encrypted.
- * The packet also must have enough free space so that the SILC header
- * and padding maybe added to the packet. The packet is encrypted after
- * this function has returned.
- *
- * The buffer sent as argument should be something like following:
- *
- * --------------------------------------------
- * | head | data | tail |
- * --------------------------------------------
- * ^ ^
- * 58 bytes x bytes
- *
- * So that the SILC header and 1 - 16 bytes of padding can fit to
- * the buffer. After assembly the buffer might look like this:
- *
- * --------------------------------------------
- * | data | |
- * --------------------------------------------
- * ^ ^
- * Start of assembled packet
- *
- * Packet construct is as follows (* = won't be encrypted):
- *
- * n bytes SILC Header
- * 2 bytes Payload length (*)
- * 1 byte Flags
- * 1 byte Packet type
- * 2 bytes Source ID Length
- * 2 bytes Destination ID Length
- * 1 byte Source ID Type
- * n bytes Source ID
- * 1 byte Destination ID Type
- * n bytes Destination ID
- *
- * 1 - 16 bytes Padding
- *
- * n bytes Data payload
- *
- * All fields in the packet will be authenticated by MAC. The MAC is
- * not computed here, it must be computed separately before encrypting
- * the packet.
+ * 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.
*
***/
-void silc_packet_assemble(SilcPacketContext *ctx, SilcCipher cipher);
+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
*
- * void silc_packet_send_prepare(SilcSocketConnection sock,
- * uint32 header_len,
- * uint32 padlen,
- * uint32 data_len);
+ * bool silc_packet_send_prepare(SilcSocketConnection sock,
+ * SilcUInt32 header_len,
+ * SilcUInt32 pad_len,
+ * SilcUInt32 data_len,
+ * SilcHmac hmac,
+ * const SilcBuffer packet);
*
* DESCRIPTION
*
- * Prepare outgoing data buffer for packet sending. This moves the data
- * area so that new packet may be added into it. If needed this allocates
- * more space to the buffer. This handles directly the connection's
- * outgoing buffer in SilcSocketConnection object.
+ * 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.
*
***/
-void silc_packet_send_prepare(SilcSocketConnection sock,
- uint32 header_len,
- uint32 padlen,
- uint32 data_len);
+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
*
- * void silc_packet_receive_process(SilcSocketConnection sock,
+ * bool silc_packet_receive_process(SilcSocketConnection sock,
* bool local_is_router,
* SilcCipher cipher, SilcHmac hmac,
* SilcPacketParserCallback parser,
*
* DESCRIPTION
*
- * Processes and decrypts the incmoing data, and calls parser callback
+ * 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
* packet was normal or special packet.
*
***/
-void silc_packet_receive_process(SilcSocketConnection sock,
+bool silc_packet_receive_process(SilcSocketConnection sock,
bool local_is_router,
SilcCipher cipher, SilcHmac hmac,
- uint32 sequence,
+ SilcUInt32 sequence,
SilcPacketParserCallback parser,
void *parser_context);
projects / silc.git / blobdiff