/*
- silcpacket.h
-
+ silcpacket.h
+
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
#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)
* Packet flags. Flags are defined above.
*
* unsigned char *src_id
- * uint16 src_id_len
+ * uint8 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;
+ * uint8 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.
*
* uint16 truelen
- * uint16 padlen
+ * uint8 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
***/
typedef struct {
SilcBuffer buffer;
- SilcPacketType type;
+
+ uint16 truelen;
SilcPacketFlags flags;
+ SilcPacketType type;
+ uint8 padlen;
unsigned char *src_id;
- uint16 src_id_len;
- unsigned char src_id_type;
+ uint8 src_id_len;
+ uint8 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;
+ 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;
} SilcPacketContext;
*
* DESCRIPTION
*
- * 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.
+ * 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:
*
* 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.
***/
typedef struct {
SilcPacketContext *packet;
+ bool normal;
SilcSocketConnection sock;
void *context;
} SilcPacketParserContext;
*
* SYNOPSIS
*
- * typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
+ * typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
* *parse_context);
*
* DESCRIPTION
* context. The application receiving the SilcPacketParserContext
* must free it.
*
- ***/
-typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
- *parse_context);
-
-/****f* silccore/SilcPacketAPI/SilcPacketCheckDecrypt
- *
- * SYNOPSIS
- *
- * typedef int (*SilcPacketCheckDecrypt)(SilcPacketType packet_type,
- * SilcBuffer buffer,
- * SilcPacketContext *packet,
- * void *context);
- *
- * DESCRIPTION
- *
- * This callback function relates to the checking whether the packet is
- * normal packet or special packet and how it should be processed. If
- * the callback returns TRUE the packet is normal and FALSE if the packet
- * is special and requires special procesing. Some of the packets in
- * SILC are special (like channel message packets that are encrypted
- * using channel specific keys) and requires special processing. That
- * is the reason for this callback function.
- *
- * The library will call this function if provided for the
- * silc_packet_decrypt function. The `packet_type' is the type of
- * packet received (this is also actually the first time application
- * receives information of the received packet, next time it receives
- * it is when the SilcPacketParserCallback function is called),
- * the `buffer' is the raw packet data the `packet' the allocated
- * SilcPacketContext that is filled when parsing the packet and `context'
- * is application specific user context.
+ * 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 int (*SilcPacketCheckDecrypt)(SilcPacketType packet_type,
- SilcBuffer buffer,
- SilcPacketContext *packet,
- void *context);
+typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
+ *parse_context, void *context);
/* Macros */
*
* DESCRIPTION
*
- * Returns true length of the packet and padded 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.
+ * 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(__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); \
+#define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_paddedlen) \
+do { \
+ SILC_GET16_MSB((__ret_truelen), (__packet)->data); \
+ (__ret_paddedlen) = (__ret_truelen) + (__packet)->data[4]; \
} while(0)
/***/
*
* SOURCE
*/
-#define SILC_PACKET_PADLEN(__packetlen) \
- SILC_PACKET_MAX_PADLEN - ((__packetlen) - 2) % SILC_PACKET_MAX_PADLEN;
+#define SILC_PACKET_PADLEN(__packetlen, __blocklen) \
+ SILC_PACKET_DEFAULT_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)
+/***/
+
+/****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 butes. 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
/***/
/* Prototypes */
*
* SYNOPSIS
*
- * int silc_packet_send(SilcSocketConnection sock, int force_send);
+ * int silc_packet_send(SilcSocketConnection sock, bool force_send);
*
* DESCRIPTION
*
* directly to the network, if FALSE, this returns -2.
*
***/
-int silc_packet_send(SilcSocketConnection sock, int force_send);
+int silc_packet_send(SilcSocketConnection sock, bool force_send);
/****f* silccore/SilcPacketAPI/silc_packet_encrypt
*
* cannot be used.
*
***/
-void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
+void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, uint32 sequence,
SilcBuffer buffer, uint32 len);
/****f* silccore/SilcPacketAPI/silc_packet_assemble
* the packet.
*
***/
-void silc_packet_assemble(SilcPacketContext *ctx);
+void silc_packet_assemble(SilcPacketContext *ctx, SilcCipher cipher);
/****f* silccore/SilcPacketAPI/silc_packet_send_prepare
*
***/
int silc_packet_receive(SilcSocketConnection sock);
-/****f* silccore/SilcPacketAPI/silc_packet_decrypt
- *
- * SYNOPSIS
- *
- * int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
- * SilcBuffer buffer, SilcPacketContext *packet,
- * SilcPacketCheckDecrypt check_packet,
- * void *context);
- *
- * DESCRIPTION
- *
- * Decrypts a packet. This assumes that typical SILC packet is the
- * packet to be decrypted and thus checks for normal and special SILC
- * packets and can handle both of them. This also computes and checks
- * the HMAC of the packet. If any other special or customized decryption
- * processing is required this function cannot be used. This returns
- * -1 on error, 0 when packet is normal packet and 1 when the packet
- * is special and requires special processing.
- *
- * The `check_packet' is a callback funtion that this function will
- * call. The callback relates to the checking whether the packet is
- * normal packet or special packet and how it should be processed. If
- * the callback return TRUE the packet is normal and FALSE if the packet
- * is special and requires special procesing.
- *
- ***/
-int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
- SilcBuffer buffer, SilcPacketContext *packet,
- SilcPacketCheckDecrypt check_packet,
- void *context);
-
/****f* silccore/SilcPacketAPI/silc_packet_receive_process
*
* 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,
- * void *context);
+ * void *parser_context);
*
* DESCRIPTION
*
- * Processes the received data. This checks the received data and
- * calls parser callback that handles the actual packet decryption
- * and 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 `context'
- * sent to this function.
+ * 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.
*
***/
-void silc_packet_receive_process(SilcSocketConnection sock,
+bool silc_packet_receive_process(SilcSocketConnection sock,
+ bool local_is_router,
SilcCipher cipher, SilcHmac hmac,
+ uint32 sequence,
SilcPacketParserCallback parser,
- void *context);
+ void *parser_context);
/****f* silccore/SilcPacketAPI/silc_packet_parse
*
* buffer is parsed, not head or tail sections.
*
***/
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
+SilcPacketType silc_packet_parse(SilcPacketContext *ctx, SilcCipher cipher);
/****f* silccore/SilcPacketAPI/silc_packet_parse_special
*
* and parses the header and padding area only.
*
***/
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
+SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx,
+ SilcCipher cipher);
/****f* silccore/SilcPacketAPI/silc_packet_context_alloc
*
projects / silc.git / blobdiff