mpls_encdec_02.c

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/******************************************************************************
 * This file contains the C implementation for encode/decode functions        * 
 * for the following types of messages: notification, hello, initialization,  *
 * keepAlive, address, address Withdraw, label Mapping, label Request, label  *
 * Withdraw and label Release. There are also encode/decode methods for all   * 
 * tlv types required by the previously enumerated messages.                  * 
 * Please remember that the pdu will always contain the header followed by 1  *
 * or more LDP messages. The file contains functions to encode/decode the LDP *
 * header as well.  							      * 
 * All the messages, header message and the tlvs are in conformity with the   * 
 * draft-ietf-mpls-ldp-04  (May 1999) and with draft-ietf-mpls-cr-ldp-01      *
 * (Jan 1999). 								      * 
 *								              *
 * Please note that the U bit in the message and the F bit in the tlv are     *
 * ignored in this version of the code.                                       *
 *								              *
 * Please note that the traffic parameters for traffic TLV have to be IEEE    *
 * single precision floating point numbers.                                   *
 *								              *
 * Please note that there might be a small chance for bit field manipulation  *
 * portability inconsistency. If such problems occure, the code requires      *
 * changes for a suitable bit-field manipulation. The code for encoding and   *
 * decoding makes the assumption that the compiler packs the bit fields in a  *
 * structure into adjacent bits of the same unit.                             * 
 *								              *
 * The usage of the encode/decode functions is described below.               * 
 *								              *
 * The encode functions take as arguments: a pointer to the structure which   *
 * implements msg/tlv, a nbuffer (where the encoding is done) and the buffer   *
 * length.							              *
 * If the encode is successfull, the function returns the total encoded       * 
 * length.								      *
 * If the encode fails, the function returns an error code.                   *
 * The encode functions for messages and message headers do not modify the    *
 * content of the struct which is to be encoded. All the other encode         *
 * functions will change the content of the structure. The pointer which      *
 * points to the beginning of the buffer is not changed.                      *
 *									      *
 * The decode functions take as arguments: a pointer to the structure which   *
 * is going to be populated after decoding, a pointer to a buffer and the     *
 * buffer length.							      *
 * If the decode is successful, the function returns the total decoded length *
 * If the decode fails, the function returns an error code. The decode        *
 * functions do not modify the pointer to the buffer which contains the data  *
 * to be decoded.							      *
 *									      *
 * Example on how to use the encode/decode functions for a keepAlive message: *
 *									      *
 *           Encode the keep alive message:                                   * 
 *           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^    				      *
 *           u_char buffer[500];	 				      *
 *           int returnCode; 						      *
 *           struct mplsLdpKeepAlMsg_s keepAliveMsg;            	      *
 *           keepAliveMsg.baseMsg.msgType   = MPLS_KEEPAL_MSGTYPE;            *
 *           keepAliveMsg.baseMsg.msgLength = MPLS_MSGIDFIXLEN;               *
 *           keepAliveMsg.baseMsg.msgId     = 123;		              *
 *           bzero(buffer, 500);                                  	      *
 *           returnCode = Mpls_encodeLdpKeepAliveMsg(&keepAliveMsg,           *
 *                                                   buffer,                  *
 *                                                   500);                    *
 *           if (returnCode < 0)                                              *
 *              check the error code				              *
 *           else                                                             *
 *              write(fd, buffer, returnCode);                                *
 *									      *
 *									      *
 *           Decode the keep alive meesage:                                   *
 *           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^		                      *
 *           u_char buffer[500];					      *
 *           int returnCode;					              *
 *           struct mplsLdpKeepAlMsg_s keepAliveMsg;	            	      *
 *           read(fd, buffer, length);                                        *
 *           returnCode =  Mpls_decodeLdpKeepAliveMsg(&keepAliveMsg,          * 
 *                                                    buffer,                 *
 *                                                    500); 		      *
 *           if (returnCode < 0)	                                      *
 *              check the error code					      *
 *           else				 			      *
 *           { 								      *
 *              printKeepAliveMsg(&keepAliveMsg);	 	              *
 *           } 						                      *
 *								              *
 * An example on how to use the decode functions for the header and the       *
 * messages can be found in the main function.                                *
 *								              *
 * The code was tested for big endian and little endian for sparc5, linux     *
 * and i960.                                                                  *
 *								              *
 * In order to compile for little endian, the LITTLE_ENDIAN_BYTE_ORDER should *
 * be defined.								      *
 *								              *
 * At the end of this file there is an examples of a hex buffers and its      *
 * corresponding values.                                                      *
 *								              *
 *								              *
 * Version History                                                            *
 * Version          Date      Authors            Description                  *
 * ===========      ========  =========          ======================       *
 * mpls_encdec_01.c 99/03/15  Antonela Paraschiv draft-ietf-mpls-ldp-03 and   * 
 *                                               draft-ietf-mpls-cr-ldp-01    *
 *								              *
 * mpls_encdec_02.c 99/05/19  Antonela Paraschiv draft-ietf-mpls-ldp-04 and   * 
 *                                               draft-ietf-mpls-cr-ldp-01    *
 *								              *
 ******************************************************************************/


#define LITTLE_ENDIAN_BYTE_ORDER 1  /* <----- Please define this accordingly */
/* #define VXWORKS                  1 */
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef VXWORKS
   #include <in.h>         /* htons, htonl, ntohs, ntohl         */
   #include <types.h>      /* u_int, u_char, u_short, float etc. */
#else
   #include <netinet/in.h> /* htons, htonl, ntohs, ntohl         */
   #include <sys/types.h>  /* u_int, u_char, u_short, float etc. */
#endif VXWORKS 


#define MEM_COPY(X, Y, Z) memcpy(X, Y, Z)

/* macros to handle different byte orders (little endian or big endian) */
#ifdef LITTLE_ENDIAN_BYTE_ORDER 
   #define BITFIELDS_ASCENDING_2(X, Y)                Y; X;
   #define BITFIELDS_ASCENDING_3(X, Y, Z)             Z; Y; X;
   #define BITFIELDS_ASCENDING_4(X, Y, Z, W)          W; Z; Y; X;
   #define BITFIELDS_ASCENDING_7(X, Y, Z, W, U, A, B) B; A; U; W; Z; Y; X;
# else
   #define BITFIELDS_ASCENDING_2(X, Y)                X; Y;
   #define BITFIELDS_ASCENDING_3(X, Y, Z)             X; Y; Z;
   #define BITFIELDS_ASCENDING_4(X, Y, Z, W)          X; Y; Z; W;
   #define BITFIELDS_ASCENDING_7(X, Y, Z, W, U, A, B) X; Y; Z; W; U; A; B;
#endif LITTLE_ENDIAN_BYTE_ORDER 

/* macros used to decode the entire LDP; they declare local var for
   different type of messages */
#define MPLS_MSGSTRUCT( e )                 \
   mplsLdp ## e ## Msg_t test ## e ## Msg;  \

#define MPLS_MSGPARAM( e )                  \
   test ## e ## Msg                         \


#define DEBUG_INFO              1  /* set this to 0 if no debug info 
				      required                      */

/* debug macros */
#define DEBUG_CALL(X)           if (DEBUG_INFO) X;
#define PRINT_2(X, Y)           if (DEBUG_INFO) printf(X, Y)
#define PRINT_4(X, Y, Z, W)     if (DEBUG_INFO) printf(X, Y, Z, W)
#define PRINT_ERR(X)            if (DEBUG_INFO) printf(X)
#define PRINT_ERR_2(X, Y)       if (DEBUG_INFO) printf(X, Y)
#define PRINT_ERR_4(X, Y, Z, W) if (DEBUG_INFO) printf(X, Y, Z, W)


/*
 *    MESSAGE TYPE CONSTANS & TLV CONSTANTS
 */

#define MPLS_LDP_HDRSIZE         10      /* the size for mpls ldp hdr  */
#define MPLS_TLVFIXLEN           4       /* type + len                 */
#define MPLS_MSGIDFIXLEN         4       /* type + len                 */
#define MPLS_LDPIDLEN            6 
#define MPLS_PDUMAXLEN           4096     /* octets                    */
#define MPLS_VERSION             0x0001  
#define MPLS_IPV4ADDRFAMILYN     0x0100   /* rfc 1700 (network order)  */
#define MPLS_INIFINITE_TIMEVAL   0xfffff

/* for initialize message */
#define MPLS_INIT_MSGTYPE        0x0200  /* initialization msg          */
#define MPLS_CSP_TLVTYPE         0x0500  /* common params for init msg  */
#define MPLS_ASP_TLVTYPE         0x0501  /* atm session params          */
#define MPLS_FSP_TLVTYPE         0x0502  /* frame relay session params  */
#define MPLS_ASPFIXLEN           4       /* M + N + D + res             */
#define MPLS_FSPFIXLEN           4       /* M + N + res                 */
#define MPLS_CSPFIXLEN           14      /* protocolV + ... + ldp ids   */
#define MPLS_ATMLBLMAXLEN        10
#define MPLS_ATMLRGFIXLEN        8      
#define MPLS_FRLRGFIXLEN         8
#define MPLS_ASP_NOMERGE         0
#define MPLS_ASP_VPMERGE         1  
#define MPLS_ASP_VCMERGE         2  
#define MPLS_ASP_VPVCMERGE       3  
#define MPLS_FRLBLMAXLEN         10
#define MPLS_FRDLCI10BITS        0
#define MPLS_FRDLCI17BITS        1
#define MPLS_FRDLCI23BITS        2
 
/* for notification message */
#define MPLS_NOT_MSGTYPE         0x0001  /* notification msg            */
#define MPLS_NOT_ST_TLVTYPE      0x0300  /* status tlv for not msg      */
#define MPLS_NOT_ES_TLVTYPE      0x0301  /* extended status for not msg */
#define MPLS_NOT_RP_TLVTYPE      0x0302  /* returned PDU for not msg    */
#define MPLS_NOT_RM_TLVTYPE      0x0303  /* returned msg for not msg    */
#define MPLS_STATUSFIXLEN        10      /* status code + id + type     */
#define MPLS_EXSTATUSLEN         4 
#define MPLS_NOT_MAXSIZE         MPLS_PDUMAXLEN - MPLS_TLVFIXLEN - \
				 MPLS_MSGIDFIXLEN 
 
/* for hello message */
#define MPLS_HELLO_MSGTYPE       0x0100  /* hello msg                   */
#define MPLS_CHP_TLVTYPE         0x0400  /* Common Hello Param Tlv      */
#define MPLS_TRADR_TLVTYPE       0x0401  /* Transport Address Param Tlv */
#define MPLS_CSN_TLVTYPE         0x0402  /* Conf Seq Number Param Tlv   */
#define MPLS_CHPFIXLEN           4 
#define MPLS_CSNFIXLEN           4 
#define MPLS_TRADRFIXLEN         4 

/* for keep alive message */
#define MPLS_KEEPAL_MSGTYPE      0x0201  /* keep alive msg              */

/* for address messages */
#define MPLS_ADDR_MSGTYPE        0x0300  /* address msg                 */
#define MPLS_ADDRWITH_MSGTYPE    0x0301  /* address withdraw msg        */
#define MPLS_ADDRLIST_TLVTYPE    0x0101  /* addrss list tlv type        */
#define MPLS_IPv4LEN             4
#define MPLS_ADDFAMFIXLEN        2
#define MPLS_ADDLISTMAXLEN       MPLS_PDUMAXLEN - 2*MPLS_TLVFIXLEN - \
			         MPLS_MSGIDFIXLEN - MPLS_ADDFAMFIXLEN 
#define MPLS_MAXNUMBERADR        MPLS_ADDLISTMAXLEN / 4 

/* for label mapping message */
#define MPLS_LBLMAP_MSGTYPE      0x0400  /* label mapping msg           */
#define MPLS_FEC_TLVTYPE         0x0100  /* label mapping msg           */
#define MPLS_GENLBL_TLVTYPE      0x0200  /* generic label tlv           */
#define MPLS_ATMLBL_TLVTYPE      0x0201  /* atm label tlv               */
#define MPLS_FRLBL_TLVTYPE       0x0202  /* frame relay label tlv       */
#define MPLS_HOPCOUNT_TLVTYPE    0x0103  /* ho count tlv                */
#define MPLS_PATH_TLVTYPE        0x0104  /* path vector tlv             */
#define MPLS_REQMSGID_TLVTYPE    0x0600  /* lbl request msg id tlv      */
#define MPLS_WC_FEC              0x01    /* wildcard fec element        */
#define MPLS_PREFIX_FEC          0x02    /* prefix fec element          */
#define MPLS_HOSTADR_FEC         0x03    /* host addr fec element       */
#define MPLS_CRLSP_FEC           0x04    /* crlsp fec element           */
#define MPLS_MARTINIVC_FEC       0x80    /* Martini VC fec element      */
#define MPLS_FECMAXLEN           MPLS_PDUMAXLEN - 2*MPLS_TLVFIXLEN - \
			         MPLS_MSGIDFIXLEN
#define MPLS_LBLFIXLEN           4       /* v + vpi + vci + res         */
#define MPLS_HOPCOUNTFIXLEN      1       /* v + vpi + vci + res         */
#define MPLS_VCIDLEN             4       /* Martini VC id length        */
#define MPLS_VCIFPARAMMAXLEN     80      /* Martini VC Intf param max size */