SNMP++  3.3.4
Classes | Macros | Typedefs | Functions
asn1.h File Reference
#include "snmp_pp/config_snmp_pp.h"
#include "snmp_pp/target.h"

Go to the source code of this file.

Classes

struct  snmp_pdu
 
struct  variable_list
 
struct  counter64
 

Macros

#define MAX_SUBID   0xFFFFFFFF
 
#define MAX_OID_LEN   128 /* max subid's in an oid */
 
#define ASN_BOOLEAN   (0x01)
 
#define ASN_INTEGER   (0x02)
 
#define ASN_BIT_STR   (0x03)
 
#define ASN_OCTET_STR   (0x04)
 
#define ASN_NULL   (0x05)
 
#define ASN_OBJECT_ID   (0x06)
 
#define ASN_SEQUENCE   (0x10)
 
#define ASN_SET   (0x11)
 
#define ASN_UNIVERSAL   (0x00)
 
#define ASN_APPLICATION   (0x40)
 
#define ASN_CONTEXT   (0x80)
 
#define ASN_PRIVATE   (0xC0)
 
#define ASN_PRIMITIVE   (0x00)
 
#define ASN_CONSTRUCTOR   (0x20)
 
#define ASN_LONG_LEN   (0x80)
 
#define ASN_EXTENSION_ID   (0x1F)
 
#define ASN_BIT8   (0x80)
 
#define IS_CONSTRUCTOR(byte)   ((byte) & ASN_CONSTRUCTOR)
 
#define IS_EXTENSION_ID(byte)   (((byte) & ASN_EXTENSION_ID) == ASN_EXTENSION_ID)
 
#define ASN_UNI_PRIM   (ASN_UNIVERSAL | ASN_PRIMITIVE)
 
#define ASN_SEQ_CON   (ASN_SEQUENCE | ASN_CONSTRUCTOR)
 
#define ASN_MAX_NAME_LEN   128
 
#define SNMP_VERSION_1   0
 
#define SNMP_VERSION_2C   1
 
#define SNMP_VERSION_2STERN   2
 
#define SNMP_VERSION_3   3
 
#define SMI_IPADDRESS   (ASN_APPLICATION | 0)
 
#define SMI_COUNTER   (ASN_APPLICATION | 1)
 
#define SMI_GAUGE   (ASN_APPLICATION | 2)
 
#define SMI_TIMETICKS   (ASN_APPLICATION | 3)
 
#define SMI_OPAQUE   (ASN_APPLICATION | 4)
 
#define SMI_NSAP   (ASN_APPLICATION | 5)
 
#define SMI_COUNTER64   (ASN_APPLICATION | 6)
 
#define SMI_UINTEGER   (ASN_APPLICATION | 7)
 
#define GET_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x0)
 
#define GETNEXT_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x1)
 
#define GET_RSP_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x2)
 
#define SET_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x3)
 
#define TRP_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x4)
 
#define GETBULK_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x5)
 
#define INFORM_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x6)
 
#define TRP2_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x7)
 
#define REPORT_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x8)
 
#define SNMP_NOSUCHOBJECT   (ASN_CONTEXT | ASN_PRIMITIVE | 0x0)
 
#define SNMP_NOSUCHINSTANCE   (ASN_CONTEXT | ASN_PRIMITIVE | 0x1)
 
#define SNMP_ENDOFMIBVIEW   (ASN_CONTEXT | ASN_PRIMITIVE | 0x2)
 
#define ASNERROR(string)   debugprintf(3, "ASN parse error (%s)\n", string )
 

Typedefs

typedef unsigned long oid
 
typedef struct sockaddr_in ipaddr
 

Functions

DLLOPT unsigned char * asn_parse_int (unsigned char *data, int *datalength, unsigned char *type, long *intp)
 
unsigned char * asn_parse_int (unsigned char *data, int *datalength, unsigned char *type, unsigned long *intp)
 
DLLOPT unsigned char * asn_parse_unsigned_int (unsigned char *data, int *datalength, unsigned char *type, unsigned long *intp)
 
unsigned char * asn_parse_unsigned_int (unsigned char *data, int *datalength, unsigned char *type, long *intp)
 
DLLOPT unsigned char * asn_build_int (unsigned char *data, int *datalength, const unsigned char type, const long *intp)
 
unsigned char * asn_build_int (unsigned char *data, int *datalength, const unsigned char type, const unsigned long *intp)
 
DLLOPT unsigned char * asn_build_unsigned_int (unsigned char *data, int *datalength, unsigned char type, unsigned long *intp)
 
DLLOPT unsigned char * asn_parse_string (unsigned char *data, int *datalength, unsigned char *type, unsigned char *string, int *strlength)
 
DLLOPT unsigned char * asn_build_string (unsigned char *data, int *datalength, const unsigned char type, const unsigned char *string, const int strlength)
 
DLLOPT unsigned char * asn_parse_header (unsigned char *data, int *datalength, unsigned char *type)
 
DLLOPT unsigned char * asn_build_header (unsigned char *data, int *datalength, unsigned char type, int length)
 
DLLOPT unsigned char * asn_build_sequence (unsigned char *data, int *datalength, unsigned char type, int length)
 
DLLOPT unsigned char * asn_parse_length (unsigned char *data, unsigned long *length)
 
DLLOPT unsigned char * asn_build_length (unsigned char *data, int *datalength, int length)
 
DLLOPT unsigned char * asn_parse_objid (unsigned char *data, int *datalength, unsigned char *type, oid *objid, int *objidlength)
 
DLLOPT unsigned char * asn_build_objid (unsigned char *data, int *datalength, unsigned char type, oid *objid, int objidlength)
 
DLLOPT void asn_build_subid (unsigned long subid, unsigned char *&bp)
 
DLLOPT unsigned char * asn_parse_null (unsigned char *data, int *datalength, unsigned char *type)
 
DLLOPT unsigned char * asn_build_null (unsigned char *data, int *datalength, unsigned char type)
 
DLLOPT unsigned char * asn_parse_bitstring (unsigned char *data, int *datalength, unsigned char *type, unsigned char *string, int *strlength)
 
DLLOPT unsigned char * asn_build_bitstring (unsigned char *data, int *datalength, unsigned char type, unsigned char *string, int strlength)
 
DLLOPT unsigned char * asn_parse_unsigned_int64 (unsigned char *data, int *datalength, unsigned char *type, struct counter64 *cp)
 
DLLOPT unsigned char * asn_build_unsigned_int64 (unsigned char *data, int *datalength, unsigned char type, struct counter64 *cp)
 
DLLOPT struct snmp_pdu * snmp_pdu_create (int command)
 
DLLOPT void snmp_free_pdu (struct snmp_pdu *pdu)
 
DLLOPT int snmp_build (struct snmp_pdu *pdu, unsigned char *packet, int *out_length, const long version, const unsigned char *community, const int community_len)
 
DLLOPT void snmp_add_var (struct snmp_pdu *pdu, oid *name, int name_length, SmiVALUE *smival)
 
DLLOPT int snmp_parse (struct snmp_pdu *pdu, unsigned char *data, int data_length, unsigned char *community_name, int &community_len, snmp_version &version)
 
DLLOPT unsigned char * build_vb (struct snmp_pdu *pdu, unsigned char *buf, int *buf_len)
 
DLLOPT unsigned char * build_data_pdu (struct snmp_pdu *pdu, unsigned char *buf, int *buf_len, unsigned char *vb_buf, int vb_buf_len)
 
DLLOPT unsigned char * snmp_build_var_op (unsigned char *data, oid *var_name, int *var_name_len, unsigned char var_val_type, int var_val_len, unsigned char *var_val, int *listlength)
 
DLLOPT unsigned char * snmp_parse_var_op (unsigned char *data, oid *var_name, int *var_name_len, unsigned char *var_val_type, int *var_val_len, unsigned char **var_val, int *listlength)
 
DLLOPT int snmp_parse_data_pdu (struct snmp_pdu *pdu, unsigned char *&data, int &length)
 
DLLOPT int snmp_parse_vb (struct snmp_pdu *pdu, unsigned char *&data, int &data_len)
 
DLLOPT void clear_pdu (struct snmp_pdu *pdu, bool clear_all=false)
 
DLLOPT unsigned char * asn1_build_header_data (unsigned char *outBuf, int *maxLength, long msgID, long maxMessageSize, unsigned char msgFlags, long securityModel)
 Encode the given values for the HeaderData into the buffer. More...
 
DLLOPT unsigned char * asn1_parse_header_data (unsigned char *buf, int *buf_len, long *msg_id, long *msg_max_size, unsigned char *msg_flags, long *msg_security_model)
 Parse the filled HeaderData of a SNMPv3 message and return the encoded values. More...
 
DLLOPT unsigned char * asn1_parse_scoped_pdu (unsigned char *scoped_pdu, int *scoped_pdu_len, unsigned char *context_engine_id, int *context_engine_id_len, unsigned char *context_name, int *context_name_len)
 Parse the ScopedPDU and return the encoded values. More...
 
DLLOPT unsigned char * asn1_build_scoped_pdu (unsigned char *outBuf, int *max_len, unsigned char *contextEngineID, long contextEngineIDLength, unsigned char *contextName, long contextNameLength, unsigned char *data, long dataLength)
 Encode the given values for the scopedPDU into the buffer. More...
 

Macro Definition Documentation

#define ASN_APPLICATION   (0x40)

Definition at line 68 of file asn1.h.

#define ASN_BIT8   (0x80)

Definition at line 84 of file asn1.h.

#define ASN_BIT_STR   (0x03)

Definition at line 54 of file asn1.h.

#define ASN_BOOLEAN   (0x01)

Definition at line 50 of file asn1.h.

#define ASN_CONSTRUCTOR   (0x20)

Definition at line 80 of file asn1.h.

#define ASN_CONTEXT   (0x80)

Definition at line 71 of file asn1.h.

#define ASN_EXTENSION_ID   (0x1F)

Definition at line 83 of file asn1.h.

#define ASN_INTEGER   (0x02)

Definition at line 52 of file asn1.h.

#define ASN_LONG_LEN   (0x80)

Definition at line 82 of file asn1.h.

#define ASN_MAX_NAME_LEN   128

Definition at line 92 of file asn1.h.

#define ASN_NULL   (0x05)

Definition at line 57 of file asn1.h.

#define ASN_OBJECT_ID   (0x06)

Definition at line 59 of file asn1.h.

#define ASN_OCTET_STR   (0x04)

Definition at line 55 of file asn1.h.

#define ASN_PRIMITIVE   (0x00)

Definition at line 77 of file asn1.h.

#define ASN_PRIVATE   (0xC0)

Definition at line 74 of file asn1.h.

#define ASN_SEQ_CON   (ASN_SEQUENCE | ASN_CONSTRUCTOR)

Definition at line 90 of file asn1.h.

#define ASN_SEQUENCE   (0x10)

Definition at line 61 of file asn1.h.

#define ASN_SET   (0x11)

Definition at line 63 of file asn1.h.

#define ASN_UNI_PRIM   (ASN_UNIVERSAL | ASN_PRIMITIVE)

Definition at line 89 of file asn1.h.

#define ASN_UNIVERSAL   (0x00)

Definition at line 65 of file asn1.h.

#define ASNERROR (   string)    debugprintf(3, "ASN parse error (%s)\n", string )

Definition at line 125 of file asn1.h.

#define GET_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x0)

Definition at line 108 of file asn1.h.

#define GET_RSP_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x2)

Definition at line 110 of file asn1.h.

#define GETBULK_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x5)

Definition at line 114 of file asn1.h.

#define GETNEXT_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x1)

Definition at line 109 of file asn1.h.

#define INFORM_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x6)

Definition at line 115 of file asn1.h.

#define IS_CONSTRUCTOR (   byte)    ((byte) & ASN_CONSTRUCTOR)

Definition at line 86 of file asn1.h.

#define IS_EXTENSION_ID (   byte)    (((byte) & ASN_EXTENSION_ID) == ASN_EXTENSION_ID)

Definition at line 87 of file asn1.h.

#define MAX_OID_LEN   128 /* max subid's in an oid */

Definition at line 47 of file asn1.h.

#define MAX_SUBID   0xFFFFFFFF

Definition at line 41 of file asn1.h.

#define REPORT_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x8)

Definition at line 117 of file asn1.h.

#define SET_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x3)

Definition at line 111 of file asn1.h.

#define SMI_COUNTER   (ASN_APPLICATION | 1)

Definition at line 100 of file asn1.h.

#define SMI_COUNTER64   (ASN_APPLICATION | 6)

Definition at line 105 of file asn1.h.

#define SMI_GAUGE   (ASN_APPLICATION | 2)

Definition at line 101 of file asn1.h.

#define SMI_IPADDRESS   (ASN_APPLICATION | 0)

Definition at line 99 of file asn1.h.

#define SMI_NSAP   (ASN_APPLICATION | 5)

Definition at line 104 of file asn1.h.

#define SMI_OPAQUE   (ASN_APPLICATION | 4)

Definition at line 103 of file asn1.h.

#define SMI_TIMETICKS   (ASN_APPLICATION | 3)

Definition at line 102 of file asn1.h.

#define SMI_UINTEGER   (ASN_APPLICATION | 7)

Definition at line 106 of file asn1.h.

#define SNMP_ENDOFMIBVIEW   (ASN_CONTEXT | ASN_PRIMITIVE | 0x2)

Definition at line 121 of file asn1.h.

#define SNMP_NOSUCHINSTANCE   (ASN_CONTEXT | ASN_PRIMITIVE | 0x1)

Definition at line 120 of file asn1.h.

#define SNMP_NOSUCHOBJECT   (ASN_CONTEXT | ASN_PRIMITIVE | 0x0)

Definition at line 119 of file asn1.h.

#define SNMP_VERSION_1   0

Definition at line 93 of file asn1.h.

#define SNMP_VERSION_2C   1

Definition at line 94 of file asn1.h.

#define SNMP_VERSION_2STERN   2

Definition at line 95 of file asn1.h.

#define SNMP_VERSION_3   3

Definition at line 96 of file asn1.h.

#define TRP2_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x7)

Definition at line 116 of file asn1.h.

#define TRP_REQ_MSG   (ASN_CONTEXT | ASN_CONSTRUCTOR | 0x4)

Definition at line 112 of file asn1.h.

Typedef Documentation

typedef struct sockaddr_in ipaddr

Definition at line 131 of file asn1.h.

typedef unsigned long oid

Definition at line 40 of file asn1.h.

Function Documentation

DLLOPT unsigned char* asn1_build_header_data ( unsigned char *  outBuf,
int *  maxLength,
long  msgID,
long  maxMessageSize,
unsigned char  msgFlags,
long  securityModel 
)

Encode the given values for the HeaderData into the buffer. 

 HeaderData ::= SEQUENCE {
   msgID      INTEGER (0..2147483647),
   msgMaxSize INTEGER (484..2147483647),
   msgFlags   OCTET STRING (SIZE(1)),
   msgSecurityModel INTEGER (0..2147483647)
 }
Parameters
outBuf- The buffer
maxLength- IN: length of the buffer OUT: free bytes left in the buffer
msgID- The message ID
maxMessageSize- The maximum size of a SNMPv3 message
msgFlags- The message Flags
securityModel- The security model
Returns
- Pointer to the first free byte in the buffer or NULL if an error occured
DLLOPT unsigned char* asn1_build_scoped_pdu ( unsigned char *  outBuf,
int *  max_len,
unsigned char *  contextEngineID,
long  contextEngineIDLength,
unsigned char *  contextName,
long  contextNameLength,
unsigned char *  data,
long  dataLength 
)

Encode the given values for the scopedPDU into the buffer. 

   ScopedPDU ::= SEQUENCE {
          contextEngineID OCTET STRING
          contextName     OCTET STRING
          data            ANY  -- PDU
      }

param outBuf - The buffer param max_len - IN: length of the buffer OUT: free bytes left in the buffer param contextEngineID - The contextEngineID param contextEngineIDLength - The length of the contextEngineID param contextName - The contextName param contextNameLength - The length of the contextName param data - The already encoded data param dataLength - The length of the data

Returns
- Pointer to the first free byte in the buffer or NULL if an error occured
DLLOPT unsigned char* asn1_parse_header_data ( unsigned char *  buf,
int *  buf_len,
long *  msg_id,
long *  msg_max_size,
unsigned char *  msg_flags,
long *  msg_security_model 
)

Parse the filled HeaderData of a SNMPv3 message and return the encoded values. 

     HeaderData ::= SEQUENCE {
         msgID      INTEGER (0..2147483647),
         msgMaxSize INTEGER (484..2147483647),
         msgFlags   OCTET STRING (SIZE(1)),
         msgSecurityModel INTEGER (0..2147483647)
     }
Parameters
buf- The buffer to parse
buf_len- IN: The length of the buffer OUT: The number of bytes after this object int the buffer
msg_id- OUT: The message id
msg_max_size- OUT: THe maximum message size of the sender
msg_flags- OUT: The message flags
msg_security_model- OUT: The security model used to build this message
Returns
- Returns a pointer to the first byte past the end of the object HeaderData (i.e. the start of the next object). Returns NULL on any error.
DLLOPT unsigned char* asn1_parse_scoped_pdu ( unsigned char *  scoped_pdu,
int *  scoped_pdu_len,
unsigned char *  context_engine_id,
int *  context_engine_id_len,
unsigned char *  context_name,
int *  context_name_len 
)

Parse the ScopedPDU and return the encoded values. 

     ScopedPDU ::= SEQUENCE {
         contextEngineID  OCTET STRING,
         contextName      OCTET STRING,
         data             ANY -- e.g., PDUs as defined in RFC 1905
     }
Parameters
scoped_pdu- The buffer to parse
scoped_pdu_len- IN: The length of the buffer OUT: The number of bytes after this object int the buffer
context_engine_id- OUT: The parsed contextEngineID
context_engine_id_len- OUT: The length of the contextEngineID
context_name- OUT: The parsed contextName
context_name_len- OUT: The length of the contextName
Returns
- Pointer to the data object of the scopedPDU or NULL on any error.
DLLOPT unsigned char* asn_build_bitstring ( unsigned char *  data,
int *  datalength,
unsigned char  type,
unsigned char *  string,
int  strlength 
)
DLLOPT unsigned char* asn_build_header ( unsigned char *  data,
int *  datalength,
unsigned char  type,
int  length 
)
DLLOPT unsigned char* asn_build_int ( unsigned char *  data,
int *  datalength,
const unsigned char  type,
const long *  intp 
)

Referenced by asn_build_int().

unsigned char* asn_build_int ( unsigned char *  data,
int *  datalength,
const unsigned char  type,
const unsigned long *  intp 
)
inline

Definition at line 204 of file asn1.h.

References asn_build_int().

DLLOPT unsigned char* asn_build_length ( unsigned char *  data,
int *  datalength,
int  length 
)
DLLOPT unsigned char* asn_build_null ( unsigned char *  data,
int *  datalength,
unsigned char  type 
)
DLLOPT unsigned char* asn_build_objid ( unsigned char *  data,
int *  datalength,
unsigned char  type,
oid *  objid,
int  objidlength 
)
DLLOPT unsigned char* asn_build_sequence ( unsigned char *  data,
int *  datalength,
unsigned char  type,
int  length 
)
DLLOPT unsigned char* asn_build_string ( unsigned char *  data,
int *  datalength,
const unsigned char  type,
const unsigned char *  string,
const int  strlength 
)
DLLOPT void asn_build_subid ( unsigned long  subid,
unsigned char *&  bp 
)
DLLOPT unsigned char* asn_build_unsigned_int ( unsigned char *  data,
int *  datalength,
unsigned char  type,
unsigned long *  intp 
)
DLLOPT unsigned char* asn_build_unsigned_int64 ( unsigned char *  data,
int *  datalength,
unsigned char  type,
struct counter64 *  cp 
)
DLLOPT unsigned char* asn_parse_bitstring ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
unsigned char *  string,
int *  strlength 
)
DLLOPT unsigned char* asn_parse_header ( unsigned char *  data,
int *  datalength,
unsigned char *  type 
)
DLLOPT unsigned char* asn_parse_int ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
long *  intp 
)

Referenced by asn_parse_int().

unsigned char* asn_parse_int ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
unsigned long *  intp 
)
inline

Definition at line 184 of file asn1.h.

References asn_parse_int().

DLLOPT unsigned char* asn_parse_length ( unsigned char *  data,
unsigned long *  length 
)
DLLOPT unsigned char* asn_parse_null ( unsigned char *  data,
int *  datalength,
unsigned char *  type 
)
DLLOPT unsigned char* asn_parse_objid ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
oid *  objid,
int *  objidlength 
)
DLLOPT unsigned char* asn_parse_string ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
unsigned char *  string,
int *  strlength 
)
DLLOPT unsigned char* asn_parse_unsigned_int ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
unsigned long *  intp 
)

Referenced by asn_parse_unsigned_int().

unsigned char* asn_parse_unsigned_int ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
long *  intp 
)
inline

Definition at line 194 of file asn1.h.

References asn_parse_unsigned_int().

DLLOPT unsigned char* asn_parse_unsigned_int64 ( unsigned char *  data,
int *  datalength,
unsigned char *  type,
struct counter64 *  cp 
)
DLLOPT unsigned char* build_data_pdu ( struct snmp_pdu *  pdu,
unsigned char *  buf,
int *  buf_len,
unsigned char *  vb_buf,
int  vb_buf_len 
)
DLLOPT unsigned char* build_vb ( struct snmp_pdu *  pdu,
unsigned char *  buf,
int *  buf_len 
)
DLLOPT void clear_pdu ( struct snmp_pdu *  pdu,
bool  clear_all = false 
)
DLLOPT void snmp_add_var ( struct snmp_pdu *  pdu,
oid *  name,
int  name_length,
SmiVALUE *  smival 
)
DLLOPT int snmp_build ( struct snmp_pdu *  pdu,
unsigned char *  packet,
int *  out_length,
const long  version,
const unsigned char *  community,
const int  community_len 
)
DLLOPT unsigned char* snmp_build_var_op ( unsigned char *  data,
oid *  var_name,
int *  var_name_len,
unsigned char  var_val_type,
int  var_val_len,
unsigned char *  var_val,
int *  listlength 
)
DLLOPT void snmp_free_pdu ( struct snmp_pdu *  pdu)
DLLOPT int snmp_parse ( struct snmp_pdu *  pdu,
unsigned char *  data,
int  data_length,
unsigned char *  community_name,
int &  community_len,
snmp_version &  version 
)
DLLOPT int snmp_parse_data_pdu ( struct snmp_pdu *  pdu,
unsigned char *&  data,
int &  length 
)
DLLOPT unsigned char* snmp_parse_var_op ( unsigned char *  data,
oid *  var_name,
int *  var_name_len,
unsigned char *  var_val_type,
int *  var_val_len,
unsigned char **  var_val,
int *  listlength 
)
DLLOPT int snmp_parse_vb ( struct snmp_pdu *  pdu,
unsigned char *&  data,
int &  data_len 
)
DLLOPT struct snmp_pdu* snmp_pdu_create ( int  command)