protocol.c

非常不错的网管开发包

	free( pdu );
	return(0);
     }
     if (!IS_AGENTX_VERSION( session->version ))
	return SNMPERR_BAD_VERSION;

#ifndef SNMPERR_INCOMPLETE_PACKET
	/*
	 *  Ideally, "short" packets on stream connections should
	 *    be handled specially, and the driving code set up to
	 *    keep reading until the full packet is received.
	 *
	 *  For now, lets assume that all packets are read in one go.
	 *    I've probably inflicted enough damage on the UCD library
	 *    for one week!
	 *
	 *  I'll come back to this once Wes is speaking to me again.
	 */
#define SNMPERR_INCOMPLETE_PACKET SNMPERR_ASN_PARSE_ERR
#endif


		/*
		 *  Handle (common) header ....
		 */
     bufp = agentx_parse_header( pdu, bufp, length );
     if ( bufp == NULL )
	return SNMPERR_INCOMPLETE_PACKET;	/* i.e. wait for the rest */

				/* Control PDU handling */
     pdu->flags |= UCD_MSG_FLAG_ALWAYS_IN_VIEW;
     pdu->flags |= UCD_MSG_FLAG_FORCE_PDU_COPY;
     pdu->flags &= (~UCD_MSG_FLAG_RESPONSE_PDU);

		/*
		 *  ... and (not-un-common) context
		 */
     if ( pdu->flags & 	AGENTX_MSG_FLAG_NON_DEFAULT_CONTEXT ) {
        DEBUGDUMPHEADER("dump_recv", "Parsing Context\n");
	bufp = agentx_parse_string( bufp, length, buffer, &buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
        DEBUGINDENTLESS();
        if ( bufp == NULL )
	    return SNMPERR_ASN_PARSE_ERR;

	pdu->community_len = buf_len;
	snmp_clone_mem((void **)&pdu->community, 
				(void *)buffer, (unsigned) buf_len);
	buf_len = BUFSIZ;
     }

     DEBUGDUMPHEADER("dump_recv", "Parsing PDU\n");
     DEBUGINDENTMORE();
     DEBUGPRINTINDENT("dump_recv");
     switch ( pdu->command ) {
	case AGENTX_MSG_OPEN:
        	DEBUGMSG(("dump_recv", "Open PDU\n"));
		pdu->time = *bufp;	/* Timeout */
		bufp     += 4;
		*length  -= 4;

			/* Store subagent OID & description in a VarBind */
                DEBUGDUMPHEADER("dump_recv", "Parsing Subagent OID\n");
		bufp = agentx_parse_oid( bufp, length, NULL,
				oid_buffer, &oid_buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
                DEBUGINDENTLESS();
		if ( bufp == NULL ) {
                    DEBUGINDENTLESS();
		    return SNMPERR_ASN_PARSE_ERR;
                }
                DEBUGDUMPHEADER("dump_recv", "Parsing Subagent Description\n");
		bufp = agentx_parse_string( bufp, length, buffer, &buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
                DEBUGINDENTLESS();
		if ( bufp == NULL ) {
                    DEBUGINDENTLESS();
		    return SNMPERR_ASN_PARSE_ERR;
                }
		snmp_pdu_add_variable( pdu, oid_buffer, oid_buf_len,
				ASN_OCTET_STR, buffer, buf_len);

		oid_buf_len = MAX_OID_LEN;
		buf_len     = BUFSIZ;
		break;

	case AGENTX_MSG_CLOSE:
        	DEBUGMSG(("dump_recv", "Close PDU\n"));
		pdu->errstat = *bufp;	/* Reason */
		bufp     += 4;
		*length  -= 4;

		break;

	case AGENTX_MSG_UNREGISTER:
        	DEBUGMSG(("dump_recv", "Un"));
	case AGENTX_MSG_REGISTER:
        	DEBUGMSG(("dump_recv", "Register PDU\n"));
		pdu->time = *bufp;	/* Timeout (Register only) */
		bufp++;
		pdu->priority = *bufp;
		bufp++;
		pdu->range_subid = *bufp;
		bufp++;
		bufp++;
		*length -= 4;

		prefix_ptr = bufp+1;
                DEBUGDUMPHEADER("dump_recv", "Parsing Registration OID\n");
		bufp = agentx_parse_oid( bufp, length, NULL,
				oid_buffer, &oid_buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
                DEBUGINDENTLESS();
		if ( bufp == NULL ) {
                    DEBUGINDENTLESS();
		    return SNMPERR_ASN_PARSE_ERR;
                }

		if ( pdu->range_subid ) {
		
			if ( *prefix_ptr ) {
			    pdu->range_subid += 5;
			}
    			range_bound = agentx_parse_int( bufp,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
			bufp    += 4;
			*length -= 4;

				/* Construct the end-OID */
			memmove( &end_oid_buf, oid_buffer, oid_buf_len*4 );
			end_oid_buf_len = oid_buf_len*4;
			end_oid_buf[ pdu->range_subid-1 ] = range_bound;
			
			snmp_pdu_add_variable( pdu, oid_buffer, oid_buf_len,
				ASN_PRIV_INCL_RANGE, (u_char *)end_oid_buf, end_oid_buf_len);
		}
		else {
			snmp_add_null_var( pdu, oid_buffer, oid_buf_len );
		}

		oid_buf_len = MAX_OID_LEN;
		break;

	case AGENTX_MSG_GETBULK:
        	DEBUGMSG(("dump_recv", "getbulk PDU\n"));
                DEBUGDUMPHEADER("dump_recv", "Parsing Non-repeaters\n");
		pdu->non_repeaters = agentx_parse_short( bufp,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
                DEBUGINDENTLESS();
                DEBUGDUMPHEADER("dump_recv", "Parsing Max-repeaters\n");
		pdu->max_repetitions = agentx_parse_short( bufp+2,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
                DEBUGINDENTLESS();
		bufp    += 4;
		*length -= 4;
		/*  Fallthrough - SearchRange handling is the same */
		
	case AGENTX_MSG_GETNEXT:
        	DEBUGMSG(("dump_recv", "next-"));
	case AGENTX_MSG_GET:
        	DEBUGMSG(("dump_recv", "get PDU\n"));

			/*
			*  SearchRange List
			*  Keep going while we have data left
			*/
                DEBUGDUMPHEADER("dump_recv", "Parsing Search Range\n");
		while ( *length > 0 ) {
		    bufp = agentx_parse_oid( bufp, length, &inc,
				oid_buffer, &oid_buf_len,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		    if ( bufp == NULL ) {
                            DEBUGINDENTLESS();
                            DEBUGINDENTLESS();
			    return SNMPERR_ASN_PARSE_ERR;
                    }
		    bufp = agentx_parse_oid( bufp, length, NULL,
				end_oid_buf, &end_oid_buf_len,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		    if ( bufp == NULL ) {
                            DEBUGINDENTLESS();
                            DEBUGINDENTLESS();
			    return SNMPERR_ASN_PARSE_ERR;
                    }
		    end_oid_buf_len *= 4;
			/* 'agentx_parse_oid()' returns the number of sub_ids */

		    if ( inc )
			snmp_pdu_add_variable( pdu, oid_buffer, oid_buf_len,
				ASN_PRIV_INCL_RANGE, (u_char *)end_oid_buf, end_oid_buf_len);
		    else
			snmp_pdu_add_variable( pdu, oid_buffer, oid_buf_len,
				ASN_PRIV_EXCL_RANGE, (u_char *)end_oid_buf, end_oid_buf_len);
		}

                DEBUGINDENTLESS();
                oid_buf_len     = MAX_OID_LEN;
		end_oid_buf_len = MAX_OID_LEN;
		break;


	case AGENTX_MSG_RESPONSE:

        	DEBUGMSG(("dump_recv", "response PDU\n"));
     		pdu->flags |= UCD_MSG_FLAG_RESPONSE_PDU;

					/* sysUpTime */
		pdu->time = agentx_parse_int( bufp,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		bufp    += 4;
		*length -= 4;
		
		pdu->errstat   = agentx_parse_short( bufp,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		pdu->errindex  = agentx_parse_short( bufp+2,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		bufp    += 4;
		*length -= 4;
		/*  Fallthrough - VarBind handling is the same */
		
	case AGENTX_MSG_INDEX_ALLOCATE:
	case AGENTX_MSG_INDEX_DEALLOCATE:
	case AGENTX_MSG_NOTIFY:
	case AGENTX_MSG_TESTSET:
	
			/*
			*  VarBind List
			*  Keep going while we have data left
			*/

                DEBUGDUMPHEADER("dump_recv", "Parsing VarBindList\n");
		while ( *length > 0 ) {
		    bufp = agentx_parse_varbind( bufp, length, &type,
				oid_buffer, &oid_buf_len,
				buffer, &buf_len,
				pdu->flags & AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		    if ( bufp == NULL ) {
                            DEBUGINDENTLESS();
                            DEBUGINDENTLESS();
			    return SNMPERR_ASN_PARSE_ERR;
                    }
		    snmp_pdu_add_variable( pdu, oid_buffer, oid_buf_len,
				type, buffer, buf_len);

		    oid_buf_len = MAX_OID_LEN;
		    buf_len     = BUFSIZ;
		}
                DEBUGINDENTLESS();
                break;

	case AGENTX_MSG_COMMITSET:
	case AGENTX_MSG_UNDOSET:
	case AGENTX_MSG_CLEANUPSET:
	case AGENTX_MSG_PING:
        	DEBUGMSG(("dump_recv", "set or ping PDU\n"));

		/* "Empty" packet */
		break;


	case AGENTX_MSG_ADD_AGENT_CAPS:
			/* Store AgentCap OID & description in a VarBind */
        	DEBUGMSG(("dump_recv", "add agent caps PDU\n"));
		bufp = agentx_parse_oid( bufp, length, NULL,
				oid_buffer, &oid_buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		if ( bufp == NULL )
		    return SNMPERR_ASN_PARSE_ERR;
		bufp = agentx_parse_string( bufp, length, buffer, &buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		if ( bufp == NULL )
		    return SNMPERR_ASN_PARSE_ERR;
		snmp_pdu_add_variable( pdu, oid_buffer, oid_buf_len,
				ASN_OCTET_STR, buffer, buf_len);

		oid_buf_len = MAX_OID_LEN;
		buf_len     = BUFSIZ;
		break;

	case AGENTX_MSG_REMOVE_AGENT_CAPS:
        	DEBUGMSG(("dump_recv", "remove agent caps PDU\n"));
			/* Store AgentCap OID & description in a VarBind */
		bufp = agentx_parse_oid( bufp, length, NULL,
				oid_buffer, &oid_buf_len,
				pdu->flags &  AGENTX_FLAGS_NETWORK_BYTE_ORDER );
		if ( bufp == NULL )
		    return SNMPERR_ASN_PARSE_ERR;
		snmp_add_null_var( pdu, oid_buffer, oid_buf_len );

		oid_buf_len = MAX_OID_LEN;
		break;

	default:
        	DEBUGMSG(("dump_recv", "Unrecognised PDU\n"));
                DEBUGINDENTLESS();
                DEBUGINDENTLESS();
		DEBUGMSGTL(("agentx","Unrecognised PDU type"));
		return SNMPERR_UNKNOWN_PDU;
     }
     DEBUGINDENTLESS();
     DEBUGINDENTLESS();
     return SNMP_ERR_NOERROR;
}


	/***********************
	*
	*  Utility functions for dumping an AgentX packet
	*	Cribbed shamelessly from the parsing code
	*
	*  TODO: Properly structured indentation
	*
	***********************/
	
int
agentx_dump_int(u_char *data, u_int network_byte_order)
{
    u_int    value = agentx_parse_int( data, network_byte_order );
    DEBUGMSGTL(("agentx","INTEGER %.2x %.2x %.2x %.2x = %d\n",
		*data, *(data+1), *(data+2), *(data+3), value));

    return value;
}


int
agentx_dump_short(u_char *data, u_int network_byte_order)
{
    u_int    value = agentx_parse_short( data, network_byte_order );
    DEBUGMSGTL(("agentx","SHORT %.2x %.2x = %d\n",
		*data, *(data+1), value));
    
    return value;
}


u_char *
agentx_dump_oid( u_char *data, size_t *length, u_int network_byte_order)
{
     u_int n_subid, subid;
     u_int prefix;
     int i;
     u_char *buf_ptr = data;

     if ( *length < 4 ) {
	DEBUGMSGTL(("agentx","Incomplete Object ID"));
	return NULL;
     }

     n_subid = data[0];
     prefix  = data[1];

DEBUGMSGTL(("agentx","OBJECT ID #subids = %d,  prefix = %d, inc = %d, (reserved %d)\n", data[1], data[0], data[2], data[3]));

      buf_ptr += 4;
     *length -= 4;

     if ( n_subid == 0 ) {
DEBUGMSGTL(("agentx","\t NULL OID\n"));
	return buf_ptr;
     }


     if ( *length < 4*n_subid ) {
	DEBUGMSGTL(("agentx","Incomplete Object ID"));
	return NULL;     
     } 
     
     if ( prefix ) {
DEBUGMSGTL(("agentx","\t [.1.3.6.1.%d]\n", prefix));
     }


     for ( i = 0  ; i<n_subid ; i++ ) {
DEBUGMSGTL(("agentx","\t "));
       	agentx_dump_int( buf_ptr, network_byte_order );
	buf_ptr += 4;
	*length -= 4;
     }

     return buf_ptr;
}



u_char *
agentx_dump_string( u_char *data, size_t *length, u_int network_byte_order)
{
     u_int len, i;

     if ( *length <= 4 ) {
	DEBUGMSGTL(("agentx","Incomplete string"));
	return NULL;
     }

DEBUGMSGTL(("agentx","STRING\n\tlength = "));
     len = agentx_dump_int( data, network_byte_order );
     if ( *length < len + 4 ) {
	DEBUGMSGTL(("agentx","Incomplete string"));
	return NULL;
     }
DEBUGMSGTL(("agentx","\t DATA "));
     for ( i = 0 ; i < len ; i++ ) {
	DEBUGMSGTL(("agentx"," %.2x", data[4+i]));
     }
DEBUGMSGTL(("agentx","\n\t = %c", '"'));
     for ( i = 0 ; i < len ; i++ ) {
	DEBUGMSGTL(("agentx"," %c", data[4+i]));
     }
DEBUGMSGTL(("agentx","%c\n", '"'));

     len += 3;	/* Extend the string length to include the padding */
     len >>= 2;
     len <<= 2;

     *length -= ( len+4 );
     return data + ( len+4 );
}


u_char *
agentx_dump_varbind( u_char *data, size_t *length, u_int network_byte_order)
{
     u_char *bufp = data;
     u_int   type;
     
DEBUGMSGTL(("agentx","VARBIND\n\ttype = "));
     type = agentx_dump_short( bufp, network_byte_order );