/************************************************************************** * * Copyright (C) 2008 Steve Karg * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * *********************************************************************/ #include #include #include #include #include "config.h" #include "bacdef.h" #include "bacdcode.h" #include "address.h" #include "tsm.h" #include "dcc.h" #include "npdu.h" #include "apdu.h" #include "device.h" #include "datalink.h" #include "iam.h" /* some demo stuff needed */ #include "handlers.h" #include "client.h" /** @file s_iam.c Send an I-Am message. */ /** Encode an I Am message to be broadcast. * @param buffer [in,out] The buffer to use for building the message. * @param dest [out] The destination address information. * @param npdu_data [out] The NPDU structure describing the message. * @return The length of the message in buffer[]. */ int iam_encode_pdu( uint8_t * buffer, BACNET_ADDRESS * dest, BACNET_NPDU_DATA * npdu_data) { int len = 0; int pdu_len = 0; BACNET_ADDRESS my_address; datalink_get_my_address(&my_address); datalink_get_broadcast_address(dest); /* encode the NPDU portion of the packet */ npdu_encode_npdu_data(npdu_data, false, MESSAGE_PRIORITY_NORMAL); pdu_len = npdu_encode_pdu(&buffer[0], dest, &my_address, npdu_data); /* encode the APDU portion of the packet */ len = iam_encode_apdu(&buffer[pdu_len], Device_Object_Instance_Number(), MAX_APDU, SEGMENTATION_NONE, Device_Vendor_Identifier()); pdu_len += len; return pdu_len; } /** Broadcast an I Am message. * @ingroup DMDDB * * @param buffer [in] The buffer to use for building and sending the message. */ void Send_I_Am( uint8_t * buffer) { int pdu_len = 0; BACNET_ADDRESS dest; int bytes_sent = 0; BACNET_NPDU_DATA npdu_data; #if 0 /* note: there is discussion in the BACnet committee that we should allow a device to reply with I-Am so that dynamic binding always work. If the DCC initiator loses the MAC address and routing info, they can never re-enable DCC because they can't find the device with WhoIs/I-Am */ /* are we are forbidden to send? */ if (!dcc_communication_enabled()) return 0; #endif /* encode the data */ pdu_len = iam_encode_pdu(buffer, &dest, &npdu_data); /* send data */ bytes_sent = datalink_send_pdu(&dest, &npdu_data, &buffer[0], pdu_len); if (bytes_sent <= 0) { #if PRINT_ENABLED fprintf(stderr, "Failed to Send I-Am Reply (%s)!\n", strerror(errno)); #endif } } /** Encode an I Am message to be unicast directly back to the src. * * @param buffer [in,out] The buffer to use for building the message. * @param src [in] The source address information. If the src address is not * given, the dest address will be a broadcast address. * @param dest [out] The destination address information. * @param npdu_data [out] The NPDU structure describing the message. * @return The length of the message in buffer[]. */ int iam_unicast_encode_pdu( uint8_t * buffer, BACNET_ADDRESS * src, BACNET_ADDRESS * dest, BACNET_NPDU_DATA * npdu_data) { int npdu_len = 0; int apdu_len = 0; int pdu_len = 0; BACNET_ADDRESS my_address; /* The destination will be the same as the src, so copy it over. */ bacnet_address_copy(dest, src); /* dest->net = 0; - no, must direct back to src->net to meet BTL tests */ datalink_get_my_address(&my_address); /* encode the NPDU portion of the packet */ npdu_encode_npdu_data(npdu_data, false, MESSAGE_PRIORITY_NORMAL); npdu_len = npdu_encode_pdu(&buffer[0], dest, &my_address, npdu_data); /* encode the APDU portion of the packet */ apdu_len = iam_encode_apdu(&buffer[npdu_len], Device_Object_Instance_Number(), MAX_APDU, SEGMENTATION_NONE, Device_Vendor_Identifier()); pdu_len = npdu_len + apdu_len; return pdu_len; } /** Send an I-Am message by unicasting directly back to the src. * @ingroup DMDDB * @note As of Addendum 135-2008q-1, unicast responses are allowed; * in modern firewalled corporate networks, this may be the * only type of response that will reach the source on * another subnet (without using the BBMD).
* However, some BACnet routers may not correctly handle this message. * * @param buffer [in] The buffer to use for building and sending the message. * @param src [in] The source address information from service handler. */ void Send_I_Am_Unicast( uint8_t * buffer, BACNET_ADDRESS * src) { int pdu_len = 0; BACNET_ADDRESS dest; int bytes_sent = 0; BACNET_NPDU_DATA npdu_data; #if 0 /* note: there is discussion in the BACnet committee that we should allow a device to reply with I-Am so that dynamic binding always work. If the DCC initiator loses the MAC address and routing info, they can never re-enable DCC because they can't find the device with WhoIs/I-Am */ /* are we are forbidden to send? */ if (!dcc_communication_enabled()) return 0; #endif /* encode the data */ pdu_len = iam_unicast_encode_pdu(buffer, src, &dest, &npdu_data); /* send data */ bytes_sent = datalink_send_pdu(&dest, &npdu_data, &buffer[0], pdu_len); #if PRINT_ENABLED if (bytes_sent <= 0) fprintf(stderr, "Failed to Send I-Am Reply (%s)!\n", strerror(errno)); #else (void)bytes_sent; #endif }