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Adding a handler for routed NPDUs (ie, Network Layer Message handling).

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The work is not complete yet; this is an interim checkin.
This commit is contained in:
tbrennan3
2010-09-29 20:52:51 +00:00
parent d39d4fded3
commit 9f4b8e5f19
3 changed files with 243 additions and 0 deletions
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bacnet-stack/demo/handler/h_routed_npdu.c
+237
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@@ -0,0 +1,237 @@
/**************************************************************************
*
* Copyright (C) 2010 Steve Karg <skarg@users.sourceforge.net>
*
* 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.
*
*********************************************************************/
/* Acknowledging the contribution of code and ideas used here that
* came from Paul Chapman's vmac demo project. */
#include <stdbool.h>
#include <stdint.h>
#include "bacdef.h"
#include "bacdcode.h"
#include "bacint.h"
#include "bacenum.h"
#include "bits.h"
#include "npdu.h"
#include "apdu.h"
#include "handlers.h"
#include "client.h"
#include "debug.h"
#if PRINT_ENABLED
#include <stdio.h>
#endif
/** @file h_routed_npdu.c Handles messages at the NPDU level of the BACnet stack,
* including routing and network control messages. */
extern int DNET_list[];
/** Handler to manage the Network Layer Control Messages received in a packet.
* This handler is called if the NCPI bit 7 indicates that this packet is a
* network layer message and there is no further DNET to pass it to.
* The NCPI has already been decoded into the npdu_data structure.
*
* @param npdu_data [in] Contains a filled-out structure with information
* decoded from the NCPI and other NPDU bytes.
* @param npdu [in] Buffer containing the rest of the NPDU, following the
* bytes that have already been decoded.
* @param npdu_len [in] The length of the remaining NPDU message in npdu[].
*/
static void network_control_handler(
BACNET_NPDU_DATA * npdu_data,
uint8_t * npdu,
uint16_t npdu_len)
{
uint16_t npdu_offset = 0;
uint16_t dnet = 0;
uint16_t len = 0;
switch (npdu_data->network_message_type) {
case NETWORK_MESSAGE_WHO_IS_ROUTER_TO_NETWORK:
/* Send I-am-router-to-network with our one-network list if
* our specific network is requested, or no specific
* network is requested. Silently drop other DNET requests.
*/
if (npdu_len >= 2)
{
uint16_t network;
len += decode_unsigned16(&npdu[len], &network);
if (network == DNET_list[0] )
{
Send_I_Am_Router_To_Network( DNET_list );
}
}
else
{
Send_I_Am_Router_To_Network( DNET_list );
}
break;
case NETWORK_MESSAGE_I_AM_ROUTER_TO_NETWORK:
/* Per the standard, we are supposed to process this message and
* add its DNETs to our routing table.
* However, since we only have one upstream port that these
* messages can come from and replies go to, it doesn't seem
* to provide us any value to do this; when we need to send to
* some remote device, we will start by pushing it out the
* upstream port and let the attached router(s) take it from there.
* Consequently, we'll do nothing interesting here.
* -- Unless we act upon NETWORK_MESSAGE_ROUTER_BUSY_TO_NETWORK
* later for congestion control - then it could matter.
*/
debug_printf("I-Am Router to Network for Networks: ");
while (npdu_len) {
len = decode_unsigned16(&npdu[npdu_offset], &dnet);
debug_printf("%hu", dnet);
npdu_len -= len;
npdu_offset += len;
if (npdu_len) {
debug_printf(", ");
}
}
debug_printf("\n");
break;
case NETWORK_MESSAGE_I_COULD_BE_ROUTER_TO_NETWORK:
/* Do nothing, same as previous case. */
break;
case NETWORK_MESSAGE_REJECT_MESSAGE_TO_NETWORK:
if ( npdu_len >= 3 ) {
decode_unsigned16(&npdu[1], &dnet);
debug_printf("Received 'Reject Message to Network' for Network: ");
debug_printf("%hu, Reason code: %d \n", dnet, npdu[0] );
}
break;
case NETWORK_MESSAGE_ROUTER_BUSY_TO_NETWORK:
case NETWORK_MESSAGE_ROUTER_AVAILABLE_TO_NETWORK:
/* Do nothing - don't support upstream traffic congestion control */
break;
case NETWORK_MESSAGE_INIT_RT_TABLE:
/* If sent with Number of Ports == 0, we respond with
* NETWORK_MESSAGE_INIT_RT_TABLE_ACK and a list of all our
* reachable networks.
*/
if ( (npdu_len > 0) && (npdu[0] == 0) ) {
BACNET_ROUTER_PORT * router_port_list = NULL;
Send_Initialize_Routing_Table_Ack(router_port_list);
break;
}
/* Else, fall through to do nothing. */
case NETWORK_MESSAGE_INIT_RT_TABLE_ACK:
/* Do nothing - don't support upstream traffic congestion control */
break;
case NETWORK_MESSAGE_ESTABLISH_CONNECTION_TO_NETWORK:
case NETWORK_MESSAGE_DISCONNECT_CONNECTION_TO_NETWORK:
/* Do nothing - don't support PTP half-router control */
break;
default:
/* An unrecognized message is bad; send an error response. */
#if PRINT_ENABLED
fprintf(stderr, "NPDU: Network Layer Message discarded!\n");
#endif
break;
}
}
static void routed_apdu_handler(
BACNET_ADDRESS * src,
BACNET_ADDRESS * dest,
uint8_t * apdu,
uint16_t apdu_len)
{
/* Handle the normal, non-routed variety for right now in development */
apdu_handler(src, apdu, apdu_len);
#if PRINT_ENABLED
printf("NPDU: DNET=%u. Discarded!\n", (unsigned) dest->net);
#endif
}
/** Handler for the NPDU portion of a received packet, which may have routing.
* This is a fuller handler than the regular npdu_handler, as it manages
* - Decoding of the NCPI byte
* - Further processing by network_control_handler() if this is a network
* layer message.
* - Further processing if it contains an APDU
* - Normally (no routing) by apdu_handler()
* - With Routing (a further destination was indicated) by
* - Errors in decoding.
* @note The npdu_data->data_expecting_reply status is discarded.
*
* @param src [out] Returned with routing source information if the NPDU
* has any and if this points to non-null storage for it.
* If src->net and src->len are 0 on return, there is no
* routing source information.
* This src describes the original source of the message when
* it had to be routed to reach this BACnet Device, and this
* is passed down into the apdu_handler; however, I don't
* think this project's code has any use for the src info
* on return from this handler, since the response has
* already been sent via the apdu_handler.
* @param pdu [in] Buffer containing the NPDU and APDU of the received packet.
* @param pdu_len [in] The size of the received message in the pdu[] buffer.
*/
void routing_npdu_handler(
BACNET_ADDRESS * src,
uint8_t * pdu,
uint16_t pdu_len)
{
int apdu_offset = 0;
BACNET_ADDRESS dest = { 0 };
BACNET_NPDU_DATA npdu_data = { 0 };
/* only handle the version that we know how to handle */
if (pdu[0] == BACNET_PROTOCOL_VERSION) {
apdu_offset = npdu_decode(&pdu[0], &dest, src, &npdu_data);
if ( apdu_offset <= 0 ) {
#if PRINT_ENABLED
printf("NPDU: Decoding failed; Discarded!\n");
#endif
} else if (npdu_data.network_layer_message) {
if ((dest.net == 0) || (dest.net == BACNET_BROADCAST_NETWORK)) {
network_control_handler( &npdu_data, &pdu[apdu_offset],
(uint16_t) (pdu_len - apdu_offset));
} else {
/* The DNET is set, but we don't support downstream routers,
* so we just silently drop this network layer message,
* since only routers can handle it (even if for our DNET) */
}
} else if (apdu_offset <= pdu_len) {
if ((dest.net == 0) || (dest.net == BACNET_BROADCAST_NETWORK)) {
/* Handle the normal, non-routed variety */
apdu_handler(src, &pdu[apdu_offset],
(uint16_t) (pdu_len - apdu_offset));
} else {
/* Handle the routed variety differently */
routed_apdu_handler(src, &dest, &pdu[apdu_offset],
(uint16_t) (pdu_len - apdu_offset));
}
}
} else {
/* Should we send NETWORK_MESSAGE_REJECT_MESSAGE_TO_NETWORK? */
#if PRINT_ENABLED
printf("NPDU: Unsupported BACnet Protocol Version=%u. Discarded!\n",
(unsigned) pdu[0]);
#endif
}
return;
}
bacnet-stack/include/handlers.h
+5
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@@ -54,6 +54,11 @@ extern "C" {
uint8_t * pdu, /* PDU data */
uint16_t pdu_len); /* length PDU */
void routing_npdu_handler(
BACNET_ADDRESS * src,
uint8_t * pdu,
uint16_t pdu_len);
void handler_who_is(
uint8_t * service_request,
uint16_t service_len,
bacnet-stack/lib/Makefile
+1
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@@ -92,6 +92,7 @@ HANDLER_SRC = \
$(BACNET_HANDLER)/txbuf.c \
$(BACNET_HANDLER)/noserv.c \
$(BACNET_HANDLER)/h_npdu.c \
$(BACNET_HANDLER)/h_routed_npdu.c \
$(BACNET_HANDLER)/h_whois.c \
$(BACNET_HANDLER)/h_iam.c \
$(BACNET_HANDLER)/h_rp.c \