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Adding BVLC handling.

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This commit is contained in:
skarg
2006-05-12 15:50:34 +00:00
parent d5124639e2
commit 2883fd39b2
2 changed files with 315 additions and 37 deletions
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bacnet-stack/bvlc.c
+314 -37
View File
@@ -43,6 +43,106 @@
Broadcast Distribution Table, and
Foreign Device Registration */
typedef struct
{
/* IP Address - stored in host byte order */
struct in_addr address;
uint16_t port;
} BIP_ADDRESS;
typedef struct
{
/* true if valid entry - false if not */
bool valid;
/* BACnet/IP address */
BIP_ADDRESS bip_address;
/* Broadcast Distribution Mask - stored in host byte order */
struct in_addr broadcast_mask;
} BBMD_TABLE_ENTRY;
#define MAX_BBMD_ENTRIES 128
static BBMD_TABLE_ENTRY BBMD_Table[MAX_BBMD_ENTRIES];
/*Each device that registers as a foreign device shall be placed
in an entry in the BBMD's Foreign Device Table (FDT). Each
entry shall consist of the 6-octet B/IP address of the registrant;
the 2-octet Time-to-Live value supplied at the time of
registration; and a 2-octet value representing the number of
seconds remaining before the BBMD will purge the registrant's FDT
entry if no re-registration occurs. This value will be initialized
to the 2-octet Time-to-Live value supplied at the time of
registration.*/
typedef struct
{
bool valid;
/* BACnet/IP address */
BIP_ADDRESS bip_address;
/* seconds for valid entry lifetime */
uint16_t time_to_live;
time_t seconds_remaining;
} FD_TABLE_ENTRY;
#define MAX_FD_ENTRIES 128
static FOREIGN_DEVICE_TABLE_ENTRY FD_Table[MAX_FD_ENTRIES];
void bvlc_maintenance_timer(unsigned seconds)
{
unsigned i = 0;
for (i = 0; i < MAX_FD_ENTRIES; i++) {
if (FD_Table[i].valid)
{
if (FD_Table[i].time_to_live
}
}
static FOREIGN_DEVICE_TABLE_ENTRY FD_Table[MAX_FD_ENTRIES];
}
int bvlc_encode_bip_address(
uint8_t *pdu,
struct in_addr *address, /* in host format */
uint16_t port)
{
int len = 0;
if (pdu) {
len = encode_unsigned32(&pdu[0], address->s_addr);
len += encode_unsigned16(&pdu[len], port);
}
return len;
}
int bvlc_decode_bip_address(
uint8_t *pdu,
struct in_addr *address, /* in host format */
uint16_t *port)
{
}
/* used for both read and write entries */
int bvlc_encode_address_entry(
uint8_t *pdu,
struct in_addr *address,
uint16_t port,
struct in_addr *mask)
{
int len = 0;
if (pdu) {
len = bvlc_encode_bip_address(pdu, address, port);
len += encode_unsigned32(&pdu[len], mask->s_addr);
}
return len;
}
int bvlc_encode_bvlc_result(
uint8_t *pdu,
BACNET_BVLC_RESULT result_code)
@@ -79,38 +179,6 @@ int bvlc_encode_write_bdt_init(
return len;
}
int bvlc_encode_address(
uint8_t *pdu,
struct in_addr *address, /* in host format */
uint16_t port)
{
int len = 0;
if (pdu) {
len = encode_unsigned32(&pdu[0], address->s_addr);
len += encode_unsigned16(&pdu[len], port);
}
return len;
}
/* used for both read and write entries */
int bvlc_encode_address_entry(
uint8_t *pdu,
struct in_addr *address,
uint16_t port,
struct in_addr *mask)
{
int len = 0;
if (pdu) {
len = bvlc_encode_address(pdu, address, port);
len += encode_unsigned32(&pdu[len], mask->s_addr);
}
return len;
}
int bvlc_encode_read_bdt(
uint8_t *pdu)
{
@@ -268,7 +336,7 @@ int bvlc_encode_distribute_broadcast_to_network(
if (pdu) {
pdu[0] = BVLL_TYPE_BACNET_IP;
pdu[1] = BVLC_FORWARDED_NPDU;
pdu[1] = BVLC_DISTRIBUTE_BROADCAST_TO_NETWORK;
/* The 2-octet BVLC Length field is the length, in octets,
of the entire BVLL message, including the two octets of the
length field itself, most significant octet first. */
@@ -330,24 +398,192 @@ int bvlc_encode_original_broadcast_npdu(
return len;
}
void bvlc_handler(uint8_t *buf, int len, struct sockaddr_in *sin)
/* copy the source internet address to the BACnet address */
/* FIXME: IPv6? */
/* FIXME: is sockaddr_in host or network order? */
void bvlc_internet_to_bacnet_address
BACNET_ADDRESS * src, /* returns the BACnet source address */
struct sockaddr_in * sin) /* source internet address */
{
int function_type = 0;
int len = 0;
if (src && sin)
{
len = encode_unsigned32(&src->mac[0], sin->sin_addr.s_addr);
len += encode_unsigned16(&src->mac[4], sin->sin_port);
src->mac_len = len;
src->net = 0;
src->len = 0;
}
return;
}
/* copy the source internet address to the BACnet address */
/* FIXME: IPv6? */
/* FIXME: is sockaddr_in host or network order? */
void bvlc_bacnet_to_internet_address
struct sockaddr_in * sin, /* source internet address */
BACNET_ADDRESS * src) /* returns the BACnet source address */
{
int len = 0;
if (src && sin)
{
if (src->mac_len == 6)
{
len = decode_unsigned32(&src->mac[0], &sin->sin_addr.s_addr);
len += decode_unsigned16(&src->mac[4], &sin->sin_port);
}
}
return;
}
void bvlc_bdt_forward_npdu(
struct sockaddr_in *sin, /* the source address */
uint8_t * npdu, /* the NPDU */
uint16_t npdu_length) /* length of the NPDU */
{
uint8_t mtu[MAX_MPDU] = { 0 };
int mtu_len = 0;
int bytes_sent = 0;
unsigned i = 0; /* loop counter */
/* assumes that the driver has already been initialized */
if (BIP_Socket < 0)
return BIP_Socket;
mtu_len = bvlc_encode_forwarded_npdu(
&mtu[0],
src,
npdu,
npdu_length);
/* loop through the BDT and send one to each entry, except us */
for (i = 0; i < MAX_BBMD_ENTRIES; i++)
{
if (BBMD_Table[i].valid)
{
/* The B/IP address to which the Forwarded-NPDU message is
sent is formed by inverting the broadcast distribution
mask in the BDT entry and logically ORing it with the
BBMD address of the same entry. */
/* Send the packet */
bytes_sent = sendto(BIP_Socket, (char *) mtu, mtu_len, 0,
(struct sockaddr *) bip_dest, sizeof(struct sockaddr));
}
return bytes_sent;
}
void bvlc_fdt_forward_npdu(
struct sockaddr_in *sin, /* the source address */
uint8_t * npdu, /* returns the NPDU */
uint16_t max_npdu) /* amount of space available in the NPDU */
{
}
uint16_t bvlc_handler(
BACNET_ADDRESS * src, /* returns the source address */
uint8_t * npdu, /* returns the NPDU */
uint16_t max_npdu, /* amount of space available in the NPDU */
unsigned timeout) /* number of milliseconds to wait for a packet */
{
int received_bytes;
uint8_t buf[MAX_MPDU] = { 0 }; /* data */
uint16_t pdu_len = 0; /* return value */
fd_set read_fds;
int max;
struct timeval select_timeout;
struct sockaddr_in sin = { -1 };
socklen_t sin_len = sizeof(sin);
int function_type = 0;
/* Make sure the socket is open */
if (BIP_Socket < 0)
return 0;
/* we could just use a non-blocking socket, but that consumes all
the CPU time. We can use a timeout; it is only supported as
a select. */
if (timeout >= 1000) {
select_timeout.tv_sec = timeout / 1000;
select_timeout.tv_usec =
1000 * (timeout - select_timeout.tv_sec * 1000);
} else {
select_timeout.tv_sec = 0;
select_timeout.tv_usec = 1000 * timeout;
}
FD_ZERO(&read_fds);
FD_SET((unsigned int) BIP_Socket, &read_fds);
max = BIP_Socket;
/* see if there is a packet for us */
if (select(max + 1, &read_fds, NULL, NULL, &select_timeout) > 0)
received_bytes = recvfrom(BIP_Socket,
(char *) &buf[0], MAX_MPDU, 0,
(struct sockaddr *) &sin, &sin_len);
else
return 0;
/* See if there is a problem */
if (received_bytes < 0) {
return 0;
}
/* no problem, just no bytes */
if (received_bytes == 0)
return 0;
/* the signature of a BACnet/IP packet */
if (buf[0] != BVLL_TYPE_BACNET_IP)
return;
return 0;
function_type = buf[1];
/* decode the length of the PDU - length is inclusive of BVLC */
(void)decode_unsigned16(&buf[2], &npdu_len);
/* subtract off the BVLC header */
npdu_len -= 4;
switch (function_type)
{
case BVLC_RESULT:
break;
case BVLC_WRITE_BROADCAST_DISTRIBUTION_TABLE:
/* Upon receipt of a BVLL Write-Broadcast-Distribution-Table
message, a BBMD shall attempt to create or replace its BDT,
depending on whether or not a BDT has previously existed.
If the creation or replacement of the BDT is successful, the BBMD
shall return a BVLC-Result message to the originating device with
a result code of X'0000'. Otherwise, the BBMD shall return a
BVLC-Result message to the originating device with a result code
of X'0010' indicating that the write attempt has failed. */
break;
case BVLC_READ_BROADCAST_DISTRIBUTION_TABLE:
break;
case BVLC_READ_BROADCAST_DISTRIBUTION_TABLE_ACK:
break;
case BVLC_FORWARDED_NPDU:
/* Upon receipt of a BVLL Forwarded-NPDU message, a BBMD shall
process it according to whether it was received from a peer
BBMD as the result of a directed broadcast or a unicast
transmission. A BBMD may ascertain the method by which Forwarded-
NPDU messages will arrive by inspecting the broadcast distribution
mask field in its own BDT entry since all BDTs are required
to be identical. If the message arrived via directed broadcast,
it was also received by the other devices on the BBMD's subnet. In
this case the BBMD merely retransmits the message directly to each
foreign device currently in the BBMD's FDT. If the
message arrived via a unicast transmission it has not yet been
received by the other devices on the BBMD's subnet. In this case,
the message is sent to the devices on the BBMD's subnet using the
B/IP broadcast address as well as to each foreign device
currently in the BBMD's FDT. A BBMD on a subnet with no other
BACnet devices may omit the broadcast using the B/IP
broadcast address. The method by which a BBMD determines whether
or not other BACnet devices are present is a local matter. */
bvlc_broadcast_npdu(&sin, &buf[4], npdu_len);
bvlc_fdt_forward_npdu(&sin, &buf[4], npdu_len);
break;
case BVLC_REGISTER_FOREIGN_DEVICE:
break;
@@ -358,14 +594,55 @@ void bvlc_handler(uint8_t *buf, int len, struct sockaddr_in *sin)
case BVLC_DELETE_FOREIGN_DEVICE_TABLE_ENTRY:
break;
case BVLC_DISTRIBUTE_BROADCAST_TO_NETWORK:
bvlc_broadcast_forward_npdu(&sin, &buf[4], npdu_len);
bvlc_fdt_forward_npdu(&sin, &buf[4], npdu_len);
break;
case BVLC_ORIGINAL_UNICAST_NPDU:
/* ignore messages from me */
if (sin.sin_addr.s_addr == BIP_Address.s_addr)
npdu_len = 0;
else {
bvlc_internet_to_bacnet_address(src,&sin);
/* copy the buffer into the PDU */
if (npdu_len < max_npdu)
memmove(&npdu[0], &buf[4], npdu_len);
/* ignore packets that are too large */
/* clients should check my max-apdu first */
else
npdu_len = 0;
}
break;
case BVLC_ORIGINAL_BROADCAST_NPDU:
/* Upon receipt of a BVLL Original-Broadcast-NPDU message,
a BBMD shall construct a BVLL Forwarded-NPDU message and
send it to each IP subnet in its BDT with the exception
of its own. The B/IP address to which the Forwarded-NPDU
message is sent is formed by inverting the broadcast
distribution mask in the BDT entry and logically ORing it
with the BBMD address of the same entry. This process
produces either the directed broadcast address of the remote
subnet or the unicast address of the BBMD on that subnet
depending on the contents of the broadcast distribution
mask. See J.4.3.2.. In addition, the received BACnet NPDU
shall be sent directly to each foreign device currently in
the BBMD's FDT also using the BVLL Forwarded-NPDU message. */
bvlc_internet_to_bacnet_address(src,&sin);
/* copy the buffer into the PDU */
if (npdu_len < max_npdu)
memmove(&npdu[0], &buf[4], npdu_len);
/* ignore packets that are too large */
/* clients should check my max-apdu first */
else
npdu_len = 0;
/* if BDT or FDT entries exist, Forward the NPDU */
bvlc_bdt_forward_npdu(&sin, &buf[4], npdu_len);
bvlc_fdt_forward_npdu(&sin, &buf[4], npdu_len);
break;
default:
break;
}
return;
return npdu_len;
}
#ifdef TEST
bacnet-stack/bvlc.h
+1
View File
@@ -42,6 +42,7 @@
extern "C" {
#endif /* __cplusplus */
/* called from BACnet/IP handler */
void bvlc_handler(uint8_t *buf, int len, struct sockaddr_in *sin);
#ifdef __cplusplus