Fixed the Network Port object subnet mask for IP example. (#573)

ports/bsd/bip-init.c

@@ -257,7 +257,6 @@ uint8_t bip_get_subnet_prefix(void)
 {
     uint32_t address = 0;
     uint32_t broadcast = 0;
-    uint32_t test_broadcast = 0;
     uint32_t mask = 0xFFFFFFFE;
     uint8_t prefix = 0;
 
@@ -265,8 +264,7 @@ uint8_t bip_get_subnet_prefix(void)
     broadcast = BIP_Broadcast_Addr.s_addr;
     /* calculate the subnet prefix from the broadcast address */
     for (prefix = 1; prefix <= 32; prefix++) {
-        test_broadcast = (address & mask) | (~mask);
-        if (test_broadcast == broadcast) {
+        if ((address | mask) == broadcast) {
             break;
         }
         mask = mask << 1;

ports/linux/bip-init.c

@@ -272,7 +272,6 @@ uint8_t bip_get_subnet_prefix(void)
 {
     uint32_t address = 0;
     uint32_t broadcast = 0;
-    uint32_t test_broadcast = 0;
     uint32_t mask = 0xFFFFFFFE;
     uint8_t prefix = 0;
 
@@ -280,8 +279,7 @@ uint8_t bip_get_subnet_prefix(void)
     broadcast = BIP_Broadcast_Addr.s_addr;
     /* calculate the subnet prefix from the broadcast address */
     for (prefix = 1; prefix <= 32; prefix++) {
-        test_broadcast = (address & mask) | (~mask);
-        if (test_broadcast == broadcast) {
+        if ((address | mask) == broadcast) {
             break;
         }
         mask = mask << 1;

ports/win32/bip-init.c

@@ -412,16 +412,14 @@ uint8_t bip_get_subnet_prefix(void)
 {
     uint32_t address = 0;
     uint32_t broadcast = 0;
-    uint32_t test_broadcast = 0;
     uint32_t mask = 0xFFFFFFFE;
     uint8_t prefix = 0;
 
-    address = BIP_Broadcast_Addr.s_addr;
+    address = BIP_Address.s_addr;
     broadcast = BIP_Broadcast_Addr.s_addr;
     /* calculate the subnet prefix from the broadcast address */
     for (prefix = 1; prefix <= 32; prefix++) {
-        test_broadcast = (address & mask) | (~mask);
-        if (test_broadcast == broadcast) {
+        if ((address | mask) == broadcast) {
             break;
         }
         mask = mask << 1;

ports/zephyr/bip-init.c

@@ -247,7 +247,6 @@ uint8_t bip_get_subnet_prefix(void)
 {
     uint32_t address = 0;
     uint32_t broadcast = 0;
-    uint32_t test_broadcast = 0;
     uint32_t mask = 0xFFFFFFFE;
     uint8_t prefix = 0;
 
@@ -255,8 +254,7 @@ uint8_t bip_get_subnet_prefix(void)
     broadcast = BIP_Broadcast_Addr.s_addr;
     /* calculate the subnet prefix from the broadcast address */
     for (prefix = 1; prefix <= 32; prefix++) {
-        test_broadcast = (address & mask) | (~mask);
-        if (test_broadcast == broadcast) {
+        if ((address | mask) == broadcast) {
             break;
         }
         mask = mask<<1;

src/bacnet/basic/object/netport.c

@@ -938,7 +938,7 @@ bool Network_Port_IP_Subnet(
     bool status = false;
     uint32_t mask = 0;
     uint32_t prefix = 0;
-    uint8_t ip_mask[4] = { 0 };
+    uint8_t ip_mask[4] = { 255, 255, 255, 255 };
 
     index = Network_Port_Instance_To_Index(object_instance);
     if (index < BACNET_NETWORK_PORTS_MAX) {
@@ -947,9 +947,8 @@ bool Network_Port_IP_Subnet(
             if ((prefix > 0) && (prefix <= 32)) {
                 mask = (0xFFFFFFFF << (32 - prefix)) & 0xFFFFFFFF;
                 encode_unsigned32(ip_mask, mask);
-                status =
-                    octetstring_init(subnet_mask, ip_mask, sizeof(ip_mask));
             }
+            status = octetstring_init(subnet_mask, ip_mask, sizeof(ip_mask));
         }
     }
 

src/bacnet/datalink/dlenv.c

@@ -357,6 +357,7 @@ void dlenv_network_port_init(void)
 {
     const uint32_t instance = 1;
     BACNET_IP_ADDRESS addr = { 0 };
+    uint8_t prefix = 0;
 #if BBMD_ENABLED
     uint8_t addr0, addr1, addr2, addr3;
 #endif
@@ -365,9 +366,22 @@ void dlenv_network_port_init(void)
     Network_Port_Name_Set(instance, "BACnet/IP Port");
     Network_Port_Type_Set(instance, PORT_TYPE_BIP);
     bip_get_addr(&addr);
+    prefix = bip_get_subnet_prefix();
+    if (BIP_DL_Debug) {
+        fprintf(stderr,
+            "BIP: Setting Network Port %lu address %u.%u.%u.%u:%u/%u\n",
+            (unsigned long)instance,
+            (unsigned)addr.address[0],
+            (unsigned)addr.address[1],
+            (unsigned)addr.address[2],
+            (unsigned)addr.address[3],
+            (unsigned)addr.port,
+            (unsigned)prefix);
+    }
     Network_Port_BIP_Port_Set(instance, addr.port);
-    Network_Port_MAC_Address_Set(instance, &addr.address[0], 6);
-    Network_Port_IP_Subnet_Prefix_Set(instance, bip_get_subnet_prefix());
+    Network_Port_IP_Address_Set(instance, addr.address[0], addr.address[1],
+        addr.address[2], addr.address[3]);
+    Network_Port_IP_Subnet_Prefix_Set(instance, prefix);
     Network_Port_Link_Speed_Set(instance, 0.0);
 #if BBMD_ENABLED
     Network_Port_BBMD_BD_Table_Set(instance, bvlc_bdt_list());