update LwIP BACnet/IP abstraction (#246)

* update LwIP BACnet/IP abstraction. Integrate LwIP build with continuous integration.

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

.github/workflows/gcc.yml

@@ -168,6 +168,19 @@ jobs:
         make atmega168
         make bdk-atxx4-mstp
 
+  ports-lwip:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Create Build Environment
+      run: |
+        sudo apt-get update -qq
+        sudo apt-get install -qq build-essential
+        sudo apt-get install -qq liblwip-dev
+    - name: ports-lwip
+      run: |
+        make lwip
+
   mingw:
     runs-on: ubuntu-latest
     steps:

Makefile

@@ -191,6 +191,10 @@ stm32f4xx-clean: ports/stm32f4xx/Makefile
 mstpsnap: ports/linux/mstpsnap.mak
 	$(MAKE) -s -C ports/linux -f mstpsnap.mak clean all
 
+.PHONY: lwip
+lwip: ports/lwip/Makefile
+	$(MAKE) -s -C ports/lwip clean all
+
 .PHONY: pretty
 pretty:
 	find ./src -iname *.h -o -iname *.c -exec \
@@ -252,6 +256,7 @@ clean: ports-clean
 	$(MAKE) -s -C apps/router-ipv6 clean
 	$(MAKE) -s -C apps/router-mstp clean
 	$(MAKE) -s -C apps/gateway clean
+	$(MAKE) -s -C ports/lwip clean
 	$(MAKE) -s -C test clean
 	rm -rf ./build
 

ports/lwip/Makefile

@@ -0,0 +1,35 @@
+# Makefile to build BACnet/IP LwIP library
+
+# Executable file name
+TARGET = bip-lwip
+
+SRC = bip.c
+
+BACNET_DIR = ../../src
+LWIP_DIR = /usr/include/lwip
+
+CFLAGS += -I$(LWIP_DIR) -I$(BACNET_DIR)
+
+OBJS += ${SRC:.c=.o}
+
+all: Makefile $(TARGET)
+
+lib: $(TARGET)
+
+$(TARGET): $(OBJS) Makefile
+	${AR} rcs $@ $(OBJS)
+
+.c.o:
+	${CC} -c ${CFLAGS} $*.c -o $@
+
+.PHONY: depend
+depend:
+	rm -f .depend
+	${CC} -MM ${CFLAGS} *.c >> .depend
+
+.PHONY: clean
+clean:
+	-rm -f core ${TARGET} ${OBJS} $(TARGET).map
+
+.PHONY: include
+include: .depend

ports/lwip/bacport.h

@@ -0,0 +1,39 @@
+/**************************************************************************
+*
+* Copyright (C) 2020 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.
+*
+*********************************************************************/
+
+#ifndef BACPORT_H
+#define BACPORT_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include "lwip/def.h"
+#include "lwip/udp.h"
+#include "lwip/memp.h"
+#include "netif/etharp.h"
+#include "lwip/dhcp.h"
+#include "lwip/inet.h"
+
+#endif

ports/lwip/bip.c

@@ -39,17 +39,17 @@
 #include "bacnet/datalink/bip.h"
 #include "bacnet/datalink/bvlc.h"
 #include "bacnet/basic/services.h"
+#include "bacnet/basic/bbmd/h_bbmd.h"
 #include "bacport.h" /* custom per port */
 
 /** @file bip.c  Configuration and Operations for BACnet/IP */
 
 /* port to use - stored in network byte order */
-static uint16_t BIP_Port = 0xBAC0U;
 static bool BIP_Port_Changed;
-/* IP Address - stored in network byte order */
+/* IP Address */
-static struct in_addr BIP_Address;
+static BACNET_IP_ADDRESS BIP_Address;
-/* Broadcast Address - stored in network byte order */
+/* Broadcast Address */
-static struct in_addr BIP_Broadcast_Address;
+static BACNET_IP_ADDRESS BIP_Broadcast_Address;
 /* lwIP socket, of sorts */
 static struct udp_pcb *Server_upcb;
 /* track packets for diagnostics */
@@ -61,41 +61,71 @@ struct bacnet_stats {
 struct bacnet_stats BIP_Stats;
 #define BIP_STATS_INC(x) ++BIP_Stats.x
 
+/**
+ * @brief Get the BACnet/IP transmit stats
+ * @return number of BACnet/IP transmitted packets
+ */
 uint32_t bip_stats_xmit(void)
 {
     return BIP_Stats.xmit;
 }
 
+/**
+ * @brief Get the BACnet/IP received stats
+ * @return number of BACnet/IP received packets
+ */
 uint32_t bip_stats_recv(void)
 {
     return BIP_Stats.recv;
 }
 
+/**
+ * @brief Get the BACnet/IP drop stats
+ * @return number of BACnet/IP drops
+ */
 uint32_t bip_stats_drop(void)
 {
     return BIP_Stats.drop;
 }
 
-void bip_set_addr(uint32_t net_address)
+/**
-{ /* in network byte order */
+ * @brief Set the BACnet/IP address
-    BIP_Address.s_addr = net_address;
+ * @param addr - network IPv4 address
-}
+ * @return true if the address is set
-
+ */
-/* returns network byte order */
+bool bip_set_addr(BACNET_IP_ADDRESS *addr)
-uint32_t bip_get_addr(void)
 {
-    return BIP_Address.s_addr;
+    return bvlc_address_copy(&BIP_Address, addr);
 }
 
-void bip_set_broadcast_addr(uint32_t net_address)
+/**
-{ /* in network byte order */
+ * @brief Get the BACnet/IP address
-    BIP_Broadcast_Address.s_addr = net_address;
+ * @param network IPv4 address
-}
+ * @return true if the address is set
-
+ */
-/* returns network byte order */
+bool bip_get_addr(BACNET_IP_ADDRESS *addr)
-uint32_t bip_get_broadcast_addr(void)
 {
-    return BIP_Broadcast_Address.s_addr;
+    return bvlc_address_copy(addr, &BIP_Address);
+}
+
+/**
+ * @brief Set the BACnet/IP broadcast address
+ * @param network IPv4 broadcast address
+ * @return true if the broadcast address is retrieved
+ */
+bool bip_set_broadcast_addr(BACNET_IP_ADDRESS *addr)
+{
+    return bvlc_address_copy(&BIP_Broadcast_Address, addr);
+}
+
+/**
+ * @brief Get the BACnet/IP broadcast address
+ * @param network IPv4 broadcast address
+ * @return true if the broadcast address is set
+ */
+bool bip_get_broadcast_addr(BACNET_IP_ADDRESS *addr)
+{
+    return bvlc_address_copy(addr, &BIP_Broadcast_Address);
 }
 
 /**
@@ -104,24 +134,36 @@ uint32_t bip_get_broadcast_addr(void)
  */
 void bip_set_port(uint16_t port)
 {
-    if (BIP_Port != htons(port)) {
+    if (BIP_Address.port != htons(port)) {
         BIP_Port_Changed = true;
-        BIP_Port = htons(port);
+        BIP_Address.port = htons(port);
     }
 }
 
+/**
+ * @brief Determine if the BACnet IPv4 UDP port number changed
+ * @return true of the BACnet IPv4 UDP port number changed
+ */
 bool bip_port_changed(void)
 {
     return BIP_Port_Changed;
 }
 
-/* returns host byte order */
+/**
+ * @brief Get the BACnet IPv4 UDP port number
+ * @return IPv4 UDP port number - in host byte order
+ */
 uint16_t bip_get_port(void)
 {
-    return ntohs(BIP_Port);
+    return ntohs(BIP_Address.port);
 }
 
-static void bip_mac_to_addr(struct ip_addr *address, uint8_t *mac)
+/**
+ * @brief Convert the BACnet IPv4 address
+ * @param address - IPv4 address from LwIP
+ * @param mac - IP address from BACnet/IP
+ */
+static void bip_mac_to_addr(ip4_addr_t *address, uint8_t *mac)
 {
     if (mac && address) {
         address->addr = ((u32_t)((((uint32_t)mac[0]) << 24) & 0xff000000));
@@ -131,7 +173,34 @@ static void bip_mac_to_addr(struct ip_addr *address, uint8_t *mac)
     }
 }
 
-static void bip_addr_to_mac(uint8_t *mac, struct ip_addr *address)
+/**
+ * @brief Convert from a BACnet/IP address
+ * @param baddr - BACnet/IP address
+ * @param address - IPv4 address from LwIP
+ * @param port - IPv4 UDP port number
+ */
+static int bip_decode_bip_address(BACNET_IP_ADDRESS *baddr,
+    ip_addr_t *address,
+    uint16_t *port)
+{
+    int len = 0;
+
+    if (baddr && address && port) {
+        address->type = IPADDR_TYPE_V4;
+        bip_mac_to_addr(&address->u_addr.ip4, &baddr->address[0]);
+        *port = baddr->port;
+        len = 6;
+    }
+
+    return len;
+}
+
+/**
+ * @brief Convert the BACnet IPv4 address
+ * @param mac - IP address from BACnet/IP
+ * @param address - IPv4 address from LwIP
+ */
+static void bip_addr_to_mac(uint8_t *mac, const ip4_addr_t *address)
 {
     if (mac && address) {
         mac[0] = (uint8_t)(address->addr >> 24);
@@ -141,16 +210,24 @@ static void bip_addr_to_mac(uint8_t *mac, struct ip_addr *address)
     }
 }
 
-static int bip_decode_bip_address(BACNET_ADDRESS *bac_addr,
+/**
-    struct ip_addr *address, /* in network format */
+ * @brief Convert to a BACnet/IP address
-    uint16_t *port)
+ * @param baddr - BACnet/IP address
-{ /* in network format */
+ * @param address - IPv4 address from LwIP
+ * @param port - IPv4 UDP port number
+ */
+static int bip_encode_bip_address(BACNET_IP_ADDRESS *baddr,
+    const ip_addr_t *address,
+    uint16_t port)
+{
     int len = 0;
 
-    if (bac_addr) {
+    if (baddr && address) {
-        bip_mac_to_addr(address, &bac_addr->mac[0]);
+        if (address->type == IPADDR_TYPE_V4) {
-        memcpy(port, &bac_addr->mac[4], 2);
+            bip_addr_to_mac(&baddr->address[0], &address->u_addr.ip4);
-        len = 6;
+            baddr->port = port;
+            len = 6;
+        }
     }
 
     return len;
@@ -159,26 +236,35 @@ static int bip_decode_bip_address(BACNET_ADDRESS *bac_addr,
 /** Function to send a packet out the BACnet/IP socket (Annex J).
  * @ingroup DLBIP
  *
- * @param dst_ip [in] Destination address
+ * @param dest [in] Destination address
  * @param port [in] UDP port number
- * @param pkt [in] PBUF packet
+ * @param mtu_len [in] PBUF packet
- *
+ * @return number of bytes sent, or 0 on failure.
- * @return true if the packet was sent
  */
-static bool bip_send_mpdu(
+int bip_send_mpdu(
-    struct ip_addr *dst_ip, uint16_t port, struct pbuf *pkt)
+    BACNET_IP_ADDRESS *dest, uint8_t *mtu, uint16_t mtu_len)
 {
+    struct pbuf *pkt = NULL;
+    /* addr and port in host format */
+    ip_addr_t dst_ip;
+    uint16_t port = 0;
     err_t status = ERR_OK;
 
-    /* Send the packet */
+    pkt = pbuf_alloc(PBUF_TRANSPORT, mtu_len, PBUF_POOL);
-    status = udp_sendto(Server_upcb, pkt, dst_ip, port);
+    if (pkt == NULL) {
-    /* free the buffer pbuf */
+        return 0;
-    pbuf_free(pkt);
+    }
+    bip_decode_bip_address(dest, &dst_ip, &port);
+    pbuf_take(pkt, mtu, mtu_len);
+    status = udp_sendto(Server_upcb, pkt, &dst_ip, port);
     if (status == ERR_OK) {
         BIP_STATS_INC(xmit);
+    } else {
+        mtu_len = 0;
     }
+    pbuf_free(pkt);
 
-    return (status == ERR_OK);
+    return mtu_len;
 }
 
 /** Send the Original Broadcast or Unicast messages
@@ -195,77 +281,7 @@ int bip_send_pdu(BACNET_ADDRESS *dest, /* destination address */
     uint8_t *pdu, /* any data to be sent - may be null */
     unsigned pdu_len)
 {
-    struct pbuf *pkt = NULL, *pkt0 = NULL;
+    return bvlc_send_pdu(dest, npdu_data, pdu, pdu_len);
-    uint8_t mtu[4] = { 0 };
-    int mtu_len = 0;
-    /* addr and port in host format */
-    struct ip_addr dst_ip;
-    uint16_t port = 0;
-    err_t status = ERR_OK;
-
-    pkt0 = pbuf_alloc(PBUF_TRANSPORT, 4, PBUF_POOL);
-    if (pkt0 == NULL) {
-        return 0;
-    }
-    pkt = pbuf_alloc(PBUF_TRANSPORT, pdu_len, PBUF_POOL);
-    if (pkt == NULL) {
-        pbuf_free(pkt0);
-        return 0;
-    }
-    mtu[0] = BVLL_TYPE_BACNET_IP;
-    if (dest->net == BACNET_BROADCAST_NETWORK) {
-        /* broadcast */
-        dst_ip.addr = BIP_Broadcast_Address.s_addr;
-        port = BIP_Port;
-        mtu[1] = BVLC_ORIGINAL_BROADCAST_NPDU;
-    } else if (dest->mac_len == 6) {
-        /* unicast */
-        bip_decode_bip_address(dest, &dst_ip, &port);
-        mtu[1] = BVLC_ORIGINAL_UNICAST_NPDU;
-    } else {
-        /* invalid address */
-        return -1;
-    }
-    mtu_len = pdu_len + 4 /*inclusive */;
-    encode_unsigned16(&mtu[2], mtu_len);
-    pbuf_take(pkt0, mtu, 4);
-    pbuf_take(pkt, pdu, pdu_len);
-    pbuf_cat(pkt0, pkt);
-    status = bip_send_mpdu(&dst_ip, port, pkt0);
-    if (!status) {
-        mtu_len = 0;
-    }
-
-    return mtu_len;
-}
-
-/** Send the BVLC Result message
- *
- * @param addr [in] Destination address
- * @param result_code - BVLC result code
- *
- * @return number of bytes encoded
- */
-static bool bvlc_send_result(struct ip_addr *addr, uint16_t result_code)
-{
-    struct pbuf *pkt = NULL;
-    uint8_t mtu[6] = { 0 };
-    uint16_t mtu_len = 6;
-
-    pkt = pbuf_alloc(PBUF_TRANSPORT, mtu_len, PBUF_POOL);
-    if (pkt == NULL) {
-        return 0;
-    }
-    mtu[0] = BVLL_TYPE_BACNET_IP;
-    mtu[1] = BVLC_RESULT;
-    /* 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. */
-    encode_unsigned16(&mtu[2], 6);
-    encode_unsigned16(&mtu[4], result_code);
-    pbuf_take(pkt, mtu, mtu_len);
-
-    return bip_send_mpdu(addr, BIP_Port, pkt);
 }
 
 /** LwIP BACnet service callback
@@ -279,99 +295,24 @@ static bool bvlc_send_result(struct ip_addr *addr, uint16_t result_code)
 void bip_server_callback(void *arg,
     struct udp_pcb *upcb,
     struct pbuf *pkt,
-    struct ip_addr *addr,
+    const ip_addr_t *addr,
     u16_t port)
 {
     uint8_t function = 0;
-    uint16_t pdu_len = 0;
+    uint16_t npdu_offset = 0;
-    uint16_t pdu_offset = 0;
     BACNET_ADDRESS src = { 0 }; /* address where message came from */
-    struct ip_addr sin_addr;
+    BACNET_IP_ADDRESS saddr;
-    uint16_t sin_port = 0;
+    uint8_t *npdu = (uint8_t *) pkt->payload;
-    uint8_t *pdu = (uint8_t *)pkt->payload;
+    uint16_t npdu_len = pkt->tot_len;
 
-    /* the signature of a BACnet/IP packet */
+    bip_encode_bip_address(&saddr, addr, port);
-    if ((pkt->tot_len >= 2) &&
+    npdu_offset = bvlc_handler(&saddr, &src, npdu, npdu_len);
-        (pdu[0] == BVLL_TYPE_BACNET_IP)) {
+    if (npdu_offset > 0) {
-        function = pdu[1];
+        BIP_STATS_INC(recv);
-        if ((function == BVLC_ORIGINAL_UNICAST_NPDU) ||
+        npdu_len -= npdu_offset;
-            (function == BVLC_ORIGINAL_BROADCAST_NPDU)) {
+        npdu_handler(&src, &npdu[npdu_offset], npdu_len);
-            /* ignore messages from me */
+    } else {
-            if ((addr->addr == BIP_Address.s_addr) && (port == BIP_Port)) {
+        BIP_STATS_INC(drop);
-                pdu_len = 0;
-            } else if (pkt->tot_len >= 4) {
-                /* data in src->mac[] is in network format */
-                src.mac_len = 6;
-                bip_addr_to_mac(&src.mac[0], addr);
-                memcpy(&src.mac[4], &port, 2);
-                /* decode the length of the PDU
-                   length is inclusive of BVLC */
-                (void)decode_unsigned16(&pdu[2], &pdu_len);
-                if (pdu_len > pkt->tot_len) {
-                    /* BVLC length is too long - someone is lying */
-                    pdu_len = 0;
-                } else {
-                    /* subtract off the BVLC header */
-                    pdu_len -= 4;
-                    pdu_offset = 4;
-                }
-            }
-        } else if (function == BVLC_FORWARDED_NPDU) {
-            if (pkt->tot_len >= 10) {
-                IP4_ADDR(&sin_addr, pdu[4], pdu[5], pdu[6], pdu[7]);
-                decode_unsigned16(&pdu[8], &sin_port);
-                if ((sin_addr.addr == BIP_Address.s_addr) &&
-                    (sin_port == BIP_Port)) {
-                    /* ignore forwarded messages from me */
-                    pdu_len = 0;
-                } else {
-                    /* data in src->mac[] is in network format */
-                    src.mac_len = 6;
-                    bip_addr_to_mac(&src.mac[0], &sin_addr);
-                    memcpy(&src.mac[4], &sin_port, 2);
-                    /* decode the length of the PDU
-                       length is inclusive of BVLC */
-                    (void)decode_unsigned16(&pdu[2], &pdu_len);
-                    if (pdu_len > pkt->tot_len) {
-                        /* BVLC length is too long - someone is lying */
-                        pdu_len = 0;
-                    } else {
-                        /* subtract off the BVLC header */
-                        pdu_len -= 10;
-                        pdu_offset = 10;
-                    }
-                }
-            }
-        } else if (function == BVLC_WRITE_BROADCAST_DISTRIBUTION_TABLE) {
-            bvlc_send_result(
-                addr, BVLC_RESULT_WRITE_BROADCAST_DISTRIBUTION_TABLE_NAK);
-        } else if (function == BVLC_READ_BROADCAST_DIST_TABLE) {
-            bvlc_send_result(
-                addr, BVLC_RESULT_READ_BROADCAST_DISTRIBUTION_TABLE_NAK);
-        } else if (function == BVLC_REGISTER_FOREIGN_DEVICE) {
-            bvlc_send_result(addr, BVLC_RESULT_REGISTER_FOREIGN_DEVICE_NAK);
-        } else if (function == BVLC_READ_FOREIGN_DEVICE_TABLE) {
-            bvlc_send_result(addr, BVLC_RESULT_READ_FOREIGN_DEVICE_TABLE_NAK);
-        } else if (function == BVLC_DELETE_FOREIGN_DEVICE_TABLE_ENTRY) {
-            bvlc_send_result(
-                addr, BVLC_RESULT_DELETE_FOREIGN_DEVICE_TABLE_ENTRY_NAK);
-        } else if (function == BVLC_DISTRIBUTE_BROADCAST_TO_NETWORK) {
-            bvlc_send_result(addr, BVLC_RESULT_DISTRIBUTE_BROADCAST_TO_NETWORK_NAK);
-        }
-        if (pdu_len) {
-            BIP_STATS_INC(recv);
-            if ((function == BVLC_ORIGINAL_BROADCAST_NPDU) &&
-                (npdu_confirmed_service(&pdu[pdu_offset], pdu_len))) {
-                /* BTL test: verifies that the IUT will quietly discard any
-                   Confirmed-Request-PDU, whose destination address is a
-                   multicast or broadcast address, received from the
-                   network layer. */
-            } else {
-                npdu_handler(&src, &pdu[pdu_offset], pdu_len);
-            }
-        } else {
-            BIP_STATS_INC(rxdrop);
-        }
     }
     /* free our packet */
     pbuf_free(pkt);
@@ -383,8 +324,8 @@ void bip_get_my_address(BACNET_ADDRESS *my_address)
 
     if (my_address) {
         my_address->mac_len = 6;
-        memcpy(&my_address->mac[0], &BIP_Address.s_addr, 4);
+        memcpy(&my_address->mac[0], &BIP_Address.address, 4);
-        memcpy(&my_address->mac[4], &BIP_Port, 2);
+        memcpy(&my_address->mac[4], &BIP_Address.port, 2);
         my_address->net = 0; /* local only, no routing */
         my_address->len = 0; /* no SLEN */
         for (i = 0; i < MAX_MAC_LEN; i++) {
@@ -402,8 +343,8 @@ void bip_get_broadcast_address(BACNET_ADDRESS *dest)
 
     if (dest) {
         dest->mac_len = 6;
-        memcpy(&dest->mac[0], &BIP_Broadcast_Address.s_addr, 4);
+        memcpy(&dest->mac[0], &BIP_Broadcast_Address.address, 4);
-        memcpy(&dest->mac[4], &BIP_Port, 2);
+        memcpy(&dest->mac[4], &BIP_Address.port, 2);
         dest->net = BACNET_BROADCAST_NETWORK;
         dest->len = 0; /* no SLEN */
         for (i = 0; i < MAX_MAC_LEN; i++) {
@@ -438,12 +379,13 @@ bool bip_init(char *ifname)
     /* Create a new UDP control block  */
     Server_upcb = udp_new();
     if (Server_upcb == NULL) {
-        /* increase MEMP_NUM_UDP_PCB in lwipopts.h */
+        while (1) {
-        while (1) { };
+            /* fixme: increase MEMP_NUM_UDP_PCB in lwipopts.h */
+        };
     }
     /* Bind the upcb to the UDP_PORT port */
     /* Using IP_ADDR_ANY allow the upcb to be used by any local interface */
-    udp_bind(Server_upcb, IP_ADDR_ANY, BIP_Port);
+    udp_bind(Server_upcb, IP_ADDR_ANY, BIP_Address.port);
     /* Set a receive callback for the upcb */
     udp_recv(Server_upcb, bip_server_callback, NULL);