Added m option to mstpcrc demo to pass a line of bytes which get encoded into Wireshark pcap file for viewing in Wireshark. Useful when someone sends you a string of bytes from an MS/TP capture and you want to quickly decoding them using Wireshark.

bacnet-stack/demo/Makefile

@@ -47,7 +47,7 @@ LFLAGS = -Wl,$(LIBRARIES)
 
 SUBDIRS = readprop writeprop readfile writefile reinit server dcc \
 	whohas whois ucov scov timesync epics readpropm \
-	mstpcap  uptransfer \
+	mstpcap mstpcrc uptransfer \
 	whoisrouter iamrouter initrouter
 ifeq (${BACNET_PORT},win32)
 SUBDIRS += ptransfer

bacnet-stack/demo/mstpcrc/Makefile

@@ -10,7 +10,7 @@ TARGET = mstpcrc
 TARGET_BIN = ${TARGET}$(TARGET_EXT)
 
 # This demo seems to be a little unique
-BACNET_INCLUDE_DIR = ../../include
+DEFINES = $(BACNET_DEFINES)
 BACNET_SOURCE_DIR = ../../src
 
 #libraries used
@@ -27,14 +27,8 @@ endif
 # search order for included libraries 
 INCLUDES = -I$(BACNET_INCLUDE_DIR)
 
-# any special defines
-DEFINES = 
-
-# put all the flags together
-CFLAGS = -Wall $(DEBUGGING) $(OPTIMIZATION) $(INCLUDES) $(DEFINES)
-LFLAGS = -Wl,$(LIBRARIES)
-
 SRCS = main.c \
+	${BACNET_PORT_DIR}/timer.c \
 	${BACNET_SOURCE_DIR}/crc.c
 
 OBJS = ${SRCS:.c=.o}

bacnet-stack/demo/mstpcrc/main.c

@@ -39,8 +39,13 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <time.h>
 #include <ctype.h>
+/* OS specific include*/
+#include "net.h"
+#include "timer.h"
 /* local includes */
+#include "bytes.h"
 #include "crc.h"
 #include "version.h"
 
@@ -55,6 +60,10 @@ static unsigned CRC_Buffer_Len = 0;
 /* flags needed for options */
 static bool ASCII_Decimal = false;
 static unsigned CRC_Size = 8;
+/* save to capture file for viewing in Wireshark */
+static bool MSTP_Cap = false;
+static char Capture_Filename[32] = "mstp_20090123091200.cap";
+static FILE *pFile = NULL;      /* stream pointer */
 
 /******************************************************************
 * DESCRIPTION:  Takes one of the arguments passed by the main function
@@ -99,6 +108,10 @@ static void Parse_Arguments(int argc, char *argv[])
                 case 'D':
                     ASCII_Decimal = true;
                     break;
+                case 'm':
+                case 'M':
+                    MSTP_Cap = true;
+                    break;
                 default:
                     break;
             }
@@ -115,6 +128,85 @@ static void Parse_Arguments(int argc, char *argv[])
     }
 }
 
+static void filename_create(
+    char *filename)
+{
+    time_t my_time;
+    struct tm *today;
+
+    if (filename) {
+        my_time = time(NULL);
+        today = localtime(&my_time);
+        sprintf(filename, "mstp_%04d%02d%02d%02d%02d%02d.cap",
+            1900 + today->tm_year, 1 + today->tm_mon, today->tm_mday,
+            today->tm_hour, today->tm_min, today->tm_sec);
+    }
+}
+
+/* write packet to file in libpcap format */
+static void write_global_header(
+    const char *filename)
+{
+    uint32_t magic_number = 0xa1b2c3d4; /* magic number */
+    uint16_t version_major = 2; /* major version number */
+    uint16_t version_minor = 4; /* minor version number */
+    int32_t thiszone = 0;       /* GMT to local correction */
+    uint32_t sigfigs = 0;       /* accuracy of timestamps */
+    uint32_t snaplen = 65535;   /* max length of captured packets, in octets */
+    uint32_t network = 165;     /* data link type - BACNET_MS_TP */
+
+    /* create a new file. */
+    pFile = fopen(filename, "wb");
+    if (pFile) {
+        (void)  fwrite(&magic_number, sizeof(magic_number), 1, pFile);
+        (void)  fwrite(&version_major, sizeof(version_major), 1, pFile);
+        (void)  fwrite(&version_minor, sizeof(version_minor), 1, pFile);
+        (void)  fwrite(&thiszone, sizeof(thiszone), 1,  pFile);
+        (void)  fwrite(&sigfigs, sizeof(sigfigs), 1, pFile);
+        (void)  fwrite(&snaplen, sizeof(snaplen), 1, pFile);
+        (void)  fwrite(&network, sizeof(network), 1, pFile);
+        fflush(pFile);
+        fprintf(stdout, "mstpcap: saving capture to %s\n", filename);
+    } else {
+        fprintf(stderr, "mstpcap[header]: failed to open %s: %s\n", filename,
+            strerror(errno));
+    }
+}
+
+static void write_received_packet(uint8_t *buffer, unsigned length)
+{
+    uint32_t ts_sec;    /* timestamp seconds */
+    uint32_t ts_usec;   /* timestamp microseconds */
+    uint32_t incl_len;  /* number of octets of packet saved in file */
+    uint32_t orig_len;  /* actual length of packet */
+    struct timeval tv;
+
+    if (pFile) {
+        gettimeofday(&tv, NULL);
+        ts_sec = tv.tv_sec;
+        ts_usec = tv.tv_usec;
+        (void) fwrite(&ts_sec, sizeof(ts_sec), 1, pFile);
+        (void) fwrite(&ts_usec, sizeof(ts_usec), 1, pFile);
+        orig_len = incl_len = length;
+        (void) fwrite(&incl_len, sizeof(incl_len), 1, pFile);
+        (void) fwrite(&orig_len, sizeof(orig_len), 1, pFile);
+        (void) fwrite(buffer, length, 1, pFile);
+    } else {
+        fprintf(stderr, "mstpcrc[packet]: failed to open %s: %s\n",
+            Capture_Filename, strerror(errno));
+    }
+}
+
+static void Write_Pcap(uint8_t *buffer, unsigned length)
+{
+    filename_create(&Capture_Filename[0]);
+    write_global_header(&Capture_Filename[0]);
+    write_received_packet(buffer, length);
+    if (pFile) {
+        fclose(pFile);
+    }
+}
+
 /* simple program to CRC the data and print the CRC */
 int main(
     int argc,
@@ -132,6 +224,7 @@ int main(
             "options:\r\n"
             "[-x] interprete the arguments as ascii hex (default)\r\n"
             "[-d] interprete the argument as ascii decimal\r\n"
+            "[-m] Write the bytes to Wireshark capture file\r\n"
             "[-8] calculate the MS/TP 8-bit Header CRC (default)\r\n"
             "[-16] calculate the MS/TP 16-bit Data CRC\r\n"
             "[-32] calculate the MS/TP 32-bit Extended Frame CRC\r\n");
@@ -147,6 +240,9 @@ int main(
     }
     Parse_Arguments(argc, argv);
     if (CRC_Buffer_Len) {
+        if (MSTP_Cap) {
+            Write_Pcap(CRC_Buffer, CRC_Buffer_Len);
+        } else {
         for (i = 0; i < CRC_Buffer_Len; i++) {
             if (CRC_Size == 8) {
                 crc8 = CRC_Calc_Header(CRC_Buffer[i], crc8);
@@ -176,6 +272,7 @@ int main(
                 printf("0x%02X Data CRC\r\n", (crc16 >> 8));
             }
         }
+        }
     }
 
     return 1;