Merged in antmerlino/apps/i8shark_fcs_suppresion (pull request #194)

i8shark: Adds support for intentionally suppressing passing the FCS so that Wireshark doesn't try to validate it.

Approved-by: Gregory Nutt <gnutt@nuttx.org>

wireless/ieee802154/i8shark/Kconfig

@@ -12,6 +12,14 @@ config IEEE802154_I8SHARK
 
 if IEEE802154_I8SHARK
 
+config IEEE802154_I8SHARK_DAEMON_PRIORITY
+	int "i8shark task priority"
+	default 100
+
+config IEEE802154_I8SHARK_DAEMON_STACKSIZE
+	int "i8shark stack size"
+	default 2048
+
 config IEEE802154_I8SHARK_DEVPATH
 	string "MAC char driver path"
 	default "/dev/ieee0"
@@ -22,6 +30,17 @@ config IEEE802154_I8SHARK_HOST_IPADDR
 	hex "Host IP address where Wireshark is running"
 	default 0x0a000001
 
+config IEEE802154_I8SHARK_SUPPRESS_FCS
+	bool "Suppress passing FCS to Wireshark"
+	default n
+	---help---
+		The current Wireshark disector does not continue processing a frame, aka
+		6LoWPAN processing, if the FCS is incorrect. Furthermore, the FCS length
+		in the disector is hard-coded to be 2 bytes. Some PHY implement different
+		length FCS. However, Wireshark will ignore the FCS checking if an FCS is
+		not provided. This option intentionally excludes the last n bytes of the
+		frame where n is the FCS length of the current radio settings.
+
 config IEEE802154_I8SHARK_XBEE_APPHDR
 	bool "XBee App Header compensation"
 	default n

wireless/ieee802154/i8shark/i8shark_main.c

@@ -104,7 +104,6 @@ struct i8shark_state_s
 
   /* User exposed settings */
 
-  uint8_t chan;
   FAR char devpath[I8SHARK_MAX_DEVPATH];
 };
 
@@ -229,7 +228,6 @@ static int i8shark_init(FAR struct i8shark_state_s *i8shark)
 
   /* Set the default settings using config options */
 
-  i8shark->chan = CONFIG_IEEE802154_I8SHARK_CHANNEL;
   strcpy(i8shark->devpath, CONFIG_IEEE802154_I8SHARK_DEVPATH);
 
   /* Flags for synchronzing with daemon state */
@@ -323,7 +321,7 @@ static int i8shark_daemon(int argc, FAR char *argv[])
       enum ieee802154_frametype_e ftype;
       uint8_t zepframe[I8SHARK_MAX_ZEPFRAME];
       clock_t systime;
-      int ind = 0;
+      int i = 0;
       int nbytes;
 
       /* Get an incoming frame from the MAC character driver */
@@ -336,12 +334,12 @@ static int i8shark_daemon(int argc, FAR char *argv[])
 
       /* First 2 bytes of packet represent preamble. For ZEP, "EX" */
 
-      zepframe[ind++] = 'E';
+      zepframe[i++] = 'E';
-      zepframe[ind++] = 'X';
+      zepframe[i++] = 'X';
 
       /* The next byte is the version. We are using V2 */
 
-      zepframe[ind++] = 2;
+      zepframe[i++] = 2;
 
       /* Next byte is type. ZEP only differentiates between ACK and Data. My
        * assumption is that Data also includes MAC command frames and beacon
@@ -353,27 +351,27 @@ static int i8shark_daemon(int argc, FAR char *argv[])
 
       if (ftype == IEEE802154_FRAME_ACK)
         {
-          zepframe[ind++] = 2;
+          zepframe[i++] = 2;
 
           /* Not sure why, but the ZEP header allows for a 4-byte sequence no.
            * despite 802.15.4 sequence number only being 1-byte
            */
 
-          zepframe[ind] = frame.meta.dsn;
+          zepframe[i] = frame.meta.dsn;
-          ind += 4;
+          i += 4;
         }
       else
         {
-          zepframe[ind++] = 1;
+          zepframe[i++] = 1;
 
           /* Next bytes is the Channel ID */
 
-          ieee802154_getchan(fd, &zepframe[ind++]);
+          ieee802154_getchan(fd, &zepframe[i++]);
 
           /* For now, just hard code the device ID to an arbitrary value */
 
-          zepframe[ind++] = 0xFA;
+          zepframe[i++] = 0xFA;
-          zepframe[ind++] = 0xDE;
+          zepframe[i++] = 0xDE;
 
           /* Not completely sure what LQI mode is. My best guess as of now based
            * on a few comments in the Wireshark code is that it determines whether
@@ -383,46 +381,46 @@ static int i8shark_daemon(int argc, FAR char *argv[])
            * may be a bad assumption for certain radios.
            */
 
-          zepframe[ind++] = 1;
+          zepframe[i++] = 1;
 
           /* Next byte is the LQI value */
 
-          zepframe[ind++] = frame.meta.lqi;
+          zepframe[i++] = frame.meta.lqi;
 
           /* Need to use NTP to get time, but for now, include the system time */
 
           systime = clock();
-          memcpy(&zepframe[ind], &systime, 8);
+          memcpy(&zepframe[i], &systime, 8);
-          ind += 8;
+          i += 8;
 
           /* Not sure why, but the ZEP header allows for a 4-byte sequence no.
            * despite 802.15.4 sequence number only being 1-byte
            */
 
-          zepframe[ind]   = frame.meta.dsn;
+          zepframe[i]   = frame.meta.dsn;
-          zepframe[ind+1] = 0;
+          zepframe[i+1] = 0;
-          zepframe[ind+2] = 0;
+          zepframe[i+2] = 0;
-          zepframe[ind+3] = 0;
+          zepframe[i+3] = 0;
-          ind += 4;
+          i += 4;
 
           /* Skip 10-bytes for reserved fields */
 
-          ind += 10;
+          i += 10;
 
           /* Last byte is the length */
 
 #ifdef CONFIG_IEEE802154_I8SHARK_XBEE_APPHDR
-          zepframe[ind++] = frame.length - 2;
+          zepframe[i++] = frame.length - 2;
 #else
-          zepframe[ind++] = frame.length;
+          zepframe[i++] = frame.length;
 #endif
         }
 
       /* The ZEP header is filled, now copy the frame in */
 
 #ifdef CONFIG_IEEE802154_I8SHARK_XBEE_APPHDR
-      memcpy(&zepframe[ind], frame.payload, frame.offset);
+      memcpy(&zepframe[i], frame.payload, frame.offset);
-      ind += frame.offset;
+      i += frame.offset;
 
       /* XBee radios use a 2 byte "application header" to support duplicate packet
        * detection.  Wireshark doesn't know how to handle this data, so we provide
@@ -436,18 +434,30 @@ static int i8shark_daemon(int argc, FAR char *argv[])
        * will not fail.
        */
 
-      memcpy(&zepframe[ind], (frame.payload + frame.offset + 2),
+      memcpy(&zepframe[i], (frame.payload + frame.offset + 2),
              (frame.length - frame.offset - 2));
-      ind += frame.length - frame.offset - 4;
+      i += frame.length - frame.offset - 4;
 #else
-      memcpy(&zepframe[ind], frame.payload, frame.length);
+      /* If FCS suppression is enabled, subtract the FCS length to reduce the
-      ind += frame.length;
+       * piece of the frame copied.
+       */
+
+#ifdef CONFIG_IEEE802154_I8SHARK_SUPPRESS_FCS
+      {
+        uint8_t fcslen;
+        ieee802154_getfcslen(fd, &fcslen);
+        frame.length -= fcslen;
+      }
+#endif
+
+      memcpy(&zepframe[i], frame.payload, frame.length);
+      i += frame.length;
 #endif
 
       /* Send the encapsulated frame to Wireshark over UDP */
 
-      nbytes = sendto(sockfd, zepframe, ind, 0, (struct sockaddr*)&raddr, addrlen);
+      nbytes = sendto(sockfd, zepframe, i, 0, (struct sockaddr*)&raddr, addrlen);
-      if (nbytes < ind)
+      if (nbytes < i)
         {
           fprintf(stderr, "ERROR: sendto() did not send all bytes. %d\n", errno);
         }