From 1be68bcc64773ededcdb67b6456a0edbe8da7dc2 Mon Sep 17 00:00:00 2001
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Wed, 29 Oct 2008 09:23:48 +0000
Subject: [PATCH] Added support for swapped byte order representation.

---
 candump.c | 12 +++++++++++-
 lib.c     | 58 +++++++++++++++++++++++++++++++++++++++++--------------
 lib.h     |  5 ++++-
 3 files changed, 58 insertions(+), 17 deletions(-)

diff --git a/candump.c b/candump.c
index cc31a39..16f9455 100644
--- a/candump.c
+++ b/candump.c
@@ -109,6 +109,7 @@ void print_usage(char *prg)
 	fprintf(stderr, "         -c          (increment color mode level)\n");
 	fprintf(stderr, "         -i          (binary output - may exceed 80 chars/line)\n");
 	fprintf(stderr, "         -a          (enable additional ASCII output)\n");
+	fprintf(stderr, "         -S          (swap byte order in printed CAN data[] - marked with '%c' )\n", SWAP_DELIMITER);
 	fprintf(stderr, "         -s <level>  (silent mode - %d: off (default) %d: animation %d: silent)\n", SILENT_OFF, SILENT_ANI, SILENT_ON);
 	fprintf(stderr, "         -b <can>    (bridge mode - send received frames to <can>)\n");
 	fprintf(stderr, "         -B <can>    (bridge mode - like '-b' with disabled loopback)\n");
@@ -235,7 +236,7 @@ int main(int argc, char **argv)
 	last_tv.tv_sec  = 0;
 	last_tv.tv_usec = 0;
 
-	while ((opt = getopt(argc, argv, "t:cias:b:B:lLh?")) != -1) {
+	while ((opt = getopt(argc, argv, "t:ciaSs:b:B:lLh?")) != -1) {
 		switch (opt) {
 		case 't':
 			timestamp = optarg[0];
@@ -259,6 +260,10 @@ int main(int argc, char **argv)
 			view |= CANLIB_VIEW_ASCII;
 			break;
 
+		case 'S':
+			view |= CANLIB_VIEW_SWAP;
+			break;
+
 		case 's':
 			silent = atoi(optarg);
 			if (silent > SILENT_ON) {
@@ -323,6 +328,11 @@ int main(int argc, char **argv)
 		exit(0);
 	}
 	
+	if (logfrmt && view) {
+		fprintf(stderr, "Log file format selected: Please disable ASCII/BINARY/SWAP options!\n");
+		exit(0);
+	}
+
 	if (silent == SILENT_INI) {
 		if (log) {
 			printf("\nDisabled standard output while logging.");
diff --git a/lib.c b/lib.c
index c969df4..7ae308a 100644
--- a/lib.c
+++ b/lib.c
@@ -244,17 +244,34 @@ void sprint_long_canframe(char *buf , struct can_frame *cf, int view) {
 
 	if (view & CANLIB_VIEW_BINARY) {
 		dlen = 9; /* _10101010 */
-		for (i = 0; i < dlc; i++) {
-			buf[offset++] = ' ';
-			for (j = 7; j >= 0; j--)
-				buf[offset++] = (1<<j & cf->data[i])?'1':'0';
+		if (view & CANLIB_VIEW_SWAP) {
+			for (i = dlc - 1; i >= 0; i--) {
+				buf[offset++] = (i == dlc-1)?' ':SWAP_DELIMITER;
+				for (j = 7; j >= 0; j--)
+					buf[offset++] = (1<<j & cf->data[i])?'1':'0';
+			}
+		} else {
+			for (i = 0; i < dlc; i++) {
+				buf[offset++] = ' ';
+				for (j = 7; j >= 0; j--)
+					buf[offset++] = (1<<j & cf->data[i])?'1':'0';
+			}
 		}
 		buf[offset] = 0; /* terminate string */
 	} else {
 		dlen = 3; /* _AA */
-		for (i = 0; i < dlc; i++) {
-			sprintf(buf+offset, " %02X", cf->data[i]);
-			offset += dlen;
+		if (view & CANLIB_VIEW_SWAP) {
+			for (i = dlc - 1; i >= 0; i--) {
+				sprintf(buf+offset, "%c%02X",
+					(i == dlc-1)?' ':SWAP_DELIMITER,
+					cf->data[i]);
+				offset += dlen;
+			}
+		} else {
+			for (i = 0; i < dlc; i++) {
+				sprintf(buf+offset, " %02X", cf->data[i]);
+				offset += dlen;
+			}
 		}
 	}
 
@@ -262,16 +279,27 @@ void sprint_long_canframe(char *buf , struct can_frame *cf, int view) {
 		sprintf(buf+offset, "%*s", dlen*(8-dlc)+13, "ERRORFRAME");
 	else if (view & CANLIB_VIEW_ASCII) {
 		j = dlen*(8-dlc)+4;
-		sprintf(buf+offset, "%*s", j, "'");
-		offset += j;
+		if (view & CANLIB_VIEW_SWAP) {
+			sprintf(buf+offset, "%*s", j, "`");
+			offset += j;
+			for (i = dlc - 1; i >= 0; i--)
+				if ((cf->data[i] > 0x1F) && (cf->data[i] < 0x7F))
+					buf[offset++] = cf->data[i];
+				else
+					buf[offset++] = '.';
 
-		for (i = 0; i < dlc; i++)
-			if ((cf->data[i] > 0x1F) && (cf->data[i] < 0x7F))
-				buf[offset++] = cf->data[i];
-			else
-				buf[offset++] = '.';
+			sprintf(buf+offset, "`");
+		} else {
+			sprintf(buf+offset, "%*s", j, "'");
+			offset += j;
+			for (i = 0; i < dlc; i++)
+				if ((cf->data[i] > 0x1F) && (cf->data[i] < 0x7F))
+					buf[offset++] = cf->data[i];
+				else
+					buf[offset++] = '.';
 
-		sprintf(buf+offset, "'");
+			sprintf(buf+offset, "'");
+		}
 	} 
 }
 
diff --git a/lib.h b/lib.h
index b356e3b..cae3d8a 100644
--- a/lib.h
+++ b/lib.h
@@ -87,7 +87,7 @@ int parse_canframe(char *cs, struct can_frame *cf);
  * Examples:
  *
  * 123# -> standard CAN-Id = 0x123, dlc = 0
- * 12345678# -> exended CAN-Id = 0x12345678, dlc = 0
+ * 12345678# -> extended CAN-Id = 0x12345678, dlc = 0
  * 123#R -> standard CAN-Id = 0x123, dlc = 0, RTR-frame
  * 7A1#r -> standard CAN-Id = 0x7A1, dlc = 0, RTR-frame
  *
@@ -126,6 +126,9 @@ void sprint_canframe(char *buf , struct can_frame *cf, int sep);
 
 #define CANLIB_VIEW_ASCII	0x1
 #define CANLIB_VIEW_BINARY	0x2
+#define CANLIB_VIEW_SWAP	0x4
+
+#define SWAP_DELIMITER '`'
 
 void fprint_long_canframe(FILE *stream , struct can_frame *cf, char *eol, int view);
 void sprint_long_canframe(char *buf , struct can_frame *cf, int view);