canbusload: fix and improve the bitrate output

With the introduction of CAN FD the bitrate has not been printed
correcty. Fix the CAN FD bitrate output and try to shrink the
bitrates by using kilo or Mega suffixes: 500000 -> 500k

Fixes: 6382765bf6 ("canbusload: count databitrate seperately")
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>

canbusload.c

@@ -70,11 +70,13 @@
 
 #define PERCENTRES 5 /* resolution in percent for bargraph */
 #define NUMBAR (100 / PERCENTRES) /* number of bargraph elements */
+#define BRSTRLEN 20
 
 extern int optind, opterr, optopt;
 
 static struct {
 	char devname[IFNAMSIZ + 1];
+	char bitratestr[BRSTRLEN]; /* 100000/2000000 => 100k/2M */
 	char recv_direction;
 	int ifindex;
 	unsigned int bitrate;
@@ -88,7 +90,7 @@ static struct {
 static volatile int running = 1;
 static volatile sig_atomic_t signal_num;
 static int max_devname_len; /* to prevent frazzled device name output */
-static int max_bitrate_len;
+static int max_bitratestr_len;
 static int currmax;
 static unsigned char redraw;
 static unsigned char timestamp;
@@ -117,14 +119,13 @@ static void print_usage(char *prg)
 	fprintf(stderr, "calculate the bus load percentage based on the received CAN frames.\n");
 	fprintf(stderr, "Due to the bitstuffing estimation the calculated busload may exceed 100%%.\n");
 	fprintf(stderr, "For each given interface the data is presented in one line which contains:\n\n");
-	fprintf(stderr, "(interface) (received CAN frames) (used bits total) (used bits for payload)\n");
+	fprintf(stderr, "(interface) (received CAN frames) (bits total) (bits payload) (bits payload brs)\n");
 	fprintf(stderr, "\nExamples:\n");
-	fprintf(stderr, "\nuser$> canbusload can0@100000 can1@500000 can2@500000 can3@500000 -r -t -b -c\n\n");
+	fprintf(stderr, "\nuser$> canbusload can0@100000 can1@500000,2000000 can2@500000 -r -t -b -c\n\n");
-	fprintf(stderr, "%s 2014-02-01 21:13:16 (worst case bitstuffing)\n", prg);
+	fprintf(stderr, "%s 2024-08-08 16:30:05 (worst case bitstuffing)\n", prg);
-	fprintf(stderr, " can0@100000   805   74491  36656  74%% |XXXXXXXXXXXXXX......|\n");
+	fprintf(stderr, " can0@100k      192   21980    9136       0  21%% |TTTT................|\n");
-	fprintf(stderr, " can1@500000   796   75140  37728  15%% |XXX.................|\n");
+	fprintf(stderr, " can1@500k/2M  2651  475500  234448  131825  74%% |XXXXXXXXXXXXXX......|\n");
-	fprintf(stderr, " can2@500000     0       0      0   0%% |....................|\n");
+	fprintf(stderr, " can2@500k      855  136777   62968   35219  27%% |RRRRR...............|\n");
-	fprintf(stderr, " can3@500000    47    4633   2424   0%% |....................|\n");
 	fprintf(stderr, "\n");
 }
 
@@ -134,6 +135,32 @@ static void sigterm(int signo)
 	signal_num = signo;
 }
 
+static int add_bitrate(char *brstr, unsigned int bitrate)
+{
+	if (bitrate % 1000000 == 0)
+		return sprintf(brstr, "%dM", bitrate / 1000000);
+
+	if (bitrate % 1000 == 0)
+		return sprintf(brstr, "%dk", bitrate / 1000);
+
+	return sprintf(brstr, "%d", bitrate);
+}
+
+static void create_bitrate_string(int stat_idx, int *max_bitratestr_len)
+{
+	int ptr;
+
+	ptr = add_bitrate(&stat[stat_idx].bitratestr[0], stat[stat_idx].bitrate);
+
+	if (stat[stat_idx].bitrate != stat[stat_idx].dbitrate) {
+		ptr += sprintf(&stat[stat_idx].bitratestr[ptr], "/");
+		ptr += add_bitrate(&stat[stat_idx].bitratestr[ptr], stat[stat_idx].dbitrate);
+	}
+
+	if (ptr > *max_bitratestr_len)
+		*max_bitratestr_len = ptr;
+}
+
 static void printstats(int signo)
 {
 	int i, j, percent;
@@ -198,9 +225,9 @@ static void printstats(int signo)
 		else
 			percent = 0;
 
-		printf(" %*s@%-*d %5d %7d %6d %6d %3d%%",
+		printf(" %*s@%-*s %5d %7d %7d %7d %3d%%",
 		       max_devname_len, stat[i].devname,
-		       max_bitrate_len, stat[i].bitrate,
+		       max_bitratestr_len, stat[i].bitratestr,
 		       stat[i].recv_frames,
 		       stat[i].recv_bits_total,
 		       stat[i].recv_bits_payload,
@@ -260,6 +287,7 @@ int main(int argc, char **argv)
 	int have_anydev = 0;
 	unsigned int anydev_bitrate = 0;
 	unsigned int anydev_dbitrate = 0;
+	char anydev_bitratestr[BRSTRLEN]; /* 100000/2000000 => 100k/2M */
 
 	signal(SIGTERM, sigterm);
 	signal(SIGHUP, sigterm);
@@ -358,15 +386,14 @@ int main(int argc, char **argv)
 		else
 			stat[i].dbitrate = stat[i].bitrate;
 
-		if (!stat[i].bitrate || stat[i].bitrate > 1000000) {
+		if (!stat[i].bitrate || stat[i].bitrate > 1000000 ||
+		    !stat[i].dbitrate || stat[i].dbitrate > 8000000) {
 			printf("invalid bitrate for CAN device '%s'!\n", ptr);
 			return 1;
 		}
 
-		/* length of entire (data)bitrate description */
+		/* prepare bitrate string for hot path */
-		nbytes = strlen(nptr + 1);
+		create_bitrate_string(i, &max_bitratestr_len);
-		if (nbytes > max_bitrate_len)
-			max_bitrate_len = nbytes; /* for nice printing */
 
 		stat[i].recv_direction = '.';
 
@@ -374,6 +401,7 @@ int main(int argc, char **argv)
 		if (have_anydev == 0 && strcmp(ANYDEV, stat[i].devname) == 0) {
 			anydev_bitrate = stat[i].bitrate;
 			anydev_dbitrate = stat[i].dbitrate;
+			memcpy(anydev_bitratestr, stat[i].bitratestr, BRSTRLEN);
 			/* no real interface: remove this command line entry */
 			have_anydev = 1;
 			currmax--;
@@ -466,6 +494,7 @@ int main(int argc, char **argv)
 			stat[i].ifindex = addr.can_ifindex;
 			stat[i].bitrate = anydev_bitrate;
 			stat[i].dbitrate = anydev_dbitrate;
+			memcpy(stat[i].bitratestr, anydev_bitratestr, BRSTRLEN);
 			stat[i].recv_direction = '.';
 			if_indextoname(addr.can_ifindex, stat[i].devname);
 			nbytes = strlen(stat[i].devname);