cangw: support new can-gw features for Linux 3.9+

Added new option '-i' for can-gw rules to allow to route CAN frames back to the
originating/incoming CAN interface (which is disabled by default).

CAN frames that are deleted due to the violation of the max_hops limit are now
printed when displaying the configured rules with 'cangw -L'.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>

cangw.c

@@ -192,6 +192,7 @@ void print_usage(char *prg)
 	fprintf(stderr, "           -d <dst_dev>  (destination netdevice)\n");
 	fprintf(stderr, "Options:   -t (preserve src_dev rx timestamp)\n");
 	fprintf(stderr, "           -e (echo sent frames - recommended on vcanx)\n");
+	fprintf(stderr, "           -i (allow to route to incoming interface)\n");
 	fprintf(stderr, "           -f <filter> (set CAN filter)\n");
 	fprintf(stderr, "           -m <mod> (set frame modifications)\n");
 	fprintf(stderr, "           -x <from_idx>:<to_idx>:<result_idx>:<init_xor_val> (XOR checksum)\n");
@@ -353,7 +354,7 @@ int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
 	struct nlmsghdr *nlh;
 	unsigned int src_ifindex = 0;
 	unsigned int dst_ifindex = 0;
-	__u32 handled, dropped;
+	__u32 handled, dropped, deleted;
 	int rtlen;
 
 
@@ -394,6 +395,7 @@ int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
 
 		handled = 0;
 		dropped = 0;
+		deleted = 0;
 		src_ifindex = 0;
 		dst_ifindex = 0;
 
@@ -432,6 +434,10 @@ int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
 				dropped = *(__u32 *)RTA_DATA(rta);
 				break;
 
+			case CGW_DELETED:
+				deleted = *(__u32 *)RTA_DATA(rta);
+				break;
+
 			default:
 				printf("Unknown attribute %d!", rta->rta_type);
 				return -EINVAL;
@@ -449,6 +455,9 @@ int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
 		if (rtc->flags & CGW_FLAGS_CAN_SRC_TSTAMP)
 			printf("-t ");
 
+		if (rtc->flags & CGW_FLAGS_CAN_IIF_TX_OK)
+			printf("-i ");
+
 		/* second parse for mod attributes */
 		rta = (struct rtattr *) RTCAN_RTA(rtc);
 		rtlen = RTCAN_PAYLOAD(nlh);
@@ -489,6 +498,7 @@ int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
 			case CGW_DST_IF:
 			case CGW_HANDLED:
 			case CGW_DROPPED:
+			case CGW_DELETED:
 				break;
 
 			default:
@@ -498,7 +508,9 @@ int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
 			}
 		}
 
-		printf("# %d handled %d dropped\n", handled, dropped); /* end of entry */
+		/* end of entry */
+		printf("# %d handled %d dropped %d deleted\n",
+		       handled, dropped, deleted);
 
 		/* jump to next NLMSG in the given buffer */
 		nlh = NLMSG_NEXT(nlh, len);
@@ -548,7 +560,7 @@ int main(int argc, char **argv)
 	memset(&cs_xor, 0, sizeof(cs_xor));
 	memset(&cs_crc8, 0, sizeof(cs_crc8));
 
-	while ((opt = getopt(argc, argv, "ADFLs:d:tef:c:p:x:m:?")) != -1) {
+	while ((opt = getopt(argc, argv, "ADFLs:d:teif:c:p:x:m:?")) != -1) {
 		switch (opt) {
 
 		case 'A':
@@ -587,6 +599,10 @@ int main(int argc, char **argv)
 			flags |= CGW_FLAGS_CAN_ECHO;
 			break;
 
+		case 'i':
+			flags |= CGW_FLAGS_CAN_IIF_TX_OK;
+			break;
+
 		case 'f':
 			if (sscanf(optarg, "%x:%x", &filter.can_id,
 				   &filter.can_mask) == 2) {

include/socketcan/can/gw.h

@@ -44,6 +44,7 @@ enum {
 	CGW_SRC_IF,	/* ifindex of source network interface */
 	CGW_DST_IF,	/* ifindex of destination network interface */
 	CGW_FILTER,	/* specify struct can_filter on source CAN device */
+	CGW_DELETED,	/* number of deleted CAN frames (see max_hops param) */
 	__CGW_MAX
 };
 
@@ -51,6 +52,7 @@ enum {
 
 #define CGW_FLAGS_CAN_ECHO 0x01
 #define CGW_FLAGS_CAN_SRC_TSTAMP 0x02
+#define CGW_FLAGS_CAN_IIF_TX_OK 0x04
 
 #define CGW_MOD_FUNCS 4 /* AND OR XOR SET */