From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Wed, 14 Nov 2012 19:20:38 +0000 (+0100)
Subject: cangw: add semantic check for checksum options
X-Git-Url: https://rtime.felk.cvut.cz/gitweb/sojka/can-utils.git/commitdiff_plain/f123d73d9a23c9c101ee1a48b1f117e69f95dea0?hp=d166ecc8a36759ca05aeb2d4e2eec744c9dfb886

cangw: add semantic check for checksum options

The options to for adding checksums (-c or -x) can only be used in conjunction
with modifications (-m) applied to the routed CAN frames.

Signed-off-by: Andre Naujoks <nautsch2@googlemail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---

diff --git a/cangw.c b/cangw.c
index 5c111f9..3d6a23e 100644
--- a/cangw.c
+++ b/cangw.c
@@ -669,6 +669,11 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
+	if (!modidx && (have_cs_crc8 || have_cs_xor)) {
+		printf("-c or -x can only be used in conjunction with -m\n");
+		exit(1);
+	}
+
 	s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 
 	switch (cmd) {