netfilter: xtables: change matches to return error code

The following semantic patch does part of the transformation:
// <smpl>
@ rule1 @
struct xt_match ops;
identifier check;
@@
 ops.checkentry = check;

@@
identifier rule1.check;
@@
 check(...) { <...
-return true;
+return 0;
 ...> }

@@
identifier rule1.check;
@@
 check(...) { <...
-return false;
+return -EINVAL;
 ...> }
// </smpl>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/ipv4/netfilter/ipt_ecn.c b/net/ipv4/netfilter/ipt_ecn.c
index d1e234f..32e2410 100644
--- a/net/ipv4/netfilter/ipt_ecn.c
+++ b/net/ipv4/netfilter/ipt_ecn.c
@@ -91,18 +91,18 @@ static int ecn_mt_check(const struct xt_mtchk_param *par)
 	const struct ipt_ip *ip = par->entryinfo;
 
 	if (info->operation & IPT_ECN_OP_MATCH_MASK)
-		return false;
+		return -EINVAL;
 
 	if (info->invert & IPT_ECN_OP_MATCH_MASK)
-		return false;
+		return -EINVAL;
 
 	if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR) &&
 	    ip->proto != IPPROTO_TCP) {
 		pr_info("cannot match TCP bits in rule for non-tcp packets\n");
-		return false;
+		return -EINVAL;
 	}
 
-	return true;
+	return 0;
 }
 
 static struct xt_match ecn_mt_reg __read_mostly = {