xshared: Introduce xtables_clear_args()

Perform struct xtables_args object deinit in a common place, even though
it merely consists of freeing any IP addresses and masks.

This fixes for a memleak in arptables-translate as the check for
h->family didn't catch the value NFPROTO_ARP.

Fixes: 5b7324e0675e3 ("nft-arp: add arptables-translate")
Signed-off-by: Phil Sutter <phil@nwl.cc>

6 files changed, 14 insertions, 23 deletions

diff --git a/iptables/ip6tables.c b/iptables/ip6tables.c
index 4b5d4ac6..f9ae18ae 100644
--- a/iptables/ip6tables.c
+++ b/iptables/ip6tables.c
@@ -892,10 +892,7 @@ int do_command6(int argc, char *argv[], char **table,
 		e = NULL;
 	}
 
-	free(saddrs);
-	free(smasks);
-	free(daddrs);
-	free(dmasks);
+	xtables_clear_args(&args);
 	xtables_free_opts(1);
 
 	return ret;
diff --git a/iptables/iptables.c b/iptables/iptables.c
index 5ae28fe0..8eb043e9 100644
--- a/iptables/iptables.c
+++ b/iptables/iptables.c
@@ -887,10 +887,7 @@ int do_command4(int argc, char *argv[], char **table,
 		e = NULL;
 	}
 
-	free(saddrs);
-	free(smasks);
-	free(daddrs);
-	free(dmasks);
+	xtables_clear_args(&args);
 	xtables_free_opts(1);
 
 	return ret;
diff --git a/iptables/xshared.c b/iptables/xshared.c
index 7d073891..0b2724a3 100644
--- a/iptables/xshared.c
+++ b/iptables/xshared.c
@@ -2185,3 +2185,11 @@ make_delete_mask(const struct xtables_rule_match *matches,
 
 	return mask;
 }
+
+void xtables_clear_args(struct xtables_args *args)
+{
+	free(args->s.addr.ptr);
+	free(args->s.mask.ptr);
+	free(args->d.addr.ptr);
+	free(args->d.mask.ptr);
+}
diff --git a/iptables/xshared.h b/iptables/xshared.h
index 2a9cdf45..7d4035ec 100644
--- a/iptables/xshared.h
+++ b/iptables/xshared.h
@@ -333,4 +333,6 @@ unsigned char *make_delete_mask(const struct xtables_rule_match *matches,
 
 void iface_to_mask(const char *ifname, unsigned char *mask);
 
+void xtables_clear_args(struct xtables_args *args);
+
 #endif /* IPTABLES_XSHARED_H */
diff --git a/iptables/xtables-translate.c b/iptables/xtables-translate.c
index ad443112..8ebe523c 100644
--- a/iptables/xtables-translate.c
+++ b/iptables/xtables-translate.c
@@ -349,17 +349,7 @@ static int do_command_xlate(struct nft_handle *h, int argc, char *argv[],
 
 	h->ops->clear_cs(&cs);
 
-	if (h->family == AF_INET) {
-		free(args.s.addr.v4);
-		free(args.s.mask.v4);
-		free(args.d.addr.v4);
-		free(args.d.mask.v4);
-	} else if (h->family == AF_INET6) {
-		free(args.s.addr.v6);
-		free(args.s.mask.v6);
-		free(args.d.addr.v6);
-		free(args.d.mask.v6);
-	}
+	xtables_clear_args(&args);
 	xtables_free_opts(1);
 
 	return ret;
diff --git a/iptables/xtables.c b/iptables/xtables.c
index 22d6ea58..5d73481c 100644
--- a/iptables/xtables.c
+++ b/iptables/xtables.c
@@ -264,10 +264,7 @@ int do_commandx(struct nft_handle *h, int argc, char *argv[], char **table,
 
 	h->ops->clear_cs(&cs);
 
-	free(args.s.addr.ptr);
-	free(args.s.mask.ptr);
-	free(args.d.addr.ptr);
-	free(args.d.mask.ptr);
+	xtables_clear_args(&args);
 	xtables_free_opts(1);
 
 	return ret;