xshared: Share print_iface() function

Merge the three identical copies into one and name it 'save_iface' (as
the printed syntax is for "save"-format). Leave arptables alone for now,
its rather complicated whitespace printing doesn't allow for use of the
shared function. Also keep ebtables' custom implementation, it is used
for the --logical-in/--logical-out long-options, too. Apart from that,
ebtables-nft does not use a mask, at all.

Signed-off-by: Phil Sutter <phil@nwl.cc>

1 files changed, 25 insertions, 0 deletions

diff --git a/iptables/xshared.c b/iptables/xshared.c
index bd545d6b..db03aaaa 100644
--- a/iptables/xshared.c
+++ b/iptables/xshared.c
@@ -637,6 +637,31 @@ void print_ifaces(const char *iniface, const char *outiface, uint8_t invflags,
 	printf(FMT("%-6s ", "out %s "), iface);
 }
 
+/* This assumes that mask is contiguous, and byte-bounded. */
+void save_iface(char letter, const char *iface,
+		const unsigned char *mask, int invert)
+{
+	unsigned int i;
+
+	if (mask[0] == 0)
+		return;
+
+	printf("%s -%c ", invert ? " !" : "", letter);
+
+	for (i = 0; i < IFNAMSIZ; i++) {
+		if (mask[i] != 0) {
+			if (iface[i] != '\0')
+				printf("%c", iface[i]);
+		} else {
+			/* we can access iface[i-1] here, because
+			 * a few lines above we make sure that mask[0] != 0 */
+			if (iface[i-1] != '\0')
+				printf("+");
+			break;
+		}
+	}
+}
+
 void command_match(struct iptables_command_state *cs, bool invert)
 {
 	struct option *opts = xt_params->opts;