contrib/fwd: rewrite rule generate to use xtables api

1 files changed, 288 insertions, 281 deletions

diff --git a/contrib/fwd/src/fwd_rules.c b/contrib/fwd/src/fwd_rules.c
index c3d4ebbe53..e6604911a7 100644
--- a/contrib/fwd/src/fwd_rules.c
+++ b/contrib/fwd/src/fwd_rules.c
@@ -22,199 +22,6 @@
 #include "fwd_rules.h"
 #include "fwd_xtables.h"
 
-static void
-fwd_ipt_rule_append(struct fwd_ipt_rulebuf *r, const char *fmt, ...)
-{
-	int len = 0;
-	char buf[256]; buf[0] = 0;
-
-	va_list ap;
-	va_start(ap, fmt);
-	len = vsnprintf(buf, sizeof(buf), fmt, ap);
-	va_end(ap);	
-
-	if( len > 0 )
-	{
-		r->buf = realloc(r->buf, r->len + len + 1);
-		memcpy(&r->buf[r->len], buf, len);
-		r->buf[r->len + len] = 0;
-		r->len += len;
-	}
-}
-
-static struct fwd_ipt_rulebuf * fwd_ipt_init(const char *table)
-{
-	struct fwd_ipt_rulebuf *r;
-
-	if( (r = fwd_alloc_ptr(struct fwd_ipt_rulebuf)) != NULL )
-	{
-		fwd_ipt_rule_append(r, IPT " -t %s", table);
-		return r;
-	}
-
-	return NULL;
-}
-
-static void fwd_ipt_add_srcport(
-	struct fwd_ipt_rulebuf *r, struct fwd_portrange *p
-) {
-	if( p != NULL )
-	{
-		if( p->min < p->max )
-			fwd_ipt_rule_append(r, " --sport %u:%u", p->min, p->max);
-		else
-			fwd_ipt_rule_append(r, " --sport %u", p->min);
-	}
-}
-
-static void fwd_ipt_add_destport(
-	struct fwd_ipt_rulebuf *r, struct fwd_portrange *p
-) {
-	if( p != NULL )
-	{
-		if( p->min < p->max )
-			fwd_ipt_rule_append(r, " --dport %u:%u", p->min, p->max);
-		else
-			fwd_ipt_rule_append(r, " --dport %u", p->min);
-	}
-}
-
-static void fwd_ipt_add_proto(
-	struct fwd_ipt_rulebuf *r, struct fwd_proto *p
-) {
-	if( p != NULL )
-	{
-		switch( p->type )
-		{
-			case FWD_PR_TCPUDP:
-				fwd_ipt_rule_append(r, " -p tcp -p udp");
-				break;
-
-			case FWD_PR_TCP:
-				fwd_ipt_rule_append(r, " -p tcp");
-				break;
-
-			case FWD_PR_UDP:
-				fwd_ipt_rule_append(r, " -p udp");
-				break;
-
-			case FWD_PR_ICMP:
-				fwd_ipt_rule_append(r, " -p icmp");
-				break;
-
-			case FWD_PR_ALL:
-				fwd_ipt_rule_append(r, " -p all");
-				break;
-
-			case FWD_PR_CUSTOM:
-				fwd_ipt_rule_append(r, " -p %u", p->proto);
-				break;
-		}
-	}
-}
-
-static void fwd_ipt_add_srcaddr(
-	struct fwd_ipt_rulebuf *r, struct fwd_cidr *c
-) {
-	if( c != NULL )
-	{
-		if( c->prefix < 32 )
-			fwd_ipt_rule_append(r, " -s %s/%u",
-				inet_ntoa(c->addr), c->prefix);
-		else
-			fwd_ipt_rule_append(r, " -s %s", inet_ntoa(c->addr));
-	}
-}
-
-static void fwd_ipt_add_destaddr(
-	struct fwd_ipt_rulebuf *r, struct fwd_cidr *c
-) {
-	if( c != NULL )
-	{
-		if( c->prefix < 32 )
-			fwd_ipt_rule_append(r, " -d %s/%u",
-				inet_ntoa(c->addr), c->prefix);
-		else
-			fwd_ipt_rule_append(r, " -d %s", inet_ntoa(c->addr));
-	}
-}
-
-static void fwd_ipt_add_srcmac(
-	struct fwd_ipt_rulebuf *r, struct fwd_mac *m
-) {
-	if( m != NULL )
-	{
-		fwd_ipt_rule_append(r,
-			" -m mac --mac-source %02x:%02x:%02x:%02x:%02x:%02x",
-			m->mac[0], m->mac[1], m->mac[2],
-			m->mac[3], m->mac[4], m->mac[5]);
-	}
-}
-
-static void fwd_ipt_add_icmptype(
-	struct fwd_ipt_rulebuf *r, struct fwd_icmptype *i
-) {
-	if( i != NULL )
-	{
-		if( i->name )
-			fwd_ipt_rule_append(r, " --icmp-type %s", i->name);
-		else if( i->code > -1 )
-			fwd_ipt_rule_append(r, " --icmp-type %u/%u", i->type, i->code);
-		else
-			fwd_ipt_rule_append(r, " --icmp-type %u", i->type);
-	}
-}
-
-static void fwd_ipt_add_dnat_target(
-	struct fwd_ipt_rulebuf *r, struct fwd_cidr *c, struct fwd_portrange *p
-) {
-	if( c != NULL )
-	{
-		fwd_ipt_rule_append(r, " -j DNAT --to-destination %s",
-			inet_ntoa(c->addr));
-
-		if( (p != NULL) && (p->min < p->max) )
-			fwd_ipt_rule_append(r, ":%u-%u", p->min, p->max);
-		else if( p != NULL )
-			fwd_ipt_rule_append(r, ":%u", p->min);
-	}
-}
-
-static void fwd_ipt_add_policy_target(
-	struct fwd_ipt_rulebuf *r, enum fwd_policy p
-) {
-	fwd_ipt_rule_append(r, " -j %s",
-		(p == FWD_P_ACCEPT)
-			? "handle_accept"
-			: (p == FWD_P_REJECT)
-				? "handle_reject"
-				: "handle_drop"
-	);
-}
-
-static void fwd_ipt_add_comment(
-	struct fwd_ipt_rulebuf *r, const char *t, struct fwd_zone *z,
-	struct fwd_network_list *n, struct fwd_network_list *n2
-) {
-	if( (n != NULL) && (n2 != NULL) )
-		fwd_ipt_add_format(r, " -m comment --comment '%s:%s src:%s dest:%s'",
-			t, z->name, n->name, n2->name);
-	else if( (n == NULL) && (n2 != NULL) )
-		fwd_ipt_add_format(r, " -m comment --comment '%s:%s dest:%s'",
-			t, z->name, n2->name);
-	else
-		fwd_ipt_add_format(r, " -m comment --comment '%s:%s src:%s'",
-			t, z->name, n->name);
-}
-
-static void fwd_ipt_exec(struct fwd_ipt_rulebuf *r)
-{
-	if( r->len )
-		printf("%s\n", r->buf);
-
-	fwd_free_ptr(r->buf);
-	fwd_free_ptr(r);
-}
 
 /* -P <chain> <policy> */
 static void fwd_r_set_policy(
@@ -252,7 +59,7 @@ static void fwd_r_drop_invalid(struct iptc_handle *h, const char *chain)
 	{
 		if( (m = fwd_xt_get_match(r, "state")) != NULL )
 		{
-			fwd_xt_parse_match(r, m, "--state", "INVALID", 0);
+			fwd_xt_parse_match(r, m, "--state", "INVALID");
 			fwd_xt_get_target(r, "DROP");
 			fwd_xt_exec_rule(r, chain);
 		}
@@ -269,7 +76,7 @@ static void fwd_r_accept_related(struct iptc_handle *h, const char *chain)
 	{
 		if( (m = fwd_xt_get_match(r, "state")) != NULL )
 		{
-			fwd_xt_parse_match(r, m, "--state", "RELATED,ESTABLISHED", 0);
+			fwd_xt_parse_match(r, m, "--state", "RELATED,ESTABLISHED");
 			fwd_xt_get_target(r, "ACCEPT");
 			fwd_xt_exec_rule(r, chain);
 		}
@@ -320,17 +127,17 @@ static void fwd_r_add_synflood(struct iptc_handle *h, struct fwd_defaults *def)
 		/* -m tcp --syn */
 		if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
 		{
-			fwd_xt_parse_match(r, m, "--syn", NULL, 0);
+			fwd_xt_parse_match(r, m, "--syn");
 		}
 
 		/* -m limit --limit x/second --limit-burst y */
 		if( (m = fwd_xt_get_match(r, "limit")) != NULL )
 		{
 			sprintf(buf, "%i/second", def->syn_rate);
-			fwd_xt_parse_match(r, m, "--limit", buf, 0);
+			fwd_xt_parse_match(r, m, "--limit", buf);
 
 			sprintf(buf, "%i", def->syn_burst);
-			fwd_xt_parse_match(r, m, "--limit-burst", buf, 0);
+			fwd_xt_parse_match(r, m, "--limit-burst", buf);
 		}
 
 		/* -j RETURN; -A syn_flood */
@@ -356,7 +163,7 @@ static void fwd_r_add_synflood(struct iptc_handle *h, struct fwd_defaults *def)
 		/* -m tcp --syn */
 		if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
 		{
-			fwd_xt_parse_match(r, m, "--syn", NULL, 0);
+			fwd_xt_parse_match(r, m, "--syn");
 		}
 
 		/* -j syn_flood; -A INPUT */
@@ -385,7 +192,7 @@ static void fwd_r_handle_reject(struct iptc_handle *h)
 		/* -j REJECT --reject-with tcp-reset */
 		if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
 		{
-			fwd_xt_parse_target(r, t, "--reject-with", "tcp-reset", 0);
+			fwd_xt_parse_target(r, t, "--reject-with", "tcp-reset");
 		}
 
 		/* -A handle_reject */
@@ -399,7 +206,7 @@ static void fwd_r_handle_reject(struct iptc_handle *h)
 		if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
 		{
 			fwd_xt_parse_target(r, t, "--reject-with",
-				"icmp-port-unreachable", 0);
+				"icmp-port-unreachable");
 		}
 
 		/* -A handle_reject */
@@ -441,6 +248,155 @@ static void fwd_r_handle_accept(struct iptc_handle *h)
 	}
 }
 
+/* add comment match */
+static void fwd_r_add_comment(
+	struct fwd_xt_rule *r, const char *t, struct fwd_zone *z,
+	struct fwd_network_list *n, struct fwd_network_list *n2
+) {
+	struct xtables_match *m;
+	char buf[256];
+
+	if( (m = fwd_xt_get_match(r, "comment")) != NULL )
+	{
+		if( (n != NULL) && (n2 != NULL) )
+			snprintf(buf, sizeof(buf), "%s:%s src:%s dest:%s",
+				t, z->name, n->name, n2->name);
+		else if( (n == NULL) && (n2 != NULL) )
+			snprintf(buf, sizeof(buf), "%s:%s dest:%s", t, z->name, n2->name);
+		else
+			snprintf(buf, sizeof(buf), "%s:%s src:%s", t, z->name, n->name);
+
+		fwd_xt_parse_match(r, m, "--comment", buf);
+	}
+}
+
+/* add --sport (if applicable) */
+static void fwd_r_add_sport(
+	struct fwd_xt_rule *r, struct fwd_portrange *p
+) {
+	int proto = r->entry->ip.proto;
+	char buf[12];
+	struct xtables_match *m;
+
+	/* have portrange and proto is tcp or udp ... */
+	if( (p != NULL) && ((proto == 6) || (proto == 17)) )
+	{
+		/* get match ... */
+		if( (m = fwd_xt_get_match(r, (proto == 6) ? "tcp" : "udp")) != NULL )
+		{
+			snprintf(buf, sizeof(buf), "%u:%u", p->min, p->max);
+			fwd_xt_parse_match(r, m, "--sport", buf);
+		}
+	}
+}
+
+/* add --dport (if applicable) */
+static void fwd_r_add_dport(
+	struct fwd_xt_rule *r, struct fwd_portrange *p
+) {
+	int proto = r->entry->ip.proto;
+	char buf[12];
+	struct xtables_match *m;
+
+	/* have portrange and proto is tcp or udp ... */
+	if( (p != NULL) && ((proto == 6) || (proto == 17)) )
+	{
+		/* get match ... */
+		if( (m = fwd_xt_get_match(r, (proto == 6) ? "tcp" : "udp")) != NULL )
+		{
+			snprintf(buf, sizeof(buf), "%u:%u", p->min, p->max);
+			fwd_xt_parse_match(r, m, "--dport", buf);
+		}
+	}
+}
+
+/* add --icmp-type (of applicable) */
+static void fwd_r_add_icmptype(
+	struct fwd_xt_rule *r, struct fwd_icmptype *i
+) {
+	int proto = r->entry->ip.proto;
+	struct xtables_match *m;
+	char buf[32];
+
+	/* have icmp-type and proto is icmp ... */
+	if( (i != NULL) && (proto == 1) )
+	{
+		/* get match ... */
+		if( (m = fwd_xt_get_match(r, "icmp")) != NULL )
+		{
+			if( i->name[0] )
+				snprintf(buf, sizeof(buf), "%s", i->name);
+			else
+				snprintf(buf, sizeof(buf), "%u/%u", i->type, i->code);
+
+			fwd_xt_parse_match(r, m, "--icmp-type", buf);
+		}
+	}
+}
+
+/* add -m mac --mac-source ... */
+static void fwd_r_add_srcmac(
+	struct fwd_xt_rule *r, struct fwd_mac *mac
+) {
+	struct xtables_match *m;
+	char buf[18];
+
+	if( mac != NULL )
+	{
+		if( (m = fwd_xt_get_match(r, "mac")) != NULL )
+		{
+			snprintf(buf, sizeof(buf), "%02x:%02x:%02x:%02x:%02x:%02x",
+				mac->mac[0], mac->mac[1], mac->mac[2],
+				mac->mac[3], mac->mac[4], mac->mac[5]);
+
+			fwd_xt_parse_match(r, m, "--mac-source", buf);
+		}
+	}
+}
+
+/* add policy target */
+static void fwd_r_add_policytarget(
+	struct fwd_xt_rule *r, enum fwd_policy pol
+) {
+	switch(pol)
+	{
+		case FWD_P_ACCEPT:
+			fwd_xt_get_target(r, "handle_accept");
+			break;
+
+		case FWD_P_REJECT:
+			fwd_xt_get_target(r, "handle_reject");
+			break;
+
+		case FWD_P_DROP:
+		case FWD_P_UNSPEC:
+			fwd_xt_get_target(r, "handle_drop");
+			break;
+	}
+}
+
+/* add dnat target */
+static void fwd_r_add_dnattarget(
+	struct fwd_xt_rule *r, struct fwd_cidr *c, struct fwd_portrange *p
+) {
+	struct xtables_target *t;
+	char buf[32];
+
+	if( c != NULL )
+	{
+		if( (t = fwd_xt_get_target(r, "DNAT")) != NULL )
+		{
+			if( p != NULL )
+				snprintf(buf, sizeof(buf), "%s:%u-%u",
+					inet_ntoa(c->addr), p->min, p->max);
+			else
+				snprintf(buf, sizeof(buf), "%s", inet_ntoa(c->addr));
+
+			fwd_xt_parse_target(r, t, "--to-destination", buf);
+		}
+	}
+}
+
 
 static void fwd_ipt_defaults_create(struct fwd_data *d)
 {
@@ -494,9 +450,10 @@ static void fwd_ipt_defaults_create(struct fwd_data *d)
 	fwd_r_jump_chain(h_filter, "FORWARD", "forwardings");
 	fwd_r_new_chain(h_nat, "zonemasq");
 	fwd_r_new_chain(h_nat, "redirects");
+	fwd_r_new_chain(h_nat, "loopback");
 	fwd_r_jump_chain(h_nat, "POSTROUTING", "zonemasq");
 	fwd_r_jump_chain(h_nat, "PREROUTING", "redirects");
-	fwd_r_jump_chain(h_nat, "POSTROUTING", "redirects");
+	fwd_r_jump_chain(h_nat, "POSTROUTING", "loopback");
 
 	/* standard drop, accept, reject chain */
 	fwd_r_handle_drop(h_filter);
@@ -589,12 +546,22 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 {
 	struct fwd_data *e;
 	struct fwd_zone *z;
-	struct fwd_ipt_rulebuf *b;
 	struct fwd_rule *c;
 	struct fwd_redirect *r;
 	struct fwd_forwarding *f;
 	struct fwd_addr_list *a, *a2;
 	struct fwd_network_list *n, *n2;
+	struct fwd_proto p;
+
+	struct fwd_xt_rule *x;
+	struct xtables_match *m;
+	struct xtables_target *t;
+
+	struct iptc_handle *h_filter, *h_nat;
+
+	if( !(h_filter = iptc_init("filter")) || !(h_nat = iptc_init("nat")) )
+		fwd_fatal("Unable to obtain libiptc handle");
+
 
 	if( !(z = fwd_lookup_zone(h, net)) )
 		return;
@@ -612,10 +579,13 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 	{
 		printf("\n# Net %s (%s) - masq\n", n->name, n->ifname);
 
-		b = fwd_ipt_init("nat");
-		fwd_ipt_add_format(b, " -A zonemasq -o %s -j MASQUERADE", n->ifname);
-		fwd_ipt_add_comment(b, "masq", z, NULL, n);
-		fwd_ipt_exec(b);
+		if( (x = fwd_xt_init_rule(h_nat)) != NULL )
+		{
+			fwd_xt_parse_out(x, n, 0);					/* -o ... */
+			fwd_xt_get_target(x, "MASQUERADE");			/* -j MASQUERADE */
+			fwd_r_add_comment(x, "masq", z, NULL, n);	/* -m comment ... */
+			fwd_xt_exec_rule(x, "zonemasq");			/* -A zonemasq */
+		}
 	}
 
 	/* Build MSS fix rule */
@@ -623,12 +593,26 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 	{
 		printf("\n# Net %s (%s) - mtu_fix\n", n->name, n->ifname);
 
-		b = fwd_ipt_init("filter");
-		fwd_ipt_add_format(b,
-			" -A mssfix -o %s -p tcp --tcp-flags SYN,RST SYN"
-			" -j TCPMSS --clamp-mss-to-pmtu", n->ifname);
-		fwd_ipt_add_comment(b, "mssfix", z, NULL, n);
-		fwd_ipt_exec(b);
+		if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+		{
+			p.type = FWD_PR_TCP;
+			fwd_xt_parse_out(x, n, 0);					/* -o ... */
+			fwd_xt_parse_proto(x, &p, 0);				/* -p tcp */
+
+			/* -m tcp --tcp-flags SYN,RST SYN */
+			if( (m = fwd_xt_get_match(x, "tcp")) != NULL )
+				fwd_xt_parse_match(x, m, "--tcp-flags", "SYN,RST", "SYN");
+
+			/* -j TCPMSS --clamp-mss-to-pmtu */
+			if( (t = fwd_xt_get_target(x, "TCPMSS")) != NULL )
+				fwd_xt_parse_target(x, t, "--clamp-mss-to-pmtu");
+
+			/* -m comment ... */
+			fwd_r_add_comment(x, "mssfix", z, NULL, n);
+
+			/* -A mssfix */
+			fwd_xt_exec_rule(x, "mssfix");
+		}
 	}
 
 	/* Build intra-zone forwarding rules */
@@ -641,12 +625,14 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 				n->name, n->ifname, z->name, n->name, n->ifname,
 				z->name, n2->name, n2->ifname);
 
-			b = fwd_ipt_init("filter");
-			fwd_ipt_add_format(b, " -A zones -i %s -o %s",
-				n->ifname, n2->ifname);
-			fwd_ipt_add_policy_target(b, z->forward);
-			fwd_ipt_add_comment(b, "zone", z, n, n2);
-			fwd_ipt_exec(b);
+			if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+			{
+				fwd_xt_parse_in(x, n, 0);				/* -i ... */
+				fwd_xt_parse_out(x, n2, 0);				/* -o ... */
+				fwd_r_add_policytarget(x, z->forward);	/* -j handle_... */
+				fwd_r_add_comment(x, "zone", z, n, n2);	/* -m comment ... */
+				fwd_xt_exec_rule(x, "zones");			/* -A zones */
+			}
 		}
 	}
 
@@ -661,12 +647,14 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 				f->dest->name, n2->name, n2->ifname);
 
 			/* Build forwarding rule */
-			b = fwd_ipt_init("filter");
-			fwd_ipt_add_format(b, " -A forwardings -i %s -o %s",
-				n->ifname, n2->ifname);
-			fwd_ipt_add_policy_target(b, FWD_P_ACCEPT);
-			fwd_ipt_add_comment(b, "forward", z, n, n2);
-			fwd_ipt_exec(b);
+			if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+			{
+				fwd_xt_parse_in(x, n, 0);					/* -i ... */
+				fwd_xt_parse_out(x, n2, 0);					/* -o ... */
+				fwd_r_add_policytarget(x, FWD_P_ACCEPT);	/* -j handle_... */
+				fwd_r_add_comment(x, "forward", z, n, n2);	/* -m comment ... */
+				fwd_xt_exec_rule(x, "forwardings");			/* -A forwardings */
+			}
 		}
 	}
 
@@ -677,43 +665,49 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 			n->name, n->ifname, z->name, n->name, n->ifname);
 
 		/* DNAT */
-		b = fwd_ipt_init("nat");
-		fwd_ipt_add_format(b, " -A redirects -i %s -d %s",
-			n->ifname, inet_ntoa(a->ipaddr.v4));
-		fwd_ipt_add_proto(b, r->proto);
-		fwd_ipt_add_srcaddr(b, r->src_ip);
-		fwd_ipt_add_srcport(b, r->src_port);
-		fwd_ipt_add_destport(b, r->src_dport);
-		fwd_ipt_add_srcmac(b, r->src_mac);
-		fwd_ipt_add_dnat_target(b, r->dest_ip, r->dest_port);
-		fwd_ipt_add_comment(b, "redir", z, n, NULL);
-		fwd_ipt_exec(b);
+		if( (x = fwd_xt_init_rule(h_nat)) != NULL )
+		{
+			fwd_xt_parse_in(x, n, 0);					/* -i ... */
+			fwd_xt_parse_src(x, r->src_ip, 0);			/* -s ... */
+			fwd_xt_parse_dest(x, &a->ipaddr, 0);		/* -d ... */
+			fwd_xt_parse_proto(x, r->proto, 0);			/* -p ... */
+			fwd_r_add_sport(x, r->src_port);			/* --sport ... */
+			fwd_r_add_dport(x, r->src_dport);			/* --dport ... */
+			fwd_r_add_srcmac(x, r->src_mac);			/* -m mac --mac-source ... */
+			fwd_r_add_dnattarget(x, r->dest_ip, r->dest_port);	/* -j DNAT ... */
+			fwd_r_add_comment(x, "redir", z, n, NULL);	/* -m comment ... */
+			fwd_xt_exec_rule(x, "redirects");			/* -A redirects */
+		}
 
 		/* Forward */
-		b = fwd_ipt_init("filter");
-		fwd_ipt_add_format(b, " -A redirects -i %s", n->ifname);
-		fwd_ipt_add_proto(b, r->proto);
-		fwd_ipt_add_srcmac(b, r->src_mac);
-		fwd_ipt_add_srcaddr(b, r->src_ip);
-		fwd_ipt_add_srcport(b, r->src_port);
-		fwd_ipt_add_destaddr(b, r->dest_ip);
-		fwd_ipt_add_destport(b, r->dest_port);
-		fwd_ipt_add_policy_target(b, FWD_P_ACCEPT);
-		fwd_ipt_add_comment(b, "redir", z, n, NULL);
-		fwd_ipt_exec(b);
+		if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+		{
+			fwd_xt_parse_in(x, n, 0);					/* -i ... */
+			fwd_xt_parse_src(x, r->src_ip, 0);			/* -s ... */
+			fwd_xt_parse_dest(x, r->dest_ip, 0);		/* -d ... */
+			fwd_xt_parse_proto(x, r->proto, 0);			/* -p ... */
+			fwd_r_add_srcmac(x, r->src_mac);			/* -m mac --mac-source ... */
+			fwd_r_add_sport(x, r->src_port);			/* --sport ... */
+			fwd_r_add_dport(x, r->dest_port);			/* --dport ... */
+			fwd_r_add_policytarget(x, FWD_P_ACCEPT);	/* -j handle_accept */
+			fwd_r_add_comment(x, "redir", z, n, NULL);	/* -m comment ... */
+			fwd_xt_exec_rule(x, "redirects");			/* -A redirects */
+		}
 
 		/* Add loopback rule if neither src_ip nor src_mac are defined */
 		if( !r->src_ip && !r->src_mac )
 		{
-			b = fwd_ipt_init("nat");
-			fwd_ipt_add_format(b, " -A redirects -i ! %s -d %s",
-				n->ifname, inet_ntoa(r->dest_ip->addr));
-			fwd_ipt_add_proto(b, r->proto);
-			fwd_ipt_add_srcport(b, r->src_port);
-			fwd_ipt_add_destport(b, r->src_dport);
-			fwd_ipt_add_format(b, " -j MASQUERADE");
-			fwd_ipt_add_comment(b, "redir", z, n, NULL);
-			fwd_ipt_exec(b);
+			if( (x = fwd_xt_init_rule(h_nat)) != NULL )
+			{
+				fwd_xt_parse_in(x, n, 1);					/* -i ! ... */
+				fwd_xt_parse_dest(x, r->dest_ip, 0);		/* -d ... */
+				fwd_xt_parse_proto(x, r->proto, 0);			/* -p ... */
+				fwd_r_add_sport(x, r->src_port);			/* --sport ... */
+				fwd_r_add_dport(x, r->src_dport);			/* --dport ... */
+				fwd_xt_get_target(x, "MASQUERADE");			/* -j MASQUERADE */
+				fwd_r_add_comment(x, "redir", z, n, NULL);	/* -m comment ... */
+				fwd_xt_exec_rule(x, "loopback");			/* -A loopback */
+			}
 		}
 	}
 
@@ -730,19 +724,21 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 					n->name, n->ifname, z->name, n->name, n->ifname,
 					f->dest->name, n2->name, n2->ifname);
 
-				b = fwd_ipt_init("filter");
-				fwd_ipt_add_format(b, " -A rules -i %s -o %s",
-					n->ifname, n2->ifname);
-				fwd_ipt_add_proto(b, c->proto);
-				fwd_ipt_add_icmptype(b, c->icmp_type);
-				fwd_ipt_add_srcmac(b, c->src_mac);
-				fwd_ipt_add_srcaddr(b, c->src_ip);
-				fwd_ipt_add_srcport(b, c->src_port);
-				fwd_ipt_add_destaddr(b, c->dest_ip);
-				fwd_ipt_add_destport(b, c->dest_port);
-				fwd_ipt_add_policy_target(b, c->target);
-				fwd_ipt_add_comment(b, "rule", z, n, n2);
-				fwd_ipt_exec(b);
+				if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+				{
+					fwd_xt_parse_in(x, n, 0);				/* -i ... */
+					fwd_xt_parse_out(x, n2, 0);				/* -o ... */
+					fwd_xt_parse_src(x, c->src_ip, 0);		/* -s ... */
+					fwd_xt_parse_dest(x, c->dest_ip, 0);	/* -d ... */
+					fwd_xt_parse_proto(x, c->proto, 0);		/* -p ... */
+					fwd_r_add_icmptype(x, c->icmp_type);	/* --icmp-type ... */
+					fwd_r_add_srcmac(x, c->src_mac);		/* --mac-source ... */
+					fwd_r_add_sport(x, c->src_port);		/* --sport ... */
+					fwd_r_add_dport(x, c->dest_port);		/* --dport ... */
+					fwd_r_add_policytarget(x, c->target);	/* -j handle_... */
+					fwd_r_add_comment(x, "rule", z, n, n2);	/* -m comment ... */
+					fwd_xt_exec_rule(x, "rules");			/* -A rules */
+				}
 			}
 		}
 
@@ -752,19 +748,30 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 			printf("\n# Net %s (%s) - rule Z:%s N:%s I:%s\n",
 				n->name, n->ifname, z->name, n->name, n->ifname);
 
-			b = fwd_ipt_init("filter");
-			fwd_ipt_add_format(b, " -A rules -i %s", n->ifname);
-			fwd_ipt_add_proto(b, c->proto);
-			fwd_ipt_add_icmptype(b, c->icmp_type);
-			fwd_ipt_add_srcmac(b, c->src_mac);
-			fwd_ipt_add_srcaddr(b, c->src_ip);
-			fwd_ipt_add_srcport(b, c->src_port);
-			fwd_ipt_add_destaddr(b, c->dest_ip);
-			fwd_ipt_add_destport(b, c->dest_port);
-			fwd_ipt_add_policy_target(b, c->target);
-			fwd_ipt_add_comment(b, "rule", z, n, n2);
-			fwd_ipt_exec(b);
+			if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+			{
+				fwd_xt_parse_in(x, n, 0);					/* -i ... */
+				fwd_xt_parse_src(x, c->src_ip, 0);			/* -s ... */
+				fwd_xt_parse_dest(x, c->dest_ip, 0);		/* -d ... */
+				fwd_xt_parse_proto(x, c->proto, 0);			/* -p ... */
+				fwd_r_add_icmptype(x, c->icmp_type);		/* --icmp-type ... */
+				fwd_r_add_srcmac(x, c->src_mac);			/* --mac-source ... */
+				fwd_r_add_sport(x, c->src_port);			/* --sport ... */
+				fwd_r_add_dport(x, c->dest_port);			/* --dport ... */
+				fwd_r_add_policytarget(x, c->target);		/* -j handle_... */
+				fwd_r_add_comment(x, "rule", z, n, NULL);	/* -m comment ... */
+				fwd_xt_exec_rule(x, "rules");				/* -A rules */
+			}
 		}
 	}
+
+	if( !iptc_commit(h_nat) )
+		fwd_fatal("Cannot commit nat table: %s", iptc_strerror(errno));
+
+	if( !iptc_commit(h_filter) )
+		fwd_fatal("Cannot commit filter table: %s", iptc_strerror(errno));
+
+	iptc_free(h_nat);
+	iptc_free(h_filter);
 }