contrib/fwd: simplify ruleset, initial xtables integration
authorJo-Philipp Wich <jow@openwrt.org>
Tue, 15 Dec 2009 11:21:42 +0000 (11:21 +0000)
committerJo-Philipp Wich <jow@openwrt.org>
Tue, 15 Dec 2009 11:21:42 +0000 (11:21 +0000)
contrib/fwd/src/fwd_rules.c

index 9c233417ef6af47aafdeca9c8aeabd89fe3729ef..c3d4ebbe5332fadab9e7f1da00211fb4963dd33e 100644 (file)
@@ -20,6 +20,7 @@
 #include "fwd.h"
 #include "fwd_addr.h"
 #include "fwd_rules.h"
+#include "fwd_xtables.h"
 
 static void
 fwd_ipt_rule_append(struct fwd_ipt_rulebuf *r, const char *fmt, ...)
@@ -179,6 +180,33 @@ static void fwd_ipt_add_dnat_target(
        }
 }
 
+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 )
@@ -188,223 +216,302 @@ static void fwd_ipt_exec(struct fwd_ipt_rulebuf *r)
        fwd_free_ptr(r);
 }
 
-static const char * fwd_str_policy(enum fwd_policy pol)
-{
-       return (pol == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
+/* -P <chain> <policy> */
+static void fwd_r_set_policy(
+       struct iptc_handle *h, const char *chain, const char *policy
+) {
+       iptc_set_policy(chain, policy, NULL, h);
 }
 
-static const char * fwd_str_target(enum fwd_policy pol)
+/* -N <chain> */
+static void fwd_r_new_chain(struct iptc_handle *h, const char *chain)
 {
-       switch(pol)
-       {
-               case FWD_P_ACCEPT:
-                       return "ACCEPT";
+       iptc_create_chain(chain, h);
+}
 
-               case FWD_P_REJECT:
-                       return "REJECT";
+/* -A <chain1> -j <chain2> */
+static void fwd_r_jump_chain(
+       struct iptc_handle *h, const char *chain1, const char *chain2
+) {
+       struct fwd_xt_rule *r;
 
-               default:
-                       return "DROP";
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               fwd_xt_get_target(r, chain2);
+               fwd_xt_exec_rule(r, chain1);
        }
-
-       return "DROP";
 }
 
-
-static void fwd_ipt_defaults_create(struct fwd_data *d)
+/* -A <chain> -m state --state INVALID -j DROP */
+static void fwd_r_drop_invalid(struct iptc_handle *h, const char *chain)
 {
-       struct fwd_defaults *def = &d->section.defaults;
-
-       /* policies */
-       fwd_ipt_exec_format("filter", " -P INPUT %s", fwd_str_policy(def->input));
-       fwd_ipt_exec_format("filter", " -P OUTPUT %s", fwd_str_policy(def->output));
-       fwd_ipt_exec_format("filter", " -P FORWARD %s", fwd_str_policy(def->forward));
+       struct fwd_xt_rule *r;
+       struct xtables_match *m;
 
-       /* invalid state drop */
-       if( def->drop_invalid )
+       if( (r = fwd_xt_init_rule(h)) != NULL )
        {
-               fwd_ipt_exec_format("filter", " -A INPUT --state INVALID -j DROP");
-               fwd_ipt_exec_format("filter", " -A OUTPUT --state INVALID -j DROP");
-               fwd_ipt_exec_format("filter", " -A FORWARD --state INVALID -j DROP");
+               if( (m = fwd_xt_get_match(r, "state")) != NULL )
+               {
+                       fwd_xt_parse_match(r, m, "--state", "INVALID", 0);
+                       fwd_xt_get_target(r, "DROP");
+                       fwd_xt_exec_rule(r, chain);
+               }
        }
+}
 
-       /* default accept related */
-       fwd_ipt_exec_format("filter", " -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT");
-       fwd_ipt_exec_format("filter", " -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT");
-       fwd_ipt_exec_format("filter", " -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT");
-
-       /* default accept on lo */
-       fwd_ipt_exec_format("filter", " -A INPUT -i lo -j ACCEPT");
-       fwd_ipt_exec_format("filter", " -A OUTPUT -o lo -j ACCEPT");
+/* -A <chain> -m state --state RELATED,ESTABLISHED -j ACCEPT */
+static void fwd_r_accept_related(struct iptc_handle *h, const char *chain)
+{
+       struct fwd_xt_rule *r;
+       struct xtables_match *m;
 
-       /* syn flood protection */
-       if( def->syn_flood )
+       if( (r = fwd_xt_init_rule(h)) != NULL )
        {
-               fwd_ipt_exec_format("filter", " -N syn_flood");
+               if( (m = fwd_xt_get_match(r, "state")) != NULL )
+               {
+                       fwd_xt_parse_match(r, m, "--state", "RELATED,ESTABLISHED", 0);
+                       fwd_xt_get_target(r, "ACCEPT");
+                       fwd_xt_exec_rule(r, chain);
+               }
+       }
+}
 
-               fwd_ipt_exec_format("filter",
-                       " -A syn_flood -p tcp --syn -m limit --limit %i/second"
-                       " --limit-burst %i -j RETURN",
-                               def->syn_rate, def->syn_burst);
+/* -A INPUT -i lo -j ACCEPT; -A OUTPUT -o lo -j ACCEPT */
+static void fwd_r_accept_lo(struct iptc_handle *h)
+{
+       struct fwd_network_list n;
+       struct fwd_xt_rule *r;
 
-               fwd_ipt_exec_format("filter", " -A syn_flood -j DROP");
-               fwd_ipt_exec_format("filter", " -A INPUT -p tcp --syn -j syn_flood");
+       n.ifname = "lo";
+
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               fwd_xt_parse_in(r, &n, 0);
+               fwd_xt_get_target(r, "ACCEPT");
+               fwd_xt_exec_rule(r, "INPUT");
        }
 
-       /* standard input/output/forward chain */
-       fwd_ipt_exec_format("filter", " -N input");
-       fwd_ipt_exec_format("filter", " -N output");
-       fwd_ipt_exec_format("filter", " -N forward");
-       fwd_ipt_exec_format("filter", " -A INPUT -j input");
-       fwd_ipt_exec_format("filter", " -A OUTPUT -j output");
-       fwd_ipt_exec_format("filter", " -A FORWARD -j forward");
-
-       /* standard reject chain */
-       fwd_ipt_exec_format("filter", " -N reject");
-       fwd_ipt_exec_format("filter", " -A reject -p tcp -j REJECT --reject-with tcp-reset");
-       fwd_ipt_exec_format("filter", " -A reject -j REJECT --reject-with icmp-port-unreachable");
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               fwd_xt_parse_out(r, &n, 0);
+               fwd_xt_get_target(r, "ACCEPT");
+               fwd_xt_exec_rule(r, "OUTPUT");
+       }
 }
 
-static void fwd_ipt_zone_create(struct fwd_data *d)
+/* build syn_flood chain and jump rule */
+static void fwd_r_add_synflood(struct iptc_handle *h, struct fwd_defaults *def)
 {
-       struct fwd_zone *z = &d->section.zone;
+       struct fwd_proto p;
+       struct fwd_xt_rule *r;
+       struct xtables_match *m;
+       char buf[32];
 
-       if( !strcmp(z->name, "loopback") )
-               return;
+       /* -N syn_flood */
+       fwd_r_new_chain(h, "syn_flood");
+
+       /* return rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               /* -p tcp */
+               p.type = FWD_PR_TCP;
+               fwd_xt_parse_proto(r, &p, 0);
 
-       fwd_ipt_exec_format("filter", " -N zone_%s",         z->name);
-       fwd_ipt_exec_format("filter", " -N zone_%s_forward", z->name);
-       fwd_ipt_exec_format("filter", " -N zone_%s_ACCEPT",  z->name);
-       fwd_ipt_exec_format("filter", " -N zone_%s_REJECT",  z->name);
-       fwd_ipt_exec_format("filter", " -N zone_%s_DROP",    z->name);
-       fwd_ipt_exec_format("filter", " -N zone_%s_MSSFIX",  z->name);
+               /* -m tcp --syn */
+               if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
+               {
+                       fwd_xt_parse_match(r, m, "--syn", NULL, 0);
+               }
 
-       if( z->forward != FWD_P_UNSPEC )
-               fwd_ipt_exec_format("filter", " -A zone_%s_forward -j zone_%s_%s",
-                       z->name, z->name, fwd_str_target(z->forward));
+               /* -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);
 
-       if( z->input != FWD_P_UNSPEC )
-               fwd_ipt_exec_format("filter", " -A zone_%s -j zone_%s_%s",
-                       z->name, z->name, fwd_str_target(z->input));
+                       sprintf(buf, "%i", def->syn_burst);
+                       fwd_xt_parse_match(r, m, "--limit-burst", buf, 0);
+               }
 
-       if( z->output != FWD_P_UNSPEC )
-               fwd_ipt_exec_format("filter", " -A output -j zone_%s_%s",
-                       z->name, fwd_str_target(z->output));
+               /* -j RETURN; -A syn_flood */
+               fwd_xt_get_target(r, "RETURN");
+               fwd_xt_exec_rule(r, "syn_flood");
+       }
 
-       fwd_ipt_exec_format("nat", " -N zone_%s_nat",        z->name);
-       fwd_ipt_exec_format("nat", " -N zone_%s_prerouting", z->name);
-       fwd_ipt_exec_format("raw", " -N zone_%s_notrack",    z->name);
+       /* drop rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {       
+               /* -j DROP; -A syn_flood */
+               fwd_xt_get_target(r, "DROP");
+               fwd_xt_exec_rule(r, "syn_flood");
+       }
 
-       if( z->masq )
-               fwd_ipt_exec_format("nat", " -A POSTROUTING -j zone_%s_nat",
-                       z->name);
+       /* jump to syn_flood rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {       
+               /* -p tcp */
+               p.type = FWD_PR_TCP;
+               fwd_xt_parse_proto(r, &p, 0);
 
-       if( z->mtu_fix )
-               fwd_ipt_exec_format("filter", " -A FORWARD -j zone_%s_MSSFIX",
-                       z->name);
+               /* -m tcp --syn */
+               if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
+               {
+                       fwd_xt_parse_match(r, m, "--syn", NULL, 0);
+               }
+
+               /* -j syn_flood; -A INPUT */
+               fwd_xt_get_target(r, "syn_flood");
+               fwd_xt_exec_rule(r, "INPUT");
+       }
 }
 
-static void fwd_ipt_forwarding_create(struct fwd_data *d)
+/* build reject target chain */
+static void fwd_r_handle_reject(struct iptc_handle *h)
 {
-       struct fwd_forwarding *f = &d->section.forwarding;
-       struct fwd_ipt_rulebuf *b;
+       struct fwd_proto p;
+       struct fwd_xt_rule *r;
+       struct xtables_target *t;
 
-       b = fwd_ipt_init("filter");
+       /* -N handle_reject */
+       fwd_r_new_chain(h, "handle_reject");
 
-       if( f->src )
-               fwd_ipt_add_format(b, " -I zone_%s_forward 1", f->src->name);
-       else
-               fwd_ipt_add_format(b, " -I forward 1");
+       /* tcp reject rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               /* -p tcp */
+               p.type = FWD_PR_TCP;
+               fwd_xt_parse_proto(r, &p, 0);
 
-       if( f->dest )
-               fwd_ipt_add_format(b, " -j zone_%s_ACCEPT", f->dest->name);
-       else
-               fwd_ipt_add_format(b, " -j ACCEPT");
+               /* -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);
+               }
+
+               /* -A handle_reject */
+               fwd_xt_exec_rule(r, "handle_reject");
+       }
+
+       /* common reject rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               /* -j REJECT --reject-with icmp-port-unreachable */
+               if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
+               {
+                       fwd_xt_parse_target(r, t, "--reject-with",
+                               "icmp-port-unreachable", 0);
+               }
 
-       fwd_ipt_exec(b);
+               /* -A handle_reject */
+               fwd_xt_exec_rule(r, "handle_reject");
+       }
 }
 
-static void fwd_ipt_redirect_create(struct fwd_data *d)
+/* build drop target chain */
+static void fwd_r_handle_drop(struct iptc_handle *h)
 {
-       struct fwd_redirect *r = &d->section.redirect;
-       struct fwd_ipt_rulebuf *b;
+       struct fwd_xt_rule *r;
+
+       /* -N handle_drop */
+       fwd_r_new_chain(h, "handle_drop");
 
-       b = fwd_ipt_init("nat");
-       fwd_ipt_add_format(b, " -A zone_%s_prerouting", r->src->name);
-       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_exec(b);
-
-       b = fwd_ipt_init("nat");
-       fwd_ipt_add_format(b, " -I zone_%s_forward 1", r->src->name);
-       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_format(b, " -j ACCEPT");
-       fwd_ipt_exec(b);
+       /* common drop rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               /* -j DROP; -A handle_reject */
+               fwd_xt_get_target(r, "DROP");
+               fwd_xt_exec_rule(r, "handle_reject");
+       }
 }
 
-static void fwd_ipt_rule_create(struct fwd_data *d)
+/* build accept target chain */
+static void fwd_r_handle_accept(struct iptc_handle *h)
 {
-       struct fwd_rule *r = &d->section.rule;
-       struct fwd_ipt_rulebuf *b;
+       struct fwd_xt_rule *r;
 
-       b = fwd_ipt_init("filter");
+       /* -N handle_accept */
+       fwd_r_new_chain(h, "handle_accept");
 
-       if( r->dest )
-               fwd_ipt_add_format(b, " -A zone_%s_forward", r->src->name);
-       else
-               fwd_ipt_add_format(b, " -A zone_%s", r->src->name);
-
-       fwd_ipt_add_proto(b, r->proto);
-       fwd_ipt_add_icmptype(b, r->icmp_type);
-       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);
-
-       if( r->dest )
-               fwd_ipt_add_format(b, " -j zone_%s_%s",
-                       r->dest->name, fwd_str_target(r->target));
-       else
-               fwd_ipt_add_format(b, " -j %s", fwd_str_target(r->target));
-
-       fwd_ipt_exec(b);
+       /* common accept rule */
+       if( (r = fwd_xt_init_rule(h)) != NULL )
+       {
+               /* -j ACCEPT; -A handle_accept */
+               fwd_xt_get_target(r, "ACCEPT");
+               fwd_xt_exec_rule(r, "handle_accept");
+       }
 }
 
 
-static struct fwd_network_list *
-fwd_lookup_network(struct fwd_network_list *n, const char *net)
+static void fwd_ipt_defaults_create(struct fwd_data *d)
 {
-       struct fwd_network_list *e;
+       struct fwd_defaults *def = &d->section.defaults;
+       struct iptc_handle *h_filter, *h_nat;
 
-       if( n != NULL )
-               for( e = n; e; e = e->next )
-                       if( !strcmp(e->name, net) )
-                               return e;
+       if( !(h_filter = iptc_init("filter")) || !(h_nat = iptc_init("nat")) )
+               fwd_fatal("Unable to obtain libiptc handle");
 
-       return NULL;
-}
+       /* policies */
+       fwd_r_set_policy(h_filter, "INPUT",
+               def->input == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
+       fwd_r_set_policy(h_filter, "OUTPUT",
+               def->output == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
+       fwd_r_set_policy(h_filter, "FORWARD",
+               def->forward == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
 
-static struct fwd_addr_list *
-fwd_lookup_addr(struct fwd_addr_list *a, const char *ifname)
-{
-       struct fwd_addr_list *e;
+       /* invalid state drop */
+       if( def->drop_invalid )
+       {
+               fwd_r_drop_invalid(h_filter, "INPUT");
+               fwd_r_drop_invalid(h_filter, "OUTPUT");
+               fwd_r_drop_invalid(h_filter, "FORWARD");
+       }
 
-       if( a != NULL )
-               for( e = a; e; e = e->next )
-                       if( !strcmp(e->ifname, ifname) )
-                               return e;
+       /* default accept related */
+       fwd_r_accept_related(h_filter, "INPUT");
+       fwd_r_accept_related(h_filter, "OUTPUT");
+       fwd_r_accept_related(h_filter, "FORWARD");
 
-       return NULL;
+       /* default accept on lo */
+       fwd_r_accept_lo(h_filter);
+
+       /* syn flood protection */
+       if( def->syn_flood )
+       {
+               fwd_r_add_synflood(h_filter, def);
+       }
+
+       /* rule container chains */
+       fwd_r_new_chain(h_filter, "mssfix");
+       fwd_r_new_chain(h_filter, "zones");
+       fwd_r_new_chain(h_filter, "rules");
+       fwd_r_new_chain(h_filter, "redirects");
+       fwd_r_new_chain(h_filter, "forwardings");
+       fwd_r_jump_chain(h_filter, "INPUT", "rules");
+       fwd_r_jump_chain(h_filter, "FORWARD", "mssfix");
+       fwd_r_jump_chain(h_filter, "FORWARD", "zones");
+       fwd_r_jump_chain(h_filter, "FORWARD", "rules");
+       fwd_r_jump_chain(h_filter, "FORWARD", "redirects");
+       fwd_r_jump_chain(h_filter, "FORWARD", "forwardings");
+       fwd_r_new_chain(h_nat, "zonemasq");
+       fwd_r_new_chain(h_nat, "redirects");
+       fwd_r_jump_chain(h_nat, "POSTROUTING", "zonemasq");
+       fwd_r_jump_chain(h_nat, "PREROUTING", "redirects");
+       fwd_r_jump_chain(h_nat, "POSTROUTING", "redirects");
+
+       /* standard drop, accept, reject chain */
+       fwd_r_handle_drop(h_filter);
+       fwd_r_handle_accept(h_filter);
+       fwd_r_handle_reject(h_filter);
+
+
+       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);
 }
 
 
@@ -412,6 +519,8 @@ void fwd_ipt_build_ruleset(struct fwd_handle *h)
 {
        struct fwd_data *e;
 
+       fwd_xt_init();
+
        for( e = h->conf; e; e = e->next )
        {
                switch(e->type)
@@ -421,97 +530,241 @@ void fwd_ipt_build_ruleset(struct fwd_handle *h)
                                fwd_ipt_defaults_create(e);
                                break;
 
-                       case FWD_S_ZONE:
-                               printf("\n## ZONE %s\n", e->section.zone.name);
-                               fwd_ipt_zone_create(e);
+                       case FWD_S_INCLUDE:
+                               printf("\n## INCLUDE %s\n", e->section.include.path);
                                break;
 
+                       case FWD_S_ZONE:
                        case FWD_S_FORWARD:
-                               printf("\n## FORWARD %s -> %s\n",
-                                       e->section.forwarding.src
-                                               ? e->section.forwarding.src->name : "(all)",
-                                       e->section.forwarding.dest
-                                               ? e->section.forwarding.dest->name : "(all)");
-                               fwd_ipt_forwarding_create(e);
-                               break;
-
                        case FWD_S_REDIRECT:
-                               printf("\n## REDIRECT %s\n", e->section.forwarding.src->name);
-                               fwd_ipt_redirect_create(e);
-                               break;
-
                        case FWD_S_RULE:
-                               printf("\n## RULE %s\n", e->section.rule.src->name);
-                               fwd_ipt_rule_create(e);
-                               break;
-
-                       case FWD_S_INCLUDE:
-                               printf("\n## INCLUDE %s\n", e->section.include.path);
+                               /* Make gcc happy */
                                break;
                }
        }
 }
 
-void fwd_ipt_addif(struct fwd_handle *h, const char *net)
+
+static struct fwd_zone *
+fwd_lookup_zone(struct fwd_handle *h, const char *net)
 {
        struct fwd_data *e;
-       struct fwd_zone *z;
-       struct fwd_addr_list *a;
        struct fwd_network_list *n;
 
        for( e = h->conf; e; e = e->next )
-       {
-               if( (e->type != FWD_S_ZONE) ||
-            !(n = fwd_lookup_network(e->section.zone.networks, net)) ||
-                       !(a = fwd_lookup_addr(h->addrs, n->ifname)) )
-                               continue;
+               if( e->type == FWD_S_ZONE )
+                       for( n = e->section.zone.networks; n; n = n->next )
+                               if( !strcmp(n->name, net) )
+                                       return &e->section.zone;
+
+       return NULL;
+}
+
+static struct fwd_network_list *
+fwd_lookup_network(struct fwd_zone *z, const char *net)
+{
+       struct fwd_network_list *n;
+
+       for( n = z->networks; n; n = n->next )
+               if( !strcmp(n->name, net) )
+                       return n;
+
+       return NULL;
+}
 
-               z = &e->section.zone;
+static struct fwd_addr_list *
+fwd_lookup_addr(struct fwd_handle *h, struct fwd_network_list *n)
+{
+       struct fwd_addr_list *a;
 
-               printf("\n## NETWORK %s (%s - %s/%u)\n",
-                       n->name, n->ifname,
-                       inet_ntoa(a->ipaddr.v4), a->prefix
-               );
+       if( n != NULL )
+               for( a = h->addrs; a; a = a->next )
+                       if( !strcmp(a->ifname, n->ifname) )
+                               return a;
 
-               fwd_ipt_exec_format("filter", " -A input -i %s -j zone_%s",
-                       n->ifname, z->name);
+       return NULL;
+}
 
-               fwd_ipt_exec_format("filter",
-                       " -I zone_%s_MSSFIX 1 -o %s -p tcp --tcp-flags SYN,RST SYN"
-                       " -j TCPMSS --clamp-mss-to-pmtu",
-                               z->name, n->ifname);
+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;
+
+       if( !(z = fwd_lookup_zone(h, net)) )
+               return;
+
+       if( !(n = fwd_lookup_network(z, net)) )
+               return;
 
-               fwd_ipt_exec_format("filter", " -I zone_%s_ACCEPT 1 -o %s -j ACCEPT",
-                       z->name, n->ifname);
+       if( !(a = fwd_lookup_addr(h, n)) )
+               return;
 
-               fwd_ipt_exec_format("filter", " -I zone_%s_DROP 1 -o %s -j DROP",
-                       z->name, n->ifname);
+       printf("\n\n#\n# addif(%s)\n#\n", net);
 
-               fwd_ipt_exec_format("filter", " -I zone_%s_REJECT 1 -o %s -j reject",
-                       z->name, n->ifname);
+       /* Build masquerading rule */
+       if( z->masq )
+       {
+               printf("\n# Net %s (%s) - masq\n", n->name, n->ifname);
 
-               fwd_ipt_exec_format("filter", " -I zone_%s_ACCEPT 1 -i %s -j ACCEPT",
-                       z->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);
+       }
 
-               fwd_ipt_exec_format("filter", " -I zone_%s_DROP 1 -i %s -j DROP",
-                       z->name, n->ifname);
+       /* Build MSS fix rule */
+       if( z->mtu_fix )
+       {
+               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);
+       }
 
-               fwd_ipt_exec_format("filter", " -I zone_%s_REJECT 1 -i %s -j reject",
-                       z->name, n->ifname);
+       /* Build intra-zone forwarding rules */
+       for( n2 = z->networks; n2; n2 = n2->next )
+       {
+               if( (a2 = fwd_lookup_addr(h, n2)) != NULL )
+               {
+                       printf("\n# Net %s (%s) - intra-zone-forwarding"
+                              " Z:%s N:%s I:%s -> Z:%s N:%s I:%s\n",
+                               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);
+               }
+       }
 
-               fwd_ipt_exec_format("filter",
-                       " -I zone_%s_nat 1 -t nat -o %s -j MASQUERADE",
-                               z->name, n->ifname);
+       /* Build inter-zone forwarding rules */
+       for( e = z->forwardings; e && (f = &e->section.forwarding); e = e->next )
+       {
+               for( n2 = f->dest->networks; n2; n2 = n2->next )
+               {
+                       printf("\n# Net %s (%s) - inter-zone-forwarding"
+                   " Z:%s N:%s I:%s -> Z:%s N:%s I:%s\n",
+                               n->name, n->ifname, z->name, n->name, n->ifname,
+                               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);
+               }
+       }
 
-               fwd_ipt_exec_format("filter",
-                       " -I PREROUTING 1 -t nat -i %s -j zone_%s_prerouting",
-                               n->ifname, z->name);
+       /* Build DNAT rules */
+       for( e = z->redirects; e && (r = &e->section.redirect); e = e->next )
+       {
+               printf("\n# Net %s (%s) - redirect Z:%s N:%s I:%s\n",
+                       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);
+
+               /* 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);
+
+               /* 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);
+               }
+       }
 
-               fwd_ipt_exec_format("filter", " -A forward -i %s -j zone_%s_forward",
-                       n->ifname, z->name);
+       /* Build rules */
+       for( e = z->rules; e && (c = &e->section.rule); e = e->next )
+       {
+               /* Has destination, add forward rule for each network in target zone */
+               if( c->dest )
+               {
+                       for( n2 = c->dest->networks; n2; n2 = n2->next )
+                       {
+                               printf("\n# Net %s (%s) - rule+dest"
+                              " Z:%s N:%s I:%s -> Z:%s N:%s I:%s\n",
+                                       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);
+                       }
+               }
 
-               fwd_ipt_exec_format("raw", " -I PREROUTING 1 -i %s -j zone_%s_notrack",
-                       n->ifname, z->name);
+               /* No destination specified, treat it as input rule */
+               else
+               {
+                       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);
+               }
        }
 }