selectively delete chains in filter and nat tables
[project/firewall3.git] / defaults.c
index 498e5d5..1a25eaf 100644 (file)
 #include "defaults.h"
 
 
+#define C(f, tbl, def, name) \
+       { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_DEFAULT_##def, name }
+
+struct chain {
+       enum fw3_family family;
+       enum fw3_table table;
+       enum fw3_default flag;
+       const char *name;
+};
+
+static const struct chain default_chains[] = {
+       C(ANY, FILTER, UNSPEC,        "delegate_input"),
+       C(ANY, FILTER, UNSPEC,        "delegate_output"),
+       C(ANY, FILTER, UNSPEC,        "delegate_forward"),
+       C(ANY, FILTER, CUSTOM_CHAINS, "input_rule"),
+       C(ANY, FILTER, CUSTOM_CHAINS, "output_rule"),
+       C(ANY, FILTER, CUSTOM_CHAINS, "forwarding_rule"),
+       C(ANY, FILTER, UNSPEC,        "reject"),
+       C(ANY, FILTER, SYN_FLOOD,     "syn_flood"),
+
+       C(V4,  NAT,    UNSPEC,        "delegate_prerouting"),
+       C(V4,  NAT,    UNSPEC,        "delegate_postrouting"),
+       C(V4,  NAT,    CUSTOM_CHAINS, "prerouting_rule"),
+       C(V4,  NAT,    CUSTOM_CHAINS, "postrouting_rule"),
+
+       C(ANY, MANGLE, UNSPEC,        "mssfix"),
+       C(ANY, RAW,    UNSPEC,        "notrack"),
+};
+
+static const struct chain toplevel_rules[] = {
+       C(ANY, FILTER, UNSPEC,        "INPUT -j delegate_input"),
+       C(ANY, FILTER, UNSPEC,        "OUTPUT -j delegate_output"),
+       C(ANY, FILTER, UNSPEC,        "FORWARD -j delegate_forward"),
+
+       C(V4,  NAT,    UNSPEC,        "PREROUTING -j delegate_prerouting"),
+       C(V4,  NAT,    UNSPEC,        "POSTROUTING -j delegate_postrouting"),
+
+       C(ANY, MANGLE, UNSPEC,        "FORWARD -j mssfix"),
+       C(ANY, RAW,    UNSPEC,        "PREROUTING -j notrack"),
+};
+
 static struct fw3_option default_opts[] = {
        FW3_OPT("input",               target,   defaults, policy_input),
        FW3_OPT("forward",             target,   defaults, policy_forward),
@@ -44,6 +85,33 @@ static struct fw3_option default_opts[] = {
 };
 
 
+static bool
+print_chains(enum fw3_table table, enum fw3_family family,
+             const char *fmt, uint8_t flags,
+             const struct chain *chains, int n)
+{
+       bool rv = false;
+       const struct chain *c;
+
+       for (c = chains; n > 0; c++, n--)
+       {
+               if (!fw3_is_family(c, family))
+                       continue;
+
+               if (c->table != table)
+                       continue;
+
+               if ((c->flag != FW3_DEFAULT_UNSPEC) && !(flags & (1 << c->flag)))
+                       continue;
+
+               fw3_pr(fmt, c->name);
+
+               rv = true;
+       }
+
+       return rv;
+}
+
 static void
 check_policy(struct uci_element *e, enum fw3_target *pol, const char *name)
 {
@@ -93,6 +161,12 @@ fw3_load_defaults(struct fw3_state *state, struct uci_package *p)
                check_policy(e, &defs->policy_input, "input");
                check_policy(e, &defs->policy_output, "output");
                check_policy(e, &defs->policy_forward, "forward");
+
+               if (defs->custom_chains)
+                       defs->has_flag |= (1 << FW3_DEFAULT_CUSTOM_CHAINS);
+
+               if (defs->syn_flood)
+                       defs->has_flag |= (1 << FW3_DEFAULT_SYN_FLOOD);
        }
 }
 
@@ -111,72 +185,53 @@ fw3_print_default_chains(enum fw3_table table, enum fw3_family family,
                "(bug)",
        };
 
-       switch (table)
+       if (table == FW3_TABLE_FILTER)
        {
-       case FW3_TABLE_FILTER:
                fw3_pr(":INPUT %s [0:0]\n", policy[defs->policy_input]);
                fw3_pr(":FORWARD %s [0:0]\n", policy[defs->policy_forward]);
                fw3_pr(":OUTPUT %s [0:0]\n", policy[defs->policy_output]);
-
-               if (defs->custom_chains)
-               {
-                       fw3_pr(":input_rule - [0:0]\n");
-                       fw3_pr(":output_rule - [0:0]\n");
-                       fw3_pr(":forwarding_rule - [0:0]\n");
-               }
-
-               fw3_pr(":delegate_input - [0:0]\n");
-               fw3_pr(":delegate_output - [0:0]\n");
-               fw3_pr(":delegate_forward - [0:0]\n");
-               fw3_pr(":reject - [0:0]\n");
-               fw3_pr(":syn_flood - [0:0]\n");
-               break;
-
-       case FW3_TABLE_NAT:
-               if (defs->custom_chains)
-               {
-                       fw3_pr(":prerouting_rule - [0:0]\n");
-                       fw3_pr(":postrouting_rule - [0:0]\n");
-               }
-               break;
-
-       case FW3_TABLE_MANGLE:
-               fw3_pr(":mssfix - [0:0]\n");
-               break;
-
-       case FW3_TABLE_RAW:
-               if (!defs->drop_invalid)
-                       fw3_pr(":notrack - [0:0]\n");
-               break;
        }
+
+       print_chains(table, family, ":%s - [0:0]\n", defs->has_flag,
+                    default_chains, ARRAY_SIZE(default_chains));
 }
 
 void
-fw3_print_default_rules(enum fw3_table table, enum fw3_family family,
-                        struct fw3_state *state)
+fw3_print_default_head_rules(enum fw3_table table, enum fw3_family family,
+                             struct fw3_state *state)
 {
        int i;
        struct fw3_defaults *defs = &state->defaults;
        const char *chains[] = {
-               "INPUT",
-               "OUTPUT",
-               "FORWARD",
+               "input",
+               "output",
+               "forward",
        };
 
+       print_chains(table, family, "-A %s\n", 0,
+                    toplevel_rules, ARRAY_SIZE(toplevel_rules));
+
        switch (table)
        {
        case FW3_TABLE_FILTER:
-               fw3_pr("-A INPUT -i lo -j ACCEPT\n");
-               fw3_pr("-A OUTPUT -o lo -j ACCEPT\n");
+               fw3_pr("-A delegate_input -i lo -j ACCEPT\n");
+               fw3_pr("-A delegate_output -o lo -j ACCEPT\n");
+
+               if (defs->custom_chains)
+               {
+                       fw3_pr("-A delegate_input -j input_rule\n");
+                       fw3_pr("-A delegate_output -j output_rule\n");
+                       fw3_pr("-A delegate_forward -j forwarding_rule\n");
+               }
 
                for (i = 0; i < ARRAY_SIZE(chains); i++)
                {
-                       fw3_pr("-A %s -m conntrack --ctstate RELATED,ESTABLISHED "
+                       fw3_pr("-A delegate_%s -m conntrack --ctstate RELATED,ESTABLISHED "
                               "-j ACCEPT\n", chains[i]);
 
                        if (defs->drop_invalid)
                        {
-                               fw3_pr("-A %s -m conntrack --ctstate INVALID -j DROP\n",
+                               fw3_pr("-A delegate_%s -m conntrack --ctstate INVALID -j DROP\n",
                                       chains[i]);
                        }
                }
@@ -188,96 +243,91 @@ fw3_print_default_rules(enum fw3_table table, enum fw3_family family,
                        fw3_pr(" -j RETURN\n");
 
                        fw3_pr("-A syn_flood -j DROP\n");
-                       fw3_pr("-A INPUT -p tcp --syn -j syn_flood\n");
-               }
-
-               if (defs->custom_chains)
-               {
-                       fw3_pr("-A INPUT -j input_rule\n");
-                       fw3_pr("-A OUTPUT -j output_rule\n");
-                       fw3_pr("-A FORWARD -j forwarding_rule\n");
+                       fw3_pr("-A delegate_input -p tcp --syn -j syn_flood\n");
                }
 
-               fw3_pr("-A INPUT -j delegate_input\n");
-               fw3_pr("-A OUTPUT -j delegate_output\n");
-               fw3_pr("-A FORWARD -j delegate_forward\n");
-
                fw3_pr("-A reject -p tcp -j REJECT --reject-with tcp-reset\n");
                fw3_pr("-A reject -j REJECT --reject-with port-unreach\n");
 
-               if (defs->policy_input == FW3_TARGET_REJECT)
-                       fw3_pr("-A INPUT -j reject\n");
-
-               if (defs->policy_output == FW3_TARGET_REJECT)
-                       fw3_pr("-A OUTPUT -j reject\n");
-
-               if (defs->policy_forward == FW3_TARGET_REJECT)
-                       fw3_pr("-A FORWARD -j reject\n");
-
                break;
 
        case FW3_TABLE_NAT:
                if (defs->custom_chains)
                {
-                       fw3_pr("-A PREROUTING -j prerouting_rule\n");
-                       fw3_pr("-A POSTROUTING -j postrouting_rule\n");
+                       fw3_pr("-A delegate_prerouting -j prerouting_rule\n");
+                       fw3_pr("-A delegate_postrouting -j postrouting_rule\n");
                }
                break;
 
-       case FW3_TABLE_MANGLE:
-               fw3_pr("-A FORWARD -j mssfix\n");
-               break;
-
-       case FW3_TABLE_RAW:
-               if (!defs->drop_invalid)
-                       fw3_pr("-A PREROUTING -j notrack\n");
+       default:
                break;
        }
 }
 
 void
-fw3_print_flush_rules(enum fw3_table table, enum fw3_family family,
-                                         struct fw3_state *state, bool complete)
+fw3_print_default_tail_rules(enum fw3_table table, enum fw3_family family,
+                             struct fw3_state *state)
 {
-       switch (table)
-       {
-       case FW3_TABLE_FILTER:
-               fw3_pr(":INPUT ACCEPT [0:0]\n");
-               fw3_pr(":OUTPUT ACCEPT [0:0]\n");
-               fw3_pr(":FORWARD ACCEPT [0:0]\n");
-               /* fall through */
+       struct fw3_defaults *defs = &state->defaults;
 
-       case FW3_TABLE_NAT:
-               fw3_pr("-F\n");
-               fw3_pr("-X\n");
-               break;
+       if (table != FW3_TABLE_FILTER)
+               return;
 
-       case FW3_TABLE_MANGLE:
-               if (complete)
-               {
-                       fw3_pr("-F\n");
-                       fw3_pr("-X\n");
-               }
-               else
-               {
-                       fw3_pr("-D FORWARD -j mssfix\n");
-                       fw3_pr("-F mssfix\n");
-                       fw3_pr("-X mssfix\n");
-               }
-               break;
+       if (defs->policy_input == FW3_TARGET_REJECT)
+               fw3_pr("-A delegate_input -j reject\n");
+
+       if (defs->policy_output == FW3_TARGET_REJECT)
+               fw3_pr("-A delegate_output -j reject\n");
+
+       if (defs->policy_forward == FW3_TARGET_REJECT)
+               fw3_pr("-A delegate_forward -j reject\n");
+}
+
+static void
+reset_policy(enum fw3_table table)
+{
+       if (table != FW3_TABLE_FILTER)
+               return;
+
+       fw3_pr(":INPUT ACCEPT [0:0]\n");
+       fw3_pr(":OUTPUT ACCEPT [0:0]\n");
+       fw3_pr(":FORWARD ACCEPT [0:0]\n");
+}
+
+void
+fw3_flush_rules(enum fw3_table table, enum fw3_family family,
+                bool pass2, struct list_head *statefile)
+{
+       struct fw3_statefile_entry *e;
 
-       case FW3_TABLE_RAW:
-               if (complete)
+       list_for_each_entry(e, statefile, list)
+       {
+               if (e->type != FW3_TYPE_DEFAULTS)
+                       continue;
+
+               if (!pass2)
                {
-                       fw3_pr("-F\n");
-                       fw3_pr("-X\n");
+                       reset_policy(table);
+
+                       print_chains(table, family, "-D %s\n", e->flags[0],
+                                    toplevel_rules, ARRAY_SIZE(toplevel_rules));
+
+                       print_chains(table, family, "-F %s\n", e->flags[0],
+                                    default_chains, ARRAY_SIZE(default_chains));
                }
                else
                {
-                       fw3_pr("-D PREROUTING -j notrack\n");
-                       fw3_pr("-F notrack\n");
-                       fw3_pr("-X notrack\n");
+                       print_chains(table, family, "-X %s\n", e->flags[0],
+                                    default_chains, ARRAY_SIZE(default_chains));
                }
-               break;
        }
 }
+
+void
+fw3_flush_all(enum fw3_table table)
+{
+       reset_policy(table);
+
+       fw3_pr("-F\n");
+       fw3_pr("-X\n");
+}