Add common fw3_address_to_string() helper function
[project/firewall3.git] / defaults.c
index 498e5d5..f87ac92 100644 (file)
 #include "defaults.h"
 
 
-static struct fw3_option default_opts[] = {
+#define C(f, tbl, def, fmt) \
+       { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_FLAG_##def, fmt }
+
+static const struct fw3_rule_spec default_chains[] = {
+       C(ANY, FILTER, UNSPEC,        "delegate_input"),
+       C(ANY, FILTER, UNSPEC,        "delegate_output"),
+       C(ANY, FILTER, UNSPEC,        "delegate_forward"),
+       C(ANY, FILTER, UNSPEC,        "reject"),
+       C(ANY, FILTER, CUSTOM_CHAINS, "input_rule"),
+       C(ANY, FILTER, CUSTOM_CHAINS, "output_rule"),
+       C(ANY, FILTER, CUSTOM_CHAINS, "forwarding_rule"),
+       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, MANGLE, UNSPEC,        "fwmark"),
+
+       C(ANY, RAW,    UNSPEC,        "notrack"),
+
+       { }
+};
+
+static const struct fw3_rule_spec 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, MANGLE, UNSPEC,        "PREROUTING -j fwmark"),
+
+       C(ANY, RAW,    UNSPEC,        "PREROUTING -j notrack"),
+
+       { }
+};
+
+const struct fw3_option fw3_flag_opts[] = {
        FW3_OPT("input",               target,   defaults, policy_input),
        FW3_OPT("forward",             target,   defaults, policy_forward),
        FW3_OPT("output",              target,   defaults, policy_output),
@@ -33,7 +75,6 @@ static struct fw3_option default_opts[] = {
 
        FW3_OPT("tcp_syncookies",      bool,     defaults, tcp_syncookies),
        FW3_OPT("tcp_ecn",             bool,     defaults, tcp_ecn),
-       FW3_OPT("tcp_westwood",        bool,     defaults, tcp_westwood),
        FW3_OPT("tcp_window_scaling",  bool,     defaults, tcp_window_scaling),
 
        FW3_OPT("accept_redirects",    bool,     defaults, accept_redirects),
@@ -41,21 +82,26 @@ static struct fw3_option default_opts[] = {
 
        FW3_OPT("custom_chains",       bool,     defaults, custom_chains),
        FW3_OPT("disable_ipv6",        bool,     defaults, disable_ipv6),
+
+       FW3_OPT("__flags_v4",          int,      defaults, flags[0]),
+       FW3_OPT("__flags_v6",          int,      defaults, flags[1]),
+
+       { }
 };
 
 
 static void
-check_policy(struct uci_element *e, enum fw3_target *pol, const char *name)
+check_policy(struct uci_element *e, enum fw3_flag *pol, const char *name)
 {
-       if (*pol == FW3_TARGET_UNSPEC)
+       if (*pol == FW3_FLAG_UNSPEC)
        {
                warn_elem(e, "has no %s policy specified, defaulting to DROP", name);
-               *pol = FW3_TARGET_DROP;
+               *pol = FW3_FLAG_DROP;
        }
-       else if (*pol > FW3_TARGET_DROP)
+       else if (*pol > FW3_FLAG_DROP)
        {
                warn_elem(e, "has invalid %s policy, defaulting to DROP", name);
-               *pol = FW3_TARGET_DROP;
+               *pol = FW3_FLAG_DROP;
        }
 }
 
@@ -87,8 +133,7 @@ fw3_load_defaults(struct fw3_state *state, struct uci_package *p)
                        continue;
                }
 
-               fw3_parse_options(&state->defaults,
-                                 default_opts, ARRAY_SIZE(default_opts), s);
+               fw3_parse_options(&state->defaults, fw3_flag_opts, s);
 
                check_policy(e, &defs->policy_input, "input");
                check_policy(e, &defs->policy_output, "output");
@@ -97,86 +142,81 @@ fw3_load_defaults(struct fw3_state *state, struct uci_package *p)
 }
 
 void
-fw3_print_default_chains(enum fw3_table table, enum fw3_family family,
-                         struct fw3_state *state)
+fw3_print_default_chains(struct fw3_state *state, enum fw3_family family,
+                         enum fw3_table table, bool reload)
 {
+       bool rv;
        struct fw3_defaults *defs = &state->defaults;
-       const char *policy[] = {
-               "(bug)",
-               "ACCEPT",
-               "DROP",
-               "DROP",
-               "(bug)",
-               "(bug)",
-               "(bug)",
-       };
+       uint32_t custom_mask = ~0;
 
-       switch (table)
+#define policy(t) \
+       ((t == FW3_FLAG_REJECT) ? "DROP" : fw3_flag_names[t])
+
+       if (family == FW3_FAMILY_V6 && defs->disable_ipv6)
+               return;
+
+       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]);
+               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");
-               }
+       /* Don't touch user chains on reload */
+       if (reload)
+               delbit(custom_mask, FW3_FLAG_CUSTOM_CHAINS);
 
-               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;
+       if (defs->custom_chains)
+               set(defs->flags, family, FW3_FLAG_CUSTOM_CHAINS);
 
-       case FW3_TABLE_NAT:
-               if (defs->custom_chains)
-               {
-                       fw3_pr(":prerouting_rule - [0:0]\n");
-                       fw3_pr(":postrouting_rule - [0:0]\n");
-               }
-               break;
+       if (defs->syn_flood)
+               set(defs->flags, family, FW3_FLAG_SYN_FLOOD);
 
-       case FW3_TABLE_MANGLE:
-               fw3_pr(":mssfix - [0:0]\n");
-               break;
+       rv = fw3_pr_rulespec(table, family, defs->flags, custom_mask,
+                            default_chains, ":%s - [0:0]\n");
 
-       case FW3_TABLE_RAW:
-               if (!defs->drop_invalid)
-                       fw3_pr(":notrack - [0:0]\n");
-               break;
-       }
+       if (rv)
+               set(defs->flags, family, table);
 }
 
 void
-fw3_print_default_rules(enum fw3_table table, enum fw3_family family,
-                        struct fw3_state *state)
+fw3_print_default_head_rules(struct fw3_state *state, enum fw3_family family,
+                             enum fw3_table table, bool reload)
 {
        int i;
        struct fw3_defaults *defs = &state->defaults;
        const char *chains[] = {
-               "INPUT",
-               "OUTPUT",
-               "FORWARD",
+               "input", "input",
+               "output", "output",
+               "forward", "forwarding",
        };
 
+       fw3_pr_rulespec(table, family, NULL, 0, toplevel_rules, "-A %s\n");
+
        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)
+               {
+                       for (i = 0; i < ARRAY_SIZE(chains); i += 2)
+                       {
+                               fw3_pr("-A delegate_%s -m comment "
+                                      "--comment \"user chain for %s\" -j %s_rule\n",
+                                          chains[i], chains[i+1], chains[i+1]);
+                       }
+               }
 
-               for (i = 0; i < ARRAY_SIZE(chains); i++)
+               for (i = 0; i < ARRAY_SIZE(chains); i += 2)
                {
-                       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 +228,128 @@ 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 "
+                              "-m comment --comment \"user chain for prerouting\" "
+                              "-j prerouting_rule\n");
+
+                       fw3_pr("-A delegate_postrouting "
+                              "-m comment --comment \"user chain for postrouting\" "
+                              "-j postrouting_rule\n");
                }
                break;
 
-       case FW3_TABLE_MANGLE:
-               fw3_pr("-A FORWARD -j mssfix\n");
+       default:
                break;
+       }
+}
 
-       case FW3_TABLE_RAW:
-               if (!defs->drop_invalid)
-                       fw3_pr("-A PREROUTING -j notrack\n");
-               break;
+void
+fw3_print_default_tail_rules(struct fw3_state *state, enum fw3_family family,
+                             enum fw3_table table, bool reload)
+{
+       struct fw3_defaults *defs = &state->defaults;
+
+       if (table != FW3_TABLE_FILTER)
+               return;
+
+       if (defs->policy_input == FW3_FLAG_REJECT)
+               fw3_pr("-A delegate_input -j reject\n");
+
+       if (defs->policy_output == FW3_FLAG_REJECT)
+               fw3_pr("-A delegate_output -j reject\n");
+
+       if (defs->policy_forward == FW3_FLAG_REJECT)
+               fw3_pr("-A delegate_forward -j reject\n");
+}
+
+static void
+set_default(const char *name, bool set)
+{
+       FILE *f;
+       char path[sizeof("/proc/sys/net/ipv4/tcp_window_scaling\0")];
+
+       snprintf(path, sizeof(path), "/proc/sys/net/ipv4/tcp_%s", name);
+
+       info(" * Set tcp_%s to %s", name, set ? "on" : "off", name);
+
+       if (!(f = fopen(path, "w")))
+       {
+               info("   ! Unable to write value: %s", strerror(errno));
+               return;
        }
+
+       fprintf(f, "%u\n", set);
+       fclose(f);
 }
 
 void
-fw3_print_flush_rules(enum fw3_table table, enum fw3_family family,
-                                         struct fw3_state *state, bool complete)
+fw3_set_defaults(struct fw3_state *state)
 {
-       switch (table)
+       set_default("ecn",            state->defaults.tcp_ecn);
+       set_default("syncookies",     state->defaults.tcp_syncookies);
+       set_default("window_scaling", state->defaults.tcp_window_scaling);
+}
+
+static void
+reset_policy(enum fw3_table table, enum fw3_flag policy)
+{
+       if (table != FW3_TABLE_FILTER)
+               return;
+
+       fw3_pr(":INPUT %s [0:0]\n", fw3_flag_names[policy]);
+       fw3_pr(":OUTPUT %s [0:0]\n", fw3_flag_names[policy]);
+       fw3_pr(":FORWARD %s [0:0]\n", fw3_flag_names[policy]);
+}
+
+void
+fw3_flush_rules(struct fw3_state *state, enum fw3_family family,
+                enum fw3_table table, bool reload, bool pass2)
+{
+       struct fw3_defaults *defs = &state->defaults;
+       uint32_t custom_mask = ~0;
+
+       if (!has(defs->flags, family, table))
+               return;
+
+       /* don't touch user chains on selective stop */
+       if (reload)
+               delbit(custom_mask, FW3_FLAG_CUSTOM_CHAINS);
+
+       if (!pass2)
        {
-       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 */
+               reset_policy(table, reload ? FW3_FLAG_DROP : FW3_FLAG_ACCEPT);
 
-       case FW3_TABLE_NAT:
-               fw3_pr("-F\n");
-               fw3_pr("-X\n");
-               break;
+               fw3_pr_rulespec(table, family, defs->flags, custom_mask,
+                               toplevel_rules, "-D %s\n");
 
-       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;
+               fw3_pr_rulespec(table, family, defs->flags, custom_mask,
+                               default_chains, "-F %s\n");
+       }
+       else
+       {
+               fw3_pr_rulespec(table, family, defs->flags, custom_mask,
+                               default_chains, "-X %s\n");
 
-       case FW3_TABLE_RAW:
-               if (complete)
-               {
-                       fw3_pr("-F\n");
-                       fw3_pr("-X\n");
-               }
-               else
-               {
-                       fw3_pr("-D PREROUTING -j notrack\n");
-                       fw3_pr("-F notrack\n");
-                       fw3_pr("-X notrack\n");
-               }
-               break;
+               del(defs->flags, family, table);
        }
 }
+
+void
+fw3_flush_all(enum fw3_table table)
+{
+       reset_policy(table, FW3_FLAG_ACCEPT);
+
+       fw3_pr("-F\n");
+       fw3_pr("-X\n");
+}