/*
* firewall3 - 3rd OpenWrt UCI firewall implementation
*
- * Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
+ * Copyright (C) 2013 Jo-Philipp Wich <jo@mein.io>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
#include "defaults.h"
-#define C(f, tbl, def, name) \
- { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_DEFAULT_##def, name }
+#define C(f, tbl, def, fmt) \
+ { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_FLAG_##def, fmt }
-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"),
+static const struct fw3_chain_spec default_chains[] = {
+ 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, 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"),
+ { }
};
-const struct fw3_option fw3_default_opts[] = {
+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),
FW3_OPT("synflood_burst", int, defaults, syn_flood_rate.burst),
FW3_OPT("tcp_syncookies", bool, defaults, tcp_syncookies),
- FW3_OPT("tcp_ecn", bool, defaults, tcp_ecn),
+ FW3_OPT("tcp_ecn", int, defaults, tcp_ecn),
FW3_OPT("tcp_window_scaling", bool, defaults, tcp_window_scaling),
FW3_OPT("accept_redirects", bool, defaults, accept_redirects),
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 bool
-print_chains(enum fw3_table table, enum fw3_family family,
- const char *fmt, uint16_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) && !hasbit(flags, 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)
+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;
}
}
defs->tcp_window_scaling = true;
defs->custom_chains = true;
- setbit(defs->flags, FW3_FAMILY_V4);
-
uci_foreach_element(&p->sections, e)
{
s = uci_to_section(e);
continue;
}
- fw3_parse_options(&state->defaults, fw3_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");
check_policy(e, &defs->policy_forward, "forward");
-
- if (!defs->disable_ipv6)
- setbit(defs->flags, FW3_FAMILY_V6);
-
- if (defs->custom_chains)
- setbit(defs->flags, FW3_DEFAULT_CUSTOM_CHAINS);
-
- if (defs->syn_flood)
- setbit(defs->flags, FW3_DEFAULT_SYN_FLOOD);
}
}
void
-fw3_print_default_chains(enum fw3_table table, enum fw3_family family,
- struct fw3_state *state)
+fw3_print_default_chains(struct fw3_ipt_handle *handle, struct fw3_state *state,
+ bool reload)
{
struct fw3_defaults *defs = &state->defaults;
- uint16_t mask = ~0;
+ const struct fw3_chain_spec *c;
#define policy(t) \
- ((t == FW3_TARGET_REJECT) ? "DROP" : fw3_flag_names[t])
+ ((t == FW3_FLAG_REJECT) ? FW3_FLAG_DROP : t)
+
+ if (handle->family == FW3_FAMILY_V6 && defs->disable_ipv6)
+ return;
- if (table == FW3_TABLE_FILTER)
+ if (handle->table == 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_ipt_set_policy(handle, "INPUT", policy(defs->policy_input));
+ fw3_ipt_set_policy(handle, "OUTPUT", policy(defs->policy_output));
+ fw3_ipt_set_policy(handle, "FORWARD", policy(defs->policy_forward));
}
- /* user chains already loaded, don't create again */
- if (hasbit(state->running_defaults.flags, FW3_DEFAULT_CUSTOM_CHAINS))
- delbit(mask, FW3_DEFAULT_CUSTOM_CHAINS);
+ if (defs->custom_chains)
+ set(defs->flags, handle->family, FW3_FLAG_CUSTOM_CHAINS);
- print_chains(table, family, ":%s - [0:0]\n", defs->flags & mask,
- default_chains, ARRAY_SIZE(default_chains));
+ if (defs->syn_flood)
+ set(defs->flags, handle->family, FW3_FLAG_SYN_FLOOD);
+
+ for (c = default_chains; c->format; c++)
+ {
+ /* don't touch user chains on selective stop */
+ if (reload && c->flag == FW3_FLAG_CUSTOM_CHAINS)
+ continue;
+
+ if (!fw3_is_family(c, handle->family))
+ continue;
+
+ if (c->table != handle->table)
+ continue;
+
+ if (c->flag &&
+ !fw3_hasbit(defs->flags[handle->family == FW3_FAMILY_V6], c->flag))
+ continue;
+
+ fw3_ipt_create_chain(handle, c->format);
+ }
+
+ set(defs->flags, handle->family, handle->table);
}
void
-fw3_print_default_head_rules(enum fw3_table table, enum fw3_family family,
- struct fw3_state *state)
+fw3_print_default_head_rules(struct fw3_ipt_handle *handle,
+ struct fw3_state *state, bool reload)
{
int i;
struct fw3_defaults *defs = &state->defaults;
+ struct fw3_device lodev = { .set = true };
+ struct fw3_protocol tcp = { .protocol = 6 };
+ struct fw3_ipt_rule *r;
+
const char *chains[] = {
- "input",
- "output",
- "forward",
+ "INPUT", "input",
+ "OUTPUT", "output",
+ "FORWARD", "forwarding",
};
- print_chains(table, family, "-A %s\n", 0,
- toplevel_rules, ARRAY_SIZE(toplevel_rules));
-
- switch (table)
+ switch (handle->table)
{
case FW3_TABLE_FILTER:
- 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 "
- "-m comment --comment \"user chain for input\"\n");
+ sprintf(lodev.name, "lo");
+
+ r = fw3_ipt_rule_create(handle, NULL, &lodev, NULL, NULL, NULL);
+ fw3_ipt_rule_target(r, "ACCEPT");
+ fw3_ipt_rule_append(r, "INPUT");
- fw3_pr("-A delegate_output -j output_rule "
- "-m comment --comment \"user chain for output\"\n");
+ r = fw3_ipt_rule_create(handle, NULL, NULL, &lodev, NULL, NULL);
+ fw3_ipt_rule_target(r, "ACCEPT");
+ fw3_ipt_rule_append(r, "OUTPUT");
- fw3_pr("-A delegate_forward -j forwarding_rule "
- "-m comment --comment \"user chain for forwarding\"\n");
+ if (defs->custom_chains)
+ {
+ for (i = 0; i < ARRAY_SIZE(chains); i += 2)
+ {
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_comment(r, "user chain for %s", chains[i+1]);
+ fw3_ipt_rule_target(r, "%s_rule", chains[i+1]);
+ fw3_ipt_rule_append(r, chains[i]);
+ }
}
- for (i = 0; i < ARRAY_SIZE(chains); i++)
+ for (i = 0; i < ARRAY_SIZE(chains); i += 2)
{
- fw3_pr("-A delegate_%s -m conntrack --ctstate RELATED,ESTABLISHED "
- "-j ACCEPT\n", chains[i]);
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_extra(r, "-m conntrack --ctstate RELATED,ESTABLISHED");
+ fw3_ipt_rule_target(r, "ACCEPT");
+ fw3_ipt_rule_append(r, chains[i]);
if (defs->drop_invalid)
{
- fw3_pr("-A delegate_%s -m conntrack --ctstate INVALID -j DROP\n",
- chains[i]);
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_extra(r, "-m conntrack --ctstate INVALID");
+ fw3_ipt_rule_target(r, "DROP");
+ fw3_ipt_rule_append(r, chains[i]);
}
}
if (defs->syn_flood)
{
- fw3_pr("-A syn_flood -p tcp --syn");
- fw3_format_limit(&defs->syn_flood_rate);
- fw3_pr(" -j RETURN\n");
-
- fw3_pr("-A syn_flood -j DROP\n");
- fw3_pr("-A delegate_input -p tcp --syn -j syn_flood\n");
+ r = fw3_ipt_rule_create(handle, &tcp, NULL, NULL, NULL, NULL);
+ fw3_ipt_rule_extra(r, "--syn");
+ fw3_ipt_rule_limit(r, &defs->syn_flood_rate);
+ fw3_ipt_rule_target(r, "RETURN");
+ fw3_ipt_rule_append(r, "syn_flood");
+
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_target(r, "DROP");
+ fw3_ipt_rule_append(r, "syn_flood");
+
+ r = fw3_ipt_rule_create(handle, &tcp, NULL, NULL, NULL, NULL);
+ fw3_ipt_rule_extra(r, "--syn");
+ fw3_ipt_rule_target(r, "syn_flood");
+ fw3_ipt_rule_append(r, "INPUT");
}
- fw3_pr("-A reject -p tcp -j REJECT --reject-with tcp-reset\n");
- fw3_pr("-A reject -j REJECT --reject-with port-unreach\n");
+ r = fw3_ipt_rule_create(handle, &tcp, NULL, NULL, NULL, NULL);
+ fw3_ipt_rule_target(r, "REJECT");
+ fw3_ipt_rule_addarg(r, false, "--reject-with", "tcp-reset");
+ fw3_ipt_rule_append(r, "reject");
+
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_target(r, "REJECT");
+ fw3_ipt_rule_addarg(r, false, "--reject-with", "port-unreach");
+ fw3_ipt_rule_append(r, "reject");
break;
case FW3_TABLE_NAT:
if (defs->custom_chains)
{
- fw3_pr("-A delegate_prerouting -j prerouting_rule "
- "-m comment --comment \"user chain for prerouting\"\n");
-
- fw3_pr("-A delegate_postrouting -j postrouting_rule "
- "-m comment --comment \"user chain for postrouting\"\n");
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_comment(r, "user chain for prerouting");
+ fw3_ipt_rule_target(r, "prerouting_rule");
+ fw3_ipt_rule_append(r, "PREROUTING");
+
+ r = fw3_ipt_rule_new(handle);
+ fw3_ipt_rule_comment(r, "user chain for postrouting");
+ fw3_ipt_rule_target(r, "postrouting_rule");
+ fw3_ipt_rule_append(r, "POSTROUTING");
}
break;
}
void
-fw3_print_default_tail_rules(enum fw3_table table, enum fw3_family family,
- struct fw3_state *state)
+fw3_print_default_tail_rules(struct fw3_ipt_handle *handle,
+ struct fw3_state *state, bool reload)
{
struct fw3_defaults *defs = &state->defaults;
+ struct fw3_ipt_rule *r;
- if (table != FW3_TABLE_FILTER)
+ if (handle->table != FW3_TABLE_FILTER)
return;
- if (defs->policy_input == FW3_TARGET_REJECT)
- fw3_pr("-A delegate_input -j reject\n");
+ if (defs->policy_input == FW3_FLAG_REJECT)
+ {
+ r = fw3_ipt_rule_new(handle);
- if (defs->policy_output == FW3_TARGET_REJECT)
- fw3_pr("-A delegate_output -j reject\n");
+ if (!r)
+ return;
- if (defs->policy_forward == FW3_TARGET_REJECT)
- fw3_pr("-A delegate_forward -j reject\n");
+ fw3_ipt_rule_target(r, "reject");
+ fw3_ipt_rule_append(r, "INPUT");
+ }
+
+ if (defs->policy_output == FW3_FLAG_REJECT)
+ {
+ r = fw3_ipt_rule_new(handle);
+
+ if (!r)
+ return;
+
+ fw3_ipt_rule_target(r, "reject");
+ fw3_ipt_rule_append(r, "OUTPUT");
+ }
+
+ if (defs->policy_forward == FW3_FLAG_REJECT)
+ {
+ r = fw3_ipt_rule_new(handle);
+
+ if (!r)
+ return;
+
+ fw3_ipt_rule_target(r, "reject");
+ fw3_ipt_rule_append(r, "FORWARD");
+ }
}
static void
-set_default(const char *name, bool set)
+set_default(const char *name, int set)
{
FILE *f;
char path[sizeof("/proc/sys/net/ipv4/tcp_window_scaling\0")];
void
fw3_set_defaults(struct fw3_state *state)
{
- info("Setting sysctl values");
-
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_target 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(enum fw3_table table, enum fw3_family family,
- bool pass2, struct fw3_state *state, enum fw3_target policy)
+fw3_flush_rules(struct fw3_ipt_handle *handle, struct fw3_state *state,
+ bool reload)
{
- struct fw3_defaults *d = &state->running_defaults;
- uint16_t mask = ~0;
+ enum fw3_flag policy = reload ? FW3_FLAG_DROP : FW3_FLAG_ACCEPT;
+ struct fw3_defaults *defs = &state->defaults;
+ const struct fw3_chain_spec *c;
- if (!hasbit(d->flags, family))
+ if (!has(defs->flags, handle->family, handle->table))
return;
- /* don't touch user chains on selective stop */
- delbit(mask, FW3_DEFAULT_CUSTOM_CHAINS);
-
- if (!pass2)
+ if (handle->table == FW3_TABLE_FILTER)
{
- reset_policy(table, policy);
+ fw3_ipt_set_policy(handle, "INPUT", policy);
+ fw3_ipt_set_policy(handle, "OUTPUT", policy);
+ fw3_ipt_set_policy(handle, "FORWARD", policy);
+ }
- print_chains(table, family, "-D %s\n", d->flags & mask,
- toplevel_rules, ARRAY_SIZE(toplevel_rules));
+ fw3_ipt_delete_id_rules(handle, "INPUT");
+ fw3_ipt_delete_id_rules(handle, "OUTPUT");
+ fw3_ipt_delete_id_rules(handle, "FORWARD");
+ fw3_ipt_delete_id_rules(handle, "PREROUTING");
+ fw3_ipt_delete_id_rules(handle, "POSTROUTING");
- print_chains(table, family, "-F %s\n", d->flags & mask,
- default_chains, ARRAY_SIZE(default_chains));
- }
- else
+ for (c = default_chains; c->format; c++)
{
- print_chains(table, family, "-X %s\n", d->flags & mask,
- default_chains, ARRAY_SIZE(default_chains));
+ /* don't touch user chains on selective stop */
+ if (reload && c->flag == FW3_FLAG_CUSTOM_CHAINS)
+ continue;
- delbit(d->flags, family);
+ if (!fw3_is_family(c, handle->family))
+ continue;
+
+ if (c->table != handle->table)
+ continue;
+
+ if (c->flag && !has(defs->flags, handle->family, c->flag))
+ continue;
+
+ fw3_ipt_flush_chain(handle, c->format);
+
+ /* keep certain basic chains that do not depend on any settings to
+ avoid purging unrelated user rules pointing to them */
+ if (reload && !c->flag)
+ continue;
+
+ fw3_ipt_delete_chain(handle, c->format);
}
+
+ del(defs->flags, handle->family, handle->table);
}
void
-fw3_flush_all(enum fw3_table table)
+fw3_flush_all(struct fw3_ipt_handle *handle)
{
- reset_policy(table, FW3_TARGET_ACCEPT);
+ if (handle->table == FW3_TABLE_FILTER)
+ {
+ fw3_ipt_set_policy(handle, "INPUT", FW3_FLAG_ACCEPT);
+ fw3_ipt_set_policy(handle, "OUTPUT", FW3_FLAG_ACCEPT);
+ fw3_ipt_set_policy(handle, "FORWARD", FW3_FLAG_ACCEPT);
+ }
- fw3_pr("-F\n");
- fw3_pr("-X\n");
+ fw3_ipt_flush(handle);
}