/*
* 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"
-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_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, SYN_FLOOD, "syn_flood"),
+
+ C(V4, NAT, CUSTOM_CHAINS, "prerouting_rule"),
+ C(V4, NAT, CUSTOM_CHAINS, "postrouting_rule"),
+
+ { }
+};
+
+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_westwood", bool, defaults, tcp_westwood),
+ 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 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;
}
}
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");
}
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;
- const char *policy[] = {
- "(bug)",
- "ACCEPT",
- "DROP",
- "DROP",
- "(bug)",
- "(bug)",
- "(bug)",
- };
+ const struct fw3_chain_spec *c;
- switch (table)
+#define policy(t) \
+ ((t == FW3_FLAG_REJECT) ? FW3_FLAG_DROP : t)
+
+ if (handle->family == FW3_FAMILY_V6 && defs->disable_ipv6)
+ return;
+
+ if (handle->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_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));
+ }
- 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");
- }
+ if (defs->custom_chains)
+ set(defs->flags, handle->family, 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->syn_flood)
+ set(defs->flags, handle->family, FW3_FLAG_SYN_FLOOD);
- case FW3_TABLE_NAT:
- if (defs->custom_chains)
- {
- fw3_pr(":prerouting_rule - [0:0]\n");
- fw3_pr(":postrouting_rule - [0:0]\n");
- }
- break;
+ for (c = default_chains; c->format; c++)
+ {
+ /* don't touch user chains on selective stop */
+ if (reload && c->flag == FW3_FLAG_CUSTOM_CHAINS)
+ continue;
- case FW3_TABLE_MANGLE:
- fw3_pr(":mssfix - [0:0]\n");
- break;
+ if (!fw3_is_family(c, handle->family))
+ continue;
- case FW3_TABLE_RAW:
- if (!defs->drop_invalid)
- fw3_pr(":notrack - [0:0]\n");
- break;
+ 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_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",
};
- switch (table)
+ switch (handle->table)
{
case FW3_TABLE_FILTER:
- fw3_pr("-A INPUT -i lo -j ACCEPT\n");
- fw3_pr("-A OUTPUT -o lo -j ACCEPT\n");
- for (i = 0; i < ARRAY_SIZE(chains); i++)
- {
- fw3_pr("-A %s -m conntrack --ctstate RELATED,ESTABLISHED "
- "-j ACCEPT\n", chains[i]);
+ sprintf(lodev.name, "lo");
- if (defs->drop_invalid)
+ r = fw3_ipt_rule_create(handle, NULL, &lodev, NULL, NULL, NULL);
+ fw3_ipt_rule_target(r, "ACCEPT");
+ fw3_ipt_rule_append(r, "INPUT");
+
+ r = fw3_ipt_rule_create(handle, NULL, NULL, &lodev, NULL, NULL);
+ fw3_ipt_rule_target(r, "ACCEPT");
+ fw3_ipt_rule_append(r, "OUTPUT");
+
+ if (defs->custom_chains)
+ {
+ for (i = 0; i < ARRAY_SIZE(chains); i += 2)
{
- fw3_pr("-A %s -m conntrack --ctstate INVALID -j DROP\n",
- chains[i]);
+ 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]);
}
}
- if (defs->syn_flood)
+ for (i = 0; i < ARRAY_SIZE(chains); i += 2)
{
- fw3_pr("-A syn_flood -p tcp --syn");
- fw3_format_limit(&defs->syn_flood_rate);
- fw3_pr(" -j RETURN\n");
+ 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]);
- fw3_pr("-A syn_flood -j DROP\n");
- fw3_pr("-A INPUT -p tcp --syn -j syn_flood\n");
+ if (defs->drop_invalid)
+ {
+ 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->custom_chains)
+ if (defs->syn_flood)
{
- fw3_pr("-A INPUT -j input_rule\n");
- fw3_pr("-A OUTPUT -j output_rule\n");
- fw3_pr("-A FORWARD -j forwarding_rule\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 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");
+ 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");
- 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");
+ 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 PREROUTING -j prerouting_rule\n");
- fw3_pr("-A POSTROUTING -j postrouting_rule\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;
- 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_ipt_handle *handle,
+ struct fw3_state *state, bool reload)
+{
+ struct fw3_defaults *defs = &state->defaults;
+ struct fw3_ipt_rule *r;
+
+ if (handle->table != FW3_TABLE_FILTER)
+ return;
+
+ if (defs->policy_input == FW3_FLAG_REJECT)
+ {
+ r = fw3_ipt_rule_new(handle);
+
+ if (!r)
+ return;
+
+ 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, int 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_set_defaults(struct fw3_state *state)
+{
+ set_default("ecn", state->defaults.tcp_ecn);
+ set_default("syncookies", state->defaults.tcp_syncookies);
+ set_default("window_scaling", state->defaults.tcp_window_scaling);
}
void
-fw3_print_flush_rules(enum fw3_table table, enum fw3_family family,
- struct fw3_state *state, bool complete)
+fw3_flush_rules(struct fw3_ipt_handle *handle, struct fw3_state *state,
+ bool reload)
{
- switch (table)
+ enum fw3_flag policy = reload ? FW3_FLAG_DROP : FW3_FLAG_ACCEPT;
+ struct fw3_defaults *defs = &state->defaults;
+ const struct fw3_chain_spec *c;
+
+ if (!has(defs->flags, handle->family, handle->table))
+ return;
+
+ if (handle->table == FW3_TABLE_FILTER)
{
- 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 */
+ fw3_ipt_set_policy(handle, "INPUT", policy);
+ fw3_ipt_set_policy(handle, "OUTPUT", policy);
+ fw3_ipt_set_policy(handle, "FORWARD", policy);
+ }
- case FW3_TABLE_NAT:
- fw3_pr("-F\n");
- fw3_pr("-X\n");
- break;
+ 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");
- 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;
+ for (c = default_chains; c->format; c++)
+ {
+ /* don't touch user chains on selective stop */
+ if (reload && c->flag == FW3_FLAG_CUSTOM_CHAINS)
+ continue;
- 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;
+ 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(struct fw3_ipt_handle *handle)
+{
+ 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_ipt_flush(handle);
}