2 * firewall3 - 3rd OpenWrt UCI firewall implementation
4 * Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 #define C(f, tbl, def, name) \
23 { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_DEFAULT_##def, name }
26 enum fw3_family family
;
28 enum fw3_default flag
;
32 static const struct chain default_chains
[] = {
33 C(ANY
, FILTER
, UNSPEC
, "delegate_input"),
34 C(ANY
, FILTER
, UNSPEC
, "delegate_output"),
35 C(ANY
, FILTER
, UNSPEC
, "delegate_forward"),
36 C(ANY
, FILTER
, CUSTOM_CHAINS
, "input_rule"),
37 C(ANY
, FILTER
, CUSTOM_CHAINS
, "output_rule"),
38 C(ANY
, FILTER
, CUSTOM_CHAINS
, "forwarding_rule"),
39 C(ANY
, FILTER
, UNSPEC
, "reject"),
40 C(ANY
, FILTER
, SYN_FLOOD
, "syn_flood"),
42 C(V4
, NAT
, UNSPEC
, "delegate_prerouting"),
43 C(V4
, NAT
, UNSPEC
, "delegate_postrouting"),
44 C(V4
, NAT
, CUSTOM_CHAINS
, "prerouting_rule"),
45 C(V4
, NAT
, CUSTOM_CHAINS
, "postrouting_rule"),
47 C(ANY
, MANGLE
, UNSPEC
, "mssfix"),
48 C(ANY
, RAW
, UNSPEC
, "notrack"),
51 static const struct chain toplevel_rules
[] = {
52 C(ANY
, FILTER
, UNSPEC
, "INPUT -j delegate_input"),
53 C(ANY
, FILTER
, UNSPEC
, "OUTPUT -j delegate_output"),
54 C(ANY
, FILTER
, UNSPEC
, "FORWARD -j delegate_forward"),
56 C(V4
, NAT
, UNSPEC
, "PREROUTING -j delegate_prerouting"),
57 C(V4
, NAT
, UNSPEC
, "POSTROUTING -j delegate_postrouting"),
59 C(ANY
, MANGLE
, UNSPEC
, "FORWARD -j mssfix"),
60 C(ANY
, RAW
, UNSPEC
, "PREROUTING -j notrack"),
63 const struct fw3_option fw3_default_opts
[] = {
64 FW3_OPT("input", target
, defaults
, policy_input
),
65 FW3_OPT("forward", target
, defaults
, policy_forward
),
66 FW3_OPT("output", target
, defaults
, policy_output
),
68 FW3_OPT("drop_invalid", bool, defaults
, drop_invalid
),
70 FW3_OPT("syn_flood", bool, defaults
, syn_flood
),
71 FW3_OPT("synflood_protect", bool, defaults
, syn_flood
),
72 FW3_OPT("synflood_rate", limit
, defaults
, syn_flood_rate
),
73 FW3_OPT("synflood_burst", int, defaults
, syn_flood_rate
.burst
),
75 FW3_OPT("tcp_syncookies", bool, defaults
, tcp_syncookies
),
76 FW3_OPT("tcp_ecn", bool, defaults
, tcp_ecn
),
77 FW3_OPT("tcp_westwood", bool, defaults
, tcp_westwood
),
78 FW3_OPT("tcp_window_scaling", bool, defaults
, tcp_window_scaling
),
80 FW3_OPT("accept_redirects", bool, defaults
, accept_redirects
),
81 FW3_OPT("accept_source_route", bool, defaults
, accept_source_route
),
83 FW3_OPT("custom_chains", bool, defaults
, custom_chains
),
84 FW3_OPT("disable_ipv6", bool, defaults
, disable_ipv6
),
91 print_chains(enum fw3_table table
, enum fw3_family family
,
92 const char *fmt
, uint16_t flags
,
93 const struct chain
*chains
, int n
)
96 const struct chain
*c
;
98 for (c
= chains
; n
> 0; c
++, n
--)
100 if (!fw3_is_family(c
, family
))
103 if (c
->table
!= table
)
106 if ((c
->flag
!= FW3_DEFAULT_UNSPEC
) && !hasbit(flags
, c
->flag
))
109 fw3_pr(fmt
, c
->name
);
118 check_policy(struct uci_element
*e
, enum fw3_target
*pol
, const char *name
)
120 if (*pol
== FW3_TARGET_UNSPEC
)
122 warn_elem(e
, "has no %s policy specified, defaulting to DROP", name
);
123 *pol
= FW3_TARGET_DROP
;
125 else if (*pol
> FW3_TARGET_DROP
)
127 warn_elem(e
, "has invalid %s policy, defaulting to DROP", name
);
128 *pol
= FW3_TARGET_DROP
;
133 fw3_load_defaults(struct fw3_state
*state
, struct uci_package
*p
)
135 struct uci_section
*s
;
136 struct uci_element
*e
;
137 struct fw3_defaults
*defs
= &state
->defaults
;
141 defs
->syn_flood_rate
.rate
= 25;
142 defs
->syn_flood_rate
.burst
= 50;
143 defs
->tcp_syncookies
= true;
144 defs
->tcp_window_scaling
= true;
145 defs
->custom_chains
= true;
147 setbit(defs
->flags
, FW3_FAMILY_V4
);
149 uci_foreach_element(&p
->sections
, e
)
151 s
= uci_to_section(e
);
153 if (strcmp(s
->type
, "defaults"))
158 warn_elem(e
, "ignoring duplicate section");
162 fw3_parse_options(&state
->defaults
, fw3_default_opts
, s
);
164 check_policy(e
, &defs
->policy_input
, "input");
165 check_policy(e
, &defs
->policy_output
, "output");
166 check_policy(e
, &defs
->policy_forward
, "forward");
168 if (!defs
->disable_ipv6
)
169 setbit(defs
->flags
, FW3_FAMILY_V6
);
171 if (defs
->custom_chains
)
172 setbit(defs
->flags
, FW3_DEFAULT_CUSTOM_CHAINS
);
175 setbit(defs
->flags
, FW3_DEFAULT_SYN_FLOOD
);
180 fw3_print_default_chains(enum fw3_table table
, enum fw3_family family
,
181 struct fw3_state
*state
)
183 struct fw3_defaults
*defs
= &state
->defaults
;
187 ((t == FW3_TARGET_REJECT) ? "DROP" : fw3_flag_names[t])
189 if (table
== FW3_TABLE_FILTER
)
191 fw3_pr(":INPUT %s [0:0]\n", policy(defs
->policy_input
));
192 fw3_pr(":FORWARD %s [0:0]\n", policy(defs
->policy_forward
));
193 fw3_pr(":OUTPUT %s [0:0]\n", policy(defs
->policy_output
));
196 /* user chains already loaded, don't create again */
197 if (hasbit(state
->running_defaults
.flags
, FW3_DEFAULT_CUSTOM_CHAINS
))
198 delbit(mask
, FW3_DEFAULT_CUSTOM_CHAINS
);
200 print_chains(table
, family
, ":%s - [0:0]\n", defs
->flags
& mask
,
201 default_chains
, ARRAY_SIZE(default_chains
));
205 fw3_print_default_head_rules(enum fw3_table table
, enum fw3_family family
,
206 struct fw3_state
*state
)
209 struct fw3_defaults
*defs
= &state
->defaults
;
210 const char *chains
[] = {
216 print_chains(table
, family
, "-A %s\n", 0,
217 toplevel_rules
, ARRAY_SIZE(toplevel_rules
));
221 case FW3_TABLE_FILTER
:
222 fw3_pr("-A delegate_input -i lo -j ACCEPT\n");
223 fw3_pr("-A delegate_output -o lo -j ACCEPT\n");
225 if (defs
->custom_chains
)
227 fw3_pr("-A delegate_input -j input_rule\n");
228 fw3_pr("-A delegate_output -j output_rule\n");
229 fw3_pr("-A delegate_forward -j forwarding_rule\n");
232 for (i
= 0; i
< ARRAY_SIZE(chains
); i
++)
234 fw3_pr("-A delegate_%s -m conntrack --ctstate RELATED,ESTABLISHED "
235 "-j ACCEPT\n", chains
[i
]);
237 if (defs
->drop_invalid
)
239 fw3_pr("-A delegate_%s -m conntrack --ctstate INVALID -j DROP\n",
246 fw3_pr("-A syn_flood -p tcp --syn");
247 fw3_format_limit(&defs
->syn_flood_rate
);
248 fw3_pr(" -j RETURN\n");
250 fw3_pr("-A syn_flood -j DROP\n");
251 fw3_pr("-A delegate_input -p tcp --syn -j syn_flood\n");
254 fw3_pr("-A reject -p tcp -j REJECT --reject-with tcp-reset\n");
255 fw3_pr("-A reject -j REJECT --reject-with port-unreach\n");
260 if (defs
->custom_chains
)
262 fw3_pr("-A delegate_prerouting -j prerouting_rule\n");
263 fw3_pr("-A delegate_postrouting -j postrouting_rule\n");
273 fw3_print_default_tail_rules(enum fw3_table table
, enum fw3_family family
,
274 struct fw3_state
*state
)
276 struct fw3_defaults
*defs
= &state
->defaults
;
278 if (table
!= FW3_TABLE_FILTER
)
281 if (defs
->policy_input
== FW3_TARGET_REJECT
)
282 fw3_pr("-A delegate_input -j reject\n");
284 if (defs
->policy_output
== FW3_TARGET_REJECT
)
285 fw3_pr("-A delegate_output -j reject\n");
287 if (defs
->policy_forward
== FW3_TARGET_REJECT
)
288 fw3_pr("-A delegate_forward -j reject\n");
292 reset_policy(enum fw3_table table
)
294 if (table
!= FW3_TABLE_FILTER
)
297 fw3_pr(":INPUT ACCEPT [0:0]\n");
298 fw3_pr(":OUTPUT ACCEPT [0:0]\n");
299 fw3_pr(":FORWARD ACCEPT [0:0]\n");
303 fw3_flush_rules(enum fw3_table table
, enum fw3_family family
,
304 bool pass2
, struct fw3_state
*state
)
306 struct fw3_defaults
*d
= &state
->running_defaults
;
309 if (!hasbit(d
->flags
, family
))
312 /* don't touch user chains on selective stop */
313 delbit(mask
, FW3_DEFAULT_CUSTOM_CHAINS
);
319 print_chains(table
, family
, "-D %s\n", d
->flags
& mask
,
320 toplevel_rules
, ARRAY_SIZE(toplevel_rules
));
322 print_chains(table
, family
, "-F %s\n", d
->flags
& mask
,
323 default_chains
, ARRAY_SIZE(default_chains
));
327 print_chains(table
, family
, "-X %s\n", d
->flags
& mask
,
328 default_chains
, ARRAY_SIZE(default_chains
));
330 delbit(d
->flags
, family
);
335 fw3_flush_all(enum fw3_table table
)