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, fmt) \
23 { FW3_FAMILY_##f, FW3_TABLE_##tbl, FW3_FLAG_##def, fmt }
25 static const struct fw3_rule_spec default_chains
[] = {
26 C(ANY
, FILTER
, UNSPEC
, "delegate_input"),
27 C(ANY
, FILTER
, UNSPEC
, "delegate_output"),
28 C(ANY
, FILTER
, UNSPEC
, "delegate_forward"),
29 C(ANY
, FILTER
, UNSPEC
, "reject"),
30 C(ANY
, FILTER
, CUSTOM_CHAINS
, "input_rule"),
31 C(ANY
, FILTER
, CUSTOM_CHAINS
, "output_rule"),
32 C(ANY
, FILTER
, CUSTOM_CHAINS
, "forwarding_rule"),
33 C(ANY
, FILTER
, SYN_FLOOD
, "syn_flood"),
35 C(V4
, NAT
, UNSPEC
, "delegate_prerouting"),
36 C(V4
, NAT
, UNSPEC
, "delegate_postrouting"),
37 C(V4
, NAT
, CUSTOM_CHAINS
, "prerouting_rule"),
38 C(V4
, NAT
, CUSTOM_CHAINS
, "postrouting_rule"),
40 C(ANY
, MANGLE
, UNSPEC
, "mssfix"),
41 C(ANY
, RAW
, UNSPEC
, "notrack"),
46 static const struct fw3_rule_spec toplevel_rules
[] = {
47 C(ANY
, FILTER
, UNSPEC
, "INPUT -j delegate_input"),
48 C(ANY
, FILTER
, UNSPEC
, "OUTPUT -j delegate_output"),
49 C(ANY
, FILTER
, UNSPEC
, "FORWARD -j delegate_forward"),
51 C(V4
, NAT
, UNSPEC
, "PREROUTING -j delegate_prerouting"),
52 C(V4
, NAT
, UNSPEC
, "POSTROUTING -j delegate_postrouting"),
54 C(ANY
, MANGLE
, UNSPEC
, "FORWARD -j mssfix"),
55 C(ANY
, RAW
, UNSPEC
, "PREROUTING -j notrack"),
60 const struct fw3_option fw3_flag_opts
[] = {
61 FW3_OPT("input", target
, defaults
, policy_input
),
62 FW3_OPT("forward", target
, defaults
, policy_forward
),
63 FW3_OPT("output", target
, defaults
, policy_output
),
65 FW3_OPT("drop_invalid", bool, defaults
, drop_invalid
),
67 FW3_OPT("syn_flood", bool, defaults
, syn_flood
),
68 FW3_OPT("synflood_protect", bool, defaults
, syn_flood
),
69 FW3_OPT("synflood_rate", limit
, defaults
, syn_flood_rate
),
70 FW3_OPT("synflood_burst", int, defaults
, syn_flood_rate
.burst
),
72 FW3_OPT("tcp_syncookies", bool, defaults
, tcp_syncookies
),
73 FW3_OPT("tcp_ecn", bool, defaults
, tcp_ecn
),
74 FW3_OPT("tcp_window_scaling", bool, defaults
, tcp_window_scaling
),
76 FW3_OPT("accept_redirects", bool, defaults
, accept_redirects
),
77 FW3_OPT("accept_source_route", bool, defaults
, accept_source_route
),
79 FW3_OPT("custom_chains", bool, defaults
, custom_chains
),
80 FW3_OPT("disable_ipv6", bool, defaults
, disable_ipv6
),
87 check_policy(struct uci_element
*e
, enum fw3_flag
*pol
, const char *name
)
89 if (*pol
== FW3_FLAG_UNSPEC
)
91 warn_elem(e
, "has no %s policy specified, defaulting to DROP", name
);
94 else if (*pol
> FW3_FLAG_DROP
)
96 warn_elem(e
, "has invalid %s policy, defaulting to DROP", name
);
102 fw3_load_defaults(struct fw3_state
*state
, struct uci_package
*p
)
104 struct uci_section
*s
;
105 struct uci_element
*e
;
106 struct fw3_defaults
*defs
= &state
->defaults
;
110 defs
->syn_flood_rate
.rate
= 25;
111 defs
->syn_flood_rate
.burst
= 50;
112 defs
->tcp_syncookies
= true;
113 defs
->tcp_window_scaling
= true;
114 defs
->custom_chains
= true;
116 uci_foreach_element(&p
->sections
, e
)
118 s
= uci_to_section(e
);
120 if (strcmp(s
->type
, "defaults"))
125 warn_elem(e
, "ignoring duplicate section");
129 fw3_parse_options(&state
->defaults
, fw3_flag_opts
, s
);
131 check_policy(e
, &defs
->policy_input
, "input");
132 check_policy(e
, &defs
->policy_output
, "output");
133 check_policy(e
, &defs
->policy_forward
, "forward");
138 fw3_print_default_chains(struct fw3_state
*state
, enum fw3_family family
,
139 enum fw3_table table
, bool reload
)
142 struct fw3_defaults
*defs
= &state
->defaults
;
143 uint32_t custom_mask
= ~0;
146 ((t == FW3_FLAG_REJECT) ? "DROP" : fw3_flag_names[t])
148 if (family
== FW3_FAMILY_V6
&& defs
->disable_ipv6
)
151 if (table
== FW3_TABLE_FILTER
)
153 fw3_pr(":INPUT %s [0:0]\n", policy(defs
->policy_input
));
154 fw3_pr(":FORWARD %s [0:0]\n", policy(defs
->policy_forward
));
155 fw3_pr(":OUTPUT %s [0:0]\n", policy(defs
->policy_output
));
158 /* Don't touch user chains on reload */
160 delbit(custom_mask
, FW3_FLAG_CUSTOM_CHAINS
);
162 if (defs
->custom_chains
)
163 set(defs
->flags
, family
, FW3_FLAG_CUSTOM_CHAINS
);
166 set(defs
->flags
, family
, FW3_FLAG_SYN_FLOOD
);
168 rv
= fw3_pr_rulespec(table
, family
, defs
->flags
, custom_mask
,
169 default_chains
, ":%s - [0:0]\n");
172 set(defs
->flags
, family
, table
);
176 fw3_print_default_head_rules(struct fw3_state
*state
, enum fw3_family family
,
177 enum fw3_table table
, bool reload
)
180 struct fw3_defaults
*defs
= &state
->defaults
;
181 const char *chains
[] = {
184 "forward", "forwarding",
187 fw3_pr_rulespec(table
, family
, NULL
, 0, toplevel_rules
, "-A %s\n");
191 case FW3_TABLE_FILTER
:
192 fw3_pr("-A delegate_input -i lo -j ACCEPT\n");
193 fw3_pr("-A delegate_output -o lo -j ACCEPT\n");
195 if (defs
->custom_chains
)
197 for (i
= 0; i
< ARRAY_SIZE(chains
); i
+= 2)
199 fw3_pr("-A delegate_%s -m comment "
200 "--comment \"user chain for %s\" -j %s_rule\n",
201 chains
[i
], chains
[i
+1], chains
[i
+1]);
205 for (i
= 0; i
< ARRAY_SIZE(chains
); i
+= 2)
207 fw3_pr("-A delegate_%s -m conntrack --ctstate RELATED,ESTABLISHED "
208 "-j ACCEPT\n", chains
[i
]);
210 if (defs
->drop_invalid
)
212 fw3_pr("-A delegate_%s -m conntrack --ctstate INVALID -j DROP\n",
219 fw3_pr("-A syn_flood -p tcp --syn");
220 fw3_format_limit(&defs
->syn_flood_rate
);
221 fw3_pr(" -j RETURN\n");
223 fw3_pr("-A syn_flood -j DROP\n");
224 fw3_pr("-A delegate_input -p tcp --syn -j syn_flood\n");
227 fw3_pr("-A reject -p tcp -j REJECT --reject-with tcp-reset\n");
228 fw3_pr("-A reject -j REJECT --reject-with port-unreach\n");
233 if (defs
->custom_chains
)
235 fw3_pr("-A delegate_prerouting "
236 "-m comment --comment \"user chain for prerouting\" "
237 "-j prerouting_rule\n");
239 fw3_pr("-A delegate_postrouting "
240 "-m comment --comment \"user chain for postrouting\" "
241 "-j postrouting_rule\n");
251 fw3_print_default_tail_rules(struct fw3_state
*state
, enum fw3_family family
,
252 enum fw3_table table
, bool reload
)
254 struct fw3_defaults
*defs
= &state
->defaults
;
256 if (table
!= FW3_TABLE_FILTER
)
259 if (defs
->policy_input
== FW3_FLAG_REJECT
)
260 fw3_pr("-A delegate_input -j reject\n");
262 if (defs
->policy_output
== FW3_FLAG_REJECT
)
263 fw3_pr("-A delegate_output -j reject\n");
265 if (defs
->policy_forward
== FW3_FLAG_REJECT
)
266 fw3_pr("-A delegate_forward -j reject\n");
270 set_default(const char *name
, bool set
)
273 char path
[sizeof("/proc/sys/net/ipv4/tcp_window_scaling\0")];
275 snprintf(path
, sizeof(path
), "/proc/sys/net/ipv4/tcp_%s", name
);
277 info(" * Set tcp_%s to %s", name
, set
? "on" : "off", name
);
279 if (!(f
= fopen(path
, "w")))
281 info(" ! Unable to write value: %s", strerror(errno
));
285 fprintf(f
, "%u\n", set
);
290 fw3_set_defaults(struct fw3_state
*state
)
292 set_default("ecn", state
->defaults
.tcp_ecn
);
293 set_default("syncookies", state
->defaults
.tcp_syncookies
);
294 set_default("window_scaling", state
->defaults
.tcp_window_scaling
);
298 reset_policy(enum fw3_table table
, enum fw3_flag policy
)
300 if (table
!= FW3_TABLE_FILTER
)
303 fw3_pr(":INPUT %s [0:0]\n", fw3_flag_names
[policy
]);
304 fw3_pr(":OUTPUT %s [0:0]\n", fw3_flag_names
[policy
]);
305 fw3_pr(":FORWARD %s [0:0]\n", fw3_flag_names
[policy
]);
309 fw3_flush_rules(struct fw3_state
*state
, enum fw3_family family
,
310 enum fw3_table table
, bool reload
, bool pass2
)
312 struct fw3_defaults
*defs
= &state
->defaults
;
313 uint32_t custom_mask
= ~0;
315 if (!has(defs
->flags
, family
, table
))
318 /* don't touch user chains on selective stop */
320 delbit(custom_mask
, FW3_FLAG_CUSTOM_CHAINS
);
324 reset_policy(table
, reload
? FW3_FLAG_DROP
: FW3_FLAG_ACCEPT
);
326 fw3_pr_rulespec(table
, family
, defs
->flags
, custom_mask
,
327 toplevel_rules
, "-D %s\n");
329 fw3_pr_rulespec(table
, family
, defs
->flags
, custom_mask
,
330 default_chains
, "-F %s\n");
334 fw3_pr_rulespec(table
, family
, defs
->flags
, custom_mask
,
335 default_chains
, "-X %s\n");
337 del(defs
->flags
, family
, table
);
342 fw3_flush_all(enum fw3_table table
)
344 reset_policy(table
, FW3_FLAG_ACCEPT
);