summaryrefslogtreecommitdiff
path: root/package/firewall/files/uci_firewall.sh
blob: 64e052fcb2e553ced338de127ac892d5a95ce4ef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
#!/bin/sh 
# Copyright (C) 2008 John Crispin <blogic@openwrt.org>

. /etc/functions.sh

IPTABLES="echo iptables"
IPTABLES=iptables

config_clear
include /lib/network
scan_interfaces

CONFIG_APPEND=1
config_load firewall

config fw_zones
ZONE_LIST=$CONFIG_SECTION

CUSTOM_CHAINS=1
DEF_INPUT=DROP
DEF_OUTPUT=DROP
DEF_FORWARD=DROP
CONNTRACK_ZONES=
NOTRACK_DISABLED=

find_item() {
	local item="$1"; shift
	for i in "$@"; do
		[ "$i" = "$item" ] && return 0
	done
	return 1
}

load_policy() {
	config_get input $1 input
	config_get output $1 output
	config_get forward $1 forward

	DEF_INPUT="${input:-$DEF_INPUT}"
	DEF_OUTPUT="${output:-$DEF_OUTPUT}"
	DEF_FORWARD="${forward:-$DEF_FORWARD}"
}

create_zone() {
	local exists
	
	[ "$1" == "loopback" ] && return

	config_get exists $ZONE_LIST $1
	[ -n "$exists" ] && return
	config_set $ZONE_LIST $1 1 

	$IPTABLES -N zone_$1
	$IPTABLES -N zone_$1_MSSFIX
	$IPTABLES -N zone_$1_ACCEPT
	$IPTABLES -N zone_$1_DROP
	$IPTABLES -N zone_$1_REJECT
	$IPTABLES -N zone_$1_forward
	[ "$5" ] && $IPTABLES -A zone_$1_forward -j zone_$1_$5
	[ "$3" ] && $IPTABLES -A zone_$1 -j zone_$1_$3
	[ "$4" ] && $IPTABLES -A output -j zone_$1_$4
	$IPTABLES -N zone_$1_nat -t nat
	$IPTABLES -N zone_$1_prerouting -t nat
	$IPTABLES -t raw -N zone_$1_notrack
	[ "$6" == "1" ] && $IPTABLES -t nat -A POSTROUTING -j zone_$1_nat
	[ "$7" == "1" ] && $IPTABLES -I FORWARD 1 -j zone_$1_MSSFIX
}

addif() {
	local network="$1"
	local ifname="$2"
	local zone="$3"

	local n_if n_zone
	config_get n_if core "${network}_ifname"
	config_get n_zone core "${network}_zone"
	[ -n "$n_zone" ] && {
		if [ "$n_zone" != "$zone" ]; then
			delif "$network" "$n_if" "$n_zone"
		else
			return
		fi
	}

	logger "adding $network ($ifname) to firewall zone $zone"
	$IPTABLES -A input -i "$ifname" -j zone_${zone}
	$IPTABLES -I zone_${zone}_MSSFIX 1 -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
	$IPTABLES -I zone_${zone}_ACCEPT 1 -o "$ifname" -j ACCEPT
	$IPTABLES -I zone_${zone}_DROP 1 -o "$ifname" -j DROP
	$IPTABLES -I zone_${zone}_REJECT 1 -o "$ifname" -j reject
	$IPTABLES -I zone_${zone}_ACCEPT 1 -i "$ifname" -j ACCEPT
	$IPTABLES -I zone_${zone}_DROP 1 -i "$ifname" -j DROP
	$IPTABLES -I zone_${zone}_REJECT 1 -i "$ifname" -j reject
	$IPTABLES -I zone_${zone}_nat 1 -t nat -o "$ifname" -j MASQUERADE 
	$IPTABLES -I PREROUTING 1 -t nat -i "$ifname" -j zone_${zone}_prerouting 
	$IPTABLES -A forward -i "$ifname" -j zone_${zone}_forward
	$IPTABLES -t raw -I PREROUTING 1 -i "$ifname" -j zone_${zone}_notrack
	uci_set_state firewall core "${network}_ifname" "$ifname"
	uci_set_state firewall core "${network}_zone" "$zone"
	ACTION=add ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
}

delif() {
	local network="$1"
	local ifname="$2"
	local zone="$3"

	logger "removing $network ($ifname) from firewall zone $zone"
	$IPTABLES -D input -i "$ifname" -j zone_$zone
	$IPTABLES -D zone_${zone}_MSSFIX -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
	$IPTABLES -D zone_${zone}_ACCEPT -o "$ifname" -j ACCEPT
	$IPTABLES -D zone_${zone}_DROP -o "$ifname" -j DROP
	$IPTABLES -D zone_${zone}_REJECT -o "$ifname" -j reject
	$IPTABLES -D zone_${zone}_ACCEPT -i "$ifname" -j ACCEPT
	$IPTABLES -D zone_${zone}_DROP -i "$ifname" -j DROP
	$IPTABLES -D zone_${zone}_REJECT -i "$ifname" -j reject
	$IPTABLES -D zone_${zone}_nat -t nat -o "$ifname" -j MASQUERADE 
	$IPTABLES -D PREROUTING -t nat -i "$ifname" -j zone_${zone}_prerouting 
	$IPTABLES -D forward -i "$ifname" -j zone_${zone}_forward
	uci_revert_state firewall core "${network}_ifname"
	uci_revert_state firewall core "${network}_zone"
	ACTION=remove ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
}

load_synflood() {
	local rate=${1:-25}
	local burst=${2:-50}
	echo "Loading synflood protection"
	$IPTABLES -N syn_flood
	$IPTABLES -A syn_flood -p tcp --syn -m limit --limit $rate/second --limit-burst $burst -j RETURN
	$IPTABLES -A syn_flood -j DROP
	$IPTABLES -A INPUT -p tcp --syn -j syn_flood
}

fw_set_chain_policy() {
	local chain=$1
	local target=$2
	[ "$target" == "REJECT" ] && {
		$IPTABLES -A $chain -j reject
		target=DROP
	}
	$IPTABLES -P $chain $target
}

fw_clear() {
	$IPTABLES -F
	$IPTABLES -t nat -F
	$IPTABLES -t nat -X
	$IPTABLES -t raw -F
	$IPTABLES -t raw -X
	$IPTABLES -X
}

fw_defaults() {
	[ -n "$DEFAULTS_APPLIED" ] && {
		echo "Error: multiple defaults sections detected"
		return;
	}
	DEFAULTS_APPLIED=1

	load_policy "$1"

	echo 1 > /proc/sys/net/ipv4/tcp_syncookies
	for f in /proc/sys/net/ipv4/conf/*/accept_redirects 
	do
		echo 0 > $f
	done
	for f in /proc/sys/net/ipv4/conf/*/accept_source_route 
	do
		echo 0 > $f
	done                                                                   
	
	uci_revert_state firewall core
	uci_set_state firewall core "" firewall_state 

	$IPTABLES -P INPUT DROP
	$IPTABLES -P OUTPUT DROP
	$IPTABLES -P FORWARD DROP

	fw_clear
	config_get_bool drop_invalid $1 drop_invalid 0

	[ "$drop_invalid" -gt 0 ] && {
		$IPTABLES -A INPUT -m state --state INVALID -j DROP
		$IPTABLES -A OUTPUT -m state --state INVALID -j DROP
		$IPTABLES -A FORWARD -m state --state INVALID -j DROP
		NOTRACK_DISABLED=1
	}

	$IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
	$IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
	$IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT

	$IPTABLES -A INPUT -i lo -j ACCEPT
	$IPTABLES -A OUTPUT -o lo -j ACCEPT

	config_get syn_flood $1 syn_flood
	config_get syn_rate $1 syn_rate
	config_get syn_burst $1 syn_burst
	[ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
	
	echo "Adding custom chains"
	fw_custom_chains

	$IPTABLES -N input
	$IPTABLES -N output
	$IPTABLES -N forward

	$IPTABLES -A INPUT -j input
	$IPTABLES -A OUTPUT -j output
	$IPTABLES -A FORWARD -j forward

	$IPTABLES -N reject
	$IPTABLES -A reject -p tcp -j REJECT --reject-with tcp-reset
	$IPTABLES -A reject -j REJECT --reject-with icmp-port-unreachable

	fw_set_chain_policy INPUT "$DEF_INPUT"
	fw_set_chain_policy OUTPUT "$DEF_OUTPUT"
	fw_set_chain_policy FORWARD "$DEF_FORWARD"
}

fw_zone() {
	local name
	local network
	local masq

	config_get name $1 name
	config_get network $1 network
	config_get_bool masq $1 masq "0"
	config_get_bool conntrack $1 conntrack "0"
	config_get_bool mtu_fix $1 mtu_fix 0

	load_policy $1
	[ "$conntrack" = "1" -o "$masq" = "1" ] && append CONNTRACK_ZONES "$name"
	[ -z "$network" ] && network=$name
	create_zone "$name" "$network" "$input" "$output" "$forward" "$masq" "$mtu_fix"
	fw_custom_chains_zone "$name"
}

fw_rule() {
	local src 
	local src_ip
	local src_mac
	local src_port
	local src_mac
	local dest
	local dest_ip
	local dest_port
	local proto
	local icmp_type
	local target
	local ruleset

	config_get src $1 src
	config_get src_ip $1 src_ip
	config_get src_mac $1 src_mac
	config_get src_port $1 src_port
	config_get dest $1 dest
	config_get dest_ip $1 dest_ip
	config_get dest_port $1 dest_port
	config_get proto $1 proto
	config_get icmp_type $1 icmp_type
	config_get target $1 target
	config_get ruleset $1 ruleset

	src_port_first=${src_port%-*}
	src_port_last=${src_port#*-}
	[ "$src_port_first" -ne "$src_port_last" ] && { \
		src_port="$src_port_first:$src_port_last"; }

	dest_port_first=${dest_port%-*}
	dest_port_last=${dest_port#*-}
	[ "$dest_port_first" -ne "$dest_port_last" ] && { \
		dest_port="$dest_port_first:$dest_port_last"; }
	
	ZONE=input
	TARGET=$target
	[ -z "$target" ] && target=DROP
	[ -n "$src" -a -z "$dest" ] && ZONE=zone_$src
	[ -n "$src" -a -n "$dest" ] && ZONE=zone_${src}_forward
	[ -n "$dest" ] && TARGET=zone_${dest}_$target
	add_rule() {
		$IPTABLES -A $ZONE \
			${proto:+-p $proto} \
			${icmp_type:+--icmp-type $icmp_type} \
			${src_ip:+-s $src_ip} \
			${src_port:+--sport $src_port} \
			${src_mac:+-m mac --mac-source $src_mac} \
			${dest_ip:+-d $dest_ip} \
			${dest_port:+--dport $dest_port} \
			-j $TARGET 
	}
	[ "$proto" == "tcpudp" -o -z "$proto" ] && {
		proto=tcp
		add_rule
		proto=udp
		add_rule
		return
	}
	add_rule
}

fw_forwarding() {
	local src
	local dest
	local masq

	config_get src $1 src
	config_get dest $1 dest
	[ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
	[ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
	$IPTABLES -I $z_src 1 -j $z_dest

	# propagate masq zone flag
	find_item "$src" $CONNTRACK_ZONES && append CONNTRACK_ZONES $dest
	find_item "$dest" $CONNTRACK_ZONES && append CONNTRACK_ZONES $src
}

fw_redirect() {
	local src
	local src_ip
	local src_port
	local src_dport
	local src_mac
	local dest_ip
	local dest_port dest_port2
	local proto
	
	config_get src $1 src
	config_get src_ip $1 src_ip
	config_get src_port $1 src_port
	config_get src_dport $1 src_dport
	config_get src_mac $1 src_mac
	config_get dest_ip $1 dest_ip
	config_get dest_port $1 dest_port
	config_get proto $1 proto
	[ -z "$src" -o -z "$dest_ip" ] && { \
		echo "redirect needs src and dest_ip"; return ; }
	
	src_port_first=${src_port%-*}
	src_port_last=${src_port#*-}
	[ "$src_port_first" -ne "$src_port_last" ] && { \
		src_port="$src_port_first:$src_port_last"; }

	src_dport_first=${src_dport%-*}
	src_dport_last=${src_dport#*-}
	[ "$src_dport_first" -ne "$src_dport_last" ] && { \
		src_dport="$src_dport_first:$src_dport_last"; }

	dest_port2=$dest_port
	dest_port_first=${dest_port2%-*}
	dest_port_last=${dest_port2#*-}
	[ "$dest_port_first" -ne "$dest_port_last" ] && { \
		dest_port2="$dest_port_first:$dest_port_last"; }

	add_rule() {
		$IPTABLES -A zone_${src}_prerouting -t nat \
			${proto:+-p $proto} \
			${src_ip:+-s $src_ip} \
			${src_port:+--sport $src_port} \
			${src_dport:+--dport $src_dport} \
			${src_mac:+-m mac --mac-source $src_mac} \
			-j DNAT --to-destination $dest_ip${dest_port:+:$dest_port}

		$IPTABLES -I zone_${src}_forward 1 \
			${proto:+-p $proto} \
			-d $dest_ip \
			${src_ip:+-s $src_ip} \
			${src_port:+--sport $src_port} \
			${dest_port2:+--dport $dest_port2} \
			${src_mac:+-m mac --mac-source $src_mac} \
			-j ACCEPT 
	}
	[ "$proto" == "tcpudp" -o -z "$proto" ] && {
		proto=tcp
		add_rule
		proto=udp
		add_rule
		return
	}
	add_rule
}

fw_include() {
	local path
	config_get path $1 path
	[ -e $path ] && . $path
}

fw_addif() {
	local up
	local ifname
	config_get up $1 up
	config_get ifname $1 ifname
	[ -n "$up" ] || return 0
	(ACTION="ifup" INTERFACE="$1" . /etc/hotplug.d/iface/20-firewall)
}

fw_custom_chains() {
	[ -n "$CUSTOM_CHAINS" ] || return 0
	$IPTABLES -N input_rule
	$IPTABLES -N output_rule
	$IPTABLES -N forwarding_rule
	$IPTABLES -N prerouting_rule -t nat
	$IPTABLES -N postrouting_rule -t nat
			
	$IPTABLES -A INPUT -j input_rule
	$IPTABLES -A OUTPUT -j output_rule
	$IPTABLES -A FORWARD -j forwarding_rule
	$IPTABLES -A PREROUTING -t nat -j prerouting_rule
	$IPTABLES -A POSTROUTING -t nat -j postrouting_rule
}

fw_custom_chains_zone() {
	local zone="$1"

	[ -n "$CUSTOM_CHAINS" ] || return 0
	$IPTABLES -N input_${zone}
	$IPTABLES -N forwarding_${zone}
	$IPTABLES -N prerouting_${zone} -t nat
	$IPTABLES -I zone_${zone} 1 -j input_${zone}
	$IPTABLES -I zone_${zone}_forward 1 -j forwarding_${zone}
	$IPTABLES -I zone_${zone}_prerouting 1 -t nat -j prerouting_${zone}
}

fw_check_notrack() {
	local zone="$1"
	config_get name "$zone" name
	[ -n "$NOTRACK_DISABLED" ] || \
		find_item "$name" $CONNTRACK_ZONES || \
		$IPTABLES -t raw -A zone_${name}_notrack -j NOTRACK
}

fw_init() {
	DEFAULTS_APPLIED=

	echo "Loading defaults"
	config_foreach fw_defaults defaults
	echo "Loading zones"
	config_foreach fw_zone zone
	echo "Loading forwarding"
	config_foreach fw_forwarding forwarding
	echo "Loading redirects"
	config_foreach fw_redirect redirect
	echo "Loading rules"
	config_foreach fw_rule rule
	echo "Loading includes"
	config_foreach fw_include include
	uci_set_state firewall core loaded 1
	config_foreach fw_check_notrack zone
	unset CONFIG_APPEND
	config_load network
	config_foreach fw_addif interface
}

fw_stop() {
	fw_clear
	$IPTABLES -P INPUT ACCEPT
	$IPTABLES -P OUTPUT ACCEPT
	$IPTABLES -P FORWARD ACCEPT
	uci_revert_state firewall
}