Root/package/firewall/files/uci_firewall.sh

1#!/bin/sh
2# Copyright (C) 2008 John Crispin <blogic@openwrt.org>
3
4. /etc/functions.sh
5
6IPTABLES="echo iptables"
7IPTABLES=iptables
8
9config_clear
10include /lib/network
11scan_interfaces
12
13CONFIG_APPEND=1
14config_load firewall
15
16config fw_zones
17ZONE_LIST=$CONFIG_SECTION
18ZONE_NAMES=
19
20CUSTOM_CHAINS=1
21DEF_INPUT=DROP
22DEF_OUTPUT=DROP
23DEF_FORWARD=DROP
24CONNTRACK_ZONES=
25NOTRACK_DISABLED=
26
27add_state() {
28    local var="$1"
29    local item="$2"
30
31    local val="$(uci_get_state firewall core $var)"
32    uci_set_state firewall core $var "${val:+$val }$item"
33}
34
35del_state() {
36    local var="$1"
37    local item="$2"
38
39    local val=" $(uci_get_state firewall core $var) "
40    val="${val// $item / }"
41    val="${val# }"
42    val="${val% }"
43    uci_set_state firewall core $var "$val"
44}
45
46find_item() {
47    local item="$1"; shift
48    for i in "$@"; do
49        [ "$i" = "$item" ] && return 0
50    done
51    return 1
52}
53
54get_portrange() {
55    local _var="$1"
56    local _range="$2"
57    local _delim="${3:-:}"
58
59    local _min="${_range%%[:-]*}"
60    local _max="${_range##*[:-]}"
61
62    [ -n "$_min" ] && [ -n "$_max" ] && [ "$_min" != "$_max" ] && \
63        export -n -- "$_var=$_min$_delim$_max" || \
64        export -n -- "$_var=${_min:-$_max}"
65}
66
67get_negation() {
68    local _var="$1"
69    local _flag="$2"
70    local _ipaddr="$3"
71
72    [ "${_ipaddr#!}" != "$_ipaddr" ] && \
73        export -n -- "$_var=! $_flag ${_ipaddr#!}" || \
74        export -n -- "$_var=${_ipaddr:+$_flag $_ipaddr}"
75}
76
77load_policy() {
78    config_get input $1 input
79    config_get output $1 output
80    config_get forward $1 forward
81
82    DEF_INPUT="${input:-$DEF_INPUT}"
83    DEF_OUTPUT="${output:-$DEF_OUTPUT}"
84    DEF_FORWARD="${forward:-$DEF_FORWARD}"
85}
86
87create_zone() {
88    local name="$1"
89    local network="$2"
90    local input="$3"
91    local output="$4"
92    local forward="$5"
93    local mtu_fix="$6"
94    local masq="$7"
95    local masq_src="$8"
96    local masq_dest="$9"
97
98    local exists
99
100    [ "$name" == "loopback" ] && return
101
102    config_get exists $ZONE_LIST $name
103    [ -n "$exists" ] && return
104    config_set $ZONE_LIST $name 1
105
106    $IPTABLES -N zone_${name}
107    $IPTABLES -N zone_${name}_MSSFIX
108    $IPTABLES -N zone_${name}_ACCEPT
109    $IPTABLES -N zone_${name}_DROP
110    $IPTABLES -N zone_${name}_REJECT
111    $IPTABLES -N zone_${name}_forward
112    [ "$output" ] && $IPTABLES -A output -j zone_${name}_${output}
113    $IPTABLES -N zone_${name}_nat -t nat
114    $IPTABLES -N zone_${name}_prerouting -t nat
115    $IPTABLES -t raw -N zone_${name}_notrack
116    [ "$mtu_fix" == "1" ] && $IPTABLES -I FORWARD 1 -j zone_${name}_MSSFIX
117
118    if [ "$masq" == "1" ]; then
119        local msrc mdst
120        for msrc in ${masq_src:-0.0.0.0/0}; do
121            get_negation msrc '-s' "$msrc"
122            for mdst in ${masq_dest:-0.0.0.0/0}; do
123                get_negation mdst '-d' "$mdst"
124                $IPTABLES -A zone_${name}_nat -t nat $msrc $mdst -j MASQUERADE
125            done
126        done
127    fi
128
129    append ZONE_NAMES "$name"
130}
131
132
133addif() {
134    local network="$1"
135    local ifname="$2"
136    local zone="$3"
137
138    local n_if n_zone
139    config_get n_if core "${network}_ifname"
140    config_get n_zone core "${network}_zone"
141    [ -n "$n_zone" ] && {
142        if [ "$n_zone" != "$zone" ]; then
143            delif "$network" "$n_if" "$n_zone"
144        else
145            return
146        fi
147    }
148
149    logger "adding $network ($ifname) to firewall zone $zone"
150    $IPTABLES -A input -i "$ifname" -j zone_${zone}
151    $IPTABLES -I zone_${zone}_MSSFIX 1 -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
152    $IPTABLES -I zone_${zone}_ACCEPT 1 -o "$ifname" -j ACCEPT
153    $IPTABLES -I zone_${zone}_DROP 1 -o "$ifname" -j DROP
154    $IPTABLES -I zone_${zone}_REJECT 1 -o "$ifname" -j reject
155    $IPTABLES -I zone_${zone}_ACCEPT 1 -i "$ifname" -j ACCEPT
156    $IPTABLES -I zone_${zone}_DROP 1 -i "$ifname" -j DROP
157    $IPTABLES -I zone_${zone}_REJECT 1 -i "$ifname" -j reject
158
159    $IPTABLES -I PREROUTING 1 -t nat -i "$ifname" -j zone_${zone}_prerouting
160    $IPTABLES -I POSTROUTING 1 -t nat -o "$ifname" -j zone_${zone}_nat
161    $IPTABLES -A forward -i "$ifname" -j zone_${zone}_forward
162    $IPTABLES -I PREROUTING 1 -t raw -i "$ifname" -j zone_${zone}_notrack
163
164    uci_set_state firewall core "${network}_ifname" "$ifname"
165    uci_set_state firewall core "${network}_zone" "$zone"
166
167    add_state "${zone}_networks" "$network"
168
169    ACTION=add ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
170}
171
172delif() {
173    local network="$1"
174    local ifname="$2"
175    local zone="$3"
176
177    logger "removing $network ($ifname) from firewall zone $zone"
178    $IPTABLES -D input -i "$ifname" -j zone_$zone
179    $IPTABLES -D zone_${zone}_MSSFIX -o "$ifname" -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
180    $IPTABLES -D zone_${zone}_ACCEPT -o "$ifname" -j ACCEPT
181    $IPTABLES -D zone_${zone}_DROP -o "$ifname" -j DROP
182    $IPTABLES -D zone_${zone}_REJECT -o "$ifname" -j reject
183    $IPTABLES -D zone_${zone}_ACCEPT -i "$ifname" -j ACCEPT
184    $IPTABLES -D zone_${zone}_DROP -i "$ifname" -j DROP
185    $IPTABLES -D zone_${zone}_REJECT -i "$ifname" -j reject
186
187    $IPTABLES -D PREROUTING -t nat -i "$ifname" -j zone_${zone}_prerouting
188    $IPTABLES -D POSTROUTING -t nat -o "$ifname" -j zone_${zone}_nat
189    $IPTABLES -D forward -i "$ifname" -j zone_${zone}_forward
190    $IPTABLES -D PREROUTING -t raw -i "$ifname" -j zone_${zone}_notrack
191
192    uci_revert_state firewall core "${network}_ifname"
193    uci_revert_state firewall core "${network}_zone"
194
195    del_state "${zone}_networks" "$network"
196
197    ACTION=remove ZONE="$zone" INTERFACE="$network" DEVICE="$ifname" /sbin/hotplug-call firewall
198}
199
200load_synflood() {
201    local rate=${1:-25}
202    local burst=${2:-50}
203    echo "Loading synflood protection"
204    $IPTABLES -N syn_flood
205    $IPTABLES -A syn_flood -p tcp --syn -m limit --limit $rate/second --limit-burst $burst -j RETURN
206    $IPTABLES -A syn_flood -j DROP
207    $IPTABLES -A INPUT -p tcp --syn -j syn_flood
208}
209
210fw_set_chain_policy() {
211    local chain=$1
212    local target=$2
213    [ "$target" == "REJECT" ] && {
214        $IPTABLES -A $chain -j reject
215        target=DROP
216    }
217    $IPTABLES -P $chain $target
218}
219
220fw_clear() {
221    $IPTABLES -F
222    $IPTABLES -t nat -F
223    $IPTABLES -t nat -X
224    $IPTABLES -t raw -F
225    $IPTABLES -t raw -X
226    $IPTABLES -X
227}
228
229fw_defaults() {
230    [ -n "$DEFAULTS_APPLIED" ] && {
231        echo "Error: multiple defaults sections detected"
232        return;
233    }
234    DEFAULTS_APPLIED=1
235
236    load_policy "$1"
237
238    echo 1 > /proc/sys/net/ipv4/tcp_syncookies
239    for f in /proc/sys/net/ipv4/conf/*/accept_redirects
240    do
241        echo 0 > $f
242    done
243    for f in /proc/sys/net/ipv4/conf/*/accept_source_route
244    do
245        echo 0 > $f
246    done
247
248    uci_revert_state firewall core
249    uci_set_state firewall core "" firewall_state
250
251    $IPTABLES -P INPUT DROP
252    $IPTABLES -P OUTPUT DROP
253    $IPTABLES -P FORWARD DROP
254
255    fw_clear
256    config_get_bool drop_invalid $1 drop_invalid 0
257
258    [ "$drop_invalid" -gt 0 ] && {
259        $IPTABLES -A INPUT -m state --state INVALID -j DROP
260        $IPTABLES -A OUTPUT -m state --state INVALID -j DROP
261        $IPTABLES -A FORWARD -m state --state INVALID -j DROP
262        NOTRACK_DISABLED=1
263    }
264
265    $IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
266    $IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
267    $IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
268
269    $IPTABLES -A INPUT -i lo -j ACCEPT
270    $IPTABLES -A OUTPUT -o lo -j ACCEPT
271
272    config_get syn_flood $1 syn_flood
273    config_get syn_rate $1 syn_rate
274    config_get syn_burst $1 syn_burst
275    [ "$syn_flood" == "1" ] && load_synflood $syn_rate $syn_burst
276
277    echo "Adding custom chains"
278    fw_custom_chains
279
280    $IPTABLES -N input
281    $IPTABLES -N output
282    $IPTABLES -N forward
283
284    $IPTABLES -A INPUT -j input
285    $IPTABLES -A OUTPUT -j output
286    $IPTABLES -A FORWARD -j forward
287
288    $IPTABLES -N reject
289    $IPTABLES -A reject -p tcp -j REJECT --reject-with tcp-reset
290    $IPTABLES -A reject -j REJECT --reject-with icmp-port-unreachable
291
292    fw_set_chain_policy INPUT "$DEF_INPUT"
293    fw_set_chain_policy OUTPUT "$DEF_OUTPUT"
294    fw_set_chain_policy FORWARD "$DEF_FORWARD"
295}
296
297fw_zone_defaults() {
298    local name
299    local network
300    local masq
301
302    config_get name $1 name
303    config_get network $1 network
304    config_get_bool masq $1 masq "0"
305    config_get_bool conntrack $1 conntrack "0"
306    config_get_bool mtu_fix $1 mtu_fix 0
307
308    load_policy $1
309    [ "$forward" ] && $IPTABLES -A zone_${name}_forward -j zone_${name}_${forward}
310    [ "$input" ] && $IPTABLES -A zone_${name} -j zone_${name}_${input}
311}
312
313fw_zone() {
314    local name
315    local network
316    local mtu_fix
317    local conntrack
318    local masq
319    local masq_src
320    local masq_dest
321
322    config_get name $1 name
323    config_get network $1 network
324    config_get_bool masq $1 masq "0"
325    config_get_bool conntrack $1 conntrack "0"
326    config_get_bool mtu_fix $1 mtu_fix 0
327    config_get masq_src $1 masq_src
328    config_get masq_dest $1 masq_dest
329
330    load_policy $1
331    [ "$conntrack" = "1" -o "$masq" = "1" ] && append CONNTRACK_ZONES "$name"
332    [ -z "$network" ] && network=$name
333
334    create_zone "$name" "$network" "$input" "$output" "$forward" "$mtu_fix" \
335        "$masq" "$masq_src" "$masq_dest"
336
337    fw_custom_chains_zone "$name"
338}
339
340fw_rule() {
341    local src
342    local src_ip
343    local src_mac
344    local src_port
345    local src_mac
346    local dest
347    local dest_ip
348    local dest_port
349    local proto
350    local icmp_type
351    local target
352    local ruleset
353
354    config_get src $1 src
355    config_get src_ip $1 src_ip
356    config_get src_mac $1 src_mac
357    config_get src_port $1 src_port
358    config_get dest $1 dest
359    config_get dest_ip $1 dest_ip
360    config_get dest_port $1 dest_port
361    config_get proto $1 proto
362    config_get icmp_type $1 icmp_type
363    config_get target $1 target
364    config_get ruleset $1 ruleset
365
366    [ "$target" != "NOTRACK" ] || [ -n "$src" ] || {
367        echo "NOTRACK rule needs src"
368        return
369    }
370
371    local srcaddr destaddr
372    get_negation srcaddr '-s' "$src_ip"
373    get_negation destaddr '-d' "$dest_ip"
374
375    local srcports destports
376    get_portrange srcports "$src_port" ":"
377    get_portrange destports "$dest_port" ":"
378
379    ZONE=input
380    TABLE=filter
381    TARGET="${target:-DROP}"
382
383    if [ "$TARGET" = "NOTRACK" ]; then
384        TABLE=raw
385        ZONE="zone_${src}_notrack"
386    else
387        [ -n "$src" ] && ZONE="zone_${src}${dest:+_forward}"
388        [ -n "$dest" ] && TARGET="zone_${dest}_${TARGET}"
389    fi
390
391    local pos
392    eval 'pos=$((++FW__RULE_COUNT_'$ZONE'))'
393
394    add_rule() {
395        $IPTABLES -t $TABLE -I $ZONE $pos \
396            $srcaddr $destaddr \
397            ${proto:+-p $proto} \
398            ${icmp_type:+--icmp-type $icmp_type} \
399            ${srcports:+--sport $srcports} \
400            ${src_mac:+-m mac --mac-source $src_mac} \
401            ${destports:+--dport $destports} \
402            -j $TARGET
403    }
404
405    [ "$proto" == "tcpudp" ] && proto="tcp udp"
406    for proto in ${proto:-tcp udp}; do
407        add_rule
408    done
409}
410
411fw_forwarding() {
412    local src
413    local dest
414    local masq
415
416    config_get src $1 src
417    config_get dest $1 dest
418    [ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
419    [ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
420    $IPTABLES -I $z_src 1 -j $z_dest
421
422    # propagate masq zone flag
423    find_item "$src" $CONNTRACK_ZONES && append CONNTRACK_ZONES $dest
424    find_item "$dest" $CONNTRACK_ZONES && append CONNTRACK_ZONES $src
425}
426
427fw_redirect() {
428    local src
429    local src_ip
430    local src_dip
431    local src_port
432    local src_dport
433    local src_mac
434    local dest
435    local dest_ip
436    local dest_port
437    local proto
438    local target
439
440    config_get src $1 src
441    config_get src_ip $1 src_ip
442    config_get src_dip $1 src_dip
443    config_get src_port $1 src_port
444    config_get src_dport $1 src_dport
445    config_get src_mac $1 src_mac
446    config_get dest $1 dest
447    config_get dest_ip $1 dest_ip
448    config_get dest_port $1 dest_port
449    config_get proto $1 proto
450    config_get target $1 target
451
452    local fwdchain natchain natopt nataddr natports srcdaddr srcdports
453    if [ "${target:-DNAT}" == "DNAT" ]; then
454        [ -n "$src" -a -n "$dest_ip$dest_port" ] || {
455            echo "DNAT redirect needs src and dest_ip or dest_port"
456            return
457        }
458
459        fwdchain="zone_${src}_forward"
460
461        natopt="--to-destination"
462        natchain="zone_${src}_prerouting"
463        nataddr="$dest_ip"
464        get_portrange natports "$dest_port" "-"
465
466        get_negation srcdaddr '-d' "$src_dip"
467        get_portrange srcdports "$src_dport" ":"
468
469        find_item "$src" $CONNTRACK_ZONES || \
470            append CONNTRACK_ZONES "$src"
471
472    elif [ "$target" == "SNAT" ]; then
473        [ -n "$dest" -a -n "$src_dip" ] || {
474            echo "SNAT redirect needs dest and src_dip"
475            return
476        }
477
478        fwdchain="${src:+zone_${src}_forward}"
479
480        natopt="--to-source"
481        natchain="zone_${dest}_nat"
482        nataddr="$src_dip"
483        get_portrange natports "$src_dport" "-"
484
485        get_negation srcdaddr '-d' "$dest_ip"
486        get_portrange srcdports "$dest_port" ":"
487
488        find_item "$dest" $CONNTRACK_ZONES || \
489            append CONNTRACK_ZONES "$dest"
490
491    else
492        echo "redirect target must be either DNAT or SNAT"
493        return
494    fi
495
496    local srcaddr destaddr
497    get_negation srcaddr '-s' "$src_ip"
498    get_negation destaddr '-d' "$dest_ip"
499
500    local srcports destports
501    get_portrange srcports "$src_port" ":"
502    get_portrange destports "${dest_port-$src_dport}" ":"
503
504    add_rule() {
505        local pos
506        eval 'pos=$((++FW__REDIR_COUNT_'$natchain'))'
507
508        $IPTABLES -I $natchain $pos -t nat \
509            $srcaddr $srcdaddr \
510            ${proto:+-p $proto} \
511            ${srcports:+--sport $srcports} \
512            ${srcdports:+--dport $srcdports} \
513            ${src_mac:+-m mac --mac-source $src_mac} \
514            -j ${target:-DNAT} $natopt $nataddr${natports:+:$natports}
515
516        [ -n "$dest_ip" ] && \
517        $IPTABLES -I ${fwdchain:-forward} 1 \
518            $srcaddr $destaddr \
519            ${proto:+-p $proto} \
520            ${srcports:+--sport $srcports} \
521            ${destports:+--dport $destports} \
522            ${src_mac:+-m mac --mac-source $src_mac} \
523            -j ACCEPT
524    }
525
526    [ "$proto" == "tcpudp" ] && proto="tcp udp"
527    for proto in ${proto:-tcp udp}; do
528        add_rule
529    done
530}
531
532fw_include() {
533    local path
534    config_get path $1 path
535    [ -e $path ] && . $path
536}
537
538get_interface_zones() {
539    local interface="$2"
540    local name
541    local network
542    local masq_src
543    local masq_dest
544    config_get name $1 name
545    config_get network $1 network
546    config_get masq_src $1 masq_src
547    config_get masq_dest $1 masq_dest
548    [ -z "$network" ] && network=$name
549    for n in $network; do
550        [ "$n" = "$interface" ] && {
551            append add_zone "$name"
552            append add_masq_src "$masq_src"
553            append add_masq_dest "$masq_dest"
554        }
555    done
556}
557
558fw_event() {
559    local action="$1"
560    local interface="$2"
561    local ifname="$(sh -c ". /etc/functions.sh; include /lib/network; scan_interfaces; config_get "$interface" ifname")"
562    local add_zone=
563    local add_masq_src=
564    local add_masq_dest=
565    local up
566
567    [ -z "$ifname" ] && return 0
568    config_foreach get_interface_zones zone "$interface"
569    [ -z "$add_zone" ] && return 0
570
571    case "$action" in
572        ifup)
573            for z in $add_zone; do
574                local loaded masq_src masq_dest
575                config_get loaded core loaded
576                [ -n "$loaded" ] && addif "$interface" "$ifname" "$z" "$add_masq_src" "$add_masq_dest"
577            done
578        ;;
579        ifdown)
580            config_get up "$interface" up
581
582            for z in $ZONE; do
583                local masq_src masq_dest
584                config_get masq_src core "${z}_masq_src"
585                config_get masq_dest core "${z}_masq_dest"
586                [ "$up" == "1" ] && delif "$interface" "$ifname" "$z" "$masq_src" "$masq_dest"
587            done
588        ;;
589    esac
590}
591
592fw_addif() {
593    local up
594    local ifname
595    config_get up $1 up
596    [ -n "$up" ] || return 0
597    fw_event ifup "$1"
598}
599
600fw_custom_chains() {
601    [ -n "$CUSTOM_CHAINS" ] || return 0
602    $IPTABLES -N input_rule
603    $IPTABLES -N output_rule
604    $IPTABLES -N forwarding_rule
605    $IPTABLES -N prerouting_rule -t nat
606    $IPTABLES -N postrouting_rule -t nat
607
608    $IPTABLES -A INPUT -j input_rule
609    $IPTABLES -A OUTPUT -j output_rule
610    $IPTABLES -A FORWARD -j forwarding_rule
611    $IPTABLES -A PREROUTING -t nat -j prerouting_rule
612    $IPTABLES -A POSTROUTING -t nat -j postrouting_rule
613}
614
615fw_custom_chains_zone() {
616    local zone="$1"
617
618    [ -n "$CUSTOM_CHAINS" ] || return 0
619    $IPTABLES -N input_${zone}
620    $IPTABLES -N forwarding_${zone}
621    $IPTABLES -N prerouting_${zone} -t nat
622    $IPTABLES -I zone_${zone} 1 -j input_${zone}
623    $IPTABLES -I zone_${zone}_forward 1 -j forwarding_${zone}
624    $IPTABLES -I zone_${zone}_prerouting 1 -t nat -j prerouting_${zone}
625}
626
627fw_check_notrack() {
628    local zone="$1"
629    config_get name "$zone" name
630    [ -n "$NOTRACK_DISABLED" ] || \
631        find_item "$name" $CONNTRACK_ZONES || \
632        $IPTABLES -t raw -A zone_${name}_notrack -j NOTRACK
633}
634
635fw_init() {
636    DEFAULTS_APPLIED=
637
638    echo "Loading defaults"
639    config_foreach fw_defaults defaults
640    echo "Loading zones"
641    config_foreach fw_zone zone
642    echo "Loading forwarding"
643    config_foreach fw_forwarding forwarding
644    echo "Loading redirects"
645    config_foreach fw_redirect redirect
646    echo "Loading rules"
647    config_foreach fw_rule rule
648    echo "Loading includes"
649    config_foreach fw_include include
650    echo "Loading zone defaults"
651    config_foreach fw_zone_defaults zone
652    uci_set_state firewall core loaded 1
653    config_set core loaded 1
654    config_foreach fw_check_notrack zone
655    INTERFACES="$(sh -c '
656        . /etc/functions.sh; config_load network
657        echo_up() { local up; config_get_bool up "$1" up 0; [ $up = 1 ] && echo "$1"; }
658        config_foreach echo_up interface
659    ')"
660    for interface in $INTERFACES; do
661        fw_event ifup "$interface"
662    done
663
664    uci_set_state firewall core zones "$ZONE_NAMES"
665}
666
667fw_stop() {
668    local z n i
669    config_get z core zones
670    for z in $z; do
671        config_get n core "${z}_networks"
672        for n in $n; do
673            config_get i core "${n}_ifname"
674            [ -n "$i" ] && env -i ACTION=remove ZONE="$z" INTERFACE="$n" DEVICE="$i" \
675                /sbin/hotplug-call firewall
676        done
677    done
678
679    fw_clear
680    $IPTABLES -P INPUT ACCEPT
681    $IPTABLES -P OUTPUT ACCEPT
682    $IPTABLES -P FORWARD ACCEPT
683    uci_revert_state firewall
684}
685

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