summaryrefslogtreecommitdiffstats
path: root/eofirewall
blob: 72b8750c1aa300d6112fb9821a07a4e38e81f313 (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
#!/bin/bash

. /lib/lsb/init-functions

NAME="eofirewall"

abort()
{
    message=$@
    log_failure_msg "$message"
    exit 1
}

chain_exists()
{
    local chain_name="$1" ; shift
    [ $# -eq 1 ] && local table="--table $1"
    $IPTABLES $table -n --list "$chain_name" >/dev/null 2>&1
}


if [ -f "/etc/firewall/firewall.conf" ]; then
    source /etc/firewall/firewall.conf
else
    log_warning_msg "No configuration file /etc/firewall/firewall.conf"
    exit 0
fi

flush()
{
    $IPTABLES -t filter -F
    $IPTABLES -t filter -X

    $IPTABLES -t filter -P INPUT   ACCEPT
    $IPTABLES -t filter -P FORWARD ACCEPT
    $IPTABLES -t filter -P OUTPUT  ACCEPT

    $IPTABLES -t nat -F
    $IPTABLES -t nat -X

    $IPTABLES -t nat -P PREROUTING  ACCEPT
    $IPTABLES -t nat -P OUTPUT      ACCEPT
    $IPTABLES -t nat -P POSTROUTING ACCEPT

    $IPTABLES -t mangle -F
    $IPTABLES -t mangle -X

    $IPTABLES -t mangle -P PREROUTING  ACCEPT
    $IPTABLES -t mangle -P INPUT       ACCEPT
    $IPTABLES -t mangle -P FORWARD     ACCEPT
}

clean()
{
    $IPTABLES -t filter -P INPUT   ACCEPT
    $IPTABLES -t filter -P FORWARD ACCEPT
    $IPTABLES -t filter -P OUTPUT  ACCEPT
    $IPTABLES -t nat -F
    $IPTABLES -t nat -X
    $IPTABLES -t mangle -F
    $IPTABLES -t mangle -X

    if chain_exists EO-INPUT; then
        $IPTABLES -D INPUT -j EO-INPUT
        $IPTABLES -D OUTPUT -j EO-OUTPUT
        $IPTABLES -D FORWARD -j EO-FORWARD
        $IPTABLES -D INPUT -j EO-LOGDROP
        $IPTABLES -D OUTPUT -j EO-LOGDROP
        $IPTABLES -D FORWARD -j EO-LOGDROP
    fi

    for chain in `$IPTABLES --list -n | grep '^Chain EO' | cut -f2 -d ' '`; do
        $IPTABLES -F $chain
        $IPTABLES -X $chain
    done

}

init()
{
    clean
    test_config
    modprobe ip_conntrack

    $IPTABLES -N EO-INPUT
    $IPTABLES -N EO-OUTPUT
    $IPTABLES -N EO-FORWARD
    $IPTABLES -N EO-LOGDROP


    # default policies
    log_action_msg "DROP Input, Forward and Output by default"
    $IPTABLES -P INPUT DROP
    $IPTABLES -P FORWARD DROP
    $IPTABLES -P OUTPUT DROP
}

test_config()
{
    # FIXME: test if the interface and the ip exist
    if [ ! "$WAN_INT" -o ! "$IP" ]; then
        abort "Bad configuration please check /etc/firewall/firewall.conf"
    fi
}

critical_return()
{
    if [ `echo $?` != 0 ]; then
        log_failure_msg  "Error on the last command firewall will be stop"
        clean
        exit 1
    fi
}

forward_port()
{
    if [ $# != 4 ]; then
        log_warning_msg "Bad syntax for port forward : $*"
        return
    fi

    local source=$1
    local port=$2
    local destination=$3
    local proto=$4

    if echo "$destination" | grep -q ":"; then
        dest_ip=$(echo $destination | cut -d ":" -f1)
        dest_port=$(echo $destination | cut -d ":" -f2)
        if [ ! "$LAN_INT" ]; then
            log_warning_msg "You must add a LAN interface (LAN_INT) for a port forward"
        else
            log_action_msg "Forward $port to $destination for protocol $proto"
            $IPTABLES -A EO-FORWARD -i $WAN_INT -o $LAN_INT -p $proto -s $source -d $dest_ip --dport $dest_port -m state --state NEW -j ACCEPT
            $IPTABLES -t nat -A PREROUTING -i $WAN_INT -p $proto -s $source -d $IP --dport $port -j DNAT --to $destination
        fi
    fi

}
open_input_port()
{
    if [ $# == 4 ]; then
        local destination=$2
        local proto=$3
        local ports=$4
    elif [ $# == 3 ]; then
        local destination=$IP
        local proto=$2
        local ports=$3
    else
        log_warning_msg  "Open port bad syntax : $*"
    fi
    source=$1
    log_action_msg "Open port(s) $ports from $source to $destination for protocol $proto"
    $IPTABLES -A EO-INPUT -i $WAN_INT -p $proto -s $source -d $destination -m multiport --dports $ports -m state --state NEW -j ACCEPT
    critical_return
}

open_output_port()
{
    if [ $# == 4 ]; then
        local source=$2
        local proto=$3
        local ports=$4
    elif [ $# == 3 ]; then
        local source=$IP
        local proto=$2
        local ports=$3
    else
        log_warning_msg  "Open output port bad syntax : $*"
    fi
    destination=$1
    log_action_msg "Open output port(s) $ports from $source to $destination for protocol $proto"
    $IPTABLES -A EO-OUTPUT -o $WAN_INT -p $proto -s $source -d $destination -m multiport --dports $ports -m state --state NEW -j ACCEPT
    critical_return
}

port_redirection()
{
    if [ $# != 4 ]; then
        log_warning_msg "Bad syntax for port redirection : $*"
        return
    fi

    local if=$1
    local proto=$2
    local srcport=$3
    local destport=$4

    log_action_msg "Redirect $if port $srcport to $destport for portocol $proto"
    $IPTABLES -t nat -A PREROUTING -i $if -p $proto --dport $srcport -j REDIRECT --to-port $destport
}

port_knocking()
{
    if [ $# != 3 ]; then
        log_warning_msg "Bad syntax for port knocking : $*"
        return
    fi

    local ports=$1
    local knock_ports=$2
    local knock_number=$3
    local i=0

    for kport in $(echo $knock_ports | sed 's/,/ /g'); do
        ((i++))
        tock_number=$knock_number$i
        if [ $i -gt 1 ]; then
            $IPTABLES -N EO-TOC${tock_number}
            $IPTABLES -A EO-TOC${tock_number} -m recent --name EO-TOC$((${tock_number}-1)) --remove
            $IPTABLES -A EO-TOC${tock_number} -m recent --name EO-TOC${tock_number} --set
            $IPTABLES -A EO-INPUT -i $WAN_INT -p tcp --dport $kport -m recent --rcheck --name EO-TOC$((${tock_number}-1)) -j EO-TOC${tock_number}
        else
            $IPTABLES -A EO-INPUT -i $WAN_INT -p tcp --dport $kport -m recent --set --name EO-TOC${tock_number}
        fi
    done
    log_action_msg "Port knocking for $ports with combinaison $knock_ports on $WAN_INT"
    for port in $(echo $ports | sed 's/,/ /g'); do
        $IPTABLES -A EO-INPUT -i $WAN_INT -p tcp --dport $port -m recent --rcheck --seconds 15 --name EO-TOC${tock_number} -m state --state NEW -j ACCEPT
    done
}

start()
{
    init

    ## allow packets coming from the machine
    log_action_msg "Accept lo interface"
    $IPTABLES -A EO-INPUT -i lo -j ACCEPT
    $IPTABLES -A EO-OUTPUT -o lo -j ACCEPT

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

    if [ $ALLOW_WAN_OUTPUT_EVERYWHERE -ne 0 ]; then
        log_action_msg "Allow WAN outgoing traffic to everywhere"
        $IPTABLES -A EO-OUTPUT -o $WAN_INT -m state --state NEW -j ACCEPT
    fi

    critical_return

    if [ $LAN == 1 ]; then
        log_action_msg "Allow WAN outgoing traffic from lan"
        $IPTABLES -A EO-FORWARD -i $LAN_INT -o $WAN_INT -s $LAN_NETWORK -m state --state NEW -j ACCEPT
        log_action_msg "Allow local network"
        $IPTABLES -A EO-OUTPUT -o $LAN_INT -s $LAN_NETWORK -j ACCEPT
        $IPTABLES -A EO-INPUT  -i $LAN_INT -d $LAN_NETWORK -j ACCEPT
   fi

    ## block spoofing
    log_action_msg "Enable rp filter"
    echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter

    ## stop sync flood
    log_action_msg "Block Syn flood"
    echo "1" >/proc/sys/net/ipv4/tcp_syncookies
    echo "1024" > /proc/sys/net/ipv4/tcp_max_syn_backlog

    if [ $PING == 1 ]; then
        log_action_msg "PING allowed"
        $IPTABLES -A EO-INPUT -p icmp --icmp-type ping -j ACCEPT
        $IPTABLES -A EO-OUTPUT -p icmp --icmp-type ping -j ACCEPT
        $IPTABLES -A EO-FORWARD -p icmp --icmp-type ping -j ACCEPT
    fi

    if [ $FTP == 1 ]; then
        log_action_msg "FTP allowed"
        modprobe ip_conntrack_ftp
        $IPTABLES -A EO-INPUT -i $WAN_INT -d $IP -p tcp --dport ftp -m state --state NEW -j ACCEPT
    fi

    ## Open input ports
    for args in "${OPEN_PORTS[@]}"; do
        open_input_port $args
    done

    ## Open ouput ports
    for args in "${OUPUT_DESTINATIONS[@]}"; do
        open_output_port $args
    done

    ## Port knocking
    local i=1
    for args in "${PORT_KNOCK[@]}"; do
        port_knocking $args $i
        ((i++))
    done

    ## Port forwading
    for args in "${TRAFFICS[@]}"; do
        forward_port $args
    done

    ## Port redirection
    for args in "${REDIRECTIONS[@]}"; do
        port_redirection $args
    done

    ## Old: Whitelist
    for arg in "${WHITELIST_SSH[@]}"; do
        log_warning_msg "WHITELIST_SSH is obsolete: this option will be removed in next version"
        open_input_port $arg tcp ssh
    done

    for ip in "${WHITELIST[@]}"; do
        for args in "${WHITELIST_OPEN_PORTS[@]}"; do
            open_input_port $ip $args
        done
    done

    ## NAT
    if [ $NAT == 1 ]; then
        log_action_msg "Activate nat"
        for proto in ftp irc sip h323; do modprobe nf_nat_$proto; done
        $IPTABLES -t nat -A POSTROUTING -s $LAN_NETWORK -j SNAT --to-source $IP
    fi

    ipt_hook

    $IPTABLES -A INPUT -j EO-INPUT
    $IPTABLES -A OUTPUT -j EO-OUTPUT
    $IPTABLES -A FORWARD -j EO-FORWARD

    ## LOG
    ## Create a EO-LOGDROP chain to log and drop packets
    $IPTABLES -A EO-LOGDROP -p tcp -m limit --limit 1/min -j LOG --log-prefix "iptables: denied tcp: " --log-level 4
    $IPTABLES -A EO-LOGDROP -p udp -m limit --limit 1/min -j LOG --log-prefix "iptables: denied udp: " --log-level 4
    $IPTABLES -A EO-LOGDROP -p icmp -m limit --limit 1/min -j LOG --log-prefix "iptables: denied icmp: " --log-level 4
    $IPTABLES -A EO-LOGDROP -j DROP

    $IPTABLES -A INPUT -j EO-LOGDROP
    $IPTABLES -A OUTPUT -j EO-LOGDROP
    $IPTABLES -A FORWARD -j EO-LOGDROP
}


load()
{
    log_action_msg "Loading old rules from /etc/network/iptables-save"
    log_action_msg "If you want to load new rules please use test and then start"
    if [ -f /etc/network/iptables-save ]; then
        iptables-restore < /etc/network/iptables-save
    else
        log_warning_msg "No iptables rules saved please use test and save script options"
    fi
}

test_rules()
{
    log_action_msg "Testing new rules"
    log_action_msg "You have 30 seconds to test your new rules"
    start || exit 1
    log_end_msg 0
    log_action_msg "... Please test your rules"
    sleep 30
    log_action_msg "---- The test is finished ----"
    if  [ -f /etc/network/iptables-save ]; then
        iptables-restore < /etc/network/iptables-save
        log_action_msg "Old rules restored"
    else
        clean
        log_action_msg "Rules cleaned"
    fi
    log_action_msg "If you are happy with this new rules please use save option"
}


case "$1" in
        load|restore)
            load || exit 1
        ;;
        test)
            test_rules || exit 1
        ;;
        start)
            log_warning_msg "WARNING: you are loading new rules you have 3 seconds to cancel (CRTL+C)"
            sleep 3
            start || exit 1
        ;;
        save)
            log_action_msg "You need to make a start before if you want to save new rules"
            log_action_msg "Saving current rules to /etc/network/iptables-save"
            iptables-save > /etc/network/iptables-save
        ;;
        flush)
            flush || exit 1
        ;;
        clean)
            clean || exit 1
        ;;
        *)
            N=/usr/bin/$NAME
            echo "Usage: $N {restore|load|save|test|clean|flush}"
            exit 2
        ;;
esac

exit 0