rc.firewall revision 200028
1#!/bin/sh - 2# Copyright (c) 1996 Poul-Henning Kamp 3# All rights reserved. 4# 5# Redistribution and use in source and binary forms, with or without 6# modification, are permitted provided that the following conditions 7# are met: 8# 1. Redistributions of source code must retain the above copyright 9# notice, this list of conditions and the following disclaimer. 10# 2. Redistributions in binary form must reproduce the above copyright 11# notice, this list of conditions and the following disclaimer in the 12# documentation and/or other materials provided with the distribution. 13# 14# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24# SUCH DAMAGE. 25# 26# $FreeBSD: head/etc/rc.firewall 200028 2009-12-02 15:05:26Z ume $ 27# 28 29# 30# Setup system for ipfw(4) firewall service. 31# 32 33# Suck in the configuration variables. 34if [ -z "${source_rc_confs_defined}" ]; then 35 if [ -r /etc/defaults/rc.conf ]; then 36 . /etc/defaults/rc.conf 37 source_rc_confs 38 elif [ -r /etc/rc.conf ]; then 39 . /etc/rc.conf 40 fi 41fi 42 43############ 44# Define the firewall type in /etc/rc.conf. Valid values are: 45# open - will allow anyone in 46# client - will try to protect just this machine 47# simple - will try to protect a whole network 48# closed - totally disables IP services except via lo0 interface 49# workstation - will try to protect just this machine using statefull 50# firewalling. See below for rc.conf variables used 51# UNKNOWN - disables the loading of firewall rules. 52# filename - will load the rules in the given filename (full path required) 53# 54# For ``client'' and ``simple'' the entries below should be customized 55# appropriately. 56 57############ 58# 59# If you don't know enough about packet filtering, we suggest that you 60# take time to read this book: 61# 62# Building Internet Firewalls, 2nd Edition 63# Brent Chapman and Elizabeth Zwicky 64# 65# O'Reilly & Associates, Inc 66# ISBN 1-56592-871-7 67# http://www.ora.com/ 68# http://www.oreilly.com/catalog/fire2/ 69# 70# For a more advanced treatment of Internet Security read: 71# 72# Firewalls and Internet Security: Repelling the Wily Hacker, 2nd Edition 73# William R. Cheswick, Steven M. Bellowin, Aviel D. Rubin 74# 75# Addison-Wesley / Prentice Hall 76# ISBN 0-201-63466-X 77# http://www.pearsonhighered.com/ 78# http://www.pearsonhighered.com/educator/academic/product/0,3110,020163466X,00.html 79# 80 81setup_loopback () { 82 ############ 83 # Only in rare cases do you want to change these rules 84 # 85 ${fwcmd} add 100 pass all from any to any via lo0 86 ${fwcmd} add 200 deny all from any to 127.0.0.0/8 87 ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 88 if [ $ipv6_available -eq 0 ]; then 89 ${fwcmd} add 400 deny all from any to ::1 90 ${fwcmd} add 500 deny all from ::1 to any 91 fi 92} 93 94setup_ipv6_mandatory () { 95 [ $ipv6_available -eq 0 ] || return 0 96 97 ############ 98 # Only in rare cases do you want to change these rules 99 # 100 # ND 101 # 102 # DAD 103 ${fwcmd} add pass ipv6-icmp from :: to ff02::/16 104 # RS, RA, NS, NA, redirect... 105 ${fwcmd} add pass ipv6-icmp from fe80::/10 to fe80::/10 106 ${fwcmd} add pass ipv6-icmp from fe80::/10 to ff02::/16 107 108 # Allow ICMPv6 destination unreach 109 ${fwcmd} add pass ipv6-icmp from any to any icmp6types 1 110 111 # Allow NS/NA/toobig (don't filter it out) 112 ${fwcmd} add pass ipv6-icmp from any to any icmp6types 2,135,136 113} 114 115if [ -n "${1}" ]; then 116 firewall_type="${1}" 117fi 118 119. /etc/rc.subr 120. /etc/network.subr 121afexists inet6 122ipv6_available=$? 123 124############ 125# Set quiet mode if requested 126# 127case ${firewall_quiet} in 128[Yy][Ee][Ss]) 129 fwcmd="/sbin/ipfw -q" 130 ;; 131*) 132 fwcmd="/sbin/ipfw" 133 ;; 134esac 135 136############ 137# Flush out the list before we begin. 138# 139${fwcmd} -f flush 140 141setup_loopback 142setup_ipv6_mandatory 143 144############ 145# Network Address Translation. All packets are passed to natd(8) 146# before they encounter your remaining rules. The firewall rules 147# will then be run again on each packet after translation by natd 148# starting at the rule number following the divert rule. 149# 150# For ``simple'' firewall type the divert rule should be put to a 151# different place to not interfere with address-checking rules. 152# 153case ${firewall_type} in 154[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 155 case ${natd_enable} in 156 [Yy][Ee][Ss]) 157 if [ -n "${natd_interface}" ]; then 158 ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface} 159 fi 160 ;; 161 esac 162 case ${firewall_nat_enable} in 163 [Yy][Ee][Ss]) 164 if [ -n "${firewall_nat_interface}" ]; then 165 if echo "${firewall_nat_interface}" | \ 166 grep -q -E '^[0-9]+(\.[0-9]+){0,3}$'; then 167 firewall_nat_flags="ip ${firewall_nat_interface} ${firewall_nat_flags}" 168 else 169 firewall_nat_flags="if ${firewall_nat_interface} ${firewall_nat_flags}" 170 fi 171 ${fwcmd} nat 123 config log ${firewall_nat_flags} 172 ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface} 173 fi 174 ;; 175 esac 176esac 177 178############ 179# If you just configured ipfw in the kernel as a tool to solve network 180# problems or you just want to disallow some particular kinds of traffic 181# then you will want to change the default policy to open. You can also 182# do this as your only action by setting the firewall_type to ``open''. 183# 184# ${fwcmd} add 65000 pass all from any to any 185 186 187# Prototype setups. 188# 189case ${firewall_type} in 190[Oo][Pp][Ee][Nn]) 191 ${fwcmd} add 65000 pass all from any to any 192 ;; 193 194[Cc][Ll][Ii][Ee][Nn][Tt]) 195 ############ 196 # This is a prototype setup that will protect your system somewhat 197 # against people from outside your own network. 198 # 199 # Configuration: 200 # firewall_client_net: Network address of local IPv4 network. 201 # firewall_client_net_ipv6: Network address of local IPv6 network. 202 ############ 203 204 # set this to your local network 205 net="$firewall_client_net" 206 net6="$firewall_client_net_ipv6" 207 208 # Allow limited broadcast traffic from my own net. 209 ${fwcmd} add pass all from ${net} to 255.255.255.255 210 211 # Allow any traffic to or from my own net. 212 ${fwcmd} add pass all from me to ${net} 213 ${fwcmd} add pass all from ${net} to me 214 if [ -n "$net6" ]; then 215 ${fwcmd} add pass all from me6 to ${net6} 216 ${fwcmd} add pass all from ${net6} to me6 217 fi 218 219 if [ -n "$net6" ]; then 220 # Allow any link-local multicast traffic 221 ${fwcmd} add pass all from fe80::/10 to ff02::/16 222 ${fwcmd} add pass all from ${net6} to ff02::/16 223 fi 224 225 # Allow TCP through if setup succeeded 226 ${fwcmd} add pass tcp from any to any established 227 228 # Allow IP fragments to pass through 229 ${fwcmd} add pass all from any to any frag 230 231 # Allow setup of incoming email 232 ${fwcmd} add pass tcp from any to me 25 setup 233 234 # Allow setup of outgoing TCP connections only 235 ${fwcmd} add pass tcp from me to any setup 236 237 # Disallow setup of all other TCP connections 238 ${fwcmd} add deny tcp from any to any setup 239 240 # Allow DNS queries out in the world 241 ${fwcmd} add pass udp from me to any 53 keep-state 242 243 # Allow NTP queries out in the world 244 ${fwcmd} add pass udp from me to any 123 keep-state 245 246 # Everything else is denied by default, unless the 247 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 248 # config file. 249 ;; 250 251[Ss][Ii][Mm][Pp][Ll][Ee]) 252 ############ 253 # This is a prototype setup for a simple firewall. Configure this 254 # machine as a DNS and NTP server, and point all the machines 255 # on the inside at this machine for those services. 256 # 257 # Configuration: 258 # firewall_simple_iif: Inside IPv4 network interface. 259 # firewall_simple_inet: Inside IPv4 network address. 260 # firewall_simple_oif: Outside IPv4 network interface. 261 # firewall_simple_onet: Outside IPv4 network address. 262 # firewall_simple_iif_ipv6: Inside IPv6 network interface. 263 # firewall_simple_inet_ipv6: Inside IPv6 network prefix. 264 # firewall_simple_oif_ipv6: Outside IPv6 network interface. 265 # firewall_simple_onet_ipv6: Outside IPv6 network prefix. 266 ############ 267 268 # set these to your outside interface network 269 oif="$firewall_simple_oif" 270 onet="$firewall_simple_onet" 271 oif6="${firewall_simple_oif_ipv6:-$firewall_simple_oif}" 272 onet6="$firewall_simple_onet_ipv6" 273 274 # set these to your inside interface network 275 iif="$firewall_simple_iif" 276 inet="$firewall_simple_inet" 277 iif6="${firewall_simple_iif_ipv6:-$firewall_simple_iif}" 278 inet6="$firewall_simple_inet_ipv6" 279 280 # Stop spoofing 281 ${fwcmd} add deny all from ${inet} to any in via ${oif} 282 ${fwcmd} add deny all from ${onet} to any in via ${iif} 283 if [ -n "$inet6" ]; then 284 ${fwcmd} add deny all from ${inet6} to any in via ${oif6} 285 if [ -n "$onet6" ]; then 286 ${fwcmd} add deny all from ${onet6} to any in \ 287 via ${iif6} 288 fi 289 fi 290 291 # Stop RFC1918 nets on the outside interface 292 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 293 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 294 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 295 296 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 297 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 298 # on the outside interface 299 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 300 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 301 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 302 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 303 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 304 305 # Network Address Translation. This rule is placed here deliberately 306 # so that it does not interfere with the surrounding address-checking 307 # rules. If for example one of your internal LAN machines had its IP 308 # address set to 192.0.2.1 then an incoming packet for it after being 309 # translated by natd(8) would match the `deny' rule above. Similarly 310 # an outgoing packet originated from it before being translated would 311 # match the `deny' rule below. 312 case ${natd_enable} in 313 [Yy][Ee][Ss]) 314 if [ -n "${natd_interface}" ]; then 315 ${fwcmd} add divert natd ip4 from any to any via ${natd_interface} 316 fi 317 ;; 318 esac 319 320 # Stop RFC1918 nets on the outside interface 321 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 322 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 323 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 324 325 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 326 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 327 # on the outside interface 328 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 329 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 330 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 331 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 332 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 333 334 if [ -n "$inet6" ]; then 335 # Stop unique local unicast address on the outside interface 336 ${fwcmd} add deny all from fc00::/7 to any via ${oif6} 337 ${fwcmd} add deny all from any to fc00::/7 via ${oif6} 338 339 # Stop site-local on the outside interface 340 ${fwcmd} add deny all from fec0::/10 to any via ${oif6} 341 ${fwcmd} add deny all from any to fec0::/10 via ${oif6} 342 343 # Disallow "internal" addresses to appear on the wire. 344 ${fwcmd} add deny all from ::ffff:0.0.0.0/96 to any \ 345 via ${oif6} 346 ${fwcmd} add deny all from any to ::ffff:0.0.0.0/96 \ 347 via ${oif6} 348 349 # Disallow packets to malicious IPv4 compatible prefix. 350 ${fwcmd} add deny all from ::224.0.0.0/100 to any via ${oif6} 351 ${fwcmd} add deny all from any to ::224.0.0.0/100 via ${oif6} 352 ${fwcmd} add deny all from ::127.0.0.0/104 to any via ${oif6} 353 ${fwcmd} add deny all from any to ::127.0.0.0/104 via ${oif6} 354 ${fwcmd} add deny all from ::0.0.0.0/104 to any via ${oif6} 355 ${fwcmd} add deny all from any to ::0.0.0.0/104 via ${oif6} 356 ${fwcmd} add deny all from ::255.0.0.0/104 to any via ${oif6} 357 ${fwcmd} add deny all from any to ::255.0.0.0/104 via ${oif6} 358 359 ${fwcmd} add deny all from ::0.0.0.0/96 to any via ${oif6} 360 ${fwcmd} add deny all from any to ::0.0.0.0/96 via ${oif6} 361 362 # Disallow packets to malicious 6to4 prefix. 363 ${fwcmd} add deny all from 2002:e000::/20 to any via ${oif6} 364 ${fwcmd} add deny all from any to 2002:e000::/20 via ${oif6} 365 ${fwcmd} add deny all from 2002:7f00::/24 to any via ${oif6} 366 ${fwcmd} add deny all from any to 2002:7f00::/24 via ${oif6} 367 ${fwcmd} add deny all from 2002:0000::/24 to any via ${oif6} 368 ${fwcmd} add deny all from any to 2002:0000::/24 via ${oif6} 369 ${fwcmd} add deny all from 2002:ff00::/24 to any via ${oif6} 370 ${fwcmd} add deny all from any to 2002:ff00::/24 via ${oif6} 371 372 ${fwcmd} add deny all from 2002:0a00::/24 to any via ${oif6} 373 ${fwcmd} add deny all from any to 2002:0a00::/24 via ${oif6} 374 ${fwcmd} add deny all from 2002:ac10::/28 to any via ${oif6} 375 ${fwcmd} add deny all from any to 2002:ac10::/28 via ${oif6} 376 ${fwcmd} add deny all from 2002:c0a8::/32 to any via ${oif6} 377 ${fwcmd} add deny all from any to 2002:c0a8::/32 via ${oif6} 378 379 ${fwcmd} add deny all from ff05::/16 to any via ${oif6} 380 ${fwcmd} add deny all from any to ff05::/16 via ${oif6} 381 fi 382 383 # Allow TCP through if setup succeeded 384 ${fwcmd} add pass tcp from any to any established 385 386 # Allow IP fragments to pass through 387 ${fwcmd} add pass all from any to any frag 388 389 # Allow setup of incoming email 390 ${fwcmd} add pass tcp from any to me 25 setup 391 392 # Allow access to our DNS 393 ${fwcmd} add pass tcp from any to me 53 setup 394 ${fwcmd} add pass udp from any to me 53 395 ${fwcmd} add pass udp from me 53 to any 396 397 # Allow access to our WWW 398 ${fwcmd} add pass tcp from any to me 80 setup 399 400 # Reject&Log all setup of incoming connections from the outside 401 ${fwcmd} add deny log ip4 from any to any in via ${oif} setup proto tcp 402 if [ -n "$inet6" ]; then 403 ${fwcmd} add deny log ip6 from any to any in via ${oif6} \ 404 setup proto tcp 405 fi 406 407 # Allow setup of any other TCP connection 408 ${fwcmd} add pass tcp from any to any setup 409 410 # Allow DNS queries out in the world 411 ${fwcmd} add pass udp from me to any 53 keep-state 412 413 # Allow NTP queries out in the world 414 ${fwcmd} add pass udp from me to any 123 keep-state 415 416 # Everything else is denied by default, unless the 417 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 418 # config file. 419 ;; 420 421[Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn]) 422 # Configuration: 423 # firewall_myservices: List of TCP ports on which this host 424 # offers services. 425 # firewall_allowservices: List of IPs which has access to 426 # $firewall_myservices. 427 # firewall_trusted: List of IPv4s which has full access 428 # to this host. Be very carefull 429 # when setting this. This option can 430 # seriously degrade the level of 431 # protection provided by the firewall. 432 # firewall_logdeny: Boolean (YES/NO) specifying if the 433 # default denied packets should be 434 # logged (in /var/log/security). 435 # firewall_nologports: List of TCP/UDP ports for which 436 # denied incomming packets are not 437 # logged. 438 # firewall_trusted_ipv6: List of IPv6s which has full access 439 # to this host. Be very carefull 440 # when setting this. This option can 441 # seriously degrade the level of 442 # protection provided by the firewall. 443 444 # Allow packets for which a state has been built. 445 ${fwcmd} add check-state 446 447 # For services permitted below. 448 ${fwcmd} add pass tcp from me to any established 449 if [ $ipv6_available -eq 0 ]; then 450 ${fwcmd} add pass tcp from me6 to any established 451 fi 452 453 # Allow any connection out, adding state for each. 454 ${fwcmd} add pass tcp from me to any setup keep-state 455 ${fwcmd} add pass udp from me to any keep-state 456 ${fwcmd} add pass icmp from me to any keep-state 457 if [ $ipv6_available -eq 0 ]; then 458 ${fwcmd} add pass tcp from me6 to any setup keep-state 459 ${fwcmd} add pass udp from me6 to any keep-state 460 ${fwcmd} add pass ipv6-icmp from me6 to any keep-state 461 fi 462 463 # Allow DHCP. 464 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out 465 ${fwcmd} add pass udp from any 67 to me 68 in 466 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in 467 if [ $ipv6_available -eq 0 ]; then 468 ${fwcmd} add pass udp from fe80::/10 to me6 546 in 469 fi 470 # Some servers will ping the IP while trying to decide if it's 471 # still in use. 472 ${fwcmd} add pass icmp from any to any icmptype 8 473 if [ $ipv6_available -eq 0 ]; then 474 ${fwcmd} add pass ipv6-icmp from any to any icmp6type 128,129 475 fi 476 477 # Allow "mandatory" ICMP in. 478 ${fwcmd} add pass icmp from any to any icmptype 3,4,11 479 480 # Add permits for this workstations published services below 481 # Only IPs and nets in firewall_allowservices is allowed in. 482 # If you really wish to let anyone use services on your 483 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf 484 # 485 # Note: We don't use keep-state as that would allow DoS of 486 # our statetable. 487 # You can add 'keep-state' to the lines for slightly 488 # better performance if you fell that DoS of your 489 # workstation won't be a problem. 490 # 491 for i in ${firewall_allowservices} ; do 492 for j in ${firewall_myservices} ; do 493 ${fwcmd} add pass tcp from $i to me $j 494 if [ $ipv6_available -eq 0 ]; then 495 ${fwcmd} add pass tcp from $i to me6 $j 496 fi 497 done 498 done 499 500 # Allow all connections from trusted IPs. 501 # Playing with the content of firewall_trusted could seriously 502 # degrade the level of protection provided by the firewall. 503 for i in ${firewall_trusted} ; do 504 ${fwcmd} add pass ip from $i to me 505 done 506 for i in ${firewall_trusted_ipv6} ; do 507 ${fwcmd} add pass all from $i to me6 508 done 509 510 ${fwcmd} add 65000 count ip from any to any 511 512 # Drop packets to ports where we don't want logging 513 for i in ${firewall_nologports} ; do 514 ${fwcmd} add deny { tcp or udp } from any to any $i in 515 done 516 517 # Broadcasts and muticasts 518 ${fwcmd} add deny ip from any to 255.255.255.255 519 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX 520 521 # Noise from routers 522 ${fwcmd} add deny udp from any to any 520 in 523 524 # Noise from webbrowsing. 525 # The statefull filter is a bit agressive, and will cause some 526 # connection teardowns to be logged. 527 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in 528 529 # Deny and (if wanted) log the rest unconditionally. 530 log="" 531 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then 532 log="log logamount 500" # The default of 100 is too low. 533 sysctl net.inet.ip.fw.verbose=1 >/dev/null 534 fi 535 ${fwcmd} add deny $log ip from any to any 536 ;; 537 538[Cc][Ll][Oo][Ss][Ee][Dd]) 539 ${fwcmd} add 65000 deny ip from any to any 540 ;; 541[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 542 ;; 543*) 544 if [ -r "${firewall_type}" ]; then 545 ${fwcmd} ${firewall_flags} ${firewall_type} 546 fi 547 ;; 548esac 549