src/initscripts/system/firewall

   1 #!/bin/sh
   2
   3 . /etc/sysconfig/rc
   4 . ${rc_functions}
   5
   6 eval $(/usr/local/bin/readhash /var/ipfire/ppp/settings)
   7 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
   8 eval $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
   9 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
  10
  11 if [ -f /var/ipfire/red/device ]; then
  12         DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
  13 fi
  14
  15 NAT_MASK="0x0f000000"
  16
  17 IPS_REPEAT_MARK="0x80000000"
  18 IPS_REPEAT_MASK="0x80000000"
  19 IPS_BYPASS_MARK="0x40000000"
  20 IPS_BYPASS_MASK="0x40000000"
  21
  22 function iptables() {
  23         /sbin/iptables --wait "$@"
  24 }
  25
  26 iptables_init() {
  27         # Flush all rules and delete all custom chains
  28         iptables -F
  29         iptables -t nat -F
  30         iptables -t mangle -F
  31         iptables -t raw -F
  32         iptables -X
  33         iptables -t nat -X
  34         iptables -t mangle -X
  35         iptables -t raw -X
  36
  37         # Set up policies
  38         iptables -P INPUT DROP
  39         iptables -P FORWARD DROP
  40         iptables -P OUTPUT ACCEPT
  41
  42         # Enable TRACE logging to syslog
  43         modprobe nf_log_ipv4
  44         sysctl -q -w net.netfilter.nf_log.2=nf_log_ipv4
  45
  46         # IPS Bypass Chain which stores the BYPASS bit in connection tracking
  47         iptables -N IPSBYPASS
  48         iptables -A IPSBYPASS -j CONNMARK --save-mark --mask "$(( ~IPS_REPEAT_MASK & 0xffffffff ))"
  49
  50         # Jump into bypass chain when the BYPASS bit is set
  51         for chain in INPUT FORWARD OUTPUT; do
  52                 iptables -A "${chain}" -m mark \
  53                         --mark "$(( IPS_REPEAT_MARK | IPS_BYPASS_MARK ))/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j IPSBYPASS
  54         done
  55
  56         # Empty LOG_DROP and LOG_REJECT chains
  57         iptables -N LOG_DROP
  58         iptables -A LOG_DROP   -m limit --limit 10/second -j LOG
  59         iptables -A LOG_DROP   -j DROP
  60         iptables -N LOG_REJECT
  61         iptables -A LOG_REJECT -m limit --limit 10/second -j LOG
  62         iptables -A LOG_REJECT -j REJECT
  63
  64         # This chain will log, then DROPs packets with certain bad combinations
  65         # of flags might indicate a port-scan attempt (xmas, null, etc.)
  66         iptables -N PSCAN
  67         if [ "$DROPPORTSCAN" == "on" ]; then
  68                 iptables -A PSCAN -p tcp  -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan "  -m comment --comment "DROP_TCP PScan"
  69                 iptables -A PSCAN -p udp  -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan "  -m comment --comment "DROP_UDP PScan"
  70                 iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
  71                 iptables -A PSCAN -f      -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
  72         fi
  73         iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
  74
  75         # New tcp packets without SYN set - could well be an obscure type of port scan
  76         # that's not covered above, may just be a broken Windows machine
  77         iptables -N NEWNOTSYN
  78         if [ "$DROPNEWNOTSYN" == "on" ]; then
  79                 iptables -A NEWNOTSYN  -m limit --limit 10/second -j LOG  --log-prefix "DROP_NEWNOTSYN "
  80         fi
  81         iptables -A NEWNOTSYN  -j DROP -m comment --comment "DROP_NEWNOTSYN"
  82
  83         # Log and subsequently drop spoofed packets or "martians", arriving from sources
  84         # on interfaces where we don't expect them
  85         iptables -N SPOOFED_MARTIAN
  86         if [ "$DROPSPOOFEDMARTIAN" == "on" ]; then
  87                 iptables -A SPOOFED_MARTIAN  -m limit --limit 10/second -j LOG  --log-prefix "DROP_SPOOFED_MARTIAN "
  88         fi
  89         iptables -A SPOOFED_MARTIAN -j DROP -m comment --comment "DROP_SPOOFED_MARTIAN"
  90
  91         # Chain to contain all the rules relating to bad TCP flags
  92         iptables -N BADTCP
  93
  94         # Don't check loopback
  95         iptables -A BADTCP -i lo -j RETURN
  96
  97         # Disallow packets frequently used by port-scanners
  98         # NMAP FIN/URG/PSH (XMAS scan)
  99         iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
 100         # SYN/RST/ACK/FIN/URG
 101         iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
 102         # ALL/ALL
 103         iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
 104         # FIN Stealth
 105         iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
 106         # SYN/RST (also catches xmas variants that set SYN+RST+...)
 107         iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
 108         # SYN/FIN (QueSO or nmap OS probe)
 109         iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
 110         # Null
 111         iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
 112         # NEW TCP without SYN
 113         iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
 114
 115         iptables -A INPUT   -p tcp -j BADTCP
 116         iptables -A FORWARD -p tcp -j BADTCP
 117
 118         # Connection tracking chains
 119         iptables -N CONNTRACK
 120         iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
 121         iptables -A CONNTRACK -m conntrack --ctstate INVALID -j LOG_DROP
 122         iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
 123
 124         # Restore any connection marks
 125         iptables -t mangle -A PREROUTING -j CONNMARK --restore-mark
 126
 127         # Fix for braindead ISPs
 128         iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 129
 130         # CUSTOM chains, can be used by the users themselves
 131         iptables -N CUSTOMINPUT
 132         iptables -A INPUT -j CUSTOMINPUT
 133         iptables -N CUSTOMFORWARD
 134         iptables -A FORWARD -j CUSTOMFORWARD
 135         iptables -N CUSTOMOUTPUT
 136         iptables -A OUTPUT -j CUSTOMOUTPUT
 137         iptables -t nat -N CUSTOMPREROUTING
 138         iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
 139         iptables -t nat -N CUSTOMPOSTROUTING
 140         iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
 141
 142         # Log and drop any traffic from and to networks known as being hostile, posing
 143         # a technical threat to our users (i. e. listed at Spamhaus DROP et al.)
 144         iptables -N HOSTILE
 145         if [ "$DROPHOSTILE" == "on" ]; then
 146                 iptables -A HOSTILE -m limit --limit 10/second -j LOG  --log-prefix "DROP_HOSTILE "
 147                 iptables -A INPUT   -i $IFACE -m geoip --src-cc XD -j HOSTILE
 148                 iptables -A FORWARD -i $IFACE -m geoip --src-cc XD -j HOSTILE
 149                 iptables -A FORWARD -o $IFACE -m geoip --dst-cc XD -j HOSTILE
 150                 iptables -A OUTPUT  -o $IFACE -m geoip --src-cc XD -j HOSTILE
 151         fi
 152         iptables -A HOSTILE -j DROP -m comment --comment "DROP_HOSTILE"
 153
 154         # P2PBLOCK
 155         iptables -N P2PBLOCK
 156         iptables -A INPUT -j P2PBLOCK
 157         iptables -A FORWARD -j P2PBLOCK
 158         iptables -A OUTPUT -j P2PBLOCK
 159
 160         # IPS (Guardian) chains
 161         iptables -N GUARDIAN
 162         iptables -A INPUT -j GUARDIAN
 163         iptables -A FORWARD -j GUARDIAN
 164
 165         # Block non-established IPsec networks
 166         iptables -N IPSECBLOCK
 167         iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
 168         iptables -A OUTPUT  -m policy --dir out --pol none -j IPSECBLOCK
 169
 170         # Block OpenVPN transfer networks
 171         iptables -N OVPNBLOCK
 172         iptables -A INPUT   -i tun+ -j OVPNBLOCK
 173         iptables -A FORWARD -i tun+ -j OVPNBLOCK
 174         iptables -A FORWARD -o tun+ -j OVPNBLOCK
 175
 176         # IPS (Suricata) chains
 177         iptables -N IPS_INPUT
 178         iptables -N IPS_FORWARD
 179         iptables -N IPS_OUTPUT
 180
 181         for chain in INPUT FORWARD OUTPUT; do
 182                 iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
 183         done
 184
 185         # OpenVPN transfer network translation
 186         iptables -t nat -N OVPNNAT
 187         iptables -t nat -A POSTROUTING -j OVPNNAT
 188
 189         # IPTV chains for IGMPPROXY
 190         iptables -N IPTVINPUT
 191         iptables -A INPUT -j IPTVINPUT
 192         iptables -N IPTVFORWARD
 193         iptables -A FORWARD -j IPTVFORWARD
 194
 195         # Allow to ping the firewall.
 196         iptables -N ICMPINPUT
 197         iptables -A INPUT -j ICMPINPUT
 198         iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
 199
 200         # Accept everything on loopback if source/destination is loopback space...
 201         iptables -N LOOPBACK
 202         iptables -A LOOPBACK -i lo -s 127.0.0.0/8 -j ACCEPT
 203         iptables -A LOOPBACK -o lo -d 127.0.0.0/8 -j ACCEPT
 204
 205         # ... and drop everything else on the loopback interface, since no other traffic should appear there
 206         iptables -A LOOPBACK -i lo -j SPOOFED_MARTIAN
 207         iptables -A LOOPBACK -o lo -j SPOOFED_MARTIAN
 208
 209         # Filter all packets with loopback addresses on non-loopback interfaces (spoofed)
 210         iptables -A LOOPBACK -s 127.0.0.0/8 -j SPOOFED_MARTIAN
 211         iptables -A LOOPBACK -d 127.0.0.0/8 -j SPOOFED_MARTIAN
 212
 213         for i in INPUT FORWARD OUTPUT; do
 214                 iptables -A ${i} -j LOOPBACK
 215         done
 216
 217         # Captive portal
 218         iptables -N CAPTIVE_PORTAL
 219         iptables -N CAPTIVE_PORTAL_CLIENTS
 220         for i in INPUT FORWARD; do
 221                 iptables -A ${i} -j CAPTIVE_PORTAL
 222         done
 223
 224         # Accept everything connected
 225         for i in INPUT FORWARD OUTPUT; do
 226                 iptables -A ${i} -j CONNTRACK
 227         done
 228
 229         # Allow DHCP
 230         iptables -N DHCPINPUT
 231         iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
 232         iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
 233
 234         iptables -N DHCPOUTPUT
 235         iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
 236         iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
 237
 238         # Allow DHCP on GREEN
 239         iptables -N DHCPGREENINPUT
 240         iptables -N DHCPGREENOUTPUT
 241         if [ -n "${GREEN_DEV}" ]; then
 242                 iptables -A INPUT  -i "${GREEN_DEV}" -j DHCPGREENINPUT
 243                 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
 244         fi
 245
 246         # Allow DHCP on BLUE to be turned on/off
 247         iptables -N DHCPBLUEINPUT
 248         iptables -N DHCPBLUEOUTPUT
 249         if [ -n "${BLUE_DEV}" ]; then
 250                 iptables -A INPUT  -i "${BLUE_DEV}" -j DHCPBLUEINPUT
 251                 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
 252         fi
 253
 254         # Tor (inbound)
 255         iptables -N TOR_INPUT
 256         iptables -A INPUT -j TOR_INPUT
 257
 258         # Location Block
 259         iptables -N LOCATIONBLOCK
 260         iptables -A INPUT -j LOCATIONBLOCK
 261         iptables -A FORWARD -j LOCATIONBLOCK
 262
 263         # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
 264         iptables -N IPSECINPUT
 265         iptables -N IPSECFORWARD
 266         iptables -N IPSECOUTPUT
 267         iptables -A INPUT -j IPSECINPUT
 268         iptables -A FORWARD -j IPSECFORWARD
 269         iptables -A OUTPUT -j IPSECOUTPUT
 270         iptables -t nat -N IPSECNAT
 271         iptables -t nat -A POSTROUTING -j IPSECNAT
 272
 273         # localhost and ethernet.
 274         # Always allow accessing the web GUI from GREEN.
 275         iptables -N GUIINPUT
 276         iptables -A INPUT -j GUIINPUT
 277         if [ -n "${GREEN_DEV}" ]; then
 278                 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
 279         fi
 280
 281         # WIRELESS chains
 282         iptables -N WIRELESSINPUT
 283         iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
 284         iptables -N WIRELESSFORWARD
 285         iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
 286
 287         # OpenVPN
 288         iptables -N OVPNINPUT
 289         iptables -A INPUT -j OVPNINPUT
 290
 291         # Tor (outbound)
 292         iptables -N TOR_OUTPUT
 293         iptables -A OUTPUT -j TOR_OUTPUT
 294
 295         # Jump into the actual firewall ruleset.
 296         iptables -N INPUTFW
 297         iptables -A INPUT -j INPUTFW
 298
 299         iptables -N OUTGOINGFW
 300         iptables -A OUTPUT -j OUTGOINGFW
 301
 302         iptables -N FORWARDFW
 303         iptables -A FORWARD -j FORWARDFW
 304
 305         # SNAT rules
 306         iptables -t nat -N NAT_SOURCE
 307         iptables -t nat -A POSTROUTING -j NAT_SOURCE
 308
 309         # Captive Portal
 310         iptables -t nat -N CAPTIVE_PORTAL
 311         iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
 312
 313         # Custom prerouting chains (for transparent proxy)
 314         iptables -t nat -N SQUID
 315         iptables -t nat -A PREROUTING -j SQUID
 316
 317         # DNAT rules
 318         iptables -t nat -N NAT_DESTINATION
 319         iptables -t nat -A PREROUTING -j NAT_DESTINATION
 320         iptables -t nat -A OUTPUT -j NAT_DESTINATION
 321
 322         iptables -t mangle -N NAT_DESTINATION
 323         iptables -t mangle -A PREROUTING -j NAT_DESTINATION
 324
 325         iptables -t nat -N NAT_DESTINATION_FIX
 326         iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
 327
 328         if [ -n "${GREEN_ADDRESS}" ]; then
 329                 iptables -t nat -A NAT_DESTINATION_FIX \
 330                         -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
 331         fi
 332
 333         if [ -n "${BLUE_ADDRESS}" ]; then
 334                 iptables -t nat -A NAT_DESTINATION_FIX \
 335                         -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
 336         fi
 337
 338         if [ -n "${ORANGE_ADDRESS}" ]; then
 339                 iptables -t nat -A NAT_DESTINATION_FIX \
 340                         -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
 341         fi
 342
 343         # RED chain, used for the red interface
 344         iptables -N REDINPUT
 345         iptables -A INPUT -j REDINPUT
 346         iptables -N REDFORWARD
 347         iptables -A FORWARD -j REDFORWARD
 348         iptables -t nat -N REDNAT
 349         iptables -t nat -A POSTROUTING -j REDNAT
 350
 351         # Populate IPsec chains
 352         /usr/lib/firewall/ipsec-policy
 353
 354         # Apply OpenVPN firewall rules
 355         /usr/local/bin/openvpnctrl --firewall-rules
 356
 357         # run wirelessctrl
 358         /usr/local/bin/wirelessctrl
 359
 360         # run captivectrl
 361         /usr/local/bin/captivectrl
 362
 363         # POLICY CHAIN
 364         iptables -N POLICYIN
 365         iptables -A INPUT -j POLICYIN
 366         iptables -N POLICYFWD
 367         iptables -A FORWARD -j POLICYFWD
 368         iptables -N POLICYOUT
 369         iptables -A OUTPUT -j POLICYOUT
 370
 371         # Initialize firewall policies.
 372         /usr/sbin/firewall-policy
 373
 374         # Install firewall rules for the red interface.
 375         iptables_red_up
 376
 377         # If red has not been brought up yet, we will
 378         # add the blocking rules for MASQUERADE
 379         if [ ! -e "/var/ipfire/red/active" ]; then
 380                 iptables_red_down
 381         fi
 382 }
 383
 384 iptables_red_up() {
 385         iptables -F REDINPUT
 386         iptables -F REDFORWARD
 387         iptables -t nat -F REDNAT
 388
 389         # Prohibit spoofing our own IP address on RED
 390         if [ -f /var/ipfire/red/active ]; then
 391                 REDIP="$( cat /var/ipfire/red/local-ipaddress )";
 392
 393                 if [ "$IFACE" != "" ]; then
 394                         iptables -A REDINPUT -s $REDIP -i $IFACE -j SPOOFED_MARTIAN
 395                 elif [ "$DEVICE" != "" ]; then
 396                         iptables -A REDINPUT -s $REDIP -i $DEVICE -j SPOOFED_MARTIAN
 397                 fi
 398         fi
 399
 400         # PPPoE / PPTP Device
 401         if [ "$IFACE" != "" ]; then
 402                 # PPPoE / PPTP
 403                 if [ "$DEVICE" != "" ]; then
 404                         iptables -A REDINPUT -i $DEVICE -j ACCEPT
 405                 fi
 406                 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
 407                         if [ "$RED_DEV" != "" ]; then
 408                                 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
 409                         fi
 410                 fi
 411         fi
 412
 413         # PPTP over DHCP
 414         if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
 415                 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 416                 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
 417         fi
 418
 419         if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
 420                 # DHCP
 421                 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
 422                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 423                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 424                 fi
 425                 if [ "$METHOD" == "DHCP"  -a "$PROTOCOL" == "RFC1483" ]; then
 426                         iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 427                         iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
 428                 fi
 429
 430                 # Outgoing masquerading (don't masqerade IPsec)
 431                 iptables -t nat -A REDNAT -m policy --pol ipsec --dir=out -o "${IFACE}" -j RETURN
 432
 433                 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
 434                         iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
 435                 fi
 436
 437                 local NO_MASQ_NETWORKS
 438
 439                 if [ "${MASQUERADE_GREEN}" = "off" ]; then
 440                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
 441                 fi
 442
 443                 if [ "${MASQUERADE_BLUE}" = "off" ]; then
 444                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
 445                 fi
 446
 447                 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
 448                         NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
 449                 fi
 450
 451                 local network
 452                 for network in ${NO_MASQ_NETWORKS}; do
 453                         iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
 454                 done
 455
 456                 # Masquerade everything else
 457                 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
 458         fi
 459
 460         # Reload all rules.
 461         /usr/local/bin/firewallctrl
 462 }
 463
 464 iptables_red_down() {
 465         # Prohibit packets to reach the masquerading rule
 466         # while the WAN interface is down - this is required to
 467         # circumvent udp related NAT issues
 468         # http://forum.ipfire.org/index.php?topic=11127.0
 469         if [ -n "${IFACE}" ]; then
 470                 iptables -F REDFORWARD
 471                 iptables -A REDFORWARD -o "${IFACE}" -j DROP
 472         fi
 473
 474         # Reload all rules.
 475         /usr/local/bin/firewallctrl
 476 }
 477
 478 # See how we were called.
 479 case "$1" in
 480   start)
 481         boot_mesg "Setting up firewall"
 482         iptables_init
 483         evaluate_retval
 484         ;;
 485   reload|up)
 486         boot_mesg "Reloading firewall"
 487         iptables_red_up
 488         evaluate_retval
 489         ;;
 490   down)
 491         boot_mesg "Disabling firewall access to RED"
 492         iptables_red_down
 493         evaluate_retval
 494         ;;
 495   restart)
 496         $0 start
 497         ;;
 498   *)
 499         echo "Usage: $0 {start|reload|restart}"
 500         exit 1
 501         ;;
 502 esac
 503
 504 exit 0