package/network/config/firewall/files/lib/core_init.sh

   1 # Copyright (C) 2009-2011 OpenWrt.org
   2 # Copyright (C) 2008 John Crispin <blogic@openwrt.org>
   3
   4 FW_INITIALIZED=
   5
   6 FW_ZONES=
   7 FW_ZONES4=
   8 FW_ZONES6=
   9 FW_CONNTRACK_ZONES=
  10 FW_NOTRACK_DISABLED=
  11
  12 FW_DEFAULTS_APPLIED=
  13 FW_ADD_CUSTOM_CHAINS=
  14 FW_ACCEPT_REDIRECTS=
  15 FW_ACCEPT_SRC_ROUTE=
  16
  17 FW_DEFAULT_INPUT_POLICY=REJECT
  18 FW_DEFAULT_OUTPUT_POLICY=REJECT
  19 FW_DEFAULT_FORWARD_POLICY=REJECT
  20
  21 FW_DISABLE_IPV4=0
  22 FW_DISABLE_IPV6=0
  23
  24
  25 fw_load_defaults() {
  26         fw_config_get_section "$1" defaults { \
  27                 string input $FW_DEFAULT_INPUT_POLICY \
  28                 string output $FW_DEFAULT_OUTPUT_POLICY \
  29                 string forward $FW_DEFAULT_FORWARD_POLICY \
  30                 boolean drop_invalid 0 \
  31                 boolean syn_flood 0 \
  32                 boolean synflood_protect 0 \
  33                 string synflood_rate 25 \
  34                 string synflood_burst 50 \
  35                 boolean tcp_syncookies 1 \
  36                 boolean tcp_ecn 0 \
  37                 boolean tcp_westwood 0 \
  38                 boolean tcp_window_scaling 1 \
  39                 boolean accept_redirects 0 \
  40                 boolean accept_source_route 0 \
  41                 boolean custom_chains 1 \
  42                 boolean disable_ipv6 0 \
  43         } || return
  44         [ -n "$FW_DEFAULTS_APPLIED" ] && {
  45                 fw_log error "duplicate defaults section detected, skipping"
  46                 return 1
  47         }
  48         FW_DEFAULTS_APPLIED=1
  49
  50         FW_DEFAULT_INPUT_POLICY=$defaults_input
  51         FW_DEFAULT_OUTPUT_POLICY=$defaults_output
  52         FW_DEFAULT_FORWARD_POLICY=$defaults_forward
  53
  54         FW_ADD_CUSTOM_CHAINS=$defaults_custom_chains
  55
  56         FW_ACCEPT_REDIRECTS=$defaults_accept_redirects
  57         FW_ACCEPT_SRC_ROUTE=$defaults_accept_source_route
  58
  59         FW_DISABLE_IPV6=$defaults_disable_ipv6
  60
  61         fw_callback pre defaults
  62
  63         # Seems like there are only one sysctl for both IP versions.
  64         for s in syncookies ecn westwood window_scaling; do
  65                 eval "sysctl -e -w net.ipv4.tcp_${s}=\$defaults_tcp_${s}" >/dev/null
  66         done
  67         fw_sysctl_interface all
  68
  69         fw add i f INPUT   ACCEPT { -m conntrack --ctstate RELATED,ESTABLISHED }
  70         fw add i f OUTPUT  ACCEPT { -m conntrack --ctstate RELATED,ESTABLISHED }
  71         fw add i f FORWARD ACCEPT { -m conntrack --ctstate RELATED,ESTABLISHED }
  72
  73         [ $defaults_drop_invalid == 1 ] && {
  74                 fw add i f INPUT   DROP { -m conntrack --ctstate INVALID }
  75                 fw add i f OUTPUT  DROP { -m conntrack --ctstate INVALID }
  76                 fw add i f FORWARD DROP { -m conntrack --ctstate INVALID }
  77                 FW_NOTRACK_DISABLED=1
  78         }
  79
  80         fw add i f INPUT  ACCEPT { -i lo }
  81         fw add i f OUTPUT ACCEPT { -o lo }
  82
  83         # Compatibility to old 'syn_flood' parameter
  84         [ $defaults_syn_flood == 1 ] && \
  85                 defaults_synflood_protect=1
  86
  87         [ "${defaults_synflood_rate%/*}" == "$defaults_synflood_rate" ] && \
  88                 defaults_synflood_rate="$defaults_synflood_rate/second"
  89
  90         [ $defaults_synflood_protect == 1 ] && {
  91                 echo "Loading synflood protection"
  92                 fw_callback pre synflood
  93                 fw add i f syn_flood
  94                 fw add i f syn_flood RETURN { \
  95                         -p tcp --syn \
  96                         -m limit --limit "${defaults_synflood_rate}" --limit-burst "${defaults_synflood_burst}" \
  97                 }
  98                 fw add i f syn_flood DROP
  99                 fw add i f INPUT syn_flood { -p tcp --syn }
 100                 fw_callback post synflood
 101         }
 102
 103         [ $defaults_custom_chains == 1 ] && {
 104                 echo "Adding custom chains"
 105                 fw add i f input_rule
 106                 fw add i f output_rule
 107                 fw add i f forwarding_rule
 108                 fw add i n prerouting_rule
 109                 fw add i n postrouting_rule
 110
 111                 fw add i f INPUT       input_rule
 112                 fw add i f OUTPUT      output_rule
 113                 fw add i f FORWARD     forwarding_rule
 114                 fw add i n PREROUTING  prerouting_rule
 115                 fw add i n POSTROUTING postrouting_rule
 116         }
 117
 118         fw add i f delegate_input
 119         fw add i f delegate_output
 120         fw add i f delegate_forward
 121
 122         fw add i f INPUT   delegate_input
 123         fw add i f OUTPUT  delegate_output
 124         fw add i f FORWARD delegate_forward
 125
 126         fw add i f reject
 127         fw add i f reject REJECT { --reject-with tcp-reset -p tcp }
 128         fw add i f reject REJECT { --reject-with port-unreach }
 129
 130         fw_set_filter_policy
 131
 132         fw_callback post defaults
 133 }
 134
 135
 136 fw_config_get_zone() {
 137         [ "${zone_NAME}" != "$1" ] || return
 138         fw_config_get_section "$1" zone { \
 139                 string name "$1" \
 140                 string network "" \
 141                 string device "" \
 142                 string subnet "" \
 143                 string input "$FW_DEFAULT_INPUT_POLICY" \
 144                 string output "$FW_DEFAULT_OUTPUT_POLICY" \
 145                 string forward "$FW_DEFAULT_FORWARD_POLICY" \
 146                 boolean masq 0 \
 147                 string masq_src "" \
 148                 string masq_dest "" \
 149                 string extra "" \
 150                 string extra_src "" \
 151                 string extra_dest "" \
 152                 boolean conntrack 0 \
 153                 boolean mtu_fix 0 \
 154                 boolean custom_chains 0 \
 155                 boolean log 0 \
 156                 string log_limit 10 \
 157                 string family "" \
 158         } || return
 159         [ -n "$zone_name" ] || zone_name=$zone_NAME
 160         [ -n "$zone_extra_src" ] || zone_extra_src="$zone_extra"
 161         [ -n "$zone_extra_dest" ] || zone_extra_dest="$zone_extra"
 162         [ -n "$zone_network$zone_subnet$zone_device$zone_extra_src$zone_extra_dest" ] || zone_network=$zone_name
 163 }
 164
 165 fw_load_zone() {
 166         fw_config_get_zone "$1"
 167
 168         list_contains FW_ZONES $zone_name && {
 169                 fw_log error "zone ${zone_name}: duplicated zone, skipping"
 170                 return 0
 171         }
 172         append FW_ZONES $zone_name
 173
 174         fw_callback pre zone
 175
 176         [ $zone_conntrack = 1 -o $zone_masq = 1 ] && \
 177                 append FW_CONNTRACK_ZONES "$zone_name"
 178
 179         local mode
 180         case "$zone_family" in
 181                 *4)
 182                         mode=4
 183                         append FW_ZONES4 $zone_name
 184                         uci_set_state firewall core ${zone_name}_ipv4 1
 185                 ;;
 186                 *6)
 187                         mode=6
 188                         append FW_ZONES6 $zone_name
 189                         uci_set_state firewall core ${zone_name}_ipv6 1
 190                 ;;
 191                 *)
 192                         mode=i
 193                         append FW_ZONES4 $zone_name
 194                         append FW_ZONES6 $zone_name
 195                         uci_set_state firewall core ${zone_name}_ipv4 1
 196                         uci_set_state firewall core ${zone_name}_ipv6 1
 197                 ;;
 198         esac
 199
 200         local chain=zone_${zone_name}
 201
 202         fw add $mode f ${chain}_src_ACCEPT
 203         fw add $mode f ${chain}_src_DROP
 204         fw add $mode f ${chain}_src_REJECT
 205
 206         fw add $mode f ${chain}_dest_ACCEPT
 207         fw add $mode f ${chain}_dest_DROP
 208         fw add $mode f ${chain}_dest_REJECT
 209
 210         fw add $mode f ${chain}_input
 211         fw add $mode f ${chain}_input ${chain}_src_${zone_input} $
 212
 213         fw add $mode f ${chain}_forward
 214         fw add $mode f ${chain}_forward ${chain}_dest_${zone_forward} $
 215
 216         fw add $mode f ${chain}_output
 217         fw add $mode f ${chain}_output ${chain}_dest_${zone_output} $
 218
 219         # TODO: Rename to ${chain}_MASQUERADE
 220         fw add $mode n ${chain}_nat
 221         fw add $mode n ${chain}_prerouting
 222
 223         fw add $mode r ${chain}_notrack
 224
 225         [ $zone_mtu_fix == 1 ] && {
 226                 fw add $mode m ${chain}_MSSFIX
 227                 fw add $mode m FORWARD ${chain}_MSSFIX ^
 228                 uci_set_state firewall core ${zone_name}_tcpmss 1
 229         }
 230
 231         [ $zone_custom_chains == 1 ] && {
 232                 [ $FW_ADD_CUSTOM_CHAINS == 1 ] || \
 233                         fw_die "zone ${zone_name}: custom_chains globally disabled"
 234
 235                 fw add $mode f input_${zone_name}
 236                 fw add $mode f ${chain}_input input_${zone_name} ^
 237
 238                 fw add $mode f forwarding_${zone_name}
 239                 fw add $mode f ${chain}_forward forwarding_${zone_name} ^
 240
 241                 fw add $mode n prerouting_${zone_name}
 242                 fw add $mode n ${chain}_prerouting prerouting_${zone_name} ^
 243         }
 244
 245         [ "$zone_log" == 1 ] && {
 246                 [ "${zone_log_limit%/*}" == "$zone_log_limit" ] && \
 247                         zone_log_limit="$zone_log_limit/minute"
 248
 249                 local t
 250                 for t in REJECT DROP; do
 251                         local d
 252                         for d in src dest; do
 253                                 fw add $mode f ${chain}_${d}_${t} LOG ^ \
 254                                         { -m limit --limit $zone_log_limit --log-prefix "$t($d:$zone_name): " }
 255                         done
 256                 done
 257
 258                 [ $zone_mtu_fix == 1 ] && \
 259                         fw add $mode m ${chain}_MSSFIX LOG ^ \
 260                                 { -p tcp --tcp-flags SYN,RST SYN -m limit --limit $zone_log_limit --log-prefix "MSSFIX($zone_name): " }
 261         }
 262
 263         # NB: if MASQUERADING for IPv6 becomes available we'll need a family check here
 264         if [ "$zone_masq" == 1 ]; then
 265                 local msrc mdst
 266                 for msrc in ${zone_masq_src:-0.0.0.0/0}; do
 267                         case "$msrc" in
 268                                 *.*) fw_get_negation msrc '-s' "$msrc" ;;
 269                                 *)   fw_get_subnet4 msrc '-s' "$msrc" || break ;;
 270                         esac
 271
 272                         for mdst in ${zone_masq_dest:-0.0.0.0/0}; do
 273                                 case "$mdst" in
 274                                         *.*) fw_get_negation mdst '-d' "$mdst" ;;
 275                                         *)   fw_get_subnet4 mdst '-d' "$mdst" || break ;;
 276                                 esac
 277
 278                                 fw add $mode n ${chain}_nat MASQUERADE $ { $msrc $mdst }
 279                         done
 280                 done
 281         fi
 282
 283         local dev
 284         for dev in ${zone_device:-""}; do
 285                 local net
 286                 for net in ${zone_subnet:-""}; do
 287                         [ -n "$dev" ] || [ -n "$net" ] || continue
 288                         fw_do_interface_rules add "${zone_name}" "$dev" "$net" \
 289                 "${zone_extra_src}" "${zone_extra_dest}"
 290                 done
 291         done
 292
 293         fw_callback post zone
 294 }
 295
 296 fw_load_notrack_zone() {
 297         fw_config_get_zone "$1"
 298         list_contains FW_CONNTRACK_ZONES "${zone_name}" && return
 299
 300         fw_callback pre notrack
 301
 302         fw add i r zone_${zone_name}_notrack NOTRACK $
 303
 304         fw_callback post notrack
 305 }
 306
 307
 308 fw_load_include() {
 309         local name="$1"
 310
 311         local path
 312         config_get path ${name} path
 313
 314         [ -e $path ] && (
 315                 config() {
 316                         fw_log error "You cannot use UCI in firewall includes!" >&2
 317                         exit 1
 318                 }
 319                 . $path
 320         )
 321 }
 322
 323
 324 fw_clear() {
 325         local policy=$1
 326
 327         fw_set_filter_policy $policy
 328
 329         local tab
 330         for tab in f n r; do
 331                 fw del i $tab
 332         done
 333 }
 334
 335 fw_set_filter_policy() {
 336         local policy=$1
 337
 338         local chn tgt
 339         for chn in INPUT OUTPUT FORWARD; do
 340                 eval "tgt=\${policy:-\${FW_DEFAULT_${chn}_POLICY}}"
 341                 [ $tgt == "REJECT" ] && tgt=reject
 342                 [ $tgt == "ACCEPT" -o $tgt == "DROP" ] || {
 343                         fw add i f $chn $tgt $
 344                         tgt=DROP
 345                 }
 346                 fw policy i f $chn $tgt
 347         done
 348 }
 349
 350
 351 fw_callback() {
 352         local pp=$1
 353         local hk=$2
 354
 355         local libs lib
 356         eval "libs=\$FW_CB_${pp}_${hk}"
 357         [ -n "$libs" ] || return
 358         for lib in $libs; do
 359                 ${lib}_${pp}_${hk}_cb
 360         done
 361 }