package/firewall/files/lib/core_init.sh

   1 # Copyright (C) 2009-2010 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                 echo "Error: multiple defaults sections detected"
  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         [ $defaults_drop_invalid == 1 ] && {
  70                 fw add i f INPUT   DROP { -m state --state INVALID }
  71                 fw add i f OUTPUT  DROP { -m state --state INVALID }
  72                 fw add i f FORWARD DROP { -m state --state INVALID }
  73                 FW_NOTRACK_DISABLED=1
  74         }
  75
  76         fw add i f INPUT   ACCEPT { -m state --state RELATED,ESTABLISHED }
  77         fw add i f OUTPUT  ACCEPT { -m state --state RELATED,ESTABLISHED }
  78         fw add i f FORWARD ACCEPT { -m state --state RELATED,ESTABLISHED }
  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         [ $defaults_custom_chains == 1 ] && {
 104                 echo "Adding custom chains"
 105                 fw add i f input_rule
 106                 fw add i f output_rule
 107                 fw add i f forwarding_rule
 108                 fw add i n prerouting_rule
 109                 fw add i n postrouting_rule
 110
 111                 fw add i f INPUT       input_rule
 112                 fw add i f OUTPUT      output_rule
 113                 fw add i f FORWARD     forwarding_rule
 114                 fw add i n PREROUTING  prerouting_rule
 115                 fw add i n POSTROUTING postrouting_rule
 116         }
 117
 118         fw add i f input
 119         fw add i f output
 120         fw add i f forward
 121
 122         fw add i f INPUT   input
 123         fw add i f OUTPUT  output
 124         fw add i f FORWARD forward
 125
 126         fw add i f reject
 127         fw add i f reject REJECT { --reject-with tcp-reset -p tcp }
 128         fw add i f reject REJECT { --reject-with port-unreach }
 129
 130         fw_set_filter_policy
 131
 132         fw_callback post defaults
 133 }
 134
 135
 136 fw_config_get_zone() {
 137         [ "${zone_NAME}" != "$1" ] || return
 138         fw_config_get_section "$1" zone { \
 139                 string name "$1" \
 140                 string network "" \
 141                 string input "$FW_DEFAULT_INPUT_POLICY" \
 142                 string output "$FW_DEFAULT_OUTPUT_POLICY" \
 143                 string forward "$FW_DEFAULT_FORWARD_POLICY" \
 144                 boolean masq 0 \
 145                 boolean conntrack 0 \
 146                 boolean mtu_fix 0 \
 147                 boolean custom_chains "$FW_ADD_CUSTOM_CHAINS" \
 148                 boolean log 0 \
 149                 string log_limit 10 \
 150                 string family "" \
 151         } || return
 152         [ -n "$zone_name" ] || zone_name=$zone_NAME
 153         [ -n "$zone_network" ] || zone_network=$zone_name
 154 }
 155
 156 fw_load_zone() {
 157         fw_config_get_zone "$1"
 158
 159         list_contains FW_ZONES $zone_name && {
 160                 fw_die "zone ${zone_name}: duplicated zone"
 161         }
 162         append FW_ZONES $zone_name
 163
 164         fw_callback pre zone
 165
 166         [ $zone_conntrack = 1 -o $zone_masq = 1 ] && \
 167                 append FW_CONNTRACK_ZONES "$zone_name"
 168
 169         local mode
 170         case "$zone_family" in
 171                 *4)
 172                         mode=4
 173                         append FW_ZONES4 $zone_name
 174                         uci_set_state firewall core ${zone_name}_ipv4 1
 175                 ;;
 176                 *6)
 177                         mode=6
 178                         append FW_ZONES6 $zone_name
 179                         uci_set_state firewall core ${zone_name}_ipv6 1
 180                 ;;
 181                 *)
 182                         mode=i
 183                         append FW_ZONES4 $zone_name
 184                         append FW_ZONES6 $zone_name
 185                         uci_set_state firewall core ${zone_name}_ipv4 1
 186                         uci_set_state firewall core ${zone_name}_ipv6 1
 187                 ;;
 188         esac
 189
 190         local chain=zone_${zone_name}
 191
 192         fw add $mode f ${chain}_ACCEPT
 193         fw add $mode f ${chain}_DROP
 194         fw add $mode f ${chain}_REJECT
 195         fw add $mode f ${chain}_MSSFIX
 196
 197         # TODO: Rename to ${chain}_input
 198         fw add $mode f ${chain}
 199         fw add $mode f ${chain} ${chain}_${zone_input} $
 200
 201         fw add $mode f ${chain}_forward
 202         fw add $mode f ${chain}_forward ${chain}_${zone_forward} $
 203
 204         # TODO: add ${chain}_output
 205         fw add $mode f output ${chain}_${zone_output} $
 206
 207         # TODO: Rename to ${chain}_MASQUERADE
 208         fw add $mode n ${chain}_nat
 209         fw add $mode n ${chain}_prerouting
 210
 211         fw add $mode r ${chain}_notrack
 212
 213         [ $zone_masq == 1 ] && \
 214                 fw add $mode n POSTROUTING ${chain}_nat $
 215
 216         [ $zone_mtu_fix == 1 ] && \
 217                 fw add $mode f FORWARD ${chain}_MSSFIX ^
 218
 219         [ $zone_custom_chains == 1 ] && {
 220                 [ $FW_ADD_CUSTOM_CHAINS == 1 ] || \
 221                         fw_die "zone ${zone_name}: custom_chains globally disabled"
 222
 223                 fw add $mode f input_${zone_name}
 224                 fw add $mode f ${chain} input_${zone_name} ^
 225
 226                 fw add $mode f forwarding_${zone_name}
 227                 fw add $mode f ${chain}_forward forwarding_${zone_name} ^
 228
 229                 fw add $mode n prerouting_${zone_name}
 230                 fw add $mode n ${chain}_prerouting prerouting_${zone_name} ^
 231         }
 232
 233         [ "$zone_log" == 1 ] && {
 234                 [ "${zone_log_limit%/*}" == "$zone_log_limit" ] && \
 235                         zone_log_limit="$zone_log_limit/minute"
 236
 237                 local t
 238                 for t in REJECT DROP MSSFIX; do
 239                         fw add $mode f ${chain}_${t} LOG ^ \
 240                                 { -m limit --limit $zone_log_limit --log-prefix "$t($zone_name): "  }
 241                 done
 242         }
 243
 244         fw_callback post zone
 245 }
 246
 247 fw_load_notrack_zone() {
 248         fw_config_get_zone "$1"
 249         list_contains FW_CONNTRACK_ZONES "${zone_name}" && return
 250
 251         fw_callback pre notrack
 252
 253         fw add i r zone_${zone_name}_notrack NOTRACK $
 254
 255         fw_callback post notrack
 256 }
 257
 258
 259 fw_load_include() {
 260         local name="$1"
 261
 262         local path; config_get path ${name} path
 263         [ -e $path ] && . $path
 264 }
 265
 266
 267 fw_clear() {
 268         local policy=$1
 269
 270         fw_set_filter_policy $policy
 271
 272         local tab
 273         for tab in f n r; do
 274                 fw del i $tab
 275         done
 276 }
 277
 278 fw_set_filter_policy() {
 279         local policy=$1
 280
 281         local chn tgt
 282         for chn in INPUT OUTPUT FORWARD; do
 283                 eval "tgt=\${policy:-\${FW_DEFAULT_${chn}_POLICY}}"
 284                 [ $tgt == "REJECT" ] && tgt=reject
 285                 [ $tgt == "ACCEPT" -o $tgt == "DROP" ] || {
 286                         fw add i f $chn $tgt $
 287                         tgt=DROP
 288                 }
 289                 fw policy i f $chn $tgt
 290         done
 291 }
 292
 293
 294 fw_callback() {
 295         local pp=$1
 296         local hk=$2
 297
 298         local libs lib
 299         eval "libs=\$FW_CB_${pp}_${hk}"
 300         [ -n "$libs" ] || return
 301         for lib in $libs; do
 302                 ${lib}_${pp}_${hk}_cb
 303         done
 304 }