functions.ipv4

   1 #!/bin/bash
   2 ###############################################################################
   3 #                                                                             #
   4 # IPFire.org - A linux based firewall                                         #
   5 # Copyright (C) 2010  Michael Tremer & Christian Schmidt                      #
   6 #                                                                             #
   7 # This program is free software: you can redistribute it and/or modify        #
   8 # it under the terms of the GNU General Public License as published by        #
   9 # the Free Software Foundation, either version 3 of the License, or           #
  10 # (at your option) any later version.                                         #
  11 #                                                                             #
  12 # This program is distributed in the hope that it will be useful,             #
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  15 # GNU General Public License for more details.                                #
  16 #                                                                             #
  17 # You should have received a copy of the GNU General Public License           #
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  19 #                                                                             #
  20 ###############################################################################
  21
  22 IP_SUPPORTED_PROTOCOLS="${IP_SUPPORTED_PROTOCOLS} ipv4"
  23
  24 function ipv4_is_valid() {
  25         ipcalc --ipv4 -c $@ >/dev/null 2>&1
  26
  27         case "$?" in
  28                 0)
  29                         return ${EXIT_OK}
  30                         ;;
  31                 *)
  32                         return ${EXIT_ERROR}
  33                         ;;
  34         esac
  35 }
  36
  37 function ipv4_detect_duplicate() {
  38         local device=${1}
  39         local address=${2}
  40
  41         assert isset address
  42         assert isset device
  43         assert device_exists ${device}
  44
  45         # Don't check on PPP devices.
  46         device_is_ppp ${device} && return ${EXIT_ERROR}
  47
  48         if ! arping -q -c 2 -w 3 -D -I ${device} ${address}; then
  49                 log DEBUG "Detected duplicate address '${address}' on device '${device}'."
  50                 return ${EXIT_OK}
  51         fi
  52
  53         return ${EXIT_ERROR}
  54 }
  55
  56 function ipv4_update_neighbours() {
  57         local device=${1}
  58         local address=${2}
  59
  60         # Don't do anything on PPP devices.
  61         device_is_ppp ${device} && return ${EXIT_OK}
  62
  63         arping -q -A -c 1 -I ${device} ${address}
  64         ( sleep 2; arping -q -U -c 1 -I ${device} ${address} ) >/dev/null 2>&1 </dev/null &
  65 }
  66
  67 function ipv4_get_netaddress() {
  68         local address=${1}
  69         assert isset address
  70
  71         local prefix=$(ip_get_prefix ${address})
  72         isset prefix || prefix="32"
  73
  74         # Assume host-only address if no prefix has been given.
  75         if [ "${prefix}" = "32" ]; then
  76                 echo "${address}/${prefix}"
  77                 return ${EXIT_OK}
  78         fi
  79
  80         local NETWORK
  81         eval $(ipcalc --network ${address})
  82         assert isset NETWORK
  83
  84         echo "${NETWORK}/${prefix}"
  85         return ${EXIT_OK}
  86 }
  87
  88 function ipv4_get_prefix() {
  89         local address=${1}
  90         local broadcast=${2}
  91
  92         assert isset address
  93         assert isset broadcast
  94
  95         local PREFIX
  96         eval $(ipcalc --prefix ${address} ${broadcast})
  97         assert isset PREFIX
  98
  99         echo "${PREFIX}"
 100         return ${EXIT_OK}
 101 }
 102
 103 function ipv4_flush_device() {
 104         #
 105         # Flushes all routes, addresses from the device
 106         # and clears the ARP cache.
 107         #
 108
 109         local device=${1}
 110         assert isset device
 111
 112         ip -4 addr flush dev ${device} >/dev/null 2>&1
 113         ip -4 route flush dev ${device} >/dev/null 2>&1
 114         ip -4 neigh flush dev ${device} >/dev/null 2>&1
 115
 116         return 0
 117 }
 118
 119 function ipv4_prefix2netmask() {
 120         local prefix=${1}
 121         shift
 122
 123         assert isinteger prefix
 124
 125         # XXX this function is a stub
 126
 127         case "${prefix}" in
 128                 24)
 129                         echo "255.255.255.0"
 130                         ;;
 131                 *)
 132                         assert false NOT IMPLEMENTED
 133                         ;;
 134         esac
 135 }
 136
 137 function ipv4_get_network() {
 138         local net=${1}
 139
 140         local prefix=$(ip_get_prefix ${net})
 141         isset prefix || prefix=32
 142
 143         local mask=0
 144         if [ ${prefix} -ne 0 ]; then
 145                 mask=$(( -1 << $(( 32 - ${prefix} )) ))
 146         fi
 147
 148         local addr=$(ip_split_prefix ${net})
 149         addr=$(ipv4_encode ${addr})
 150
 151         ipv4_decode $(( ${addr} & ${mask} ))
 152 }
 153
 154 function ipv4_get_broadcast() {
 155         local net=${1}
 156
 157         local prefix=$(ip_get_prefix ${net})
 158         assert isset prefix
 159
 160         prefix=$(( 32 - ${prefix} ))
 161
 162         local netmask=0
 163         local broadcast=-1
 164         if [ ${prefix} -eq 32 ]; then
 165                 :
 166         else
 167                 netmask=$(( -1 << ${prefix} ))
 168                 broadcast=$(( $(( 1 << ${prefix} )) - 1))
 169         fi
 170
 171         local addr=$(ip_split_prefix ${net})
 172         addr=$(ipv4_encode ${addr})
 173
 174         ipv4_decode $(( $(( ${addr} & ${netmask} )) | ${broadcast} ))
 175 }
 176
 177 function ipv4_encode() {
 178         local addr=${1}
 179         local int=0
 180
 181         local field
 182         for field in ${addr//./ }; do
 183                 int=$(( $(( ${int} << 8 )) | ${field} ))
 184         done
 185
 186         print "${int}"
 187 }
 188
 189 function ipv4_decode() {
 190         local int=${1}
 191
 192         local addr=$(( ${int} & 255 ))
 193
 194         local i
 195         for i in 1 2 3; do
 196                 int=$(( ${int} >> 8 ))
 197                 addr="$(( ${int} & 255 )).${addr}"
 198         done
 199
 200         print "${addr}"
 201 }
 202
 203 function ipv4_range() {
 204         local range=${1}
 205
 206         local first=${1%-*}
 207         local last=${1#*-}
 208
 209         _ipv4_range "$(ipv4_encode ${first})" "$(ipv4_encode ${last})"
 210 }
 211
 212 function _ipv4_range() {
 213         local first=${1}
 214         local last=${2}
 215
 216         if [ ${first} -gt ${last} ]; then
 217                 local range="$(ipv4_decode ${first})-$(ipv4_decode ${last})"
 218
 219                 error "Invalid IPv4 address range: ${range}"
 220                 return ${EXIT_ERROR}
 221         fi
 222
 223         last=$(( ${last} + 1 ))
 224
 225         local prefix
 226         local x y z
 227         while [ ${last} -gt ${first} ]; do
 228                 prefix=
 229                 x=31
 230                 y=2
 231                 z=1
 232
 233                 while [ $(( ${first} % ${y} )) -eq 0 ] && [ ${last} -gt $(( ${first} + ${y} )) ]; do
 234                         prefix="/${x}"
 235                         x=$(( ${x} - 1 ))
 236                         z=${y}
 237                         y=$(( ${y} * 2 ))
 238                 done
 239
 240                 print "$(ipv4_decode ${first})${prefix}"
 241                 first=$(( ${first} + ${z} ))
 242         done
 243 }
 244
 245 function ipv4_range_explicit() {
 246         local range=${1}
 247
 248         local first last
 249
 250         case "${range}" in
 251                 *.*.*.*-*.*.*.*)
 252                         first=${range%-*}
 253                         last=${range#*-}
 254                         ;;
 255                 *.*.*.*/*)
 256                         first=$(ipv4_get_network ${range})
 257                         last=$(ipv4_get_broadcast ${range})
 258                         ;;
 259         esac
 260
 261         _ipv4_range_explicit "$(ipv4_encode ${first})" "$(ipv4_encode ${last})"
 262 }
 263
 264 function _ipv4_range_explicit() {
 265         local first=${1}
 266         local last=${2}
 267
 268         if [ ${first} -gt ${last} ]; then
 269                 local range="$(ipv4_decode ${first})-$(ipv4_decode ${last})"
 270
 271                 error "Invalid IPv4 address range: ${range}"
 272                 return ${EXIT_ERROR}
 273         fi
 274
 275         while [ ${first} -le ${last} ]; do
 276                 ipv4_decode ${first}
 277                 first=$(( ${first} + 1 ))
 278         done
 279 }