X-Git-Url: https://git.distorted.org.uk/~mdw/firewall/blobdiff_plain/429f4314d0d1be69f7500cf7f97671595804fdd0..06ff80827cd67ab85ee31fc32fc5e740bda9193e:/classify.m4

diff --git a/classify.m4 b/classify.m4
index 25b1693..8b6a650 100644
--- a/classify.m4
+++ b/classify.m4
@@ -115,26 +115,129 @@ m4_divert(42)m4_dnl
 done
 
 m4_divert(46)m4_dnl
-## Mark addresses reachable on non-default interfaces as not reachable on the
-## default interface.
-trace "nets = $allnets $allnets6"
+## Build the input classification chains.  There's one chain `in-IFACE' for
+## each local interface.  This chain does a further dispatch on the source
+## address to the appropriate `mark-from-CLASS' chain for the source network
+## class.
+seen=:
+for iface in $host_ifaces_<::>FWHOST; do
+  ifname=${iface%=*}
+  case $seen in *:$ifname:*) continue ;; esac
+  seen=$seen$ifname:
+  clearchain mangle:in-$ifname
+  run ip46tables -t mangle -A in-classify -i $ifname -g in-$ifname
+done
+
+## Now populate the `in-IFACE' and `out-classify' chains.  We iterate over
+## the available networks and add addresses to the appropriate chains.  Also,
+## build up a map of which interfaces receive from which address ranged so
+## that we can finish the chains off properly later.  This contains entries
+## of the form IFACE=:ADDR:ADDR:...:
+ifnets=""
 for net in $allnets; do
-  case $net in
-    "$defaultiface":*)
-      ;;
-    *)
-      run iptables -t mangle -A in-$defaultiface \
-	      -s ${net#*:} -g bad-source-address
-      ;;
-  esac
+
+  ## Determine the addresses and class for this network, and populate the
+  ## `out-classify' chains.
+  eval addr=\$net_inet_$net addr6=\$net_inet6_$net class=\$net_class_$net
+  case $class in virtual) continue ;; esac
+  trace "$net : $class"
+  for a in $addr; do
+    run iptables -t mangle -A out-classify -g mark-to-$class -d $a
+  done
+  for a in $addr6; do
+    run ip6tables -t mangle -A out-classify -g mark-to-$class -d $a
+  done
+
+  ## Now work through the interfaces.
+  for iface in $(net_interfaces FWHOST $net); do
+    nets=""
+    case $iface in
+
+      -)
+	## A special `no interface' marker: we should not receive packets
+	## from this network at all.
+	continue
+	;;
+
+      *-+)
+	## A special marker indicating a collection of point-to-point
+	## interfaces.  We should match an address to a particular interface.
+	## Later, we'll cap this chain off by rejecting all other traffic.
+	eval hosts=\$net_hosts_$net
+	for host in $hosts; do
+	  eval ha=\$host_inet_$host ha6=\$host_inet6_$host
+	  trace "$host : $class -> $iface"
+	  for a in $ha; do
+	    run iptables -t mangle -A in-$iface \
+		    -i ${iface%+}$host -s $a -g mark-from-$class
+	    nets=$nets$a:
+	  done
+	  for a in $ha6; do
+	    run ip6tables -t mangle -A in-$iface \
+		    -i ${iface%+}$host -s $a -g mark-from-$class
+	    nets=$nets$a:
+	  done
+	done
+	;;
+
+      *)
+	## A normal interface.  Classify incoming traffic according to the
+	## source address.
+	trace "$net : $class -> $iface"
+	for a in $addr; do
+	  run iptables -t mangle -A in-$iface -g mark-from-$class -s $a
+	  nets=$nets$a:
+	done
+	for a in $addr6; do
+	  run ip6tables -t mangle -A in-$iface -g mark-from-$class -s $a
+	  nets=$nets$a:
+	done
+	case $net in default) nets=${nets}default: ;; esac
+	;;
+    esac
+
+    ## Record that this interface receives traffic from this network.
+    unset nifnets
+    foundp=nil
+    for ifnet in $ifnets; do
+      case $ifnet in
+	$iface=*:$net:*) addword nifnets $ifnet; foundp=t ;;
+	$iface=*) addword nifnets $ifnet$nets; foundp=t ;;
+	*) addword nifnets $ifnet ;;
+      esac
+    done
+    case $foundp in nil) addword nifnets $iface=:$nets ;; esac
+    ifnets=$nifnets
+
+  done
 done
-for net in $allnets6; do
-  case $net in
-    "$defaultiface":*)
+
+## Wrap up all of the `in-IFACE' chains.  A chain which matches the `default'
+## net should have unmatched but known networks blocked off, and then chain
+## onto `in-default'.  Other chains should just chain onto
+## `bad-source-address'.
+trace "ifnets = $ifnets"
+for ifnet in $ifnets; do
+  iface=${ifnet%%=*} nets=${ifnet#*=}
+  case $nets in
+    *:default:*)
+      for n in $allnets; do
+	eval addr=\$net_inet_$n addr6=\$net_inet6_$n
+	for a in $addr; do
+	  case $nets in *:$a:*) continue ;; esac
+	  nets=$nets$a
+	  run iptables -t mangle -A in-$iface -s $a -g bad-source-address
+	done
+	for a in $addr6; do
+	  case $nets in *:$a:*) continue ;; esac
+	  nets=$nets$a
+	  run ip6tables -t mangle -A in-$iface -s $a -g bad-source-address
+	done
+      done
+      run ip46tables -t mangle -A in-$iface -g in-default
       ;;
     *)
-      run ip6tables -t mangle -A in-$defaultiface \
-	      -s ${net#*:} -g bad-source-address
+      run ip46tables -t mangle -A in-$iface -g bad-source-address
       ;;
   esac
 done
@@ -152,11 +255,15 @@ for addr in \
 do
   run ip6tables -t mangle -A in-default -s $addr -g bad-source-address
 done
+run ip46tables -t mangle -A in-default -g mark-from-$net_class_default
 
 m4_divert(92)m4_dnl
 ## Put the final default decision on the in-default chain, and attach the
 ## classification chains to the PREROUTING hook.
-run ip46tables -t mangle -A in-$defaultiface -g mark-from-$defaultclass
+for iface in $defaultifaces; do
+  run ip46tables -t mangle -A in-$iface -g in-default
+done
+run ip46tables -t mangle -A out-classify -g mark-to-$net_class_default
 run ip46tables -t mangle -A PREROUTING -j in-classify
 run ip46tables -t mangle -A PREROUTING -j out-classify