From ed4a493b734cac1fbf73df4a067a12d52d3fea57 Mon Sep 17 00:00:00 2001
From: Gabriel Skupien <g.skupien@vyos.io>
Date: Sun, 26 Apr 2020 12:23:58 +0200
Subject: dhclient: T1381: Improved RFC3442 routes processing

Several improvements in processing RFC3442 routes (support for route deletion, DHCP RENEW and link-local routes)
---
 src/etc/dhcp/dhclient-exit-hooks.d/01-vyos-cleanup | 64 +++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

(limited to 'src/etc/dhcp/dhclient-exit-hooks.d/01-vyos-cleanup')

diff --git a/src/etc/dhcp/dhclient-exit-hooks.d/01-vyos-cleanup b/src/etc/dhcp/dhclient-exit-hooks.d/01-vyos-cleanup
index ce846f6c3..88a4d9db9 100644
--- a/src/etc/dhcp/dhclient-exit-hooks.d/01-vyos-cleanup
+++ b/src/etc/dhcp/dhclient-exit-hooks.d/01-vyos-cleanup
@@ -1,12 +1,74 @@
+# NOTE: here we use 'ip' wrapper, therefore a route will be actually deleted via /usr/sbin/ip or vtysh, according to the system state
+
 if [[ $reason =~ (EXPIRE|FAIL|RELEASE|STOP) ]]; then
     # delete dynamic nameservers from a configuration if lease was deleted
     logmsg info "Deleting nameservers with tag \"dhcp-${interface}\" via vyos-hostsd-client"
     vyos-hostsd-client --delete-name-servers --tag dhcp-${interface}
-    # try to delete default ip route (NOTE: here we use 'ip' wrapper, therefore a route will be actually deleted via /usr/sbin/ip or vtysh, according to the system state)
+    # try to delete default ip route 
     for router in $old_routers; do
         logmsg info "Deleting default route: via $router dev ${interface}"
         ip -4 route del default via $router dev ${interface}
     done
+    # delete rfc3442 routes
+    if [ -n "$old_rfc3442_classless_static_routes" ]; then
+        set -- $old_rfc3442_classless_static_routes
+        while [ $# -gt 0 ]; do
+            net_length=$1
+            via_arg=''
+            case $net_length in
+                32|31|30|29|28|27|26|25)
+                    if [ $# -lt 9 ]; then
+                        return 1
+                    fi
+                    net_address="${2}.${3}.${4}.${5}"
+                    gateway="${6}.${7}.${8}.${9}"
+                    shift 9
+                    ;;
+                24|23|22|21|20|19|18|17)
+                    if [ $# -lt 8 ]; then
+                        return 1
+                    fi
+                    net_address="${2}.${3}.${4}.0"
+                    gateway="${5}.${6}.${7}.${8}"
+                    shift 8
+                    ;;
+                16|15|14|13|12|11|10|9)
+                    if [ $# -lt 7 ]; then
+                        return 1
+                    fi
+                    net_address="${2}.${3}.0.0"
+                    gateway="${4}.${5}.${6}.${7}"
+                    shift 7
+                    ;;
+                8|7|6|5|4|3|2|1)
+                    if [ $# -lt 6 ]; then
+                        return 1
+                    fi
+                    net_address="${2}.0.0.0"
+                    gateway="${3}.${4}.${5}.${6}"
+                    shift 6
+                    ;;
+                0)  # default route
+                    if [ $# -lt 5 ]; then
+                        return 1
+                    fi
+                    net_address="0.0.0.0"
+                    gateway="${2}.${3}.${4}.${5}"
+                    shift 5
+                    ;;
+                *)  # error
+                    return 1
+                    ;;
+            esac
+            # take care of link-local routes
+            if [ "${gateway}" != '0.0.0.0' ]; then
+                via_arg="via ${gateway}"
+            fi
+            # delete route (ip detects host routes automatically)
+            ip -4 route del "${net_address}/${net_length}" \
+                ${via_arg} dev "${interface}" >/dev/null 2>&1
+        done
+    fi
 fi
 
 if [[ $reason =~ (EXPIRE6|RELEASE6|STOP6) ]]; then
-- 
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