unbound: Set EDNS buffer size to 1232 bytes

Fixes: #12240
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/config/unbound/unbound.conf b/config/unbound/unbound.conf
index 4d492a5bc13ac36de4b9f18b41e9ef5373bcdfdb..9fca7ef225cdd56729d3d1f75a75fb8cec3b5e6f 100644 (file)
--- a/config/unbound/unbound.conf
+++ b/config/unbound/unbound.conf
@@ -62,6 +62,9 @@ server:
        use-caps-for-id: yes
        aggressive-nsec: yes
 
+       # EDNS Buffer Size (#12240)
+       edns-buffer-size: 1232
+
        # Harden against DNS cache poisoning
        unwanted-reply-threshold: 1000000
 

diff --git a/src/initscripts/system/unbound b/src/initscripts/system/unbound
index 61d62beb155f8319ddf40dfdb8a54cc5f7717e8b..1c9f4288ca485592e2c7d5aa0b3b7f8383a12ac4 100644 (file)
--- a/src/initscripts/system/unbound
+++ b/src/initscripts/system/unbound
@@ -20,9 +20,6 @@ FORCE_TCP=off
 # Cache any local zones for 60 seconds
 LOCAL_TTL=60
 
-# EDNS buffer size
-EDNS_DEFAULT_BUFFER_SIZE=4096
-
 # Load optional configuration
 [ -e "/etc/sysconfig/unbound" ] && . /etc/sysconfig/unbound
 
@@ -90,25 +87,6 @@ update_forwarders() {
                        esac
                done
 
-               # Determine EDNS buffer size
-               local new_edns_buffer_size=${EDNS_DEFAULT_BUFFER_SIZE}
-
-               for ns in ${forwarders}; do
-                       local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
-                       if [ -n "${edns_buffer_size}" ]; then
-                               if [ ${edns_buffer_size} -lt ${new_edns_buffer_size} ]; then
-                                       new_edns_buffer_size=${edns_buffer_size}
-                               fi
-                       fi
-               done
-
-               if [ ${new_edns_buffer_size} -lt ${EDNS_DEFAULT_BUFFER_SIZE} ]; then
-                       boot_mesg "EDNS buffer size reduced to ${new_edns_buffer_size}" ${WARNING}
-                       echo_warning
-
-                       unbound-control -q set_option edns-buffer-size: ${new_edns_buffer_size}
-               fi
-
                # Show warning for any broken upstream name servers
                if [ -n "${broken_forwarders}" ]; then
                        boot_mesg "Ignoring broken upstream name server(s): ${broken_forwarders:1}" ${WARNING}
@@ -129,7 +107,7 @@ update_forwarders() {
                # In case we have found no working forwarders
                else
                        # Test if the recursor mode is available
-                       if can_resolve_root +bufsize=${new_edns_buffer_size}; then
+                       if can_resolve_root; then
                                # Make sure DNSSEC is activated
                                enable_dnssec
 
@@ -374,12 +352,6 @@ test_name_server() {
        # Exit when the server is not reachable
        ns_is_online ${ns} || return 1
 
-       # Determine the maximum edns buffer size that works
-       local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
-       if [ -n "${edns_buffer_size}" ]; then
-               args="${args} +bufsize=${edns_buffer_size}"
-       fi
-
        local errors
        for rr in DNSKEY DS RRSIG; do
                if ! ns_forwards_${rr} ${ns} ${args}; then
@@ -457,21 +429,6 @@ ns_supports_tcp() {
        dig "${DIG_ARGS[@]}" @${ns} +tcp A ${TEST_DOMAIN} $@ >/dev/null || return 1
 }
 
-ns_determine_edns_buffer_size() {
-       local ns=${1}
-       shift
-
-       local b
-       for b in 4096 2048 1500 1480 1464 1400 1280 512; do
-               if dig "${DIG_ARGS[@]}" @${ns} +dnssec +bufsize=${b} A ${TEST_DOMAIN} $@ >/dev/null; then
-                       echo "${b}"
-                       return 0
-               fi
-       done
-
-       return 1
-}
-
 get_root_nameservers() {
        while read -r hostname ttl record address; do
                # Searching for A records
@@ -905,11 +862,6 @@ case "$1" in
                        echo "${ns} does not support TCP fallback"
                fi
 
-               edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
-               if [ -n "${edns_buffer_size}" ]; then
-                       echo "EDNS buffer size for ${ns}: ${edns_buffer_size}"
-               fi
-
                exit ${ret}
                ;;