service-relay.sh

gehe zur Dokumentation dieser Datei

## @defgroup on-service-relay Dienst-Weiterleitungen
# Beginn der Doku-Gruppe
## @{

## für die Kompatibilität mit Firmware vor v0.5
UGW_LOCAL_SERVICE_PORT_LEGACY=1600
DEFAULT_MESH_OPENVPN_PORT=1602
## falls mehr als ein GW-Dienst weitergereicht wird, wird dieser Port und die folgenden verwendet
SERVICE_RELAY_LOCAL_RELAY_PORT_START=5100


# Pruefung ob ein lokaler Port bereits fuer einen ugw-Dienst weitergeleitet wird
_is_local_service_relay_port_unused() {
    local port="$1"
    local collisions
    collisions=$(get_services | filter_services_by_value "local_relay_port" "$port")
    [ -n "$collisions" ] && trap "" $GUARD_TRAPS && return 1
    # keine Kollision entdeckt
    return 0
}


# Liefere den Port zurueck, der einer Dienst-Weiterleitung lokal zugewiesen wurde.
# Falls noch kein Port definiert ist, dann waehle einen neuen Port.
# Parameter: config_name
pick_local_service_relay_port() {
    trap "error_trap pick_local_service_relay_port '$*'" $GUARD_TRAPS
    local service_name="$1"
    local port
    port=$(get_service_value "$service_name" "local_relay_port")
    # falls unbelegt: suche einen unbenutzten lokalen Port
    if [ -z "$port" ]; then
        # fuer IGW-Verbindungen: belege zuerst den alten Standard-Port (fuer alte Clients)
        if [ "$(get_service_value "$service_name" "service")" = "gw" ]; then
            _is_local_service_relay_port_unused "$UGW_LOCAL_SERVICE_PORT_LEGACY" \
                && port="$UGW_LOCAL_SERVICE_PORT_LEGACY"
            true
        fi
    fi
    if [ -z "$port" ]; then
        port="$SERVICE_RELAY_LOCAL_RELAY_PORT_START"
        until _is_local_service_relay_port_unused "$port"; do
            : $((port++))
        done
    fi
    set_service_value "$service_name" "local_relay_port" "$port"
    echo "$port"
}


## @fn update_relay_firewall_rules
## @brief Erstelle die Liste aller Firewall-Regeln fuer Service-Relay-Weiterleitungen neu.
## @details Diese Funktion wird als Teil des Firewall-Reload-Prozess und nach Service-Relay-Aenderungen
##   aufgerufen.
update_relay_firewall_rules() {
    trap "error_trap update_relay_firewall_rules '$*'" $GUARD_TRAPS
    local host
    local port
    local protocol
    local target_ip
    local main_ip
    local dnat_chain="on_service_relay_dnat"
    local parent_dnat_chain="prerouting_${ZONE_MESH}_rule"
    local tos_chain="on_service_relay_tos"
    local parent_tos_chain="PREROUTING"
    main_ip=$(get_main_ip)
    # neue Chains erzeugen
    iptables -t nat --new-chain "$dnat_chain" 2>/dev/null || iptables -t nat --flush "$dnat_chain"
    iptables -t mangle --new-chain "$tos_chain" 2>/dev/null || iptables -t mangle --flush "$tos_chain"
    # Verweis auf die neue Chain erzeugen
    iptables -t nat --check "$parent_dnat_chain" -j "$dnat_chain" 2>/dev/null \
        || iptables -t nat --insert "$parent_dnat_chain" -j "$dnat_chain"
    iptables -t mangle --check "$parent_tos_chain" -j "$tos_chain" 2>/dev/null \
        || iptables -t mangle --insert "$parent_tos_chain" -j "$tos_chain"
    # DNAT- und TOS-Chain fuellen
    get_services | filter_relay_services | while read service; do
        is_service_relay_possible "$service" || continue
        host=$(get_service_value "$service" "host")
        port=$(get_service_value "$service" "port")
        protocol=$(get_service_value "$service" "protocol")
        local_port=$(get_service_value "$service" "local_relay_port")
        target_ip=$(query_dns "$host" | filter_routable_addresses | tail -n 1)
        iptables -t nat -A "$dnat_chain" --destination "$main_ip" --protocol "$protocol" --dport "$local_port" \
            -j DNAT --to-destination "${target_ip}:${port}"
        # falls on-openvpn vorhanden ist, wollen wir vermeiden, dass mesh-Tunnel ueber den Internet-Tunnel laufen
        [ -z "${TOS_NON_TUNNEL:-}" ] || iptables -t mangle -A "$tos_chain" --destination "$main_ip" \
            --protocol "$protocol" --dport "$local_port" -j TOS --set-tos "$TOS_NON_TUNNEL"
    done

}


_get_service_relay_olsr_announcement_prefix() {
    trap "error_trap _get_service_relay_olsr_announcement_prefix '$*'" $GUARD_TRAPS
    local service_name="$1"
    local main_ip
    local service_type
    local scheme
    local host
    local port
    local protocol
    main_ip=$(get_main_ip)
    service_type=$(get_service_value "$service_name" "service")
    # remove prefix
    service_type="${service_type#$RELAYABLE_SERVICE_PREFIX}"
    scheme=$(get_service_value "$service_name" "scheme")
    host=$(get_service_value "$service_name" "host")
    port=$(pick_local_service_relay_port "$service_name")
    protocol=$(get_service_value "$service_name" "protocol")
    # announce the service
    echo "${scheme}://${main_ip}:${port}|${protocol}|${service_type}"
}


## @fn get_service_relay_olsr_announcement()
## @brief Ermittle den oder die OLSR-Nameservice-Announcements, die zu dem Dienst gehoeren.
get_service_relay_olsr_announcement() {
    trap "error_trap get_service_relay_olsr_announcement '$*'" $GUARD_TRAPS
    local service_name="$1"
    local announce_unique
    local uci_prefix
    announce_unique=$(_get_service_relay_olsr_announcement_prefix "$service_name")
    uci_prefix=$(get_and_enable_olsrd_library_uci_prefix "nameservice")
    uci_get_list "${uci_prefix}.service" | awk '{ if ($1 == "'$announce_unique'") print $0; }'
}


## @fn announce_olsr_service_relay()
## @brief Verkuende das lokale Relay eines öffentlichen Dienstes inkl. Geschwindigkeitsdaten via olsr nameservice.
## @param service_name Name des zu veröffentlichenden Diensts
## @attention Anschließend muss die uci-Sektion 'olsrd' committed werden.
announce_olsr_service_relay() {
    trap "error_trap announce_olsr_service_relay '$*'" $GUARD_TRAPS
    local service_name="$1"
    local service_unique
    local service_details
    service_unique=$(_get_service_relay_olsr_announcement_prefix "$service_name")
    # das 'service_name'-Detail wird fuer die anschliessende Beraeumung (firewall-Regeln usw.) verwendet
    # nur nicht-leere Attribute werden geschrieben
    service_details=$(while read key value; do [ -z "$value" ] && continue; echo "$key:$value"; done <<EOF
        public_host $(get_service_value "$service_name" "host")
        upload $(get_service_value "$service_name" "wan_speed_upload")
        download $(get_service_value "$service_name" "wan_speed_download")
        ping $(get_service_value "$service_name" "wan_ping")
EOF
)
    # Zeilenumbrueche durch Leerzeichen ersetzen, abschliessendes Leerzeichen entfernen
    service_details=$(echo "$service_details" | tr '\n' ' ' | sed 's/ $//')
    # loesche alte Dienst-Announcements mit demselben Prefix
    local this_unique
    local this_details
    local uci_prefix
    uci_prefix=$(get_and_enable_olsrd_library_uci_prefix "nameservice")
    get_service_relay_olsr_announcement "$service_name" | while read this_unique this_details; do
        # der Wert ist bereits korrekt - wir koennen abbrechen
        [ "$this_details" = "$service_details" ] && break
        # der Wert ist falsch: loeschen und am Ende neu hinzufuegen
        msg_debug "Deleting outdated service-relay announcement: $service_unique $this_details"
        uci_delete_list "${uci_prefix}.service" "$service_unique $this_details"
    done
    # falls keine Treffer gibt, fuegen wir ein neues Announcement hinzu
    if [ -z "$(get_service_relay_olsr_announcement "$service_name")" ]; then
        msg_debug "Adding new service-relay announcement: $service_unique $service_details"
        uci_add_list "${uci_prefix}.service" "$service_unique $service_details"
    fi
}


## @fn get_olsr_relay_service_name_from_description()
## @brief Ermittle den Dienstnamen, der zu einer olsr-Relay-Service-Definition gehoert.
get_olsr_relay_service_name_from_description() {
    trap "error_trap get_olsr_relay_service_name_from_description '$*'" $GUARD_TRAPS
    local service_description="$1"
    local fields
    local port
    local service_type
    fields=$(echo "$service_description" | parse_olsr_service_descriptions)
    port=$(echo "$fields" | cut -f 3)
    service_type=$(echo "$fields" | cut -f 6)
    get_services "${RELAYABLE_SERVICE_PREFIX}$service_type" | filter_services_by_value "local_relay_port" "$port"
}


# olsr-Nameservice-Beschreibungen entfernen falls der dazugehoerige Dienst nicht mehr relay-tauglich ist
deannounce_unused_olsr_service_relays() {
    # wir erwarten einen ausführbaren Testnamen
    local test_for_activity="$1"
    local service_description
    local service_name
    local uci_prefix
    uci_prefix=$(get_and_enable_olsrd_library_uci_prefix "nameservice")
    uci_get_list "${uci_prefix}.service" | while read service_description; do
        # unbenutzte Eintraege entfernen
        service_name=$(get_olsr_relay_service_name_from_description "$service_description")
        [ -z "$service_name" ] && msg_info "Failed to parse olsr service description: $service_description" && continue
        "$test_for_activity" "$service_name" && continue
        uci_delete_list "${uci_prefix}.service" "$service_description"
    done
    return 0
}


## @fn is_service_relay_possible()
## @brief Pruefe ob ein Relay-Dienst aktiviert (nicht "disabled") ist und ob das WAN-Routing korrekt ist.
is_service_relay_possible() {
    trap "error_trap is_service_relay_possible '$*'" $GUARD_TRAPS
    local service_name="$1"
    local enabled
    local wan_routing
    disabled=$(get_service_value "$service_name" "disabled" "false")
    uci_is_true "$disabled" && trap "" $GUARD_TRAPS && return 1
    wan_routing=$(get_service_value "$service_name" "wan_status" "false")
    uci_is_false "$wan_routing" && trap "" $GUARD_TRAPS && return 1
    return 0
}


## @fn update_service_relay_status()
## @brief Pruefe regelmaessig, ob Weiterleitungen für alle bekannten durchgereichten Diensten existieren.
## @details Fehlende Weiterleitungen oder olsr-Announcements werden angelegt.
update_service_relay_status() {
    trap "error_trap update_service_relay_status '$*'" $GUARD_TRAPS
    local service_name
    local wan_status
    if is_on_module_installed_and_enabled "on-usergw"; then
        get_services | filter_relay_services | while read service_name; do
            # WAN-Routing pruefen und aktualisieren
            is_service_routed_via_wan "$service_name" && wan_status="true" || wan_status="false"
            set_service_value "$service_name" "wan_status" "$wan_status"
            is_service_relay_possible "$service_name" || continue
            announce_olsr_service_relay "$service_name"
        done
        update_mesh_gateway_firewall_rules
        deannounce_unused_olsr_service_relays is_service_relay_possible
    else
        deannounce_unused_olsr_service_relays false
    fi
    apply_changes olsrd
}


## @fn filter_relay_services()
## @brief Filtere aus einer Reihe eingehender Dienste diejenigen heraus, die als Dienst-Relay fungieren.
## @details Die Dienst-Namen werden über die Standardeingabe gelesen und an die Standardausgabe
##   weitergeleitet, falls es sich um einen Relay-Dienst handelt.
filter_relay_services() {
    local service_name
    while read service_name; do
        [ -n "$(get_service_value "$service_name" "local_relay_port")" ] && echo "$service_name"
        true
    done
}

# Ende der Doku-Gruppe
## @}