/
run_linux.go
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/
run_linux.go
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// Copyright Istio Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package capture
import (
"fmt"
"net"
"strconv"
"github.com/vishvananda/netlink"
"golang.org/x/sys/unix"
"istio.io/istio/tools/istio-iptables/pkg/config"
"istio.io/istio/tools/istio-iptables/pkg/constants"
)
// configureTProxyRoutes configures ip firewall rules to enable TPROXY support.
// See https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/original_src_filter
func configureTProxyRoutes(cfg *config.Config) error {
if cfg.InboundPortsInclude != "" {
if cfg.InboundInterceptionMode == constants.TPROXY {
link, err := netlink.LinkByName("lo")
if err != nil {
return fmt.Errorf("failed to find 'lo' link: %v", err)
}
tproxyTable, err := strconv.Atoi(cfg.InboundTProxyRouteTable)
if err != nil {
return fmt.Errorf("failed to parse InboundTProxyRouteTable: %v", err)
}
tproxyMark, err := strconv.Atoi(cfg.InboundTProxyMark)
if err != nil {
return fmt.Errorf("failed to parse InboundTProxyMark: %v", err)
}
// Route all packets marked in chain ISTIODIVERT using routing table ${INBOUND_TPROXY_ROUTE_TABLE}.
// Equivalent to `ip rule add fwmark <tproxyMark> lookup <tproxyTable>`
families := []int{unix.AF_INET}
if cfg.EnableInboundIPv6 {
families = append(families, unix.AF_INET6)
}
for _, family := range families {
r := netlink.NewRule()
r.Family = family
r.Table = tproxyTable
r.Mark = tproxyMark
if err := netlink.RuleAdd(r); err != nil {
return fmt.Errorf("failed to configure netlink rule: %v", err)
}
}
// In routing table ${INBOUND_TPROXY_ROUTE_TABLE}, create a single default rule to route all traffic to
// the loopback interface.
// Equivalent to `ip route add local default dev lo table <table>`
cidrs := []string{"0.0.0.0/0"}
if cfg.EnableInboundIPv6 {
cidrs = append(cidrs, "0::0/0")
}
for _, fullCIDR := range cidrs {
_, dst, err := net.ParseCIDR(fullCIDR)
if err != nil {
return fmt.Errorf("parse CIDR: %v", err)
}
if err := netlink.RouteAdd(&netlink.Route{
Dst: dst,
Scope: netlink.SCOPE_HOST,
Type: unix.RTN_LOCAL,
Table: tproxyTable,
LinkIndex: link.Attrs().Index,
}); ignoreExists(err) != nil {
return fmt.Errorf("failed to add route: %v", err)
}
}
}
}
return nil
}