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//go:build linux
package iptables
import (
"context"
"errors"
"net"
"syscall"
"github.com/containerd/log"
"github.com/docker/docker/internal/nlwrap"
"github.com/docker/docker/libnetwork/types"
"github.com/vishvananda/netlink"
)
// checkConntrackProgrammable checks if the handle supports the
// NETLINK_NETFILTER and the base modules are loaded.
func checkConntrackProgrammable(nlh nlwrap.Handle) error {
if !nlh.SupportsNetlinkFamily(syscall.NETLINK_NETFILTER) {
return errors.New("conntrack is not available")
}
return nil
}
// DeleteConntrackEntries deletes all the conntrack connections on the host for the specified IP
// Returns the number of flows deleted for IPv4, IPv6 else error
func DeleteConntrackEntries(nlh nlwrap.Handle, ipv4List []net.IP, ipv6List []net.IP) error {
if err := checkConntrackProgrammable(nlh); err != nil {
return err
}
var totalIPv4FlowPurged uint
for _, ipAddress := range ipv4List {
flowPurged, err := purgeConntrackState(nlh, syscall.AF_INET, ipAddress)
if err != nil {
log.G(context.TODO()).Warnf("Failed to delete conntrack state for %s: %v", ipAddress, err)
continue
}
totalIPv4FlowPurged += flowPurged
}
var totalIPv6FlowPurged uint
for _, ipAddress := range ipv6List {
flowPurged, err := purgeConntrackState(nlh, syscall.AF_INET6, ipAddress)
if err != nil {
log.G(context.TODO()).Warnf("Failed to delete conntrack state for %s: %v", ipAddress, err)
continue
}
totalIPv6FlowPurged += flowPurged
}
if totalIPv4FlowPurged > 0 || totalIPv6FlowPurged > 0 {
log.G(context.TODO()).Debugf("DeleteConntrackEntries purged ipv4:%d, ipv6:%d", totalIPv4FlowPurged, totalIPv6FlowPurged)
}
return nil
}
func DeleteConntrackEntriesByPort(nlh nlwrap.Handle, proto types.Protocol, ports []uint16) error {
if err := checkConntrackProgrammable(nlh); err != nil {
return err
}
var totalIPv4FlowPurged uint
var totalIPv6FlowPurged uint
for _, port := range ports {
filter := &netlink.ConntrackFilter{}
if err := filter.AddProtocol(uint8(proto)); err != nil {
log.G(context.TODO()).Warnf("Failed to delete conntrack state for %s port %d: %v", proto.String(), port, err)
continue
}
if err := filter.AddPort(netlink.ConntrackOrigDstPort, port); err != nil {
log.G(context.TODO()).Warnf("Failed to delete conntrack state for %s port %d: %v", proto.String(), port, err)
continue
}
v4FlowPurged, err := nlh.ConntrackDeleteFilters(netlink.ConntrackTable, syscall.AF_INET, filter)
if err != nil {
log.G(context.TODO()).Warnf("Failed to delete conntrack state for IPv4 %s port %d: %v", proto.String(), port, err)
}
totalIPv4FlowPurged += v4FlowPurged
v6FlowPurged, err := nlh.ConntrackDeleteFilters(netlink.ConntrackTable, syscall.AF_INET6, filter)
if err != nil {
log.G(context.TODO()).Warnf("Failed to delete conntrack state for IPv6 %s port %d: %v", proto.String(), port, err)
}
totalIPv6FlowPurged += v6FlowPurged
}
if totalIPv4FlowPurged > 0 || totalIPv6FlowPurged > 0 {
log.G(context.TODO()).Debugf("DeleteConntrackEntriesByPort for %s ports purged ipv4:%d, ipv6:%d", proto.String(), totalIPv4FlowPurged, totalIPv6FlowPurged)
}
return nil
}
func purgeConntrackState(nlh nlwrap.Handle, family netlink.InetFamily, ipAddress net.IP) (uint, error) {
filter := &netlink.ConntrackFilter{}
// NOTE: doing the flush using the ipAddress is safe because today there cannot be multiple networks with the same subnet
// so it will not be possible to flush flows that are of other containers
if err := filter.AddIP(netlink.ConntrackNatAnyIP, ipAddress); err != nil {
return 0, err
}
return nlh.ConntrackDeleteFilters(netlink.ConntrackTable, family, filter)
}
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