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- package iptables
- import (
- "errors"
- "net"
- "syscall"
- "github.com/Sirupsen/logrus"
- "github.com/vishvananda/netlink"
- )
- var (
- // ErrConntrackNotConfigurable means that conntrack module is not loaded or does not have the netlink module loaded
- ErrConntrackNotConfigurable = errors.New("conntrack is not available")
- )
- // IsConntrackProgrammable returns true if the handle supports the NETLINK_NETFILTER and the base modules are loaded
- func IsConntrackProgrammable(nlh *netlink.Handle) bool {
- return nlh.SupportsNetlinkFamily(syscall.NETLINK_NETFILTER)
- }
- // 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 *netlink.Handle, ipv4List []net.IP, ipv6List []net.IP) (uint, uint, error) {
- if !IsConntrackProgrammable(nlh) {
- return 0, 0, ErrConntrackNotConfigurable
- }
- var totalIPv4FlowPurged uint
- for _, ipAddress := range ipv4List {
- flowPurged, err := purgeConntrackState(nlh, syscall.AF_INET, ipAddress)
- if err != nil {
- logrus.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 {
- logrus.Warnf("Failed to delete conntrack state for %s: %v", ipAddress, err)
- continue
- }
- totalIPv6FlowPurged += flowPurged
- }
- logrus.Debugf("DeleteConntrackEntries purged ipv4:%d, ipv6:%d", totalIPv4FlowPurged, totalIPv6FlowPurged)
- return totalIPv4FlowPurged, totalIPv6FlowPurged, nil
- }
- func purgeConntrackState(nlh *netlink.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
- filter.AddIP(netlink.ConntrackNatAnyIP, ipAddress)
- return nlh.ConntrackDeleteFilter(netlink.ConntrackTable, family, filter)
- }
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