60 lines
2.1 KiB
Go
60 lines
2.1 KiB
Go
package iptables
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import (
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"errors"
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"net"
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"syscall"
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"github.com/sirupsen/logrus"
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"github.com/vishvananda/netlink"
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)
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var (
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// ErrConntrackNotConfigurable means that conntrack module is not loaded or does not have the netlink module loaded
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ErrConntrackNotConfigurable = errors.New("conntrack is not available")
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)
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// IsConntrackProgrammable returns true if the handle supports the NETLINK_NETFILTER and the base modules are loaded
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func IsConntrackProgrammable(nlh *netlink.Handle) bool {
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return nlh.SupportsNetlinkFamily(syscall.NETLINK_NETFILTER)
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}
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// DeleteConntrackEntries deletes all the conntrack connections on the host for the specified IP
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// Returns the number of flows deleted for IPv4, IPv6 else error
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func DeleteConntrackEntries(nlh *netlink.Handle, ipv4List []net.IP, ipv6List []net.IP) (uint, uint, error) {
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if !IsConntrackProgrammable(nlh) {
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return 0, 0, ErrConntrackNotConfigurable
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}
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var totalIPv4FlowPurged uint
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for _, ipAddress := range ipv4List {
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flowPurged, err := purgeConntrackState(nlh, syscall.AF_INET, ipAddress)
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if err != nil {
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logrus.Warnf("Failed to delete conntrack state for %s: %v", ipAddress, err)
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continue
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}
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totalIPv4FlowPurged += flowPurged
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}
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var totalIPv6FlowPurged uint
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for _, ipAddress := range ipv6List {
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flowPurged, err := purgeConntrackState(nlh, syscall.AF_INET6, ipAddress)
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if err != nil {
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logrus.Warnf("Failed to delete conntrack state for %s: %v", ipAddress, err)
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continue
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}
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totalIPv6FlowPurged += flowPurged
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}
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logrus.Debugf("DeleteConntrackEntries purged ipv4:%d, ipv6:%d", totalIPv4FlowPurged, totalIPv6FlowPurged)
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return totalIPv4FlowPurged, totalIPv6FlowPurged, nil
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}
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func purgeConntrackState(nlh *netlink.Handle, family netlink.InetFamily, ipAddress net.IP) (uint, error) {
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filter := &netlink.ConntrackFilter{}
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// NOTE: doing the flush using the ipAddress is safe because today there cannot be multiple networks with the same subnet
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// so it will not be possible to flush flows that are of other containers
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filter.AddIP(netlink.ConntrackNatAnyIP, ipAddress)
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return nlh.ConntrackDeleteFilter(netlink.ConntrackTable, family, filter)
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}
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