69 lines
1.9 KiB
Go
69 lines
1.9 KiB
Go
// Copyright 2017 CNI authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package ip
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import (
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"fmt"
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"syscall"
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"time"
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"github.com/vishvananda/netlink"
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)
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const SETTLE_INTERVAL = 50 * time.Millisecond
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// SettleAddresses waits for all addresses on a link to leave tentative state.
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// This is particularly useful for ipv6, where all addresses need to do DAD.
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// There is no easy way to wait for this as an event, so just loop until the
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// addresses are no longer tentative.
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// If any addresses are still tentative after timeout seconds, then error.
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func SettleAddresses(ifName string, timeout int) error {
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link, err := netlink.LinkByName(ifName)
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if err != nil {
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return fmt.Errorf("failed to retrieve link: %v", err)
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}
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deadline := time.Now().Add(time.Duration(timeout) * time.Second)
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for {
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addrs, err := netlink.AddrList(link, netlink.FAMILY_ALL)
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if err != nil {
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return fmt.Errorf("could not list addresses: %v", err)
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}
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if len(addrs) == 0 {
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return nil
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}
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ok := true
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for _, addr := range addrs {
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if addr.Flags&(syscall.IFA_F_TENTATIVE|syscall.IFA_F_DADFAILED) > 0 {
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ok = false
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break // Break out of the `range addrs`, not the `for`
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}
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}
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if ok {
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return nil
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}
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if time.Now().After(deadline) {
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return fmt.Errorf("link %s still has tentative addresses after %d seconds",
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ifName,
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timeout)
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}
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time.Sleep(SETTLE_INTERVAL)
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}
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}
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