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| 1 | +/* |
| 2 | +Copyright 2025 Google LLC |
| 3 | +
|
| 4 | +Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | +you may not use this file except in compliance with the License. |
| 6 | +You may obtain a copy of the License at |
| 7 | +
|
| 8 | + https://www.apache.org/licenses/LICENSE-2.0 |
| 9 | +
|
| 10 | +Unless required by applicable law or agreed to in writing, software |
| 11 | +distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | +See the License for the specific language governing permissions and |
| 14 | +limitations under the License. |
| 15 | +*/ |
| 16 | + |
| 17 | +package driver |
| 18 | + |
| 19 | +import ( |
| 20 | + "errors" |
| 21 | + "fmt" |
| 22 | + "os" |
| 23 | + "path/filepath" |
| 24 | + "runtime" |
| 25 | + |
| 26 | + "github.com/cilium/ebpf" |
| 27 | + "github.com/cilium/ebpf/link" |
| 28 | + "github.com/vishvananda/netlink" |
| 29 | + "github.com/vishvananda/netns" |
| 30 | + "k8s.io/klog/v2" |
| 31 | +) |
| 32 | + |
| 33 | +// unpinBPFPrograms runs in the host namespace to delete all the pinned bpf programs |
| 34 | +func unpinBPFPrograms(ifName string) error { |
| 35 | + device, err := netlink.LinkByName(ifName) |
| 36 | + if err != nil && !errors.Is(err, netlink.ErrDumpInterrupted) { |
| 37 | + return err |
| 38 | + } |
| 39 | + ifIndex := uint32(device.Attrs().Index) |
| 40 | + |
| 41 | + klog.V(2).Infof("Attempting to unpin eBPF programs from interface %s", ifName) |
| 42 | + return filepath.Walk("/sys/fs/bpf", func(pinPath string, info os.FileInfo, err error) error { |
| 43 | + if err != nil { |
| 44 | + return err |
| 45 | + } |
| 46 | + |
| 47 | + if info.IsDir() { |
| 48 | + return nil |
| 49 | + } |
| 50 | + |
| 51 | + l, err := link.LoadPinnedLink(pinPath, &ebpf.LoadPinOptions{}) |
| 52 | + if err != nil { |
| 53 | + klog.V(4).Infof("error getting link %s: %v", pinPath, err) |
| 54 | + return nil |
| 55 | + } |
| 56 | + |
| 57 | + linkInfo, err := l.Info() |
| 58 | + if err != nil { |
| 59 | + klog.Infof("error link info: %v", err) |
| 60 | + return nil |
| 61 | + } |
| 62 | + |
| 63 | + var linkIfIndex uint32 |
| 64 | + switch linkInfo.Type { |
| 65 | + case link.TCXType: |
| 66 | + extra := linkInfo.TCX() |
| 67 | + if extra != nil { |
| 68 | + linkIfIndex = extra.Ifindex |
| 69 | + } |
| 70 | + case link.NetkitType: |
| 71 | + extra := linkInfo.Netkit() |
| 72 | + if extra != nil { |
| 73 | + linkIfIndex = extra.Ifindex |
| 74 | + } |
| 75 | + case link.XDPType: |
| 76 | + extra := linkInfo.XDP() |
| 77 | + if extra != nil { |
| 78 | + linkIfIndex = extra.Ifindex |
| 79 | + } |
| 80 | + default: |
| 81 | + return nil |
| 82 | + } |
| 83 | + if linkIfIndex != ifIndex { |
| 84 | + return nil |
| 85 | + } |
| 86 | + err = l.Unpin() |
| 87 | + if err != nil { |
| 88 | + klog.Infof("fail to unpin bpf link %v", err) |
| 89 | + } else { |
| 90 | + klog.V(2).Infof("succesfully unpin bpf from link %d", linkInfo.ID) |
| 91 | + } |
| 92 | + return nil |
| 93 | + }) |
| 94 | + |
| 95 | +} |
| 96 | + |
| 97 | +// detachEBPFPrograms detaches all eBPF programs (TC and TCX) from a given network interface. |
| 98 | +// It attempts to remove both classic TC filters and newer TCX programs. |
| 99 | +// It runs inside the network namespace to avoid programs on the root namespace |
| 100 | +// to cause issues detaching the programs. |
| 101 | +func detachEBPFPrograms(containerNsPAth string, ifName string) error { |
| 102 | + origns, err := netns.Get() |
| 103 | + if err != nil { |
| 104 | + return fmt.Errorf("unexpected error trying to get namespace: %v", err) |
| 105 | + } |
| 106 | + defer origns.Close() |
| 107 | + containerNs, err := netns.GetFromPath(containerNsPAth) |
| 108 | + if err != nil { |
| 109 | + return fmt.Errorf("could not get network namespace from path %s for network device %s : %w", containerNsPAth, ifName, err) |
| 110 | + } |
| 111 | + defer containerNs.Close() |
| 112 | + |
| 113 | + runtime.LockOSThread() |
| 114 | + defer runtime.UnlockOSThread() |
| 115 | + err = netns.Set(containerNs) |
| 116 | + if err != nil { |
| 117 | + return fmt.Errorf("failt to join network namespace %s : %v", containerNsPAth, err) |
| 118 | + } |
| 119 | + // Switch back to the original namespace |
| 120 | + defer netns.Set(origns) // nolint:errcheck |
| 121 | + |
| 122 | + var errs []error |
| 123 | + device, err := netlink.LinkByName(ifName) |
| 124 | + if err != nil && !errors.Is(err, netlink.ErrDumpInterrupted) { |
| 125 | + return err |
| 126 | + } |
| 127 | + |
| 128 | + // Detach TC filters (legacy) |
| 129 | + klog.V(2).Infof("Attempting to detach TC filters from interface %s", device.Attrs().Name) |
| 130 | + for _, parent := range []uint32{netlink.HANDLE_MIN_INGRESS, netlink.HANDLE_MIN_EGRESS} { |
| 131 | + filters, err := netlink.FilterList(device, parent) |
| 132 | + if err != nil { |
| 133 | + klog.V(4).Infof("Could not list TC filters for interface %s (parent %d): %v", device.Attrs().Name, parent, err) |
| 134 | + continue |
| 135 | + } |
| 136 | + for _, f := range filters { |
| 137 | + if bpfFilter, ok := f.(*netlink.BpfFilter); ok { |
| 138 | + klog.V(4).Infof("Deleting TC filter %s from interface %s (parent %d)", bpfFilter.Name, device.Attrs().Name, parent) |
| 139 | + if err := netlink.FilterDel(f); err != nil { |
| 140 | + klog.V(2).Infof("failed to delete TC filter %s on %s: %v", bpfFilter.Name, device.Attrs().Name, err) |
| 141 | + } |
| 142 | + } |
| 143 | + } |
| 144 | + } |
| 145 | + |
| 146 | + // Detach TCX programs |
| 147 | + klog.V(2).Infof("Attempting to detach TCX programs from interface %s", device.Attrs().Name) |
| 148 | + for _, attach := range []ebpf.AttachType{ebpf.AttachTCXIngress, ebpf.AttachTCXEgress} { |
| 149 | + klog.V(2).Infof("Attempting to detach programs from attachment %s interface %s", attach.String(), device.Attrs().Name) |
| 150 | + result, err := link.QueryPrograms(link.QueryOptions{ |
| 151 | + Target: int(device.Attrs().Index), |
| 152 | + Attach: attach, |
| 153 | + }) |
| 154 | + if err != nil { |
| 155 | + errs = append(errs, err) |
| 156 | + continue |
| 157 | + } |
| 158 | + for _, p := range result.Programs { |
| 159 | + klog.V(2).Infof("Attempting to detach program %d from interface %s", p.ID, device.Attrs().Name) |
| 160 | + err = tryDetach(p.ID, device.Attrs().Index, attach) |
| 161 | + if err != nil { |
| 162 | + klog.V(2).Infof("Failed to detach program %d from interface %s", p.ID, device.Attrs().Name) |
| 163 | + errs = append(errs, err) |
| 164 | + } |
| 165 | + } |
| 166 | + } |
| 167 | + |
| 168 | + return errors.Join(errs...) |
| 169 | +} |
| 170 | + |
| 171 | +func tryDetach(id ebpf.ProgramID, deviceIdx int, attach ebpf.AttachType) error { |
| 172 | + prog, err := ebpf.NewProgramFromID(id) |
| 173 | + if err != nil { |
| 174 | + klog.V(2).Infof("failed to get eBPF program with ID %d: %v", id, err) |
| 175 | + return err |
| 176 | + } |
| 177 | + |
| 178 | + if err := prog.Unpin(); err != nil { |
| 179 | + klog.Infof("failed to unpin eBPF program %s: %v", prog.String(), err) |
| 180 | + return err |
| 181 | + } |
| 182 | + |
| 183 | + err = link.RawDetachProgram(link.RawDetachProgramOptions{ |
| 184 | + Target: deviceIdx, |
| 185 | + Program: prog, |
| 186 | + Attach: attach, |
| 187 | + }) |
| 188 | + if err != nil { |
| 189 | + klog.V(2).Infof("failed to detach eBPF program with ID %d: %v", id, err) |
| 190 | + } |
| 191 | + |
| 192 | + err = prog.Close() |
| 193 | + if err != nil { |
| 194 | + klog.Infof("failed to close eBPF program %s: %v", prog.String(), err) |
| 195 | + return err |
| 196 | + } |
| 197 | + return nil |
| 198 | +} |
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