github.com/looshlee/cilium@v1.6.12/pkg/probe/probe.go (about) 1 // Copyright 2019 Authors of Cilium 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package probe 16 17 import ( 18 "fmt" 19 "unsafe" 20 21 "github.com/cilium/cilium/pkg/bpf" 22 ) 23 24 type probeKey struct { 25 Prefixlen uint32 26 Key uint32 27 } 28 29 type probeValue struct { 30 Value uint32 31 } 32 33 func (p *probeKey) String() string { return fmt.Sprintf("key=%d", p.Key) } 34 func (p *probeKey) GetKeyPtr() unsafe.Pointer { return unsafe.Pointer(p) } 35 func (p *probeKey) NewValue() bpf.MapValue { return &probeValue{} } 36 func (p *probeKey) DeepCopyMapKey() bpf.MapKey { return &probeKey{p.Prefixlen, p.Key} } 37 38 func (p *probeValue) String() string { return fmt.Sprintf("value=%d", p.Value) } 39 func (p *probeValue) GetValuePtr() unsafe.Pointer { return unsafe.Pointer(p) } 40 func (p *probeValue) DeepCopyMapValue() bpf.MapValue { return &probeValue{p.Value} } 41 42 // HaveFullLPM tests whether kernel supports fully functioning BPF LPM map 43 // with proper bpf.GetNextKey() traversal. Needs 4.16 or higher. 44 func HaveFullLPM() bool { 45 m := bpf.NewMap("cilium_test", bpf.MapTypeLPMTrie, 46 &probeKey{}, int(unsafe.Sizeof(probeKey{})), 47 &probeValue{}, int(unsafe.Sizeof(probeValue{})), 48 1, bpf.BPF_F_NO_PREALLOC, 0, bpf.ConvertKeyValue).WithCache() 49 _, err := m.OpenOrCreateUnpinned() 50 defer m.Close() 51 if err != nil { 52 return false 53 } 54 err = bpf.UpdateElement(m.GetFd(), unsafe.Pointer(&probeKey{}), 55 unsafe.Pointer(&probeValue{}), bpf.BPF_ANY) 56 if err != nil { 57 return false 58 } 59 err = bpf.GetNextKey(m.GetFd(), nil, unsafe.Pointer(&probeKey{})) 60 if err != nil { 61 return false 62 } 63 return true 64 }