github.com/noironetworks/cilium-net@v1.6.12/pkg/endpoint/id/allocator.go (about) 1 // Copyright 2018 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 id 16 17 import ( 18 "fmt" 19 20 "github.com/cilium/cilium/pkg/idpool" 21 "github.com/cilium/cilium/pkg/logging" 22 "github.com/cilium/cilium/pkg/logging/logfields" 23 ) 24 25 const ( 26 minID = idpool.ID(1) 27 maxID = idpool.ID(4095) 28 ) 29 30 var ( 31 pool = idpool.NewIDPool(minID, maxID) 32 log = logging.DefaultLogger.WithField(logfields.LogSubsys, "endpoint") 33 ) 34 35 // ReallocatePool starts over with a new pool. 36 func ReallocatePool() { 37 pool = idpool.NewIDPool(minID, maxID) 38 } 39 40 // Allocate returns a new random ID from the pool 41 func Allocate() uint16 { 42 id := pool.AllocateID() 43 44 // Out of endpoint IDs 45 if id == idpool.NoID { 46 return uint16(0) 47 } 48 49 return uint16(id) 50 } 51 52 // Reuse grabs a specific endpoint ID for reuse. This can be used when 53 // restoring endpoints. 54 func Reuse(id uint16) error { 55 if idpool.ID(id) < minID { 56 return fmt.Errorf("unable to reuse endpoint: %d < %d", id, minID) 57 } 58 59 // When restoring endpoints, the existing endpoint ID can be outside of 60 // the range. This is fine (tm) and we can just skip to reserve the ID 61 // from the pool as the pool will not cover it. 62 if idpool.ID(id) > maxID { 63 return nil 64 } 65 66 if !pool.Remove(idpool.ID(id)) { 67 return fmt.Errorf("endpoint ID %d is already in use", id) 68 } 69 70 return nil 71 } 72 73 // Release releases an endpoint ID that was previously allocated or reused 74 func Release(id uint16) error { 75 if !pool.Insert(idpool.ID(id)) { 76 return fmt.Errorf("Unable to release endpoint ID %d", id) 77 } 78 79 return nil 80 }