1// Copyright 2020 The Prometheus Authors 2// Licensed under the Apache License, Version 2.0 (the "License"); 3// you may not use this file except in compliance with the License. 4// You may obtain a copy of the License at 5// 6// http://www.apache.org/licenses/LICENSE-2.0 7// 8// Unless required by applicable law or agreed to in writing, software 9// distributed under the License is distributed on an "AS IS" BASIS, 10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 11// See the License for the specific language governing permissions and 12// limitations under the License. 13 14// +build !windows 15 16package procfs 17 18import ( 19 "os" 20 21 "github.com/prometheus/procfs/internal/util" 22) 23 24// KernelRandom contains information about to the kernel's random number generator. 25type KernelRandom struct { 26 // EntropyAvaliable gives the available entropy, in bits. 27 EntropyAvaliable *uint64 28 // PoolSize gives the size of the entropy pool, in bits. 29 PoolSize *uint64 30 // URandomMinReseedSeconds is the number of seconds after which the DRNG will be reseeded. 31 URandomMinReseedSeconds *uint64 32 // WriteWakeupThreshold the number of bits of entropy below which we wake up processes 33 // that do a select(2) or poll(2) for write access to /dev/random. 34 WriteWakeupThreshold *uint64 35 // ReadWakeupThreshold is the number of bits of entropy required for waking up processes that sleep 36 // waiting for entropy from /dev/random. 37 ReadWakeupThreshold *uint64 38} 39 40// KernelRandom returns values from /proc/sys/kernel/random. 41func (fs FS) KernelRandom() (KernelRandom, error) { 42 random := KernelRandom{} 43 44 for file, p := range map[string]**uint64{ 45 "entropy_avail": &random.EntropyAvaliable, 46 "poolsize": &random.PoolSize, 47 "urandom_min_reseed_secs": &random.URandomMinReseedSeconds, 48 "write_wakeup_threshold": &random.WriteWakeupThreshold, 49 "read_wakeup_threshold": &random.ReadWakeupThreshold, 50 } { 51 val, err := util.ReadUintFromFile(fs.proc.Path("sys", "kernel", "random", file)) 52 if os.IsNotExist(err) { 53 continue 54 } 55 if err != nil { 56 return random, err 57 } 58 *p = &val 59 } 60 61 return random, nil 62} 63