cubefs

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// Copyright 2020 The Prometheus Authors
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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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//go:build !windows
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// +build !windows
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package procfs
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import (
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	"os"
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	"github.com/prometheus/procfs/internal/util"
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)
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// KernelRandom contains information about to the kernel's random number generator.
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type KernelRandom struct {
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	// EntropyAvaliable gives the available entropy, in bits.
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	EntropyAvaliable *uint64
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	// PoolSize gives the size of the entropy pool, in bits.
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	PoolSize *uint64
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	// URandomMinReseedSeconds is the number of seconds after which the DRNG will be reseeded.
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	URandomMinReseedSeconds *uint64
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	// WriteWakeupThreshold the number of bits of entropy below which we wake up processes
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	// that do a select(2) or poll(2) for write access to /dev/random.
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	WriteWakeupThreshold *uint64
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	// ReadWakeupThreshold is the number of bits of entropy required for waking up processes that sleep
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	// waiting for entropy from /dev/random.
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	ReadWakeupThreshold *uint64
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}
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// KernelRandom returns values from /proc/sys/kernel/random.
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func (fs FS) KernelRandom() (KernelRandom, error) {
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	random := KernelRandom{}
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	for file, p := range map[string]**uint64{
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		"entropy_avail":           &random.EntropyAvaliable,
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		"poolsize":                &random.PoolSize,
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		"urandom_min_reseed_secs": &random.URandomMinReseedSeconds,
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		"write_wakeup_threshold":  &random.WriteWakeupThreshold,
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		"read_wakeup_threshold":   &random.ReadWakeupThreshold,
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	} {
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		val, err := util.ReadUintFromFile(fs.proc.Path("sys", "kernel", "random", file))
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		if os.IsNotExist(err) {
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			continue
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		}
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		if err != nil {
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			return random, err
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		}
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		*p = &val
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	}
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	return random, nil
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}
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