diff --git a/fixtures.ttar b/fixtures.ttar index 97f1f9268..868c8573d 100644 --- a/fixtures.ttar +++ b/fixtures.ttar @@ -2346,6 +2346,32 @@ Mode: 644 Directory: fixtures/proc/sys Mode: 775 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +Directory: fixtures/proc/sys/kernel +Mode: 775 +# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +Directory: fixtures/proc/sys/kernel/random +Mode: 755 +# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +Path: fixtures/proc/sys/kernel/random/entropy_avail +Lines: 1 +3943 +Mode: 644 +# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +Path: fixtures/proc/sys/kernel/random/poolsize +Lines: 1 +4096 +Mode: 644 +# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +Path: fixtures/proc/sys/kernel/random/urandom_min_reseed_secs +Lines: 1 +60 +Mode: 644 +# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +Path: fixtures/proc/sys/kernel/random/write_wakeup_threshold +Lines: 1 +3072 +Mode: 644 +# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Directory: fixtures/proc/sys/vm Mode: 775 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - diff --git a/kernel_random.go b/kernel_random.go new file mode 100644 index 000000000..beefdf02e --- /dev/null +++ b/kernel_random.go @@ -0,0 +1,62 @@ +// Copyright 2020 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build !windows + +package procfs + +import ( + "os" + + "github.com/prometheus/procfs/internal/util" +) + +// KernelRandom contains information about to the kernel's random number generator. +type KernelRandom struct { + // EntropyAvaliable gives the available entropy, in bits. + EntropyAvaliable *uint64 + // PoolSize gives the size of the entropy pool, in bytes. + PoolSize *uint64 + // URandomMinReseedSeconds is the number of seconds after which the DRNG will be reseeded. + URandomMinReseedSeconds *uint64 + // WriteWakeupThreshold the number of bits of entropy below which we wake up processes + // that do a select(2) or poll(2) for write access to /dev/random. + WriteWakeupThreshold *uint64 + // ReadWakeupThreshold is the number of bits of entropy required for waking up processes that sleep + // waiting for entropy from /dev/random. + ReadWakeupThreshold *uint64 +} + +// KernelRandom returns values from /proc/sys/kernel/random. +func (fs FS) KernelRandom() (KernelRandom, error) { + random := KernelRandom{} + + for file, p := range map[string]**uint64{ + "entropy_avail": &random.EntropyAvaliable, + "poolsize": &random.PoolSize, + "urandom_min_reseed_secs": &random.URandomMinReseedSeconds, + "write_wakeup_threshold": &random.WriteWakeupThreshold, + "read_wakeup_threshold": &random.ReadWakeupThreshold, + } { + val, err := util.ReadUintFromFile(fs.proc.Path("sys", "kernel", "random", file)) + if os.IsNotExist(err) { + continue + } + if err != nil { + return random, err + } + *p = &val + } + + return random, nil +} diff --git a/kernel_random_test.go b/kernel_random_test.go new file mode 100644 index 000000000..da9b93cc6 --- /dev/null +++ b/kernel_random_test.go @@ -0,0 +1,50 @@ +// Copyright 2020 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build !windows + +package procfs + +import ( + "testing" +) + +const procfsFixtures = "fixtures/proc" + +func TestKernelRandom(t *testing.T) { + fs, err := NewFS(procfsFixtures) + if err != nil { + t.Fatalf("failed to access %s: %v", procfsFixtures, err) + } + + random, err := fs.KernelRandom() + if err != nil { + t.Fatalf("failed to collect %s/sys/kernel/random: %v", procfsFixtures, err) + } + + if *random.EntropyAvaliable != 3943 { + t.Errorf("entropy_avail, want %d got %d", 3943, *random.EntropyAvaliable) + } + if *random.PoolSize != 4096 { + t.Errorf("poolsize, want %d got %d", 4096, *random.PoolSize) + } + if *random.URandomMinReseedSeconds != 60 { + t.Errorf("urandom_min_reseed_secs, want %d got %d", 60, *random.URandomMinReseedSeconds) + } + if *random.WriteWakeupThreshold != 3072 { + t.Errorf("write_wakeup_threshold, want %d got %d", 3072, *random.WriteWakeupThreshold) + } + if random.ReadWakeupThreshold != nil { + t.Errorf("read_wakeup_threshold, want %v got %d", nil, *random.ReadWakeupThreshold) + } +}