Update to kube v1.17

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/github.com/prometheus/procfs/cpuinfo.go

@@ -16,9 +16,10 @@ package procfs
 import (
 	"bufio"
 	"bytes"
-	"io/ioutil"
 	"strconv"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // CPUInfo contains general information about a system CPU found in /proc/cpuinfo
@@ -54,7 +55,7 @@ type CPUInfo struct {
 // CPUInfo returns information about current system CPUs.
 // See https://www.kernel.org/doc/Documentation/filesystems/proc.txt
 func (fs FS) CPUInfo() ([]CPUInfo, error) {
-	data, err := ioutil.ReadFile(fs.proc.Path("cpuinfo"))
+	data, err := util.ReadFileNoStat(fs.proc.Path("cpuinfo"))
 	if err != nil {
 		return nil, err
 	}

vendor/github.com/prometheus/procfs/internal/fs/fs.go

@@ -26,7 +26,7 @@ const (
 	// DefaultSysMountPoint is the common mount point of the sys filesystem.
 	DefaultSysMountPoint = "/sys"
 
-	// DefaultConfigfsMountPoint is the commont mount point of the configfs
+	// DefaultConfigfsMountPoint is the common mount point of the configfs
 	DefaultConfigfsMountPoint = "/sys/kernel/config"
 )
 

vendor/github.com/prometheus/procfs/internal/util/readfile.go

@@ -0,0 +1,38 @@
+// Copyright 2019 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.
+
+package util
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+)
+
+// ReadFileNoStat uses ioutil.ReadAll to read contents of entire file.
+// This is similar to ioutil.ReadFile but without the call to os.Stat, because
+// many files in /proc and /sys report incorrect file sizes (either 0 or 4096).
+// Reads a max file size of 512kB.  For files larger than this, a scanner
+// should be used.
+func ReadFileNoStat(filename string) ([]byte, error) {
+	const maxBufferSize = 1024 * 512
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	reader := io.LimitReader(f, maxBufferSize)
+	return ioutil.ReadAll(reader)
+}

vendor/github.com/prometheus/procfs/internal/util/sysreadfile.go

@@ -23,6 +23,8 @@ import (
 
 // SysReadFile is a simplified ioutil.ReadFile that invokes syscall.Read directly.
 // https://github.com/prometheus/node_exporter/pull/728/files
+//
+// Note that this function will not read files larger than 128 bytes.
 func SysReadFile(file string) (string, error) {
 	f, err := os.Open(file)
 	if err != nil {
@@ -35,7 +37,8 @@ func SysReadFile(file string) (string, error) {
 	//
 	// Since we either want to read data or bail immediately, do the simplest
 	// possible read using syscall directly.
-	b := make([]byte, 128)
+	const sysFileBufferSize = 128
+	b := make([]byte, sysFileBufferSize)
 	n, err := syscall.Read(int(f.Fd()), b)
 	if err != nil {
 		return "", err

vendor/github.com/prometheus/procfs/internal/util/valueparser.go

@@ -33,6 +33,9 @@ func NewValueParser(v string) *ValueParser {
 	return &ValueParser{v: v}
 }
 
+// Int interprets the underlying value as an int and returns that value.
+func (vp *ValueParser) Int() int { return int(vp.int64()) }
+
 // PInt64 interprets the underlying value as an int64 and returns a pointer to
 // that value.
 func (vp *ValueParser) PInt64() *int64 {
@@ -40,16 +43,27 @@ func (vp *ValueParser) PInt64() *int64 {
 		return nil
 	}
 
+	v := vp.int64()
+	return &v
+}
+
+// int64 interprets the underlying value as an int64 and returns that value.
+// TODO: export if/when necessary.
+func (vp *ValueParser) int64() int64 {
+	if vp.err != nil {
+		return 0
+	}
+
 	// A base value of zero makes ParseInt infer the correct base using the
 	// string's prefix, if any.
 	const base = 0
 	v, err := strconv.ParseInt(vp.v, base, 64)
 	if err != nil {
 		vp.err = err
-		return nil
+		return 0
 	}
 
-	return &v
+	return v
 }
 
 // PUInt64 interprets the underlying value as an uint64 and returns a pointer to

vendor/github.com/prometheus/procfs/ipvs.go

@@ -15,6 +15,7 @@ package procfs
 
 import (
 	"bufio"
+	"bytes"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -24,6 +25,8 @@ import (
 	"os"
 	"strconv"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // IPVSStats holds IPVS statistics, as exposed by the kernel in `/proc/net/ip_vs_stats`.
@@ -64,17 +67,16 @@ type IPVSBackendStatus struct {
 
 // IPVSStats reads the IPVS statistics from the specified `proc` filesystem.
 func (fs FS) IPVSStats() (IPVSStats, error) {
-	file, err := os.Open(fs.proc.Path("net/ip_vs_stats"))
+	data, err := util.ReadFileNoStat(fs.proc.Path("net/ip_vs_stats"))
 	if err != nil {
 		return IPVSStats{}, err
 	}
-	defer file.Close()
 
-	return parseIPVSStats(file)
+	return parseIPVSStats(bytes.NewReader(data))
 }
 
 // parseIPVSStats performs the actual parsing of `ip_vs_stats`.
-func parseIPVSStats(file io.Reader) (IPVSStats, error) {
+func parseIPVSStats(r io.Reader) (IPVSStats, error) {
 	var (
 		statContent []byte
 		statLines   []string
@@ -82,7 +84,7 @@ func parseIPVSStats(file io.Reader) (IPVSStats, error) {
 		stats       IPVSStats
 	)
 
-	statContent, err := ioutil.ReadAll(file)
+	statContent, err := ioutil.ReadAll(r)
 	if err != nil {
 		return IPVSStats{}, err
 	}

vendor/github.com/prometheus/procfs/meminfo.go

@@ -0,0 +1,277 @@
+// Copyright 2019 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.
+
+package procfs
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// Meminfo represents memory statistics.
+type Meminfo struct {
+	// Total usable ram (i.e. physical ram minus a few reserved
+	// bits and the kernel binary code)
+	MemTotal uint64
+	// The sum of LowFree+HighFree
+	MemFree uint64
+	// An estimate of how much memory is available for starting
+	// new applications, without swapping. Calculated from
+	// MemFree, SReclaimable, the size of the file LRU lists, and
+	// the low watermarks in each zone.  The estimate takes into
+	// account that the system needs some page cache to function
+	// well, and that not all reclaimable slab will be
+	// reclaimable, due to items being in use. The impact of those
+	// factors will vary from system to system.
+	MemAvailable uint64
+	// Relatively temporary storage for raw disk blocks shouldn't
+	// get tremendously large (20MB or so)
+	Buffers uint64
+	Cached  uint64
+	// Memory that once was swapped out, is swapped back in but
+	// still also is in the swapfile (if memory is needed it
+	// doesn't need to be swapped out AGAIN because it is already
+	// in the swapfile. This saves I/O)
+	SwapCached uint64
+	// Memory that has been used more recently and usually not
+	// reclaimed unless absolutely necessary.
+	Active uint64
+	// Memory which has been less recently used.  It is more
+	// eligible to be reclaimed for other purposes
+	Inactive     uint64
+	ActiveAnon   uint64
+	InactiveAnon uint64
+	ActiveFile   uint64
+	InactiveFile uint64
+	Unevictable  uint64
+	Mlocked      uint64
+	// total amount of swap space available
+	SwapTotal uint64
+	// Memory which has been evicted from RAM, and is temporarily
+	// on the disk
+	SwapFree uint64
+	// Memory which is waiting to get written back to the disk
+	Dirty uint64
+	// Memory which is actively being written back to the disk
+	Writeback uint64
+	// Non-file backed pages mapped into userspace page tables
+	AnonPages uint64
+	// files which have been mapped, such as libraries
+	Mapped uint64
+	Shmem  uint64
+	// in-kernel data structures cache
+	Slab uint64
+	// Part of Slab, that might be reclaimed, such as caches
+	SReclaimable uint64
+	// Part of Slab, that cannot be reclaimed on memory pressure
+	SUnreclaim  uint64
+	KernelStack uint64
+	// amount of memory dedicated to the lowest level of page
+	// tables.
+	PageTables uint64
+	// NFS pages sent to the server, but not yet committed to
+	// stable storage
+	NFSUnstable uint64
+	// Memory used for block device "bounce buffers"
+	Bounce uint64
+	// Memory used by FUSE for temporary writeback buffers
+	WritebackTmp uint64
+	// Based on the overcommit ratio ('vm.overcommit_ratio'),
+	// this is the total amount of  memory currently available to
+	// be allocated on the system. This limit is only adhered to
+	// if strict overcommit accounting is enabled (mode 2 in
+	// 'vm.overcommit_memory').
+	// The CommitLimit is calculated with the following formula:
+	// CommitLimit = ([total RAM pages] - [total huge TLB pages]) *
+	//                overcommit_ratio / 100 + [total swap pages]
+	// For example, on a system with 1G of physical RAM and 7G
+	// of swap with a `vm.overcommit_ratio` of 30 it would
+	// yield a CommitLimit of 7.3G.
+	// For more details, see the memory overcommit documentation
+	// in vm/overcommit-accounting.
+	CommitLimit uint64
+	// The amount of memory presently allocated on the system.
+	// The committed memory is a sum of all of the memory which
+	// has been allocated by processes, even if it has not been
+	// "used" by them as of yet. A process which malloc()'s 1G
+	// of memory, but only touches 300M of it will show up as
+	// using 1G. This 1G is memory which has been "committed" to
+	// by the VM and can be used at any time by the allocating
+	// application. With strict overcommit enabled on the system
+	// (mode 2 in 'vm.overcommit_memory'),allocations which would
+	// exceed the CommitLimit (detailed above) will not be permitted.
+	// This is useful if one needs to guarantee that processes will
+	// not fail due to lack of memory once that memory has been
+	// successfully allocated.
+	CommittedAS uint64
+	// total size of vmalloc memory area
+	VmallocTotal uint64
+	// amount of vmalloc area which is used
+	VmallocUsed uint64
+	// largest contiguous block of vmalloc area which is free
+	VmallocChunk      uint64
+	HardwareCorrupted uint64
+	AnonHugePages     uint64
+	ShmemHugePages    uint64
+	ShmemPmdMapped    uint64
+	CmaTotal          uint64
+	CmaFree           uint64
+	HugePagesTotal    uint64
+	HugePagesFree     uint64
+	HugePagesRsvd     uint64
+	HugePagesSurp     uint64
+	Hugepagesize      uint64
+	DirectMap4k       uint64
+	DirectMap2M       uint64
+	DirectMap1G       uint64
+}
+
+// Meminfo returns an information about current kernel/system memory statistics.
+// See https://www.kernel.org/doc/Documentation/filesystems/proc.txt
+func (fs FS) Meminfo() (Meminfo, error) {
+	b, err := util.ReadFileNoStat(fs.proc.Path("meminfo"))
+	if err != nil {
+		return Meminfo{}, err
+	}
+
+	m, err := parseMemInfo(bytes.NewReader(b))
+	if err != nil {
+		return Meminfo{}, fmt.Errorf("failed to parse meminfo: %v", err)
+	}
+
+	return *m, nil
+}
+
+func parseMemInfo(r io.Reader) (*Meminfo, error) {
+	var m Meminfo
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		// Each line has at least a name and value; we ignore the unit.
+		fields := strings.Fields(s.Text())
+		if len(fields) < 2 {
+			return nil, fmt.Errorf("malformed meminfo line: %q", s.Text())
+		}
+
+		v, err := strconv.ParseUint(fields[1], 0, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		switch fields[0] {
+		case "MemTotal:":
+			m.MemTotal = v
+		case "MemFree:":
+			m.MemFree = v
+		case "MemAvailable:":
+			m.MemAvailable = v
+		case "Buffers:":
+			m.Buffers = v
+		case "Cached:":
+			m.Cached = v
+		case "SwapCached:":
+			m.SwapCached = v
+		case "Active:":
+			m.Active = v
+		case "Inactive:":
+			m.Inactive = v
+		case "Active(anon):":
+			m.ActiveAnon = v
+		case "Inactive(anon):":
+			m.InactiveAnon = v
+		case "Active(file):":
+			m.ActiveFile = v
+		case "Inactive(file):":
+			m.InactiveFile = v
+		case "Unevictable:":
+			m.Unevictable = v
+		case "Mlocked:":
+			m.Mlocked = v
+		case "SwapTotal:":
+			m.SwapTotal = v
+		case "SwapFree:":
+			m.SwapFree = v
+		case "Dirty:":
+			m.Dirty = v
+		case "Writeback:":
+			m.Writeback = v
+		case "AnonPages:":
+			m.AnonPages = v
+		case "Mapped:":
+			m.Mapped = v
+		case "Shmem:":
+			m.Shmem = v
+		case "Slab:":
+			m.Slab = v
+		case "SReclaimable:":
+			m.SReclaimable = v
+		case "SUnreclaim:":
+			m.SUnreclaim = v
+		case "KernelStack:":
+			m.KernelStack = v
+		case "PageTables:":
+			m.PageTables = v
+		case "NFS_Unstable:":
+			m.NFSUnstable = v
+		case "Bounce:":
+			m.Bounce = v
+		case "WritebackTmp:":
+			m.WritebackTmp = v
+		case "CommitLimit:":
+			m.CommitLimit = v
+		case "Committed_AS:":
+			m.CommittedAS = v
+		case "VmallocTotal:":
+			m.VmallocTotal = v
+		case "VmallocUsed:":
+			m.VmallocUsed = v
+		case "VmallocChunk:":
+			m.VmallocChunk = v
+		case "HardwareCorrupted:":
+			m.HardwareCorrupted = v
+		case "AnonHugePages:":
+			m.AnonHugePages = v
+		case "ShmemHugePages:":
+			m.ShmemHugePages = v
+		case "ShmemPmdMapped:":
+			m.ShmemPmdMapped = v
+		case "CmaTotal:":
+			m.CmaTotal = v
+		case "CmaFree:":
+			m.CmaFree = v
+		case "HugePages_Total:":
+			m.HugePagesTotal = v
+		case "HugePages_Free:":
+			m.HugePagesFree = v
+		case "HugePages_Rsvd:":
+			m.HugePagesRsvd = v
+		case "HugePages_Surp:":
+			m.HugePagesSurp = v
+		case "Hugepagesize:":
+			m.Hugepagesize = v
+		case "DirectMap4k:":
+			m.DirectMap4k = v
+		case "DirectMap2M:":
+			m.DirectMap2M = v
+		case "DirectMap1G:":
+			m.DirectMap1G = v
+		}
+	}
+
+	return &m, nil
+}

vendor/github.com/prometheus/procfs/mountinfo.go

@@ -15,19 +15,13 @@ package procfs
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
-	"io"
-	"os"
 	"strconv"
 	"strings"
-)
 
-var validOptionalFields = map[string]bool{
-	"shared":         true,
-	"master":         true,
-	"propagate_from": true,
-	"unbindable":     true,
-}
+	"github.com/prometheus/procfs/internal/util"
+)
 
 // A MountInfo is a type that describes the details, options
 // for each mount, parsed from /proc/self/mountinfo.
@@ -58,18 +52,10 @@ type MountInfo struct {
 	SuperOptions map[string]string
 }
 
-// Returns part of the mountinfo line, if it exists, else an empty string.
-func getStringSliceElement(parts []string, idx int, defaultValue string) string {
-	if idx >= len(parts) {
-		return defaultValue
-	}
-	return parts[idx]
-}
-
 // Reads each line of the mountinfo file, and returns a list of formatted MountInfo structs.
-func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
+func parseMountInfo(info []byte) ([]*MountInfo, error) {
 	mounts := []*MountInfo{}
-	scanner := bufio.NewScanner(r)
+	scanner := bufio.NewScanner(bytes.NewReader(info))
 	for scanner.Scan() {
 		mountString := scanner.Text()
 		parsedMounts, err := parseMountInfoString(mountString)
@@ -89,57 +75,75 @@ func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
 func parseMountInfoString(mountString string) (*MountInfo, error) {
 	var err error
 
-	// OptionalFields can be zero, hence these checks to ensure we do not populate the wrong values in the wrong spots
-	separatorIndex := strings.Index(mountString, "-")
-	if separatorIndex == -1 {
-		return nil, fmt.Errorf("no separator found in mountinfo string: %s", mountString)
+	mountInfo := strings.Split(mountString, " ")
+	mountInfoLength := len(mountInfo)
+	if mountInfoLength < 11 {
+		return nil, fmt.Errorf("couldn't find enough fields in mount string: %s", mountString)
 	}
-	beforeFields := strings.Fields(mountString[:separatorIndex])
-	afterFields := strings.Fields(mountString[separatorIndex+1:])
-	if (len(beforeFields) + len(afterFields)) < 7 {
-		return nil, fmt.Errorf("too few fields")
+
+	if mountInfo[mountInfoLength-4] != "-" {
+		return nil, fmt.Errorf("couldn't find separator in expected field: %s", mountInfo[mountInfoLength-4])
 	}
 
 	mount := &MountInfo{
-		MajorMinorVer:  getStringSliceElement(beforeFields, 2, ""),
-		Root:           getStringSliceElement(beforeFields, 3, ""),
-		MountPoint:     getStringSliceElement(beforeFields, 4, ""),
-		Options:        mountOptionsParser(getStringSliceElement(beforeFields, 5, "")),
+		MajorMinorVer:  mountInfo[2],
+		Root:           mountInfo[3],
+		MountPoint:     mountInfo[4],
+		Options:        mountOptionsParser(mountInfo[5]),
 		OptionalFields: nil,
-		FSType:         getStringSliceElement(afterFields, 0, ""),
-		Source:         getStringSliceElement(afterFields, 1, ""),
-		SuperOptions:   mountOptionsParser(getStringSliceElement(afterFields, 2, "")),
+		FSType:         mountInfo[mountInfoLength-3],
+		Source:         mountInfo[mountInfoLength-2],
+		SuperOptions:   mountOptionsParser(mountInfo[mountInfoLength-1]),
 	}
 
-	mount.MountId, err = strconv.Atoi(getStringSliceElement(beforeFields, 0, ""))
+	mount.MountId, err = strconv.Atoi(mountInfo[0])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse mount ID")
 	}
-	mount.ParentId, err = strconv.Atoi(getStringSliceElement(beforeFields, 1, ""))
+	mount.ParentId, err = strconv.Atoi(mountInfo[1])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse parent ID")
 	}
 	// Has optional fields, which is a space separated list of values.
 	// Example: shared:2 master:7
-	if len(beforeFields) > 6 {
-		mount.OptionalFields = make(map[string]string)
-		optionalFields := beforeFields[6:]
-		for _, field := range optionalFields {
-			optionSplit := strings.Split(field, ":")
-			target, value := optionSplit[0], ""
-			if len(optionSplit) == 2 {
-				value = optionSplit[1]
-			}
-			// Checks if the 'keys' in the optional fields in the mountinfo line are acceptable.
-			// Allowed 'keys' are shared, master, propagate_from, unbindable.
-			if _, ok := validOptionalFields[target]; ok {
-				mount.OptionalFields[target] = value
-			}
+	if mountInfo[6] != "" {
+		mount.OptionalFields, err = mountOptionsParseOptionalFields(mountInfo[6 : mountInfoLength-4])
+		if err != nil {
+			return nil, err
 		}
 	}
 	return mount, nil
 }
 
+// mountOptionsIsValidField checks a string against a valid list of optional fields keys.
+func mountOptionsIsValidField(s string) bool {
+	switch s {
+	case
+		"shared",
+		"master",
+		"propagate_from",
+		"unbindable":
+		return true
+	}
+	return false
+}
+
+// mountOptionsParseOptionalFields parses a list of optional fields strings into a double map of strings.
+func mountOptionsParseOptionalFields(o []string) (map[string]string, error) {
+	optionalFields := make(map[string]string)
+	for _, field := range o {
+		optionSplit := strings.SplitN(field, ":", 2)
+		value := ""
+		if len(optionSplit) == 2 {
+			value = optionSplit[1]
+		}
+		if mountOptionsIsValidField(optionSplit[0]) {
+			optionalFields[optionSplit[0]] = value
+		}
+	}
+	return optionalFields, nil
+}
+
 // Parses the mount options, superblock options.
 func mountOptionsParser(mountOptions string) map[string]string {
 	opts := make(map[string]string)
@@ -159,20 +163,18 @@ func mountOptionsParser(mountOptions string) map[string]string {
 
 // Retrieves mountinfo information from `/proc/self/mountinfo`.
 func GetMounts() ([]*MountInfo, error) {
-	f, err := os.Open("/proc/self/mountinfo")
+	data, err := util.ReadFileNoStat("/proc/self/mountinfo")
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-	return parseMountInfo(f)
+	return parseMountInfo(data)
 }
 
 // Retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
 func GetProcMounts(pid int) ([]*MountInfo, error) {
-	f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))
+	data, err := util.ReadFileNoStat(fmt.Sprintf("/proc/%d/mountinfo", pid))
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-	return parseMountInfo(f)
+	return parseMountInfo(data)
 }

vendor/github.com/prometheus/procfs/net_dev.go

@@ -183,7 +183,6 @@ func (netDev NetDev) Total() NetDevLine {
 		names = append(names, ifc.Name)
 		total.RxBytes += ifc.RxBytes
 		total.RxPackets += ifc.RxPackets
-		total.RxPackets += ifc.RxPackets
 		total.RxErrors += ifc.RxErrors
 		total.RxDropped += ifc.RxDropped
 		total.RxFIFO += ifc.RxFIFO

vendor/github.com/prometheus/procfs/net_sockstat.go

@@ -0,0 +1,163 @@
+// Copyright 2019 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.
+
+package procfs
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// A NetSockstat contains the output of /proc/net/sockstat{,6} for IPv4 or IPv6,
+// respectively.
+type NetSockstat struct {
+	// Used is non-nil for IPv4 sockstat results, but nil for IPv6.
+	Used      *int
+	Protocols []NetSockstatProtocol
+}
+
+// A NetSockstatProtocol contains statistics about a given socket protocol.
+// Pointer fields indicate that the value may or may not be present on any
+// given protocol.
+type NetSockstatProtocol struct {
+	Protocol string
+	InUse    int
+	Orphan   *int
+	TW       *int
+	Alloc    *int
+	Mem      *int
+	Memory   *int
+}
+
+// NetSockstat retrieves IPv4 socket statistics.
+func (fs FS) NetSockstat() (*NetSockstat, error) {
+	return readSockstat(fs.proc.Path("net", "sockstat"))
+}
+
+// NetSockstat6 retrieves IPv6 socket statistics.
+//
+// If IPv6 is disabled on this kernel, the returned error can be checked with
+// os.IsNotExist.
+func (fs FS) NetSockstat6() (*NetSockstat, error) {
+	return readSockstat(fs.proc.Path("net", "sockstat6"))
+}
+
+// readSockstat opens and parses a NetSockstat from the input file.
+func readSockstat(name string) (*NetSockstat, error) {
+	// This file is small and can be read with one syscall.
+	b, err := util.ReadFileNoStat(name)
+	if err != nil {
+		// Do not wrap this error so the caller can detect os.IsNotExist and
+		// similar conditions.
+		return nil, err
+	}
+
+	stat, err := parseSockstat(bytes.NewReader(b))
+	if err != nil {
+		return nil, fmt.Errorf("failed to read sockstats from %q: %v", name, err)
+	}
+
+	return stat, nil
+}
+
+// parseSockstat reads the contents of a sockstat file and parses a NetSockstat.
+func parseSockstat(r io.Reader) (*NetSockstat, error) {
+	var stat NetSockstat
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		// Expect a minimum of a protocol and one key/value pair.
+		fields := strings.Split(s.Text(), " ")
+		if len(fields) < 3 {
+			return nil, fmt.Errorf("malformed sockstat line: %q", s.Text())
+		}
+
+		// The remaining fields are key/value pairs.
+		kvs, err := parseSockstatKVs(fields[1:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing sockstat key/value pairs from %q: %v", s.Text(), err)
+		}
+
+		// The first field is the protocol. We must trim its colon suffix.
+		proto := strings.TrimSuffix(fields[0], ":")
+		switch proto {
+		case "sockets":
+			// Special case: IPv4 has a sockets "used" key/value pair that we
+			// embed at the top level of the structure.
+			used := kvs["used"]
+			stat.Used = &used
+		default:
+			// Parse all other lines as individual protocols.
+			nsp := parseSockstatProtocol(kvs)
+			nsp.Protocol = proto
+			stat.Protocols = append(stat.Protocols, nsp)
+		}
+	}
+
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	return &stat, nil
+}
+
+// parseSockstatKVs parses a string slice into a map of key/value pairs.
+func parseSockstatKVs(kvs []string) (map[string]int, error) {
+	if len(kvs)%2 != 0 {
+		return nil, errors.New("odd number of fields in key/value pairs")
+	}
+
+	// Iterate two values at a time to gather key/value pairs.
+	out := make(map[string]int, len(kvs)/2)
+	for i := 0; i < len(kvs); i += 2 {
+		vp := util.NewValueParser(kvs[i+1])
+		out[kvs[i]] = vp.Int()
+
+		if err := vp.Err(); err != nil {
+			return nil, err
+		}
+	}
+
+	return out, nil
+}
+
+// parseSockstatProtocol parses a NetSockstatProtocol from the input kvs map.
+func parseSockstatProtocol(kvs map[string]int) NetSockstatProtocol {
+	var nsp NetSockstatProtocol
+	for k, v := range kvs {
+		// Capture the range variable to ensure we get unique pointers for
+		// each of the optional fields.
+		v := v
+		switch k {
+		case "inuse":
+			nsp.InUse = v
+		case "orphan":
+			nsp.Orphan = &v
+		case "tw":
+			nsp.TW = &v
+		case "alloc":
+			nsp.Alloc = &v
+		case "mem":
+			nsp.Mem = &v
+		case "memory":
+			nsp.Memory = &v
+		}
+	}
+
+	return nsp
+}

vendor/github.com/prometheus/procfs/net_unix.go

@@ -207,10 +207,6 @@ func (u NetUnix) parseUsers(hexStr string) (uint64, error) {
 	return strconv.ParseUint(hexStr, 16, 32)
 }
 
-func (u NetUnix) parseProtocol(hexStr string) (uint64, error) {
-	return strconv.ParseUint(hexStr, 16, 32)
-}
-
 func (u NetUnix) parseType(hexStr string) (NetUnixType, error) {
 	typ, err := strconv.ParseUint(hexStr, 16, 16)
 	if err != nil {

vendor/github.com/prometheus/procfs/proc.go

@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	"github.com/prometheus/procfs/internal/fs"
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // Proc provides information about a running process.
@@ -121,13 +122,7 @@ func (fs FS) AllProcs() (Procs, error) {
 
 // CmdLine returns the command line of a process.
 func (p Proc) CmdLine() ([]string, error) {
-	f, err := os.Open(p.path("cmdline"))
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("cmdline"))
 	if err != nil {
 		return nil, err
 	}
@@ -141,13 +136,7 @@ func (p Proc) CmdLine() ([]string, error) {
 
 // Comm returns the command name of a process.
 func (p Proc) Comm() (string, error) {
-	f, err := os.Open(p.path("comm"))
-	if err != nil {
-		return "", err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("comm"))
 	if err != nil {
 		return "", err
 	}
@@ -252,13 +241,11 @@ func (p Proc) MountStats() ([]*Mount, error) {
 // It supplies information missing in `/proc/self/mounts` and
 // fixes various other problems with that file too.
 func (p Proc) MountInfo() ([]*MountInfo, error) {
-	f, err := os.Open(p.path("mountinfo"))
+	data, err := util.ReadFileNoStat(p.path("mountinfo"))
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-
-	return parseMountInfo(f)
+	return parseMountInfo(data)
 }
 
 func (p Proc) fileDescriptors() ([]string, error) {

vendor/github.com/prometheus/procfs/proc_environ.go

@@ -14,22 +14,16 @@
 package procfs
 
 import (
-	"io/ioutil"
-	"os"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // Environ reads process environments from /proc/<pid>/environ
 func (p Proc) Environ() ([]string, error) {
 	environments := make([]string, 0)
 
-	f, err := os.Open(p.path("environ"))
-	if err != nil {
-		return environments, err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("environ"))
 	if err != nil {
 		return environments, err
 	}

vendor/github.com/prometheus/procfs/proc_fdinfo.go

@@ -15,11 +15,10 @@ package procfs
 
 import (
 	"bufio"
-	"fmt"
-	"io/ioutil"
-	"os"
+	"bytes"
 	"regexp"
-	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // Regexp variables
@@ -46,21 +45,15 @@ type ProcFDInfo struct {
 
 // FDInfo constructor. On kernels older than 3.8, InotifyInfos will always be empty.
 func (p Proc) FDInfo(fd string) (*ProcFDInfo, error) {
-	f, err := os.Open(p.path("fdinfo", fd))
+	data, err := util.ReadFileNoStat(p.path("fdinfo", fd))
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
-
-	fdinfo, err := ioutil.ReadAll(f)
-	if err != nil {
-		return nil, fmt.Errorf("could not read %s: %s", f.Name(), err)
-	}
 
 	var text, pos, flags, mntid string
 	var inotify []InotifyInfo
 
-	scanner := bufio.NewScanner(strings.NewReader(string(fdinfo)))
+	scanner := bufio.NewScanner(bytes.NewReader(data))
 	for scanner.Scan() {
 		text = scanner.Text()
 		if rPos.MatchString(text) {

vendor/github.com/prometheus/procfs/proc_io.go

@@ -15,8 +15,8 @@ package procfs
 
 import (
 	"fmt"
-	"io/ioutil"
-	"os"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // ProcIO models the content of /proc/<pid>/io.
@@ -43,13 +43,7 @@ type ProcIO struct {
 func (p Proc) IO() (ProcIO, error) {
 	pio := ProcIO{}
 
-	f, err := os.Open(p.path("io"))
-	if err != nil {
-		return pio, err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("io"))
 	if err != nil {
 		return pio, err
 	}

vendor/github.com/prometheus/procfs/proc_psi.go

@@ -24,11 +24,13 @@ package procfs
 // > full avg10=0.00 avg60=0.13 avg300=0.96 total=8183134
 
 import (
+	"bufio"
+	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
-	"os"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 const lineFormat = "avg10=%f avg60=%f avg300=%f total=%d"
@@ -55,24 +57,21 @@ type PSIStats struct {
 // resource from /proc/pressure/<resource>. At time of writing this can be
 // either "cpu", "memory" or "io".
 func (fs FS) PSIStatsForResource(resource string) (PSIStats, error) {
-	file, err := os.Open(fs.proc.Path(fmt.Sprintf("%s/%s", "pressure", resource)))
+	data, err := util.ReadFileNoStat(fs.proc.Path(fmt.Sprintf("%s/%s", "pressure", resource)))
 	if err != nil {
 		return PSIStats{}, fmt.Errorf("psi_stats: unavailable for %s", resource)
 	}
 
-	defer file.Close()
-	return parsePSIStats(resource, file)
+	return parsePSIStats(resource, bytes.NewReader(data))
 }
 
 // parsePSIStats parses the specified file for pressure stall information
-func parsePSIStats(resource string, file io.Reader) (PSIStats, error) {
+func parsePSIStats(resource string, r io.Reader) (PSIStats, error) {
 	psiStats := PSIStats{}
-	stats, err := ioutil.ReadAll(file)
-	if err != nil {
-		return psiStats, fmt.Errorf("psi_stats: unable to read data for %s", resource)
-	}
 
-	for _, l := range strings.Split(string(stats), "\n") {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		l := scanner.Text()
 		prefix := strings.Split(l, " ")[0]
 		switch prefix {
 		case "some":

vendor/github.com/prometheus/procfs/proc_stat.go

@@ -16,10 +16,10 @@ package procfs
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"github.com/prometheus/procfs/internal/fs"
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // Originally, this USER_HZ value was dynamically retrieved via a sysconf call
@@ -113,13 +113,7 @@ func (p Proc) NewStat() (ProcStat, error) {
 
 // Stat returns the current status information of the process.
 func (p Proc) Stat() (ProcStat, error) {
-	f, err := os.Open(p.path("stat"))
-	if err != nil {
-		return ProcStat{}, err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("stat"))
 	if err != nil {
 		return ProcStat{}, err
 	}

vendor/github.com/prometheus/procfs/proc_status.go

@@ -15,10 +15,10 @@ package procfs
 
 import (
 	"bytes"
-	"io/ioutil"
-	"os"
 	"strconv"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // ProcStatus provides status information about the process,
@@ -75,13 +75,7 @@ type ProcStatus struct {
 
 // NewStatus returns the current status information of the process.
 func (p Proc) NewStatus() (ProcStatus, error) {
-	f, err := os.Open(p.path("status"))
-	if err != nil {
-		return ProcStatus{}, err
-	}
-	defer f.Close()
-
-	data, err := ioutil.ReadAll(f)
+	data, err := util.ReadFileNoStat(p.path("status"))
 	if err != nil {
 		return ProcStatus{}, err
 	}

vendor/github.com/prometheus/procfs/stat.go

@@ -15,13 +15,14 @@ package procfs
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"io"
-	"os"
 	"strconv"
 	"strings"
 
 	"github.com/prometheus/procfs/internal/fs"
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // CPUStat shows how much time the cpu spend in various stages.
@@ -164,16 +165,15 @@ func (fs FS) NewStat() (Stat, error) {
 // Stat returns information about current cpu/process statistics.
 // See https://www.kernel.org/doc/Documentation/filesystems/proc.txt
 func (fs FS) Stat() (Stat, error) {
-
-	f, err := os.Open(fs.proc.Path("stat"))
+	fileName := fs.proc.Path("stat")
+	data, err := util.ReadFileNoStat(fileName)
 	if err != nil {
 		return Stat{}, err
 	}
-	defer f.Close()
 
 	stat := Stat{}
 
-	scanner := bufio.NewScanner(f)
+	scanner := bufio.NewScanner(bytes.NewReader(data))
 	for scanner.Scan() {
 		line := scanner.Text()
 		parts := strings.Fields(scanner.Text())
@@ -237,7 +237,7 @@ func (fs FS) Stat() (Stat, error) {
 	}
 
 	if err := scanner.Err(); err != nil {
-		return Stat{}, fmt.Errorf("couldn't parse %s: %s", f.Name(), err)
+		return Stat{}, fmt.Errorf("couldn't parse %s: %s", fileName, err)
 	}
 
 	return stat, nil