blob: e36f4872dd62f9351b3ac9528cd2ea6f051888fe [file] [log] [blame]
khenaidoo26721882021-08-11 17:42:52 -04001// Copyright 2019 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
14package procfs
15
16import (
17 "bufio"
18 "bytes"
19 "errors"
20 "fmt"
21 "io"
22 "strings"
23
24 "github.com/prometheus/procfs/internal/util"
25)
26
27// A NetSockstat contains the output of /proc/net/sockstat{,6} for IPv4 or IPv6,
28// respectively.
29type NetSockstat struct {
30 // Used is non-nil for IPv4 sockstat results, but nil for IPv6.
31 Used *int
32 Protocols []NetSockstatProtocol
33}
34
35// A NetSockstatProtocol contains statistics about a given socket protocol.
36// Pointer fields indicate that the value may or may not be present on any
37// given protocol.
38type NetSockstatProtocol struct {
39 Protocol string
40 InUse int
41 Orphan *int
42 TW *int
43 Alloc *int
44 Mem *int
45 Memory *int
46}
47
48// NetSockstat retrieves IPv4 socket statistics.
49func (fs FS) NetSockstat() (*NetSockstat, error) {
50 return readSockstat(fs.proc.Path("net", "sockstat"))
51}
52
53// NetSockstat6 retrieves IPv6 socket statistics.
54//
55// If IPv6 is disabled on this kernel, the returned error can be checked with
56// os.IsNotExist.
57func (fs FS) NetSockstat6() (*NetSockstat, error) {
58 return readSockstat(fs.proc.Path("net", "sockstat6"))
59}
60
61// readSockstat opens and parses a NetSockstat from the input file.
62func readSockstat(name string) (*NetSockstat, error) {
63 // This file is small and can be read with one syscall.
64 b, err := util.ReadFileNoStat(name)
65 if err != nil {
66 // Do not wrap this error so the caller can detect os.IsNotExist and
67 // similar conditions.
68 return nil, err
69 }
70
71 stat, err := parseSockstat(bytes.NewReader(b))
72 if err != nil {
73 return nil, fmt.Errorf("failed to read sockstats from %q: %w", name, err)
74 }
75
76 return stat, nil
77}
78
79// parseSockstat reads the contents of a sockstat file and parses a NetSockstat.
80func parseSockstat(r io.Reader) (*NetSockstat, error) {
81 var stat NetSockstat
82 s := bufio.NewScanner(r)
83 for s.Scan() {
84 // Expect a minimum of a protocol and one key/value pair.
85 fields := strings.Split(s.Text(), " ")
86 if len(fields) < 3 {
87 return nil, fmt.Errorf("malformed sockstat line: %q", s.Text())
88 }
89
90 // The remaining fields are key/value pairs.
91 kvs, err := parseSockstatKVs(fields[1:])
92 if err != nil {
93 return nil, fmt.Errorf("error parsing sockstat key/value pairs from %q: %w", s.Text(), err)
94 }
95
96 // The first field is the protocol. We must trim its colon suffix.
97 proto := strings.TrimSuffix(fields[0], ":")
98 switch proto {
99 case "sockets":
100 // Special case: IPv4 has a sockets "used" key/value pair that we
101 // embed at the top level of the structure.
102 used := kvs["used"]
103 stat.Used = &used
104 default:
105 // Parse all other lines as individual protocols.
106 nsp := parseSockstatProtocol(kvs)
107 nsp.Protocol = proto
108 stat.Protocols = append(stat.Protocols, nsp)
109 }
110 }
111
112 if err := s.Err(); err != nil {
113 return nil, err
114 }
115
116 return &stat, nil
117}
118
119// parseSockstatKVs parses a string slice into a map of key/value pairs.
120func parseSockstatKVs(kvs []string) (map[string]int, error) {
121 if len(kvs)%2 != 0 {
122 return nil, errors.New("odd number of fields in key/value pairs")
123 }
124
125 // Iterate two values at a time to gather key/value pairs.
126 out := make(map[string]int, len(kvs)/2)
127 for i := 0; i < len(kvs); i += 2 {
128 vp := util.NewValueParser(kvs[i+1])
129 out[kvs[i]] = vp.Int()
130
131 if err := vp.Err(); err != nil {
132 return nil, err
133 }
134 }
135
136 return out, nil
137}
138
139// parseSockstatProtocol parses a NetSockstatProtocol from the input kvs map.
140func parseSockstatProtocol(kvs map[string]int) NetSockstatProtocol {
141 var nsp NetSockstatProtocol
142 for k, v := range kvs {
143 // Capture the range variable to ensure we get unique pointers for
144 // each of the optional fields.
145 v := v
146 switch k {
147 case "inuse":
148 nsp.InUse = v
149 case "orphan":
150 nsp.Orphan = &v
151 case "tw":
152 nsp.TW = &v
153 case "alloc":
154 nsp.Alloc = &v
155 case "mem":
156 nsp.Mem = &v
157 case "memory":
158 nsp.Memory = &v
159 }
160 }
161
162 return nsp
163}