| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | //go:build linux |
| 4 | |
| 5 | package dnsmasq_dhcp |
| 6 | |
| 7 | import ( |
| 8 | "bufio" |
| 9 | "io" |
| 10 | "math" |
| 11 | "math/big" |
| 12 | "net/netip" |
| 13 | "os" |
| 14 | "strings" |
| 15 | "time" |
| 16 | |
| 17 | "github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/iprange" |
| 18 | ) |
| 19 | |
| 20 | func (c *Collector) collect() (map[string]int64, error) { |
| 21 | now := time.Now() |
| 22 | var updated bool |
| 23 | |
| 24 | if now.Sub(c.parseConfigTime) > c.parseConfigEvery { |
| 25 | c.parseConfigTime = now |
| 26 | |
| 27 | dhcpRanges, dhcpHosts := c.parseDnsmasqDHCPConfiguration() |
| 28 | c.dhcpRanges, c.dhcpHosts = dhcpRanges, dhcpHosts |
| 29 | updated = c.updateCharts() |
| 30 | |
| 31 | c.collectV4V6Stats() |
| 32 | } |
| 33 | |
| 34 | f, err := os.Open(c.LeasesPath) |
| 35 | if err != nil { |
| 36 | return nil, err |
| 37 | } |
| 38 | defer func() { _ = f.Close() }() |
| 39 | |
| 40 | if !updated { |
| 41 | fi, err := f.Stat() |
| 42 | if err != nil { |
| 43 | return nil, err |
| 44 | } |
| 45 | |
| 46 | if c.leasesModTime.Equal(fi.ModTime()) { |
| 47 | c.Debug("lease database file modification time has not changed, old data is returned") |
| 48 | return c.mx, nil |
| 49 | } |
| 50 | |
| 51 | c.Debug("leases db file modification time has changed, reading it") |
| 52 | c.leasesModTime = fi.ModTime() |
| 53 | } |
| 54 | |
| 55 | leases := findLeases(f) |
| 56 | c.collectRangesStats(leases) |
| 57 | |
| 58 | return c.mx, nil |
| 59 | } |
| 60 | |
| 61 | func (c *Collector) collectV4V6Stats() { |
| 62 | c.mx["ipv4_dhcp_ranges"], c.mx["ipv6_dhcp_ranges"] = 0, 0 |
| 63 | for _, r := range c.dhcpRanges { |
| 64 | if r.Family() == iprange.V6Family { |
| 65 | c.mx["ipv6_dhcp_ranges"]++ |
| 66 | } else { |
| 67 | c.mx["ipv4_dhcp_ranges"]++ |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | c.mx["ipv4_dhcp_hosts"], c.mx["ipv6_dhcp_hosts"] = 0, 0 |
| 72 | for _, ip := range c.dhcpHosts { |
| 73 | if ip.Is6() { |
| 74 | c.mx["ipv6_dhcp_hosts"]++ |
| 75 | } else { |
| 76 | c.mx["ipv4_dhcp_hosts"]++ |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | func (c *Collector) collectRangesStats(leases []netip.Addr) { |
| 82 | for _, r := range c.dhcpRanges { |
| 83 | c.mx["dhcp_range_"+r.String()+"_allocated_leases"] = 0 |
| 84 | c.mx["dhcp_range_"+r.String()+"_utilization"] = 0 |
| 85 | } |
| 86 | |
| 87 | for _, addr := range leases { |
| 88 | for _, r := range c.dhcpRanges { |
| 89 | if r.Contains(addr) { |
| 90 | c.mx["dhcp_range_"+r.String()+"_allocated_leases"]++ |
| 91 | break |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | for _, addr := range c.dhcpHosts { |
| 97 | for _, r := range c.dhcpRanges { |
| 98 | if r.Contains(addr) { |
| 99 | c.mx["dhcp_range_"+r.String()+"_allocated_leases"]++ |
| 100 | break |
| 101 | } |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | for _, r := range c.dhcpRanges { |
| 106 | name := "dhcp_range_" + r.String() + "_allocated_leases" |
| 107 | numOfIps, ok := c.mx[name] |
| 108 | if !ok { |
| 109 | c.mx[name] = 0 |
| 110 | } |
| 111 | c.mx["dhcp_range_"+r.String()+"_utilization"] = int64(math.Round(calcPercent(numOfIps, r.Size()))) |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | func (c *Collector) updateCharts() bool { |
| 116 | var updated bool |
| 117 | seen := make(map[string]bool) |
| 118 | for _, r := range c.dhcpRanges { |
| 119 | seen[r.String()] = true |
| 120 | if !c.cacheDHCPRanges[r.String()] { |
| 121 | c.cacheDHCPRanges[r.String()] = true |
| 122 | c.addDHCPRangeCharts(r.String()) |
| 123 | updated = true |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | for v := range c.cacheDHCPRanges { |
| 128 | if !seen[v] { |
| 129 | delete(c.cacheDHCPRanges, v) |
| 130 | c.removeDHCPRangeCharts(v) |
| 131 | updated = true |
| 132 | } |
| 133 | } |
| 134 | return updated |
| 135 | } |
| 136 | |
| 137 | func findLeases(r io.Reader) []netip.Addr { |
| 138 | /* |
| 139 | 1560300536 08:00:27:61:3c:ee 2.2.2.3 debian8 * |
| 140 | duid 00:01:00:01:24:90:cf:5b:08:00:27:61:2e:2c |
| 141 | 1560300414 660684014 1234::20b * 00:01:00:01:24:90:cf:a3:08:00:27:61:3c:ee |
| 142 | */ |
| 143 | var addrs []netip.Addr |
| 144 | s := bufio.NewScanner(r) |
| 145 | |
| 146 | for s.Scan() { |
| 147 | parts := strings.Fields(s.Text()) |
| 148 | if len(parts) != 5 { |
| 149 | continue |
| 150 | } |
| 151 | |
| 152 | addr, err := netip.ParseAddr(parts[2]) |
| 153 | if err != nil { |
| 154 | continue |
| 155 | } |
| 156 | addrs = append(addrs, addr) |
| 157 | } |
| 158 | |
| 159 | return addrs |
| 160 | } |
| 161 | |
| 162 | func calcPercent(ips int64, hosts *big.Int) float64 { |
| 163 | h := hosts.Int64() |
| 164 | if ips == 0 || h == 0 || !hosts.IsInt64() { |
| 165 | return 0 |
| 166 | } |
| 167 | return float64(ips) * 100 / float64(h) |
| 168 | } |