Sergiusz Bazanski | 9dc4b68 | 2019-04-05 23:51:49 +0200 | [diff] [blame] | 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "bufio" |
| 5 | "context" |
| 6 | "flag" |
| 7 | "fmt" |
| 8 | "io" |
| 9 | "net" |
| 10 | "os" |
| 11 | "strings" |
| 12 | "time" |
| 13 | |
| 14 | "github.com/golang/glog" |
| 15 | |
| 16 | mirko "code.hackerspace.pl/hscloud/go/mirko" |
| 17 | hpb "code.hackerspace.pl/hscloud/proto/hswaw" |
| 18 | ) |
| 19 | |
| 20 | type lease struct { |
| 21 | hardware net.HardwareAddr |
| 22 | ip net.IP |
| 23 | from time.Time |
| 24 | to time.Time |
| 25 | } |
| 26 | |
| 27 | const timeFmt = "2006/01/02 15:04:05" |
| 28 | |
| 29 | func parseLeases(f io.Reader, now time.Time) ([]lease, error) { |
| 30 | scanner := bufio.NewScanner(f) |
| 31 | |
| 32 | leases := make(map[string]*lease) |
| 33 | |
| 34 | var curAddr *net.IP |
| 35 | var curStart *time.Time |
| 36 | var curEnd *time.Time |
| 37 | var curHW *net.HardwareAddr |
| 38 | |
| 39 | for scanner.Scan() { |
| 40 | l := scanner.Text() |
| 41 | l = strings.TrimSpace(l) |
| 42 | if len(l) < 1 { |
| 43 | continue |
| 44 | } |
| 45 | |
| 46 | if strings.HasPrefix(l, "#") { |
| 47 | continue |
| 48 | } |
| 49 | |
| 50 | parts := strings.Fields(l) |
| 51 | if len(parts) < 1 { |
| 52 | continue |
| 53 | } |
| 54 | |
| 55 | if curAddr == nil { |
| 56 | switch parts[0] { |
| 57 | case "lease": |
| 58 | if len(parts) < 3 || parts[2] != "{" { |
| 59 | glog.Warningf("invalid lease line %q", l) |
| 60 | break |
| 61 | } |
| 62 | |
| 63 | ip := net.ParseIP(parts[1]) |
| 64 | if ip == nil { |
| 65 | glog.Warningf("invalid lease line %q: invalid ip") |
| 66 | break |
| 67 | } |
| 68 | curAddr = &ip |
| 69 | } |
| 70 | } else { |
| 71 | parts[len(parts)-1] = strings.TrimRight(parts[len(parts)-1], ";") |
| 72 | |
| 73 | switch parts[0] { |
| 74 | case "starts": |
| 75 | fallthrough |
| 76 | case "ends": |
| 77 | if len(parts) != 4 { |
| 78 | glog.Warningf("invalid time line %q", l) |
| 79 | break |
| 80 | } |
| 81 | t, err := time.Parse(timeFmt, fmt.Sprintf("%s %s", parts[2], parts[3])) |
| 82 | if err != nil { |
| 83 | glog.Warningf("invalid time line %q: %v", l, err) |
| 84 | break |
| 85 | } |
| 86 | if parts[0] == "starts" { |
| 87 | curStart = &t |
| 88 | } else { |
| 89 | curEnd = &t |
| 90 | } |
| 91 | case "hardware": |
| 92 | if len(parts) < 2 { |
| 93 | glog.Warningf("invalid hardware line %q", l) |
| 94 | break |
| 95 | } |
| 96 | if parts[1] != "ethernet" { |
| 97 | break |
| 98 | } |
| 99 | if len(parts) != 3 { |
| 100 | glog.Warningf("invalid hardware ethernet line %q", l) |
| 101 | break |
| 102 | } |
| 103 | hw, err := net.ParseMAC(parts[2]) |
| 104 | if err != nil { |
| 105 | glog.Warningf("invalid hardware ethernet line %q: %v", l, err) |
| 106 | break |
| 107 | } |
| 108 | curHW = &hw |
| 109 | case "}": |
| 110 | if curStart == nil || curEnd == nil || curHW == nil { |
| 111 | glog.V(2).Info("Invalid block for %q, not enough fields", curAddr.String()) |
| 112 | } else if curEnd.Before(now) { |
| 113 | // skip. |
| 114 | } else { |
| 115 | leases[curHW.String()] = &lease{ |
| 116 | hardware: *curHW, |
| 117 | ip: *curAddr, |
| 118 | from: *curStart, |
| 119 | to: *curEnd, |
| 120 | } |
| 121 | } |
| 122 | curAddr = nil |
| 123 | curStart = nil |
| 124 | curEnd = nil |
| 125 | curHW = nil |
| 126 | } |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | ret := make([]lease, len(leases)) |
| 131 | i := 0 |
| 132 | for _, v := range leases { |
| 133 | ret[i] = *v |
| 134 | i += 1 |
| 135 | } |
| 136 | |
| 137 | return ret, nil |
| 138 | } |
| 139 | |
| 140 | type service struct { |
| 141 | leaseFile string |
| 142 | leaseC chan chan []lease |
| 143 | } |
| 144 | |
| 145 | func (s *service) work(ctx context.Context) { |
| 146 | leases := []lease{} |
| 147 | |
| 148 | ticker := time.NewTicker(30 * time.Second) |
| 149 | start := make(chan struct{}, 1) |
| 150 | start <- struct{}{} |
| 151 | |
| 152 | work := func() { |
| 153 | glog.Infof("Parsing leases...") |
| 154 | f, err := os.Open(s.leaseFile) |
| 155 | if err != nil { |
| 156 | glog.Errorf("Could not open lease file: %v", err) |
| 157 | return |
| 158 | } |
| 159 | l, err := parseLeases(f, time.Now()) |
| 160 | f.Close() |
| 161 | if err != nil { |
| 162 | glog.Errorf("Could not parse lease file: %v", err) |
| 163 | return |
| 164 | } |
| 165 | leases = l |
| 166 | glog.Infof("Got %d leases", len(leases)) |
| 167 | } |
| 168 | |
| 169 | glog.Infof("Worker started.") |
| 170 | |
| 171 | for { |
| 172 | select { |
| 173 | case <-start: |
| 174 | work() |
| 175 | case <-ticker.C: |
| 176 | work() |
| 177 | case c := <-s.leaseC: |
| 178 | c <- leases |
| 179 | case <-ctx.Done(): |
| 180 | glog.Infof("Worker quitting.") |
| 181 | close(start) |
| 182 | return |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | func (s *service) Leases(ctx context.Context, req *hpb.LeasifierLeasesRequest) (*hpb.LeasifierLeasesResponse, error) { |
| 188 | c := make(chan []lease) |
| 189 | s.leaseC <- c |
| 190 | leases := <-c |
| 191 | |
| 192 | res := &hpb.LeasifierLeasesResponse{} |
| 193 | |
| 194 | for i, l := range leases { |
| 195 | res.Leases[i] = &hpb.LeasifierLease{ |
| 196 | PhysicalAddress: l.hardware.String(), |
| 197 | IpAddress: l.ip.String(), |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | return res, nil |
| 202 | } |
| 203 | |
| 204 | func main() { |
| 205 | s := &service{ |
| 206 | leaseC: make(chan chan []lease), |
| 207 | } |
| 208 | |
| 209 | flag.StringVar(&s.leaseFile, "lease_file", "/var/db/dhcpd.leases", "Location of leasefile") |
| 210 | flag.Parse() |
| 211 | |
| 212 | m := mirko.New() |
| 213 | if err := m.Listen(); err != nil { |
| 214 | glog.Exitf("Could not listen: %v", err) |
| 215 | } |
| 216 | |
| 217 | hpb.RegisterLeasifierServer(m.GRPC(), s) |
| 218 | |
| 219 | go s.work(m.Context()) |
| 220 | |
| 221 | if err := m.Serve(); err != nil { |
| 222 | glog.Exitf("Could not run: %v", err) |
| 223 | } |
| 224 | |
| 225 | glog.Info("Running.") |
| 226 | <-m.Done() |
| 227 | |
| 228 | } |