AdGuardHome-0.104.3.tar.gz: .../dhcpd/dhcpd.go

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Member "AdGuardHome-0.104.3/internal/dhcpd/dhcpd.go" (19 Nov 2020, 6157 Bytes) of package /linux/misc/dns/AdGuardHome-0.104.3.tar.gz:

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0.104.1_vs_0.104.3.

1 // Package dhcpd provides a DHCP server. 2 package dhcpd 3 4 import ( 5 "encoding/hex" 6 "net" 7 "net/http" 8 "path/filepath" 9 "runtime" 10 "strconv" 11 "strings" 12 "time" 13 14 "github.com/AdguardTeam/AdGuardHome/internal/util" 15 "github.com/AdguardTeam/golibs/log" 16 ) 17 18 const ( 19 defaultDiscoverTime = time.Second * 3 20 leaseExpireStatic = 1 21 ) 22 23 var webHandlersRegistered = false 24 25 // Lease contains the necessary information about a DHCP lease 26 type Lease struct { 27 HWAddr net.HardwareAddr `json:"mac"` 28 IP net.IP `json:"ip"` 29 Hostname string `json:"hostname"` 30 31 // Lease expiration time 32 // 1: static lease 33 Expiry time.Time `json:"expires"` 34 } 35 36 // ServerConfig - DHCP server configuration 37 // field ordering is important -- yaml fields will mirror ordering from here 38 type ServerConfig struct { 39 Enabled bool `yaml:"enabled"` 40 InterfaceName string `yaml:"interface_name"` 41 42 Conf4 V4ServerConf `yaml:"dhcpv4"` 43 Conf6 V6ServerConf `yaml:"dhcpv6"` 44 45 WorkDir string `yaml:"-"` 46 DBFilePath string `yaml:"-"` // path to DB file 47 48 // Called when the configuration is changed by HTTP request 49 ConfigModified func() `yaml:"-"` 50 51 // Register an HTTP handler 52 HTTPRegister func(string, string, func(http.ResponseWriter, *http.Request)) `yaml:"-"` 53 } 54 55 type OnLeaseChangedT func(flags int) 56 57 // flags for onLeaseChanged() 58 const ( 59 LeaseChangedAdded = iota 60 LeaseChangedAddedStatic 61 LeaseChangedRemovedStatic 62 63 LeaseChangedDBStore 64 ) 65 66 // Server - the current state of the DHCP server 67 type Server struct { 68 srv4 DHCPServer 69 srv6 DHCPServer 70 71 conf ServerConfig 72 73 // Called when the leases DB is modified 74 onLeaseChanged []OnLeaseChangedT 75 } 76 77 type ServerInterface interface { 78 Leases(flags int) []Lease 79 SetOnLeaseChanged(onLeaseChanged OnLeaseChangedT) 80 } 81 82 // CheckConfig checks the configuration 83 func (s *Server) CheckConfig(config ServerConfig) error { 84 return nil 85 } 86 87 // Create - create object 88 func Create(config ServerConfig) *Server { 89 s := &Server{} 90 91 s.conf.Enabled = config.Enabled 92 s.conf.InterfaceName = config.InterfaceName 93 s.conf.HTTPRegister = config.HTTPRegister 94 s.conf.ConfigModified = config.ConfigModified 95 s.conf.DBFilePath = filepath.Join(config.WorkDir, dbFilename) 96 97 if !webHandlersRegistered && s.conf.HTTPRegister != nil { 98 if runtime.GOOS == "windows" { 99 // Our DHCP server doesn't work on Windows yet, so 100 // signal that to the front with an HTTP 501. 101 // 102 // TODO(a.garipov): This needs refactoring. We 103 // shouldn't even try and initialize a DHCP server on 104 // Windows, but there are currently too many 105 // interconnected parts--such as HTTP handlers and 106 // frontend--to make that work properly. 107 s.registerNotImplementedHandlers() 108 } else { 109 s.registerHandlers() 110 } 111 112 webHandlersRegistered = true 113 } 114 115 var err4, err6 error 116 v4conf := config.Conf4 117 v4conf.Enabled = s.conf.Enabled 118 if len(v4conf.RangeStart) == 0 { 119 v4conf.Enabled = false 120 } 121 v4conf.InterfaceName = s.conf.InterfaceName 122 v4conf.notify = s.onNotify 123 s.srv4, err4 = v4Create(v4conf) 124 125 v6conf := config.Conf6 126 v6conf.Enabled = s.conf.Enabled 127 if len(v6conf.RangeStart) == 0 { 128 v6conf.Enabled = false 129 } 130 v6conf.InterfaceName = s.conf.InterfaceName 131 v6conf.notify = s.onNotify 132 s.srv6, err6 = v6Create(v6conf) 133 134 if err4 != nil { 135 log.Error("%s", err4) 136 return nil 137 } 138 if err6 != nil { 139 log.Error("%s", err6) 140 return nil 141 } 142 143 if s.conf.Enabled && !v4conf.Enabled && !v6conf.Enabled { 144 log.Error("Can't enable DHCP server because neither DHCPv4 nor DHCPv6 servers are configured") 145 return nil 146 } 147 148 // we can't delay database loading until DHCP server is started, 149 // because we need static leases functionality available beforehand 150 s.dbLoad() 151 return s 152 } 153 154 // server calls this function after DB is updated 155 func (s *Server) onNotify(flags uint32) { 156 if flags == LeaseChangedDBStore { 157 s.dbStore() 158 return 159 } 160 161 s.notify(int(flags)) 162 } 163 164 // SetOnLeaseChanged - set callback 165 func (s *Server) SetOnLeaseChanged(onLeaseChanged OnLeaseChangedT) { 166 s.onLeaseChanged = append(s.onLeaseChanged, onLeaseChanged) 167 } 168 169 func (s *Server) notify(flags int) { 170 if len(s.onLeaseChanged) == 0 { 171 return 172 } 173 for _, f := range s.onLeaseChanged { 174 f(flags) 175 } 176 } 177 178 // WriteDiskConfig - write configuration 179 func (s *Server) WriteDiskConfig(c *ServerConfig) { 180 c.Enabled = s.conf.Enabled 181 c.InterfaceName = s.conf.InterfaceName 182 s.srv4.WriteDiskConfig4(&c.Conf4) 183 s.srv6.WriteDiskConfig6(&c.Conf6) 184 } 185 186 // Start will listen on port 67 and serve DHCP requests. 187 func (s *Server) Start() error { 188 err := s.srv4.Start() 189 if err != nil { 190 log.Error("DHCPv4: start: %s", err) 191 return err 192 } 193 194 err = s.srv6.Start() 195 if err != nil { 196 log.Error("DHCPv6: start: %s", err) 197 return err 198 } 199 200 return nil 201 } 202 203 // Stop closes the listening UDP socket 204 func (s *Server) Stop() { 205 s.srv4.Stop() 206 s.srv6.Stop() 207 } 208 209 // flags for Leases() function 210 const ( 211 LeasesDynamic = 1 212 LeasesStatic = 2 213 LeasesAll = LeasesDynamic | LeasesStatic 214 ) 215 216 // Leases returns the list of current DHCP leases (thread-safe) 217 func (s *Server) Leases(flags int) []Lease { 218 result := s.srv4.GetLeases(flags) 219 220 v6leases := s.srv6.GetLeases(flags) 221 result = append(result, v6leases...) 222 223 return result 224 } 225 226 // FindMACbyIP - find a MAC address by IP address in the currently active DHCP leases 227 func (s *Server) FindMACbyIP(ip net.IP) net.HardwareAddr { 228 if ip.To4() != nil { 229 return s.srv4.FindMACbyIP(ip) 230 } 231 return s.srv6.FindMACbyIP(ip) 232 } 233 234 // AddStaticLease - add static v4 lease 235 func (s *Server) AddStaticLease(lease Lease) error { 236 return s.srv4.AddStaticLease(lease) 237 } 238 239 // Parse option string 240 // Format: 241 // CODE TYPE VALUE 242 func parseOptionString(s string) (uint8, []byte) { 243 s = strings.TrimSpace(s) 244 scode := util.SplitNext(&s, ' ') 245 t := util.SplitNext(&s, ' ') 246 sval := util.SplitNext(&s, ' ') 247 248 code, err := strconv.Atoi(scode) 249 if err != nil || code <= 0 || code > 255 { 250 return 0, nil 251 } 252 253 var val []byte 254 255 switch t { 256 case "hex": 257 val, err = hex.DecodeString(sval) 258 if err != nil { 259 return 0, nil 260 } 261 262 case "ip": 263 ip := net.ParseIP(sval) 264 if ip == nil { 265 return 0, nil 266 } 267 val = ip 268 if ip.To4() != nil { 269 val = ip.To4() 270 } 271 272 default: 273 return 0, nil 274 } 275 276 return uint8(code), val 277 }