AdGuardHome/dhcpd/dhcp_http.go

327 lines
8.4 KiB
Go

package dhcpd
import (
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"os"
"strings"
"time"
"github.com/AdguardTeam/golibs/log"
)
func httpError(r *http.Request, w http.ResponseWriter, code int, format string, args ...interface{}) {
text := fmt.Sprintf(format, args...)
log.Info("DHCP: %s %s: %s", r.Method, r.URL, text)
http.Error(w, text, code)
}
// []Lease -> JSON
func convertLeases(inputLeases []Lease, includeExpires bool) []map[string]string {
leases := []map[string]string{}
for _, l := range inputLeases {
lease := map[string]string{
"mac": l.HWAddr.String(),
"ip": l.IP.String(),
"hostname": l.Hostname,
}
if includeExpires {
lease["expires"] = l.Expiry.Format(time.RFC3339)
}
leases = append(leases, lease)
}
return leases
}
func (s *Server) handleDHCPStatus(w http.ResponseWriter, r *http.Request) {
leases := convertLeases(s.Leases(LeasesDynamic), true)
staticLeases := convertLeases(s.Leases(LeasesStatic), false)
status := map[string]interface{}{
"config": s.conf,
"leases": leases,
"static_leases": staticLeases,
}
w.Header().Set("Content-Type", "application/json")
err := json.NewEncoder(w).Encode(status)
if err != nil {
httpError(r, w, http.StatusInternalServerError, "Unable to marshal DHCP status json: %s", err)
return
}
}
type staticLeaseJSON struct {
HWAddr string `json:"mac"`
IP string `json:"ip"`
Hostname string `json:"hostname"`
}
type dhcpServerConfigJSON struct {
ServerConfig `json:",inline"`
StaticLeases []staticLeaseJSON `json:"static_leases"`
}
func (s *Server) handleDHCPSetConfig(w http.ResponseWriter, r *http.Request) {
newconfig := dhcpServerConfigJSON{}
err := json.NewDecoder(r.Body).Decode(&newconfig)
if err != nil {
httpError(r, w, http.StatusBadRequest, "Failed to parse new DHCP config json: %s", err)
return
}
err = s.CheckConfig(newconfig.ServerConfig)
if err != nil {
httpError(r, w, http.StatusBadRequest, "Invalid DHCP configuration: %s", err)
return
}
err = s.Stop()
if err != nil {
log.Error("failed to stop the DHCP server: %s", err)
}
err = s.Init(newconfig.ServerConfig)
if err != nil {
httpError(r, w, http.StatusBadRequest, "Invalid DHCP configuration: %s", err)
return
}
s.conf.ConfigModified()
if newconfig.Enabled {
staticIP, err := HasStaticIP(newconfig.InterfaceName)
if !staticIP && err == nil {
err = SetStaticIP(newconfig.InterfaceName)
if err != nil {
httpError(r, w, http.StatusInternalServerError, "Failed to configure static IP: %s", err)
return
}
}
err = s.Start()
if err != nil {
httpError(r, w, http.StatusBadRequest, "Failed to start DHCP server: %s", err)
return
}
}
}
type netInterfaceJSON struct {
Name string `json:"name"`
MTU int `json:"mtu"`
HardwareAddr string `json:"hardware_address"`
Addresses []string `json:"ip_addresses"`
Flags string `json:"flags"`
}
func (s *Server) handleDHCPInterfaces(w http.ResponseWriter, r *http.Request) {
response := map[string]interface{}{}
ifaces, err := GetValidNetInterfaces()
if err != nil {
httpError(r, w, http.StatusInternalServerError, "Couldn't get interfaces: %s", err)
return
}
for _, iface := range ifaces {
if iface.Flags&net.FlagLoopback != 0 {
// it's a loopback, skip it
continue
}
if iface.Flags&net.FlagBroadcast == 0 {
// this interface doesn't support broadcast, skip it
continue
}
addrs, err := iface.Addrs()
if err != nil {
httpError(r, w, http.StatusInternalServerError, "Failed to get addresses for interface %s: %s", iface.Name, err)
return
}
jsonIface := netInterfaceJSON{
Name: iface.Name,
MTU: iface.MTU,
HardwareAddr: iface.HardwareAddr.String(),
}
if iface.Flags != 0 {
jsonIface.Flags = iface.Flags.String()
}
// we don't want link-local addresses in json, so skip them
for _, addr := range addrs {
ipnet, ok := addr.(*net.IPNet)
if !ok {
// not an IPNet, should not happen
httpError(r, w, http.StatusInternalServerError, "SHOULD NOT HAPPEN: got iface.Addrs() element %s that is not net.IPNet, it is %T", addr, addr)
return
}
// ignore link-local
if ipnet.IP.IsLinkLocalUnicast() {
continue
}
jsonIface.Addresses = append(jsonIface.Addresses, ipnet.IP.String())
}
if len(jsonIface.Addresses) != 0 {
response[iface.Name] = jsonIface
}
}
err = json.NewEncoder(w).Encode(response)
if err != nil {
httpError(r, w, http.StatusInternalServerError, "Failed to marshal json with available interfaces: %s", err)
return
}
}
// Perform the following tasks:
// . Search for another DHCP server running
// . Check if a static IP is configured for the network interface
// Respond with results
func (s *Server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Request) {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
errorText := fmt.Sprintf("failed to read request body: %s", err)
log.Error(errorText)
http.Error(w, errorText, http.StatusBadRequest)
return
}
interfaceName := strings.TrimSpace(string(body))
if interfaceName == "" {
errorText := fmt.Sprintf("empty interface name specified")
log.Error(errorText)
http.Error(w, errorText, http.StatusBadRequest)
return
}
found, err := CheckIfOtherDHCPServersPresent(interfaceName)
othSrv := map[string]interface{}{}
foundVal := "no"
if found {
foundVal = "yes"
} else if err != nil {
foundVal = "error"
othSrv["error"] = err.Error()
}
othSrv["found"] = foundVal
staticIP := map[string]interface{}{}
isStaticIP, err := HasStaticIP(interfaceName)
staticIPStatus := "yes"
if err != nil {
staticIPStatus = "error"
staticIP["error"] = err.Error()
} else if !isStaticIP {
staticIPStatus = "no"
staticIP["ip"] = GetFullIP(interfaceName)
}
staticIP["static"] = staticIPStatus
result := map[string]interface{}{}
result["other_server"] = othSrv
result["static_ip"] = staticIP
w.Header().Set("Content-Type", "application/json")
err = json.NewEncoder(w).Encode(result)
if err != nil {
httpError(r, w, http.StatusInternalServerError, "Failed to marshal DHCP found json: %s", err)
return
}
}
func (s *Server) handleDHCPAddStaticLease(w http.ResponseWriter, r *http.Request) {
lj := staticLeaseJSON{}
err := json.NewDecoder(r.Body).Decode(&lj)
if err != nil {
httpError(r, w, http.StatusBadRequest, "json.Decode: %s", err)
return
}
ip, _ := parseIPv4(lj.IP)
if ip == nil {
httpError(r, w, http.StatusBadRequest, "invalid IP")
return
}
mac, _ := net.ParseMAC(lj.HWAddr)
lease := Lease{
IP: ip,
HWAddr: mac,
Hostname: lj.Hostname,
}
err = s.AddStaticLease(lease)
if err != nil {
httpError(r, w, http.StatusBadRequest, "%s", err)
return
}
}
func (s *Server) handleDHCPRemoveStaticLease(w http.ResponseWriter, r *http.Request) {
lj := staticLeaseJSON{}
err := json.NewDecoder(r.Body).Decode(&lj)
if err != nil {
httpError(r, w, http.StatusBadRequest, "json.Decode: %s", err)
return
}
ip, _ := parseIPv4(lj.IP)
if ip == nil {
httpError(r, w, http.StatusBadRequest, "invalid IP")
return
}
mac, _ := net.ParseMAC(lj.HWAddr)
lease := Lease{
IP: ip,
HWAddr: mac,
Hostname: lj.Hostname,
}
err = s.RemoveStaticLease(lease)
if err != nil {
httpError(r, w, http.StatusBadRequest, "%s", err)
return
}
}
func (s *Server) handleReset(w http.ResponseWriter, r *http.Request) {
err := s.Stop()
if err != nil {
log.Error("DHCP: Stop: %s", err)
}
err = os.Remove(s.conf.DBFilePath)
if err != nil && !os.IsNotExist(err) {
log.Error("DHCP: os.Remove: %s: %s", s.conf.DBFilePath, err)
}
oldconf := s.conf
s.conf = ServerConfig{}
s.conf.LeaseDuration = 86400
s.conf.ICMPTimeout = 1000
s.conf.WorkDir = oldconf.WorkDir
s.conf.HTTPRegister = oldconf.HTTPRegister
s.conf.ConfigModified = oldconf.ConfigModified
s.conf.DBFilePath = oldconf.DBFilePath
s.conf.ConfigModified()
}
func (s *Server) registerHandlers() {
s.conf.HTTPRegister("GET", "/control/dhcp/status", s.handleDHCPStatus)
s.conf.HTTPRegister("GET", "/control/dhcp/interfaces", s.handleDHCPInterfaces)
s.conf.HTTPRegister("POST", "/control/dhcp/set_config", s.handleDHCPSetConfig)
s.conf.HTTPRegister("POST", "/control/dhcp/find_active_dhcp", s.handleDHCPFindActiveServer)
s.conf.HTTPRegister("POST", "/control/dhcp/add_static_lease", s.handleDHCPAddStaticLease)
s.conf.HTTPRegister("POST", "/control/dhcp/remove_static_lease", s.handleDHCPRemoveStaticLease)
s.conf.HTTPRegister("POST", "/control/dhcp/reset", s.handleReset)
}