Pull request 1978: 4923 gopacket dhcp vol.2

Merge in DNS/adguard-home from 4923-gopacket-dhcp-vol.2 to master Updates #4923. Squashed commit of the following: commit d0ef7d44af9790ed55401f6f65c7149f4c3658f7 Merge: f92b4c72d a4fdc3e8e Author: Eugene Burkov <E.Burkov@AdGuard.COM> Date: Wed Aug 30 13:43:41 2023 +0300 Merge branch 'master' into 4923-gopacket-dhcp-vol.2 commit f92b4c72de03ceacb9b8890b7cf4307688795ce5 Author: Eugene Burkov <E.Burkov@AdGuard.COM> Date: Mon Aug 28 12:33:29 2023 +0300 dhcpd: imp code commit 63f0fce99a0343af2670943770cfef4694ae93ed Author: Eugene Burkov <E.Burkov@AdGuard.COM> Date: Thu Aug 24 15:01:34 2023 +0300 all: imp dhcpd code commit 563b43b4b5ab6c9c9046c7f09008ea3ef344f4e9 Author: Eugene Burkov <E.Burkov@AdGuard.COM> Date: Fri Jul 28 17:03:55 2023 +0300 dhcpd: imp indexing commit 340d3efa90ac4d34ba3d18702692de0fbc0247be Author: Eugene Burkov <E.Burkov@AdGuard.COM> Date: Fri Jul 28 16:22:43 2023 +0300 all: adapt current code
2023-08-30 14:02:12 +03:00
parent a4fdc3e8ed
commit a325c9b6bb
18 changed files with 502 additions and 394 deletions
--- a/internal/dhcpd/config.go
+++ b/internal/dhcpd/config.go
@@ -23,9 +23,12 @@ type ServerConfig struct {
 	Enabled       bool   `yaml:"enabled"`
 	InterfaceName string `yaml:"interface_name"`

-	// LocalDomainName is the domain name used for DHCP hosts.  For example,
-	// a DHCP client with the hostname "myhost" can be addressed as "myhost.lan"
+	// LocalDomainName is the domain name used for DHCP hosts.  For example, a
+	// DHCP client with the hostname "myhost" can be addressed as "myhost.lan"
 	// when LocalDomainName is "lan".
+	//
+	// TODO(e.burkov):  Probably, remove this field.  See the TODO on
+	// [Interface.Enabled].
 	LocalDomainName string `yaml:"local_domain_name"`

 	Conf4 V4ServerConf `yaml:"dhcpv4"`
@@ -58,6 +61,14 @@ type DHCPServer interface {
 	// there is one.
 	FindMACbyIP(ip netip.Addr) (mac net.HardwareAddr)

+	// HostByIP returns a hostname by the IP address of its lease, if there is
+	// one.
+	HostByIP(ip netip.Addr) (host string)
+
+	// IPByHost returns an IP address by the hostname of its lease, if there is
+	// one.
+	IPByHost(host string) (ip netip.Addr)
+
 	// WriteDiskConfig4 - copy disk configuration
 	WriteDiskConfig4(c *V4ServerConf)
 	// WriteDiskConfig6 - copy disk configuration
--- a/internal/dhcpd/dhcpd.go
+++ b/internal/dhcpd/dhcpd.go
@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"time"

+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpsvc"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/timeutil"
 	"golang.org/x/exp/slices"
@@ -31,6 +32,8 @@ const (
 // Lease contains the necessary information about a DHCP lease.  It's used as is
 // in the database, so don't change it until it's absolutely necessary, see
 // [dataVersion].
+//
+// TODO(e.burkov):  Unexport it and use [dhcpsvc.Lease].
 type Lease struct {
 	// Expiry is the expiration time of the lease.
 	Expiry time.Time `json:"expires"`
@@ -153,53 +156,37 @@ const (
 type Interface interface {
 	Start() (err error)
 	Stop() (err error)
+
+	// Enabled returns true if the DHCP server is running.
+	//
+	// TODO(e.burkov):  Currently, we need this method to determine whether the
+	// local domain suffix should be considered while resolving A/AAAA requests.
+	// This is because other parts of the code aren't aware of the DNS suffixes
+	// in DHCP clients names and caller is responsible for trimming it.  This
+	// behavior should be changed in the future.
 	Enabled() (ok bool)

-	Leases(flags GetLeasesFlags) (leases []*Lease)
-	SetOnLeaseChanged(onLeaseChanged OnLeaseChangedT)
-	FindMACbyIP(ip netip.Addr) (mac net.HardwareAddr)
+	// Leases returns all the leases in the database.
+	Leases() (leases []*dhcpsvc.Lease)
+
+	// MacByIP returns the MAC address of a client with ip.  It returns nil if
+	// there is no such client, due to an assumption that a DHCP client must
+	// always have a HardwareAddr.
+	MACByIP(ip netip.Addr) (mac net.HardwareAddr)
+
+	// HostByIP returns the hostname of the DHCP client with the given IP
+	// address.  The address will be netip.Addr{} if there is no such client,
+	// due to an assumption that a DHCP client must always have an IP address.
+	HostByIP(ip netip.Addr) (host string)
+
+	// IPByHost returns the IP address of the DHCP client with the given
+	// hostname.  The address will be netip.Addr{} if there is no such client,
+	// due to an assumption that a DHCP client must always have an IP address.
+	IPByHost(host string) (ip netip.Addr)

 	WriteDiskConfig(c *ServerConfig)
 }

-// MockInterface is a mock Interface implementation.
-//
-// TODO(e.burkov):  Move to aghtest when the API stabilized.
-type MockInterface struct {
-	OnStart             func() (err error)
-	OnStop              func() (err error)
-	OnEnabled           func() (ok bool)
-	OnLeases            func(flags GetLeasesFlags) (leases []*Lease)
-	OnSetOnLeaseChanged func(f OnLeaseChangedT)
-	OnFindMACbyIP       func(ip netip.Addr) (mac net.HardwareAddr)
-	OnWriteDiskConfig   func(c *ServerConfig)
-}
-
-var _ Interface = (*MockInterface)(nil)
-
-// Start implements the Interface for *MockInterface.
-func (s *MockInterface) Start() (err error) { return s.OnStart() }
-
-// Stop implements the Interface for *MockInterface.
-func (s *MockInterface) Stop() (err error) { return s.OnStop() }
-
-// Enabled implements the Interface for *MockInterface.
-func (s *MockInterface) Enabled() (ok bool) { return s.OnEnabled() }
-
-// Leases implements the Interface for *MockInterface.
-func (s *MockInterface) Leases(flags GetLeasesFlags) (ls []*Lease) { return s.OnLeases(flags) }
-
-// SetOnLeaseChanged implements the Interface for *MockInterface.
-func (s *MockInterface) SetOnLeaseChanged(f OnLeaseChangedT) { s.OnSetOnLeaseChanged(f) }
-
-// FindMACbyIP implements the [Interface] for *MockInterface.
-func (s *MockInterface) FindMACbyIP(ip netip.Addr) (mac net.HardwareAddr) {
-	return s.OnFindMACbyIP(ip)
-}
-
-// WriteDiskConfig implements the Interface for *MockInterface.
-func (s *MockInterface) WriteDiskConfig(c *ServerConfig) { s.OnWriteDiskConfig(c) }
-
 // server is the DHCP service that handles DHCPv4, DHCPv6, and HTTP API.
 type server struct {
 	srv4 DHCPServer
@@ -269,7 +256,8 @@ func Create(conf *ServerConfig) (s *server, err error) {
 }

 // setServers updates DHCPv4 and DHCPv6 servers created from the provided
-// configuration conf.
+// configuration conf.  It returns the status of both the DHCPv4 and the DHCPv6
+// servers, which is always false for corresponding server on any error.
 func (s *server) setServers(conf *ServerConfig) (v4Enabled, v6Enabled bool, err error) {
 	v4conf := conf.Conf4
 	v4conf.InterfaceName = s.conf.InterfaceName
@@ -279,7 +267,7 @@ func (s *server) setServers(conf *ServerConfig) (v4Enabled, v6Enabled bool, err
 	s.srv4, err = v4Create(&v4conf)
 	if err != nil {
 		if v4conf.Enabled {
-			return true, false, fmt.Errorf("creating dhcpv4 srv: %w", err)
+			return false, false, fmt.Errorf("creating dhcpv4 srv: %w", err)
 		}

 		log.Debug("dhcpd: warning: creating dhcpv4 srv: %s", err)
@@ -288,14 +276,11 @@ func (s *server) setServers(conf *ServerConfig) (v4Enabled, v6Enabled bool, err
 	v6conf := conf.Conf6
 	v6conf.InterfaceName = s.conf.InterfaceName
 	v6conf.notify = s.onNotify
-	v6conf.Enabled = s.conf.Enabled
-	if len(v6conf.RangeStart) == 0 {
-		v6conf.Enabled = false
-	}
+	v6conf.Enabled = s.conf.Enabled && len(v6conf.RangeStart) != 0

 	s.srv6, err = v6Create(v6conf)
 	if err != nil {
-		return v4conf.Enabled, v6conf.Enabled, fmt.Errorf("creating dhcpv6 srv: %w", err)
+		return v4conf.Enabled, false, fmt.Errorf("creating dhcpv6 srv: %w", err)
 	}

 	return v4conf.Enabled, v6conf.Enabled, nil
@@ -337,11 +322,6 @@ func (s *server) onNotify(flags uint32) {
 	s.notify(int(flags))
 }

-// SetOnLeaseChanged - set callback
-func (s *server) SetOnLeaseChanged(onLeaseChanged OnLeaseChangedT) {
-	s.onLeaseChanged = append(s.onLeaseChanged, onLeaseChanged)
-}
-
 func (s *server) notify(flags int) {
 	for _, f := range s.onLeaseChanged {
 		f(flags)
@@ -388,15 +368,26 @@ func (s *server) Stop() (err error) {
 	return nil
 }

-// Leases returns the list of active IPv4 and IPv6 DHCP leases.  It's safe for
-// concurrent use.
-func (s *server) Leases(flags GetLeasesFlags) (leases []*Lease) {
-	return append(s.srv4.GetLeases(flags), s.srv6.GetLeases(flags)...)
+// Leases returns the list of active DHCP leases.
+func (s *server) Leases() (leases []*dhcpsvc.Lease) {
+	ls := append(s.srv4.GetLeases(LeasesAll), s.srv6.GetLeases(LeasesAll)...)
+	leases = make([]*dhcpsvc.Lease, len(ls))
+	for i, l := range ls {
+		leases[i] = &dhcpsvc.Lease{
+			Expiry:   l.Expiry,
+			Hostname: l.Hostname,
+			HWAddr:   l.HWAddr,
+			IP:       l.IP,
+			IsStatic: l.IsStatic,
+		}
+	}
+
+	return leases
 }

-// FindMACbyIP returns a MAC address by the IP address of its lease, if there is
+// MACByIP returns a MAC address by the IP address of its lease, if there is
 // one.
-func (s *server) FindMACbyIP(ip netip.Addr) (mac net.HardwareAddr) {
+func (s *server) MACByIP(ip netip.Addr) (mac net.HardwareAddr) {
 	if ip.Is4() {
 		return s.srv4.FindMACbyIP(ip)
 	}
@@ -404,6 +395,24 @@ func (s *server) FindMACbyIP(ip netip.Addr) (mac net.HardwareAddr) {
 	return s.srv6.FindMACbyIP(ip)
 }

+// HostByIP implements the [Interface] interface for *server.
+//
+// TODO(e.burkov):  Implement this method for DHCPv6.
+func (s *server) HostByIP(ip netip.Addr) (host string) {
+	if ip.Is4() {
+		return s.srv4.HostByIP(ip)
+	}
+
+	return ""
+}
+
+// IPByHost implements the [Interface] interface for *server.
+//
+// TODO(e.burkov):  Implement this method for DHCPv6.
+func (s *server) IPByHost(host string) (ip netip.Addr) {
+	return s.srv4.IPByHost(host)
+}
+
 // AddStaticLease - add static v4 lease
 func (s *server) AddStaticLease(l *Lease) error {
 	return s.srv4.AddStaticLease(l)
--- a/internal/dhcpd/http_unix.go
+++ b/internal/dhcpd/http_unix.go
@@ -14,9 +14,11 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/aghalg"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpsvc"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
+	"golang.org/x/exp/slices"
 )

 type v4ServerConfJSON struct {
@@ -75,7 +77,7 @@ type leaseStatic struct {
 }

 // leasesToStatic converts list of leases to their JSON form.
-func leasesToStatic(leases []*Lease) (static []*leaseStatic) {
+func leasesToStatic(leases []*dhcpsvc.Lease) (static []*leaseStatic) {
 	static = make([]*leaseStatic, len(leases))

 	for i, l := range leases {
@@ -113,7 +115,7 @@ type leaseDynamic struct {
 }

 // leasesToDynamic converts list of leases to their JSON form.
-func leasesToDynamic(leases []*Lease) (dynamic []*leaseDynamic) {
+func leasesToDynamic(leases []*dhcpsvc.Lease) (dynamic []*leaseDynamic) {
 	dynamic = make([]*leaseDynamic, len(leases))

 	for i, l := range leases {
@@ -143,8 +145,27 @@ func (s *server) handleDHCPStatus(w http.ResponseWriter, r *http.Request) {
 	s.srv4.WriteDiskConfig4(&status.V4)
 	s.srv6.WriteDiskConfig6(&status.V6)

-	status.Leases = leasesToDynamic(s.Leases(LeasesDynamic))
-	status.StaticLeases = leasesToStatic(s.Leases(LeasesStatic))
+	leases := s.Leases()
+	slices.SortFunc(leases, func(a, b *dhcpsvc.Lease) (res int) {
+		if a.IsStatic == b.IsStatic {
+			return 0
+		} else if a.IsStatic {
+			return -1
+		} else {
+			return 1
+		}
+	})
+
+	dynamicIdx := slices.IndexFunc(leases, func(l *dhcpsvc.Lease) (ok bool) {
+		return !l.IsStatic
+	})
+
+	if dynamicIdx == -1 {
+		dynamicIdx = len(leases)
+	}
+
+	status.Leases = leasesToDynamic(leases[dynamicIdx:])
+	status.StaticLeases = leasesToStatic(leases[:dynamicIdx])

 	aghhttp.WriteJSONResponseOK(w, r, status)
 }
--- a/internal/dhcpd/v46_windows.go
+++ b/internal/dhcpd/v46_windows.go
@@ -24,6 +24,8 @@ func (winServer) WriteDiskConfig4(_ *V4ServerConf)                {}
 func (winServer) WriteDiskConfig6(_ *V6ServerConf)                {}
 func (winServer) Start() (err error)                              { return nil }
 func (winServer) Stop() (err error)                               { return nil }
+func (winServer) HostByIP(_ netip.Addr) (host string)             { return "" }
+func (winServer) IPByHost(_ string) (ip netip.Addr)               { return netip.Addr{} }

 func v4Create(_ *V4ServerConf) (s DHCPServer, err error) { return winServer{}, nil }
 func v6Create(_ V6ServerConf) (s DHCPServer, err error)  { return winServer{}, nil }
--- a/internal/dhcpd/v4_unix.go
+++ b/internal/dhcpd/v4_unix.go
@@ -15,7 +15,6 @@ import (
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/golibs/timeutil"
 	"github.com/go-ping/ping"
 	"github.com/insomniacslk/dhcp/dhcpv4"
@@ -46,11 +45,14 @@ type v4Server struct {
 	// leased.
 	leasedOffsets *bitSet

-	// leaseHosts is the set of all hostnames of all known DHCP clients.
-	leaseHosts *stringutil.Set
-
 	// leases contains all dynamic and static leases.
 	leases []*Lease
+
+	// hostsIndex is the set of all hostnames of all known DHCP clients.
+	hostsIndex map[string]*Lease
+
+	// ipIndex is an index of leases by their IP addresses.
+	ipIndex map[netip.Addr]*Lease
 }

 func (s *v4Server) enabled() (ok bool) {
@@ -114,6 +116,30 @@ func (s *v4Server) validHostnameForClient(cliHostname string, ip netip.Addr) (ho
 	return hostname
 }

+// HostByIP implements the [Interface] interface for *v4Server.
+func (s *v4Server) HostByIP(ip netip.Addr) (host string) {
+	s.leasesLock.Lock()
+	defer s.leasesLock.Unlock()
+
+	if l, ok := s.ipIndex[ip]; ok {
+		return l.Hostname
+	}
+
+	return ""
+}
+
+// IPByHost implements the [Interface] interface for *v4Server.
+func (s *v4Server) IPByHost(host string) (ip netip.Addr) {
+	s.leasesLock.Lock()
+	defer s.leasesLock.Unlock()
+
+	if l, ok := s.hostsIndex[host]; ok {
+		return l.IP
+	}
+
+	return netip.Addr{}
+}
+
 // ResetLeases resets leases.
 func (s *v4Server) ResetLeases(leases []*Lease) (err error) {
 	defer func() { err = errors.Annotate(err, "dhcpv4: %w") }()
@@ -123,7 +149,8 @@ func (s *v4Server) ResetLeases(leases []*Lease) (err error) {
 	}

 	s.leasedOffsets = newBitSet()
-	s.leaseHosts = stringutil.NewSet()
+	s.hostsIndex = make(map[string]*Lease, len(leases))
+	s.ipIndex = make(map[netip.Addr]*Lease, len(leases))
 	s.leases = nil

 	for _, l := range leases {
@@ -199,20 +226,18 @@ func (s *v4Server) GetLeases(flags GetLeasesFlags) (leases []*Lease) {

 // FindMACbyIP implements the [Interface] for *v4Server.
 func (s *v4Server) FindMACbyIP(ip netip.Addr) (mac net.HardwareAddr) {
+	if !ip.Is4() {
+		return nil
+	}
+
 	now := time.Now()

 	s.leasesLock.Lock()
 	defer s.leasesLock.Unlock()

-	if !ip.Is4() {
-		return nil
-	}
-
-	for _, l := range s.leases {
-		if l.IP == ip {
-			if l.IsStatic || l.Expiry.After(now) {
-				return l.HWAddr
-			}
+	if l, ok := s.ipIndex[ip]; ok {
+		if l.IsStatic || l.Expiry.After(now) {
+			return l.HWAddr
 		}
 	}

@@ -249,7 +274,8 @@ func (s *v4Server) rmLeaseByIndex(i int) {
 		s.leasedOffsets.set(offset, false)
 	}

-	s.leaseHosts.Del(l.Hostname)
+	delete(s.hostsIndex, l.Hostname)
+	delete(s.ipIndex, l.IP)

 	log.Debug("dhcpv4: removed lease %s (%s)", l.IP, l.HWAddr)
 }
@@ -303,13 +329,15 @@ func (s *v4Server) addLease(l *Lease) (err error) {
 		return fmt.Errorf("lease %s (%s) out of range, not adding", l.IP, l.HWAddr)
 	}

+	// TODO(e.burkov):  l must have a valid hostname here, investigate.
 	if l.Hostname != "" {
-		if s.leaseHosts.Has(l.Hostname) {
+		if _, ok := s.hostsIndex[l.Hostname]; ok {
 			return ErrDupHostname
 		}

-		s.leaseHosts.Add(l.Hostname)
+		s.hostsIndex[l.Hostname] = l
 	}
+	s.ipIndex[l.IP] = l

 	s.leases = append(s.leases, l)
 	s.leasedOffsets.set(offset, true)
@@ -574,7 +602,7 @@ func (s *v4Server) commitLease(l *Lease, hostname string) {
 	prev := l.Hostname
 	hostname = s.validHostnameForClient(hostname, l.IP)

-	if s.leaseHosts.Has(hostname) {
+	if _, ok := s.hostsIndex[hostname]; ok {
 		log.Info("dhcpv4: hostname %q already exists", hostname)

 		if prev == "" {
@@ -590,11 +618,12 @@ func (s *v4Server) commitLease(l *Lease, hostname string) {

 	l.Expiry = time.Now().Add(s.conf.leaseTime)
 	if prev != "" && prev != l.Hostname {
-		s.leaseHosts.Del(prev)
+		delete(s.hostsIndex, prev)
 	}
 	if l.Hostname != "" {
-		s.leaseHosts.Add(l.Hostname)
+		s.hostsIndex[l.Hostname] = l
 	}
+	s.ipIndex[l.IP] = l
 }

 // allocateLease allocates a new lease for the MAC address.  If there are no IP
@@ -1292,7 +1321,8 @@ func (s *v4Server) Stop() (err error) {
 // Create DHCPv4 server
 func v4Create(conf *V4ServerConf) (srv *v4Server, err error) {
 	s := &v4Server{
-		leaseHosts: stringutil.NewSet(),
+		hostsIndex: map[string]*Lease{},
+		ipIndex:    map[netip.Addr]*Lease{},
 	}

 	err = conf.Validate()
--- a/internal/dhcpd/v4_unix_test.go
+++ b/internal/dhcpd/v4_unix_test.go
@@ -791,6 +791,14 @@ func TestV4Server_FindMACbyIP(t *testing.T) {
 			IP:       anotherIP,
 		}},
 	}
+	s.ipIndex = map[netip.Addr]*Lease{
+		staticIP:  s.leases[0],
+		anotherIP: s.leases[1],
+	}
+	s.hostsIndex = map[string]*Lease{
+		staticName:  s.leases[0],
+		anotherName: s.leases[1],
+	}

 	testCases := []struct {
 		want net.HardwareAddr
--- a/internal/dhcpd/v6_unix.go
+++ b/internal/dhcpd/v6_unix.go
@@ -26,15 +26,14 @@ const valueIAID = "ADGH" // value for IANA.ID
 //
 // TODO(a.garipov): Think about unifying this and v4Server.
 type v6Server struct {
-	srv        *server6.Server
-	leasesLock sync.Mutex
-	leases     []*Lease
-	ipAddrs    [256]byte
-	sid        dhcpv6.DUID
-
-	ra raCtx // RA module
-
+	ra   raCtx
 	conf V6ServerConf
+	sid  dhcpv6.DUID
+	srv  *server6.Server
+
+	leases     []*Lease
+	leasesLock sync.Mutex
+	ipAddrs    [256]byte
 }

 // WriteDiskConfig4 - write configuration
@@ -59,6 +58,34 @@ func ip6InRange(start, ip net.IP) bool {
 	return start[15] <= ip[15]
 }

+// HostByIP implements the [Interface] interface for *v6Server.
+func (s *v6Server) HostByIP(ip netip.Addr) (host string) {
+	s.leasesLock.Lock()
+	defer s.leasesLock.Unlock()
+
+	for _, l := range s.leases {
+		if l.IP == ip {
+			return l.Hostname
+		}
+	}
+
+	return ""
+}
+
+// IPByHost implements the [Interface] interface for *v6Server.
+func (s *v6Server) IPByHost(host string) (ip netip.Addr) {
+	s.leasesLock.Lock()
+	defer s.leasesLock.Unlock()
+
+	for _, l := range s.leases {
+		if l.Hostname == host {
+			return l.IP
+		}
+	}
+
+	return netip.Addr{}
+}
+
 // ResetLeases resets leases.
 func (s *v6Server) ResetLeases(leases []*Lease) (err error) {
 	defer func() { err = errors.Annotate(err, "dhcpv6: %w") }()