Pull request: all: do not use dhcp clients when server is off

Closes #2934.

Squashed commit of the following:

commit 856ea4ec0c3ffb1da447b93260da90d37cd5d45d
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Apr 15 17:39:46 2021 +0300

    dnsforward: imp spacing

commit fa748e5a26cb6a38b5f87c5498287cb734ce7a59
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Apr 15 17:33:44 2021 +0300

    dnsforward: imp code

commit 771ba0de449faffff1cea523e8bbcc1039c992db
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Apr 15 17:06:03 2021 +0300

    all: do not use dhcp clients when server is off
This commit is contained in:
Ainar Garipov 2021-04-15 17:52:53 +03:00
parent b0013065a2
commit a1450c5595
8 changed files with 131 additions and 68 deletions

View File

@ -47,6 +47,8 @@ and this project adheres to
### Fixed
- Inconsistent resolving of DHCP clients when the DHCP server is disabled
([#2934]).
- Comment handling in clients' custom upstreams ([#2947]).
- Overwriting of DHCPv4 options when using the HTTP API ([#2927]).
- Assumption that MAC addresses always have the length of 6 octets ([#2828]).
@ -75,6 +77,7 @@ and this project adheres to
[#2838]: https://github.com/AdguardTeam/AdGuardHome/issues/2838
[#2889]: https://github.com/AdguardTeam/AdGuardHome/issues/2889
[#2927]: https://github.com/AdguardTeam/AdGuardHome/issues/2927
[#2934]: https://github.com/AdguardTeam/AdGuardHome/issues/2934
[#2945]: https://github.com/AdguardTeam/AdGuardHome/issues/2945
[#2947]: https://github.com/AdguardTeam/AdGuardHome/issues/2947

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@ -115,6 +115,7 @@ const (
LeaseChangedAdded = iota
LeaseChangedAddedStatic
LeaseChangedRemovedStatic
LeaseChangedRemovedAll
LeaseChangedDBStore
)

View File

@ -801,6 +801,10 @@ func (s *v4Server) Start() error {
log.Debug("dhcpv4: srv.Serve: %s", err)
}()
// Signal to the clients containers in packages home and dnsforward that
// it should reload the DHCP clients.
s.conf.notify(LeaseChangedAdded)
return nil
}
@ -815,7 +819,11 @@ func (s *v4Server) Stop() {
if err != nil {
log.Error("dhcpv4: srv.Close: %s", err)
}
// now s.srv.Serve() will return
// Signal to the clients containers in packages home and dnsforward that
// it should remove all DHCP clients.
s.conf.notify(LeaseChangedRemovedAll)
s.srv = nil
}

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@ -23,7 +23,7 @@ func TestV4_AddRemove_static(t *testing.T) {
SubnetMask: net.IP{255, 255, 255, 0},
notify: notify4,
})
require.Nil(t, err)
require.NoError(t, err)
ls := s.GetLeases(LeasesStatic)
assert.Empty(t, ls)
@ -33,23 +33,30 @@ func TestV4_AddRemove_static(t *testing.T) {
IP: net.IP{192, 168, 10, 150},
HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA},
}
require.Nil(t, s.AddStaticLease(l))
assert.NotNil(t, s.AddStaticLease(l))
err = s.AddStaticLease(l)
require.NoError(t, err)
err = s.AddStaticLease(l)
assert.Error(t, err)
ls = s.GetLeases(LeasesStatic)
require.Len(t, ls, 1)
assert.True(t, l.IP.Equal(ls[0].IP))
assert.Equal(t, l.HWAddr, ls[0].HWAddr)
assert.True(t, ls[0].IsStatic())
// Try to remove static lease.
assert.NotNil(t, s.RemoveStaticLease(Lease{
err = s.RemoveStaticLease(Lease{
IP: net.IP{192, 168, 10, 110},
HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA},
}))
})
assert.Error(t, err)
// Remove static lease.
require.Nil(t, s.RemoveStaticLease(l))
err = s.RemoveStaticLease(l)
require.NoError(t, err)
ls = s.GetLeases(LeasesStatic)
assert.Empty(t, ls)
}
@ -63,7 +70,7 @@ func TestV4_AddReplace(t *testing.T) {
SubnetMask: net.IP{255, 255, 255, 0},
notify: notify4,
})
require.Nil(t, err)
require.NoError(t, err)
s, ok := sIface.(*v4Server)
require.True(t, ok)
@ -78,7 +85,7 @@ func TestV4_AddReplace(t *testing.T) {
for i := range dynLeases {
err = s.addLease(&dynLeases[i])
require.Nil(t, err)
require.NoError(t, err)
}
stLeases := []Lease{{
@ -90,7 +97,8 @@ func TestV4_AddReplace(t *testing.T) {
}}
for _, l := range stLeases {
require.Nil(t, s.AddStaticLease(l))
err = s.AddStaticLease(l)
require.NoError(t, err)
}
ls := s.GetLeases(LeasesStatic)
@ -113,32 +121,35 @@ func TestV4StaticLease_Get(t *testing.T) {
SubnetMask: net.IP{255, 255, 255, 0},
notify: notify4,
})
require.Nil(t, err)
require.NoError(t, err)
s, ok := sIface.(*v4Server)
require.True(t, ok)
s.conf.dnsIPAddrs = []net.IP{{192, 168, 10, 1}}
l := Lease{
IP: net.IP{192, 168, 10, 150},
HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA},
}
require.Nil(t, s.AddStaticLease(l))
err = s.AddStaticLease(l)
require.NoError(t, err)
var req, resp *dhcpv4.DHCPv4
mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}
t.Run("discover", func(t *testing.T) {
var terr error
req, err = dhcpv4.NewDiscovery(mac)
require.NoError(t, err)
req, terr = dhcpv4.NewDiscovery(mac)
require.Nil(t, terr)
resp, err = dhcpv4.NewReplyFromRequest(req)
require.NoError(t, err)
resp, terr = dhcpv4.NewReplyFromRequest(req)
require.Nil(t, terr)
assert.Equal(t, 1, s.process(req, resp))
})
require.Nil(t, err)
// Don't continue if we got any errors in the previous subtest.
require.NoError(t, err)
t.Run("offer", func(t *testing.T) {
assert.Equal(t, dhcpv4.MessageTypeOffer, resp.MessageType())
@ -152,13 +163,15 @@ func TestV4StaticLease_Get(t *testing.T) {
t.Run("request", func(t *testing.T) {
req, err = dhcpv4.NewRequestFromOffer(resp)
require.Nil(t, err)
require.NoError(t, err)
resp, err = dhcpv4.NewReplyFromRequest(req)
require.Nil(t, err)
require.NoError(t, err)
assert.Equal(t, 1, s.process(req, resp))
})
require.Nil(t, err)
require.NoError(t, err)
t.Run("ack", func(t *testing.T) {
assert.Equal(t, dhcpv4.MessageTypeAck, resp.MessageType())
@ -172,11 +185,13 @@ func TestV4StaticLease_Get(t *testing.T) {
dnsAddrs := resp.DNS()
require.Len(t, dnsAddrs, 1)
assert.True(t, s.conf.GatewayIP.Equal(dnsAddrs[0]))
t.Run("check_lease", func(t *testing.T) {
ls := s.GetLeases(LeasesStatic)
require.Len(t, ls, 1)
assert.True(t, l.IP.Equal(ls[0].IP))
assert.Equal(t, mac, ls[0].HWAddr)
})
@ -196,10 +211,11 @@ func TestV4DynamicLease_Get(t *testing.T) {
"82 ip 1.2.3.4",
},
})
require.Nil(t, err)
require.NoError(t, err)
s, ok := sIface.(*v4Server)
require.True(t, ok)
s.conf.dnsIPAddrs = []net.IP{{192, 168, 10, 1}}
var req, resp *dhcpv4.DHCPv4
@ -207,15 +223,16 @@ func TestV4DynamicLease_Get(t *testing.T) {
t.Run("discover", func(t *testing.T) {
req, err = dhcpv4.NewDiscovery(mac)
require.Nil(t, err)
require.NoError(t, err)
resp, err = dhcpv4.NewReplyFromRequest(req)
require.Nil(t, err)
require.NoError(t, err)
assert.Equal(t, 1, s.process(req, resp))
})
// Don't continue if we got any errors in the previous subtest.
require.Nil(t, err)
require.NoError(t, err)
t.Run("offer", func(t *testing.T) {
assert.Equal(t, dhcpv4.MessageTypeOffer, resp.MessageType())
@ -226,6 +243,7 @@ func TestV4DynamicLease_Get(t *testing.T) {
router := resp.Router()
require.Len(t, router, 1)
assert.Equal(t, s.conf.GatewayIP, router[0])
assert.Equal(t, s.conf.subnetMask, resp.SubnetMask())
@ -236,16 +254,16 @@ func TestV4DynamicLease_Get(t *testing.T) {
})
t.Run("request", func(t *testing.T) {
var terr error
req, err = dhcpv4.NewRequestFromOffer(resp)
require.NoError(t, err)
req, terr = dhcpv4.NewRequestFromOffer(resp)
require.Nil(t, terr)
resp, err = dhcpv4.NewReplyFromRequest(req)
require.NoError(t, err)
resp, terr = dhcpv4.NewReplyFromRequest(req)
require.Nil(t, terr)
assert.Equal(t, 1, s.process(req, resp))
})
require.Nil(t, err)
require.NoError(t, err)
t.Run("ack", func(t *testing.T) {
assert.Equal(t, dhcpv4.MessageTypeAck, resp.MessageType())
@ -259,12 +277,14 @@ func TestV4DynamicLease_Get(t *testing.T) {
dnsAddrs := resp.DNS()
require.Len(t, dnsAddrs, 1)
assert.True(t, net.IP{192, 168, 10, 1}.Equal(dnsAddrs[0]))
// check lease
t.Run("check_lease", func(t *testing.T) {
ls := s.GetLeases(LeasesDynamic)
assert.Len(t, ls, 1)
require.Len(t, ls, 1)
assert.True(t, net.IP{192, 168, 10, 100}.Equal(ls[0].IP))
assert.Equal(t, mac, ls[0].HWAddr)
})

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@ -154,18 +154,38 @@ func isHostnameOK(hostname string) bool {
return true
}
func (s *Server) setTableHostToIP(t hostToIPTable) {
s.tableHostToIPLock.Lock()
defer s.tableHostToIPLock.Unlock()
s.tableHostToIP = t
}
func (s *Server) setTableIPToHost(t ipToHostTable) {
s.tableIPToHostLock.Lock()
defer s.tableIPToHostLock.Unlock()
s.tableIPToHost = t
}
func (s *Server) onDHCPLeaseChanged(flags int) {
add := true
switch flags {
case dhcpd.LeaseChangedAdded,
dhcpd.LeaseChangedAddedStatic,
dhcpd.LeaseChangedRemovedStatic:
//
// Go on.
case dhcpd.LeaseChangedRemovedAll:
add = false
default:
return
}
hostToIP := make(map[string]net.IP)
m := make(map[string]string)
var hostToIP hostToIPTable
var ipToHost ipToHostTable
if add {
hostToIP = make(hostToIPTable)
ipToHost = make(ipToHostTable)
ll := s.dhcpServer.Leases(dhcpd.LeasesAll)
@ -176,22 +196,18 @@ func (s *Server) onDHCPLeaseChanged(flags int) {
lowhost := strings.ToLower(l.Hostname)
m[l.IP.String()] = lowhost
ipToHost[l.IP.String()] = lowhost
ip := make(net.IP, 4)
copy(ip, l.IP.To4())
hostToIP[lowhost] = ip
}
log.Debug("dns: added %d A/PTR entries from DHCP", len(m))
log.Debug("dns: added %d A/PTR entries from DHCP", len(ipToHost))
}
s.tableHostToIPLock.Lock()
s.tableHostToIP = hostToIP
s.tableHostToIPLock.Unlock()
s.tablePTRLock.Lock()
s.tablePTR = m
s.tablePTRLock.Unlock()
s.setTableHostToIP(hostToIP)
s.setTableIPToHost(ipToHost)
}
// processDetermineLocal determines if the client's IP address is from
@ -336,14 +352,14 @@ func (s *Server) processRestrictLocal(ctx *dnsContext) (rc resultCode) {
// ipToHost tries to get a hostname leased by DHCP. It's safe for concurrent
// use.
func (s *Server) ipToHost(ip net.IP) (host string, ok bool) {
s.tablePTRLock.Lock()
defer s.tablePTRLock.Unlock()
s.tableIPToHostLock.Lock()
defer s.tableIPToHostLock.Unlock()
if s.tablePTR == nil {
if s.tableIPToHost == nil {
return "", false
}
host, ok = s.tablePTR[ip.String()]
host, ok = s.tableIPToHost[ip.String()]
return host, ok
}

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@ -91,7 +91,7 @@ func TestServer_ProcessInternalHosts_localRestriction(t *testing.T) {
t.Run(tc.name, func(t *testing.T) {
s := &Server{
autohostSuffix: defaultAutohostSuffix,
tableHostToIP: map[string]net.IP{
tableHostToIP: hostToIPTable{
"example": knownIP,
},
}
@ -202,7 +202,7 @@ func TestServer_ProcessInternalHosts(t *testing.T) {
t.Run(tc.name, func(t *testing.T) {
s := &Server{
autohostSuffix: tc.suffix,
tableHostToIP: map[string]net.IP{
tableHostToIP: hostToIPTable{
"example": knownIP,
},
}

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@ -43,6 +43,15 @@ var defaultBlockedHosts = []string{"version.bind", "id.server", "hostname.bind"}
var webRegistered bool
// hostToIPTable is an alias for the type of Server.tableHostToIP.
type hostToIPTable = map[string]net.IP
// ipToHostTable is an alias for the type of Server.tableIPToHost.
//
// TODO(a.garipov): Define an IPMap type in aghnet and use here and in other
// places?
type ipToHostTable = map[string]string
// Server is the main way to start a DNS server.
//
// Example:
@ -69,11 +78,11 @@ type Server struct {
subnetDetector *aghnet.SubnetDetector
localResolvers *proxy.Proxy
tableHostToIP map[string]net.IP // "hostname -> IP" table for internal addresses (DHCP)
tableHostToIP hostToIPTable
tableHostToIPLock sync.Mutex
tablePTR map[string]string // "IP -> hostname" table for reverse lookup
tablePTRLock sync.Mutex
tableIPToHost ipToHostTable
tableIPToHostLock sync.Mutex
// DNS proxy instance for internal usage
// We don't Start() it and so no listen port is required.

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@ -121,7 +121,7 @@ func (clients *clientsContainer) Init(
clients.addFromConfig(objects)
if !clients.testing {
clients.addFromDHCP()
clients.updateFromDHCP(true)
if clients.dhcpServer != nil {
clients.dhcpServer.SetOnLeaseChanged(clients.onDHCPLeaseChanged)
}
@ -244,7 +244,9 @@ func (clients *clientsContainer) onDHCPLeaseChanged(flags int) {
case dhcpd.LeaseChangedAdded,
dhcpd.LeaseChangedAddedStatic,
dhcpd.LeaseChangedRemovedStatic:
clients.addFromDHCP()
clients.updateFromDHCP(true)
case dhcpd.LeaseChangedRemovedAll:
clients.updateFromDHCP(false)
}
}
@ -768,9 +770,9 @@ func (clients *clientsContainer) addFromSystemARP() {
log.Debug("clients: added %d client aliases from 'arp -a' command output", n)
}
// addFromDHCP adds the clients that have a non-empty hostname from the DHCP
// updateFromDHCP adds the clients that have a non-empty hostname from the DHCP
// server.
func (clients *clientsContainer) addFromDHCP() {
func (clients *clientsContainer) updateFromDHCP(add bool) {
if clients.dhcpServer == nil {
return
}
@ -780,6 +782,10 @@ func (clients *clientsContainer) addFromDHCP() {
clients.rmHostsBySrc(ClientSourceDHCP)
if !add {
return
}
leases := clients.dhcpServer.Leases(dhcpd.LeasesAll)
n := 0
for _, l := range leases {