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Pull request: dhcpd imp code

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Merge in DNS/adguard-home from dhcpd-imp-code to master

Squashed commit of the following:

commit 413403c169bd3f6b5f2ed63b783d078dbb15e054
Merge: eed183850 0fec990bc
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Fri May 26 12:46:25 2023 +0300

    Merge remote-tracking branch 'origin/master' into dhcpd-imp-code

commit eed1838502add1e16e5d3ada03778f21913fd5e5
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Fri May 26 12:16:46 2023 +0300

    dhcpd: imp docs

commit fa4fe036f7b1f2b49201bf0b5b904f99989082f0
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu May 25 11:32:34 2023 +0300

    all: lint script

commit a4022b3d4bbfa709e5096397bbe64ea406c8a366
Merge: e08ff3a26 cbc7985e7
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu May 25 11:29:57 2023 +0300

    Merge remote-tracking branch 'origin/master' into dhcpd-imp-code

    # Conflicts:
    #	scripts/make/go-lint.sh

commit e08ff3a26414e201d6e75608363db941fa2f5b39
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Wed May 24 15:43:11 2023 +0300

    dhcpd: imp code

commit 970b538f8ea94d3732d77bfb648e402a1d28ab06
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Wed May 24 15:40:36 2023 +0300

    dhcpd: imp code

commit 0e5916ddd7514af983e8557080d55d6aeb6fbbc0
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Wed May 24 15:37:17 2023 +0300

    dhcpd: imp code

commit e06a6c6031b232e76ae2be3e3b8fe1a2ffa715e0
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 16:40:09 2023 +0300

    dhcpd: imp code

commit eed4ff10ff1b29c71d70fb7978706efde89afee1
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 15:45:06 2023 +0300

    all: lint script

commit 87f84ace5f6f34dbc28befa8257d1d2492c5e0a4
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 15:44:23 2023 +0300

    dhcpd: imp code

commit a54c9929d51de1f1e6807d650fd08dd80ddbf147
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 14:29:42 2023 +0300

    dhcpd: imp code

commit 1bbea342f7f55587724aa9a29d9657e5ce75f5d8
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 14:12:09 2023 +0300

    dhcpd: imp code

commit 48fb4eff73683e799ddb3076afdcf7b067ca24b6
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 13:57:59 2023 +0300

    dhcpd: imp code

commit f6cd7fcb8d4c1c815a20875d777ea1eca2c8ea89
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 13:17:54 2023 +0300

    dhcpd: imp code

commit 2b91dc25bbaa16dba6d9389a4e2224cf91eb4554
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Tue May 23 12:57:46 2023 +0300

    dhcpd: imp code

commit 34f5dd58764080f6202fc9a1abd751a15dbf7090
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 22 15:31:39 2023 +0300

    dhcpd: imp code

commit 12ef0d225064a1b78adf7b2cfca21a8dba92ca8e
Merge: 6b62a7665 24b41100c
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 22 13:03:41 2023 +0300

    Merge remote-tracking branch 'origin/master' into dhcpd-imp-code

commit 6b62a7665720b85398d65a1926518a63e6bb6403
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 22 12:55:43 2023 +0300

    dhcpd: imp code

commit 18c5cdf0480fac7711282027a64d58704c75af5f
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 22 12:48:30 2023 +0300

    dhcpd: imp code

commit e7c1f4324cba3fe86cf56df6b971791a5a8790de
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 22 12:37:15 2023 +0300

    dhcpd: imp code

... and 1 more commit
This commit is contained in:
Dimitry Kolyshev
2023-05-26 12:50:03 +03:00
parent 0fec990bcf
commit ea8d634f65
8 changed files with 401 additions and 296 deletions
Download Patch File Download Diff File Expand all files Collapse all files

271
internal/dhcpd/v4_unix.go
View File

@@ -342,8 +342,8 @@ func (s *v4Server) rmLease(lease *Lease) (err error) {
// server to be configured and it's not.
const ErrUnconfigured errors.Error = "server is unconfigured"
// AddStaticLease implements the DHCPServer interface for *v4Server. It is safe
// for concurrent use.
// AddStaticLease implements the DHCPServer interface for *v4Server. It is
// safe for concurrent use.
func (s *v4Server) AddStaticLease(l *Lease) (err error) {
defer func() { err = errors.Annotate(err, "dhcpv4: adding static lease: %w") }()
@@ -354,21 +354,23 @@ func (s *v4Server) AddStaticLease(l *Lease) (err error) {
l.IP = l.IP.Unmap()
if !l.IP.Is4() {
return fmt.Errorf("invalid ip %q, only ipv4 is supported", l.IP)
return fmt.Errorf("invalid IP %q: only IPv4 is supported", l.IP)
} else if gwIP := s.conf.GatewayIP; gwIP == l.IP {
return fmt.Errorf("can't assign the gateway IP %s to the lease", gwIP)
return fmt.Errorf("can't assign the gateway IP %q to the lease", gwIP)
}
l.IsStatic = true
err = netutil.ValidateMAC(l.HWAddr)
if err != nil {
// Don't wrap the error, because it's informative enough as is.
return err
}
if hostname := l.Hostname; hostname != "" {
hostname, err = normalizeHostname(hostname)
if err != nil {
// Don't wrap the error, because it's informative enough as is.
return err
}
@@ -386,32 +388,9 @@ func (s *v4Server) AddStaticLease(l *Lease) (err error) {
l.Hostname = hostname
}
// Perform the following actions in an anonymous function to make sure
// that the lock gets unlocked before the notification step.
func() {
s.leasesLock.Lock()
defer s.leasesLock.Unlock()
err = s.rmDynamicLease(l)
if err != nil {
err = fmt.Errorf(
"removing dynamic leases for %s (%s): %w",
l.IP,
l.HWAddr,
err,
)
return
}
err = s.addLease(l)
if err != nil {
err = fmt.Errorf("adding static lease for %s (%s): %w", l.IP, l.HWAddr, err)
return
}
}()
err = s.updateStaticLease(l)
if err != nil {
// Don't wrap the error, because it's informative enough as is.
return err
}
@@ -421,6 +400,25 @@ func (s *v4Server) AddStaticLease(l *Lease) (err error) {
return nil
}
// updateStaticLease safe removes dynamic lease with the same properties and
// then adds a static lease l.
func (s *v4Server) updateStaticLease(l *Lease) (err error) {
s.leasesLock.Lock()
defer s.leasesLock.Unlock()
err = s.rmDynamicLease(l)
if err != nil {
return fmt.Errorf("removing dynamic leases for %s (%s): %w", l.IP, l.HWAddr, err)
}
err = s.addLease(l)
if err != nil {
return fmt.Errorf("adding static lease for %s (%s): %w", l.IP, l.HWAddr, err)
}
return nil
}
// RemoveStaticLease removes a static lease. It is safe for concurrent use.
func (s *v4Server) RemoveStaticLease(l *Lease) (err error) {
defer func() { err = errors.Annotate(err, "dhcpv4: %w") }()
@@ -894,24 +892,9 @@ func (s *v4Server) handleDecline(req, resp *dhcpv4.DHCPv4) (err error) {
reqIP = req.ClientIPAddr
}
netIP, ok := netip.AddrFromSlice(reqIP)
if !ok {
log.Info("dhcpv4: invalid IP: %s", reqIP)
return nil
}
var oldLease *Lease
for _, l := range s.leases {
if bytes.Equal(l.HWAddr, mac) && l.IP == netIP {
oldLease = l
break
}
}
oldLease := s.findLeaseForIP(reqIP, mac)
if oldLease == nil {
log.Info("dhcpv4: lease with ip %s for %s not found", reqIP, mac)
log.Info("dhcpv4: lease with IP %s for %s not found", reqIP, mac)
return nil
}
@@ -925,7 +908,7 @@ func (s *v4Server) handleDecline(req, resp *dhcpv4.DHCPv4) (err error) {
if err != nil {
return fmt.Errorf("allocating new lease for %s: %w", mac, err)
} else if newLease == nil {
log.Info("dhcpv4: allocating new lease for %s: no more ip addresses", mac)
log.Info("dhcpv4: allocating new lease for %s: no more IP addresses", mac)
resp.YourIPAddr = make([]byte, 4)
resp.UpdateOption(dhcpv4.OptMessageType(dhcpv4.MessageTypeAck))
@@ -941,15 +924,32 @@ func (s *v4Server) handleDecline(req, resp *dhcpv4.DHCPv4) (err error) {
return fmt.Errorf("adding new lease for %s: %w", mac, err)
}
log.Info("dhcpv4: changed ip from %s to %s for %s", reqIP, newLease.IP, mac)
resp.YourIPAddr = net.IP(newLease.IP.AsSlice())
log.Info("dhcpv4: changed IP from %s to %s for %s", reqIP, newLease.IP, mac)
resp.YourIPAddr = newLease.IP.AsSlice()
resp.UpdateOption(dhcpv4.OptMessageType(dhcpv4.MessageTypeAck))
return nil
}
// findLeaseForIP returns a lease for provided ip and mac.
func (s *v4Server) findLeaseForIP(ip net.IP, mac net.HardwareAddr) (l *Lease) {
netIP, ok := netip.AddrFromSlice(ip)
if !ok {
log.Info("dhcpv4: invalid IP: %s", ip)
return nil
}
for _, il := range s.leases {
if bytes.Equal(il.HWAddr, mac) && il.IP == netIP {
return il
}
}
return nil
}
// handleRelease is the handler for the DHCP Release request.
func (s *v4Server) handleRelease(req, resp *dhcpv4.DHCPv4) (err error) {
mac := req.ClientHWAddr
@@ -995,11 +995,80 @@ func (s *v4Server) handleRelease(req, resp *dhcpv4.DHCPv4) (err error) {
return nil
}
// Find a lease associated with MAC and prepare response
// Return 1: OK
// Return 0: error; reply with Nak
// Return -1: error; don't reply
func (s *v4Server) handle(req, resp *dhcpv4.DHCPv4) int {
// messageHandler describes a DHCPv4 message handler function.
type messageHandler func(s *v4Server, req, resp *dhcpv4.DHCPv4) (rCode int, l *Lease, err error)
// messageHandlers is a map of handlers for various messages with message types
// keys.
var messageHandlers = map[dhcpv4.MessageType]messageHandler{
dhcpv4.MessageTypeDiscover: func(
s *v4Server,
req *dhcpv4.DHCPv4,
resp *dhcpv4.DHCPv4,
) (rCode int, l *Lease, err error) {
l, err = s.handleDiscover(req, resp)
if err != nil {
return 0, nil, fmt.Errorf("handling discover: %s", err)
}
if l == nil {
return 0, nil, nil
}
return 1, l, nil
},
dhcpv4.MessageTypeRequest: func(
s *v4Server,
req *dhcpv4.DHCPv4,
resp *dhcpv4.DHCPv4,
) (rCode int, l *Lease, err error) {
var toReply bool
l, toReply = s.handleRequest(req, resp)
if l == nil {
if toReply {
return 0, nil, nil
}
// Drop the packet.
return -1, nil, nil
}
return 1, l, nil
},
dhcpv4.MessageTypeDecline: func(
s *v4Server,
req *dhcpv4.DHCPv4,
resp *dhcpv4.DHCPv4,
) (rCode int, l *Lease, err error) {
err = s.handleDecline(req, resp)
if err != nil {
return 0, nil, fmt.Errorf("handling decline: %s", err)
}
return 1, nil, nil
},
dhcpv4.MessageTypeRelease: func(
s *v4Server,
req *dhcpv4.DHCPv4,
resp *dhcpv4.DHCPv4,
) (rCode int, l *Lease, err error) {
err = s.handleRelease(req, resp)
if err != nil {
return 0, nil, fmt.Errorf("handling release: %s", err)
}
return 1, nil, nil
},
}
// handle processes request, it finds a lease associated with MAC address and
// prepares response.
//
// Possible return values are:
// - "1": OK,
// - "0": error, reply with Nak,
// - "-1": error, don't reply.
func (s *v4Server) handle(req, resp *dhcpv4.DHCPv4) (rCode int) {
var err error
// Include server's identifier option since any reply should contain it.
@@ -1007,47 +1076,26 @@ func (s *v4Server) handle(req, resp *dhcpv4.DHCPv4) int {
// See https://datatracker.ietf.org/doc/html/rfc2131#page-29.
resp.UpdateOption(dhcpv4.OptServerIdentifier(s.conf.dnsIPAddrs[0].AsSlice()))
// TODO(a.garipov): Refactor this into handlers.
var l *Lease
switch mt := req.MessageType(); mt {
case dhcpv4.MessageTypeDiscover:
l, err = s.handleDiscover(req, resp)
if err != nil {
log.Error("dhcpv4: handling discover: %s", err)
handler := messageHandlers[req.MessageType()]
if handler == nil {
s.updateOptions(req, resp)
return 0
}
return 1
}
if l == nil {
return 0
}
case dhcpv4.MessageTypeRequest:
var toReply bool
l, toReply = s.handleRequest(req, resp)
if l == nil {
if toReply {
return 0
}
return -1 // drop packet
}
case dhcpv4.MessageTypeDecline:
err = s.handleDecline(req, resp)
if err != nil {
log.Error("dhcpv4: handling decline: %s", err)
rCode, l, err := handler(s, req, resp)
if err != nil {
log.Error("dhcpv4: %s", err)
return 0
}
case dhcpv4.MessageTypeRelease:
err = s.handleRelease(req, resp)
if err != nil {
log.Error("dhcpv4: handling release: %s", err)
return 0
}
return 0
}
if rCode != 1 {
return rCode
}
if l != nil {
resp.YourIPAddr = net.IP(l.IP.AsSlice())
resp.YourIPAddr = l.IP.AsSlice()
}
s.updateOptions(req, resp)
@@ -1162,23 +1210,8 @@ func (s *v4Server) Start() (err error) {
// No available IP addresses which may appear later.
return nil
}
// Update the value of Domain Name Server option separately from others if
// not assigned yet since its value is available only at server's start.
//
// TODO(e.burkov): Initialize as implicit option with the rest of default
// options when it will be possible to do before the call to Start.
if !s.explicitOpts.Has(dhcpv4.OptionDomainNameServer) {
s.implicitOpts.Update(dhcpv4.OptDNS(dnsIPAddrs...))
}
for _, ip := range dnsIPAddrs {
ip = ip.To4()
if ip == nil {
continue
}
s.conf.dnsIPAddrs = append(s.conf.dnsIPAddrs, netip.AddrFrom4(*(*[4]byte)(ip)))
}
s.configureDNSIPAddrs(dnsIPAddrs)
var c net.PacketConn
if c, err = s.newDHCPConn(iface); err != nil {
@@ -1199,10 +1232,10 @@ func (s *v4Server) Start() (err error) {
log.Info("dhcpv4: listening")
go func() {
if serr := s.srv.Serve(); errors.Is(serr, net.ErrClosed) {
if sErr := s.srv.Serve(); errors.Is(sErr, net.ErrClosed) {
log.Info("dhcpv4: server is closed")
} else if serr != nil {
log.Error("dhcpv4: srv.Serve: %s", serr)
} else if sErr != nil {
log.Error("dhcpv4: srv.Serve: %s", sErr)
}
}()
@@ -1213,6 +1246,28 @@ func (s *v4Server) Start() (err error) {
return nil
}
// configureDNSIPAddrs updates v4Server configuration with provided slice of
// dns IP addresses.
func (s *v4Server) configureDNSIPAddrs(dnsIPAddrs []net.IP) {
// Update the value of Domain Name Server option separately from others if
// not assigned yet since its value is available only at server's start.
//
// TODO(e.burkov): Initialize as implicit option with the rest of default
// options when it will be possible to do before the call to Start.
if !s.explicitOpts.Has(dhcpv4.OptionDomainNameServer) {
s.implicitOpts.Update(dhcpv4.OptDNS(dnsIPAddrs...))
}
for _, ip := range dnsIPAddrs {
vAddr, err := netutil.IPToAddr(ip, netutil.AddrFamilyIPv4)
if err != nil {
continue
}
s.conf.dnsIPAddrs = append(s.conf.dnsIPAddrs, vAddr)
}
}
// Stop - stop server
func (s *v4Server) Stop() (err error) {
if s.srv == nil {