Pull request 2100: v0.107.42-rc

Squashed commit of the following:

commit 284190f748345c7556e60b67f051ec5f6f080948
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Dec 6 19:36:00 2023 +0300

    all: sync with master; upd chlog

internal/dhcpsvc/v6.go

@@ -0,0 +1,88 @@
+package dhcpsvc
+
+import (
+	"fmt"
+	"net/netip"
+	"time"
+
+	"github.com/google/gopacket/layers"
+)
+
+// IPv6Config is the interface-specific configuration for DHCPv6.
+type IPv6Config struct {
+	// RangeStart is the first address in the range to assign to DHCP clients.
+	RangeStart netip.Addr
+
+	// Options is the list of DHCP options to send to DHCP clients.
+	Options layers.DHCPOptions
+
+	// LeaseDuration is the TTL of a DHCP lease.
+	LeaseDuration time.Duration
+
+	// RASlaacOnly defines whether the DHCP clients should only use SLAAC for
+	// address assignment.
+	RASLAACOnly bool
+
+	// RAAllowSlaac defines whether the DHCP clients may use SLAAC for address
+	// assignment.
+	RAAllowSLAAC bool
+
+	// Enabled is the state of the DHCPv6 service, whether it is enabled or not
+	// on the specific interface.
+	Enabled bool
+}
+
+// validate returns an error in conf if any.
+func (conf *IPv6Config) validate() (err error) {
+	switch {
+	case conf == nil:
+		return errNilConfig
+	case !conf.Enabled:
+		return nil
+	case !conf.RangeStart.Is6():
+		return fmt.Errorf("range start %s should be a valid ipv6", conf.RangeStart)
+	case conf.LeaseDuration <= 0:
+		return fmt.Errorf("lease duration %s must be positive", conf.LeaseDuration)
+	default:
+		return nil
+	}
+}
+
+// iface6 is a DHCP interface for IPv6 address family.
+//
+// TODO(e.burkov):  Add options.
+type iface6 struct {
+	// rangeStart is the first IP address in the range.
+	rangeStart netip.Addr
+
+	// name is the name of the interface.
+	name string
+
+	// leaseTTL is the time-to-live of dynamic leases on this interface.
+	leaseTTL time.Duration
+
+	// raSLAACOnly defines if DHCP should send ICMPv6.RA packets without MO
+	// flags.
+	raSLAACOnly bool
+
+	// raAllowSLAAC defines if DHCP should send ICMPv6.RA packets with MO flags.
+	raAllowSLAAC bool
+}
+
+// newIface6 creates a new DHCP interface for IPv6 address family with the given
+// configuration.
+//
+// TODO(e.burkov):  Validate properly.
+func newIface6(name string, conf *IPv6Config) (i *iface6) {
+	if !conf.Enabled {
+		return nil
+	}
+
+	return &iface6{
+		name:         name,
+		rangeStart:   conf.RangeStart,
+		leaseTTL:     conf.LeaseDuration,
+		raSLAACOnly:  conf.RASLAACOnly,
+		raAllowSLAAC: conf.RAAllowSLAAC,
+	}
+}