Pull request 1755: imp-home-gocyclo

Updates #2646.

Squashed commit of the following:

commit 9db0df757ef4e61a066264948436d465a720e2ec
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Mar 1 13:24:12 2023 +0300

    home: imp docs

commit d1e419962d7b0fa2347e141f600c89854bf7ebb2
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Mar 1 13:19:42 2023 +0300

    home: imp docs, names

commit 176368649729e6949ef2f7325aafa336f4725d88
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Feb 28 20:45:50 2023 +0300

    all: imp cyclo, docs; use netip.Addr

internal/home/client.go

@@ -0,0 +1,102 @@
+package home
+
+import (
+	"encoding"
+	"fmt"
+
+	"github.com/AdguardTeam/dnsproxy/proxy"
+)
+
+// Client contains information about persistent clients.
+type Client struct {
+	// upstreamConfig is the custom upstream config for this client.  If
+	// it's nil, it has not been initialized yet.  If it's non-nil and
+	// empty, there are no valid upstreams.  If it's non-nil and non-empty,
+	// these upstream must be used.
+	upstreamConfig *proxy.UpstreamConfig
+
+	Name string
+
+	IDs             []string
+	Tags            []string
+	BlockedServices []string
+	Upstreams       []string
+
+	UseOwnSettings        bool
+	FilteringEnabled      bool
+	SafeSearchEnabled     bool
+	SafeBrowsingEnabled   bool
+	ParentalEnabled       bool
+	UseOwnBlockedServices bool
+}
+
+// closeUpstreams closes the client-specific upstream config of c if any.
+func (c *Client) closeUpstreams() (err error) {
+	if c.upstreamConfig != nil {
+		err = c.upstreamConfig.Close()
+		if err != nil {
+			return fmt.Errorf("closing upstreams of client %q: %w", c.Name, err)
+		}
+	}
+
+	return nil
+}
+
+// clientSource represents the source from which the information about the
+// client has been obtained.
+type clientSource uint
+
+// Clients information sources.  The order determines the priority.
+const (
+	ClientSourceNone clientSource = iota
+	ClientSourceWHOIS
+	ClientSourceARP
+	ClientSourceRDNS
+	ClientSourceDHCP
+	ClientSourceHostsFile
+	ClientSourcePersistent
+)
+
+// type check
+var _ fmt.Stringer = clientSource(0)
+
+// String returns a human-readable name of cs.
+func (cs clientSource) String() (s string) {
+	switch cs {
+	case ClientSourceWHOIS:
+		return "WHOIS"
+	case ClientSourceARP:
+		return "ARP"
+	case ClientSourceRDNS:
+		return "rDNS"
+	case ClientSourceDHCP:
+		return "DHCP"
+	case ClientSourceHostsFile:
+		return "etc/hosts"
+	default:
+		return ""
+	}
+}
+
+// type check
+var _ encoding.TextMarshaler = clientSource(0)
+
+// MarshalText implements encoding.TextMarshaler for the clientSource.
+func (cs clientSource) MarshalText() (text []byte, err error) {
+	return []byte(cs.String()), nil
+}
+
+// RuntimeClient is a client information about which has been obtained using the
+// source described in the Source field.
+type RuntimeClient struct {
+	WHOISInfo *RuntimeClientWHOISInfo
+	Host      string
+	Source    clientSource
+}
+
+// RuntimeClientWHOISInfo is the filtered WHOIS data for a runtime client.
+type RuntimeClientWHOISInfo struct {
+	City    string `json:"city,omitempty"`
+	Country string `json:"country,omitempty"`
+	Orgname string `json:"orgname,omitempty"`
+}