all: add clients list command to debug Mac discovery

cmd/ctrld/cli.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"crypto/x509"
 	"encoding/base64"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -26,6 +27,7 @@ import (
 	"github.com/go-playground/validator/v10"
 	"github.com/kardianos/service"
 	"github.com/miekg/dns"
+	"github.com/olekukonko/tablewriter"
 	"github.com/pelletier/go-toml/v2"
 	"github.com/rs/zerolog"
 	"github.com/spf13/cobra"
@@ -35,6 +37,7 @@ import (
 	"tailscale.com/net/interfaces"
 
 	"github.com/Control-D-Inc/ctrld"
+	"github.com/Control-D-Inc/ctrld/internal/clientinfo"
 	"github.com/Control-D-Inc/ctrld/internal/controld"
 	ctrldnet "github.com/Control-D-Inc/ctrld/internal/net"
 	"github.com/Control-D-Inc/ctrld/internal/router"
@@ -751,6 +754,66 @@ NOTE: Uninstalling will set DNS to values provided by DHCP.`,
 	uninstallCmdAlias.Flags().StringVarP(&ifaceStartStop, "iface", "", "auto", `Reset DNS setting for iface, "auto" means the default interface gateway`)
 	uninstallCmdAlias.Flags().AddFlagSet(stopCmd.Flags())
 	rootCmd.AddCommand(uninstallCmdAlias)
+
+	listClientsCmd := &cobra.Command{
+		Use:   "list",
+		Short: "List clients that ctrld discovered",
+		Args:  cobra.NoArgs,
+		PreRun: func(cmd *cobra.Command, args []string) {
+			initConsoleLogging()
+			checkHasElevatedPrivilege()
+		},
+		Run: func(cmd *cobra.Command, args []string) {
+			dir, err := userHomeDir()
+			if err != nil {
+				mainLog.Fatal().Err(err).Msg("failed to find ctrld home dir")
+			}
+			cc := newControlClient(filepath.Join(dir, ctrldControlUnixSock))
+			resp, err := cc.post(listClientsPath, nil)
+			if err != nil {
+				mainLog.Fatal().Err(err).Msg("failed to get clients list")
+			}
+			defer resp.Body.Close()
+
+			var clients []*clientinfo.Client
+			if err := json.NewDecoder(resp.Body).Decode(&clients); err != nil {
+				mainLog.Fatal().Err(err).Msg("failed to decode clients list result")
+			}
+			map2Slice := func(m map[string]struct{}) []string {
+				s := make([]string, 0, len(m))
+				for k := range m {
+					s = append(s, k)
+				}
+				sort.Strings(s)
+				return s
+			}
+			data := make([][]string, len(clients))
+			for i, c := range clients {
+				row := []string{
+					c.IP.String(),
+					c.Hostname,
+					c.Mac,
+					strings.Join(map2Slice(c.Source), ","),
+				}
+				data[i] = row
+			}
+			table := tablewriter.NewWriter(os.Stdout)
+			table.SetHeader([]string{"IP", "Hostname", "Mac", "Discovered"})
+			table.SetAutoFormatHeaders(false)
+			table.AppendBulk(data)
+			table.Render()
+		},
+	}
+	clientsCmd := &cobra.Command{
+		Use:   "clients",
+		Short: "Manage clients",
+		Args:  cobra.OnlyValidArgs,
+		ValidArgs: []string{
+			listClientsCmd.Use,
+		},
+	}
+	clientsCmd.AddCommand(listClientsCmd)
+	rootCmd.AddCommand(clientsCmd)
 }
 
 func writeConfigFile() error {

cmd/ctrld/control_server.go

@@ -2,13 +2,18 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"net"
 	"net/http"
 	"os"
+	"sort"
 	"time"
 )
 
-const contentTypeJson = "application/json"
+const (
+	contentTypeJson = "application/json"
+	listClientsPath = "/clients"
+)
 
 type controlServer struct {
 	server *http.Server
@@ -48,7 +53,16 @@ func (s *controlServer) register(pattern string, handler http.Handler) {
 }
 
 func (p *prog) registerControlServerHandler() {
-	// TODO: register handler here.
+	p.cs.mux.Handle(listClientsPath, http.HandlerFunc(func(w http.ResponseWriter, request *http.Request) {
+		clients := p.ciTable.ListClients()
+		sort.Slice(clients, func(i, j int) bool {
+			return clients[i].IP.Less(clients[j].IP)
+		})
+		if err := json.NewEncoder(w).Encode(&clients); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	}))
 }
 
 func jsonResponse(next http.Handler) http.Handler {

go.mod

@@ -15,10 +15,12 @@ require (
 	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86
 	github.com/kardianos/service v1.2.1
 	github.com/miekg/dns v1.1.55
+	github.com/olekukonko/tablewriter v0.0.5
 	github.com/pelletier/go-toml/v2 v2.0.8
 	github.com/quic-go/quic-go v0.32.0
 	github.com/rs/zerolog v1.28.0
 	github.com/spf13/cobra v1.7.0
+	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.16.0
 	github.com/stretchr/testify v1.8.3
 	github.com/vishvananda/netlink v1.2.1-beta.2
@@ -48,6 +50,7 @@ require (
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.18 // indirect
+	github.com/mattn/go-runewidth v0.0.14 // indirect
 	github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7 // indirect
 	github.com/mdlayher/netlink v1.7.2 // indirect
 	github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065 // indirect
@@ -60,11 +63,11 @@ require (
 	github.com/quic-go/qtls-go1-18 v0.2.0 // indirect
 	github.com/quic-go/qtls-go1-19 v0.2.0 // indirect
 	github.com/quic-go/qtls-go1-20 v0.1.0 // indirect
+	github.com/rivo/uniseg v0.4.4 // indirect
 	github.com/rogpeppe/go-internal v1.10.0 // indirect
 	github.com/spf13/afero v1.9.5 // indirect
 	github.com/spf13/cast v1.5.1 // indirect
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
-	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/subosito/gotenv v1.4.2 // indirect
 	github.com/u-root/uio v0.0.0-20230305220412-3e8cd9d6bf63 // indirect
 	github.com/vishvananda/netns v0.0.4 // indirect

go.sum

@@ -193,6 +193,9 @@ github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27k
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.18 h1:DOKFKCQ7FNG2L1rbrmstDN4QVRdS89Nkh85u68Uwp98=
 github.com/mattn/go-isatty v0.0.18/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/mattn/go-runewidth v0.0.14 h1:+xnbZSEeDbOIg5/mE6JF0w6n9duR1l3/WmbinWVwUuU=
+github.com/mattn/go-runewidth v0.0.14/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7 h1:lez6TS6aAau+8wXUP3G9I3TGlmPFEq2CTxBaRqY6AGE=
 github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7/go.mod h1:U6ZQobyTjI/tJyq2HG+i/dfSoFUt8/aZCM+GKtmFk/Y=
 github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/g=
@@ -206,6 +209,8 @@ github.com/miekg/dns v1.1.55 h1:GoQ4hpsj0nFLYe+bWiCToyrBEJXkQfOOIvFGFy0lEgo=
 github.com/miekg/dns v1.1.55/go.mod h1:uInx36IzPl7FYnDcMeVWxj9byh7DutNykX4G9Sj60FY=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
 github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/olekukonko/tablewriter v0.0.5 h1:P2Ga83D34wi1o9J6Wh1mRuqd4mF/x/lgBS7N7AbDhec=
+github.com/olekukonko/tablewriter v0.0.5/go.mod h1:hPp6KlRPjbx+hW8ykQs1w3UBbZlj6HuIJcUGPhkA7kY=
 github.com/onsi/ginkgo/v2 v2.2.0 h1:3ZNA3L1c5FYDFTTxbFeVGGD8jYvjYauHD30YgLxVsNI=
 github.com/onsi/ginkgo/v2 v2.2.0/go.mod h1:MEH45j8TBi6u9BMogfbp0stKC5cdGjumZj5Y7AG4VIk=
 github.com/onsi/gomega v1.20.1 h1:PA/3qinGoukvymdIDV8pii6tiZgC8kbmJO6Z5+b002Q=
@@ -230,6 +235,9 @@ github.com/quic-go/qtls-go1-20 v0.1.0 h1:d1PK3ErFy9t7zxKsG3NXBJXZjp/kMLoIb3y/kV5
 github.com/quic-go/qtls-go1-20 v0.1.0/go.mod h1:JKtK6mjbAVcUTN/9jZpvLbGxvdWIKS8uT7EiStoU1SM=
 github.com/quic-go/quic-go v0.32.0 h1:lY02md31s1JgPiiyfqJijpu/UX/Iun304FI3yUqX7tA=
 github.com/quic-go/quic-go v0.32.0/go.mod h1:/fCsKANhQIeD5l76c2JFU+07gVE3KaA0FP+0zMWwfwo=
+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
+github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 github.com/rogpeppe/go-internal v1.8.0/go.mod h1:WmiCO8CzOY8rg0OYDC4/i/2WRWAB6poM+XZ2dLUbcbE=

internal/clientinfo/arp.go

@@ -27,3 +27,20 @@ func (a *arpDiscover) LookupMac(ip string) string {
 	}
 	return val.(string)
 }
+
+func (a *arpDiscover) String() string {
+	return "arp"
+}
+
+func (a *arpDiscover) List() []string {
+	var ips []string
+	a.ip.Range(func(key, value any) bool {
+		ips = append(ips, value.(string))
+		return true
+	})
+	a.mac.Range(func(key, value any) bool {
+		ips = append(ips, key.(string))
+		return true
+	})
+	return ips
+}

internal/clientinfo/client_info.go

@@ -1,6 +1,8 @@
 package clientinfo
 
 import (
+	"fmt"
+	"net/netip"
 	"strings"
 	"time"
 
@@ -9,25 +11,35 @@ import (
 
 // IpResolver is the interface for retrieving IP from Mac.
 type IpResolver interface {
+	fmt.Stringer
+	// LookupIP returns ip of the device with given mac.
 	LookupIP(mac string) string
+	// List returns list of ip known by the resolver.
+	List() []string
 }
 
 // MacResolver is the interface for retrieving Mac from IP.
 type MacResolver interface {
+	fmt.Stringer
+	// LookupMac returns mac of the device with given ip.
 	LookupMac(ip string) string
 }
 
 // HostnameByIpResolver is the interface for retrieving hostname from IP.
 type HostnameByIpResolver interface {
+	// LookupHostnameByIP returns hostname of the given ip.
 	LookupHostnameByIP(ip string) string
 }
 
 // HostnameByMacResolver is the interface for retrieving hostname from Mac.
 type HostnameByMacResolver interface {
+	// LookupHostnameByMac returns hostname of the device with given mac.
 	LookupHostnameByMac(mac string) string
 }
 
+// HostnameResolver is the interface for retrieving hostname from either IP or Mac.
 type HostnameResolver interface {
+	fmt.Stringer
 	HostnameByIpResolver
 	HostnameByMacResolver
 }
@@ -36,6 +48,13 @@ type refresher interface {
 	refresh() error
 }
 
+type Client struct {
+	IP       netip.Addr
+	Mac      string
+	Hostname string
+	Source   map[string]struct{}
+}
+
 type Table struct {
 	ipResolvers       []IpResolver
 	macResolvers      []MacResolver
@@ -146,9 +165,6 @@ func (t *Table) LookupIP(mac string) string {
 }
 
 func (t *Table) LookupMac(ip string) string {
-	t.arp.mac.Range(func(key, value any) bool {
-		return true
-	})
 	for _, r := range t.macResolvers {
 		if mac := r.LookupMac(ip); mac != "" {
 			return mac
@@ -169,6 +185,86 @@ func (t *Table) LookupHostname(ip, mac string) string {
 	return ""
 }
 
+type macEntry struct {
+	mac string
+	src string
+}
+
+type hostnameEntry struct {
+	name string
+	src  string
+}
+
+func (t *Table) lookupMacAll(ip string) []*macEntry {
+	var res []*macEntry
+	for _, r := range t.macResolvers {
+		res = append(res, &macEntry{mac: r.LookupMac(ip), src: r.String()})
+	}
+	return res
+}
+
+func (t *Table) lookupHostnameAll(ip, mac string) []*hostnameEntry {
+	var res []*hostnameEntry
+	for _, r := range t.hostnameResolvers {
+		src := r.String()
+		if name := r.LookupHostnameByIP(ip); name != "" {
+			res = append(res, &hostnameEntry{name: name, src: src})
+			continue
+		}
+		if name := r.LookupHostnameByMac(mac); name != "" {
+			res = append(res, &hostnameEntry{name: name, src: src})
+			continue
+		}
+	}
+	return res
+}
+
+// ListClients returns list of clients discovered by ctrld.
+func (t *Table) ListClients() []*Client {
+	for _, r := range t.refreshers {
+		_ = r.refresh()
+	}
+	ipMap := make(map[string]*Client)
+	for _, ir := range t.ipResolvers {
+		for _, ip := range ir.List() {
+			c, ok := ipMap[ip]
+			if !ok {
+				c = &Client{
+					IP:     netip.MustParseAddr(ip),
+					Source: map[string]struct{}{ir.String(): {}},
+				}
+				ipMap[ip] = c
+			} else {
+				c.Source[ir.String()] = struct{}{}
+			}
+		}
+	}
+	for ip := range ipMap {
+		c := ipMap[ip]
+		for _, e := range t.lookupMacAll(ip) {
+			if c.Mac == "" && e.mac != "" {
+				c.Mac = e.mac
+			}
+			if e.mac != "" {
+				c.Source[e.src] = struct{}{}
+			}
+		}
+		for _, e := range t.lookupHostnameAll(ip, c.Mac) {
+			if c.Hostname == "" && e.name != "" {
+				c.Hostname = e.name
+			}
+			if e.name != "" {
+				c.Source[e.src] = struct{}{}
+			}
+		}
+	}
+	clients := make([]*Client, 0, len(ipMap))
+	for _, c := range ipMap {
+		clients = append(clients, c)
+	}
+	return clients
+}
+
 func (t *Table) discoverDHCP() bool {
 	if t.cfg.Service.DiscoverDHCP == nil {
 		return true

internal/clientinfo/dhcp.go

@@ -100,6 +100,23 @@ func (d *dhcp) LookupHostnameByMac(mac string) string {
 	return val.(string)
 }
 
+func (d *dhcp) String() string {
+	return "dhcp"
+}
+
+func (d *dhcp) List() []string {
+	var ips []string
+	d.ip.Range(func(key, value any) bool {
+		ips = append(ips, value.(string))
+		return true
+	})
+	d.mac.Range(func(key, value any) bool {
+		ips = append(ips, key.(string))
+		return true
+	})
+	return ips
+}
+
 // AddLeaseFile adds given lease file for reading/watching clients info.
 func (d *dhcp) addLeaseFile(name string, format ctrld.LeaseFileFormat) error {
 	if d.watcher == nil {

internal/clientinfo/mdns.go

@@ -43,6 +43,10 @@ func (m *mdns) LookupHostnameByMac(mac string) string {
 	return ""
 }
 
+func (m *mdns) String() string {
+	return "mdns"
+}
+
 func (m *mdns) init(quitCh chan struct{}) error {
 	ifaces, err := multicastInterfaces()
 	if err != nil {

internal/clientinfo/merlin.go

@@ -65,3 +65,7 @@ func (m *merlinDiscover) parseMerlinCustomClientList(data string) {
 		m.hostname.Store(mac, hostname)
 	}
 }
+
+func (m *merlinDiscover) String() string {
+	return "merlin"
+}

internal/clientinfo/ptr_lookup.go

@@ -36,6 +36,10 @@ func (p *ptrDiscover) LookupHostnameByMac(mac string) string {
 	return ""
 }
 
+func (p *ptrDiscover) String() string {
+	return "ptr"
+}
+
 func (p *ptrDiscover) lookupHostname(ip string) string {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
 	defer cancel()