cmd/tailscale/cli: unit tests for tailscale ip

Updates #20035

Signed-off-by: Adriano Sela Aviles <adriano@tailscale.com>

cmd/tailscale/cli/ip.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/peterbourgon/ff/v3/ffcli"
 	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/tailcfg"
 )
 
 var ipCmd = &ffcli.Command{
@@ -130,12 +131,18 @@ func serviceAddrsMatchingIP(ctx context.Context, ipStr string) ([]netip.Addr, er
 	if err != nil {
 		return nil, err
 	}
+	return allIPsForServiceWithIP(services, ip), nil
+}
+
+// allIPsForServiceWithIP returns the Addrs of the service whose VIP addresses
+// contain ip, or nil if no service matches.
+func allIPsForServiceWithIP(services map[tailcfg.ServiceName]tailcfg.ServiceDetails, ip netip.Addr) []netip.Addr {
 	for _, svc := range services {
 		if slices.Contains(svc.Addrs, ip) {
-			return svc.Addrs, nil
+			return svc.Addrs
 		}
 	}
-	return nil, nil
+	return nil
 }
 
 func peerMatchingIP(st *ipnstate.Status, ipStr string) (ps *ipnstate.PeerStatus, ok bool) {

cmd/tailscale/cli/ip_test.go

@@ -0,0 +1,199 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+package cli
+
+import (
+	"net/netip"
+	"testing"
+
+	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/key"
+)
+
+func TestPeerMatchingIP(t *testing.T) {
+	st := &ipnstate.Status{
+		Self: &ipnstate.PeerStatus{
+			TailscaleIPs: []netip.Addr{netip.MustParseAddr("100.64.0.1"), netip.MustParseAddr("fd7a:115c:a1e0::1")},
+		},
+		Peer: map[key.NodePublic]*ipnstate.PeerStatus{
+			key.NewNode().Public(): {
+				TailscaleIPs: []netip.Addr{netip.MustParseAddr("100.64.0.2"), netip.MustParseAddr("fd7a:115c:a1e0::2")},
+			},
+			key.NewNode().Public(): {
+				TailscaleIPs: []netip.Addr{netip.MustParseAddr("100.64.0.3")},
+			},
+		},
+	}
+
+	tests := []struct {
+		name    string
+		ipStr   string
+		wantOK  bool
+		wantIPs []netip.Addr
+	}{
+		{
+			name:    "match_self_v4",
+			ipStr:   "100.64.0.1",
+			wantOK:  true,
+			wantIPs: []netip.Addr{netip.MustParseAddr("100.64.0.1"), netip.MustParseAddr("fd7a:115c:a1e0::1")},
+		},
+		{
+			name:    "match_self_v6",
+			ipStr:   "fd7a:115c:a1e0::1",
+			wantOK:  true,
+			wantIPs: []netip.Addr{netip.MustParseAddr("100.64.0.1"), netip.MustParseAddr("fd7a:115c:a1e0::1")},
+		},
+		{
+			name:    "match_peer_v4",
+			ipStr:   "100.64.0.2",
+			wantOK:  true,
+			wantIPs: []netip.Addr{netip.MustParseAddr("100.64.0.2"), netip.MustParseAddr("fd7a:115c:a1e0::2")},
+		},
+		{
+			name:    "match_peer_single_ip",
+			ipStr:   "100.64.0.3",
+			wantOK:  true,
+			wantIPs: []netip.Addr{netip.MustParseAddr("100.64.0.3")},
+		},
+		{
+			name:   "no_match",
+			ipStr:  "100.64.0.99",
+			wantOK: false,
+		},
+		{
+			name:   "invalid_ip",
+			ipStr:  "not-an-ip",
+			wantOK: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ps, ok := peerMatchingIP(st, tt.ipStr)
+			if ok != tt.wantOK {
+				t.Fatalf("peerMatchingIP(%q) ok = %v, want %v", tt.ipStr, ok, tt.wantOK)
+			}
+			if ok {
+				if len(ps.TailscaleIPs) != len(tt.wantIPs) {
+					t.Fatalf("got %d IPs, want %d", len(ps.TailscaleIPs), len(tt.wantIPs))
+				}
+				for i, ip := range ps.TailscaleIPs {
+					if ip != tt.wantIPs[i] {
+						t.Errorf("IP[%d] = %v, want %v", i, ip, tt.wantIPs[i])
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestAllIPsForServiceWithIP(t *testing.T) {
+	services := map[tailcfg.ServiceName]tailcfg.ServiceDetails{
+		"svc:web": {
+			Name: "svc:web",
+			Addrs: []netip.Addr{
+				netip.MustParseAddr("100.100.0.1"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::1"),
+			},
+		},
+		"svc:api": {
+			Name:  "svc:api",
+			Addrs: []netip.Addr{netip.MustParseAddr("100.100.0.2")},
+		},
+	}
+	// Services should have at most 2 addrs (one v4, one v6), but
+	// we handle more gracefully if the server ever returns them.
+	multiAddr := map[tailcfg.ServiceName]tailcfg.ServiceDetails{
+		"svc:multi": {
+			Name: "svc:multi",
+			Addrs: []netip.Addr{
+				netip.MustParseAddr("100.100.0.3"),
+				netip.MustParseAddr("100.100.0.4"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::3"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::4"),
+			},
+		},
+	}
+
+	tests := []struct {
+		name     string
+		services map[tailcfg.ServiceName]tailcfg.ServiceDetails
+		ip       netip.Addr
+		wantIPs  []netip.Addr
+	}{
+		{
+			name:     "match_service_v4",
+			services: services,
+			ip:       netip.MustParseAddr("100.100.0.1"),
+			wantIPs: []netip.Addr{
+				netip.MustParseAddr("100.100.0.1"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::1"),
+			},
+		},
+		{
+			name:     "match_service_v6",
+			services: services,
+			ip:       netip.MustParseAddr("fd7a:115c:a1e0:ab12::1"),
+			wantIPs: []netip.Addr{
+				netip.MustParseAddr("100.100.0.1"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::1"),
+			},
+		},
+		{
+			name:     "match_single_addr_service",
+			services: services,
+			ip:       netip.MustParseAddr("100.100.0.2"),
+			wantIPs:  []netip.Addr{netip.MustParseAddr("100.100.0.2")},
+		},
+		{
+			name:     "match_service_multiple_addrs_v4",
+			services: multiAddr,
+			ip:       netip.MustParseAddr("100.100.0.3"),
+			wantIPs: []netip.Addr{
+				netip.MustParseAddr("100.100.0.3"),
+				netip.MustParseAddr("100.100.0.4"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::3"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::4"),
+			},
+		},
+		{
+			name:     "match_service_multiple_addrs_v6",
+			services: multiAddr,
+			ip:       netip.MustParseAddr("fd7a:115c:a1e0:ab12::3"),
+			wantIPs: []netip.Addr{
+				netip.MustParseAddr("100.100.0.3"),
+				netip.MustParseAddr("100.100.0.4"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::3"),
+				netip.MustParseAddr("fd7a:115c:a1e0:ab12::4"),
+			},
+		},
+		{
+			name:     "no_match",
+			services: services,
+			ip:       netip.MustParseAddr("100.100.0.99"),
+			wantIPs:  nil,
+		},
+		{
+			name:     "empty_services",
+			services: nil,
+			ip:       netip.MustParseAddr("100.100.0.1"),
+			wantIPs:  nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := allIPsForServiceWithIP(tt.services, tt.ip)
+			if len(got) != len(tt.wantIPs) {
+				t.Fatalf("allIPsForServiceWithIP(%v) returned %d IPs, want %d", tt.ip, len(got), len(tt.wantIPs))
+			}
+			for i, ip := range got {
+				if ip != tt.wantIPs[i] {
+					t.Errorf("IP[%d] = %v, want %v", i, ip, tt.wantIPs[i])
+				}
+			}
+		})
+	}
+}