hscontrol: route hostname handling through dnsname and NodeStore

Ingest (registration and MapRequest updates) now calls
dnsname.SanitizeHostname directly and lets NodeStore auto-bump on
collision. Admin rename uses dnsname.ValidLabel + SetGivenName so
conflicts are surfaced to the caller instead of silently mutated.

Three duplicate invalidDNSRegex definitions, the old NormaliseHostname
and ValidateHostname helpers, EnsureHostname, InvalidString,
ApplyHostnameFromHostInfo, GivenNameHasBeenChanged, generateGivenName
and EnsureUniqueGivenName are removed along with their tests.
ValidateHostname's username half is retained as ValidateUsername for
users.go.

The SaaS-matching collision rule replaces the random "invalid-xxxxxx"
fallback and the 8-character hash suffix; the empty-input fallback is
the literal "node". TestUpdateHostnameFromClient now exercises the
rewrite end-to-end with awkward macOS/Windows names.

Fixes #3188
Fixes #2926
Fixes #2343
Fixes #2762
Fixes #2449
Updates #2177
Updates #2121
Updates #363

hscontrol/util/util_test.go

@@ -7,11 +7,8 @@ import (
 	"time"
 
 	"github.com/google/go-cmp/cmp"
-	"tailscale.com/tailcfg"
 )
 
-const testUnknownNode = "unknown-node"
-
 func TestTailscaleVersionNewerOrEqual(t *testing.T) {
 	type args struct {
 		minimum string
@@ -799,514 +796,6 @@ over a maximum of 30 hops:
 	}
 }
 
-func TestEnsureHostname(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name       string
-		hostinfo   *tailcfg.Hostinfo
-		machineKey string
-		nodeKey    string
-		want       string
-	}{
-		{
-			name: "valid_hostname",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "test-node",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "test-node",
-		},
-		{
-			name:       "nil_hostinfo_with_machine_key",
-			hostinfo:   nil,
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "node-mkey1234",
-		},
-		{
-			name:       "nil_hostinfo_with_node_key_only",
-			hostinfo:   nil,
-			machineKey: "",
-			nodeKey:    "nkey12345678",
-			want:       "node-nkey1234",
-		},
-		{
-			name:       "nil_hostinfo_no_keys",
-			hostinfo:   nil,
-			machineKey: "",
-			nodeKey:    "",
-			want:       testUnknownNode,
-		},
-		{
-			name: "empty_hostname_with_machine_key",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "node-mkey1234",
-		},
-		{
-			name: "empty_hostname_with_node_key_only",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-			},
-			machineKey: "",
-			nodeKey:    "nkey12345678",
-			want:       "node-nkey1234",
-		},
-		{
-			name: "empty_hostname_no_keys",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-			},
-			machineKey: "",
-			nodeKey:    "",
-			want:       testUnknownNode,
-		},
-		{
-			name: "hostname_exactly_63_chars",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "123456789012345678901234567890123456789012345678901234567890123",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "123456789012345678901234567890123456789012345678901234567890123",
-		},
-		{
-			name: "hostname_64_chars_truncated",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "1234567890123456789012345678901234567890123456789012345678901234",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "hostname_very_long_truncated",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "test-node-with-very-long-hostname-that-exceeds-dns-label-limits-of-63-characters-and-should-be-truncated",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "hostname_with_special_chars",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "node-with-special!@#$%",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "hostname_with_unicode",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "node-ñoño-测试", //nolint:gosmopolitan
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "short_machine_key",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-			},
-			machineKey: "short",
-			nodeKey:    "nkey12345678",
-			want:       "node-short",
-		},
-		{
-			name: "short_node_key",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-			},
-			machineKey: "",
-			nodeKey:    "short",
-			want:       "node-short",
-		},
-		{
-			name: "hostname_with_emoji_replaced",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "hostname-with-💩",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "hostname_only_emoji_replaced",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "🚀",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "hostname_with_multiple_emojis_replaced",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "node-🎉-🚀-test",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "uppercase_to_lowercase",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "User2-Host",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "user2-host",
-		},
-		{
-			name: "underscore_removed",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "test_node",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "at_sign_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "Test@Host",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "chinese_chars_with_dash_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "server-北京-01", //nolint:gosmopolitan
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "chinese_only_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "我的电脑", //nolint:gosmopolitan
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "emoji_with_text_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "laptop-🚀",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "mixed_chinese_emoji_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "测试💻机器", //nolint:gosmopolitan // intentional i18n test data
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "only_emojis_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "🎉🎊",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "only_at_signs_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "@@@",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "starts_with_dash_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "-test",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "ends_with_dash_invalid",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "test-",
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-		{
-			name: "very_long_hostname_truncated",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: strings.Repeat("t", 70),
-			},
-			machineKey: "mkey12345678",
-			nodeKey:    "nkey12345678",
-			want:       "invalid-",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			got := EnsureHostname(tt.hostinfo.View(), tt.machineKey, tt.nodeKey)
-			// For invalid hostnames, we just check the prefix since the random part varies
-			if strings.HasPrefix(tt.want, "invalid-") {
-				if !strings.HasPrefix(got, "invalid-") {
-					t.Errorf("EnsureHostname() = %v, want prefix %v", got, tt.want)
-				}
-			} else if got != tt.want {
-				t.Errorf("EnsureHostname() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestEnsureHostnameWithHostinfo(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name          string
-		hostinfo      *tailcfg.Hostinfo
-		machineKey    string
-		nodeKey       string
-		wantHostname  string
-		checkHostinfo func(*testing.T, *tailcfg.Hostinfo)
-	}{
-		{
-			name: "valid_hostinfo_unchanged",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "test-node",
-				OS:       "linux",
-			},
-			machineKey:   "mkey12345678",
-			nodeKey:      "nkey12345678",
-			wantHostname: "test-node",
-			checkHostinfo: func(t *testing.T, hi *tailcfg.Hostinfo) { //nolint:thelper
-				if hi == nil {
-					t.Fatal("hostinfo should not be nil")
-				}
-
-				if hi.Hostname != "test-node" {
-					t.Errorf("hostname = %v, want test-node", hi.Hostname)
-				}
-
-				if hi.OS != "linux" {
-					t.Errorf("OS = %v, want linux", hi.OS)
-				}
-			},
-		},
-		{
-			name:         "nil_hostinfo_creates_default",
-			hostinfo:     nil,
-			machineKey:   "mkey12345678",
-			nodeKey:      "nkey12345678",
-			wantHostname: "node-mkey1234",
-		},
-		{
-			name: "empty_hostname_updated",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-				OS:       "darwin",
-			},
-			machineKey:   "mkey12345678",
-			nodeKey:      "nkey12345678",
-			wantHostname: "node-mkey1234",
-		},
-		{
-			name: "long_hostname_rejected",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "test-node-with-very-long-hostname-that-exceeds-dns-label-limits-of-63-characters",
-			},
-			machineKey:   "mkey12345678",
-			nodeKey:      "nkey12345678",
-			wantHostname: "invalid-",
-		},
-		{
-			name:         "nil_hostinfo_node_key_only",
-			hostinfo:     nil,
-			machineKey:   "",
-			nodeKey:      "nkey12345678",
-			wantHostname: "node-nkey1234",
-			checkHostinfo: func(t *testing.T, hi *tailcfg.Hostinfo) { //nolint:thelper
-				if hi == nil {
-					t.Fatal("hostinfo should not be nil")
-				}
-
-				if hi.Hostname != "node-nkey1234" {
-					t.Errorf("hostname = %v, want node-nkey1234", hi.Hostname)
-				}
-			},
-		},
-		{
-			name:         "nil_hostinfo_no_keys",
-			hostinfo:     nil,
-			machineKey:   "",
-			nodeKey:      "",
-			wantHostname: testUnknownNode,
-			checkHostinfo: func(t *testing.T, hi *tailcfg.Hostinfo) { //nolint:thelper
-				if hi == nil {
-					t.Fatal("hostinfo should not be nil")
-				}
-
-				if hi.Hostname != testUnknownNode {
-					t.Errorf("hostname = %v, want unknown-node", hi.Hostname)
-				}
-			},
-		},
-		{
-			name: "empty_hostname_no_keys",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "",
-			},
-			machineKey:   "",
-			nodeKey:      "",
-			wantHostname: testUnknownNode,
-			checkHostinfo: func(t *testing.T, hi *tailcfg.Hostinfo) { //nolint:thelper
-				if hi == nil {
-					t.Fatal("hostinfo should not be nil")
-				}
-
-				if hi.Hostname != testUnknownNode {
-					t.Errorf("hostname = %v, want unknown-node", hi.Hostname)
-				}
-			},
-		},
-		{
-			name: "preserves_other_fields",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname:     "test",
-				OS:           "windows",
-				OSVersion:    "10.0.19044",
-				DeviceModel:  "test-device",
-				BackendLogID: "log123",
-			},
-			machineKey:   "mkey12345678",
-			nodeKey:      "nkey12345678",
-			wantHostname: "test",
-			checkHostinfo: func(t *testing.T, hi *tailcfg.Hostinfo) { //nolint:thelper
-				if hi == nil {
-					t.Fatal("hostinfo should not be nil")
-				}
-
-				if hi.Hostname != "test" {
-					t.Errorf("hostname = %v, want test", hi.Hostname)
-				}
-
-				if hi.OS != "windows" {
-					t.Errorf("OS = %v, want windows", hi.OS)
-				}
-
-				if hi.OSVersion != "10.0.19044" {
-					t.Errorf("OSVersion = %v, want 10.0.19044", hi.OSVersion)
-				}
-
-				if hi.DeviceModel != "test-device" {
-					t.Errorf("DeviceModel = %v, want test-device", hi.DeviceModel)
-				}
-
-				if hi.BackendLogID != "log123" {
-					t.Errorf("BackendLogID = %v, want log123", hi.BackendLogID)
-				}
-			},
-		},
-		{
-			name: "exactly_63_chars_unchanged",
-			hostinfo: &tailcfg.Hostinfo{
-				Hostname: "123456789012345678901234567890123456789012345678901234567890123",
-			},
-			machineKey:   "mkey12345678",
-			nodeKey:      "nkey12345678",
-			wantHostname: "123456789012345678901234567890123456789012345678901234567890123",
-			checkHostinfo: func(t *testing.T, hi *tailcfg.Hostinfo) { //nolint:thelper
-				if hi == nil {
-					t.Fatal("hostinfo should not be nil")
-				}
-
-				if len(hi.Hostname) != 63 {
-					t.Errorf("hostname length = %v, want 63", len(hi.Hostname))
-				}
-			},
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			gotHostname := EnsureHostname(tt.hostinfo.View(), tt.machineKey, tt.nodeKey)
-			// For invalid hostnames, we just check the prefix since the random part varies
-			if strings.HasPrefix(tt.wantHostname, "invalid-") {
-				if !strings.HasPrefix(gotHostname, "invalid-") {
-					t.Errorf("EnsureHostname() = %v, want prefix %v", gotHostname, tt.wantHostname)
-				}
-			} else if gotHostname != tt.wantHostname {
-				t.Errorf("EnsureHostname() hostname = %v, want %v", gotHostname, tt.wantHostname)
-			}
-		})
-	}
-}
-
-func TestEnsureHostname_DNSLabelLimit(t *testing.T) {
-	t.Parallel()
-
-	testCases := []string{
-		"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
-		"bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
-		"cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
-		"dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd",
-	}
-
-	for i, hostname := range testCases {
-		t.Run(cmp.Diff("", ""), func(t *testing.T) {
-			t.Parallel()
-
-			hostinfo := &tailcfg.Hostinfo{Hostname: hostname}
-
-			result := EnsureHostname(hostinfo.View(), "mkey", "nkey")
-			if len(result) > 63 {
-				t.Errorf("test case %d: hostname length = %d, want <= 63", i, len(result))
-			}
-		})
-	}
-}
-
-func TestEnsureHostname_Idempotent(t *testing.T) {
-	t.Parallel()
-
-	originalHostinfo := &tailcfg.Hostinfo{
-		Hostname: "test-node",
-		OS:       "linux",
-	}
-
-	hostname1 := EnsureHostname(originalHostinfo.View(), "mkey", "nkey")
-	hostname2 := EnsureHostname(originalHostinfo.View(), "mkey", "nkey")
-
-	if hostname1 != hostname2 {
-		t.Errorf("hostnames not equal: %v != %v", hostname1, hostname2)
-	}
-}
 
 func TestGenerateRegistrationKey(t *testing.T) {
 	t.Parallel()