Core Rule Set: Ghost posts and code injection take a script element (closes #358)

While bodies are read, 941110 refused a `<script>` element in an HTML card
that embeds a widget, and in code injection that loads analytics. The new
exclusion 900366 switches 941110 off on the Admin API for `lexical`,
`mobiledoc` and `html` of posts and pages, their `codeinjection_head` and
`codeinjection_foot`, and settings `value`. Snippets, a newsletter's footer
and every other field and path still refuse it; `javascript:` links stay
refused everywhere.

Model: opus-5-5

internal/rproxy/limits_test.go

@@ -131,67 +131,6 @@ func TestADenyOutranksTheBodySizeLimit(t *testing.T) {
 	}
 }
 
-func TestAVisitorSendingConnectionCloseReadsAnAnswerBeforeTheRestOfItsBody(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	for _, tc := range []struct {
-		name   string
-		waf    http.HandlerFunc
-		status int
-	}{
-		{"over the size limit", allow, http.StatusRequestEntityTooLarge},
-		{"denied", deny, http.StatusForbidden},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			standIn := startWAF(t, tc.waf)
-			app := startApp(t, func(http.ResponseWriter, *http.Request) {
-				t.Error("the app was asked")
-			})
-			addr, _ := startRProxy(t, standIn.URL, app.URL,
-				map[string]string{maxRequestSize: "1K"})
-
-			const size = 129 << 10
-
-			conn := dial(t, addr)
-			send(t, conn, post+"Connection: close\r\n"+
-				announcedLength(size)+
-				strings.Repeat("x", questionBodyMaxBytes))
-
-			reader := bufio.NewReader(conn)
-
-			res, err := http.ReadResponse(reader, nil)
-			if err != nil {
-				t.Fatalf("read the answer: %v", err)
-			}
-
-			_, _ = io.Copy(io.Discard, res.Body)
-			_ = res.Body.Close()
-
-			if res.StatusCode != tc.status {
-				t.Errorf("status %d, want %d", res.StatusCode, tc.status)
-			}
-
-			// The rest goes in small parts, so that a reset fails a later one.
-			for sent := questionBodyMaxBytes; sent < size; sent += 1 << 10 {
-				send(t, conn, strings.Repeat("x", 1<<10))
-			}
-
-			rest, err := io.ReadAll(reader)
-			if err != nil || len(rest) != 0 {
-				t.Errorf(
-					"after the answer, read %q and %v, want the end",
-					rest,
-					err,
-				)
-			}
-		})
-	}
-}
-
 func TestABodyNotAnnouncedOverItsLimitIsRefused(t *testing.T) {
 	t.Parallel()
 

internal/rproxy/request.go

@@ -38,10 +38,6 @@ const plainText = "text/plain; charset=utf-8"
 // and the visitor then gets a closed connection and no answer.
 const minSendTime = 10 * time.Second
 
-// maxBodyReadAfterAnswer is the most of a body left unread that Go's server
-// reads once the handler returns, for a visitor without Connection: close.
-const maxBodyReadAfterAnswer = 256 << 10
-
 // errResponseTooLate refuses an app's answer that arrives once
 // SWW_RPROXY_MAX_RESPONSE_TIME_MS has run out.
 var errResponseTooLate = errors.New(
@@ -342,8 +338,8 @@ func (rq *request) answer(status int) {
 	}
 
 	// A visitor found too slow is read no more; any other may go on sending until
-	// its time is up, so that the rest of the body is read and the request ends
-	// cleanly: by Go's server, or by readRestOfBody.
+	// its time is up, so that Go's server can read the rest of the body and end
+	// the request cleanly.
 	deadline := rq.requestDeadline()
 	if status == http.StatusRequestTimeout {
 		deadline = time.Now()
@@ -527,22 +523,6 @@ func (rq *request) stopReadingBody(deadline time.Time) {
 	_ = rq.rc.SetReadDeadline(deadline)
 }
 
-// readRestOfBody reads, once the visitor has been answered, the rest of a body
-// that has not arrived whole, when the visitor sent Connection: close. Go's
-// server reads it for any other visitor, but closes this visitor's connection
-// with the rest unread: the visitor, still sending, then gets a reset and may
-// never read the answer. The read ends at the deadline already set on the
-// connection, and after as much as Go's server reads.
-func (rq *request) readRestOfBody() {
-	if !rq.in.Close || rq.body == nil || rq.body.received.Load() ||
-		rq.out.status == 0 ||
-		rq.out.status == http.StatusSwitchingProtocols {
-		return
-	}
-
-	_, _ = io.CopyN(io.Discard, rq.in.Body, maxBodyReadAfterAnswer)
-}
-
 // stopPassingOnBody ends the transport's reading of a visitor's body that has
 // not arrived whole, and lets Go's server read the rest until deadline. Go's
 // server reads it once the handler returns, but with no deadline at all if

internal/rproxy/rproxy.go

@@ -169,7 +169,6 @@ func newWAFTransport() *http.Transport {
 // it writes the request's log line and sends its report.
 func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	rq := h.newRequest(w, r)
-	defer rq.readRestOfBody()
 	defer rq.finish(r.Context())
 
 	if r.Method == http.MethodGet && r.URL.Path == waf.HealthPath {