1 files changed, 282 insertions, 0 deletions
diff --git a/src/net/http/sniff_test.go b/src/net/http/sniff_test.go
new file mode 100644
index 0000000..d6ef409
--- /dev/null
+++ b/src/net/http/sniff_test.go
@@ -0,0 +1,282 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http_test
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	. "net/http"
+	"reflect"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+var sniffTests = []struct {
+	desc        string
+	data        []byte
+	contentType string
+}{
+	// Some nonsense.
+	{"Empty", []byte{}, "text/plain; charset=utf-8"},
+	{"Binary", []byte{1, 2, 3}, "application/octet-stream"},
+
+	{"HTML document #1", []byte(`<HtMl><bOdY>blah blah blah</body></html>`), "text/html; charset=utf-8"},
+	{"HTML document #2", []byte(`<HTML></HTML>`), "text/html; charset=utf-8"},
+	{"HTML document #3 (leading whitespace)", []byte(`   <!DOCTYPE HTML>...`), "text/html; charset=utf-8"},
+	{"HTML document #4 (leading CRLF)", []byte("\r\n<html>..."), "text/html; charset=utf-8"},
+
+	{"Plain text", []byte(`This is not HTML. It has ☃ though.`), "text/plain; charset=utf-8"},
+
+	{"XML", []byte("\n<?xml!"), "text/xml; charset=utf-8"},
+
+	// Image types.
+	{"Windows icon", []byte("\x00\x00\x01\x00"), "image/x-icon"},
+	{"Windows cursor", []byte("\x00\x00\x02\x00"), "image/x-icon"},
+	{"BMP image", []byte("BM..."), "image/bmp"},
+	{"GIF 87a", []byte(`GIF87a`), "image/gif"},
+	{"GIF 89a", []byte(`GIF89a...`), "image/gif"},
+	{"WEBP image", []byte("RIFF\x00\x00\x00\x00WEBPVP"), "image/webp"},
+	{"PNG image", []byte("\x89PNG\x0D\x0A\x1A\x0A"), "image/png"},
+	{"JPEG image", []byte("\xFF\xD8\xFF"), "image/jpeg"},
+
+	// Audio types.
+	{"MIDI audio", []byte("MThd\x00\x00\x00\x06\x00\x01"), "audio/midi"},
+	{"MP3 audio/MPEG audio", []byte("ID3\x03\x00\x00\x00\x00\x0f"), "audio/mpeg"},
+	{"WAV audio #1", []byte("RIFFb\xb8\x00\x00WAVEfmt \x12\x00\x00\x00\x06"), "audio/wave"},
+	{"WAV audio #2", []byte("RIFF,\x00\x00\x00WAVEfmt \x12\x00\x00\x00\x06"), "audio/wave"},
+	{"AIFF audio #1", []byte("FORM\x00\x00\x00\x00AIFFCOMM\x00\x00\x00\x12\x00\x01\x00\x00\x57\x55\x00\x10\x40\x0d\xf3\x34"), "audio/aiff"},
+
+	{"OGG audio", []byte("OggS\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x7e\x46\x00\x00\x00\x00\x00\x00\x1f\xf6\xb4\xfc\x01\x1e\x01\x76\x6f\x72"), "application/ogg"},
+	{"Must not match OGG", []byte("owow\x00"), "application/octet-stream"},
+	{"Must not match OGG", []byte("oooS\x00"), "application/octet-stream"},
+	{"Must not match OGG", []byte("oggS\x00"), "application/octet-stream"},
+
+	// Video types.
+	{"MP4 video", []byte("\x00\x00\x00\x18ftypmp42\x00\x00\x00\x00mp42isom<\x06t\xbfmdat"), "video/mp4"},
+	{"AVI video #1", []byte("RIFF,O\n\x00AVI LISTÀ"), "video/avi"},
+	{"AVI video #2", []byte("RIFF,\n\x00\x00AVI LISTÀ"), "video/avi"},
+
+	// Font types.
+	// {"MS.FontObject", []byte("\x00\x00")},
+	{"TTF sample  I", []byte("\x00\x01\x00\x00\x00\x17\x01\x00\x00\x04\x01\x60\x4f"), "font/ttf"},
+	{"TTF sample II", []byte("\x00\x01\x00\x00\x00\x0e\x00\x80\x00\x03\x00\x60\x46"), "font/ttf"},
+
+	{"OTTO sample  I", []byte("\x4f\x54\x54\x4f\x00\x0e\x00\x80\x00\x03\x00\x60\x42\x41\x53\x45"), "font/otf"},
+
+	{"woff sample  I", []byte("\x77\x4f\x46\x46\x00\x01\x00\x00\x00\x00\x30\x54\x00\x0d\x00\x00"), "font/woff"},
+	{"woff2 sample", []byte("\x77\x4f\x46\x32\x00\x01\x00\x00\x00"), "font/woff2"},
+	{"wasm sample", []byte("\x00\x61\x73\x6d\x01\x00"), "application/wasm"},
+
+	// Archive types
+	{"RAR v1.5-v4.0", []byte("Rar!\x1A\x07\x00"), "application/x-rar-compressed"},
+	{"RAR v5+", []byte("Rar!\x1A\x07\x01\x00"), "application/x-rar-compressed"},
+	{"Incorrect RAR v1.5-v4.0", []byte("Rar \x1A\x07\x00"), "application/octet-stream"},
+	{"Incorrect RAR v5+", []byte("Rar \x1A\x07\x01\x00"), "application/octet-stream"},
+}
+
+func TestDetectContentType(t *testing.T) {
+	for _, tt := range sniffTests {
+		ct := DetectContentType(tt.data)
+		if ct != tt.contentType {
+			t.Errorf("%v: DetectContentType = %q, want %q", tt.desc, ct, tt.contentType)
+		}
+	}
+}
+
+func TestServerContentTypeSniff(t *testing.T) { run(t, testServerContentTypeSniff) }
+func testServerContentTypeSniff(t *testing.T, mode testMode) {
+	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
+		i, _ := strconv.Atoi(r.FormValue("i"))
+		tt := sniffTests[i]
+		n, err := w.Write(tt.data)
+		if n != len(tt.data) || err != nil {
+			log.Fatalf("%v: Write(%q) = %v, %v want %d, nil", tt.desc, tt.data, n, err, len(tt.data))
+		}
+	}))
+	defer cst.close()
+
+	for i, tt := range sniffTests {
+		resp, err := cst.c.Get(cst.ts.URL + "/?i=" + strconv.Itoa(i))
+		if err != nil {
+			t.Errorf("%v: %v", tt.desc, err)
+			continue
+		}
+		// DetectContentType is defined to return
+		// text/plain; charset=utf-8 for an empty body,
+		// but as of Go 1.10 the HTTP server has been changed
+		// to return no content-type at all for an empty body.
+		// Adjust the expectation here.
+		wantContentType := tt.contentType
+		if len(tt.data) == 0 {
+			wantContentType = ""
+		}
+		if ct := resp.Header.Get("Content-Type"); ct != wantContentType {
+			t.Errorf("%v: Content-Type = %q, want %q", tt.desc, ct, wantContentType)
+		}
+		data, err := io.ReadAll(resp.Body)
+		if err != nil {
+			t.Errorf("%v: reading body: %v", tt.desc, err)
+		} else if !bytes.Equal(data, tt.data) {
+			t.Errorf("%v: data is %q, want %q", tt.desc, data, tt.data)
+		}
+		resp.Body.Close()
+	}
+}
+
+// Issue 5953: shouldn't sniff if the handler set a Content-Type header,
+// even if it's the empty string.
+func TestServerIssue5953(t *testing.T) { run(t, testServerIssue5953) }
+func testServerIssue5953(t *testing.T, mode testMode) {
+	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
+		w.Header()["Content-Type"] = []string{""}
+		fmt.Fprintf(w, "<html><head></head><body>hi</body></html>")
+	}))
+
+	resp, err := cst.c.Get(cst.ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	got := resp.Header["Content-Type"]
+	want := []string{""}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("Content-Type = %q; want %q", got, want)
+	}
+	resp.Body.Close()
+}
+
+type byteAtATimeReader struct {
+	buf []byte
+}
+
+func (b *byteAtATimeReader) Read(p []byte) (n int, err error) {
+	if len(p) < 1 {
+		return 0, nil
+	}
+	if len(b.buf) == 0 {
+		return 0, io.EOF
+	}
+	p[0] = b.buf[0]
+	b.buf = b.buf[1:]
+	return 1, nil
+}
+
+func TestContentTypeWithVariousSources(t *testing.T) { run(t, testContentTypeWithVariousSources) }
+func testContentTypeWithVariousSources(t *testing.T, mode testMode) {
+	const (
+		input    = "\n<html>\n\t<head>\n"
+		expected = "text/html; charset=utf-8"
+	)
+
+	for _, test := range []struct {
+		name    string
+		handler func(ResponseWriter, *Request)
+	}{{
+		name: "write",
+		handler: func(w ResponseWriter, r *Request) {
+			// Write the whole input at once.
+			n, err := w.Write([]byte(input))
+			if int(n) != len(input) || err != nil {
+				t.Errorf("w.Write(%q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}, {
+		name: "write one byte at a time",
+		handler: func(w ResponseWriter, r *Request) {
+			// Write the input one byte at a time.
+			buf := []byte(input)
+			for i := range buf {
+				n, err := w.Write(buf[i : i+1])
+				if n != 1 || err != nil {
+					t.Errorf("w.Write(%q) = %v, %v want 1, nil", input, n, err)
+				}
+			}
+		},
+	}, {
+		name: "copy from Reader",
+		handler: func(w ResponseWriter, r *Request) {
+			// Use io.Copy from a plain Reader.
+			type readerOnly struct{ io.Reader }
+			buf := bytes.NewBuffer([]byte(input))
+			n, err := io.Copy(w, readerOnly{buf})
+			if int(n) != len(input) || err != nil {
+				t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}, {
+		name: "copy from bytes.Buffer",
+		handler: func(w ResponseWriter, r *Request) {
+			// Use io.Copy from a bytes.Buffer to trigger ReadFrom.
+			buf := bytes.NewBuffer([]byte(input))
+			n, err := io.Copy(w, buf)
+			if int(n) != len(input) || err != nil {
+				t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}, {
+		name: "copy one byte at a time",
+		handler: func(w ResponseWriter, r *Request) {
+			// Use io.Copy from a Reader that returns one byte at a time.
+			n, err := io.Copy(w, &byteAtATimeReader{[]byte(input)})
+			if int(n) != len(input) || err != nil {
+				t.Errorf("io.Copy(w, %q) = %v, %v want %d, nil", input, n, err, len(input))
+			}
+		},
+	}} {
+		t.Run(test.name, func(t *testing.T) {
+			cst := newClientServerTest(t, mode, HandlerFunc(test.handler))
+
+			resp, err := cst.c.Get(cst.ts.URL)
+			if err != nil {
+				t.Fatalf("Get: %v", err)
+			}
+			if ct := resp.Header.Get("Content-Type"); ct != expected {
+				t.Errorf("Content-Type = %q, want %q", ct, expected)
+			}
+			if want, got := resp.Header.Get("Content-Length"), fmt.Sprint(len(input)); want != got {
+				t.Errorf("Content-Length = %q, want %q", want, got)
+			}
+			data, err := io.ReadAll(resp.Body)
+			if err != nil {
+				t.Errorf("reading body: %v", err)
+			} else if !bytes.Equal(data, []byte(input)) {
+				t.Errorf("data is %q, want %q", data, input)
+			}
+			resp.Body.Close()
+
+		})
+
+	}
+}
+
+func TestSniffWriteSize(t *testing.T) { run(t, testSniffWriteSize) }
+func testSniffWriteSize(t *testing.T, mode testMode) {
+	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
+		size, _ := strconv.Atoi(r.FormValue("size"))
+		written, err := io.WriteString(w, strings.Repeat("a", size))
+		if err != nil {
+			t.Errorf("write of %d bytes: %v", size, err)
+			return
+		}
+		if written != size {
+			t.Errorf("write of %d bytes wrote %d bytes", size, written)
+		}
+	}))
+	for _, size := range []int{0, 1, 200, 600, 999, 1000, 1023, 1024, 512 << 10, 1 << 20} {
+		res, err := cst.c.Get(fmt.Sprintf("%s/?size=%d", cst.ts.URL, size))
+		if err != nil {
+			t.Fatalf("size %d: %v", size, err)
+		}
+		if _, err := io.Copy(io.Discard, res.Body); err != nil {
+			t.Fatalf("size %d: io.Copy of body = %v", size, err)
+		}
+		if err := res.Body.Close(); err != nil {
+			t.Fatalf("size %d: body Close = %v", size, err)
+		}
+	}
+}