TUN-3403: Unit test for origin/proxy to test serving HTTP and Websocket

vendor/github.com/gobwas/ws/wsutil/utf8.go

@@ -0,0 +1,140 @@
+package wsutil
+
+import (
+	"fmt"
+	"io"
+)
+
+// ErrInvalidUTF8 is returned by UTF8 reader on invalid utf8 sequence.
+var ErrInvalidUTF8 = fmt.Errorf("invalid utf8")
+
+// UTF8Reader implements io.Reader that calculates utf8 validity state after
+// every read byte from Source.
+//
+// Note that in some cases client must call r.Valid() after all bytes are read
+// to ensure that all of them are valid utf8 sequences. That is, some io helper
+// functions such io.ReadAtLeast or io.ReadFull could discard the error
+// information returned by the reader when they receive all of requested bytes.
+// For example, the last read sequence is invalid and UTF8Reader returns number
+// of bytes read and an error. But helper function decides to discard received
+// error due to all requested bytes are completely read from the source.
+//
+// Another possible case is when some valid sequence become split by the read
+// bound. Then UTF8Reader can not make decision about validity of the last
+// sequence cause it is not fully read yet. And if the read stops, Valid() will
+// return false, even if Read() by itself dit not.
+type UTF8Reader struct {
+	Source io.Reader
+
+	accepted int
+
+	state uint32
+	codep uint32
+}
+
+// NewUTF8Reader creates utf8 reader that reads from r.
+func NewUTF8Reader(r io.Reader) *UTF8Reader {
+	return &UTF8Reader{
+		Source: r,
+	}
+}
+
+// Reset resets utf8 reader to read from r.
+func (u *UTF8Reader) Reset(r io.Reader) {
+	u.Source = r
+	u.state = 0
+	u.codep = 0
+}
+
+// Read implements io.Reader.
+func (u *UTF8Reader) Read(p []byte) (n int, err error) {
+	n, err = u.Source.Read(p)
+
+	accepted := 0
+	s, c := u.state, u.codep
+	for i := 0; i < n; i++ {
+		c, s = decode(s, c, p[i])
+		if s == utf8Reject {
+			u.state = s
+			return accepted, ErrInvalidUTF8
+		}
+		if s == utf8Accept {
+			accepted = i + 1
+		}
+	}
+	u.state, u.codep = s, c
+	u.accepted = accepted
+
+	return
+}
+
+// Valid checks current reader state. It returns true if all read bytes are
+// valid UTF-8 sequences, and false if not.
+func (u *UTF8Reader) Valid() bool {
+	return u.state == utf8Accept
+}
+
+// Accepted returns number of valid bytes in last Read().
+func (u *UTF8Reader) Accepted() int {
+	return u.accepted
+}
+
+// Below is port of UTF-8 decoder from http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
+//
+// Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+
+const (
+	utf8Accept = 0
+	utf8Reject = 12
+)
+
+var utf8d = [...]byte{
+	// The first part of the table maps bytes to character classes that
+	// to reduce the size of the transition table and create bitmasks.
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+	8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	10, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 11, 6, 6, 6, 5, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+
+	// The second part is a transition table that maps a combination
+	// of a state of the automaton and a character class to a state.
+	0, 12, 24, 36, 60, 96, 84, 12, 12, 12, 48, 72, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+	12, 0, 12, 12, 12, 12, 12, 0, 12, 0, 12, 12, 12, 24, 12, 12, 12, 12, 12, 24, 12, 24, 12, 12,
+	12, 12, 12, 12, 12, 12, 12, 24, 12, 12, 12, 12, 12, 24, 12, 12, 12, 12, 12, 12, 12, 24, 12, 12,
+	12, 12, 12, 12, 12, 12, 12, 36, 12, 36, 12, 12, 12, 36, 12, 12, 12, 12, 12, 36, 12, 36, 12, 12,
+	12, 36, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+}
+
+func decode(state, codep uint32, b byte) (uint32, uint32) {
+	t := uint32(utf8d[b])
+
+	if state != utf8Accept {
+		codep = (uint32(b) & 0x3f) | (codep << 6)
+	} else {
+		codep = (0xff >> t) & uint32(b)
+	}
+
+	return codep, uint32(utf8d[256+state+t])
+}