From 8c12c6939aab9106db14ec2d11d983bc5b29fb2c Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 7 Jul 2019 21:33:44 +0100 Subject: Switch to modules --- vendor/golang.org/x/net/http2/hpack/hpack.go | 496 --------------------------- 1 file changed, 496 deletions(-) delete mode 100644 vendor/golang.org/x/net/http2/hpack/hpack.go (limited to 'vendor/golang.org/x/net/http2/hpack/hpack.go') diff --git a/vendor/golang.org/x/net/http2/hpack/hpack.go b/vendor/golang.org/x/net/http2/hpack/hpack.go deleted file mode 100644 index 166788c..0000000 --- a/vendor/golang.org/x/net/http2/hpack/hpack.go +++ /dev/null @@ -1,496 +0,0 @@ -// Copyright 2014 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 hpack implements HPACK, a compression format for -// efficiently representing HTTP header fields in the context of HTTP/2. -// -// See http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-09 -package hpack - -import ( - "bytes" - "errors" - "fmt" -) - -// A DecodingError is something the spec defines as a decoding error. -type DecodingError struct { - Err error -} - -func (de DecodingError) Error() string { - return fmt.Sprintf("decoding error: %v", de.Err) -} - -// An InvalidIndexError is returned when an encoder references a table -// entry before the static table or after the end of the dynamic table. -type InvalidIndexError int - -func (e InvalidIndexError) Error() string { - return fmt.Sprintf("invalid indexed representation index %d", int(e)) -} - -// A HeaderField is a name-value pair. Both the name and value are -// treated as opaque sequences of octets. -type HeaderField struct { - Name, Value string - - // Sensitive means that this header field should never be - // indexed. - Sensitive bool -} - -// IsPseudo reports whether the header field is an http2 pseudo header. -// That is, it reports whether it starts with a colon. -// It is not otherwise guaranteed to be a valid pseudo header field, -// though. -func (hf HeaderField) IsPseudo() bool { - return len(hf.Name) != 0 && hf.Name[0] == ':' -} - -func (hf HeaderField) String() string { - var suffix string - if hf.Sensitive { - suffix = " (sensitive)" - } - return fmt.Sprintf("header field %q = %q%s", hf.Name, hf.Value, suffix) -} - -// Size returns the size of an entry per RFC 7541 section 4.1. -func (hf HeaderField) Size() uint32 { - // http://http2.github.io/http2-spec/compression.html#rfc.section.4.1 - // "The size of the dynamic table is the sum of the size of - // its entries. The size of an entry is the sum of its name's - // length in octets (as defined in Section 5.2), its value's - // length in octets (see Section 5.2), plus 32. The size of - // an entry is calculated using the length of the name and - // value without any Huffman encoding applied." - - // This can overflow if somebody makes a large HeaderField - // Name and/or Value by hand, but we don't care, because that - // won't happen on the wire because the encoding doesn't allow - // it. - return uint32(len(hf.Name) + len(hf.Value) + 32) -} - -// A Decoder is the decoding context for incremental processing of -// header blocks. -type Decoder struct { - dynTab dynamicTable - emit func(f HeaderField) - - emitEnabled bool // whether calls to emit are enabled - maxStrLen int // 0 means unlimited - - // buf is the unparsed buffer. It's only written to - // saveBuf if it was truncated in the middle of a header - // block. Because it's usually not owned, we can only - // process it under Write. - buf []byte // not owned; only valid during Write - - // saveBuf is previous data passed to Write which we weren't able - // to fully parse before. Unlike buf, we own this data. - saveBuf bytes.Buffer -} - -// NewDecoder returns a new decoder with the provided maximum dynamic -// table size. The emitFunc will be called for each valid field -// parsed, in the same goroutine as calls to Write, before Write returns. -func NewDecoder(maxDynamicTableSize uint32, emitFunc func(f HeaderField)) *Decoder { - d := &Decoder{ - emit: emitFunc, - emitEnabled: true, - } - d.dynTab.table.init() - d.dynTab.allowedMaxSize = maxDynamicTableSize - d.dynTab.setMaxSize(maxDynamicTableSize) - return d -} - -// ErrStringLength is returned by Decoder.Write when the max string length -// (as configured by Decoder.SetMaxStringLength) would be violated. -var ErrStringLength = errors.New("hpack: string too long") - -// SetMaxStringLength sets the maximum size of a HeaderField name or -// value string. If a string exceeds this length (even after any -// decompression), Write will return ErrStringLength. -// A value of 0 means unlimited and is the default from NewDecoder. -func (d *Decoder) SetMaxStringLength(n int) { - d.maxStrLen = n -} - -// SetEmitFunc changes the callback used when new header fields -// are decoded. -// It must be non-nil. It does not affect EmitEnabled. -func (d *Decoder) SetEmitFunc(emitFunc func(f HeaderField)) { - d.emit = emitFunc -} - -// SetEmitEnabled controls whether the emitFunc provided to NewDecoder -// should be called. The default is true. -// -// This facility exists to let servers enforce MAX_HEADER_LIST_SIZE -// while still decoding and keeping in-sync with decoder state, but -// without doing unnecessary decompression or generating unnecessary -// garbage for header fields past the limit. -func (d *Decoder) SetEmitEnabled(v bool) { d.emitEnabled = v } - -// EmitEnabled reports whether calls to the emitFunc provided to NewDecoder -// are currently enabled. The default is true. -func (d *Decoder) EmitEnabled() bool { return d.emitEnabled } - -// TODO: add method *Decoder.Reset(maxSize, emitFunc) to let callers re-use Decoders and their -// underlying buffers for garbage reasons. - -func (d *Decoder) SetMaxDynamicTableSize(v uint32) { - d.dynTab.setMaxSize(v) -} - -// SetAllowedMaxDynamicTableSize sets the upper bound that the encoded -// stream (via dynamic table size updates) may set the maximum size -// to. -func (d *Decoder) SetAllowedMaxDynamicTableSize(v uint32) { - d.dynTab.allowedMaxSize = v -} - -type dynamicTable struct { - // http://http2.github.io/http2-spec/compression.html#rfc.section.2.3.2 - table headerFieldTable - size uint32 // in bytes - maxSize uint32 // current maxSize - allowedMaxSize uint32 // maxSize may go up to this, inclusive -} - -func (dt *dynamicTable) setMaxSize(v uint32) { - dt.maxSize = v - dt.evict() -} - -func (dt *dynamicTable) add(f HeaderField) { - dt.table.addEntry(f) - dt.size += f.Size() - dt.evict() -} - -// If we're too big, evict old stuff. -func (dt *dynamicTable) evict() { - var n int - for dt.size > dt.maxSize && n < dt.table.len() { - dt.size -= dt.table.ents[n].Size() - n++ - } - dt.table.evictOldest(n) -} - -func (d *Decoder) maxTableIndex() int { - // This should never overflow. RFC 7540 Section 6.5.2 limits the size of - // the dynamic table to 2^32 bytes, where each entry will occupy more than - // one byte. Further, the staticTable has a fixed, small length. - return d.dynTab.table.len() + staticTable.len() -} - -func (d *Decoder) at(i uint64) (hf HeaderField, ok bool) { - // See Section 2.3.3. - if i == 0 { - return - } - if i <= uint64(staticTable.len()) { - return staticTable.ents[i-1], true - } - if i > uint64(d.maxTableIndex()) { - return - } - // In the dynamic table, newer entries have lower indices. - // However, dt.ents[0] is the oldest entry. Hence, dt.ents is - // the reversed dynamic table. - dt := d.dynTab.table - return dt.ents[dt.len()-(int(i)-staticTable.len())], true -} - -// Decode decodes an entire block. -// -// TODO: remove this method and make it incremental later? This is -// easier for debugging now. -func (d *Decoder) DecodeFull(p []byte) ([]HeaderField, error) { - var hf []HeaderField - saveFunc := d.emit - defer func() { d.emit = saveFunc }() - d.emit = func(f HeaderField) { hf = append(hf, f) } - if _, err := d.Write(p); err != nil { - return nil, err - } - if err := d.Close(); err != nil { - return nil, err - } - return hf, nil -} - -func (d *Decoder) Close() error { - if d.saveBuf.Len() > 0 { - d.saveBuf.Reset() - return DecodingError{errors.New("truncated headers")} - } - return nil -} - -func (d *Decoder) Write(p []byte) (n int, err error) { - if len(p) == 0 { - // Prevent state machine CPU attacks (making us redo - // work up to the point of finding out we don't have - // enough data) - return - } - // Only copy the data if we have to. Optimistically assume - // that p will contain a complete header block. - if d.saveBuf.Len() == 0 { - d.buf = p - } else { - d.saveBuf.Write(p) - d.buf = d.saveBuf.Bytes() - d.saveBuf.Reset() - } - - for len(d.buf) > 0 { - err = d.parseHeaderFieldRepr() - if err == errNeedMore { - // Extra paranoia, making sure saveBuf won't - // get too large. All the varint and string - // reading code earlier should already catch - // overlong things and return ErrStringLength, - // but keep this as a last resort. - const varIntOverhead = 8 // conservative - if d.maxStrLen != 0 && int64(len(d.buf)) > 2*(int64(d.maxStrLen)+varIntOverhead) { - return 0, ErrStringLength - } - d.saveBuf.Write(d.buf) - return len(p), nil - } - if err != nil { - break - } - } - return len(p), err -} - -// errNeedMore is an internal sentinel error value that means the -// buffer is truncated and we need to read more data before we can -// continue parsing. -var errNeedMore = errors.New("need more data") - -type indexType int - -const ( - indexedTrue indexType = iota - indexedFalse - indexedNever -) - -func (v indexType) indexed() bool { return v == indexedTrue } -func (v indexType) sensitive() bool { return v == indexedNever } - -// returns errNeedMore if there isn't enough data available. -// any other error is fatal. -// consumes d.buf iff it returns nil. -// precondition: must be called with len(d.buf) > 0 -func (d *Decoder) parseHeaderFieldRepr() error { - b := d.buf[0] - switch { - case b&128 != 0: - // Indexed representation. - // High bit set? - // http://http2.github.io/http2-spec/compression.html#rfc.section.6.1 - return d.parseFieldIndexed() - case b&192 == 64: - // 6.2.1 Literal Header Field with Incremental Indexing - // 0b10xxxxxx: top two bits are 10 - // http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.1 - return d.parseFieldLiteral(6, indexedTrue) - case b&240 == 0: - // 6.2.2 Literal Header Field without Indexing - // 0b0000xxxx: top four bits are 0000 - // http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.2 - return d.parseFieldLiteral(4, indexedFalse) - case b&240 == 16: - // 6.2.3 Literal Header Field never Indexed - // 0b0001xxxx: top four bits are 0001 - // http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.3 - return d.parseFieldLiteral(4, indexedNever) - case b&224 == 32: - // 6.3 Dynamic Table Size Update - // Top three bits are '001'. - // http://http2.github.io/http2-spec/compression.html#rfc.section.6.3 - return d.parseDynamicTableSizeUpdate() - } - - return DecodingError{errors.New("invalid encoding")} -} - -// (same invariants and behavior as parseHeaderFieldRepr) -func (d *Decoder) parseFieldIndexed() error { - buf := d.buf - idx, buf, err := readVarInt(7, buf) - if err != nil { - return err - } - hf, ok := d.at(idx) - if !ok { - return DecodingError{InvalidIndexError(idx)} - } - d.buf = buf - return d.callEmit(HeaderField{Name: hf.Name, Value: hf.Value}) -} - -// (same invariants and behavior as parseHeaderFieldRepr) -func (d *Decoder) parseFieldLiteral(n uint8, it indexType) error { - buf := d.buf - nameIdx, buf, err := readVarInt(n, buf) - if err != nil { - return err - } - - var hf HeaderField - wantStr := d.emitEnabled || it.indexed() - if nameIdx > 0 { - ihf, ok := d.at(nameIdx) - if !ok { - return DecodingError{InvalidIndexError(nameIdx)} - } - hf.Name = ihf.Name - } else { - hf.Name, buf, err = d.readString(buf, wantStr) - if err != nil { - return err - } - } - hf.Value, buf, err = d.readString(buf, wantStr) - if err != nil { - return err - } - d.buf = buf - if it.indexed() { - d.dynTab.add(hf) - } - hf.Sensitive = it.sensitive() - return d.callEmit(hf) -} - -func (d *Decoder) callEmit(hf HeaderField) error { - if d.maxStrLen != 0 { - if len(hf.Name) > d.maxStrLen || len(hf.Value) > d.maxStrLen { - return ErrStringLength - } - } - if d.emitEnabled { - d.emit(hf) - } - return nil -} - -// (same invariants and behavior as parseHeaderFieldRepr) -func (d *Decoder) parseDynamicTableSizeUpdate() error { - // RFC 7541, sec 4.2: This dynamic table size update MUST occur at the - // beginning of the first header block following the change to the dynamic table size. - if d.dynTab.size > 0 { - return DecodingError{errors.New("dynamic table size update MUST occur at the beginning of a header block")} - } - - buf := d.buf - size, buf, err := readVarInt(5, buf) - if err != nil { - return err - } - if size > uint64(d.dynTab.allowedMaxSize) { - return DecodingError{errors.New("dynamic table size update too large")} - } - d.dynTab.setMaxSize(uint32(size)) - d.buf = buf - return nil -} - -var errVarintOverflow = DecodingError{errors.New("varint integer overflow")} - -// readVarInt reads an unsigned variable length integer off the -// beginning of p. n is the parameter as described in -// http://http2.github.io/http2-spec/compression.html#rfc.section.5.1. -// -// n must always be between 1 and 8. -// -// The returned remain buffer is either a smaller suffix of p, or err != nil. -// The error is errNeedMore if p doesn't contain a complete integer. -func readVarInt(n byte, p []byte) (i uint64, remain []byte, err error) { - if n < 1 || n > 8 { - panic("bad n") - } - if len(p) == 0 { - return 0, p, errNeedMore - } - i = uint64(p[0]) - if n < 8 { - i &= (1 << uint64(n)) - 1 - } - if i < (1< 0 { - b := p[0] - p = p[1:] - i += uint64(b&127) << m - if b&128 == 0 { - return i, p, nil - } - m += 7 - if m >= 63 { // TODO: proper overflow check. making this up. - return 0, origP, errVarintOverflow - } - } - return 0, origP, errNeedMore -} - -// readString decodes an hpack string from p. -// -// wantStr is whether s will be used. If false, decompression and -// []byte->string garbage are skipped if s will be ignored -// anyway. This does mean that huffman decoding errors for non-indexed -// strings past the MAX_HEADER_LIST_SIZE are ignored, but the server -// is returning an error anyway, and because they're not indexed, the error -// won't affect the decoding state. -func (d *Decoder) readString(p []byte, wantStr bool) (s string, remain []byte, err error) { - if len(p) == 0 { - return "", p, errNeedMore - } - isHuff := p[0]&128 != 0 - strLen, p, err := readVarInt(7, p) - if err != nil { - return "", p, err - } - if d.maxStrLen != 0 && strLen > uint64(d.maxStrLen) { - return "", nil, ErrStringLength - } - if uint64(len(p)) < strLen { - return "", p, errNeedMore - } - if !isHuff { - if wantStr { - s = string(p[:strLen]) - } - return s, p[strLen:], nil - } - - if wantStr { - buf := bufPool.Get().(*bytes.Buffer) - buf.Reset() // don't trust others - defer bufPool.Put(buf) - if err := huffmanDecode(buf, d.maxStrLen, p[:strLen]); err != nil { - buf.Reset() - return "", nil, err - } - s = buf.String() - buf.Reset() // be nice to GC - } - return s, p[strLen:], nil -} -- cgit v1.2.3