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author | Valentin Rothberg <rothberg@redhat.com> | 2019-01-08 14:52:57 +0100 |
---|---|---|
committer | Valentin Rothberg <rothberg@redhat.com> | 2019-01-11 13:38:11 +0100 |
commit | bd40dcfc2bc7c9014ea1f33482fb63aacbcdfe87 (patch) | |
tree | 5f06e4e289f16d9164d692590a3fe6541b5384cf /vendor/golang.org/x/net/http2/hpack/hpack.go | |
parent | 545f24421247c9f6251a634764db3f8f8070a812 (diff) | |
download | podman-bd40dcfc2bc7c9014ea1f33482fb63aacbcdfe87.tar.gz podman-bd40dcfc2bc7c9014ea1f33482fb63aacbcdfe87.tar.bz2 podman-bd40dcfc2bc7c9014ea1f33482fb63aacbcdfe87.zip |
vendor: update everything
* If possible, update each dependency to the latest available version.
* Use releases over commit IDs and avoid vendoring branches.
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'vendor/golang.org/x/net/http2/hpack/hpack.go')
-rw-r--r-- | vendor/golang.org/x/net/http2/hpack/hpack.go | 118 |
1 files changed, 40 insertions, 78 deletions
diff --git a/vendor/golang.org/x/net/http2/hpack/hpack.go b/vendor/golang.org/x/net/http2/hpack/hpack.go index 135b9f62c..85f18a2b0 100644 --- a/vendor/golang.org/x/net/http2/hpack/hpack.go +++ b/vendor/golang.org/x/net/http2/hpack/hpack.go @@ -61,7 +61,7 @@ func (hf HeaderField) String() string { 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 + // 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 @@ -92,6 +92,8 @@ type Decoder struct { // 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 + + firstField bool // processing the first field of the header block } // NewDecoder returns a new decoder with the provided maximum dynamic @@ -101,7 +103,9 @@ func NewDecoder(maxDynamicTableSize uint32, emitFunc func(f HeaderField)) *Decod d := &Decoder{ emit: emitFunc, emitEnabled: true, + firstField: true, } + d.dynTab.table.init() d.dynTab.allowedMaxSize = maxDynamicTableSize d.dynTab.setMaxSize(maxDynamicTableSize) return d @@ -154,12 +158,9 @@ func (d *Decoder) SetAllowedMaxDynamicTableSize(v uint32) { } type dynamicTable struct { - // ents is the FIFO described at // http://http2.github.io/http2-spec/compression.html#rfc.section.2.3.2 - // The newest (low index) is append at the end, and items are - // evicted from the front. - ents []HeaderField - size uint32 + table headerFieldTable + size uint32 // in bytes maxSize uint32 // current maxSize allowedMaxSize uint32 // maxSize may go up to this, inclusive } @@ -169,95 +170,45 @@ func (dt *dynamicTable) setMaxSize(v uint32) { dt.evict() } -// TODO: change dynamicTable to be a struct with a slice and a size int field, -// per http://http2.github.io/http2-spec/compression.html#rfc.section.4.1: -// -// -// Then make add increment the size. maybe the max size should move from Decoder to -// dynamicTable and add should return an ok bool if there was enough space. -// -// Later we'll need a remove operation on dynamicTable. - func (dt *dynamicTable) add(f HeaderField) { - dt.ents = append(dt.ents, f) + dt.table.addEntry(f) dt.size += f.Size() dt.evict() } -// If we're too big, evict old stuff (front of the slice) +// If we're too big, evict old stuff. func (dt *dynamicTable) evict() { - base := dt.ents // keep base pointer of slice - for dt.size > dt.maxSize { - dt.size -= dt.ents[0].Size() - dt.ents = dt.ents[1:] - } - - // Shift slice contents down if we evicted things. - if len(dt.ents) != len(base) { - copy(base, dt.ents) - dt.ents = base[:len(dt.ents)] - } -} - -// constantTimeStringCompare compares string a and b in a constant -// time manner. -func constantTimeStringCompare(a, b string) bool { - if len(a) != len(b) { - return false - } - - c := byte(0) - - for i := 0; i < len(a); i++ { - c |= a[i] ^ b[i] + var n int + for dt.size > dt.maxSize && n < dt.table.len() { + dt.size -= dt.table.ents[n].Size() + n++ } - - return c == 0 -} - -// Search searches f in the table. The return value i is 0 if there is -// no name match. If there is name match or name/value match, i is the -// index of that entry (1-based). If both name and value match, -// nameValueMatch becomes true. -func (dt *dynamicTable) search(f HeaderField) (i uint64, nameValueMatch bool) { - l := len(dt.ents) - for j := l - 1; j >= 0; j-- { - ent := dt.ents[j] - if !constantTimeStringCompare(ent.Name, f.Name) { - continue - } - if i == 0 { - i = uint64(l - j) - } - if f.Sensitive { - continue - } - if !constantTimeStringCompare(ent.Value, f.Value) { - continue - } - i = uint64(l - j) - nameValueMatch = true - return - } - return + dt.table.evictOldest(n) } func (d *Decoder) maxTableIndex() int { - return len(d.dynTab.ents) + len(staticTable) + // 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) { - if i < 1 { + // 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 } - if i <= uint64(len(staticTable)) { - return staticTable[i-1], true - } - dents := d.dynTab.ents - return dents[len(dents)-(int(i)-len(staticTable))], true + // 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. @@ -278,11 +229,15 @@ func (d *Decoder) DecodeFull(p []byte) ([]HeaderField, error) { return hf, nil } +// Close declares that the decoding is complete and resets the Decoder +// to be reused again for a new header block. If there is any remaining +// data in the decoder's buffer, Close returns an error. func (d *Decoder) Close() error { if d.saveBuf.Len() > 0 { d.saveBuf.Reset() return DecodingError{errors.New("truncated headers")} } + d.firstField = true return nil } @@ -307,7 +262,7 @@ func (d *Decoder) Write(p []byte) (n int, err error) { err = d.parseHeaderFieldRepr() if err == errNeedMore { // Extra paranoia, making sure saveBuf won't - // get too large. All the varint and string + // 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. @@ -318,6 +273,7 @@ func (d *Decoder) Write(p []byte) (n int, err error) { d.saveBuf.Write(d.buf) return len(p), nil } + d.firstField = false if err != nil { break } @@ -441,6 +397,12 @@ func (d *Decoder) callEmit(hf HeaderField) error { // (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.firstField && 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 { |