Files
quic-go/handshake/connection_parameters_manager.go
2016-05-05 11:29:12 +07:00

80 lines
2.0 KiB
Go

package handshake
import (
"bytes"
"encoding/binary"
"errors"
"sync"
)
// ConnectionParametersManager stores the connection parameters
type ConnectionParametersManager struct {
params map[Tag][]byte
mutex sync.RWMutex
}
// ErrTagNotInConnectionParameterMap is returned when a tag is not present in the connection parameters
var ErrTagNotInConnectionParameterMap = errors.New("Tag not found in ConnectionsParameter map")
// NewConnectionParamatersManager creates a new connection parameters manager
func NewConnectionParamatersManager() *ConnectionParametersManager {
cpm := &ConnectionParametersManager{
params: make(map[Tag][]byte),
}
// set default parameters
cpm.mutex.Lock()
cpm.params[TagSFCW] = []byte{0x0, 0x40, 0x0, 0x0} // Stream Flow Control Window
cpm.params[TagCFCW] = []byte{0x0, 0x40, 0x0, 0x0} // Connection Flow Control WindowWindow
cpm.mutex.Unlock()
return cpm
}
// SetFromMap reads all params
func (h *ConnectionParametersManager) SetFromMap(params map[Tag][]byte) error {
h.mutex.Lock()
for key, value := range params {
h.params[key] = value
}
h.mutex.Unlock()
return nil
}
// GetRawValue gets the byte-slice for a tag
func (h *ConnectionParametersManager) GetRawValue(tag Tag) ([]byte, error) {
h.mutex.RLock()
rawValue, ok := h.params[tag]
h.mutex.RUnlock()
if !ok {
return nil, ErrTagNotInConnectionParameterMap
}
return rawValue, nil
}
// GetSHLOMap gets all values (except crypto values) needed for the SHLO
func (h *ConnectionParametersManager) GetSHLOMap() map[Tag][]byte {
return map[Tag][]byte{
TagICSL: []byte{0x1e, 0x00, 0x00, 0x00}, //30
TagMSPC: []byte{0x64, 0x00, 0x00, 0x00}, //100
}
}
// GetStreamFlowControlWindow gets the size of the stream-level flow control window
func (h *ConnectionParametersManager) GetStreamFlowControlWindow() (uint32, error) {
rawValue, err := h.GetRawValue(TagSFCW)
if err != nil {
return 0, err
}
var value uint32
buf := bytes.NewBuffer(rawValue)
err = binary.Read(buf, binary.LittleEndian, &value)
if err != nil {
return 0, err
}
return value, nil
}