2018-07-04 10:51:47 +00:00
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package yamux
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import (
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2021-10-19 13:43:41 +00:00
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"errors"
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2018-07-04 10:51:47 +00:00
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"fmt"
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"io"
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2019-06-09 07:24:20 +00:00
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"net"
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2018-07-04 10:51:47 +00:00
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"os"
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"time"
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)
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// Config is used to tune the Yamux session
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type Config struct {
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// AcceptBacklog is used to limit how many streams may be
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// waiting an accept.
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AcceptBacklog int
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// PingBacklog is used to limit how many ping acks we can queue.
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PingBacklog int
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2018-07-04 10:51:47 +00:00
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// EnableKeepalive is used to do a period keep alive
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// messages using a ping.
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EnableKeepAlive bool
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// KeepAliveInterval is how often to perform the keep alive
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KeepAliveInterval time.Duration
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// ConnectionWriteTimeout is meant to be a "safety valve" timeout after
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// we which will suspect a problem with the underlying connection and
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// close it. This is only applied to writes, where's there's generally
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// an expectation that things will move along quickly.
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ConnectionWriteTimeout time.Duration
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// InitialStreamWindowSize is used to control the initial
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// window size that we allow for a stream.
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InitialStreamWindowSize uint32
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2018-07-04 10:51:47 +00:00
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// MaxStreamWindowSize is used to control the maximum
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// window size that we allow for a stream.
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MaxStreamWindowSize uint32
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// LogOutput is used to control the log destination
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LogOutput io.Writer
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// ReadBufSize controls the size of the read buffer.
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//
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// Set to 0 to disable it.
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ReadBufSize int
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// WriteCoalesceDelay is the maximum amount of time we'll delay
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// coalescing a packet before sending it. This should be on the order of
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// micro-milliseconds.
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WriteCoalesceDelay time.Duration
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// MaxMessageSize is the maximum size of a message that we'll send on a
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// stream. This ensures that a single stream doesn't hog a connection.
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MaxMessageSize uint32
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}
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// DefaultConfig is used to return a default configuration
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func DefaultConfig() *Config {
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return &Config{
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AcceptBacklog: 256,
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PingBacklog: 32,
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EnableKeepAlive: true,
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KeepAliveInterval: 30 * time.Second,
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ConnectionWriteTimeout: 10 * time.Second,
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InitialStreamWindowSize: initialStreamWindow,
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MaxStreamWindowSize: maxStreamWindow,
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LogOutput: os.Stderr,
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ReadBufSize: 4096,
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MaxMessageSize: 64 * 1024,
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WriteCoalesceDelay: 100 * time.Microsecond,
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}
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}
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// VerifyConfig is used to verify the sanity of configuration
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func VerifyConfig(config *Config) error {
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if config.AcceptBacklog <= 0 {
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return fmt.Errorf("backlog must be positive")
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}
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if config.KeepAliveInterval == 0 {
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return fmt.Errorf("keep-alive interval must be positive")
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}
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if config.InitialStreamWindowSize < initialStreamWindow {
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return errors.New("InitialStreamWindowSize must be larger or equal 256 kB")
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}
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if config.MaxStreamWindowSize < config.InitialStreamWindowSize {
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return errors.New("MaxStreamWindowSize must be larger than the InitialStreamWindowSize")
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}
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if config.MaxMessageSize < 1024 {
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return fmt.Errorf("MaxMessageSize must be greater than a kilobyte")
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}
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if config.WriteCoalesceDelay < 0 {
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return fmt.Errorf("WriteCoalesceDelay must be >= 0")
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}
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if config.PingBacklog < 1 {
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return fmt.Errorf("PingBacklog must be > 0")
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}
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return nil
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}
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// Server is used to initialize a new server-side connection.
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// There must be at most one server-side connection. If a nil config is
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// provided, the DefaultConfiguration will be used.
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func Server(conn net.Conn, config *Config) (*Session, error) {
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if config == nil {
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config = DefaultConfig()
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}
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if err := VerifyConfig(config); err != nil {
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return nil, err
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}
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return newSession(config, conn, false, config.ReadBufSize), nil
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}
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// Client is used to initialize a new client-side connection.
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// There must be at most one client-side connection.
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func Client(conn net.Conn, config *Config) (*Session, error) {
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if config == nil {
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config = DefaultConfig()
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}
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if err := VerifyConfig(config); err != nil {
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return nil, err
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}
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return newSession(config, conn, true, config.ReadBufSize), nil
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2018-07-04 10:51:47 +00:00
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}
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