Go_I2p/lib/tunnel/doc.md

# tunnel
--
    import "github.com/go-i2p/go-i2p/lib/tunnel"

i2p garlic tunnel implementation

## Usage

```go
const (
	DT_LOCAL = iota
	DT_TUNNEL
	DT_ROUTER
	DT_UNUSED
)
```

```go
const (
	FIRST_FRAGMENT = iota
	FOLLOW_ON_FRAGMENT
)
```

```go
const (
	FLAG_SIZE                 = 1
	TUNNEL_ID_SIZE            = 4
	HASH_SIZE                 = 32
	DELAY_SIZE                = 1
	MESSAGE_ID_SIZE           = 4
	EXTENDED_OPTIONS_MIN_SIZE = 2
	SIZE_FIELD_SIZE           = 2
)
```

#### type DecryptedTunnelMessage

```go
type DecryptedTunnelMessage [1028]byte
```


#### func (DecryptedTunnelMessage) Checksum

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) Checksum() crypto.TunnelIV
```

#### func (DecryptedTunnelMessage) DeliveryInstructionsWithFragments

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) DeliveryInstructionsWithFragments() []DeliveryInstructionsWithFragment
```
Returns a slice of DeliveryInstructionWithFragment structures, which all of the
Delivery Instructions in the tunnel message and their corresponding
MessageFragment structures.

#### func (DecryptedTunnelMessage) ID

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) ID() TunnelID
```

#### func (DecryptedTunnelMessage) IV

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) IV() crypto.TunnelIV
```

#### type DelayFactor

```go
type DelayFactor byte
```


#### type DeliveryInstructions

```go
type DeliveryInstructions []byte
```


#### func (DeliveryInstructions) Delay

```go
func (delivery_instructions DeliveryInstructions) Delay() (delay_factor DelayFactor, err error)
```
Return the DelayFactor if present and any errors encountered parsing the
DeliveryInstructions.

#### func (DeliveryInstructions) DeliveryType

```go
func (delivery_instructions DeliveryInstructions) DeliveryType() (byte, error)
```
Return the delivery type for these DeliveryInstructions, can be of type
DT_LOCAL, DT_TUNNEL, DT_ROUTER, or DT_UNUSED.

#### func (DeliveryInstructions) ExtendedOptions

```go
func (delivery_instructions DeliveryInstructions) ExtendedOptions() (data []byte, err error)
```
Return the Extended Options data if present, or an error if not present.
Extended Options in unimplemented in the Java router and the presence of
extended options will generate a warning.

#### func (DeliveryInstructions) FragmentNumber

```go
func (delivery_instructions DeliveryInstructions) FragmentNumber() (int, error)
```
Read the integer stored in the 6-1 bits of a FOLLOW_ON_FRAGMENT's flag,
indicating the fragment number.

#### func (DeliveryInstructions) FragmentSize

```go
func (delivery_instructions DeliveryInstructions) FragmentSize() (frag_size uint16, err error)
```
Return the size of the associated I2NP fragment and an error if the data is
unavailable.

#### func (DeliveryInstructions) Fragmented

```go
func (delivery_instructions DeliveryInstructions) Fragmented() (bool, error)
```
Returns true if the Delivery Instructions are fragmented or false if the
following data contains the entire message

#### func (DeliveryInstructions) HasDelay

```go
func (delivery_instructions DeliveryInstructions) HasDelay() (bool, error)
```
Check if the delay bit is set. This feature in unimplemented in the Java router.

#### func (DeliveryInstructions) HasExtendedOptions

```go
func (delivery_instructions DeliveryInstructions) HasExtendedOptions() (bool, error)
```
Check if the extended options bit is set. This feature in unimplemented in the
Java router.

#### func (DeliveryInstructions) HasHash

```go
func (delivery_instructions DeliveryInstructions) HasHash() (bool, error)
```

#### func (DeliveryInstructions) HasTunnelID

```go
func (delivery_instructions DeliveryInstructions) HasTunnelID() (bool, error)
```
Check if the DeliveryInstructions is of type DT_TUNNEL.

#### func (DeliveryInstructions) Hash

```go
func (delivery_instructions DeliveryInstructions) Hash() (hash common.Hash, err error)
```
Return the hash for these DeliveryInstructions, which varies by hash type.

    If the type is DT_TUNNEL, hash is the SHA256 of the gateway router, if
    the type is DT_ROUTER it is the SHA256 of the router.

#### func (DeliveryInstructions) LastFollowOnFragment

```go
func (delivery_instructions DeliveryInstructions) LastFollowOnFragment() (bool, error)
```
Read the value of the 0 bit of a FOLLOW_ON_FRAGMENT, which is set to 1 to
indicate the last fragment.

#### func (DeliveryInstructions) MessageID

```go
func (delivery_instructions DeliveryInstructions) MessageID() (msgid uint32, err error)
```
Return the I2NP Message ID or 0 and an error if the data is not available for
this DeliveryInstructions.

#### func (DeliveryInstructions) TunnelID

```go
func (delivery_instructions DeliveryInstructions) TunnelID() (tunnel_id uint32, err error)
```
Return the tunnel ID in this DeliveryInstructions or 0 and an error if the
DeliveryInstructions are not of type DT_TUNNEL.

#### func (DeliveryInstructions) Type

```go
func (delivery_instructions DeliveryInstructions) Type() (int, error)
```
Return if the DeliveryInstructions are of type FIRST_FRAGMENT or
FOLLOW_ON_FRAGMENT.

#### type DeliveryInstructionsWithFragment

```go
type DeliveryInstructionsWithFragment struct {
	DeliveryInstructions DeliveryInstructions
	MessageFragment      []byte
}
```


#### type EncryptedTunnelMessage

```go
type EncryptedTunnelMessage crypto.TunnelData
```


#### func (EncryptedTunnelMessage) Data

```go
func (tm EncryptedTunnelMessage) Data() crypto.TunnelIV
```

#### func (EncryptedTunnelMessage) ID

```go
func (tm EncryptedTunnelMessage) ID() (tid TunnelID)
```

#### func (EncryptedTunnelMessage) IV

```go
func (tm EncryptedTunnelMessage) IV() crypto.TunnelIV
```

#### type Participant

```go
type Participant struct {
}
```


#### type Pool

```go
type Pool struct{}
```

a pool of tunnels which we have created

#### type TunnelID

```go
type TunnelID uint32
```

# tunnel
--
    import "github.com/go-i2p/go-i2p/lib/tunnel"

i2p garlic tunnel implementation

![tunnel.svg](tunnel)

## Usage

```go
const (
	DT_LOCAL = iota
	DT_TUNNEL
	DT_ROUTER
	DT_UNUSED
)
```

```go
const (
	FIRST_FRAGMENT = iota
	FOLLOW_ON_FRAGMENT
)
```

```go
const (
	FLAG_SIZE                 = 1
	TUNNEL_ID_SIZE            = 4
	HASH_SIZE                 = 32
	DELAY_SIZE                = 1
	MESSAGE_ID_SIZE           = 4
	EXTENDED_OPTIONS_MIN_SIZE = 2
	SIZE_FIELD_SIZE           = 2
)
```

#### type DecryptedTunnelMessage

```go
type DecryptedTunnelMessage [1028]byte
```


#### func (DecryptedTunnelMessage) Checksum

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) Checksum() crypto.TunnelIV
```

#### func (DecryptedTunnelMessage) DeliveryInstructionsWithFragments

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) DeliveryInstructionsWithFragments() []DeliveryInstructionsWithFragment
```
Returns a slice of DeliveryInstructionWithFragment structures, which all of the
Delivery Instructions in the tunnel message and their corresponding
MessageFragment structures.

#### func (DecryptedTunnelMessage) ID

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) ID() TunnelID
```

#### func (DecryptedTunnelMessage) IV

```go
func (decrypted_tunnel_message DecryptedTunnelMessage) IV() crypto.TunnelIV
```

#### type DelayFactor

```go
type DelayFactor byte
```


#### type DeliveryInstructions

```go
type DeliveryInstructions []byte
```


#### func (DeliveryInstructions) Delay

```go
func (delivery_instructions DeliveryInstructions) Delay() (delay_factor DelayFactor, err error)
```
Return the DelayFactor if present and any errors encountered parsing the
DeliveryInstructions.

#### func (DeliveryInstructions) DeliveryType

```go
func (delivery_instructions DeliveryInstructions) DeliveryType() (byte, error)
```
Return the delivery type for these DeliveryInstructions, can be of type
DT_LOCAL, DT_TUNNEL, DT_ROUTER, or DT_UNUSED.

#### func (DeliveryInstructions) ExtendedOptions

```go
func (delivery_instructions DeliveryInstructions) ExtendedOptions() (data []byte, err error)
```
Return the Extended Options data if present, or an error if not present.
Extended Options in unimplemented in the Java router and the presence of
extended options will generate a warning.

#### func (DeliveryInstructions) FragmentNumber

```go
func (delivery_instructions DeliveryInstructions) FragmentNumber() (int, error)
```
Read the integer stored in the 6-1 bits of a FOLLOW_ON_FRAGMENT's flag,
indicating the fragment number.

#### func (DeliveryInstructions) FragmentSize

```go
func (delivery_instructions DeliveryInstructions) FragmentSize() (frag_size uint16, err error)
```
Return the size of the associated I2NP fragment and an error if the data is
unavailable.

#### func (DeliveryInstructions) Fragmented

```go
func (delivery_instructions DeliveryInstructions) Fragmented() (bool, error)
```
Returns true if the Delivery Instructions are fragmented or false if the
following data contains the entire message

#### func (DeliveryInstructions) HasDelay

```go
func (delivery_instructions DeliveryInstructions) HasDelay() (bool, error)
```
Check if the delay bit is set. This feature in unimplemented in the Java router.

#### func (DeliveryInstructions) HasExtendedOptions

```go
func (delivery_instructions DeliveryInstructions) HasExtendedOptions() (bool, error)
```
Check if the extended options bit is set. This feature in unimplemented in the
Java router.

#### func (DeliveryInstructions) HasHash

```go
func (delivery_instructions DeliveryInstructions) HasHash() (bool, error)
```

#### func (DeliveryInstructions) HasTunnelID

```go
func (delivery_instructions DeliveryInstructions) HasTunnelID() (bool, error)
```
Check if the DeliveryInstructions is of type DT_TUNNEL.

#### func (DeliveryInstructions) Hash

```go
func (delivery_instructions DeliveryInstructions) Hash() (hash common.Hash, err error)
```
Return the hash for these DeliveryInstructions, which varies by hash type.

    If the type is DT_TUNNEL, hash is the SHA256 of the gateway router, if
    the type is DT_ROUTER it is the SHA256 of the router.

#### func (DeliveryInstructions) LastFollowOnFragment

```go
func (delivery_instructions DeliveryInstructions) LastFollowOnFragment() (bool, error)
```
Read the value of the 0 bit of a FOLLOW_ON_FRAGMENT, which is set to 1 to
indicate the last fragment.

#### func (DeliveryInstructions) MessageID

```go
func (delivery_instructions DeliveryInstructions) MessageID() (msgid uint32, err error)
```
Return the I2NP Message ID or 0 and an error if the data is not available for
this DeliveryInstructions.

#### func (DeliveryInstructions) TunnelID

```go
func (delivery_instructions DeliveryInstructions) TunnelID() (tunnel_id uint32, err error)
```
Return the tunnel ID in this DeliveryInstructions or 0 and an error if the
DeliveryInstructions are not of type DT_TUNNEL.

#### func (DeliveryInstructions) Type

```go
func (delivery_instructions DeliveryInstructions) Type() (int, error)
```
Return if the DeliveryInstructions are of type FIRST_FRAGMENT or
FOLLOW_ON_FRAGMENT.

#### type DeliveryInstructionsWithFragment

```go
type DeliveryInstructionsWithFragment struct {
	DeliveryInstructions DeliveryInstructions
	MessageFragment      []byte
}
```


#### type EncryptedTunnelMessage

```go
type EncryptedTunnelMessage crypto.TunnelData
```


#### func (EncryptedTunnelMessage) Data

```go
func (tm EncryptedTunnelMessage) Data() crypto.TunnelIV
```

#### func (EncryptedTunnelMessage) ID

```go
func (tm EncryptedTunnelMessage) ID() (tid TunnelID)
```

#### func (EncryptedTunnelMessage) IV

```go
func (tm EncryptedTunnelMessage) IV() crypto.TunnelIV
```

#### type Participant

```go
type Participant struct {
}
```


#### type Pool

```go
type Pool struct{}
```

a pool of tunnels which we have created

#### type TunnelID

```go
type TunnelID uint32
```



tunnel

github.com/go-i2p/go-i2p/lib/tunnel