SshChannelManager¶

[Source]

Tracks channel state keyed by local channel id. The local id (the map key) is the value we advertise to the peer as sender_channel; the peer echoes it back as the recipient_channel of every message it sends us, so the connection layer uses an inbound recipient_channel directly as the local key. A channel's remote_id is stored only to fill the recipient_channel field of messages we send to the peer. Anyone changing how outbound messages are keyed must preserve this local-id == map-key == peer's recipient_channel invariant, or inbound routing will look up the wrong channel.

class ref SshChannelManager

Constructors¶

create¶

[Source]

The receive window is at least 256 bytes, even for smaller inputs.

new ref create(
  initial_window': U32 val = SshChannelWindow.initial())
: SshChannelManager ref^

Parameters¶

initial_window': U32 val = SshChannelWindow.initial()

Returns¶

SshChannelManager ref^

Public fields¶

let initial_window: U32 val¶

[Source]

Public Functions¶

open_channel¶

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Allocate local channel ID and create pending state.

fun ref open_channel(
  channel_type: String val)
: U32 val

Parameters¶

channel_type: String val

Returns¶

U32 val

confirm_channel¶

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Confirm a pending channel open. The peer accepting the channel we opened is what authorizes it, so this is where a channel of ours becomes usable.

fun ref confirm_channel(
  local_id: U32 val,
  remote_id: U32 val,
  remote_window: U32 val,
  max_packet_size: U32 val)
: (None val | SshChannelError)

Parameters¶

local_id: U32 val
remote_id: U32 val
remote_window: U32 val
max_packet_size: U32 val

Returns¶

(None val | SshChannelError)

accept_channel¶

[Source]

Accept an incoming channel open from remote (server side).

fun ref accept_channel(
  local_id: U32 val,
  remote_id: U32 val,
  remote_window: U32 val,
  max_packet_size: U32 val,
  channel_type: String val)
: (U32 val | SshChannelUnsupportedPacketSize val)

Parameters¶

local_id: U32 val
remote_id: U32 val
remote_window: U32 val
max_packet_size: U32 val
channel_type: String val

Returns¶

(U32 val | SshChannelUnsupportedPacketSize val)

channel_remote_id_if_open¶

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Return the peer's channel ID when the local channel is open.

fun box channel_remote_id_if_open(
  local_id: U32 val)
: (U32 val | SshChannelError)

Parameters¶

local_id: U32 val

Returns¶

(U32 val | SshChannelError)

channel_data_admitted¶

[Source]

Debit the peer window after a segment has been admitted to transport.

fun ref channel_data_admitted(
  local_id: U32 val,
  data_size: USize val)
: (None val | SshChannelError)

Parameters¶

local_id: U32 val
data_size: USize val

Returns¶

(None val | SshChannelError)

clear_send_blocked¶

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Clear blocked-send state when the session ends.

fun ref clear_send_blocked()
: None val

Returns¶

None val

channel_data_received¶

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Account for received data against the receive window. Returns the remaining window on success, or SshWindowExhausted if the peer sent more than the window we advertised (a flow-control violation we must not silently absorb).

fun ref channel_data_received(
  local_id: U32 val,
  data_size: USize val)
: (U32 val | SshChannelError)

Parameters¶

local_id: U32 val
data_size: USize val

Returns¶

(U32 val | SshChannelError)

replenish_local_window¶

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If the receive window has fallen below half its initial size, top it back up to the initial size and return the increment to advertise to the peer via SSH_MSG_CHANNEL_WINDOW_ADJUST. Returns None when no adjustment is due. Without this the peer's send window decays to zero and the channel stalls.

fun ref replenish_local_window(
  local_id: U32 val)
: (U32 val | None val)

Parameters¶

local_id: U32 val

Returns¶

(U32 val | None val)

window_adjust¶

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Increase the remote send window for a channel. Saturates at U32 max rather than wrapping: a peer that sums WINDOW_ADJUSTs past 2^32 (which RFC 4254 §5.2 forbids) must not silently wrap our window back to a small value.

fun ref window_adjust(
  local_id: U32 val,
  bytes: U32 val)
: None val

Parameters¶

local_id: U32 val
bytes: U32 val

Returns¶

None val

close_channel¶

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Remove channel state.

fun ref close_channel(
  local_id: U32 val)
: None val

Parameters¶

local_id: U32 val

Returns¶

None val

get¶

[Source]

fun ref get(
  local_id: U32 val)
: (SshChannelState ref | None val)

Parameters¶

local_id: U32 val

Returns¶

(SshChannelState ref | None val)

channel_count¶

[Source]

fun box channel_count()
: USize val

Returns¶

USize val

at_capacity¶

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True once the concurrent-channel cap is reached; reject further opens.

fun box at_capacity()
: Bool val

Returns¶

Bool val