Merge branch 'release/2.2.0' into 'stable'v2.2.0

Release/2.2.0

See merge request pleroma/secteam/pleroma!19

1 files changed, 185 insertions, 0 deletions

diff --git a/lib/pleroma/web/fed_sockets.ex b/lib/pleroma/web/fed_sockets.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.FedSockets do
+  @moduledoc """
+  This documents the FedSockets framework. A framework for federating
+  ActivityPub objects between servers via persistant WebSocket connections.
+
+  FedSockets allow servers to authenticate on first contact and maintain that
+  connection, eliminating the need to authenticate every time data needs to be shared.
+
+  ## Protocol
+  FedSockets currently support 2 types of data transfer:
+    * `publish` method which doesn't require a response
+    * `fetch` method requires a response be sent
+
+    ### Publish
+    The publish operation sends a json encoded map of the shape:
+      %{action: :publish, data: json}
+    and accepts (but does not require) a reply of form:
+      %{"action" => "publish_reply"}
+
+    The outgoing params represent
+      * data: ActivityPub object encoded into json
+
+
+    ### Fetch
+    The fetch operation sends a json encoded map of the shape:
+      %{action: :fetch, data: id, uuid: fetch_uuid}
+    and requires a reply of form:
+      %{"action" => "fetch_reply", "uuid" => uuid, "data" => data}
+
+    The outgoing params represent
+      * id: an ActivityPub object URI
+      * uuid: a unique uuid generated by the sender
+
+    The reply params represent
+      * data: an ActivityPub object encoded into json
+      * uuid: the uuid sent along with the fetch request
+
+  ## Examples
+  Clients of FedSocket transfers shouldn't need to use any of the functions outside of this module.
+
+  A typical publish operation can be performed through the following code, and a fetch operation in a similar manner.
+
+    case FedSockets.get_or_create_fed_socket(inbox) do
+      {:ok, fedsocket} ->
+        FedSockets.publish(fedsocket, json)
+
+      _ ->
+        alternative_publish(inbox, actor, json, params)
+    end
+
+  ## Configuration
+  FedSockets have the following config settings
+
+  config :pleroma, :fed_sockets,
+  enabled: true,
+  ping_interval: :timer.seconds(15),
+  connection_duration: :timer.hours(1),
+  rejection_duration: :timer.hours(1),
+  fed_socket_fetches: [
+    default: 12_000,
+    interval: 3_000,
+    lazy: false
+  ]
+    * enabled - turn FedSockets on or off with this flag. Can be toggled at runtime.
+    * connection_duration - How long a FedSocket can sit idle before it's culled.
+    * rejection_duration - After failing to make a FedSocket connection a host will be excluded
+    from further connections for this amount of time
+    * fed_socket_fetches - Use these parameters to pass options to the Cachex queue backing the FetchRegistry
+    * fed_socket_rejections - Use these parameters to pass options to the Cachex queue backing the FedRegistry
+
+    Cachex options are
+      * default: the minimum amount of time a fetch can wait before it times out.
+      * interval: the interval between checks for timed out entries. This plus the default represent the maximum time allowed
+      * lazy: leave at false for consistant and fast lookups, set to true for stricter timeout enforcement
+
+  """
+  require Logger
+
+  alias Pleroma.Web.FedSockets.FedRegistry
+  alias Pleroma.Web.FedSockets.FedSocket
+  alias Pleroma.Web.FedSockets.SocketInfo
+
+  @doc """
+  returns a FedSocket for the given origin. Will reuse an existing one or create a new one.
+
+  address is expected to be a fully formed URL such as:
+  "http://www.example.com" or "http://www.example.com:8080"
+
+  It can and usually does include additional path parameters,
+  but these are ignored as the FedSockets are organized by host and port info alone.
+  """
+  def get_or_create_fed_socket(address) do
+    with {:cache, {:error, :missing}} <- {:cache, get_fed_socket(address)},
+         {:connect, {:ok, _pid}} <- {:connect, FedSocket.connect_to_host(address)},
+         {:cache, {:ok, fed_socket}} <- {:cache, get_fed_socket(address)} do
+      Logger.debug("fedsocket created for - #{inspect(address)}")
+      {:ok, fed_socket}
+    else
+      {:cache, {:ok, socket}} ->
+        Logger.debug("fedsocket found in cache - #{inspect(address)}")
+        {:ok, socket}
+
+      {:cache, {:error, :rejected} = e} ->
+        e
+
+      {:connect, {:error, _host}} ->
+        Logger.debug("set host rejected for - #{inspect(address)}")
+        FedRegistry.set_host_rejected(address)
+        {:error, :rejected}
+
+      {_, {:error, :disabled}} ->
+        {:error, :disabled}
+
+      {_, {:error, reason}} ->
+        Logger.warn("get_or_create_fed_socket error - #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  returns a FedSocket for the given origin. Will not create a new FedSocket if one does not exist.
+
+  address is expected to be a fully formed URL such as:
+    "http://www.example.com" or "http://www.example.com:8080"
+  """
+  def get_fed_socket(address) do
+    origin = SocketInfo.origin(address)
+
+    with {:config, true} <- {:config, Pleroma.Config.get([:fed_sockets, :enabled], false)},
+         {:ok, socket} <- FedRegistry.get_fed_socket(origin) do
+      {:ok, socket}
+    else
+      {:config, _} ->
+        {:error, :disabled}
+
+      {:error, :rejected} ->
+        Logger.debug("FedSocket previously rejected - #{inspect(origin)}")
+        {:error, :rejected}
+
+      {:error, reason} ->
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Sends the supplied data via the publish protocol.
+  It will not block waiting for a reply.
+  Returns :ok but this is not an indication of a successful transfer.
+
+  the data is expected to be JSON encoded binary data.
+  """
+  def publish(%SocketInfo{} = fed_socket, json) do
+    FedSocket.publish(fed_socket, json)
+  end
+
+  @doc """
+  Sends the supplied data via the fetch protocol.
+  It will block waiting for a reply or timeout.
+
+  Returns {:ok, object} where object is the requested object (or nil)
+          {:error, :timeout} in the event the message was not responded to
+
+  the id is expected to be the URI of an ActivityPub object.
+  """
+  def fetch(%SocketInfo{} = fed_socket, id) do
+    FedSocket.fetch(fed_socket, id)
+  end
+
+  @doc """
+  Disconnect all and restart FedSockets.
+  This is mainly used in development and testing but could be useful in production.
+  """
+  def reset do
+    FedRegistry
+    |> Process.whereis()
+    |> Process.exit(:testing)
+  end
+
+  def uri_for_origin(origin),
+    do: "ws://#{origin}/api/fedsocket/v1"
+end