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akkoma/lib/pleroma/web/activity_pub/publisher.ex
2020-04-10 06:20:02 +02:00

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7.8 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.ActivityPub.Publisher do
alias Pleroma.Activity
alias Pleroma.Config
alias Pleroma.Delivery
alias Pleroma.HTTP
alias Pleroma.Instances
alias Pleroma.Object
alias Pleroma.Repo
alias Pleroma.User
alias Pleroma.Web.ActivityPub.Relay
alias Pleroma.Web.ActivityPub.Transmogrifier
require Pleroma.Constants
import Pleroma.Web.ActivityPub.Visibility
@behaviour Pleroma.Web.Federator.Publisher
require Logger
@moduledoc """
ActivityPub outgoing federation module.
"""
@doc """
Determine if an activity can be represented by running it through Transmogrifier.
"""
def is_representable?(%Activity{} = activity) do
with {:ok, _data} <- Transmogrifier.prepare_outgoing(activity.data) do
true
else
_e ->
false
end
end
@doc """
Publish a single message to a peer. Takes a struct with the following
parameters set:
* `inbox`: the inbox to publish to
* `json`: the JSON message body representing the ActivityPub message
* `actor`: the actor which is signing the message
* `id`: the ActivityStreams URI of the message
"""
def publish_one(%{inbox: inbox, json: json, actor: %User{} = actor, id: id} = params) do
Logger.debug("Federating #{id} to #{inbox}")
%{host: host, path: path} = URI.parse(inbox)
digest = "SHA-256=" <> (:crypto.hash(:sha256, json) |> Base.encode64())
date = Pleroma.Signature.signed_date()
signature =
Pleroma.Signature.sign(actor, %{
"(request-target)": "post #{path}",
host: host,
"content-length": byte_size(json),
digest: digest,
date: date
})
with {:ok, %{status: code}} when code in 200..299 <-
result =
HTTP.post(
inbox,
json,
[
{"Content-Type", "application/activity+json"},
{"Date", date},
{"signature", signature},
{"digest", digest}
]
) do
if !Map.has_key?(params, :unreachable_since) || params[:unreachable_since],
do: Instances.set_reachable(inbox)
result
else
{_post_result, response} ->
unless params[:unreachable_since], do: Instances.set_unreachable(inbox)
{:error, response}
end
end
def publish_one(%{actor_id: actor_id} = params) do
actor = User.get_cached_by_id(actor_id)
params
|> Map.delete(:actor_id)
|> Map.put(:actor, actor)
|> publish_one()
end
defp should_federate?(inbox, public) do
if public do
true
else
%{host: host} = URI.parse(inbox)
quarantined_instances =
Config.get([:instance, :quarantined_instances], [])
|> Pleroma.Web.ActivityPub.MRF.subdomains_regex()
!Pleroma.Web.ActivityPub.MRF.subdomain_match?(quarantined_instances, host)
end
end
@spec recipients(User.t(), Activity.t()) :: list(User.t()) | []
defp recipients(actor, activity) do
followers =
if actor.follower_address in activity.recipients do
User.get_external_followers(actor)
else
[]
end
fetchers =
with %Activity{data: %{"type" => "Delete"}} <- activity,
%Object{id: object_id} <- Object.normalize(activity),
fetchers <- User.get_delivered_users_by_object_id(object_id),
_ <- Delivery.delete_all_by_object_id(object_id) do
fetchers
else
_ ->
[]
end
Pleroma.Web.Federator.Publisher.remote_users(actor, activity) ++ followers ++ fetchers
end
defp get_cc_ap_ids(ap_id, recipients) do
host = Map.get(URI.parse(ap_id), :host)
recipients
|> Enum.filter(fn %User{ap_id: ap_id} -> Map.get(URI.parse(ap_id), :host) == host end)
|> Enum.map(& &1.ap_id)
end
defp maybe_use_sharedinbox(%User{shared_inbox: nil, inbox: inbox}), do: inbox
defp maybe_use_sharedinbox(%User{shared_inbox: shared_inbox}), do: shared_inbox
@doc """
Determine a user inbox to use based on heuristics. These heuristics
are based on an approximation of the ``sharedInbox`` rules in the
[ActivityPub specification][ap-sharedinbox].
Please do not edit this function (or its children) without reading
the spec, as editing the code is likely to introduce some breakage
without some familiarity.
[ap-sharedinbox]: https://www.w3.org/TR/activitypub/#shared-inbox-delivery
"""
def determine_inbox(
%Activity{data: activity_data},
%User{inbox: inbox} = user
) do
to = activity_data["to"] || []
cc = activity_data["cc"] || []
type = activity_data["type"]
cond do
type == "Delete" ->
maybe_use_sharedinbox(user)
Pleroma.Constants.as_public() in to || Pleroma.Constants.as_public() in cc ->
maybe_use_sharedinbox(user)
length(to) + length(cc) > 1 ->
maybe_use_sharedinbox(user)
true ->
inbox
end
end
@doc """
Publishes an activity with BCC to all relevant peers.
"""
def publish(%User{} = actor, %{data: %{"bcc" => bcc}} = activity)
when is_list(bcc) and bcc != [] do
public = is_public?(activity)
{:ok, data} = Transmogrifier.prepare_outgoing(activity.data)
recipients = recipients(actor, activity)
inboxes =
recipients
|> Enum.filter(&User.ap_enabled?/1)
|> Enum.map(fn actor -> actor.inbox end)
|> Enum.filter(fn inbox -> should_federate?(inbox, public) end)
|> Instances.filter_reachable()
Repo.checkout(fn ->
Enum.each(inboxes, fn {inbox, unreachable_since} ->
%User{ap_id: ap_id} = Enum.find(recipients, fn actor -> actor.inbox == inbox end)
# Get all the recipients on the same host and add them to cc. Otherwise, a remote
# instance would only accept a first message for the first recipient and ignore the rest.
cc = get_cc_ap_ids(ap_id, recipients)
json =
data
|> Map.put("cc", cc)
|> Jason.encode!()
Pleroma.Web.Federator.Publisher.enqueue_one(__MODULE__, %{
inbox: inbox,
json: json,
actor_id: actor.id,
id: activity.data["id"],
unreachable_since: unreachable_since
})
end)
end)
end
@doc """
Publishes an activity to all relevant peers.
"""
def publish(%User{} = actor, %Activity{} = activity) do
public = is_public?(activity)
if public && Config.get([:instance, :allow_relay]) do
Logger.debug(fn -> "Relaying #{activity.data["id"]} out" end)
Relay.publish(activity)
end
{:ok, data} = Transmogrifier.prepare_outgoing(activity.data)
json = Jason.encode!(data)
recipients(actor, activity)
|> Enum.filter(fn user -> User.ap_enabled?(user) end)
|> Enum.map(fn %User{} = user ->
determine_inbox(activity, user)
end)
|> Enum.uniq()
|> Enum.filter(fn inbox -> should_federate?(inbox, public) end)
|> Instances.filter_reachable()
|> Enum.each(fn {inbox, unreachable_since} ->
Pleroma.Web.Federator.Publisher.enqueue_one(
__MODULE__,
%{
inbox: inbox,
json: json,
actor_id: actor.id,
id: activity.data["id"],
unreachable_since: unreachable_since
}
)
end)
end
def gather_webfinger_links(%User{} = user) do
[
%{"rel" => "self", "type" => "application/activity+json", "href" => user.ap_id},
%{
"rel" => "self",
"type" => "application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"",
"href" => user.ap_id
},
%{
"rel" => "http://ostatus.org/schema/1.0/subscribe",
"template" => "#{Pleroma.Web.base_url()}/ostatus_subscribe?acct={uri}"
}
]
end
def gather_nodeinfo_protocol_names, do: ["activitypub"]
end