-pub mod send;
+use crate::{
+ generate_moderators_url,
+ insert_activity,
+ local_instance,
+ objects::{community::ApubCommunity, person::ApubPerson},
+ ActorType,
+ CONTEXT,
+};
+use activitypub_federation::{
+ core::{activity_queue::send_activity, object_id::ObjectId},
+ deser::context::WithContext,
+ traits::{ActivityHandler, Actor},
+};
+use activitystreams_kinds::public;
+use anyhow::anyhow;
+use lemmy_api_common::utils::blocking;
+use lemmy_db_schema::source::community::Community;
+use lemmy_db_views_actor::structs::{CommunityPersonBanView, CommunityView};
+use lemmy_utils::error::LemmyError;
+use lemmy_websocket::LemmyContext;
+use serde::Serialize;
+use std::ops::Deref;
+use tracing::info;
+use url::{ParseError, Url};
+use uuid::Uuid;
+
+pub mod block;
+pub mod community;
+pub mod create_or_update;
+pub mod deletion;
+pub mod following;
+pub mod voting;
+
+/// Checks that the specified Url actually identifies a Person (by fetching it), and that the person
+/// doesn't have a site ban.
+#[tracing::instrument(skip_all)]
+async fn verify_person(
+ person_id: &ObjectId<ApubPerson>,
+ context: &LemmyContext,
+ request_counter: &mut i32,
+) -> Result<(), LemmyError> {
+ let person = person_id
+ .dereference(context, local_instance(context), request_counter)
+ .await?;
+ if person.banned {
+ let err = anyhow!("Person {} is banned", person_id);
+ return Err(LemmyError::from_error_message(err, "banned"));
+ }
+ Ok(())
+}
+
+/// Fetches the person and community to verify their type, then checks if person is banned from site
+/// or community.
+#[tracing::instrument(skip_all)]
+pub(crate) async fn verify_person_in_community(
+ person_id: &ObjectId<ApubPerson>,
+ community: &ApubCommunity,
+ context: &LemmyContext,
+ request_counter: &mut i32,
+) -> Result<(), LemmyError> {
+ let person = person_id
+ .dereference(context, local_instance(context), request_counter)
+ .await?;
+ if person.banned {
+ return Err(LemmyError::from_message("Person is banned from site"));
+ }
+ let person_id = person.id;
+ let community_id = community.id;
+ let is_banned =
+ move |conn: &mut _| CommunityPersonBanView::get(conn, person_id, community_id).is_ok();
+ if blocking(context.pool(), is_banned).await? {
+ return Err(LemmyError::from_message("Person is banned from community"));
+ }
+
+ Ok(())
+}
+
+/// Verify that the actor is a community mod. This check is only run if the community is local,
+/// because in case of remote communities, admins can also perform mod actions. As admin status
+/// is not federated, we cant verify their actions remotely.
+///
+/// * `mod_id` - Activitypub ID of the mod or admin who performed the action
+/// * `object_id` - Activitypub ID of the actor or object that is being moderated
+/// * `community` - The community inside which moderation is happening
+#[tracing::instrument(skip_all)]
+pub(crate) async fn verify_mod_action(
+ mod_id: &ObjectId<ApubPerson>,
+ object_id: &Url,
+ community: &ApubCommunity,
+ context: &LemmyContext,
+ request_counter: &mut i32,
+) -> Result<(), LemmyError> {
+ if community.local {
+ let actor = mod_id
+ .dereference(context, local_instance(context), request_counter)
+ .await?;
+
+ // Note: this will also return true for admins in addition to mods, but as we dont know about
+ // remote admins, it doesnt make any difference.
+ let community_id = community.id;
+ let actor_id = actor.id;
+
+ let is_mod_or_admin = blocking(context.pool(), move |conn| {
+ CommunityView::is_mod_or_admin(conn, actor_id, community_id)
+ })
+ .await?;
+
+ // mod action was done either by a community mod or a local admin, so its allowed
+ if is_mod_or_admin {
+ return Ok(());
+ }
+
+ // mod action comes from the same instance as the moderated object, so it was presumably done
+ // by an instance admin and is legitimate (admin status is not federated).
+ if mod_id.inner().domain() == object_id.domain() {
+ return Ok(());
+ }
+
+ // the user is not a valid mod
+ return Err(LemmyError::from_message("Not a mod"));
+ }
+ Ok(())
+}
+
+/// For Add/Remove community moderator activities, check that the target field actually contains
+/// /c/community/moderators. Any different values are unsupported.
+fn verify_add_remove_moderator_target(
+ target: &Url,
+ community: &ApubCommunity,
+) -> Result<(), LemmyError> {
+ if target != &generate_moderators_url(&community.actor_id)?.into() {
+ return Err(LemmyError::from_message("Unkown target url"));
+ }
+ Ok(())
+}
+
+pub(crate) fn verify_is_public(to: &[Url], cc: &[Url]) -> Result<(), LemmyError> {
+ if ![to, cc].iter().any(|set| set.contains(&public())) {
+ return Err(LemmyError::from_message("Object is not public"));
+ }
+ Ok(())
+}
+
+pub(crate) fn check_community_deleted_or_removed(community: &Community) -> Result<(), LemmyError> {
+ if community.deleted || community.removed {
+ Err(LemmyError::from_message(
+ "New post or comment cannot be created in deleted or removed community",
+ ))
+ } else {
+ Ok(())
+ }
+}
+
+/// Generate a unique ID for an activity, in the format:
+/// `http(s)://example.com/receive/create/202daf0a-1489-45df-8d2e-c8a3173fed36`
+fn generate_activity_id<T>(kind: T, protocol_and_hostname: &str) -> Result<Url, ParseError>
+where
+ T: ToString,
+{
+ let id = format!(
+ "{}/activities/{}/{}",
+ protocol_and_hostname,
+ kind.to_string().to_lowercase(),
+ Uuid::new_v4()
+ );
+ Url::parse(&id)
+}
+
+#[tracing::instrument(skip_all)]
+async fn send_lemmy_activity<Activity, ActorT>(
+ context: &LemmyContext,
+ activity: Activity,
+ actor: &ActorT,
+ inbox: Vec<Url>,
+ sensitive: bool,
+) -> Result<(), LemmyError>
+where
+ Activity: ActivityHandler + Serialize,
+ ActorT: Actor + ActorType,
+ Activity: ActivityHandler<Error = LemmyError>,
+{
+ info!("Sending activity {}", activity.id().to_string());
+ let activity = WithContext::new(activity, CONTEXT.deref().clone());
+
+ let object_value = serde_json::to_value(&activity)?;
+ insert_activity(activity.id(), object_value, true, sensitive, context.pool()).await?;
+
+ send_activity(
+ activity,
+ actor.get_public_key(),
+ actor.private_key().expect("actor has private key"),
+ inbox,
+ local_instance(context),
+ )
+ .await?;
+
+ Ok(())
+}
projects / lemmy.git / blobdiff