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, 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, 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: &'_ _| 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, 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(kind: T, protocol_and_hostname: &str) -> Result 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( context: &LemmyContext, activity: Activity, actor: &ActorT, inbox: Vec, sensitive: bool, ) -> Result<(), LemmyError> where Activity: ActivityHandler + Serialize, ActorT: Actor + ActorType, Activity: ActivityHandler, { 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(()) }