crates/apub/src/activities/mod.rs

   1 use self::following::send_follow_community;
   2 use crate::{
   3   activities::{
   4     deletion::{send_apub_delete_in_community, DeletableObjects},
   5     voting::send_like_activity,
   6   },
   7   objects::{community::ApubCommunity, person::ApubPerson},
   8   protocol::activities::{
   9     create_or_update::{note::CreateOrUpdateNote, page::CreateOrUpdatePage},
  10     CreateOrUpdateType,
  11   },
  12   CONTEXT,
  13 };
  14 use activitypub_federation::{
  15   activity_queue::send_activity,
  16   config::Data,
  17   fetch::object_id::ObjectId,
  18   kinds::public,
  19   protocol::context::WithContext,
  20   traits::{ActivityHandler, Actor},
  21 };
  22 use anyhow::anyhow;
  23 use lemmy_api_common::{
  24   context::LemmyContext,
  25   send_activity::{ActivityChannel, SendActivityData},
  26 };
  27 use lemmy_db_schema::{
  28   newtypes::CommunityId,
  29   source::{
  30     activity::{SentActivity, SentActivityForm},
  31     community::Community,
  32     instance::Instance,
  33   },
  34 };
  35 use lemmy_db_views_actor::structs::{CommunityPersonBanView, CommunityView};
  36 use lemmy_utils::{
  37   error::{LemmyError, LemmyErrorExt, LemmyErrorType, LemmyResult},
  38   spawn_try_task,
  39   SYNCHRONOUS_FEDERATION,
  40 };
  41 use moka::future::Cache;
  42 use once_cell::sync::Lazy;
  43 use serde::Serialize;
  44 use std::{ops::Deref, sync::Arc, time::Duration};
  45 use tracing::info;
  46 use url::{ParseError, Url};
  47 use uuid::Uuid;
  48
  49 pub mod block;
  50 pub mod community;
  51 pub mod create_or_update;
  52 pub mod deletion;
  53 pub mod following;
  54 pub mod unfederated;
  55 pub mod voting;
  56
  57 /// Amount of time that the list of dead instances is cached. This is only updated once a day,
  58 /// so there is no harm in caching it for a longer time.
  59 pub static DEAD_INSTANCE_LIST_CACHE_DURATION: Duration = Duration::from_secs(30 * 60);
  60
  61 /// Checks that the specified Url actually identifies a Person (by fetching it), and that the person
  62 /// doesn't have a site ban.
  63 #[tracing::instrument(skip_all)]
  64 async fn verify_person(
  65   person_id: &ObjectId<ApubPerson>,
  66   context: &Data<LemmyContext>,
  67 ) -> Result<(), LemmyError> {
  68   let person = person_id.dereference(context).await?;
  69   if person.banned {
  70     return Err(anyhow!("Person {} is banned", person_id))
  71       .with_lemmy_type(LemmyErrorType::CouldntUpdateComment);
  72   }
  73   Ok(())
  74 }
  75
  76 /// Fetches the person and community to verify their type, then checks if person is banned from site
  77 /// or community.
  78 #[tracing::instrument(skip_all)]
  79 pub(crate) async fn verify_person_in_community(
  80   person_id: &ObjectId<ApubPerson>,
  81   community: &ApubCommunity,
  82   context: &Data<LemmyContext>,
  83 ) -> Result<(), LemmyError> {
  84   let person = person_id.dereference(context).await?;
  85   if person.banned {
  86     return Err(LemmyErrorType::PersonIsBannedFromSite)?;
  87   }
  88   let person_id = person.id;
  89   let community_id = community.id;
  90   let is_banned = CommunityPersonBanView::get(&mut context.pool(), person_id, community_id)
  91     .await
  92     .is_ok();
  93   if is_banned {
  94     return Err(LemmyErrorType::PersonIsBannedFromCommunity)?;
  95   }
  96
  97   Ok(())
  98 }
  99
 100 /// Verify that mod action in community was performed by a moderator.
 101 ///
 102 /// * `mod_id` - Activitypub ID of the mod or admin who performed the action
 103 /// * `object_id` - Activitypub ID of the actor or object that is being moderated
 104 /// * `community` - The community inside which moderation is happening
 105 #[tracing::instrument(skip_all)]
 106 pub(crate) async fn verify_mod_action(
 107   mod_id: &ObjectId<ApubPerson>,
 108   object_id: &Url,
 109   community_id: CommunityId,
 110   context: &Data<LemmyContext>,
 111 ) -> Result<(), LemmyError> {
 112   let mod_ = mod_id.dereference(context).await?;
 113
 114   let is_mod_or_admin =
 115     CommunityView::is_mod_or_admin(&mut context.pool(), mod_.id, community_id).await?;
 116   if is_mod_or_admin {
 117     return Ok(());
 118   }
 119
 120   // mod action comes from the same instance as the moderated object, so it was presumably done
 121   // by an instance admin.
 122   // TODO: federate instance admin status and check it here
 123   if mod_id.inner().domain() == object_id.domain() {
 124     return Ok(());
 125   }
 126
 127   Err(LemmyErrorType::NotAModerator)?
 128 }
 129
 130 pub(crate) fn verify_is_public(to: &[Url], cc: &[Url]) -> Result<(), LemmyError> {
 131   if ![to, cc].iter().any(|set| set.contains(&public())) {
 132     return Err(LemmyErrorType::ObjectIsNotPublic)?;
 133   }
 134   Ok(())
 135 }
 136
 137 pub(crate) fn verify_community_matches<T>(
 138   a: &ObjectId<ApubCommunity>,
 139   b: T,
 140 ) -> Result<(), LemmyError>
 141 where
 142   T: Into<ObjectId<ApubCommunity>>,
 143 {
 144   let b: ObjectId<ApubCommunity> = b.into();
 145   if a != &b {
 146     return Err(LemmyErrorType::InvalidCommunity)?;
 147   }
 148   Ok(())
 149 }
 150
 151 pub(crate) fn check_community_deleted_or_removed(community: &Community) -> Result<(), LemmyError> {
 152   if community.deleted || community.removed {
 153     Err(LemmyErrorType::CannotCreatePostOrCommentInDeletedOrRemovedCommunity)?
 154   } else {
 155     Ok(())
 156   }
 157 }
 158
 159 /// Generate a unique ID for an activity, in the format:
 160 /// `http(s)://example.com/receive/create/202daf0a-1489-45df-8d2e-c8a3173fed36`
 161 fn generate_activity_id<T>(kind: T, protocol_and_hostname: &str) -> Result<Url, ParseError>
 162 where
 163   T: ToString,
 164 {
 165   let id = format!(
 166     "{}/activities/{}/{}",
 167     protocol_and_hostname,
 168     kind.to_string().to_lowercase(),
 169     Uuid::new_v4()
 170   );
 171   Url::parse(&id)
 172 }
 173
 174 #[tracing::instrument(skip_all)]
 175 async fn send_lemmy_activity<Activity, ActorT>(
 176   data: &Data<LemmyContext>,
 177   activity: Activity,
 178   actor: &ActorT,
 179   mut inbox: Vec<Url>,
 180   sensitive: bool,
 181 ) -> Result<(), LemmyError>
 182 where
 183   Activity: ActivityHandler + Serialize + Send + Sync + Clone,
 184   ActorT: Actor,
 185   Activity: ActivityHandler<Error = LemmyError>,
 186 {
 187   static CACHE: Lazy<Cache<(), Arc<Vec<String>>>> = Lazy::new(|| {
 188     Cache::builder()
 189       .max_capacity(1)
 190       .time_to_live(DEAD_INSTANCE_LIST_CACHE_DURATION)
 191       .build()
 192   });
 193   let dead_instances = CACHE
 194     .try_get_with((), async {
 195       Ok::<_, diesel::result::Error>(Arc::new(Instance::dead_instances(&mut data.pool()).await?))
 196     })
 197     .await?;
 198
 199   inbox.retain(|i| {
 200     let domain = i.domain().expect("has domain").to_string();
 201     !dead_instances.contains(&domain)
 202   });
 203   info!("Sending activity {}", activity.id().to_string());
 204   let activity = WithContext::new(activity, CONTEXT.deref().clone());
 205
 206   let form = SentActivityForm {
 207     ap_id: activity.id().clone().into(),
 208     data: serde_json::to_value(activity.clone())?,
 209     sensitive,
 210   };
 211   SentActivity::create(&mut data.pool(), form).await?;
 212   send_activity(activity, actor, inbox, data).await?;
 213
 214   Ok(())
 215 }
 216
 217 pub async fn handle_outgoing_activities(context: Data<LemmyContext>) -> LemmyResult<()> {
 218   while let Some(data) = ActivityChannel::retrieve_activity().await {
 219     match_outgoing_activities(data, &context.reset_request_count()).await?
 220   }
 221   Ok(())
 222 }
 223
 224 pub async fn match_outgoing_activities(
 225   data: SendActivityData,
 226   context: &Data<LemmyContext>,
 227 ) -> LemmyResult<()> {
 228   let context = context.reset_request_count();
 229   let fed_task = async {
 230     use SendActivityData::*;
 231     match data {
 232       CreatePost(post) | UpdatePost(post) => {
 233         let creator_id = post.creator_id;
 234         CreateOrUpdatePage::send(post, creator_id, CreateOrUpdateType::Create, context).await
 235       }
 236       CreateComment(comment) | UpdateComment(comment) => {
 237         let creator_id = comment.creator_id;
 238         CreateOrUpdateNote::send(comment, creator_id, CreateOrUpdateType::Create, context).await
 239       }
 240       DeleteComment(comment, actor, community) => {
 241         let is_deleted = comment.deleted;
 242         let deletable = DeletableObjects::Comment(comment.into());
 243         send_apub_delete_in_community(actor, community, deletable, None, is_deleted, &context).await
 244       }
 245       RemoveComment(comment, actor, community, reason) => {
 246         let is_removed = comment.removed;
 247         let deletable = DeletableObjects::Comment(comment.into());
 248         send_apub_delete_in_community(actor, community, deletable, reason, is_removed, &context)
 249           .await
 250       }
 251       LikePostOrComment(object_id, person, community, score) => {
 252         send_like_activity(object_id, person, community, score, context).await
 253       }
 254       SendActivityData::FollowCommunity(community, person, follow) => {
 255         send_follow_community(community, person, follow, &context).await
 256       }
 257     }
 258   };
 259   if *SYNCHRONOUS_FEDERATION {
 260     fed_task.await?;
 261   } else {
 262     spawn_try_task(fed_task);
 263   }
 264   Ok(())
 265 }