crates/apub/src/objects/mod.rs

   1 use crate::{
   2   check_is_apub_id_valid,
   3   fetcher::{community::get_or_fetch_and_upsert_community, user::get_or_fetch_and_upsert_user},
   4   inbox::community_inbox::check_community_or_site_ban,
   5 };
   6 use activitystreams::{
   7   base::{AsBase, BaseExt, ExtendsExt},
   8   markers::Base,
   9   mime::{FromStrError, Mime},
  10   object::{ApObjectExt, Object, ObjectExt, Tombstone, TombstoneExt},
  11 };
  12 use anyhow::{anyhow, Context};
  13 use chrono::NaiveDateTime;
  14 use diesel::result::Error::NotFound;
  15 use lemmy_api_structs::blocking;
  16 use lemmy_db_queries::{ApubObject, Crud, DbPool};
  17 use lemmy_db_schema::{source::community::Community, DbUrl};
  18 use lemmy_utils::{
  19   location_info,
  20   settings::structs::Settings,
  21   utils::{convert_datetime, markdown_to_html},
  22   LemmyError,
  23 };
  24 use lemmy_websocket::LemmyContext;
  25 use url::Url;
  26
  27 pub(crate) mod comment;
  28 pub(crate) mod community;
  29 pub(crate) mod post;
  30 pub(crate) mod private_message;
  31 pub(crate) mod user;
  32
  33 /// Trait for converting an object or actor into the respective ActivityPub type.
  34 #[async_trait::async_trait(?Send)]
  35 pub(crate) trait ToApub {
  36   type ApubType;
  37   async fn to_apub(&self, pool: &DbPool) -> Result<Self::ApubType, LemmyError>;
  38   fn to_tombstone(&self) -> Result<Tombstone, LemmyError>;
  39 }
  40
  41 #[async_trait::async_trait(?Send)]
  42 pub(crate) trait FromApub {
  43   type ApubType;
  44   /// Converts an object from ActivityPub type to Lemmy internal type.
  45   ///
  46   /// * `apub` The object to read from
  47   /// * `context` LemmyContext which holds DB pool, HTTP client etc
  48   /// * `expected_domain` Domain where the object was received from. None in case of mod action.
  49   /// * `is_mod_action` True if the object was sent in a mod activity, ignore `expected_domain` in this case
  50   async fn from_apub(
  51     apub: &Self::ApubType,
  52     context: &LemmyContext,
  53     expected_domain: Url,
  54     request_counter: &mut i32,
  55     is_mod_action: bool,
  56   ) -> Result<Self, LemmyError>
  57   where
  58     Self: Sized;
  59 }
  60
  61 #[async_trait::async_trait(?Send)]
  62 pub(in crate::objects) trait FromApubToForm<ApubType> {
  63   async fn from_apub(
  64     apub: &ApubType,
  65     context: &LemmyContext,
  66     expected_domain: Url,
  67     request_counter: &mut i32,
  68     is_mod_action: bool,
  69   ) -> Result<Self, LemmyError>
  70   where
  71     Self: Sized;
  72 }
  73
  74 /// Updated is actually the deletion time
  75 fn create_tombstone<T>(
  76   deleted: bool,
  77   object_id: Url,
  78   updated: Option<NaiveDateTime>,
  79   former_type: T,
  80 ) -> Result<Tombstone, LemmyError>
  81 where
  82   T: ToString,
  83 {
  84   if deleted {
  85     if let Some(updated) = updated {
  86       let mut tombstone = Tombstone::new();
  87       tombstone.set_id(object_id);
  88       tombstone.set_former_type(former_type.to_string());
  89       tombstone.set_deleted(convert_datetime(updated));
  90       Ok(tombstone)
  91     } else {
  92       Err(anyhow!("Cant convert to tombstone because updated time was None.").into())
  93     }
  94   } else {
  95     Err(anyhow!("Cant convert object to tombstone if it wasnt deleted").into())
  96   }
  97 }
  98
  99 pub(in crate::objects) fn check_object_domain<T, Kind>(
 100   apub: &T,
 101   expected_domain: Url,
 102 ) -> Result<DbUrl, LemmyError>
 103 where
 104   T: Base + AsBase<Kind>,
 105 {
 106   let domain = expected_domain.domain().context(location_info!())?;
 107   let object_id = apub.id(domain)?.context(location_info!())?;
 108   check_is_apub_id_valid(object_id)?;
 109   Ok(object_id.to_owned().into())
 110 }
 111
 112 pub(in crate::objects) fn set_content_and_source<T, Kind1, Kind2>(
 113   object: &mut T,
 114   markdown_text: &str,
 115 ) -> Result<(), LemmyError>
 116 where
 117   T: ApObjectExt<Kind1> + ObjectExt<Kind2> + AsBase<Kind2>,
 118 {
 119   let mut source = Object::<()>::new_none_type();
 120   source
 121     .set_content(markdown_text)
 122     .set_media_type(mime_markdown()?);
 123   object.set_source(source.into_any_base()?);
 124
 125   object.set_content(markdown_to_html(markdown_text));
 126   object.set_media_type(mime_html()?);
 127   Ok(())
 128 }
 129
 130 pub(in crate::objects) fn get_source_markdown_value<T, Kind1, Kind2>(
 131   object: &T,
 132 ) -> Result<Option<String>, LemmyError>
 133 where
 134   T: ApObjectExt<Kind1> + ObjectExt<Kind2> + AsBase<Kind2>,
 135 {
 136   let content = object
 137     .content()
 138     .map(|s| s.as_single_xsd_string().map(|s2| s2.to_string()))
 139     .flatten();
 140   if content.is_some() {
 141     let source = object.source().context(location_info!())?;
 142     let source = Object::<()>::from_any_base(source.to_owned())?.context(location_info!())?;
 143     check_is_markdown(source.media_type())?;
 144     let source_content = source
 145       .content()
 146       .map(|s| s.as_single_xsd_string().map(|s2| s2.to_string()))
 147       .flatten()
 148       .context(location_info!())?;
 149     return Ok(Some(source_content));
 150   }
 151   Ok(None)
 152 }
 153
 154 fn mime_markdown() -> Result<Mime, FromStrError> {
 155   "text/markdown".parse()
 156 }
 157
 158 fn mime_html() -> Result<Mime, FromStrError> {
 159   "text/html".parse()
 160 }
 161
 162 pub(in crate::objects) fn check_is_markdown(mime: Option<&Mime>) -> Result<(), LemmyError> {
 163   let mime = mime.context(location_info!())?;
 164   if !mime.eq(&mime_markdown()?) {
 165     Err(LemmyError::from(anyhow!(
 166       "Lemmy only supports markdown content"
 167     )))
 168   } else {
 169     Ok(())
 170   }
 171 }
 172
 173 /// Converts an ActivityPub object (eg `Note`) to a database object (eg `Comment`). If an object
 174 /// with the same ActivityPub ID already exists in the database, it is returned directly. Otherwise
 175 /// the apub object is parsed, inserted and returned.
 176 pub(in crate::objects) async fn get_object_from_apub<From, Kind, To, ToForm>(
 177   from: &From,
 178   context: &LemmyContext,
 179   expected_domain: Url,
 180   request_counter: &mut i32,
 181   is_mod_action: bool,
 182 ) -> Result<To, LemmyError>
 183 where
 184   From: BaseExt<Kind>,
 185   To: ApubObject<ToForm> + Crud<ToForm> + Send + 'static,
 186   ToForm: FromApubToForm<From> + Send + 'static,
 187 {
 188   let object_id = from.id_unchecked().context(location_info!())?.to_owned();
 189   let domain = object_id.domain().context(location_info!())?;
 190
 191   // if its a local object, return it directly from the database
 192   if Settings::get().hostname() == domain {
 193     let object = blocking(context.pool(), move |conn| {
 194       To::read_from_apub_id(conn, &object_id.into())
 195     })
 196     .await??;
 197     Ok(object)
 198   }
 199   // otherwise parse and insert, assuring that it comes from the right domain
 200   else {
 201     let to_form = ToForm::from_apub(
 202       &from,
 203       context,
 204       expected_domain,
 205       request_counter,
 206       is_mod_action,
 207     )
 208     .await?;
 209
 210     let to = blocking(context.pool(), move |conn| To::upsert(conn, &to_form)).await??;
 211     Ok(to)
 212   }
 213 }
 214
 215 pub(in crate::objects) async fn check_object_for_community_or_site_ban<T, Kind>(
 216   object: &T,
 217   community_id: i32,
 218   context: &LemmyContext,
 219   request_counter: &mut i32,
 220 ) -> Result<(), LemmyError>
 221 where
 222   T: ObjectExt<Kind>,
 223 {
 224   let user_id = object
 225     .attributed_to()
 226     .context(location_info!())?
 227     .as_single_xsd_any_uri()
 228     .context(location_info!())?;
 229   let user = get_or_fetch_and_upsert_user(user_id, context, request_counter).await?;
 230   check_community_or_site_ban(&user, community_id, context.pool()).await
 231 }
 232
 233 pub(in crate::objects) async fn get_to_community<T, Kind>(
 234   object: &T,
 235   context: &LemmyContext,
 236   request_counter: &mut i32,
 237 ) -> Result<Community, LemmyError>
 238 where
 239   T: ObjectExt<Kind>,
 240 {
 241   let community_ids = object
 242     .to()
 243     .context(location_info!())?
 244     .as_many()
 245     .context(location_info!())?
 246     .iter()
 247     .map(|a| a.as_xsd_any_uri().context(location_info!()))
 248     .collect::<Result<Vec<&Url>, anyhow::Error>>()?;
 249   for cid in community_ids {
 250     let community = get_or_fetch_and_upsert_community(&cid, context, request_counter).await;
 251     if community.is_ok() {
 252       return community;
 253     }
 254   }
 255   Err(NotFound.into())
 256 }