crates/apub/src/objects/mod.rs

   1 use crate::{
   2   check_is_apub_id_valid,
   3   fetcher::{community::get_or_fetch_and_upsert_community, person::get_or_fetch_and_upsert_person},
   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, CommunityId, 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 person;
  30 pub(crate) mod post;
  31 pub(crate) mod private_message;
  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
  49   async fn from_apub(
  50     apub: &Self::ApubType,
  51     context: &LemmyContext,
  52     expected_domain: Url,
  53     request_counter: &mut i32,
  54   ) -> Result<Self, LemmyError>
  55   where
  56     Self: Sized;
  57 }
  58
  59 #[async_trait::async_trait(?Send)]
  60 pub(in crate::objects) trait FromApubToForm<ApubType> {
  61   async fn from_apub(
  62     apub: &ApubType,
  63     context: &LemmyContext,
  64     expected_domain: Url,
  65     request_counter: &mut i32,
  66   ) -> Result<Self, LemmyError>
  67   where
  68     Self: Sized;
  69 }
  70
  71 /// Updated is actually the deletion time
  72 fn create_tombstone<T>(
  73   deleted: bool,
  74   object_id: Url,
  75   updated: Option<NaiveDateTime>,
  76   former_type: T,
  77 ) -> Result<Tombstone, LemmyError>
  78 where
  79   T: ToString,
  80 {
  81   if deleted {
  82     if let Some(updated) = updated {
  83       let mut tombstone = Tombstone::new();
  84       tombstone.set_id(object_id);
  85       tombstone.set_former_type(former_type.to_string());
  86       tombstone.set_deleted(convert_datetime(updated));
  87       Ok(tombstone)
  88     } else {
  89       Err(anyhow!("Cant convert to tombstone because updated time was None.").into())
  90     }
  91   } else {
  92     Err(anyhow!("Cant convert object to tombstone if it wasnt deleted").into())
  93   }
  94 }
  95
  96 pub(in crate::objects) fn check_object_domain<T, Kind>(
  97   apub: &T,
  98   expected_domain: Url,
  99 ) -> Result<DbUrl, LemmyError>
 100 where
 101   T: Base + AsBase<Kind>,
 102 {
 103   let domain = expected_domain.domain().context(location_info!())?;
 104   let object_id = apub.id(domain)?.context(location_info!())?;
 105   check_is_apub_id_valid(object_id)?;
 106   Ok(object_id.to_owned().into())
 107 }
 108
 109 pub(in crate::objects) fn set_content_and_source<T, Kind1, Kind2>(
 110   object: &mut T,
 111   markdown_text: &str,
 112 ) -> Result<(), LemmyError>
 113 where
 114   T: ApObjectExt<Kind1> + ObjectExt<Kind2> + AsBase<Kind2>,
 115 {
 116   let mut source = Object::<()>::new_none_type();
 117   source
 118     .set_content(markdown_text)
 119     .set_media_type(mime_markdown()?);
 120   object.set_source(source.into_any_base()?);
 121
 122   object.set_content(markdown_to_html(markdown_text));
 123   object.set_media_type(mime_html()?);
 124   Ok(())
 125 }
 126
 127 pub(in crate::objects) fn get_source_markdown_value<T, Kind1, Kind2>(
 128   object: &T,
 129 ) -> Result<Option<String>, LemmyError>
 130 where
 131   T: ApObjectExt<Kind1> + ObjectExt<Kind2> + AsBase<Kind2>,
 132 {
 133   let content = object
 134     .content()
 135     .map(|s| s.as_single_xsd_string())
 136     .flatten()
 137     .map(|s| s.to_string());
 138   if content.is_some() {
 139     let source = object.source().context(location_info!())?;
 140     let source = Object::<()>::from_any_base(source.to_owned())?.context(location_info!())?;
 141     check_is_markdown(source.media_type())?;
 142     let source_content = source
 143       .content()
 144       .map(|s| s.as_single_xsd_string())
 145       .flatten()
 146       .context(location_info!())?
 147       .to_string();
 148     return Ok(Some(source_content));
 149   }
 150   Ok(None)
 151 }
 152
 153 fn mime_markdown() -> Result<Mime, FromStrError> {
 154   "text/markdown".parse()
 155 }
 156
 157 fn mime_html() -> Result<Mime, FromStrError> {
 158   "text/html".parse()
 159 }
 160
 161 pub(in crate::objects) fn check_is_markdown(mime: Option<&Mime>) -> Result<(), LemmyError> {
 162   let mime = mime.context(location_info!())?;
 163   if !mime.eq(&mime_markdown()?) {
 164     Err(LemmyError::from(anyhow!(
 165       "Lemmy only supports markdown content"
 166     )))
 167   } else {
 168     Ok(())
 169   }
 170 }
 171
 172 /// Converts an ActivityPub object (eg `Note`) to a database object (eg `Comment`). If an object
 173 /// with the same ActivityPub ID already exists in the database, it is returned directly. Otherwise
 174 /// the apub object is parsed, inserted and returned.
 175 pub(in crate::objects) async fn get_object_from_apub<From, Kind, To, ToForm, IdType>(
 176   from: &From,
 177   context: &LemmyContext,
 178   expected_domain: Url,
 179   request_counter: &mut i32,
 180 ) -> Result<To, LemmyError>
 181 where
 182   From: BaseExt<Kind>,
 183   To: ApubObject<ToForm> + Crud<ToForm, IdType> + Send + 'static,
 184   ToForm: FromApubToForm<From> + Send + 'static,
 185 {
 186   let object_id = from.id_unchecked().context(location_info!())?.to_owned();
 187   let domain = object_id.domain().context(location_info!())?;
 188
 189   // if its a local object, return it directly from the database
 190   if Settings::get().hostname() == domain {
 191     let object = blocking(context.pool(), move |conn| {
 192       To::read_from_apub_id(conn, &object_id.into())
 193     })
 194     .await??;
 195     Ok(object)
 196   }
 197   // otherwise parse and insert, assuring that it comes from the right domain
 198   else {
 199     let to_form = ToForm::from_apub(&from, context, expected_domain, request_counter).await?;
 200
 201     let to = blocking(context.pool(), move |conn| To::upsert(conn, &to_form)).await??;
 202     Ok(to)
 203   }
 204 }
 205
 206 pub(in crate::objects) async fn check_object_for_community_or_site_ban<T, Kind>(
 207   object: &T,
 208   community_id: CommunityId,
 209   context: &LemmyContext,
 210   request_counter: &mut i32,
 211 ) -> Result<(), LemmyError>
 212 where
 213   T: ObjectExt<Kind>,
 214 {
 215   let person_id = object
 216     .attributed_to()
 217     .context(location_info!())?
 218     .as_single_xsd_any_uri()
 219     .context(location_info!())?;
 220   let person = get_or_fetch_and_upsert_person(person_id, context, request_counter).await?;
 221   check_community_or_site_ban(&person, community_id, context.pool()).await
 222 }
 223
 224 pub(in crate::objects) async fn get_to_community<T, Kind>(
 225   object: &T,
 226   context: &LemmyContext,
 227   request_counter: &mut i32,
 228 ) -> Result<Community, LemmyError>
 229 where
 230   T: ObjectExt<Kind>,
 231 {
 232   let community_ids = object
 233     .to()
 234     .context(location_info!())?
 235     .as_many()
 236     .context(location_info!())?
 237     .iter()
 238     .map(|a| a.as_xsd_any_uri().context(location_info!()))
 239     .collect::<Result<Vec<&Url>, anyhow::Error>>()?;
 240   for cid in community_ids {
 241     let community = get_or_fetch_and_upsert_community(&cid, context, request_counter).await;
 242     if community.is_ok() {
 243       return community;
 244     }
 245   }
 246   Err(NotFound.into())
 247 }