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