crates/apub/src/objects/mod.rs

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