lemmy/crates/apub/src/activities/mod.rs

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use crate::{
check_community_or_site_ban,
check_is_apub_id_valid,
fetcher::object_id::ObjectId,
generate_moderators_url,
objects::{community::ApubCommunity, person::ApubPerson},
};
use anyhow::anyhow;
use lemmy_api_common::blocking;
use lemmy_apub_lib::{traits::ActivityFields, verify::verify_domains_match};
use lemmy_db_schema::source::community::Community;
use lemmy_db_views_actor::community_view::CommunityView;
use lemmy_utils::{settings::structs::Settings, LemmyError};
use lemmy_websocket::LemmyContext;
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use serde::{Deserialize, Serialize};
use std::ops::Deref;
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use strum_macros::ToString;
use url::{ParseError, Url};
use uuid::Uuid;
pub mod comment;
pub mod community;
pub mod deletion;
pub mod following;
pub mod post;
pub mod private_message;
pub mod report;
pub mod undo_remove;
pub mod voting;
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#[derive(Clone, Debug, ToString, Deserialize, Serialize)]
pub enum CreateOrUpdateType {
Create,
Update,
}
/// Checks that the specified Url actually identifies a Person (by fetching it), and that the person
/// doesn't have a site ban.
async fn verify_person(
person_id: &ObjectId<ApubPerson>,
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<(), LemmyError> {
let person = person_id.dereference(context, request_counter).await?;
if person.banned {
return Err(anyhow!("Person {} is banned", person_id).into());
}
Ok(())
}
pub(crate) async fn extract_community(
cc: &[Url],
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<ApubCommunity, LemmyError> {
let mut cc_iter = cc.iter();
loop {
if let Some(cid) = cc_iter.next() {
let cid = ObjectId::new(cid.clone());
if let Ok(c) = cid.dereference(context, request_counter).await {
break Ok(c);
}
} else {
return Err(anyhow!("No community found in cc").into());
}
}
}
/// Fetches the person and community to verify their type, then checks if person is banned from site
/// or community.
pub(crate) async fn verify_person_in_community(
person_id: &ObjectId<ApubPerson>,
community_id: &ObjectId<ApubCommunity>,
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<(), LemmyError> {
let community = community_id.dereference(context, request_counter).await?;
let person = person_id.dereference(context, request_counter).await?;
check_community_or_site_ban(person.deref(), community.id, context.pool()).await
}
/// Simply check that the url actually refers to a valid group.
async fn verify_community(
community_id: &ObjectId<ApubCommunity>,
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<(), LemmyError> {
community_id.dereference(context, request_counter).await?;
Ok(())
}
fn verify_activity(activity: &dyn ActivityFields, settings: &Settings) -> Result<(), LemmyError> {
check_is_apub_id_valid(activity.actor(), false, settings)?;
verify_domains_match(activity.id_unchecked(), activity.actor())?;
Ok(())
}
/// Verify that the actor is a community mod. This check is only run if the community is local,
/// because in case of remote communities, admins can also perform mod actions. As admin status
/// is not federated, we cant verify their actions remotely.
pub(crate) async fn verify_mod_action(
actor_id: &ObjectId<ApubPerson>,
community_id: &ObjectId<ApubCommunity>,
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<(), LemmyError> {
let community = community_id.dereference_local(context).await?;
if community.local {
let actor = actor_id.dereference(context, request_counter).await?;
// Note: this will also return true for admins in addition to mods, but as we dont know about
// remote admins, it doesnt make any difference.
let community_id = community.id;
let actor_id = actor.id;
let is_mod_or_admin = blocking(context.pool(), move |conn| {
CommunityView::is_mod_or_admin(conn, actor_id, community_id)
})
.await?;
if !is_mod_or_admin {
return Err(anyhow!("Not a mod").into());
}
}
Ok(())
}
/// For Add/Remove community moderator activities, check that the target field actually contains
/// /c/community/moderators. Any different values are unsupported.
fn verify_add_remove_moderator_target(
target: &Url,
community: &ObjectId<ApubCommunity>,
) -> Result<(), LemmyError> {
if target != &generate_moderators_url(&community.clone().into())?.into_inner() {
return Err(anyhow!("Unkown target url").into());
}
Ok(())
}
pub(crate) fn check_community_deleted_or_removed(community: &Community) -> Result<(), LemmyError> {
if community.deleted || community.removed {
Err(anyhow!("New post or comment cannot be created in deleted or removed community").into())
} else {
Ok(())
}
}
/// Generate a unique ID for an activity, in the format:
/// `http(s)://example.com/receive/create/202daf0a-1489-45df-8d2e-c8a3173fed36`
fn generate_activity_id<T>(kind: T, protocol_and_hostname: &str) -> Result<Url, ParseError>
where
T: ToString,
{
let id = format!(
"{}/activities/{}/{}",
protocol_and_hostname,
kind.to_string().to_lowercase(),
Uuid::new_v4()
);
Url::parse(&id)
}