lemmy/crates/apub/src/lib.rs
Nutomic 28d6370c35
Rewrite delete activities (#1699)
* Limit type/method visibility in apub code

* Simplify db_queries traits by removing generics

* Simplify delete activity implementation

* Rewrite delete activities

* Implement helper functions for websocket message sending

* When receiving delete reason as empty string, change to none
2021-08-17 14:04:58 -04:00

390 lines
11 KiB
Rust

#[macro_use]
extern crate lazy_static;
pub mod activities;
pub mod activity_queue;
pub mod extensions;
pub mod fetcher;
pub mod http;
pub mod migrations;
pub mod objects;
use crate::extensions::signatures::PublicKey;
use activitystreams::base::AnyBase;
use anyhow::{anyhow, Context};
use diesel::NotFound;
use lemmy_api_common::blocking;
use lemmy_db_queries::{source::activity::Activity_, ApubObject, DbPool};
use lemmy_db_schema::{
source::{
activity::Activity,
comment::Comment,
community::Community,
person::{Person as DbPerson, Person},
post::Post,
private_message::PrivateMessage,
},
CommunityId,
DbUrl,
};
use lemmy_db_views_actor::community_person_ban_view::CommunityPersonBanView;
use lemmy_utils::{location_info, settings::structs::Settings, LemmyError};
use lemmy_websocket::LemmyContext;
use serde::Serialize;
use std::net::IpAddr;
use url::{ParseError, Url};
static APUB_JSON_CONTENT_TYPE: &str = "application/activity+json";
/// Checks if the ID is allowed for sending or receiving.
///
/// In particular, it checks for:
/// - federation being enabled (if its disabled, only local URLs are allowed)
/// - the correct scheme (either http or https)
/// - URL being in the allowlist (if it is active)
/// - URL not being in the blocklist (if it is active)
///
pub(crate) fn check_is_apub_id_valid(
apub_id: &Url,
use_strict_allowlist: bool,
) -> Result<(), LemmyError> {
let settings = Settings::get();
let domain = apub_id.domain().context(location_info!())?.to_string();
let local_instance = settings.get_hostname_without_port()?;
if !settings.federation.enabled {
return if domain == local_instance {
Ok(())
} else {
Err(
anyhow!(
"Trying to connect with {}, but federation is disabled",
domain
)
.into(),
)
};
}
let host = apub_id.host_str().context(location_info!())?;
let host_as_ip = host.parse::<IpAddr>();
if host == "localhost" || host_as_ip.is_ok() {
return Err(anyhow!("invalid hostname {}: {}", host, apub_id).into());
}
if apub_id.scheme() != Settings::get().get_protocol_string() {
return Err(anyhow!("invalid apub id scheme {}: {}", apub_id.scheme(), apub_id).into());
}
// TODO: might be good to put the part above in one method, and below in another
// (which only gets called in apub::objects)
// -> no that doesnt make sense, we still need the code below for blocklist and strict allowlist
if let Some(blocked) = Settings::get().federation.blocked_instances {
if blocked.contains(&domain) {
return Err(anyhow!("{} is in federation blocklist", domain).into());
}
}
if let Some(mut allowed) = Settings::get().federation.allowed_instances {
// Only check allowlist if this is a community, or strict allowlist is enabled.
let strict_allowlist = Settings::get().federation.strict_allowlist;
if use_strict_allowlist || strict_allowlist {
// need to allow this explicitly because apub receive might contain objects from our local
// instance.
allowed.push(local_instance);
if !allowed.contains(&domain) {
return Err(anyhow!("{} not in federation allowlist", domain).into());
}
}
}
Ok(())
}
/// Common methods provided by ActivityPub actors (community and person). Not all methods are
/// implemented by all actors.
trait ActorType {
fn is_local(&self) -> bool;
fn actor_id(&self) -> Url;
fn name(&self) -> String;
// TODO: every actor should have a public key, so this shouldnt be an option (needs to be fixed in db)
fn public_key(&self) -> Option<String>;
fn private_key(&self) -> Option<String>;
fn get_shared_inbox_or_inbox_url(&self) -> Url;
/// Outbox URL is not generally used by Lemmy, so it can be generated on the fly (but only for
/// local actors).
fn get_outbox_url(&self) -> Result<Url, LemmyError> {
/* TODO
if !self.is_local() {
return Err(anyhow!("get_outbox_url() called for remote actor").into());
}
*/
Ok(Url::parse(&format!("{}/outbox", &self.actor_id()))?)
}
fn get_public_key(&self) -> Result<PublicKey, LemmyError> {
Ok(PublicKey {
id: format!("{}#main-key", self.actor_id()),
owner: self.actor_id(),
public_key_pem: self.public_key().context(location_info!())?,
})
}
}
#[async_trait::async_trait(?Send)]
pub trait CommunityType {
fn followers_url(&self) -> Url;
async fn get_follower_inboxes(&self, pool: &DbPool) -> Result<Vec<Url>, LemmyError>;
async fn send_update(&self, mod_: Person, context: &LemmyContext) -> Result<(), LemmyError>;
async fn send_announce(
&self,
activity: AnyBase,
object: Option<Url>,
context: &LemmyContext,
) -> Result<(), LemmyError>;
async fn send_add_mod(
&self,
actor: &Person,
added_mod: Person,
context: &LemmyContext,
) -> Result<(), LemmyError>;
async fn send_remove_mod(
&self,
actor: &Person,
removed_mod: Person,
context: &LemmyContext,
) -> Result<(), LemmyError>;
async fn send_block_user(
&self,
actor: &Person,
blocked_user: Person,
context: &LemmyContext,
) -> Result<(), LemmyError>;
async fn send_undo_block_user(
&self,
actor: &Person,
blocked_user: Person,
context: &LemmyContext,
) -> Result<(), LemmyError>;
}
pub enum EndpointType {
Community,
Person,
Post,
Comment,
PrivateMessage,
}
/// Generates an apub endpoint for a given domain, IE xyz.tld
fn generate_apub_endpoint_for_domain(
endpoint_type: EndpointType,
name: &str,
domain: &str,
) -> Result<DbUrl, ParseError> {
let point = match endpoint_type {
EndpointType::Community => "c",
EndpointType::Person => "u",
EndpointType::Post => "post",
EndpointType::Comment => "comment",
EndpointType::PrivateMessage => "private_message",
};
Ok(Url::parse(&format!("{}/{}/{}", domain, point, name))?.into())
}
/// Generates the ActivityPub ID for a given object type and ID.
pub fn generate_apub_endpoint(
endpoint_type: EndpointType,
name: &str,
) -> Result<DbUrl, ParseError> {
generate_apub_endpoint_for_domain(
endpoint_type,
name,
&Settings::get().get_protocol_and_hostname(),
)
}
pub fn generate_followers_url(actor_id: &DbUrl) -> Result<DbUrl, ParseError> {
Ok(Url::parse(&format!("{}/followers", actor_id))?.into())
}
pub fn generate_inbox_url(actor_id: &DbUrl) -> Result<DbUrl, ParseError> {
Ok(Url::parse(&format!("{}/inbox", actor_id))?.into())
}
pub fn generate_shared_inbox_url(actor_id: &DbUrl) -> Result<DbUrl, LemmyError> {
let actor_id: Url = actor_id.clone().into();
let url = format!(
"{}://{}{}/inbox",
&actor_id.scheme(),
&actor_id.host_str().context(location_info!())?,
if let Some(port) = actor_id.port() {
format!(":{}", port)
} else {
"".to_string()
},
);
Ok(Url::parse(&url)?.into())
}
fn generate_moderators_url(community_id: &DbUrl) -> Result<DbUrl, LemmyError> {
Ok(Url::parse(&format!("{}/moderators", community_id))?.into())
}
/// Takes in a shortname of the type dessalines@xyz.tld or dessalines (assumed to be local), and outputs the actor id.
/// Used in the API for communities and users.
pub fn build_actor_id_from_shortname(
endpoint_type: EndpointType,
short_name: &str,
) -> Result<DbUrl, ParseError> {
let split = short_name.split('@').collect::<Vec<&str>>();
let name = split[0];
// If there's no @, its local
let domain = if split.len() == 1 {
Settings::get().get_protocol_and_hostname()
} else {
format!("{}://{}", Settings::get().get_protocol_string(), split[1])
};
generate_apub_endpoint_for_domain(endpoint_type, name, &domain)
}
/// Store a sent or received activity in the database, for logging purposes. These records are not
/// persistent.
async fn insert_activity<T>(
ap_id: &Url,
activity: T,
local: bool,
sensitive: bool,
pool: &DbPool,
) -> Result<(), LemmyError>
where
T: Serialize + std::fmt::Debug + Send + 'static,
{
let ap_id = ap_id.to_owned().into();
blocking(pool, move |conn| {
Activity::insert(conn, ap_id, &activity, local, sensitive)
})
.await??;
Ok(())
}
pub enum PostOrComment {
Comment(Box<Comment>),
Post(Box<Post>),
}
impl PostOrComment {
pub(crate) fn ap_id(&self) -> Url {
match self {
PostOrComment::Post(p) => p.ap_id.clone(),
PostOrComment::Comment(c) => c.ap_id.clone(),
}
.into()
}
}
/// Tries to find a post or comment in the local database, without any network requests.
/// This is used to handle deletions and removals, because in case we dont have the object, we can
/// simply ignore the activity.
pub(crate) async fn find_post_or_comment_by_id(
context: &LemmyContext,
apub_id: Url,
) -> Result<PostOrComment, LemmyError> {
let ap_id = apub_id.clone();
let post = blocking(context.pool(), move |conn| {
Post::read_from_apub_id(conn, &ap_id.into())
})
.await?;
if let Ok(p) = post {
return Ok(PostOrComment::Post(Box::new(p)));
}
let ap_id = apub_id.clone();
let comment = blocking(context.pool(), move |conn| {
Comment::read_from_apub_id(conn, &ap_id.into())
})
.await?;
if let Ok(c) = comment {
return Ok(PostOrComment::Comment(Box::new(c)));
}
Err(NotFound.into())
}
#[derive(Debug)]
enum Object {
Comment(Box<Comment>),
Post(Box<Post>),
Community(Box<Community>),
Person(Box<DbPerson>),
PrivateMessage(Box<PrivateMessage>),
}
async fn find_object_by_id(context: &LemmyContext, apub_id: Url) -> Result<Object, LemmyError> {
let ap_id = apub_id.clone();
if let Ok(pc) = find_post_or_comment_by_id(context, ap_id.to_owned()).await {
return Ok(match pc {
PostOrComment::Post(p) => Object::Post(Box::new(*p)),
PostOrComment::Comment(c) => Object::Comment(Box::new(*c)),
});
}
let ap_id = apub_id.clone();
let person = blocking(context.pool(), move |conn| {
DbPerson::read_from_apub_id(conn, &ap_id.into())
})
.await?;
if let Ok(u) = person {
return Ok(Object::Person(Box::new(u)));
}
let ap_id = apub_id.clone();
let community = blocking(context.pool(), move |conn| {
Community::read_from_apub_id(conn, &ap_id.into())
})
.await?;
if let Ok(c) = community {
return Ok(Object::Community(Box::new(c)));
}
let private_message = blocking(context.pool(), move |conn| {
PrivateMessage::read_from_apub_id(conn, &apub_id.into())
})
.await?;
if let Ok(pm) = private_message {
return Ok(Object::PrivateMessage(Box::new(pm)));
}
Err(NotFound.into())
}
async fn check_community_or_site_ban(
person: &Person,
community_id: CommunityId,
pool: &DbPool,
) -> Result<(), LemmyError> {
if person.banned {
return Err(anyhow!("Person is banned from site").into());
}
let person_id = person.id;
let is_banned =
move |conn: &'_ _| CommunityPersonBanView::get(conn, person_id, community_id).is_ok();
if blocking(pool, is_banned).await? {
return Err(anyhow!("Person is banned from community").into());
}
Ok(())
}