lemmy/crates/apub/src/lib.rs
Dessalines eb40aeb89b
Remove last Option<Vec.. from API. Fixes #2820 (#2822)
* Remove last Option<Vec.. from API. Fixes #2820

* Add empty allowed_instances check.

* Adding comment for allowed_instances.
2023-04-21 23:41:03 +02:00

193 lines
5.3 KiB
Rust

use crate::fetcher::post_or_comment::PostOrComment;
use activitypub_federation::config::{Data, UrlVerifier};
use async_trait::async_trait;
use lemmy_api_common::context::LemmyContext;
use lemmy_db_schema::{
source::{
activity::{Activity, ActivityInsertForm},
instance::Instance,
local_site::LocalSite,
},
traits::Crud,
utils::DbPool,
};
use lemmy_utils::{error::LemmyError, settings::structs::Settings};
use once_cell::sync::Lazy;
use serde::Serialize;
use url::Url;
pub mod activities;
pub(crate) mod activity_lists;
pub mod api;
pub(crate) mod collections;
pub mod fetcher;
pub mod http;
pub(crate) mod mentions;
pub mod objects;
pub mod protocol;
pub const FEDERATION_HTTP_FETCH_LIMIT: u32 = 50;
static CONTEXT: Lazy<Vec<serde_json::Value>> = Lazy::new(|| {
serde_json::from_str(include_str!("../assets/lemmy/context.json")).expect("parse context")
});
#[derive(Clone)]
pub struct VerifyUrlData(pub DbPool);
#[async_trait]
impl UrlVerifier for VerifyUrlData {
async fn verify(&self, url: &Url) -> Result<(), &'static str> {
let local_site_data = fetch_local_site_data(&self.0)
.await
.expect("read local site data");
check_apub_id_valid(url, &local_site_data)?;
Ok(())
}
}
/// 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)
///
/// `use_strict_allowlist` should be true only when parsing a remote community, or when parsing a
/// post/comment in a local community.
#[tracing::instrument(skip(local_site_data))]
fn check_apub_id_valid(apub_id: &Url, local_site_data: &LocalSiteData) -> Result<(), &'static str> {
let domain = apub_id.domain().expect("apud id has domain").to_string();
if !local_site_data
.local_site
.as_ref()
.map(|l| l.federation_enabled)
.unwrap_or(true)
{
return Err("Federation disabled");
}
if local_site_data
.blocked_instances
.iter()
.any(|i| domain.eq(&i.domain))
{
return Err("Domain is blocked");
}
// Only check this if there are instances in the allowlist
if !local_site_data.allowed_instances.is_empty()
&& !local_site_data
.allowed_instances
.iter()
.any(|i| domain.eq(&i.domain))
{
return Err("Domain is not in allowlist");
}
Ok(())
}
#[derive(Clone)]
pub(crate) struct LocalSiteData {
local_site: Option<LocalSite>,
allowed_instances: Vec<Instance>,
blocked_instances: Vec<Instance>,
}
pub(crate) async fn fetch_local_site_data(
pool: &DbPool,
) -> Result<LocalSiteData, diesel::result::Error> {
// LocalSite may be missing
let local_site = LocalSite::read(pool).await.ok();
let allowed_instances = Instance::allowlist(pool).await?;
let blocked_instances = Instance::blocklist(pool).await?;
Ok(LocalSiteData {
local_site,
allowed_instances,
blocked_instances,
})
}
#[tracing::instrument(skip(settings, local_site_data))]
pub(crate) fn check_apub_id_valid_with_strictness(
apub_id: &Url,
is_strict: bool,
local_site_data: &LocalSiteData,
settings: &Settings,
) -> Result<(), LemmyError> {
let domain = apub_id.domain().expect("apud id has domain").to_string();
let local_instance = settings
.get_hostname_without_port()
.expect("local hostname is valid");
if domain == local_instance {
return Ok(());
}
check_apub_id_valid(apub_id, local_site_data).map_err(LemmyError::from_message)?;
// Only check allowlist if this is a community, and there are instances in the allowlist
if is_strict && !local_site_data.allowed_instances.is_empty() {
// need to allow this explicitly because apub receive might contain objects from our local
// instance.
let mut allowed_and_local = local_site_data
.allowed_instances
.iter()
.map(|i| i.domain.clone())
.collect::<Vec<String>>();
let local_instance = settings
.get_hostname_without_port()
.expect("local hostname is valid");
allowed_and_local.push(local_instance);
let domain = apub_id.domain().expect("apud id has domain").to_string();
if !allowed_and_local.contains(&domain) {
return Err(LemmyError::from_message(
"Federation forbidden by strict allowlist",
));
}
}
Ok(())
}
/// Store a sent or received activity in the database.
///
/// Stored activities are served over the HTTP endpoint `GET /activities/{type_}/{id}`. This also
/// ensures that the same activity cannot be received more than once.
#[tracing::instrument(skip(data, activity))]
async fn insert_activity<T>(
ap_id: &Url,
activity: &T,
local: bool,
sensitive: bool,
data: &Data<LemmyContext>,
) -> Result<(), LemmyError>
where
T: Serialize,
{
let ap_id = ap_id.clone().into();
let form = ActivityInsertForm {
ap_id,
data: serde_json::to_value(activity)?,
local: Some(local),
sensitive: Some(sensitive),
updated: None,
};
Activity::create(data.pool(), &form).await?;
Ok(())
}
#[async_trait::async_trait]
pub trait SendActivity: Sync {
type Response: Sync + Send;
async fn send_activity(
_request: &Self,
_response: &Self::Response,
_context: &Data<LemmyContext>,
) -> Result<(), LemmyError> {
Ok(())
}
}