add slugs check

env.example

@@ -3,3 +3,4 @@ DATABASE_FILE=${HOME}/.hitman.db
 LISTENING_ADDR=0.0.0.0
 LISTENING_PORT=5000
 HITMAN_ORIGIN=http://localhost:3000
+RUST_LOG=hitman=info

migrations/20240331234446_slugs.down.sql

@@ -0,0 +1 @@
+drop table if exists slugs;

migrations/20240331234446_slugs.up.sql

@@ -0,0 +1,7 @@
+create table if not exists slugs (
+  id integer primary key,
+  slug text not null unique,
+  created_at timestamp not null default CURRENT_TIMESTAMP
+);
+
+create index if not exists created_slugs_dex on slugs(created_at);

src/main.rs

@@ -1,4 +1,5 @@
 use std::{
+    collections::HashSet,
     env::VarError,
     ffi::OsString,
     io::Write,
@@ -78,6 +79,18 @@ async fn register_hit(
 ) -> String {
     let slug = &slug;
 
+    let slugs: HashSet<String> = sqlx::query!("select slug from slugs")
+        .fetch_all(&db)
+        .await
+        .unwrap_or(Vec::new())
+        .iter()
+        .map(|r| r.slug.to_string())
+        .collect();
+    if !slugs.contains(slug) {
+        log::info!("rejecting invalid slug {slug}");
+        return "".to_string();
+    }
+
     let host = ip.to_string();
 
     let now = chrono::Utc::now();