fix some more panics when the database is empty

README.md

@@ -27,7 +27,7 @@ Also if you do intend on using any of the code here, please read the [license](L
 
 It is assumed that you know the basics of server scanning. Otherwise, I recommend reading the [masscan readme](https://github.com/robertdavidgraham/masscan/blob/master/README.md) and [documentation](https://github.com/robertdavidgraham/masscan/blob/master/doc/masscan.8.markdown). Also be aware that matscan only supports Linux, but you probably shouldn't be running it at home anyways.
 
-Rename `config.toml.example` to `config.toml` and fill in the fields.
+Rename `example-config.toml` to `config.toml` and fill in the fields.
 
 You'll also have to make a MongoDB database called `mcscanner` with two collections called `servers` and `bad_servers`. You should add a unique index for `addr+port` and a normal index for `timestamp` in the `servers` collection.
 

src/database/mod.rs

@@ -262,32 +262,33 @@ pub async fn collect_all_servers(
             doc! {
                 "timestamp": {
                     // up to 30 days ago
-                    "$gt": bson::DateTime::from(SystemTime::now() - std::time::Duration::from_secs(60 * 60 * 24 * 30)),
+                    "$gt": bson::DateTime::from(SystemTime::now() - Duration::from_secs(60 * 60 * 24 * 30)),
                 }
             }
         }
         CollectServersFilter::New => {
             if let Some((cached, cached_time)) = &database.shared.lock().cached_all_servers_new {
                 // if it was more than 24 hours ago, download again
-                if cached_time.elapsed().as_secs() < 60 * 60 * 24 {
+                if cached_time.elapsed() < Duration::from_secs(60 * 60 * 24) {
                     return Ok(cached.clone());
                 }
             }
-            // first 4 bytes are seconds since epoch
-            // other 12 are 0
-            let seconds_since_epoch = (SystemTime::now()
-                - std::time::Duration::from_secs(60 * 60 * 24 * 7))
+
+            // inserted in the past 7 days
+            let inserted_after_secs_since_epoch = (SystemTime::now()
+                - Duration::from_secs(60 * 60 * 24 * 7))
             .duration_since(UNIX_EPOCH)?
             .as_secs() as u32;
 
             doc! {
-                "_id": {
-                    // inserted in the past 7 days
+            "_id": {
+                    // first 4 bytes are seconds since epoch
+                    // other 12 are 0
                     "$gt": bson::oid::ObjectId::from_bytes([
-                        (seconds_since_epoch >> 24) as u8,
-                        (seconds_since_epoch >> 16) as u8,
-                        (seconds_since_epoch >> 8) as u8,
-                        seconds_since_epoch as u8,
+                        (inserted_after_secs_since_epoch >> 24) as u8,
+                        (inserted_after_secs_since_epoch >> 16) as u8,
+                        (inserted_after_secs_since_epoch >> 8) as u8,
+                        inserted_after_secs_since_epoch as u8,
                         0, 0, 0, 0, 0, 0, 0, 0
                     ])
                 }

src/modes/fingerprint.rs

@@ -26,9 +26,7 @@ pub async fn get_addrs_and_protocol_versions(
                     "$lt": bson::DateTime::from(SystemTime::now() - Duration::from_secs(60 * 60 * 24 * 7)),
                 }
             },
-            {
-                "fingerprint.activeMinecraft": { "$exists": false }
-            },
+            { "fingerprint.activeMinecraft": { "$exists": false } },
         ]
     };
 

src/modes/rescan.rs

@@ -34,7 +34,6 @@ pub async fn get_ranges(
 
     let mut filter = doc! {
         "timestamp": {
-            // up to 2 hours ago
             "$gt": bson::DateTime::from(SystemTime::now() - Duration::from_secs(last_ping_ago_max_secs)),
             "$lt": bson::DateTime::from(SystemTime::now() - Duration::from_secs(rescan_every_secs))
         }

src/modes/slash24.rs

@@ -21,6 +21,10 @@ pub async fn get_ranges(database: &Database) -> anyhow::Result<Vec<ScanRange>> {
     let ranges: HashMap<(u8, u8, u8), ServerGroup> = to_ranges(&known_servers);
     println!("converted into {} ranges", ranges.len());
 
+    if ranges.is_empty() {
+        return Ok(vec![]);
+    }
+
     let mut rng = thread_rng();
     let mut target_ranges = Vec::new();
 

src/modes/slash24_few_ports.rs

@@ -18,6 +18,10 @@ pub async fn get_ranges(database: &Database) -> anyhow::Result<Vec<ScanRange>> {
     let ranges: HashMap<(u8, u8, u8), ServerGroup> = to_ranges(&known_servers);
     println!("converted into {} ranges", ranges.len());
 
+    if ranges.is_empty() {
+        return Ok(vec![]);
+    }
+
     let mut rng = thread_rng();
     let mut target_ranges = Vec::new();
 

src/modes/slash24_few_ports_new.rs

@@ -18,6 +18,10 @@ pub async fn get_ranges(database: &Database) -> anyhow::Result<Vec<ScanRange>> {
     let ranges: HashMap<(u8, u8, u8), ServerGroup> = to_ranges(&known_servers);
     println!("converted into {} ranges", ranges.len());
 
+    if ranges.is_empty() {
+        return Ok(vec![]);
+    }
+
     let mut rng = thread_rng();
     let mut target_ranges = Vec::new();
 

src/modes/slash24_new.rs

@@ -22,6 +22,10 @@ pub async fn get_ranges(database: &Database) -> anyhow::Result<Vec<ScanRange>> {
     let ranges: HashMap<(u8, u8, u8), ServerGroup> = to_ranges(&known_servers);
     println!("converted into {} ranges", ranges.len());
 
+    if ranges.is_empty() {
+        return Ok(vec![]);
+    }
+
     let mut rng = thread_rng();
     let mut target_ranges = Vec::new();
 

src/scanner/protocols/minecraft_fingerprinting.rs

@@ -55,9 +55,9 @@ pub fn build_fingerprint_request(hostname: &str, port: u16, protocol_version: i3
 
     // ServerboundHelloPacket was changed in 23w31a (1.20.2) so the uuid is no
     // longer optional
-    if (protocol_version >= 764 && protocol_version < 0x40000000)
-        || (protocol_version >= 1073741968)
-    {
+    // if (protocol_version >= 764 && protocol_version < 0x40000000)
+    //     || (protocol_version >= 1073741968)
+    if matches!(protocol_version, 764..=0x40000000 | 1073741968..) {
         #[rustfmt::skip]
         full_buffer.extend_from_slice(&[
             19,   // length of following data