protocol: add challenge key to game requests

Cargo.lock

@@ -509,6 +509,7 @@ dependencies = [
 name = "xash3d-query"
 version = "0.1.0"
 dependencies = [
+ "fastrand",
  "getopts",
  "libc",
  "serde",

master/src/master_server.rs

@@ -231,7 +231,7 @@ impl MasterServer {
                     trace!("{}: recv {:?}", from, p);
                     if p.filter.clver.map_or(false, |v| v < self.clver) {
                         let iter = std::iter::once(self.update_addr);
-                        self.send_server_list(from, iter)?;
+                        self.send_server_list(from, p.filter.key, iter)?;
                     } else {
                         let now = self.now();
                         let iter = self
@@ -240,7 +240,7 @@ impl MasterServer {
                             .filter(|i| i.1.is_valid(now, self.timeout.server))
                             .filter(|i| i.1.matches(*i.0, p.region, &p.filter))
                             .map(|i| *i.0);
-                        self.send_server_list(from, iter)?;
+                        self.send_server_list(from, p.filter.key, iter)?;
                     }
                 }
                 game::Packet::GetServerInfo(p) => {
@@ -399,12 +399,12 @@ impl MasterServer {
         }
     }
 
-    fn send_server_list<A, I>(&self, to: A, iter: I) -> Result<(), Error>
+    fn send_server_list<A, I>(&self, to: A, key: Option<u32>, iter: I) -> Result<(), Error>
     where
         A: ToSocketAddrs,
         I: Iterator<Item = SocketAddrV4>,
     {
-        let mut list = master::QueryServersResponse::new(iter);
+        let mut list = master::QueryServersResponse::new(iter, key);
         loop {
             let mut buf = [0; MAX_PACKET_SIZE];
             let (n, is_end) = list.encode(&mut buf)?;

protocol/src/filter.rs

@@ -141,6 +141,7 @@ pub struct Filter<'a> {
     pub map: Option<Str<&'a [u8]>>,
     /// Client version.
     pub clver: Option<Version>,
+    pub key: Option<u32>,
 
     pub flags: FilterFlags,
     pub flags_mask: FilterFlags,
@@ -192,6 +193,13 @@ impl<'a> TryFrom<&'a [u8]> for Filter<'a> {
                 b"nat" => filter.insert_flag(FilterFlags::NAT, cur.get_key_value()?),
                 b"lan" => filter.insert_flag(FilterFlags::LAN, cur.get_key_value()?),
                 b"bots" => filter.insert_flag(FilterFlags::BOTS, cur.get_key_value()?),
+                b"key" => {
+                    filter.key = {
+                        let s = cur.get_key_value::<&str>()?;
+                        let x = u32::from_str_radix(s, 16).map_err(|_| Error::InvalidPacket)?;
+                        Some(x)
+                    }
+                }
                 _ => {
                     // skip unknown fields
                     let value = Str(cur.get_key_value_raw()?);
@@ -234,6 +242,9 @@ impl fmt::Display for &Filter<'_> {
         display_flag!("nat", FilterFlags::NAT);
         display_flag!("lan", FilterFlags::LAN);
         display_flag!("bots", FilterFlags::BOTS);
+        if let Some(x) = self.key {
+            write!(fmt, "\\key\\{:x}", x)?;
+        }
 
         Ok(())
     }

protocol/src/game.rs

@@ -120,6 +120,7 @@ mod tests {
             filter: Filter {
                 gamedir: Some(Str(&b"valve"[..])),
                 map: Some(Str(&b"crossfire"[..])),
+                key: Some(0xdeadbeef),
                 clver: Some(Version::new(0, 20)),
                 flags: FilterFlags::all(),
                 flags_mask: FilterFlags::all(),

protocol/src/master.rs

@@ -46,6 +46,7 @@ impl ChallengeResponse {
 #[derive(Clone, Debug, PartialEq)]
 pub struct QueryServersResponse<I> {
     inner: I,
+    pub key: Option<u32>,
 }
 
 impl QueryServersResponse<()> {
@@ -60,12 +61,20 @@ impl<'a> QueryServersResponse<&'a [u8]> {
             return Err(Error::InvalidPacket);
         }
         let s = cur.get_bytes(cur.remaining())?;
+
+        // extra header for key sent in QueryServers packet
+        let (s, key) = if s.len() >= 6 && s[0] == 0x7f {
+            (&s[6..], Some(u32::from_le_bytes([s[1], s[2], s[3], s[4]])))
+        } else {
+            (s, None)
+        };
+
         let inner = if s.ends_with(&[0; 6]) {
             &s[..s.len() - 6]
         } else {
             s
         };
-        Ok(Self { inner })
+        Ok(Self { inner, key })
     }
 
     pub fn iter(&self) -> impl 'a + Iterator<Item = SocketAddrV4> {
@@ -86,13 +95,18 @@ impl<I> QueryServersResponse<I>
 where
     I: Iterator<Item = SocketAddrV4>,
 {
-    pub fn new(iter: I) -> Self {
-        Self { inner: iter }
+    pub fn new(iter: I, key: Option<u32>) -> Self {
+        Self { inner: iter, key }
     }
 
     pub fn encode(&mut self, buf: &mut [u8]) -> Result<(usize, bool), Error> {
         let mut cur = CursorMut::new(buf);
         cur.put_bytes(QueryServersResponse::HEADER)?;
+        if let Some(key) = self.key {
+            cur.put_u8(0x7f)?;
+            cur.put_u32_le(key)?;
+            cur.put_u8(8)?;
+        }
         let mut is_end = false;
         while cur.remaining() >= 12 {
             match self.inner.next() {
@@ -191,7 +205,7 @@ mod tests {
             "1.2.3.4:27003".parse().unwrap(),
             "1.2.3.4:27004".parse().unwrap(),
         ];
-        let mut p = QueryServersResponse::new(servers.iter().cloned());
+        let mut p = QueryServersResponse::new(servers.iter().cloned(), Some(0xdeadbeef));
         let mut buf = [0; 512];
         let (n, _) = p.encode(&mut buf).unwrap();
         let e = QueryServersResponse::decode(&buf[..n]).unwrap();

query/Cargo.toml

@@ -14,6 +14,7 @@ color = ["termion"]
 libc = "0.2.148"
 thiserror = "1.0.49"
 getopts = "0.2.21"
+fastrand = "2.0.1"
 serde = { version = "1.0.188", features = ["derive"] }
 serde_json = "1.0.107"
 termion = { version = "2", optional = true }

query/src/cli.rs

@@ -25,6 +25,7 @@ pub struct Cli {
     pub debug: bool,
     pub force_color: bool,
     pub filter: String,
+    pub key: Option<u32>,
 }
 
 impl Default for Cli {
@@ -43,6 +44,7 @@ impl Default for Cli {
             force_color: false,
             // if changed do not forget to update cli parsing
             filter: format!("\\gamedir\\valve\\clver\\{}", proto::CLIENT_VERSION),
+            key: None,
         }
     }
 }
@@ -99,6 +101,7 @@ pub fn parse() -> Cli {
     opts.optflag("j", "json", "output JSON");
     opts.optflag("d", "debug", "output debug");
     opts.optflag("F", "force-color", "force colored output");
+    opts.optflag("k", "key", "send challenge key to master");
     let help = format!("query filter [default: {:?}]", cli.filter);
     opts.optopt("f", "filter", &help, "FILTER");
 
@@ -180,6 +183,12 @@ pub fn parse() -> Cli {
         cli.filter = filter;
     }
 
+    if matches.opt_present("key") {
+        let key = fastrand::u32(..);
+        cli.key = Some(key);
+        cli.filter.push_str(&format!("\\key\\{:x}", key));
+    }
+
     cli.json = matches.opt_present("json");
     cli.debug = matches.opt_present("debug");
     cli.force_color = matches.opt_present("force-color");

query/src/main.rs

@@ -36,8 +36,13 @@ enum ServerResultKind {
         #[serde(flatten)]
         info: ServerInfo,
     },
-    Error { message: String },
-    Invalid { message: String, response: String },
+    Error {
+        message: String,
+    },
+    Invalid {
+        message: String,
+        response: String,
+    },
     Timeout,
     Protocol,
 }
@@ -298,7 +303,9 @@ impl<'a> Scan<'a> {
 
             if self.is_master(&from) {
                 if let Ok(packet) = master::QueryServersResponse::decode(&buf[..n]) {
-                    set.extend(packet.iter());
+                    if self.check_key(&from, packet.key) {
+                        set.extend(packet.iter());
+                    }
                 } else {
                     eprintln!("warn: invalid packet from master {}", from);
                 }
@@ -367,19 +374,22 @@ impl<'a> Scan<'a> {
 
             if self.is_master(&from) {
                 if let Ok(packet) = master::QueryServersResponse::decode(raw) {
-                    for addr in packet.iter().filter(|i| set.insert(*i)) {
-                        let mut buf = [0; 512];
-                        let n = game::GetServerInfo::new(self.cli.protocol[0]).encode(&mut buf)?;
-
-                        match self.sock.send_to(&buf[..n], addr) {
-                            Ok(_) => {
-                                let query = ServerQuery::new(0);
-                                server_end = query.start + server_timeout;
-                                active.insert(addr, query);
-                            }
-                            Err(e) => {
-                                let res = ServerResult::error(addr, e);
-                                out.insert(addr, res);
+                    if self.check_key(&from, packet.key) {
+                        for addr in packet.iter().filter(|i| set.insert(*i)) {
+                            let mut buf = [0; 512];
+                            let n =
+                                game::GetServerInfo::new(self.cli.protocol[0]).encode(&mut buf)?;
+
+                            match self.sock.send_to(&buf[..n], addr) {
+                                Ok(_) => {
+                                    let query = ServerQuery::new(0);
+                                    server_end = query.start + server_timeout;
+                                    active.insert(addr, query);
+                                }
+                                Err(e) => {
+                                    let res = ServerResult::error(addr, e);
+                                    out.insert(addr, res);
+                                }
                             }
                         }
                     }
@@ -426,6 +436,18 @@ impl<'a> Scan<'a> {
 
         Ok(out)
     }
+
+    fn check_key(&self, from: &SocketAddrV4, key: Option<u32>) -> bool {
+        let res = match (self.cli.key, key) {
+            (Some(a), Some(b)) => a == b,
+            (None, None) => true,
+            _ => false,
+        };
+        if !res {
+            eprintln!("error: invalid key from master({})", from);
+        }
+        res
+    }
 }
 
 fn query_server_info(cli: &Cli, servers: &[String]) -> Result<(), Error> {