xash3d_protocol/
game.rs

1// SPDX-License-Identifier: LGPL-3.0-only
2// SPDX-FileCopyrightText: 2023 Denis Drakhnia <numas13@gmail.com>
3
4//! Game client packets.
5
6use std::fmt;
7use std::net::SocketAddr;
8
9use crate::cursor::{Cursor, CursorMut};
10use crate::filter::Filter;
11use crate::server::Region;
12use crate::Error;
13
14/// Request a list of server addresses from master servers.
15#[derive(Clone, Debug, PartialEq)]
16pub struct QueryServers<T> {
17    /// Servers must be from the `region`.
18    pub region: Region,
19    /// Last received server address __(not used)__.
20    pub last: SocketAddr,
21    /// Select only servers that match the `filter`.
22    pub filter: T,
23}
24
25impl QueryServers<()> {
26    /// Packet header.
27    pub const HEADER: &'static [u8] = b"1";
28}
29
30impl<'a, T: 'a> QueryServers<T>
31where
32    T: TryFrom<&'a [u8], Error = Error>,
33{
34    /// Decode packet from `src`.
35    pub fn decode(src: &'a [u8]) -> Result<Self, Error> {
36        let mut cur = Cursor::new(src);
37        cur.expect(QueryServers::HEADER)?;
38        let region = cur.get_u8()?.try_into().map_err(|_| Error::InvalidRegion)?;
39        let last = cur.get_cstr_as_str()?;
40        let filter = match cur.get_bytes(cur.remaining())? {
41            // some clients may have bug and filter will be with zero at the end
42            [x @ .., 0] => x,
43            x => x,
44        };
45        Ok(Self {
46            region,
47            last: last.parse().map_err(|_| Error::InvalidQueryServersLast)?,
48            filter: T::try_from(filter)?,
49        })
50    }
51}
52
53impl<'a, T: 'a> QueryServers<T>
54where
55    for<'b> &'b T: fmt::Display,
56{
57    /// Encode packet to `buf`.
58    pub fn encode(&self, buf: &mut [u8]) -> Result<usize, Error> {
59        Ok(CursorMut::new(buf)
60            .put_bytes(QueryServers::HEADER)?
61            .put_u8(self.region as u8)?
62            .put_as_str(self.last)?
63            .put_u8(0)?
64            .put_as_str(&self.filter)?
65            .put_u8(0)?
66            .pos())
67    }
68}
69
70/// Request an information from a game server.
71#[derive(Clone, Debug, PartialEq)]
72pub struct GetServerInfo {
73    /// Client protocol version.
74    pub protocol: u8,
75}
76
77impl GetServerInfo {
78    /// Packet header.
79    pub const HEADER: &'static [u8] = b"\xff\xff\xff\xffinfo ";
80
81    /// Creates a new `GetServerInfo`.
82    pub fn new(protocol: u8) -> Self {
83        Self { protocol }
84    }
85
86    /// Decode packet from `src`.
87    pub fn decode(src: &[u8]) -> Result<Self, Error> {
88        let mut cur = Cursor::new(src);
89        cur.expect(Self::HEADER)?;
90        let protocol = cur
91            .get_str(cur.remaining())?
92            .parse()
93            .map_err(|_| Error::InvalidPacket)?;
94        Ok(Self { protocol })
95    }
96
97    /// Encode packet to `buf`.
98    pub fn encode(&self, buf: &mut [u8]) -> Result<usize, Error> {
99        Ok(CursorMut::new(buf)
100            .put_bytes(Self::HEADER)?
101            .put_as_str(self.protocol)?
102            .pos())
103    }
104}
105
106/// Game client packets.
107#[derive(Clone, Debug, PartialEq)]
108pub enum Packet<'a> {
109    /// Request a list of server addresses from master servers.
110    QueryServers(QueryServers<Filter<'a>>),
111    /// Request an information from a game server.
112    GetServerInfo(GetServerInfo),
113}
114
115impl<'a> Packet<'a> {
116    /// Decode packet from `src`.
117    pub fn decode(src: &'a [u8]) -> Result<Option<Self>, Error> {
118        if src.starts_with(QueryServers::HEADER) {
119            QueryServers::decode(src).map(Self::QueryServers)
120        } else if src.starts_with(GetServerInfo::HEADER) {
121            GetServerInfo::decode(src).map(Self::GetServerInfo)
122        } else {
123            return Ok(None);
124        }
125        .map(Some)
126    }
127}
128
129#[cfg(test)]
130mod tests {
131    use super::*;
132    use crate::filter::{FilterFlags, Version};
133    use crate::wrappers::Str;
134    use std::net::{IpAddr, Ipv4Addr};
135
136    #[test]
137    fn query_servers() {
138        let p = QueryServers {
139            region: Region::RestOfTheWorld,
140            last: SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), 0),
141            filter: Filter {
142                gamedir: Some(Str(&b"valve"[..])),
143                map: Some(Str(&b"crossfire"[..])),
144                key: Some(0xdeadbeef),
145                protocol: Some(49),
146                clver: Some(Version::new(0, 20)),
147                flags: FilterFlags::all(),
148                flags_mask: FilterFlags::all(),
149            },
150        };
151        let mut buf = [0; 512];
152        let n = p.encode(&mut buf).unwrap();
153        assert_eq!(Packet::decode(&buf[..n]), Ok(Some(Packet::QueryServers(p))));
154    }
155
156    #[test]
157    fn query_servers_filter_bug() {
158        let p = QueryServers {
159            region: Region::RestOfTheWorld,
160            last: SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), 0),
161            filter: Filter {
162                gamedir: None,
163                protocol: Some(48),
164                map: None,
165                key: None,
166                clver: Some(Version::new(0, 20)),
167                flags: FilterFlags::empty(),
168                flags_mask: FilterFlags::NAT,
169            },
170        };
171
172        let s = b"1\xff0.0.0.0:0\x00\\protocol\\48\\clver\\0.20\\nat\\0\0";
173        assert_eq!(Packet::decode(s), Ok(Some(Packet::QueryServers(p.clone()))));
174
175        let s = b"1\xff0.0.0.0:0\x00\\protocol\\48\\clver\\0.20\\nat\\0";
176        assert_eq!(Packet::decode(s), Ok(Some(Packet::QueryServers(p))));
177    }
178
179    #[test]
180    fn get_server_info() {
181        let p = GetServerInfo::new(49);
182        let mut buf = [0; 512];
183        let n = p.encode(&mut buf).unwrap();
184        assert_eq!(
185            Packet::decode(&buf[..n]),
186            Ok(Some(Packet::GetServerInfo(p)))
187        );
188    }
189}
xash3d_protocol/game.rs

xash3d_protocol/
game.rs
