aquatic_http: add ipv6 compact responses; fix ipv4/ipv6 issue

TODO.md

@@ -2,6 +2,7 @@
 
 ## General
 
+* use ipv4-mapped address functions
 * avx-512 should be avoided, maybe this should be mentioned in README
   and maybe run scripts should be adjusted
 
@@ -10,9 +11,9 @@
   * test tls
   * current serialized byte strings valid
 * scrape: does it work with multiple hashes?
-* ipv6 response peers: use https://www.bittorrent.org/beps/bep_0007.html?
-  (peers6 compact key)
-  * compact=0 should result in error response
+* store Ipv4Addr / Ipv6 addr in peer map, for correctness and so that strange
+  conversion in handler doesn't have to occur
+* compact=0 should result in error response
 * tests of request parsing
 * tests of response serialization (against data known to be good would be nice)
 * Connection.send_response: handle case when all bytes are not written: can

aquatic_common/src/lib.rs

@@ -1,4 +1,5 @@
 use std::time::{Duration, Instant};
+use std::net::IpAddr;
 
 use indexmap::IndexMap;
 use rand::Rng;
@@ -77,4 +78,18 @@ pub fn extract_response_peers<K, V, R, F>(
 
         peers
     }
+}
+
+
+#[inline]
+pub fn convert_ipv4_mapped_ipv4(ip_address: IpAddr) -> IpAddr {
+    if let IpAddr::V6(ip) = ip_address {
+        if let [0, 0, 0, 0, 0, 0xffff, ..] = ip.segments(){
+            ip.to_ipv4().expect("convert ipv4-mapped ip").into()
+        } else {
+            ip_address
+        }   
+    } else {
+        ip_address
+    }
 }

aquatic_http/src/lib/common.rs

@@ -9,7 +9,7 @@ use log::error;
 use mio::Token;
 use parking_lot::Mutex;
 
-pub use aquatic_common::ValidUntil;
+pub use aquatic_common::{ValidUntil, convert_ipv4_mapped_ipv4};
 
 use crate::protocol::common::*;
 use crate::protocol::request::Request;
@@ -26,6 +26,22 @@ pub struct ConnectionMeta {
 }
 
 
+impl ConnectionMeta {
+    pub fn map_ipv4_ip(&self) -> Self {
+        let peer_addr = SocketAddr::new(
+            convert_ipv4_mapped_ipv4(self.peer_addr.ip()),
+            self.peer_addr.port()
+        );
+
+        Self {
+            worker_index: self.worker_index,
+            peer_addr,
+            poll_token: self.poll_token
+        }
+    }
+}
+
+
 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
 pub enum PeerStatus {
     Seeding,

aquatic_http/src/lib/handler.rs

@@ -1,5 +1,6 @@
 use std::time::Duration;
 use std::vec::Drain;
+use std::net::IpAddr;
 
 use either::Either;
 use hashbrown::HashMap;
@@ -96,7 +97,9 @@ pub fn handle_announce_requests(
     let valid_until = ValidUntil::new(config.cleaning.max_peer_age);
 
     responses.extend(requests.map(|(request_sender_meta, request)| {
-        let torrent_data: &mut TorrentData = if request_sender_meta.peer_addr.is_ipv4(){
+        let converted_request_sender_meta = request_sender_meta.map_ipv4_ip();
+
+        let torrent_data: &mut TorrentData = if converted_request_sender_meta.peer_addr.is_ipv4(){
             torrent_maps.ipv4.entry(request.info_hash).or_default()
         } else {
             torrent_maps.ipv6.entry(request.info_hash).or_default()
@@ -104,6 +107,8 @@ pub fn handle_announce_requests(
 
         // Insert/update/remove peer who sent this request
         {
+            let request_sender_meta = converted_request_sender_meta;
+
             let peer_status = PeerStatus::from_event_and_bytes_left(
                 request.event,
                 Some(request.bytes_left)
@@ -159,18 +164,48 @@ pub fn handle_announce_requests(
             Some(numwant) => numwant.min(config.protocol.max_peers),
         };
 
+        // FIXME: proper protocol peer should be extracted here, not below.
+        // Ideally, protocol-specific IP should be stored in connection meta
+        // in peer map.
         let response_peers: Vec<ResponsePeer> = extract_response_peers(
             rng,
             &torrent_data.peers,
             max_num_peers_to_take,
-            ResponsePeer::from_peer
+            ResponsePeer::from_peer 
         );
 
+        let response_peers_v4 = response_peers.iter()
+            .filter_map(|peer| {
+                if let IpAddr::V4(ip_address) = peer.ip_address {
+                    Some(ResponsePeerV4 {
+                        ip_address,
+                        port: peer.port
+                    })
+                } else {
+                    None
+                }
+            })
+            .collect();
+
+        let response_peers_v6 = response_peers.iter()
+            .filter_map(|peer| {
+                if let IpAddr::V6(ip_address) = peer.ip_address {
+                    Some(ResponsePeerV6 {
+                        ip_address,
+                        port: peer.port
+                    })
+                } else {
+                    None
+                }
+            })
+            .collect();
+
         let response = Response::Announce(AnnounceResponse {
             complete: torrent_data.num_seeders,
             incomplete: torrent_data.num_leechers,
             announce_interval: config.protocol.peer_announce_interval,
-            peers: response_peers,
+            peers: ResponsePeerListV4(response_peers_v4),
+            peers6: ResponsePeerListV6(response_peers_v6),
         });
 
         (request_sender_meta, response)

aquatic_http/src/lib/protocol/response.rs

@@ -1,4 +1,4 @@
-use std::net::IpAddr;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 
 use hashbrown::HashMap;
 use serde::Serialize;
@@ -9,7 +9,6 @@ use super::common::*;
 use super::utils::*;
 
 
-#[derive(Clone, Copy, Debug, Serialize)]
 pub struct ResponsePeer {
     pub ip_address: IpAddr,
     pub port: u16
@@ -28,6 +27,36 @@ impl ResponsePeer {
 }
 
 
+#[derive(Clone, Copy, Debug, Serialize)]
+pub struct ResponsePeerV4 {
+    pub ip_address: Ipv4Addr,
+    pub port: u16
+}
+
+
+#[derive(Clone, Copy, Debug, Serialize)]
+pub struct ResponsePeerV6 {
+    pub ip_address: Ipv6Addr,
+    pub port: u16
+}
+
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(transparent)]
+pub struct ResponsePeerListV4(
+    #[serde(serialize_with = "serialize_response_peers_ipv4")]
+    pub Vec<ResponsePeerV4>
+);
+
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(transparent)]
+pub struct ResponsePeerListV6(
+    #[serde(serialize_with = "serialize_response_peers_ipv6")]
+    pub Vec<ResponsePeerV6>
+);
+
+
 #[derive(Debug, Clone, Serialize)]
 pub struct ScrapeStatistics {
     pub complete: usize,
@@ -42,10 +71,8 @@ pub struct AnnounceResponse {
     pub announce_interval: usize,
     pub complete: usize,
     pub incomplete: usize,
-    #[serde(
-        serialize_with = "serialize_response_peers_compact"
-    )]
-    pub peers: Vec<ResponsePeer>,
+    pub peers: ResponsePeerListV4,
+    pub peers6: ResponsePeerListV6,
 }
 
 

aquatic_http/src/lib/protocol/utils.rs

@@ -1,8 +1,6 @@
-use std::net::IpAddr;
-
 use serde::Serializer;
 
-use super::response::ResponsePeer;
+use super::response::{ResponsePeerV4, ResponsePeerV6};
 
 
 /// Not for serde
@@ -42,22 +40,30 @@ pub fn serialize_20_bytes<S>(
 }
 
 
-pub fn serialize_response_peers_compact<S>(
-    response_peers: &[ResponsePeer],
+pub fn serialize_response_peers_ipv4<S>(
+    response_peers: &[ResponsePeerV4],
     serializer: S
 ) -> Result<S::Ok, S::Error> where S: Serializer {
     let mut bytes = Vec::with_capacity(response_peers.len() * 6);
 
     for peer in response_peers {
-        match peer.ip_address {
-            IpAddr::V4(ip) => {
-                bytes.extend_from_slice(&u32::from(ip).to_be_bytes());
-                bytes.extend_from_slice(&peer.port.to_be_bytes())
-            },
-            IpAddr::V6(_) => {
-                continue;
-            }
-        }
+        bytes.extend_from_slice(&u32::from(peer.ip_address).to_be_bytes());
+        bytes.extend_from_slice(&peer.port.to_be_bytes())
+    }
+
+    serializer.serialize_bytes(&bytes)
+}
+
+
+pub fn serialize_response_peers_ipv6<S>(
+    response_peers: &[ResponsePeerV6],
+    serializer: S
+) -> Result<S::Ok, S::Error> where S: Serializer {
+    let mut bytes = Vec::with_capacity(response_peers.len() * 6);
+
+    for peer in response_peers {
+        bytes.extend_from_slice(&u128::from(peer.ip_address).to_be_bytes());
+        bytes.extend_from_slice(&peer.port.to_be_bytes())
     }
 
     serializer.serialize_bytes(&bytes)