From 47857fc10fbfbee4a1ab69f48f31da884af811a0 Mon Sep 17 00:00:00 2001
From: Ruihan Li <lrh2000@pku.edu.cn>
Date: Sat, 27 Jul 2024 09:39:54 +0800
Subject: [PATCH] Fix remote addresses in connected UNIX sockets

---
 .../src/net/socket/unix/stream/init.rs        | 10 ++----
 .../src/net/socket/unix/stream/listener.rs    | 34 ++++++++++++++-----
 test/apps/network/unix_err.c                  | 19 ++++++-----
 3 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/kernel/aster-nix/src/net/socket/unix/stream/init.rs b/kernel/aster-nix/src/net/socket/unix/stream/init.rs
index 2284e27a..75c8b68a 100644
--- a/kernel/aster-nix/src/net/socket/unix/stream/init.rs
+++ b/kernel/aster-nix/src/net/socket/unix/stream/init.rs
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
 
-use super::{connected::Connected, endpoint::Endpoint, listener::push_incoming};
+use super::{connected::Connected, listener::push_incoming};
 use crate::{
     events::{IoEvents, Observer},
     fs::{
@@ -45,12 +45,8 @@ impl Init {
     }
 
     pub(super) fn connect(&self, remote_addr: &UnixSocketAddrBound) -> Result<Connected> {
-        let (this_end, remote_end) =
-            Endpoint::new_pair(self.addr.clone(), Some(remote_addr.clone()));
-
-        push_incoming(remote_addr, remote_end)?;
-
-        Ok(Connected::new(this_end))
+        let endpoint = push_incoming(remote_addr, self.addr.clone())?;
+        Ok(Connected::new(endpoint))
     }
 
     pub(super) fn addr(&self) -> Option<&UnixSocketAddrBound> {
diff --git a/kernel/aster-nix/src/net/socket/unix/stream/listener.rs b/kernel/aster-nix/src/net/socket/unix/stream/listener.rs
index 727dc1bd..2d217acf 100644
--- a/kernel/aster-nix/src/net/socket/unix/stream/listener.rs
+++ b/kernel/aster-nix/src/net/socket/unix/stream/listener.rs
@@ -118,15 +118,19 @@ impl BacklogTable {
             .ok_or_else(|| Error::with_message(Errno::EINVAL, "the socket is not listened"))
     }
 
-    fn push_incoming(&self, addr: &UnixSocketAddrBound, endpoint: Endpoint) -> Result<()> {
-        let backlog = self.get_backlog(addr).map_err(|_| {
+    fn push_incoming(
+        &self,
+        server_addr: &UnixSocketAddrBound,
+        client_addr: Option<UnixSocketAddrBound>,
+    ) -> Result<Endpoint> {
+        let backlog = self.get_backlog(server_addr).map_err(|_| {
             Error::with_message(
                 Errno::ECONNREFUSED,
                 "no socket is listened at the remote address",
             )
         })?;
 
-        backlog.push_incoming(endpoint)
+        backlog.push_incoming(client_addr)
     }
 
     fn remove_backlog(&self, addr: &UnixSocketAddrBound) {
@@ -160,14 +164,23 @@ impl Backlog {
         &self.addr
     }
 
-    fn push_incoming(&self, endpoint: Endpoint) -> Result<()> {
+    fn push_incoming(&self, client_addr: Option<UnixSocketAddrBound>) -> Result<Endpoint> {
         let mut endpoints = self.incoming_endpoints.lock();
+
         if endpoints.len() >= self.backlog.load(Ordering::Relaxed) {
-            return_errno_with_message!(Errno::ECONNREFUSED, "incoming_endpoints is full");
+            return_errno_with_message!(
+                Errno::ECONNREFUSED,
+                "the pending connection queue on the listening socket is full"
+            );
         }
-        endpoints.push_back(endpoint);
+
+        let (server_endpoint, client_endpoint) =
+            Endpoint::new_pair(Some(self.addr.clone()), client_addr);
+        endpoints.push_back(server_endpoint);
+
         self.pollee.add_events(IoEvents::IN);
-        Ok(())
+
+        Ok(client_endpoint)
     }
 
     fn pop_incoming(&self) -> Result<Endpoint> {
@@ -216,6 +229,9 @@ fn unregister_backlog(addr: &UnixSocketAddrBound) {
     BACKLOG_TABLE.remove_backlog(addr);
 }
 
-pub(super) fn push_incoming(remote_addr: &UnixSocketAddrBound, remote_end: Endpoint) -> Result<()> {
-    BACKLOG_TABLE.push_incoming(remote_addr, remote_end)
+pub(super) fn push_incoming(
+    server_addr: &UnixSocketAddrBound,
+    client_addr: Option<UnixSocketAddrBound>,
+) -> Result<Endpoint> {
+    BACKLOG_TABLE.push_incoming(server_addr, client_addr)
 }
diff --git a/test/apps/network/unix_err.c b/test/apps/network/unix_err.c
index 00aa4288..e6df2abd 100644
--- a/test/apps/network/unix_err.c
+++ b/test/apps/network/unix_err.c
@@ -83,18 +83,21 @@ static int sk_listen;
 static int sk_connected;
 static int sk_accepted;
 
-#define UNNAMED_ADDR \
-	((struct sockaddr_un){ .sun_family = AF_UNIX, .sun_path = "" })
+#define UNIX_ADDR(path) \
+	((struct sockaddr_un){ .sun_family = AF_UNIX, .sun_path = path })
+
+#define UNNAMED_ADDR UNIX_ADDR("")
 #define UNNAMED_ADDRLEN PATH_OFFSET
 
-#define BOUND_ADDR \
-	((struct sockaddr_un){ .sun_family = AF_UNIX, .sun_path = "//tmp/B0" })
+#define BOUND_ADDR UNIX_ADDR("//tmp/B0")
 #define BOUND_ADDRLEN (PATH_OFFSET + 9)
 
-#define LISTEN_ADDR \
-	((struct sockaddr_un){ .sun_family = AF_UNIX, .sun_path = "/tmp//L0" })
+#define LISTEN_ADDR UNIX_ADDR("/tmp//L0")
 #define LISTEN_ADDRLEN (PATH_OFFSET + 9)
 
+#define LISTEN_ADDR2 UNIX_ADDR("/tmp/L0")
+#define LISTEN_ADDRLEN2 (PATH_OFFSET + 8)
+
 FN_SETUP(unbound)
 {
 	sk_unbound = CHECK(socket(PF_UNIX, SOCK_STREAM, 0));
@@ -123,8 +126,8 @@ FN_SETUP(connected)
 {
 	sk_connected = CHECK(socket(PF_UNIX, SOCK_STREAM, 0));
 
-	CHECK(connect(sk_connected, (struct sockaddr *)&LISTEN_ADDR,
-		      LISTEN_ADDRLEN));
+	CHECK(connect(sk_connected, (struct sockaddr *)&LISTEN_ADDR2,
+		      LISTEN_ADDRLEN2));
 }
 END_SETUP()