Merge "daemon: get peer pid, gid for socket connection on darwin" into main

doc/manual/rl-next/darwin-daemon-client-pid.md

@@ -0,0 +1,12 @@
+---
+synopsis: "Fetch peer PID for daemon connections on macOS"
+issues: [fj#640]
+cls: [2453]
+category: Fixes
+credits: [lilyball]
+---
+
+`nix-daemon` will now fetch the peer PID for connections on macOS, to match behavior with Linux.
+Besides showing up in the log output line, If `nix-daemon` is given an argument (such as `--daemon`)
+that argument will be overwritten with the peer PID for the forked process that handles the connection,
+which can be used for debugging purposes.

lix/nix/daemon.cc

@@ -188,7 +188,13 @@ static PeerInfo getPeerInfo(int remote)
     socklen_t credLen = sizeof(cred);
     if (getsockopt(remote, SOL_LOCAL, LOCAL_PEERCRED, &cred, &credLen) == -1)
         throw SysError("getting peer credentials");
-    peer = { false, 0, true, cred.cr_uid, false, 0 };
+    peer = { false, 0, true, cred.cr_uid, true, cred.cr_gid };
+
+#if defined(LOCAL_PEERPID)
+    socklen_t pidLen = sizeof(peer.pid);
+    if (!getsockopt(remote, SOL_LOCAL, LOCAL_PEERPID, &peer.pid, &pidLen))
+        peer.pidKnown = true;
+#endif
 
 #endif
 

misc/launchd/org.nixos.nix-daemon.plist.in

@@ -12,7 +12,7 @@
     <array>
       <string>/bin/sh</string>
       <string>-c</string>
-      <string>/bin/wait4path /nix/var/nix/profiles/default/bin/nix-daemon &amp;&amp; exec /nix/var/nix/profiles/default/bin/nix-daemon</string>
+      <string>/bin/wait4path /nix/var/nix/profiles/default/bin/nix-daemon &amp;&amp; exec /nix/var/nix/profiles/default/bin/nix-daemon --daemon</string>
     </array>
     <key>StandardErrorPath</key>
     <string>/var/log/nix-daemon.log</string>