@fpaquet - thank you for an excellent fault report.

If you're in a position where you can take a patch, this will fix it for you:-

--- a/sesman/scp_process.c
+++ b/sesman/scp_process.c
@@ -102,6 +102,14 @@ process_sys_login_request(struct pre_session_item *psi)
         }
         else
         {
+            /*
+             * Copy the IP address of the requesting user, anticipating a
+             * successful login. We need this so we can search for a session
+             * with a matching IP address if required.
+             */
+            g_snprintf(psi->start_ip_addr, sizeof(psi->start_ip_addr),
+                       "%s", ip_addr);
+
             /* Create a sesexec process to handle the login
              *
              * We won't check for the user being valid here, as this might

After you've had to spend so much time on this, I feel I owe you an explanation.

The basic explanation, is that I omitted to initialise this field, so not being able to find where it is initialised is not surprising!

The more detailed explanation needs an understanding of the Session Management Architecture

The IP address for a login attempt is passed from sesman to sesexec when the user is authenticated. This IP address is received back from sesexec via a 'session announce' event, and this is used to populate the session entry. This is a little convoluted, but it's there to support sesman restarts in the future. The idea is that when sesman restarts, all the sesexec processes send a session announce event to sesman, and sesman is able to reconstruct its state.

At the moment though, this isn't implemented.

If you can't take a patch, I'll add a PR here and we'll get this in the next xrdp release. Being on EPEL, you will get this when we release it.

Hello Matt
Great to hear you found and fixed it so quickly.

For the time being, we can live with installing the old xrdp-0.9.25-2.el8.x86_64.rpm on RHEL8,
downloaded from https://rpm.pbone.net/info_idpl_85646712_distro_redhatel8_com_xrdp-0.9.25-2.el8.x86_64.rpm.html
(the link maybe helpful for others)

We'll give it a try when new release is out.

The new feature seams very useful to us, to prevent lost sessions when restarting sesman.
Super!

I'll keep this open for now, so I don't lose track of it...

Hello Matt
While switching to the Workaround with xrdp 0.9.25, we found a bug in the Policy comment.
The quotes around the policy string shoud be removed in the comment, in sesman.ini

;; Policy - session allocation policy
; Type: enum [ "Default" | "UBD" | "UBI" | "UBC" | "UBDI" | "UBDC" ]
; "Default" session per <User,BitPerPixel>
; "UBD" session per <User,BitPerPixel,DisplaySize>
; "UBI" session per <User,BitPerPixel,IPAddr>
; "UBC" session per <User,BitPerPixel,Connection>
; "UBDI" session per <User,BitPerPixel,DisplaySize,IPAddr>
; "UBDC" session per <User,BitPerPixel,DisplaySize,Connection>

Using the following setting fails:
Policy="UBDI"

Using this setting is very successful:
Policy=UBDI

regards
fp

Thanks for raising this @fpaquet