Set ietf-netconf-server idle-timeout to 0 will causes the client can not connected.([ERR]: LN: Session 2: Client <hello> timeout elapsed) libnetconf2 3.0.8

[starx1000]

Hi,
In Libnetconf2 version Version 3.0.8.

when add <idle-timeout>0</idle-timeout> setting to ietf-netconf-server the client can not be connected,
the server will always report
[ERR]: LN: Session 2: Client <hello> timeout elapsed.

the reason is that in

libnetconf2/src/session.c

Line 1484 in d44d328

timeout_io = server_opts.idle_timeout * 1000;

timeout_io used the same value for ietf-netconf-server's idle-timeout value, if the idle_timeout set to 0, this timeout_io == 0,
causes the r = nc_read_msg_poll_io(session, timeout_io, &msg); Return immediately and failed.

As according to ietf-netconf-server.yang , 0 should be supported for never drops inactive client session.

Can you please have a look for this?

Maybe we can change it like this?

  if(server_opts.idle_timeout ==0)
     timeout_io = 180 * 1000;  // 180 seconds default value
 else
     timeout_io = server_opts.idle_timeout * 1000;

or simply change to timeout_io = 180 * 1000; // 180 seconds default value ?
Will it block the server here forever if the client have no password action if set timeout_io to -1( permanent)?

References:

libnetconf2/modules/ietf-netconf-server@2023-12-28.yang

Line 452 in d44d328

leaf idle-timeout {

If set to zero, then the server
will never drop a session because it is idle.

      leaf idle-timeout {
        type uint16;
        units "seconds";
        default "180"; // three minutes
        description
          "Specifies the maximum number of seconds that a NETCONF
           session may remain idle. A NETCONF session will be
           dropped if it is idle for an interval longer than this
           number of seconds.  If set to zero, then the server
           will never drop a session because it is idle.";
      }

Detect session timeout:

libnetconf2/src/session_server.c

Line 1591 in d44d328

(now_mono >= session->opts.server.last_rpc + (unsigned) server_opts.idle_timeout)) {

XML configuration:

<netconf-server xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
    <listen>
        <idle-timeout>0</idle-timeout>
        <endpoints>
            <endpoint>
                <name>default-ssh</name>

[michalvasko]

Yes, 0 was not supported, fixed.

[starx1000]

OK, thank you