Port knock of 445 prevents smbd from starting

[Jeremy Allison]

On Tue, Jan 14, 2020 at 10:08:27PM +0000, Christopher O Cowan - Christopher.O.Cowan--- via samba-technical wrote:
> Smbd -V says
> Version 4.12.0pre1-GIT-375ee2d8fee
> 
> I did a fetch this morning.     I have one patch from Amitay but that's for ctdb_recovery_helper.
> Which messages?

read_fd_with_timeout: blocking read. EOF from client.

matches,

but:

"receive_smb_raw_talloc failed for client" doesn't.

Should be "read_fd_with_timeout failed for client ".

being called inside receive_smb_raw_talloc_partial_read().

You should probably add some debugs to show the len value
returned from read_smb_length_return_keepalive() and
also the timeout being used.

> On 1/14/20, 3:56 PM, "Jeremy Allison" <jra at samba.org> wrote:
> 
>     On Tue, Jan 14, 2020 at 09:26:24PM +0000, Christopher O Cowan - Christopher.O.Cowan--- via samba-technical wrote:
>     > In our cluster setup here, we use a load-balancer in front of our ctdb cluster to steer the SMB traffic.
>     > We've been doing this for years.    It does a simple TCP connect on 445 to verify that each node's smbd is still alive.
>     > 
>     > This is all on AIX, and some time, in the past few weeks these knocks started causing smbd to exit.   Here's the output from an smbd -i -d10.
>     > 
>     > First I see this (x.y.z.219 is the address of the LB.  202 is the server).    I changed the addresses
>     > 
>     > -----------------------------------------------------------------------------------------------------------------------------------------
>     > 
>     > Allowed connection from x.y.z.219 (x.y.z.219)
>     > Connection allowed from ipv4:x.y.z.219:49463 to ipv4:x.y.z.202:445
>     > ctdbd_control: Sending ctdb packet reqid=7, vnn=4026531841, opcode=23, srvid=17509995351216488448
>     > ctdbd_control: Sending ctdb packet reqid=8, vnn=4026531841, opcode=44, srvid=0
>     > INFO: Current debug levels:
>     > -----------------------------------------------------------------------------------------------------------------------------------------
>     > Then after the debug settings, I see:
>     > -----------------------------------------------------------------------------------------------------------------------------------------
>     > init_oplocks: initializing messages.
>     > Registering messaging pointer for type 774 - private_data=20141c48
>     > Registering messaging pointer for type 778 - private_data=20141c48
>     > Registering messaging pointer for type 770 - private_data=20141c48
>     > Registering messaging pointer for type 787 - private_data=20141c48
>     > Registering messaging pointer for type 779 - private_data=20141c48
>     > Registering messaging pointer for type 15 - private_data=0
>     > Overriding messaging pointer for type 15 - private_data=0
>     > Deregistering messaging pointer for type 16 - private_data=0
>     > Registering messaging pointer for type 16 - private_data=20141c48
>     > Deregistering messaging pointer for type 33 - private_data=2011cf18
>     > Registering messaging pointer for type 33 - private_data=20141c48
>     > Deregistering messaging pointer for type 790 - private_data=0
>     > Registering messaging pointer for type 790 - private_data=20141c48
>     > Deregistering messaging pointer for type 791 - private_data=0
>     > Deregistering messaging pointer for type 1 - private_data=0
>     > Registering messaging pointer for type 1 - private_data=0
>     > event_add_idle: idle_evt(keepalive) 20203538
>     > event_add_idle: idle_evt(deadtime) 202040b8
>     > event_add_idle: idle_evt(housekeeping) 202041c8
>     > read_fd_with_timeout: blocking read. EOF from client.
>     > receive_smb_raw_talloc failed for client ipv4:x.y.z.219:49463 read error = NT_STATUS_END_OF_FILE.
>     
>     What version of Samba. These debug messages don't
>     quite match current master code.
>     
>