[PATCH] (partial) tevent_req_poll() loops for ever....

Stefan (metze) Metzmacher metze at samba.org
Sun May 17 08:36:03 GMT 2009


boyang schrieb:
> Volker Lendecke wrote:
>> On Mon, Apr 20, 2009 at 10:04:55AM -0600, Bo Yang wrote:
>>   
>>> Taking cm_connect_lsa() for example. Assuming network
>>> connectionis good initially, but when
>>> cli_rpc_pipe_open_spnego_ntlmssp() isinvoked, remote end
>>> is closed. So, it returnsNT_STATUS_BROKEN_PIPE(mapped from
>>> EPIPE). Then we go to schannel oranonymous, which makes no
>>> difference. Because the socket is brokennow(but fd is
>>> owned by current process, winbindd), the fd(socket)
>>> won'tbe writable or readable any more. Then have a look at
>>> whattevent_req_poll() does, req is always in progress,
>>> tevent_loop_once()--> s3_event_loop_once() ---> add the fd
>>> to select's writefds set---> select times out and returns
>>> 0. again and again,tevent_req_poll() loops forever........
>>>
>>> I think we should do a test after each rpc call to see if
>>> thestatus is BROKEN PIPE, if it is, we must close the
>>> socket and free allpipes. We must close socket first, and
>>> set cli->fd to -1. Otherwise,pipe's destructor will try to
>>> write to the fd, which causetevent_req_poll() loops
>>> forever. My previous patch to test ifcli->fd must be there
>>> to make this work, otherwise, winbindd justcrash in
>>> FD_SET(-1, &writefds)....
>>>     
>> Isn't it that we eventually end up in an smb request? What
>> happens if we close the fd at the right place?
>>
>> What about the attached patch?
>>   
> looks like it will work for name pipe and transport smbd. it won't work
> with ncacn_ip_tcp and ncalrpc.

Yes, the rpc layer needs it's own error handling, but for the smb layer
it's fine.

metze

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 252 bytes
Desc: OpenPGP digital signature
Url : http://lists.samba.org/archive/samba-technical/attachments/20090517/f5fb90c9/signature.bin


More information about the samba-technical mailing list