Re: [Qemu-devel] slirp smb with modern win guests when samba is also running on host

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2013-11-28 20:32, Michael Tokarev wrote:
> After numerous reports that -smb (or -netdev user,smb=foo) not working
> with modern windows (win7 and vista are reported as non-working), I
> started digging myself.  And found that indeed it doesn't work, and
> why.
> 
> The thing is that modern win tries to connect to port 445 (microsoft-ds)
> first, and if that fails, it falls back to old port 139 (netbios-ssn).
> 
> slirp code in qemu only redirects port 139, it does not touch port 445.
> 
> So the prob is that if samba is also running on the host, guest will try
> to communicate using port 445, and that will succed, but ofcourse guest
> will not talk with our samba but with samba running on the host.
> 
> If samba is not running on the host, guest will fall back to port 139,
> and will reach the redirecting rule and qemu will spawn smbd correctly.
> 
> The solution is to redirect both ports (139 and 445), and the fix is
> a one-liner, adding second call to slirp_add_exec() at the end of
> net/slirp.c:slirp_smb() function (provided below).
> 
> But it looks like that is not a proper fix really, since in theory
> we should redirect both ports to the SAME, single samba instance,
> but I'm not sure this is possible with slirp.  Well, even if two
> smbd processes will be run on the same config dir, it should not
> be a problem.

I don't see either that this is expressible with the current exec
feature of slirp.

> 
> The one-liner (not exactly 1 since it touches previous line too) is like
> this:
> 
> Signed-off-By: Michael Tokarev <mjt@tls.msk.ru>
> 
> diff --git a/net/slirp.c b/net/slirp.c
> index 124e953..a22e976 100644
> --- a/net/slirp.c
> +++ b/net/slirp.c
> @@ -549,7 +549,8 @@ static int slirp_smb(SlirpState* s, const char *exported_dir
>      snprintf(smb_cmdline, sizeof(smb_cmdline), "%s -s %s",
>               CONFIG_SMBD_COMMAND, smb_conf);
> 
> -    if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0) {
> +    if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0 ||
> +        slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 445) < 0) {
>          slirp_smb_cleanup(s);
>          error_report("conflicting/invalid smbserver address");
>          return -1;
> 

Thanks, merged to my slirp queue. Will send this out ASAP, sorry for the
excessive delay.

JAn

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