Re: [PATCH] Print sec=<type> in /proc/mounts if not set from cmdline.

[Kenneth Dsouza <kdsouza@redhat.com>]

Will send out a v2 patch to print Security type in /proc/fs/cifs/DebugData
This would help end users to know with what security type the share is mounted.

Example:
# cat /proc/fs/cifs/DebugData | grep -w "Security type"
1) Name: x.x.x.x Uses: 1 Capability: 0x8001f3fc    Session Status: 1
Security type: RawNTLMSSP

On Wed, Jun 3, 2020 at 10:40 AM Steve French <smfrench@gmail.com> wrote:
>
> This is a good point. Iit can be helpful to see if we defaulted to
> krb5 or ntlmssp in a particular mount - but printing sectype in mount
> options when it is "Default" (ie unspecified) may be confusing.
>
> I prefer that you change this to simply print KRB5 or NTLMSSP in
> /proc/fs/cifs/DebugData so we know what is negotiated.
> We already include whether "signed" or "sealed" (encrypted) and
> whether "guest" or whether "anonymous" etc. so could add whether
> NTLMSSP or KRB5 around line 368 of cifs_debug.c
> e.g. after
>                                 if (ses->session_flags &
> SMB2_SESSION_FLAG_IS_GUEST)
>                                         seq_printf(m, "Guest\t");
>                                 else if (ses->session_flags &
> SMB2_SESSION_FLAG_IS_NULL)
>                                         seq_printf(m, "Anonymous\t");
>
> Probably easiest to check the values of server->sec_mskerberos vs.
> server->sec_kerberosu2u vs. server->sec_ntlmssp and print it to
> /proc/fs/cifs/DebugData
>
> It is more helpful to show in /proc/mounts what we actually passed in
> on mount (or the default if not passed in in some cases can be shown)
> - while /proc/fs/cifs/DebugData shows more information about what was
> negotiated (not just encryption and signing but number of credits
> etc.) - seems better to put this in /proc/fs/cifs/DebugData
>
> On Tue, Jun 2, 2020 at 9:32 AM Kenneth D'souza <kdsouza@redhat.com> wrote:
> >
> > Currently the end user is unaware with what sec type the
> > cifs share is mounted if no sec=<type> option is parsed.
> >
> > Example:
> > $ echo 0x3 > /proc/fs/cifs/SecurityFlags
> >
> > Mount a cifs share with vers=1.0, it should pick sec=ntlm.
> > If mount is successful we print sec=ntlm
> >
> > //smb-server/data /cifs cifs rw,relatime,vers=1.0,sec=ntlm,cache=strict,username=testuser,uid=0,noforceuid,gid=0,noforcegid,addr=x.x.x.x,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=61440,wsize=16580,bsize=1048576,echo_interval=60,actimeo=1
> >
> > Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
> > Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
> > ---
> >  fs/cifs/sess.c    | 1 +
> >  fs/cifs/smb2pdu.c | 1 +
> >  2 files changed, 2 insertions(+)
> >
> > diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
> > index 43a88e26d26b..a5673fcab2f7 100644
> > --- a/fs/cifs/sess.c
> > +++ b/fs/cifs/sess.c
> > @@ -1698,6 +1698,7 @@ static int select_sec(struct cifs_ses *ses, struct sess_data *sess_data)
> >                 return -ENOSYS;
> >         }
> >
> > +       ses->sectype = type;
> >         return 0;
> >  }
> >
> > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> > index b30aa3cdd845..bce8a0137fa4 100644
> > --- a/fs/cifs/smb2pdu.c
> > +++ b/fs/cifs/smb2pdu.c
> > @@ -1601,6 +1601,7 @@ SMB2_select_sec(struct cifs_ses *ses, struct SMB2_sess_data *sess_data)
> >                 return -EOPNOTSUPP;
> >         }
> >
> > +       ses->sectype = type;
> >         return 0;
> >  }
> >
> > --
> > 2.21.1
> >
>
>
> --
> Thanks,
>
> Steve
>