[linux-cifs-client] [patch][linux-cifs] login as anonymous for -o guest option

[Steve French]

ACKing Jeff's points

On Thu, Feb 19, 2009 at 5:54 PM, Jeff Layton <jlayton at redhat.com> wrote:
> On Thu, 19 Feb 2009 10:51:29 -0600
> Shirish Pargaonkar <shirishpargaonkar at gmail.com> wrote:
>
>> On Wed, Feb 18, 2009 at 3:07 PM, Jeff Layton <jlayton at redhat.com> wrote:
>> > On Wed, 18 Feb 2009 14:47:16 -0600
>> > Shirish Pargaonkar <shirishpargaonkar at gmail.com> wrote:
>> >
>> >> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
>> >> index d6a3c1c..dc05bf9 100644
>> >> --- a/fs/cifs/connect.c
>> >> +++ b/fs/cifs/connect.c
>> >> @@ -69,6 +69,7 @@ struct smb_vol {
>> >>       mode_t file_mode;
>> >>       mode_t dir_mode;
>> >>       unsigned secFlg;
>> >> +     unsigned guest;
>> >>       bool rw:1;
>> >>       bool retry:1;
>> >>       bool intr:1;
>> >> @@ -1183,7 +1184,7 @@ cifs_parse_mount_options(char *options,
>> >>               } else if (strnicmp(data, "version", 3) == 0) {
>> >>                       /* ignore */
>> >>               } else if (strnicmp(data, "guest", 5) == 0) {
>> >> -                     /* ignore */
>> >> +                     vol->guest = true;
>> >>               } else if (strnicmp(data, "rw", 2) == 0) {
>> >>                       vol->rw = true;
>> >>               } else if (strnicmp(data, "noblocksend", 11) == 0) {
>> >> @@ -2266,6 +2267,13 @@ cifs_mount(struct super_block *sb, struc
>> >>               list_add(&pSesInfo->smb_ses_list, &srvTcp->smb_ses_list);
>> >>               write_unlock(&cifs_tcp_ses_lock);
>> >>
>> >> +             if (volume_info->guest) {
>> >> +                     volume_info->guest = false;
>> >> +                     volume_info->username = NULL;
>> >> +                     volume_info->password = NULL;
>> >> +                     strcpy(pSesInfo->userName, ""); /* anonymous user */
>> >> +             }
>> >> +
>> >>               /* volume_info->password freed at unmount */
>> >>               if (volume_info->password) {
>> >>                       pSesInfo->password = volume_info->password;
>> >
>> > We already have the ability to do a guest login. You just send a blank
>> > user= option and that just ensures that volume_info->nullauth gets
>> > set. A better scheme to me would be to have mount.cifs just turn the
>> > username into an empty string. It seems like that should do what you
>> > want...
>> >
>> > --
>> > Jeff Layton <jlayton at redhat.com>
>> >
>>
>> Jeff,
>>
>> -o user=
>>
>> would prompt you for a password.  -o guest is not supposed to.
>>
>
> mount.cifs is what prompts you for the password. I'm simply suggesting
> that if "guest" is specified that we don't prompt for a password and
> send the "user=" option in such a way that you get an anonymous login.
> That should give you the effect you want without needing to add any
> more stuff to the option parsing code in the kernel.
>
> My main point is that we already have code to handle guest logins in
> the kernel -- that's what the "nullauth" thing is all about. If you're
> going to add something like this, then that should probably be ripped
> out.
>
> PS: setting username=NULL may be problematic as well. I made that
> change at one point (maybe when I did some changes for sec=none ?). It
> led to oopses and I had to revert it. If you want to do that, it's fine
> but you'll need to make sure that nothing assumes that it's a valid
> pointer.
>
> --
> Jeff Layton <jlayton at redhat.com>
>



-- 
Thanks,

Steve