• Aurelien Aptel's avatar
    cifs: try opening channels after mounting · d70e9fa5
    Aurelien Aptel authored
    After doing mount() successfully we call cifs_try_adding_channels()
    which will open as many channels as it can.
    
    Channels are closed when the master session is closed.
    
    The master connection becomes the first channel.
    
    ,-------------> global cifs_tcp_ses_list <-------------------------.
    |                                                                  |
    '- TCP_Server_Info  <-->  TCP_Server_Info  <-->  TCP_Server_Info <-'
          (master con)           (chan#1 con)         (chan#2 con)
          |      ^                    ^                    ^
          v      '--------------------|--------------------'
       cifs_ses                       |
       - chan_count = 3               |
       - chans[] ---------------------'
       - smb3signingkey[]
          (master signing key)
    
    Note how channel connections don't have sessions. That's because
    cifs_ses can only be part of one linked list (list_head are internal
    to the elements).
    
    For signing keys, each channel has its own signing key which must be
    used only after the channel has been bound. While it's binding it must
    use the master session signing key.
    
    For encryption keys, since channel connections do not have sessions
    attached we must now find matching session by looping over all sessions
    in smb2_get_enc_key().
    
    Each channel is opened like a regular server connection but at the
    session setup request step it must set the
    SMB2_SESSION_REQ_FLAG_BINDING flag and use the session id to bind to.
    
    Finally, while sending in compound_send_recv() for requests that
    aren't negprot, ses-setup or binding related, use a channel by cycling
    through the available ones (round-robin).
    Signed-off-by: default avatarAurelien Aptel <aaptel@suse.com>
    Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
    d70e9fa5
smb2misc.c 25.2 KB