Merged v4 of this into cifs-2.6.git for-next On Tue, Feb 28, 2017 at 12:40 PM, Aurelien Aptel <aaptel@xxxxxxxx> wrote: > This series of patch tries to implement the get_dfs_refer operation > for SMB2+. > > In SMB2+, DFS resolving is now done through an FSCTL (patch #7). The > relevant Microsoft specifications for this are: > > MS-SMB2: 3.2.4.20 Application Requests an IO Control Code Operation > MS-SMB2: 3.2.4.20.3 Application Requests DFS Referral Information > MS-SMB2: 3.2.5.14 Receiving an SMB2 IOCTL Response > MS-SMB2: 3.2.5.14.4 Handling a DFS Referral Information Response > > MS-DFSC: 2.2 Message Syntax (but really the whole document is useful) > > The DFS response payload however is identical. Patch #1 moves the > DFS response parsing out of SMB1 code and makes it work on any version > of SMB. > > DFS code has 2 "main" entry points: initial mounting and automount > (when a DFS link is accessed/traversed). > > When automounting, cifs.ko calls build_path_from_dentry() which only > makes treename-prefixed paths when the tcon has the > SMB_IN_DFS_SHARE. This flag is checked in tcon->Flags which is never > touched by SMB2 code as it sets tcon->share_flags on connexion. > > * CIFS requires to prefix all pathnames with the treename prefix when > connected to a DFS server, so the current build_path_from_dentry() > makes sense for CIFS. > * For SMB2+ it seems only the Create request requires the treename > prefix. Simply making the function check for both CIFS SMB2+ flag > for DFS to add a prefix does not work as the server has different > expectations about which packet can have/require a DFS pathname. > > Patch #2 adds build_path_from_dentry_optional_prefix() with an extra > bool arg to decide to prefix or not. The automount code path always > ask for it. Patch #6 modifies SMB2_open() to add the treename prefix > to the given path if the server requires it. > > We try to use an IPC connection first for the DFS request. Patch #3 > adds a flag to SMB2_ioctl() to force the usage of ipc_tid. The SMB2 > get_dfs_refer operation tries with the flag set and fallback to a > share connection if that doesn't work. > > Patch #4 updates the type of ipc_tid from u16 to u32 as that is what a > Tid is in SMB2+. This is correct and really needed since in SMB2 Samba > doesn't use sequential tree id but random ones in the 32bit space. > > As part of the mouting process a IPC tcon is made (I suspect we don't > need it anymore in SMB3). This tcon doesn't respect the signing > requirement. This is fixed by patch #5. > > Finally the SMB2+ implementation of the get_dfs_referral operation is > added in all supported SMB versions in patch #7. > > I've sucessfuly tested this (v1.0 and v3.0) against a Windows Server > 2016 DFS setup and a Samba DFS setup. > > Samba used to only accepts DFS referrals requests on an IPC connexion, > which is in violation of the spec. A patch was sent on samba-technical > and merged. It is not required anymore. > > https://lists.samba.org/archive/samba-technical/2017-February/118859.html > > Changes since v2: > > * add use_ipc flag to SMB2_open() > * make smb2_get_dfs_refer() try IPC connections first > * use first_entry_or_null() instead of first_entry() on the tcon list > * protect tcon list access with spinlock > * add inc/dec of the tcon reference number, protected by spinlock > > Aurelien Aptel (7): > CIFS: move DFS response parsing out of SMB1 code > CIFS: add build_path_from_dentry_optional_prefix() > CIFS: add use_ipc flag to SMB2_ioctl() > CIFS: let ses->ipc_tid hold smb2 TreeIds > CIFS: set signing flag in SMB2+ TreeConnect if needed > CIFS: use DFS pathnames in SMB2+ Create requests > CIFS: implement get_dfs_refer for SMB2+ > > fs/cifs/cifs_dfs_ref.c | 4 +- > fs/cifs/cifsglob.h | 2 +- > fs/cifs/cifspdu.h | 16 ++++--- > fs/cifs/cifsproto.h | 7 +++ > fs/cifs/cifssmb.c | 119 ++--------------------------------------------- > fs/cifs/dir.c | 13 +++++- > fs/cifs/misc.c | 105 +++++++++++++++++++++++++++++++++++++++++ > fs/cifs/smb2file.c | 3 +- > fs/cifs/smb2ops.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++--- > fs/cifs/smb2pdu.c | 114 +++++++++++++++++++++++++++++++++++++-------- > fs/cifs/smb2pdu.h | 8 ++++ > fs/cifs/smb2proto.h | 3 +- > 12 files changed, 365 insertions(+), 152 deletions(-) > > -- > 2.10.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
