Won't this need to be undone for multichannel support? The client GUID needs to be the same when connecting multiple channels, a different one will break cross-channel replay detection. It's definitely true that if you intend to negotiate a different dialect, then the client GUID should not be reused. > -----Original Message----- > From: linux-cifs-owner@xxxxxxxxxxxxxxx [mailto:linux-cifs- > owner@xxxxxxxxxxxxxxx] On Behalf Of Steve French > Sent: Tuesday, May 13, 2014 10:49 PM > To: Sachin Prabhu > Cc: linux-cifs > Subject: Re: [PATCH] cifs: Set client guid on per connection basis > > merged into cifs-2.6.git for-next > > but added an additional patch to fix the problem where we are sending a > non-zero ClientGUID for SMB2.02 dialect (where it MUST be zero according > to MS-SMB2, it is non-zero starting in SMB2.1) > > On Tue, May 13, 2014 at 1:48 AM, Sachin Prabhu <sprabhu@xxxxxxxxxx> > wrote: > > When mounting from a Windows 2012R2 server, we hit the following > > problem: > > 1) Mount with any of the following versions - 2.0, 2.1 or 3.0 > > 2) unmount > > 3) Attempt a mount again using a different SMB version >= 2.0. > > > > You end up with the following failure: > > Status code returned 0xc0000203 STATUS_USER_SESSION_DELETED CIFS > VFS: > > Send error in SessSetup = -5 CIFS VFS: cifs_mount failed w/return code > > = -5 > > > > I cannot reproduce this issue using a Windows 2008 R2 server. > > > > This appears to be caused because we use the same client guid for the > > connection on first mount which we then disconnect and attempt to > > mount again using a different protocol version. By generating a new > > guid each time a new connection is Negotiated, we avoid hitting this > problem. > > > > Signed-off-by: Sachin Prabhu <sprabhu@xxxxxxxxxx> > > --- > > fs/cifs/cifsfs.c | 8 -------- > > fs/cifs/cifsglob.h | 1 + > > fs/cifs/connect.c | 3 +++ > > fs/cifs/smb2pdu.c | 5 +++-- > > fs/cifs/smb2pdu.h | 2 -- > > 5 files changed, 7 insertions(+), 12 deletions(-) > > > > diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index > > 5be1f99..c80aa5a 100644 > > --- a/fs/cifs/cifsfs.c > > +++ b/fs/cifs/cifsfs.c > > @@ -87,10 +87,6 @@ extern mempool_t *cifs_mid_poolp; > > > > struct workqueue_struct *cifsiod_wq; > > > > -#ifdef CONFIG_CIFS_SMB2 > > -__u8 cifs_client_guid[SMB2_CLIENT_GUID_SIZE]; > > -#endif > > - > > /* > > * Bumps refcount for cifs super block. > > * Note that it should be only called if a referece to VFS super > > block is @@ -1192,10 +1188,6 @@ init_cifs(void) > > spin_lock_init(&cifs_file_list_lock); > > spin_lock_init(&GlobalMid_Lock); > > > > -#ifdef CONFIG_CIFS_SMB2 > > - get_random_bytes(cifs_client_guid, SMB2_CLIENT_GUID_SIZE); > > -#endif > > - > > if (cifs_max_pending < 2) { > > cifs_max_pending = 2; > > cifs_dbg(FYI, "cifs_max_pending set to min of 2\n"); > > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index > > 30f6e92..f74edd2 100644 > > --- a/fs/cifs/cifsglob.h > > +++ b/fs/cifs/cifsglob.h > > @@ -559,6 +559,7 @@ struct TCP_Server_Info { > > int echo_credits; /* echo reserved slots */ > > int oplock_credits; /* oplock break reserved slots */ > > bool echoes:1; /* enable echoes */ > > + __u8 client_guid[SMB2_CLIENT_GUID_SIZE]; /* Client GUID */ > > #endif > > u16 dialect; /* dialect index that server chose */ > > bool oplocks:1; /* enable oplocks */ diff --git > > a/fs/cifs/connect.c b/fs/cifs/connect.c index 8813ff7..8b8fe9b 100644 > > --- a/fs/cifs/connect.c > > +++ b/fs/cifs/connect.c > > @@ -2144,6 +2144,9 @@ cifs_get_tcp_session(struct smb_vol > *volume_info) > > sizeof(tcp_ses->srcaddr)); > > memcpy(&tcp_ses->dstaddr, &volume_info->dstaddr, > > sizeof(tcp_ses->dstaddr)); > > +#ifdef CONFIG_CIFS_SMB2 > > + get_random_bytes(tcp_ses->client_guid, SMB2_CLIENT_GUID_SIZE); > > +#endif > > /* > > * at this point we are the only ones with the pointer > > * to the struct since the kernel thread not created yet diff > > --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 3802f8c..dc44610 > > 100644 > > --- a/fs/cifs/smb2pdu.c > > +++ b/fs/cifs/smb2pdu.c > > @@ -375,7 +375,7 @@ SMB2_negotiate(const unsigned int xid, struct > > cifs_ses *ses) > > > > req->Capabilities = > > cpu_to_le32(ses->server->vals->req_capabilities); > > > > - memcpy(req->ClientGUID, cifs_client_guid, > SMB2_CLIENT_GUID_SIZE); > > + memcpy(req->ClientGUID, server->client_guid, > > + SMB2_CLIENT_GUID_SIZE); > > > > iov[0].iov_base = (char *)req; > > /* 4 for rfc1002 length field */ @@ -478,7 +478,8 @@ int > > smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon > > *tcon) > > > > vneg_inbuf.Capabilities = > > cpu_to_le32(tcon->ses->server->vals->req_capabilities); > > - memcpy(vneg_inbuf.Guid, cifs_client_guid, > SMB2_CLIENT_GUID_SIZE); > > + memcpy(vneg_inbuf.Guid, tcon->ses->server->client_guid, > > + SMB2_CLIENT_GUID_SIZE); > > > > if (tcon->ses->sign) > > vneg_inbuf.SecurityMode = diff --git > > a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index 2022c54..743e11e 100644 > > --- a/fs/cifs/smb2pdu.h > > +++ b/fs/cifs/smb2pdu.h > > @@ -183,8 +183,6 @@ struct smb2_symlink_err_rsp { > > > > #define SMB2_CLIENT_GUID_SIZE 16 > > > > -extern __u8 cifs_client_guid[SMB2_CLIENT_GUID_SIZE]; > > - > > struct smb2_negotiate_req { > > struct smb2_hdr hdr; > > __le16 StructureSize; /* Must be 36 */ > > -- > > 1.8.4.2 > > > > -- > > 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 ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
