From patchwork Thu Mar 22 04:23:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronnie Sahlberg X-Patchwork-Id: 10300857 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 281FE600F6 for ; Thu, 22 Mar 2018 04:25:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15D0B298C6 for ; Thu, 22 Mar 2018 04:25:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0A9E4298E9; Thu, 22 Mar 2018 04:25:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA181298C6 for ; Thu, 22 Mar 2018 04:25:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751943AbeCVEZb (ORCPT ); Thu, 22 Mar 2018 00:25:31 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45380 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751848AbeCVEZb (ORCPT ); Thu, 22 Mar 2018 00:25:31 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B341C4023457; Thu, 22 Mar 2018 04:25:30 +0000 (UTC) Received: from test1190.test.redhat.com (vpn2-54-110.bne.redhat.com [10.64.54.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id F3BC52166BB2; Thu, 22 Mar 2018 04:25:28 +0000 (UTC) From: Ronnie Sahlberg To: linux-cifs Cc: Steve French Subject: [PATCH 01/16] cifs: add server->vals->header_preamble_size Date: Thu, 22 Mar 2018 15:23:52 +1100 Message-Id: <20180322042407.7599-2-lsahlber@redhat.com> In-Reply-To: <20180322042407.7599-1-lsahlber@redhat.com> References: <20180322042407.7599-1-lsahlber@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 22 Mar 2018 04:25:30 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 22 Mar 2018 04:25:30 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lsahlber@redhat.com' RCPT:'' Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This variable is set to 4 for all protocol versions and replaces the hardcoded constant 4 throughought the code. This will later be updated to reflect whether a response packet has a 4 byte length preamble or not once we start removing this field from the SMB2+ dialects. Signed-off-by: Ronnie Sahlberg --- fs/cifs/cifsglob.h | 1 + fs/cifs/cifssmb.c | 6 ++++-- fs/cifs/connect.c | 16 ++++++++++----- fs/cifs/smb1ops.c | 1 + fs/cifs/smb2misc.c | 17 ++++++++-------- fs/cifs/smb2ops.c | 57 +++++++++++++++++++++++++++++++++-------------------- fs/cifs/transport.c | 3 ++- 7 files changed, 64 insertions(+), 37 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index c294093f04d5..3e3f86841372 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -468,6 +468,7 @@ struct smb_version_values { __u32 exclusive_lock_type; __u32 shared_lock_type; __u32 unlock_lock_type; + size_t header_preamble_size; size_t header_size; size_t max_header_size; size_t read_rsp_size; diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 9ceebf30eb22..59c09a596c0a 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -1454,7 +1454,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) unsigned int data_offset, data_len; struct cifs_readdata *rdata = mid->callback_data; char *buf = server->smallbuf; - unsigned int buflen = get_rfc1002_length(buf) + 4; + unsigned int buflen = get_rfc1002_length(buf) + + server->vals->header_preamble_size; bool use_rdma_mr = false; cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n", @@ -1504,7 +1505,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) return cifs_readv_discard(server, mid); } - data_offset = server->ops->read_data_offset(buf) + 4; + data_offset = server->ops->read_data_offset(buf) + + server->vals->header_preamble_size; if (data_offset < server->total_read) { /* * win2k8 sometimes sends an offset of 0 when the read diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index a726f524fb84..1f2e3b15b2b1 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -775,7 +775,8 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid) unsigned int pdu_length = get_rfc1002_length(buf); /* make sure this will fit in a large buffer */ - if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) - 4) { + if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) - + server->vals->header_preamble_size) { cifs_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length); cifs_reconnect(server); wake_up(&server->response_q); @@ -791,7 +792,9 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid) /* now read the rest */ length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1, - pdu_length - HEADER_SIZE(server) + 1 + 4); + pdu_length - HEADER_SIZE(server) + 1 + + server->vals->header_preamble_size); + if (length < 0) return length; server->total_read += length; @@ -884,7 +887,8 @@ cifs_demultiplex_thread(void *p) continue; /* make sure we have enough to get to the MID */ - if (pdu_length < HEADER_SIZE(server) - 1 - 4) { + if (pdu_length < HEADER_SIZE(server) - 1 - + server->vals->header_preamble_size) { cifs_dbg(VFS, "SMB response too short (%u bytes)\n", pdu_length); cifs_reconnect(server); @@ -893,8 +897,10 @@ cifs_demultiplex_thread(void *p) } /* read down to the MID */ - length = cifs_read_from_socket(server, buf + 4, - HEADER_SIZE(server) - 1 - 4); + length = cifs_read_from_socket(server, + buf + server->vals->header_preamble_size, + HEADER_SIZE(server) - 1 + - server->vals->header_preamble_size); if (length < 0) continue; server->total_read += length; diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index 3d495e440c87..aff8ce8ba34d 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -1122,6 +1122,7 @@ struct smb_version_values smb1_values = { .exclusive_lock_type = 0, .shared_lock_type = LOCKING_ANDX_SHARED_LOCK, .unlock_lock_type = 0, + .header_preamble_size = 4, .header_size = sizeof(struct smb_hdr), .max_header_size = MAX_CIFS_HDR_SIZE, .read_rsp_size = sizeof(READ_RSP), diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index da012c3ab700..566871185b98 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -150,7 +150,8 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) } return 1; } - if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) { + if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - + srvr->vals->header_preamble_size) { cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n", mid); return 1; @@ -189,17 +190,17 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) } } - if (4 + len != length) { + if (srvr->vals->header_preamble_size + len != length) { cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n", - length, 4 + len, mid); + length, srvr->vals->header_preamble_size + len, mid); return 1; } clc_len = smb2_calc_size(hdr); - if (4 + len != clc_len) { + if (srvr->vals->header_preamble_size + len != clc_len) { cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n", - clc_len, 4 + len, mid); + clc_len, srvr->vals->header_preamble_size + len, mid); /* create failed on symlink */ if (command == SMB2_CREATE_HE && shdr->Status == STATUS_STOPPED_ON_SYMLINK) @@ -208,7 +209,7 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE) return 0; /* server can return one byte more due to implied bcc[0] */ - if (clc_len == 4 + len + 1) + if (clc_len == srvr->vals->header_preamble_size + len + 1) return 0; /* @@ -218,10 +219,10 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) * Log the server error (once), but allow it and continue * since the frame is parseable. */ - if (clc_len < 4 /* RFC1001 header size */ + len) { + if (clc_len < srvr->vals->header_preamble_size /* RFC1001 header size */ + len) { printk_once(KERN_WARNING "SMB2 server sent bad RFC1001 len %d not %d\n", - len, clc_len - 4); + len, clc_len - srvr->vals->header_preamble_size); return 0; } diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index dfd6fb02b7a3..09d3a2912869 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -1457,6 +1457,8 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, unsigned int sub_offset; unsigned int print_len; unsigned int print_offset; + struct cifs_ses *ses = tcon->ses; + struct TCP_Server_Info *server = ses->server; cifs_dbg(FYI, "%s: path: %s\n", __func__, full_path); @@ -1479,7 +1481,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, } if (le32_to_cpu(err_buf->ByteCount) < sizeof(struct smb2_symlink_err_rsp) || - get_rfc1002_length(err_buf) + 4 < SMB2_SYMLINK_STRUCT_SIZE) { + get_rfc1002_length(err_buf) + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE) { kfree(utf16_path); return -ENOENT; } @@ -1492,13 +1494,13 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, print_len = le16_to_cpu(symlink->PrintNameLength); print_offset = le16_to_cpu(symlink->PrintNameOffset); - if (get_rfc1002_length(err_buf) + 4 < + if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE + sub_offset + sub_len) { kfree(utf16_path); return -ENOENT; } - if (get_rfc1002_length(err_buf) + 4 < + if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE + print_offset + print_len) { kfree(utf16_path); return -ENOENT; @@ -2050,7 +2052,8 @@ smb2_dir_needs_close(struct cifsFileInfo *cfile) } static void -fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq) +fill_transform_hdr(struct TCP_Server_Info *server, + struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq) { struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)old_rq->rq_iov[1].iov_base; @@ -2062,7 +2065,7 @@ fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq) tr_hdr->Flags = cpu_to_le16(0x01); get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CMM_NONCE); memcpy(&tr_hdr->SessionId, &shdr->SessionId, 8); - inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - 4); + inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - server->vals->header_preamble_size); inc_rfc1001_len(tr_hdr, orig_len); } @@ -2262,7 +2265,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq, goto err_free_iov; /* fill the 1st iov with a transform header */ - fill_transform_hdr(tr_hdr, old_rq); + fill_transform_hdr(server, tr_hdr, old_rq); new_rq->rq_iov[0].iov_base = tr_hdr; new_rq->rq_iov[0].iov_len = sizeof(struct smb2_transform_hdr); @@ -2344,10 +2347,10 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf, if (rc) return rc; - memmove(buf + 4, iov[1].iov_base, buf_data_size); + memmove(buf + server->vals->header_preamble_size, iov[1].iov_base, buf_data_size); hdr = (struct smb2_hdr *)buf; hdr->smb2_buf_length = cpu_to_be32(buf_data_size + page_data_size); - server->total_read = buf_data_size + page_data_size + 4; + server->total_read = buf_data_size + page_data_size + server->vals->header_preamble_size; return rc; } @@ -2451,7 +2454,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid, return 0; } - data_offset = server->ops->read_data_offset(buf) + 4; + data_offset = server->ops->read_data_offset(buf) + server->vals->header_preamble_size; #ifdef CONFIG_CIFS_SMB_DIRECT use_rdma_mr = rdata->mr; #endif @@ -2547,11 +2550,12 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid) unsigned int npages; struct page **pages; unsigned int len; - unsigned int buflen = get_rfc1002_length(buf) + 4; + unsigned int buflen = get_rfc1002_length(buf) + server->vals->header_preamble_size; int rc; int i = 0; - len = min_t(unsigned int, buflen, server->vals->read_rsp_size - 4 + + len = min_t(unsigned int, buflen, server->vals->read_rsp_size - + server->vals->header_preamble_size + sizeof(struct smb2_transform_hdr)) - HEADER_SIZE(server) + 1; rc = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1, len); @@ -2559,8 +2563,9 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid) return rc; server->total_read += rc; - len = le32_to_cpu(tr_hdr->OriginalMessageSize) + 4 - - server->vals->read_rsp_size; + len = le32_to_cpu(tr_hdr->OriginalMessageSize) + + server->vals->header_preamble_size - + server->vals->read_rsp_size; npages = DIV_ROUND_UP(len, PAGE_SIZE); pages = kmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); @@ -2586,7 +2591,8 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid) if (rc) goto free_pages; - rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size - 4, + rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size - + server->vals->header_preamble_size, pages, npages, len); if (rc) goto free_pages; @@ -2623,7 +2629,7 @@ receive_encrypted_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid_entry; /* switch to large buffer if too big for a small one */ - if (pdu_length + 4 > MAX_CIFS_SMALL_BUFFER_SIZE) { + if (pdu_length + server->vals->header_preamble_size > MAX_CIFS_SMALL_BUFFER_SIZE) { server->large_buf = true; memcpy(server->bigbuf, buf, server->total_read); buf = server->bigbuf; @@ -2631,12 +2637,13 @@ receive_encrypted_standard(struct TCP_Server_Info *server, /* now read the rest */ length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1, - pdu_length - HEADER_SIZE(server) + 1 + 4); + pdu_length - HEADER_SIZE(server) + 1 + + server->vals->header_preamble_size); if (length < 0) return length; server->total_read += length; - buf_size = pdu_length + 4 - sizeof(struct smb2_transform_hdr); + buf_size = pdu_length + server->vals->header_preamble_size - sizeof(struct smb2_transform_hdr); length = decrypt_raw_data(server, buf, buf_size, NULL, 0, 0); if (length) return length; @@ -2665,7 +2672,7 @@ smb3_receive_transform(struct TCP_Server_Info *server, struct mid_q_entry **mid) struct smb2_transform_hdr *tr_hdr = (struct smb2_transform_hdr *)buf; unsigned int orig_len = le32_to_cpu(tr_hdr->OriginalMessageSize); - if (pdu_length + 4 < sizeof(struct smb2_transform_hdr) + + if (pdu_length + server->vals->header_preamble_size < sizeof(struct smb2_transform_hdr) + sizeof(struct smb2_sync_hdr)) { cifs_dbg(VFS, "Transform message is too small (%u)\n", pdu_length); @@ -2674,14 +2681,14 @@ smb3_receive_transform(struct TCP_Server_Info *server, struct mid_q_entry **mid) return -ECONNABORTED; } - if (pdu_length + 4 < orig_len + sizeof(struct smb2_transform_hdr)) { + if (pdu_length + server->vals->header_preamble_size < orig_len + sizeof(struct smb2_transform_hdr)) { cifs_dbg(VFS, "Transform message is broken\n"); cifs_reconnect(server); wake_up(&server->response_q); return -ECONNABORTED; } - if (pdu_length + 4 > CIFSMaxBufSize + MAX_HEADER_SIZE(server)) + if (pdu_length + server->vals->header_preamble_size > CIFSMaxBufSize + MAX_HEADER_SIZE(server)) return receive_encrypted_read(server, mid); return receive_encrypted_standard(server, mid); @@ -2692,7 +2699,8 @@ smb3_handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid) { char *buf = server->large_buf ? server->bigbuf : server->smallbuf; - return handle_read_data(server, mid, buf, get_rfc1002_length(buf) + 4, + return handle_read_data(server, mid, buf, get_rfc1002_length(buf) + + server->vals->header_preamble_size, NULL, 0, 0); } @@ -3097,6 +3105,7 @@ struct smb_version_values smb20_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, @@ -3117,6 +3126,7 @@ struct smb_version_values smb21_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, @@ -3137,6 +3147,7 @@ struct smb_version_values smb3any_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, @@ -3157,6 +3168,7 @@ struct smb_version_values smbdefault_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, @@ -3177,6 +3189,7 @@ struct smb_version_values smb30_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, @@ -3197,6 +3210,7 @@ struct smb_version_values smb302_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, @@ -3218,6 +3232,7 @@ struct smb_version_values smb311_values = { .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, .unlock_lock_type = SMB2_LOCKFLAG_UNLOCK, .header_size = sizeof(struct smb2_hdr), + .header_preamble_size = 4, .max_header_size = MAX_SMB2_HDR_SIZE, .read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .lock_cmd = SMB2_LOCK, diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 665661464067..279718dcb2ed 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -790,7 +790,8 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses, buf = (char *)midQ->resp_buf; resp_iov->iov_base = buf; - resp_iov->iov_len = get_rfc1002_length(buf) + 4; + resp_iov->iov_len = get_rfc1002_length(buf) + + ses->server->vals->header_preamble_size; if (midQ->large_buf) *resp_buf_type = CIFS_LARGE_BUFFER; else