smbd: Move fcb_or_dos_open() out of open_file_ntcreate()

This is SMB1-only and pre-ntcreate with only 3 callers that look at
NTCREATEX_OPTIONS_PRIVATE_DENY_[DOS|FCB]. It is a bit less efficient
if it kicks in (we have to recreate the fsp), but SMB1 is less and
less popular, and this particular share mode combination from the
open&x family of calls might not be worth optimizing for.

This adds smb1_utils.[ch] as a kitchen sink for functions that can go
away once we drop SMB1.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

6 files changed, 207 insertions, 104 deletions

diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index ef73aa219ea..2ee4a2c4fca 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -21,6 +21,7 @@
 */
 
 #include "includes.h"
+#include "smb1_utils.h"
 #include "system/filesys.h"
 #include "lib/util/server_id.h"
 #include "printing.h"
@@ -2608,69 +2609,6 @@ static bool open_match_attributes(connection_struct *conn,
 	return True;
 }
 
-/****************************************************************************
- Special FCB or DOS processing in the case of a sharing violation.
- Try and find a duplicated file handle.
-****************************************************************************/
-
-static NTSTATUS fcb_or_dos_open(struct smb_request *req,
-				connection_struct *conn,
-				files_struct *fsp_to_dup_into,
-				const struct smb_filename *smb_fname,
-				struct file_id id,
-				uint16_t file_pid,
-				uint64_t vuid,
-				uint32_t access_mask,
-				uint32_t share_access,
-				uint32_t create_options)
-{
-	files_struct *fsp;
-
-	DEBUG(5,("fcb_or_dos_open: attempting old open semantics for "
-		 "file %s.\n", smb_fname_str_dbg(smb_fname)));
-
-	for(fsp = file_find_di_first(conn->sconn, id); fsp;
-	    fsp = file_find_di_next(fsp)) {
-
-		DEBUG(10,("fcb_or_dos_open: checking file %s, fd = %d, "
-			  "vuid = %llu, file_pid = %u, private_options = 0x%x "
-			  "access_mask = 0x%x\n", fsp_str_dbg(fsp),
-			  fsp->fh->fd, (unsigned long long)fsp->vuid,
-			  (unsigned int)fsp->file_pid,
-			  (unsigned int)fsp->fh->private_options,
-			  (unsigned int)fsp->access_mask ));
-
-		if (fsp != fsp_to_dup_into &&
-		    fsp->fh->fd != -1 &&
-		    fsp->vuid == vuid &&
-		    fsp->file_pid == file_pid &&
-		    (fsp->fh->private_options & (NTCREATEX_OPTIONS_PRIVATE_DENY_DOS |
-						 NTCREATEX_OPTIONS_PRIVATE_DENY_FCB)) &&
-		    (fsp->access_mask & FILE_WRITE_DATA) &&
-		    strequal(fsp->fsp_name->base_name, smb_fname->base_name) &&
-		    strequal(fsp->fsp_name->stream_name,
-			     smb_fname->stream_name)) {
-			DEBUG(10,("fcb_or_dos_open: file match\n"));
-			break;
-		}
-	}
-
-	if (!fsp) {
-		return NT_STATUS_NOT_FOUND;
-	}
-
-	/* quite an insane set of semantics ... */
-	if (is_executable(smb_fname->base_name) &&
-	    (fsp->fh->private_options & NTCREATEX_OPTIONS_PRIVATE_DENY_DOS)) {
-		DEBUG(10,("fcb_or_dos_open: file fail due to is_executable.\n"));
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	/* We need to duplicate this fsp. */
-	return dup_file_fsp(req, fsp, access_mask, share_access,
-			    create_options, fsp_to_dup_into);
-}
-
 static void schedule_defer_open(struct share_mode_lock *lck,
 				struct file_id id,
 				struct timeval request_time,
@@ -3547,41 +3485,6 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn,
 
 		SMB_ASSERT(NT_STATUS_EQUAL(status, NT_STATUS_SHARING_VIOLATION));
 
-		/* Check if this can be done with the deny_dos and fcb
-		 * calls. */
-		if (private_flags &
-		    (NTCREATEX_OPTIONS_PRIVATE_DENY_DOS|
-		     NTCREATEX_OPTIONS_PRIVATE_DENY_FCB)) {
-			if (req == NULL) {
-				DEBUG(0, ("DOS open without an SMB "
-					  "request!\n"));
-				TALLOC_FREE(lck);
-				fd_close(fsp);
-				return NT_STATUS_INTERNAL_ERROR;
-			}
-
-			/* Use the client requested access mask here,
-			 * not the one we open with. */
-			status = fcb_or_dos_open(req,
-						 conn,
-						 fsp,
-						 smb_fname,
-						 id,
-						 req->smbpid,
-						 req->vuid,
-						 access_mask,
-						 share_access,
-						 create_options);
-
-			if (NT_STATUS_IS_OK(status)) {
-				TALLOC_FREE(lck);
-				if (pinfo) {
-					*pinfo = FILE_WAS_OPENED;
-				}
-				return NT_STATUS_OK;
-			}
-		}
-
 		/*
 		 * This next line is a subtlety we need for
 		 * MS-Access. If a file open will fail due to share
diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c
index 87729b23a83..2622681a2da 100644
--- a/source3/smbd/reply.c
+++ b/source3/smbd/reply.c
@@ -45,6 +45,7 @@
 #include "libcli/smb/smb_signing.h"
 #include "lib/util/sys_rw_data.h"
 #include "librpc/gen_ndr/open_files.h"
+#include "smb1_utils.h"
 
 /****************************************************************************
  Ensure we check the path in *exactly* the same way as W2K for a findfirst/findnext
@@ -2219,8 +2220,23 @@ void reply_open(struct smb_request *req)
 			/* We have re-scheduled this call. */
 			goto out;
 		}
-		reply_openerror(req, status);
-		goto out;
+
+		if (!NT_STATUS_EQUAL(status, NT_STATUS_SHARING_VIOLATION)) {
+			reply_openerror(req, status);
+			goto out;
+		}
+
+		fsp = fcb_or_dos_open(
+			req,
+			smb_fname,
+			access_mask,
+			share_mode,
+			create_options,
+			private_flags);
+		if (fsp == NULL) {
+			reply_openerror(req, status);
+			goto out;
+		}
 	}
 
 	/* Ensure we're pointing at the correct stat struct. */
@@ -2392,8 +2408,24 @@ void reply_open_and_X(struct smb_request *req)
 			/* We have re-scheduled this call. */
 			goto out;
 		}
-		reply_openerror(req, status);
-		goto out;
+
+		if (!NT_STATUS_EQUAL(status, NT_STATUS_SHARING_VIOLATION)) {
+			reply_openerror(req, status);
+			goto out;
+		}
+
+		fsp = fcb_or_dos_open(
+			req,
+			smb_fname,
+			access_mask,
+			share_mode,
+			create_options,
+			private_flags);
+		if (fsp == NULL) {
+			reply_openerror(req, status);
+			goto out;
+		}
+		smb_action = FILE_WAS_OPENED;
 	}
 
 	/* Setting the "size" field in vwv9 and vwv10 causes the file to be set to this size,
diff --git a/source3/smbd/smb1_utils.c b/source3/smbd/smb1_utils.c
new file mode 100644
index 00000000000..8a7e66e2ae3
--- /dev/null
+++ b/source3/smbd/smb1_utils.c
@@ -0,0 +1,113 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Util functions valid in the SMB1 server
+ *
+ * Copyright (C) Volker Lendecke 2019
+ * Copyright by the authors of the functions moved here eventually
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "includes.h"
+#include "smb1_utils.h"
+#include "libcli/security/security.h"
+
+/****************************************************************************
+ Special FCB or DOS processing in the case of a sharing violation.
+ Try and find a duplicated file handle.
+****************************************************************************/
+
+struct files_struct *fcb_or_dos_open(
+	struct smb_request *req,
+	const struct smb_filename *smb_fname,
+	uint32_t access_mask,
+	uint32_t share_access,
+	uint32_t create_options,
+	uint32_t private_flags)
+{
+	struct connection_struct *conn = req->conn;
+	struct file_id id = vfs_file_id_from_sbuf(conn, &smb_fname->st);
+	struct files_struct *fsp = NULL, *new_fsp = NULL;
+	NTSTATUS status;
+
+	if ((private_flags &
+	     (NTCREATEX_OPTIONS_PRIVATE_DENY_DOS|
+	      NTCREATEX_OPTIONS_PRIVATE_DENY_FCB))
+	    == 0) {
+		return NULL;
+	}
+
+	for(fsp = file_find_di_first(conn->sconn, id);
+	    fsp != NULL;
+	    fsp = file_find_di_next(fsp)) {
+
+		DBG_DEBUG("Checking file %s, fd = %d, vuid = %"PRIu64", "
+			  "file_pid = %"PRIu16", "
+			  "private_options = 0x%"PRIx32", "
+			  "access_mask = 0x%"PRIx32"\n",
+			  fsp_str_dbg(fsp),
+			  fsp->fh->fd,
+			  fsp->vuid,
+			  fsp->file_pid,
+			  fsp->fh->private_options,
+			  fsp->access_mask);
+
+		if (fsp->fh->fd != -1 &&
+		    fsp->vuid == req->vuid &&
+		    fsp->file_pid == req->smbpid &&
+		    (fsp->fh->private_options &
+		     (NTCREATEX_OPTIONS_PRIVATE_DENY_DOS |
+		      NTCREATEX_OPTIONS_PRIVATE_DENY_FCB)) &&
+		    (fsp->access_mask & FILE_WRITE_DATA) &&
+		    strequal(fsp->fsp_name->base_name, smb_fname->base_name) &&
+		    strequal(fsp->fsp_name->stream_name,
+			     smb_fname->stream_name)) {
+			DBG_DEBUG("file match\n");
+			break;
+		}
+	}
+
+	if (fsp == NULL) {
+		return NULL;
+	}
+
+	/* quite an insane set of semantics ... */
+	if (is_executable(smb_fname->base_name) &&
+	    (fsp->fh->private_options & NTCREATEX_OPTIONS_PRIVATE_DENY_DOS)) {
+		DBG_DEBUG("file fail due to is_executable.\n");
+		return NULL;
+	}
+
+	status = file_new(req, conn, &new_fsp);
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_DEBUG("file_new failed: %s\n", nt_errstr(status));
+		return NULL;
+	}
+
+	status = dup_file_fsp(
+		req,
+		fsp,
+		access_mask,
+		share_access,
+		create_options,
+		new_fsp);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_DEBUG("dup_file_fsp failed: %s\n", nt_errstr(status));
+		file_free(req, new_fsp);
+		return NULL;
+	}
+
+	return new_fsp;
+}
diff --git a/source3/smbd/smb1_utils.h b/source3/smbd/smb1_utils.h
new file mode 100644
index 00000000000..719eb3eb3a2
--- /dev/null
+++ b/source3/smbd/smb1_utils.h
@@ -0,0 +1,37 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Util functions valid in the SMB1 server
+ *
+ * Copyright (C) Volker Lendecke 2019
+ * Copyright by the authors of the functions moved here eventually
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __SMBD_SMB1_UTILS_H__
+#define __SMBD_SMB1_UTILS_H__
+
+#include "includes.h"
+#include "vfs.h"
+#include "proto.h"
+
+struct files_struct *fcb_or_dos_open(
+	struct smb_request *req,
+	const struct smb_filename *smb_fname,
+	uint32_t access_mask,
+	uint32_t share_access,
+	uint32_t create_options,
+	uint32_t private_flags);
+
+#endif
diff --git a/source3/smbd/trans2.c b/source3/smbd/trans2.c
index 4342b03a8c9..5b99240e9e8 100644
--- a/source3/smbd/trans2.c
+++ b/source3/smbd/trans2.c
@@ -41,6 +41,7 @@
 #include "lib/util_ea.h"
 #include "lib/readdir_attr.h"
 #include "messages.h"
+#include "smb1_utils.h"
 
 #define DIR_ENTRY_SAFETY_MARGIN 4096
 
@@ -1440,8 +1441,24 @@ static void call_trans2open(connection_struct *conn,
 			/* We have re-scheduled this call. */
 			goto out;
 		}
-		reply_openerror(req, status);
-		goto out;
+
+		if (!NT_STATUS_EQUAL(status, NT_STATUS_SHARING_VIOLATION)) {
+			reply_openerror(req, status);
+			goto out;
+		}
+
+		fsp = fcb_or_dos_open(
+			req,
+			smb_fname,
+			access_mask,
+			share_mode,
+			create_options,
+			private_flags);
+		if (fsp == NULL) {
+			reply_openerror(req, status);
+			goto out;
+		}
+		smb_action = FILE_WAS_OPENED;
 	}
 
 	size = get_file_size_stat(&smb_fname->st);
diff --git a/source3/wscript_build b/source3/wscript_build
index 7d44071225e..aa3c7175202 100644
--- a/source3/wscript_build
+++ b/source3/wscript_build
@@ -718,6 +718,7 @@ bld.SAMBA3_LIBRARY('smbd_base',
                           smbd/notify.c
                           smbd/notify_msg.c
                           smbd/build_options.c
+                          smbd/smb1_utils.c
                           ''' + NOTIFY_SOURCES,
                    deps='''
                         talloc