Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1948 insertions, 0 deletions

diff --git a/source3/smbd/msdfs.c b/source3/smbd/msdfs.c
new file mode 100644
index 0000000..4819df3
--- /dev/null
+++ b/source3/smbd/msdfs.c
@@ -0,0 +1,1948 @@
+/*
+   Unix SMB/Netbios implementation.
+   Version 3.0
+   MSDFS services for Samba
+   Copyright (C) Shirish Kalele 2000
+   Copyright (C) Jeremy Allison 2007
+   Copyright (C) Robin McCorkell 2015
+
+   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/>.
+
+*/
+
+#define DBGC_CLASS DBGC_MSDFS
+#include "includes.h"
+#include "system/filesys.h"
+#include "smbd/smbd.h"
+#include "smbd/globals.h"
+#include "msdfs.h"
+#include "auth.h"
+#include "../auth/auth_util.h"
+#include "lib/param/loadparm.h"
+#include "libcli/security/security.h"
+#include "librpc/gen_ndr/ndr_dfsblobs.h"
+#include "lib/tsocket/tsocket.h"
+#include "lib/global_contexts.h"
+#include "source3/lib/substitute.h"
+
+/**********************************************************************
+ Function to determine if a given sharename matches a connection.
+**********************************************************************/
+
+static bool msdfs_servicename_matches_connection(struct connection_struct *conn,
+						 const char *servicename,
+						 const char *vfs_user)
+{
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	char *conn_servicename = NULL;
+	int snum;
+	bool match = false;
+
+	if (conn == NULL) {
+		/* No connection always matches. */
+		return true;
+	}
+
+	snum = SNUM(conn);
+
+	conn_servicename = lp_servicename(talloc_tos(), lp_sub, snum);
+	if (conn_servicename == NULL) {
+		DBG_ERR("lp_servicename() failed, OOM!\n");
+		return false;
+	}
+
+	if (strequal(servicename, conn_servicename)) {
+		match = true;
+		goto done;
+	}
+	if (strequal(servicename, HOMES_NAME)) {
+		match = true;
+		goto done;
+	}
+	if (strequal(vfs_user, conn_servicename)) {
+		match = true;
+		goto done;
+	}
+done:
+	TALLOC_FREE(conn_servicename);
+	return match;
+}
+
+/**********************************************************************
+ Parse a DFS pathname of the form /hostname/service/reqpath
+ into the dfs_path structure.
+
+ NB. srvstr_get_path_internal() now *always* calls
+ check_path_syntax_XXX() on an incoming name, so
+ the path separator is now always '/', even from
+ Windows clients.
+
+ Unfortunately, due to broken clients who might set the
+ SVAL(inbuf,smb_flg2) & FLAGS2_DFS_PATHNAMES bit and then
+ send a local path, we have to cope with that too....
+
+ If conn != NULL then ensure the provided service is
+ the one pointed to by the connection.
+
+ This version does everything using pointers within one copy of the
+ pathname string, talloced on the struct dfs_path pointer (which
+ must be talloced). This may be too clever to live....
+ JRA.
+**********************************************************************/
+
+static NTSTATUS parse_dfs_path(TALLOC_CTX *ctx,
+				connection_struct *conn,
+				const char *pathname,
+				bool allow_broken_path,
+				char **_hostname,
+				char **_servicename,
+				char **_remaining_path)
+{
+	char *hostname = NULL;
+	char *pathname_local = NULL;
+	char *p = NULL;
+	char *servicename = NULL;
+	char *reqpath = NULL;
+	char *eos_ptr = NULL;
+	bool servicename_matches = false;
+
+	pathname_local = talloc_strdup(ctx, pathname);
+	if (pathname_local == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	/*
+	 * parse_dfs_path() can be called from
+	 * get_referred_path() and create_junction()
+	 * which use Windows DFS paths of \server\share.
+	 * Ensure we only have to cope with '/' separators.
+	 */
+	string_replace(pathname_local, '\\', '/');
+
+	/* Get a pointer to the terminating '\0' */
+	eos_ptr = &pathname_local[strlen(pathname_local)];
+	p = pathname_local;
+
+	/*
+	 * Non-broken DFS paths *must* start with the
+	 * path separator '/'.
+	 */
+
+	if (allow_broken_path && (*p != '/')) {
+		DBG_ERR("path %s doesn't start with /\n", p);
+		/*
+		 * Possibly client sent a local path by mistake.
+		 * Try and convert to a local path.
+		 * Note that this is an SMB1-only fallback
+		 * to cope with known broken SMB1 clients.
+		 */
+
+		hostname = eos_ptr; /* "" */
+		servicename = eos_ptr; /* "" */
+
+		DBG_ERR("trying to convert %s to a local path\n", p);
+		goto local_path;
+	}
+
+	/*
+	 * Safe to use on talloc'ed string as it only shrinks.
+	 * It also doesn't affect the eos_ptr.
+	 */
+	trim_char(p, '/', '/');
+
+	DBG_DEBUG("p = |%s| after trimming /'s\n", p);
+
+	/* Now tokenize. */
+	/* Parse out hostname. */
+	p = strchr(p,'/');
+	if(p == NULL) {
+		DBG_ERR("can't parse hostname from path %s\n", pathname_local);
+		/*
+		 * Possibly client sent a local path by mistake.
+		 * Try and convert to a local path.
+		 */
+
+		hostname = eos_ptr; /* "" */
+		servicename = eos_ptr; /* "" */
+
+		p = pathname_local;
+		DBG_ERR("trying to convert %s to a local path\n", p);
+		goto local_path;
+	}
+	*p = '\0';
+	hostname = pathname_local;
+
+	DBG_DEBUG("hostname: %s\n", hostname);
+
+	/* Parse out servicename. */
+	servicename = p+1;
+	p = strchr(servicename, '/');
+	if (p) {
+		*p = '\0';
+	}
+
+	/* Is this really our servicename ? */
+	servicename_matches = msdfs_servicename_matches_connection(
+					conn,
+					servicename,
+					get_current_username());
+
+	if (!servicename_matches) {
+		DBG_ERR("%s is not our servicename\n", servicename);
+
+		/*
+		 * Possibly client sent a local path by mistake.
+		 * Try and convert to a local path.
+		 */
+
+		/* Repair the path - replace the sepchar's
+		   we nulled out */
+		servicename--;
+		*servicename = '/';
+		if (p) {
+			*p = '/';
+		}
+
+		hostname = eos_ptr; /* "" */
+		servicename = eos_ptr; /* "" */
+
+		p = pathname_local;
+		DBG_ERR("trying to convert %s to a local path\n",
+			pathname_local);
+		goto local_path;
+	}
+
+	servicename = servicename;
+
+	DBG_DEBUG("servicename: %s\n", servicename);
+
+	if(p == NULL) {
+		/* Client sent self referral \server\share. */
+		reqpath = eos_ptr; /* "" */
+		goto out;
+	}
+
+	p++;
+
+  local_path:
+
+	/*
+	 * As check_path_syntax_XXX() has already been
+	 * called we know this is a normal path containing
+	 * '/' separators.
+	 */
+
+	reqpath = p;
+
+  out:
+
+	DBG_DEBUG("rest of the path: %s\n", reqpath);
+
+	if (_hostname != NULL) {
+		*_hostname = talloc_strdup(ctx, hostname);
+		if (*_hostname == NULL) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	if (_servicename != NULL) {
+		*_servicename = talloc_strdup(ctx, servicename);
+		if (*_servicename == NULL) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	if (_remaining_path != NULL) {
+		*_remaining_path = talloc_strdup(ctx, reqpath);
+		if (*_remaining_path == NULL) {
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	TALLOC_FREE(pathname_local);
+	return NT_STATUS_OK;
+}
+
+/********************************************************
+ Fake up a connection struct for the VFS layer, for use in
+ applications (such as the python bindings), that do not want the
+ global working directory changed under them.
+
+ SMB_VFS_CONNECT requires root privileges.
+*********************************************************/
+
+static NTSTATUS create_conn_struct_as_root(TALLOC_CTX *ctx,
+			    struct tevent_context *ev,
+			    struct messaging_context *msg,
+			    connection_struct **pconn,
+			    int snum,
+			    const char *path,
+			    const struct auth_session_info *session_info)
+{
+	connection_struct *conn;
+	char *connpath;
+	const char *vfs_user;
+	struct smbd_server_connection *sconn;
+	const char *servicename = lp_const_servicename(snum);
+	bool ok;
+
+	sconn = talloc_zero(ctx, struct smbd_server_connection);
+	if (sconn == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	sconn->ev_ctx = ev;
+	sconn->msg_ctx = msg;
+
+	conn = conn_new(sconn);
+	if (conn == NULL) {
+		TALLOC_FREE(sconn);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* Now we have conn, we need to make sconn a child of conn,
+	 * for a proper talloc tree */
+	talloc_steal(conn, sconn);
+
+	if (snum == -1 && servicename == NULL) {
+		servicename = "Unknown Service (snum == -1)";
+	}
+
+	connpath = talloc_strdup(conn, path);
+	if (!connpath) {
+		TALLOC_FREE(conn);
+		return NT_STATUS_NO_MEMORY;
+	}
+	connpath = talloc_string_sub(conn,
+				     connpath,
+				     "%S",
+				     servicename);
+	if (!connpath) {
+		TALLOC_FREE(conn);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* needed for smbd_vfs_init() */
+
+	conn->params->service = snum;
+	conn->cnum = TID_FIELD_INVALID;
+
+	SMB_ASSERT(session_info != NULL);
+
+	conn->session_info = copy_session_info(conn, session_info);
+	if (conn->session_info == NULL) {
+		DBG_ERR("copy_serverinfo failed\n");
+		TALLOC_FREE(conn);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* unix_info could be NULL in session_info */
+	if (conn->session_info->unix_info != NULL) {
+		vfs_user = conn->session_info->unix_info->unix_name;
+	} else {
+		vfs_user = get_current_username();
+	}
+
+	conn_setup_case_options(conn);
+
+	set_conn_connectpath(conn, connpath);
+
+	/*
+	 * New code to check if there's a share security descriptor
+	 * added from NT server manager. This is done after the
+	 * smb.conf checks are done as we need a uid and token. JRA.
+	 *
+	 */
+	share_access_check(conn->session_info->security_token,
+			   servicename,
+			   MAXIMUM_ALLOWED_ACCESS,
+			   &conn->share_access);
+
+	if ((conn->share_access & FILE_WRITE_DATA) == 0) {
+		if ((conn->share_access & FILE_READ_DATA) == 0) {
+			/* No access, read or write. */
+			DBG_WARNING("connection to %s "
+				    "denied due to security "
+				    "descriptor.\n",
+				    servicename);
+			conn_free(conn);
+			return NT_STATUS_ACCESS_DENIED;
+		}
+		conn->read_only = true;
+	}
+
+	if (!smbd_vfs_init(conn)) {
+		NTSTATUS status = map_nt_error_from_unix(errno);
+		DEBUG(0,("create_conn_struct: smbd_vfs_init failed.\n"));
+		conn_free(conn);
+		return status;
+	}
+
+	/* this must be the first filesystem operation that we do */
+	if (SMB_VFS_CONNECT(conn, servicename, vfs_user) < 0) {
+		DEBUG(0,("VFS connect failed!\n"));
+		conn_free(conn);
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+
+	ok = canonicalize_connect_path(conn);
+	if (!ok) {
+		DBG_ERR("Failed to canonicalize sharepath\n");
+		conn_free(conn);
+		return NT_STATUS_ACCESS_DENIED;
+	}
+
+	conn->fs_capabilities = SMB_VFS_FS_CAPABILITIES(conn, &conn->ts_res);
+	conn->tcon_done = true;
+	*pconn = talloc_move(ctx, &conn);
+
+	return NT_STATUS_OK;
+}
+
+static int conn_struct_tos_destructor(struct conn_struct_tos *c)
+{
+	if (c->oldcwd_fname != NULL) {
+		vfs_ChDir(c->conn, c->oldcwd_fname);
+		TALLOC_FREE(c->oldcwd_fname);
+	}
+	SMB_VFS_DISCONNECT(c->conn);
+	conn_free(c->conn);
+	return 0;
+}
+
+/********************************************************
+ Fake up a connection struct for the VFS layer, for use in
+ applications (such as the python bindings), that do not want the
+ global working directory changed under them.
+
+ SMB_VFS_CONNECT requires root privileges.
+ This temporary uses become_root() and unbecome_root().
+
+ But further impersonation has to be cone by the caller.
+*********************************************************/
+NTSTATUS create_conn_struct_tos(struct messaging_context *msg,
+				int snum,
+				const char *path,
+				const struct auth_session_info *session_info,
+				struct conn_struct_tos **_c)
+{
+	struct conn_struct_tos *c = NULL;
+	struct tevent_context *ev = NULL;
+	NTSTATUS status;
+
+	*_c = NULL;
+
+	c = talloc_zero(talloc_tos(), struct conn_struct_tos);
+	if (c == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ev = samba_tevent_context_init(c);
+	if (ev == NULL) {
+		TALLOC_FREE(c);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	become_root();
+	status = create_conn_struct_as_root(c,
+					    ev,
+					    msg,
+					    &c->conn,
+					    snum,
+					    path,
+					    session_info);
+	unbecome_root();
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(c);
+		return status;
+	}
+
+	talloc_set_destructor(c, conn_struct_tos_destructor);
+
+	*_c = c;
+	return NT_STATUS_OK;
+}
+
+/********************************************************
+ Fake up a connection struct for the VFS layer.
+ Note: this performs a vfs connect and CHANGES CWD !!!! JRA.
+
+ See also the comment for create_conn_struct_tos() above!
+
+ The CWD change is reverted by the destructor of
+ conn_struct_tos when the current talloc_tos() is destroyed.
+*********************************************************/
+NTSTATUS create_conn_struct_tos_cwd(struct messaging_context *msg,
+				    int snum,
+				    const char *path,
+				    const struct auth_session_info *session_info,
+				    struct conn_struct_tos **_c)
+{
+	struct conn_struct_tos *c = NULL;
+	struct smb_filename smb_fname_connectpath = {0};
+	NTSTATUS status;
+
+	*_c = NULL;
+
+	status = create_conn_struct_tos(msg,
+					snum,
+					path,
+					session_info,
+					&c);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	/*
+	 * Windows seems to insist on doing trans2getdfsreferral() calls on
+	 * the IPC$ share as the anonymous user. If we try to chdir as that
+	 * user we will fail.... WTF ? JRA.
+	 */
+
+	c->oldcwd_fname = vfs_GetWd(c, c->conn);
+	if (c->oldcwd_fname == NULL) {
+		status = map_nt_error_from_unix(errno);
+		DEBUG(3, ("vfs_GetWd failed: %s\n", strerror(errno)));
+		TALLOC_FREE(c);
+		return status;
+	}
+
+	smb_fname_connectpath = (struct smb_filename) {
+		.base_name = c->conn->connectpath
+	};
+
+	if (vfs_ChDir(c->conn, &smb_fname_connectpath) != 0) {
+		status = map_nt_error_from_unix(errno);
+		DBG_NOTICE("Can't ChDir to new conn path %s. "
+			   "Error was %s\n",
+			   c->conn->connectpath, strerror(errno));
+		TALLOC_FREE(c->oldcwd_fname);
+		TALLOC_FREE(c);
+		return status;
+	}
+
+	*_c = c;
+	return NT_STATUS_OK;
+}
+
+/********************************************************
+ Fake up a connection struct for the VFS layer.
+ This takes an TALLOC_CTX and tevent_context from the
+ caller and the resulting connection_struct is stable
+ across the lifetime of mem_ctx and ev.
+
+ Note: this performs a vfs connect and changes cwd.
+
+ See also the comment for create_conn_struct_tos() above!
+*********************************************************/
+
+NTSTATUS create_conn_struct_cwd(TALLOC_CTX *mem_ctx,
+				struct tevent_context *ev,
+				struct messaging_context *msg,
+				const struct auth_session_info *session_info,
+				int snum,
+				const char *path,
+				struct connection_struct **c)
+{
+	NTSTATUS status;
+
+	become_root();
+	status = create_conn_struct_as_root(mem_ctx,
+					    ev,
+					    msg,
+					    c,
+					    snum,
+					    path,
+					    session_info);
+	unbecome_root();
+	return status;
+}
+
+static void shuffle_strlist(char **list, int count)
+{
+	int i;
+	uint32_t r;
+	char *tmp;
+
+	for (i = count; i > 1; i--) {
+		r = generate_random() % i;
+
+		tmp = list[i-1];
+		list[i-1] = list[r];
+		list[r] = tmp;
+	}
+}
+
+/**********************************************************************
+ Parse the contents of a symlink to verify if it is an msdfs referral
+ A valid referral is of the form:
+
+ msdfs:server1\share1,server2\share2
+ msdfs:server1\share1\pathname,server2\share2\pathname
+ msdfs:server1/share1,server2/share2
+ msdfs:server1/share1/pathname,server2/share2/pathname.
+
+ Note that the alternate paths returned here must be of the canonicalized
+ form:
+
+ \server\share or
+ \server\share\path\to\file,
+
+ even in posix path mode. This is because we have no knowledge if the
+ server we're referring to understands posix paths.
+ **********************************************************************/
+
+bool parse_msdfs_symlink(TALLOC_CTX *ctx,
+			bool shuffle_referrals,
+			const char *target,
+			struct referral **ppreflist,
+			size_t *prefcount)
+{
+	char *temp = NULL;
+	char *prot;
+	char **alt_path = NULL;
+	size_t count = 0, i;
+	struct referral *reflist = NULL;
+	char *saveptr;
+
+	temp = talloc_strdup(ctx, target);
+	if (!temp) {
+		return false;
+	}
+	prot = strtok_r(temp, ":", &saveptr);
+	if (!prot) {
+		DEBUG(0,("parse_msdfs_symlink: invalid path !\n"));
+		TALLOC_FREE(temp);
+		return false;
+	}
+
+	alt_path = talloc_array(ctx, char *, MAX_REFERRAL_COUNT);
+	if (!alt_path) {
+		TALLOC_FREE(temp);
+		return false;
+	}
+
+	/* parse out the alternate paths */
+	while((count<MAX_REFERRAL_COUNT) &&
+	      ((alt_path[count] = strtok_r(NULL, ",", &saveptr)) != NULL)) {
+		count++;
+	}
+
+	/* shuffle alternate paths */
+	if (shuffle_referrals) {
+		shuffle_strlist(alt_path, count);
+	}
+
+	DBG_DEBUG("count=%zu\n", count);
+
+	if (count) {
+		reflist = talloc_zero_array(ctx,
+				struct referral, count);
+		if(reflist == NULL) {
+			TALLOC_FREE(temp);
+			TALLOC_FREE(alt_path);
+			return false;
+		}
+	} else {
+		reflist = NULL;
+	}
+
+	for(i=0;i<count;i++) {
+		char *p;
+
+		/* Canonicalize link target.
+		 * Replace all /'s in the path by a \ */
+		string_replace(alt_path[i], '/', '\\');
+
+		/* Remove leading '\\'s */
+		p = alt_path[i];
+		while (*p && (*p == '\\')) {
+			p++;
+		}
+
+		reflist[i].alternate_path = talloc_asprintf(reflist,
+				"\\%s",
+				p);
+		if (!reflist[i].alternate_path) {
+			TALLOC_FREE(temp);
+			TALLOC_FREE(alt_path);
+			TALLOC_FREE(reflist);
+			return false;
+		}
+
+		reflist[i].proximity = 0;
+		reflist[i].ttl = REFERRAL_TTL;
+		DBG_DEBUG("Created alt path: %s\n",
+			reflist[i].alternate_path);
+	}
+
+	if (ppreflist != NULL) {
+		*ppreflist = reflist;
+	} else {
+		TALLOC_FREE(reflist);
+	}
+	if (prefcount != NULL) {
+		*prefcount = count;
+	}
+	TALLOC_FREE(temp);
+	TALLOC_FREE(alt_path);
+	return true;
+}
+
+/**********************************************************************
+ Returns true if the unix path is a valid msdfs symlink.
+**********************************************************************/
+
+bool is_msdfs_link(struct files_struct *dirfsp,
+		   struct smb_filename *atname)
+{
+	NTSTATUS status = SMB_VFS_READ_DFS_PATHAT(dirfsp->conn,
+					talloc_tos(),
+					dirfsp,
+					atname,
+					NULL,
+					NULL);
+	return (NT_STATUS_IS_OK(status));
+}
+
+/*****************************************************************
+ Used by other functions to decide if a dfs path is remote,
+ and to get the list of referred locations for that remote path.
+
+ consumedcntp: how much of the dfs path is being redirected. the client
+ should try the remaining path on the redirected server.
+*****************************************************************/
+
+static NTSTATUS dfs_path_lookup(TALLOC_CTX *ctx,
+		connection_struct *conn,
+		const char *dfspath, /* Incoming complete dfs path */
+		const char *reqpath, /* Parsed out remaining path. */
+		uint32_t ucf_flags,
+		size_t *consumedcntp,
+		struct referral **ppreflist,
+		size_t *preferral_count)
+{
+	NTSTATUS status;
+	struct smb_filename *parent_smb_fname = NULL;
+	struct smb_filename *smb_fname_rel = NULL;
+	NTTIME twrp = 0;
+	char *local_pathname = NULL;
+	char *last_component = NULL;
+	char *atname = NULL;
+	size_t removed_components = 0;
+	bool posix = (ucf_flags & UCF_POSIX_PATHNAMES);
+	char *p = NULL;
+	char *canon_dfspath = NULL;
+
+	DBG_DEBUG("Conn path = %s reqpath = %s\n", conn->connectpath, reqpath);
+
+	local_pathname = talloc_strdup(ctx, reqpath);
+	if (local_pathname == NULL) {
+		status = NT_STATUS_NO_MEMORY;
+		goto out;
+	}
+
+	/* We know reqpath isn't a DFS path. */
+	ucf_flags &= ~UCF_DFS_PATHNAME;
+
+	if (ucf_flags & UCF_GMT_PATHNAME) {
+		extract_snapshot_token(local_pathname, &twrp);
+		ucf_flags &= ~UCF_GMT_PATHNAME;
+	}
+
+	/*
+	 * We should have been given a DFS path to resolve.
+	 * This should return NT_STATUS_PATH_NOT_COVERED.
+	 *
+	 * Do a pathname walk, stripping off components
+	 * until we get NT_STATUS_OK instead of
+	 * NT_STATUS_PATH_NOT_COVERED.
+	 *
+	 * Fail on any other error.
+	 */
+
+	for (;;) {
+		TALLOC_CTX *frame = NULL;
+		struct files_struct *dirfsp = NULL;
+		struct smb_filename *smb_fname_walk = NULL;
+
+		TALLOC_FREE(parent_smb_fname);
+
+		/*
+		 * Use a local stackframe as filename_convert_dirfsp()
+		 * opens handles on the last two components in the path.
+		 * Allow these to be freed as we step back through
+		 * the local_pathname.
+		 */
+		frame = talloc_stackframe();
+		status = filename_convert_dirfsp(frame,
+						 conn,
+						 local_pathname,
+						 ucf_flags,
+						 twrp,
+						 &dirfsp,
+						 &smb_fname_walk);
+		/* If we got a name, save it. */
+		if (smb_fname_walk != NULL) {
+			parent_smb_fname = talloc_move(ctx, &smb_fname_walk);
+		}
+		TALLOC_FREE(frame);
+
+		if (!NT_STATUS_EQUAL(status, NT_STATUS_PATH_NOT_COVERED)) {
+			/*
+			 * For any other status than NT_STATUS_PATH_NOT_COVERED
+			 * (including NT_STATUS_OK) we exit the walk.
+			 * If it's an error we catch it outside the loop.
+			 */
+			break;
+		}
+
+		/* Step back one component and save it off as last_component. */
+		TALLOC_FREE(last_component);
+		p = strrchr(local_pathname, '/');
+		if (p == NULL) {
+			/*
+			 * We removed all components.
+			 * Go around once more to make
+			 * sure we can open the root '\0'.
+			 */
+			last_component = talloc_strdup(ctx, local_pathname);
+			*local_pathname = '\0';
+		} else {
+			last_component = talloc_strdup(ctx, p+1);
+			*p = '\0';
+		}
+		if (last_component == NULL) {
+			status = NT_STATUS_NO_MEMORY;
+			goto out;
+		}
+		/* Integer wrap check. */
+		if (removed_components + 1 < removed_components) {
+			status = NT_STATUS_INVALID_PARAMETER;
+			goto out;
+		}
+		removed_components++;
+	}
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_DEBUG("dfspath = %s. reqpath = %s. Error %s.\n",
+			dfspath,
+			reqpath,
+			nt_errstr(status));
+		goto out;
+	}
+
+	if (parent_smb_fname->fsp == NULL) {
+		/* Unable to open parent. */
+		DBG_DEBUG("dfspath = %s. reqpath = %s. "
+			  "Unable to open parent directory (%s).\n",
+			dfspath,
+			reqpath,
+			smb_fname_str_dbg(parent_smb_fname));
+		status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
+		goto out;
+	}
+
+	if (removed_components == 0) {
+		/*
+		 * We never got NT_STATUS_PATH_NOT_COVERED.
+		 * There was no DFS redirect.
+		 */
+		DBG_DEBUG("dfspath = %s. reqpath = %s. "
+			"No removed components.\n",
+			dfspath,
+			reqpath);
+		status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
+		goto out;
+	}
+
+	/*
+	 * One of the removed_components was the MSDFS link
+	 * at the end. We need to count this in the resolved
+	 * path below, so remove one from removed_components.
+	 */
+	removed_components--;
+
+	/*
+	 * Now parent_smb_fname->fsp is the parent directory dirfsp,
+	 * last_component is the untranslated MS-DFS link name.
+	 * Search for it in the parent directory to get the real
+	 * filename on disk.
+	 */
+	status = get_real_filename_at(parent_smb_fname->fsp,
+				      last_component,
+				      ctx,
+				      &atname);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_DEBUG("dfspath = %s. reqpath = %s "
+			"get_real_filename_at(%s, %s) error (%s)\n",
+			dfspath,
+			reqpath,
+			smb_fname_str_dbg(parent_smb_fname),
+			last_component,
+			nt_errstr(status));
+		goto out;
+	}
+
+        smb_fname_rel = synthetic_smb_fname(ctx,
+				atname,
+				NULL,
+				NULL,
+				twrp,
+				posix ? SMB_FILENAME_POSIX_PATH : 0);
+	if (smb_fname_rel == NULL) {
+		status = NT_STATUS_NO_MEMORY;
+		goto out;
+	}
+
+	/* Get the referral to return. */
+	status = SMB_VFS_READ_DFS_PATHAT(conn,
+					 ctx,
+					 parent_smb_fname->fsp,
+					 smb_fname_rel,
+					 ppreflist,
+					 preferral_count);
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_DEBUG("dfspath = %s. reqpath = %s. "
+			"SMB_VFS_READ_DFS_PATHAT(%s, %s) error (%s)\n",
+			dfspath,
+			reqpath,
+			smb_fname_str_dbg(parent_smb_fname),
+			smb_fname_str_dbg(smb_fname_rel),
+			nt_errstr(status));
+		goto out;
+	}
+
+	/*
+	 * Now we must work out how much of the
+	 * given pathname we consumed.
+	 */
+	canon_dfspath = talloc_strdup(ctx, dfspath);
+	if (!canon_dfspath) {
+		status = NT_STATUS_NO_MEMORY;
+		goto out;
+	}
+	/* Canonicalize the raw dfspath. */
+	string_replace(canon_dfspath, '\\', '/');
+
+	/*
+	 * reqpath comes out of parse_dfs_path(), so it has
+	 * no trailing backslash. Make sure that canon_dfspath hasn't either.
+	 */
+	trim_char(canon_dfspath, 0, '/');
+
+	DBG_DEBUG("Unconsumed path: %s\n", canon_dfspath);
+
+	while (removed_components > 0) {
+		p = strrchr(canon_dfspath, '/');
+		if (p != NULL) {
+			*p = '\0';
+		}
+		removed_components--;
+		if (p == NULL && removed_components != 0) {
+			DBG_ERR("Component missmatch. path = %s, "
+				"%zu components left\n",
+				canon_dfspath,
+				removed_components);
+			status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
+			goto out;
+		}
+	}
+	*consumedcntp = strlen(canon_dfspath);
+	DBG_DEBUG("Path consumed: %s (%zu)\n", canon_dfspath, *consumedcntp);
+	status = NT_STATUS_OK;
+
+  out:
+
+	TALLOC_FREE(parent_smb_fname);
+	TALLOC_FREE(local_pathname);
+	TALLOC_FREE(last_component);
+	TALLOC_FREE(atname);
+	TALLOC_FREE(smb_fname_rel);
+	TALLOC_FREE(canon_dfspath);
+	return status;
+}
+
+/*****************************************************************
+ Decides if a dfs pathname should be redirected or not.
+ If not, the pathname is converted to a tcon-relative local unix path
+ This is now a simple wrapper around parse_dfs_path()
+ as it does all the required checks.
+*****************************************************************/
+
+NTSTATUS dfs_filename_convert(TALLOC_CTX *ctx,
+			      connection_struct *conn,
+			      uint32_t ucf_flags,
+			      const char *dfs_path_in,
+			      char **pp_path_out)
+{
+	char *hostname = NULL;
+	char *servicename = NULL;
+	char *reqpath = NULL;
+	NTSTATUS status;
+
+	status = parse_dfs_path(ctx,
+				conn,
+				dfs_path_in,
+				!conn->sconn->using_smb2,
+				&hostname,
+				&servicename,
+				&reqpath);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	/*
+	 * Caller doesn't care about hostname
+	 * or servicename.
+	 */
+	TALLOC_FREE(hostname);
+	TALLOC_FREE(servicename);
+
+	/*
+	 * If parse_dfs_path fell back to a local path
+	 * after skipping hostname or servicename, ensure
+	 * we still have called check_path_syntax()
+	 * on the full returned local path. check_path_syntax()
+	 * is idempotent so this is safe.
+	 */
+	if (ucf_flags & UCF_POSIX_PATHNAMES) {
+		status = check_path_syntax_posix(reqpath);
+	} else {
+		status = check_path_syntax(reqpath);
+	}
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+	/*
+	 * Previous (and current logic) just ignores
+	 * the server, share components if a DFS
+	 * path is sent on a non-DFS share except to
+	 * check that they match an existing share. Should
+	 * we tighten this up to return an error here ?
+	 */
+	*pp_path_out = reqpath;
+	return NT_STATUS_OK;
+}
+
+/**********************************************************************
+ Return a self referral.
+**********************************************************************/
+
+static NTSTATUS self_ref(TALLOC_CTX *ctx,
+			const char *dfs_path,
+			struct junction_map *jucn,
+			size_t *consumedcntp,
+			bool *self_referralp)
+{
+	struct referral *ref;
+
+	*self_referralp = True;
+
+	jucn->referral_count = 1;
+	if((ref = talloc_zero(ctx, struct referral)) == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ref->alternate_path = talloc_strdup(ctx, dfs_path);
+	if (!ref->alternate_path) {
+		TALLOC_FREE(ref);
+		return NT_STATUS_NO_MEMORY;
+	}
+	ref->proximity = 0;
+	ref->ttl = REFERRAL_TTL;
+	jucn->referral_list = ref;
+	*consumedcntp = strlen(dfs_path);
+	return NT_STATUS_OK;
+}
+
+/**********************************************************************
+ Gets valid referrals for a dfs path and fills up the
+ junction_map structure.
+**********************************************************************/
+
+NTSTATUS get_referred_path(TALLOC_CTX *ctx,
+			   struct auth_session_info *session_info,
+			   const char *dfs_path,
+			   const struct tsocket_address *remote_address,
+			   const struct tsocket_address *local_address,
+			   bool allow_broken_path,
+			   struct junction_map *jucn,
+			   size_t *consumedcntp,
+			   bool *self_referralp)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	struct conn_struct_tos *c = NULL;
+	struct connection_struct *conn = NULL;
+	char *servicename = NULL;
+	char *reqpath = NULL;
+	int snum;
+	NTSTATUS status = NT_STATUS_NOT_FOUND;
+
+	*self_referralp = False;
+
+	status = parse_dfs_path(frame,
+				NULL,
+				dfs_path,
+				allow_broken_path,
+				NULL,
+				&servicename,
+				&reqpath);
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	/* Path referrals are always non-POSIX. */
+	status = check_path_syntax(reqpath);
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	jucn->service_name = talloc_strdup(ctx, servicename);
+	jucn->volume_name = talloc_strdup(ctx, reqpath);
+	if (!jucn->service_name || !jucn->volume_name) {
+		TALLOC_FREE(frame);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* Verify the share is a dfs root */
+	snum = lp_servicenumber(jucn->service_name);
+	if(snum < 0) {
+		char *service_name = NULL;
+		if ((snum = find_service(ctx, jucn->service_name, &service_name)) < 0) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_NOT_FOUND;
+		}
+		if (!service_name) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_NO_MEMORY;
+		}
+		TALLOC_FREE(jucn->service_name);
+		jucn->service_name = talloc_strdup(ctx, service_name);
+		if (!jucn->service_name) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+
+	if (!lp_msdfs_root(snum) && (*lp_msdfs_proxy(talloc_tos(), lp_sub, snum) == '\0')) {
+		DEBUG(3,("get_referred_path: |%s| in dfs path %s is not "
+			"a dfs root.\n",
+			servicename, dfs_path));
+		TALLOC_FREE(frame);
+		return NT_STATUS_NOT_FOUND;
+	}
+
+	/*
+	 * Self referrals are tested with a anonymous IPC connection and
+	 * a GET_DFS_REFERRAL call to \\server\share. (which means
+	 * dp.reqpath[0] points to an empty string). create_conn_struct cd's
+	 * into the directory and will fail if it cannot (as the anonymous
+	 * user). Cope with this.
+	 */
+
+	if (reqpath[0] == '\0') {
+		char *tmp;
+		struct referral *ref;
+		size_t refcount;
+
+		if (*lp_msdfs_proxy(talloc_tos(), lp_sub, snum) == '\0') {
+			TALLOC_FREE(frame);
+			return self_ref(ctx,
+					dfs_path,
+					jucn,
+					consumedcntp,
+					self_referralp);
+		}
+
+		/*
+		 * It's an msdfs proxy share. Redirect to
+ 		 * the configured target share.
+ 		 */
+
+		tmp = talloc_asprintf(frame, "msdfs:%s",
+				      lp_msdfs_proxy(frame, lp_sub, snum));
+		if (tmp == NULL) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_NO_MEMORY;
+		}
+
+		if (!parse_msdfs_symlink(ctx,
+				lp_msdfs_shuffle_referrals(snum),
+				tmp,
+				&ref,
+				&refcount)) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+		jucn->referral_count = refcount;
+		jucn->referral_list = ref;
+		*consumedcntp = strlen(dfs_path);
+		TALLOC_FREE(frame);
+		return NT_STATUS_OK;
+	}
+
+	status = create_conn_struct_tos_cwd(global_messaging_context(),
+					    snum,
+					    lp_path(frame, lp_sub, snum),
+					    session_info,
+					    &c);
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(frame);
+		return status;
+	}
+	conn = c->conn;
+
+	/*
+	 * TODO
+	 *
+	 * The remote and local address should be passed down to
+	 * create_conn_struct_cwd.
+	 */
+	if (conn->sconn->remote_address == NULL) {
+		conn->sconn->remote_address =
+			tsocket_address_copy(remote_address, conn->sconn);
+		if (conn->sconn->remote_address == NULL) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+	if (conn->sconn->local_address == NULL) {
+		conn->sconn->local_address =
+			tsocket_address_copy(local_address, conn->sconn);
+		if (conn->sconn->local_address == NULL) {
+			TALLOC_FREE(frame);
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+
+	status = dfs_path_lookup(ctx,
+				conn,
+				dfs_path,
+				reqpath,
+				0, /* ucf_flags */
+				consumedcntp,
+				&jucn->referral_list,
+				&jucn->referral_count);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DBG_NOTICE("No valid referrals for path %s (%s)\n",
+			dfs_path,
+			nt_errstr(status));
+	}
+
+	TALLOC_FREE(frame);
+	return status;
+}
+
+/******************************************************************
+ Set up the DFS referral for the dfs pathname. This call returns
+ the amount of the path covered by this server, and where the
+ client should be redirected to. This is the meat of the
+ TRANS2_GET_DFS_REFERRAL call.
+******************************************************************/
+
+int setup_dfs_referral(connection_struct *orig_conn,
+			const char *dfs_path,
+			int max_referral_level,
+			char **ppdata, NTSTATUS *pstatus)
+{
+	char *pdata = *ppdata;
+	int reply_size = 0;
+	struct dfs_GetDFSReferral *r;
+	DATA_BLOB blob = data_blob_null;
+	NTSTATUS status;
+	enum ndr_err_code ndr_err;
+
+	r = talloc_zero(talloc_tos(), struct dfs_GetDFSReferral);
+	if (r == NULL) {
+		*pstatus = NT_STATUS_NO_MEMORY;
+		return -1;
+	}
+
+	r->in.req.max_referral_level = max_referral_level;
+	r->in.req.servername = talloc_strdup(r, dfs_path);
+	if (r->in.req.servername == NULL) {
+		talloc_free(r);
+		*pstatus = NT_STATUS_NO_MEMORY;
+		return -1;
+	}
+
+	status = SMB_VFS_GET_DFS_REFERRALS(orig_conn, r);
+	if (!NT_STATUS_IS_OK(status)) {
+		talloc_free(r);
+		*pstatus = status;
+		return -1;
+	}
+
+	ndr_err = ndr_push_struct_blob(&blob, r,
+				r->out.resp,
+				(ndr_push_flags_fn_t)ndr_push_dfs_referral_resp);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		TALLOC_FREE(r);
+		*pstatus = NT_STATUS_INVALID_PARAMETER;
+		return -1;
+	}
+
+	pdata = (char *)SMB_REALLOC(pdata, blob.length);
+	if(pdata == NULL) {
+		TALLOC_FREE(r);
+		DEBUG(0,("referral setup:"
+			 "malloc failed for Realloc!\n"));
+		return -1;
+	}
+	*ppdata = pdata;
+	reply_size = blob.length;
+	memcpy(pdata, blob.data, blob.length);
+	TALLOC_FREE(r);
+
+	*pstatus = NT_STATUS_OK;
+	return reply_size;
+}
+
+/**********************************************************************
+ The following functions are called by the NETDFS RPC pipe functions
+ **********************************************************************/
+
+/*********************************************************************
+ Creates a junction structure from a DFS pathname
+**********************************************************************/
+
+bool create_junction(TALLOC_CTX *ctx,
+		const char *dfs_path,
+		bool allow_broken_path,
+		struct junction_map *jucn)
+{
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	int snum;
+	char *hostname = NULL;
+	char *servicename = NULL;
+	char *reqpath = NULL;
+	NTSTATUS status;
+
+	status = parse_dfs_path(ctx,
+				NULL,
+				dfs_path,
+				allow_broken_path,
+				&hostname,
+				&servicename,
+				&reqpath);
+	if (!NT_STATUS_IS_OK(status)) {
+		return False;
+	}
+
+	/* check if path is dfs : validate first token */
+	if (!is_myname_or_ipaddr(hostname)) {
+		DEBUG(4,("create_junction: Invalid hostname %s "
+			"in dfs path %s\n",
+			hostname, dfs_path));
+		return False;
+	}
+
+	/* Check for a non-DFS share */
+	snum = lp_servicenumber(servicename);
+
+	if(snum < 0 || !lp_msdfs_root(snum)) {
+		DEBUG(4,("create_junction: %s is not an msdfs root.\n",
+			servicename));
+		return False;
+	}
+
+	/* Junction create paths are always non-POSIX. */
+	status = check_path_syntax(reqpath);
+	if (!NT_STATUS_IS_OK(status)) {
+		return false;
+	}
+
+	jucn->service_name = talloc_strdup(ctx, servicename);
+	jucn->volume_name = talloc_strdup(ctx, reqpath);
+	jucn->comment = lp_comment(ctx, lp_sub, snum);
+
+	if (!jucn->service_name || !jucn->volume_name || ! jucn->comment) {
+		return False;
+	}
+	return True;
+}
+
+/**********************************************************************
+ Forms a valid Unix pathname from the junction
+ **********************************************************************/
+
+static bool junction_to_local_path_tos(const struct junction_map *jucn,
+				       struct auth_session_info *session_info,
+				       char **pp_path_out,
+				       connection_struct **conn_out)
+{
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	struct conn_struct_tos *c = NULL;
+	int snum;
+	char *path_out = NULL;
+	NTSTATUS status;
+
+	snum = lp_servicenumber(jucn->service_name);
+	if(snum < 0) {
+		return False;
+	}
+	status = create_conn_struct_tos_cwd(global_messaging_context(),
+					    snum,
+					    lp_path(talloc_tos(), lp_sub, snum),
+					    session_info,
+					    &c);
+	if (!NT_STATUS_IS_OK(status)) {
+		return False;
+	}
+
+	path_out = talloc_asprintf(c,
+			"%s/%s",
+			lp_path(talloc_tos(), lp_sub, snum),
+			jucn->volume_name);
+	if (path_out == NULL) {
+		TALLOC_FREE(c);
+		return False;
+	}
+	*pp_path_out = path_out;
+	*conn_out = c->conn;
+	return True;
+}
+
+/*
+ * Create a msdfs string in Samba format we can store
+ * in a filesystem object (currently a symlink).
+ */
+
+char *msdfs_link_string(TALLOC_CTX *ctx,
+			const struct referral *reflist,
+			size_t referral_count)
+{
+	char *refpath = NULL;
+	bool insert_comma = false;
+	char *msdfs_link = NULL;
+	size_t i;
+
+	/* Form the msdfs_link contents */
+	msdfs_link = talloc_strdup(ctx, "msdfs:");
+	if (msdfs_link == NULL) {
+		goto err;
+	}
+
+	for( i= 0; i < referral_count; i++) {
+		refpath = talloc_strdup(ctx, reflist[i].alternate_path);
+
+		if (refpath == NULL) {
+			goto err;
+		}
+
+		/* Alternate paths always use Windows separators. */
+		trim_char(refpath, '\\', '\\');
+		if (*refpath == '\0') {
+			if (i == 0) {
+				insert_comma = false;
+			}
+			continue;
+		}
+		if (i > 0 && insert_comma) {
+			msdfs_link = talloc_asprintf_append_buffer(msdfs_link,
+					",%s",
+					refpath);
+		} else {
+			msdfs_link = talloc_asprintf_append_buffer(msdfs_link,
+					"%s",
+					refpath);
+		}
+
+		if (msdfs_link == NULL) {
+			goto err;
+		}
+
+		if (!insert_comma) {
+			insert_comma = true;
+		}
+
+		TALLOC_FREE(refpath);
+	}
+
+	return msdfs_link;
+
+  err:
+
+	TALLOC_FREE(refpath);
+	TALLOC_FREE(msdfs_link);
+	return NULL;
+}
+
+bool create_msdfs_link(const struct junction_map *jucn,
+		       struct auth_session_info *session_info)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	char *path = NULL;
+	connection_struct *conn;
+	struct smb_filename *smb_fname = NULL;
+	struct smb_filename *parent_fname = NULL;
+	struct smb_filename *at_fname = NULL;
+	bool ok;
+	NTSTATUS status;
+	bool ret = false;
+
+	ok = junction_to_local_path_tos(jucn, session_info, &path, &conn);
+	if (!ok) {
+		goto out;
+	}
+
+	if (!CAN_WRITE(conn)) {
+		const struct loadparm_substitution *lp_sub =
+			loadparm_s3_global_substitution();
+		int snum = lp_servicenumber(jucn->service_name);
+
+		DBG_WARNING("Can't create DFS entry on read-only share %s\n",
+			lp_servicename(frame, lp_sub, snum));
+		goto out;
+	}
+
+	smb_fname = synthetic_smb_fname(frame,
+				path,
+				NULL,
+				NULL,
+				0,
+				0);
+	if (smb_fname == NULL) {
+		goto out;
+	}
+
+	status = parent_pathref(frame,
+				conn->cwd_fsp,
+				smb_fname,
+				&parent_fname,
+				&at_fname);
+	if (!NT_STATUS_IS_OK(status)) {
+		goto out;
+	}
+
+	status = SMB_VFS_CREATE_DFS_PATHAT(conn,
+				parent_fname->fsp,
+				at_fname,
+				jucn->referral_list,
+				jucn->referral_count);
+	if (!NT_STATUS_IS_OK(status)) {
+		if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_COLLISION)) {
+			int retval = SMB_VFS_UNLINKAT(conn,
+						parent_fname->fsp,
+						at_fname,
+						0);
+			if (retval != 0) {
+				goto out;
+			}
+		}
+		status = SMB_VFS_CREATE_DFS_PATHAT(conn,
+				parent_fname->fsp,
+				at_fname,
+				jucn->referral_list,
+				jucn->referral_count);
+		if (!NT_STATUS_IS_OK(status)) {
+			DBG_WARNING("SMB_VFS_CREATE_DFS_PATHAT failed "
+				"%s - Error: %s\n",
+				path,
+				nt_errstr(status));
+			goto out;
+		}
+	}
+
+	ret = true;
+
+out:
+	TALLOC_FREE(frame);
+	return ret;
+}
+
+bool remove_msdfs_link(const struct junction_map *jucn,
+		       struct auth_session_info *session_info)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	char *path = NULL;
+	connection_struct *conn;
+	bool ret = False;
+	struct smb_filename *smb_fname;
+	struct smb_filename *parent_fname = NULL;
+	struct smb_filename *at_fname = NULL;
+	NTSTATUS status;
+	bool ok;
+	int retval;
+
+	ok = junction_to_local_path_tos(jucn, session_info, &path, &conn);
+	if (!ok) {
+		TALLOC_FREE(frame);
+		return false;
+	}
+
+	if (!CAN_WRITE(conn)) {
+		const struct loadparm_substitution *lp_sub =
+			loadparm_s3_global_substitution();
+		int snum = lp_servicenumber(jucn->service_name);
+
+		DBG_WARNING("Can't remove DFS entry on read-only share %s\n",
+			lp_servicename(frame, lp_sub, snum));
+		TALLOC_FREE(frame);
+		return false;
+	}
+
+	smb_fname = synthetic_smb_fname(frame,
+					path,
+					NULL,
+					NULL,
+					0,
+					0);
+	if (smb_fname == NULL) {
+		TALLOC_FREE(frame);
+		errno = ENOMEM;
+		return false;
+	}
+
+	status = parent_pathref(frame,
+				conn->cwd_fsp,
+				smb_fname,
+				&parent_fname,
+				&at_fname);
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(frame);
+		return false;
+	}
+
+	retval = SMB_VFS_UNLINKAT(conn,
+			parent_fname->fsp,
+			at_fname,
+			0);
+	if (retval == 0) {
+		ret = True;
+	}
+
+	TALLOC_FREE(frame);
+	return ret;
+}
+
+/*********************************************************************
+ Return the number of DFS links at the root of this share.
+*********************************************************************/
+
+static size_t count_dfs_links(TALLOC_CTX *ctx,
+			      struct auth_session_info *session_info,
+			      int snum)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	size_t cnt = 0;
+	const char *dname = NULL;
+	char *talloced = NULL;
+	const char *connect_path = lp_path(frame, lp_sub, snum);
+	const char *msdfs_proxy = lp_msdfs_proxy(frame, lp_sub, snum);
+	struct conn_struct_tos *c = NULL;
+	connection_struct *conn = NULL;
+	NTSTATUS status;
+	struct smb_filename *smb_fname = NULL;
+	struct smb_Dir *dir_hnd = NULL;
+	long offset = 0;
+
+	if(*connect_path == '\0') {
+		TALLOC_FREE(frame);
+		return 0;
+	}
+
+	/*
+	 * Fake up a connection struct for the VFS layer.
+	 */
+
+	status = create_conn_struct_tos_cwd(global_messaging_context(),
+					    snum,
+					    connect_path,
+					    session_info,
+					    &c);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("create_conn_struct failed: %s\n",
+			  nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return 0;
+	}
+	conn = c->conn;
+
+	/* Count a link for the msdfs root - convention */
+	cnt = 1;
+
+	/* No more links if this is an msdfs proxy. */
+	if (*msdfs_proxy != '\0') {
+		goto out;
+	}
+
+	smb_fname = synthetic_smb_fname(frame,
+					".",
+					NULL,
+					NULL,
+					0,
+					0);
+	if (smb_fname == NULL) {
+		goto out;
+	}
+
+	/* Now enumerate all dfs links */
+	status = OpenDir(frame,
+			 conn,
+			 smb_fname,
+			 NULL,
+			 0,
+			 &dir_hnd);
+	if (!NT_STATUS_IS_OK(status)) {
+		errno = map_errno_from_nt_status(status);
+		goto out;
+	}
+
+        while ((dname = ReadDirName(dir_hnd, &offset, NULL, &talloced))
+	       != NULL)
+	{
+		struct smb_filename *smb_dname =
+			synthetic_smb_fname(frame,
+					dname,
+					NULL,
+					NULL,
+					0,
+					0);
+		if (smb_dname == NULL) {
+			goto out;
+		}
+		if (is_msdfs_link(dir_hnd_fetch_fsp(dir_hnd), smb_dname)) {
+			if (cnt + 1 < cnt) {
+				cnt = 0;
+				goto out;
+			}
+			cnt++;
+		}
+		TALLOC_FREE(talloced);
+		TALLOC_FREE(smb_dname);
+	}
+
+out:
+	TALLOC_FREE(frame);
+	return cnt;
+}
+
+/*********************************************************************
+*********************************************************************/
+
+static int form_junctions(TALLOC_CTX *ctx,
+			  struct auth_session_info *session_info,
+				int snum,
+				struct junction_map *jucn,
+				size_t jn_remain)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	const struct loadparm_substitution *lp_sub =
+		loadparm_s3_global_substitution();
+	size_t cnt = 0;
+	const char *dname = NULL;
+	char *talloced = NULL;
+	const char *connect_path = lp_path(frame, lp_sub, snum);
+	char *service_name = lp_servicename(frame, lp_sub, snum);
+	const char *msdfs_proxy = lp_msdfs_proxy(frame, lp_sub, snum);
+	struct conn_struct_tos *c = NULL;
+	connection_struct *conn = NULL;
+	struct referral *ref = NULL;
+	struct smb_filename *smb_fname = NULL;
+	struct smb_Dir *dir_hnd = NULL;
+	long offset = 0;
+	NTSTATUS status;
+
+	if (jn_remain == 0) {
+		TALLOC_FREE(frame);
+		return 0;
+	}
+
+	if(*connect_path == '\0') {
+		TALLOC_FREE(frame);
+		return 0;
+	}
+
+	/*
+	 * Fake up a connection struct for the VFS layer.
+	 */
+
+	status = create_conn_struct_tos_cwd(global_messaging_context(),
+					    snum,
+					    connect_path,
+					    session_info,
+					    &c);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("create_conn_struct failed: %s\n",
+			  nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return 0;
+	}
+	conn = c->conn;
+
+	/* form a junction for the msdfs root - convention
+	   DO NOT REMOVE THIS: NT clients will not work with us
+	   if this is not present
+	*/
+	jucn[cnt].service_name = talloc_strdup(ctx,service_name);
+	jucn[cnt].volume_name = talloc_strdup(ctx, "");
+	if (!jucn[cnt].service_name || !jucn[cnt].volume_name) {
+		goto out;
+	}
+	jucn[cnt].comment = "";
+	jucn[cnt].referral_count = 1;
+
+	ref = jucn[cnt].referral_list = talloc_zero(ctx, struct referral);
+	if (jucn[cnt].referral_list == NULL) {
+		goto out;
+	}
+
+	ref->proximity = 0;
+	ref->ttl = REFERRAL_TTL;
+	if (*msdfs_proxy != '\0') {
+		ref->alternate_path = talloc_strdup(ctx,
+						msdfs_proxy);
+	} else {
+		ref->alternate_path = talloc_asprintf(ctx,
+			"\\\\%s\\%s",
+			get_local_machine_name(),
+			service_name);
+	}
+
+	if (!ref->alternate_path) {
+		goto out;
+	}
+	cnt++;
+
+	/* Don't enumerate if we're an msdfs proxy. */
+	if (*msdfs_proxy != '\0') {
+		goto out;
+	}
+
+	smb_fname = synthetic_smb_fname(frame,
+					".",
+					NULL,
+					NULL,
+					0,
+					0);
+	if (smb_fname == NULL) {
+		goto out;
+	}
+
+	/* Now enumerate all dfs links */
+	status = OpenDir(frame,
+			 conn,
+			 smb_fname,
+			 NULL,
+			 0,
+			 &dir_hnd);
+	if (!NT_STATUS_IS_OK(status)) {
+		errno = map_errno_from_nt_status(status);
+		goto out;
+	}
+
+        while ((dname = ReadDirName(dir_hnd, &offset, NULL, &talloced))
+	       != NULL)
+	{
+		struct smb_filename *smb_dname = NULL;
+
+		if (cnt >= jn_remain) {
+			DEBUG(2, ("form_junctions: ran out of MSDFS "
+				"junction slots"));
+			TALLOC_FREE(talloced);
+			goto out;
+		}
+		smb_dname = synthetic_smb_fname(talloc_tos(),
+				dname,
+				NULL,
+				NULL,
+				0,
+				0);
+		if (smb_dname == NULL) {
+			TALLOC_FREE(talloced);
+			goto out;
+		}
+
+		status = SMB_VFS_READ_DFS_PATHAT(conn,
+				ctx,
+				conn->cwd_fsp,
+				smb_dname,
+				&jucn[cnt].referral_list,
+				&jucn[cnt].referral_count);
+
+		if (NT_STATUS_IS_OK(status)) {
+			jucn[cnt].service_name = talloc_strdup(ctx,
+							service_name);
+			jucn[cnt].volume_name = talloc_strdup(ctx, dname);
+			if (!jucn[cnt].service_name || !jucn[cnt].volume_name) {
+				TALLOC_FREE(talloced);
+				goto out;
+			}
+			jucn[cnt].comment = "";
+			cnt++;
+		}
+		TALLOC_FREE(talloced);
+		TALLOC_FREE(smb_dname);
+	}
+
+out:
+	TALLOC_FREE(frame);
+	return cnt;
+}
+
+struct junction_map *enum_msdfs_links(TALLOC_CTX *ctx,
+				      struct auth_session_info *session_info,
+				      size_t *p_num_jn)
+{
+	struct junction_map *jn = NULL;
+	int i=0;
+	size_t jn_count = 0;
+	int sharecount = 0;
+
+	*p_num_jn = 0;
+	if(!lp_host_msdfs()) {
+		return NULL;
+	}
+
+	/* Ensure all the usershares are loaded. */
+	become_root();
+	load_registry_shares();
+	sharecount = load_usershare_shares(NULL, connections_snum_used);
+	unbecome_root();
+
+	for(i=0;i < sharecount;i++) {
+		if(lp_msdfs_root(i)) {
+			jn_count += count_dfs_links(ctx, session_info, i);
+		}
+	}
+	if (jn_count == 0) {
+		return NULL;
+	}
+	jn = talloc_array(ctx,  struct junction_map, jn_count);
+	if (!jn) {
+		return NULL;
+	}
+	for(i=0; i < sharecount; i++) {
+		if (*p_num_jn >= jn_count) {
+			break;
+		}
+		if(lp_msdfs_root(i)) {
+			*p_num_jn += form_junctions(ctx,
+					session_info,
+					i,
+					&jn[*p_num_jn],
+					jn_count - *p_num_jn);
+		}
+	}
+	return jn;
+}