Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 810 insertions, 0 deletions

diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c
new file mode 100644
index 000000000..e90a1e8c1
--- /dev/null
+++ b/fs/smb/server/smb_common.c
@@ -0,0 +1,810 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ *   Copyright (C) 2018 Namjae Jeon <linkinjeon@kernel.org>
+ */
+
+#include <linux/user_namespace.h>
+
+#include "smb_common.h"
+#include "server.h"
+#include "misc.h"
+#include "smbstatus.h"
+#include "connection.h"
+#include "ksmbd_work.h"
+#include "mgmt/user_session.h"
+#include "mgmt/user_config.h"
+#include "mgmt/tree_connect.h"
+#include "mgmt/share_config.h"
+
+/*for shortname implementation */
+static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
+#define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1)
+#define MAGIC_CHAR '~'
+#define PERIOD '.'
+#define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
+
+struct smb_protocol {
+	int		index;
+	char		*name;
+	char		*prot;
+	__u16		prot_id;
+};
+
+static struct smb_protocol smb1_protos[] = {
+	{
+		SMB21_PROT,
+		"\2SMB 2.1",
+		"SMB2_10",
+		SMB21_PROT_ID
+	},
+	{
+		SMB2X_PROT,
+		"\2SMB 2.???",
+		"SMB2_22",
+		SMB2X_PROT_ID
+	},
+};
+
+static struct smb_protocol smb2_protos[] = {
+	{
+		SMB21_PROT,
+		"\2SMB 2.1",
+		"SMB2_10",
+		SMB21_PROT_ID
+	},
+	{
+		SMB30_PROT,
+		"\2SMB 3.0",
+		"SMB3_00",
+		SMB30_PROT_ID
+	},
+	{
+		SMB302_PROT,
+		"\2SMB 3.02",
+		"SMB3_02",
+		SMB302_PROT_ID
+	},
+	{
+		SMB311_PROT,
+		"\2SMB 3.1.1",
+		"SMB3_11",
+		SMB311_PROT_ID
+	},
+};
+
+unsigned int ksmbd_server_side_copy_max_chunk_count(void)
+{
+	return 256;
+}
+
+unsigned int ksmbd_server_side_copy_max_chunk_size(void)
+{
+	return (2U << 30) - 1;
+}
+
+unsigned int ksmbd_server_side_copy_max_total_size(void)
+{
+	return (2U << 30) - 1;
+}
+
+inline int ksmbd_min_protocol(void)
+{
+	return SMB21_PROT;
+}
+
+inline int ksmbd_max_protocol(void)
+{
+	return SMB311_PROT;
+}
+
+int ksmbd_lookup_protocol_idx(char *str)
+{
+	int offt = ARRAY_SIZE(smb1_protos) - 1;
+	int len = strlen(str);
+
+	while (offt >= 0) {
+		if (!strncmp(str, smb1_protos[offt].prot, len)) {
+			ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
+				    smb1_protos[offt].prot, offt);
+			return smb1_protos[offt].index;
+		}
+		offt--;
+	}
+
+	offt = ARRAY_SIZE(smb2_protos) - 1;
+	while (offt >= 0) {
+		if (!strncmp(str, smb2_protos[offt].prot, len)) {
+			ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
+				    smb2_protos[offt].prot, offt);
+			return smb2_protos[offt].index;
+		}
+		offt--;
+	}
+	return -1;
+}
+
+/**
+ * ksmbd_verify_smb_message() - check for valid smb2 request header
+ * @work:	smb work
+ *
+ * check for valid smb signature and packet direction(request/response)
+ *
+ * Return:      0 on success, otherwise -EINVAL
+ */
+int ksmbd_verify_smb_message(struct ksmbd_work *work)
+{
+	struct smb2_hdr *smb2_hdr = ksmbd_req_buf_next(work);
+	struct smb_hdr *hdr;
+
+	if (smb2_hdr->ProtocolId == SMB2_PROTO_NUMBER)
+		return ksmbd_smb2_check_message(work);
+
+	hdr = work->request_buf;
+	if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER &&
+	    hdr->Command == SMB_COM_NEGOTIATE) {
+		work->conn->outstanding_credits++;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * ksmbd_smb_request() - check for valid smb request type
+ * @conn:	connection instance
+ *
+ * Return:      true on success, otherwise false
+ */
+bool ksmbd_smb_request(struct ksmbd_conn *conn)
+{
+	__le32 *proto;
+
+	if (conn->request_buf[0] != 0)
+		return false;
+
+	proto = (__le32 *)smb2_get_msg(conn->request_buf);
+	if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) {
+		pr_err_ratelimited("smb2 compression not support yet");
+		return false;
+	}
+
+	if (*proto != SMB1_PROTO_NUMBER &&
+	    *proto != SMB2_PROTO_NUMBER &&
+	    *proto != SMB2_TRANSFORM_PROTO_NUM)
+		return false;
+
+	return true;
+}
+
+static bool supported_protocol(int idx)
+{
+	if (idx == SMB2X_PROT &&
+	    (server_conf.min_protocol >= SMB21_PROT ||
+	     server_conf.max_protocol <= SMB311_PROT))
+		return true;
+
+	return (server_conf.min_protocol <= idx &&
+		idx <= server_conf.max_protocol);
+}
+
+static char *next_dialect(char *dialect, int *next_off, int bcount)
+{
+	dialect = dialect + *next_off;
+	*next_off = strnlen(dialect, bcount);
+	if (dialect[*next_off] != '\0')
+		return NULL;
+	return dialect;
+}
+
+static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count)
+{
+	int i, seq_num, bcount, next;
+	char *dialect;
+
+	for (i = ARRAY_SIZE(smb1_protos) - 1; i >= 0; i--) {
+		seq_num = 0;
+		next = 0;
+		dialect = cli_dialects;
+		bcount = le16_to_cpu(byte_count);
+		do {
+			dialect = next_dialect(dialect, &next, bcount);
+			if (!dialect)
+				break;
+			ksmbd_debug(SMB, "client requested dialect %s\n",
+				    dialect);
+			if (!strcmp(dialect, smb1_protos[i].name)) {
+				if (supported_protocol(smb1_protos[i].index)) {
+					ksmbd_debug(SMB,
+						    "selected %s dialect\n",
+						    smb1_protos[i].name);
+					if (smb1_protos[i].index == SMB1_PROT)
+						return seq_num;
+					return smb1_protos[i].prot_id;
+				}
+			}
+			seq_num++;
+			bcount -= (++next);
+		} while (bcount > 0);
+	}
+
+	return BAD_PROT_ID;
+}
+
+int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count)
+{
+	int i;
+	int count;
+
+	for (i = ARRAY_SIZE(smb2_protos) - 1; i >= 0; i--) {
+		count = le16_to_cpu(dialects_count);
+		while (--count >= 0) {
+			ksmbd_debug(SMB, "client requested dialect 0x%x\n",
+				    le16_to_cpu(cli_dialects[count]));
+			if (le16_to_cpu(cli_dialects[count]) !=
+					smb2_protos[i].prot_id)
+				continue;
+
+			if (supported_protocol(smb2_protos[i].index)) {
+				ksmbd_debug(SMB, "selected %s dialect\n",
+					    smb2_protos[i].name);
+				return smb2_protos[i].prot_id;
+			}
+		}
+	}
+
+	return BAD_PROT_ID;
+}
+
+static int ksmbd_negotiate_smb_dialect(void *buf)
+{
+	int smb_buf_length = get_rfc1002_len(buf);
+	__le32 proto = ((struct smb2_hdr *)smb2_get_msg(buf))->ProtocolId;
+
+	if (proto == SMB2_PROTO_NUMBER) {
+		struct smb2_negotiate_req *req;
+		int smb2_neg_size =
+			offsetof(struct smb2_negotiate_req, Dialects);
+
+		req = (struct smb2_negotiate_req *)smb2_get_msg(buf);
+		if (smb2_neg_size > smb_buf_length)
+			goto err_out;
+
+		if (struct_size(req, Dialects, le16_to_cpu(req->DialectCount)) >
+		    smb_buf_length)
+			goto err_out;
+
+		return ksmbd_lookup_dialect_by_id(req->Dialects,
+						  req->DialectCount);
+	}
+
+	proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol;
+	if (proto == SMB1_PROTO_NUMBER) {
+		struct smb_negotiate_req *req;
+
+		req = (struct smb_negotiate_req *)buf;
+		if (le16_to_cpu(req->ByteCount) < 2)
+			goto err_out;
+
+		if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 +
+			le16_to_cpu(req->ByteCount) > smb_buf_length) {
+			goto err_out;
+		}
+
+		return ksmbd_lookup_dialect_by_name(req->DialectsArray,
+						    req->ByteCount);
+	}
+
+err_out:
+	return BAD_PROT_ID;
+}
+
+#define SMB_COM_NEGOTIATE_EX	0x0
+
+/**
+ * get_smb1_cmd_val() - get smb command value from smb header
+ * @work:	smb work containing smb header
+ *
+ * Return:      smb command value
+ */
+static u16 get_smb1_cmd_val(struct ksmbd_work *work)
+{
+	return SMB_COM_NEGOTIATE_EX;
+}
+
+/**
+ * init_smb1_rsp_hdr() - initialize smb negotiate response header
+ * @work:	smb work containing smb request
+ *
+ * Return:      0 on success, otherwise -EINVAL
+ */
+static int init_smb1_rsp_hdr(struct ksmbd_work *work)
+{
+	struct smb_hdr *rsp_hdr = (struct smb_hdr *)work->response_buf;
+	struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf;
+
+	rsp_hdr->Command = SMB_COM_NEGOTIATE;
+	*(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER;
+	rsp_hdr->Flags = SMBFLG_RESPONSE;
+	rsp_hdr->Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS |
+		SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME;
+	rsp_hdr->Pid = rcv_hdr->Pid;
+	rsp_hdr->Mid = rcv_hdr->Mid;
+	return 0;
+}
+
+/**
+ * smb1_check_user_session() - check for valid session for a user
+ * @work:	smb work containing smb request buffer
+ *
+ * Return:      0 on success, otherwise error
+ */
+static int smb1_check_user_session(struct ksmbd_work *work)
+{
+	unsigned int cmd = work->conn->ops->get_cmd_val(work);
+
+	if (cmd == SMB_COM_NEGOTIATE_EX)
+		return 0;
+
+	return -EINVAL;
+}
+
+/**
+ * smb1_allocate_rsp_buf() - allocate response buffer for a command
+ * @work:	smb work containing smb request
+ *
+ * Return:      0 on success, otherwise -ENOMEM
+ */
+static int smb1_allocate_rsp_buf(struct ksmbd_work *work)
+{
+	work->response_buf = kzalloc(MAX_CIFS_SMALL_BUFFER_SIZE,
+			GFP_KERNEL);
+	work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE;
+
+	if (!work->response_buf) {
+		pr_err("Failed to allocate %u bytes buffer\n",
+				MAX_CIFS_SMALL_BUFFER_SIZE);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/**
+ * set_smb1_rsp_status() - set error type in smb response header
+ * @work:	smb work containing smb response header
+ * @err:	error code to set in response
+ */
+static void set_smb1_rsp_status(struct ksmbd_work *work, __le32 err)
+{
+	work->send_no_response = 1;
+}
+
+static struct smb_version_ops smb1_server_ops = {
+	.get_cmd_val = get_smb1_cmd_val,
+	.init_rsp_hdr = init_smb1_rsp_hdr,
+	.allocate_rsp_buf = smb1_allocate_rsp_buf,
+	.check_user_session = smb1_check_user_session,
+	.set_rsp_status = set_smb1_rsp_status,
+};
+
+static int smb1_negotiate(struct ksmbd_work *work)
+{
+	return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE);
+}
+
+static struct smb_version_cmds smb1_server_cmds[1] = {
+	[SMB_COM_NEGOTIATE_EX]	= { .proc = smb1_negotiate, },
+};
+
+static int init_smb1_server(struct ksmbd_conn *conn)
+{
+	conn->ops = &smb1_server_ops;
+	conn->cmds = smb1_server_cmds;
+	conn->max_cmds = ARRAY_SIZE(smb1_server_cmds);
+	return 0;
+}
+
+int ksmbd_init_smb_server(struct ksmbd_work *work)
+{
+	struct ksmbd_conn *conn = work->conn;
+	__le32 proto;
+
+	proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol;
+	if (conn->need_neg == false) {
+		if (proto == SMB1_PROTO_NUMBER)
+			return -EINVAL;
+		return 0;
+	}
+
+	if (proto == SMB1_PROTO_NUMBER)
+		return init_smb1_server(conn);
+	return init_smb3_11_server(conn);
+}
+
+int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
+				      struct ksmbd_file *dir,
+				      struct ksmbd_dir_info *d_info,
+				      char *search_pattern,
+				      int (*fn)(struct ksmbd_conn *, int,
+						struct ksmbd_dir_info *,
+						struct ksmbd_kstat *))
+{
+	int i, rc = 0;
+	struct ksmbd_conn *conn = work->conn;
+	struct user_namespace *user_ns = file_mnt_user_ns(dir->filp);
+
+	for (i = 0; i < 2; i++) {
+		struct kstat kstat;
+		struct ksmbd_kstat ksmbd_kstat;
+		struct dentry *dentry;
+
+		if (!dir->dot_dotdot[i]) { /* fill dot entry info */
+			if (i == 0) {
+				d_info->name = ".";
+				d_info->name_len = 1;
+				dentry = dir->filp->f_path.dentry;
+			} else {
+				d_info->name = "..";
+				d_info->name_len = 2;
+				dentry = dir->filp->f_path.dentry->d_parent;
+			}
+
+			if (!match_pattern(d_info->name, d_info->name_len,
+					   search_pattern)) {
+				dir->dot_dotdot[i] = 1;
+				continue;
+			}
+
+			ksmbd_kstat.kstat = &kstat;
+			ksmbd_vfs_fill_dentry_attrs(work,
+						    user_ns,
+						    dentry,
+						    &ksmbd_kstat);
+			rc = fn(conn, info_level, d_info, &ksmbd_kstat);
+			if (rc)
+				break;
+			if (d_info->out_buf_len <= 0)
+				break;
+
+			dir->dot_dotdot[i] = 1;
+			if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) {
+				d_info->out_buf_len = 0;
+				break;
+			}
+		}
+	}
+
+	return rc;
+}
+
+/**
+ * ksmbd_extract_shortname() - get shortname from long filename
+ * @conn:	connection instance
+ * @longname:	source long filename
+ * @shortname:	destination short filename
+ *
+ * Return:	shortname length or 0 when source long name is '.' or '..'
+ * TODO: Though this function comforms the restriction of 8.3 Filename spec,
+ * but the result is different with Windows 7's one. need to check.
+ */
+int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname,
+			    char *shortname)
+{
+	const char *p;
+	char base[9], extension[4];
+	char out[13] = {0};
+	int baselen = 0;
+	int extlen = 0, len = 0;
+	unsigned int csum = 0;
+	const unsigned char *ptr;
+	bool dot_present = true;
+
+	p = longname;
+	if ((*p == '.') || (!(strcmp(p, "..")))) {
+		/*no mangling required */
+		return 0;
+	}
+
+	p = strrchr(longname, '.');
+	if (p == longname) { /*name starts with a dot*/
+		strscpy(extension, "___", strlen("___"));
+	} else {
+		if (p) {
+			p++;
+			while (*p && extlen < 3) {
+				if (*p != '.')
+					extension[extlen++] = toupper(*p);
+				p++;
+			}
+			extension[extlen] = '\0';
+		} else {
+			dot_present = false;
+		}
+	}
+
+	p = longname;
+	if (*p == '.') {
+		p++;
+		longname++;
+	}
+	while (*p && (baselen < 5)) {
+		if (*p != '.')
+			base[baselen++] = toupper(*p);
+		p++;
+	}
+
+	base[baselen] = MAGIC_CHAR;
+	memcpy(out, base, baselen + 1);
+
+	ptr = longname;
+	len = strlen(longname);
+	for (; len > 0; len--, ptr++)
+		csum += *ptr;
+
+	csum = csum % (MANGLE_BASE * MANGLE_BASE);
+	out[baselen + 1] = mangle(csum / MANGLE_BASE);
+	out[baselen + 2] = mangle(csum);
+	out[baselen + 3] = PERIOD;
+
+	if (dot_present)
+		memcpy(out + baselen + 4, extension, 4);
+	else
+		out[baselen + 4] = '\0';
+	smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX,
+			  conn->local_nls, 0);
+	len = strlen(out) * 2;
+	return len;
+}
+
+static int __smb2_negotiate(struct ksmbd_conn *conn)
+{
+	return (conn->dialect >= SMB20_PROT_ID &&
+		conn->dialect <= SMB311_PROT_ID);
+}
+
+static int smb_handle_negotiate(struct ksmbd_work *work)
+{
+	struct smb_negotiate_rsp *neg_rsp = work->response_buf;
+
+	ksmbd_debug(SMB, "Unsupported SMB1 protocol\n");
+
+	if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp,
+			      sizeof(struct smb_negotiate_rsp) - 4))
+		return -ENOMEM;
+
+	neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS;
+	neg_rsp->hdr.WordCount = 1;
+	neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect);
+	neg_rsp->ByteCount = 0;
+	return 0;
+}
+
+int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)
+{
+	struct ksmbd_conn *conn = work->conn;
+	int ret;
+
+	conn->dialect =
+		ksmbd_negotiate_smb_dialect(work->request_buf);
+	ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect);
+
+	if (command == SMB2_NEGOTIATE_HE) {
+		ret = smb2_handle_negotiate(work);
+		return ret;
+	}
+
+	if (command == SMB_COM_NEGOTIATE) {
+		if (__smb2_negotiate(conn)) {
+			init_smb3_11_server(conn);
+			init_smb2_neg_rsp(work);
+			ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n");
+			return 0;
+		}
+		return smb_handle_negotiate(work);
+	}
+
+	pr_err("Unknown SMB negotiation command: %u\n", command);
+	return -EINVAL;
+}
+
+enum SHARED_MODE_ERRORS {
+	SHARE_DELETE_ERROR,
+	SHARE_READ_ERROR,
+	SHARE_WRITE_ERROR,
+	FILE_READ_ERROR,
+	FILE_WRITE_ERROR,
+	FILE_DELETE_ERROR,
+};
+
+static const char * const shared_mode_errors[] = {
+	"Current access mode does not permit SHARE_DELETE",
+	"Current access mode does not permit SHARE_READ",
+	"Current access mode does not permit SHARE_WRITE",
+	"Desired access mode does not permit FILE_READ",
+	"Desired access mode does not permit FILE_WRITE",
+	"Desired access mode does not permit FILE_DELETE",
+};
+
+static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp,
+				  struct ksmbd_file *curr_fp)
+{
+	ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]);
+	ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n",
+		    prev_fp->saccess, curr_fp->daccess);
+}
+
+int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp)
+{
+	int rc = 0;
+	struct ksmbd_file *prev_fp;
+
+	/*
+	 * Lookup fp in master fp list, and check desired access and
+	 * shared mode between previous open and current open.
+	 */
+	read_lock(&curr_fp->f_ci->m_lock);
+	list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) {
+		if (file_inode(filp) != file_inode(prev_fp->filp))
+			continue;
+
+		if (filp == prev_fp->filp)
+			continue;
+
+		if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp))
+			if (strcmp(prev_fp->stream.name, curr_fp->stream.name))
+				continue;
+
+		if (prev_fp->attrib_only != curr_fp->attrib_only)
+			continue;
+
+		if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) &&
+		    curr_fp->daccess & FILE_DELETE_LE) {
+			smb_shared_mode_error(SHARE_DELETE_ERROR,
+					      prev_fp,
+					      curr_fp);
+			rc = -EPERM;
+			break;
+		}
+
+		/*
+		 * Only check FILE_SHARE_DELETE if stream opened and
+		 * normal file opened.
+		 */
+		if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp))
+			continue;
+
+		if (!(prev_fp->saccess & FILE_SHARE_READ_LE) &&
+		    curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) {
+			smb_shared_mode_error(SHARE_READ_ERROR,
+					      prev_fp,
+					      curr_fp);
+			rc = -EPERM;
+			break;
+		}
+
+		if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) &&
+		    curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) {
+			smb_shared_mode_error(SHARE_WRITE_ERROR,
+					      prev_fp,
+					      curr_fp);
+			rc = -EPERM;
+			break;
+		}
+
+		if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) &&
+		    !(curr_fp->saccess & FILE_SHARE_READ_LE)) {
+			smb_shared_mode_error(FILE_READ_ERROR,
+					      prev_fp,
+					      curr_fp);
+			rc = -EPERM;
+			break;
+		}
+
+		if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) &&
+		    !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) {
+			smb_shared_mode_error(FILE_WRITE_ERROR,
+					      prev_fp,
+					      curr_fp);
+			rc = -EPERM;
+			break;
+		}
+
+		if (prev_fp->daccess & FILE_DELETE_LE &&
+		    !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) {
+			smb_shared_mode_error(FILE_DELETE_ERROR,
+					      prev_fp,
+					      curr_fp);
+			rc = -EPERM;
+			break;
+		}
+	}
+	read_unlock(&curr_fp->f_ci->m_lock);
+
+	return rc;
+}
+
+bool is_asterisk(char *p)
+{
+	return p && p[0] == '*';
+}
+
+int ksmbd_override_fsids(struct ksmbd_work *work)
+{
+	struct ksmbd_session *sess = work->sess;
+	struct ksmbd_share_config *share = work->tcon->share_conf;
+	struct cred *cred;
+	struct group_info *gi;
+	unsigned int uid;
+	unsigned int gid;
+
+	uid = user_uid(sess->user);
+	gid = user_gid(sess->user);
+	if (share->force_uid != KSMBD_SHARE_INVALID_UID)
+		uid = share->force_uid;
+	if (share->force_gid != KSMBD_SHARE_INVALID_GID)
+		gid = share->force_gid;
+
+	cred = prepare_kernel_cred(NULL);
+	if (!cred)
+		return -ENOMEM;
+
+	cred->fsuid = make_kuid(&init_user_ns, uid);
+	cred->fsgid = make_kgid(&init_user_ns, gid);
+
+	gi = groups_alloc(0);
+	if (!gi) {
+		abort_creds(cred);
+		return -ENOMEM;
+	}
+	set_groups(cred, gi);
+	put_group_info(gi);
+
+	if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID))
+		cred->cap_effective = cap_drop_fs_set(cred->cap_effective);
+
+	WARN_ON(work->saved_cred);
+	work->saved_cred = override_creds(cred);
+	if (!work->saved_cred) {
+		abort_creds(cred);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+void ksmbd_revert_fsids(struct ksmbd_work *work)
+{
+	const struct cred *cred;
+
+	WARN_ON(!work->saved_cred);
+
+	cred = current_cred();
+	revert_creds(work->saved_cred);
+	put_cred(cred);
+	work->saved_cred = NULL;
+}
+
+__le32 smb_map_generic_desired_access(__le32 daccess)
+{
+	if (daccess & FILE_GENERIC_READ_LE) {
+		daccess |= cpu_to_le32(GENERIC_READ_FLAGS);
+		daccess &= ~FILE_GENERIC_READ_LE;
+	}
+
+	if (daccess & FILE_GENERIC_WRITE_LE) {
+		daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS);
+		daccess &= ~FILE_GENERIC_WRITE_LE;
+	}
+
+	if (daccess & FILE_GENERIC_EXECUTE_LE) {
+		daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS);
+		daccess &= ~FILE_GENERIC_EXECUTE_LE;
+	}
+
+	if (daccess & FILE_GENERIC_ALL_LE) {
+		daccess |= cpu_to_le32(GENERIC_ALL_FLAGS);
+		daccess &= ~FILE_GENERIC_ALL_LE;
+	}
+
+	return daccess;
+}