// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
 *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
 */

#include <linux/inetdevice.h>
#include <net/addrconf.h>
#include <linux/syscalls.h>
#include <linux/namei.h>
#include <linux/statfs.h>
#include <linux/ethtool.h>
#include <linux/falloc.h>

#include "glob.h"
#include "smb2pdu.h"
#include "smbfsctl.h"
#include "oplock.h"
#include "smbacl.h"

#include "auth.h"
#include "asn1.h"
#include "connection.h"
#include "transport_ipc.h"
#include "transport_rdma.h"
#include "vfs.h"
#include "vfs_cache.h"
#include "misc.h"

#include "server.h"
#include "smb_common.h"
#include "smbstatus.h"
#include "ksmbd_work.h"
#include "mgmt/user_config.h"
#include "mgmt/share_config.h"
#include "mgmt/tree_connect.h"
#include "mgmt/user_session.h"
#include "mgmt/ksmbd_ida.h"
#include "ndr.h"

static void __wbuf(struct ksmbd_work *work, void **req, void **rsp)
{
        if (work->next_smb2_rcv_hdr_off) {
                *req = ksmbd_req_buf_next(work);
                *rsp = ksmbd_resp_buf_next(work);
        } else {
                *req = work->request_buf;
                *rsp = work->response_buf;
        }
}

#define WORK_BUFFERS(w, rq, rs) __wbuf((w), (void **)&(rq), (void **)&(rs))

/**
 * check_session_id() - check for valid session id in smb header
 * @conn:       connection instance
 * @id:         session id from smb header
 *
 * Return:      1 if valid session id, otherwise 0
 */
static inline bool check_session_id(struct ksmbd_conn *conn, u64 id)
{
        struct ksmbd_session *sess;

        if (id == 0 || id == -1)
                return false;

        sess = ksmbd_session_lookup_all(conn, id);
        if (sess)
                return true;
        pr_err("Invalid user session id: %llu\n", id);
        return false;
}

struct channel *lookup_chann_list(struct ksmbd_session *sess, struct ksmbd_conn *conn)
{
        struct channel *chann;

        list_for_each_entry(chann, &sess->ksmbd_chann_list, chann_list) {
                if (chann->conn == conn)
                        return chann;
        }

        return NULL;
}

/**
 * smb2_get_ksmbd_tcon() - get tree connection information using a tree id.
 * @work:       smb work
 *
 * Return:      0 if there is a tree connection matched or these are
 *              skipable commands, otherwise error
 */
int smb2_get_ksmbd_tcon(struct ksmbd_work *work)
{
        struct smb2_hdr *req_hdr = work->request_buf;
        int tree_id;

        work->tcon = NULL;
        if (work->conn->ops->get_cmd_val(work) == SMB2_TREE_CONNECT_HE ||
            work->conn->ops->get_cmd_val(work) ==  SMB2_CANCEL_HE ||
            work->conn->ops->get_cmd_val(work) ==  SMB2_LOGOFF_HE) {
                ksmbd_debug(SMB, "skip to check tree connect request\n");
                return 0;
        }

        if (xa_empty(&work->sess->tree_conns)) {
                ksmbd_debug(SMB, "NO tree connected\n");
                return -ENOENT;
        }

        tree_id = le32_to_cpu(req_hdr->Id.SyncId.TreeId);
        work->tcon = ksmbd_tree_conn_lookup(work->sess, tree_id);
        if (!work->tcon) {
                pr_err("Invalid tid %d\n", tree_id);
                return -EINVAL;
        }

        return 1;
}

/**
 * smb2_set_err_rsp() - set error response code on smb response
 * @work:       smb work containing response buffer
 */
void smb2_set_err_rsp(struct ksmbd_work *work)
{
        struct smb2_err_rsp *err_rsp;

        if (work->next_smb2_rcv_hdr_off)
                err_rsp = ksmbd_resp_buf_next(work);
        else
                err_rsp = work->response_buf;

        if (err_rsp->hdr.Status != STATUS_STOPPED_ON_SYMLINK) {
                err_rsp->StructureSize = SMB2_ERROR_STRUCTURE_SIZE2_LE;
                err_rsp->ErrorContextCount = 0;
                err_rsp->Reserved = 0;
                err_rsp->ByteCount = 0;
                err_rsp->ErrorData[0] = 0;
                inc_rfc1001_len(work->response_buf, SMB2_ERROR_STRUCTURE_SIZE2);
        }
}

/**
 * is_smb2_neg_cmd() - is it smb2 negotiation command
 * @work:       smb work containing smb header
 *
 * Return:      true if smb2 negotiation command, otherwise false
 */
bool is_smb2_neg_cmd(struct ksmbd_work *work)
{
        struct smb2_hdr *hdr = work->request_buf;

        /* is it SMB2 header ? */
        if (hdr->ProtocolId != SMB2_PROTO_NUMBER)
                return false;

        /* make sure it is request not response message */
        if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
                return false;

        if (hdr->Command != SMB2_NEGOTIATE)
                return false;

        return true;
}

/**
 * is_smb2_rsp() - is it smb2 response
 * @work:       smb work containing smb response buffer
 *
 * Return:      true if smb2 response, otherwise false
 */
bool is_smb2_rsp(struct ksmbd_work *work)
{
        struct smb2_hdr *hdr = work->response_buf;

        /* is it SMB2 header ? */
        if (hdr->ProtocolId != SMB2_PROTO_NUMBER)
                return false;

        /* make sure it is response not request message */
        if (!(hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR))
                return false;

        return true;
}

/**
 * get_smb2_cmd_val() - get smb command code from smb header
 * @work:       smb work containing smb request buffer
 *
 * Return:      smb2 request command value
 */
u16 get_smb2_cmd_val(struct ksmbd_work *work)
{
        struct smb2_hdr *rcv_hdr;

        if (work->next_smb2_rcv_hdr_off)
                rcv_hdr = ksmbd_req_buf_next(work);
        else
                rcv_hdr = work->request_buf;
        return le16_to_cpu(rcv_hdr->Command);
}

/**
 * set_smb2_rsp_status() - set error response code on smb2 header
 * @work:       smb work containing response buffer
 * @err:        error response code
 */
void set_smb2_rsp_status(struct ksmbd_work *work, __le32 err)
{
        struct smb2_hdr *rsp_hdr;

        if (work->next_smb2_rcv_hdr_off)
                rsp_hdr = ksmbd_resp_buf_next(work);
        else
                rsp_hdr = work->response_buf;
        rsp_hdr->Status = err;
        smb2_set_err_rsp(work);
}

/**
 * init_smb2_neg_rsp() - initialize smb2 response for negotiate command
 * @work:       smb work containing smb request buffer
 *
 * smb2 negotiate response is sent in reply of smb1 negotiate command for
 * dialect auto-negotiation.
 */
int init_smb2_neg_rsp(struct ksmbd_work *work)
{
        struct smb2_hdr *rsp_hdr;
        struct smb2_negotiate_rsp *rsp;
        struct ksmbd_conn *conn = work->conn;

        if (conn->need_neg == false)
                return -EINVAL;

        rsp_hdr = work->response_buf;

        memset(rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);

        rsp_hdr->smb2_buf_length =
                cpu_to_be32(smb2_hdr_size_no_buflen(conn->vals));

        rsp_hdr->ProtocolId = SMB2_PROTO_NUMBER;
        rsp_hdr->StructureSize = SMB2_HEADER_STRUCTURE_SIZE;
        rsp_hdr->CreditRequest = cpu_to_le16(2);
        rsp_hdr->Command = SMB2_NEGOTIATE;
        rsp_hdr->Flags = (SMB2_FLAGS_SERVER_TO_REDIR);
        rsp_hdr->NextCommand = 0;
        rsp_hdr->MessageId = 0;
        rsp_hdr->Id.SyncId.ProcessId = 0;
        rsp_hdr->Id.SyncId.TreeId = 0;
        rsp_hdr->SessionId = 0;
        memset(rsp_hdr->Signature, 0, 16);

        rsp = work->response_buf;

        WARN_ON(ksmbd_conn_good(work));

        rsp->StructureSize = cpu_to_le16(65);
        ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect);
        rsp->DialectRevision = cpu_to_le16(conn->dialect);
        /* Not setting conn guid rsp->ServerGUID, as it
         * not used by client for identifying connection
         */
        rsp->Capabilities = cpu_to_le32(conn->vals->capabilities);
        /* Default Max Message Size till SMB2.0, 64K*/
        rsp->MaxTransactSize = cpu_to_le32(conn->vals->max_trans_size);
        rsp->MaxReadSize = cpu_to_le32(conn->vals->max_read_size);
        rsp->MaxWriteSize = cpu_to_le32(conn->vals->max_write_size);

        rsp->SystemTime = cpu_to_le64(ksmbd_systime());
        rsp->ServerStartTime = 0;

        rsp->SecurityBufferOffset = cpu_to_le16(128);
        rsp->SecurityBufferLength = cpu_to_le16(AUTH_GSS_LENGTH);
        ksmbd_copy_gss_neg_header(((char *)(&rsp->hdr) +
                sizeof(rsp->hdr.smb2_buf_length)) +
                le16_to_cpu(rsp->SecurityBufferOffset));
        inc_rfc1001_len(rsp, sizeof(struct smb2_negotiate_rsp) -
                sizeof(struct smb2_hdr) - sizeof(rsp->Buffer) +
                AUTH_GSS_LENGTH);
        rsp->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED_LE;
        if (server_conf.signing == KSMBD_CONFIG_OPT_MANDATORY)
                rsp->SecurityMode |= SMB2_NEGOTIATE_SIGNING_REQUIRED_LE;
        conn->use_spnego = true;

        ksmbd_conn_set_need_negotiate(work);
        return 0;
}

/**
 * smb2_set_rsp_credits() - set number of credits in response buffer
 * @work:       smb work containing smb response buffer
 */
int smb2_set_rsp_credits(struct ksmbd_work *work)
{
        struct smb2_hdr *req_hdr = ksmbd_req_buf_next(work);
        struct smb2_hdr *hdr = ksmbd_resp_buf_next(work);
        struct ksmbd_conn *conn = work->conn;
        unsigned short credits_requested;
        unsigned short credit_charge, credits_granted = 0;
        unsigned short aux_max, aux_credits;

        if (work->send_no_response)
                return 0;

        hdr->CreditCharge = req_hdr->CreditCharge;

        if (conn->total_credits > conn->max_credits) {
                hdr->CreditRequest = 0;
                pr_err("Total credits overflow: %d\n", conn->total_credits);
                return -EINVAL;
        }

        credit_charge = max_t(unsigned short,
                              le16_to_cpu(req_hdr->CreditCharge), 1);
        credits_requested = max_t(unsigned short,
                                  le16_to_cpu(req_hdr->CreditRequest), 1);

        /* according to smb2.credits smbtorture, Windows server
         * 2016 or later grant up to 8192 credits at once.
         *
         * TODO: Need to adjuct CreditRequest value according to
         * current cpu load
         */
        aux_credits = credits_requested - 1;
        if (hdr->Command == SMB2_NEGOTIATE)
                aux_max = 0;
        else
                aux_max = conn->max_credits - credit_charge;
        aux_credits = min_t(unsigned short, aux_credits, aux_max);
        credits_granted = credit_charge + aux_credits;

        if (conn->max_credits - conn->total_credits < credits_granted)
                credits_granted = conn->max_credits -
                        conn->total_credits;

        conn->total_credits += credits_granted;
        work->credits_granted += credits_granted;

        if (!req_hdr->NextCommand) {
                /* Update CreditRequest in last request */
                hdr->CreditRequest = cpu_to_le16(work->credits_granted);
        }
        ksmbd_debug(SMB,
                    "credits: requested[%d] granted[%d] total_granted[%d]\n",
                    credits_requested, credits_granted,
                    conn->total_credits);
        return 0;
}

/**
 * init_chained_smb2_rsp() - initialize smb2 chained response
 * @work:       smb work containing smb response buffer
 */
static void init_chained_smb2_rsp(struct ksmbd_work *work)
{
        struct smb2_hdr *req = ksmbd_req_buf_next(work);
        struct smb2_hdr *rsp = ksmbd_resp_buf_next(work);
        struct smb2_hdr *rsp_hdr;
        struct smb2_hdr *rcv_hdr;
        int next_hdr_offset = 0;
        int len, new_len;

        /* Len of this response = updated RFC len - offset of previous cmd
         * in the compound rsp
         */

        /* Storing the current local FID which may be needed by subsequent
         * command in the compound request
         */
        if (req->Command == SMB2_CREATE && rsp->Status == STATUS_SUCCESS) {
                work->compound_fid =
                        le64_to_cpu(((struct smb2_create_rsp *)rsp)->
                                VolatileFileId);
                work->compound_pfid =
                        le64_to_cpu(((struct smb2_create_rsp *)rsp)->
                                PersistentFileId);
                work->compound_sid = le64_to_cpu(rsp->SessionId);
        }

        len = get_rfc1002_len(work->response_buf) - work->next_smb2_rsp_hdr_off;
        next_hdr_offset = le32_to_cpu(req->NextCommand);

        new_len = ALIGN(len, 8);
        inc_rfc1001_len(work->response_buf, ((sizeof(struct smb2_hdr) - 4)
                        + new_len - len));
        rsp->NextCommand = cpu_to_le32(new_len);

        work->next_smb2_rcv_hdr_off += next_hdr_offset;
        work->next_smb2_rsp_hdr_off += new_len;
        ksmbd_debug(SMB,
                    "Compound req new_len = %d rcv off = %d rsp off = %d\n",
                    new_len, work->next_smb2_rcv_hdr_off,
                    work->next_smb2_rsp_hdr_off);

        rsp_hdr = ksmbd_resp_buf_next(work);
        rcv_hdr = ksmbd_req_buf_next(work);

        if (!(rcv_hdr->Flags & SMB2_FLAGS_RELATED_OPERATIONS)) {
                ksmbd_debug(SMB, "related flag should be set\n");
                work->compound_fid = KSMBD_NO_FID;
                work->compound_pfid = KSMBD_NO_FID;
        }
        memset((char *)rsp_hdr + 4, 0, sizeof(struct smb2_hdr) + 2);
        rsp_hdr->ProtocolId = SMB2_PROTO_NUMBER;
        rsp_hdr->StructureSize = SMB2_HEADER_STRUCTURE_SIZE;
        rsp_hdr->Command = rcv_hdr->Command;

        /*
         * Message is response. We don't grant oplock yet.
         */
        rsp_hdr->Flags = (SMB2_FLAGS_SERVER_TO_REDIR |
                                SMB2_FLAGS_RELATED_OPERATIONS);
        rsp_hdr->NextCommand = 0;
        rsp_hdr->MessageId = rcv_hdr->MessageId;
        rsp_hdr->Id.SyncId.ProcessId = rcv_hdr->Id.SyncId.ProcessId;
        rsp_hdr->Id.SyncId.TreeId = rcv_hdr->Id.SyncId.TreeId;
        rsp_hdr->SessionId = rcv_hdr->SessionId;
        memcpy(rsp_hdr->Signature, rcv_hdr->Signature, 16);
}

/**
 * is_chained_smb2_message() - check for chained command
 * @work:       smb work containing smb request buffer
 *
 * Return:      true if chained request, otherwise false
 */
bool is_chained_smb2_message(struct ksmbd_work *work)
{
        struct smb2_hdr *hdr = work->request_buf;
        unsigned int len, next_cmd;

        if (hdr->ProtocolId != SMB2_PROTO_NUMBER)
                return false;

        hdr = ksmbd_req_buf_next(work);
        next_cmd = le32_to_cpu(hdr->NextCommand);
        if (next_cmd > 0) {
                if ((u64)work->next_smb2_rcv_hdr_off + next_cmd +
                        __SMB2_HEADER_STRUCTURE_SIZE >
                    get_rfc1002_len(work->request_buf)) {
                        pr_err("next command(%u) offset exceeds smb msg size\n",
                               next_cmd);
                        return false;
                }

                if ((u64)get_rfc1002_len(work->response_buf) + MAX_CIFS_SMALL_BUFFER_SIZE >
                    work->response_sz) {
                        pr_err("next response offset exceeds response buffer size\n");
                        return false;
                }

                ksmbd_debug(SMB, "got SMB2 chained command\n");
                init_chained_smb2_rsp(work);
                return true;
        } else if (work->next_smb2_rcv_hdr_off) {
                /*
                 * This is last request in chained command,
                 * align response to 8 byte
                 */
                len = ALIGN(get_rfc1002_len(work->response_buf), 8);
                len = len - get_rfc1002_len(work->response_buf);
                if (len) {
                        ksmbd_debug(SMB, "padding len %u\n", len);
                        inc_rfc1001_len(work->response_buf, len);
                        if (work->aux_payload_sz)
                                work->aux_payload_sz += len;
                }
        }
        return false;
}

/**
 * init_smb2_rsp_hdr() - initialize smb2 response
 * @work:       smb work containing smb request buffer
 *
 * Return:      0
 */
int init_smb2_rsp_hdr(struct ksmbd_work *work)
{
        struct smb2_hdr *rsp_hdr = work->response_buf;
        struct smb2_hdr *rcv_hdr = work->request_buf;
        struct ksmbd_conn *conn = work->conn;

        memset(rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
        rsp_hdr->smb2_buf_length =
                cpu_to_be32(smb2_hdr_size_no_buflen(conn->vals));
        rsp_hdr->ProtocolId = rcv_hdr->ProtocolId;
        rsp_hdr->StructureSize = SMB2_HEADER_STRUCTURE_SIZE;
        rsp_hdr->Command = rcv_hdr->Command;

        /*
         * Message is response. We don't grant oplock yet.
         */
        rsp_hdr->Flags = (SMB2_FLAGS_SERVER_TO_REDIR);
        rsp_hdr->NextCommand = 0;
        rsp_hdr->MessageId = rcv_hdr->MessageId;
        rsp_hdr->Id.SyncId.ProcessId = rcv_hdr->Id.SyncId.ProcessId;
        rsp_hdr->Id.SyncId.TreeId = rcv_hdr->Id.SyncId.TreeId;
        rsp_hdr->SessionId = rcv_hdr->SessionId;
        memcpy(rsp_hdr->Signature, rcv_hdr->Signature, 16);

        work->syncronous = true;
        if (work->async_id) {
                ksmbd_release_id(&conn->async_ida, work->async_id);
                work->async_id = 0;
        }

        return 0;
}

/**
 * smb2_allocate_rsp_buf() - allocate smb2 response buffer
 * @work:       smb work containing smb request buffer
 *
 * Return:      0 on success, otherwise -ENOMEM
 */
int smb2_allocate_rsp_buf(struct ksmbd_work *work)
{
        struct smb2_hdr *hdr = work->request_buf;
        size_t small_sz = MAX_CIFS_SMALL_BUFFER_SIZE;
        size_t large_sz = small_sz + work->conn->vals->max_trans_size;
        size_t sz = small_sz;
        int cmd = le16_to_cpu(hdr->Command);

        if (cmd == SMB2_IOCTL_HE || cmd == SMB2_QUERY_DIRECTORY_HE)
                sz = large_sz;

        if (cmd == SMB2_QUERY_INFO_HE) {
                struct smb2_query_info_req *req;

                req = work->request_buf;
                if (req->InfoType == SMB2_O_INFO_FILE &&
                    (req->FileInfoClass == FILE_FULL_EA_INFORMATION ||
                     req->FileInfoClass == FILE_ALL_INFORMATION))
                        sz = large_sz;
        }

        /* allocate large response buf for chained commands */
        if (le32_to_cpu(hdr->NextCommand) > 0)
                sz = large_sz;

        work->response_buf = kvmalloc(sz, GFP_KERNEL | __GFP_ZERO);
        if (!work->response_buf)
                return -ENOMEM;

        work->response_sz = sz;
        return 0;
}

/**
 * smb2_check_user_session() - check for valid session for a user
 * @work:       smb work containing smb request buffer
 *
 * Return:      0 on success, otherwise error
 */
int smb2_check_user_session(struct ksmbd_work *work)
{
        struct smb2_hdr *req_hdr = work->request_buf;
        struct ksmbd_conn *conn = work->conn;
        unsigned int cmd = conn->ops->get_cmd_val(work);
        unsigned long long sess_id;

        work->sess = NULL;
        /*
         * SMB2_ECHO, SMB2_NEGOTIATE, SMB2_SESSION_SETUP command do not
         * require a session id, so no need to validate user session's for
         * these commands.
         */
        if (cmd == SMB2_ECHO_HE || cmd == SMB2_NEGOTIATE_HE ||
            cmd == SMB2_SESSION_SETUP_HE)
                return 0;

        if (!ksmbd_conn_good(work))
                return -EINVAL;

        sess_id = le64_to_cpu(req_hdr->SessionId);
        /* Check for validity of user session */
        work->sess = ksmbd_session_lookup_all(conn, sess_id);
        if (work->sess)
                return 1;
        ksmbd_debug(SMB, "Invalid user session, Uid %llu\n", sess_id);
        return -EINVAL;
}

static void destroy_previous_session(struct ksmbd_user *user, u64 id)
{
        struct ksmbd_session *prev_sess = ksmbd_session_lookup_slowpath(id);
        struct ksmbd_user *prev_user;

        if (!prev_sess)
                return;

        prev_user = prev_sess->user;

        if (!prev_user ||
            strcmp(user->name, prev_user->name) ||
            user->passkey_sz != prev_user->passkey_sz ||
            memcmp(user->passkey, prev_user->passkey, user->passkey_sz)) {
                put_session(prev_sess);
                return;
        }

        put_session(prev_sess);
        ksmbd_session_destroy(prev_sess);
}

/**
 * smb2_get_name() - get filename string from on the wire smb format
 * @share:      ksmbd_share_config pointer
 * @src:        source buffer
 * @maxlen:     maxlen of source string
 * @nls_table:  nls_table pointer
 *
 * Return:      matching converted filename on success, otherwise error ptr
 */
static char *
smb2_get_name(struct ksmbd_share_config *share, const char *src,
              const int maxlen, struct nls_table *local_nls)
{
        char *name;

        name = smb_strndup_from_utf16(src, maxlen, 1, local_nls);
        if (IS_ERR(name)) {
                pr_err("failed to get name %ld\n", PTR_ERR(name));
                return name;
        }

        ksmbd_conv_path_to_unix(name);
        ksmbd_strip_last_slash(name);
        return name;
}

int setup_async_work(struct ksmbd_work *work, void (*fn)(void **), void **arg)
{
        struct smb2_hdr *rsp_hdr;
        struct ksmbd_conn *conn = work->conn;
        int id;

        rsp_hdr = work->response_buf;
        rsp_hdr->Flags |= SMB2_FLAGS_ASYNC_COMMAND;

        id = ksmbd_acquire_async_msg_id(&conn->async_ida);
        if (id < 0) {
                pr_err("Failed to alloc async message id\n");
                return id;
        }
        work->syncronous = false;
        work->async_id = id;
        rsp_hdr->Id.AsyncId = cpu_to_le64(id);

        ksmbd_debug(SMB,
                    "Send interim Response to inform async request id : %d\n",
                    work->async_id);

        work->cancel_fn = fn;
        work->cancel_argv = arg;

        if (list_empty(&work->async_request_entry)) {
                spin_lock(&conn->request_lock);
                list_add_tail(&work->async_request_entry, &conn->async_requests);
                spin_unlock(&conn->request_lock);
        }

        return 0;
}

void smb2_send_interim_resp(struct ksmbd_work *work, __le32 status)
{
        struct smb2_hdr *rsp_hdr;

        rsp_hdr = work->response_buf;
        smb2_set_err_rsp(work);
        rsp_hdr->Status = status;

        work->multiRsp = 1;
        ksmbd_conn_write(work);
        rsp_hdr->Status = 0;
        work->multiRsp = 0;
}

static __le32 smb2_get_reparse_tag_special_file(umode_t mode)
{
        if (S_ISDIR(mode) || S_ISREG(mode))
                return 0;

        if (S_ISLNK(mode))
                return IO_REPARSE_TAG_LX_SYMLINK_LE;
        else if (S_ISFIFO(mode))
                return IO_REPARSE_TAG_LX_FIFO_LE;
        else if (S_ISSOCK(mode))
                return IO_REPARSE_TAG_AF_UNIX_LE;
        else if (S_ISCHR(mode))
                return IO_REPARSE_TAG_LX_CHR_LE;
        else if (S_ISBLK(mode))
                return IO_REPARSE_TAG_LX_BLK_LE;

        return 0;
}

/**
 * smb2_get_dos_mode() - get file mode in dos format from unix mode
 * @stat:       kstat containing file mode
 * @attribute:  attribute flags
 *
 * Return:      converted dos mode
 */
static int smb2_get_dos_mode(struct kstat *stat, int attribute)
{
        int attr = 0;

        if (S_ISDIR(stat->mode)) {
                attr = ATTR_DIRECTORY |
                        (attribute & (ATTR_HIDDEN | ATTR_SYSTEM));
        } else {
                attr = (attribute & 0x00005137) | ATTR_ARCHIVE;
                attr &= ~(ATTR_DIRECTORY);
                if (S_ISREG(stat->mode) && (server_conf.share_fake_fscaps &
                                FILE_SUPPORTS_SPARSE_FILES))
                        attr |= ATTR_SPARSE;

                if (smb2_get_reparse_tag_special_file(stat->mode))
                        attr |= ATTR_REPARSE;
        }

        return attr;
}

static void build_preauth_ctxt(struct smb2_preauth_neg_context *pneg_ctxt,
                               __le16 hash_id)
{
        pneg_ctxt->ContextType = SMB2_PREAUTH_INTEGRITY_CAPABILITIES;
        pneg_ctxt->DataLength = cpu_to_le16(38);
        pneg_ctxt->HashAlgorithmCount = cpu_to_le16(1);
        pneg_ctxt->Reserved = cpu_to_le32(0);
        pneg_ctxt->SaltLength = cpu_to_le16(SMB311_SALT_SIZE);
        get_random_bytes(pneg_ctxt->Salt, SMB311_SALT_SIZE);
        pneg_ctxt->HashAlgorithms = hash_id;
}

static void build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt,
                               __le16 cipher_type)
{
        pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
        pneg_ctxt->DataLength = cpu_to_le16(4);
        pneg_ctxt->Reserved = cpu_to_le32(0);
        pneg_ctxt->CipherCount = cpu_to_le16(1);
        pneg_ctxt->Ciphers[0] = cipher_type;
}

static void build_compression_ctxt(struct smb2_compression_ctx *pneg_ctxt,
                                   __le16 comp_algo)
{
        pneg_ctxt->ContextType = SMB2_COMPRESSION_CAPABILITIES;
        pneg_ctxt->DataLength =
                cpu_to_le16(sizeof(struct smb2_compression_ctx)
                        - sizeof(struct smb2_neg_context));
        pneg_ctxt->Reserved = cpu_to_le32(0);
        pneg_ctxt->CompressionAlgorithmCount = cpu_to_le16(1);
        pneg_ctxt->Reserved1 = cpu_to_le32(0);
        pneg_ctxt->CompressionAlgorithms[0] = comp_algo;
}

static void build_sign_cap_ctxt(struct smb2_signing_capabilities *pneg_ctxt,
                                __le16 sign_algo)
{
        pneg_ctxt->ContextType = SMB2_SIGNING_CAPABILITIES;
        pneg_ctxt->DataLength =
                cpu_to_le16((sizeof(struct smb2_signing_capabilities) + 2)
                        - sizeof(struct smb2_neg_context));
        pneg_ctxt->Reserved = cpu_to_le32(0);
        pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(1);
        pneg_ctxt->SigningAlgorithms[0] = sign_algo;
}

static void build_posix_ctxt(struct smb2_posix_neg_context *pneg_ctxt)
{
        pneg_ctxt->ContextType = SMB2_POSIX_EXTENSIONS_AVAILABLE;
        pneg_ctxt->DataLength = cpu_to_le16(POSIX_CTXT_DATA_LEN);
        /* SMB2_CREATE_TAG_POSIX is "0x93AD25509CB411E7B42383DE968BCD7C" */
        pneg_ctxt->Name[0] = 0x93;
        pneg_ctxt->Name[1] = 0xAD;
        pneg_ctxt->Name[2] = 0x25;
        pneg_ctxt->Name[3] = 0x50;
        pneg_ctxt->Name[4] = 0x9C;
        pneg_ctxt->Name[5] = 0xB4;
        pneg_ctxt->Name[6] = 0x11;
        pneg_ctxt->Name[7] = 0xE7;
        pneg_ctxt->Name[8] = 0xB4;
        pneg_ctxt->Name[9] = 0x23;
        pneg_ctxt->Name[10] = 0x83;
        pneg_ctxt->Name[11] = 0xDE;
        pneg_ctxt->Name[12] = 0x96;
        pneg_ctxt->Name[13] = 0x8B;
        pneg_ctxt->Name[14] = 0xCD;
        pneg_ctxt->Name[15] = 0x7C;
}

static void assemble_neg_contexts(struct ksmbd_conn *conn,
                                  struct smb2_negotiate_rsp *rsp)
{
        /* +4 is to account for the RFC1001 len field */
        char *pneg_ctxt = (char *)rsp +
                        le32_to_cpu(rsp->NegotiateContextOffset) + 4;
        int neg_ctxt_cnt = 1;
        int ctxt_size;

        ksmbd_debug(SMB,
                    "assemble SMB2_PREAUTH_INTEGRITY_CAPABILITIES context\n");
        build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt,
                           conn->preauth_info->Preauth_HashId);
        rsp->NegotiateContextCount = cpu_to_le16(neg_ctxt_cnt);
        inc_rfc1001_len(rsp, AUTH_GSS_PADDING);
        ctxt_size = sizeof(struct smb2_preauth_neg_context);
        /* Round to 8 byte boundary */
        pneg_ctxt += round_up(sizeof(struct smb2_preauth_neg_context), 8);

        if (conn->cipher_type) {
                ctxt_size = round_up(ctxt_size, 8);
                ksmbd_debug(SMB,
                            "assemble SMB2_ENCRYPTION_CAPABILITIES context\n");
                build_encrypt_ctxt((struct smb2_encryption_neg_context *)pneg_ctxt,
                                   conn->cipher_type);
                rsp->NegotiateContextCount = cpu_to_le16(++neg_ctxt_cnt);
                ctxt_size += sizeof(struct smb2_encryption_neg_context) + 2;
                /* Round to 8 byte boundary */
                pneg_ctxt +=
                        round_up(sizeof(struct smb2_encryption_neg_context) + 2,
                                 8);
        }

        if (conn->compress_algorithm) {
                ctxt_size = round_up(ctxt_size, 8);
                ksmbd_debug(SMB,
                            "assemble SMB2_COMPRESSION_CAPABILITIES context\n");
                /* Temporarily set to SMB3_COMPRESS_NONE */
                build_compression_ctxt((struct smb2_compression_ctx *)pneg_ctxt,
                                       conn->compress_algorithm);
                rsp->NegotiateContextCount = cpu_to_le16(++neg_ctxt_cnt);
                ctxt_size += sizeof(struct smb2_compression_ctx) + 2;
                /* Round to 8 byte boundary */
                pneg_ctxt += round_up(sizeof(struct smb2_compression_ctx) + 2,
                                      8);
        }

        if (conn->posix_ext_supported) {
                ctxt_size = round_up(ctxt_size, 8);
                ksmbd_debug(SMB,
                            "assemble SMB2_POSIX_EXTENSIONS_AVAILABLE context\n");
                build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
                rsp->NegotiateContextCount = cpu_to_le16(++neg_ctxt_cnt);
                ctxt_size += sizeof(struct smb2_posix_neg_context);
                /* Round to 8 byte boundary */
                pneg_ctxt += round_up(sizeof(struct smb2_posix_neg_context), 8);
        }

        if (conn->signing_negotiated) {
                ctxt_size = round_up(ctxt_size, 8);
                ksmbd_debug(SMB,
                            "assemble SMB2_SIGNING_CAPABILITIES context\n");
                build_sign_cap_ctxt((struct smb2_signing_capabilities *)pneg_ctxt,
                                    conn->signing_algorithm);
                rsp->NegotiateContextCount = cpu_to_le16(++neg_ctxt_cnt);
                ctxt_size += sizeof(struct smb2_signing_capabilities) + 2;
        }

        inc_rfc1001_len(rsp, ctxt_size);
}

static __le32 decode_preauth_ctxt(struct ksmbd_conn *conn,
                                  struct smb2_preauth_neg_context *pneg_ctxt)
{
        __le32 err = STATUS_NO_PREAUTH_INTEGRITY_HASH_OVERLAP;

        if (pneg_ctxt->HashAlgorithms == SMB2_PREAUTH_INTEGRITY_SHA512) {
                conn->preauth_info->Preauth_HashId =
                        SMB2_PREAUTH_INTEGRITY_SHA512;
                err = STATUS_SUCCESS;
        }

        return err;
}

static void decode_encrypt_ctxt(struct ksmbd_conn *conn,
                                struct smb2_encryption_neg_context *pneg_ctxt,
                                int len_of_ctxts)
{
        int cph_cnt = le16_to_cpu(pneg_ctxt->CipherCount);
        int i, cphs_size = cph_cnt * sizeof(__le16);

        conn->cipher_type = 0;

        if (sizeof(struct smb2_encryption_neg_context) + cphs_size >
            len_of_ctxts) {
                pr_err("Invalid cipher count(%d)\n", cph_cnt);
                return;
        }

        if (!(server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION))
                return;

        for (i = 0; i < cph_cnt; i++) {
                if (pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES128_GCM ||
                    pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES128_CCM ||
                    pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES256_CCM ||
                    pneg_ctxt->Ciphers[i] == SMB2_ENCRYPTION_AES256_GCM) {
                        ksmbd_debug(SMB, "Cipher ID = 0x%x\n",
                                    pneg_ctxt->Ciphers[i]);
                        conn->cipher_type = pneg_ctxt->Ciphers[i];
                        break;
                }
        }
}

static void decode_compress_ctxt(struct ksmbd_conn *conn,
                                 struct smb2_compression_ctx *pneg_ctxt)
{
        conn->compress_algorithm = SMB3_COMPRESS_NONE;
}

static void decode_sign_cap_ctxt(struct ksmbd_conn *conn,
                                 struct smb2_signing_capabilities *pneg_ctxt,
                                 int len_of_ctxts)
{
        int sign_algo_cnt = le16_to_cpu(pneg_ctxt->SigningAlgorithmCount);
        int i, sign_alos_size = sign_algo_cnt * sizeof(__le16);

        conn->signing_negotiated = false;

        if (sizeof(struct smb2_signing_capabilities) + sign_alos_size >
            len_of_ctxts) {
                pr_err("Invalid signing algorithm count(%d)\n", sign_algo_cnt);
                return;
        }

        for (i = 0; i < sign_algo_cnt; i++) {
                if (pneg_ctxt->SigningAlgorithms[i] == SIGNING_ALG_HMAC_SHA256 ||
                    pneg_ctxt->SigningAlgorithms[i] == SIGNING_ALG_AES_CMAC) {
                        ksmbd_debug(SMB, "Signing Algorithm ID = 0x%x\n",
                                    pneg_ctxt->SigningAlgorithms[i]);
                        conn->signing_negotiated = true;
                        conn->signing_algorithm =
                                pneg_ctxt->SigningAlgorithms[i];
                        break;
                }
        }
}

static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn,
                                      struct smb2_negotiate_req *req)
{
        /* +4 is to account for the RFC1001 len field */
        struct smb2_neg_context *pctx = (struct smb2_neg_context *)((char *)req + 4);
        int i = 0, len_of_ctxts;
        int offset = le32_to_cpu(req->NegotiateContextOffset);
        int neg_ctxt_cnt = le16_to_cpu(req->NegotiateContextCount);
        int len_of_smb = be32_to_cpu(req->hdr.smb2_buf_length);
        __le32 status = STATUS_INVALID_PARAMETER;

        ksmbd_debug(SMB, "decoding %d negotiate contexts\n", neg_ctxt_cnt);
        if (len_of_smb <= offset) {
                ksmbd_debug(SMB, "Invalid response: negotiate context offset\n");
                return status;
        }

        len_of_ctxts = len_of_smb - offset;

        while (i++ < neg_ctxt_cnt) {
                int clen;

                /* check that offset is not beyond end of SMB */
                if (len_of_ctxts == 0)
                        break;

                if (len_of_ctxts < sizeof(struct smb2_neg_context))
                        break;

                pctx = (struct smb2_neg_context *)((char *)pctx + offset);
                clen = le16_to_cpu(pctx->DataLength);
                if (clen + sizeof(struct smb2_neg_context) > len_of_ctxts)
                        break;

                if (pctx->ContextType == SMB2_PREAUTH_INTEGRITY_CAPABILITIES) {
                        ksmbd_debug(SMB,
                                    "deassemble SMB2_PREAUTH_INTEGRITY_CAPABILITIES context\n");
                        if (conn->preauth_info->Preauth_HashId)
                                break;

                        status = decode_preauth_ctxt(conn,
                                                     (struct smb2_preauth_neg_context *)pctx);
                        if (status != STATUS_SUCCESS)
                                break;
                } else if (pctx->ContextType == SMB2_ENCRYPTION_CAPABILITIES) {
                        ksmbd_debug(SMB,
                                    "deassemble SMB2_ENCRYPTION_CAPABILITIES context\n");

                        if (conn->cipher_type)
                                break;

                        decode_encrypt_ctxt(conn,
                                            (struct smb2_encryption_neg_context *)pctx,
                                            len_of_ctxts);
                } else if (pctx->ContextType == SMB2_COMPRESSION_CAPABILITIES) {
                        ksmbd_debug(SMB,
                                    "deassemble SMB2_COMPRESSION_CAPABILITIES context\n");
                        if (conn->compress_algorithm)
                                break;

                        decode_compress_ctxt(conn,
                                             (struct smb2_compression_ctx *)pctx);
                } else if (pctx->ContextType == SMB2_NETNAME_NEGOTIATE_CONTEXT_ID) {
                        ksmbd_debug(SMB,
                                    "deassemble SMB2_NETNAME_NEGOTIATE_CONTEXT_ID context\n");
                } else if (pctx->ContextType == SMB2_POSIX_EXTENSIONS_AVAILABLE) {
                        ksmbd_debug(SMB,
                                    "deassemble SMB2_POSIX_EXTENSIONS_AVAILABLE context\n");
                        conn->posix_ext_supported = true;
                } else if (pctx->ContextType == SMB2_SIGNING_CAPABILITIES) {
                        ksmbd_debug(SMB,
                                    "deassemble SMB2_SIGNING_CAPABILITIES context\n");
                        decode_sign_cap_ctxt(conn,
                                             (struct smb2_signing_capabilities *)pctx,
                                             len_of_ctxts);
                }

                /* offsets must be 8 byte aligned */
                clen = (clen + 7) & ~0x7;
                offset = clen + sizeof(struct smb2_neg_context);
                len_of_ctxts -= clen + sizeof(struct smb2_neg_context);
        }
        return status;
}

/**
 * smb2_handle_negotiate() - handler for smb2 negotiate command
 * @work:       smb work containing smb request buffer
 *
 * Return:      0
 */
int smb2_handle_negotiate(struct ksmbd_work *work)
{
        struct ksmbd_conn *conn = work->conn;
        struct smb2_negotiate_req *req = work->request_buf;
        struct smb2_negotiate_rsp *rsp = work->response_buf;
        int rc = 0;
        unsigned int smb2_buf_len, smb2_neg_size;
        __le32 status;

        ksmbd_debug(SMB, "Received negotiate request\n");
        conn->need_neg = false;
        if (ksmbd_conn_good(work)) {
                pr_err("conn->tcp_status is already in CifsGood State\n");
                work->send_no_response = 1;
                return rc;
        }

        if (req->DialectCount == 0) {
                pr_err("malformed packet\n");
                rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                rc = -EINVAL;
                goto err_out;
        }

        smb2_buf_len = get_rfc1002_len(work->request_buf);
        smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects) - 4;
        if (smb2_neg_size > smb2_buf_len) {
                rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                rc = -EINVAL;
                goto err_out;
        }

        if (conn->dialect == SMB311_PROT_ID) {
                unsigned int nego_ctxt_off = le32_to_cpu(req->NegotiateContextOffset);

                if (smb2_buf_len < nego_ctxt_off) {
                        rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                        rc = -EINVAL;
                        goto err_out;
                }

                if (smb2_neg_size > nego_ctxt_off) {
                        rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                        rc = -EINVAL;
                        goto err_out;
                }

                if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) >
                    nego_ctxt_off) {
                        rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                        rc = -EINVAL;
                        goto err_out;
                }
        } else {
                if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) >
                    smb2_buf_len) {
                        rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                        rc = -EINVAL;
                        goto err_out;
                }
        }

        conn->cli_cap = le32_to_cpu(req->Capabilities);
        switch (conn->dialect) {
        case SMB311_PROT_ID:
                conn->preauth_info =
                        kzalloc(sizeof(struct preauth_integrity_info),
                                GFP_KERNEL);
                if (!conn->preauth_info) {
                        rc = -ENOMEM;
                        rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                        goto err_out;
                }

                status = deassemble_neg_contexts(conn, req);
                if (status != STATUS_SUCCESS) {
                        pr_err("deassemble_neg_contexts error(0x%x)\n",
                               status);
                        rsp->hdr.Status = status;
                        rc = -EINVAL;
                        goto err_out;
                }

                rc = init_smb3_11_server(conn);
                if (rc < 0) {
                        rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                        goto err_out;
                }

                ksmbd_gen_preauth_integrity_hash(conn,
                                                 work->request_buf,
                                                 conn->preauth_info->Preauth_HashValue);
                rsp->NegotiateContextOffset =
                                cpu_to_le32(OFFSET_OF_NEG_CONTEXT);
                assemble_neg_contexts(conn, rsp);
                break;
        case SMB302_PROT_ID:
                init_smb3_02_server(conn);
                break;
        case SMB30_PROT_ID:
                init_smb3_0_server(conn);
                break;
        case SMB21_PROT_ID:
                init_smb2_1_server(conn);
                break;
        case SMB2X_PROT_ID:
        case BAD_PROT_ID:
        default:
                ksmbd_debug(SMB, "Server dialect :0x%x not supported\n",
                            conn->dialect);
                rsp->hdr.Status = STATUS_NOT_SUPPORTED;
                rc = -EINVAL;
                goto err_out;
        }
        rsp->Capabilities = cpu_to_le32(conn->vals->capabilities);

        /* For stats */
        conn->connection_type = conn->dialect;

        rsp->MaxTransactSize = cpu_to_le32(conn->vals->max_trans_size);
        rsp->MaxReadSize = cpu_to_le32(conn->vals->max_read_size);
        rsp->MaxWriteSize = cpu_to_le32(conn->vals->max_write_size);

        memcpy(conn->ClientGUID, req->ClientGUID,
                        SMB2_CLIENT_GUID_SIZE);
        conn->cli_sec_mode = le16_to_cpu(req->SecurityMode);

        rsp->StructureSize = cpu_to_le16(65);
        rsp->DialectRevision = cpu_to_le16(conn->dialect);
        /* Not setting conn guid rsp->ServerGUID, as it
         * not used by client for identifying server
         */
        memset(rsp->ServerGUID, 0, SMB2_CLIENT_GUID_SIZE);

        rsp->SystemTime = cpu_to_le64(ksmbd_systime());
        rsp->ServerStartTime = 0;
        ksmbd_debug(SMB, "negotiate context offset %d, count %d\n",
                    le32_to_cpu(rsp->NegotiateContextOffset),
                    le16_to_cpu(rsp->NegotiateContextCount));

        rsp->SecurityBufferOffset = cpu_to_le16(128);
        rsp->SecurityBufferLength = cpu_to_le16(AUTH_GSS_LENGTH);
        ksmbd_copy_gss_neg_header(((char *)(&rsp->hdr) +
                                  sizeof(rsp->hdr.smb2_buf_length)) +
                                   le16_to_cpu(rsp->SecurityBufferOffset));
        inc_rfc1001_len(rsp, sizeof(struct smb2_negotiate_rsp) -
                        sizeof(struct smb2_hdr) - sizeof(rsp->Buffer) +
                         AUTH_GSS_LENGTH);
        rsp->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED_LE;
        conn->use_spnego = true;

        if ((server_conf.signing == KSMBD_CONFIG_OPT_AUTO ||
             server_conf.signing == KSMBD_CONFIG_OPT_DISABLED) &&
            req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED_LE)
                conn->sign = true;
        else if (server_conf.signing == KSMBD_CONFIG_OPT_MANDATORY) {
                server_conf.enforced_signing = true;
                rsp->SecurityMode |= SMB2_NEGOTIATE_SIGNING_REQUIRED_LE;
                conn->sign = true;
        }

        conn->srv_sec_mode = le16_to_cpu(rsp->SecurityMode);
        ksmbd_conn_set_need_negotiate(work);

err_out:
        if (rc < 0)
                smb2_set_err_rsp(work);

        return rc;
}

static int alloc_preauth_hash(struct ksmbd_session *sess,
                              struct ksmbd_conn *conn)
{
        if (sess->Preauth_HashValue)
                return 0;

        sess->Preauth_HashValue = kmemdup(conn->preauth_info->Preauth_HashValue,
                                          PREAUTH_HASHVALUE_SIZE, GFP_KERNEL);
        if (!sess->Preauth_HashValue)
                return -ENOMEM;

        return 0;
}

static int generate_preauth_hash(struct ksmbd_work *work)
{
        struct ksmbd_conn *conn = work->conn;
        struct ksmbd_session *sess = work->sess;
        u8 *preauth_hash;

        if (conn->dialect != SMB311_PROT_ID)
                return 0;

        if (conn->binding) {
                struct preauth_session *preauth_sess;

                preauth_sess = ksmbd_preauth_session_lookup(conn, sess->id);
                if (!preauth_sess) {
                        preauth_sess = ksmbd_preauth_session_alloc(conn, sess->id);
                        if (!preauth_sess)
                                return -ENOMEM;
                }

                preauth_hash = preauth_sess->Preauth_HashValue;
        } else {
                if (!sess->Preauth_HashValue)
                        if (alloc_preauth_hash(sess, conn))
                                return -ENOMEM;
                preauth_hash = sess->Preauth_HashValue;
        }

        ksmbd_gen_preauth_integrity_hash(conn, work->request_buf, preauth_hash);
        return 0;
}

static int decode_negotiation_token(struct ksmbd_conn *conn,
                                    struct negotiate_message *negblob,
                                    size_t sz)
{
        if (!conn->use_spnego)
                return -EINVAL;

        if (ksmbd_decode_negTokenInit((char *)negblob, sz, conn)) {
                if (ksmbd_decode_negTokenTarg((char *)negblob, sz, conn)) {
                        conn->auth_mechs |= KSMBD_AUTH_NTLMSSP;
                        conn->preferred_auth_mech = KSMBD_AUTH_NTLMSSP;
                        conn->use_spnego = false;
                }
        }
        return 0;
}

static int ntlm_negotiate(struct ksmbd_work *work,
                          struct negotiate_message *negblob,
                          size_t negblob_len)
{
        struct smb2_sess_setup_rsp *rsp = work->response_buf;
        struct challenge_message *chgblob;
        unsigned char *spnego_blob = NULL;
        u16 spnego_blob_len;
        char *neg_blob;
        int sz, rc;

        ksmbd_debug(SMB, "negotiate phase\n");
        rc = ksmbd_decode_ntlmssp_neg_blob(negblob, negblob_len, work->sess);
        if (rc)
                return rc;

        sz = le16_to_cpu(rsp->SecurityBufferOffset);
        chgblob =
                (struct challenge_message *)((char *)&rsp->hdr.ProtocolId + sz);
        memset(chgblob, 0, sizeof(struct challenge_message));

        if (!work->conn->use_spnego) {
                sz = ksmbd_build_ntlmssp_challenge_blob(chgblob, work->sess);
                if (sz < 0)
                        return -ENOMEM;

                rsp->SecurityBufferLength = cpu_to_le16(sz);
                return 0;
        }

        sz = sizeof(struct challenge_message);
        sz += (strlen(ksmbd_netbios_name()) * 2 + 1 + 4) * 6;

        neg_blob = kzalloc(sz, GFP_KERNEL);
        if (!neg_blob)
                return -ENOMEM;

        chgblob = (struct challenge_message *)neg_blob;
        sz = ksmbd_build_ntlmssp_challenge_blob(chgblob, work->sess);
        if (sz < 0) {
                rc = -ENOMEM;
                goto out;
        }

        rc = build_spnego_ntlmssp_neg_blob(&spnego_blob, &spnego_blob_len,
                                           neg_blob, sz);
        if (rc) {
                rc = -ENOMEM;
                goto out;
        }

        sz = le16_to_cpu(rsp->SecurityBufferOffset);
        memcpy((char *)&rsp->hdr.ProtocolId + sz, spnego_blob, spnego_blob_len);
        rsp->SecurityBufferLength = cpu_to_le16(spnego_blob_len);

out:
        kfree(spnego_blob);
        kfree(neg_blob);
        return rc;
}

static struct authenticate_message *user_authblob(struct ksmbd_conn *conn,
                                                  struct smb2_sess_setup_req *req)
{
        int sz;

        if (conn->use_spnego && conn->mechToken)
                return (struct authenticate_message *)conn->mechToken;

        sz = le16_to_cpu(req->SecurityBufferOffset);
        return (struct authenticate_message *)((char *)&req->hdr.ProtocolId
                                               + sz);
}

static struct ksmbd_user *session_user(struct ksmbd_conn *conn,
                                       struct smb2_sess_setup_req *req)
{
        struct authenticate_message *authblob;
        struct ksmbd_user *user;
        char *name;
        unsigned int auth_msg_len, name_off, name_len, secbuf_len;

        secbuf_len = le16_to_cpu(req->SecurityBufferLength);
        if (secbuf_len < sizeof(struct authenticate_message)) {
                ksmbd_debug(SMB, "blob len %d too small\n", secbuf_len);
                return NULL;
        }
        authblob = user_authblob(conn, req);
        name_off = le32_to_cpu(authblob->UserName.BufferOffset);
        name_len = le16_to_cpu(authblob->UserName.Length);
        auth_msg_len = le16_to_cpu(req->SecurityBufferOffset) + secbuf_len;

        if (auth_msg_len < (u64)name_off + name_len)
                return NULL;

        name = smb_strndup_from_utf16((const char *)authblob + name_off,
                                      name_len,
                                      true,
                                      conn->local_nls);
        if (IS_ERR(name)) {
                pr_err("cannot allocate memory\n");
                return NULL;
        }

        ksmbd_debug(SMB, "session setup request for user %s\n", name);
        user = ksmbd_login_user(name);
        kfree(name);
        return user;
}

static int ntlm_authenticate(struct ksmbd_work *work)
{
        struct smb2_sess_setup_req *req = work->request_buf;
        struct smb2_sess_setup_rsp *rsp = work->response_buf;
        struct ksmbd_conn *conn = work->conn;
        struct ksmbd_session *sess = work->sess;
        struct channel *chann = NULL;
        struct ksmbd_user *user;
        u64 prev_id;
        int sz, rc;

        ksmbd_debug(SMB, "authenticate phase\n");
        if (conn->use_spnego) {
                unsigned char *spnego_blob;
                u16 spnego_blob_len;

                rc = build_spnego_ntlmssp_auth_blob(&spnego_blob,
                                                    &spnego_blob_len,
                                                    0);
                if (rc)
                        return -ENOMEM;

                sz = le16_to_cpu(rsp->SecurityBufferOffset);
                memcpy((char *)&rsp->hdr.ProtocolId + sz, spnego_blob, spnego_blob_len);
                rsp->SecurityBufferLength = cpu_to_le16(spnego_blob_len);
                kfree(spnego_blob);
                inc_rfc1001_len(rsp, spnego_blob_len - 1);
        }

        user = session_user(conn, req);
        if (!user) {
                ksmbd_debug(SMB, "Unknown user name or an error\n");
                return -EPERM;
        }

        /* Check for previous session */
        prev_id = le64_to_cpu(req->PreviousSessionId);
        if (prev_id && prev_id != sess->id)
                destroy_previous_session(user, prev_id);

        if (sess->state == SMB2_SESSION_VALID) {
                /*
                 * Reuse session if anonymous try to connect
                 * on reauthetication.
                 */
                if (ksmbd_anonymous_user(user)) {
                        ksmbd_free_user(user);
                        return 0;
                }
                ksmbd_free_user(sess->user);
        }

        sess->user = user;
        if (user_guest(sess->user)) {
                if (conn->sign) {
                        ksmbd_debug(SMB, "Guest login not allowed when signing enabled\n");
                        return -EPERM;
                }

                rsp->SessionFlags = SMB2_SESSION_FLAG_IS_GUEST_LE;
        } else {
                struct authenticate_message *authblob;

                authblob = user_authblob(conn, req);
                sz = le16_to_cpu(req->SecurityBufferLength);
                rc = ksmbd_decode_ntlmssp_auth_blob(authblob, sz, sess);
                if (rc) {
                        set_user_flag(sess->user, KSMBD_USER_FLAG_BAD_PASSWORD);
                        ksmbd_debug(SMB, "authentication failed\n");
                        return -EPERM;
                }

                /*
                 * If session state is SMB2_SESSION_VALID, We can assume
                 * that it is reauthentication. And the user/password
                 * has been verified, so return it here.
                 */
                if (sess->state == SMB2_SESSION_VALID) {
                        if (conn->binding)
                                goto binding_session;
                        return 0;
                }

                if ((conn->sign || server_conf.enforced_signing) ||
                    (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED))
                        sess->sign = true;

                if (conn->vals->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION &&
                    conn->ops->generate_encryptionkey &&
                    !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) {
                        rc = conn->ops->generate_encryptionkey(sess);
                        if (rc) {
                                ksmbd_debug(SMB,
                                            "SMB3 encryption key generation failed\n");
                                return -EINVAL;
                        }
                        sess->enc = true;
                        rsp->SessionFlags = SMB2_SESSION_FLAG_ENCRYPT_DATA_LE;
                        /*
                         * signing is disable if encryption is enable
                         * on this session
                         */
                        sess->sign = false;
                }
        }

binding_session:
        if (conn->dialect >= SMB30_PROT_ID) {
                chann = lookup_chann_list(sess, conn);
                if (!chann) {
                        chann = kmalloc(sizeof(struct channel), GFP_KERNEL);
                        if (!chann)
                                return -ENOMEM;

                        chann->conn = conn;
                        INIT_LIST_HEAD(&chann->chann_list);
                        list_add(&chann->chann_list, &sess->ksmbd_chann_list);
                }
        }

        if (conn->ops->generate_signingkey) {
                rc = conn->ops->generate_signingkey(sess, conn);
                if (rc) {
                        ksmbd_debug(SMB, "SMB3 signing key generation failed\n");
                        return -EINVAL;
                }
        }

        if (!ksmbd_conn_lookup_dialect(conn)) {
                pr_err("fail to verify the dialect\n");
                return -ENOENT;
        }
        return 0;
}

#ifdef CONFIG_SMB_SERVER_KERBEROS5
static int krb5_authenticate(struct ksmbd_work *work)
{
        struct smb2_sess_setup_req *req = work->request_buf;
        struct smb2_sess_setup_rsp *rsp = work->response_buf;
        struct ksmbd_conn *conn = work->conn;
        struct ksmbd_session *sess = work->sess;
        char *in_blob, *out_blob;
        struct channel *chann = NULL;
        u64 prev_sess_id;
        int in_len, out_len;
        int retval;

        in_blob = (char *)&req->hdr.ProtocolId +
                le16_to_cpu(req->SecurityBufferOffset);
        in_len = le16_to_cpu(req->SecurityBufferLength);
        out_blob = (char *)&rsp->hdr.ProtocolId +
                le16_to_cpu(rsp->SecurityBufferOffset);
        out_len = work->response_sz -
                offsetof(struct smb2_hdr, smb2_buf_length) -
                le16_to_cpu(rsp->SecurityBufferOffset);

        /* Check previous session */
        prev_sess_id = le64_to_cpu(req->PreviousSessionId);
        if (prev_sess_id && prev_sess_id != sess->id)
                destroy_previous_session(sess->user, prev_sess_id);

        if (sess->state == SMB2_SESSION_VALID)
                ksmbd_free_user(sess->user);

        retval = ksmbd_krb5_authenticate(sess, in_blob, in_len,
                                         out_blob, &out_len);
        if (retval) {
                ksmbd_debug(SMB, "krb5 authentication failed\n");
                return -EINVAL;
        }
        rsp->SecurityBufferLength = cpu_to_le16(out_len);
        inc_rfc1001_len(rsp, out_len - 1);

        if ((conn->sign || server_conf.enforced_signing) ||
            (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED))
                sess->sign = true;

        if ((conn->vals->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) &&
            conn->ops->generate_encryptionkey) {
                retval = conn->ops->generate_encryptionkey(sess);
                if (retval) {
                        ksmbd_debug(SMB,
                                    "SMB3 encryption key generation failed\n");
                        return -EINVAL;
                }
                sess->enc = true;
                rsp->SessionFlags = SMB2_SESSION_FLAG_ENCRYPT_DATA_LE;
                sess->sign = false;
        }

        if (conn->dialect >= SMB30_PROT_ID) {
                chann = lookup_chann_list(sess, conn);
                if (!chann) {
                        chann = kmalloc(sizeof(struct channel), GFP_KERNEL);
                        if (!chann)
                                return -ENOMEM;

                        chann->conn = conn;
                        INIT_LIST_HEAD(&chann->chann_list);
                        list_add(&chann->chann_list, &sess->ksmbd_chann_list);
                }
        }

        if (conn->ops->generate_signingkey) {
                retval = conn->ops->generate_signingkey(sess, conn);
                if (retval) {
                        ksmbd_debug(SMB, "SMB3 signing key generation failed\n");
                        return -EINVAL;
                }
        }

        if (!ksmbd_conn_lookup_dialect(conn)) {
                pr_err("fail to verify the dialect\n");
                return -ENOENT;
        }
        return 0;
}
#else
static int krb5_authenticate(struct ksmbd_work *work)
{
        return -EOPNOTSUPP;
}
#endif

int smb2_sess_setup(struct ksmbd_work *work)
{
        struct ksmbd_conn *conn = work->conn;
        struct smb2_sess_setup_req *req = work->request_buf;
        struct smb2_sess_setup_rsp *rsp = work->response_buf;
        struct ksmbd_session *sess;
        struct negotiate_message *negblob;
        unsigned int negblob_len, negblob_off;
        int rc = 0;

        ksmbd_debug(SMB, "Received request for session setup\n");

        rsp->StructureSize = cpu_to_le16(9);
        rsp->SessionFlags = 0;
        rsp->SecurityBufferOffset = cpu_to_le16(72);
        rsp->SecurityBufferLength = 0;
        inc_rfc1001_len(rsp, 9);

        if (!req->hdr.SessionId) {
                sess = ksmbd_smb2_session_create();
                if (!sess) {
                        rc = -ENOMEM;
                        goto out_err;
                }
                rsp->hdr.SessionId = cpu_to_le64(sess->id);
                ksmbd_session_register(conn, sess);
        } else if (conn->dialect >= SMB30_PROT_ID &&
                   (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL) &&
                   req->Flags & SMB2_SESSION_REQ_FLAG_BINDING) {
                u64 sess_id = le64_to_cpu(req->hdr.SessionId);

                sess = ksmbd_session_lookup_slowpath(sess_id);
                if (!sess) {
                        rc = -ENOENT;
                        goto out_err;
                }

                if (conn->dialect != sess->conn->dialect) {
                        rc = -EINVAL;
                        goto out_err;
                }

                if (!(req->hdr.Flags & SMB2_FLAGS_SIGNED)) {
                        rc = -EINVAL;
                        goto out_err;
                }

                if (strncmp(conn->ClientGUID, sess->conn->ClientGUID,
                            SMB2_CLIENT_GUID_SIZE)) {
                        rc = -ENOENT;
                        goto out_err;
                }

                if (sess->state == SMB2_SESSION_IN_PROGRESS) {
                        rc = -EACCES;
                        goto out_err;
                }

                if (sess->state == SMB2_SESSION_EXPIRED) {
                        rc = -EFAULT;
                        goto out_err;
                }

                if (ksmbd_session_lookup(conn, sess_id)) {
                        rc = -EACCES;
                        goto out_err;
                }

                conn->binding = true;
        } else if ((conn->dialect < SMB30_PROT_ID ||
                    server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL) &&
                   (req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) {
                sess = NULL;
                rc = -EACCES;
                goto out_err;
        } else {
                sess = ksmbd_session_lookup(conn,
                                            le64_to_cpu(req->hdr.SessionId));
                if (!sess) {
                        rc = -ENOENT;
                        goto out_err;
                }
        }
        work->sess = sess;

        if (sess->state == SMB2_SESSION_EXPIRED)
                sess->state = SMB2_SESSION_IN_PROGRESS;

        negblob_off = le16_to_cpu(req->SecurityBufferOffset);
        negblob_len = le16_to_cpu(req->SecurityBufferLength);
        if (negblob_off < (offsetof(struct smb2_sess_setup_req, Buffer) - 4) ||
            negblob_len < offsetof(struct negotiate_message, NegotiateFlags))
                return -EINVAL;

        negblob = (struct negotiate_message *)((char *)&req->hdr.ProtocolId +
                        negblob_off);

        if (decode_negotiation_token(conn, negblob, negblob_len) == 0) {
                if (conn->mechToken)
                        negblob = (struct negotiate_message *)conn->mechToken;
        }

        if (server_conf.auth_mechs & conn->auth_mechs) {
                rc = generate_preauth_hash(work);
                if (rc)
                        goto out_err;

                if (conn->preferred_auth_mech &
                                (KSMBD_AUTH_KRB5 | KSMBD_AUTH_MSKRB5)) {
                        rc = krb5_authenticate(work);
                        if (rc) {
                                rc = -EINVAL;
                                goto out_err;
                        }

                        ksmbd_conn_set_good(work);
                        sess->state = SMB2_SESSION_VALID;
                        kfree(sess->Preauth_HashValue);
                        sess->Preauth_HashValue = NULL;
                } else if (conn->preferred_auth_mech == KSMBD_AUTH_NTLMSSP) {
                        if (negblob->MessageType == NtLmNegotiate) {
                                rc = ntlm_negotiate(work, negblob, negblob_len);
                                if (rc)
                                        goto out_err;
                                rsp->hdr.Status =
                                        STATUS_MORE_PROCESSING_REQUIRED;
                                /*
                                 * Note: here total size -1 is done as an
                                 * adjustment for 0 size blob
                                 */
                                inc_rfc1001_len(rsp, le16_to_cpu(rsp->SecurityBufferLength) - 1);

                        } else if (negblob->MessageType == NtLmAuthenticate) {
                                rc = ntlm_authenticate(work);
                                if (rc)
                                        goto out_err;

                                ksmbd_conn_set_good(work);
                                sess->state = SMB2_SESSION_VALID;
                                if (conn->binding) {
                                        struct preauth_session *preauth_sess;

                                        preauth_sess =
                                                ksmbd_preauth_session_lookup(conn, sess->id);
                                        if (preauth_sess) {
                                                list_del(&preauth_sess->preauth_entry);
                                                kfree(preauth_sess);
                                        }
                                }
                                kfree(sess->Preauth_HashValue);
                                sess->Preauth_HashValue = NULL;
                        }
                } else {
                        /* TODO: need one more negotiation */
                        pr_err("Not support the preferred authentication\n");
                        rc = -EINVAL;
                }
        } else {
                pr_err("Not support authentication\n");
                rc = -EINVAL;
        }

out_err:
        if (rc == -EINVAL)
                rsp->hdr.Status = STATUS_INVALID_PARAMETER;
        else if (rc == -ENOENT)
                rsp->hdr.Status = STATUS_USER_SESSION_DELETED;
        else if (rc == -EACCES)
                rsp->hdr.Status = STATUS_REQUEST_NOT_ACCEPTED;
        else if (rc == -EFAULT)
                rsp->hdr.Status = STATUS_NETWORK_SESSION_EXPIRED;
        else if (rc == -ENOMEM)
                rsp->hdr.Status = STATUS_INSUFFICIENT_RESOURCES;
        else if (rc)
                rsp->hdr.Status = STATUS_LOGON_FAILURE;

        if (conn->use_spnego && conn->mechToken) {
                kfree(conn->mechToken);
                conn->mechToken = NULL;
        }

        if (rc < 0) {
                /*
                 * SecurityBufferOffset should be set to zero
                 * in session setup error response.
                 */
                rsp->SecurityBufferOffset = 0;

                if (sess) {
                        bool try_delay = false;

                        /*
                         * To avoid dictionary attacks (repeated session setups rapidly sent) to
                         * connect to server, ksmbd make a delay of a 5 seconds on session setup
                         * failure to make it harder to send enough random connection requests
                         * to break into a server.
                         */
                        if (sess->user && sess->user->flags & KSMBD_USER_FLAG_DELAY_SESSION)
                                try_delay = true;

                        ksmbd_session_destroy(sess);
                        work->sess = NULL;
                        if (try_delay)
                                ssleep(5);
                }
        }

        return rc;
}

/**
 * smb2_tree_connect() - handler for smb2 tree connect command
 * @work:       smb work containing smb request buffer
 *
 * Return:      0 on success, otherwise error
 */
int smb2_tree_connect(struct ksmbd_work *work)
{
        struct ksmbd_conn *conn = work->conn;
        struct smb2_tree_connect_req *req = work->request_buf;
        struct smb2_tree_connect_rsp *rsp = work->response_buf;
        struct ksmbd_session *sess = work->sess;
        char *treename = NULL, *name = NULL;
        struct ksmbd_tree_conn_status status;
        struct ksmbd_share_config *share;
        int rc = -EINVAL;

        treename = smb_strndup_from_utf16(req->Buffer,
                                          le16_to_cpu(req->PathLength), true,
                                          conn->local_nls);
        if (IS_ERR(treename)) {
                pr_err("treename is NULL\n");
                status.ret = KSMBD_TREE_CONN_STATUS_ERROR;
                goto out_err1;
        }

        name = ksmbd_extract_sharename(treename);
        if (IS_ERR(name)) {
                status.ret = KSMBD_TREE_CONN_STATUS_ERROR;
                goto out_err1;
        }

        ksmbd_debug(SMB, "tree connect request for tree %s treename %s\n",
                    name, treename);

        status = ksmbd_tree_conn_connect(sess, name);
        if (status.ret == KSMBD_TREE_CONN_STATUS_OK)
                rsp->hdr.Id.SyncId.TreeId = cpu_to_le32(status.tree_conn->id);
        else
                goto out_err1;

        share = status.tree_conn->share_conf;
        if (test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) {
                ksmbd_debug(SMB, "IPC share path request\n");
                rsp->ShareType = SMB2_SHARE_TYPE_PIPE;
                rsp->MaximalAccess = FILE_READ_DATA_LE | FILE_READ_EA_LE |
                        FILE_EXECUTE_LE | FILE_READ_ATTRIBUTES_LE |
                        FILE_DELETE_LE | FILE_READ_CONTROL_LE |
                        FILE_WRITE_DAC_LE | FILE_WRITE_OWNER_LE |
                        FILE_SYNCHRONIZE_LE;
        } else {
                rsp->ShareType = SMB2_SHARE_TYPE_DISK;
                rsp->MaximalAccess = FILE_READ_DATA_LE | FILE_READ_EA_LE |
                        FILE_EXECUTE_LE | FILE_READ_ATTRIBUTES_LE;
                if (test_tree_conn_flag(status.tree_conn,
                                        KSMBD_TREE_CONN_FLAG_WRITABLE)) {
                        rsp->MaximalAccess |= FILE_WRITE_DATA_LE |
                                FILE_APPEND_DATA_LE | FILE_WRITE_EA_LE |
                                FILE_DELETE_LE | FILE_WRITE_ATTRIBUTES_LE |
                                FILE_DELETE_CHILD_LE | FILE_READ_CONTROL_LE |
                                FILE_WRITE_DAC_LE | FILE_WRITE_OWNER_LE |
                                FILE_SYNCHRONIZE_LE;
                }
        }

        status.tree_conn->maximal_access = le32_to_cpu(rsp->MaximalAccess);
        if (conn->posix_ext_supported)
                status.tree_conn->posix_extensions = true;

out_err1:
        rsp->StructureSize = cpu_to_le16(16);
        rsp->Capabilities = 0;
        rsp->Reserved = 0;
        /* default manual caching */
        rsp->ShareFlags = SMB2_SHAREFLAG_MANUAL_CACHING;
        inc_rfc1001_len(rsp, 16);

        if (!IS_ERR(treename))
                kfree(treename);
        if (!IS_ERR(name))
                kfree(name);

        switch (status.ret) {
        case KSMBD_TREE_CONN_STATUS_OK:
                rsp->hdr.Status = STATUS_SUCCESS;
                rc = 0;
                break;
        case KSMBD_TREE_CONN_STATUS_NO_SHARE:
                rsp->hdr.Status = STATUS_BAD_NETWORK_PATH;
                break;
        case -ENOMEM:
        case KSMBD_TREE_CONN_STATUS_NOMEM:
                rsp->hdr.Status = STATUS_NO_MEMORY;
                break;
        case KSMBD_TREE_CONN_STATUS_ERROR:
        case KSMBD_TREE_CONN_STATUS_TOO_MANY_CONNS:
        case KSMBD_TREE_CONN_STATUS_TOO_MANY_SESSIONS:
                rsp->hdr.Status = STATUS_ACCESS_DENIED;
                break;
        case -EINVAL:
                rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                break;
        default:
                rsp->hdr.Status = STATUS_ACCESS_DENIED;
        }

        return rc;
}

/**
 * smb2_create_open_flags() - convert smb open flags to unix open flags
 * @file_present:       is file already present
 * @access:             file access flags
 * @disposition:        file disposition flags
 * @may_flags:          set with MAY_ flags
 *
 * Return:      file open flags
 */
static int smb2_create_open_flags(bool file_present, __le32 access,
                                  __le32 disposition,
                                  int *may_flags)
{
        int oflags = O_NONBLOCK | O_LARGEFILE;

        if (access & FILE_READ_DESIRED_ACCESS_LE &&
            access & FILE_WRITE_DESIRE_ACCESS_LE) {
                oflags |= O_RDWR;
                *may_flags = MAY_OPEN | MAY_READ | MAY_WRITE;
        } else if (access & FILE_WRITE_DESIRE_ACCESS_LE) {
                oflags |= O_WRONLY;
                *may_flags = MAY_OPEN | MAY_WRITE;
        } else {
                oflags |= O_RDONLY;
                *may_flags = MAY_OPEN | MAY_READ;
        }

        if (access == FILE_READ_ATTRIBUTES_LE)
                oflags |= O_PATH;

        if (file_present) {
                switch (disposition & FILE_CREATE_MASK_LE) {
                case FILE_OPEN_LE:
                case FILE_CREATE_LE:
                        break;
                case FILE_SUPERSEDE_LE:
                case FILE_OVERWRITE_LE:
                case FILE_OVERWRITE_IF_LE:
                        oflags |= O_TRUNC;
                        break;
                default:
                        break;
                }
        } else {
                switch (disposition & FILE_CREATE_MASK_LE) {
                case FILE_SUPERSEDE_LE:
                case FILE_CREATE_LE:
                case FILE_OPEN_IF_LE:
                case FILE_OVERWRITE_IF_LE:
                        oflags |= O_CREAT;
                        break;
                case FILE_OPEN_LE:
                case FILE_OVERWRITE_LE:
                        oflags &= ~O_CREAT;
                        break;
                default:
                        break;
                }
        }

        return oflags;
}

/**
 * smb2_tree_disconnect() - handler for smb tree connect request
 * @work:       smb work containing request buffer
 *
 * Return:      0
 */
int smb2_tree_disconnect(struct ksmbd_work *work)

{
        struct smb2_tree_disconnect_rsp *rsp = work->response_buf;
        struct ksmbd_session *sess = work->sess;
        struct ksmbd_tree_connect *tcon = work->tcon;

        rsp->StructureSize = cpu_to_le16(4);
        inc_rfc1001_len(rsp, 4);

        ksmbd_debug(SMB, "request\n");

        if (!tcon) {
                struct smb2_tree_disconnect_req *req = work->request_buf;

                ksmbd_debug(SMB, "Invalid tid %d\n", req->hdr.Id.SyncId.TreeId);
                rsp->hdr.Status = STATUS_NETWORK_NAME_DELETED;
                smb2_set_err_rsp(work);
                return 0;
        }

        ksmbd_close_tree_conn_fds(work);
        ksmbd_tree_conn_disconnect(sess, tcon);
        return 0;
}

/**
 * smb2_session_logoff() - handler for session log off request
 * @work:       smb work containing request buffer
 *
 * Return:      0
 */
int smb2_session_logoff(struct ksmbd_work *work)
{
        struct ksmbd_conn *conn = work->conn;
        struct smb2_logoff_rsp *rsp = work->response_buf;
        struct ksmbd_session *sess = work->sess;

        rsp->StructureSize = cpu_to_le16(4);
        inc_rfc1001_len(rsp, 4);

        ksmbd_debug(SMB, "request\n");

        /* Got a valid session, set connection state */
        WARN_ON(sess->conn != conn);

        /* setting CifsExiting here may race with start_tcp_sess */
        ksmbd_conn_set_need_reconnect(work);
        ksmbd_close_session_fds(work);
        ksmbd_conn_wait_idle(conn);

        if (ksmbd_tree_conn_session_logoff(sess)) {
                struct smb2_logoff_req *req = work->request_buf;

                ksmbd_debug(SMB, "Invalid tid %d\n", req->hdr.Id.SyncId.TreeId);
                rsp->hdr.Status = STATUS_NETWORK_NAME_DELETED;
                smb2_set_err_rsp(work);
                return 0;
        }

        ksmbd_destroy_file_table(&sess->file_table);
        sess->state = SMB2_SESSION_EXPIRED;

        ksmbd_free_user(sess->user);
        sess->user = NULL;

        /* let start_tcp_sess free connection info now */
        ksmbd_conn_set_need_negotiate(work);
        return 0;
}

/**
 * create_smb2_pipe() - create IPC pipe
 * @work:       smb work containing request buffer
 *
 * Return:      0 on success, otherwise error
 */
static noinline int create_smb2_pipe(struct ksmbd_work *work)
{
        struct smb2_create_rsp *rsp = work->response_buf;
        struct smb2_create_req *req = work->request_buf;
        int id;
        int err;
        char *name;

        name = smb_strndup_from_utf16(req->Buffer, le16_to_cpu(req->NameLength),
                                      1, work->conn->local_nls);
        if (IS_ERR(name)) {
                rsp->hdr.Status = STATUS_NO_MEMORY;
                err = PTR_ERR(name);
                goto out;
        }

        id = ksmbd_session_rpc_open(work->sess, name);
        if (id < 0) {
                pr_err("Unable to open RPC pipe: %d\n", id);
                err = id;
                goto out;
        }

        rsp->hdr.Status = STATUS_SUCCESS;
        rsp->StructureSize = cpu_to_le16(89);
        rsp->OplockLevel = SMB2_OPLOCK_LEVEL_NONE;
        rsp->Reserved = 0;
        rsp->CreateAction = cpu_to_le32(FILE_OPENED);

        rsp->CreationTime = cpu_to_le64(0);
        rsp->LastAccessTime = cpu_to_le64(0);
        rsp->ChangeTime = cpu_to_le64(0);
        rsp->AllocationSize = cpu_to_le64(0);
        rsp->EndofFile = cpu_to_le64(0);
        rsp->FileAttributes = ATTR_NORMAL_LE;
        rsp->Reserved2 = 0;
        rsp->VolatileFileId = cpu_to_le64(id);
        rsp->PersistentFileId = 0;
        rsp->CreateContextsOffset = 0;
        rsp->CreateContextsLength = 0;

        inc_rfc1001_len(rsp, 88); /* StructureSize - 1*/
        kfree(name);
        return 0;

out:
        switch (err) {
        case -EINVAL:
                rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                break;
        case -ENOSPC:
        case -ENOMEM:
                rsp->hdr.Status = STATUS_NO_MEMORY;
                break;
        }

        if (!IS_ERR(name))
                kfree(name);

        smb2_set_err_rsp(work);
        return err;
}

/**
 * smb2_set_ea() - handler for setting extended attributes using set
 *              info command
 * @eabuf:      set info command buffer
 * @buf_len:    set info command buffer length
 * @path:       dentry path for get ea
 *
 * Return:      0 on success, otherwise error
 */
static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len,
                       struct path *path)
{
        struct user_namespace *user_ns = mnt_user_ns(path->mnt);
        char *attr_name = NULL, *value;
        int rc = 0;
        unsigned int next = 0;

        if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength +
                        le16_to_cpu(eabuf->EaValueLength))
                return -EINVAL;

        attr_name = kmalloc(XATTR_NAME_MAX + 1, GFP_KERNEL);
        if (!attr_name)
                return -ENOMEM;

        do {
                if (!eabuf->EaNameLength)
                        goto next;

                ksmbd_debug(SMB,
                            "name : <%s>, name_len : %u, value_len : %u, next : %u\n",
                            eabuf->name, eabuf->EaNameLength,
                            le16_to_cpu(eabuf->EaValueLength),
                            le32_to_cpu(eabuf->NextEntryOffset));

                if (eabuf->EaNameLength >
                    (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN)) {
                        rc = -EINVAL;
                        break;
                }

                memcpy(attr_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
                memcpy(&attr_name[XATTR_USER_PREFIX_LEN], eabuf->name,
                       eabuf->EaNameLength);
                attr_name[XATTR_USER_PREFIX_LEN + eabuf->EaNameLength] = '\0';
                value = (char *)&eabuf->name + eabuf->EaNameLength + 1;

                if (!eabuf->EaValueLength) {
                        rc = ksmbd_vfs_casexattr_len(user_ns,
                                                     path->dentry,
                                                     attr_name,
                                                     XATTR_USER_PREFIX_LEN +
                                                     eabuf->EaNameLength);

                        /* delete the EA only when it exits */
                        if (rc > 0) {
                                rc = ksmbd_vfs_remove_xattr(user_ns,
                                                            path->dentry,
                                                            attr_name);

                                if (rc < 0) {
                                        ksmbd_debug(SMB,
                                                    "remove xattr failed(%d)\n",
                                                    rc);
                                        break;
                                }
                        }

                        /* if the EA doesn't exist, just do nothing. */
                        rc = 0;
                } else {
                        rc = ksmbd_vfs_setxattr(user_ns,
                                                path->dentry, attr_name, value,
                                                le16_to_cpu(eabuf->EaValueLength), 0);
                        if (rc < 0) {
                                ksmbd_debug(SMB,
                                            "ksmbd_vfs_setxattr is failed(%d)\n",
                                            rc);
                                break;
                        }
                }

next:
                next = le32_to_cpu(eabuf->NextEntryOffset);
                if (next == 0 || buf_len < next)
                        break;
                buf_len -= next;
                eabuf = (struct smb2_ea_info *)((char *)eabuf + next);
                if (next < (u32)eabuf->EaNameLength + le16_to_cpu(eabuf->EaValueLength))
                        break;

        } while (next != 0);

        kfree(attr_name);
        return rc;
}

static noinline int smb2_set_stream_name_xattr(struct path *path,
                                               struct ksmbd_file *fp,
                                               char *stream_name, int s_type)
{
        struct user_namespace *user_ns = mnt_user_ns(path->mnt);
        size_t xattr_stream_size;
        char *xattr_stream_name;
        int rc;

        rc = ksmbd_vfs_xattr_stream_name(stream_name,
                                         &xattr_stream_name,
                                         &xattr_stream_size,
                                         s_type);
        if (rc)
                return rc;

        fp->stream.name = xattr_stream_name;
        fp->stream.size = xattr_stream_size;

        /* Check if there is stream prefix in xattr space */
        rc = ksmbd_vfs_casexattr_len(user_ns,
                                     path->dentry,
                                     xattr_stream_name,
                                     xattr_stream_size);
        if (rc >= 0)
                return 0;

        if (fp->cdoption == FILE_OPEN_LE) {
                ksmbd_debug(SMB, "XATTR stream name lookup failed: %d\n", rc);
                return -EBADF;
        }

        rc = ksmbd_vfs_setxattr(user_ns, path->dentry,
                                xattr_stream_name, NULL, 0, 0);
        if (rc < 0)
                pr_err("Failed to store XATTR stream name :%d\n", rc);
        return 0;
}

static int smb2_remove_smb_xattrs(struct path *path)
{
        struct user_namespace *user_ns = mnt_user_ns(path->mnt);
        char *name, *xattr_list = NULL;
        ssize_t xattr_list_len;
        int err = 0;

        xattr_list_len = ksmbd_vfs_listxattr(path->dentry, &xattr_list);
        if (xattr_list_len < 0) {
                goto out;
        } else if (!xattr_list_len) {
                ksmbd_debug(SMB, "empty xattr in the file\n");
                goto out;
        }

        for (name = xattr_list; name - xattr_list < xattr_list_len;
                        name += strlen(name) + 1) {
                ksmbd_debug(SMB, "%s, len %zd\n", name, strlen(name));

                if (strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
                    strncmp(&name[XATTR_USER_PREFIX_LEN], DOS_ATTRIBUTE_PREFIX,
                            DOS_ATTRIBUTE_PREFIX_LEN) &&
                    strncmp(&name[XATTR_USER_PREFIX_LEN], STREAM_PREFIX, STREAM_PREFIX_LEN))
                        continue;

                err = ksmbd_vfs_remove_xattr(user_ns, path->dentry, name);
                if (err)
                        ksmbd_debug(SMB, "remove xattr failed : %s\n", name);
        }
out:
        kvfree(xattr_list);
        return err;
}

static int smb2_create_truncate(struct path *path)
{
        int rc = vfs_truncate(path, 0);

        if (rc) {
                pr_err("vfs_truncate failed, rc %d\n", rc);
                return rc;
        }

        rc = smb2_remove_smb_xattrs(path);
        if (rc == -EOPNOTSUPP)
                rc = 0;
        if (rc)
                ksmbd_debug(SMB,
                            "ksmbd_truncate_stream_name_xattr failed, rc %d\n",
                            rc);
        return rc;
}

static void smb2_new_xattrs(struct ksmbd_tree_connect *tcon, struct path *path,
                            struct ksmbd_file *fp)
{
        struct xattr_dos_attrib da = {0};
        int rc;

        if (!test_share_config_flag(tcon->share_conf,
                                    KSMBD_SHARE_FLAG_STORE_DOS_ATTRS))
                return;

        da.version = 4;
        da.attr = le32_to_cpu(fp->f_ci->m_fattr);
        da.itime = da.create_time = fp->create_time;
        da.flags = XATTR_DOSINFO_ATTRIB | XATTR_DOSINFO_CREATE_TIME |
                XATTR_DOSINFO_ITIME;

        rc = ksmbd_vfs_set_dos_attrib_xattr(mnt_user_ns(path->mnt),
                                            path->dentry, &da);
        if (rc)
                ksmbd_debug(SMB, "failed to store file attribute into xattr\n");
}

static void smb2_update_xattrs(struct ksmbd_tree_connect *tcon,
                               struct path *path, struct ksmbd_file *fp)
{
        struct xattr_dos_attrib da;
        int rc;

        fp->f_ci->m_fattr &= ~(ATTR_HIDDEN_LE | ATTR_SYSTEM_LE);

        /* get FileAttributes from XATTR_NAME_DOS_ATTRIBUTE */
        if (!test_share_config_flag(tcon->share_conf,
                                    KSMBD_SHARE_FLAG_STORE_DOS_ATTRS))
                return;

        rc = ksmbd_vfs_get_dos_attrib_xattr(mnt_user_ns(path->mnt),
                                            path->dentry, &da);
        if (rc > 0) {
                fp->f_ci->m_fattr = cpu_to_le32(da.attr);
                fp->create_time = da.create_time;
                fp->itime = da.itime;
        }
}

static int smb2_creat(struct ksmbd_work *work, struct path *path, char *name,
                      int open_flags, umode_t posix_mode, bool is_dir)
{
        struct ksmbd_tree_connect *tcon = work->tcon;
        struct ksmbd_share_config *share = tcon->share_conf;
        umode_t mode;
        int rc;

        if (!(open_flags & O_CREAT))
                return -EBADF;

        ksmbd_debug(SMB, "file does not exist, so creating\n");
        if (is_dir == true) {
                ksmbd_debug(SMB, "creating directory\n");

                mode = share_config_directory_mode(share, posix_mode);
                rc = ksmbd_vfs_mkdir(work, name, mode);
                if (rc)
                        return rc;
        } else {
                ksmbd_debug(SMB, "creating regular file\n");

                mode = share_config_create_mode(share, posix_mode);
                rc = ksmbd_vfs_create(work, name, mode);
                if (rc)
                        return rc;
        }

        rc = ksmbd_vfs_kern_path(work, name, 0, path, 0);
        if (rc) {
                pr_err("cannot get linux path (%s), err = %d\n",
                       name, rc);
                return rc;
        }
        return 0;
}

static int smb2_create_sd_buffer(struct ksmbd_work *work,
                                 struct smb2_create_req *req,
                                 struct path *path)
{
        struct create_context *context;
        struct create_sd_buf_req *sd_buf;

        if (!req->CreateContextsOffset)
                return -ENOENT;

        /* Parse SD BUFFER create contexts */
        context = smb2_find_context_vals(req, SMB2_CREATE_SD_BUFFER);
        if (!context)
                return -ENOENT;
        else if (IS_ERR(context))
                return PTR_ERR(context);

        ksmbd_debug(SMB,
                    "Set ACLs using SMB2_CREATE_SD_BUFFER context\n");
        sd_buf = (struct create_sd_buf_req *)context;
        if (le16_to_cpu(context->DataOffset) +
            le32_to_cpu(context->DataLength) <
            sizeof(struct create_sd_buf_req))
                return -EINVAL;
        return set_info_sec(work->conn, work->tcon, path, &sd_buf->ntsd,
                            le32_to_cpu(sd_buf->ccontext.DataLength), true);
}

static void ksmbd_acls_fattr(struct smb_fattr *fattr,
                             struct user_namespace *mnt_userns,
                             struct inode *inode)
{
        fattr->cf_uid = i_uid_into_mnt(mnt_userns, inode);
        fattr->cf_gid = i_gid_into_mnt(mnt_userns, inode);
        fattr->cf_mode = inode->i_mode;
        fattr->cf_acls = NULL;
        fattr->cf_dacls = NULL;

        if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
                fattr->cf_acls = get_acl(inode, ACL_TYPE_ACCESS);
                if (S_ISDIR(inode->i_mode))
                        fattr->cf_dacls = get_acl(inode, ACL_TYPE_DEFAULT);
        }
}

/**
 * smb2_open() - handler for smb file open request
 * @work:       smb work containing request buffer
 *
 * Return:      0 on success, otherwise error
 */
int smb2_open(struct ksmbd_work *work)
{
        struct ksmbd_conn *conn = work->conn;
        struct ksmbd_session *sess = work->sess;
        struct ksmbd_tree_connect *tcon = work->tcon;
        struct smb2_create_req *req;
        struct smb2_create_rsp *rsp, *rsp_org;
        struct path path;
        struct ksmbd_share_config *share = tcon->share_conf;
        struct ksmbd_file *fp = NULL;
        struct file *filp = NULL;
        struct user_namespace *user_ns = NULL;
        struct kstat stat;
        struct create_context *context;
        struct lease_ctx_info *lc = NULL;
        struct create_ea_buf_req *ea_buf = NULL;
        struct oplock_info *opinfo;
        __le32 *next_ptr = NULL;
        int req_op_level = 0, open_flags = 0, may_flags = 0, file_info = 0;
        int rc = 0;
        int contxt_cnt = 0, query_disk_id = 0;
        int maximal_access_ctxt = 0, posix_ctxt = 0;
        int s_type = 0;
        int next_off = 0;
        char *name = NULL;
        char *stream_name = NULL;
        bool file_present = false, created = false, already_permitted = false;
        int share_ret, need_truncate = 0;
        u64 time;
        umode_t posix_mode = 0;
        __le32 daccess, maximal_access = 0;

        rsp_org = work->response_buf;
        WORK_BUFFERS(work, req, rsp);

        if (req->hdr.NextCommand && !work->next_smb2_rcv_hdr_off &&
            (req->hdr.Flags & SMB2_FLAGS_RELATED_OPERATIONS)) {
                ksmbd_debug(SMB, "invalid flag in chained command\n");
                rsp->hdr.Status = STATUS_INVALID_PARAMETER;
                smb2_set_err_rsp(work);
                return -EINVAL;
        }

        if (test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) {
                ksmbd_debug(SMB, "IPC pipe create request\n");
                return create_smb2_pipe(work);
        }

        if (req->NameLength) {
                if ((req->CreateOptions & FILE_DIRECTORY_FILE_LE) &&
                    *(char *)req->Buffer == '\\') {
                        pr_err("not allow directory name included leading slash\n");
                        rc = -EINVAL;
                        goto err_out1;
                }

                name = smb2_get_name(share,
                                     req->Buffer,
                                     le16_to_cpu(req->NameLength),
                                     work->conn->local_nls);
                if (IS_ERR(name)) {
                        rc = PTR_ERR(name);
                        if (rc != -ENOMEM)
                                rc = -ENOENT;
                        name = NULL;
                        goto err_out1;
                }

                ksmbd_debug(SMB, "converted name = %s\n", name);
                if (strchr(name, ':')) {
                        if (!test_share_config_flag(work->tcon->share_conf,
                                                    KSMBD_SHARE_FLAG_STREAMS)) {
                                rc = -EBADF;
                                goto err_out1;
                        }
                        rc = parse_stream_name(name, &stream_name, &s_type);
                        if (rc < 0)
                                goto err_out1;
                }

                rc = ksmbd_validate_filename(name);
                if (rc < 0)
                        goto err_out1;

                if (ksmbd_share_veto_filename(share, name)) {
                        rc = -ENOENT;
                        ksmbd_debug(SMB, "Reject open(), vetoed file: %s\n",
                                    name);
                        goto err_out1;
                }
        } else {
                name = kstrdup("", GFP_KERNEL);
                if (!name) {
                        rc = -ENOMEM;
                        goto err_out1;
                }
        }

        req_op_level = req->RequestedOplockLevel;
        if (req_op_level == SMB2_OPLOCK_LEVEL_LEASE)
                lc = parse_lease_state(req);

        if (le32_to_cpu(req->ImpersonationLevel) > le32_to_cpu(IL_DELEGATE_LE)) {
                pr_err("Invalid impersonationlevel : 0x%x\n",
                       le32_to_cpu(req->ImpersonationLevel));
                rc = -EIO;
                rsp->hdr.Status = STATUS_BAD_IMPERSONATION_LEVEL;
                goto err_out1;
        }

        if (req->CreateOptions && !(req->CreateOptions & CREATE_OPTIONS_MASK)) {
                pr_err("Invalid create options : 0x%x\n",
                       le32_to_cpu(req->CreateOptions));
                rc = -EINVAL;
                goto err_out1;
        } else {
                if (req->CreateOptions & FILE_SEQUENTIAL_ONLY_LE &&
                    req->CreateOptions & FILE_RANDOM_ACCESS_LE)
                        req->CreateOptions = ~(FILE_SEQUENTIAL_ONLY_LE);

                if (req->CreateOptions &
                    (FILE_OPEN_BY_FILE_ID_LE | CREATE_TREE_CONNECTION |
                     FILE_RESERVE_OPFILTER_LE)) {
                        rc = -EOPNOTSUPP;
                        goto err_out1;
                }

                if (req->CreateOptions & FILE_DIRECTORY_FILE_LE) {
                        if (req->CreateOptions & FILE_NON_DIRECTORY_FILE_LE) {
                                rc = -EINVAL;
                                goto err_out1;
                        } else if (req->CreateOptions & FILE_NO_COMPRESSION_LE) {
                                req->CreateOptions = ~(FILE_NO_COMPRESSION_LE);
                        }
                }
        }

        if (le32_to_cpu(req->CreateDisposition) >
            le32_to_cpu(FILE_OVERWRITE_IF_LE)) {
                pr_err("Invalid create disposition : 0x%x\n",
                       le32_to_cpu(req->CreateDisposition));
                rc = -EINVAL;
                goto err_out1;
        }

        if (!(req->DesiredAccess & DESIRED_ACCESS_MASK)) {
                pr_err("Invalid desired access : 0x%x\n",
                       le32_to_cpu(req->DesiredAccess));
                rc = -EACCES;
                goto err_out1;
        }

        if (req->FileAttributes && !(req->FileAttributes & ATTR_MASK_LE)) {
                pr_err("Invalid file attribute : 0x%x\n",
                       le32_to_cpu(req->FileAttributes));
                rc = -EINVAL;
                goto err_out1;
        }

        if (req->CreateContextsOffset) {
                /* Parse non-durable handle create contexts */
                context = smb2_find_context_vals(req, SMB2_CREATE_EA_BUFFER);
                if (IS_ERR(context)) {
                        rc = PTR_ERR(context);
                        goto err_out1;
                } else if (context) {
                        ea_buf = (struct create_ea_buf_req *)context;
                        if (le16_to_cpu(context->DataOffset) +
                            le32_to_cpu(context->DataLength) <
                            sizeof(struct create_ea_buf_req)) {
                                rc = -EINVAL;
                                goto err_out1;
                        }
                        if (req->CreateOptions & FILE_NO_EA_KNOWLEDGE_LE) {
                                rsp->hdr.Status = STATUS_ACCESS_DENIED;
                                rc = -EACCES;
                                goto err_out1;
                        }
                }

                context = smb2_find_context_vals(req,
                                                 SMB2_CREATE_QUERY_MAXIMAL_ACCESS_REQUEST);
                if (IS_ERR(context)) {
                        rc = PTR_ERR(context);
                        goto err_out1;
                } else if (context) {
                        ksmbd_debug(SMB,
                                    "get query maximal access context\n");
                        maximal_access_ctxt = 1;
                }

                context = smb2_find_context_vals(req,
                                                 SMB2_CREATE_TIMEWARP_REQUEST);
                if (IS_ERR(context)) {
                        rc = PTR_ERR(context);
                        goto err_out1;
                } else if (context) {
                        ksmbd_debug(SMB, "get timewarp context\n");
                        rc = -EBADF;
                        goto err_out1;
                }

                if (tcon->posix_extensions) {
                        context = smb2_find_context_vals(req,
                                                         SMB2_CREATE_TAG_POSIX);
                        if (IS_ERR(context)) {
                                rc = PTR_ERR(context);
                                goto err_out1;
                        } else if (context) {
                                struct create_posix *posix =
                                        (struct create_posix *)context;
                                if (le16_to_cpu(context->DataOffset) +
                                    le32_to_cpu(context->DataLength) <
                                    sizeof(struct create_posix)) {
                                        rc = -EINVAL;
                                        goto err_out1;
                                }
                                ksmbd_debug(SMB, "get posix context\n");

                                posix_mode = le32_to_cpu(posix->Mode);
                                posix_ctxt = 1;
                        }
                }
        }

        if (ksmbd_override_fsids(work)) {
                rc = -ENOMEM;
                goto err_out1;
        }

        rc = ksmbd_vfs_kern_path(work, name, LOOKUP_NO_SYMLINKS, &path, 1);
        if (!rc) {
                if (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE) {
                        /*
                         * If file exists with under flags, return access
                         * denied error.
                         */
                        if (req->CreateDisposition == FILE_OVERWRITE_IF_LE ||
                            req->CreateDisposition == FILE_OPEN_IF_LE) {
                                rc = -EACCES;
                                path_put(&path);
                                goto err_out;
                        }

                        if (!test_tree_conn_flag(tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
                                ksmbd_debug(SMB,
                                            "User does not have write permission\n");
                                rc = -EACCES;
                                path_put(&path);
                                goto err_out;
                        }
                } else if (d_is_symlink(path.dentry)) {
                        rc = -EACCES;
                        path_put(&path);
                        goto err_out;
                }
        }

        if (rc) {
                if (rc != -ENOENT)
                        goto err_out;
                ksmbd_debug(SMB, "can not get linux path for %s, rc = %d\n",
                            name, rc);
                rc = 0;
        } else {
                file_present = true;
                user_ns = mnt_user_ns(path.mnt);
                generic_fillattr(user_ns, d_inode(path.dentry), &stat);
        }
        if (stream_name) {
                if (req->CreateOptions & FILE_DIRECTORY_FILE_LE) {
                        if (s_type == DATA_STREAM) {
                                rc = -EIO;
                                rsp->hdr.Status = STATUS_NOT_A_DIRECTORY;
                        }
                } else {
                        if (S_ISDIR(stat.mode) && s_type == DATA_STREAM) {
                                rc = -EIO;
                                rsp->hdr.Status = STATUS_FILE_IS_A_DIRECTORY;
                        }
                }

                if (req->CreateOptions & FILE_DIRECTORY_FILE_LE &&
                    req->FileAttributes & ATTR_NORMAL_LE) {
                        rsp->hdr.Status = STATUS_NOT_A_DIRECTORY;
                        rc = -EIO;
                }

                if (rc < 0)
                        goto err_out;
        }

        if (file_present && req->CreateOptions & FILE_NON_DIRECTORY_FILE_LE &&
            S_ISDIR(stat.mode) && !(req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) {
                ksmbd_debug(SMB, "open() argument is a directory: %s, %x\n",
                            name, req->CreateOptions);
                rsp->hdr.Status = STATUS_FILE_IS_A_DIRECTORY;
                rc = -EIO;
                goto err_out;
        }

        if (file_present && (req->CreateOptions & FILE_DIRECTORY_FILE_LE) &&
            !(req->CreateDisposition == FILE_CREATE_LE) &&
            !S_ISDIR(stat.mode)) {
                rsp->hdr.Status = STATUS_NOT_A_DIRECTORY;
                rc = -EIO;
                goto err_out;
        }

        if (!stream_name && file_present &&
            req->CreateDisposition == FILE_CREATE_LE) {
                rc = -EEXIST;
                goto err_out;
        }

        daccess = smb_map_generic_desired_access(req->DesiredAccess);

        if (file_present && !(req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) {
                rc = smb_check_perm_dacl(conn, &path, &daccess,
                                         sess->user->uid);
                if (rc)
                        goto err_out;
        }

        if (daccess & FILE_MAXIMAL_ACCESS_LE) {
                if (!file_present) {
                        daccess = cpu_to_le32(GENERIC_ALL_FLAGS);
                } else {
                        rc = ksmbd_vfs_query_maximal_access(user_ns,
                                                            path.dentry,
                                                            &daccess);
                        if (rc)
                                goto err_out;
                        already_permitted = true;
                }
                maximal_access = daccess;
        }

        open_flags = smb2_create_open_flags(file_present, daccess,
                                            req->CreateDisposition,
                                            &may_flags);

        if (!test_tree_conn_flag(tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
                if (open_flags & O_CREAT) {
                        ksmbd_debug(SMB,
                                    "User does not have write permission\n");
                        rc = -EACCES;
                        goto err_out;
                }
        }

        /*create file if not present */
        if (!file_present) {
                rc = smb2_creat(work, &path, name, open_flags, posix_mode,
                                req->CreateOptions & FILE_DIRECTORY_FILE_LE);
                if (rc) {
                        if (rc == -ENOENT) {
                                rc = -EIO;
                                rsp->hdr.Status = STATUS_OBJECT_PATH_NOT_FOUND;
                        }
                        goto err_out;
                }

                created = true;
                user_ns = mnt_user_ns(path.mnt);
                if (ea_buf) {
                        if (le32_to_cpu(ea_buf->ccontext.DataLength) <
                            sizeof(struct smb2_ea_info)) {
                                rc = -EINVAL;
                                goto err_out;
                        }

                        rc = smb2_set_ea(&ea_buf->ea,
                                         le32_to_cpu(ea_buf->ccontext.DataLength),
                                         &path);
                        if (rc == -EOPNOTSUPP)
                                rc = 0;
                        else if (rc)
                                goto err_out;
                }
        } else if (!already_permitted) {
                /* FILE_READ_ATTRIBUTE is allowed without inode_permission,
                 * because execute(search) permission on a parent directory,
                 * is already granted.
                 */
                if (daccess & ~(FILE_READ_ATTRIBUTES_LE | FILE_READ_CONTROL_LE)) {
                        rc = inode_permission(user_ns,
                                              d_inode(path.dentry),
                                              may_flags);
                        if (rc)
                                goto err_out;

                        if ((daccess & FILE_DELETE_LE) ||
                            (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) {
                                rc = ksmbd_vfs_may_delete(user_ns,
                                                          path.dentry);
                                if (rc)
                                        goto err_out;
                        }
                }
        }

        rc = ksmbd_query_inode_status(d_inode(path.dentry->d_parent));
        if (rc == KSMBD_INODE_STATUS_PENDING_DELETE) {
                rc = -EBUSY;
                goto err_out;
        }

        rc = 0;
        filp = dentry_open(&path, open_flags, current_cred());
        if (IS_ERR(filp)) {
                rc = PTR_ERR(filp);
                pr_err("dentry open for dir failed, rc %d\n", rc);
                goto err_out;
        }

        if (file_present) {
                if (!(open_flags & O_TRUNC))
                        file_info = FILE_OPENED;
                else
                        file_info = FILE_OVERWRITTEN;

                if ((req->CreateDisposition & FILE_CREATE_MASK_LE) ==
                    FILE_SUPERSEDE_LE)
                        file_info = FILE_SUPERSEDED;
        } else if (open_flags & O_CREAT) {
                file_info = FILE_CREATED;
        }

        ksmbd_vfs_set_fadvise(filp, req->CreateOptions);

        /* Obtain Volatile-ID */
        fp = ksmbd_open_fd(work, filp);
        if (IS_ERR(fp)) {
                fput(filp);
                rc = PTR_ERR(fp);
                fp = NULL;
                goto err_out;
        }

        /* Get Persistent-ID */
        ksmbd_open_durable_fd(fp);
        if (!has_file_id(fp->persistent_id)) {
                rc = -ENOMEM;
                goto err_out;
        }

        fp->filename = name;
        fp->cdoption = req->CreateDisposition;
        fp->daccess = daccess;
        fp->saccess = req->ShareAccess;
        fp->coption = req->CreateOptions;

        /* Set default windows and posix acls if creating new file */
        if (created) {
                int posix_acl_rc;
                struct inode *inode = d_inode(path.dentry);

                posix_acl_rc = ksmbd_vfs_inherit_posix_acl(user_ns,
                                                           inode,
                                                           d_inode(path.dentry->d_parent));
                if (posix_acl_rc)
                        ksmbd_debug(SMB, "inherit posix acl failed : %d\n", posix_acl_rc);

                if (test_share_config_flag(work->tcon->share_conf,
                                           KSMBD_SHARE_FLAG_ACL_XATTR)) {
                        rc = smb_inherit_dacl(conn, &path, sess->user->uid,
                                              sess->user->gid);
                }

                if (rc) {
                        rc = smb2_create_sd_buffer(work, req, &path);
                        if (rc) {
                                if (posix_acl_rc)
                                        ksmbd_vfs_set_init_posix_acl(user_ns,
                                                                     inode);

                                if (test_share_config_flag(work->tcon->share_conf,
                                                           KSMBD_SHARE_FLAG_ACL_XATTR)) {
                                        struct smb_fattr fattr;
                                        struct smb_ntsd *pntsd;
                                        int pntsd_size, ace_num = 0;

                                        ksmbd_acls_fattr(&fattr, user_ns, inode);
                                        if (fattr.cf_acls)
                                                ace_num = fattr.cf_acls->a_count;
                                        if (fattr.cf_dacls)
                                                ace_num += fattr.cf_dacls->a_count;

                                        pntsd = kmalloc(sizeof(struct smb_ntsd) +
                                                        sizeof(struct smb_sid) * 3 +
                                                        sizeof(struct smb_acl) +
                                                        sizeof(struct smb_ace) * ace_num * 2,
                                                        GFP_KERNEL);
                                        if (!pntsd)
                                                goto err_out;

                                        rc = build_sec_desc(user_ns,
                                                            pntsd, NULL,
                                                            OWNER_SECINFO |
                                                            GROUP_SECINFO |
                                                            DACL_SECINFO,
                                                            &pntsd_size, &fattr);
                                        posix_acl_release(fattr.cf_acls);
                                        posix_acl_release(fattr.cf_dacls);

                                        rc = ksmbd_vfs_set_sd_xattr(conn,
                                                                    user_ns,
                                                                    path.dentry,
                                                                    pntsd,
                                                                    pntsd_size);
                                        kfree(pntsd);
                                        if (rc)
                                                pr_err("failed to store ntacl in xattr : %d\n",
                                                       rc);
                                }
                        }
                }
                rc = 0;
        }

        if (stream_name) {
                rc = smb2_set_stream_name_xattr(&path,
                                                fp,
                                                stream_name,
                                                s_type);
                if (rc)
                        goto err_out;
                file_info = FILE_CREATED;
        }

        fp->attrib_only = !(req->DesiredAccess & ~(FILE_READ_ATTRIBUTES_LE |
                        FILE_WRITE_ATTRIBUTES_LE | FILE_SYNCHRONIZE_LE));
        if (!S_ISDIR(file_inode(filp)->i_mode) && open_flags & O_TRUNC &&
            !fp->attrib_only && !stream_name) {
                smb_break_all_oplock(work, fp);
                need_truncate = 1;
        }

        /* fp should be searchable through ksmbd_inode.m_fp_list
         * after daccess, saccess, attrib_only, and stream are