/*
 *   fs/cifs/connect.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2011
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/pagevec.h>
#include <linux/freezer.h>
#include <linux/namei.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <linux/inet.h>
#include <linux/module.h>
#include <keys/user-type.h>
#include <net/ipv6.h>
#include <linux/parser.h>

#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "ntlmssp.h"
#include "nterr.h"
#include "rfc1002pdu.h"
#include "fscache.h"

#define CIFS_PORT 445
#define RFC1001_PORT 139

extern mempool_t *cifs_req_poolp;

/* FIXME: should these be tunable? */
#define TLINK_ERROR_EXPIRE      (1 * HZ)
#define TLINK_IDLE_EXPIRE       (600 * HZ)

enum {

        /* Mount options that take no arguments */
        Opt_user_xattr, Opt_nouser_xattr,
        Opt_forceuid, Opt_noforceuid,
        Opt_forcegid, Opt_noforcegid,
        Opt_noblocksend, Opt_noautotune,
        Opt_hard, Opt_soft, Opt_perm, Opt_noperm,
        Opt_mapchars, Opt_nomapchars, Opt_sfu,
        Opt_nosfu, Opt_nodfs, Opt_posixpaths,
        Opt_noposixpaths, Opt_nounix,
        Opt_nocase,
        Opt_brl, Opt_nobrl,
        Opt_forcemandatorylock, Opt_setuids,
        Opt_nosetuids, Opt_dynperm, Opt_nodynperm,
        Opt_nohard, Opt_nosoft,
        Opt_nointr, Opt_intr,
        Opt_nostrictsync, Opt_strictsync,
        Opt_serverino, Opt_noserverino,
        Opt_rwpidforward, Opt_cifsacl, Opt_nocifsacl,
        Opt_acl, Opt_noacl, Opt_locallease,
        Opt_sign, Opt_seal, Opt_direct,
        Opt_strictcache, Opt_noac,
        Opt_fsc, Opt_mfsymlinks,
        Opt_multiuser, Opt_sloppy,

        /* Mount options which take numeric value */
        Opt_backupuid, Opt_backupgid, Opt_uid,
        Opt_cruid, Opt_gid, Opt_file_mode,
        Opt_dirmode, Opt_port,
        Opt_rsize, Opt_wsize, Opt_actimeo,

        /* Mount options which take string value */
        Opt_user, Opt_pass, Opt_ip,
        Opt_unc, Opt_domain,
        Opt_srcaddr, Opt_prefixpath,
        Opt_iocharset, Opt_sockopt,
        Opt_netbiosname, Opt_servern,
        Opt_ver, Opt_vers, Opt_sec, Opt_cache,

        /* Mount options to be ignored */
        Opt_ignore,

        /* Options which could be blank */
        Opt_blank_pass,
        Opt_blank_user,
        Opt_blank_ip,

        Opt_err
};

static const match_table_t cifs_mount_option_tokens = {

        { Opt_user_xattr, "user_xattr" },
        { Opt_nouser_xattr, "nouser_xattr" },
        { Opt_forceuid, "forceuid" },
        { Opt_noforceuid, "noforceuid" },
        { Opt_forcegid, "forcegid" },
        { Opt_noforcegid, "noforcegid" },
        { Opt_noblocksend, "noblocksend" },
        { Opt_noautotune, "noautotune" },
        { Opt_hard, "hard" },
        { Opt_soft, "soft" },
        { Opt_perm, "perm" },
        { Opt_noperm, "noperm" },
        { Opt_mapchars, "mapchars" },
        { Opt_nomapchars, "nomapchars" },
        { Opt_sfu, "sfu" },
        { Opt_nosfu, "nosfu" },
        { Opt_nodfs, "nodfs" },
        { Opt_posixpaths, "posixpaths" },
        { Opt_noposixpaths, "noposixpaths" },
        { Opt_nounix, "nounix" },
        { Opt_nounix, "nolinux" },
        { Opt_nocase, "nocase" },
        { Opt_nocase, "ignorecase" },
        { Opt_brl, "brl" },
        { Opt_nobrl, "nobrl" },
        { Opt_nobrl, "nolock" },
        { Opt_forcemandatorylock, "forcemandatorylock" },
        { Opt_forcemandatorylock, "forcemand" },
        { Opt_setuids, "setuids" },
        { Opt_nosetuids, "nosetuids" },
        { Opt_dynperm, "dynperm" },
        { Opt_nodynperm, "nodynperm" },
        { Opt_nohard, "nohard" },
        { Opt_nosoft, "nosoft" },
        { Opt_nointr, "nointr" },
        { Opt_intr, "intr" },
        { Opt_nostrictsync, "nostrictsync" },
        { Opt_strictsync, "strictsync" },
        { Opt_serverino, "serverino" },
        { Opt_noserverino, "noserverino" },
        { Opt_rwpidforward, "rwpidforward" },
        { Opt_cifsacl, "cifsacl" },
        { Opt_nocifsacl, "nocifsacl" },
        { Opt_acl, "acl" },
        { Opt_noacl, "noacl" },
        { Opt_locallease, "locallease" },
        { Opt_sign, "sign" },
        { Opt_seal, "seal" },
        { Opt_direct, "direct" },
        { Opt_direct, "directio" },
        { Opt_direct, "forcedirectio" },
        { Opt_strictcache, "strictcache" },
        { Opt_noac, "noac" },
        { Opt_fsc, "fsc" },
        { Opt_mfsymlinks, "mfsymlinks" },
        { Opt_multiuser, "multiuser" },
        { Opt_sloppy, "sloppy" },

        { Opt_backupuid, "backupuid=%s" },
        { Opt_backupgid, "backupgid=%s" },
        { Opt_uid, "uid=%s" },
        { Opt_cruid, "cruid=%s" },
        { Opt_gid, "gid=%s" },
        { Opt_file_mode, "file_mode=%s" },
        { Opt_dirmode, "dirmode=%s" },
        { Opt_dirmode, "dir_mode=%s" },
        { Opt_port, "port=%s" },
        { Opt_rsize, "rsize=%s" },
        { Opt_wsize, "wsize=%s" },
        { Opt_actimeo, "actimeo=%s" },

        { Opt_blank_user, "user=" },
        { Opt_blank_user, "username=" },
        { Opt_user, "user=%s" },
        { Opt_user, "username=%s" },
        { Opt_blank_pass, "pass=" },
        { Opt_pass, "pass=%s" },
        { Opt_pass, "password=%s" },
        { Opt_blank_ip, "ip=" },
        { Opt_blank_ip, "addr=" },
        { Opt_ip, "ip=%s" },
        { Opt_ip, "addr=%s" },
        { Opt_unc, "unc=%s" },
        { Opt_unc, "target=%s" },
        { Opt_unc, "path=%s" },
        { Opt_domain, "dom=%s" },
        { Opt_domain, "domain=%s" },
        { Opt_domain, "workgroup=%s" },
        { Opt_srcaddr, "srcaddr=%s" },
        { Opt_prefixpath, "prefixpath=%s" },
        { Opt_iocharset, "iocharset=%s" },
        { Opt_sockopt, "sockopt=%s" },
        { Opt_netbiosname, "netbiosname=%s" },
        { Opt_servern, "servern=%s" },
        { Opt_ver, "ver=%s" },
        { Opt_vers, "vers=%s" },
        { Opt_sec, "sec=%s" },
        { Opt_cache, "cache=%s" },

        { Opt_ignore, "cred" },
        { Opt_ignore, "credentials" },
        { Opt_ignore, "cred=%s" },
        { Opt_ignore, "credentials=%s" },
        { Opt_ignore, "guest" },
        { Opt_ignore, "rw" },
        { Opt_ignore, "ro" },
        { Opt_ignore, "suid" },
        { Opt_ignore, "nosuid" },
        { Opt_ignore, "exec" },
        { Opt_ignore, "noexec" },
        { Opt_ignore, "nodev" },
        { Opt_ignore, "noauto" },
        { Opt_ignore, "dev" },
        { Opt_ignore, "mand" },
        { Opt_ignore, "nomand" },
        { Opt_ignore, "_netdev" },

        { Opt_err, NULL }
};

enum {
        Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
        Opt_sec_ntlmsspi, Opt_sec_ntlmssp,
        Opt_ntlm, Opt_sec_ntlmi, Opt_sec_ntlmv2,
        Opt_sec_ntlmv2i, Opt_sec_lanman,
        Opt_sec_none,

        Opt_sec_err
};

static const match_table_t cifs_secflavor_tokens = {
        { Opt_sec_krb5, "krb5" },
        { Opt_sec_krb5i, "krb5i" },
        { Opt_sec_krb5p, "krb5p" },
        { Opt_sec_ntlmsspi, "ntlmsspi" },
        { Opt_sec_ntlmssp, "ntlmssp" },
        { Opt_ntlm, "ntlm" },
        { Opt_sec_ntlmi, "ntlmi" },
        { Opt_sec_ntlmv2, "nontlm" },
        { Opt_sec_ntlmv2, "ntlmv2" },
        { Opt_sec_ntlmv2i, "ntlmv2i" },
        { Opt_sec_lanman, "lanman" },
        { Opt_sec_none, "none" },

        { Opt_sec_err, NULL }
};

/* cache flavors */
enum {
        Opt_cache_loose,
        Opt_cache_strict,
        Opt_cache_none,
        Opt_cache_err
};

static const match_table_t cifs_cacheflavor_tokens = {
        { Opt_cache_loose, "loose" },
        { Opt_cache_strict, "strict" },
        { Opt_cache_none, "none" },
        { Opt_cache_err, NULL }
};

static const match_table_t cifs_smb_version_tokens = {
        { Smb_1, SMB1_VERSION_STRING },
        { Smb_21, SMB21_VERSION_STRING },
};

static int ip_connect(struct TCP_Server_Info *server);
static int generic_ip_connect(struct TCP_Server_Info *server);
static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
static void cifs_prune_tlinks(struct work_struct *work);
static int cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data,
                                        const char *devname);

/*
 * cifs tcp session reconnection
 *
 * mark tcp session as reconnecting so temporarily locked
 * mark all smb sessions as reconnecting for tcp session
 * reconnect tcp session
 * wake up waiters on reconnection? - (not needed currently)
 */
int
cifs_reconnect(struct TCP_Server_Info *server)
{
        int rc = 0;
        struct list_head *tmp, *tmp2;
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;
        struct mid_q_entry *mid_entry;
        struct list_head retry_list;

        spin_lock(&GlobalMid_Lock);
        if (server->tcpStatus == CifsExiting) {
                /* the demux thread will exit normally
                next time through the loop */
                spin_unlock(&GlobalMid_Lock);
                return rc;
        } else
                server->tcpStatus = CifsNeedReconnect;
        spin_unlock(&GlobalMid_Lock);
        server->maxBuf = 0;
#ifdef CONFIG_CIFS_SMB2
        server->max_read = 0;
#endif

        cFYI(1, "Reconnecting tcp session");

        /* before reconnecting the tcp session, mark the smb session (uid)
                and the tid bad so they are not used until reconnected */
        cFYI(1, "%s: marking sessions and tcons for reconnect", __func__);
        spin_lock(&cifs_tcp_ses_lock);
        list_for_each(tmp, &server->smb_ses_list) {
                ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
                ses->need_reconnect = true;
                ses->ipc_tid = 0;
                list_for_each(tmp2, &ses->tcon_list) {
                        tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);
                        tcon->need_reconnect = true;
                }
        }
        spin_unlock(&cifs_tcp_ses_lock);

        /* do not want to be sending data on a socket we are freeing */
        cFYI(1, "%s: tearing down socket", __func__);
        mutex_lock(&server->srv_mutex);
        if (server->ssocket) {
                cFYI(1, "State: 0x%x Flags: 0x%lx", server->ssocket->state,
                        server->ssocket->flags);
                kernel_sock_shutdown(server->ssocket, SHUT_WR);
                cFYI(1, "Post shutdown state: 0x%x Flags: 0x%lx",
                        server->ssocket->state,
                        server->ssocket->flags);
                sock_release(server->ssocket);
                server->ssocket = NULL;
        }
        server->sequence_number = 0;
        server->session_estab = false;
        kfree(server->session_key.response);
        server->session_key.response = NULL;
        server->session_key.len = 0;
        server->lstrp = jiffies;
        mutex_unlock(&server->srv_mutex);

        /* mark submitted MIDs for retry and issue callback */
        INIT_LIST_HEAD(&retry_list);
        cFYI(1, "%s: moving mids to private list", __func__);
        spin_lock(&GlobalMid_Lock);
        list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
                mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
                        mid_entry->mid_state = MID_RETRY_NEEDED;
                list_move(&mid_entry->qhead, &retry_list);
        }
        spin_unlock(&GlobalMid_Lock);

        cFYI(1, "%s: issuing mid callbacks", __func__);
        list_for_each_safe(tmp, tmp2, &retry_list) {
                mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                list_del_init(&mid_entry->qhead);
                mid_entry->callback(mid_entry);
        }

        do {
                try_to_freeze();

                /* we should try only the port we connected to before */
                rc = generic_ip_connect(server);
                if (rc) {
                        cFYI(1, "reconnect error %d", rc);
                        msleep(3000);
                } else {
                        atomic_inc(&tcpSesReconnectCount);
                        spin_lock(&GlobalMid_Lock);
                        if (server->tcpStatus != CifsExiting)
                                server->tcpStatus = CifsNeedNegotiate;
                        spin_unlock(&GlobalMid_Lock);
                }
        } while (server->tcpStatus == CifsNeedReconnect);

        return rc;
}

static void
cifs_echo_request(struct work_struct *work)
{
        int rc;
        struct TCP_Server_Info *server = container_of(work,
                                        struct TCP_Server_Info, echo.work);

        /*
         * We cannot send an echo if it is disabled or until the
         * NEGOTIATE_PROTOCOL request is done, which is indicated by
         * server->ops->need_neg() == true. Also, no need to ping if
         * we got a response recently.
         */
        if (!server->ops->need_neg || server->ops->need_neg(server) ||
            (server->ops->can_echo && !server->ops->can_echo(server)) ||
            time_before(jiffies, server->lstrp + SMB_ECHO_INTERVAL - HZ))
                goto requeue_echo;

        rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
        if (rc)
                cFYI(1, "Unable to send echo request to server: %s",
                        server->hostname);

requeue_echo:
        queue_delayed_work(cifsiod_wq, &server->echo, SMB_ECHO_INTERVAL);
}

static bool
allocate_buffers(struct TCP_Server_Info *server)
{
        if (!server->bigbuf) {
                server->bigbuf = (char *)cifs_buf_get();
                if (!server->bigbuf) {
                        cERROR(1, "No memory for large SMB response");
                        msleep(3000);
                        /* retry will check if exiting */
                        return false;
                }
        } else if (server->large_buf) {
                /* we are reusing a dirty large buf, clear its start */
                memset(server->bigbuf, 0, HEADER_SIZE(server));
        }

        if (!server->smallbuf) {
                server->smallbuf = (char *)cifs_small_buf_get();
                if (!server->smallbuf) {
                        cERROR(1, "No memory for SMB response");
                        msleep(1000);
                        /* retry will check if exiting */
                        return false;
                }
                /* beginning of smb buffer is cleared in our buf_get */
        } else {
                /* if existing small buf clear beginning */
                memset(server->smallbuf, 0, HEADER_SIZE(server));
        }

        return true;
}

static bool
server_unresponsive(struct TCP_Server_Info *server)
{
        /*
         * We need to wait 2 echo intervals to make sure we handle such
         * situations right:
         * 1s  client sends a normal SMB request
         * 2s  client gets a response
         * 30s echo workqueue job pops, and decides we got a response recently
         *     and don't need to send another
         * ...
         * 65s kernel_recvmsg times out, and we see that we haven't gotten
         *     a response in >60s.
         */
        if (server->tcpStatus == CifsGood &&
            time_after(jiffies, server->lstrp + 2 * SMB_ECHO_INTERVAL)) {
                cERROR(1, "Server %s has not responded in %d seconds. "
                          "Reconnecting...", server->hostname,
                          (2 * SMB_ECHO_INTERVAL) / HZ);
                cifs_reconnect(server);
                wake_up(&server->response_q);
                return true;
        }

        return false;
}

/*
 * kvec_array_init - clone a kvec array, and advance into it
 * @new:        pointer to memory for cloned array
 * @iov:        pointer to original array
 * @nr_segs:    number of members in original array
 * @bytes:      number of bytes to advance into the cloned array
 *
 * This function will copy the array provided in iov to a section of memory
 * and advance the specified number of bytes into the new array. It returns
 * the number of segments in the new array. "new" must be at least as big as
 * the original iov array.
 */
static unsigned int
kvec_array_init(struct kvec *new, struct kvec *iov, unsigned int nr_segs,
                size_t bytes)
{
        size_t base = 0;

        while (bytes || !iov->iov_len) {
                int copy = min(bytes, iov->iov_len);

                bytes -= copy;
                base += copy;
                if (iov->iov_len == base) {
                        iov++;
                        nr_segs--;
                        base = 0;
                }
        }
        memcpy(new, iov, sizeof(*iov) * nr_segs);
        new->iov_base += base;
        new->iov_len -= base;
        return nr_segs;
}

static struct kvec *
get_server_iovec(struct TCP_Server_Info *server, unsigned int nr_segs)
{
        struct kvec *new_iov;

        if (server->iov && nr_segs <= server->nr_iov)
                return server->iov;

        /* not big enough -- allocate a new one and release the old */
        new_iov = kmalloc(sizeof(*new_iov) * nr_segs, GFP_NOFS);
        if (new_iov) {
                kfree(server->iov);
                server->iov = new_iov;
                server->nr_iov = nr_segs;
        }
        return new_iov;
}

int
cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
                       unsigned int nr_segs, unsigned int to_read)
{
        int length = 0;
        int total_read;
        unsigned int segs;
        struct msghdr smb_msg;
        struct kvec *iov;

        iov = get_server_iovec(server, nr_segs);
        if (!iov)
                return -ENOMEM;

        smb_msg.msg_control = NULL;
        smb_msg.msg_controllen = 0;

        for (total_read = 0; to_read; total_read += length, to_read -= length) {
                try_to_freeze();

                if (server_unresponsive(server)) {
                        total_read = -EAGAIN;
                        break;
                }

                segs = kvec_array_init(iov, iov_orig, nr_segs, total_read);

                length = kernel_recvmsg(server->ssocket, &smb_msg,
                                        iov, segs, to_read, 0);

                if (server->tcpStatus == CifsExiting) {
                        total_read = -ESHUTDOWN;
                        break;
                } else if (server->tcpStatus == CifsNeedReconnect) {
                        cifs_reconnect(server);
                        total_read = -EAGAIN;
                        break;
                } else if (length == -ERESTARTSYS ||
                           length == -EAGAIN ||
                           length == -EINTR) {
                        /*
                         * Minimum sleep to prevent looping, allowing socket
                         * to clear and app threads to set tcpStatus
                         * CifsNeedReconnect if server hung.
                         */
                        usleep_range(1000, 2000);
                        length = 0;
                        continue;
                } else if (length <= 0) {
                        cFYI(1, "Received no data or error: expecting %d "
                                "got %d", to_read, length);
                        cifs_reconnect(server);
                        total_read = -EAGAIN;
                        break;
                }
        }
        return total_read;
}

int
cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
                      unsigned int to_read)
{
        struct kvec iov;

        iov.iov_base = buf;
        iov.iov_len = to_read;

        return cifs_readv_from_socket(server, &iov, 1, to_read);
}

static bool
is_smb_response(struct TCP_Server_Info *server, unsigned char type)
{
        /*
         * The first byte big endian of the length field,
         * is actually not part of the length but the type
         * with the most common, zero, as regular data.
         */
        switch (type) {
        case RFC1002_SESSION_MESSAGE:
                /* Regular SMB response */
                return true;
        case RFC1002_SESSION_KEEP_ALIVE:
                cFYI(1, "RFC 1002 session keep alive");
                break;
        case RFC1002_POSITIVE_SESSION_RESPONSE:
                cFYI(1, "RFC 1002 positive session response");
                break;
        case RFC1002_NEGATIVE_SESSION_RESPONSE:
                /*
                 * We get this from Windows 98 instead of an error on
                 * SMB negprot response.
                 */
                cFYI(1, "RFC 1002 negative session response");
                /* give server a second to clean up */
                msleep(1000);
                /*
                 * Always try 445 first on reconnect since we get NACK
                 * on some if we ever connected to port 139 (the NACK
                 * is since we do not begin with RFC1001 session
                 * initialize frame).
                 */
                cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
                cifs_reconnect(server);
                wake_up(&server->response_q);
                break;
        default:
                cERROR(1, "RFC 1002 unknown response type 0x%x", type);
                cifs_reconnect(server);
        }

        return false;
}

void
dequeue_mid(struct mid_q_entry *mid, bool malformed)
{
#ifdef CONFIG_CIFS_STATS2
        mid->when_received = jiffies;
#endif
        spin_lock(&GlobalMid_Lock);
        if (!malformed)
                mid->mid_state = MID_RESPONSE_RECEIVED;
        else
                mid->mid_state = MID_RESPONSE_MALFORMED;
        list_del_init(&mid->qhead);
        spin_unlock(&GlobalMid_Lock);
}

static void
handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
           char *buf, int malformed)
{
        if (server->ops->check_trans2 &&
            server->ops->check_trans2(mid, server, buf, malformed))
                return;
        mid->resp_buf = buf;
        mid->large_buf = server->large_buf;
        /* Was previous buf put in mpx struct for multi-rsp? */
        if (!mid->multiRsp) {
                /* smb buffer will be freed by user thread */
                if (server->large_buf)
                        server->bigbuf = NULL;
                else
                        server->smallbuf = NULL;
        }
        dequeue_mid(mid, malformed);
}

static void clean_demultiplex_info(struct TCP_Server_Info *server)
{
        int length;

        /* take it off the list, if it's not already */
        spin_lock(&cifs_tcp_ses_lock);
        list_del_init(&server->tcp_ses_list);
        spin_unlock(&cifs_tcp_ses_lock);

        spin_lock(&GlobalMid_Lock);
        server->tcpStatus = CifsExiting;
        spin_unlock(&GlobalMid_Lock);
        wake_up_all(&server->response_q);

        /* check if we have blocked requests that need to free */
        spin_lock(&server->req_lock);
        if (server->credits <= 0)
                server->credits = 1;
        spin_unlock(&server->req_lock);
        /*
         * Although there should not be any requests blocked on this queue it
         * can not hurt to be paranoid and try to wake up requests that may
         * haven been blocked when more than 50 at time were on the wire to the
         * same server - they now will see the session is in exit state and get
         * out of SendReceive.
         */
        wake_up_all(&server->request_q);
        /* give those requests time to exit */
        msleep(125);

        if (server->ssocket) {
                sock_release(server->ssocket);
                server->ssocket = NULL;
        }

        if (!list_empty(&server->pending_mid_q)) {
                struct list_head dispose_list;
                struct mid_q_entry *mid_entry;
                struct list_head *tmp, *tmp2;

                INIT_LIST_HEAD(&dispose_list);
                spin_lock(&GlobalMid_Lock);
                list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
                        mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                        cFYI(1, "Clearing mid 0x%llx", mid_entry->mid);
                        mid_entry->mid_state = MID_SHUTDOWN;
                        list_move(&mid_entry->qhead, &dispose_list);
                }
                spin_unlock(&GlobalMid_Lock);

                /* now walk dispose list and issue callbacks */
                list_for_each_safe(tmp, tmp2, &dispose_list) {
                        mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                        cFYI(1, "Callback mid 0x%llx", mid_entry->mid);
                        list_del_init(&mid_entry->qhead);
                        mid_entry->callback(mid_entry);
                }
                /* 1/8th of sec is more than enough time for them to exit */
                msleep(125);
        }

        if (!list_empty(&server->pending_mid_q)) {
                /*
                 * mpx threads have not exited yet give them at least the smb
                 * send timeout time for long ops.
                 *
                 * Due to delays on oplock break requests, we need to wait at
                 * least 45 seconds before giving up on a request getting a
                 * response and going ahead and killing cifsd.
                 */
                cFYI(1, "Wait for exit from demultiplex thread");
                msleep(46000);
                /*
                 * If threads still have not exited they are probably never
                 * coming home not much else we can do but free the memory.
                 */
        }

        kfree(server->hostname);
        kfree(server->iov);
        kfree(server);

        length = atomic_dec_return(&tcpSesAllocCount);
        if (length > 0)
                mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
                                GFP_KERNEL);
}

static int
standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
        int length;
        char *buf = server->smallbuf;
        unsigned int pdu_length = get_rfc1002_length(buf);

        /* make sure this will fit in a large buffer */
        if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) - 4) {
                cERROR(1, "SMB response too long (%u bytes)",
                        pdu_length);
                cifs_reconnect(server);
                wake_up(&server->response_q);
                return -EAGAIN;
        }

        /* switch to large buffer if too big for a small one */
        if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
                server->large_buf = true;
                memcpy(server->bigbuf, buf, server->total_read);
                buf = server->bigbuf;
        }

        /* now read the rest */
        length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
                                pdu_length - HEADER_SIZE(server) + 1 + 4);
        if (length < 0)
                return length;
        server->total_read += length;

        dump_smb(buf, server->total_read);

        /*
         * We know that we received enough to get to the MID as we
         * checked the pdu_length earlier. Now check to see
         * if the rest of the header is OK. We borrow the length
         * var for the rest of the loop to avoid a new stack var.
         *
         * 48 bytes is enough to display the header and a little bit
         * into the payload for debugging purposes.
         */
        length = server->ops->check_message(buf, server->total_read);
        if (length != 0)
                cifs_dump_mem("Bad SMB: ", buf,
                        min_t(unsigned int, server->total_read, 48));

        if (!mid)
                return length;

        handle_mid(mid, server, buf, length);
        return 0;
}

static int
cifs_demultiplex_thread(void *p)
{
        int length;
        struct TCP_Server_Info *server = p;
        unsigned int pdu_length;
        char *buf = NULL;
        struct task_struct *task_to_wake = NULL;
        struct mid_q_entry *mid_entry;

        current->flags |= PF_MEMALLOC;
        cFYI(1, "Demultiplex PID: %d", task_pid_nr(current));

        length = atomic_inc_return(&tcpSesAllocCount);
        if (length > 1)
                mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
                                GFP_KERNEL);

        set_freezable();
        while (server->tcpStatus != CifsExiting) {
                if (try_to_freeze())
                        continue;

                if (!allocate_buffers(server))
                        continue;

                server->large_buf = false;
                buf = server->smallbuf;
                pdu_length = 4; /* enough to get RFC1001 header */

                length = cifs_read_from_socket(server, buf, pdu_length);
                if (length < 0)
                        continue;
                server->total_read = length;

                /*
                 * The right amount was read from socket - 4 bytes,
                 * so we can now interpret the length field.
                 */
                pdu_length = get_rfc1002_length(buf);

                cFYI(1, "RFC1002 header 0x%x", pdu_length);
                if (!is_smb_response(server, buf[0]))
                        continue;

                /* make sure we have enough to get to the MID */
                if (pdu_length < HEADER_SIZE(server) - 1 - 4) {
                        cERROR(1, "SMB response too short (%u bytes)",
                                pdu_length);
                        cifs_reconnect(server);
                        wake_up(&server->response_q);
                        continue;
                }

                /* read down to the MID */
                length = cifs_read_from_socket(server, buf + 4,
                                               HEADER_SIZE(server) - 1 - 4);
                if (length < 0)
                        continue;
                server->total_read += length;

                mid_entry = server->ops->find_mid(server, buf);

                if (!mid_entry || !mid_entry->receive)
                        length = standard_receive3(server, mid_entry);
                else
                        length = mid_entry->receive(server, mid_entry);

                if (length < 0)
                        continue;

                if (server->large_buf)
                        buf = server->bigbuf;

                server->lstrp = jiffies;
                if (mid_entry != NULL) {
                        if (!mid_entry->multiRsp || mid_entry->multiEnd)
                                mid_entry->callback(mid_entry);
                } else if (!server->ops->is_oplock_break ||
                           !server->ops->is_oplock_break(buf, server)) {
                        cERROR(1, "No task to wake, unknown frame received! "
                                   "NumMids %d", atomic_read(&midCount));
                        cifs_dump_mem("Received Data is: ", buf,
                                      HEADER_SIZE(server));
#ifdef CONFIG_CIFS_DEBUG2
                        if (server->ops->dump_detail)
                                server->ops->dump_detail(buf);
                        cifs_dump_mids(server);
#endif /* CIFS_DEBUG2 */

                }
        } /* end while !EXITING */

        /* buffer usually freed in free_mid - need to free it here on exit */
        cifs_buf_release(server->bigbuf);
        if (server->smallbuf) /* no sense logging a debug message if NULL */
                cifs_small_buf_release(server->smallbuf);

        task_to_wake = xchg(&server->tsk, NULL);
        clean_demultiplex_info(server);

        /* if server->tsk was NULL then wait for a signal before exiting */
        if (!task_to_wake) {
                set_current_state(TASK_INTERRUPTIBLE);
                while (!signal_pending(current)) {
                        schedule();
                        set_current_state(TASK_INTERRUPTIBLE);
                }
                set_current_state(TASK_RUNNING);
        }

        module_put_and_exit(0);
}

/* extract the host portion of the UNC string */
static char *
extract_hostname(const char *unc)
{
        const char *src;
        char *dst, *delim;
        unsigned int len;

        /* skip double chars at beginning of string */
        /* BB: check validity of these bytes? */
        src = unc + 2;

        /* delimiter between hostname and sharename is always '\\' now */
        delim = strchr(src, '\\');
        if (!delim)
                return ERR_PTR(-EINVAL);

        len = delim - src;
        dst = kmalloc((len + 1), GFP_KERNEL);
        if (dst == NULL)
                return ERR_PTR(-ENOMEM);

        memcpy(dst, src, len);
        dst[len] = '\0';

        return dst;
}

static int get_option_ul(substring_t args[], unsigned long *option)
{
        int rc;
        char *string;

        string = match_strdup(args);
        if (string == NULL)
                return -ENOMEM;
        rc = kstrtoul(string, 0, option);
        kfree(string);

        return rc;
}


static int cifs_parse_security_flavors(char *value,
                                       struct smb_vol *vol)
{

        substring_t args[MAX_OPT_ARGS];

        switch (match_token(value, cifs_secflavor_tokens, args)) {
        case Opt_sec_krb5:
                vol->secFlg |= CIFSSEC_MAY_KRB5;
                break;
        case Opt_sec_krb5i:
                vol->secFlg |= CIFSSEC_MAY_KRB5 | CIFSSEC_MUST_SIGN;

                break;
        case Opt_sec_krb5p:
                /* vol->secFlg |= CIFSSEC_MUST_SEAL | CIFSSEC_MAY_KRB5; */
                cERROR(1, "Krb5 cifs privacy not supported");
                break;
        case Opt_sec_ntlmssp:
                vol->secFlg |= CIFSSEC_MAY_NTLMSSP;
                break;
        case Opt_sec_ntlmsspi:
                vol->secFlg |= CIFSSEC_MAY_NTLMSSP | CIFSSEC_MUST_SIGN;
                break;
        case Opt_ntlm:
                /* ntlm is default so can be turned off too */
                vol->secFlg |= CIFSSEC_MAY_NTLM;
                break;
        case Opt_sec_ntlmi:
                vol->secFlg |= CIFSSEC_MAY_NTLM | CIFSSEC_MUST_SIGN;
                break;
        case Opt_sec_ntlmv2:
                vol->secFlg |= CIFSSEC_MAY_NTLMV2;
                break;
        case Opt_sec_ntlmv2i:
                vol->secFlg |= CIFSSEC_MAY_NTLMV2 | CIFSSEC_MUST_SIGN;
                break;
#ifdef CONFIG_CIFS_WEAK_PW_HASH
        case Opt_sec_lanman:
                vol->secFlg |= CIFSSEC_MAY_LANMAN;
                break;
#endif
        case Opt_sec_none:
                vol->nullauth = 1;
                break;
        default:
                cERROR(1, "bad security option: %s", value);
                return 1;
        }

        return 0;
}

static int
cifs_parse_cache_flavor(char *value, struct smb_vol *vol)
{
        substring_t args[MAX_OPT_ARGS];

        switch (match_token(value, cifs_cacheflavor_tokens, args)) {
        case Opt_cache_loose:
                vol->direct_io = false;
                vol->strict_io = false;
                break;
        case Opt_cache_strict:
                vol->direct_io = false;
                vol->strict_io = true;
                break;
        case Opt_cache_none:
                vol->direct_io = true;
                vol->strict_io = false;
                break;
        default:
                cERROR(1, "bad cache= option: %s", value);
                return 1;
        }
        return 0;
}

static int
cifs_parse_smb_version(char *value, struct smb_vol *vol)
{
        substring_t args[MAX_OPT_ARGS];

        switch (match_token(value, cifs_smb_version_tokens, args)) {
        case Smb_1:
                vol->ops = &smb1_operations;
                vol->vals = &smb1_values;
                break;
#ifdef CONFIG_CIFS_SMB2
        case Smb_21:
                vol->ops = &smb21_operations;
                vol->vals = &smb21_values;
                break;
#endif
        default:
                cERROR(1, "Unknown vers= option specified: %s", value);
                return 1;
        }
        return 0;
}

static int
cifs_parse_mount_options(const char *mountdata, const char *devname,
                         struct smb_vol *vol)
{
        char *data, *end;
        char *mountdata_copy = NULL, *options;
        unsigned int  temp_len, i, j;
        char separator[2];
        short int override_uid = -1;
        short int override_gid = -1;
        bool uid_specified = false;
        bool gid_specified = false;
        bool sloppy = false;
        char *invalid = NULL;
        char *nodename = utsname()->nodename;
        char *string = NULL;
        char *tmp_end, *value;
        char delim;
        bool cache_specified = false;
        static bool cache_warned = false;

        separator[0] = ',';
        separator[1] = 0;
        delim = separator[0];

        /*
         * does not have to be perfect mapping since field is
         * informational, only used for servers that do not support
         * port 445 and it can be overridden at mount time
         */
        memset(vol->source_rfc1001_name, 0x20, RFC1001_NAME_LEN);
        for (i = 0; i < strnlen(nodename, RFC1001_NAME_LEN); i++)
                vol->source_rfc1001_name[i] = toupper(nodename[i]);

        vol->source_rfc1001_name[RFC1001_NAME_LEN] = 0;
        /* null target name indicates to use *SMBSERVR default called name
           if we end up sending RFC1001 session initialize */
        vol->target_rfc1001_name[0] = 0;
        vol->cred_uid = current_uid();
        vol->linux_uid = current_uid();
        vol->linux_gid = current_gid();

        /* default to only allowing write access to owner of the mount */
        vol->dir_mode = vol->file_mode = S_IRUGO | S_IXUGO | S_IWUSR;

        /* vol->retry default is 0 (i.e. "soft" limited retry not hard retry) */
        /* default is always to request posix paths. */
        vol->posix_paths = 1;
        /* default to using server inode numbers where available */
        vol->server_ino = 1;

        vol->actimeo = CIFS_DEF_ACTIMEO;

        /* FIXME: add autonegotiation -- for now, SMB1 is default */
        vol->ops = &smb1_operations;
        vol->vals = &smb1_values;

        if (!mountdata)
                goto cifs_parse_mount_err;

        mountdata_copy = kstrndup(mountdata, PAGE_SIZE, GFP_KERNEL);
        if (!mountdata_copy)
                goto cifs_parse_mount_err;

        options = mountdata_copy;
        end = options + strlen(options);

        if (strncmp(options, "sep=", 4) == 0) {
                if (options[4] != 0) {
                        separator[0] = options[4];
                        options += 5;
                } else {
                        cFYI(1, "Null separator not allowed");
                }
        }
        vol->backupuid_specified = false; /* no backup intent for a user */
        vol->backupgid_specified = false; /* no backup intent for a group */

        while ((data = strsep(&options, separator)) != NULL) {
                substring_t args[MAX_OPT_ARGS];
                unsigned long option;
                int token;

                if (!*data)
                        continue;

                token = match_token(data, cifs_mount_option_tokens, args);

                switch (token) {

                /* Ingnore the following */
                case Opt_ignore:
                        break;

                /* Boolean values */
                case Opt_user_xattr:
                        vol->no_xattr = 0;
                        break;
                case Opt_nouser_xattr:
                        vol->no_xattr = 1;
                        break;
                case Opt_forceuid:
                        override_uid = 1;
                        break;
                case Opt_noforceuid:
                        override_uid = 0;
                        break;
                case Opt_forcegid:
                        override_gid = 1;
                        break;
                case Opt_noforcegid:
                        override_gid = 0;
                        break;
                case Opt_noblocksend:
                        vol->noblocksnd = 1;
                        break;
                case Opt_noautotune:
                        vol->noautotune = 1;
                        break;
                case Opt_hard:
                        vol->retry = 1;
                        break;
                case Opt_soft:
                        vol->retry = 0;
                        break;
                case Opt_perm:
                        vol->noperm = 0;
                        break;
                case Opt_noperm:
                        vol->noperm = 1;
                        break;
                case Opt_mapchars:
                        vol->remap = 1;
                        break;
                case Opt_nomapchars:
                        vol->remap = 0;
                        break;
                case Opt_sfu:
                        vol->sfu_emul = 1;
                        break;
                case Opt_nosfu:
                        vol->sfu_emul = 0;
                        break;
                case Opt_nodfs:
                        vol->nodfs = 1;
                        break;
                case Opt_posixpaths:
                        vol->posix_paths = 1;
                        break;
                case Opt_noposixpaths:
                        vol->posix_paths = 0;
                        break;
                case Opt_nounix:
                        vol->no_linux_ext = 1;
                        break;
                case Opt_nocase:
                        vol->nocase = 1;
                        break;
                case Opt_brl:
                        vol->nobrl =  0;
                        break;
                case Opt_nobrl:
                        vol->nobrl =  1;
                        /*
                         * turn off mandatory locking in mode
                         * if remote locking is turned off since the
                         * local vfs will do advisory
                         */
                        if (vol->file_mode ==
                                (S_IALLUGO & ~(S_ISUID | S_IXGRP)))
                                vol->file_mode = S_IALLUGO;
                        break;
                case Opt_forcemandatorylock:
                        vol->mand_lock = 1;
                        break;
                case Opt_setuids:
                        vol->setuids = 1;
                        break;
                case Opt_nosetuids:
                        vol->setuids = 0;
                        break;
                case Opt_dynperm:
                        vol->dynperm = true;
                        break;
                case Opt_nodynperm:
                        vol->dynperm = false;
                        break;
                case Opt_nohard:
                        vol->retry = 0;
                        break;
                case Opt_nosoft:
                        vol->retry = 1;
                        break;
                case Opt_nointr:
                        vol->intr = 0;
                        break;
                case Opt_intr:
                        vol->intr = 1;
                        break;
                case Opt_nostrictsync:
                        vol->nostrictsync = 1;
                        break;
                case Opt_strictsync:
                        vol->nostrictsync = 0;
                        break;
                case Opt_serverino:
                        vol->server_ino = 1;
                        break;
                case Opt_noserverino:
                        vol->server_ino = 0;
                        break;
                case Opt_rwpidforward:
                        vol->rwpidforward = 1;
                        break;
                case Opt_cifsacl:
                        vol->cifs_acl = 1;
                        break;
                case Opt_nocifsacl:
                        vol->cifs_acl = 0;
                        break;
                case Opt_acl:
                        vol->no_psx_acl = 0;
                        break;
                case Opt_noacl:
                        vol->no_psx_acl = 1;
                        break;
                case Opt_locallease:
                        vol->local_lease = 1;
                        break;
                case Opt_sign:
                        vol->secFlg |= CIFSSEC_MUST_SIGN;
                        break;
                case Opt_seal:
                        /* we do not do the following in secFlags because seal
                         * is a per tree connection (mount) not a per socket
                         * or per-smb connection option in the protocol
                         * vol->secFlg |= CIFSSEC_MUST_SEAL;
                         */
                        vol->seal = 1;
                        break;
                case Opt_direct:
                        cache_specified = true;
                        vol->direct_io = true;
                        vol->strict_io = false;
                        cERROR(1, "The \"directio\" option will be removed in "
                                  "3.7. Please switch to the \"cache=none\" "
                                  "option.");
                        break;
                case Opt_strictcache:
                        cache_specified = true;
                        vol->direct_io = false;
                        vol->strict_io = true;
                        cERROR(1, "The \"strictcache\" option will be removed "
                                "in 3.7. Please switch to the \"cache=strict\" "
                                "option.");
                        break;
                case Opt_noac:
                        printk(KERN_WARNING "CIFS: Mount option noac not "
                                "supported. Instead set "
                                "/proc/fs/cifs/LookupCacheEnabled to 0\n");
                        break;
                case Opt_fsc:
#ifndef CONFIG_CIFS_FSCACHE
                        cERROR(1, "FS-Cache support needs CONFIG_CIFS_FSCACHE "
                                  "kernel config option set");
                        goto cifs_parse_mount_err;
#endif
                        vol->fsc = true;
                        break;
                case Opt_mfsymlinks:
                        vol->mfsymlinks = true;
                        break;
                case Opt_multiuser:
                        vol->multiuser = true;
                        break;
                case Opt_sloppy:
                        sloppy = true;
                        break;

                /* Numeric Values */
                case Opt_backupuid:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid backupuid value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->backupuid = option;
                        vol->backupuid_specified = true;
                        break;
                case Opt_backupgid:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid backupgid value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->backupgid = option;
                        vol->backupgid_specified = true;
                        break;
                case Opt_uid:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid uid value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->linux_uid = option;
                        uid_specified = true;
                        break;
                case Opt_cruid:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid cruid value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->cred_uid = option;
                        break;
                case Opt_gid:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid gid value",
                                                __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->linux_gid = option;
                        gid_specified = true;
                        break;
                case Opt_file_mode:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid file_mode value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->file_mode = option;
                        break;
                case Opt_dirmode:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid dir_mode value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->dir_mode = option;
                        break;
                case Opt_port:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid port value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->port = option;
                        break;
                case Opt_rsize:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid rsize value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->rsize = option;
                        break;
                case Opt_wsize:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid wsize value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->wsize = option;
                        break;
                case Opt_actimeo:
                        if (get_option_ul(args, &option)) {
                                cERROR(1, "%s: Invalid actimeo value",
                                        __func__);
                                goto cifs_parse_mount_err;
                        }
                        vol->actimeo = HZ * option;
                        if (vol->actimeo > CIFS_MAX_ACTIMEO) {
                                cERROR(1, "CIFS: attribute cache"
                                          "timeout too large");
                                goto cifs_parse_mount_err;
                        }
                        break;

                /* String Arguments */

                case Opt_blank_user:
                        /* null user, ie. anonymous authentication */
                        vol->nullauth = 1;
                        vol->username = NULL;
                        break;
                case Opt_user:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (strnlen(string, MAX_USERNAME_SIZE) >
                                                        MAX_USERNAME_SIZE) {
                                printk(KERN_WARNING "CIFS: username too long\n");
                                goto cifs_parse_mount_err;
                        }
                        vol->username = kstrdup(string, GFP_KERNEL);
                        if (!vol->username) {
                                printk(KERN_WARNING "CIFS: no memory "
                                                    "for username\n");
                                goto cifs_parse_mount_err;
                        }
                        break;
                case Opt_blank_pass:
                        vol->password = NULL;
                        break;
                case Opt_pass:
                        /* passwords have to be handled differently
                         * to allow the character used for deliminator
                         * to be passed within them
                         */

                        /* Obtain the value string */
                        value = strchr(data, '=');
                        value++;

                        /* Set tmp_end to end of the string */
                        tmp_end = (char *) value + strlen(value);

                        /* Check if following character is the deliminator
                         * If yes, we have encountered a double deliminator
                         * reset the NULL character to the deliminator
                         */
                        if (tmp_end < end && tmp_end[1] == delim) {
                                tmp_end[0] = delim;

                                /* Keep iterating until we get to a single
                                 * deliminator OR the end
                                 */
                                while ((tmp_end = strchr(tmp_end, delim))
                                        != NULL && (tmp_end[1] == delim)) {
                                                tmp_end = (char *) &tmp_end[2];
                                }

                                /* Reset var options to point to next element */
                                if (tmp_end) {
                                        tmp_end[0] = '\0';
                                        options = (char *) &tmp_end[1];
                                } else
                                        /* Reached the end of the mount option
                                         * string */
                                        options = end;
                        }

                        /* Now build new password string */
                        temp_len = strlen(value);
                        vol->password = kzalloc(temp_len+1, GFP_KERNEL);
                        if (vol->password == NULL) {
                                printk(KERN_WARNING "CIFS: no memory "
                                                    "for password\n");
                                goto cifs_parse_mount_err;
                        }

                        for (i = 0, j = 0; i < temp_len; i++, j++) {
                                vol->password[j] = value[i];
                                if ((value[i] == delim) &&
                                     value[i+1] == delim)
                                        /* skip the second deliminator */
                                        i++;
                        }
                        vol->password[j] = '\0';
                        break;
                case Opt_blank_ip:
                        vol->UNCip = NULL;
                        break;
                case Opt_ip:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (strnlen(string, INET6_ADDRSTRLEN) >
                                                INET6_ADDRSTRLEN) {
                                printk(KERN_WARNING "CIFS: ip address "
                                                    "too long\n");
                                goto cifs_parse_mount_err;
                        }
                        vol->UNCip = kstrdup(string, GFP_KERNEL);
                        if (!vol->UNCip) {
                                printk(KERN_WARNING "CIFS: no memory "
                                                    "for UNC IP\n");
                                goto cifs_parse_mount_err;
                        }
                        break;
                case Opt_unc:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        temp_len = strnlen(string, 300);
                        if (temp_len  == 300) {
                                printk(KERN_WARNING "CIFS: UNC name too long\n");
                                goto cifs_parse_mount_err;
                        }

                        vol->UNC = kmalloc(temp_len+1, GFP_KERNEL);
                        if (vol->UNC == NULL) {
                                printk(KERN_WARNING "CIFS: no memory for UNC\n");
                                goto cifs_parse_mount_err;
                        }
                        strcpy(vol->UNC, string);

                        if (strncmp(string, "//", 2) == 0) {
                                vol->UNC[0] = '\\';
                                vol->UNC[1] = '\\';
                        } else if (strncmp(string, "\\\\", 2) != 0) {
                                printk(KERN_WARNING "CIFS: UNC Path does not "
                                                    "begin with // or \\\\\n");
                                goto cifs_parse_mount_err;
                        }

                        break;
                case Opt_domain:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (strnlen(string, 256) == 256) {
                                printk(KERN_WARNING "CIFS: domain name too"
                                                    " long\n");
                                goto cifs_parse_mount_err;
                        }

                        vol->domainname = kstrdup(string, GFP_KERNEL);
                        if (!vol->domainname) {
                                printk(KERN_WARNING "CIFS: no memory "
                                                    "for domainname\n");
                                goto cifs_parse_mount_err;
                        }
                        cFYI(1, "Domain name set");
                        break;
                case Opt_srcaddr:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (!cifs_convert_address(
                                        (struct sockaddr *)&vol->srcaddr,
                                        string, strlen(string))) {
                                printk(KERN_WARNING "CIFS:  Could not parse"
                                                    " srcaddr: %s\n", string);
                                goto cifs_parse_mount_err;
                        }
                        break;
                case Opt_prefixpath:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        temp_len = strnlen(string, 1024);
                        if (string[0] != '/')
                                temp_len++; /* missing leading slash */
                        if (temp_len > 1024) {
                                printk(KERN_WARNING "CIFS: prefix too long\n");
                                goto cifs_parse_mount_err;
                        }

                        vol->prepath = kmalloc(temp_len+1, GFP_KERNEL);
                        if (vol->prepath == NULL) {
                                printk(KERN_WARNING "CIFS: no memory "
                                                    "for path prefix\n");
                                goto cifs_parse_mount_err;
                        }

                        if (string[0] != '/') {
                                vol->prepath[0] = '/';
                                strcpy(vol->prepath+1, string);
                        } else
                                strcpy(vol->prepath, string);

                        break;
                case Opt_iocharset:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (strnlen(string, 1024) >= 65) {
                                printk(KERN_WARNING "CIFS: iocharset name "
                                                    "too long.\n");
                                goto cifs_parse_mount_err;
                        }

                         if (strnicmp(string, "default", 7) != 0) {
                                vol->iocharset = kstrdup(string,
                                                         GFP_KERNEL);
                                if (!vol->iocharset) {
                                        printk(KERN_WARNING "CIFS: no memory"
                                                            "for charset\n");
                                        goto cifs_parse_mount_err;
                                }
                        }
                        /* if iocharset not set then load_nls_default
                         * is used by caller
                         */
                        cFYI(1, "iocharset set to %s", string);
                        break;
                case Opt_sockopt:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (strnicmp(string, "TCP_NODELAY", 11) == 0)
                                vol->sockopt_tcp_nodelay = 1;
                        break;
                case Opt_netbiosname:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        memset(vol->source_rfc1001_name, 0x20,
                                RFC1001_NAME_LEN);
                        /*
                         * FIXME: are there cases in which a comma can
                         * be valid in workstation netbios name (and
                         * need special handling)?
                         */
                        for (i = 0; i < RFC1001_NAME_LEN; i++) {
                                /* don't ucase netbiosname for user */
                                if (string[i] == 0)
                                        break;
                                vol->source_rfc1001_name[i] = string[i];
                        }
                        /* The string has 16th byte zero still from
                         * set at top of the function
                         */
                        if (i == RFC1001_NAME_LEN && string[i] != 0)
                                printk(KERN_WARNING "CIFS: netbiosname"
                                       " longer than 15 truncated.\n");

                        break;
                case Opt_servern:
                        /* servernetbiosname specified override *SMBSERVER */
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        /* last byte, type, is 0x20 for servr type */
                        memset(vol->target_rfc1001_name, 0x20,
                                RFC1001_NAME_LEN_WITH_NULL);

                        /* BB are there cases in which a comma can be
                           valid in this workstation netbios name
                           (and need special handling)? */

                        /* user or mount helper must uppercase the
                           netbios name */
                        for (i = 0; i < 15; i++) {
                                if (string[i] == 0)
                                        break;
                                vol->target_rfc1001_name[i] = string[i];
                        }
                        /* The string has 16th byte zero still from
                           set at top of the function  */
                        if (i == RFC1001_NAME_LEN && string[i] != 0)
                                printk(KERN_WARNING "CIFS: server net"
                                       "biosname longer than 15 truncated.\n");
                        break;
                case Opt_ver:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (strnicmp(string, "1", 1) == 0) {
                                /* This is the default */
                                break;
                        }
                        /* For all other value, error */
                        printk(KERN_WARNING "CIFS: Invalid version"
                                            " specified\n");
                        goto cifs_parse_mount_err;
                case Opt_vers:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (cifs_parse_smb_version(string, vol) != 0)
                                goto cifs_parse_mount_err;
                        break;
                case Opt_sec:
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (cifs_parse_security_flavors(string, vol) != 0)
                                goto cifs_parse_mount_err;
                        break;
                case Opt_cache:
                        cache_specified = true;
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;

                        if (cifs_parse_cache_flavor(string, vol) != 0)
                                goto cifs_parse_mount_err;
                        break;
                default:
                        /*
                         * An option we don't recognize. Save it off for later
                         * if we haven't already found one
                         */
                        if (!invalid)
                                invalid = data;
                        break;
                }
                /* Free up any allocated string */
                kfree(string);
                string = NULL;
        }

        if (!sloppy && invalid) {
                printk(KERN_ERR "CIFS: Unknown mount option \"%s\"\n", invalid);
                goto cifs_parse_mount_err;
        }

#ifndef CONFIG_KEYS
        /* Muliuser mounts require CONFIG_KEYS support */
        if (vol->multiuser) {
                cERROR(1, "Multiuser mounts require kernels with "
                          "CONFIG_KEYS enabled.");
                goto cifs_parse_mount_err;
        }
#endif

        if (vol->UNCip == NULL)
                vol->UNCip = &vol->UNC[2];

        if (uid_specified)
                vol->override_uid = override_uid;
        else if (override_uid == 1)
                printk(KERN_NOTICE "CIFS: ignoring forceuid mount option "
                                   "specified with no uid= option.\n");

        if (gid_specified)
                vol->override_gid = override_gid;
        else if (override_gid == 1)
                printk(KERN_NOTICE "CIFS: ignoring forcegid mount option "
                                   "specified with no gid= option.\n");

        /* FIXME: remove this block in 3.7 */
        if (!cache_specified && !cache_warned) {
                cache_warned = true;
                printk(KERN_NOTICE "CIFS: no cache= option specified, using "
                                   "\"cache=loose\". This default will change "
                                   "to \"cache=strict\" in 3.7.\n");
        }

        kfree(mountdata_copy);
        return 0;

out_nomem:
        printk(KERN_WARNING "Could not allocate temporary buffer\n");
cifs_parse_mount_err:
        kfree(string);
        kfree(mountdata_copy);
        return 1;
}

/** Returns true if srcaddr isn't specified and rhs isn't
 * specified, or if srcaddr is specified and
 * matches the IP address of the rhs argument.
 */
static bool
srcip_matches(struct sockaddr *srcaddr, struct sockaddr *rhs)
{
        switch (srcaddr->sa_family) {
        case AF_UNSPEC:
                return (rhs->sa_family == AF_UNSPEC);
        case AF_INET: {
                struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
                struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
                return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
        }
        case AF_INET6: {
                struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
                struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)&rhs;
                return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
        }
        default:
                WARN_ON(1);
                return false; /* don't expect to be here */
        }
}

/*
 * If no port is specified in addr structure, we try to match with 445 port
 * and if it fails - with 139 ports. It should be called only if address
 * families of server and addr are equal.
 */
static bool
match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
{
        __be16 port, *sport;

        switch (addr->sa_family) {
        case AF_INET:
                sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
                port = ((struct sockaddr_in *) addr)->sin_port;
                break;
        case AF_INET6:
                sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
                port = ((struct sockaddr_in6 *) addr)->sin6_port;
                break;
        default:
                WARN_ON(1);
                return false;
        }

        if (!port) {
                port = htons(CIFS_PORT);
                if (port == *sport)
                        return true;

                port = htons(RFC1001_PORT);
        }

        return port == *sport;
}

static bool
match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
              struct sockaddr *srcaddr)
{
        switch (addr->sa_family) {
        case AF_INET: {
                struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
                struct sockaddr_in *srv_addr4 =
                                        (struct sockaddr_in *)&server->dstaddr;

                if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
                        return false;
                break;
        }
        case AF_INET6: {
                struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
                struct sockaddr_in6 *srv_addr6 =
                                        (struct sockaddr_in6 *)&server->dstaddr;

                if (!ipv6_addr_equal(&addr6->sin6_addr,
                                     &srv_addr6->sin6_addr))
                        return false;
                if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
                        return false;
                break;
        }
        default:
                WARN_ON(1);
                return false; /* don't expect to be here */
        }

        if (!srcip_matches(srcaddr, (struct sockaddr *)&server->srcaddr))
                return false;

        return true;
}

static bool
match_security(struct TCP_Server_Info *server, struct smb_vol *vol)
{
        unsigned int secFlags;

        if (vol->secFlg & (~(CIFSSEC_MUST_SIGN | CIFSSEC_MUST_SEAL)))
                secFlags = vol->secFlg;
        else
                secFlags = global_secflags | vol->secFlg;

        switch (server->secType) {
        case LANMAN:
                if (!(secFlags & (CIFSSEC_MAY_LANMAN|CIFSSEC_MAY_PLNTXT)))
                        return false;
                break;
        case NTLMv2:
                if (!(secFlags & CIFSSEC_MAY_NTLMV2))
                        return false;
                break;
        case NTLM:
                if (!(secFlags & CIFSSEC_MAY_NTLM))
                        return false;
                break;
        case Kerberos:
                if (!(secFlags & CIFSSEC_MAY_KRB5))
                        return false;
                break;
        case RawNTLMSSP:
                if (!(secFlags & CIFSSEC_MAY_NTLMSSP))
                        return false;
                break;
        default:
                /* shouldn't happen */
                return false;
        }

        /* now check if signing mode is acceptable */
        if ((secFlags & CIFSSEC_MAY_SIGN) == 0 &&
            (server->sec_mode & SECMODE_SIGN_REQUIRED))
                        return false;
        else if (((secFlags & CIFSSEC_MUST_SIGN) == CIFSSEC_MUST_SIGN) &&
                 (server->sec_mode &
                  (SECMODE_SIGN_ENABLED|SECMODE_SIGN_REQUIRED)) == 0)
                        return false;

        return true;
}

static int match_server(struct TCP_Server_Info *server, struct sockaddr *addr,
                         struct smb_vol *vol)
{
        if ((server->vals != vol->vals) || (server->ops != vol->ops))
                return 0;

        if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
                return 0;

        if (!match_address(server, addr,
                           (struct sockaddr *)&vol->srcaddr))

                return 0;

        if (!match_port(server, addr))
                return 0;

        if (!match_security(server, vol))
                return 0;

        return 1;
}

static struct TCP_Server_Info *
cifs_find_tcp_session(struct sockaddr *addr, struct smb_vol *vol)
{
        struct TCP_Server_Info *server;

        spin_lock(&cifs_tcp_ses_lock);
        list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
                if (!match_server(server, addr, vol))
                        continue;

                ++server->srv_count;
                spin_unlock(&cifs_tcp_ses_lock);
                cFYI(1, "Existing tcp session with server found");
                return server;
        }
        spin_unlock(&cifs_tcp_ses_lock);
        return NULL;
}

static void
cifs_put_tcp_session(struct TCP_Server_Info *server)
{
        struct task_struct *task;

        spin_lock(&cifs_tcp_ses_lock);
        if (--server->srv_count > 0) {
                spin_unlock(&cifs_tcp_ses_lock);
                return;
        }

        put_net(cifs_net_ns(server));

        list_del_init(&server->tcp_ses_list);
        spin_unlock(&cifs_tcp_ses_lock);

        cancel_delayed_work_sync(&server->echo);

        spin_lock(&GlobalMid_Lock);
        server->tcpStatus = CifsExiting;
        spin_unlock(&GlobalMid_Lock);

        cifs_crypto_shash_release(server);
        cifs_fscache_release_client_cookie(server);

        kfree(server->session_key.response);
        server->session_key.response = NULL;
        server->session_key.len = 0;

        task = xchg(&server->tsk, NULL);
        if (task)
                force_sig(SIGKILL, task);
}

static struct TCP_Server_Info *
cifs_get_tcp_session(struct smb_vol *volume_info)
{
        struct TCP_Server_Info *tcp_ses = NULL;
        struct sockaddr_storage addr;
        struct sockaddr_in *sin_server = (struct sockaddr_in *) &addr;
        struct sockaddr_in6 *sin_server6 = (struct sockaddr_in6 *) &addr;
        int rc;

        memset(&addr, 0, sizeof(struct sockaddr_storage));

        cFYI(1, "UNC: %s ip: %s", volume_info->UNC, volume_info->UNCip);

        if (volume_info->UNCip && volume_info->UNC) {
                rc = cifs_fill_sockaddr((struct sockaddr *)&addr,
                                        volume_info->UNCip,
                                        strlen(volume_info->UNCip),
                                        volume_info->port);
                if (!rc) {
                        /* we failed translating address */
                        rc = -EINVAL;
                        goto out_err;
                }
        } else if (volume_info->UNCip) {
                /* BB using ip addr as tcp_ses name to connect to the
                   DFS root below */
                cERROR(1, "Connecting to DFS root not implemented yet");
                rc = -EINVAL;
                goto out_err;
        } else /* which tcp_sess DFS root would we conect to */ {
                cERROR(1, "CIFS mount error: No UNC path (e.g. -o "
                        "unc=//192.168.1.100/public) specified");
                rc = -EINVAL;
                goto out_err;
        }

        /* see if we already have a matching tcp_ses */
        tcp_ses = cifs_find_tcp_session((struct sockaddr *)&addr, volume_info);
        if (tcp_ses)
                return tcp_ses;

        tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
        if (!tcp_ses) {
                rc = -ENOMEM;
                goto out_err;
        }

        rc = cifs_crypto_shash_allocate(tcp_ses);
        if (rc) {
                cERROR(1, "could not setup hash structures rc %d", rc);
                goto out_err;
        }

        tcp_ses->ops = volume_info->ops;
        tcp_ses->vals = volume_info->vals;
        cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
        tcp_ses->hostname = extract_hostname(volume_info->UNC);
        if (IS_ERR(tcp_ses->hostname)) {
                rc = PTR_ERR(tcp_ses->hostname);
                goto out_err_crypto_release;
        }

        tcp_ses->noblocksnd = volume_info->noblocksnd;
        tcp_ses->noautotune = volume_info->noautotune;
        tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
        tcp_ses->in_flight = 0;
        tcp_ses->credits = 1;
        init_waitqueue_head(&tcp_ses->response_q);
        init_waitqueue_head(&tcp_ses->request_q);
        INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
        mutex_init(&tcp_ses->srv_mutex);
        memcpy(tcp_ses->workstation_RFC1001_name,
                volume_info->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
        memcpy(tcp_ses->server_RFC1001_name,
                volume_info->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
        tcp_ses->session_estab = false;
        tcp_ses->sequence_number = 0;
        tcp_ses->lstrp = jiffies;
        spin_lock_init(&tcp_ses->req_lock);
        INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
        INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
        INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);

        /*
         * at this point we are the only ones with the pointer
         * to the struct since the kernel thread not created yet
         * no need to spinlock this init of tcpStatus or srv_count
         */
        tcp_ses->tcpStatus = CifsNew;
        memcpy(&tcp_ses->srcaddr, &volume_info->srcaddr,
               sizeof(tcp_ses->srcaddr));
        ++tcp_ses->srv_count;

        if (addr.ss_family == AF_INET6) {
                cFYI(1, "attempting ipv6 connect");
                /* BB should we allow ipv6 on port 139? */
                /* other OS never observed in Wild doing 139 with v6 */
                memcpy(&tcp_ses->dstaddr, sin_server6,
                       sizeof(struct sockaddr_in6));
        } else
                memcpy(&tcp_ses->dstaddr, sin_server,
                       sizeof(struct sockaddr_in));

        rc = ip_connect(tcp_ses);
        if (rc < 0) {
                cERROR(1, "Error connecting to socket. Aborting operation");
                goto out_err_crypto_release;
        }

        /*
         * since we're in a cifs function already, we know that
         * this will succeed. No need for try_module_get().
         */
        __module_get(THIS_MODULE);
        tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
                                  tcp_ses, "cifsd");
        if (IS_ERR(tcp_ses->tsk)) {
                rc = PTR_ERR(tcp_ses->tsk);
                cERROR(1, "error %d create cifsd thread", rc);
                module_put(THIS_MODULE);
                goto out_err_crypto_release;
        }
        tcp_ses->tcpStatus = CifsNeedNegotiate;

        /* thread spawned, put it on the list */
        spin_lock(&cifs_tcp_ses_lock);
        list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
        spin_unlock(&cifs_tcp_ses_lock);

        cifs_fscache_get_client_cookie(tcp_ses);

        /* queue echo request delayed work */
        queue_delayed_work(cifsiod_wq, &tcp_ses->echo, SMB_ECHO_INTERVAL);

        return tcp_ses;

out_err_crypto_release:
        cifs_crypto_shash_release(tcp_ses);

        put_net(cifs_net_ns(tcp_ses));

out_err:
        if (tcp_ses) {
                if (!IS_ERR(tcp_ses->hostname))
                        kfree(tcp_ses->hostname);
                if (tcp_ses->ssocket)
                        sock_release(tcp_ses->ssocket);
                kfree(tcp_ses);
        }
        return ERR_PTR(rc);
}

static int match_session(struct cifs_ses *ses, struct smb_vol *vol)
{
        switch (ses->server->secType) {
        case Kerberos:
                if (vol->cred_uid != ses->cred_uid)
                        return 0;
                break;
        default:
                /* NULL username means anonymous session */
                if (ses->user_name == NULL) {
                        if (!vol->nullauth)
                                return 0;
                        break;
                }

                /* anything else takes username/password */
                if (strncmp(ses->user_name,
                            vol->username ? vol->username : "",
                            MAX_USERNAME_SIZE))
                        return 0;
                if (strlen(vol->username) != 0 &&
                    ses->password != NULL &&
                    strncmp(ses->password,
                            vol->password ? vol->password : "",
                            MAX_PASSWORD_SIZE))
                        return 0;
        }
        return 1;
}

static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb_vol *vol)
{
        struct cifs_ses *ses;

        spin_lock(&cifs_tcp_ses_lock);
        list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
                if (!match_session(ses, vol))
                        continue;
                ++ses->ses_count;
                spin_unlock(&cifs_tcp_ses_lock);
                return ses;
        }
        spin_unlock(&cifs_tcp_ses_lock);
        return NULL;
}

static void
cifs_put_smb_ses(struct cifs_ses *ses)
{
        unsigned int xid;
        struct TCP_Server_Info *server = ses->server;

        cFYI(1, "%s: ses_count=%d", __func__, ses->ses_count);
        spin_lock(&cifs_tcp_ses_lock);
        if (--ses->ses_count > 0) {
                spin_unlock(&cifs_tcp_ses_lock);
                return;
        }

        list_del_init(&ses->smb_ses_list);
        spin_unlock(&cifs_tcp_ses_lock);

        if (ses->status == CifsGood && server->ops->logoff) {
                xid = get_xid();
                server->ops->logoff(xid, ses);
                _free_xid(xid);
        }
        sesInfoFree(ses);
        cifs_put_tcp_session(server);
}

#ifdef CONFIG_KEYS

/* strlen("cifs:a:") + INET6_ADDRSTRLEN + 1 */
#define CIFSCREDS_DESC_SIZE (7 + INET6_ADDRSTRLEN + 1)

/* Populate username and pw fields from keyring if possible */
static int
cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
{
        int rc = 0;
        char *desc, *delim, *payload;
        ssize_t len;
        struct key *key;
        struct TCP_Server_Info *server = ses->server;
        struct sockaddr_in *sa;
        struct sockaddr_in6 *sa6;
        struct user_key_payload *upayload;

        desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
        if (!desc)
                return -ENOMEM;

        /* try to find an address key first */
        switch (server->dstaddr.ss_family) {
        case AF_INET:
                sa = (struct sockaddr_in *)&server->dstaddr;
                sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
                break;
        case AF_INET6:
                sa6 = (struct sockaddr_in6 *)&server->dstaddr;
                sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
                break;
        default:
                cFYI(1, "Bad ss_family (%hu)", server->dstaddr.ss_family);
                rc = -EINVAL;
                goto out_err;
        }

        cFYI(1, "%s: desc=%s", __func__, desc);
        key = request_key(&key_type_logon, desc, "");
        if (IS_ERR(key)) {
                if (!ses->domainName) {
                        cFYI(1, "domainName is NULL");
                        rc = PTR_ERR(key);
                        goto out_err;
                }

                /* didn't work, try to find a domain key */
                sprintf(desc, "cifs:d:%s", ses->domainName);
                cFYI(1, "%s: desc=%s", __func__, desc);
                key = request_key(&key_type_logon, desc, "");
                if (IS_ERR(key)) {
                        rc = PTR_ERR(key);
                        goto out_err;
                }
        }

        down_read(&key->sem);
        upayload = key->payload.data;
        if (IS_ERR_OR_NULL(upayload)) {
                rc = upayload ? PTR_ERR(upayload) : -EINVAL;
                goto out_key_put;
        }

        /* find first : in payload */
        payload = (char *)upayload->data;
        delim = strnchr(payload, upayload->datalen, ':');
        cFYI(1, "payload=%s", payload);
        if (!delim) {
                cFYI(1, "Unable to find ':' in payload (datalen=%d)",
                                upayload->datalen);
                rc = -EINVAL;
                goto out_key_put;
        }

        len = delim - payload;
        if (len > MAX_USERNAME_SIZE || len <= 0) {
                cFYI(1, "Bad value from username search (len=%zd)", len);
                rc = -EINVAL;
                goto out_key_put;
        }

        vol->username = kstrndup(payload, len, GFP_KERNEL);
        if (!vol->username) {
                cFYI(1, "Unable to allocate %zd bytes for username", len);
                rc = -ENOMEM;
                goto out_key_put;
        }
        cFYI(1, "%s: username=%s", __func__, vol->username);

        len = key->datalen - (len + 1);
        if (len > MAX_PASSWORD_SIZE || len <= 0) {
                cFYI(1, "Bad len for password search (len=%zd)", len);
                rc = -EINVAL;
                kfree(vol->username);
                vol->username = NULL;
                goto out_key_put;
        }

        ++delim;
        vol->password = kstrndup(delim, len, GFP_KERNEL);
        if (!vol->password) {
                cFYI(1, "Unable to allocate %zd bytes for password", len);
                rc = -ENOMEM;
                kfree(vol->username);
                vol->username = NULL;
                goto out_key_put;
        }

out_key_put:
        up_read(&key->sem);
        key_put(key);
out_err:
        kfree(desc);
        cFYI(1, "%s: returning %d", __func__, rc);
        return rc;
}
#else /* ! CONFIG_KEYS */
static inline int
cifs_set_cifscreds(struct smb_vol *vol __attribute__((unused)),
                   struct cifs_ses *ses __attribute__((unused)))
{
        return -ENOSYS;
}
#endif /* CONFIG_KEYS */

static bool warned_on_ntlm;  /* globals init to false automatically */

static struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb_vol *volume_info)
{
        int rc = -ENOMEM;
        unsigned int xid;
        struct cifs_ses *ses;
        struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
        struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;

        xid = get_xid();

        ses = cifs_find_smb_ses(server, volume_info);
        if (ses) {
                cFYI(1, "Existing smb sess found (status=%d)", ses->status);

                mutex_lock(&ses->session_mutex);
                rc = cifs_negotiate_protocol(xid, ses);
                if (rc) {
                        mutex_unlock(&ses->session_mutex);
                        /* problem -- put our ses reference */
                        cifs_put_smb_ses(ses);
                        free_xid(xid);
                        return ERR_PTR(rc);
                }
                if (ses->need_reconnect) {
                        cFYI(1, "Session needs reconnect");
                        rc = cifs_setup_session(xid, ses,
                                                volume_info->local_nls);
                        if (rc) {
                                mutex_unlock(&ses->session_mutex);
                                /* problem -- put our reference */
                                cifs_put_smb_ses(ses);
                                free_xid(xid);
                                return ERR_PTR(rc);
                        }
                }
                mutex_unlock(&ses->session_mutex);

                /* existing SMB ses has a server reference already */
                cifs_put_tcp_session(server);
                free_xid(xid);
                return ses;
        }

        cFYI(1, "Existing smb sess not found");
        ses = sesInfoAlloc();
        if (ses == NULL)
                goto get_ses_fail;

        /* new SMB session uses our server ref */
        ses->server = server;
        if (server->dstaddr.ss_family == AF_INET6)
                sprintf(ses->serverName, "%pI6", &addr6->sin6_addr);
        else
                sprintf(ses->serverName, "%pI4", &addr->sin_addr);

        if (volume_info->username) {
                ses->user_name = kstrdup(volume_info->username, GFP_KERNEL);
                if (!ses->user_name)
                        goto get_ses_fail;
        }

        /* volume_info->password freed at unmount */
        if (volume_info->password) {
                ses->password = kstrdup(volume_info->password, GFP_KERNEL);
                if (!ses->password)
                        goto get_ses_fail;
        }
        if (volume_info->domainname) {
                ses->domainName = kstrdup(volume_info->domainname, GFP_KERNEL);
                if (!ses->domainName)
                        goto get_ses_fail;
        }
        ses->cred_uid = volume_info->cred_uid;
        ses->linux_uid = volume_info->linux_uid;

        /* ntlmv2 is much stronger than ntlm security, and has been broadly
        supported for many years, time to update default security mechanism */
        if ((volume_info->secFlg == 0) && warned_on_ntlm == false) {
                warned_on_ntlm = true;
                cERROR(1, "default security mechanism requested.  The default "
                        "security mechanism will be upgraded from ntlm to "
                        "ntlmv2 in kernel release 3.3");
        }
        ses->overrideSecFlg = volume_info->secFlg;

        mutex_lock(&ses->session_mutex);
        rc = cifs_negotiate_protocol(xid, ses);
        if (!rc)
                rc = cifs_setup_session(xid, ses, volume_info->local_nls);
        mutex_unlock(&ses->session_mutex);
        if (rc)
                goto get_ses_fail;

        /* success, put it on the list */
        spin_lock(&cifs_tcp_ses_lock);
        list_add(&ses->smb_ses_list, &server->smb_ses_list);
        spin_unlock(&cifs_tcp_ses_lock);

        free_xid(xid);
        return ses;

get_ses_fail:
        sesInfoFree(ses);
        free_xid(xid);
        return ERR_PTR(rc);
}

static int match_tcon(struct cifs_tcon *tcon, const char *unc)
{
        if (tcon->tidStatus == CifsExiting)
                return 0;
        if (strncmp(tcon->treeName, unc, MAX_TREE_SIZE))
                return 0;
        return 1;
}

static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses *ses, const char *unc)
{
        struct list_head *tmp;
        struct cifs_tcon *tcon;

        spin_lock(&cifs_tcp_ses_lock);
        list_for_each(tmp, &ses->tcon_list) {
                tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
                if (!match_tcon(tcon, unc))
                        continue;
                ++tcon->tc_count;
                spin_unlock(&cifs_tcp_ses_lock);
                return tcon;
        }
        spin_unlock(&cifs_tcp_ses_lock);
        return NULL;
}

static void
cifs_put_tcon(struct cifs_tcon *tcon)
{
        unsigned int xid;
        struct cifs_ses *ses = tcon->ses;

        cFYI(1, "%s: tc_count=%d", __func__, tcon->tc_count);
        spin_lock(&cifs_tcp_ses_lock);
        if (--tcon->tc_count > 0) {
                spin_unlock(&cifs_tcp_ses_lock);
                return;
        }

        list_del_init(&tcon->tcon_list);
        spin_unlock(&cifs_tcp_ses_lock);

        xid = get_xid();
        if (ses->server->ops->tree_disconnect)
                ses->server->ops->tree_disconnect(xid, tcon);
        _free_xid(xid);

        cifs_fscache_release_super_cookie(tcon);
        tconInfoFree(tcon);
        cifs_put_smb_ses(ses);
}

static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
{
        int rc, xid;
        struct cifs_tcon *tcon;

        tcon = cifs_find_tcon(ses, volume_info->UNC);
        if (tcon) {
                cFYI(1, "Found match on UNC path");
                /* existing tcon already has a reference */
                cifs_put_smb_ses(ses);
                if (tcon->seal != volume_info->seal)
                        cERROR(1, "transport encryption setting "
                                   "conflicts with existing tid");
                return tcon;
        }

        if (!ses->server->ops->tree_connect) {
                rc = -ENOSYS;
                goto out_fail;
        }

        tcon = tconInfoAlloc();
        if (tcon == NULL) {
                rc = -ENOMEM;
                goto out_fail;
        }

        tcon->ses = ses;
        if (volume_info->password) {
                tcon->password = kstrdup(volume_info->password, GFP_KERNEL);
                if (!tcon->password) {
                        rc = -ENOMEM;
                        goto out_fail;
                }
        }

        if (strchr(volume_info->UNC + 3, '\\') == NULL
            && strchr(volume_info->UNC + 3, '/') == NULL) {
                cERROR(1, "Missing share name");
                rc = -ENODEV;
                goto out_fail;
        }

        /*
         * BB Do we need to wrap session_mutex around this TCon call and Unix
         * SetFS as we do on SessSetup and reconnect?
         */
        xid = get_xid();
        rc = ses->server->ops->tree_connect(xid, ses, volume_info->UNC, tcon,
                                            volume_info->local_nls);
        free_xid(xid);
        cFYI(1, "Tcon rc = %d", rc);
        if (rc)
                goto out_fail;

        if (volume_info->nodfs) {
                tcon->Flags &= ~SMB_SHARE_IS_IN_DFS;
                cFYI(1, "DFS disabled (%d)", tcon->Flags);
        }
        tcon->seal = volume_info->seal;
        /*
         * We can have only one retry value for a connection to a share so for
         * resources mounted more than once to the same server share the last
         * value passed in for the retry flag is used.
         */
        tcon->retry = volume_info->retry;
        tcon->nocase = volume_info->nocase;
        tcon->local_lease = volume_info->local_lease;

        spin_lock(&cifs_tcp_ses_lock);
        list_add(&tcon->tcon_list, &ses->tcon_list);
        spin_unlock(&cifs_tcp_ses_lock);

        cifs_fscache_get_super_cookie(tcon);

        return tcon;

out_fail:
        tconInfoFree(tcon);
        return ERR_PTR(rc);
}

void
cifs_put_tlink(struct tcon_link *tlink)
{
        if (!tlink || IS_ERR(tlink))
                return;

        if (!atomic_dec_and_test(&tlink->tl_count) ||
            test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
                tlink->tl_time = jiffies;
                return;
        }

        if (!IS_ERR(tlink_tcon(tlink)))
                cifs_put_tcon(tlink_tcon(tlink));
        kfree(tlink);
        return;
}

static inline struct tcon_link *
cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb)
{
        return cifs_sb->master_tlink;
}

static int
compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
{
        struct cifs_sb_info *old = CIFS_SB(sb);
        struct cifs_sb_info *new = mnt_data->cifs_sb;

        if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
                return 0;

        if ((old->mnt_cifs_flags & CIFS_MOUNT_MASK) !=
            (new->mnt_cifs_flags & CIFS_MOUNT_MASK))
                return 0;

        /*
         * We want to share sb only if we don't specify an r/wsize or
         * specified r/wsize is greater than or equal to existing one.
         */
        if (new->wsize && new->wsize < old->wsize)
                return 0;

        if (new->rsize && new->rsize < old->rsize)
                return 0;

        if (old->mnt_uid != new->mnt_uid || old->mnt_gid != new->mnt_gid)
                return 0;

        if (old->mnt_file_mode != new->mnt_file_mode ||
            old->mnt_dir_mode != new->mnt_dir_mode)
                return 0;

        if (strcmp(old->local_nls->charset, new->local_nls->charset))
                return 0;

        if (old->actimeo != new->actimeo)
                return 0;

        return 1;
}

int
cifs_match_super(struct super_block *sb, void *data)
{
        struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
        struct smb_vol *volume_info;
        struct cifs_sb_info *cifs_sb;
        struct TCP_Server_Info *tcp_srv;
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;
        struct tcon_link *tlink;
        struct sockaddr_storage addr;
        int rc = 0;

        memset(&addr, 0, sizeof(struct sockaddr_storage));

        spin_lock(&cifs_tcp_ses_lock);
        cifs_sb = CIFS_SB(sb);
        tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
        if (IS_ERR(tlink)) {
                spin_unlock(&cifs_tcp_ses_lock);
                return rc;
        }
        tcon = tlink_tcon(tlink);
        ses = tcon->ses;
        tcp_srv = ses->server;

        volume_info = mnt_data->vol;

        if (!volume_info->UNCip || !volume_info->UNC)
                goto out;

        rc = cifs_fill_sockaddr((struct sockaddr *)&addr,
                                volume_info->UNCip,
                                strlen(volume_info->UNCip),
                                volume_info->port);
        if (!rc)
                goto out;

        if (!match_server(tcp_srv, (struct sockaddr *)&addr, volume_info) ||
            !match_session(ses, volume_info) ||
            !match_tcon(tcon, volume_info->UNC)) {
                rc = 0;
                goto out;
        }

        rc = compare_mount_options(sb, mnt_data);
out:
        spin_unlock(&cifs_tcp_ses_lock);
        cifs_put_tlink(tlink);
        return rc;
}

int
get_dfs_path(const unsigned int xid, struct cifs_ses *ses, const char *old_path,
             const struct nls_table *nls_codepage, unsigned int *num_referrals,
             struct dfs_info3_param **referrals, int remap)
{
        char *temp_unc;
        int rc = 0;

        if (!ses->server->ops->tree_connect || !ses->server->ops->get_dfs_refer)
                return -ENOSYS;

        *num_referrals = 0;
        *referrals = NULL;

        if (ses->ipc_tid == 0) {
                temp_unc = kmalloc(2 /* for slashes */ +
                        strnlen(ses->serverName, SERVER_NAME_LEN_WITH_NULL * 2)
                                + 1 + 4 /* slash IPC$ */ + 2, GFP_KERNEL);
                if (temp_unc == NULL)
                        return -ENOMEM;
                temp_unc[0] = '\\';
                temp_unc[1] = '\\';
                strcpy(temp_unc + 2, ses->serverName);
                strcpy(temp_unc + 2 + strlen(ses->serverName), "\\IPC$");
                rc = ses->server->ops->tree_connect(xid, ses, temp_unc, NULL,
                                                    nls_codepage);
                cFYI(1, "Tcon rc = %d ipc_tid = %d", rc, ses->ipc_tid);
                kfree(temp_unc);
        }
        if (rc == 0)
                rc = ses->server->ops->get_dfs_refer(xid, ses, old_path,
                                                     referrals, num_referrals,
                                                     nls_codepage, remap);
        /*
         * BB - map targetUNCs to dfs_info3 structures, here or in
         * ses->server->ops->get_dfs_refer.
         */

        return rc;
}

#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key cifs_key[2];
static struct lock_class_key cifs_slock_key[2];

static inline void
cifs_reclassify_socket4(struct socket *sock)
{
        struct sock *sk = sock->sk;
        BUG_ON(sock_owned_by_user(sk));
        sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
                &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
}

static inline void
cifs_reclassify_socket6(struct socket *sock)
{
        struct sock *sk = sock->sk;
        BUG_ON(sock_owned_by_user(sk));
        sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
                &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
}
#else
static inline void
cifs_reclassify_socket4(struct socket *sock)
{
}

static inline void
cifs_reclassify_socket6(struct socket *sock)
{
}
#endif

/* See RFC1001 section 14 on representation of Netbios names */
static void rfc1002mangle(char *target, char *source, unsigned int length)
{
        unsigned int i, j;

        for (i = 0, j = 0; i < (length); i++) {
                /* mask a nibble at a time and encode */
                target[j] = 'A' + (0x0F & (source[i] >> 4));
                target[j+1] = 'A' + (0x0F & source[i]);
                j += 2;
        }

}

static int
bind_socket(struct TCP_Server_Info *server)
{
        int rc = 0;
        if (server->srcaddr.ss_family != AF_UNSPEC) {
                /* Bind to the specified local IP address */
                struct socket *socket = server->ssocket;
                rc = socket->ops->bind(socket,
                                       (struct sockaddr *) &server->srcaddr,
                                       sizeof(server->srcaddr));
                if (rc < 0) {
                        struct sockaddr_in *saddr4;
                        struct sockaddr_in6 *saddr6;
                        saddr4 = (struct sockaddr_in *)&server->srcaddr;
                        saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
                        if (saddr6->sin6_family == AF_INET6)
                                cERROR(1, "cifs: "
                                       "Failed to bind to: %pI6c, error: %d",
                                       &saddr6->sin6_addr, rc);
                        else
                                cERROR(1, "cifs: "
                                       "Failed to bind to: %pI4, error: %d",
                                       &saddr4->sin_addr.s_addr, rc);
                }
        }
        return rc;
}

static int
ip_rfc1001_connect(struct TCP_Server_Info *server)
{
        int rc = 0;
        /*
         * some servers require RFC1001 sessinit before sending
         * negprot - BB check reconnection in case where second
         * sessinit is sent but no second negprot
         */
        struct rfc1002_session_packet *ses_init_buf;
        struct smb_hdr *smb_buf;
        ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
                               GFP_KERNEL);
        if (ses_init_buf) {
                ses_init_buf->trailer.session_req.called_len = 32;

                if (server->server_RFC1001_name &&
                    server->server_RFC1001_name[0] != 0)
                        rfc1002mangle(ses_init_buf->trailer.
                                      session_req.called_name,
                                      server->server_RFC1001_name,
                                      RFC1001_NAME_LEN_WITH_NULL);
                else
                        rfc1002mangle(ses_init_buf->trailer.
                                      session_req.called_name,
                                      DEFAULT_CIFS_CALLED_NAME,
                                      RFC1001_NAME_LEN_WITH_NULL);

                ses_init_buf->trailer.session_req.calling_len = 32;

                /*
                 * calling name ends in null (byte 16) from old smb
                 * convention.
                 */
                if (server->workstation_RFC1001_name &&
                    server->workstation_RFC1001_name[0] != 0)
                        rfc1002mangle(ses_init_buf->trailer.
                                      session_req.calling_name,
                                      server->workstation_RFC1001_name,
                                      RFC1001_NAME_LEN_WITH_NULL);
                else
                        rfc1002mangle(ses_init_buf->trailer.
                                      session_req.calling_name,
                                      "LINUX_CIFS_CLNT",
                                      RFC1001_NAME_LEN_WITH_NULL);

                ses_init_buf->trailer.session_req.scope1 = 0;
                ses_init_buf->trailer.session_req.scope2 = 0;
                smb_buf = (struct smb_hdr *)ses_init_buf;

                /* sizeof RFC1002_SESSION_REQUEST with no scope */
                smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
                rc = smb_send(server, smb_buf, 0x44);
                kfree(ses_init_buf);
                /*
                 * RFC1001 layer in at least one server
                 * requires very short break before negprot
                 * presumably because not expecting negprot
                 * to follow so fast.  This is a simple
                 * solution that works without
                 * complicating the code and causes no
                 * significant slowing down on mount
                 * for everyone else
                 */
                usleep_range(1000, 2000);
        }
        /*
         * else the negprot may still work without this
         * even though malloc failed
         */

        return rc;
}

static int
generic_ip_connect(struct TCP_Server_Info *server)
{
        int rc = 0;
        __be16 sport;
        int slen, sfamily;
        struct socket *socket = server->ssocket;
        struct sockaddr *saddr;

        saddr = (struct sockaddr *) &server->dstaddr;

        if (server->dstaddr.ss_family == AF_INET6) {
                sport = ((struct sockaddr_in6 *) saddr)->sin6_port;
                slen = sizeof(struct sockaddr_in6);
                sfamily = AF_INET6;
        } else {
                sport = ((struct sockaddr_in *) saddr)->sin_port;
                slen = sizeof(struct sockaddr_in);
                sfamily = AF_INET;
        }

        if (socket == NULL) {
                rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
                                   IPPROTO_TCP, &socket, 1);
                if (rc < 0) {
                        cERROR(1, "Error %d creating socket", rc);
                        server->ssocket = NULL;
                        return rc;
                }

                /* BB other socket options to set KEEPALIVE, NODELAY? */
                cFYI(1, "Socket created");
                server->ssocket = socket;
                socket->sk->sk_allocation = GFP_NOFS;