libsmb: Make cli_ntcreate cancellable

[Samba.git] / source3 / libsmb / clidfs.c

/*
   Unix SMB/CIFS implementation.
   client connect/disconnect routines
   Copyright (C) Andrew Tridgell                  1994-1998
   Copyright (C) Gerald (Jerry) Carter            2004
   Copyright (C) Jeremy Allison                   2007-2009

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "libsmb/libsmb.h"
#include "libsmb/clirap.h"
#include "msdfs.h"
#include "trans2.h"
#include "libsmb/nmblib.h"
#include "../libcli/smb/smbXcli_base.h"

/********************************************************************
 Important point.

 DFS paths are *always* of the form \server\share\<pathname> (the \ characters
 are not C escaped here).

 - but if we're using POSIX paths then <pathname> may contain
   '/' separators, not '\\' separators. So cope with '\\' or '/'
   as a separator when looking at the pathname part.... JRA.
********************************************************************/

/********************************************************************
 Ensure a connection is encrypted.
********************************************************************/

NTSTATUS cli_cm_force_encryption(struct cli_state *c,
                        const char *username,
                        const char *password,
                        const char *domain,
                        const char *sharename)
{
        NTSTATUS status;

        if (smbXcli_conn_protocol(c->conn) >= PROTOCOL_SMB2_02) {
                status = smb2cli_session_encryption_on(c->smb2.session);
                if (NT_STATUS_EQUAL(status,NT_STATUS_NOT_SUPPORTED)) {
                        d_printf("Encryption required and "
                                "server doesn't support "
                                "SMB3 encryption - failing connect\n");
                } else if (!NT_STATUS_IS_OK(status)) {
                        d_printf("Encryption required and "
                                "setup failed with error %s.\n",
                                nt_errstr(status));
                }
                return status;
        }

        status = cli_force_encryption(c,
                                        username,
                                        password,
                                        domain);

        if (NT_STATUS_EQUAL(status,NT_STATUS_NOT_SUPPORTED)) {
                d_printf("Encryption required and "
                        "server that doesn't support "
                        "UNIX extensions - failing connect\n");
        } else if (NT_STATUS_EQUAL(status,NT_STATUS_UNKNOWN_REVISION)) {
                d_printf("Encryption required and "
                        "can't get UNIX CIFS extensions "
                        "version from server.\n");
        } else if (NT_STATUS_EQUAL(status,NT_STATUS_UNSUPPORTED_COMPRESSION)) {
                d_printf("Encryption required and "
                        "share %s doesn't support "
                        "encryption.\n", sharename);
        } else if (!NT_STATUS_IS_OK(status)) {
                d_printf("Encryption required and "
                        "setup failed with error %s.\n",
                        nt_errstr(status));
        }

        return status;
}

/********************************************************************
 Return a connection to a server.
********************************************************************/

static NTSTATUS do_connect(TALLOC_CTX *ctx,
                                        const char *server,
                                        const char *share,
                                        const struct user_auth_info *auth_info,
                                        bool show_sessetup,
                                        bool force_encrypt,
                                        int max_protocol,
                                        int port,
                                        int name_type,
                                        struct cli_state **pcli)
{
        struct cli_state *c = NULL;
        char *servicename;
        char *sharename;
        char *newserver, *newshare;
        const char *username;
        const char *password;
        NTSTATUS status;
        int flags = 0;

        /* make a copy so we don't modify the global string 'service' */
        servicename = talloc_strdup(ctx,share);
        if (!servicename) {
                return NT_STATUS_NO_MEMORY;
        }
        sharename = servicename;
        if (*sharename == '\\') {
                sharename += 2;
                if (server == NULL) {
                        server = sharename;
                }
                sharename = strchr_m(sharename,'\\');
                if (!sharename) {
                        return NT_STATUS_NO_MEMORY;
                }
                *sharename = 0;
                sharename++;
        }
        if (server == NULL) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (get_cmdline_auth_info_use_kerberos(auth_info)) {
                flags |= CLI_FULL_CONNECTION_USE_KERBEROS;
        }
        if (get_cmdline_auth_info_fallback_after_kerberos(auth_info)) {
                flags |= CLI_FULL_CONNECTION_FALLBACK_AFTER_KERBEROS;
        }
        if (get_cmdline_auth_info_use_ccache(auth_info)) {
                flags |= CLI_FULL_CONNECTION_USE_CCACHE;
        }
        if (get_cmdline_auth_info_use_pw_nt_hash(auth_info)) {
                flags |= CLI_FULL_CONNECTION_USE_NT_HASH;
        }

        status = cli_connect_nb(
                server, NULL, port, name_type, NULL,
                get_cmdline_auth_info_signing_state(auth_info),
                flags, &c);

        if (!NT_STATUS_IS_OK(status)) {
                d_printf("Connection to %s failed (Error %s)\n",
                                server,
                                nt_errstr(status));
                return status;
        }

        if (max_protocol == 0) {
                max_protocol = PROTOCOL_NT1;
        }
        DEBUG(4,(" session request ok\n"));

        status = smbXcli_negprot(c->conn, c->timeout,
                                 lp_client_min_protocol(),
                                 max_protocol);

        if (!NT_STATUS_IS_OK(status)) {
                d_printf("protocol negotiation failed: %s\n",
                         nt_errstr(status));
                cli_shutdown(c);
                return status;
        }

        if (smbXcli_conn_protocol(c->conn) >= PROTOCOL_SMB2_02) {
                /* Ensure we ask for some initial credits. */
                smb2cli_conn_set_max_credits(c->conn, DEFAULT_SMB2_MAX_CREDITS);
        }

        username = get_cmdline_auth_info_username(auth_info);
        password = get_cmdline_auth_info_password(auth_info);

        status = cli_session_setup(c, username,
                                   password, strlen(password),
                                   password, strlen(password),
                                   lp_workgroup());
        if (!NT_STATUS_IS_OK(status)) {
                /* If a password was not supplied then
                 * try again with a null username. */
                if (password[0] || !username[0] ||
                        get_cmdline_auth_info_use_kerberos(auth_info) ||
                        !NT_STATUS_IS_OK(status = cli_session_setup(c, "",
                                                "", 0,
                                                "", 0,
                                               lp_workgroup()))) {
                        d_printf("session setup failed: %s\n",
                                 nt_errstr(status));
                        if (NT_STATUS_EQUAL(status,
                                            NT_STATUS_MORE_PROCESSING_REQUIRED))
                                d_printf("did you forget to run kinit?\n");
                        cli_shutdown(c);
                        return status;
                }
                d_printf("Anonymous login successful\n");
                status = cli_init_creds(c, "", lp_workgroup(), "");
        } else {
                status = cli_init_creds(c, username, lp_workgroup(), password);
        }

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10,("cli_init_creds() failed: %s\n", nt_errstr(status)));
                cli_shutdown(c);
                return status;
        }

        if ( show_sessetup ) {
                if (*c->server_domain) {
                        DEBUG(0,("Domain=[%s] OS=[%s] Server=[%s]\n",
                                c->server_domain,c->server_os,c->server_type));
                } else if (*c->server_os || *c->server_type) {
                        DEBUG(0,("OS=[%s] Server=[%s]\n",
                                 c->server_os,c->server_type));
                }
        }
        DEBUG(4,(" session setup ok\n"));

        /* here's the fun part....to support 'msdfs proxy' shares
           (on Samba or windows) we have to issues a TRANS_GET_DFS_REFERRAL
           here before trying to connect to the original share.
           cli_check_msdfs_proxy() will fail if it is a normal share. */

        if (smbXcli_conn_dfs_supported(c->conn) &&
                        cli_check_msdfs_proxy(ctx, c, sharename,
                                &newserver, &newshare,
                                force_encrypt,
                                username,
                                password,
                                lp_workgroup())) {
                cli_shutdown(c);
                return do_connect(ctx, newserver,
                                newshare, auth_info, false,
                                force_encrypt, max_protocol,
                                port, name_type, pcli);
        }

        /* must be a normal share */

        status = cli_tree_connect(c, sharename, "?????",
                                  password, strlen(password)+1);
        if (!NT_STATUS_IS_OK(status)) {
                d_printf("tree connect failed: %s\n", nt_errstr(status));
                cli_shutdown(c);
                return status;
        }

        if (force_encrypt) {
                status = cli_cm_force_encryption(c,
                                        username,
                                        password,
                                        lp_workgroup(),
                                        sharename);
                if (!NT_STATUS_IS_OK(status)) {
                        cli_shutdown(c);
                        return status;
                }
        }

        DEBUG(4,(" tconx ok\n"));
        *pcli = c;
        return NT_STATUS_OK;
}

/****************************************************************************
****************************************************************************/

static void cli_set_mntpoint(struct cli_state *cli, const char *mnt)
{
        char *name = clean_name(NULL, mnt);
        if (!name) {
                return;
        }
        TALLOC_FREE(cli->dfs_mountpoint);
        cli->dfs_mountpoint = talloc_strdup(cli, name);
        TALLOC_FREE(name);
}

/********************************************************************
 Add a new connection to the list.
 referring_cli == NULL means a new initial connection.
********************************************************************/

static NTSTATUS cli_cm_connect(TALLOC_CTX *ctx,
                               struct cli_state *referring_cli,
                               const char *server,
                               const char *share,
                               const struct user_auth_info *auth_info,
                               bool show_hdr,
                               bool force_encrypt,
                               int max_protocol,
                               int port,
                               int name_type,
                               struct cli_state **pcli)
{
        struct cli_state *cli;
        NTSTATUS status;

        status = do_connect(ctx, server, share,
                                auth_info,
                                show_hdr, force_encrypt, max_protocol,
                                port, name_type, &cli);

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* Enter into the list. */
        if (referring_cli) {
                DLIST_ADD_END(referring_cli, cli, struct cli_state *);
        }

        if (referring_cli && referring_cli->requested_posix_capabilities) {
                uint16 major, minor;
                uint32 caplow, caphigh;
                status = cli_unix_extensions_version(cli, &major, &minor,
                                                     &caplow, &caphigh);
                if (NT_STATUS_IS_OK(status)) {
                        cli_set_unix_extensions_capabilities(cli,
                                        major, minor,
                                        caplow, caphigh);
                }
        }

        *pcli = cli;
        return NT_STATUS_OK;
}

/********************************************************************
 Return a connection to a server on a particular share.
********************************************************************/

static struct cli_state *cli_cm_find(struct cli_state *cli,
                                const char *server,
                                const char *share)
{
        struct cli_state *p;

        if (cli == NULL) {
                return NULL;
        }

        /* Search to the start of the list. */
        for (p = cli; p; p = DLIST_PREV(p)) {
                const char *remote_name =
                        smbXcli_conn_remote_name(p->conn);

                if (strequal(server, remote_name) &&
                                strequal(share,p->share)) {
                        return p;
                }
        }

        /* Search to the end of the list. */
        for (p = cli->next; p; p = p->next) {
                const char *remote_name =
                        smbXcli_conn_remote_name(p->conn);

                if (strequal(server, remote_name) &&
                                strequal(share,p->share)) {
                        return p;
                }
        }

        return NULL;
}

/****************************************************************************
 Open a client connection to a \\server\share.
****************************************************************************/

NTSTATUS cli_cm_open(TALLOC_CTX *ctx,
                                struct cli_state *referring_cli,
                                const char *server,
                                const char *share,
                                const struct user_auth_info *auth_info,
                                bool show_hdr,
                                bool force_encrypt,
                                int max_protocol,
                                int port,
                                int name_type,
                                struct cli_state **pcli)
{
        /* Try to reuse an existing connection in this list. */
        struct cli_state *c = cli_cm_find(referring_cli, server, share);
        NTSTATUS status;

        if (c) {
                *pcli = c;
                return NT_STATUS_OK;
        }

        if (auth_info == NULL) {
                /* Can't do a new connection
                 * without auth info. */
                d_printf("cli_cm_open() Unable to open connection [\\%s\\%s] "
                        "without auth info\n",
                        server, share );
                return NT_STATUS_INVALID_PARAMETER;
        }

        status = cli_cm_connect(ctx,
                                referring_cli,
                                server,
                                share,
                                auth_info,
                                show_hdr,
                                force_encrypt,
                                max_protocol,
                                port,
                                name_type,
                                &c);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }
        *pcli = c;
        return NT_STATUS_OK;
}

/****************************************************************************
****************************************************************************/

void cli_cm_display(struct cli_state *cli)
{
        int i;

        for (i=0; cli; cli = cli->next,i++ ) {
                d_printf("%d:\tserver=%s, share=%s\n",
                        i, smbXcli_conn_remote_name(cli->conn), cli->share);
        }
}

/****************************************************************************
****************************************************************************/

/****************************************************************************
****************************************************************************/

#if 0
void cli_cm_set_credentials(struct user_auth_info *auth_info)
{
        SAFE_FREE(cm_creds.username);
        cm_creds.username = SMB_STRDUP(get_cmdline_auth_info_username(
                                               auth_info));

        if (get_cmdline_auth_info_got_pass(auth_info)) {
                cm_set_password(get_cmdline_auth_info_password(auth_info));
        }

        cm_creds.use_kerberos = get_cmdline_auth_info_use_kerberos(auth_info);
        cm_creds.fallback_after_kerberos = false;
        cm_creds.signing_state = get_cmdline_auth_info_signing_state(auth_info);
}
#endif

/**********************************************************************
 split a dfs path into the server, share name, and extrapath components
**********************************************************************/

static bool split_dfs_path(TALLOC_CTX *ctx,
                                const char *nodepath,
                                char **pp_server,
                                char **pp_share,
                                char **pp_extrapath)
{
        char *p, *q;
        char *path;

        *pp_server = NULL;
        *pp_share = NULL;
        *pp_extrapath = NULL;

        path = talloc_strdup(ctx, nodepath);
        if (!path) {
                goto fail;
        }

        if ( path[0] != '\\' ) {
                goto fail;
        }

        p = strchr_m( path + 1, '\\' );
        if ( !p ) {
                goto fail;
        }

        *p = '\0';
        p++;

        /* Look for any extra/deep path */
        q = strchr_m(p, '\\');
        if (q != NULL) {
                *q = '\0';
                q++;
                *pp_extrapath = talloc_strdup(ctx, q);
        } else {
                *pp_extrapath = talloc_strdup(ctx, "");
        }
        if (*pp_extrapath == NULL) {
                goto fail;
        }

        *pp_share = talloc_strdup(ctx, p);
        if (*pp_share == NULL) {
                goto fail;
        }

        *pp_server = talloc_strdup(ctx, &path[1]);
        if (*pp_server == NULL) {
                goto fail;
        }

        TALLOC_FREE(path);
        return true;

fail:
        TALLOC_FREE(*pp_share);
        TALLOC_FREE(*pp_extrapath);
        TALLOC_FREE(path);
        return false;
}

/****************************************************************************
 Return the original path truncated at the directory component before
 the first wildcard character. Trust the caller to provide a NULL
 terminated string
****************************************************************************/

static char *clean_path(TALLOC_CTX *ctx, const char *path)
{
        size_t len;
        char *p1, *p2, *p;
        char *path_out;

        /* No absolute paths. */
        while (IS_DIRECTORY_SEP(*path)) {
                path++;
        }

        path_out = talloc_strdup(ctx, path);
        if (!path_out) {
                return NULL;
        }

        p1 = strchr_m(path_out, '*');
        p2 = strchr_m(path_out, '?');

        if (p1 || p2) {
                if (p1 && p2) {
                        p = MIN(p1,p2);
                } else if (!p1) {
                        p = p2;
                } else {
                        p = p1;
                }
                *p = '\0';

                /* Now go back to the start of this component. */
                p1 = strrchr_m(path_out, '/');
                p2 = strrchr_m(path_out, '\\');
                p = MAX(p1,p2);
                if (p) {
                        *p = '\0';
                }
        }

        /* Strip any trailing separator */

        len = strlen(path_out);
        if ( (len > 0) && IS_DIRECTORY_SEP(path_out[len-1])) {
                path_out[len-1] = '\0';
        }

        return path_out;
}

/****************************************************************************
****************************************************************************/

static char *cli_dfs_make_full_path(TALLOC_CTX *ctx,
                                        struct cli_state *cli,
                                        const char *dir)
{
        char path_sep = '\\';

        /* Ensure the extrapath doesn't start with a separator. */
        while (IS_DIRECTORY_SEP(*dir)) {
                dir++;
        }

        if (cli->requested_posix_capabilities & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
                path_sep = '/';
        }
        return talloc_asprintf(ctx, "%c%s%c%s%c%s",
                        path_sep,
                        smbXcli_conn_remote_name(cli->conn),
                        path_sep,
                        cli->share,
                        path_sep,
                        dir);
}

/********************************************************************
 check for dfs referral
********************************************************************/

static bool cli_dfs_check_error(struct cli_state *cli, NTSTATUS expected,
                                NTSTATUS status)
{
        /* only deal with DS when we negotiated NT_STATUS codes and UNICODE */

        if (!(smbXcli_conn_use_unicode(cli->conn))) {
                return false;
        }
        if (!(smb1cli_conn_capabilities(cli->conn) & CAP_STATUS32)) {
                return false;
        }
        if (NT_STATUS_EQUAL(status, expected)) {
                return true;
        }
        return false;
}

/********************************************************************
 Get the dfs referral link.
********************************************************************/

NTSTATUS cli_dfs_get_referral(TALLOC_CTX *ctx,
                        struct cli_state *cli,
                        const char *path,
                        struct client_dfs_referral **refs,
                        size_t *num_refs,
                        size_t *consumed)
{
        unsigned int param_len = 0;
        uint16_t recv_flags2;
        uint8_t *param = NULL;
        uint8_t *rdata = NULL;
        char *p;
        char *endp;
        smb_ucs2_t *path_ucs;
        char *consumed_path = NULL;
        uint16_t consumed_ucs;
        uint16 num_referrals;
        struct client_dfs_referral *referrals = NULL;
        NTSTATUS status;
        TALLOC_CTX *frame = talloc_stackframe();

        *num_refs = 0;
        *refs = NULL;

        param = talloc_array(talloc_tos(), uint8_t, 2);
        if (!param) {
                status = NT_STATUS_NO_MEMORY;
                goto out;
        }
        SSVAL(param, 0, 0x03);  /* max referral level */

        param = trans2_bytes_push_str(param, smbXcli_conn_use_unicode(cli->conn),
                                      path, strlen(path)+1,
                                      NULL);
        if (!param) {
                status = NT_STATUS_NO_MEMORY;
                goto out;
        }
        param_len = talloc_get_size(param);
        path_ucs = (smb_ucs2_t *)&param[2];

        if (smbXcli_conn_protocol(cli->conn) >= PROTOCOL_SMB2_02) {
                DATA_BLOB in_input_buffer;
                DATA_BLOB in_output_buffer = data_blob_null;
                DATA_BLOB out_input_buffer = data_blob_null;
                DATA_BLOB out_output_buffer = data_blob_null;

                in_input_buffer.data = param;
                in_input_buffer.length = param_len;

                status = smb2cli_ioctl(cli->conn,
                                       cli->timeout,
                                       cli->smb2.session,
                                       cli->smb2.tcon,
                                       UINT64_MAX, /* in_fid_persistent */
                                       UINT64_MAX, /* in_fid_volatile */
                                       FSCTL_DFS_GET_REFERRALS,
                                       0, /* in_max_input_length */
                                       &in_input_buffer,
                                       CLI_BUFFER_SIZE, /* in_max_output_length */
                                       &in_output_buffer,
                                       SMB2_IOCTL_FLAG_IS_FSCTL,
                                       talloc_tos(),
                                       &out_input_buffer,
                                       &out_output_buffer);
                if (!NT_STATUS_IS_OK(status)) {
                        goto out;
                }

                if (out_output_buffer.length < 4) {
                        status = NT_STATUS_INVALID_NETWORK_RESPONSE;
                        goto out;
                }

                recv_flags2 = FLAGS2_UNICODE_STRINGS;
                rdata = out_output_buffer.data;
                endp = (char *)rdata + out_output_buffer.length;
        } else {
                unsigned int data_len = 0;
                uint16_t setup[1];

                SSVAL(setup, 0, TRANSACT2_GET_DFS_REFERRAL);

                status = cli_trans(talloc_tos(), cli, SMBtrans2,
                                   NULL, 0xffff, 0, 0,
                                   setup, 1, 0,
                                   param, param_len, 2,
                                   NULL, 0, CLI_BUFFER_SIZE,
                                   &recv_flags2,
                                   NULL, 0, NULL, /* rsetup */
                                   NULL, 0, NULL,
                                   &rdata, 4, &data_len);
                if (!NT_STATUS_IS_OK(status)) {
                        goto out;
                }

                endp = (char *)rdata + data_len;
        }

        consumed_ucs  = SVAL(rdata, 0);
        num_referrals = SVAL(rdata, 2);

        /* consumed_ucs is the number of bytes
         * of the UCS2 path consumed not counting any
         * terminating null. We need to convert
         * back to unix charset and count again
         * to get the number of bytes consumed from
         * the incoming path. */

        errno = 0;
        if (pull_string_talloc(talloc_tos(),
                        NULL,
                        0,
                        &consumed_path,
                        path_ucs,
                        consumed_ucs,
                        STR_UNICODE) == 0) {
                if (errno != 0) {
                        status = map_nt_error_from_unix(errno);
                } else {
                        status = NT_STATUS_INVALID_NETWORK_RESPONSE;
                }
                goto out;
        }
        if (consumed_path == NULL) {
                status = map_nt_error_from_unix(errno);
                goto out;
        }
        *consumed = strlen(consumed_path);

        if (num_referrals != 0) {
                uint16 ref_version;
                uint16 ref_size;
                int i;
                uint16 node_offset;

                referrals = talloc_array(ctx, struct client_dfs_referral,
                                         num_referrals);

                if (!referrals) {
                        status = NT_STATUS_NO_MEMORY;
                        goto out;
                }
                /* start at the referrals array */

                p = (char *)rdata+8;
                for (i=0; i<num_referrals && p < endp; i++) {
                        if (p + 18 > endp) {
                                goto out;
                        }
                        ref_version = SVAL(p, 0);
                        ref_size    = SVAL(p, 2);
                        node_offset = SVAL(p, 16);

                        if (ref_version != 3) {
                                p += ref_size;
                                continue;
                        }

                        referrals[i].proximity = SVAL(p, 8);
                        referrals[i].ttl       = SVAL(p, 10);

                        if (p + node_offset > endp) {
                                status = NT_STATUS_INVALID_NETWORK_RESPONSE;
                                goto out;
                        }
                        clistr_pull_talloc(referrals,
                                           (const char *)rdata,
                                           recv_flags2,
                                           &referrals[i].dfspath,
                                           p+node_offset,
                                           PTR_DIFF(endp, p+node_offset),
                                           STR_TERMINATE|STR_UNICODE);

                        if (!referrals[i].dfspath) {
                                status = map_nt_error_from_unix(errno);
                                goto out;
                        }
                        p += ref_size;
                }
                if (i < num_referrals) {
                        status = NT_STATUS_INVALID_NETWORK_RESPONSE;
                        goto out;
                }
        }

        *num_refs = num_referrals;
        *refs = referrals;

  out:

        TALLOC_FREE(frame);
        return status;
}

/********************************************************************
********************************************************************/

NTSTATUS cli_resolve_path(TALLOC_CTX *ctx,
                          const char *mountpt,
                          const struct user_auth_info *dfs_auth_info,
                          struct cli_state *rootcli,
                          const char *path,
                          struct cli_state **targetcli,
                          char **pp_targetpath)
{
        struct client_dfs_referral *refs = NULL;
        size_t num_refs = 0;
        size_t consumed = 0;
        struct cli_state *cli_ipc = NULL;
        char *dfs_path = NULL;
        char *cleanpath = NULL;
        char *extrapath = NULL;
        int pathlen;
        char *server = NULL;
        char *share = NULL;
        struct cli_state *newcli = NULL;
        char *newpath = NULL;
        char *newmount = NULL;
        char *ppath = NULL;
        SMB_STRUCT_STAT sbuf;
        uint32 attributes;
        NTSTATUS status;
        struct smbXcli_tcon *root_tcon = NULL;
        struct smbXcli_tcon *target_tcon = NULL;

        if ( !rootcli || !path || !targetcli ) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        /* Don't do anything if this is not a DFS root. */

        if (smbXcli_conn_protocol(rootcli->conn) >= PROTOCOL_SMB2_02) {
                root_tcon = rootcli->smb2.tcon;
        } else {
                root_tcon = rootcli->smb1.tcon;
        }

        if (!smbXcli_tcon_is_dfs_share(root_tcon)) {
                *targetcli = rootcli;
                *pp_targetpath = talloc_strdup(ctx, path);
                if (!*pp_targetpath) {
                        return NT_STATUS_NO_MEMORY;
                }
                return NT_STATUS_OK;
        }

        *targetcli = NULL;

        /* Send a trans2_query_path_info to check for a referral. */

        cleanpath = clean_path(ctx, path);
        if (!cleanpath) {
                return NT_STATUS_NO_MEMORY;
        }

        dfs_path = cli_dfs_make_full_path(ctx, rootcli, cleanpath);
        if (!dfs_path) {
                return NT_STATUS_NO_MEMORY;
        }

        status = cli_qpathinfo_basic( rootcli, dfs_path, &sbuf, &attributes);
        if (NT_STATUS_IS_OK(status)) {
                /* This is an ordinary path, just return it. */
                *targetcli = rootcli;
                *pp_targetpath = talloc_strdup(ctx, path);
                if (!*pp_targetpath) {
                        return NT_STATUS_NO_MEMORY;
                }
                goto done;
        }

        /* Special case where client asked for a path that does not exist */

        if (cli_dfs_check_error(rootcli, NT_STATUS_OBJECT_NAME_NOT_FOUND,
                                status)) {
                *targetcli = rootcli;
                *pp_targetpath = talloc_strdup(ctx, path);
                if (!*pp_targetpath) {
                        return NT_STATUS_NO_MEMORY;
                }
                goto done;
        }

        /* We got an error, check for DFS referral. */

        if (!cli_dfs_check_error(rootcli, NT_STATUS_PATH_NOT_COVERED,
                                 status)) {
                return status;
        }

        /* Check for the referral. */

        status = cli_cm_open(ctx,
                             rootcli,
                             smbXcli_conn_remote_name(rootcli->conn),
                             "IPC$",
                             dfs_auth_info,
                             false,
                             smb1cli_conn_encryption_on(rootcli->conn),
                             smbXcli_conn_protocol(rootcli->conn),
                             0,
                             0x20,
                             &cli_ipc);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        status = cli_dfs_get_referral(ctx, cli_ipc, dfs_path, &refs,
                                      &num_refs, &consumed);
        if (!NT_STATUS_IS_OK(status) || !num_refs) {
                return status;
        }

        /* Just store the first referral for now. */

        if (!refs[0].dfspath) {
                return NT_STATUS_NOT_FOUND;
        }
        if (!split_dfs_path(ctx, refs[0].dfspath, &server, &share,
                            &extrapath)) {
                return NT_STATUS_NOT_FOUND;
        }

        /* Make sure to recreate the original string including any wildcards. */

        dfs_path = cli_dfs_make_full_path(ctx, rootcli, path);
        if (!dfs_path) {
                return NT_STATUS_NO_MEMORY;
        }
        pathlen = strlen(dfs_path);
        consumed = MIN(pathlen, consumed);
        *pp_targetpath = talloc_strdup(ctx, &dfs_path[consumed]);
        if (!*pp_targetpath) {
                return NT_STATUS_NO_MEMORY;
        }
        dfs_path[consumed] = '\0';

        /*
         * *pp_targetpath is now the unconsumed part of the path.
         * dfs_path is now the consumed part of the path
         * (in \server\share\path format).
         */

        /* Open the connection to the target server & share */
        status = cli_cm_open(ctx, rootcli,
                             server,
                             share,
                             dfs_auth_info,
                             false,
                             smb1cli_conn_encryption_on(rootcli->conn),
                             smbXcli_conn_protocol(rootcli->conn),
                             0,
                             0x20,
                             targetcli);
        if (!NT_STATUS_IS_OK(status)) {
                d_printf("Unable to follow dfs referral [\\%s\\%s]\n",
                        server, share );
                return status;
        }

        if (extrapath && strlen(extrapath) > 0) {
                /* EMC Celerra NAS version 5.6.50 (at least) doesn't appear to */
                /* put the trailing \ on the path, so to be save we put one in if needed */
                if (extrapath[strlen(extrapath)-1] != '\\' && **pp_targetpath != '\\') {
                        *pp_targetpath = talloc_asprintf(ctx,
                                                  "%s\\%s",
                                                  extrapath,
                                                  *pp_targetpath);
                } else {
                        *pp_targetpath = talloc_asprintf(ctx,
                                                  "%s%s",
                                                  extrapath,
                                                  *pp_targetpath);
                }
                if (!*pp_targetpath) {
                        return NT_STATUS_NO_MEMORY;
                }
        }

        /* parse out the consumed mount path */
        /* trim off the \server\share\ */

        ppath = dfs_path;

        if (*ppath != '\\') {
                d_printf("cli_resolve_path: "
                        "dfs_path (%s) not in correct format.\n",
                        dfs_path );
                return NT_STATUS_NOT_FOUND;
        }

        ppath++; /* Now pointing at start of server name. */

        if ((ppath = strchr_m( dfs_path, '\\' )) == NULL) {
                return NT_STATUS_NOT_FOUND;
        }

        ppath++; /* Now pointing at start of share name. */

        if ((ppath = strchr_m( ppath+1, '\\' )) == NULL) {
                return NT_STATUS_NOT_FOUND;
        }

        ppath++; /* Now pointing at path component. */

        newmount = talloc_asprintf(ctx, "%s\\%s", mountpt, ppath );
        if (!newmount) {
                return NT_STATUS_NOT_FOUND;
        }

        cli_set_mntpoint(*targetcli, newmount);

        /* Check for another dfs referral, note that we are not
           checking for loops here. */

        if (!strequal(*pp_targetpath, "\\") && !strequal(*pp_targetpath, "/")) {
                status = cli_resolve_path(ctx,
                                          newmount,
                                          dfs_auth_info,
                                          *targetcli,
                                          *pp_targetpath,
                                          &newcli,
                                          &newpath);
                if (NT_STATUS_IS_OK(status)) {
                        /*
                         * When cli_resolve_path returns true here it's always
                         * returning the complete path in newpath, so we're done
                         * here.
                         */
                        *targetcli = newcli;
                        *pp_targetpath = newpath;
                        return status;
                }
        }

  done:

        if (smbXcli_conn_protocol((*targetcli)->conn) >= PROTOCOL_SMB2_02) {
                target_tcon = (*targetcli)->smb2.tcon;
        } else {
                target_tcon = (*targetcli)->smb1.tcon;
        }

        /* If returning true ensure we return a dfs root full path. */
        if (smbXcli_tcon_is_dfs_share(target_tcon)) {
                dfs_path = talloc_strdup(ctx, *pp_targetpath);
                if (!dfs_path) {
                        return NT_STATUS_NO_MEMORY;
                }
                *pp_targetpath = cli_dfs_make_full_path(ctx, *targetcli, dfs_path);
                if (*pp_targetpath == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
        }

        return NT_STATUS_OK;
}

/********************************************************************
********************************************************************/

bool cli_check_msdfs_proxy(TALLOC_CTX *ctx,
                                struct cli_state *cli,
                                const char *sharename,
                                char **pp_newserver,
                                char **pp_newshare,
                                bool force_encrypt,
                                const char *username,
                                const char *password,
                                const char *domain)
{
        struct client_dfs_referral *refs = NULL;
        size_t num_refs = 0;
        size_t consumed = 0;
        char *fullpath = NULL;
        bool res;
        uint16 cnum;
        char *newextrapath = NULL;
        NTSTATUS status;
        const char *remote_name;

        if (!cli || !sharename) {
                return false;
        }

        remote_name = smbXcli_conn_remote_name(cli->conn);
        cnum = cli_state_get_tid(cli);

        /* special case.  never check for a referral on the IPC$ share */

        if (strequal(sharename, "IPC$")) {
                return false;
        }

        /* send a trans2_query_path_info to check for a referral */

        fullpath = talloc_asprintf(ctx, "\\%s\\%s", remote_name, sharename);
        if (!fullpath) {
                return false;
        }

        /* check for the referral */

        if (!NT_STATUS_IS_OK(cli_tree_connect(cli, "IPC$", "IPC", NULL, 0))) {
                return false;
        }

        if (force_encrypt) {
                status = cli_cm_force_encryption(cli,
                                        username,
                                        password,
                                        lp_workgroup(),
                                        "IPC$");
                if (!NT_STATUS_IS_OK(status)) {
                        return false;
                }
        }

        status = cli_dfs_get_referral(ctx, cli, fullpath, &refs,
                                      &num_refs, &consumed);
        res = NT_STATUS_IS_OK(status);

        status = cli_tdis(cli);
        if (!NT_STATUS_IS_OK(status)) {
                return false;
        }

        cli_state_set_tid(cli, cnum);

        if (!res || !num_refs) {
                return false;
        }

        if (!refs[0].dfspath) {
                return false;
        }

        if (!split_dfs_path(ctx, refs[0].dfspath, pp_newserver,
                            pp_newshare, &newextrapath)) {
                return false;
        }

        /* check that this is not a self-referral */

        if (strequal(remote_name, *pp_newserver) &&
                        strequal(sharename, *pp_newshare)) {
                return false;
        }

        return true;
}