source: trunk/samba-3.0.25pre1/source/smbd/msdfs.c@ 7

/* 
   Unix SMB/Netbios implementation.
   Version 3.0
   MSDfs services for Samba
   Copyright (C) Shirish Kalele 2000

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#define DBGC_CLASS DBGC_MSDFS
#include "includes.h"

extern uint32 global_client_caps;

/**********************************************************************
  Parse the pathname  of the form \hostname\service\reqpath
  into the dfs_path structure 
 **********************************************************************/

static BOOL parse_dfs_path(const char *pathname, struct dfs_path *pdp)
{
        pstring pathname_local;
        char *p, *temp;

        pstrcpy(pathname_local,pathname);
        p = temp = pathname_local;

        ZERO_STRUCTP(pdp);

        trim_char(temp,'\\','\\');
        DEBUG(10,("temp in parse_dfs_path: .%s. after trimming \\'s\n",temp));

        /* now tokenize */
        /* parse out hostname */
        p = strchr_m(temp,'\\');
        if(p == NULL) {
                return False;
        }
        *p = '\0';
        pstrcpy(pdp->hostname,temp);
        DEBUG(10,("parse_dfs_path: hostname: %s\n",pdp->hostname));

        /* parse out servicename */
        temp = p+1;
        p = strchr_m(temp,'\\');
        if(p == NULL) {
                pstrcpy(pdp->servicename,temp);
                pdp->reqpath[0] = '\0';
                return True;
        }
        *p = '\0';
        pstrcpy(pdp->servicename,temp);
        DEBUG(10,("parse_dfs_path: servicename: %s\n",pdp->servicename));

        /* rest is reqpath */
        check_path_syntax(pdp->reqpath, p+1);

        DEBUG(10,("parse_dfs_path: rest of the path: %s\n",pdp->reqpath));
        return True;
}

/**********************************************************************
 Parse the pathname  of the form /hostname/service/reqpath
 into the dfs_path structure 
 This code is dependent on the fact that check_path_syntax() will
 convert '\\' characters to '/'.
 When POSIX pathnames have been selected this doesn't happen, so we
 must look for the unaltered separator of '\\' instead of the modified '/'.
 JRA.
 **********************************************************************/

static BOOL parse_processed_dfs_path(char* pathname, struct dfs_path *pdp, BOOL allow_wcards)
{
        pstring pathname_local;
        char *p,*temp;
        const char sepchar = lp_posix_pathnames() ? '\\' : '/';

        pstrcpy(pathname_local,pathname);
        p = temp = pathname_local;

        ZERO_STRUCTP(pdp);

        trim_char(temp,sepchar,sepchar);
        DEBUG(10,("temp in parse_processed_dfs_path: .%s. after trimming \\'s\n",temp));

        /* now tokenize */
        /* parse out hostname */
        p = strchr_m(temp,sepchar);
        if(p == NULL) {
                return False;
        }
        *p = '\0';
        pstrcpy(pdp->hostname,temp);
        DEBUG(10,("parse_processed_dfs_path: hostname: %s\n",pdp->hostname));

        /* parse out servicename */
        temp = p+1;
        p = strchr_m(temp,sepchar);
        if(p == NULL) {
                pstrcpy(pdp->servicename,temp);
                pdp->reqpath[0] = '\0';
                return True;
        }
        *p = '\0';
        pstrcpy(pdp->servicename,temp);
        DEBUG(10,("parse_processed_dfs_path: servicename: %s\n",pdp->servicename));

        /* rest is reqpath */
        if (allow_wcards) {
                BOOL path_contains_wcard;
                check_path_syntax_wcard(pdp->reqpath, p+1, &path_contains_wcard);
        } else {
                check_path_syntax(pdp->reqpath, p+1);
        }

        DEBUG(10,("parse_processed_dfs_path: rest of the path: %s\n",pdp->reqpath));
        return True;
}

/********************************************************
 Fake up a connection struct for the VFS layer.
 Note this CHANGES CWD !!!! JRA.
*********************************************************/

static BOOL create_conn_struct(connection_struct *conn, int snum, char *path)
{
        pstring connpath;

        ZERO_STRUCTP(conn);

        pstrcpy(connpath, path);
        pstring_sub(connpath , "%S", lp_servicename(snum));

        /* needed for smbd_vfs_init() */
        
        if ( (conn->mem_ctx=talloc_init("connection_struct")) == NULL ) {
                DEBUG(0,("talloc_init(connection_struct) failed!\n"));
                return False;
        }

        if (!(conn->params = TALLOC_P(conn->mem_ctx, struct share_params))) {
                DEBUG(0, ("TALLOC failed\n"));
                return False;
        }
        
        conn->params->service = snum;
        
        set_conn_connectpath(conn, connpath);

        if (!smbd_vfs_init(conn)) {
                DEBUG(0,("create_conn_struct: smbd_vfs_init failed.\n"));
                conn_free_internal(conn);
                return False;
        }

        /*
         * Windows seems to insist on doing trans2getdfsreferral() calls on the IPC$
         * share as the anonymous user. If we try to chdir as that user we will
         * fail.... WTF ? JRA.
         */

        if (vfs_ChDir(conn,conn->connectpath) != 0) {
                DEBUG(3,("create_conn_struct: Can't ChDir to new conn path %s. Error was %s\n",
                                        conn->connectpath, strerror(errno) ));
                conn_free_internal(conn);
                return False;
        }

        return True;
}

/**********************************************************************
 Parse the contents of a symlink to verify if it is an msdfs referral
 A valid referral is of the form: msdfs:server1\share1,server2\share2
 talloc CTX can be NULL here if preflist and refcount pointers are null.
 **********************************************************************/

static BOOL parse_symlink(TALLOC_CTX *ctx, char *buf, struct referral **preflist, int *refcount)
{
        pstring temp;
        char *prot;
        char *alt_path[MAX_REFERRAL_COUNT];
        int count = 0, i;
        struct referral *reflist;

        pstrcpy(temp,buf);
  
        prot = strtok(temp,":");

        if (!strequal(prot, "msdfs")) {
                return False;
        }

        /* No referral list requested. Just yes/no. */
        if (!preflist) {
                return True;
        }

        if (!ctx) {
                DEBUG(0,("parse_symlink: logic error. TALLOC_CTX should not be null.\n"));
                return True;
        }

        /* parse out the alternate paths */
        while((count<MAX_REFERRAL_COUNT) &&
              ((alt_path[count] = strtok(NULL,",")) != NULL)) {
                count++;
        }

        DEBUG(10,("parse_symlink: count=%d\n", count));

        reflist = *preflist = TALLOC_ARRAY(ctx, struct referral, count);
        if(reflist == NULL) {
                DEBUG(0,("parse_symlink: talloc failed!\n"));
                return False;
        }
        
        for(i=0;i<count;i++) {
                char *p;

                /* replace all /'s in the alternate path by a \ */
                for(p = alt_path[i]; *p && ((p = strchr_m(p,'/'))!=NULL); p++) {
                        *p = '\\'; 
                }

                /* Remove leading '\\'s */
                p = alt_path[i];
                while (*p && (*p == '\\')) {
                        p++;
                }

                pstrcpy(reflist[i].alternate_path, "\\");
                pstrcat(reflist[i].alternate_path, p);
                reflist[i].proximity = 0;
                reflist[i].ttl = REFERRAL_TTL;
                DEBUG(10, ("parse_symlink: Created alt path: %s\n", reflist[i].alternate_path));
        }

        if(refcount) {
                *refcount = count;
        }

        return True;
}
 
/**********************************************************************
 Returns true if the unix path is a valid msdfs symlink
 talloc CTX can be NULL here if reflistp and refcnt pointers are null.
 **********************************************************************/

BOOL is_msdfs_link(TALLOC_CTX *ctx, connection_struct *conn, const char *path,
                   struct referral **reflistp, int *refcnt,
                   SMB_STRUCT_STAT *sbufp)
{
        SMB_STRUCT_STAT st;
        pstring referral;
        int referral_len = 0;

        if (!path || !conn) {
                return False;
        }

        if (sbufp == NULL) {
                sbufp = &st;
        }

        if (SMB_VFS_LSTAT(conn, path, sbufp) != 0) {
                DEBUG(5,("is_msdfs_link: %s does not exist.\n",path));
                return False;
        }
  
        if (S_ISLNK(sbufp->st_mode)) {
                /* open the link and read it */
                referral_len = SMB_VFS_READLINK(conn, path, referral, sizeof(pstring)-1);
                if (referral_len == -1) {
                        DEBUG(0,("is_msdfs_link: Error reading msdfs link %s: %s\n", path, strerror(errno)));
                        return False;
                }

                referral[referral_len] = '\0';
                DEBUG(5,("is_msdfs_link: %s -> %s\n",path,referral));
                if (parse_symlink(ctx, referral, reflistp, refcnt)) {
                        return True;
                }
        }
        return False;
}

/*****************************************************************
 Used by other functions to decide if a dfs path is remote,
and to get the list of referred locations for that remote path.
 
findfirst_flag: For findfirsts, dfs links themselves are not
redirected, but paths beyond the links are. For normal smb calls,
even dfs links need to be redirected.

self_referralp: clients expect a dfs referral for the same share when
they request referrals for dfs roots on a server. 

consumedcntp: how much of the dfs path is being redirected. the client
should try the remaining path on the redirected server.

TALLOC_CTX can be NULL here if struct referral **reflistpp, int *refcntp
are also NULL.
*****************************************************************/

static BOOL resolve_dfs_path(TALLOC_CTX *ctx,
                        const char *dfspath, 
                        struct dfs_path *dp, 
                        connection_struct *conn,
                        BOOL search_flag, 
                        struct referral **reflistpp,
                        int *refcntp,
                        BOOL *self_referralp,
                        int *consumedcntp)
{
        pstring localpath;
        int consumed_level = 1;
        char *p;
        SMB_STRUCT_STAT sbuf;
        NTSTATUS status;
        pstring reqpath;

        if (!dp || !conn) {
                DEBUG(1,("resolve_dfs_path: NULL dfs_path* or NULL connection_struct*!\n"));
                return False;
        }

        if (!ctx && (reflistpp || refcntp)) {
                DEBUG(0,("resolve_dfs_path: logic error. TALLOC_CTX must not be NULL.\n"));
        }

        if (dp->reqpath[0] == '\0') {
                if (self_referralp) {
                        DEBUG(6,("resolve_dfs_path: self-referral. returning False\n"));
                        *self_referralp = True;
                }
                return False;
        }

        DEBUG(10,("resolve_dfs_path: Conn path = %s req_path = %s\n", conn->connectpath, dp->reqpath));

        /* 
         * Note the unix path conversion here we're doing we can
         * throw away. We're looking for a symlink for a dfs
         * resolution, if we don't find it we'll do another
         * unix_convert later in the codepath.
         * If we needed to remember what we'd resolved in
         * dp->reqpath (as the original code did) we'd
         * pstrcpy(localhost, dp->reqpath) on any code
         * path below that returns True - but I don't
         * think this is needed. JRA.
         */

        pstrcpy(localpath, dp->reqpath);

        status = unix_convert(conn, localpath, False, NULL, &sbuf);
        if (!NT_STATUS_IS_OK(status)) {
                return False;
        }

        /* check if need to redirect */
        if (is_msdfs_link(ctx, conn, localpath, reflistpp, refcntp, NULL)) {
                if ( search_flag ) {
                        DEBUG(6,("resolve_dfs_path (FindFirst) No redirection "
                                 "for dfs link %s.\n", dfspath));
                        return False;
                }

                DEBUG(6,("resolve_dfs_path: %s resolves to a valid Dfs link.\n", dfspath));
                if (consumedcntp) {
                        *consumedcntp = strlen(dfspath);
                }
                return True;
        }

        /* redirect if any component in the path is a link */
        pstrcpy(reqpath, localpath);
        p = strrchr_m(reqpath, '/');
        while (p) {
                *p = '\0';
                pstrcpy(localpath, reqpath);
                if (is_msdfs_link(ctx, conn, localpath, reflistpp, refcntp, NULL)) {
                        DEBUG(4, ("resolve_dfs_path: Redirecting %s because parent %s is dfs link\n", dfspath, localpath));

                        /* To find the path consumed, we truncate the original
                           DFS pathname passed to use to remove the last
                           component. The length of the resulting string is
                           the path consumed 
                        */
                        
                        if (consumedcntp) {
                                char *q;
                                pstring buf;
                                pstrcpy(buf, dfspath);
                                trim_char(buf, '\0', '\\');
                                for (; consumed_level; consumed_level--) {
                                        q = strrchr_m(buf, '\\');
                                        if (q) {
                                                *q = 0;
                                        }
                                }
                                *consumedcntp = strlen(buf);
                                DEBUG(10, ("resolve_dfs_path: Path consumed: %s (%d)\n", buf, *consumedcntp));
                        }
                        
                        return True;
                }
                p = strrchr_m(reqpath, '/');
                consumed_level++;
        }

        return False;
}

/*****************************************************************
  Decides if a dfs pathname should be redirected or not.
  If not, the pathname is converted to a tcon-relative local unix path

  search_wcard_flag: this flag performs 2 functions bother related
  to searches.  See resolve_dfs_path() and parse_processed_dfs_path()
  for details.
*****************************************************************/

BOOL dfs_redirect( pstring pathname, connection_struct *conn, BOOL search_wcard_flag )
{
        struct dfs_path dp;
        
        if (!conn || !pathname) {
                return False;
        }

        parse_processed_dfs_path(pathname, &dp, search_wcard_flag);

        /* if dfs pathname for a non-dfs share, convert to tcon-relative
           path and return false */
        if (!lp_msdfs_root(SNUM(conn))) {
                pstrcpy(pathname, dp.reqpath);
                return False;
        }
        
        if ( !( strequal(dp.servicename, lp_servicename(SNUM(conn))) 
                || ( strequal(dp.servicename, HOMES_NAME) 
                     && strequal(lp_servicename(SNUM(conn)), get_current_username()) )) ) 
        {
                return False;
        }

        if (resolve_dfs_path(NULL, pathname, &dp, conn, search_wcard_flag,
                             NULL, NULL, NULL, NULL)) {
                DEBUG(3,("dfs_redirect: Redirecting %s\n", pathname));
                return True;
        } else {
                DEBUG(3,("dfs_redirect: Not redirecting %s.\n", pathname));

                /* Form non-dfs tcon-relative path */
                pstrcpy(pathname, dp.reqpath);

                DEBUG(3,("dfs_redirect: Path converted to non-dfs path %s\n", pathname));
                return False;
        }

        /* never reached */
}

/**********************************************************************
 Return a self referral.
**********************************************************************/

static BOOL self_ref(TALLOC_CTX *ctx, const char *pathname, struct junction_map *jucn,
                        int *consumedcntp, BOOL *self_referralp)
{
        struct referral *ref;

        if (self_referralp != NULL) {
                *self_referralp = True;
        }

        jucn->referral_count = 1;
        if((ref = TALLOC_P(ctx, struct referral)) == NULL) {
                DEBUG(0,("self_ref: malloc failed for referral\n"));
                return False;
        }

        pstrcpy(ref->alternate_path,pathname);
        ref->proximity = 0;
        ref->ttl = REFERRAL_TTL;
        jucn->referral_list = ref;
        if (consumedcntp) {
                *consumedcntp = strlen(pathname);
        }

        return True;
}

/**********************************************************************
 Gets valid referrals for a dfs path and fills up the
 junction_map structure.
**********************************************************************/

BOOL get_referred_path(TALLOC_CTX *ctx, const char *pathname, struct junction_map *jucn,
                       int *consumedcntp, BOOL *self_referralp)
{
        struct dfs_path dp;

        struct connection_struct conns;
        struct connection_struct *conn = &conns;
        pstring conn_path;
        int snum;
        BOOL ret = False;
        BOOL self_referral = False;

        if (!pathname || !jucn) {
                return False;
        }

        ZERO_STRUCT(conns);

        if (self_referralp) {
                *self_referralp = False;
        } else {
                self_referralp = &self_referral;
        }

        parse_dfs_path(pathname, &dp);

        /* Verify hostname in path */
        if (!is_myname_or_ipaddr(dp.hostname)) {
                DEBUG(3, ("get_referred_path: Invalid hostname %s in path %s\n",
                        dp.hostname, pathname));
                return False;
        }

        pstrcpy(jucn->service_name, dp.servicename);
        pstrcpy(jucn->volume_name, dp.reqpath);

        /* Verify the share is a dfs root */
        snum = lp_servicenumber(jucn->service_name);
        if(snum < 0) {
                if ((snum = find_service(jucn->service_name)) < 0) {
                        return False;
                }
        }

        if (!lp_msdfs_root(snum)) {
                DEBUG(3,("get_referred_path: .%s. in dfs path %s is not a dfs root.\n",
                         dp.servicename, pathname));
                goto out;
        }

        /*
         * Self referrals are tested with a anonymous IPC connection and
         * a GET_DFS_REFERRAL call to \\server\share. (which means dp.reqpath[0] points
         * to an empty string). create_conn_struct cd's into the directory and will
         * fail if it cannot (as the anonymous user). Cope with this.
         */

        if (dp.reqpath[0] == '\0') {

                struct referral* ref;

                if (*lp_msdfs_proxy(snum) == '\0') {
                        return self_ref(ctx, pathname, jucn, consumedcntp, self_referralp);
                }

                jucn->referral_count = 1;
                if ((ref = TALLOC_P(ctx, struct referral)) == NULL) {
                        DEBUG(0, ("malloc failed for referral\n"));
                        goto out;
                }

                pstrcpy(ref->alternate_path, lp_msdfs_proxy(snum));
                if (dp.reqpath[0] != '\0') {
                        pstrcat(ref->alternate_path, dp.reqpath);
                }
                ref->proximity = 0;
                ref->ttl = REFERRAL_TTL;
                jucn->referral_list = ref;
                if (consumedcntp) {
                        *consumedcntp = strlen(pathname);
                }
                ret = True;
                goto out;
        }

        pstrcpy(conn_path, lp_pathname(snum));
        if (!create_conn_struct(conn, snum, conn_path)) {
                return False;
        }

        /* If not remote & not a self referral, return False */
        if (!resolve_dfs_path(ctx, pathname, &dp, conn, False, 
                              &jucn->referral_list, &jucn->referral_count,
                              self_referralp, consumedcntp)) {
                if (!*self_referralp) {
                        DEBUG(3,("get_referred_path: No valid referrals for path %s\n", pathname));
                        goto out;
                }
        }
        
        /* if self_referral, fill up the junction map */
        if (*self_referralp) {
                if (self_ref(ctx, pathname, jucn, consumedcntp, self_referralp) == False) {
                        goto out;
                }
        }
        
        ret = True;

out:

        conn_free_internal(conn);
        return ret;
}

static int setup_ver2_dfs_referral(char *pathname, char **ppdata, 
                                   struct junction_map *junction,
                                   int consumedcnt,
                                   BOOL self_referral)
{
        char* pdata = *ppdata;

        unsigned char uni_requestedpath[1024];
        int uni_reqpathoffset1,uni_reqpathoffset2;
        int uni_curroffset;
        int requestedpathlen=0;
        int offset;
        int reply_size = 0;
        int i=0;

        DEBUG(10,("setting up version2 referral\nRequested path:\n"));

        requestedpathlen = rpcstr_push(uni_requestedpath, pathname, sizeof(pstring),
                                       STR_TERMINATE);

        if (DEBUGLVL(10)) {
            dump_data(0, (const char *) uni_requestedpath,requestedpathlen);
        }

        DEBUG(10,("ref count = %u\n",junction->referral_count));

        uni_reqpathoffset1 = REFERRAL_HEADER_SIZE + 
                        VERSION2_REFERRAL_SIZE * junction->referral_count;

        uni_reqpathoffset2 = uni_reqpathoffset1 + requestedpathlen;

        uni_curroffset = uni_reqpathoffset2 + requestedpathlen;

        reply_size = REFERRAL_HEADER_SIZE + VERSION2_REFERRAL_SIZE*junction->referral_count +
                                        2 * requestedpathlen;
        DEBUG(10,("reply_size: %u\n",reply_size));

        /* add up the unicode lengths of all the referral paths */
        for(i=0;i<junction->referral_count;i++) {
                DEBUG(10,("referral %u : %s\n",i,junction->referral_list[i].alternate_path));
                reply_size += (strlen(junction->referral_list[i].alternate_path)+1)*2;
        }

        DEBUG(10,("reply_size = %u\n",reply_size));
        /* add the unexplained 0x16 bytes */
        reply_size += 0x16;

        pdata = (char *)SMB_REALLOC(pdata,reply_size);
        if(pdata == NULL) {
                DEBUG(0,("malloc failed for Realloc!\n"));
                return -1;
        }
        *ppdata = pdata;

        /* copy in the dfs requested paths.. required for offset calculations */
        memcpy(pdata+uni_reqpathoffset1,uni_requestedpath,requestedpathlen);
        memcpy(pdata+uni_reqpathoffset2,uni_requestedpath,requestedpathlen);

        /* create the header */
        SSVAL(pdata,0,consumedcnt * 2); /* path consumed */
        SSVAL(pdata,2,junction->referral_count); /* number of referral in this pkt */
        if(self_referral) {
                SIVAL(pdata,4,DFSREF_REFERRAL_SERVER | DFSREF_STORAGE_SERVER); 
        } else {
                SIVAL(pdata,4,DFSREF_STORAGE_SERVER);
        }

        offset = 8;
        /* add the referral elements */
        for(i=0;i<junction->referral_count;i++) {
                struct referral* ref = &junction->referral_list[i];
                int unilen;

                SSVAL(pdata,offset,2); /* version 2 */
                SSVAL(pdata,offset+2,VERSION2_REFERRAL_SIZE);
                if(self_referral) {
                        SSVAL(pdata,offset+4,1);
                } else {
                        SSVAL(pdata,offset+4,0);
                }
                SSVAL(pdata,offset+6,0); /* ref_flags :use path_consumed bytes? */
                SIVAL(pdata,offset+8,ref->proximity);
                SIVAL(pdata,offset+12,ref->ttl);

                SSVAL(pdata,offset+16,uni_reqpathoffset1-offset);
                SSVAL(pdata,offset+18,uni_reqpathoffset2-offset);
                /* copy referred path into current offset */
                unilen = rpcstr_push(pdata+uni_curroffset, ref->alternate_path,
                                     sizeof(pstring), STR_UNICODE);

                SSVAL(pdata,offset+20,uni_curroffset-offset);

                uni_curroffset += unilen;
                offset += VERSION2_REFERRAL_SIZE;
        }
        /* add in the unexplained 22 (0x16) bytes at the end */
        memset(pdata+uni_curroffset,'\0',0x16);
        return reply_size;
}

static int setup_ver3_dfs_referral(char *pathname, char **ppdata, 
                                   struct junction_map *junction,
                                   int consumedcnt,
                                   BOOL self_referral)
{
        char* pdata = *ppdata;

        unsigned char uni_reqpath[1024];
        int uni_reqpathoffset1, uni_reqpathoffset2;
        int uni_curroffset;
        int reply_size = 0;

        int reqpathlen = 0;
        int offset,i=0;
        
        DEBUG(10,("setting up version3 referral\n"));

        reqpathlen = rpcstr_push(uni_reqpath, pathname, sizeof(pstring), STR_TERMINATE);
        
        if (DEBUGLVL(10)) {
            dump_data(0, (char *) uni_reqpath,reqpathlen);
        }

        uni_reqpathoffset1 = REFERRAL_HEADER_SIZE + VERSION3_REFERRAL_SIZE * junction->referral_count;
        uni_reqpathoffset2 = uni_reqpathoffset1 + reqpathlen;
        reply_size = uni_curroffset = uni_reqpathoffset2 + reqpathlen;

        for(i=0;i<junction->referral_count;i++) {
                DEBUG(10,("referral %u : %s\n",i,junction->referral_list[i].alternate_path));
                reply_size += (strlen(junction->referral_list[i].alternate_path)+1)*2;
        }

        pdata = (char *)SMB_REALLOC(pdata,reply_size);
        if(pdata == NULL) {
                DEBUG(0,("version3 referral setup: malloc failed for Realloc!\n"));
                return -1;
        }
        *ppdata = pdata;

        /* create the header */
        SSVAL(pdata,0,consumedcnt * 2); /* path consumed */
        SSVAL(pdata,2,junction->referral_count); /* number of referral */
        if(self_referral) {
                SIVAL(pdata,4,DFSREF_REFERRAL_SERVER | DFSREF_STORAGE_SERVER); 
        } else {
                SIVAL(pdata,4,DFSREF_STORAGE_SERVER);
        }
        
        /* copy in the reqpaths */
        memcpy(pdata+uni_reqpathoffset1,uni_reqpath,reqpathlen);
        memcpy(pdata+uni_reqpathoffset2,uni_reqpath,reqpathlen);
        
        offset = 8;
        for(i=0;i<junction->referral_count;i++) {
                struct referral* ref = &(junction->referral_list[i]);
                int unilen;

                SSVAL(pdata,offset,3); /* version 3 */
                SSVAL(pdata,offset+2,VERSION3_REFERRAL_SIZE);
                if(self_referral) {
                        SSVAL(pdata,offset+4,1);
                } else {
                        SSVAL(pdata,offset+4,0);
                }

                SSVAL(pdata,offset+6,0); /* ref_flags :use path_consumed bytes? */
                SIVAL(pdata,offset+8,ref->ttl);
            
                SSVAL(pdata,offset+12,uni_reqpathoffset1-offset);
                SSVAL(pdata,offset+14,uni_reqpathoffset2-offset);
                /* copy referred path into current offset */
                unilen = rpcstr_push(pdata+uni_curroffset,ref->alternate_path,
                                     sizeof(pstring), STR_UNICODE | STR_TERMINATE);
                SSVAL(pdata,offset+16,uni_curroffset-offset);
                /* copy 0x10 bytes of 00's in the ServiceSite GUID */
                memset(pdata+offset+18,'\0',16);

                uni_curroffset += unilen;
                offset += VERSION3_REFERRAL_SIZE;
        }
        return reply_size;
}

/******************************************************************
 Set up the Dfs referral for the dfs pathname
******************************************************************/

int setup_dfs_referral(connection_struct *orig_conn, char *pathname, int max_referral_level, char **ppdata)
{
        struct junction_map junction;
        int consumedcnt;
        BOOL self_referral = False;
        pstring buf;
        int reply_size = 0;
        char *pathnamep = pathname;
        TALLOC_CTX *ctx;

        if (!(ctx=talloc_init("setup_dfs_referral"))) {
                return -1;
        }

        ZERO_STRUCT(junction);

        /* get the junction entry */
        if (!pathnamep) {
                talloc_destroy(ctx);
                return -1;
        }

        /* Trim pathname sent by client so it begins with only one backslash.
           Two backslashes confuse some dfs clients
         */
        while (pathnamep[0] == '\\' && pathnamep[1] == '\\') {
                pathnamep++;
        }

        pstrcpy(buf, pathnamep);
        /* The following call can change cwd. */
        if (!get_referred_path(ctx, buf, &junction, &consumedcnt, &self_referral)) {
                vfs_ChDir(orig_conn,orig_conn->connectpath);
                talloc_destroy(ctx);
                return -1;
        }
        vfs_ChDir(orig_conn,orig_conn->connectpath);
        
        if (!self_referral) {
                pathnamep[consumedcnt] = '\0';

                if( DEBUGLVL( 3 ) ) {
                        int i=0;
                        dbgtext("setup_dfs_referral: Path %s to alternate path(s):",pathnamep);
                        for(i=0;i<junction.referral_count;i++)
                                dbgtext(" %s",junction.referral_list[i].alternate_path);
                        dbgtext(".\n");
                }
        }

        /* create the referral depeding on version */
        DEBUG(10,("max_referral_level :%d\n",max_referral_level));

        if (max_referral_level < 2) {
                max_referral_level = 2;
        }
        if (max_referral_level > 3) {
                max_referral_level = 3;
        }

        switch(max_referral_level) {
        case 2:
                reply_size = setup_ver2_dfs_referral(pathnamep, ppdata, &junction, 
                                                     consumedcnt, self_referral);
                break;
        case 3:
                reply_size = setup_ver3_dfs_referral(pathnamep, ppdata, &junction, 
                                                     consumedcnt, self_referral);
                break;
        default:
                DEBUG(0,("setup_dfs_referral: Invalid dfs referral version: %d\n", max_referral_level));
                talloc_destroy(ctx);
                return -1;
        }
      
        if (DEBUGLVL(10)) {
                DEBUGADD(0,("DFS Referral pdata:\n"));
                dump_data(0,*ppdata,reply_size);
        }

        talloc_destroy(ctx);
        return reply_size;
}

/**********************************************************************
 The following functions are called by the NETDFS RPC pipe functions
 **********************************************************************/

/*********************************************************************
 Creates a junction structure from a Dfs pathname
**********************************************************************/

BOOL create_junction(const char *pathname, struct junction_map *jucn)
{
        struct dfs_path dp;
 
        parse_dfs_path(pathname,&dp);

        /* check if path is dfs : validate first token */
        if (!is_myname_or_ipaddr(dp.hostname)) {
                DEBUG(4,("create_junction: Invalid hostname %s in dfs path %s\n",
                        dp.hostname, pathname));
                return False;
        }

        /* Check for a non-DFS share */
        if(!lp_msdfs_root(lp_servicenumber(dp.servicename))) {
                DEBUG(4,("create_junction: %s is not an msdfs root.\n", dp.servicename));
                return False;
        }

        pstrcpy(jucn->service_name,dp.servicename);
        pstrcpy(jucn->volume_name,dp.reqpath);
        pstrcpy(jucn->comment, lp_comment(lp_servicenumber(dp.servicename)));
        return True;
}

/**********************************************************************
 Forms a valid Unix pathname from the junction 
 **********************************************************************/

static BOOL junction_to_local_path(struct junction_map *jucn, char *path,
                                   int max_pathlen, connection_struct *conn)
{
        int snum;
        pstring conn_path;

        if(!path || !jucn) {
                return False;
        }

        snum = lp_servicenumber(jucn->service_name);
        if(snum < 0) {
                return False;
        }

        safe_strcpy(path, lp_pathname(snum), max_pathlen-1);
        safe_strcat(path, "/", max_pathlen-1);
        safe_strcat(path, jucn->volume_name, max_pathlen-1);

        pstrcpy(conn_path, lp_pathname(snum));
        if (!create_conn_struct(conn, snum, conn_path)) {
                return False;
        }

        return True;
}

BOOL create_msdfs_link(struct junction_map *jucn, BOOL exists)
{
        pstring path;
        pstring msdfs_link;
        connection_struct conns;
        connection_struct *conn = &conns;
        int i=0;
        BOOL insert_comma = False;
        BOOL ret = False;

        ZERO_STRUCT(conns);

        if(!junction_to_local_path(jucn, path, sizeof(path), conn)) {
                return False;
        }
  
        /* form the msdfs_link contents */
        pstrcpy(msdfs_link, "msdfs:");
        for(i=0; i<jucn->referral_count; i++) {
                char* refpath = jucn->referral_list[i].alternate_path;
      
                trim_char(refpath, '\\', '\\');
                if(*refpath == '\0') {
                        if (i == 0) {
                                insert_comma = False;
                        }
                        continue;
                }
                if (i > 0 && insert_comma) {
                        pstrcat(msdfs_link, ",");
                }

                pstrcat(msdfs_link, refpath);
                if (!insert_comma) {
                        insert_comma = True;
                }
        }

        DEBUG(5,("create_msdfs_link: Creating new msdfs link: %s -> %s\n", path, msdfs_link));

        if(exists) {
                if(SMB_VFS_UNLINK(conn,path)!=0) {
                        goto out;
                }
        }

        if(SMB_VFS_SYMLINK(conn, msdfs_link, path) < 0) {
                DEBUG(1,("create_msdfs_link: symlink failed %s -> %s\nError: %s\n", 
                                path, msdfs_link, strerror(errno)));
                goto out;
        }
        
        
        ret = True;
        
out:

        conn_free_internal(conn);
        return ret;
}

BOOL remove_msdfs_link(struct junction_map *jucn)
{
        pstring path;
        connection_struct conns;
        connection_struct *conn = &conns;
        BOOL ret = False;

        ZERO_STRUCT(conns);

        if( junction_to_local_path(jucn, path, sizeof(path), conn) ) {
                if( SMB_VFS_UNLINK(conn, path) == 0 ) {
                        ret = True;
                }
                talloc_destroy( conn->mem_ctx );
        }

        conn_free_internal(conn);
        return ret;
}

static int form_junctions(TALLOC_CTX *ctx, int snum, struct junction_map *jucn, int jn_remain)
{
        int cnt = 0;
        SMB_STRUCT_DIR *dirp;
        char* dname;
        pstring connect_path;
        char* service_name = lp_servicename(snum);
        connection_struct conn;
        struct referral *ref = NULL;
 
        ZERO_STRUCT(conn);

        if (jn_remain <= 0) {
                return 0;
        }

        pstrcpy(connect_path,lp_pathname(snum));

        if(*connect_path == '\0') {
                return 0;
        }

        /*
         * Fake up a connection struct for the VFS layer.
         */

        if (!create_conn_struct(&conn, snum, connect_path)) {
                return 0;
        }

        /* form a junction for the msdfs root - convention 
           DO NOT REMOVE THIS: NT clients will not work with us
           if this is not present
        */ 
        pstrcpy(jucn[cnt].service_name, service_name);
        jucn[cnt].volume_name[0] = '\0';
        jucn[cnt].referral_count = 1;

        ref = jucn[cnt].referral_list = TALLOC_P(ctx, struct referral);
        if (jucn[cnt].referral_list == NULL) {
                DEBUG(0, ("Malloc failed!\n"));
                goto out;
        }

        ref->proximity = 0;
        ref->ttl = REFERRAL_TTL;
        if (*lp_msdfs_proxy(snum) != '\0') {
                pstrcpy(ref->alternate_path, lp_msdfs_proxy(snum));
                cnt++;
                goto out;
        }
                
        slprintf(ref->alternate_path, sizeof(pstring)-1,
                 "\\\\%s\\%s", get_local_machine_name(), service_name);
        cnt++;

        /* Now enumerate all dfs links */
        dirp = SMB_VFS_OPENDIR(&conn, ".", NULL, 0);
        if(!dirp) {
                goto out;
        }

        while ((dname = vfs_readdirname(&conn, dirp)) != NULL) {
                if (cnt >= jn_remain) {
                        SMB_VFS_CLOSEDIR(&conn,dirp);
                        DEBUG(2, ("ran out of MSDFS junction slots"));
                        goto out;
                }
                if (is_msdfs_link(ctx, &conn, dname, &jucn[cnt].referral_list,
                                  &jucn[cnt].referral_count, NULL)) {
                        pstrcpy(jucn[cnt].service_name, service_name);
                        pstrcpy(jucn[cnt].volume_name, dname);
                        cnt++;
                }
        }
        
        SMB_VFS_CLOSEDIR(&conn,dirp);

out:

        conn_free_internal(&conn);
        return cnt;
}

int enum_msdfs_links(TALLOC_CTX *ctx, struct junction_map *jucn, int jn_max)
{
        int i=0;
        int sharecount = 0;
        int jn_count = 0;

        if(!lp_host_msdfs()) {
                return 0;
        }

        /* Ensure all the usershares are loaded. */
        become_root();
        sharecount = load_usershare_shares();
        unbecome_root();

        for(i=0;i < sharecount && (jn_max - jn_count) > 0;i++) {
                if(lp_msdfs_root(i)) {
                        jn_count += form_junctions(ctx, i,jucn,jn_max - jn_count);
                }
        }
        return jn_count;
}