source: branches/samba-3.3.x/source/rpc_server/srv_lsa_hnd.c@ 221

/* 
 *  Unix SMB/CIFS implementation.
 *  RPC Pipe client / server routines
 *  Copyright (C) Andrew Tridgell              1992-1997,
 *  Copyright (C) Luke Kenneth Casson Leighton 1996-1997,
 *  Copyright (C) Jeremy Allison                           2001.
 *  
 *  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"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_RPC_SRV

/* This is the max handles across all instances of a pipe name. */
#ifndef MAX_OPEN_POLS
#define MAX_OPEN_POLS 1024
#endif

/****************************************************************************
 Hack as handles need to be persisant over lsa pipe closes so long as a samr
 pipe is open. JRA.
****************************************************************************/

static bool is_samr_lsa_pipe(const char *pipe_name)
{
        return (strstr(pipe_name, "samr") || strstr(pipe_name, "lsa"));
}

/****************************************************************************
 Initialise a policy handle list on a pipe. Handle list is shared between all
 pipes of the same name.
****************************************************************************/

bool init_pipe_handle_list(pipes_struct *p, const char *pipe_name)
{
        pipes_struct *plist = get_first_internal_pipe();
        struct handle_list *hl = NULL;

        for (plist = get_first_internal_pipe(); plist; plist = get_next_internal_pipe(plist)) {
                if (strequal( plist->name, pipe_name) ||
                                (is_samr_lsa_pipe(plist->name) && is_samr_lsa_pipe(pipe_name))) {
                        if (!plist->pipe_handles) {
                                char *msg;
                                if (asprintf(&msg, "init_pipe_handles: NULL "
                                                 "pipe_handle pointer in pipe %s",
                                                 pipe_name) != -1) {
                                        smb_panic(msg);
                                } else {
                                        smb_panic("init_pipe_handle_list");
                                }
                        }
                        hl = plist->pipe_handles;
                        break;
                }
        }

        if (!hl) {
                /*
                 * No handle list for this pipe (first open of pipe).
                 * Create list.
                 */

                if ((hl = SMB_MALLOC_P(struct handle_list)) == NULL)
                        return False;
                ZERO_STRUCTP(hl);

                DEBUG(10,("init_pipe_handles: created handle list for pipe %s\n", pipe_name ));
        }

        /*
         * One more pipe is using this list.
         */

        hl->pipe_ref_count++;

        /*
         * Point this pipe at this list.
         */

        p->pipe_handles = hl;

        DEBUG(10,("init_pipe_handles: pipe_handles ref count = %lu for pipe %s\n",
                  (unsigned long)p->pipe_handles->pipe_ref_count, pipe_name ));

        return True;
}

/****************************************************************************
  find first available policy slot.  creates a policy handle for you.
****************************************************************************/

bool create_policy_hnd(pipes_struct *p, POLICY_HND *hnd, void (*free_fn)(void *), void *data_ptr)
{
        static uint32 pol_hnd_low  = 0;
        static uint32 pol_hnd_high = 0;
        time_t t = time(NULL);

        struct policy *pol;

        if (p->pipe_handles->count > MAX_OPEN_POLS) {
                DEBUG(0,("create_policy_hnd: ERROR: too many handles (%d) on this pipe.\n",
                                (int)p->pipe_handles->count));
                return False;
        }

        pol = SMB_MALLOC_P(struct policy);
        if (!pol) {
                DEBUG(0,("create_policy_hnd: ERROR: out of memory!\n"));
                return False;
        }

        ZERO_STRUCTP(pol);

        pol->data_ptr = data_ptr;
        pol->free_fn = free_fn;

        pol_hnd_low++;
        if (pol_hnd_low == 0)
                (pol_hnd_high)++;

        SIVAL(&pol->pol_hnd.handle_type, 0 , 0);  /* first bit must be null */
        SIVAL(&pol->pol_hnd.uuid.time_low, 0 , pol_hnd_low ); /* second bit is incrementing */
        SSVAL(&pol->pol_hnd.uuid.time_mid, 0 , pol_hnd_high); /* second bit is incrementing */
        SSVAL(&pol->pol_hnd.uuid.time_hi_and_version, 0 , (pol_hnd_high>>16)); /* second bit is incrementing */

        /* split the current time into two 16 bit values */

        SSVAL(pol->pol_hnd.uuid.clock_seq, 0, (t>>16)); /* something random */
        SSVAL(pol->pol_hnd.uuid.node, 0, t); /* something random */

        SIVAL(pol->pol_hnd.uuid.node, 2, sys_getpid()); /* something more random */

        DLIST_ADD(p->pipe_handles->Policy, pol);
        p->pipe_handles->count++;

        *hnd = pol->pol_hnd;
        
        DEBUG(4,("Opened policy hnd[%d] ", (int)p->pipe_handles->count));
        dump_data(4, (uint8 *)hnd, sizeof(*hnd));

        return True;
}

/****************************************************************************
  find policy by handle - internal version.
****************************************************************************/

static struct policy *find_policy_by_hnd_internal(pipes_struct *p, POLICY_HND *hnd, void **data_p)
{
        struct policy *pol;
        size_t i;

        if (data_p)
                *data_p = NULL;

        for (i = 0, pol=p->pipe_handles->Policy;pol;pol=pol->next, i++) {
                if (memcmp(&pol->pol_hnd, hnd, sizeof(*hnd)) == 0) {
                        DEBUG(4,("Found policy hnd[%d] ", (int)i));
                        dump_data(4, (uint8 *)hnd, sizeof(*hnd));
                        if (data_p)
                                *data_p = pol->data_ptr;
                        return pol;
                }
        }

        DEBUG(4,("Policy not found: "));
        dump_data(4, (uint8 *)hnd, sizeof(*hnd));

        p->bad_handle_fault_state = True;

        return NULL;
}

/****************************************************************************
  find policy by handle
****************************************************************************/

bool find_policy_by_hnd(pipes_struct *p, POLICY_HND *hnd, void **data_p)
{
        return find_policy_by_hnd_internal(p, hnd, data_p) == NULL ? False : True;
}

/****************************************************************************
  Close a policy.
****************************************************************************/

bool close_policy_hnd(pipes_struct *p, POLICY_HND *hnd)
{
        struct policy *pol = find_policy_by_hnd_internal(p, hnd, NULL);

        if (!pol) {
                DEBUG(3,("Error closing policy\n"));
                return False;
        }

        DEBUG(3,("Closed policy\n"));

        if (pol->free_fn && pol->data_ptr)
                (*pol->free_fn)(pol->data_ptr);

        p->pipe_handles->count--;

        DLIST_REMOVE(p->pipe_handles->Policy, pol);

        ZERO_STRUCTP(pol);

        SAFE_FREE(pol);

        return True;
}

/****************************************************************************
 Close a pipe - free the handle list if it was the last pipe reference.
****************************************************************************/

void close_policy_by_pipe(pipes_struct *p)
{
        p->pipe_handles->pipe_ref_count--;

        if (p->pipe_handles->pipe_ref_count == 0) {
                /*
                 * Last pipe open on this list - free the list.
                 */
                while (p->pipe_handles->Policy)
                        close_policy_hnd(p, &p->pipe_handles->Policy->pol_hnd);

                p->pipe_handles->Policy = NULL;
                p->pipe_handles->count = 0;

                SAFE_FREE(p->pipe_handles);
                DEBUG(10,("close_policy_by_pipe: deleted handle list for pipe %s\n", p->name ));
        }
}

/*******************************************************************
Shall we allow access to this rpc?  Currently this function
implements the 'restrict anonymous' setting by denying access to
anonymous users if the restrict anonymous level is > 0.  Further work
will be checking a security descriptor to determine whether a user
token has enough access to access the pipe.
********************************************************************/

bool pipe_access_check(pipes_struct *p)
{
        /* Don't let anonymous users access this RPC if restrict
           anonymous > 0 */

        if (lp_restrict_anonymous() > 0) {

                /* schannel, so we must be ok */
                if (p->pipe_bound && (p->auth.auth_type == PIPE_AUTH_TYPE_SCHANNEL)) {
                        return True;
                }

                if (p->server_info->guest) {
                        return False;
                }
        }

        return True;
}