s3: Fix Coverity ID 2195: NO_EFFECT

[Samba.git] / source3 / winbindd / idmap.c

/*
   Unix SMB/CIFS implementation.
   ID Mapping
   Copyright (C) Tim Potter 2000
   Copyright (C) Jim McDonough <jmcd@us.ibm.com>        2003
   Copyright (C) Simo Sorce 2003-2007
   Copyright (C) Jeremy Allison 2006
   Copyright (C) Michael Adam 2010

   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 "winbindd.h"
#include "idmap.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_IDMAP

static_decl_idmap;

static void idmap_init(void)
{
        static bool initialized;

        if (initialized) {
                return;
        }

        DEBUG(10, ("idmap_init(): calling static_init_idmap\n"));

        static_init_idmap;

        initialized = true;
}

/**
 * Pointer to the backend methods. Modules register themselves here via
 * smb_register_idmap.
 */

struct idmap_backend {
        const char *name;
        struct idmap_methods *methods;
        struct idmap_backend *prev, *next;
};
static struct idmap_backend *backends = NULL;

/**
 * Default idmap domain configured via "idmap backend".
 */
static struct idmap_domain *default_idmap_domain;

/**
 * Passdb idmap domain, not configurable. winbind must always give passdb a
 * chance to map ids.
 */
static struct idmap_domain *passdb_idmap_domain;

/**
 * List of specially configured idmap domains. This list is filled on demand
 * in the winbind idmap child when the parent winbind figures out via the
 * special range parameter or via the domain SID that a special "idmap config
 * domain" configuration is present.
 */
static struct idmap_domain **idmap_domains = NULL;
static int num_domains = 0;

static struct idmap_methods *get_methods(const char *name)
{
        struct idmap_backend *b;

        for (b = backends; b; b = b->next) {
                if (strequal(b->name, name)) {
                        return b->methods;
                }
        }

        return NULL;
}

bool idmap_is_offline(void)
{
        return ( lp_winbind_offline_logon() &&
             get_global_winbindd_state_offline() );
}

bool idmap_is_online(void)
{
        return !idmap_is_offline();
}

/**********************************************************************
 Allow a module to register itself as a method.
**********************************************************************/

NTSTATUS smb_register_idmap(int version, const char *name,
                            struct idmap_methods *methods)
{
        struct idmap_backend *entry;

        if ((version != SMB_IDMAP_INTERFACE_VERSION)) {
                DEBUG(0, ("Failed to register idmap module.\n"
                          "The module was compiled against "
                          "SMB_IDMAP_INTERFACE_VERSION %d,\n"
                          "current SMB_IDMAP_INTERFACE_VERSION is %d.\n"
                          "Please recompile against the current version "
                          "of samba!\n",
                          version, SMB_IDMAP_INTERFACE_VERSION));
                return NT_STATUS_OBJECT_TYPE_MISMATCH;
        }

        if (!name || !name[0] || !methods) {
                DEBUG(0,("Called with NULL pointer or empty name!\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        for (entry = backends; entry != NULL; entry = entry->next) {
                if (strequal(entry->name, name)) {
                        DEBUG(0,("Idmap module %s already registered!\n",
                                 name));
                        return NT_STATUS_OBJECT_NAME_COLLISION;
                }
        }

        entry = talloc(NULL, struct idmap_backend);
        if ( ! entry) {
                DEBUG(0,("Out of memory!\n"));
                TALLOC_FREE(entry);
                return NT_STATUS_NO_MEMORY;
        }
        entry->name = talloc_strdup(entry, name);
        if ( ! entry->name) {
                DEBUG(0,("Out of memory!\n"));
                TALLOC_FREE(entry);
                return NT_STATUS_NO_MEMORY;
        }
        entry->methods = methods;

        DLIST_ADD(backends, entry);
        DEBUG(5, ("Successfully added idmap backend '%s'\n", name));
        return NT_STATUS_OK;
}

/**
 * Initialize a domain structure
 * @param[in] mem_ctx           memory context for the result
 * @param[in] domainname        which domain is this for
 * @param[in] modulename        which backend module
 * @param[in] check_range       whether range checking should be done
 * @result The initialized structure
 */
static struct idmap_domain *idmap_init_domain(TALLOC_CTX *mem_ctx,
                                              const char *domainname,
                                              const char *modulename,
                                              bool check_range)
{
        struct idmap_domain *result;
        NTSTATUS status;
        char *config_option = NULL;
        const char *range;

        result = talloc_zero(mem_ctx, struct idmap_domain);
        if (result == NULL) {
                DEBUG(0, ("talloc failed\n"));
                return NULL;
        }

        result->name = talloc_strdup(result, domainname);
        if (result->name == NULL) {
                DEBUG(0, ("talloc failed\n"));
                goto fail;
        }

        /*
         * load ranges and read only information from the config
         */

        config_option = talloc_asprintf(result, "idmap config %s",
                                        result->name);
        if (config_option == NULL) {
                DEBUG(0, ("Out of memory!\n"));
                goto fail;
        }

        range = lp_parm_const_string(-1, config_option, "range", NULL);
        if (range == NULL) {
                DEBUG(1, ("idmap range not specified for domain %s\n",
                          result->name));
                if (check_range) {
                        goto fail;
                }
        } else if (sscanf(range, "%u - %u", &result->low_id,
                          &result->high_id) != 2)
        {
                DEBUG(1, ("invalid range '%s' specified for domain "
                          "'%s'\n", range, result->name));
                if (check_range) {
                        goto fail;
                }
        }

        result->read_only = lp_parm_bool(-1, config_option, "read only", false);

        talloc_free(config_option);

        if (result->low_id > result->high_id) {
                DEBUG(1, ("Error: invalid idmap range detected: %lu - %lu\n",
                          (unsigned long)result->low_id,
                          (unsigned long)result->high_id));
                if (check_range) {
                        goto fail;
                }
        }

        result->methods = get_methods(modulename);
        if (result->methods == NULL) {
                DEBUG(3, ("idmap backend %s not found\n", modulename));

                status = smb_probe_module("idmap", modulename);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(3, ("Could not probe idmap module %s\n",
                                  modulename));
                        goto fail;
                }

                result->methods = get_methods(modulename);
        }
        if (result->methods == NULL) {
                DEBUG(1, ("idmap backend %s not found\n", modulename));
                goto fail;
        }

        status = result->methods->init(result);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("idmap initialization returned %s\n",
                          nt_errstr(status)));
                goto fail;
        }

        return result;

fail:
        TALLOC_FREE(result);
        return NULL;
}

/**
 * Initialize a named domain structure
 * @param[in] mem_ctx           memory context for the result
 * @param[in] domname           the domain name
 * @result The default domain structure
 *
 * This routine looks at the "idmap config <domname>" parameters to figure out
 * the configuration.
 */

static struct idmap_domain *idmap_init_named_domain(TALLOC_CTX *mem_ctx,
                                                    const char *domname)
{
        struct idmap_domain *result = NULL;
        char *config_option;
        const char *backend;

        idmap_init();

        config_option = talloc_asprintf(talloc_tos(), "idmap config %s",
                                        domname);
        if (config_option == NULL) {
                DEBUG(0, ("talloc failed\n"));
                goto fail;
        }

        backend = lp_parm_const_string(-1, config_option, "backend", NULL);
        if (backend == NULL) {
                DEBUG(1, ("no backend defined for %s\n", config_option));
                goto fail;
        }

        result = idmap_init_domain(mem_ctx, domname, backend, true);
        if (result == NULL) {
                goto fail;
        }

        TALLOC_FREE(config_option);
        return result;

fail:
        TALLOC_FREE(config_option);
        TALLOC_FREE(result);
        return NULL;
}

/**
 * Initialize the default domain structure
 * @param[in] mem_ctx           memory context for the result
 * @result The default domain structure
 *
 * This routine takes the module name from the "idmap backend" parameter,
 * passing a possible parameter like ldap:ldap://ldap-url/ to the module.
 */

static struct idmap_domain *idmap_init_default_domain(TALLOC_CTX *mem_ctx)
{
        return idmap_init_named_domain(mem_ctx, "*");
}

/**
 * Initialize the passdb domain structure
 * @param[in] mem_ctx           memory context for the result
 * @result The default domain structure
 *
 * No config, passdb has its own configuration.
 */

static struct idmap_domain *idmap_init_passdb_domain(TALLOC_CTX *mem_ctx)
{
        idmap_init();

        /*
         * Always init the default domain, we can't go without one
         */
        if (default_idmap_domain == NULL) {
                default_idmap_domain = idmap_init_default_domain(NULL);
        }
        if (default_idmap_domain == NULL) {
                return NULL;
        }

        if (passdb_idmap_domain != NULL) {
                return passdb_idmap_domain;
        }

        passdb_idmap_domain = idmap_init_domain(NULL, get_global_sam_name(),
                                                "passdb", false);
        if (passdb_idmap_domain == NULL) {
                DEBUG(1, ("Could not init passdb idmap domain\n"));
        }

        return passdb_idmap_domain;
}

/**
 * Find a domain struct according to a domain name
 * @param[in] domname           Domain name to get the config for
 * @result The default domain structure that fits
 *
 * This is the central routine in the winbindd-idmap child to pick the correct
 * domain for looking up IDs. If domname is NULL or empty, we use the default
 * domain. If it contains something, we try to use idmap_init_named_domain()
 * to fetch the correct backend.
 *
 * The choice about "domname" is being made by the winbind parent, look at the
 * "have_idmap_config" of "struct winbindd_domain" which is set in
 * add_trusted_domain.
 */

static struct idmap_domain *idmap_find_domain(const char *domname)
{
        struct idmap_domain *result;
        int i;

        DEBUG(10, ("idmap_find_domain called for domain '%s'\n",
                   domname?domname:"NULL"));

        idmap_init();

        /*
         * Always init the default domain, we can't go without one
         */
        if (default_idmap_domain == NULL) {
                default_idmap_domain = idmap_init_default_domain(NULL);
        }
        if (default_idmap_domain == NULL) {
                return NULL;
        }

        if ((domname == NULL) || (domname[0] == '\0')) {
                return default_idmap_domain;
        }

        for (i=0; i<num_domains; i++) {
                if (strequal(idmap_domains[i]->name, domname)) {
                        return idmap_domains[i];
                }
        }

        if (idmap_domains == NULL) {
                /*
                 * talloc context for all idmap domains
                 */
                idmap_domains = TALLOC_ARRAY(NULL, struct idmap_domain *, 1);
        }

        if (idmap_domains == NULL) {
                DEBUG(0, ("talloc failed\n"));
                return NULL;
        }

        result = idmap_init_named_domain(idmap_domains, domname);
        if (result == NULL) {
                /*
                 * Could not init that domain -- try the default one
                 */
                return default_idmap_domain;
        }

        ADD_TO_ARRAY(idmap_domains, struct idmap_domain *, result,
                     &idmap_domains, &num_domains);
        return result;
}

void idmap_close(void)
{
        TALLOC_FREE(default_idmap_domain);
        TALLOC_FREE(passdb_idmap_domain);
        TALLOC_FREE(idmap_domains);
        num_domains = 0;
}

/**************************************************************************
 idmap allocator interface functions
**************************************************************************/

static NTSTATUS idmap_allocate_unixid(struct unixid *id)
{
        struct idmap_domain *dom;
        NTSTATUS ret;

        dom = idmap_find_domain(NULL);

        if (dom == NULL) {
                return NT_STATUS_UNSUCCESSFUL;
        }

        if (dom->methods->allocate_id == NULL) {
                return NT_STATUS_NOT_IMPLEMENTED;
        }

        ret = dom->methods->allocate_id(dom, id);

        return ret;
}


NTSTATUS idmap_allocate_uid(struct unixid *id)
{
        id->type = ID_TYPE_UID;
        return idmap_allocate_unixid(id);
}

NTSTATUS idmap_allocate_gid(struct unixid *id)
{
        id->type = ID_TYPE_GID;
        return idmap_allocate_unixid(id);
}

NTSTATUS idmap_backends_unixid_to_sid(const char *domname, struct id_map *id)
{
        struct idmap_domain *dom;
        struct id_map *maps[2];

         DEBUG(10, ("idmap_backend_unixid_to_sid: domain = '%s', xid = %d "
                    "(type %d)\n",
                    domname?domname:"NULL", id->xid.id, id->xid.type));

        maps[0] = id;
        maps[1] = NULL;

        /*
         * Always give passdb a chance first
         */

        dom = idmap_init_passdb_domain(NULL);
        if ((dom != NULL)
            && NT_STATUS_IS_OK(dom->methods->unixids_to_sids(dom, maps))
            && id->status == ID_MAPPED) {
                return NT_STATUS_OK;
        }

        dom = idmap_find_domain(domname);
        if (dom == NULL) {
                return NT_STATUS_NONE_MAPPED;
        }

        return dom->methods->unixids_to_sids(dom, maps);
}

NTSTATUS idmap_backends_sid_to_unixid(const char *domain, struct id_map *id)
{
        struct idmap_domain *dom;
        struct id_map *maps[2];

        DEBUG(10, ("idmap_backends_sid_to_unixid: domain = '%s', sid = [%s]\n",
                   domain?domain:"NULL", sid_string_dbg(id->sid)));

        maps[0] = id;
        maps[1] = NULL;

        if (sid_check_is_in_builtin(id->sid)
            || (sid_check_is_in_our_domain(id->sid)))
        {
                NTSTATUS status;

                DEBUG(10, ("asking passdb...\n"));

                dom = idmap_init_passdb_domain(NULL);
                if (dom == NULL) {
                        return NT_STATUS_NONE_MAPPED;
                }
                status = dom->methods->sids_to_unixids(dom, maps);

                if (NT_STATUS_IS_OK(status) && id->status == ID_MAPPED) {
                        return status;
                }

                DEBUG(10, ("passdb could not map.\n"));

                return NT_STATUS_NONE_MAPPED;
        }

        dom = idmap_find_domain(domain);
        if (dom == NULL) {
                return NT_STATUS_NONE_MAPPED;
        }

        return dom->methods->sids_to_unixids(dom, maps);
}