map.c

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/*
 *   This program is 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: a00fade6649731a05920c07d638977d893320820 $
 * @file src/lib/ldap/map.c
 * @brief Functions for mapping between LDAP and FreeRADIUS attributes.
 *
 * @author Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 * @copyright 2013 Network RADIUS SAS (legal@networkradius.com)
 * @copyright 2013 The FreeRADIUS Server Project.
 */
RCSID("$Id: a00fade6649731a05920c07d638977d893320820 $")
 
USES_APPLE_DEPRECATED_API
 
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/ldap/base.h>
 
/** Callback for map_to_request
 *
 * Performs exactly the same job as map_to_vp, but pulls attribute values from LDAP entries
 *
 * @see map_to_vp
 */
int fr_ldap_map_getvalue(TALLOC_CTX *ctx, fr_pair_list_t *out, request_t *request, map_t const *map, void *uctx)
{
        fr_ldap_result_t        *self = uctx;
        fr_pair_list_t          head;
        fr_pair_t               *vp;
        int                     i;
 
        fr_pair_list_init(&head);
 
        fr_assert(map->lhs->type == TMPL_TYPE_ATTR);
 
        /*
         *      This is a mapping in the form of:
         *              <list>. += <ldap attr>
         *
         *      Where <ldap attr> is:
         *              <list>.<attr> <op> <value>
         *
         *      It is to allow for legacy installations which stored
         *      RADIUS control and reply attributes in separate LDAP
         *      attributes.
         */
        if (tmpl_is_list(map->lhs)) {
                for (i = 0; i < self->count; i++) {
                        map_t   *attr = NULL;
                        char    *attr_str;
 
                        tmpl_rules_t    lhs_rules = {
                                .attr = {
                                        .dict_def = request->local_dict,
                                        .request_def = tmpl_request(map->lhs),
                                        .list_def = tmpl_list(map->lhs),
                                },
                                .xlat = {
                                        .runtime_el = unlang_interpret_event_list(request),
                                },
                                .at_runtime = true,
                        };
 
                        tmpl_rules_t rhs_rules = {
                                .attr = {
                                        .dict_def = request->local_dict
                                },
                                .xlat = {
                                        .runtime_el = lhs_rules.xlat.runtime_el,
                                },
                                .at_runtime = true,
                        };
 
                        RDEBUG3("Parsing valuepair string \"%pV\"",
                                fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len));
 
                        /*
                         *      bv_val is NOT \0 terminated, so we need to make it
                         *      safe (\0 terminate it) before passing it to any
                         *      functions which take C strings and no lengths.
                         */
                        attr_str = talloc_bstrndup(NULL, self->values[i]->bv_val, self->values[i]->bv_len);
                        if (!attr_str) {
                                RWDEBUG("Failed making attribute string safe");
                                continue;
                        }
 
                        if (map_afrom_attr_str(ctx, &attr,
                                               attr_str,
                                               &lhs_rules, &rhs_rules) < 0) {
                                RPWDEBUG("Failed parsing \"%pV\" as valuepair, skipping...",
                                         fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len));
                                talloc_free(attr_str);
                                continue;
                        }
 
                        talloc_free(attr_str);
 
                        if (tmpl_is_data_unresolved(attr->lhs)) {
                            RWDEBUG("Failed parsing left side of \"%pV\", skipping...",
                                        fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len));
                                talloc_free(attr);
                                continue;
                        }
 
                        if (tmpl_request_ref_list_cmp(tmpl_request(attr->lhs), tmpl_request(map->lhs)) != 0) {
                                char *attr_request;
                                char *map_request;
 
                                tmpl_request_ref_list_aprint(NULL, &attr_request, tmpl_request(attr->lhs));
                                tmpl_request_ref_list_aprint(NULL, &map_request, tmpl_request(map->lhs));
 
                                RWDEBUG("valuepair \"%pV\" has conflicting request qualifier (%s vs %s), skipping...",
                                        fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len),
                                        attr_request, map_request);
 
                                talloc_free(attr_request);
                                talloc_free(map_request);
 
                        next_pair:
                                talloc_free(attr);
                                continue;
                        }
 
                        if ((tmpl_list(attr->lhs) != tmpl_list(map->lhs))) {
                                RWDEBUG("valuepair \"%pV\" has conflicting list qualifier (%s vs %s), skipping...",
                                        fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len),
                                        tmpl_list_name(tmpl_list(attr->lhs), "<INVALID>"),
                                        tmpl_list_name(tmpl_list(map->lhs), "<INVALID>"));
                                goto next_pair;
                        }
 
                        if (map_to_request(request, attr, map_to_vp, NULL) < 0) {
                                RWDEBUG("Failed creating attribute for valuepair \"%pV\", skipping...",
                                        fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len));
                                goto next_pair;
                        }
 
                        talloc_free(attr);
 
                        /*
                         *      Only process the first value, unless the operator is +=
                         */
                        if (map->op != T_OP_ADD_EQ) break;
                }
                goto finish;
        }
 
        /*
         *      Iterate over all the retrieved values,
         *      don't try and be clever about changing operators
         *      just use whatever was set in the attribute map.
         */
        for (i = 0; i < self->count; i++) {
                if (!self->values[i]->bv_len) continue;
 
                MEM(vp = fr_pair_afrom_da(ctx, tmpl_attr_tail_da(map->lhs)));
 
                if (fr_pair_value_from_str(vp, self->values[i]->bv_val,
                                           self->values[i]->bv_len, NULL, true) < 0) {
                        RPWDEBUG("Failed parsing value \"%pV\" for attribute %s",
                                 fr_box_strvalue_len(self->values[i]->bv_val, self->values[i]->bv_len),
                                 tmpl_attr_tail_da(map->lhs)->name);
 
                        talloc_free(vp);
                        continue;
                }
 
                fr_pair_append(&head, vp);
 
                /*
                 *      Only process the first value, unless the operator is +=
                 */
                if (map->op != T_OP_ADD_EQ) break;
        }
 
finish:
        fr_pair_list_append(out, &head);
 
        return 0;
}
 
/** Callback for map_to_request
 *
 * Performs exactly the same job as map_to_vp, but pulls value from the entry DN.
 *
 * @see map_to_vp
 */
static int fr_ldap_map_getdn(TALLOC_CTX *ctx, fr_pair_list_t *out, request_t *request, map_t const *map, void *uctx)
{
        char const              *dn = uctx;
        fr_pair_t               *vp;
 
        fr_assert(map->lhs->type == TMPL_TYPE_ATTR);
        switch (tmpl_attr_tail_da(map->lhs)->type) {
        case FR_TYPE_STRING:
        case FR_TYPE_OCTETS:
                break;
 
        default:
                RERROR("Cannot store DN in %s",
                        fr_table_str_by_value(fr_type_table, tmpl_attr_tail_da(map->lhs)->type, "<INVALID>"));
                return -1;
        }
 
        MEM(vp = fr_pair_afrom_da(ctx, tmpl_attr_tail_da(map->lhs)));
 
        if (fr_pair_value_from_str(vp, dn, strlen(dn), NULL, true) < 0) {
                RPWDEBUG("Failed parsing value \"%pV\" for attribute %s", dn,
                                 tmpl_attr_tail_da(map->lhs)->name);
                talloc_free(vp);
        }
 
        fr_pair_append(out, vp);
 
        return 0;
}
 
int fr_ldap_map_verify(map_t *map, UNUSED void *instance)
{
        /*
         *      Destinations where we can put the fr_pair_ts we
         *      create using LDAP values.
         */
        switch (map->lhs->type) {
        case TMPL_TYPE_ATTR:
                break;
 
        case TMPL_TYPE_ATTR_UNRESOLVED:
                cf_log_err(map->ci, "Unknown attribute %s", tmpl_attr_tail_unresolved(map->lhs));
                return -1;
 
        default:
                cf_log_err(map->ci, "Left hand side of map must be an attribute or list, not a %s",
                           tmpl_type_to_str(map->lhs->type));
                return -1;
        }
 
        /*
         *      Sources we can use to get the name of the attribute
         *      we're retrieving from LDAP.
         */
        switch (map->rhs->type) {
        case TMPL_TYPE_XLAT_UNRESOLVED:
        case TMPL_TYPE_ATTR:
        case TMPL_TYPE_EXEC:
        case TMPL_TYPE_DATA:
                break;
 
        case TMPL_TYPE_ATTR_UNRESOLVED:
                cf_log_err(map->ci, "Unknown attribute %s", tmpl_attr_tail_unresolved(map->rhs));
                return -1;
 
        case TMPL_TYPE_DATA_UNRESOLVED:
                if (tmpl_resolve(map->rhs, NULL) < 0) {
                        cf_log_err(map->ci, "Invalid data %s", map->rhs->name);
                        return -1;
                }
                break;
 
        default:
                cf_log_err(map->ci, "Right hand side of map must be an xlat, attribute, exec, or literal, not a %s",
                           tmpl_type_to_str(map->rhs->type));
                return -1;
        }
 
        /*
         *      Only =, :=, += and -= operators are supported for LDAP mappings.
         */
        switch (map->op) {
        case T_OP_SET:
        case T_OP_EQ:
        case T_OP_SUB_EQ:
        case T_OP_ADD_EQ:
                break;
 
        default:
                cf_log_err(map->ci, "Operator \"%s\" not allowed for LDAP mappings",
                           fr_table_str_by_value(fr_tokens_table, map->op, "<INVALID>"));
                return -1;
        }
 
        return 0;
}
 
/** Expand values in an attribute map where needed
 *
 * @param[in] ctx               o allocate any dynamic expansions in.
 * @param[out] expanded         array of attributes. Need not be initialised (we'll initialise).
 * @param[in] request           The current request.
 * @param[in] maps              to expand.
 * @param[in] generic_attr      name to append to the attribute list.
 * @param[in] check_attr        name to append to the attribute list.
 * @param[in] fallthrough_attr  name to append to the attribute list.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int fr_ldap_map_expand(TALLOC_CTX *ctx, fr_ldap_map_exp_t *expanded, request_t *request, map_list_t const *maps,
                       char const *generic_attr, char const *check_attr, char const *fallthrough_attr)
{
        map_t const     *map = NULL;
        unsigned int    total = 0;
 
        TALLOC_CTX      *our_ctx = NULL;
        char const      *attr;
        char            attr_buff[1024 + 1];    /* X.501 says we need to support at least 1024 chars for attr names */
 
        while ((map = map_list_next(maps, map))) {
                if (tmpl_expand(&attr, attr_buff, sizeof(attr_buff), request, map->rhs) < 0) {
                        REDEBUG("Expansion of LDAP attribute \"%s\" failed", map->rhs->name);
                        TALLOC_FREE(our_ctx);
                        return -1;
                }
 
                /*
                 *      Dynamic value
                 */
                if (attr == attr_buff) {
                        if (!our_ctx) our_ctx = talloc_new(ctx);
                        expanded->attrs[total++] = talloc_strdup(our_ctx, attr_buff);
                        continue;
                }
                expanded->attrs[total++] = attr;
        }
 
        if (generic_attr) expanded->attrs[total++] = generic_attr;
        if (check_attr) expanded->attrs[total++] = check_attr;
        if (fallthrough_attr) expanded->attrs[total++] = fallthrough_attr;
 
        expanded->attrs[total] = NULL;
        expanded->count = total;
        expanded->maps = maps;
 
        return 0;
}
 
 
/** Convert attribute map into valuepairs
 *
 * Use the attribute map built earlier to convert LDAP values into valuepairs and insert them into whichever
 * list they need to go into.
 *
 * This is *NOT* atomic, but there's no condition for which we should error out...
 *
 * @param[in] request           Current request.
 * @param[in] check_attr        Treat attribute with this name as a condition to process the map.
 * @param[in] valuepair_attr    Treat attribute with this name as holding complete AVP definitions.
 * @param[in] expanded          attributes (rhs of map).
 * @param[in] entry             to retrieve attributes from.
 * @return
 *      - Number of maps successfully applied.
 *      - -1 on failure.
 */
int fr_ldap_map_do(request_t *request, char const *check_attr,
                   char const *valuepair_attr, fr_ldap_map_exp_t const *expanded, LDAPMessage *entry)
{
        map_t const             *map = NULL;
        unsigned int            total = 0;
        int                     applied = 0;    /* How many maps have been applied to the current request */
 
        fr_ldap_result_t        result;
        char const              *name;
        LDAP                    *handle = fr_ldap_handle_thread_local();
 
        if (check_attr) {
                struct berval   **values;
                int             count, i;
                tmpl_rules_t const parse_rules = {
                        .attr = {
                                .dict_def = request->local_dict,
                                .list_def = request_attr_request,
                        },
                        .xlat = {
                                .runtime_el = unlang_interpret_event_list(request),
                        },
                        .at_runtime = true,
                };
 
                values = ldap_get_values_len(handle, entry, check_attr);
                count = ldap_count_values_len(values);
 
                for (i = 0; i < count; i++) {
                        char                    *value = fr_ldap_berval_to_string(request, values[i]);
                        xlat_exp_head_t         *cond_expr = NULL;
                        fr_value_box_list_t     res;
 
                        RDEBUG3("Parsing condition %s", value);
 
                        if (xlat_tokenize_expression(request, &cond_expr,
                                                     &FR_SBUFF_IN(value, talloc_strlen(value)),
                                                     NULL, &parse_rules) < 0) {
                                RPEDEBUG("Failed parsing '%s' value \"%s\"", check_attr, value);
                        fail:
                                applied = -1;
                        free:
                                talloc_free(cond_expr);
                                talloc_free(value);
                                ldap_value_free_len(values);
                                return applied;
                        }
 
                        if (xlat_impure_func(cond_expr)) {
                                fr_strerror_const("Condition expression cannot depend on functions which call external databases");
                                goto fail;
                        }
 
                        RDEBUG2("Checking condition %s", value);
                        fr_value_box_list_init(&res);
                        if (unlang_xlat_eval(request, &res, request, cond_expr) < 0) {
                                RPEDEBUG("Failed evaluating condition");
                                goto fail;
                        }
                        if (!fr_value_box_list_head(&res) || !fr_value_box_is_truthy(fr_value_box_list_head(&res))) {
                                RDEBUG2("Failed match: skipping this profile");
                                fr_value_box_list_talloc_free(&res);
                                goto free;
                        }
                        talloc_free(value);
                        talloc_free(cond_expr);
                        fr_value_box_list_talloc_free(&res);
                }
                ldap_value_free_len(values);
        }
 
        while ((map = map_list_next(expanded->maps, map))) {
                int ret;
 
                name = expanded->attrs[total++];
 
                /*
                 *      Binary safe
                 */
                result.values = ldap_get_values_len(handle, entry, name);
                if (!result.values) {
                        /*
                         *  dn is different - it's not (normally) an LDAP attribute
                         *  so requires special handling.
                         */
                        if (strcmp(name, "dn") == 0) {
                                char *dn = ldap_get_dn(handle, entry);
                                fr_ldap_util_normalise_dn(dn, dn);
                                ret = map_to_request(request, map, fr_ldap_map_getdn, dn);
                                ldap_memfree(dn);
                                if (ret == -1) return -1;
                                applied++;
                                continue;
                        }
 
                        RDEBUG3("Attribute \"%s\" not found in LDAP object", name);
 
                        goto next;
                }
 
                /*
                 *      Find out how many values there are for the
                 *      attribute and extract all of them.
                 */
                result.count = ldap_count_values_len(result.values);
 
                /*
                 *      If something bad happened, just skip, this is probably
                 *      a case of the dst being incorrect for the current
                 *      request context
                 */
                ret = map_to_request(request, map, fr_ldap_map_getvalue, &result);
                if (ret == -1) return -1;       /* Fail */
 
                /*
                 *      How many maps we've processed
                 */
                applied++;
 
        next:
                ldap_value_free_len(result.values);
        }
 
 
        /*
         *      Retrieve any valuepair attributes from the result, these are generic values specifying
         *      a radius list, operator and value.
         */
        if (valuepair_attr) {
                struct berval   **values;
                int             count, i;
 
                values = ldap_get_values_len(handle, entry, valuepair_attr);
                count = ldap_count_values_len(values);
 
                for (i = 0; i < count; i++) {
                        map_t   *attr;
                        char            *value;
 
                        tmpl_rules_t const parse_rules = {
                                .attr = {
                                        .dict_def = request->local_dict,
                                        .list_def = request_attr_request,
                                },
                                .xlat = {
                                        .runtime_el = unlang_interpret_event_list(request),
                                },
                                .at_runtime = true,
                        };
 
                        value = fr_ldap_berval_to_string(request, values[i]);
                        RDEBUG3("Parsing attribute string '%s'", value);
                        if (map_afrom_attr_str(request, &attr, value,
                                               &parse_rules, &parse_rules) < 0) {
                                RPWDEBUG("Failed parsing '%s' value \"%s\" as valuepair, skipping...",
                                         valuepair_attr, value);
                                talloc_free(value);
                                continue;
                        }
                        if (map_to_request(request, attr, map_to_vp, NULL) < 0) {
                                RWDEBUG("Failed adding \"%s\" to request, skipping...", value);
                        } else {
                                applied++;
                        }
                        talloc_free(attr);
                        talloc_free(value);
                }
                ldap_value_free_len(values);
        }
 
        return applied;
}