switch.c

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/*
 *   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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: eb3adecdd471407c6a8955bddab5bfe09877e686 $
 *
 * @file unlang/switch.c
 * @brief Unlang "switch" keyword evaluation.
 *
 * @copyright 2006-2019 The FreeRADIUS server project
 */
RCSID("$Id: eb3adecdd471407c6a8955bddab5bfe09877e686 $")
 
#include "group_priv.h"
#include "switch_priv.h"
 
static unlang_action_t unlang_switch(rlm_rcode_t *p_result, request_t *request, unlang_stack_frame_t *frame)
{
        unlang_t                *found;
 
        unlang_group_t          *switch_g;
        unlang_switch_t         *switch_gext;
 
        tmpl_t                  vpt;
        fr_value_box_t const    *box = NULL;
 
        fr_pair_t               *vp;
 
        /*
         *      Mock up an unlang_cast_t.  Note that these on-stack
         *      buffers are the reason why case_cmp(), case_hash(),
         *      and case_to_key() use direct casts, and not the
         *      "generic to x" functions.
         */
        tmpl_t                  case_vpt = (tmpl_t) {
                                        .type = TMPL_TYPE_DATA,
                                };
        unlang_case_t           my_case = (unlang_case_t) {
                                        .group = (unlang_group_t) {
                                                .self = (unlang_t) {
                                                        .type = UNLANG_TYPE_CASE,
                                                },
                                        },
                                        .vpt = &case_vpt,
                                };
 
        switch_g = unlang_generic_to_group(frame->instruction);
        switch_gext = unlang_group_to_switch(switch_g);
 
        found = NULL;
 
        /*
         *      The attribute doesn't exist.  We can skip
         *      directly to the default 'case' statement.
         */
        if (tmpl_is_attr(switch_gext->vpt)) {
                if (tmpl_find_vp(&vp, request, switch_gext->vpt) < 0) {
                        found = switch_gext->default_case;
                        goto do_null_case;
                } else {
                        box = &vp->data;
                }
 
        /*
         *      Expand the template if necessary, so that it
         *      is evaluated once instead of for each 'case'
         *      statement.
         */
        } else if (tmpl_is_xlat(switch_gext->vpt) ||
                   tmpl_is_xlat_unresolved(switch_gext->vpt) ||
                   tmpl_is_exec(switch_gext->vpt)) {
                char *p;
                ssize_t len;
 
                len = tmpl_aexpand(request, &p, request, switch_gext->vpt, NULL, NULL);
                if (len < 0) goto find_null_case;
 
                tmpl_init_shallow(&vpt, TMPL_TYPE_DATA, T_SINGLE_QUOTED_STRING, p, len, NULL);
                fr_value_box_bstrndup_shallow(&vpt.data.literal, NULL, p, len, false);
                box = tmpl_value(&vpt);
        } else if (!fr_cond_assert_msg(0, "Invalid tmpl type %s", tmpl_type_to_str(switch_gext->vpt->type))) {
                return UNLANG_ACTION_FAIL;
        }
 
        /*
         *      case_gext->vpt.data.literal is an in-line box, so we
         *      have to make a shallow copy of its contents.
         *
         *      Note: We do not pass a ctx here as we don't want to
         *      create a reference.
         */
        fr_value_box_copy_shallow(NULL, &case_vpt.data.literal, box);
        found = fr_htrie_find(switch_gext->ht, &my_case);
        if (!found) {
        find_null_case:
                found = switch_gext->default_case;
        }
 
do_null_case:
        if (box == tmpl_value(&vpt)) fr_value_box_clear_value(&vpt.data.literal);
 
        /*
         *      Nothing found.  Just continue, and ignore the "switch"
         *      statement.
         */
        if (!found) return UNLANG_ACTION_EXECUTE_NEXT;
 
        if (unlang_interpret_push(request, found, frame->result, UNLANG_NEXT_STOP, UNLANG_SUB_FRAME) < 0) {
                *p_result = RLM_MODULE_FAIL;
                return UNLANG_ACTION_STOP_PROCESSING;
        }
 
        return UNLANG_ACTION_PUSHED_CHILD;
}
 
 
static unlang_action_t unlang_case(rlm_rcode_t *p_result, request_t *request, unlang_stack_frame_t *frame)
{
        unlang_group_t          *g = unlang_generic_to_group(frame->instruction);
 
        if (!g->children) {
                *p_result = RLM_MODULE_NOOP;
                return UNLANG_ACTION_CALCULATE_RESULT;
        }
 
        return unlang_group(p_result, request, frame);
}
 
void unlang_switch_init(void)
{
        unlang_register(UNLANG_TYPE_SWITCH,
                           &(unlang_op_t){
                                .name = "switch",
                                .interpret = unlang_switch,
                                .debug_braces = true
                           });
 
        unlang_register(UNLANG_TYPE_CASE,
                           &(unlang_op_t){
                                .name = "case",
                                .interpret = unlang_case,
                                .debug_braces = true
                           });
}