map_proc.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: 7b885f40b9d6c73144fb67d24104f4e64d226782 $
 *
 * @brief Map processor functions
 * @file src/lib/server/map_proc.c
 *
 * @copyright 2015 The FreeRADIUS server project
 * @copyright 2015 Arran Cudbard-bell (a.cudbardb@freeradius.org)
 */
 
RCSID("$Id: 7b885f40b9d6c73144fb67d24104f4e64d226782 $")
 
#include <freeradius-devel/server/base.h>
 
static fr_rb_tree_t *map_proc_root = NULL;
 
/** Compare two map_proc_t structs, based ONLY on the name
 *
 * @param[in] one First map struct.
 * @param[in] two Second map struct.
 * @return Integer specifying order of map func instances.
 */
static fr_cmp_ret_t map_proc_cmp(void const *one, void const *two)
{
        map_proc_t const *a = one, *b = two;
 
        return MEMCMP_FIELDS(a, b, name, length);
}
 
/** Unregister a map processor
 *
 * @param[in] proc to unregister.
 */
static int _map_proc_talloc_free(map_proc_t *proc)
{
        map_proc_t find;
        map_proc_t *found;
 
        if (!map_proc_root) return 0;
 
        strlcpy(find.name, proc->name, sizeof(find.name));
        find.length = strlen(find.name);
 
        fr_rb_find((void **)&found, map_proc_root, &find);
        if (!found) return 0;
 
        fr_rb_delete(map_proc_root, found);
 
        return 0;
}
 
fr_value_box_safe_for_t map_proc_literals_safe_for(map_proc_t const *proc)
{
        return proc->literals_safe_for;
}
 
/** Find a map processor by name
 *
 * @param[in] name of map processor.
 * @return
 *      - #map_proc matching name.
 *      - NULL if none was found.
 */
map_proc_t *map_proc_find(char const *name)
{
        map_proc_t find;
        map_proc_t *found;
 
        if (!map_proc_root) return NULL;
 
        strlcpy(find.name, name, sizeof(find.name));
        find.length = strlen(find.name);
 
        fr_rb_find((void **)&found, map_proc_root, &find);
 
        return found;
}
 
static int _map_proc_tree_init(UNUSED void *uctx)
{
        MEM(map_proc_root = fr_rb_inline_talloc_alloc(NULL, map_proc_t, node, map_proc_cmp, NULL));
        return 0;
}
 
static int _map_proc_tree_free(UNUSED void *uctx)
{
        fr_rb_tree_t *mpr = map_proc_root;
 
        fr_assert_msg(fr_rb_num_elements(mpr) == 0, "map_proc_t still registered");
 
        map_proc_root = NULL;
        talloc_free(mpr);
        return 0;
}
 
/** Register a map processor
 *
 * This should be called by every module that provides a map processing function.
 *
 * @param[in] ctx               if non-null, the ctx to bind this map processor to.
 * @param[in] mod_inst          of module registering the map_proc.
 * @param[in] name              of map processor. If processor already exists, it is replaced.
 * @param[in] evaluate          Module's map processor function.
 * @param[in] instantiate       function (optional).
 * @param[in] inst_size         of talloc chunk to allocate for instance data (optional).
 * @param[in] literals_safe_for What safe_for value to assign to literals.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int map_proc_register(TALLOC_CTX *ctx, void const *mod_inst, char const *name,
                      map_proc_func_t evaluate,
                      map_proc_instantiate_t instantiate, size_t inst_size, fr_value_box_safe_for_t literals_safe_for)
{
        map_proc_t *proc;
 
        fr_assert(name && name[0]);
 
        fr_atexit_global_once(_map_proc_tree_init, _map_proc_tree_free, NULL);
 
        /*
         *      If it already exists, replace it.
         */
        proc = map_proc_find(name);
        if (!proc) {
                /*
                *       Don't allocate directly in the parent ctx, it might be mprotected
                *       later, and that'll cause segfaults if any of the map_proc_t are still
                *       protected when we start shuffling the contents of the rbtree.
                */
                proc = talloc_zero(NULL, map_proc_t);
                if (ctx) talloc_link_ctx(ctx, proc);
 
                strlcpy(proc->name, name, sizeof(proc->name));
                proc->length = strlen(proc->name);
 
                if (fr_rb_replace(NULL, map_proc_root, proc) < 0) {
                        talloc_free(proc);
                        return -1;
                }
 
                talloc_set_destructor(proc, _map_proc_talloc_free);
        }
 
        DEBUG3("map_proc_register: %s", proc->name);
 
        proc->mod_inst = mod_inst;
        proc->evaluate = evaluate;
        proc->instantiate = instantiate;
        proc->inst_size = inst_size;
        proc->literals_safe_for = literals_safe_for;
 
        return 0;
}
 
/** Unregister a map processor by name
 *
 * @param[in] name      of map processor to unregister.
 * @return
 *      - 0 if map processor was found and unregistered.
 *      - -1 if map processor was not found.
 */
int map_proc_unregister(char const *name)
{
        map_proc_t *proc;
 
        proc = map_proc_find(name);
        if (proc) {
                talloc_free(proc);
                return 0;
        }
 
        return -1;
}
 
 
/** Create a new map proc instance
 *
 * This should be called for every map {} section in the configuration.
 *
 * @param[in] ctx       to allocate proc instance in.
 * @param[in] proc      resolved with #map_proc_find.
 * @param[in] cs        #CONF_SECTION representing this instance of a map processor.
 * @param[in] src       template.
 * @param[in] maps      Head of the list of maps.
 * @return
 *      - New #map_proc_inst_t on success.
 *      - NULL on error.
 */
map_proc_inst_t *map_proc_instantiate(TALLOC_CTX *ctx, map_proc_t const *proc,
                                      CONF_SECTION *cs, tmpl_t const *src, map_list_t const *maps)
{
        map_proc_inst_t *inst;
 
        inst = talloc_zero(ctx, map_proc_inst_t);
        inst->proc = proc;
        inst->src = src;
        inst->maps = maps;
 
        if (proc->instantiate) {
                if (proc->inst_size > 0) {
                        inst->data = talloc_zero_array(inst, uint8_t, proc->inst_size);
                        if (!inst->data) return NULL;
                }
 
                if (proc->instantiate(cs, proc->mod_inst, inst->data, src, maps) < 0) {
                        talloc_free(inst);
                        return NULL;
                }
        }
 
        return inst;
}