Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
       3             :  *
       4             :  * This file is part of Quagga
       5             :  *
       6             :  * Quagga is free software; you can redistribute it and/or modify it
       7             :  * under the terms of the GNU General Public License as published by the
       8             :  * Free Software Foundation; either version 2, or (at your option) any
       9             :  * later version.
      10             :  *
      11             :  * Quagga is distributed in the hope that it will be useful, but
      12             :  * WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14             :  * General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU General Public License along
      17             :  * with this program; see the file COPYING; if not, write to the Free Software
      18             :  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
      19             :  */
      20             : 
      21             : #include <zebra.h>
      22             : 
      23             : #include "thread.h"
      24             : #include "memory.h"
      25             : #include "hash.h"
      26             : #include "log.h"
      27             : #include "qobj.h"
      28             : #include "jhash.h"
      29             : #include "network.h"
      30             : 
      31          50 : static uint32_t qobj_hash(const struct qobj_node *node)
      32             : {
      33          50 :         return (uint32_t)node->nid;
      34             : }
      35             : 
      36          12 : static int qobj_cmp(const struct qobj_node *na, const struct qobj_node *nb)
      37             : {
      38          12 :         if (na->nid < nb->nid)
      39             :                 return -1;
      40          12 :         if (na->nid > nb->nid)
      41             :                 return 1;
      42             :         return 0;
      43             : }
      44             : 
      45         221 : DECLARE_HASH(qobj_nodes, struct qobj_node, nodehash,
      46             :                         qobj_cmp, qobj_hash);
      47             : 
      48             : static pthread_rwlock_t nodes_lock;
      49             : static struct qobj_nodes_head nodes = { };
      50             : 
      51             : 
      52          21 : void qobj_reg(struct qobj_node *node, const struct qobj_nodetype *type)
      53             : {
      54          21 :         node->type = type;
      55          21 :         pthread_rwlock_wrlock(&nodes_lock);
      56          21 :         do {
      57          21 :                 node->nid = (uint64_t)frr_weak_random();
      58          21 :                 node->nid ^= (uint64_t)frr_weak_random() << 32;
      59          42 :         } while (!node->nid || qobj_nodes_find(&nodes, node));
      60          21 :         qobj_nodes_add(&nodes, node);
      61          21 :         pthread_rwlock_unlock(&nodes_lock);
      62          21 : }
      63             : 
      64          17 : void qobj_unreg(struct qobj_node *node)
      65             : {
      66          17 :         pthread_rwlock_wrlock(&nodes_lock);
      67          17 :         qobj_nodes_del(&nodes, node);
      68          17 :         pthread_rwlock_unlock(&nodes_lock);
      69          17 : }
      70             : 
      71           0 : struct qobj_node *qobj_get(uint64_t id)
      72             : {
      73           0 :         struct qobj_node dummy = {.nid = id}, *rv;
      74           0 :         pthread_rwlock_rdlock(&nodes_lock);
      75           0 :         rv = qobj_nodes_find(&nodes, &dummy);
      76           0 :         pthread_rwlock_unlock(&nodes_lock);
      77           0 :         return rv;
      78             : }
      79             : 
      80          12 : void *qobj_get_typed(uint64_t id, const struct qobj_nodetype *type)
      81             : {
      82          12 :         struct qobj_node dummy = {.nid = id};
      83          12 :         struct qobj_node *node;
      84          12 :         void *rv;
      85             : 
      86          12 :         pthread_rwlock_rdlock(&nodes_lock);
      87          12 :         node = qobj_nodes_find(&nodes, &dummy);
      88             : 
      89             :         /* note: we explicitly hold the lock until after we have checked the
      90             :          * type.
      91             :          * if the caller holds a lock that for example prevents the deletion of
      92             :          * route-maps, we can still race against a delete of something that
      93             :          * isn't
      94             :          * a route-map. */
      95          12 :         if (!node || node->type != type)
      96             :                 rv = NULL;
      97             :         else
      98          12 :                 rv = (char *)node - node->type->node_member_offset;
      99             : 
     100          12 :         pthread_rwlock_unlock(&nodes_lock);
     101          12 :         return rv;
     102             : }
     103             : 
     104           6 : void qobj_init(void)
     105             : {
     106           6 :         pthread_rwlock_init(&nodes_lock, NULL);
     107           6 :         qobj_nodes_init(&nodes);
     108           6 : }
     109             : 
     110           4 : void qobj_finish(void)
     111             : {
     112           4 :         struct qobj_node *node;
     113           8 :         while ((node = qobj_nodes_pop(&nodes)))
     114           4 :                 qobj_nodes_del(&nodes, node);
     115           4 :         pthread_rwlock_destroy(&nodes_lock);
     116           4 : }