lib/hook.c

   1 // SPDX-License-Identifier: ISC
   2 /*
   3  * Copyright (c) 2016  David Lamparter, for NetDEF, Inc.
   4  */
   5
   6 #ifdef HAVE_CONFIG_H
   7 #include "config.h"
   8 #endif
   9
  10 #include <string.h>
  11
  12 #include "memory.h"
  13 #include "hook.h"
  14
  15 DEFINE_MTYPE_STATIC(LIB, HOOK_ENTRY, "Hook entry");
  16
  17 void _hook_register(struct hook *hook, struct hookent *stackent, void *funcptr,
  18                     void *arg, bool has_arg, struct frrmod_runtime *module,
  19                     const char *funcname, int priority)
  20 {
  21         struct hookent *he, **pos;
  22
  23         if (!stackent->ent_used)
  24                 he = stackent;
  25         else {
  26                 he = XCALLOC(MTYPE_HOOK_ENTRY, sizeof(*he));
  27                 he->ent_on_heap = true;
  28         }
  29         he->ent_used = true;
  30         he->hookfn = funcptr;
  31         he->hookarg = arg;
  32         he->has_arg = has_arg;
  33         he->module = module;
  34         he->fnname = funcname;
  35         he->priority = priority;
  36
  37         for (pos = &hook->entries; *pos; pos = &(*pos)->next)
  38                 if (hook->reverse ? (*pos)->priority < priority
  39                                   : (*pos)->priority >= priority)
  40                         break;
  41
  42         he->next = *pos;
  43         *pos = he;
  44 }
  45
  46 void _hook_unregister(struct hook *hook, void *funcptr, void *arg, bool has_arg)
  47 {
  48         struct hookent *he, **prev;
  49
  50         for (prev = &hook->entries; (he = *prev) != NULL; prev = &he->next)
  51                 if (he->hookfn == funcptr && he->hookarg == arg
  52                     && he->has_arg == has_arg) {
  53                         *prev = he->next;
  54                         if (he->ent_on_heap)
  55                                 XFREE(MTYPE_HOOK_ENTRY, he);
  56                         else
  57                                 memset(he, 0, sizeof(*he));
  58                         break;
  59                 }
  60 }