lib/hook.c

   1 /*
   2  * Copyright (c) 2016  David Lamparter, for NetDEF, Inc.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <string.h>
  22
  23 #include "memory.h"
  24 #include "hook.h"
  25
  26 DEFINE_MTYPE_STATIC(LIB, HOOK_ENTRY, "Hook entry")
  27
  28 void _hook_register(struct hook *hook, struct hookent *stackent, void *funcptr,
  29                     void *arg, bool has_arg, struct frrmod_runtime *module,
  30                     const char *funcname, int priority)
  31 {
  32         struct hookent *he, **pos;
  33
  34         if (!stackent->ent_used)
  35                 he = stackent;
  36         else {
  37                 he = XCALLOC(MTYPE_HOOK_ENTRY, sizeof(*he));
  38                 he->ent_on_heap = true;
  39         }
  40         he->ent_used = true;
  41         he->hookfn = funcptr;
  42         he->hookarg = arg;
  43         he->has_arg = has_arg;
  44         he->module = module;
  45         he->fnname = funcname;
  46         he->priority = priority;
  47
  48         for (pos = &hook->entries; *pos; pos = &(*pos)->next)
  49                 if (hook->reverse ? (*pos)->priority < priority
  50                                   : (*pos)->priority >= priority)
  51                         break;
  52
  53         he->next = *pos;
  54         *pos = he;
  55 }
  56
  57 void _hook_unregister(struct hook *hook, void *funcptr, void *arg, bool has_arg)
  58 {
  59         struct hookent *he, **prev;
  60
  61         for (prev = &hook->entries; (he = *prev) != NULL; prev = &he->next)
  62                 if (he->hookfn == funcptr && he->hookarg == arg
  63                     && he->has_arg == has_arg) {
  64                         *prev = he->next;
  65                         if (he->ent_on_heap)
  66                                 XFREE(MTYPE_HOOK_ENTRY, he);
  67                         else
  68                                 memset(he, 0, sizeof(*he));
  69                         break;
  70                 }
  71 }