src/notifier.c

   1 /*
   2  * transsip - the telephony toolkit
   3  * By Daniel Borkmann <daniel@transsip.org>
   4  * Copyright 2011, 2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
   5  * Swiss federal institute of technology (ETH Zurich)
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 #include <stdint.h>
  10 #include <errno.h>
  11
  12 #include "notifier.h"
  13 #include "built_in.h"
  14
  15 int register_event_hook(struct event_block **head,
  16                         struct event_block *block)
  17 {
  18         if (!block || !head)
  19                 return -EINVAL;
  20         if (!block->hook)
  21                 return -EINVAL;
  22
  23         while ((*head) != NULL) {
  24                 if (block->prio > (*head)->prio)
  25                         break;
  26
  27                 head = &((*head)->next);
  28         }
  29
  30         block->next = (*head);
  31         (*head) = block;
  32
  33         return 0;
  34 }
  35
  36 int register_event_hook_once(struct event_block **head,
  37                              struct event_block *block)
  38 {
  39         if (!block || !head)
  40                 return -EINVAL;
  41         if (!block->hook)
  42                 return -EINVAL;
  43
  44         while ((*head) != NULL) {
  45                 if (unlikely(block == (*head)))
  46                         return -EEXIST;
  47
  48                 if (block->prio > (*head)->prio)
  49                         break;
  50
  51                 head = &((*head)->next);
  52         }
  53
  54         block->next = (*head);
  55         (*head) = block;
  56
  57         return 0;
  58 }
  59
  60 int unregister_event_hook(struct event_block **head,
  61                           struct event_block *block)
  62 {
  63         if (!block || !head)
  64                 return -EINVAL;
  65
  66         while ((*head) != NULL) {
  67                 if (unlikely(block == (*head))) {
  68                         (*head) = block->next;
  69                         break;
  70                 }
  71
  72                 head = &((*head)->next);
  73         }
  74
  75         return 0;
  76 }
  77
  78 int call_event_hooks(struct event_block **head, unsigned long event,
  79                      const void *arg, int *called)
  80 {
  81         int ret = BLOCK_SUCC_DONE;
  82         struct event_block *block = *head, *next_block;
  83
  84         if (!head || !arg)
  85                 return -EINVAL;
  86         if (called)
  87                 (*called) = 0;
  88
  89         while (block) {
  90                 next_block = block->next;
  91
  92                 ret = block->hook(block, event, arg);
  93                 if (ret & BLOCK_STOP_CHAIN)
  94                         break;
  95
  96                 if(called)
  97                         (*called)++;
  98
  99                 block = next_block;
 100         }
 101
 102         return ret;
 103 }