hackedteam/vector-ipa

/*
    MODULE -- hook points handling

    Copyright (C) Alberto Ornaghi 

    $Id: hook.c 790 2009-08-03 14:34:04Z alor $
*/

#include <main.h>
#include <hook.h>
#include <packet.h>

#include <pthread.h>

struct hook_list {
   int point;
   void (*func)(struct packet_object *po);
   LIST_ENTRY (hook_list) next;
};

/* global data */

/* the list for the HOOK_* */
static LIST_HEAD(, hook_list) hook_list_head;
/* the list for the PACKET_* */
static LIST_HEAD(, hook_list) hook_pck_list_head;

pthread_mutex_t hook_mutex = PTHREAD_MUTEX_INITIALIZER;
#define HOOK_LOCK     do{ pthread_mutex_lock(&hook_mutex); } while(0)
#define HOOK_UNLOCK   do{ pthread_mutex_unlock(&hook_mutex); } while(0)
   
pthread_mutex_t hook_pck_mutex = PTHREAD_MUTEX_INITIALIZER;
#define HOOK_PCK_LOCK     do{ pthread_mutex_lock(&hook_pck_mutex); } while(0)
#define HOOK_PCK_UNLOCK   do{ pthread_mutex_unlock(&hook_pck_mutex); } while(0)

/* protos... */

void hook_point(int point, struct packet_object *po);
void hook_add(int point, void (*func)(struct packet_object *po) );
int hook_del(int point, void (*func)(struct packet_object *po) );

/*******************************************/

/* execute the functions registered in that hook point */

void hook_point(int point, struct packet_object *po)
{
   struct hook_list *current;

   /* the hook is for a HOOK_PACKET_* type */
   if (point > HOOK_PACKET_BASE) {
      
      HOOK_PCK_LOCK;
   
      LIST_FOREACH(current, &hook_pck_list_head, next) 
         if (current->point == point)
            current->func(po);
   
      HOOK_PCK_UNLOCK;
   
   } else {
   
      HOOK_LOCK;
   
      LIST_FOREACH(current, &hook_list_head, next) 
         if (current->point == point)
            current->func(po);
   
      HOOK_UNLOCK;
   }
   
   return;
}


/* add a function to an hook point */

void hook_add(int point, void (*func)(struct packet_object *po) )
{
   struct hook_list *newelem;

   SAFE_CALLOC(newelem, 1, sizeof(struct hook_list));
              
   newelem->point = point;
   newelem->func = func;

   /* the hook is for a HOOK_PACKET_* type */
   if (point > HOOK_PACKET_BASE) {
      HOOK_PCK_LOCK;
      LIST_INSERT_HEAD(&hook_pck_list_head, newelem, next);
      HOOK_PCK_UNLOCK;
   } else {
      HOOK_LOCK;
      LIST_INSERT_HEAD(&hook_list_head, newelem, next);
      HOOK_UNLOCK;
   }
   
}

/* remove a function from an hook point */

int hook_del(int point, void (*func)(struct packet_object *po) )
{
   struct hook_list *current;


   /* the hook is for a HOOK_PACKET_* type */
   if (point > HOOK_PACKET_BASE) {
      HOOK_PCK_LOCK;
   
      LIST_FOREACH(current, &hook_pck_list_head, next) {
         if (current->point == point && current->func == func) {
            LIST_REMOVE(current, next);
            SAFE_FREE(current);
            HOOK_PCK_UNLOCK;
            DEBUG_MSG(D_DEBUG, "hook_del -- %d [%p]", point, func);
            return ESUCCESS;
         }
      }
 
      HOOK_PCK_UNLOCK;
   } else {
      HOOK_LOCK;
   
      LIST_FOREACH(current, &hook_list_head, next) {
         if (current->point == point && current->func == func) {
            LIST_REMOVE(current, next);
            SAFE_FREE(current);
            HOOK_UNLOCK;
            DEBUG_MSG(D_DEBUG, "hook_del -- %d [%p]", point, func);
            return ESUCCESS;
         }
      }
 
      HOOK_UNLOCK;
   }
   
   return -ENOTFOUND;
}


/* EOF */

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