h_table.c

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/*
 * $Id: h_table.c 5666 2009-03-03 12:13:46Z henningw $
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History
 * -------
 * 2003-03-06  200/INV to-tag list deallocation added;
 *             setting "kill_reason" moved in here -- it is moved
 *             from transaction state to a static var(jiri)
 * 2003-03-16  removed _TOTAG (jiri)
 * 2003-03-30  set_kr for requests only (jiri)
 * 2003-04-04  bug_fix: REQ_IN callback not called for local 
 *             UAC transactions (jiri)
 * 2003-09-12  timer_link->tg will be set only if EXTRA_DEBUG (andrei)
 * 2003-12-04  global callbacks replaceed with callbacks per transaction;
 *             completion callback merged into them as LOCAL_COMPETED (bogdan)
 * 2004-02-11  FIFO/CANCEL + alignments (hash=f(callid,cseq)) (uli+jiri)
 * 2004-02-13  t->is_invite and t->local replaced with flags;
 *             timer_link.payload removed (bogdan)
 * 2004-08-23  avp support added - move and remove avp list to/from
 *             transactions (bogdan)
 * 2007-01-25  DNS failover at transaction level added (bogdan)
 */

/*! \file
 * \brief TM :: Hash tables
 *
 * \ingroup tm
 * - Module: \ref tm
 */


#include <stdlib.h>


#include "../../mem/shm_mem.h"
#include "../../hash_func.h"
#include "../../dprint.h"
#include "../../md5utils.h"
#include "../../ut.h"
#include "../../error.h"
#include "t_reply.h"
#include "t_cancel.h"
#include "t_stats.h"
#include "h_table.h"
#include "fix_lumps.h" /* free_via_clen_lump */
#include "t_hooks.h"
#include "t_fwd.h"

static enum kill_reason kr;

/*! \brief pointer to the big table where all the transaction data
   lives */
static struct s_table*  tm_table;

int syn_branch = 1;


void reset_kr(void)
{
   kr = 0;
}

void set_kr( enum kill_reason _kr )
{
   kr|=_kr;
}


enum kill_reason get_kr(void) {
   return kr;
}


void lock_hash(int i) 
{
   lock(&tm_table->entrys[i].mutex);
}


void unlock_hash(int i) 
{
   unlock(&tm_table->entrys[i].mutex);
}


struct s_table* get_tm_table(void)
{
   return tm_table;
}


unsigned int transaction_count( void )
{
   unsigned int i;
   unsigned int count;

   count=0; 
   for (i=0; i<TM_TABLE_ENTRIES; i++) 
      count+=tm_table->entrys[i].cur_entries;
   return count;
}



void free_cell( struct cell* dead_cell )
{
   char *b;
   int i;
   struct sip_msg *rpl;
   struct totag_elem *tt, *foo;
   struct proxy_l *p;

   if ( has_tran_tmcbs( dead_cell, TMCB_TRANS_DELETED) )
      run_trans_callbacks( TMCB_TRANS_DELETED, dead_cell, 0, 0, 0);

   empty_tmcb_list(&dead_cell->tmcb_hl);

   shm_lock();

   /* UA Server */
   if ( dead_cell->uas.request )
      sip_msg_free_unsafe( dead_cell->uas.request );
   if ( dead_cell->uas.response.buffer.s )
      shm_free_unsafe( dead_cell->uas.response.buffer.s );

   /* UA Clients */
   for ( i =0 ; i<dead_cell->nr_of_outgoings;  i++ )
   {
      /* retransmission buffer */
      if ( (b=dead_cell->uac[i].request.buffer.s) )
         shm_free_unsafe( b );
      b=dead_cell->uac[i].local_cancel.buffer.s;
      if (b!=0 && b!=BUSY_BUFFER)
         shm_free_unsafe( b );
      rpl=dead_cell->uac[i].reply;
      if (rpl && rpl!=FAKED_REPLY && rpl->msg_flags&FL_SHM_CLONE) {
         sip_msg_free_unsafe( rpl );
      }
      if ( (p=dead_cell->uac[i].proxy)!=NULL ) {
         if ( p->host.h_addr_list )
            shm_free_unsafe( p->host.h_addr_list );
         if ( p->dn ) {
            if ( p->dn->kids )
               shm_free_unsafe( p->dn->kids );
            shm_free_unsafe( p->dn );
         }
         shm_free_unsafe(p);
      }
      if (dead_cell->uac[i].path_vec.s) {
         shm_free_unsafe(dead_cell->uac[i].path_vec.s);
      }
   }

   /* collected to tags */
   tt=dead_cell->fwded_totags;
   while(tt) {
      foo=tt->next;
      shm_free_unsafe(tt->tag.s);
      shm_free_unsafe(tt);
      tt=foo;
   }

   /* free the avp list */
   if (dead_cell->user_avps)
      destroy_avp_list_unsafe( &dead_cell->user_avps );

   /* the cell's body */
   shm_free_unsafe( dead_cell );

   shm_unlock();
}



static inline void init_synonym_id( struct cell *t )
{
   struct sip_msg *p_msg;
   int size;
   char *c;
   unsigned int myrand;

   if (!syn_branch) {
      p_msg=t->uas.request;
      if (p_msg) {
         /* char value of a proxied transaction is
            calculated out of header-fields forming
            transaction key
         */
         char_msg_val( p_msg, t->md5 );
      } else {
         /* char value for a UAC transaction is created
            randomly -- UAC is an originating stateful element 
            which cannot be refreshed, so the value can be
            anything
         */
         /* HACK : not long enough */
         myrand=rand();
         c=t->md5;
         size=MD5_LEN;
         memset(c, '0', size );
         int2reverse_hex( &c, &size, myrand );
      }
   }
}

static inline void init_branches(struct cell *t)
{
   unsigned int i;
   struct ua_client *uac;

   for(i=0;i<MAX_BRANCHES;i++)
   {
      uac=&t->uac[i];
      uac->request.my_T = t;
      uac->request.branch = i;
#ifdef EXTRA_DEBUG
      uac->request.fr_timer.tg = TG_FR;
      uac->request.retr_timer.tg = TG_RT;
#endif
      uac->local_cancel=uac->request;
   }
}


struct cell*  build_cell( struct sip_msg* p_msg )
{
   struct cell* new_cell;
   int          sip_msg_len;
   struct usr_avp **old;
   struct tm_callback *cbs, *cbs_tmp;

   /* allocs a new cell */
   new_cell = (struct cell*)shm_malloc( sizeof( struct cell ) );
   if  ( !new_cell ) {
      ser_error=E_OUT_OF_MEM;
      return NULL;
   }

   /* filling with 0 */
   memset( new_cell, 0, sizeof( struct cell ) );

   /* UAS */
#ifdef EXTRA_DEBUG
   new_cell->uas.response.retr_timer.tg=TG_RT;
   new_cell->uas.response.fr_timer.tg=TG_FR;
#endif
   new_cell->uas.response.my_T=new_cell;

   /* dcm: - local generation transactions should not inherit AVPs 
    * - commpletely new message */
   if(p_msg) {
      /* move the current avp list to transaction -bogdan */
      old = set_avp_list( &new_cell->user_avps );
      new_cell->user_avps = *old;
      *old = 0;

      /* move the pending callbacks to transaction -bogdan */
      if (p_msg->id==tmcb_pending_id) {
         new_cell->tmcb_hl = tmcb_pending_hl;
         tmcb_pending_hl.first = 0;
      }

      /* enter callback, which may potentially want to parse some stuff,
       * before the request is shmem-ized */
      if (has_reqin_tmcbs() )
         run_reqin_callbacks( new_cell, p_msg, p_msg->REQ_METHOD);

      /* clean possible previous added vias/clen header or else they would
       * get propagated in the failure routes */
      free_via_clen_lump(&p_msg->add_rm);
      new_cell->uas.request = sip_msg_cloner(p_msg,&sip_msg_len);
      if (!new_cell->uas.request)
         goto error;
      new_cell->uas.end_request=((char*)new_cell->uas.request)+sip_msg_len;
   }

   /* UAC */
   init_branches(new_cell);

   new_cell->relayed_reply_branch   = -1;
   /* new_cell->T_canceled = T_UNDEFINED; */
#ifdef EXTRA_DEBUG
   new_cell->wait_tl.tg=TG_WT;
   new_cell->dele_tl.tg=TG_DEL;
#endif

   init_synonym_id(new_cell);
   init_cell_lock(  new_cell );
   return new_cell;

error:
   if (new_cell->user_avps)
      destroy_avp_list( &new_cell->user_avps );
   if (new_cell->tmcb_hl.first) {
      for( cbs=new_cell->tmcb_hl.first ; cbs ; ) {
         cbs_tmp = cbs;
         cbs = cbs->next;
         shm_free( cbs_tmp );
      }
   }
   shm_free(new_cell);
   /* unlink transaction AVP list and link back the global AVP list (bogdan)*/
   reset_avps();
   return NULL;
}



/*! \brief Release all the data contained by the hash table. All the aux. structures
 *  as sems, lists, etc, are also released */
void free_hash_table(void)
{
   struct cell* p_cell;
   struct cell* tmp_cell;
   int    i;

   if (tm_table)
   {
      /* remove the data contained by each entry */
      for( i = 0 ; i<TM_TABLE_ENTRIES; i++)
      {
         /* delete all synonyms at hash-collision-slot i */
         p_cell=tm_table->entrys[i].first_cell;
         for( ; p_cell; p_cell = tmp_cell )
         {
            tmp_cell = p_cell->next_cell;
            free_cell( p_cell );
         }
      }
      shm_free(tm_table);
   }
}


/*
 */
struct s_table* init_hash_table(void)
{
   int              i;

   /*allocs the table*/
   tm_table= (struct s_table*)shm_malloc( sizeof( struct s_table ) );
   if ( !tm_table) {
      LM_ERR("no more share memory\n");
      goto error0;
   }

   memset( tm_table, 0, sizeof (struct s_table ) );

   /* try first allocating all the structures needed for syncing */
   if (lock_initialize()==-1)
      goto error1;

   /* inits the entrys */
   for(  i=0 ; i<TM_TABLE_ENTRIES; i++ )
   {
      init_entry_lock( tm_table, (tm_table->entrys)+i );
      tm_table->entrys[i].next_label = rand();
   }

   return  tm_table;

error1:
   free_hash_table( );
error0:
   return 0;
}


/*! \brief  Takes an already created cell and links it into hash table on the
 *  appropriate entry. */
void insert_into_hash_table_unsafe( struct cell * p_cell, unsigned int _hash )
{
   struct entry* p_entry;

   p_cell->hash_index=_hash;

   /* locates the appropriate entry */
   p_entry = &tm_table->entrys[ _hash ];

   p_cell->label = p_entry->next_label++;
   if ( p_entry->last_cell )
   {
      p_entry->last_cell->next_cell = p_cell;
      p_cell->prev_cell = p_entry->last_cell;
   } else p_entry->first_cell = p_cell;

   p_entry->last_cell = p_cell;

   /* update stats */
   p_entry->cur_entries++;
   p_entry->acc_entries++;
   stats_trans_new( is_local(p_cell) );
}


/*! \brief  Un-link a  cell from hash_table, but the cell itself is not released */
void remove_from_hash_table_unsafe( struct cell * p_cell)
{
   struct entry*  p_entry  = &(tm_table->entrys[p_cell->hash_index]);

   if ( p_cell->prev_cell )
      p_cell->prev_cell->next_cell = p_cell->next_cell;
   else
      p_entry->first_cell = p_cell->next_cell;

   if ( p_cell->next_cell )
      p_cell->next_cell->prev_cell = p_cell->prev_cell;
   else
      p_entry->last_cell = p_cell->prev_cell;
# ifdef EXTRA_DEBUG
   if (p_entry->cur_entries==0) {
      LM_CRIT("bad things happened: cur_entries=0\n");
      abort();
   }
# endif
   /* update stats */
   p_entry->cur_entries--;
   if_update_stat(tm_enable_stats, tm_trans_inuse , -1 );
}