rd_funcs.c

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/*
 * $Id: rd_funcs.c 4918 2008-09-15 16:53:10Z carstenbock $
 *
 * Copyright (C) 2005 Voice Sistem SRL
 *
 * 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:
 * ---------
 *  2005-06-22  first version (bogdan)
 *  2006-05-23  push also q value into branches (bogdan)
 */


#include "../../usr_avp.h"
#include "../../dset.h"
#include "../../dprint.h"
#include "../../qvalue.h"
#include "../../parser/contact/parse_contact.h"
#include "../../qvalue.h"
#include "rd_filter.h"
#include "rd_funcs.h"


#define MAX_CONTACTS_PER_REPLY   16
#define DEFAULT_Q_VALUE          10

static int shmcontact2dset(struct sip_msg *req, struct sip_msg *shrpl,
      long max, struct acc_param *reason, unsigned int bflags);


int get_redirect( struct sip_msg *msg , int maxt, int maxb,
                           struct acc_param *reason, unsigned int bflags)
{
   struct cell *t;
   str backup_uri;
   int max;
   int cts_added;
   int n;
   int i;

   /* get transaction */
   t = rd_tmb.t_gett();
   if (t==T_UNDEFINED || t==T_NULL_CELL)
   {
      LM_CRIT("no current transaction found\n");
      goto error;
   }

   LM_DBG("resume branch=%d\n", t->first_branch);

   cts_added = 0; /* no contact added */
   backup_uri = msg->new_uri; /* shmcontact2dset will ater this value */

   /* look if there are any 3xx branches starting from resume_branch */
   for( i=t->first_branch ; i<t->nr_of_outgoings ; i++) {
      LM_DBG("checking branch=%d (added=%d)\n", i, cts_added);
      /* is a redirected branch? */
      if (t->uac[i].last_received<300 || t->uac[i].last_received>399)
         continue;
      LM_DBG("branch=%d is a redirect (added=%d)\n", i, cts_added);
      /* ok - we have a new redirected branch -> how many contacts can
       * we get from it*/
      if (maxb==0) {
         max = maxt?(maxt-cts_added):(-1);
      } else {
         max = maxt?((maxt-cts_added>=maxb)?maxb:(maxt-cts_added)):maxb;
      }
      if (max==0)
         continue;
      /* get the contact from it */
      n = shmcontact2dset( msg, t->uac[i].reply, max, reason, bflags);
      if ( n<0 ) {
         LM_ERR("get contact from shm_reply branch %d failed\n",i);
         /* do not go to error, try next branches */
      } else {
         /* count the added contacts */
         cts_added += n;
      }
   }

   /* restore original new_uri */
   msg->new_uri = backup_uri;

   /* return false if no contact was appended */
   return (cts_added>0)?1:-1;
error:
   return -1;
}



/* returns the number of contacts put in the sorted array */
static int sort_contacts(contact_t *ct_list, contact_t **ct_array,
                                          qvalue_t *q_array)
{
   param_t *q_para;
   qvalue_t q;
   int n;
   int i,j;
   char backup;

   n = 0; /* number of sorted contacts */

   for( ; ct_list ; ct_list = ct_list->next ) {
      /* check the filters first */
      backup = ct_list->uri.s[ct_list->uri.len];
      ct_list->uri.s[ct_list->uri.len] = 0;
      if ( run_filters( ct_list->uri.s )==-1 ){
         ct_list->uri.s[ct_list->uri.len] = backup;
         continue;
      }
      ct_list->uri.s[ct_list->uri.len] = backup;
      /* does the contact has a q val? */
      q_para = ct_list->q;
      if (q_para==0 || q_para->body.len==0) {
         q = DEFAULT_Q_VALUE;
      } else {
         if (str2q( &q, q_para->body.s, q_para->body.len)!=0) {
            LM_ERR("invalid q param\n");
            /* skip this contact */
            continue;
         }
      }
      LM_DBG("sort_contacts: <%.*s> q=%d\n",
            ct_list->uri.len,ct_list->uri.s,q);
      /*insert the contact into the sorted array */
      for(i=0;i<n;i++) {
         /* keep in mind that the contact list is reversts */
         if (q_array[i]<=q)
            continue;
         break;
      }
      if (i!=MAX_CONTACTS_PER_REPLY) {
         /* insert the contact at this position */
         for( j=n-1-1*(n==MAX_CONTACTS_PER_REPLY) ; j>=i ; j-- ) {
            ct_array[j+1] = ct_array[j];
            q_array[j+1] = q_array[j];
         }
         ct_array[j+1] = ct_list;
         q_array[j+1] = q;
         if (n!=MAX_CONTACTS_PER_REPLY)
            n++;
      }
   }
   return n;
}



/* returns : -1 - error
 *            0 - ok, but no contact added
 *            n - ok and n contacts added
 */
static int shmcontact2dset(struct sip_msg *req, struct sip_msg *sh_rpl,
                        long max, struct acc_param *reason, unsigned int bflags)
{
   static struct sip_msg  dup_rpl;
   static contact_t *scontacts[MAX_CONTACTS_PER_REPLY];
   static qvalue_t  sqvalues[MAX_CONTACTS_PER_REPLY];
   struct hdr_field *hdr;
   struct hdr_field *contact_hdr;
   contact_t        *contacts;
   int n,i;
   int added;
   int dup;
   int ret;

   /* dup can be:
    *    0 - sh reply but nothing duplicated 
    *    1 - sh reply but only contact body parsed
    *    2 - sh reply and contact header and body parsed
    *    3 - private reply
    */
   dup = 0; /* sh_rpl not duplicated */
   ret = 0; /* success and no contact added */
   contact_hdr = 0;

   if (sh_rpl==0 || sh_rpl==FAKED_REPLY)
      return 0;

   if (sh_rpl->contact==0) {
      /* contact header is not parsed */
      if ( sh_rpl->msg_flags&FL_SHM_CLONE ) {
         /* duplicate the reply into private memory to be able 
          * to parse it and after words to free the parsed mems */
         memcpy( &dup_rpl, sh_rpl, sizeof(struct sip_msg) );
         dup = 2;
         /* ok -> force the parsing of contact header */
         if ( parse_headers( &dup_rpl, HDR_CONTACT_T, 0)<0 ) {
            LM_ERR("dup_rpl parse failed\n");
            ret = -1;
            goto restore;
         }
         if (dup_rpl.contact==0) {
            LM_DBG("contact hdr not found in dup_rpl\n");
            goto restore;
         }
         contact_hdr = dup_rpl.contact;
      } else {
         dup = 3;
         /* force the parsing of contact header */
         if ( parse_headers( sh_rpl, HDR_CONTACT_T, 0)<0 ) {
            LM_ERR("sh_rpl parse failed\n");
            ret = -1;
            goto restore;
         }
         if (sh_rpl->contact==0) {
            LM_DBG("contact hdr not found in sh_rpl\n");
            goto restore;
         }
         contact_hdr = sh_rpl->contact;
      }
   } else {
      contact_hdr = sh_rpl->contact;
   }

   /* parse the body of contact header */
   if (contact_hdr->parsed==0) {
      if ( parse_contact(contact_hdr)<0 ) {
         LM_ERR("contact hdr parse failed\n");
         ret = -1;
         goto restore;
      }
      if (dup==0)
         dup = 1;
   }


   /* we have the contact header and its body parsed -> sort the contacts
    * based on the q value */
   contacts = ((contact_body_t*)contact_hdr->parsed)->contacts;
   if (contacts==0) {
      LM_DBG("contact hdr has no contacts\n");
      goto restore;
   }
   n = sort_contacts( contacts, scontacts, sqvalues);
   if (n==0) {
      LM_DBG("no contacts left after filtering\n");
      goto restore;
   }

   /* to many branches ? */
   if (max!=-1 && n>max)
      n = max;

   added = 0;

   /* add the sortet contacts as branches in dset and log this! */
   for ( i=0 ; i<n ; i++ ) {
      LM_DBG("adding contact <%.*s>\n", scontacts[i]->uri.len, scontacts[i]->uri.s);
      if (append_branch( 0, &scontacts[i]->uri, 0, 0, sqvalues[i], bflags, 0)<0) {
         LM_ERR("failed to add contact to dset\n");
      } else {
         added++;
         if (rd_acc_fct!=0 && reason) {
            /* log the redirect */
            req->new_uri =  scontacts[i]->uri;
            //FIXME
            rd_acc_fct( req, (char*)reason, acc_db_table, NULL, NULL, NULL, NULL);
         }
      }
   }

   ret = (added==0)?-1:added;
restore:
   if (dup==1) {
      free_contact( (contact_body_t**)(void*)(&contact_hdr->parsed) );
   } else if (dup==2) {
      /* are any new headers found? */
      if (dup_rpl.last_header!=sh_rpl->last_header) {
         /* identify in the new headere list (from dup_rpl) 
          * the sh_rpl->last_header and start remove everything after */
         hdr = sh_rpl->last_header;
         free_hdr_field_lst(hdr->next);
         hdr->next=0;
      }
   }
   return ret;

}