/*

 * Copyright (C) 2010-2014 OpenSIPS Solutions

 * Copyright (C) 2001-2003 FhG Fokus

 *

 * This file is part of opensips, a free SIP server.

 *

 * opensips 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

 *

 * opensips 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA

 *

 * History:

 * ---------

 * 2003-02-28 scratchpad compatibility abandoned (jiri)

 * 2003-01-29 transport-independent message zero-termination in

 *            receive_msg (jiri)

 * 2003-02-07 undoed jiri's zero term. changes (they break tcp) (andrei)

 * 2003-02-10 moved zero-term in the calling functions (udp_receive &

 *            tcp_read_req)

 * 2003-08-13 fixed exec_pre_cb returning 0 (backported from stable) (andrei)

 * 2004-02-06 added user preferences support - destroy_avps() (bogdan)

 * 2004-04-30 exec_pre_cb is called after basic sanity checks (at least one

 *            via present & parsed ok)  (andrei)

 * 2004-08-23 avp core changed - destroy_avp-> reset_avps (bogdan)

 * 2005-07-26 default onreply route added (andrei)

 * 2006-12-22 functions for script flags added (bogdan)

 */

/*!

 * \file

 * \brief Receive message and process routing for it

 */

#include <string.h>

#include <stdlib.h>

#include <sys/time.h>

#include "receive.h"

#include "globals.h"

#include "dprint.h"

#include "route.h"

#include "parser/msg_parser.h"

#include "forward.h"

#include "action.h"

#include "mem/mem.h"

#include "ip_addr.h"

#include "script_cb.h"

#include "dset.h"

#include "usr_avp.h"

#include "core_stats.h"

#include "ut.h"

#include "context.h"

#ifdef DEBUG_DMALLOC

#include <mem/dmalloc.h>

#endif

static unsigned int msg_no=0;

/* address preset vars */

str * const default_global_address=&STR_NULL;

str * const default_global_port=&STR_NULL;

str * const default_via_address=&STR_NULL;

str * const default_via_port=&STR_NULL;

unsigned int get_next_msg_no(void)

{

  return ++msg_no;

}

#define prepare_context( _ctx, _err ) \

  do { \

    if (_ctx==NULL) { \

      _ctx = context_alloc(CONTEXT_GLOBAL);\

      if (_ctx==NULL) { \

        LM_ERR("failed to allocated new context, skipping\n"); \

        goto _err; \

      } \

    } \

    memset( _ctx, 0, context_size(CONTEXT_GLOBAL)); \

  }while(0)

/*! \note WARNING: buf must be 0 terminated (buf[len]=0) or some things might

 * break (e.g.: modules/textops)

 */

int receive_msg(char* buf, unsigned int len, struct receive_info* rcv_info,

    context_p existing_context, unsigned int msg_flags)

{

  #define reset_global_context() \

    do {\

      if (!current_processing_ctx) { \

        ctx = NULL; \

      } else { \

        context_destroy(CONTEXT_GLOBAL, ctx); \

        set_global_context(NULL); \

      } \

    } while (0)

  static context_p ctx = NULL;

  struct sip_msg* msg;

  struct timeval start;

  int rc, old_route_type;

  char *tmp;

  str in_buff;

  in_buff.len = len;

  in_buff.s = buf;

  if (existing_context) {

    context_free(ctx);

    ctx = existing_context;

  }

  /* the raw processing callbacks can change the buffer,

  further use in_buff.s and at the end try to free in_buff.s

  if changed by callbacks */

  if (run_pre_raw_processing_cb(PRE_RAW_PROCESSING,&in_buff,NULL)<0) {

    LM_ERR("error in running pre raw callbacks, dropping\n");

    goto error;

  }

  /* update the length for further processing */

  len = in_buff.len;

  msg=pkg_malloc(sizeof(struct sip_msg));

  if (msg==0) {

    LM_ERR("no pkg mem left for sip_msg\n");

    goto error;

  }

  msg_no++;

  /* number of vias parsed -- good for diagnostic info in replies */

  via_cnt=0;

  memset(msg,0, sizeof(struct sip_msg)); /* init everything to 0 */

  /* fill in msg */

  msg->buf=in_buff.s;

  msg->len=len;

  msg->rcv=*rcv_info;

  msg->id=msg_no;

  msg->msg_flags=msg_flags;

  msg->ruri_q = Q_UNSPECIFIED;

  if (parse_msg_opt(in_buff.s,len, msg, 0)!=0){

    tmp=ip_addr2a(&(rcv_info->src_ip));

    LM_ERR("Unable to parse msg received from [%s:%d]\n",

      tmp, rcv_info->src_port);

    /* if a REQUEST msg was detected (first line was successfully parsed)

       we should trigger the error route */

    if ( msg->first_line.type==SIP_REQUEST && sroutes->error.a!=NULL ) {

      if (existing_context == NULL)

        prepare_context( ctx, parse_error );

      set_global_context(ctx);

      run_error_route(msg, 1);

      reset_global_context();

    }

    goto parse_error;

  }

  LM_DBG("After parse_msg...\n");

  start_expire_timer(start,execmsgthreshold);

  /* jumpt to parse_error_reset (not to parse_error) while

   * start_expire_timer() is still on */

  /* ... clear branches from previous message */

  clear_dset();

  if (msg->first_line.type==SIP_REQUEST) {

    update_stat( rcv_reqs, 1);

    /* sanity checks */

    if ((msg->via1==0) || (msg->via1->error!=PARSE_OK)){

      /* no via, send back error ? */

      LM_ERR("no via found in request\n");

      update_stat( err_reqs, 1);

      goto parse_error_reset;

    }

    /* check if necessary to add receive?->moved to forward_req */

    /* should we reuse this connection for the opposite direction? */

    if (is_tcp_based_proto(rcv_info->proto)

        && tcpconn_add_alias(msg, rcv_info->proto_reserved1,

                           msg->via1->port, rcv_info->proto) != 0) {

      LM_WARN("tcp alias failed\n");

      /* continue */

    }

    LM_DBG("preparing to run routing scripts...\n");

    /* set request route type --bogdan*/

    set_route_type( REQUEST_ROUTE );

    /* prepare and set a new processing context for this request only if

     * no context was set from the upper layers */

    if (existing_context == NULL)

      prepare_context( ctx, parse_error_reset );

    set_global_context(ctx);

    /* execute pre-script callbacks, if any;

     * if some of the callbacks said not to continue with

     * script processing, don't do so;

     * if we are here basic sanity checks are already done

     * (like presence of at least one via), so you can count

     * on via1 being parsed in a pre-script callback --andrei

     */

    rc = exec_pre_req_cb(msg);

    if (rc == SCB_DROP_MSG) {

      update_stat( drp_reqs, 1);

      goto end; /* drop the message */

    }

    /* exec the routing script */

    if (rc & SCB_RUN_TOP_ROUTE)

      /* run the main request route and skip post_script callbacks

       * if the TOBE_CONTINUE flag is returned */

      if ( run_top_route(sroutes->request[DEFAULT_RT], msg) &

      ACT_FL_TBCONT )

        goto end;

    /* execute post request-script callbacks */

    if (rc & SCB_RUN_POST_CBS)

      exec_post_req_cb(msg);

  } else if (msg->first_line.type==SIP_REPLY) {

    update_stat( rcv_rpls, 1);

    /* sanity checks */

    if ((msg->via1==0) || (msg->via1->error!=PARSE_OK)){

      /* no via, send back error ? */

      LM_ERR("no via found in reply\n");

      update_stat( err_rpls, 1);

      goto parse_error_reset;

    }

    /* set reply route type --bogdan*/

    set_route_type( ONREPLY_ROUTE );

    /* prepare and set a new processing context for this reply only if

     * no context was set from the upper layers */

    if (existing_context == NULL)

      prepare_context( ctx, parse_error_reset );

    set_global_context(ctx);

    /* execute pre-script callbacks, if any ;

     * if some of the callbacks said not to continue with

     * script processing, don't do so ;

     * if we are here, basic sanity checks are already done

     * (like presence of at least one via), so you can count

     * on via1 being parsed in a pre-script callback --andrei

     */

    rc = exec_pre_rpl_cb(msg);

    if (rc == SCB_DROP_MSG) {

      update_stat( drp_rpls, 1);

      goto end; /* drop the reply */

    }

    swap_route_type(old_route_type, ONREPLY_ROUTE);

    /* exec the onreply routing script */

    if (rc & SCB_RUN_TOP_ROUTE && sroutes->onreply[DEFAULT_RT].a &&

        (run_top_route(sroutes->onreply[DEFAULT_RT],msg) & ACT_FL_DROP)

        && msg->REPLY_STATUS < 200) {

      set_route_type(old_route_type);

      LM_DBG("dropping provisional reply %d\n", msg->REPLY_STATUS);

      update_stat( drp_rpls, 1);

      goto end; /* drop the message */

    } else {

      set_route_type(old_route_type);

      /* send the msg */

      forward_reply(msg);

      /* TODO - TX reply stat */

    }

    /* execute post reply-script callbacks */

    if (rc & SCB_RUN_POST_CBS)

      exec_post_rpl_cb(msg);

  }

end:

  reset_global_context();

  __stop_expire_timer( start, execmsgthreshold, "msg processing",

    msg->buf, msg->len, 0, slow_msgs);

  reset_longest_action_list(execmsgthreshold);

  /* free possible loaded avps -bogdan */

  reset_avps();

  LM_DBG("cleaning up\n");

  free_sip_msg(msg);

  pkg_free(msg);

  if (in_buff.s != buf)

    pkg_free(in_buff.s);

  return 0;

parse_error_reset:

  reset_longest_action_list(execmsgthreshold);

parse_error:

  exec_parse_err_cb(msg);

  free_sip_msg(msg);

  pkg_free(msg);

error:

  if (in_buff.s != buf)

    pkg_free(in_buff.s);

  return -1;

}