/*

 * Copyright (C) 2001-2003 FhG Fokus

 *

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

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 *

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

 *

 */

/*!

 * \file

 * \brief Kamailio core ::

 * \ingroup core

 * Module: \ref core

 */

#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 "nonsip_hooks.h"

#include "dset.h"

#include "fmsg.h"

#include "usr_avp.h"

#include "xavp.h"

#include "select_buf.h"

#include "locking.h"

#include "tcp_server.h"  /* for tcpconn_add_alias */

#include "tcp_options.h" /* for access to tcp_accept_aliases*/

#include "cfg/cfg.h"

#include "core_stats.h"

#include "kemi.h"

#ifdef DEBUG_DMALLOC

#include <mem/dmalloc.h>

#endif

int _sr_ip_free_bind = 0;

unsigned int msg_no = 0;

/* address preset vars */

str default_global_address = {0, 0};

str default_global_port = {0, 0};

str default_via_address = {0, 0};

str default_via_port = {0, 0};

int ksr_route_locks_size = 0;

static rec_lock_set_t *ksr_route_locks_set = NULL;

int ksr_route_locks_set_init(void)

{

  if(ksr_route_locks_set != NULL || ksr_route_locks_size <= 0)

    return 0;

  ksr_route_locks_set = rec_lock_set_alloc(ksr_route_locks_size);

  if(ksr_route_locks_set == NULL) {

    LM_ERR("failed to allocate route locks set\n");

    return -1;

  }

  if(rec_lock_set_init(ksr_route_locks_set) == NULL) {

    LM_ERR("failed to init route locks set\n");

    return -1;

  }

  return 0;

}

void ksr_route_locks_set_destroy(void)

{

  if(ksr_route_locks_set == NULL)

    return;

  rec_lock_set_destroy(ksr_route_locks_set);

  rec_lock_set_dealloc(ksr_route_locks_set);

  ksr_route_locks_set = NULL;

}

/**

 * increment msg_no and return the new value

 */

unsigned int inc_msg_no(void)

{

  return ++msg_no;

}

/**

 *

 */

int sip_check_fline(char *buf, unsigned int len)

{

  char *p;

  int m;

  m = 0;

  for(p = buf; p < buf + len; p++) {

    /* first check if is a reply - starts with SIP/2.0 */

    if(m == 0) {

      if(*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n')

        continue;

      if(buf + len - p < 10)

        return -1;

      if(strncmp(p, "SIP/2.0 ", 8) == 0) {

        LM_DBG("first line indicates a SIP reply\n");

        return 0;

      }

      m = 1;

    } else {

      /* check if a request - before end of first line is SIP/2.0 */

      if(*p != '\r' && *p != '\n')

        continue;

      if(p - 10 >= buf) {

        if(strncmp(p - 8, " SIP/2.0", 8) == 0) {

          LM_DBG("first line indicates a SIP request\n");

          return 0;

        }

      }

      return -1;

    }

  }

  return -1;

}

/**

 *

 */

static sr_net_info_t *ksr_evrt_rcvnetinfo = NULL;

int ksr_evrt_received_mode = 0;

str kemi_received_route_callback = STR_NULL;

/**

 *

 */

sr_net_info_t *ksr_evrt_rcvnetinfo_get(void)

{

  return ksr_evrt_rcvnetinfo;

}

/**

 *

 */

int ksr_evrt_received(char *buf, unsigned int *len, receive_info_t *rcv_info)

{

  sr_kemi_eng_t *keng = NULL;

  sr_net_info_t netinfo;

  int ret = 0;

  int rt = -1;

  run_act_ctx_t ra_ctx;

  run_act_ctx_t *bctx = NULL;

  sip_msg_t *fmsg = NULL;

  str evname = str_init("core:msg-received");

  if(len == 0 || rcv_info == NULL || buf == NULL) {

    LM_ERR("required parameters are not available\n");

    return -1;

  }

  if(kemi_received_route_callback.len > 0) {

    keng = sr_kemi_eng_get();

    if(keng == NULL) {

      LM_DBG("kemi enabled with no core:msg-receive event route "

           "callback\n");

      return 0;

    }

  } else {

    rt = route_lookup(&event_rt, evname.s);

    if(rt < 0 || event_rt.rlist[rt] == NULL) {

      LM_DBG("event route core:msg-received not defined\n");

      return 0;

    }

  }

  memset(&netinfo, 0, sizeof(sr_net_info_t));

  netinfo.data.s = buf;

  netinfo.data.len = *len;

  netinfo.bufsize = BUF_SIZE;

  netinfo.rcv = rcv_info;

  ksr_evrt_rcvnetinfo = &netinfo;

  set_route_type(REQUEST_ROUTE);

  fmsg = faked_msg_get_next();

  init_run_actions_ctx(&ra_ctx);

  if(keng) {

    bctx = sr_kemi_act_ctx_get();

    sr_kemi_act_ctx_set(&ra_ctx);

    ret = sr_kemi_route(

        keng, fmsg, REQUEST_ROUTE, &kemi_received_route_callback, NULL);

    sr_kemi_act_ctx_set(bctx);

  } else {

    ret = run_actions(&ra_ctx, event_rt.rlist[rt], fmsg);

  }

  if(ra_ctx.run_flags & DROP_R_F) {

    LM_DBG("dropping received message\n");

    ret = -1;

  }

  *len = netinfo.data.len;

  ksr_evrt_rcvnetinfo = NULL;

  return ret;

}

static int ksr_evrt_pre_routing_idx = -1;

str kemi_pre_routing_callback = STR_NULL;

/**

 *

 */

int ksr_evrt_pre_routing(sip_msg_t *msg)

{

  int ret = 0;

  int rt = -1;

  run_act_ctx_t ra_ctx;

  run_act_ctx_t *bctx = NULL;

  sr_kemi_eng_t *keng = NULL;

  str evname = str_init("core:pre-routing");

  recv_flags_t brflags;

  if(msg->rcv.rflags & RECV_F_INTERNAL) {

    DBG("skip internal routed message\n");

    return 0;

  }

  if(kemi_pre_routing_callback.len > 0) {

    keng = sr_kemi_eng_get();

    if(keng == NULL) {

      LM_DBG("kemi enabled with no core:pre-routing event route "

           "callback\n");

      return 0;

    }

  } else {

    if(ksr_evrt_pre_routing_idx == -1) {

      rt = route_lookup(&event_rt, evname.s);

      if(rt < 0 || event_rt.rlist[rt] == NULL) {

        ksr_evrt_pre_routing_idx = -2;

      }

    } else {

      rt = ksr_evrt_pre_routing_idx;

    }

    if(rt < 0 || event_rt.rlist[rt] == NULL) {

      LM_DBG("event route core:pre-routing not defined\n");

      return 0;

    }

  }

  set_route_type(REQUEST_ROUTE);

  init_run_actions_ctx(&ra_ctx);

  brflags = msg->rcv.rflags;

  msg->rcv.rflags |= RECV_F_PREROUTING;

  if(keng) {

    bctx = sr_kemi_act_ctx_get();

    sr_kemi_act_ctx_set(&ra_ctx);

    ret = sr_kemi_route(

        keng, msg, REQUEST_ROUTE, &kemi_pre_routing_callback, &evname);

    sr_kemi_act_ctx_set(bctx);

  } else {

    ret = run_actions(&ra_ctx, event_rt.rlist[rt], msg);

  }

  msg->rcv.rflags = brflags;

  if(ra_ctx.run_flags & DROP_R_F) {

    LM_DBG("drop was used\n");

    return 1;

  }

  LM_DBG("execution returned %d\n", ret);

  return 0;

}

/** Receive message

 *  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, receive_info_t *rcv_info)

{

  struct sip_msg *msg = NULL;

  struct run_act_ctx ctx;

  struct run_act_ctx *bctx = NULL;

  int ret = -1;

  struct timeval tvb = {0}, tve = {0};

  unsigned int diff = 0;

  str inb = STR_NULL;

  sr_net_info_t netinfo = {0};

  sr_kemi_eng_t *keng = NULL;

  sr_event_param_t evp = {0};

  unsigned int cidlockidx = 0;

  unsigned int cidlockset = 0;

  int errsipmsg = 0;

  int exectime = 0;

  if(rcv_info->bind_address == NULL) {

    LM_ERR("critical - incoming message without local socket [%.*s ...]\n",

        (len > 128) ? 128 : len, buf);

    return -1;

  }

  if(ksr_evrt_received_mode != 0) {

    if(ksr_evrt_received(buf, &len, rcv_info) < 0) {

      LM_DBG("dropping the received message\n");

      goto error00;

    }

  }

  if(sr_event_enabled(SREV_NET_DATA_RECV)) {

    if(sip_check_fline(buf, len) == 0) {

      memset(&netinfo, 0, sizeof(sr_net_info_t));

      netinfo.data.s = buf;

      netinfo.data.len = len;

      netinfo.rcv = rcv_info;

      evp.data = (void *)&netinfo;

      sr_event_exec(SREV_NET_DATA_RECV, &evp);

    }

  }

  inb.s = buf;

  inb.len = len;

  evp.data = (void *)&inb;

  evp.rcv = rcv_info;

  sr_event_exec(SREV_NET_DATA_IN, &evp);

  len = inb.len;

  msg = pkg_malloc(sizeof(struct sip_msg));

  if(unlikely(msg == 0)) {

    PKG_MEM_ERROR;

    goto error00;

  }

  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 = buf;

  msg->len = len;

  /* zero termination (termination of orig message below not that

   * useful as most of the work is done with scratch-pad; -jiri  */

  /* buf[len]=0; */ /* WARNING: zero term removed! */

  msg->rcv = *rcv_info;

  msg->id = msg_no;

  msg->pid = my_pid();

  msg->set_global_address = default_global_address;

  msg->set_global_port = default_global_port;

  if(likely(sr_msg_time == 1))

    msg_set_time(msg);

  if(parse_msg(buf, len, msg) != 0) {

    errsipmsg = 1;

    evp.data = (void *)msg;

    if((ret = sr_event_exec(SREV_RCV_NOSIP, &evp)) < NONSIP_MSG_DROP) {

      LM_DBG("attempt of nonsip message processing failed\n");

    } else if(ret == NONSIP_MSG_DROP) {

      LM_DBG("nonsip message processing completed\n");

      goto end;

    }

  }

  if(errsipmsg == 1) {

    LOG(cfg_get(core, core_cfg, sip_parser_log),

        "core parsing of SIP message failed (%s:%d/%d)\n",

        ip_addr2a(&msg->rcv.src_ip), (int)msg->rcv.src_port,

        (int)msg->rcv.proto);

    sr_core_ert_run(msg, SR_CORE_ERT_RECEIVE_PARSE_ERROR);

    goto error02;

  }

  if(unlikely(parse_headers(msg,

            HDR_FROM_F | HDR_TO_F | HDR_CALLID_F | HDR_CSEQ_F, 0)

        < 0)) {

    LOG(cfg_get(core, core_cfg, sip_parser_log),

        "parsing relevant headers failed\n");

  }

  LM_DBG("--- received sip message - %s - call-id: [%.*s] - cseq: [%.*s]\n",

      (msg->first_line.type == SIP_REQUEST) ? "request" : "reply",

      (msg->callid && msg->callid->body.s) ? msg->callid->body.len : 0,

      (msg->callid && msg->callid->body.s) ? msg->callid->body.s : "",

      (msg->cseq && msg->cseq->body.s) ? msg->cseq->body.len : 0,

      (msg->cseq && msg->cseq->body.s) ? msg->cseq->body.s : "");

  /* set log prefix */

  log_prefix_set(msg);

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

  clear_branches();

  ret = ksr_evrt_pre_routing(msg);

  if(ret < 0) {

    goto error02;

  }

  if(ret == 1) {

    /* finished */

    goto end;

  }

  if(unlikely(ksr_route_locks_set != NULL && msg->callid

        && msg->callid->body.s && msg->callid->body.len > 0)) {

    cidlockidx = get_hash1_raw(msg->callid->body.s, msg->callid->body.len);

    cidlockidx = cidlockidx % ksr_route_locks_set->size;

    cidlockset = 1;

  }

  if(is_printable(cfg_get(core, core_cfg, latency_cfg_log))) {

    exectime = 1;

  }

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

    ruri_mark_new(); /* ruri is usable for forking (not consumed yet) */

    if(!IS_SIP(msg)) {

      LM_DBG("handling non-sip request message\n");

      if((ret = nonsip_msg_run_hooks(msg)) != NONSIP_MSG_ACCEPT) {

        if(unlikely(ret == NONSIP_MSG_ERROR)) {

          LM_DBG("failed handling non-sip request message\n");

          goto error03;

        }

        LM_DBG("finished handling non-sip request message\n");

        goto end; /* drop the message */

      }

    }

    /* sanity checks */

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

      /* no via, send back error ? */

      LOG(cfg_get(core, core_cfg, sip_parser_log),

          "no via found in request\n");

      STATS_BAD_MSG();

      goto error02;

    }

    if(unlikely((msg->callid == 0) || (msg->cseq == 0) || (msg->from == 0)

          || (msg->to == 0))) {

      /* no required headers -- send back error ? */

      LOG(cfg_get(core, core_cfg, sip_parser_log),

          "required headers not found in request\n");

      STATS_BAD_MSG();

      goto error02;

    }

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

/* check for the alias stuff */

#ifdef USE_TCP

    if(msg->via1->alias && cfg_get(tcp, tcp_cfg, accept_aliases)

        && (((rcv_info->proto == PROTO_TCP) && !tcp_disable)

#ifdef USE_TLS

            || ((rcv_info->proto == PROTO_TLS) && !tls_disable)

#endif

                )) {

      if(tcpconn_add_alias(rcv_info->proto_reserved1, msg->via1->port,

             rcv_info->proto)

          != 0) {

        LM_ERR("tcp alias failed\n");

        /* continue */

      }

    }

#endif

    /*  skip: */

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

    if(exectime) {

      gettimeofday(&tvb, NULL);

    }

    /* execute pre-script callbacks, if any; -jiri */

    /* 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

    */

    if(exec_pre_script_cb(msg, REQUEST_CB_TYPE) == 0) {

      STATS_REQ_FWD_DROP();

      goto end; /* drop the request */

    }

    set_route_type(REQUEST_ROUTE);

    /* exec the routing script */

    if(unlikely(main_rt.rlist[DEFAULT_RT] == NULL)) {

      keng = sr_kemi_eng_get();

      if(keng == NULL) {

        LM_ERR("no request_route {...} and no other config routing"

             " engine registered\n");

        goto error_req;

      }

      if(unlikely(cidlockset)) {

        rec_lock_set_get(ksr_route_locks_set, cidlockidx);

        if(sr_kemi_route(keng, msg, REQUEST_ROUTE, NULL, NULL) < 0)

          LM_NOTICE("negative return code from engine function\n");

        rec_lock_set_release(ksr_route_locks_set, cidlockidx);

      } else {

        if(sr_kemi_route(keng, msg, REQUEST_ROUTE, NULL, NULL) < 0)

          LM_NOTICE("negative return code from engine function\n");

      }

    } else {

      if(unlikely(cidlockset)) {

        rec_lock_set_get(ksr_route_locks_set, cidlockidx);

        if(run_top_route(main_rt.rlist[DEFAULT_RT], msg, 0) < 0) {

          rec_lock_set_release(ksr_route_locks_set, cidlockidx);

          LM_WARN("error while trying script\n");

          goto error_req;

        }

        rec_lock_set_release(ksr_route_locks_set, cidlockidx);

      } else {

        if(run_top_route(main_rt.rlist[DEFAULT_RT], msg, 0) < 0) {

          LM_WARN("error while trying script\n");

          goto error_req;

        }

      }

    }

    if(exectime) {

      gettimeofday(&tve, NULL);

      diff = (tve.tv_sec - tvb.tv_sec) * 1000000

           + (tve.tv_usec - tvb.tv_usec);

      if(cfg_get(core, core_cfg, latency_limit_cfg) == 0

          || cfg_get(core, core_cfg, latency_limit_cfg) <= diff) {

        LOG(cfg_get(core, core_cfg, latency_cfg_log),

            "request-route executed in: %d usec\n", diff);

      }

    }

    /* execute post request-script callbacks */

    exec_post_script_cb(msg, REQUEST_CB_TYPE);

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

    /* sanity checks */

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

      /* no via, send back error ? */

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

      STATS_BAD_RPL();

      goto error02;

    }

    if(unlikely((msg->callid == 0) || (msg->cseq == 0) || (msg->from == 0)

          || (msg->to == 0))) {

      /* no required headers -- send back error ? */

      LOG(cfg_get(core, core_cfg, sip_parser_log),

          "required headers not found in reply\n");

      STATS_BAD_RPL();

      goto error02;

    }

    if(exectime) {

      gettimeofday(&tvb, NULL);

    }

    /* execute pre-script callbacks, if any; -jiri */

    /* 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

    */

    if(exec_pre_script_cb(msg, ONREPLY_CB_TYPE) == 0) {

      STATS_RPL_FWD_DROP();

      goto end; /* drop the reply */

    }

    /* exec the onreply routing script */

    if(kemi_reply_route_callback.len > 0) {

      keng = sr_kemi_eng_get();

    }

    if(onreply_rt.rlist[DEFAULT_RT] != NULL || keng != NULL) {

      set_route_type(CORE_ONREPLY_ROUTE);

      ret = 1;

      if(unlikely(keng != NULL)) {

        bctx = sr_kemi_act_ctx_get();

        init_run_actions_ctx(&ctx);

        sr_kemi_act_ctx_set(&ctx);

        if(unlikely(cidlockset)) {

          rec_lock_set_get(ksr_route_locks_set, cidlockidx);

          ret = sr_kemi_route(

              keng, msg, CORE_ONREPLY_ROUTE, NULL, NULL);

          rec_lock_set_release(ksr_route_locks_set, cidlockidx);

        } else {

          ret = sr_kemi_route(

              keng, msg, CORE_ONREPLY_ROUTE, NULL, NULL);

        }

        sr_kemi_act_ctx_set(bctx);

      } else {

        if(unlikely(cidlockset)) {

          rec_lock_set_get(ksr_route_locks_set, cidlockidx);

          ret = run_top_route(

              onreply_rt.rlist[DEFAULT_RT], msg, &ctx);

          rec_lock_set_release(ksr_route_locks_set, cidlockidx);

        } else {

          ret = run_top_route(

              onreply_rt.rlist[DEFAULT_RT], msg, &ctx);

        }

      }

#ifndef NO_ONREPLY_ROUTE_ERROR

      if(unlikely(ret < 0)) {

        LM_WARN("error while trying onreply script\n");

        goto error_rpl;

      } else

#endif /* NO_ONREPLY_ROUTE_ERROR */

        if(unlikely(ret == 0 || (ctx.run_flags & DROP_R_F))) {

          STATS_RPL_FWD_DROP();

          LM_DBG("drop flag set - skip forwarding the reply\n");

          goto skip_send_reply; /* drop the message, no error */

        }

    }

    /* send the msg */

    forward_reply(msg);

  skip_send_reply:

    if(exectime) {

      gettimeofday(&tve, NULL);

      diff = (tve.tv_sec - tvb.tv_sec) * 1000000

           + (tve.tv_usec - tvb.tv_usec);

      if(cfg_get(core, core_cfg, latency_limit_cfg) == 0

          || cfg_get(core, core_cfg, latency_limit_cfg) <= diff) {

        LOG(cfg_get(core, core_cfg, latency_cfg_log),

            "reply-route executed in: %d usec\n", diff);

      }

    }

    /* execute post reply-script callbacks */

    exec_post_script_cb(msg, ONREPLY_CB_TYPE);

  }

end:

  ksr_msg_env_reset();

  LM_DBG("cleaning up\n");

  free_sip_msg(msg);

  pkg_free(msg);

  /* reset log prefix */

  log_prefix_set(NULL);

  return 0;

#ifndef NO_ONREPLY_ROUTE_ERROR

error_rpl:

  /* execute post reply-script callbacks */

  exec_post_script_cb(msg, ONREPLY_CB_TYPE);

  goto error02;

#endif /* NO_ONREPLY_ROUTE_ERROR */

error_req:

  LM_DBG("error:...\n");

  /* execute post request-script callbacks */

  exec_post_script_cb(msg, REQUEST_CB_TYPE);

error03:

error02:

  free_sip_msg(msg);

  pkg_free(msg);

error00:

  ksr_msg_env_reset();

  /* reset log prefix */

  log_prefix_set(NULL);

  return -1;

}

/**

 * clean up msg environment, such as avp, xavp and xavu lists

 */

void ksr_msg_env_reset(void)

{

  reset_avps();

  xavp_reset_list();

  xavu_reset_list();

  xavi_reset_list();

}