/*
 * Secure Network Transport Layer Library implementation.
 * This is a proprietary software. See COPYING for further details.
 *
 * (c) 2013-2014 Copyright Askele, inc. <http://askele.com>
 * (c) 2013-2014 Copyright Askele Ingria, inc. <http://askele-ingria.com>
 */

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/select.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>

#include <uuid/uuid.h>
#include <openssl/ssl.h>

#include <tdata/usrtc.h>
#include <sexpr/sexp.h>

#include <sntl/connection.h>

struct __rpc_job
{
  sxmsg_t *msg;
  sexp_t *sx;
  int (*rpcf) (void *, sexp_t *);
};

conn_sys_t *conn_sys = NULL;

static long __cmp_ulong(const void *a, const void *b);

/* message alloc and destroy */
static sxmsg_t *__allocate_msg(int *res);
static void __destroy_msg(sxmsg_t *msg);

static int __rpc_callback(void *data)
{
  struct __rpc_job *job = (struct __rpc_job *)data;
  
  return job->rpcf((void *)(job->msg), job->sx);
}

int __alloc_channel(ulong_t cid, conn_t *co, rpc_typed_list_t *rlist, chnl_t **channel)
{
  int r = 0;
  chnl_t *ch = malloc(sizeof(chnl_t));
  usrtc_t *msg_tree = malloc(sizeof(usrtc_t));
  idx_allocator_t *idx_msg = malloc(sizeof(idx_allocator_t));
  
  if(!idx_msg) goto __fin_enomem;
  else if(idx_allocator_init(idx_msg, MAX_MSGINDEX, 0)) goto __fin_enomem;

  if(!ch || !msg_tree) {
  __fin_enomem:
    r = ENOMEM;
    goto __fin_up;
  } else {
    usrtc_init(msg_tree, USRTC_REDBLACK, MAX_PENDINGMSG, __cmp_ulong);
    ch->cid = cid;
    ch->flags = ch->use_count = 0;
    usrtc_node_init(&ch->node, ch);
    if(rlist) ch->rpc_list = rlist->rpc_list;
    /* init locks */
    if(pthread_rwlock_init(&(ch->msglock), NULL)) {
      r = ENOMEM;
      goto __fin_up;
    }
    if(pthread_mutex_init(&(ch->oplock), NULL)) {
      pthread_rwlock_destroy(&(ch->msglock));
      r = ENOMEM;
      goto __fin_up;
    }
    /* assign all the stuff */
    ch->idx_msg = idx_msg;
    ch->msgs_tree = msg_tree;
    ch->connection = co;
  }

 __fin_up:
  if(r) {
    if(idx_msg) free(idx_msg);
    if(ch) free(ch);
    if(msg_tree) free(msg_tree);
    return r;
  } else {
    *channel = ch;
    return 0;
  }
}

static int __conn_read(conn_t *co, void *buf, size_t buf_len)
{
  int rfd = SSL_get_fd(co->ssl), r;
  fd_set readset;
  
  fprintf(stderr, "\tListening ... on %s\n", co->uuid);
  /* get prepare to select */
  FD_ZERO(&readset);
  FD_SET(rfd, &readset);
  /* waits until something will be ready to read */
  r = select(FD_SETSIZE, &readset, NULL, NULL, NULL);
  if(r < 0) {
    printf("select (%d)\n", errno);
    return -1;
  }
  if(!r) {
    printf("Nothing to wait for\n");
    return 0;
  }

  if(r && FD_ISSET(rfd, &readset)) {
    do {
      //pthread_mutex_lock(&(co->oplock));
      /* ok, now we're ready to perform SSL_read */
      r = SSL_read(co->ssl, buf, (int)buf_len);
      switch(SSL_get_error(co->ssl, r)) {
      case SSL_ERROR_NONE:
        //printf("Read done (f:%d)\n", rfd);
        /* this is means we're get ridden it all */
        return r;	break;
      case SSL_ERROR_ZERO_RETURN:
        printf("No data to read\n");
        /* no data to read ... */
        return 0; break;
      case SSL_ERROR_WANT_READ:
      case SSL_ERROR_WANT_WRITE:
        printf("Bypass until SSL buffer not ready.\n");
        return 0;
      default: /* seems the connection lost */
        fprintf(stderr, "(RD)Unknown error on %s\n", co->uuid);
        return -1;
      }
      //pthread_mutex_unlock(&(co->oplock));
    } while(SSL_pending(co->ssl));
  }

  return 0;
}

static int __conn_write(conn_t *co, void *buf, size_t buf_len)
{
  int r;

  pthread_mutex_lock(&(co->oplock));
 __retry:
  r = SSL_write(co->ssl, buf, (int)buf_len);
  switch(SSL_get_error(co->ssl, r)) {
  case SSL_ERROR_WANT_READ:
  case SSL_ERROR_WANT_WRITE:
    goto __retry;
    break;
  default:
    pthread_mutex_unlock(&(co->oplock));
    if(r < 0) {
      fprintf(stderr, "(WR)Unknown error on %s (%d)\n", co->uuid, r);
      return -1;
    } else return 0;
  }
  pthread_mutex_unlock(&(co->oplock));

  return 0;
}

static long __cmp_cstr(const void *a, const void *b)
{
  return strcmp((char *)a, (char *)b);
}

static long __cmp_int(const void *a, const void *b)
{
  return *(int *)a - *(int *)b;
}

static long __cmp_ulong(const void *a, const void *b)
{
  //printf("(??cmp_ulong)a = %ld b = %ld\n", *(ulong_t *)a , *(ulong_t *)b);
  return *(ulong_t *)a - *(ulong_t *)b;
}

static int __resolvehost(const char *hostname, char *buf, int buf_len, 
                         struct hostent **rhp)
{
  struct hostent *hostbuf = malloc(sizeof(struct hostent));
  struct hostent *hp = *rhp = NULL;
  int herr = 0, hres = 0;

  if(!hostbuf) return NO_ADDRESS;

  hres = gethostbyname_r(hostname, hostbuf,
                         buf, buf_len, &hp, &herr);

  if (!hp) return NO_ADDRESS;

  *rhp = hp;

  return NETDB_SUCCESS;
}

static void __destroy_rpc_list_tree(usrtc_t *tree)
{
  usrtc_node_t *node;
  cx_rpc_t *ent;

  for(node = usrtc_first(tree); node != NULL; node = usrtc_first(tree)) {
    ent = (cx_rpc_t *)usrtc_node_getdata(node);
    usrtc_delete(tree, node);
    free(ent->name);
    free(ent);
  }

  return;
}

static int __insert_rpc_function(usrtc_t *tree, const char *name, int (*rpcf)(void *, sexp_t *))
{
  cx_rpc_t *ent = malloc(sizeof(cx_rpc_t));
  usrtc_node_t *node;

  if(!ent) return ENOMEM;
  else node = &ent->node;

  if(!(ent->name = strdup(name))) {
    free(ent);
    return ENOMEM;
  } else ent->rpcf = rpcf;

  usrtc_node_init(node, ent);
  usrtc_insert(tree, node, ent->name);

  return 0;
}

static void __wake_up_waiters(conn_t *co, int opcode)
{
  usrtc_node_t *node = NULL, *last_node = NULL;
  usrtc_node_t *msg_node = NULL, *last_msg_node = NULL;
  chnl_t *ch;
  sxmsg_t *smsg = NULL;
  
  pthread_rwlock_wrlock(&(co->chnl_lock));

  node = usrtc_first(co->chnl_tree);
  last_node = usrtc_last(co->chnl_tree);
  while(!usrtc_isempty(co->chnl_tree)) {
    ch = (chnl_t *)usrtc_node_getdata(node);
    pthread_rwlock_rdlock(&(ch->msglock));
    msg_node = usrtc_first(ch->msgs_tree);
    last_msg_node = usrtc_last(ch->msgs_tree);
    while(!usrtc_isempty(ch->msgs_tree)) {
      smsg = (sxmsg_t *)usrtc_node_getdata(msg_node);
      smsg->opcode = opcode;
      pthread_mutex_unlock(&(smsg->wait));
      if(msg_node == last_msg_node) break;
      msg_node = usrtc_next(ch->msgs_tree, msg_node);
    }
    pthread_rwlock_unlock(&(ch->msglock));
    if(node == last_node) break;
    node = usrtc_next(co->chnl_tree, node);
  }

  pthread_rwlock_unlock(&(co->chnl_lock));
}

static int __default_auth_set_context(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  char *val, *var, *tbuf;
  sexp_t *lsx, *sx_iter, *sx_in;
  int llen, idx, err;

  //co->pctx = malloc(sizeof(perm_ctx_t));

  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    err = ESXRCBADPROT;
    goto __reply;
  }
  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return 0; /* other side will not set any security attributes */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sexp_list_car(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        err = ESXRCBADPROT;
        goto __reply;
      } else val = sx_in->val;

      if(sexp_list_length(sx_iter) < 2) continue; /* we will ignore it */

      sexp_list_cdr(sx_iter, &sx_in);
      if(!SEXP_IS_TYPE(sx_in, SEXP_DQUOTE)) {
        err = ESXRCBADPROT;
        goto __reply;
      } else var = sx_in->val;

      /* ok, now we need to analyze parameters */
      if(!strcmp(val, ":user") && var) {
        co->pctx->login = strdup(var);
      } else if(!strcmp(val, ":passwd") && var) {
        co->pctx->passwd = strdup(var);
      } else {
        /* just ignore in default implementation */
      }
    } else continue; /* ignore */
  }

  /* ok, now we need to fill security context */
  tbuf = malloc(2048);
  if(conn_sys->secure_check)
    err = conn_sys->secure_check(co);
  
__reply:
  if(err) {
    snprintf(tbuf, 2048, "(auth-set-error (%d))", err);
  } else {
    snprintf(tbuf, 2048, "(auth-set-attr (:attr %d)(:uid %ld)(:gid %ld))",
             co->pctx->p_attr, co->pctx->uid, co->pctx->gid);
  }
  /* we will send it */
  if(__conn_write(co, tbuf, strlen(tbuf)) < 0) {
    co->flags &= ~CXCONN_ESTABL;
    __wake_up_waiters(co, ESXNOCONNECT);
  }
  destroy_sexp(sx);

  free(tbuf);
  return err;
  
}

static int __default_auth_set_attr(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  char *val, *var;
  sexp_t *lsx, *sx_iter, *sx_in;
  int llen, idx, r = 0;

  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    //    printf("%s:%d\n", __FUNCTION__, __LINE__);
    r = ESXRCBADPROT;
    goto __finish;
  }
  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return 0; /* other side will not set any security attributes */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sexp_list_car(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __finish;
      } else val = sx_in->val;

      if(sexp_list_length(sx_iter) < 2) continue; /* we will ignore it */

      sexp_list_cdr(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __finish;
      } else var = sx_in->val;

      /* ok, now we need to analyze parameters */
      if(!strcmp(val, ":attr")) {
        co->pctx->p_attr = atoi(var);
      } else if(!strcmp(val, ":uid")) {
        co->pctx->uid = (ulong_t)atoll(var);
      } else if(!strcmp(val, ":gid")) {
        co->pctx->gid = (ulong_t)atoll(var);
      } else {
        /* just ignore in default implementation */
      }
    } else continue; /* ignore */
  }

__finish:
  destroy_sexp(sx);
  return r;
}

static int __default_auth_set_error(void *cctx, sexp_t *sx)
{
  char *errstr = NULL;
  int r;

  /* skip keyword itself */
  sx->list = sx->list->next;
  /* be sure - this is a list */
  if(sx->ty != SEXP_LIST) return ESXRCBADPROT;
  else sx = sx->list; /* get it */
  errstr = sx->list->val;
  r = atoi(errstr);

  destroy_sexp(sx);
  return r;
}

static int __default_ch_get_types(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node;
  rpc_typed_list_t *list_ent;
  char *tbuf = malloc(4096), *tt;
  int err = 0;

  /* if we cannot allocate anything ... */
  if(!tbuf) return ENOMEM;
  /* ok here we go */
  co->rpc_list = conn_sys->get_rpc_typed_list_tree(co);
  /* ok, here we're don't need to parse anything */
  if(!usrtc_count(co->rpc_list)) {
    err = ENXIO;
    snprintf(tbuf, 4096, "(ch-gl-error (%d))", err);
  } else {
    tt = tbuf;
    snprintf(tt, 4096, "(ch-set-types (");
    tt += strlen(tt);
    for(node = usrtc_first(co->rpc_list); node != NULL;
        node = usrtc_next(co->rpc_list, node), tt += strlen(tt)) {
      list_ent = (rpc_typed_list_t *)usrtc_node_getdata(node);
      snprintf(tt, 4096, "(:%d \"%s\")", list_ent->type_id, list_ent->description);
    }
    snprintf(tt, 4096, "))");
  }

  /* reply to this rpc */
  if(__conn_write(co, tbuf, strlen(tbuf)) < 0) {
    co->flags &= ~CXCONN_ESTABL;
    __wake_up_waiters(co, ESXNOCONNECT);
  }
  free(tbuf);
  destroy_sexp(sx);

  return err;
}

static int __default_ch_set_types(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  char buf[1024], *val, *var;
  int r = 0, llen, typeid, idx;
  sexp_t *lsx, *sx_iter, *sx_in;

  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    r = ESXRCBADPROT;
    goto __send_reply;
  }
  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return 0; /* other side will not set any security attributes */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sexp_list_car(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __send_reply;
      } else val = sx_in->val;

      if(sexp_list_length(sx_iter) < 2) continue; /* we will ignore it */

      sexp_list_cdr(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_DQUOTE)) {
        r = ESXRCBADPROT;
        goto __send_reply;
      } else var = sx_in->val;

      /* ok, now we need to analyze parameters */
      if(*val != ':') {
        r = ESXRCBADPROT;
        goto __send_reply;
      } else {
        if(conn_sys->set_typed_list_callback) {
          typeid = atoi((char *)(val + sizeof(char)));
          if(conn_sys->set_typed_list_callback(co, typeid, var)) {
            destroy_sexp(sx);
            return ENXIO;
          }
        } /* FIXME: if no function, accept or decline ? */
      }
    } else continue; /* ignore */
  }

__send_reply:
  snprintf(buf, 1024, "(ch-gl-error (%d))", r);
  if(__conn_write(co, buf, strlen(buf)) < 0) {
    co->flags &= ~CXCONN_ESTABL;
    __wake_up_waiters(co, ESXNOCONNECT);
  }
  destroy_sexp(sx);
  return r;
  
}

static int __default_ch_gl_error(void *cctx, sexp_t *sx)
{
  int r;
  char *errstr;
  conn_t *co = (conn_t *)cctx;

  if(co->flags & CXCONN_ESTABL) return EINVAL; /* error, we're already have channels list */

  /* skip keyword itself */
  sx->list = sx->list->next;
  /* be sure - this is a list */
  if(sx->ty != SEXP_LIST) return ESXRCBADPROT;
  else sx = sx->list; /* get it */
  errstr = sx->list->val;
  r = atoi(errstr);

  if(!r) co->flags |= CXCONN_ESTABL;

  return r;
}

static int __default_ch_open(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node;
  char *val, *var, *uuid = NULL, *buf;
  int typ = -1, idx, llen, r;
  ulong_t cid;
  sexp_t *lsx, *sx_iter, *sx_in;
  rpc_typed_list_t *rlist;
  chnl_t *channel;

  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    printf("%s:%d\n", __FUNCTION__, __LINE__);
    r = ESXRCBADPROT;
    goto __send_repl;
  }

  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return 0; /* other side will not set any security attributes */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sexp_list_car(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        printf("%s:%d\n", __FUNCTION__, __LINE__);
        r = ESXRCBADPROT;
        goto __send_repl;
      } else val = sx_in->val;

      if(sexp_list_length(sx_iter) < 2) continue; /* we will ignore it */

      sexp_list_cdr(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        printf("%s:%d\n", __FUNCTION__, __LINE__);
        goto __send_repl;
      } else var = sx_in->val;

      /* ok, now we need to analyze parameters */
      if(*val != ':') {
        r = ESXRCBADPROT;
        goto __send_repl;
      } else {
        if(!strcmp((char *)(val + sizeof(char)), "type"))
          typ = atoi(var);
        else if(!strcmp((char *)(val + sizeof(char)), "id"))
          cid = atoll(var);
        else if(!strcmp((char *)(val + sizeof(char)), "uuid"))
          uuid = var;
      }
    } else continue; /* ignore */
  }

  /* additional check for type of the channel */
  node = usrtc_lookup(co->rpc_list, &typ);
  if(!node) {
    r = ESXNOCHANSUP;
    /*    printf("%s:%d (usrtc count: %d) (typ %d)\n", __FUNCTION__, __LINE__,
          usrtc_count(co->rpc_list), typ);*/
    node = usrtc_first(co->rpc_list);
    rlist = (rpc_typed_list_t *)usrtc_node_getdata(node);
    printf("---- rlist->type_id = %d\n", rlist->type_id);
    goto __send_repl;
  } else rlist = (rpc_typed_list_t *)usrtc_node_getdata(node);

  /* now we need to check up the channel */
  pthread_rwlock_rdlock(&(co->chnl_lock));
  node = usrtc_lookup(co->chnl_tree, &cid);
  if(node) {
    pthread_rwlock_unlock(&(co->chnl_lock));
    r = EEXIST;
    goto __send_repl;
  } else {
    idx_reserve(co->idx_ch, cid);
    pthread_rwlock_unlock(&(co->chnl_lock)); /* now we should alloc channel */
    if((r = __alloc_channel(cid, co, rlist, &channel))) {
      pthread_rwlock_wrlock(&(co->chnl_lock));
      idx_free(co->idx_ch, cid);
      pthread_rwlock_unlock(&(co->chnl_lock));
      goto __send_repl;
    } else {
      /* now we ready to confirm channel creation */
      pthread_rwlock_wrlock(&(co->chnl_lock));
      usrtc_insert(co->chnl_tree, &(channel->node), &(channel->cid));
      pthread_rwlock_unlock(&(co->chnl_lock));
      r = 0;
    }
  }

 __send_repl:
  buf = malloc(2048);
  snprintf(buf, 2048, "(ch-open-ret ((:error %d)(:uuid %s)(:id %ld)))", r, 
		uuid, cid);
  if(__conn_write(co, buf, strlen(buf)) < 0) {
    co->flags &= ~CXCONN_ESTABL;
    __wake_up_waiters(co, ESXNOCONNECT);
  }
  destroy_sexp(sx);
  free(buf);

  return r;
}

static int __default_ch_open_ret(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  chnl_t *chan;
  usrtc_node_t *node;
  int err = 0, r, llen, idx;
  ulong_t id;
  char *val, *var;
  sexp_t *lsx, *sx_iter, *sx_in;
  sxmsg_t *sms = NULL;

  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    //printf("%s:%d\n", __FUNCTION__, __LINE__);
    r = ESXRCBADPROT;
    goto __mark_msg;
  }
  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return EINVAL; /* !! other side will not set any security attributes */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sexp_list_car(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __mark_msg;
      } else val = sx_in->val;

      if(sexp_list_length(sx_iter) < 2) continue; /* we will ignore it */

      sexp_list_cdr(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __mark_msg;
      } else var = sx_in->val;

      /* ok, now we need to analyze parameters */
      if(*val != ':') {
        r = ESXRCBADPROT;
        goto __mark_msg;
      } else {
        if(!strcmp((char *)(val + sizeof(char)), "error"))
          err = atoi(var);
        else if(!strcmp((char *)(val + sizeof(char)), "id"))
          id = atoll(var);
      }
    } else continue; /* ignore */
  }

  /* try to find desired channel to intercept message */
  pthread_rwlock_rdlock(&(co->chnl_lock));
  node = usrtc_lookup(co->chnl_tree, (void *)&id);
  //printf("channels (%d)\n", usrtc_count(co->chnl_tree));
  pthread_rwlock_unlock(&(co->chnl_lock));
  if(node) {
    chan = (chnl_t *)usrtc_node_getdata(node);
    sms = chan->sysmsg;
  }

 __mark_msg:
  if(!sms) return r;
  sms->flags &= ~ESXMSG_PENDING; /* the message is done */
  sms->opcode = err;

  destroy_sexp(sx);

  /* unlock mutex to wake up the waiting thread */
  pthread_mutex_unlock(&(sms->wait));

  return 0;
}

static int __default_ch_close(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node;
  char *val, *var, *buf;
  int idx, llen, r;
  ulong_t cid = -1;
  sexp_t *lsx, *sx_iter, *sx_in;
  chnl_t *channel = NULL;

  r = 0;
  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    printf("%s:%d\n", __FUNCTION__, __LINE__);
    r = ESXRCBADPROT;
    goto __send_repl;
  }

  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return 0; /* other side will not set any security attributes */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      continue;
    }
    if(!SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
      printf("%s:%d\n", __FUNCTION__, __LINE__);
      r = ESXRCBADPROT;
      goto __send_repl;
    } else val = sx_iter->val;

    sx_in = sx_iter->next;

    if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
      r = ESXRCBADPROT;
      printf("%s:%d\n", __FUNCTION__, __LINE__);
      goto __send_repl;
    } else var = sx_in->val;

    /* ok, now we need to analyze parameters */
    if(*val != ':') {
      r = ESXRCBADPROT;
      goto __send_repl;
    } else {
      if(!strcmp((char *)(val + sizeof(char)), "id")) {
        cid = atoll(var);
        break;
      }
    }
  }

  //printf("%s(%ld)\n", __FUNCTION__, cid);

  /* additional check for type of the channel */
  pthread_rwlock_rdlock(&(co->chnl_lock));
  node = usrtc_lookup(co->chnl_tree, &cid);
  pthread_rwlock_unlock(&(co->chnl_lock));
  if(!node) {
    r = ENOENT;
    printf("there is no channel with id=%ld\n", cid);
    goto __send_repl;
  }
  channel = (chnl_t *)usrtc_node_getdata(node);

__send_repl:
  buf = malloc(2048);
  snprintf(buf, 2048, "(ch-close-ret ((:id %ld) (:error %d)))", 
          channel->cid, r);

  /* check up the message queue */
  pthread_rwlock_rdlock(&(channel->msglock));
  if(usrtc_count(channel->msgs_tree)) {
    fprintf(stderr, "Operation is not permitted. There are some "
            "undelivered messages in the message tree");
    free(buf);
    destroy_sexp(sx);
    return EPERM;
  }
  pthread_rwlock_unlock(&(channel->msglock));

  /* remove channel from the search tree */
  pthread_rwlock_wrlock(&(co->chnl_lock));
  usrtc_delete(co->chnl_tree, &(channel->node));
  /* free index */
  idx_free(co->idx_ch, channel->cid);
  pthread_rwlock_unlock(&(co->chnl_lock));

  idx_allocator_destroy(channel->idx_msg);
  free(channel->idx_msg);
  free(channel->msgs_tree);
  pthread_mutex_destroy(&(channel->oplock));
  pthread_rwlock_destroy(&(channel->msglock));
  free(channel);

  destroy_sexp(sx);
  if(__conn_write(co, buf, strlen(buf)) < 0) {
    co->flags &= ~CXCONN_ESTABL;
    __wake_up_waiters(co, ESXNOCONNECT);
  }
  free(buf);

  return 0;
}

static int __default_ch_close_ret(void *cctx, sexp_t *sx)
{
  ;
  conn_t *co = (conn_t *)cctx;
  chnl_t *chan;
  usrtc_node_t *node;
  int err = 0, r, llen, idx;
  ulong_t id;
  char *val, *var;
  sexp_t *lsx, *sx_iter, *sx_in;
  sxmsg_t *sms = NULL;

  /* skip keyword itself */
  lsx = sx->list->next;
  /* now we expect a list of lists */
  if(lsx->ty != SEXP_LIST) {
    //printf("%s:%d\n", __FUNCTION__, __LINE__);
    r = ESXRCBADPROT;
    goto __mark_msg;
  }
  /* take length of the list */
  llen = sexp_list_length(lsx);
  if(!llen) return EINVAL; /* !! other side will not set any security attributes */
  ;
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sexp_list_car(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __mark_msg;
      } else val = sx_in->val;

      if(sexp_list_length(sx_iter) < 2) continue; /* we will ignore it */

      sexp_list_cdr(sx_iter, &sx_in);

      if(!SEXP_IS_TYPE(sx_in, SEXP_BASIC)) {
        r = ESXRCBADPROT;
        goto __mark_msg;
      } else var = sx_in->val;

      /* ok, now we need to analyze parameters */
      if(*val != ':') {
        r = ESXRCBADPROT;
        goto __mark_msg;
      } else {
        if(!strcmp((char *)(val + sizeof(char)), "error"))
          err = atoi(var);
        else if(!strcmp((char *)(val + sizeof(char)), "id"))
          id = atoll(var);
      }
    } else continue; /* ignore */
  }
  ;
  /* try to find desired channel to intercept message */
  pthread_rwlock_rdlock(&(co->chnl_lock));
  node = usrtc_lookup(co->chnl_tree, (void *)&id);
  //printf("channels (%d)\n", usrtc_count(co->chnl_tree));
  pthread_rwlock_unlock(&(co->chnl_lock));
  if(node) {
    chan = (chnl_t *)usrtc_node_getdata(node);
    sms = chan->sysmsg;
  }
  ;
 __mark_msg:
  ;
  if(!sms) return r;
  sms->flags &= ~ESXMSG_PENDING; /* the message is done */
  sms->opcode = err;

  destroy_sexp(sx);
  /* unlock mutex to wake up the waiting thread */
  pthread_mutex_unlock(&(sms->wait));

  return 0;
}

/* create a nould of the message */
static int __create_reg_msg_mould(sxmsg_t **msg, chnl_t *ch, ulong_t mid)
{
  int r = 0;
  sxmsg_t *sm = __allocate_msg(&r);

  if(r) return r;
  else {
    sm->pch = ch;
    sm->flags = (ESXMSG_USR | ESXMSG_PENDING);
    sm->mid = mid;

    /* ok reserve message ID */
    pthread_mutex_lock(&(ch->oplock));
    idx_reserve(ch->idx_msg, mid);
    pthread_mutex_unlock(&(ch->oplock));

    pthread_mutex_lock(&(sm->wait));
    *msg = sm;
  }

  return 0;
}

// TODO: check and continue
static int __default_msg_pulse(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node = NULL;
  chnl_t *chan = NULL;
  int r = 0;
  sexp_t *lsx = NULL, *sx_iter = NULL;
  sexp_t *sx_sublist = NULL, *sx_value = NULL;
  ulong_t chnl_id = -1;
  ulong_t msg_id = -1;
  sexp_t *msg = NULL;
  sxmsg_t *smsg = NULL;
  int idx;

  /* get parameters from the message */
  if(sexp_list_cdr(sx, &lsx)) return ESXRCBADPROT;
  if(!SEXP_IS_LIST(lsx)) return ESXRCBADPROT;

  /* find channel id */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sx_sublist = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":chid")) {
          continue; // ignore it
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        chnl_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }
  lsx = sx_sublist;
  /* find message id */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      msg = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":msgid")) {
          continue; // ignore
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        msg_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }

  if(msg_id < 0 || chnl_id < 0) {
    return ESXRCBADPROT;
  }
  /* find channel */
  if(!(node = usrtc_lookup(co->chnl_tree, &chnl_id))) return ENOENT;
  else chan = (chnl_t *)usrtc_node_getdata(node);
  /* lookup for the message */
  pthread_rwlock_rdlock(&(chan->msglock));
  if(!(node = usrtc_lookup(chan->msgs_tree, &msg_id))) {
    pthread_rwlock_unlock(&(chan->msglock));
    /* here, rpc lookup has no sense, just put this job to the queue */
    /* btw, we're need to create a message first */
    r = __create_reg_msg_mould(&smsg, chan, msg_id);
    if(r) return r;

    /* assign the message */
    smsg->opcode = 0;
    smsg->payload = (void *)msg;

    /* assign initial S-expression structure */
    smsg->initial_sx = sx;

    /* put the message to the search tree */
    pthread_rwlock_wrlock(&(chan->msglock));
    usrtc_insert(chan->msgs_tree, &(smsg->pendingq_node), &(smsg->mid));
    pthread_rwlock_unlock(&(chan->msglock));
  } else {
    //printf(">>>>>>>>>>>>>>>>>>>msg_id = %lu\n", msg_id);
    pthread_rwlock_unlock(&(chan->msglock));
    smsg = (sxmsg_t *)usrtc_node_getdata(node);
    msg_return(smsg, EEXIST);
    return EEXIST;
  }
  /* put job to the queue and give up */
  r = pth_queue_add(co->rqueue, (void *)smsg, USR_MSG);
  if(r) { /* cannot put job to the queue */
    pthread_rwlock_wrlock(&(chan->msglock));
    usrtc_delete(chan->msgs_tree, &(smsg->pendingq_node));
    pthread_rwlock_unlock(&(chan->msglock));
    __destroy_msg(smsg);
    return r;
  }
  
  //msg_return(smsg, r);
  
  /* put to the IN queue */
  return r;
}

static int __default_msg_pulse_ret(void *cctx, sexp_t *sx)
{
  return 0;
}

static int __default_msg(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node = NULL;
  chnl_t *chan = NULL;
  int r = 0;
  sexp_t *lsx = NULL, *sx_iter = NULL;
  sexp_t *sx_sublist = NULL, *sx_value = NULL;
  ulong_t chnl_id = -1;
  ulong_t msg_id = -1;
  sexp_t *msg = NULL;
  sxmsg_t *smsg = NULL;
  int idx;

  /* get parameters from the message */
  if(sexp_list_cdr(sx, &lsx)) return ESXRCBADPROT;
  if(!SEXP_IS_LIST(lsx)) return ESXRCBADPROT;

  /* find channel id */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sx_sublist = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":chid")) {
          continue; // ignore it
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        chnl_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }
  lsx = sx_sublist;
  /* find message id */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      msg = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":msgid")) {
          continue; // ignore
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        msg_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }

  if(msg_id < 0 || chnl_id < 0) {
    return ESXRCBADPROT;
  }
  /* find channel */
  if(!(node = usrtc_lookup(co->chnl_tree, &chnl_id))) return ENOENT;
  else chan = (chnl_t *)usrtc_node_getdata(node);
  /* lookup for the message */
  pthread_rwlock_rdlock(&(chan->msglock));
  if(!(node = usrtc_lookup(chan->msgs_tree, &msg_id))) {
    pthread_rwlock_unlock(&(chan->msglock));
    /* here, rpc lookup has no sense, just put this job to the queue */
    /* btw, we're need to create a message first */
    r = __create_reg_msg_mould(&smsg, chan, msg_id);
    if(r) return r;

    /* assign the message */
    smsg->opcode = 0;
    smsg->payload = (void *)msg;

    /* assign initial S-expression structure */
    smsg->initial_sx = sx;

    /* put the message to the search tree */
    pthread_rwlock_wrlock(&(chan->msglock));
    usrtc_insert(chan->msgs_tree, &(smsg->pendingq_node), &(smsg->mid));
    pthread_rwlock_unlock(&(chan->msglock));
  } else {
    //printf(">>>>>>>>>>>>>>>>>>>msg_id = %lu\n", msg_id);
    pthread_rwlock_unlock(&(chan->msglock));
    smsg = (sxmsg_t *)usrtc_node_getdata(node);
    msg_return(smsg, EEXIST);
    return EEXIST;
  }
  /* put job to the queue and give up */
  r = pth_queue_add(co->rqueue, (void *)smsg, USR_MSG);
  if(r) { /* cannot put job to the queue */
    msg_return(smsg, r);
    pthread_rwlock_wrlock(&(chan->msglock));
    usrtc_delete(chan->msgs_tree, &(smsg->pendingq_node));
    pthread_rwlock_unlock(&(chan->msglock));
    __destroy_msg(smsg);
    return r;
  }

  /* put to the IN queue */
  return r;
}

/* TODO: optimize amount of code: (must be first)
 * __default_msg_return
 * __default_msg_reply
 * there are many copy-n-paste code!!!!!
 */

static int __default_msg_return(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node = NULL;
  chnl_t *chan = NULL;
  int r = 0;
  sexp_t *lsx = NULL, *sx_iter = NULL;
  sexp_t *sx_sublist = NULL, *sx_value = NULL;
  ulong_t chnl_id = -1;
  ulong_t msg_id = -1;
  sexp_t *msg = NULL;
  sxmsg_t *smsg = NULL;
  int idx, opcode;

  /* get parameters from the message */
  if(sexp_list_cdr(sx, &lsx)) {
    r = ESXRCBADPROT;
    goto __finish;
  }
  if(!SEXP_IS_LIST(lsx)) {
    r = ESXRCBADPROT;
    goto __finish;
  }

  /* get parameters */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sx_sublist = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":chid")) {
          continue; // ignore it
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        chnl_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }
  lsx = sx_sublist;
  /* find message id */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      msg = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":msgid")) {
          continue; // ignore
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        msg_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }
  /* get opcode */
  sexp_list_car(msg, &lsx);
  opcode = atoi(lsx->val);

  if(msg_id < 0 || chnl_id < 0) {
    r = ESXRCBADPROT;
    goto __finish;
  }
  //printf("chnl_id = %ld\n", chnl_id);
  if(!(node = usrtc_lookup(co->chnl_tree, &chnl_id))) return ENOENT;
  else chan = (chnl_t *)usrtc_node_getdata(node);
  /* lookup for the message */
  pthread_rwlock_rdlock(&(chan->msglock));
  if(!(node = usrtc_lookup(chan->msgs_tree, &msg_id))) {
    pthread_rwlock_unlock(&(chan->msglock));
    r = ENOENT;
    goto __finish;
  } else {
    pthread_rwlock_unlock(&(chan->msglock));
    smsg = (sxmsg_t *)usrtc_node_getdata(node);
    pthread_rwlock_wrlock(&(chan->msglock));
    idx_free(chan->idx_msg, msg_id);
    usrtc_delete(chan->msgs_tree, node);
    pthread_rwlock_unlock(&(chan->msglock));
    //smsg = (sxmsg_t *)usrtc_node_getdata(node);
    smsg->opcode = opcode;
    smsg->payload = NULL;
    pthread_mutex_unlock(&(smsg->wait));
  }
  
__finish:
  destroy_sexp(sx);
  return r;
}

static int __default_msg_reply(void *cctx, sexp_t *sx)
{
  conn_t *co = (conn_t *)cctx;
  usrtc_node_t *node = NULL;
  chnl_t *chan = NULL;
  int r = 0;
  sexp_t *lsx = NULL, *sx_iter = NULL;
  sexp_t *sx_sublist = NULL, *sx_value = NULL;
  ulong_t chnl_id = -1;
  ulong_t msg_id = -1;
  sexp_t *msg = NULL;
  sxmsg_t *smsg = NULL;
  int idx;

  /* get parameters from the message */
  if(sexp_list_cdr(sx, &lsx)) {
    r = ESXRCBADPROT;
    goto __finish;
  }
  if(!SEXP_IS_LIST(lsx)) {
    r = ESXRCBADPROT;
    goto __finish;
  }

  /* get parameters */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      sx_sublist = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":chid")) {
          continue; // ignore it
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        chnl_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }
  lsx = sx_sublist;
  /* find message id */
  SEXP_ITERATE_LIST(lsx, sx_iter, idx) {
    if(SEXP_IS_LIST(sx_iter)) {
      msg = sx_iter;
      continue;
    } else {
      if(SEXP_IS_TYPE(sx_iter, SEXP_BASIC)) {
        if(strcmp(sx_iter->val, ":msgid")) {
          continue; // ignore
        }
        sx_value = sx_iter->next;
        if(!sx_value || !SEXP_IS_TYPE(sx_value, SEXP_BASIC)) {
          continue;
        }
        msg_id = atol(sx_value->val);
      } else continue;  // ignore it
    }
  }

  if(msg_id < 0 || chnl_id < 0) {
    r = ESXRCBADPROT;
    goto __finish;
  }

  if(!(node = usrtc_lookup(co->chnl_tree, &chnl_id))) return ENOENT;
  else chan = (chnl_t *)usrtc_node_getdata(node);
  /* lookup for the message */
  pthread_rwlock_rdlock(&(chan->msglock));
  if(!(node = usrtc_lookup(chan->msgs_tree, &msg_id))) {
    pthread_rwlock_unlock(&(chan->msglock));
    r = ENOENT;
    goto __finish;
  } else {
    pthread_rwlock_unlock(&(chan->msglock));
    smsg = (sxmsg_t *)usrtc_node_getdata(node);
    smsg->opcode = SXOREPLYREQ;
    smsg->payload = copy_sexp(msg);
    smsg->flags |= ESXMSG_ISREPLY;
    pthread_mutex_unlock(&(smsg->wait));
  }

__finish:
  destroy_sexp(sx);
  return r;
}

static int __init_systemrpc_tree(usrtc_t *rtree)
{
  /* security context functions */
  if(__insert_rpc_function(rtree, "auth-set-context", __default_auth_set_context)) goto __fail;
  if(__insert_rpc_function(rtree, "auth-set-attr", __default_auth_set_attr)) goto __fail;
  if(__insert_rpc_function(rtree, "auth-set-error", __default_auth_set_error)) goto __fail;
  /* channels negotiation ops */
  if(__insert_rpc_function(rtree, "ch-get-types", __default_ch_get_types)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-gl-error", __default_ch_gl_error)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-set-types", __default_ch_set_types)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-open", __default_ch_open)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-open-ret", __default_ch_open_ret)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-close", __default_ch_close)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-close-ret", __default_ch_close_ret)) goto __fail;
  /* messaging functions */
  if(__insert_rpc_function(rtree, "ch-msg-pulse", __default_msg_pulse)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-msg-pulse-ret", __default_msg_pulse_ret)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-msg", __default_msg)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-msg-rete", __default_msg_return)) goto __fail;
  if(__insert_rpc_function(rtree, "ch-msg-repl", __default_msg_reply)) goto __fail;

  return 0;

 __fail:
  __destroy_rpc_list_tree(rtree);
  return ENOMEM;
}

static int __eval_cstr(char *cstr, cx_rpc_list_t *rpc_list, void *ctx)
{
  int r = ENOENT;
  sexp_t *sx;
  usrtc_node_t *node;
  cx_rpc_t *rentry;
  char *rpcf;

  if(!(sx = parse_sexp(cstr, strlen(cstr))))     return EBADE;
  if(sx->ty == SEXP_LIST)
    rpcf = sx->list->val;
  else rpcf = sx->val;

  /* find an appropriate function */
  //printf("rpcf = %s (sx = %p)\n", rpcf, sx);
  node = usrtc_lookup(rpc_list->rpc_tree, rpcf);
  if(!node) return ENOENT;
  else rentry = (cx_rpc_t *)usrtc_node_getdata(node);
  /* call it */
  //printf("rentry->rpcf = %p\n", rentry->rpcf);
  r = rentry->rpcf(ctx, sx);

  return r;
}

static void *__cxslave_thread_listener(void *wctx)
{
  conn_t *co = (conn_t *)wctx;
  char *buf = malloc(4096);
  int r;

  while((r = __conn_read(co, buf, 4096)) != -1) {
    buf[r] = '\0';
    if(r) printf("Got the message %s (%d bytes)\n", buf, r);
    r = __eval_cstr(buf, conn_sys->system_rpc, co);
  }
  co->flags &= ~CXCONN_ESTABL;
  __wake_up_waiters(co, ESXNOCONNECT);

  free(buf);

  return NULL;
}

static void *__cxmaster_thread_listener(void *wctx)
{
  conn_t *co = (conn_t *)wctx;
  char *buf = malloc(4096);
  int r;

  while((r = __conn_read(co, buf, 4096)) != -1) {
    buf[r] = '\0';
    if(r) printf("Got the message %s (%d bytes)\n", buf, r);
    r = __eval_cstr(buf, conn_sys->system_rpc, co);
  }
  co->flags &= ~CXCONN_ESTABL;
  __wake_up_waiters(co, ESXNOCONNECT);

  free(buf);

  return NULL;
}

static void *__rmsg_queue_thread(void *ctx)
{
  conn_t *co = (conn_t *)ctx;
  pth_msg_t *tmp = malloc(sizeof(pth_msg_t));
  sxmsg_t *msg;
  chnl_t *ch;
  int r = 0;
  char *rpcf;
  sexp_t *sx;
  usrtc_node_t *node = NULL;
  cx_rpc_t *rpccall;
  struct __rpc_job *rjob = NULL;

  if(!tmp) return NULL;

  while(1) {
    r = pth_queue_get(co->rqueue, NULL, tmp);
    if(r) {
      free(tmp);
      return NULL;
    }
    msg = tmp->data;
    if(!msg) continue; /* spurious !! */

    /* check to right job */
    if(!(msg->flags & ESXMSG_USR)) { /* not a regular message */
      msg->flags |= ESXMSG_NOWAY; /* mark it's as undeliverable */
      msg->flags &= ~ESXMSG_PENDING;
      ;
      pthread_mutex_unlock(&(msg->wait)); /* wake up the waitee */
      continue;
    } else {
      /* now we're need to have a deal with the rpc calling, other - we don't care */
      ch = msg->pch;
      sx = (sexp_t *)msg->payload;
      /* get the function name */
      if(sx->ty == SEXP_LIST) rpcf = sx->list->val;
      else rpcf = sx->val;
      //printf("Inbound queue RPC call = '%s'\n", rpcf);

      node = usrtc_lookup(ch->rpc_list->rpc_tree, rpcf);
      if(!node) {
        printf("RPC call illegal!\n");
        r = ENOENT;
        msg_return(msg, r);
      } else {
        rpccall = (cx_rpc_t *)usrtc_node_getdata(node);
        /* call this ! */
        rjob = malloc(sizeof(struct __rpc_job));  // TODO: check it
        rjob->msg = msg;
        rjob->sx = sx;
        rjob->rpcf = rpccall->rpcf;
        pth_dqtpoll_add(co->tpoll, (void *)rjob, USR_MSG);  // TODO: check it
        //rpccall->rpcf((void *)msg, sx);
        
      }
    }
  }

  return NULL;
}

static void *__msg_queue_thread(void *ctx)
{
  conn_t *co = (conn_t *)ctx;
  pth_msg_t *tmp = malloc(sizeof(pth_msg_t));
  sxmsg_t *msg;
  chnl_t *ch;
  int r = 0, len;
  char *buf = malloc(4096), *tb;
  sexp_t *sx;

  if(!tmp || !buf) {
    if(tmp) free(tmp);
    if(buf) free(buf);
    return NULL;
  }
  ;
  while(1) {
    r = pth_queue_get(co->mqueue, NULL, tmp);
    if(r) {
      free(buf);
      free(tmp);
      return NULL;
    }
    ;

    /* message workout */
    msg = tmp->data;
    if(!msg) continue; /* spurious message */

    if(!(msg->flags & ESXMSG_USR)) { /* not a regular message */
      msg->flags |= ESXMSG_NOWAY; /* mark it's as undeliverable */
      msg->flags &= ~ESXMSG_PENDING;
      ;
      pthread_mutex_unlock(&(msg->wait)); /* wake up the waitee */
      continue;
    } else {
      ch = msg->pch;
      /* now we need to complete the request */
      sx = (sexp_t *)msg->payload; tb = buf;
      if(!(msg->flags & ESXMSG_PULSE)) { /* %s))) */
        if(!(msg->flags & ESXMSG_ISREPLY))
          snprintf(buf, 4096, "(ch-msg (:chid %lu (:msgid %lu ", ch->cid,
                   msg->mid);
        else {
          if(!sx) {
            snprintf(buf, 4096, "(ch-msg-rete (:chid %lu (:msgid %lu (%d))))", ch->cid,
                     msg->mid, msg->opcode);
            /* mark it to close */
            msg->flags |= ESXMSG_CLOSURE;
            /* ok, here we will write it and wait, destroying dialog while reply */
            ;
            goto __ssl_write;
          } else snprintf(buf, 4096, "(ch-msg-repl (:chid %lu (:msgid %lu ", ch->cid,
                          msg->mid);
        }
        ;
        len = strlen(buf);
        tb += len*sizeof(char);
        if(print_sexp(tb, 4096 - (len + 4*sizeof(char)), sx) == -1) {
          msg->opcode = ENOMEM;
          /* we don't need to wake up anybody */
          if(msg->flags & ESXMSG_TIMEDOUT) {
            /* clean up all the shit:
             * 1. remove from message tree
             * 2. destroy message itself
             */
            destroy_sexp(msg->initial_sx);
            msg->initial_sx = NULL;
            msg->payload = NULL;
            destroy_sexp(msg->payload);
          } else {
            ;
            pthread_mutex_unlock(&(msg->wait));
          }
        }
      } else { /* pulse messages */
        /* here we're shouldn't process reply procedure */
        snprintf(buf, 4096, "(ch-msg-pulse (:chid %lu (:msgid %lu ", ch->cid,
                 msg->mid);
        len = strlen(buf); /* FIXME: code double shit ! */
        tb += len*sizeof(char);
        if(print_sexp(tb, 4096 - (len + 4*sizeof(char)), sx) == -1) {
          msg->opcode = ENOMEM;
          /* we don't need to wake up anybody */
          if(msg->flags & ESXMSG_TIMEDOUT) {
            /* clean up all the shit:
             * 1. remove from message tree
             * 2. destroy message itself
             */
            destroy_sexp(msg->initial_sx);
            msg->initial_sx = NULL;
            msg->payload = NULL;
            __destroy_msg(msg);
          } else
            pthread_mutex_unlock(&(msg->wait));
        }
      }
      
      len = strlen(tb);
      tb += len*sizeof(char);
      strcat(tb, ")))");

    __ssl_write:
      /* write it */
      if(__conn_write(co, (void *)buf, strlen(buf) + sizeof(char)) < 0) {
        co->flags &= ~CXCONN_ESTABL;
        __wake_up_waiters(co, ESXNOCONNECT);
      }
    
      if(msg->flags & ESXMSG_CLOSURE) {
        /* first remove the message from tree */
        pthread_rwlock_wrlock(&(ch->msglock));
        usrtc_delete(ch->msgs_tree, &(msg->pendingq_node));
        pthread_rwlock_unlock(&(ch->msglock));
        /* destroy */
        destroy_sexp(msg->initial_sx);
        __destroy_msg(msg);
      }
      
      fprintf(stderr, "\t-->%s wrote %s\n", __FUNCTION__, buf);
    }

    len = 0;
  }

  free(buf);

  return NULL;
}

/* this function is an ugly implementation to get C string with uuid */
static char *__generate_uuid(void)
{
  char *uuidc = NULL;
  uuid_t uuid;
  int len, i = 0;

  len = sizeof(char)*(sizeof(uuid_t)*2) + sizeof(char);
  if(!(uuidc = malloc(len))) return NULL;

  uuid_generate_time_safe(uuid);

  for(i = 0; i < sizeof(uuid_t); i++)
    snprintf(uuidc+(2*i*sizeof(char)), len, "%02x", uuid[i]);

  return uuidc;
}

/* this is a callback to perform a custom SSL certs chain validation,
 * as I promised here the comments, a lot of ...
 * The first shit: 0 means validation failed, 1 otherwise
 * The second shit: X509 API, I guess u will love it ;-)
 * openssl calls this function for each certificate in chain,
 * since our case is a simple (depth of chain is one, since we're
 * don't care for public certificates lists or I cannot find any reasons to
 * do it ...), amount of calls reduced, and in this case we're interested
 * only in top of chain i.e. actual certificate used on client side,
 * the validity of signing for other certificates within chain is
 * guaranteed by the ssl itself.
 * u know, we need to lookup in database, or elsewhere... some information
 * about client certificate, and decide - is it valid, or not?, if so
 * yep I mean it's valid, we can assign it's long fucking number to
 * security context, to use in ongoing full scaled connection handshaking.
 */
static int __verify_certcall(int preverify_ok, X509_STORE_CTX *ctx)
{
  X509 *cert = X509_STORE_CTX_get_current_cert(ctx);
  int err = X509_STORE_CTX_get_error(ctx), depth = X509_STORE_CTX_get_error_depth(ctx);
  SSL *ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
  conn_t *co = SSL_get_ex_data(ssl, conn_sys->ex_ssldata_index); /* this is a custom data we're set before */

  /* now we need to check for certificates with a long chain,
   * so since we have a short one, reject long ones */
  if(depth > VERIFY_DEPTH) { /* longer than we expect */
    preverify_ok = 0; /* yep, 0 means error for those function callback in openssl, fucking set */
    err = X509_V_ERR_CERT_CHAIN_TOO_LONG;
    X509_STORE_CTX_set_error(ctx, err);
  }

  /* ok, now we're on top of SSL (depth == 0) certs chain,
   * and we can validate client certificate */
  if(!depth) {
    /* TODO: check serial number and other stuff */
    co->pctx = malloc(sizeof(perm_ctx_t));
    co->pctx->certid =
      ASN1_INTEGER_get((const ASN1_INTEGER *)X509_get_serialNumber(ctx->current_cert));
    printf("Certificate ID: %lu\n", co->pctx->certid);
    /* now we're need to check the ssl cert */
    if(conn_sys->validate_sslpem) {
      if(conn_sys->validate_sslpem(co)) return 0;
      else return 1;
    } else return 0;
  }

  return preverify_ok;
}

/* subsystem: here u can told me about how it's ugly to use global pointers,
 * yep, it's a business of fucking morons, btw it works (heh, openssl uses this
 * ancient shit method too, many many and many others too, trust me ...).
 * subsystem required to define varios RPC lists, control list for connections,
 * general queues, certificates (all connections uses the same set of certificates
 * within application), general calls such as ... calls to get info about client
 * cert and ... many other things.
 */

void *__system_queue_listener(void *data)
{
  int r;
  pth_msg_t *tmp = malloc(sizeof(pth_msg_t));
  sxmsg_t *sysmsg;
  sxpayload_t *payload;
  chnl_t *chan;
  conn_t *co;

  if(!tmp) return NULL;

  while(1) {
    r = pth_queue_get(conn_sys->ioqueue, NULL, tmp);
    if(r) {
      free(tmp);
      return NULL;
    }

    /* ok message is delivered */
    sysmsg = tmp->data;
    if(!sysmsg) continue; /* ignore dummy messages */

    if(!(sysmsg->flags & ESXMSG_SYS)) { /* not a system message */
      sysmsg->flags |= ESXMSG_NOWAY; /* mark it's as undeliverable */
      sysmsg->flags &= ~ESXMSG_PENDING;
      pthread_mutex_unlock(&(sysmsg->wait)); /* wake up the waitee */
      continue;
    } else {
      chan = sysmsg->pch;
      co = chan->connection;
      payload = (sxpayload_t *)sysmsg->payload;
      /* write the buf */
      if(__conn_write(co, (void *)payload->cstr, strlen(payload->cstr) + 1) < 0) {
        co->flags &= ~CXCONN_ESTABL;
        __wake_up_waiters(co, ESXNOCONNECT);
      }
    }
  }

  return NULL;
}

/* general initialization must be called within app uses connection layer */
int connections_subsystem_init(void)
{
  int r = 0;

  if(!(conn_sys = malloc(sizeof(conn_sys_t)))) return ENOMEM;
  else if(!(conn_sys->connections = malloc(sizeof(usrtc_t)))) {
    r = ENOMEM;
    goto __fail;
  }

  /* zeroing */
  conn_sys->rootca = conn_sys->certkey = conn_sys->certpem = NULL;
  conn_sys->validate_sslpem = NULL;
  conn_sys->secure_check = NULL;
  /* init connections list */
  usrtc_init(conn_sys->connections, USRTC_REDBLACK, MAX_CONNECTIONS,
             __cmp_cstr);
  if((r = pthread_rwlock_init(&(conn_sys->rwlock), NULL)))
    goto __fail_1;

  /* init queues */
  if(!(conn_sys->ioq = malloc(sizeof(pth_queue_t)))) { /* general io queue */
    r = ENOMEM;
    goto __fail_2;
  }
  if((r = pth_queue_init(conn_sys->ioq))) goto __fail_3;
  if(!(conn_sys->ioqueue = malloc(sizeof(pth_queue_t)))) { /* system io queue */
    r = ENOMEM;
    goto __fail_2;
  }
  if((r = pth_queue_init(conn_sys->ioqueue))) goto __fail_3_1;

  /* init SSL certificates checking functions */
  /* init RPC list related functions */
  if(!(conn_sys->system_rpc = malloc(sizeof(cx_rpc_list_t)))) {
    r = ENOMEM;
    goto __fail_3;
  } else {
    if(!(conn_sys->system_rpc->rpc_tree = malloc(sizeof(usrtc_t)))) {
      r = ENOMEM;
    __fail_rpc:
      free(conn_sys->system_rpc);
      goto __fail_3_1;
    }
    usrtc_init(conn_sys->system_rpc->rpc_tree, USRTC_SPLAY, 256, __cmp_cstr);
    r = __init_systemrpc_tree(conn_sys->system_rpc->rpc_tree);
    if(r) {
      free(conn_sys->system_rpc->rpc_tree);
      goto __fail_rpc;
    }
  }

  /* init SSL library */
  SSL_library_init();

  OpenSSL_add_all_algorithms();
  SSL_load_error_strings();

  conn_sys->ex_ssldata_index = SSL_get_ex_new_index(0, "__ssldata index", NULL, NULL, NULL);

  /* create threads for queue */
  if((r = pthread_create(&conn_sys->ios_thread, NULL, __system_queue_listener, NULL))) {
    goto __fail_rpc;
  }

  return 0;

 __fail_3_1:
  free(conn_sys->ioqueue);
 __fail_3:
  free(conn_sys->ioq);
 __fail_2:
  pthread_rwlock_destroy(&(conn_sys->rwlock));
 __fail_1:
  free(conn_sys->connections);
 __fail:
  free(conn_sys);

  return r;
}

/* load certificates */
int connections_subsystem_setsslserts(const char *rootca, const char *certpem,
                                      const char *certkey)
{
  int r = ENOMEM;

  if(!conn_sys) return EINVAL;
  /* simply copying */
  if(!(conn_sys->rootca = strdup(rootca))) return ENOMEM;
  if(!(conn_sys->certkey = strdup(certkey)))     goto __fail;
  if(!(conn_sys->certpem = strdup(certpem)))     goto __fail;

  r = 0;
  return 0;
 __fail:
  if(conn_sys->rootca) free(conn_sys->rootca);
  if(conn_sys->certkey) free(conn_sys->certkey);
  if(conn_sys->certpem) free(conn_sys->certpem);

  return r;
}

int connections_subsystem_setrpclist_function(usrtc_t* (*get_rpc_typed_list_tree)(conn_t *))
{
  conn_sys->get_rpc_typed_list_tree = get_rpc_typed_list_tree;
  return 0;
}

#define __TMPBUFLEN  2048

/* connection_initiate: perform a connection thru the socket to the
 * host with master certificate, i.e. it's a slave one for client.
 */
int connection_initiate(conn_t *co, const char *host, int port,
                        const char *SSL_cert, perm_ctx_t *pctx)
{
  int r = 0, sd;
  int bytes = 0;
  char *uuid;
  char *buf = NULL;
  struct hostent *host_;
  struct sockaddr_in addr;
  usrtc_t *ch_tree, *rpc_tree;
  pth_queue_t *mqueue = malloc(sizeof(pth_queue_t));
  if(!mqueue) return ENOMEM;
  pth_dqtpoll_t *tpoll = malloc(sizeof(pth_dqtpoll_t));
  if(!tpoll)  return ENOMEM;  // TODO: fallback
  idx_allocator_t *idx_ch = malloc(sizeof(idx_allocator_t));
  if(!idx_ch) return ENOMEM;

  if(!co) return EINVAL;
  if(!host) return EINVAL;
  if(!SSL_cert) return EINVAL;
  if(!pctx) return EINVAL;

  memset(co, 0, sizeof(conn_t));
  
  pth_dqtpoll_init(tpoll, __rpc_callback);

  if(!idx_ch) return ENOMEM;
  else r = idx_allocator_init(idx_ch, MAX_CHANNELS*MAX_MULTI, 0);
  if(r) return r;

  if(!(uuid = __generate_uuid())) return ENOMEM;
  if(!(ch_tree = malloc(sizeof(usrtc_t)))) {
    r = ENOMEM;
    goto __fail;
  }
  if(!(rpc_tree = malloc(sizeof(usrtc_t)))) {
    r = ENOMEM;
    goto __fail_1;
  }
  if((r = pthread_mutex_init(&co->oplock, NULL))) goto __fail_2;
  if((r = pthread_rwlock_init(&co->chnl_lock, NULL))) goto __fail_3;

  usrtc_init(rpc_tree, USRTC_REDBLACK, MAX_RPC_LIST, __cmp_int);
  usrtc_init(ch_tree, USRTC_REDBLACK, MAX_CHANNELS, __cmp_ulong);

  co->idx_ch = idx_ch;

  /* assign message queue */
  if((r = pth_queue_init(mqueue))) goto __fail_3;
  co->mqueue = mqueue;

  /* init SSL certificates and context */
  co->ctx = SSL_CTX_new(SSLv3_client_method());
  if(!co->ctx) { ERR_print_errors_fp(stderr);
    r = EINVAL; goto __fail_3; }
  else SSL_CTX_set_verify_depth(co->ctx, 1); /* FIXME: use configuration */

  /* load certificates */
  SSL_CTX_load_verify_locations(co->ctx, conn_sys->rootca, NULL);
  /* set the local certificate from CertFile */
  if(SSL_CTX_use_certificate_file(co->ctx, SSL_cert,
                                  SSL_FILETYPE_PEM)<=0) {
    r = EINVAL; printf("%s:%d\n", __FUNCTION__, __LINE__);
    goto __fail_3;
  }
  /* set the private key from KeyFile (may be the same as CertFile) */
  if(SSL_CTX_use_PrivateKey_file(co->ctx, SSL_cert,
                                 SSL_FILETYPE_PEM)<=0) {
    r = EINVAL; printf("%s:%d\n", __FUNCTION__, __LINE__);
    goto __fail_3;
  }
  /* verify private key */
  if (!SSL_CTX_check_private_key(co->ctx)) {
    r = EINVAL;
    goto __fail_3;
  }

  /* assign allocated memory */
  co->rpc_list = rpc_tree;
  co->chnl_tree = ch_tree;
  co->uuid = uuid;

  /* connect to the pointed server */
  /* resolve host */
  if(!(buf = malloc(__TMPBUFLEN))) {
    r = ENOMEM;
    goto __fail_3;
  }
  if(__resolvehost(host, buf, __TMPBUFLEN, &host_) != NETDB_SUCCESS) {
    r = ENOENT;
    free(buf);
    goto __fail_3;
  }
  /* create a socket */
  sd = socket(PF_INET, SOCK_STREAM, 0);
  bzero(&addr, sizeof(addr));
  /* try to connect it */
  addr.sin_family = AF_INET;
  addr.sin_port = htons(port);
  //printf("addr.sin_addr.s_addr = %p, host_ = %p\n", &addr.sin_addr.s_addr, host_);
  addr.sin_addr.s_addr = *(uint32_t*)(host_->h_addr);
  free(host_);
  if (connect(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0) {
    close(sd);
    free(buf);
    r = ENOENT; /* couldn't connect to the desired host */
    goto __fail_3;
  }

  /* now we will create an SSL connection */
  co->ssl = SSL_new(co->ctx);
  SSL_set_fd(co->ssl, sd); /* attach connected socket */
  if(SSL_connect(co->ssl) == -1) {
    r = EBADE;
    free(buf);
    /* shutdown connection */
    goto __fail_3;
  } /* if success we're ready to use established SSL channel */
  /* auth and RPC contexts sync */
  co->pctx = pctx;
  snprintf(buf, __TMPBUFLEN, "(auth-set-context ((:user \"%s\")(:passwd \"%s\")))",
           pctx->login, pctx->passwd);
  /* send an auth request */
  SSL_write(co->ssl, buf, strlen(buf) + sizeof(char));
  /* read the message reply */
  bytes = __conn_read(co, buf, __TMPBUFLEN);
  if(bytes == -1) {
    // we've lost the connection
    co->flags &= ~CXCONN_ESTABL;
    r = ESXNOCONNECT;
    __wake_up_waiters(co, ESXNOCONNECT);
    free(buf);
    /* shutdown connection */
    goto __fail_3;
  }
  buf[bytes] = 0;
  /* perform an rpc call */
  r = __eval_cstr(buf, conn_sys->system_rpc, (void *)co);
  if(!r) { /* all is fine security context is good */
    snprintf(buf, __TMPBUFLEN, "(ch-get-types)"); /* now we should receive possible channel types */
    SSL_write(co->ssl, buf, strlen(buf) + sizeof(char));
    /* read the message reply */
    bytes = __conn_read(co, buf, __TMPBUFLEN);
    if(bytes == -1) {
      // we've lost the connection
      co->flags &= ~CXCONN_ESTABL;
      r = ESXNOCONNECT;
      __wake_up_waiters(co, ESXNOCONNECT);
      free(buf);
      /* shutdown connection */
      goto __fail_3;
    }
    buf[bytes] = 0;
    /* perform an rpc call */
    r = __eval_cstr(buf, conn_sys->system_rpc, (void *)co);
  }

  free(buf); /* now we can free the temporary buffer */
  /* a listening thread creation (incoming messages) */
  printf("%s:%d r = %d\n", __FUNCTION__, __LINE__, r);
  if(!r) { /* success let's start a listening thread */
    r = pthread_create(&co->cthread, NULL, __cxslave_thread_listener, (void *)co);
    if(!r) {
      /* add connection to the list */
      usrtc_node_init(&co->csnode, co);
      co->flags = (CXCONN_SLAVE | CXCONN_ESTABL); /* set the right flags */
      pthread_rwlock_wrlock(&conn_sys->rwlock);
      usrtc_insert(conn_sys->connections, &co->csnode, (void *)co->uuid);
      pthread_rwlock_unlock(&conn_sys->rwlock);
      //return 0; /* FIXME: */
    }
    r = pthread_create(&co->msgthread, NULL, __msg_queue_thread, (void *)co);
    if(r) goto __fail_3;
    
    pth_dqtpoll_run(tpoll);
    co->tpoll = tpoll;
    
    return 0;
  }

 __fail_3:
  pthread_mutex_destroy(&co->oplock);
 __fail_2:
  free(rpc_tree);
 __fail_1:
  free(ch_tree);
 __fail:
  free(uuid);
  return r;
}

int connection_create(conn_t *co, int sck)
{
  int r = 0, sd;
  int bytes = 0;
  char *uuid;
  char *buf = NULL;
  usrtc_t *ch_tree, *rpc_tree;
  pth_queue_t *rqueue = malloc(sizeof(pth_queue_t));
  pth_queue_t *mqueue = malloc(sizeof(pth_queue_t));
  pth_dqtpoll_t *tpoll = malloc(sizeof(pth_dqtpoll_t));
  if(!tpoll)  return ENOMEM;  // TODO: fallback
  idx_allocator_t *idx_ch = malloc(sizeof(idx_allocator_t));

  if(!co) return EINVAL;
  else memset(co, 0, sizeof(co));
  
  pth_dqtpoll_init(tpoll, __rpc_callback);  // TODO: check it

  if(!idx_ch) return ENOMEM;
  else r = idx_allocator_init(idx_ch, MAX_CHANNELS*MAX_MULTI, 0);
  if(r) return r;

  if(!(uuid = __generate_uuid())) return ENOMEM;
  if(!(ch_tree = malloc(sizeof(usrtc_t)))) {
    r = ENOMEM;
    goto __fail;
  }
  if(!(rpc_tree = malloc(sizeof(usrtc_t)))) {
    r = ENOMEM;
    goto __fail_1;
  }
  if((r = pthread_mutex_init(&co->oplock, NULL))) goto __fail_2;
  if((r = pthread_rwlock_init(&co->chnl_lock, NULL))) goto __fail_3;

  usrtc_init(rpc_tree, USRTC_REDBLACK, MAX_RPC_LIST, __cmp_int);
  usrtc_init(ch_tree, USRTC_REDBLACK, MAX_CHANNELS, __cmp_ulong);

  co->idx_ch = idx_ch;

  /* assign message queue */
  r = pth_queue_init(rqueue);
  if(r) goto __fail_3;
  co->rqueue = rqueue;
  /* assigned outbone message queue master also has this one */
  r = pth_queue_init(mqueue);
  if(r) goto __fail_3;
  co->mqueue = mqueue;

  /* init SSL certificates and context */
  co->ctx = SSL_CTX_new(SSLv3_server_method());
  if(!co->ctx) { r = EINVAL; printf("%s:%d\n", __FUNCTION__, __LINE__);goto __fail_3; }
  else {
    /* set verify context */
    SSL_CTX_set_verify(co->ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
                       __verify_certcall);
    /* set verify depth */
    SSL_CTX_set_verify_depth(co->ctx, VERIFY_DEPTH);
  }

  /* load certificates */
  SSL_CTX_load_verify_locations(co->ctx, conn_sys->rootca, NULL);
  /* set the local certificate from CertFile */
  if(SSL_CTX_use_certificate_file(co->ctx, conn_sys->certpem,
                                  SSL_FILETYPE_PEM)<=0) {
    printf("certpem1 = %s\n", conn_sys->certpem);
    ERR_print_errors_fp(stderr);
    r = EINVAL; printf("%s:%d\n", __FUNCTION__, __LINE__);
    goto __fail_3;
  }
  /* set the private key from KeyFile (may be the same as CertFile) */
  if(SSL_CTX_use_PrivateKey_file(co->ctx, conn_sys->certkey,
                                 SSL_FILETYPE_PEM)<=0) {
    r = EINVAL; printf("%s:%d\n", __FUNCTION__, __LINE__);
    goto __fail_3;
  }
  /* verify private key */
  if (!SSL_CTX_check_private_key(co->ctx)) {
    r = EINVAL; printf("%s:%d\n", __FUNCTION__, __LINE__);
    goto __fail_3;
  }

  /* assign allocated memory */
  co->rpc_list = rpc_tree;
  co->chnl_tree = ch_tree;
  co->uuid = uuid;

  if(!(buf = malloc(__TMPBUFLEN))) {
    r = ENOMEM;
    goto __fail_3;
  }

  /* now we will create an SSL connection */
  co->ssl = SSL_new(co->ctx);
  SSL_set_fd(co->ssl, sck); /* attach connected socket */
  /* set the context to verify ssl connection */
  SSL_set_ex_data(co->ssl, conn_sys->ex_ssldata_index, (void *)co);
  if(SSL_accept(co->ssl) == -1) {
    r = EBADE;
    free(buf);
    /* shutdown connection */
    goto __fail_3;
  } /* if success we're ready to use established SSL channel */
  printf("%s:%d\n", __FUNCTION__, __LINE__);
  BIO_set_nbio(SSL_get_rbio(co->ssl), 1);
  /*******************************************/
  /*-=Protocol part of connection establish=-*/
  /*******************************************/
  while(!(co->flags & CXCONN_ESTABL)) { /* read the initiation stage connections */
    bytes = __conn_read(co, buf, __TMPBUFLEN);
    if(bytes > 0) {
      buf[bytes] = 0;
      r = __eval_cstr(buf, conn_sys->system_rpc, (void *)co);
      printf("%s return %d (bytes %d)\n", buf, r, bytes);
      if(r) goto __fail_3;
    } else {
      printf("bytes = %d\n", bytes);
      if(bytes < 0) {
        printf("Terminate SSL connection, the other end is lost.\n");
        co->flags &= ~CXCONN_ESTABL;
        __wake_up_waiters(co, ESXNOCONNECT);
        r = ESXNOCONNECT;
        goto __fail_3;
      }
    }
  }

  /* before it will be done assign rpc list */
  if(conn_sys->get_rpc_typed_list_tree)
    co->rpc_list = conn_sys->get_rpc_typed_list_tree(co);

  free(buf);
  r = pthread_create(&co->cthread, NULL, __cxmaster_thread_listener, (void *)co);
  if(!r) {
    /* add connection to the list */
    usrtc_node_init(&co->csnode, co);
    co->flags |= CXCONN_MASTER; /* set the right flags */
    pthread_rwlock_wrlock(&conn_sys->rwlock);
    usrtc_insert(conn_sys->connections, &co->csnode, (void *)co->uuid);
    pthread_rwlock_unlock(&conn_sys->rwlock);
    /* threads poll --- */
    r = pthread_create(&co->msgthread, NULL, __msg_queue_thread, (void *)co);
    if(r) goto __fail_3;
    r = pthread_create(&co->rmsgthread, NULL, __rmsg_queue_thread, (void *)co);
    if(r) goto __fail_3;
    
    pth_dqtpoll_run(tpoll);
    co->tpoll = tpoll;
  }

  return r;

 __fail_3:
  pthread_mutex_destroy(&co->oplock);
 __fail_2:
  free(rpc_tree);
 __fail_1:
  free(ch_tree);
 __fail:
  free(uuid);
  return r;
}

int connection_close(conn_t *co) /* TODO: */
{
  return 0;
}

int connection_reinit(conn_t *co) /* TODO: */
{
  return 0;
}

static sxmsg_t *__allocate_msg(int *res)
{
  sxmsg_t *msg = malloc(sizeof(sxmsg_t));
  int r = 0;

  if(!msg) {
    *res = ENOMEM;
    return NULL;
  } else {
    memset(msg, 0, sizeof(sxmsg_t));
    if((r = pthread_mutex_init(&(msg->wait), NULL))) {
      free(msg);
      *res = r;
      return NULL;
    }

    usrtc_node_init(&(msg->chnl_node), msg);
    usrtc_node_init(&(msg->poll_node), msg);
    usrtc_node_init(&(msg->pendingq_node), msg);
  }

  *res = 0;

  return msg;
}

static void __destroy_msg(sxmsg_t *msg)
{
  chnl_t *ch = msg->pch;

  if(msg->flags & ESXMSG_USR) {
    pthread_mutex_lock(&(ch->oplock));
    idx_free(ch->idx_msg, msg->mid);
    pthread_mutex_unlock(&(ch->oplock));
  } else if(msg->flags & ESXMSG_SYS) {
    //if(msg->uuid) free(msg->uuid);
  }

  pthread_mutex_unlock(&(msg->wait));
  pthread_mutex_destroy(&(msg->wait));
  free(msg);
  return;
}

static int __create_reg_msg(sxmsg_t **msg, chnl_t *ch)
{
  int r = 0;
  sxmsg_t *sm = __allocate_msg(&r);

  if(r) return r;
  else {
    sm->pch = ch;
    sm->flags = (ESXMSG_USR | ESXMSG_PENDING);

    /* ok allocate message ID */
    pthread_mutex_lock(&(ch->oplock));
    sm->mid = idx_allocate(ch->idx_msg);
    pthread_mutex_unlock(&(ch->oplock));

    pthread_mutex_lock(&(sm->wait));
    *msg = sm;
  }

  return 0;
}

static int __create_sys_msg(sxmsg_t **msg, char *uuid, chnl_t *ch, sxpayload_t *data)
{
  int r = 0;
  sxmsg_t *m = __allocate_msg(&r);

  if(r) return r;
  else {
    /* fill values */
    m->pch = ch;
    m->uuid = uuid;
    m->payload = data;
    /* set the right flags */
    m->flags = (ESXMSG_SYS | ESXMSG_PENDING);
    /* we need to lock the wait mutex */
    pthread_mutex_lock(&(m->wait));

    *msg = m;
  }

  return 0;
}

/* channels */
int channel_open(conn_t *co, chnl_t **ch, int type)
{
  chnl_t *nch = NULL;
  int r = 0;
  char *uuid_;
  sxpayload_t *pl;
  ulong_t cid;
  rpc_typed_list_t *rpclist;
  usrtc_node_t *node;
  sxmsg_t *sms;
  
  if(!(co->flags & CXCONN_ESTABL)) {
    return ESXNOCONNECT;
  }
  
  uuid_ = __generate_uuid();
  pl = malloc(sizeof(sxpayload_t));
  node = usrtc_lookup(co->rpc_list, &type);
  /*
  if(!node) {
    r = EINVAL; printf("fuck\n");
    goto __fini_op;
  } else rpclist = (rpc_typed_list_t *)usrtc_node_getdata(node);
  */
  if(!uuid_) {
    if(pl) free(pl);
    return ENOMEM;
  }

  if(!pl) {
  __ffail:
    if(uuid_) free(uuid_);
    return ENOMEM;
  } else {
    pl->sx = NULL;
    if(!(pl->cstr = malloc(sizeof(char)*ESX_SYSMSG_SIZE))) {
      free(pl);      goto __ffail;
    } else memset(pl->cstr, 0, sizeof(char)*ESX_SYSMSG_SIZE);
  }

  pthread_rwlock_wrlock(&(co->chnl_lock));
  cid = idx_allocate(co->idx_ch);
  pthread_rwlock_unlock(&(co->chnl_lock));
  if(cid == IDX_INVAL) {
    r = ENOMEM;
    goto __fini_op;
  }

  if((r = __alloc_channel(cid, co, rpclist, &nch))) {
    goto __fini_op;
  } else nch->flags |= ESXCHAN_PENDING;

  nch->uuid = uuid_;

  /* ok now we're ready to create a message and push channel to the list */
  if((r = __create_sys_msg(&sms, uuid_, nch, pl))) {
  __fail_chan:
    /* destroy the channel*/
    goto __fini_op;
  } else {
    /* put the channel to the channels search tree */
    pthread_rwlock_wrlock(&(co->chnl_lock));
    //printf("inserting cid = %d\n", nch->cid);
    usrtc_insert(co->chnl_tree, &nch->node, &nch->cid);
    pthread_rwlock_unlock(&(co->chnl_lock));

    /* put system message to the run queue */
    /* first form the message */
    snprintf(pl->cstr, sizeof(char)*ESX_SYSMSG_SIZE, 
             "(ch-open ((:id %ld)(:uuid %s)(:type %d)))", nch->cid, nch->uuid, type);
    nch->sysmsg = sms; /* assign system message to the channel */
    /* put it */
    if((r = pth_queue_add(conn_sys->ioqueue, (void *)sms, SYS_MSG))) {
    __fail_chan_r:
      /* remove it from the search tree */
      pthread_rwlock_wrlock(&(co->chnl_lock));
      usrtc_delete(co->chnl_tree, &nch->node);
      pthread_rwlock_unlock(&(co->chnl_lock));
      goto __fail_chan;
    }
    if(!(sms->flags & ESXMSG_PENDING)) {
      /* was processed too fast */
      goto __process_smsg;
    } else pthread_mutex_lock(&(sms->wait)); /* will sleep until got a reply */
  __process_smsg:
    if(sms->opcode) {
      r = sms->opcode;
      goto __fail_chan_r;
    } else		r = 0;
    nch->flags &= ~ESXCHAN_PENDING; /* mark it as established */
    free(pl->cstr);
    free(pl);
    __destroy_msg(nch->sysmsg);
  }

 __fini_op:
  if(r) {
    if(uuid_) free(uuid_);
    if(pl) {
      if(pl->cstr) free(pl->cstr);
      free(pl);
    }
    pthread_rwlock_wrlock(&(co->chnl_lock));
    idx_free(co->idx_ch, nch->cid);
    pthread_rwlock_unlock(&(co->chnl_lock));
    idx_allocator_destroy(nch->idx_msg);
    free(nch->idx_msg);
    free(nch->msgs_tree);
    pthread_mutex_destroy(&(nch->oplock));
    pthread_rwlock_destroy(&(nch->msglock));

    free(nch);
  } else *ch = nch;

  return r;
}

int channel_close(chnl_t *chnl)
{
  char *uuid_;
  usrtc_node_t *node = NULL;
  int r;
  conn_t *co = chnl->connection;
  sxmsg_t *sms;
  sxpayload_t *pl;
  
  if(!(co->flags & CXCONN_ESTABL)) {
    return ESXNOCONNECT;
  }
  
  uuid_ = __generate_uuid();

  pthread_rwlock_rdlock(&(co->chnl_lock));
  node = usrtc_lookup(co->chnl_tree, &chnl->cid);
  pthread_rwlock_unlock(&(co->chnl_lock));
  if(!node) {
    fprintf(stderr, "No such channel\n");
    return ENOENT;
  }

  pthread_rwlock_wrlock(&(chnl->msglock));
  /* check unprocessed messages */
  if(!usrtc_isempty(chnl->msgs_tree)) {
    pthread_rwlock_unlock(&(chnl->msglock));
    fprintf(stderr, "Unable to close channel\n");
    return EBUSY;
  }

  pl = malloc(sizeof(sxpayload_t));
  if(!pl) return ENOMEM;
  if(__create_sys_msg(&sms, uuid_, chnl, pl)) {
    if(chnl->idx_msg) free(chnl->idx_msg);
    if(chnl->msgs_tree) free(chnl->msgs_tree);
    free(chnl);
    return ENOMEM;
  }

  pl->sx = NULL;
  if(!(pl->cstr = malloc(sizeof(char) * ESX_SYSMSG_SIZE))) {
    pthread_rwlock_unlock(&(chnl->msglock));
    free(pl);
    return ENOMEM;
  }
  memset(pl->cstr, 0, sizeof(char) * ESX_SYSMSG_SIZE);

  /* put system message to the run queue */
  /* first form the message */
  snprintf(pl->cstr, sizeof(char) * ESX_SYSMSG_SIZE,
          "(ch-close (:id %ld))", chnl->cid);
  chnl->sysmsg = sms; /* assign system message to the channel */
  /* put it */
  if((r = pth_queue_add(conn_sys->ioqueue, (void *)sms, SYS_MSG))) {
    pthread_rwlock_unlock(&(chnl->msglock));
    return r;
  }
  if(!(sms->flags & ESXMSG_PENDING)) {
    /* was processed too fast */
    goto __process_smsg;
  } else pthread_mutex_lock(&(sms->wait)); /* will sleep until got a reply */

__process_smsg:
  if(sms->opcode) {
    r = sms->opcode;
    return r;
  } else		r = 0;
  chnl->flags &= ~ESXCHAN_PENDING; /* mark it as established */
  /* remove channel from the search tree */
  pthread_rwlock_wrlock(&(chnl->connection->chnl_lock));
  usrtc_delete(chnl->connection->chnl_tree, &chnl->node);
  /* free index */
  idx_free(co->idx_ch, chnl->cid);
  pthread_rwlock_unlock(&(chnl->connection->chnl_lock));

  pthread_rwlock_unlock(&(chnl->msglock));

  __destroy_msg(chnl->sysmsg);
  free(uuid_);

  free(pl->cstr);
  free(pl);
  free(chnl->uuid);
  idx_allocator_destroy(chnl->idx_msg);
  free(chnl->idx_msg);
  free(chnl->msgs_tree);
  pthread_mutex_destroy(&(chnl->oplock));
  pthread_rwlock_destroy(&(chnl->msglock));

  free(chnl);

  return 0;
}

/* message passing */

/*
 * How message sending works:
 * 1. Create a message structure assigned to the channel,
 * 2. Put S-expression context to it
 * 3. Put the message to the queue
 * 4. expect the result waiting on the lock mutex
 */
static int __message_send(chnl_t *ch, sexp_t *sx, sxmsg_t **msg, struct timespec *tio)
{
  int r = 0;
  sxmsg_t *m = NULL;
  conn_t *co = ch->connection;
  
  if(!(co->flags & CXCONN_ESTABL)) {
    destroy_sexp(sx);
    return ESXNOCONNECT;
  }

  *msg = NULL;

  r = __create_reg_msg(&m, ch);
  if(r) return r;
  else {
    /* put the message to the search tree */
    pthread_rwlock_wrlock(&(ch->msglock));
    usrtc_insert(ch->msgs_tree, &(m->pendingq_node), &(m->mid));
    pthread_rwlock_unlock(&(ch->msglock));

    /* message assign */
    m->opcode = 0;
    m->payload = (void *)sx;
    /* assign initial sx */
    m->initial_sx = sx;

    /* put the message to the run queue */
    r = pth_queue_add(co->mqueue, (void *)m, USR_MSG);
    if(r) return r; /* FIXME: better give up */

    if(m->flags & ESXMSG_PENDING) {
      if(!tio) pthread_mutex_lock(&(m->wait));
      else pthread_mutex_timedlock(&(m->wait), tio);
    }
    if(tio && (m->flags & ESXMSG_PENDING))
      return SXOTIMEDOUT;
    if(!m->payload) {
      r = m->opcode;
      /* first remove the message from tree */
      pthread_rwlock_wrlock(&(ch->msglock));
      usrtc_delete(ch->msgs_tree, &(m->pendingq_node));
      pthread_rwlock_unlock(&(ch->msglock));
      /* destroy s expression */
      destroy_sexp(m->initial_sx);
      /* destroy */
      __destroy_msg(m);
    } else {
      *msg = m;
      r = SXOREPLYREQ;
    }
  }

  return r;
}

int msg_send(chnl_t *ch, sexp_t *sx, sxmsg_t **msg)
{
  return __message_send(ch, sx, msg, NULL);
}

int msg_send_timed(chnl_t *ch, sexp_t *sx, sxmsg_t **msg, struct timespec *tio)
{
  return __message_send(ch, sx, msg, tio);
}

static int __msg_reply(sxmsg_t *msg, sexp_t *sx, struct timespec *tio, int opcode)
{
  int r = 0;
  chnl_t *ch = msg->pch;
  conn_t *co = ch->connection;
  
  if(!(co->flags & CXCONN_ESTABL)) {
    destroy_sexp(sx);
    return ESXNOCONNECT;
  }

  msg->payload = sx;
  msg->opcode = opcode;
  msg->flags |= ESXMSG_PENDING; /* pending */
  msg->flags |= ESXMSG_ISREPLY; /* this is a reply */

  if(!sx) msg->flags &= ~ESXMSG_PENDING;

  /* put the message to the queue */
  r = pth_queue_add(co->mqueue, (void *)msg, USR_MSG);
  if(r) return r; /* FIXME: better give up */
  if(!sx) return 0;

  if(msg->flags & ESXMSG_PENDING) {
    if(!tio) pthread_mutex_lock(&(msg->wait));
    else pthread_mutex_timedlock(&(msg->wait), tio);
  }

  if(tio && (msg->flags & ESXMSG_PENDING))
    return SXOTIMEDOUT;

  r = msg->opcode;

#if 0
  if(msg->flags & ESXMSG_CLOSURE) {
    /* first remove the message from tree */
    pthread_rwlock_wrlock(&(ch->msglock));
    usrtc_delete(ch->msgs_tree, &(msg->pendingq_node));
    pthread_rwlock_unlock(&(ch->msglock));
    /* destroy */
    destroy_sexp(msg->initial_sx);
    __destroy_msg(msg);
  }
#endif

  return r;
}

int msg_return(sxmsg_t *msg, int opcode)
{
  return __msg_reply(msg, NULL, NULL, opcode);
}

int msg_reply(sxmsg_t *msg, sexp_t *sx)
{
  return __msg_reply(msg, sx, NULL, 0);
}

int msg_reply_timed(sxmsg_t *msg, sexp_t *sx, struct timespec *tio)
{
  return __msg_reply(msg, sx, tio, 0);
}

//TODO: continue. Implement wait for delivery and queue addition
/*
 * How message sending works:
 * 1. Create a message structure assigned to the channel,
 * 2. Put S-expression context to it
 * 3. Put the message to the queue
 * 4. Wait for job execution
 */
static int __message_send_pulse(chnl_t *ch, sexp_t *sx, struct timespec *tio)
{
  int r = 0;
  sxmsg_t *m = NULL;
  conn_t *co = ch->connection;
  
  if(!(co->flags & CXCONN_ESTABL)) {
    destroy_sexp(sx);
    return ESXNOCONNECT;
  }

  r = __create_reg_msg(&m, ch);
  if(r) return r;
  else {
    /* put the message to the search tree */
    pthread_rwlock_wrlock(&(ch->msglock));
    usrtc_insert(ch->msgs_tree, &(m->pendingq_node), &(m->mid));
    pthread_rwlock_unlock(&(ch->msglock));

    /* message assign */
    m->opcode = 0;
    m->payload = (void *)sx;
    /* assign initial sx */
    m->initial_sx = sx;
    m->flags |= ESXMSG_PULSE;

    /* put the message to the run queue */
    r = pth_queue_add(co->mqueue, (void *)m, USR_MSG);
    if(r) return r; /* FIXME: better give up */

    if(m->flags & ESXMSG_PENDING) {
      if(!tio) pthread_mutex_lock(&(m->wait));
      else pthread_mutex_timedlock(&(m->wait), tio);
    }
    if(tio && (m->flags & ESXMSG_PENDING))
      return SXOTIMEDOUT;
    if(!m->payload) {
      r = m->opcode;
      /* first remove the message from tree */
      pthread_rwlock_wrlock(&(ch->msglock));
      usrtc_delete(ch->msgs_tree, &(m->pendingq_node));
      pthread_rwlock_unlock(&(ch->msglock));
      /* destroy s expression */
      destroy_sexp(m->initial_sx);
      /* destroy */
      __destroy_msg(m);
    } else {
      r = SXOREPLYREQ;
    }
  }

  return r;
}

int msg_send_pulse(chnl_t *ch, sexp_t *sx)
{
  return __message_send_pulse(ch, sx, NULL);
}

int msg_send_pulse_timed(chnl_t *ch, sexp_t *sx, struct timespec *tio)
{
  return 0;
}

int msg_send_pulse_nowait(chnl_t *ch, sexp_t *sx)
{
  return 0;
}

/* sexp helpers */
int sexp_list_car(sexp_t *expr, sexp_t **sx)
{
  if (!SEXP_IS_LIST(expr) || expr->list->ty != SEXP_VALUE)    return 1;

  *sx = expr->list;

  return 0;
}

int sexp_list_cdr(sexp_t *expr, sexp_t **sx)
{
  /* Dummy function. Can we do cdr properly? */
  if (!SEXP_IS_LIST(expr) || expr->list->ty != SEXP_VALUE)    return 1;

  if (!expr->list->next)    *sx = NULL;
  else    *sx = expr->list->next;

  return 0;
}