Example #1
0
static int
ci_udp_disconnect(citp_socket* ep, ci_udp_state* us, ci_fd_t os_sock)
{
    int rc;

    if( (rc = ci_udp_sys_getsockname(os_sock, ep)) != 0 ) {
        LOG_E(log(FNS_FMT "ERROR: sys_getsockname failed (%d)",
                  FNS_PRI_ARGS(ep->netif, ep->s), errno));
        return rc;
    }
    ci_udp_set_raddr(us, 0, 0);
    /* TODO: We shouldn't really clear then set here; instead we should
     * insert wildcard filters before removing the full-match ones.  ie. The
     * reverse of what we do in connect().  But probably not worth worrying
     * about in this case.
     */
    ci_udp_clr_filters(ep);

#ifdef ONLOAD_OFE
    if( ep->netif->ofe != NULL )
        us->s.ofe_code_start = ofe_socktbl_find(
                                   ep->netif->ofe, OFE_SOCKTYPE_UDP,
                                   udp_laddr_be32(us), udp_raddr_be32(us),
                                   udp_lport_be16(us), udp_rport_be16(us));
#endif

    if( (rc = ci_udp_set_filters(ep, us)) != 0 )
        /* Not too bad -- should still get packets via OS socket. */
        LOG_U(log(FNS_FMT "ERROR: ci_udp_set_filters failed (%d)",
                  FNS_PRI_ARGS(ep->netif, ep->s), errno));
    us->s.cp.sock_cp_flags &= ~OO_SCP_CONNECTED;
    return 0;
}
Example #2
0
/* Conclude the EP's binding.  This function is abstracted from the
 * main bind code to allow implicit binds that occur when sendto() is
 * called on an OS socket.  [lport] and CI_SIN(addr)->sin_port do not
 * have to be the same value. */
static int ci_udp_bind_conclude(citp_socket* ep, const struct sockaddr* addr,
                                ci_uint16 lport )
{
    ci_udp_state* us;
    ci_uint32 addr_be32;
    int rc;

    CHECK_UEP(ep);
    ci_assert(addr != NULL);

    if( ci_udp_should_handover(ep, addr, lport) )
        goto handover;

    addr_be32 = ci_get_ip4_addr(ep->s->domain, addr);

    ci_udp_set_laddr(ep, addr_be32, lport);
    us = SOCK_TO_UDP(ep->s);
    if( addr_be32 != 0 )
        us->s.cp.sock_cp_flags |= OO_SCP_LADDR_BOUND;
    /* reset any rx/tx that have taken place already */
    UDP_CLR_FLAG(us, CI_UDPF_EF_SEND);

#ifdef ONLOAD_OFE
    if( ep->netif->ofe != NULL )
        us->s.ofe_code_start = ofe_socktbl_find(
                                   ep->netif->ofe, OFE_SOCKTYPE_UDP,
                                   udp_laddr_be32(us), udp_raddr_be32(us),
                                   udp_lport_be16(us), udp_rport_be16(us));
#endif

    /* OS source addrs have already been handed-over, so this must be one of
     * our src addresses.
     */
    rc = ci_udp_set_filters( ep, us);
    ci_assert( !UDP_GET_FLAG(us, CI_UDPF_EF_BIND) );
    /*! \todo FIXME isn't the port the thing to be testing here? */
    if( udp_laddr_be32(us) != INADDR_ANY_BE32 )
        UDP_SET_FLAG(us, CI_UDPF_EF_BIND);
    CI_UDPSTATE_SHOW_EP( ep );
    if( rc == CI_SOCKET_ERROR && CITP_OPTS.no_fail) {
        CITP_STATS_NETIF(++ep->netif->state->stats.udp_bind_no_filter);
        goto handover;
    }
    return rc;

handover:
    LOG_UV(log("%s: "SK_FMT" HANDOVER", __FUNCTION__, SK_PRI_ARGS(ep)));
    return CI_SOCKET_HANDOVER;
}
Example #3
0
/* Complete a UDP U/L connect.  The sys connect() call must have been made
 * (and succeeded) before calling this function.  So if anything goes wrong
 * in here, then it can be consider an internal error or failing of onload.
 */
int ci_udp_connect_conclude(citp_socket* ep, ci_fd_t fd,
                            const struct sockaddr* serv_addr,
                            socklen_t addrlen, ci_fd_t os_sock)
{
    const struct sockaddr_in* serv_sin = (const struct sockaddr_in*) serv_addr;
    ci_uint32 dst_be32;
    ci_udp_state* us = SOCK_TO_UDP(ep->s);
    int onloadable;
    int rc = 0;

    CHECK_UEP(ep);

    UDP_CLR_FLAG(us, CI_UDPF_EF_SEND);
    us->s.rx_errno = 0;
    us->s.tx_errno = 0;

    if( IS_DISCONNECTING(serv_sin) ) {
        rc = ci_udp_disconnect(ep, us, os_sock);
        goto out;
    }
#if CI_CFG_FAKE_IPV6
    if( us->s.domain == PF_INET6 && !ci_tcp_ipv6_is_ipv4(serv_addr) ) {
        LOG_UC(log(FNT_FMT "HANDOVER not IPv4", FNT_PRI_ARGS(ep->netif, us)));
        goto handover;
    }
#endif

    dst_be32 = ci_get_ip4_addr(serv_sin->sin_family, serv_addr);
    if( (rc = ci_udp_sys_getsockname(os_sock, ep)) != 0 ) {
        LOG_E(log(FNT_FMT "ERROR: (%s:%d) sys_getsockname failed (%d)",
                  FNT_PRI_ARGS(ep->netif, us), ip_addr_str(dst_be32),
                  CI_BSWAP_BE16(serv_sin->sin_port), errno));
        goto out;
    }

    us->s.cp.sock_cp_flags |= OO_SCP_CONNECTED;
    ci_udp_set_raddr(us, dst_be32, serv_sin->sin_port);
    cicp_user_retrieve(ep->netif, &us->s.pkt, &us->s.cp);

    switch( us->s.pkt.status ) {
    case retrrc_success:
    case retrrc_nomac:
        onloadable = 1;
        break;
    default:
        onloadable = 0;
        if( NI_OPTS(ep->netif).udp_connect_handover ) {
            LOG_UC(log(FNT_FMT "HANDOVER %s:%d", FNT_PRI_ARGS(ep->netif, us),
                       ip_addr_str(dst_be32), CI_BSWAP_BE16(serv_sin->sin_port)));
            goto handover;
        }
        break;
    }

    if( dst_be32 == INADDR_ANY_BE32 || serv_sin->sin_port == 0 ) {
        LOG_UC(log(FNT_FMT "%s:%d - route via OS socket",
                   FNT_PRI_ARGS(ep->netif, us), ip_addr_str(dst_be32),
                   CI_BSWAP_BE16(serv_sin->sin_port)));
        ci_udp_clr_filters(ep);
        return 0;
    }
    if( CI_IP_IS_LOOPBACK(dst_be32) ) {
        /* After connecting via loopback it is not possible to connect anywhere
         * else.
         */
        LOG_UC(log(FNT_FMT "HANDOVER %s:%d", FNT_PRI_ARGS(ep->netif, us),
                   ip_addr_str(dst_be32), CI_BSWAP_BE16(serv_sin->sin_port)));
        goto handover;
    }

    if( onloadable ) {
#ifdef ONLOAD_OFE
        if( ep->netif->ofe != NULL )
            us->s.ofe_code_start = ofe_socktbl_find(
                                       ep->netif->ofe, OFE_SOCKTYPE_UDP,
                                       udp_laddr_be32(us), udp_raddr_be32(us),
                                       udp_lport_be16(us), udp_rport_be16(us));
#endif

        if( (rc = ci_udp_set_filters(ep, us)) != 0 ) {
            /* Failed to set filters.  Most likely we've run out of h/w filters.
             * Handover to O/S to avoid breaking the app.
             *
             * TODO: Actually we probably won't break the app if we don't
             * handover, as packets will still get delivered via the kernel
             * stack.  Might be worth having a runtime option to choose whether
             * or not to handover in such cases.
             */
            LOG_U(log(FNT_FMT "ERROR: (%s:%d) ci_udp_set_filters failed (%d)",
                      FNT_PRI_ARGS(ep->netif, us), ip_addr_str(dst_be32),
                      CI_BSWAP_BE16(serv_sin->sin_port), rc));
            CITP_STATS_NETIF(++ep->netif->state->stats.udp_connect_no_filter);
            goto out;
        }
    }
    else {
        ci_udp_clr_filters(ep);
    }

    LOG_UC(log(LPF "connect: "SF_FMT" %sCONNECTED L:%s:%u R:%s:%u (err:%d)",
               SF_PRI_ARGS(ep,fd), udp_raddr_be32(us) ? "" : "DIS",
               ip_addr_str(udp_laddr_be32(us)),
               (unsigned) CI_BSWAP_BE16(udp_lport_be16(us)),
               ip_addr_str(udp_raddr_be32(us)),
               (unsigned) CI_BSWAP_BE16(udp_rport_be16(us)), errno));
    return 0;

out:
    if( rc < 0 && CITP_OPTS.no_fail )
        goto handover;
    return rc;

handover:
    ci_udp_clr_filters(ep);
    return CI_SOCKET_HANDOVER;
}
Example #4
0
static int ci_tcp_connect_ul_start(ci_netif *ni, ci_tcp_state* ts,
				   ci_uint32 dst_be32, unsigned dport_be16,
                                   int* fail_rc)
{
  ci_ip_pkt_fmt* pkt;
  int rc = 0;

  ci_assert(ts->s.pkt.mtu);

  /* Now that we know the outgoing route, set the MTU related values.
   * Note, even these values are speculative since the real MTU
   * could change between now and passing the packet to the lower layers
   */
  ts->amss = ts->s.pkt.mtu - sizeof(ci_tcp_hdr) - sizeof(ci_ip4_hdr);
#if CI_CFG_LIMIT_AMSS
  ts->amss = ci_tcp_limit_mss(ts->amss, ni, __FUNCTION__);
#endif

  /* Default smss until discovered by MSS option in SYN - RFC1122 4.2.2.6 */
  ts->smss = CI_CFG_TCP_DEFAULT_MSS;

  /* set pmtu, eff_mss, snd_buf and adjust windows */
  ci_pmtu_set(ni, &ts->pmtus, ts->s.pkt.mtu);
  ci_tcp_set_eff_mss(ni, ts);
  ci_tcp_set_initialcwnd(ni, ts);

  /* Send buffer adjusted by ci_tcp_set_eff_mss(), but we want it to stay
   * zero until the connection is established.
   */
  ts->so_sndbuf_pkts = 0;

  /* 
   * 3. State and address are OK. It's address routed through our NIC.
   *    Do connect().
   */
  ci_assert_nequal(ts->s.pkt.ip.ip_saddr_be32, INADDR_ANY);

  if( ts->s.s_flags & CI_SOCK_FLAG_CONNECT_MUST_BIND ) {
    ci_sock_cmn* s = &ts->s;
    ci_uint16 source_be16 = 0;

    if( s->s_flags & CI_SOCK_FLAG_ADDR_BOUND )
      rc = __ci_bind(ni, &ts->s, ts->s.pkt.ip.ip_saddr_be32, &source_be16);
    else 
      rc = __ci_bind(ni, &ts->s, INADDR_ANY, &source_be16);
    if(CI_LIKELY( rc == 0 )) {
      TS_TCP(ts)->tcp_source_be16 = source_be16;
      ts->s.cp.lport_be16 = source_be16;
      LOG_TC(log(LNT_FMT "connect: our bind returned %s:%u", 
                 LNT_PRI_ARGS(ni, ts),
                 ip_addr_str(INADDR_ANY),
                 (unsigned) CI_BSWAP_BE16(TS_TCP(ts)->tcp_source_be16)));
    }
    else {
      LOG_U(ci_log("__ci_bind returned %d at %s:%d", CI_GET_ERROR(rc),
                   __FILE__, __LINE__));
      *fail_rc = rc;
      return CI_CONNECT_UL_FAIL;
    }
    if(CI_UNLIKELY( ts->s.pkt.ip.ip_saddr_be32 == 0 )) {
      CI_SET_ERROR(*fail_rc, EINVAL);
      return CI_CONNECT_UL_FAIL;
    }
  }

  ci_tcp_set_peer(ts, dst_be32, dport_be16);

  /* Make sure we can get a buffer before we change state. */
  pkt = ci_netif_pkt_tx_tcp_alloc(ni);
  if( CI_UNLIKELY(! pkt) ) {
    /* NB. We've already done a poll above. */
    rc = ci_netif_pkt_wait(ni, &ts->s, CI_SLEEP_NETIF_LOCKED|CI_SLEEP_NETIF_RQ);
    if( ci_netif_pkt_wait_was_interrupted(rc) ) {
      CI_SET_ERROR(*fail_rc, -rc);
      return CI_CONNECT_UL_LOCK_DROPPED;
    }
    /* OK, there are (probably) packets available - go try again.  Note we
     * jump back to the top of the function because someone may have
     * connected this socket in the mean-time, so we need to check the
     * state once more.
     */
    return CI_CONNECT_UL_START_AGAIN;
  }

#ifdef ONLOAD_OFE
    if( ni->ofe != NULL )
      ts->s.ofe_code_start = ofe_socktbl_find(
                        ni->ofe, OFE_SOCKTYPE_TCP_ACTIVE,
                        tcp_laddr_be32(ts), tcp_raddr_be32(ts),
                        tcp_lport_be16(ts), tcp_rport_be16(ts));
#endif

  rc = ci_tcp_ep_set_filters(ni, S_SP(ts), ts->s.cp.so_bindtodevice,
                             OO_SP_NULL);
  if( rc < 0 ) {
    /* Perhaps we've run out of filters?  See if we can push a socket out
     * of timewait and steal its filter.
     */
    ci_assert_nequal(rc, -EFILTERSSOME);
    if( rc != -EBUSY || ! ci_netif_timewait_try_to_free_filter(ni) ||
        (rc = ci_tcp_ep_set_filters(ni, S_SP(ts),
                                    ts->s.cp.so_bindtodevice,
                                    OO_SP_NULL)) < 0 ) {
      ci_assert_nequal(rc, -EFILTERSSOME);
      /* Either a different error, or our efforts to free a filter did not
       * work.
       */
      if( ! (ts->s.s_flags & CI_SOCK_FLAG_ADDR_BOUND) ) {
        ts->s.pkt.ip.ip_saddr_be32 = 0;
        ts->s.cp.ip_laddr_be32 = 0;
      }
      ci_netif_pkt_release(ni, pkt);
      CI_SET_ERROR(*fail_rc, -rc);
      return CI_CONNECT_UL_FAIL;
    }
  }

  LOG_TC(log(LNT_FMT "CONNECT %s:%u->%s:%u", LNT_PRI_ARGS(ni, ts),
	     ip_addr_str(ts->s.pkt.ip.ip_saddr_be32),
	     (unsigned) CI_BSWAP_BE16(TS_TCP(ts)->tcp_source_be16),
	     ip_addr_str(ts->s.pkt.ip.ip_daddr_be32),
	     (unsigned) CI_BSWAP_BE16(TS_TCP(ts)->tcp_dest_be16)));

  /* We are going to send the SYN - set states appropriately */
  tcp_snd_una(ts) = tcp_snd_nxt(ts) = tcp_enq_nxt(ts) = tcp_snd_up(ts) =
    ci_tcp_initial_seqno(ni);
  ts->snd_max = tcp_snd_nxt(ts) + 1;

  /* Must be after initialising snd_una. */
  ci_tcp_clear_rtt_timing(ts);
  ci_tcp_set_flags(ts, CI_TCP_FLAG_SYN);
  ts->tcpflags &=~ CI_TCPT_FLAG_OPT_MASK;
  ts->tcpflags |= NI_OPTS(ni).syn_opts;

  if( (ts->tcpflags & CI_TCPT_FLAG_WSCL) ) {
    ts->rcv_wscl = ci_tcp_wscl_by_buff(ni, ci_tcp_rcvbuf_established(ni, &ts->s));
    CI_IP_SOCK_STATS_VAL_RXWSCL(ts, ts->rcv_wscl);
  }
  else {
    ts->rcv_wscl = 0;
    CI_IP_SOCK_STATS_VAL_RXWSCL(ts, 0);
  }
  ci_tcp_set_rcvbuf(ni, ts);
  ci_tcp_init_rcv_wnd(ts, "CONNECT");

  /* outgoing_hdrs_len is initialised to include timestamp option. */
  if( ! (ts->tcpflags & CI_TCPT_FLAG_TSO) )
    ts->outgoing_hdrs_len = sizeof(ci_ip4_hdr)+sizeof(ci_tcp_hdr);
  if( ci_tcp_can_stripe(ni, ts->s.pkt.ip.ip_saddr_be32,
			ts->s.pkt.ip.ip_daddr_be32) )
    ts->tcpflags |= CI_TCPT_FLAG_STRIPE;
  ci_tcp_set_slow_state(ni, ts, CI_TCP_SYN_SENT);

  /* If the app trys to send data on a socket in SYN_SENT state
  ** then the data is queued for send until the SYN gets ACKed.
  ** (rfc793 p56)
  **
  ** Receive calls on the socket should block until data arrives
  ** (rfc793 p58)
  **
  ** Clearing tx_errno and rx_errno acheive this. The transmit window
  ** is set to 1 byte which ensures that only the SYN packet gets
  ** sent until the ACK is received with more window. 
  */
  ci_assert(ts->snd_max == tcp_snd_nxt(ts) + 1);
  ts->s.rx_errno = 0;
  ts->s.tx_errno = 0; 
  ci_tcp_enqueue_no_data(ts, ni, pkt);
  ci_tcp_set_flags(ts, CI_TCP_FLAG_ACK);  

  if( ts->s.b.sb_aflags & (CI_SB_AFLAG_O_NONBLOCK | CI_SB_AFLAG_O_NDELAY) ) {
    ts->tcpflags |= CI_TCPT_FLAG_NONBLOCK_CONNECT;
    LOG_TC(log( LNT_FMT "Non-blocking connect - return EINPROGRESS",
		LNT_PRI_ARGS(ni, ts)));
    CI_SET_ERROR(*fail_rc, EINPROGRESS);
    return CI_CONNECT_UL_FAIL;
  }

  return CI_CONNECT_UL_OK;
}
Example #5
0
int ci_tcp_listen(citp_socket* ep, ci_fd_t fd, int backlog)
{
  /* 
  ** ?? error handling on possible fails not handled robustly...
  ** ?? Need to check port number is valid TODO
  */

  /*! \todo If not bound then we have to be listening on all interfaces.
   * It's likely that we won't be coming through here as we have to
   * listen on the OS socket too! */
  ci_tcp_state* ts;
  ci_tcp_socket_listen* tls;
  ci_netif* netif = ep->netif;
  ci_sock_cmn* s = ep->s;
  unsigned ul_backlog = backlog;
  int rc;
  oo_p sp;

  LOG_TC(log("%s "SK_FMT" listen backlog=%d", __FUNCTION__, SK_PRI_ARGS(ep), 
             backlog));
  CHECK_TEP(ep);

  if( NI_OPTS(netif).tcp_listen_handover )
    return CI_SOCKET_HANDOVER;
  if( !NI_OPTS(netif).tcp_server_loopback) {
    /* We should handover if the socket is bound to alien address. */
    if( s->s_flags & CI_SOCK_FLAG_BOUND_ALIEN )
      return CI_SOCKET_HANDOVER;
  }

  if( ul_backlog < 0 )
    ul_backlog = NI_OPTS(netif).max_ep_bufs;
  else if( ul_backlog < NI_OPTS(netif).acceptq_min_backlog )
    ul_backlog = NI_OPTS(netif).acceptq_min_backlog;

  if( s->b.state == CI_TCP_LISTEN ) {
    tls = SOCK_TO_TCP_LISTEN(s);
    tls->acceptq_max = ul_backlog;
    ci_tcp_helper_listen_os_sock(fd, ul_backlog);
    return 0;
  }

  if( s->b.state != CI_TCP_CLOSED ) {
    CI_SET_ERROR(rc, EINVAL);
    return rc;
  }


  ts = SOCK_TO_TCP(s);

  /* Bug 3376: if socket used for a previous, failed, connect then the error
   * numbers will not be as expected.  Only seen when not using listening
   * netifs (as moving the EP to the new netif resets them). 
   */

  ts->s.tx_errno = EPIPE;



  ts->s.rx_errno = ENOTCONN;

  /* fill in address/ports and all TCP state */
  if( !(ts->s.s_flags & CI_SOCK_FLAG_BOUND) ) {
    ci_uint16 source_be16;

    /* They haven't previously done a bind, so we need to choose 
     * a port.  As we haven't been given a hint we let the OS choose. */

    source_be16 = 0;
    rc = __ci_bind(ep->netif, ep->s, ts->s.pkt.ip.ip_saddr_be32, &source_be16);
    if (CI_LIKELY( rc==0 )) {
      TS_TCP(ts)->tcp_source_be16 = source_be16;
      ts->s.cp.lport_be16 = source_be16;
      LOG_TC(log(LNT_FMT "listen: our bind returned %s:%u", 
                 LNT_PRI_ARGS(ep->netif, ts),
                 ip_addr_str(ts->s.pkt.ip.ip_saddr_be32),
                 (unsigned) CI_BSWAP_BE16(TS_TCP(ts)->tcp_source_be16)));

    } else {
      LOG_U(ci_log("__ci_bind returned %d at %s:%d", CI_GET_ERROR(rc),
                   __FILE__, __LINE__));
      return rc;
    }
  } 

  ci_sock_lock(netif, &ts->s.b);
  ci_tcp_set_slow_state(netif, ts, CI_TCP_LISTEN);
  tls = SOCK_TO_TCP_LISTEN(&ts->s);

  tcp_raddr_be32(tls) = 0u;
  tcp_rport_be16(tls) = 0u;

  ci_assert_equal(tls->s.tx_errno, EPIPE);



  ci_assert_equal(tls->s.rx_errno, ENOTCONN);

  /* setup listen timer - do it before the first return statement,
   * because __ci_tcp_listen_to_normal() will be called on error path. */
  if( ~tls->s.s_flags & CI_SOCK_FLAG_BOUND_ALIEN ) {
    sp = TS_OFF(netif, tls);
    OO_P_ADD(sp, CI_MEMBER_OFFSET(ci_tcp_socket_listen, listenq_tid));
    ci_ip_timer_init(netif, &tls->listenq_tid, sp, "lstq");
    tls->listenq_tid.param1 = S_SP(tls);
    tls->listenq_tid.fn = CI_IP_TIMER_TCP_LISTEN;
  }

  rc = ci_tcp_listen_init(netif, tls);
  ci_sock_unlock(netif, &ts->s.b);
  if( rc != 0 ) {
    CI_SET_ERROR(rc, -rc);
    goto listen_fail;
  }
  tls->acceptq_max = ul_backlog;

  CITP_STATS_TCP_LISTEN(CI_ZERO(&tls->stats));

  /* install all the filters needed for this connection 
   *    - tcp_laddr_be32(ts) = 0 for IPADDR_ANY
   *
   *  TODO: handle BINDTODEVICE by setting phys_port paramter to correct 
   *        physical L5 port index
   *  TODO: handle REUSEADDR by setting last paramter to TRUE
   */
  if( ~s->s_flags & CI_SOCK_FLAG_BOUND_ALIEN ) {
#ifdef ONLOAD_OFE
    if( netif->ofe != NULL ) {
      tls->s.ofe_code_start = ofe_socktbl_find(
                        netif->ofe, OFE_SOCKTYPE_TCP_LISTEN,
                        tcp_laddr_be32(tls), INADDR_ANY,
                        tcp_lport_be16(ts), 0);
      tls->ofe_promote = ofe_socktbl_find(
                        netif->ofe, OFE_SOCKTYPE_TCP_PASSIVE,
                        tcp_laddr_be32(tls), INADDR_ANY,
                        tcp_lport_be16(ts), 0);
    }
#endif
    rc = ci_tcp_ep_set_filters(netif, S_SP(tls), tls->s.cp.so_bindtodevice,
                               OO_SP_NULL);
    if( rc == -EFILTERSSOME ) {
      if( CITP_OPTS.no_fail )
        rc = 0;
      else {
        ci_tcp_ep_clear_filters(netif, S_SP(tls), 0);
        rc = -ENOBUFS;
      }
    }
    ci_assert_nequal(rc, -EFILTERSSOME);
    VERB(ci_log("%s: set_filters  returned %d", __FUNCTION__, rc));
    if (rc < 0) {
      CI_SET_ERROR(rc, -rc);
      goto post_listen_fail;
    }
  }


  /* 
   * Call of system listen() is required for listen any, local host
   * communications server and multi-homed server (to accept connections
   * to L5 assigned address(es), but incoming from other interfaces).
   */
#ifdef __ci_driver__
  {
    rc = efab_tcp_helper_listen_os_sock( netif2tcp_helper_resource(netif),
					 S_SP(tls), backlog);
  }
#else
  rc = ci_tcp_helper_listen_os_sock(fd, backlog);
#endif
  if ( rc < 0 ) {
    /* clear the filter we've just set */
    ci_tcp_ep_clear_filters(netif, S_SP(tls), 0);
    goto post_listen_fail;
  }
  return 0;

 post_listen_fail:
  ci_tcp_listenq_drop_all(netif, tls);
 listen_fail:
  /* revert TCP state to a non-listening socket format */
  __ci_tcp_listen_to_normal(netif, tls);
  /* Above function sets orphan flag but we are attached to an FD. */
  ci_bit_clear(&tls->s.b.sb_aflags, CI_SB_AFLAG_ORPHAN_BIT);
#ifdef __ci_driver__
  return rc;
#else
  return CI_SOCKET_ERROR;
#endif
}