/* Timeout */      if (readset)        FD_ZERO(readset);      if (writeset)        FD_ZERO(writeset);      if (exceptset)        FD_ZERO(exceptset);        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: timeout expired\r\n"));      set_errno(0);        return 0;    }        if (readset)      lreadset = *readset;    else      FD_ZERO(&lreadset);    if (writeset)      lwriteset = *writeset;    else      FD_ZERO(&lwriteset);    if (exceptset)      lexceptset = *exceptset;    else      FD_ZERO(&lexceptset);        /* See what's set */    nready = lwip_selscan(maxfdp1, &lreadset, &lwriteset, &lexceptset);  } else    sys_sem_signal(selectsem);    if (readset)    *readset = lreadset;  if (writeset)    *writeset = lwriteset;  if (exceptset)    *exceptset = lexceptset;    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: nready=%d\r\n", nready));  set_errno(0);    return nready;}/** * Callback registered in the netconn layer for each socket-netconn. * Processes recvevent (data available) and wakes up tasks waiting for select. */static voidevent_callback(struct netconn *conn, enum netconn_evt evt, u16_t len){  int s;  struct lwip_socket *sock;  struct lwip_select_cb *scb;  LWIP_UNUSED_ARG(len);  /* Get socket */  if (conn) {    s = conn->socket;    if (s < 0) {      /* Data comes in right away after an accept, even though       * the server task might not have created a new socket yet.       * Just count down (or up) if that's the case and we       * will use the data later. Note that only receive events       * can happen before the new socket is set up. */      sys_sem_wait(socksem);      if (conn->socket < 0) {        if (evt == NETCONN_EVT_RCVPLUS) {          conn->socket--;        }        sys_sem_signal(socksem);        return;      }      s = conn->socket;      sys_sem_signal(socksem);    }    sock = get_socket(s);    if (!sock) {      return;    }  } else {    return;  }  sys_sem_wait(selectsem);  /* Set event as required */  switch (evt) {    case NETCONN_EVT_RCVPLUS:      sock->rcvevent++;      break;    case NETCONN_EVT_RCVMINUS:      sock->rcvevent--;      break;    case NETCONN_EVT_SENDPLUS:      sock->sendevent = 1;      break;    case NETCONN_EVT_SENDMINUS:      sock->sendevent = 0;      break;    default:      LWIP_ASSERT("unknown event", 0);      break;  }  sys_sem_signal(selectsem);  /* Now decide if anyone is waiting for this socket */  /* NOTE: This code is written this way to protect the select link list     but to avoid a deadlock situation by releasing socksem before     signalling for the select. This means we need to go through the list     multiple times ONLY IF a select was actually waiting. We go through     the list the number of waiting select calls + 1. This list is     expected to be small. */  while (1) {    sys_sem_wait(selectsem);    for (scb = select_cb_list; scb; scb = scb->next) {      if (scb->sem_signalled == 0) {        /* Test this select call for our socket */        if (scb->readset && FD_ISSET(s, scb->readset))          if (sock->rcvevent > 0)            break;        if (scb->writeset && FD_ISSET(s, scb->writeset))          if (sock->sendevent)            break;      }    }    if (scb) {      scb->sem_signalled = 1;      sys_sem_signal(scb->sem);      sys_sem_signal(selectsem);    } else {      sys_sem_signal(selectsem);      break;    }  }}/** * Unimplemented: Close one end of a full-duplex connection. * Currently, the full connection is closed. */intlwip_shutdown(int s, int how){  LWIP_UNUSED_ARG(how);  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_shutdown(%d, how=%d)\r\n", s, how));  return lwip_close(s); /* XXX temporary hack until proper implementation */}static intlwip_getaddrname(int s, struct sockaddr *name, socklen_t *namelen, u8_t local){  struct lwip_socket *sock;  struct sockaddr_in sin;  struct ip_addr naddr;  sock = get_socket(s);  if (!sock)    return -1;  memset(&sin, 0, sizeof(sin));  sin.sin_len = sizeof(sin);  sin.sin_family = AF_INET;  /* get the IP address and port */  netconn_getaddr(sock->conn, &naddr, &sin.sin_port, local);  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getaddrname(%d, addr=", s));  ip_addr_debug_print(SOCKETS_DEBUG, &naddr);  LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F")\r\n", sin.sin_port));  sin.sin_port = htons(sin.sin_port);  sin.sin_addr.s_addr = naddr.addr;  if (*namelen > sizeof(sin))    *namelen = sizeof(sin);  MEMCPY(name, &sin, *namelen);  sock_set_errno(sock, 0);  return 0;}intlwip_getpeername(int s, struct sockaddr *name, socklen_t *namelen){  return lwip_getaddrname(s, name, namelen, 0);}intlwip_getsockname(int s, struct sockaddr *name, socklen_t *namelen){  return lwip_getaddrname(s, name, namelen, 1);}intlwip_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen){  err_t err = ERR_OK;  struct lwip_socket *sock = get_socket(s);  struct lwip_setgetsockopt_data data;  if (!sock)    return -1;  if ((NULL == optval) || (NULL == optlen)) {    sock_set_errno(sock, EFAULT);    return -1;  }  /* Do length and type checks for the various options first, to keep it readable. */  switch (level) {   /* Level: SOL_SOCKET */  case SOL_SOCKET:    switch (optname) {           case SO_ACCEPTCONN:    case SO_BROADCAST:    /* UNIMPL case SO_DEBUG: */    /* UNIMPL case SO_DONTROUTE: */    case SO_ERROR:    case SO_KEEPALIVE:    /* UNIMPL case SO_CONTIMEO: */    /* UNIMPL case SO_SNDTIMEO: */#if LWIP_SO_RCVTIMEO    case SO_RCVTIMEO:#endif /* LWIP_SO_RCVTIMEO */#if LWIP_SO_RCVBUF    case SO_RCVBUF:#endif /* LWIP_SO_RCVBUF */    /* UNIMPL case SO_OOBINLINE: */    /* UNIMPL case SO_SNDBUF: */    /* UNIMPL case SO_RCVLOWAT: */    /* UNIMPL case SO_SNDLOWAT: */#if SO_REUSE    case SO_REUSEADDR:    case SO_REUSEPORT:#endif /* SO_REUSE */    case SO_TYPE:    /* UNIMPL case SO_USELOOPBACK: */      if (*optlen < sizeof(int)) {        err = EINVAL;      }      break;    case SO_NO_CHECK:      if (*optlen < sizeof(int)) {        err = EINVAL;      }#if LWIP_UDP      if ((sock->conn->type != NETCONN_UDP) ||          ((udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_UDPLITE) != 0)) {        /* this flag is only available for UDP, not for UDP lite */        err = EAFNOSUPPORT;      }#endif /* LWIP_UDP */      break;    default:      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, UNIMPL: optname=0x%x, ..)\r\n",                                  s, optname));      err = ENOPROTOOPT;    }  /* switch (optname) */    break;                     /* Level: IPPROTO_IP */  case IPPROTO_IP:    switch (optname) {    /* UNIMPL case IP_HDRINCL: */    /* UNIMPL case IP_RCVDSTADDR: */    /* UNIMPL case IP_RCVIF: */    case IP_TTL:    case IP_TOS:      if (*optlen < sizeof(int)) {        err = EINVAL;      }      break;#if LWIP_IGMP    case IP_MULTICAST_TTL:      if (*optlen < sizeof(u8_t)) {        err = EINVAL;      }      break;    case IP_MULTICAST_IF:      if (*optlen < sizeof(struct in_addr)) {        err = EINVAL;      }      break;#endif /* LWIP_IGMP */    default:      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, UNIMPL: optname=0x%x, ..)\r\n",                                  s, optname));      err = ENOPROTOOPT;    }  /* switch (optname) */    break;         #if LWIP_TCP/* Level: IPPROTO_TCP */  case IPPROTO_TCP:    if (*optlen < sizeof(int)) {      err = EINVAL;      break;    }        /* If this is no TCP socket, ignore any options. */    if (sock->conn->type != NETCONN_TCP)      return 0;    switch (optname) {    case TCP_NODELAY:    case TCP_KEEPALIVE:#if LWIP_TCP_KEEPALIVE    case TCP_KEEPIDLE:    case TCP_KEEPINTVL:    case TCP_KEEPCNT:#endif /* LWIP_TCP_KEEPALIVE */      break;           default:      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_TCP, UNIMPL: optname=0x%x, ..)\r\n",                                  s, optname));      err = ENOPROTOOPT;    }  /* switch (optname) */    break;#endif /* LWIP_TCP */#if LWIP_UDP && LWIP_UDPLITE/* Level: IPPROTO_UDPLITE */  case IPPROTO_UDPLITE:    if (*optlen < sizeof(int)) {      err = EINVAL;      break;    }        /* If this is no UDP lite socket, ignore any options. */    if (sock->conn->type != NETCONN_UDPLITE)      return 0;    switch (optname) {    case UDPLITE_SEND_CSCOV:    case UDPLITE_RECV_CSCOV:      break;           default:      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_UDPLITE, UNIMPL: optname=0x%x, ..)\r\n",                                  s, optname));      err = ENOPROTOOPT;    }  /* switch (optname) */    break;#endif /* LWIP_UDP && LWIP_UDPLITE*//* UNDEFINED LEVEL */  default:      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, level=0x%x, UNIMPL: optname=0x%x, ..)\r\n",                                  s, level, optname));      err = ENOPROTOOPT;  }  /* switch */     if (err != ERR_OK) {    sock_set_errno(sock, err);    return -1;  }  /* Now do the actual option processing */  data.sock = sock;  data.level = level;  data.optname = optname;  data.optval = optval;  data.optlen = optlen;  data.err = err;  tcpip_callback(lwip_getsockopt_internal, &data);  sys_arch_sem_wait(sock->conn->op_completed, 0);  /* maybe lwip_getsockopt_internal has changed err */  err = data.err;  sock_set_errno(sock, err);  return err ? -1 : 0;}static voidlwip_getsockopt_internal(void *arg){  struct lwip_socket *sock;#ifdef LWIP_DEBUG  int s;#endif /* LWIP_DEBUG */  int level, optname;  void *optval;  struct lwip_setgetsockopt_data *data;  LWIP_ASSERT("arg != NULL", arg != NULL);  data = (struct lwip_setgetsockopt_data*)arg;  sock = data->sock;#ifdef LWIP_DEBUG  s = data->s;#endif /* LWIP_DEBUG */  level = data->level;  optname = data->optname;  optval = data->optval;  switch (level) {   /* Level: SOL_SOCKET */  case SOL_SOCKET:    switch (optname) {    /* The option flags */    case SO_ACCEPTCONN:    case SO_BROADCAST:    /* UNIMPL case SO_DEBUG: */    /* UNIMPL case SO_DONTROUTE: */    case SO_KEEPALIVE:    /* UNIMPL case SO_OOBINCLUDE: */#if SO_REUSE    case SO_REUSEADDR:    case SO_REUSEPORT:#endif /* SO_REUSE */    /*case SO_USELOOPBACK: UNIMPL */      *(int*)optval = sock->conn->pcb.ip->so_options & optname;      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, optname=0x%x, ..) = %s\r\n",                                  s, optname, (*(int*)optval?"on":"off")));      break;    case SO_TYPE:      switch (NETCONNTYPE_GROUP(sock->conn->type)) {      case NETCONN_RAW:        *(int*)optval = SOCK_RAW;        break;      case NETCONN_TCP:        *(int*)optval = SOCK_STREAM;        break;      case NETCONN_UDP:        *(int*)optval = SOCK_DGRAM;        break;      default: /* unrecognized socket type */        *(int*)optval = sock->conn->type;        LWIP_DEBUGF(SOCKETS_DEBUG,                    ("lwip_getsockopt(%d, SOL_SOCKET, SO_TYPE): unrecognized socket type %d\r\n",                    s, *(int *)optval));      }  /* switch (sock->conn->type) */      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, SO_TYPE) = %d\r\n",                  s, *(int *)optval));      break;    case SO_ERROR:      if (sock->err == 0) {        sock_set_errno(sock, err_to_errno(sock->conn->err));      }       *(int *)optval = sock->err;      sock->err = 0;      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, SOL_SOCKET, SO_ERROR) = %d\r\n",                  s, *(int *)optval));      break;#if LWIP_SO_RCVTIMEO    case SO_RCVTIMEO:      *(int *)optval = sock->conn->recv_timeout;      break;#endif /* LWIP_SO_RCVTIMEO */#if LWIP_SO_RCVBUF    case SO_RCVBUF:      *(int *)optval = sock->conn->recv_bufsize;      break;#endif /* LWIP_SO_RCVBUF */#if LWIP_UDP    case SO_NO_CHECK:      *(int*)optval = (udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_NOCHKSUM) ? 1 : 0;      break;#endif /* LWIP_UDP*/    }  /* switch (optname) */    break;/* Level: IPPROTO_IP */  case IPPROTO_IP:    switch (optname) {    case IP_TTL:      *(int*)optval = sock->conn->pcb.ip->ttl;      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_TTL) = %d\r\n",                  s, *(int *)optval));      break;    case IP_TOS:      *(int*)optval = sock->conn->pcb.ip->tos;      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_TOS) = %d\r\n",                  s, *(int *)optval));      break;#if LWIP_IGMP    case IP_MULTICAST_TTL:      *(u8_t*)optval = sock->conn->pcb.ip->ttl;      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_getsockopt(%d, IPPROTO_IP, IP_MULTICAST_TTL) = %d\r\n",                  s, *(int *)optval));