lwip_recv(int s, void *mem, int len, unsigned int flags){  return lwip_recvfrom(s, mem, len, flags, NULL, NULL);}intlwip_send(int s, void *data, int size, unsigned int flags){  struct lwip_socket *sock;  struct netbuf *buf;  err_t err;  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d, data=%p, size=%d, flags=0x%x)\n", s, data, size, flags));  sock = get_socket(s);  if (!sock) {    set_errno(EBADF);    return -1;  }  switch (netconn_type(sock->conn)) {  case NETCONN_RAW:  case NETCONN_UDP:  case NETCONN_UDPLITE:  case NETCONN_UDPNOCHKSUM:    /* create a buffer */    buf = netbuf_new();    if (!buf) {      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d) ENOBUFS\n", s));      sock_set_errno(sock, ENOBUFS);      return -1;    }    /* make the buffer point to the data that should       be sent */    netbuf_ref(buf, data, size);    /* send the data */    err = netconn_send(sock->conn, buf);    /* deallocated the buffer */    netbuf_delete(buf);    break;  case NETCONN_TCP:    err = netconn_write(sock->conn, data, size, NETCONN_COPY);    break;  default:    err = ERR_ARG;    break;  }  if (err != ERR_OK) {    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d) err=%d\n", s, err));    sock_set_errno(sock, err_to_errno(err));    return -1;  }  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_send(%d) ok size=%d\n", s, size));  sock_set_errno(sock, 0);  return size;}intlwip_sendto(int s, void *data, int size, unsigned int flags,       struct sockaddr *to, socklen_t tolen){  struct lwip_socket *sock;  struct ip_addr remote_addr, addr;  u16_t remote_port, port;  int ret,connected;  sock = get_socket(s);  if (!sock) {    set_errno(EBADF);    return -1;  }  /* get the peer if currently connected */  connected = (netconn_peer(sock->conn, &addr, &port) == ERR_OK);  remote_addr.addr = ((struct sockaddr_in *)to)->sin_addr.s_addr;  remote_port = ((struct sockaddr_in *)to)->sin_port;  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_sendto(%d, data=%p, size=%d, flags=0x%x to=", s, data, size, flags));  ip_addr_debug_print(SOCKETS_DEBUG, &remote_addr);  LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%u\n", ntohs(remote_port)));  netconn_connect(sock->conn, &remote_addr, ntohs(remote_port));  ret = lwip_send(s, data, size, flags);  /* reset the remote address and port number     of the connection */  if (connected)    netconn_connect(sock->conn, &addr, port);  else  netconn_disconnect(sock->conn);  return ret;}intlwip_socket(int domain, int type, int protocol){  struct netconn *conn;  int i;  /* create a netconn */  switch (type) {  case SOCK_RAW:    conn = netconn_new_with_proto_and_callback(NETCONN_RAW, protocol, event_callback);    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_RAW, %d) = ", domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));    break;  case SOCK_DGRAM:    conn = netconn_new_with_callback(NETCONN_UDP, event_callback);    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_DGRAM, %d) = ", domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));    break;  case SOCK_STREAM:    conn = netconn_new_with_callback(NETCONN_TCP, event_callback);    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%s, SOCK_STREAM, %d) = ", domain == PF_INET ? "PF_INET" : "UNKNOWN", protocol));    break;  default:    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_socket(%d, %d/UNKNOWN, %d) = -1\n", domain, type, protocol));    set_errno(EINVAL);    return -1;  }  if (!conn) {    LWIP_DEBUGF(SOCKETS_DEBUG, ("-1 / ENOBUFS (could not create netconn)\n"));    set_errno(ENOBUFS);    return -1;  }  i = alloc_socket(conn);  if (i == -1) {    netconn_delete(conn);  set_errno(ENOBUFS);  return -1;  }  conn->socket = i;  LWIP_DEBUGF(SOCKETS_DEBUG, ("%d\n", i));  set_errno(0);  return i;}intlwip_write(int s, void *data, int size){   return lwip_send(s, data, size, 0);}static intlwip_selscan(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset){    int i, nready = 0;    fd_set lreadset, lwriteset, lexceptset;    struct lwip_socket *p_sock;    FD_ZERO(&lreadset);    FD_ZERO(&lwriteset);    FD_ZERO(&lexceptset);    /* Go through each socket in each list to count number of sockets which       currently match */    for(i = 0; i < maxfdp1; i++)    {        if (FD_ISSET(i, readset))        {            /* See if netconn of this socket is ready for read */            p_sock = get_socket(i);            if (p_sock && (p_sock->lastdata || p_sock->rcvevent))            {                FD_SET(i, &lreadset);		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for reading\n", i));                nready++;            }        }        if (FD_ISSET(i, writeset))        {            /* See if netconn of this socket is ready for write */            p_sock = get_socket(i);            if (p_sock && p_sock->sendevent)            {                FD_SET(i, &lwriteset);		LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_selscan: fd=%d ready for writing\n", i));                nready++;            }        }    }    *readset = lreadset;    *writeset = lwriteset;    FD_ZERO(exceptset);    return nready;}intlwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,               struct timeval *timeout){    int i;    int nready;    fd_set lreadset, lwriteset, lexceptset;    u32_t msectimeout;    struct lwip_select_cb select_cb;    struct lwip_select_cb *p_selcb;    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select(%d, %p, %p, %p, tvsec=%ld tvusec=%ld)\n", maxfdp1, (void *)readset, (void *) writeset, (void *) exceptset, timeout ? timeout->tv_sec : -1L, timeout ? timeout->tv_usec : -1L));    select_cb.next = 0;    select_cb.readset = readset;    select_cb.writeset = writeset;    select_cb.exceptset = exceptset;    select_cb.sem_signalled = 0;    /* Protect ourselves searching through the list */    if (!selectsem)        selectsem = sys_sem_new(1);    sys_sem_wait(selectsem);    if (readset)        lreadset = *readset;    else        FD_ZERO(&lreadset);    if (writeset)        lwriteset = *writeset;    else        FD_ZERO(&lwriteset);    if (exceptset)        lexceptset = *exceptset;    else        FD_ZERO(&lexceptset);    /* Go through each socket in each list to count number of sockets which       currently match */    nready = lwip_selscan(maxfdp1, &lreadset, &lwriteset, &lexceptset);    /* If we don't have any current events, then suspend if we are supposed to */    if (!nready)    {        if (timeout && timeout->tv_sec == 0 && timeout->tv_usec == 0)        {            sys_sem_signal(selectsem);            if (readset)                FD_ZERO(readset);            if (writeset)                FD_ZERO(writeset);            if (exceptset)                FD_ZERO(exceptset);	    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: no timeout, returning 0\n"));	    set_errno(0);            return 0;        }        /* add our semaphore to list */        /* We don't actually need any dynamic memory. Our entry on the         * list is only valid while we are in this function, so it's ok         * to use local variables */        select_cb.sem = sys_sem_new(0);        /* Note that we are still protected */        /* Put this select_cb on top of list */        select_cb.next = select_cb_list;        select_cb_list = &select_cb;        /* Now we can safely unprotect */        sys_sem_signal(selectsem);        /* Now just wait to be woken */        if (timeout == 0)            /* Wait forever */            msectimeout = 0;        else            msectimeout =  ((timeout->tv_sec * 1000) + ((timeout->tv_usec + 500)/1000));        i = sys_sem_wait_timeout(select_cb.sem, msectimeout);        /* Take us off the list */        sys_sem_wait(selectsem);        if (select_cb_list == &select_cb)            select_cb_list = select_cb.next;        else            for (p_selcb = select_cb_list; p_selcb; p_selcb = p_selcb->next)                if (p_selcb->next == &select_cb)                {                    p_selcb->next = select_cb.next;                    break;                }        sys_sem_signal(selectsem);        sys_sem_free(select_cb.sem);        if (i == 0)             /* Timeout */        {            if (readset)                FD_ZERO(readset);            if (writeset)                FD_ZERO(writeset);            if (exceptset)                FD_ZERO(exceptset);	    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_select: timeout expired\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\n", nready));    set_errno(0);    return nready;}static voidevent_callback(struct netconn *conn, enum netconn_evt evt, u16_t len){    int s;    struct lwip_socket *sock;    struct lwip_select_cb *scb;    /* 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. */            if (evt == NETCONN_EVT_RCVPLUS)                conn->socket--;            return;        }        sock = get_socket(s);        if (!sock)            return;    }    else        return;    if (!selectsem)        selectsem = sys_sem_new(1);    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;    }    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)                        break;                if (scb->writeset && FD_ISSET(s, scb->writeset))                    if (sock->sendevent)                        break;            }        }        if (scb)        {            scb->sem_signalled = 1;            sys_sem_signal(selectsem);            sys_sem_signal(scb->sem);        } else {            sys_sem_signal(selectsem);            break;        }    }}int lwip_shutdown(int s, int how){  LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_shutdown(%d, how=%d)\n", s, how));  return lwip_close(s); /* XXX temporary hack until proper implementation */}int lwip_getpeername (int s, struct sockaddr *name, socklen_t *namelen){  struct lwip_socket *sock;  struct sockaddr_in sin;  struct ip_addr naddr;  sock = get_socket(s);  if (!sock) {    set_errno(EBADF);    return -1;  }