sockets.c

《嵌入式网络系统设计-基于Atmel ARM7 系列》这个本书的光盘资料

}

int
lwip_recv(int s, void *mem, int len, unsigned int flags)
{
  return lwip_recvfrom(s, mem, len, flags, NULL, NULL);
}

int
lwip_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;
}

int
lwip_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;
}

int
lwip_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;
}

int
lwip_write(int s, void *data, int size)
{
   return lwip_send(s, data, size, 0);
}


static int
lwip_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;
}



int
lwip_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 void
event_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;