api_msg.c

NXPl788上lwip的无操作系统移植,基于Embest开发板

  if ((old_state == NETCONN_WRITE) || (old_state == NETCONN_CLOSE) ||
      (old_state == NETCONN_CONNECT)) {
    /* calling do_writemore/do_close_internal is not necessary
       since the pcb has already been deleted! */
    int was_nonblocking_connect = IN_NONBLOCKING_CONNECT(conn);
    SET_NONBLOCKING_CONNECT(conn, 0);

    if (!was_nonblocking_connect) {
      /* set error return code */
      LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);
      conn->current_msg->err = err;
      conn->current_msg = NULL;
      /* wake up the waiting task */
      sys_sem_signal(&conn->op_completed);
    }
  } else {
    LWIP_ASSERT("conn->current_msg == NULL", conn->current_msg == NULL);
  }
}

/**
 * Setup a tcp_pcb with the correct callback function pointers
 * and their arguments.
 *
 * @param conn the TCP netconn to setup
 */
static void
setup_tcp(struct netconn *conn)
{
  struct tcp_pcb *pcb;

  pcb = conn->pcb.tcp;
  tcp_arg(pcb, conn);
  tcp_recv(pcb, recv_tcp);
  tcp_sent(pcb, sent_tcp);
  tcp_poll(pcb, poll_tcp, 4);
  tcp_err(pcb, err_tcp);
}

/**
 * Accept callback function for TCP netconns.
 * Allocates a new netconn and posts that to conn->acceptmbox.
 *
 * @see tcp.h (struct tcp_pcb_listen.accept) for parameters and return value
 */
static err_t
accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
{
  struct netconn *newconn;
  struct netconn *conn = (struct netconn *)arg;

  LWIP_DEBUGF(API_MSG_DEBUG, ("accept_function: newpcb->tate: %s\n", tcp_debug_state_str(newpcb->state)));

  if (!sys_mbox_valid(&conn->acceptmbox)) {
    LWIP_DEBUGF(API_MSG_DEBUG, ("accept_function: acceptmbox already deleted\n"));
    return ERR_VAL;
  }

  /* We have to set the callback here even though
   * the new socket is unknown. conn->socket is marked as -1. */
  newconn = netconn_alloc(conn->type, conn->callback);
  if (newconn == NULL) {
    return ERR_MEM;
  }
  newconn->pcb.tcp = newpcb;
  setup_tcp(newconn);
  /* no protection: when creating the pcb, the netconn is not yet known
     to the application thread */
  newconn->last_err = err;

  if (sys_mbox_trypost(&conn->acceptmbox, newconn) != ERR_OK) {
    /* When returning != ERR_OK, the pcb is aborted in tcp_process(),
       so do nothing here! */
    newconn->pcb.tcp = NULL;
    /* no need to drain since we know the recvmbox is empty. */
    sys_mbox_free(&newconn->recvmbox);
    sys_mbox_set_invalid(&newconn->recvmbox);
    netconn_free(newconn);
    return ERR_MEM;
  } else {
    /* Register event with callback */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
  }

  return ERR_OK;
}
#endif /* LWIP_TCP */

/**
 * Create a new pcb of a specific type.
 * Called from do_newconn().
 *
 * @param msg the api_msg_msg describing the connection type
 * @return msg->conn->err, but the return value is currently ignored
 */
static void
pcb_new(struct api_msg_msg *msg)
{
  LWIP_ASSERT("pcb_new: pcb already allocated", msg->conn->pcb.tcp == NULL);

  /* Allocate a PCB for this connection */
  switch(NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
  case NETCONN_RAW:
    msg->conn->pcb.raw = raw_new(msg->msg.n.proto);
    if(msg->conn->pcb.raw == NULL) {
      msg->err = ERR_MEM;
      break;
    }
    raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
    break;
#endif /* LWIP_RAW */
#if LWIP_UDP
  case NETCONN_UDP:
    msg->conn->pcb.udp = udp_new();
    if(msg->conn->pcb.udp == NULL) {
      msg->err = ERR_MEM;
      break;
    }
#if LWIP_UDPLITE
    if (msg->conn->type==NETCONN_UDPLITE) {
      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
    }
#endif /* LWIP_UDPLITE */
    if (msg->conn->type==NETCONN_UDPNOCHKSUM) {
      udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
    }
    udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
    break;
#endif /* LWIP_UDP */
#if LWIP_TCP
  case NETCONN_TCP:
    msg->conn->pcb.tcp = tcp_new();
    if(msg->conn->pcb.tcp == NULL) {
      msg->err = ERR_MEM;
      break;
    }
    setup_tcp(msg->conn);
    break;
#endif /* LWIP_TCP */
  default:
    /* Unsupported netconn type, e.g. protocol disabled */
    msg->err = ERR_VAL;
    break;
  }
}

/**
 * Create a new pcb of a specific type inside a netconn.
 * Called from netconn_new_with_proto_and_callback.
 *
 * @param msg the api_msg_msg describing the connection type
 */
void
do_newconn(struct api_msg_msg *msg)
{
  msg->err = ERR_OK;
  if(msg->conn->pcb.tcp == NULL) {
    pcb_new(msg);
  }
  /* Else? This "new" connection already has a PCB allocated. */
  /* Is this an error condition? Should it be deleted? */
  /* We currently just are happy and return. */

  TCPIP_APIMSG_ACK(msg);
}

/**
 * Create a new netconn (of a specific type) that has a callback function.
 * The corresponding pcb is NOT created!
 *
 * @param t the type of 'connection' to create (@see enum netconn_type)
 * @param proto the IP protocol for RAW IP pcbs
 * @param callback a function to call on status changes (RX available, TX'ed)
 * @return a newly allocated struct netconn or
 *         NULL on memory error
 */
struct netconn*
netconn_alloc(enum netconn_type t, netconn_callback callback)
{
  struct netconn *conn;
  int size;

  conn = (struct netconn *)memp_malloc(MEMP_NETCONN);
  if (conn == NULL) {
    return NULL;
  }

  conn->last_err = ERR_OK;
  conn->type = t;
  conn->pcb.tcp = NULL;

#if (DEFAULT_RAW_RECVMBOX_SIZE == DEFAULT_UDP_RECVMBOX_SIZE) && \
    (DEFAULT_RAW_RECVMBOX_SIZE == DEFAULT_TCP_RECVMBOX_SIZE)
  size = DEFAULT_RAW_RECVMBOX_SIZE;
#else
  switch(NETCONNTYPE_GROUP(t)) {
#if LWIP_RAW
  case NETCONN_RAW:
    size = DEFAULT_RAW_RECVMBOX_SIZE;
    break;
#endif /* LWIP_RAW */
#if LWIP_UDP
  case NETCONN_UDP:
    size = DEFAULT_UDP_RECVMBOX_SIZE;
    break;
#endif /* LWIP_UDP */
#if LWIP_TCP
  case NETCONN_TCP:
    size = DEFAULT_TCP_RECVMBOX_SIZE;
    break;
#endif /* LWIP_TCP */
  default:
    LWIP_ASSERT("netconn_alloc: undefined netconn_type", 0);
    break;
  }
#endif

  if (sys_sem_new(&conn->op_completed, 0) != ERR_OK) {
    memp_free(MEMP_NETCONN, conn);
    return NULL;
  }
  if (sys_mbox_new(&conn->recvmbox, size) != ERR_OK) {
    sys_sem_free(&conn->op_completed);
    memp_free(MEMP_NETCONN, conn);
    return NULL;
  }

#if LWIP_TCP
  sys_mbox_set_invalid(&conn->acceptmbox);
#endif
  conn->state        = NETCONN_NONE;
#if LWIP_SOCKET
  /* initialize socket to -1 since 0 is a valid socket */
  conn->socket       = -1;
#endif /* LWIP_SOCKET */
  conn->callback     = callback;
#if LWIP_TCP
  conn->current_msg  = NULL;
  conn->write_offset = 0;
#endif /* LWIP_TCP */
#if LWIP_SO_RCVTIMEO
  conn->recv_timeout = 0;
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
  conn->recv_bufsize = RECV_BUFSIZE_DEFAULT;
  conn->recv_avail   = 0;
#endif /* LWIP_SO_RCVBUF */
  conn->flags = 0;
  return conn;
}

/**
 * Delete a netconn and all its resources.
 * The pcb is NOT freed (since we might not be in the right thread context do this).
 *
 * @param conn the netconn to free
 */
void
netconn_free(struct netconn *conn)
{
  LWIP_ASSERT("PCB must be deallocated outside this function", conn->pcb.tcp == NULL);
  LWIP_ASSERT("recvmbox must be deallocated before calling this function",
    !sys_mbox_valid(&conn->recvmbox));
#if LWIP_TCP
  LWIP_ASSERT("acceptmbox must be deallocated before calling this function",
    !sys_mbox_valid(&conn->acceptmbox));
#endif /* LWIP_TCP */

  sys_sem_free(&conn->op_completed);
  sys_sem_set_invalid(&conn->op_completed);

  memp_free(MEMP_NETCONN, conn);
}

/**
 * Delete rcvmbox and acceptmbox of a netconn and free the left-over data in
 * these mboxes
 *
 * @param conn the netconn to free
 * @bytes_drained bytes drained from recvmbox
 * @accepts_drained pending connections drained from acceptmbox
 */
static void
netconn_drain(struct netconn *conn)
{
  void *mem;
#if LWIP_TCP
  struct pbuf *p;
#endif /* LWIP_TCP */

  /* This runs in tcpip_thread, so we don't need to lock against rx packets */

  /* Delete and drain the recvmbox. */
  if (sys_mbox_valid(&conn->recvmbox)) {
    while (sys_mbox_tryfetch(&conn->recvmbox, &mem) != SYS_MBOX_EMPTY) {
#if LWIP_TCP
      if (conn->type == NETCONN_TCP) {
        if(mem != NULL) {
          p = (struct pbuf*)mem;
          /* pcb might be set to NULL already by err_tcp() */
          if (conn->pcb.tcp != NULL) {
            tcp_recved(conn->pcb.tcp, p->tot_len);
          }
          pbuf_free(p);
        }
      } else
#endif /* LWIP_TCP */
      {
        netbuf_delete((struct netbuf *)mem);
      }
    }
    sys_mbox_free(&conn->recvmbox);
    sys_mbox_set_invalid(&conn->recvmbox);
  }

  /* Delete and drain the acceptmbox. */
#if LWIP_TCP
  if (sys_mbox_valid(&conn->acceptmbox)) {
    while (sys_mbox_tryfetch(&conn->acceptmbox, &mem) != SYS_MBOX_EMPTY) {
      struct netconn *newconn = (struct netconn *)mem;
      /* Only tcp pcbs have an acceptmbox, so no need to check conn->type */
      /* pcb might be set to NULL already by err_tcp() */
      if (conn->pcb.tcp != NULL) {
        tcp_accepted(conn->pcb.tcp);
      }
      /* drain recvmbox */
      netconn_drain(newconn);
      if (newconn->pcb.tcp != NULL) {
        tcp_abort(newconn->pcb.tcp);
        newconn->pcb.tcp = NULL;
      }
      netconn_free(newconn);
    }
    sys_mbox_free(&conn->acceptmbox);
    sys_mbox_set_invalid(&conn->acceptmbox);
  }
#endif /* LWIP_TCP */
}

#if LWIP_TCP
/**
 * Internal helper function to close a TCP netconn: since this sometimes
 * doesn't work at the first attempt, this function is called from multiple
 * places.
 *
 * @param conn the TCP netconn to close
 */
static void
do_close_internal(struct netconn *conn)
{
  err_t err;
  u8_t shut, shut_rx, shut_tx, close;

  LWIP_ASSERT("invalid conn", (conn != NULL));
  LWIP_ASSERT("this is for tcp netconns only", (conn->type == NETCONN_TCP));
  LWIP_ASSERT("conn must be in state NETCONN_CLOSE", (conn->state == NETCONN_CLOSE));
  LWIP_ASSERT("pcb already closed", (conn->pcb.tcp != NULL));
  LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);

  shut = conn->current_msg->msg.sd.shut;
  shut_rx = shut & NETCONN_SHUT_RD;
  shut_tx = shut & NETCONN_SHUT_WR;
  /* shutting down both ends is the same as closing */
  close = shut == NETCONN_SHUT_RDWR;

  /* Set back some callback pointers */
  if (close) {
    tcp_arg(conn->pcb.tcp, NULL);
  }
  if (conn->pcb.tcp->state == LISTEN) {
    tcp_accept(conn->pcb.tcp, NULL);
  } else {
    /* some callbacks have to be reset if tcp_close is not successful */
    if (shut_rx) {
      tcp_recv(conn->pcb.tcp, NULL);
      tcp_accept(conn->pcb.tcp, NULL);
    }
    if (shut_tx) {
      tcp_sent(conn->pcb.tcp, NULL);
    }
    if (close) {
      tcp_poll(conn->pcb.tcp, NULL, 4);