api_msg.c

lwip-1.4.0

    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);
      tcp_err(conn->pcb.tcp, NULL);
    }
  }
  /* Try to close the connection */
  if (shut == NETCONN_SHUT_RDWR) {
    err = tcp_close(conn->pcb.tcp);
  } else {
    err = tcp_shutdown(conn->pcb.tcp, shut & NETCONN_SHUT_RD, shut & NETCONN_SHUT_WR);
  }
  if (err == ERR_OK) {
    /* Closing succeeded */
    conn->current_msg->err = ERR_OK;
    conn->current_msg = NULL;
    conn->state = NETCONN_NONE;
    /* Set back some callback pointers as conn is going away */
    conn->pcb.tcp = NULL;
    /* Trigger select() in socket layer. Make sure everybody notices activity
       on the connection, error first! */
    if (close) {
      API_EVENT(conn, NETCONN_EVT_ERROR, 0);
    }
    if (shut_rx) {
      API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
    }
    if (shut_tx) {
      API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);
    }
    /* wake up the application task */
    sys_sem_signal(&conn->op_completed);
  } else {
    /* Closing failed, restore some of the callbacks */
    /* Closing of listen pcb will never fail! */
    LWIP_ASSERT("Closing a listen pcb may not fail!", (conn->pcb.tcp->state != LISTEN));
    tcp_sent(conn->pcb.tcp, sent_tcp);
    tcp_poll(conn->pcb.tcp, poll_tcp, 4);
    tcp_err(conn->pcb.tcp, err_tcp);
    tcp_arg(conn->pcb.tcp, conn);
    /* don't restore recv callback: we don't want to receive any more data */
  }
  /* If closing didn't succeed, we get called again either
     from poll_tcp or from sent_tcp */
}
#endif /* LWIP_TCP */

/**
 * Delete the pcb inside a netconn.
 * Called from netconn_delete.
 *
 * @param msg the api_msg_msg pointing to the connection
 */
void
do_delconn(struct api_msg_msg *msg)
{
  /* @todo TCP: abort running write/connect? */
 if ((msg->conn->state != NETCONN_NONE) &&
     (msg->conn->state != NETCONN_LISTEN) &&
     (msg->conn->state != NETCONN_CONNECT)) {
    /* this only happens for TCP netconns */
    LWIP_ASSERT("msg->conn->type == NETCONN_TCP", msg->conn->type == NETCONN_TCP);
    msg->err = ERR_INPROGRESS;
  } else {
    LWIP_ASSERT("blocking connect in progress",
      (msg->conn->state != NETCONN_CONNECT) || IN_NONBLOCKING_CONNECT(msg->conn));
    /* Drain and delete mboxes */
    netconn_drain(msg->conn);

    if (msg->conn->pcb.tcp != NULL) {

      switch (NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
      case NETCONN_RAW:
        raw_remove(msg->conn->pcb.raw);
        break;
#endif /* LWIP_RAW */
#if LWIP_UDP
      case NETCONN_UDP:
        msg->conn->pcb.udp->recv_arg = NULL;
        udp_remove(msg->conn->pcb.udp);
        break;
#endif /* LWIP_UDP */
#if LWIP_TCP
      case NETCONN_TCP:
        LWIP_ASSERT("already writing or closing", msg->conn->current_msg == NULL &&
          msg->conn->write_offset == 0);
        msg->conn->state = NETCONN_CLOSE;
        msg->msg.sd.shut = NETCONN_SHUT_RDWR;
        msg->conn->current_msg = msg;
        do_close_internal(msg->conn);
        /* API_EVENT is called inside do_close_internal, before releasing
           the application thread, so we can return at this point! */
        return;
#endif /* LWIP_TCP */
      default:
        break;
      }
      msg->conn->pcb.tcp = NULL;
    }
    /* tcp netconns don't come here! */

    /* @todo: this lets select make the socket readable and writable,
       which is wrong! errfd instead? */
    API_EVENT(msg->conn, NETCONN_EVT_RCVPLUS, 0);
    API_EVENT(msg->conn, NETCONN_EVT_SENDPLUS, 0);
  }
  if (sys_sem_valid(&msg->conn->op_completed)) {
    sys_sem_signal(&msg->conn->op_completed);
  }
}

/**
 * Bind a pcb contained in a netconn
 * Called from netconn_bind.
 *
 * @param msg the api_msg_msg pointing to the connection and containing
 *            the IP address and port to bind to
 */
void
do_bind(struct api_msg_msg *msg)
{
  if (ERR_IS_FATAL(msg->conn->last_err)) {
    msg->err = msg->conn->last_err;
  } else {
    msg->err = ERR_VAL;
    if (msg->conn->pcb.tcp != NULL) {
      switch (NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
      case NETCONN_RAW:
        msg->err = raw_bind(msg->conn->pcb.raw, msg->msg.bc.ipaddr);
        break;
#endif /* LWIP_RAW */
#if LWIP_UDP
      case NETCONN_UDP:
        msg->err = udp_bind(msg->conn->pcb.udp, msg->msg.bc.ipaddr, msg->msg.bc.port);
        break;
#endif /* LWIP_UDP */
#if LWIP_TCP
      case NETCONN_TCP:
        msg->err = tcp_bind(msg->conn->pcb.tcp, msg->msg.bc.ipaddr, msg->msg.bc.port);
        break;
#endif /* LWIP_TCP */
      default:
        break;
      }
    }
  }
  TCPIP_APIMSG_ACK(msg);
}

#if LWIP_TCP
/**
 * TCP callback function if a connection (opened by tcp_connect/do_connect) has
 * been established (or reset by the remote host).
 *
 * @see tcp.h (struct tcp_pcb.connected) for parameters and return values
 */
static err_t
do_connected(void *arg, struct tcp_pcb *pcb, err_t err)
{
  struct netconn *conn;
  int was_blocking;

  LWIP_UNUSED_ARG(pcb);

  conn = (struct netconn *)arg;

  if (conn == NULL) {
    return ERR_VAL;
  }

  LWIP_ASSERT("conn->state == NETCONN_CONNECT", conn->state == NETCONN_CONNECT);
  LWIP_ASSERT("(conn->current_msg != NULL) || conn->in_non_blocking_connect",
    (conn->current_msg != NULL) || IN_NONBLOCKING_CONNECT(conn));

  if (conn->current_msg != NULL) {
    conn->current_msg->err = err;
  }
  if ((conn->type == NETCONN_TCP) && (err == ERR_OK)) {
    setup_tcp(conn);
  }
  was_blocking = !IN_NONBLOCKING_CONNECT(conn);
  SET_NONBLOCKING_CONNECT(conn, 0);
  conn->current_msg = NULL;
  conn->state = NETCONN_NONE;
  if (!was_blocking) {
    NETCONN_SET_SAFE_ERR(conn, ERR_OK);
  }
  API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);

  if (was_blocking) {
    sys_sem_signal(&conn->op_completed);
  }
  return ERR_OK;
}
#endif /* LWIP_TCP */

/**
 * Connect a pcb contained inside a netconn
 * Called from netconn_connect.
 *
 * @param msg the api_msg_msg pointing to the connection and containing
 *            the IP address and port to connect to
 */
void
do_connect(struct api_msg_msg *msg)
{
  if (msg->conn->pcb.tcp == NULL) {
    /* This may happen when calling netconn_connect() a second time */
    msg->err = ERR_CLSD;
  } else {
    switch (NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
  case NETCONN_RAW:
    msg->err = raw_connect(msg->conn->pcb.raw, msg->msg.bc.ipaddr);
    break;
#endif /* LWIP_RAW */
#if LWIP_UDP
  case NETCONN_UDP:
    msg->err = udp_connect(msg->conn->pcb.udp, msg->msg.bc.ipaddr, msg->msg.bc.port);
    break;
#endif /* LWIP_UDP */
#if LWIP_TCP
  case NETCONN_TCP:
    /* Prevent connect while doing any other action. */
    if (msg->conn->state != NETCONN_NONE) {
      msg->err = ERR_ISCONN;
    } else {
      setup_tcp(msg->conn);
      msg->err = tcp_connect(msg->conn->pcb.tcp, msg->msg.bc.ipaddr,
        msg->msg.bc.port, do_connected);
      if (msg->err == ERR_OK) {
        u8_t non_blocking = netconn_is_nonblocking(msg->conn);
        msg->conn->state = NETCONN_CONNECT;
        SET_NONBLOCKING_CONNECT(msg->conn, non_blocking);
        if (non_blocking) {
          msg->err = ERR_INPROGRESS;
        } else {
          msg->conn->current_msg = msg;
          /* sys_sem_signal() is called from do_connected (or err_tcp()),
          * when the connection is established! */
          return;
        }
      }
    }
    break;
#endif /* LWIP_TCP */
  default:
    LWIP_ERROR("Invalid netconn type", 0, do{ msg->err = ERR_VAL; }while(0));
    break;
    }
  }
  sys_sem_signal(&msg->conn->op_completed);
}

/**
 * Connect a pcb contained inside a netconn
 * Only used for UDP netconns.