/**************************************************************************** * net/udp/udp_netpoll.c * * Copyright (C) 2008-2009, 2011-2015, 2018 Gregory Nutt. All rights * reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "devif/devif.h" #include "netdev/netdev.h" #include "socket/socket.h" #include "udp/udp.h" /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: udp_poll_eventhandler * * Description: * This function is called to perform the actual UDP receive operation * via the device interface layer. * * Input Parameters: * dev The structure of the network driver that caused the event * conn The connection structure associated with the socket * flags Set of events describing why the callback was invoked * * Returned Value: * None * * Assumptions: * This function must be called with the network locked. * ****************************************************************************/ static uint16_t udp_poll_eventhandler(FAR struct net_driver_s *dev, FAR void *conn, FAR void *pvpriv, uint16_t flags) { FAR struct udp_poll_s *info = (FAR struct udp_poll_s *)pvpriv; ninfo("flags: %04x\n", flags); DEBUGASSERT(!info || (info->psock && info->fds)); /* 'priv' might be null in some race conditions (?) */ if (info) { pollevent_t eventset = 0; /* Check for data or connection availability events. */ if ((flags & UDP_NEWDATA) != 0) { eventset |= (POLLIN & info->fds->events); } /* Check for loss of connection events. */ if ((flags & NETDEV_DOWN) != 0) { eventset |= (POLLHUP | POLLERR); } /* A poll is a sign that we are free to send data. */ else if ((flags & UDP_POLL) != 0 && psock_udp_cansend(info->psock) >= 0) { eventset |= (POLLOUT & info->fds->events); } /* Awaken the caller of poll() is requested event occurred. */ if (eventset) { info->fds->revents |= eventset; nxsem_post(info->fds->sem); } } return flags; } /**************************************************************************** * Name: udp_iob_work * * Description: * Work thread callback function execute when an IOB because available. * * Input Parameters: * psock - Socket state structure * * Returned Value: * None * ****************************************************************************/ #if defined(CONFIG_NET_UDP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER) static inline void udp_iob_work(FAR void *arg) { FAR struct udp_poll_s *pinfo; FAR struct socket *psock; FAR struct pollfd *fds; pinfo = (FAR struct udp_poll_s *)arg; DEBUGASSERT(pinfo->psock != NULL && pinfo->fds != NULL); psock = pinfo->psock; fds = pinfo->fds; /* Handle a race condition. Check if we have already posted the POLLOUT * event. If so, don't do it again. */ if ((fds->events & POLLWRNORM) != 0 && (fds->revents & POLLWRNORM) == 0) { /* Check if we are now able to send */ if (psock_udp_cansend(psock) >= 0) { /* Yes.. then signal the poll logic */ fds->revents |= POLLWRNORM; nxsem_post(fds->sem); } else { /* No.. ask for the IOB free notification again */ pinfo->key = iob_notifier_setup(LPWORK, udp_iob_work, pinfo); } } } #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: udp_pollsetup * * Description: * Setup to monitor events on one UDP/IP socket * * Input Parameters: * psock - The UDP/IP socket of interest * fds - The structure describing the events to be monitored, OR NULL if * this is a request to stop monitoring events. * * Returned Value: * 0: Success; Negated errno on failure * ****************************************************************************/ int udp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds) { FAR struct udp_conn_s *conn = psock->s_conn; FAR struct udp_poll_s *info; FAR struct devif_callback_s *cb; int ret = OK; /* Sanity check */ #ifdef CONFIG_DEBUG_FEATURES if (conn == NULL || fds == NULL) { return -EINVAL; } #endif /* Some of the following must be atomic */ net_lock(); /* Find a container to hold the poll information */ info = conn->pollinfo; while (info->psock != NULL) { if (++info >= &conn->pollinfo[CONFIG_NET_UDP_NPOLLWAITERS]) { ret = -ENOMEM; goto errout_with_lock; } } /* Get the device that will provide the provide the NETDEV_DOWN event. * NOTE: in the event that the local socket is bound to INADDR_ANY, the * dev value will be zero and there will be no NETDEV_DOWN notifications. */ info->dev = udp_find_laddr_device(conn); /* Allocate a UDP callback structure */ cb = udp_callback_alloc(info->dev, conn); if (cb == NULL) { ret = -EBUSY; goto errout_with_lock; } /* Initialize the poll info container */ info->psock = psock; info->fds = fds; info->cb = cb; #if defined(CONFIG_NET_UDP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER) info->key = 0; #endif /* Initialize the callback structure. Save the reference to the info * structure as callback private data so that it will be available during * callback processing. */ cb->flags = NETDEV_DOWN; cb->priv = (FAR void *)info; cb->event = udp_poll_eventhandler; if ((fds->events & POLLOUT) != 0) { cb->flags |= UDP_POLL; } if ((fds->events & POLLIN) != 0) { cb->flags |= UDP_NEWDATA; } /* Save the reference in the poll info structure as fds private as well * for use during poll teardown as well. */ fds->priv = (FAR void *)info; #ifdef CONFIG_NET_UDP_READAHEAD /* Check for read data availability now */ if (!IOB_QEMPTY(&conn->readahead)) { /* Normal data may be read without blocking. */ fds->revents |= (POLLRDNORM & fds->events); } #endif if (psock_udp_cansend(psock) >= 0) { /* Normal data may be sent without blocking (at least one byte). */ fds->revents |= (POLLWRNORM & fds->events); } /* Check if any requested events are already in effect */ if (fds->revents != 0) { /* Yes.. then signal the poll logic */ nxsem_post(fds->sem); } #if defined(CONFIG_NET_UDP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER) /* If (1) revents == 0, (2) write buffering is enabled, and (3) the * POLLOUT event is needed, then setup to receive a notification an IOB * is freed. */ else if ((fds->events & POLLOUT) != 0) { /* Ask for the IOB free notification */ info->key = iob_notifier_setup(LPWORK, udp_iob_work, info); } #endif errout_with_lock: net_unlock(); return ret; } /**************************************************************************** * Name: udp_pollteardown * * Description: * Teardown monitoring of events on an UDP/IP socket * * Input Parameters: * psock - The UDP socket of interest * fds - The structure describing the events to be monitored, OR NULL if * this is a request to stop monitoring events. * * Returned Value: * 0: Success; Negated errno on failure * ****************************************************************************/ int udp_pollteardown(FAR struct socket *psock, FAR struct pollfd *fds) { FAR struct udp_conn_s *conn = psock->s_conn; FAR struct udp_poll_s *info; /* Sanity check */ #ifdef CONFIG_DEBUG_FEATURES if (!conn || !fds->priv) { return -EINVAL; } #endif /* Recover the socket descriptor poll state info from the poll structure */ info = (FAR struct udp_poll_s *)fds->priv; DEBUGASSERT(info != NULL && info->fds != NULL && info->cb != NULL); if (info != NULL) { #if defined(CONFIG_NET_UDP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER) /* Cancel any pending IOB free notification */ if (info->key > 0) { /* Ask for the IOB free notification */ iob_notifier_teardown(info->key); } #endif /* Release the callback */ udp_callback_free(info->dev, conn, info->cb); /* Release the poll/select data slot */ info->fds->priv = NULL; /* Then free the poll info container */ info->psock = NULL; } return OK; }