/**************************************************************************** * net/tcp/tcp_netpoll.c * * Copyright (C) 2008-2009, 2011-2016, 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 #include "devif/devif.h" #include "netdev/netdev.h" #include "socket/socket.h" #include "inet/inet.h" #include "tcp/tcp.h" #ifdef HAVE_TCP_POLL /**************************************************************************** * Private Types ****************************************************************************/ /* This is an allocated container that holds the poll-related information */ struct tcp_poll_s { FAR struct socket *psock; /* Needed to handle loss of connection */ struct pollfd *fds; /* Needed to handle poll events */ FAR struct devif_callback_s *cb; /* Needed to teardown the poll */ #if defined(CONFIG_NET_TCP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER) int16_t key; /* Needed to cancel pending notification */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: tcp_poll_eventhandler * * Description: * This function is called to perform the actual TCP 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: * The network is locked * ****************************************************************************/ static uint16_t tcp_poll_eventhandler(FAR struct net_driver_s *dev, FAR void *conn, FAR void *pvpriv, uint16_t flags) { FAR struct tcp_poll_s *info = (FAR struct tcp_poll_s *)pvpriv; ninfo("flags: %04x\n", flags); DEBUGASSERT(info == NULL || (info->psock != NULL && info->fds != NULL)); /* 'priv' might be null in some race conditions (?) */ if (info != NULL) { pollevent_t eventset = 0; /* Check for data or connection availability events. */ if ((flags & (TCP_NEWDATA | TCP_BACKLOG)) != 0) { eventset |= POLLIN & info->fds->events; } /* A poll is a sign that we are free to send data. * REVISIT: This is bogus: If CONFIG_TCP_WRITE_BUFFERS=y then * we never have to wait to send; otherwise, we always have to * wait to send. Receiving a poll is irrelevant. */ if ((flags & TCP_POLL) != 0) { eventset |= (POLLOUT & info->fds->events); } /* Check for a loss of connection events. */ if ((flags & TCP_DISCONN_EVENTS) != 0) { /* Mark that the connection has been lost */ tcp_lost_connection(info->psock, info->cb, flags); eventset |= (POLLERR | POLLHUP); } /* Awaken the caller of poll() if requested event occurred. */ if (eventset != 0) { /* Stop further callbacks */ info->cb->flags = 0; info->cb->priv = NULL; info->cb->event = NULL; info->fds->revents |= eventset; nxsem_post(info->fds->sem); } } return flags; } /**************************************************************************** * Name: tcp_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_TCP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER) static inline void tcp_iob_work(FAR void *arg) { FAR struct work_notifier_entry_s *entry; FAR struct work_notifier_s *ninfo; FAR struct tcp_poll_s *pinfo; FAR struct socket *psock; FAR struct pollfd *fds; entry = (FAR struct work_notifier_entry_s *)arg; DEBUGASSERT(entry != NULL); ninfo = &entry->info; DEBUGASSERT(ninfo->arg != NULL); pinfo = (FAR struct tcp_poll_s *)ninfo->arg; DEBUGASSERT(pinfo->psock != NULL && pinfo->fds != NULL); psock = pinfo->psock; fds = pinfo->fds; /* Verify that we still have a connection */ if (!_SS_ISCONNECTED(psock->s_flags) && !_SS_ISLISTENING(psock->s_flags)) { /* Don't report more than once. Might happen in a race condition */ if ((fds->revents & (POLLERR | POLLHUP)) == 0) { /* We were previously connected but lost the connection either due * to a graceful shutdown by the remote peer or because of some * exceptional event. */ fds->revents |= (POLLERR | POLLHUP); nxsem_post(fds->sem); } } /* Handle a race condition. Check if we have already posted the POLLOUT * event. If so, don't do it again and don't setup notification again. */ else if ((fds->events && POLLWRNORM) == 0 || (fds->revents && POLLWRNORM) != 0) { /* Check if we are now able to send */ if (psock_tcp_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, tcp_iob_work, pinfo); } } /* Protocol for the use of the IOB notifier is that we free the argument * after the notification has been processed. */ kmm_free(arg); } #endif /**************************************************************************** * Name: tcp_poll_txnotify * * Description: * Notify the appropriate device driver that we are have data ready to * be sent (TCP) * * Input Parameters: * psock - Socket state structure * * Returned Value: * None * ****************************************************************************/ #if !defined(CONFIG_NET_TCP_WRITE_BUFFERS) || !defined(CONFIG_IOB_NOTIFIER) static inline void tcp_poll_txnotify(FAR struct socket *psock) { FAR struct tcp_conn_s *conn = psock->s_conn; #ifdef CONFIG_NET_IPv4 #ifdef CONFIG_NET_IPv6 /* If both IPv4 and IPv6 support are enabled, then we will need to select * the device driver using the appropriate IP domain. */ if (psock->s_domain == PF_INET) #endif { /* Notify the device driver that send data is available */ netdev_ipv4_txnotify(conn->u.ipv4.laddr, conn->u.ipv4.raddr); } #endif /* CONFIG_NET_IPv4 */ #ifdef CONFIG_NET_IPv6 #ifdef CONFIG_NET_IPv4 else /* if (psock->s_domain == PF_INET6) */ #endif /* CONFIG_NET_IPv4 */ { /* Notify the device driver that send data is available */ DEBUGASSERT(psock->s_domain == PF_INET6); netdev_ipv6_txnotify(conn->u.ipv6.laddr, conn->u.ipv6.raddr); } #endif /* CONFIG_NET_IPv6 */ } #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: tcp_pollsetup * * Description: * Setup to monitor events on one TCP/IP socket * * Input Parameters: * psock - The TCP/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 tcp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds) { FAR struct tcp_conn_s *conn = psock->s_conn; FAR struct tcp_poll_s *info; FAR struct devif_callback_s *cb; int ret; /* Sanity check */ #ifdef CONFIG_DEBUG_FEATURES if (!conn || !fds) { return -EINVAL; } #endif /* Allocate a container to hold the poll information */ info = (FAR struct tcp_poll_s *)kmm_malloc(sizeof(struct tcp_poll_s)); if (!info) { return -ENOMEM; } /* Some of the following must be atomic */ net_lock(); /* Allocate a TCP/IP callback structure */ cb = tcp_callback_alloc(conn); if (!cb) { ret = -EBUSY; goto errout_with_lock; } /* Initialize the poll info container */ info->psock = psock; info->fds = fds; info->cb = cb; #if defined(CONFIG_NET_TCP_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 = (TCP_NEWDATA | TCP_BACKLOG | TCP_POLL | TCP_DISCONN_EVENTS); cb->priv = (FAR void *)info; cb->event = tcp_poll_eventhandler; /* 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_TCPBACKLOG /* Check for read data or backlogged connection availability now */ if (!IOB_QEMPTY(&conn->readahead) || tcp_backlogavailable(conn)) #else /* Check for read data availability now */ if (!IOB_QEMPTY(&conn->readahead)) #endif { /* Normal data may be read without blocking. */ fds->revents |= (POLLRDNORM & fds->events); } /* Check for a loss of connection events. We need to be careful here. * There are four possibilities: * * 1) The socket is connected and we are waiting for data availability * events. * * __SS_ISCONNECTED(f) == true * __SS_ISLISTENING(f) == false * __SS_ISCLOSED(f) == false * * Action: Wait for data availability events * * 2) This is a listener socket that was never connected and we are * waiting for connection events. * * __SS_ISCONNECTED(f) == false * __SS_ISLISTENING(f) == true * __SS_ISCLOSED(f) == false * * Action: Wait for connection events * * 3) This socket was previously connected, but the peer has gracefully * closed the connection. * * __SS_ISCONNECTED(f) == false * __SS_ISLISTENING(f) == false * __SS_ISCLOSED(f) == true * * Action: Return with POLLHUP|POLLERR events * * 4) This socket was previously connected, but we lost the connection * due to some exceptional event. * * __SS_ISCONNECTED(f) == false * __SS_ISLISTENING(f) == false * __SS_ISCLOSED(f) == false * * Action: Return with POLLHUP|POLLERR events */ if (!_SS_ISCONNECTED(psock->s_flags) && !_SS_ISLISTENING(psock->s_flags)) { /* We were previously connected but lost the connection either due * to a graceful shutdown by the remote peer or because of some * exceptional event. */ fds->revents |= (POLLERR | POLLHUP); } else if (_SS_ISCONNECTED(psock->s_flags) && psock_tcp_cansend(psock) >= 0) { 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_TCP_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, tcp_iob_work, info); } #else /* If (1) the socket is in a bound state, (2) revents == 0, (3) write * buffering is not enabled (determined by a configuration setting), and * (4) the POLLOUT event is needed then request an immediate Tx poll from * the device associated with the binding. */ else if (_SS_ISBOUND(psock->s_flags) && (fds->events & POLLOUT) != 0) { /* Note that the notification will fail if the socket is bound to * INADDR_ANY or the IPv6 unspecified address! In that case the * notification will fail. */ tcp_poll_txnotify(psock); } #endif net_unlock(); return OK; errout_with_lock: kmm_free(info); net_unlock(); return ret; } /**************************************************************************** * Name: tcp_pollteardown * * Description: * Teardown monitoring of events on an TCP/IP socket * * Input Parameters: * psock - The TCP/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 tcp_pollteardown(FAR struct socket *psock, FAR struct pollfd *fds) { FAR struct tcp_conn_s *conn = psock->s_conn; FAR struct tcp_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 tcp_poll_s *)fds->priv; DEBUGASSERT(info != NULL && info->fds != NULL && info->cb != NULL); if (info != NULL) { #if defined(CONFIG_NET_TCP_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 */ net_lock(); tcp_callback_free(conn, info->cb); net_unlock(); /* Release the poll/select data slot */ info->fds->priv = NULL; /* Then free the poll info container */ kmm_free(info); } return OK; } #endif /* HAVE_TCP_POLL */