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- /****************************************************************************
- * net/tcp/tcp_send_unbuffered.c
- *
- * Copyright (C) 2007-2014, 2016-2017, 2019 Gregory Nutt. All rights
- * reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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 <nuttx/config.h>
- #if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) && \
- !defined(CONFIG_NET_TCP_WRITE_BUFFERS)
- #include <sys/types.h>
- #include <sys/socket.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <string.h>
- #include <errno.h>
- #include <assert.h>
- #include <debug.h>
- #include <arch/irq.h>
- #include <nuttx/semaphore.h>
- #include <nuttx/net/net.h>
- #include <nuttx/net/netdev.h>
- #include <nuttx/net/arp.h>
- #include <nuttx/net/tcp.h>
- #include "netdev/netdev.h"
- #include "devif/devif.h"
- #include "socket/socket.h"
- #include "inet/inet.h"
- #include "arp/arp.h"
- #include "icmpv6/icmpv6.h"
- #include "neighbor/neighbor.h"
- #include "route/route.h"
- #include "tcp/tcp.h"
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- /* If both IPv4 and IPv6 support are both enabled, then we will need to build
- * in some additional domain selection support.
- */
- #if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
- # define NEED_IPDOMAIN_SUPPORT 1
- #endif
- #if defined(CONFIG_NET_TCP_SPLIT) && !defined(CONFIG_NET_TCP_SPLIT_SIZE)
- # define CONFIG_NET_TCP_SPLIT_SIZE 40
- #endif
- #define TCPIPv4BUF ((struct tcp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN])
- #define TCPIPv6BUF ((struct tcp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
- /****************************************************************************
- * Private Types
- ****************************************************************************/
- /* This structure holds the state of the send operation until it can be
- * operated upon when the TX poll event occurs.
- */
- struct send_s
- {
- FAR struct socket *snd_sock; /* Points to the parent socket structure */
- FAR struct devif_callback_s *snd_cb; /* Reference to callback instance */
- sem_t snd_sem; /* Used to wake up the waiting thread */
- FAR const uint8_t *snd_buffer; /* Points to the buffer of data to send */
- size_t snd_buflen; /* Number of bytes in the buffer to send */
- ssize_t snd_sent; /* The number of bytes sent */
- uint32_t snd_isn; /* Initial sequence number */
- uint32_t snd_acked; /* The number of bytes acked */
- #if defined(CONFIG_NET_TCP_SPLIT)
- bool snd_odd; /* True: Odd packet in pair transaction */
- #endif
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: tcpsend_ipselect
- *
- * Description:
- * If both IPv4 and IPv6 support are enabled, then we will need to select
- * which one to use when generating the outgoing packet. If only one
- * domain is selected, then the setup is already in place and we need do
- * nothing.
- *
- * Input Parameters:
- * dev - The structure of the network driver that caused the event
- * pstate - sendto state structure
- *
- * Returned Value:
- * None
- *
- * Assumptions:
- * The network is locked.
- *
- ****************************************************************************/
- #ifdef NEED_IPDOMAIN_SUPPORT
- static inline void tcpsend_ipselect(FAR struct net_driver_s *dev,
- FAR struct tcp_conn_s *conn)
- {
- /* Which domain does the socket support */
- if (conn->domain == PF_INET)
- {
- /* Select the IPv4 domain */
- tcp_ipv4_select(dev);
- }
- else /* if (conn->domain == PF_INET6) */
- {
- /* Select the IPv6 domain */
- DEBUGASSERT(conn->domain == PF_INET6);
- tcp_ipv6_select(dev);
- }
- }
- #endif
- /****************************************************************************
- * Name: tcpsend_eventhandler
- *
- * Description:
- * This function is called to perform the actual send operation when
- * polled by the lower, device interfacing 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 tcpsend_eventhandler(FAR struct net_driver_s *dev,
- FAR void *pvconn,
- FAR void *pvpriv, uint16_t flags)
- {
- FAR struct tcp_conn_s *conn = (FAR struct tcp_conn_s *)pvconn;
- FAR struct send_s *pstate = (FAR struct send_s *)pvpriv;
- /* The TCP socket is connected and, hence, should be bound to a device.
- * Make sure that the polling device is the one that we are bound to.
- */
- DEBUGASSERT(conn->dev != NULL);
- if (dev != conn->dev)
- {
- return flags;
- }
- ninfo("flags: %04x acked: %d sent: %d\n",
- flags, pstate->snd_acked, pstate->snd_sent);
- /* If this packet contains an acknowledgement, then update the count of
- * acknowledged bytes.
- */
- if ((flags & TCP_ACKDATA) != 0)
- {
- FAR struct tcp_hdr_s *tcp;
- /* Get the offset address of the TCP header */
- #ifdef CONFIG_NET_IPv4
- #ifdef CONFIG_NET_IPv6
- if (conn->domain == PF_INET)
- #endif
- {
- DEBUGASSERT(IFF_IS_IPv4(dev->d_flags));
- tcp = TCPIPv4BUF;
- }
- #endif /* CONFIG_NET_IPv4 */
- #ifdef CONFIG_NET_IPv6
- #ifdef CONFIG_NET_IPv4
- else
- #endif
- {
- DEBUGASSERT(IFF_IS_IPv6(dev->d_flags));
- tcp = TCPIPv6BUF;
- }
- #endif /* CONFIG_NET_IPv6 */
- /* The current acknowledgement number is the (relative) offset of the
- * next byte needed by the receiver. The snd_isn is the offset of the
- * first byte to send to the receiver. The difference is the number
- * of bytes to be acknowledged.
- */
- pstate->snd_acked = tcp_getsequence(tcp->ackno) - pstate->snd_isn;
- ninfo("ACK: acked=%d sent=%d buflen=%d\n",
- pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen);
- /* Have all of the bytes in the buffer been sent and acknowledged? */
- if (pstate->snd_acked >= pstate->snd_buflen)
- {
- /* Yes. Then pstate->snd_buflen should hold the number of bytes
- * actually sent.
- */
- goto end_wait;
- }
- /* No.. fall through to send more data if necessary */
- }
- /* Check if we are being asked to retransmit data */
- else if ((flags & TCP_REXMIT) != 0)
- {
- /* Yes.. in this case, reset the number of bytes that have been sent
- * to the number of bytes that have been ACKed.
- */
- pstate->snd_sent = pstate->snd_acked;
- #if defined(CONFIG_NET_TCP_SPLIT)
- /* Reset the even/odd indicator to even since we need to
- * retransmit.
- */
- pstate->snd_odd = false;
- #endif
- /* Fall through to re-send data from the last that was ACKed */
- }
- /* Check for a loss of connection */
- else if ((flags & TCP_DISCONN_EVENTS) != 0)
- {
- FAR struct socket *psock = pstate->snd_sock;
- ninfo("Lost connection\n");
- /* We could get here recursively through the callback actions of
- * tcp_lost_connection(). So don't repeat that action if we have
- * already been disconnected.
- */
- DEBUGASSERT(psock != NULL);
- if (_SS_ISCONNECTED(psock->s_flags))
- {
- /* Report not connected */
- tcp_lost_connection(psock, pstate->snd_cb, flags);
- }
- pstate->snd_sent = -ENOTCONN;
- goto end_wait;
- }
- /* Check if the outgoing packet is available (it may have been claimed
- * by a sendto event serving a different thread).
- */
- #if 0 /* We can't really support multiple senders on the same TCP socket */
- else if (dev->d_sndlen > 0)
- {
- /* Another thread has beat us sending data, wait for the next poll */
- return flags;
- }
- #endif
- /* We get here if (1) not all of the data has been ACKed, (2) we have been
- * asked to retransmit data, (3) the connection is still healthy, and (4)
- * the outgoing packet is available for our use. In this case, we are
- * now free to send more data to receiver -- UNLESS the buffer contains
- * unprocessed incoming data. In that event, we will have to wait for the
- * next polling cycle.
- */
- if ((flags & TCP_NEWDATA) == 0 && pstate->snd_sent < pstate->snd_buflen)
- {
- uint32_t seqno;
- /* Get the amount of data that we can send in the next packet */
- uint32_t sndlen = pstate->snd_buflen - pstate->snd_sent;
- #if defined(CONFIG_NET_TCP_SPLIT)
- /* RFC 1122 states that a host may delay ACKing for up to 500ms but
- * must respond to every second segment). This logic here will trick
- * the RFC 1122 recipient into responding sooner. This logic will be
- * activated if:
- *
- * 1. An even number of packets has been send (where zero is an even
- * number),
- * 2. There is more data be sent (more than or equal to
- * CONFIG_NET_TCP_SPLIT_SIZE), but
- * 3. Not enough data for two packets.
- *
- * Then we will split the remaining, single packet into two partial
- * packets. This will stimulate the RFC 1122 peer to ACK sooner.
- *
- * Don't try to split very small packets (less than
- * CONFIG_NET_TCP_SPLIT_SIZE). Only the first even packet and the
- * last odd packets could have sndlen less than
- * CONFIG_NET_TCP_SPLIT_SIZE. The value of sndlen on the last even
- * packet is guaranteed to be at least MSS / 2 by the logic below.
- */
- if (sndlen >= CONFIG_NET_TCP_SPLIT_SIZE)
- {
- /* sndlen is the number of bytes remaining to be sent.
- * conn->mss will provide the number of bytes that can sent
- * in one packet. The difference, then, is the number of bytes
- * that would be sent in the next packet after this one.
- */
- int32_t next_sndlen = sndlen - conn->mss;
- /* Is this the even packet in the packet pair transaction? */
- if (!pstate->snd_odd)
- {
- /* next_sndlen <= 0 means that the entire remaining data
- * could fit into this single packet. This is condition
- * in which we must do the split.
- */
- if (next_sndlen <= 0)
- {
- /* Split so that there will be an odd packet. Here
- * we know that 0 < sndlen <= MSS
- */
- sndlen = (sndlen / 2) + 1;
- }
- }
- /* No... this is the odd packet in the packet pair transaction */
- else
- {
- /* Will there be another (even) packet after this one?
- * (next_sndlen > 0) Will the split condition occur on that
- * next, even packet? ((next_sndlen - conn->mss) < 0) If
- * so, then perform the split now to avoid the case where the
- * byte count is less than CONFIG_NET_TCP_SPLIT_SIZE on the
- * next pair.
- */
- if (next_sndlen > 0 && (next_sndlen - conn->mss) < 0)
- {
- /* Here, we know that sndlen must be MSS < sndlen <= 2*MSS
- * and so (sndlen / 2) is <= MSS.
- */
- sndlen /= 2;
- }
- }
- }
- /* Toggle the even/odd indicator */
- pstate->snd_odd ^= true;
- #endif /* CONFIG_NET_TCP_SPLIT */
- if (sndlen > conn->mss)
- {
- sndlen = conn->mss;
- }
- /* Check if we have "space" in the window */
- if ((pstate->snd_sent - pstate->snd_acked + sndlen) < conn->winsize)
- {
- /* Set the sequence number for this packet. NOTE: The network
- * updates sndseq on receipt of ACK *before* this function is
- * called. In that case sndseq will point to the next
- * unacknowledged byte (which might have already been sent). We
- * will overwrite the value of sndseq here before the packet is
- * sent.
- */
- seqno = pstate->snd_sent + pstate->snd_isn;
- ninfo("SEND: sndseq %08x->%08x\n", conn->sndseq, seqno);
- tcp_setsequence(conn->sndseq, seqno);
- #ifdef NEED_IPDOMAIN_SUPPORT
- /* If both IPv4 and IPv6 support are enabled, then we will need to
- * select which one to use when generating the outgoing packet.
- * If only one domain is selected, then the setup is already in
- * place and we need do nothing.
- */
- tcpsend_ipselect(dev, conn);
- #endif
- /* Then set-up to send that amount of data. (this won't actually
- * happen until the polling cycle completes).
- */
- devif_send(dev, &pstate->snd_buffer[pstate->snd_sent], sndlen);
- /* Update the amount of data sent (but not necessarily ACKed) */
- pstate->snd_sent += sndlen;
- ninfo("SEND: acked=%d sent=%d buflen=%d\n",
- pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen);
- }
- }
- /* Continue waiting */
- return flags;
- end_wait:
- /* Do not allow any further callbacks */
- pstate->snd_cb->flags = 0;
- pstate->snd_cb->priv = NULL;
- pstate->snd_cb->event = NULL;
- /* There are no outstanding, unacknowledged bytes */
- conn->tx_unacked = 0;
- /* Wake up the waiting thread */
- nxsem_post(&pstate->snd_sem);
- return flags;
- }
- /****************************************************************************
- * Name: send_txnotify
- *
- * Description:
- * Notify the appropriate device driver that we are have data ready to
- * be send (TCP)
- *
- * Input Parameters:
- * psock - Socket state structure
- * conn - The TCP connection structure
- *
- * Returned Value:
- * None
- *
- ****************************************************************************/
- static inline void send_txnotify(FAR struct socket *psock,
- FAR struct tcp_conn_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 */
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: psock_tcp_send
- *
- * Description:
- * psock_tcp_send() call may be used only when the TCP socket is in a
- * connected state (so that the intended recipient is known).
- *
- * Input Parameters:
- * psock An instance of the internal socket structure.
- * buf Data to send
- * len Length of data to send
- * flags Send flags
- *
- * Returned Value:
- * On success, returns the number of characters sent. On error,
- * a negated errno value is returned.
- *
- * EAGAIN or EWOULDBLOCK
- * The socket is marked non-blocking and the requested operation
- * would block.
- * EBADF
- * An invalid descriptor was specified.
- * ECONNRESET
- * Connection reset by peer.
- * EDESTADDRREQ
- * The socket is not connection-mode, and no peer address is set.
- * EFAULT
- * An invalid user space address was specified for a parameter.
- * EINTR
- * A signal occurred before any data was transmitted.
- * EINVAL
- * Invalid argument passed.
- * EISCONN
- * The connection-mode socket was connected already but a recipient
- * was specified. (Now either this error is returned, or the recipient
- * specification is ignored.)
- * EMSGSIZE
- * The socket type requires that message be sent atomically, and the
- * size of the message to be sent made this impossible.
- * ENOBUFS
- * The output queue for a network interface was full. This generally
- * indicates that the interface has stopped sending, but may be
- * caused by transient congestion.
- * ENOMEM
- * No memory available.
- * ENOTCONN
- * The socket is not connected, and no target has been given.
- * ENOTSOCK
- * The argument s is not a socket.
- * EPIPE
- * The local end has been shut down on a connection oriented socket.
- * In this case the process will also receive a SIGPIPE unless
- * MSG_NOSIGNAL is set.
- *
- ****************************************************************************/
- ssize_t psock_tcp_send(FAR struct socket *psock,
- FAR const void *buf, size_t len, int flags)
- {
- FAR struct tcp_conn_s *conn;
- struct send_s state;
- int ret = OK;
- /* Verify that the sockfd corresponds to valid, allocated socket */
- if (psock == NULL || psock->s_crefs <= 0)
- {
- nerr("ERROR: Invalid socket\n");
- ret = -EBADF;
- goto errout;
- }
- /* If this is an un-connected socket, then return ENOTCONN */
- if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
- {
- nerr("ERROR: Not connected\n");
- ret = -ENOTCONN;
- goto errout;
- }
- /* Make sure that we have the IP address mapping */
- conn = (FAR struct tcp_conn_s *)psock->s_conn;
- DEBUGASSERT(conn);
- #if defined(CONFIG_NET_ARP_SEND) || defined(CONFIG_NET_ICMPv6_NEIGHBOR)
- #ifdef CONFIG_NET_ARP_SEND
- #ifdef CONFIG_NET_ICMPv6_NEIGHBOR
- if (psock->s_domain == PF_INET)
- #endif
- {
- /* Make sure that the IP address mapping is in the ARP table */
- ret = arp_send(conn->u.ipv4.raddr);
- }
- #endif /* CONFIG_NET_ARP_SEND */
- #ifdef CONFIG_NET_ICMPv6_NEIGHBOR
- #ifdef CONFIG_NET_ARP_SEND
- else
- #endif
- {
- /* Make sure that the IP address mapping is in the Neighbor Table */
- ret = icmpv6_neighbor(conn->u.ipv6.raddr);
- }
- #endif /* CONFIG_NET_ICMPv6_NEIGHBOR */
- /* Did we successfully get the address mapping? */
- if (ret < 0)
- {
- nerr("ERROR: Not reachable\n");
- ret = -ENETUNREACH;
- goto errout;
- }
- #endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */
- /* Perform the TCP send operation */
- /* Initialize the state structure. This is done with the network
- * locked because we don't want anything to happen until we are
- * ready.
- */
- net_lock();
- memset(&state, 0, sizeof(struct send_s));
- /* This semaphore is used for signaling and, hence, should not have
- * priority inheritance enabled.
- */
- nxsem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */
- nxsem_set_protocol(&state.snd_sem, SEM_PRIO_NONE);
- state.snd_sock = psock; /* Socket descriptor to use */
- state.snd_buflen = len; /* Number of bytes to send */
- state.snd_buffer = buf; /* Buffer to send from */
- if (len > 0)
- {
- /* Allocate resources to receive a callback */
- ret = -ENOMEM; /* Assume allocation failure */
- state.snd_cb = tcp_callback_alloc(conn);
- if (state.snd_cb)
- {
- /* Get the initial sequence number that will be used */
- state.snd_isn = tcp_getsequence(conn->sndseq);
- /* There is no outstanding, unacknowledged data after this
- * initial sequence number.
- */
- conn->tx_unacked = 0;
- /* Set up the callback in the connection */
- state.snd_cb->flags = (TCP_ACKDATA | TCP_REXMIT | TCP_POLL |
- TCP_DISCONN_EVENTS);
- state.snd_cb->priv = (FAR void *)&state;
- state.snd_cb->event = tcpsend_eventhandler;
- /* Notify the device driver of the availability of TX data */
- send_txnotify(psock, conn);
- /* Wait for the send to complete or an error to occur: NOTES:
- * net_lockedwait will also terminate if a signal is received.
- */
- for (; ; )
- {
- uint32_t acked = state.snd_acked;
- ret = net_timedwait(&state.snd_sem,
- _SO_TIMEOUT(psock->s_sndtimeo));
- if (ret != -ETIMEDOUT || acked == state.snd_acked)
- {
- break; /* Timeout without any progress */
- }
- }
- /* Make sure that no further events are processed */
- tcp_callback_free(conn, state.snd_cb);
- }
- }
- nxsem_destroy(&state.snd_sem);
- net_unlock();
- /* Check for a errors. Errors are signalled by negative errno values
- * for the send length
- */
- if (state.snd_sent < 0)
- {
- ret = state.snd_sent;
- goto errout;
- }
- /* If net_timedwait failed, then we were probably reawakened by a signal.
- * In this case, net_timedwait will have returned negated errno
- * appropriately.
- */
- if (ret < 0)
- {
- goto errout;
- }
- /* Return the number of bytes actually sent */
- ret = state.snd_sent;
- errout:
- return ret;
- }
- /****************************************************************************
- * Name: psock_tcp_cansend
- *
- * Description:
- * psock_tcp_cansend() returns a value indicating if a write to the socket
- * would block. It is still possible that the write may block if another
- * write occurs first.
- *
- * Input Parameters:
- * psock An instance of the internal socket structure.
- *
- * Returned Value:
- * OK (Always can send).
- *
- * Assumptions:
- * None
- *
- ****************************************************************************/
- int psock_tcp_cansend(FAR struct socket *psock)
- {
- return OK;
- }
- #endif /* CONFIG_NET && CONFIG_NET_TCP && !CONFIG_NET_TCP_WRITE_BUFFERS */
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