| /**************************************************************************** |
| * net/tcp/tcp_send_unbuffered.c |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. The |
| * ASF licenses this file to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance with the |
| * License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations |
| * under the License. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * 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 <inttypes.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/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 |
| |
| /**************************************************************************** |
| * 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 tcp_conn_s *snd_conn; /* The TCP connection of interest */ |
| 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 */ |
| #ifdef CONFIG_NET_TCP_FAST_RETRANSMIT |
| uint32_t snd_prev_ack; /* The previous ACKed seq number */ |
| #ifdef CONFIG_NET_TCP_WINDOW_SCALE |
| uint32_t snd_prev_wnd; /* The advertised window in the last |
| * incoming acknowledgment |
| */ |
| #else |
| uint16_t snd_prev_wnd; |
| #endif |
| int snd_dup_acks; /* Duplicate ACK counter */ |
| #endif |
| }; |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * 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 |
| * pvpriv An instance of struct send_s cast to void* |
| * 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 *pvpriv, uint16_t flags) |
| { |
| FAR struct send_s *pstate = pvpriv; |
| FAR struct tcp_conn_s *conn; |
| int ret; |
| |
| DEBUGASSERT(pstate != NULL); |
| |
| /* Get the TCP connection pointer reliably from |
| * the corresponding TCP socket. |
| */ |
| |
| conn = pstate->snd_conn; |
| DEBUGASSERT(conn != NULL); |
| |
| /* 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: %" PRId32 " sent: %zd\n", |
| flags, pstate->snd_acked, pstate->snd_sent); |
| |
| /* The TCP_ACKDATA, TCP_REXMIT and TCP_DISCONN_EVENTS flags are expected to |
| * appear here strictly one at a time, except for the FIN + ACK case. |
| */ |
| |
| DEBUGASSERT((flags & TCP_ACKDATA) == 0 || |
| (flags & TCP_REXMIT) == 0); |
| DEBUGASSERT((flags & TCP_DISCONN_EVENTS) == 0 || |
| (flags & TCP_REXMIT) == 0); |
| |
| /* If this packet contains an acknowledgement, then update the count of |
| * acknowledged bytes. |
| * This condition is located here for performance reasons |
| * (TCP_ACKDATA is the most frequent event). |
| */ |
| |
| if ((flags & TCP_ACKDATA) != 0) |
| { |
| uint32_t ackno; |
| 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 |
| { |
| tcp = TCPIPv4BUF; |
| } |
| #endif /* CONFIG_NET_IPv4 */ |
| |
| #ifdef CONFIG_NET_IPv6 |
| #ifdef CONFIG_NET_IPv4 |
| else |
| #endif |
| { |
| 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. |
| */ |
| |
| ackno = tcp_getsequence(tcp->ackno); |
| pstate->snd_acked = TCP_SEQ_SUB(ackno, |
| pstate->snd_isn); |
| ninfo("ACK: acked=%" PRId32 " sent=%zd buflen=%zu\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; |
| } |
| |
| #ifdef CONFIG_NET_TCP_FAST_RETRANSMIT |
| /* Fast Retransmit (RFC 5681): an acknowledgment is considered a |
| * "duplicate" when (a) the receiver of the ACK has outstanding data, |
| * (b) the incoming acknowledgment carries no data, (c) the SYN and |
| * FIN bits are both off, (d) the acknowledgment number is equal to |
| * the greatest acknowledgment received on the given connection |
| * and (e) the advertised window in the incoming acknowledgment equals |
| * the advertised window in the last incoming acknowledgment. |
| */ |
| |
| if (pstate->snd_acked < pstate->snd_sent && |
| (flags & TCP_NEWDATA) == 0 && |
| (tcp->flags & (TCP_SYN | TCP_FIN)) == 0 && |
| ackno == pstate->snd_prev_ack && |
| conn->snd_wnd == pstate->snd_prev_wnd) |
| { |
| if (++pstate->snd_dup_acks >= TCP_FAST_RETRANSMISSION_THRESH) |
| { |
| flags |= TCP_REXMIT; |
| pstate->snd_dup_acks = 0; |
| } |
| } |
| else |
| { |
| pstate->snd_dup_acks = 0; |
| } |
| |
| pstate->snd_prev_ack = ackno; |
| pstate->snd_prev_wnd = conn->snd_wnd; |
| #endif |
| } |
| |
| /* Check if we are being asked to retransmit data. |
| * This condition is located here after TCP_ACKDATA for performance reasons |
| * (TCP_REXMIT is less frequent than TCP_ACKDATA). |
| */ |
| |
| if ((flags & TCP_REXMIT) != 0) |
| { |
| uint32_t sndlen; |
| |
| nwarn("WARNING: TCP_REXMIT\n"); |
| |
| /* According to RFC 6298 (5.4), retransmit the earliest segment |
| * that has not been acknowledged by the TCP receiver. |
| */ |
| |
| /* Reconstruct the length of the earliest segment to be retransmitted */ |
| |
| sndlen = pstate->snd_buflen - pstate->snd_acked; |
| |
| if (sndlen > conn->mss) |
| { |
| sndlen = conn->mss; |
| } |
| |
| conn->rexmit_seq = pstate->snd_isn + pstate->snd_acked; |
| |
| #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. |
| */ |
| |
| tcp_ip_select(conn); |
| #endif |
| /* Then set-up to send that amount of data. (this won't actually |
| * happen until the polling cycle completes). |
| */ |
| |
| ret = devif_send(dev, &pstate->snd_buffer[pstate->snd_acked], |
| sndlen, tcpip_hdrsize(conn)); |
| if (ret <= 0) |
| { |
| pstate->snd_sent = ret; |
| goto end_wait; |
| } |
| |
| /* Continue waiting */ |
| |
| return flags; |
| } |
| |
| /* Check for a loss of connection. |
| * This condition is located here after both the TCP_ACKDATA and TCP_REXMIT |
| * because TCP_DISCONN_EVENTS is the least frequent event. |
| */ |
| |
| else if ((flags & TCP_DISCONN_EVENTS) != 0) |
| { |
| 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. |
| */ |
| |
| if (_SS_ISCONNECTED(conn->sconn.s_flags)) |
| { |
| /* Report not connected */ |
| |
| tcp_lost_connection(conn, 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) |
| { |
| /* Get the amount of data that we can send in the next packet */ |
| |
| uint32_t sndlen = pstate->snd_buflen - pstate->snd_sent; |
| |
| if (sndlen > conn->mss) |
| { |
| sndlen = conn->mss; |
| } |
| |
| /* Check if we have "space" in the window */ |
| |
| if ((pstate->snd_sent - pstate->snd_acked + sndlen) < conn->snd_wnd) |
| { |
| #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. |
| */ |
| |
| tcp_ip_select(conn); |
| #endif |
| /* Then set-up to send that amount of data. (this won't actually |
| * happen until the polling cycle completes). |
| */ |
| |
| ret = devif_send(dev, &pstate->snd_buffer[pstate->snd_sent], |
| sndlen, tcpip_hdrsize(conn)); |
| if (ret <= 0) |
| { |
| pstate->snd_sent = ret; |
| goto end_wait; |
| } |
| |
| /* Update the amount of data sent (but not necessarily ACKed) */ |
| |
| pstate->snd_sent += sndlen; |
| ninfo("SEND: acked=%" PRId32 " sent=%zd buflen=%zu\n", |
| pstate->snd_acked, pstate->snd_sent, pstate->snd_buflen); |
| } |
| else |
| { |
| nwarn("WARNING: Window full, wait for ack\n"); |
| } |
| } |
| |
| /* Continue waiting */ |
| |
| return flags; |
| |
| end_wait: |
| |
| /* Do not allow any further callbacks */ |
| |
| DEBUGASSERT(pstate->snd_cb != NULL); |
| |
| 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; |
| } |
| |
| /**************************************************************************** |
| * 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_type != SOCK_STREAM || |
| psock->s_conn == NULL) |
| { |
| nerr("ERROR: Invalid socket\n"); |
| ret = -EBADF; |
| goto errout; |
| } |
| |
| conn = psock->s_conn; |
| |
| /* Check early if this is an un-connected socket, if so, then |
| * return -ENOTCONN. Note, we will have to check this again, as we can't |
| * guarantee the state won't change until we have the network locked. |
| */ |
| |
| if (!_SS_ISCONNECTED(conn->sconn.s_flags)) |
| { |
| nerr("ERROR: Not connected\n"); |
| ret = -ENOTCONN; |
| goto errout; |
| } |
| |
| /* Make sure that we have the IP address mapping */ |
| |
| #if defined(CONFIG_NET_ARP_SEND) || defined(CONFIG_NET_ICMPv6_NEIGHBOR) |
| #ifdef CONFIG_NET_ARP_SEND |
| if (psock->s_domain == PF_INET) |
| { |
| /* 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 |
| if (psock->s_domain == PF_INET6) |
| { |
| /* Make sure that the IP address mapping is in the Neighbor Table */ |
| |
| ret = icmpv6_neighbor(NULL, 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(); |
| |
| /* Now that we have the network locked, we need to check the connection |
| * state again to ensure the connection is still valid. |
| */ |
| |
| if (!_SS_ISCONNECTED(conn->sconn.s_flags)) |
| { |
| nerr("ERROR: No longer connected\n"); |
| net_unlock(); |
| ret = -ENOTCONN; |
| goto errout; |
| } |
| |
| memset(&state, 0, sizeof(struct send_s)); |
| nxsem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */ |
| |
| state.snd_conn = conn; /* 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 */ |
| |
| tcp_send_txnotify(psock, conn); |
| |
| /* Wait for the send to complete or an error to occur: NOTES: |
| * net_sem_wait will also terminate if a signal is received. |
| */ |
| |
| for (; ; ) |
| { |
| uint32_t acked = state.snd_acked; |
| |
| ret = net_sem_timedwait(&state.snd_sem, |
| _SO_TIMEOUT(conn->sconn.s_sndtimeo)); |
| if (ret != -ETIMEDOUT || acked == state.snd_acked) |
| { |
| if (ret == -ETIMEDOUT) |
| { |
| ret = -EAGAIN; |
| } |
| |
| 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_sem_timedwait failed, then we were probably reawakened by a |
| * signal. In this case, net_sem_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: |
| * conn The TCP connection of interest |
| * |
| * Returned Value: |
| * OK (Always can send). |
| * |
| * Assumptions: |
| * None |
| * |
| ****************************************************************************/ |
| |
| int psock_tcp_cansend(FAR struct tcp_conn_s *conn) |
| { |
| return OK; |
| } |
| |
| #endif /* CONFIG_NET && CONFIG_NET_TCP && !CONFIG_NET_TCP_WRITE_BUFFERS */ |
