nuttx/net/tcp/tcp_sendfile.c
Xiang Xiao 906cb8b0f4 net/tcp: tcp_sendfile need restore the file location at the end
quote from https://man7.org/linux/man-pages/man2/sendfile.2.html:
If offset is not NULL, then it points to a variable holding the
file offset from which sendfile() will start reading data from
in_fd.  When sendfile() returns, this variable will be set to the
offset of the byte following the last byte that was read.  If
offset is not NULL, then sendfile() does not modify the file
offset of in_fd; otherwise the file offset is adjusted to reflect
the number of bytes read from in_fd.
If offset is NULL, then data will be read from in_fd starting at
the file offset, and the file offset will be updated by the call.

The change also align with the implementation at:
libs/libc/misc/lib_sendfile.c

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: I607944f40b04f76731af7b205dcd319b0637fa04
2021-07-12 05:20:45 -07:00

632 lines
18 KiB
C

/****************************************************************************
* net/tcp/tcp_sendfile.c
*
* Copyright (C) 2013 UVC Ingenieure. All rights reserved.
* Copyright (C) 2007-2017 Gregory Nutt. All rights reserved.
* Authors: Gregory Nutt <gnutt@nuttx.org>
* Max Holtzberg <mh@uvc.de>
*
* 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>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <arch/irq.h>
#include <nuttx/semaphore.h>
#include <nuttx/fs/fs.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 "arp/arp.h"
#include "icmpv6/icmpv6.h"
#include "neighbor/neighbor.h"
#include "socket/socket.h"
#include "tcp/tcp.h"
#if defined(CONFIG_NET_SENDFILE) && defined(CONFIG_NET_TCP) && \
defined(NET_TCP_HAVE_STACK)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#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 from the driver poll event.
*/
struct sendfile_s
{
FAR struct socket *snd_sock; /* Points to the parent socket structure */
FAR struct devif_callback_s *snd_datacb; /* Data callback */
FAR struct devif_callback_s *snd_ackcb; /* ACK callback */
FAR struct file *snd_file; /* File structure of the input file */
sem_t snd_sem; /* Used to wake up the waiting thread */
off_t snd_foffset; /* Input file offset */
size_t snd_flen; /* File length */
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 */
};
/****************************************************************************
* Private Functions
****************************************************************************/
static uint16_t ack_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvconn,
FAR void *pvpriv, uint16_t flags)
{
FAR struct sendfile_s *pstate = (FAR struct sendfile_s *)pvpriv;
ninfo("flags: %04x\n", flags);
if ((flags & TCP_ACKDATA) != 0)
{
FAR struct tcp_hdr_s *tcp;
/* Get the offset address of the TCP header */
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
DEBUGASSERT(pstate->snd_sock->s_domain == PF_INET6);
tcp = TCPIPv6BUF;
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
DEBUGASSERT(pstate->snd_sock->s_domain == PF_INET);
tcp = TCPIPv4BUF;
}
#endif /* CONFIG_NET_IPv4 */
/* The current acknowledgement number number is the (relative) offset
* of the 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=%" PRId32 " sent=%zd flen=%zu\n",
pstate->snd_acked, pstate->snd_sent, pstate->snd_flen);
dev->d_sndlen = 0;
flags &= ~TCP_ACKDATA;
}
else if ((flags & TCP_REXMIT) != 0)
{
nwarn("WARNING: TCP_REXMIT\n");
/* 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;
}
/* Check for a loss of connection */
else if ((flags & TCP_DISCONN_EVENTS) != 0)
{
FAR struct socket *psock = pstate->snd_sock;
nwarn("WARNING: 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_ackcb, flags);
}
/* Report not connected */
pstate->snd_sent = -ENOTCONN;
}
/* Prohibit further callbacks */
pstate->snd_ackcb->flags = 0;
pstate->snd_ackcb->priv = NULL;
pstate->snd_ackcb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->snd_sem);
return flags;
}
/****************************************************************************
* Name: sendfile_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 sendfile_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 sendfile_s *pstate = (FAR struct sendfile_s *)pvpriv;
int ret;
/* Check for a loss of connection */
if ((flags & TCP_DISCONN_EVENTS) != 0)
{
FAR struct socket *psock = pstate->snd_sock;
nwarn("WARNING: 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_datacb, flags);
}
/* Report not connected */
pstate->snd_sent = -ENOTCONN;
goto end_wait;
}
/* The TCP socket is connected and, hence, should be bound to a device.
* Make sure that the polling device is the own that we are bound to.
*/
DEBUGASSERT(conn);
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);
/* 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
* unprocessing 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_flen)
{
/* Get the amount of data that we can send in the next packet */
uint32_t sndlen = pstate->snd_flen - 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)
{
uint32_t seqno;
/* Then set-up to send that amount of data. (this won't actually
* happen until the polling cycle completes).
*/
ret = file_seek(pstate->snd_file,
pstate->snd_foffset + pstate->snd_sent, SEEK_SET);
if (ret < 0)
{
nerr("ERROR: Failed to lseek: %d\n", ret);
pstate->snd_sent = ret;
goto end_wait;
}
ret = file_read(pstate->snd_file, dev->d_appdata, sndlen);
if (ret < 0)
{
nerr("ERROR: Failed to read from input file: %d\n", (int)ret);
pstate->snd_sent = ret;
goto end_wait;
}
dev->d_sndlen = sndlen;
/* Set the sequence number for this packet. NOTE: The network
* updates sndseq on recept of ACK *before* this function is
* called. In that case sndseq will point to the next
* unacknowledge 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 %08" PRIx32 "->%08" PRIx32 " len: %d\n",
tcp_getsequence(conn->sndseq), seqno, ret);
tcp_setsequence(conn->sndseq, seqno);
/* Update the amount of data sent (but not necessarily ACKed) */
pstate->snd_sent += sndlen;
ninfo("pid: %d SEND: acked=%" PRId32 " sent=%zd flen=%zu\n",
getpid(),
pstate->snd_acked, pstate->snd_sent, pstate->snd_flen);
}
else
{
nwarn("WARNING: Window full, wait for ack\n");
goto wait;
}
}
if (pstate->snd_sent >= pstate->snd_flen
&& pstate->snd_acked < pstate->snd_flen)
{
/* All data has been sent, but there are outstanding ACK's */
goto wait;
}
end_wait:
/* Do not allow any further callbacks */
pstate->snd_datacb->flags = 0;
pstate->snd_datacb->priv = NULL;
pstate->snd_datacb->event = NULL;
/* Wake up the waiting thread */
nxsem_post(&pstate->snd_sem);
wait:
return flags;
}
/****************************************************************************
* Name: sendfile_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 sendfile_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: tcp_sendfile
*
* Description:
* The tcp_sendfile() call may be used only when the INET 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. See sendfile() for a list
* appropriate error return values.
*
****************************************************************************/
ssize_t tcp_sendfile(FAR struct socket *psock, FAR struct file *infile,
FAR off_t *offset, size_t count)
{
FAR struct tcp_conn_s *conn;
struct sendfile_s state;
off_t startpos;
int ret;
/* 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");
return -ENOTCONN;
}
/* Make sure that we have the IP address mapping */
conn = (FAR struct tcp_conn_s *)psock->s_conn;
DEBUGASSERT(conn != NULL);
#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");
return -ENETUNREACH;
}
#endif /* CONFIG_NET_ARP_SEND || CONFIG_NET_ICMPv6_NEIGHBOR */
/* Get the current file position. */
startpos = file_seek(infile, 0, SEEK_CUR);
if (startpos < 0)
{
return startpos;
}
/* 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 sendfile_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_foffset = offset ? *offset : startpos; /* Input file offset */
state.snd_flen = count; /* Number of bytes to send */
state.snd_file = infile; /* File to read from */
/* Allocate resources to receive a callback */
state.snd_datacb = tcp_callback_alloc(conn);
if (state.snd_datacb == NULL)
{
nerr("ERROR: Failed to allocate data callback\n");
ret = -ENOMEM;
goto errout_locked;
}
state.snd_ackcb = tcp_callback_alloc(conn);
if (state.snd_ackcb == NULL)
{
nerr("ERROR: Failed to allocate ack callback\n");
ret = -ENOMEM;
goto errout_datacb;
}
/* 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 ACK callback in the connection */
state.snd_ackcb->flags = (TCP_ACKDATA | TCP_REXMIT | TCP_DISCONN_EVENTS);
state.snd_ackcb->priv = (FAR void *)&state;
state.snd_ackcb->event = ack_eventhandler;
/* Perform the TCP send operation */
state.snd_datacb->flags = TCP_POLL;
state.snd_datacb->priv = (FAR void *)&state;
state.snd_datacb->event = sendfile_eventhandler;
/* Notify the device driver of the availability of TX data */
sendfile_txnotify(psock, conn);
for (; ; )
{
uint32_t acked = state.snd_acked;
ret = net_timedwait_uninterruptible(&state.snd_sem,
_SO_TIMEOUT(psock->s_sndtimeo));
if (ret != -ETIMEDOUT || acked == state.snd_acked)
{
break; /* Timeout without any progress */
}
}
tcp_callback_free(conn, state.snd_ackcb);
errout_datacb:
tcp_callback_free(conn, state.snd_datacb);
errout_locked:
nxsem_destroy(&state.snd_sem);
net_unlock();
/* Return the current file position */
if (offset)
{
/* Use lseek to get the current file position */
off_t curpos = file_seek(infile, 0, SEEK_CUR);
if (curpos < 0)
{
return curpos;
}
/* Return the current file position */
*offset = curpos;
/* Use lseek again to restore the original file position */
startpos = file_seek(infile, startpos, SEEK_SET);
if (startpos < 0)
{
return startpos;
}
}
if (ret < 0)
{
return ret;
}
else
{
return state.snd_sent;
}
}
#endif /* CONFIG_NET_SENDFILE && CONFIG_NET_TCP && NET_TCP_HAVE_STACK */