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incubator-nuttx/drivers/net/tun.c

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/****************************************************************************
* drivers/net/tun.c
*
* Copyright (C) 2015 Max Nekludov. All rights reserved.
* Author: Max Nekludov <macscomp@gmail.com>
*
* 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_TUN)
#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <fcntl.h>
#include <debug.h>
#ifndef CONFIG_DISABLE_POLL
# include <poll.h>
#endif
#include <arpa/inet.h>
#include <nuttx/arch.h>
#include <nuttx/irq.h>
#include <nuttx/wdog.h>
#include <nuttx/net/arp.h>
#include <nuttx/net/netdev.h>
#include <net/if.h>
#include <nuttx/net/tun.h>
#ifdef CONFIG_NET_NOINTS
# include <nuttx/wqueue.h>
#endif
#ifdef CONFIG_NET_PKT
# include <nuttx/net/pkt.h>
#endif
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* If processing is not done at the interrupt level, then high priority
* work queue support is required.
*/
#if defined(CONFIG_NET_NOINTS) && !defined(CONFIG_SCHED_HPWORK)
# error High priority work queue support is required
#endif
/* CONFIG_TUN_NINTERFACES determines the number of physical interfaces
* that will be supported.
*/
#ifndef CONFIG_TUN_NINTERFACES
# define CONFIG_TUN_NINTERFACES 1
#endif
/* TX poll delay = 1 seconds. CLK_TCK is the number of clock ticks per
* second
*/
#define TUN_WDDELAY (1*CLK_TCK)
/****************************************************************************
* Private Types
****************************************************************************/
/* The tun_device_s encapsulates all state information for a single hardware
* interface
*/
struct tun_device_s
{
bool bifup; /* true:ifup false:ifdown */
WDOG_ID txpoll; /* TX poll timer */
#ifdef CONFIG_NET_NOINTS
struct work_s work; /* For deferring work to the work queue */
#endif
FAR struct file *filep;
#ifndef CONFIG_DISABLE_POLL
FAR struct pollfd *poll_fds;
#endif
bool read_wait;
uint8_t read_buf[CONFIG_NET_TUN_MTU];
size_t read_d_len;
uint8_t write_buf[CONFIG_NET_TUN_MTU];
size_t write_d_len;
sem_t waitsem;
sem_t read_wait_sem;
/* This holds the information visible to uIP/NuttX */
struct net_driver_s dev; /* Interface understood by uIP */
};
struct tun_driver_s
{
uint8_t free_tuns;
sem_t waitsem;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void tun_lock(FAR struct tun_device_s *priv);
static void tun_unlock(FAR struct tun_device_s *priv);
/* Common TX logic */
static int tun_transmit(FAR struct tun_device_s *priv);
static int tun_txpoll(struct net_driver_s *dev);
/* Interrupt handling */
static void tun_receive(FAR struct tun_device_s *priv);
static void tun_txdone(FAR struct tun_device_s *priv);
/* Watchdog timer expirations */
static inline void tun_poll_process(FAR struct tun_device_s *priv);
#ifdef CONFIG_NET_NOINTS
static void tun_poll_work(FAR void *arg);
#endif
static void tun_poll_expiry(int argc, wdparm_t arg, ...);
/* NuttX callback functions */
static int tun_ifup(FAR struct net_driver_s *dev);
static int tun_ifdown(FAR struct net_driver_s *dev);
static int tun_txavail(FAR struct net_driver_s *dev);
#if defined(CONFIG_NET_IGMP) || defined(CONFIG_NET_ICMPv6)
static int tun_addmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac);
#endif
#ifdef CONFIG_NET_IGMP
static int tun_rmmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac);
#endif
#ifdef CONFIG_NET_ICMPv6
static void tun_ipv6multicast(FAR struct tun_device_s *priv);
#endif
static int tun_dev_init(FAR struct tun_device_s *priv,
FAR struct file *filep, FAR const char *devfmt);
static int tun_dev_uninit(FAR struct tun_device_s *priv);
/* File interface */
static int tun_open(FAR struct file *filep);
static int tun_close(FAR struct file *filep);
static ssize_t tun_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t tun_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int tun_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
#ifndef CONFIG_DISABLE_POLL
static int tun_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static struct tun_driver_s g_tun;
static struct tun_device_s g_tun_devices[CONFIG_TUN_NINTERFACES];
static const struct file_operations g_tun_file_ops =
{
tun_open, /* open */
tun_close, /* close */
tun_read, /* read */
tun_write, /* write */
0, /* seek */
tun_ioctl, /* ioctl */
#ifndef CONFIG_DISABLE_POLL
tun_poll, /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: tundev_lock
****************************************************************************/
static void tundev_lock(FAR struct tun_driver_s *tun)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&tun->waitsem) != 0)
{
/* The only case that an error should occur here is if
* the wait was awakened by a signal.
*/
ASSERT(errno == EINTR);
}
}
/****************************************************************************
* Name: tundev_unlock
****************************************************************************/
static void tundev_unlock(FAR struct tun_driver_s *tun)
{
sem_post(&tun->waitsem);
}
/****************************************************************************
* Name: tun_lock
****************************************************************************/
static void tun_lock(FAR struct tun_device_s *priv)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&priv->waitsem) != 0)
{
/* The only case that an error should occur here is if
* the wait was awakened by a signal.
*/
ASSERT(errno == EINTR);
}
}
/****************************************************************************
* Name: tun_unlock
****************************************************************************/
static void tun_unlock(FAR struct tun_device_s *priv)
{
sem_post(&priv->waitsem);
}
/****************************************************************************
* Name: tun_pollnotify
****************************************************************************/
#ifndef CONFIG_DISABLE_POLL
static void tun_pollnotify(FAR struct tun_device_s *priv, pollevent_t eventset)
{
FAR struct pollfd *fds = priv->poll_fds;
if (fds == NULL)
{
return;
}
eventset &= fds->events;
if (eventset != 0)
{
fds->revents |= eventset;
sem_post(fds->sem);
}
}
#else
# define tun_pollnotify(dev, event)
#endif
/****************************************************************************
* Function: tun_transmit
*
* Description:
* Start hardware transmission. Called either from the txdone interrupt
* handling or from watchdog based polling.
*
* Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* OK on success; a negated errno on failure
*
* Assumptions:
* May or may not be called from an interrupt handler. In either case,
* global interrupts are disabled, either explicitly or indirectly through
* interrupt handling logic.
*
****************************************************************************/
static int tun_transmit(FAR struct tun_device_s *priv)
{
NETDEV_TXPACKETS(&priv->dev);
/* Verify that the hardware is ready to send another packet. If we get
* here, then we are committed to sending a packet; Higher level logic
* must have assured that there is no transmission in progress.
*/
if (priv->read_wait)
{
priv->read_wait = false;
sem_post(&priv->read_wait_sem);
}
tun_pollnotify(priv, POLLIN);
return OK;
}
/****************************************************************************
* Function: tun_txpoll
*
* Description:
* The transmitter is available, check if uIP has any outgoing packets
* ready to send. This is a callback from devif_poll(). devif_poll() may
* be called:
*
* 1. When the preceding TX packet send is complete,
* 2. When the preceding TX packet send timesout and the interface is reset
* 3. During normal TX polling
*
* Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* OK on success; a negated errno on failure
*
* Assumptions:
* May or may not be called from an interrupt handler. In either case,
* global interrupts are disabled, either explicitly or indirectly through
* interrupt handling logic.
*
****************************************************************************/
static int tun_txpoll(struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
/* If the polling resulted in data that should be sent out on the network,
* the field d_len is set to a value > 0.
*/
if (priv->dev.d_len > 0)
{
/* Send the packet */
priv->read_d_len = priv->dev.d_len;
tun_transmit(priv);
return 1;
}
/* If zero is returned, the polling will continue until all connections have
* been examined.
*/
return 0;
}
/****************************************************************************
* Function: tun_receive
*
* Description:
* An interrupt was received indicating the availability of a new RX packet
*
* Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Global interrupts are disabled by interrupt handling logic.
*
****************************************************************************/
static void tun_receive(FAR struct tun_device_s *priv)
{
/* Copy the data data from the hardware to priv->dev.d_buf. Set amount of
* data in priv->dev.d_len
*/
NETDEV_RXPACKETS(&priv->dev);
#ifdef CONFIG_NET_PKT
/* When packet sockets are enabled, feed the frame into the packet tap */
pkt_input(&priv->dev);
#endif
/* We only accept IP packets of the configured type and ARP packets */
#if defined(CONFIG_NET_IPv4)
nllvdbg("IPv4 frame\n");
NETDEV_RXIPV4(&priv->dev);
/* Give the IPv4 packet to the network layer */
ipv4_input(&priv->dev);
/* If the above function invocation resulted in data that should be
* sent out on the network, the field d_len will set to a value > 0.
*/
if (priv->dev.d_len > 0)
{
priv->write_d_len = priv->dev.d_len;
tun_transmit(priv);
}
else
{
priv->write_d_len = 0;
tun_pollnotify(priv, POLLOUT);
}
#elif defined(CONFIG_NET_IPv6)
nllvdbg("Iv6 frame\n");
NETDEV_RXIPV6(&priv->dev);
/* Give the IPv6 packet to the network layer */
ipv6_input(&priv->dev);
/* If the above function invocation resulted in data that should be
* sent out on the network, the field d_len will set to a value > 0.
*/
if (priv->dev.d_len > 0)
{
priv->write_d_len = priv->dev.d_len;
tun_transmit(priv);
}
else
{
priv->write_d_len = 0;
tun_pollnotify(priv, POLLOUT);
}
#else
NETDEV_RXDROPPED(&priv->dev);
#endif
}
/****************************************************************************
* Function: tun_txdone
*
* Description:
* An interrupt was received indicating that the last TX packet(s) is done
*
* Parameters:
* dev - Reference to the driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Global interrupts are disabled by the watchdog logic.
*
****************************************************************************/
static void tun_txdone(FAR struct tun_device_s *priv)
{
/* Check for errors and update statistics */
NETDEV_TXDONE(&priv->dev);
/* Then poll uIP for new XMIT data */
priv->dev.d_buf = priv->read_buf;
(void)devif_poll(&priv->dev, tun_txpoll);
}
/****************************************************************************
* Function: tun_poll_process
*
* Description:
* Perform the periodic poll. This may be called either from watchdog
* timer logic or from the worker thread, depending upon the configuration.
*
* Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static void tun_poll_process(FAR struct tun_device_s *priv)
{
/* Check if there is room in the send another TX packet. We cannot perform
* the TX poll if he are unable to accept another packet for transmission.
*/
if (priv->read_d_len == 0)
{
/* If so, poll uIP for new XMIT data. */
priv->dev.d_buf = priv->read_buf;
(void)devif_timer(&priv->dev, tun_txpoll);
}
/* Setup the watchdog poll timer again */
(void)wd_start(priv->txpoll, TUN_WDDELAY, tun_poll_expiry, 1, priv);
}
/****************************************************************************
* Function: tun_poll_work
*
* Description:
* Perform periodic polling from the worker thread
*
* Parameters:
* arg - The argument passed when work_queue() as called.
*
* Returned Value:
* OK on success
*
* Assumptions:
* Ethernet interrupts are disabled
*
****************************************************************************/
#ifdef CONFIG_NET_NOINTS
static void tun_poll_work(FAR void *arg)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)arg;
net_lock_t state;
/* Perform the poll */
tun_lock(priv);
state = net_lock();
tun_poll_process(priv);
net_unlock(state);
tun_unlock(priv);
}
#endif
/****************************************************************************
* Function: tun_poll_expiry
*
* Description:
* Periodic timer handler. Called from the timer interrupt handler.
*
* Parameters:
* argc - The number of available arguments
* arg - The first argument
*
* Returned Value:
* None
*
* Assumptions:
* Global interrupts are disabled by the watchdog logic.
*
****************************************************************************/
static void tun_poll_expiry(int argc, wdparm_t arg, ...)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)arg;
#ifdef CONFIG_NET_NOINTS
/* Is our single work structure available? It may not be if there are
* pending interrupt actions.
*/
if (work_available(&priv->work))
{
/* Schedule to perform the interrupt processing on the worker thread. */
work_queue(HPWORK, &priv->work, tun_poll_work, priv, 0);
}
else
{
/* No.. Just re-start the watchdog poll timer, missing one polling
* cycle.
*/
(void)wd_start(priv->txpoll, TUN_WDDELAY, tun_poll_expiry, 1, arg);
}
#else
/* Process the interrupt now */
tun_poll_process(priv);
#endif
}
/****************************************************************************
* Function: tun_ifup
*
* Description:
* NuttX Callback: Bring up the Ethernet interface when an IP address is
* provided
*
* Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static int tun_ifup(struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
#ifdef CONFIG_NET_IPv4
ndbg("Bringing up: %d.%d.%d.%d\n",
dev->d_ipaddr & 0xff, (dev->d_ipaddr >> 8) & 0xff,
(dev->d_ipaddr >> 16) & 0xff, dev->d_ipaddr >> 24);
#endif
#ifdef CONFIG_NET_IPv6
ndbg("Bringing up: %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
dev->d_ipv6addr[0], dev->d_ipv6addr[1], dev->d_ipv6addr[2],
dev->d_ipv6addr[3], dev->d_ipv6addr[4], dev->d_ipv6addr[5],
dev->d_ipv6addr[6], dev->d_ipv6addr[7]);
#endif
/* Initialize PHYs, the Ethernet interface, and setup up Ethernet interrupts */
/* Instantiate the MAC address from priv->dev.d_mac.ether_addr_octet */
#ifdef CONFIG_NET_ICMPv6
/* Set up IPv6 multicast address filtering */
tun_ipv6multicast(priv);
#endif
/* Set and activate a timer process */
(void)wd_start(priv->txpoll, TUN_WDDELAY, tun_poll_expiry, 1, (wdparm_t)priv);
priv->bifup = true;
return OK;
}
/****************************************************************************
* Function: tun_ifdown
*
* Description:
* NuttX Callback: Stop the interface.
*
* Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static int tun_ifdown(struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
tun_lock(priv);
/* Cancel the TX poll timer */
wd_cancel(priv->txpoll);
/* Mark the device "down" */
priv->bifup = false;
tun_unlock(priv);
return OK;
}
/****************************************************************************
* Function: tun_txavail
*
* Description:
* Driver callback invoked when new TX data is available. This is a
* stimulus perform an out-of-cycle poll and, thereby, reduce the TX
* latency.
*
* Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Called in normal user mode
*
****************************************************************************/
static int tun_txavail(struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
net_lock_t state;
tun_lock(priv);
/* Check if there is room to hold another network packet. */
if (priv->read_d_len)
{
tun_unlock(priv);
return OK;
}
state = net_lock();
if (priv->bifup)
{
/* Poll uIP for new XMIT data */
priv->dev.d_buf = priv->read_buf;
(void)devif_poll(&priv->dev, tun_txpoll);
}
net_unlock(state);
tun_unlock(priv);
return OK;
}
/****************************************************************************
* Function: tun_addmac
*
* Description:
* NuttX Callback: Add the specified MAC address to the hardware multicast
* address filtering
*
* Parameters:
* dev - Reference to the NuttX driver state structure
* mac - The MAC address to be added
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#if defined(CONFIG_NET_IGMP) || defined(CONFIG_NET_ICMPv6)
static int tun_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
{
/* Add the MAC address to the hardware multicast routing table */
return OK;
}
#endif
/****************************************************************************
* Function: tun_rmmac
*
* Description:
* NuttX Callback: Remove the specified MAC address from the hardware multicast
* address filtering
*
* Parameters:
* dev - Reference to the NuttX driver state structure
* mac - The MAC address to be removed
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_NET_IGMP
static int tun_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac)
{
/* Add the MAC address to the hardware multicast routing table */
return OK;
}
#endif
/****************************************************************************
* Function: tun_ipv6multicast
*
* Description:
* Configure the IPv6 multicast MAC address.
*
* Parameters:
* priv - A reference to the private driver state structure
*
* Returned Value:
* OK on success; Negated errno on failure.
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_NET_ICMPv6
static void tun_ipv6multicast(FAR struct tun_device_s *priv)
{
}
#endif /* CONFIG_NET_ICMPv6 */
/****************************************************************************
* Function: tun_dev_init
*
* Description:
* Initialize the TUN device
*
* Parameters:
*
* Returned Value:
* OK on success; Negated errno on failure.
*
* Assumptions:
*
****************************************************************************/
static int tun_dev_init(FAR struct tun_device_s *priv, FAR struct file *filep,
FAR const char *devfmt)
{
int ret;
/* Initialize the driver structure */
memset(priv, 0, sizeof(struct tun_device_s));
priv->dev.d_ifup = tun_ifup; /* I/F up (new IP address) callback */
priv->dev.d_ifdown = tun_ifdown; /* I/F down callback */
priv->dev.d_txavail = tun_txavail; /* New TX data callback */
#ifdef CONFIG_NET_IGMP
priv->dev.d_addmac = tun_addmac; /* Add multicast MAC address */
priv->dev.d_rmmac = tun_rmmac; /* Remove multicast MAC address */
#endif
priv->dev.d_private = (FAR void *)priv; /* Used to recover private state from dev */
/* Initialize the wait semaphore */
sem_init(&priv->waitsem, 0, 1);
sem_init(&priv->read_wait_sem, 0, 0);
/* Create a watchdog for timing polling for and timing of transmisstions */
priv->txpoll = wd_create(); /* Create periodic poll timer */
/* Initialize other variables */
priv->write_d_len = 0;
priv->read_wait = false;
/* Put the interface in the down state */
tun_ifdown(&priv->dev);
if (devfmt)
{
strncpy(priv->dev.d_ifname, devfmt, IFNAMSIZ);
}
/* Register the device with the OS so that socket IOCTLs can be performed */
ret = netdev_register(&priv->dev, NET_LL_TUN);
if (ret != OK)
{
sem_destroy(&priv->waitsem);
sem_destroy(&priv->read_wait_sem);
return ret;
}
priv->filep = filep; /* Set link to file */
filep->f_priv = priv; /* Set link to TUN device */
return ret;
}
/****************************************************************************
* Name: tun_dev_uninit
****************************************************************************/
static int tun_dev_uninit(FAR struct tun_device_s *priv)
{
/* Put the interface in the down state */
tun_ifdown(&priv->dev);
/* Remove the device from the OS */
(void)netdev_unregister(&priv->dev);
sem_destroy(&priv->waitsem);
sem_destroy(&priv->read_wait_sem);
return OK;
}
/****************************************************************************
* Name: tun_open
****************************************************************************/
static int tun_open(FAR struct file *filep)
{
filep->f_priv = 0;
return OK;
}
/****************************************************************************
* Name: tun_close
****************************************************************************/
static int tun_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct tun_driver_s *tun = inode->i_private;
FAR struct tun_device_s *priv = filep->f_priv;
int intf;
if (!priv)
{
return OK;
}
intf = priv - g_tun_devices;
tundev_lock(tun);
tun->free_tuns |= (1 << intf);
(void)tun_dev_uninit(priv);
tundev_unlock(tun);
return OK;
}
/****************************************************************************
* Name: tun_write
****************************************************************************/
static ssize_t tun_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
FAR struct tun_device_s *priv = filep->f_priv;
net_lock_t state;
ssize_t ret;
if (!priv)
{
return -EINVAL;
}
tun_lock(priv);
if (priv->write_d_len > 0)
{
tun_unlock(priv);
return -EBUSY;
}
state = net_lock();
if (buflen > CONFIG_NET_TUN_MTU)
{
ret = -EINVAL;
}
else
{
memcpy(priv->write_buf, buffer, buflen);
priv->dev.d_buf = priv->write_buf;
priv->dev.d_len = buflen;
tun_receive(priv);
ret = (ssize_t)buflen;
}
net_unlock(state);
tun_unlock(priv);
return ret;
}
/****************************************************************************
* Name: tun_read
****************************************************************************/
static ssize_t tun_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct tun_device_s *priv = filep->f_priv;
net_lock_t state;
ssize_t ret;
size_t write_d_len;
size_t read_d_len;
if (!priv)
{
return -EINVAL;
}
tun_lock(priv);
/* Check if there are data to read in write buffer */
write_d_len = priv->write_d_len;
if (write_d_len > 0)
{
if (buflen < write_d_len)
{
ret = -EINVAL;
goto out;
}
memcpy(buffer, priv->write_buf, write_d_len);
ret = (ssize_t)write_d_len;
priv->write_d_len = 0;
tun_pollnotify(priv, POLLOUT);
goto out;
}
if (priv->read_d_len == 0)
{
if ((filep->f_oflags & O_NONBLOCK) != 0)
{
ret = -EAGAIN;
goto out;
}
priv->read_wait = true;
tun_unlock(priv);
sem_wait(&priv->read_wait_sem);
tun_lock(priv);
}
state = net_lock();
read_d_len = priv->read_d_len;
if (buflen < read_d_len)
{
ret = -EINVAL;
}
else
{
memcpy(buffer, priv->read_buf, read_d_len);
ret = (ssize_t)read_d_len;
}
priv->read_d_len = 0;
tun_txdone(priv);
net_unlock(state);
out:
tun_unlock(priv);
return ret;
}
/****************************************************************************
* Name: tun_poll
****************************************************************************/
#ifndef CONFIG_DISABLE_POLL
int tun_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
{
FAR struct tun_device_s *priv = filep->f_priv;
pollevent_t eventset;
int ret = OK;
if (!priv)
{
return -EINVAL;
}
/* Some sanity checking */
if (!priv || !fds)
{
return -ENODEV;
}
tun_lock(priv);
if (setup)
{
if (priv->poll_fds)
{
ret = -EBUSY;
goto errout;
}
priv->poll_fds = fds;
eventset = 0;
/* If write buffer is empty notify App. */
if (priv->write_d_len == 0)
{
eventset |= (fds->events & POLLOUT);
}
/* The write buffer sometimes could be used for TX.
* So check it too.
*/
if (priv->read_d_len != 0 || priv->write_d_len != 0)
{
eventset |= (fds->events & POLLIN);
}
if (eventset)
{
tun_pollnotify(priv, eventset);
}
}
else
{
priv->poll_fds = 0;
}
errout:
tun_unlock(priv);
return ret;
}
#endif
/****************************************************************************
* Name: tun_ioctl
****************************************************************************/
static int tun_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct tun_driver_s *tun = inode->i_private;
FAR struct tun_device_s *priv = filep->f_priv;
int ret = OK;
if (cmd == TUNSETIFF && !priv)
{
uint8_t free_tuns;
int intf;
FAR struct ifreq *ifr = (FAR struct ifreq *)arg;
if (!ifr || (ifr->ifr_flags & IFF_MASK) != IFF_TUN)
{
return -EINVAL;
}
tundev_lock(tun);
free_tuns = tun->free_tuns;
if (free_tuns == 0)
{
tundev_unlock(tun);
return -ENOMEM;
}
for (intf = 0;
intf < CONFIG_TUN_NINTERFACES && !(free_tuns & 1);
intf++, free_tuns >>= 1);
ret = tun_dev_init(&g_tun_devices[intf], filep,
*ifr->ifr_name ? ifr->ifr_name : 0);
if (ret != OK)
{
tundev_unlock(tun);
return ret;
}
tun->free_tuns &= ~(1 << intf);
priv = filep->f_priv;
strncpy(ifr->ifr_name, priv->dev.d_ifname, IFNAMSIZ);
tundev_unlock(tun);
return OK;
}
return -EBADFD;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: tun_initialize
*
* Description:
* Instantiate a SLIP network interface.
*
* Parameters:
*
* Returned Value:
* OK on success; Negated errno on failure.
*
* Assumptions:
*
****************************************************************************/
int tun_initialize(void)
{
sem_init(&g_tun.waitsem, 0, 1);
g_tun.free_tuns = (1 << CONFIG_TUN_NINTERFACES) - 1;
(void)register_driver("/dev/tun", &g_tun_file_ops, 0644, &g_tun);
return OK;
}
#endif /* CONFIG_NET && CONFIG_NET_TUN */
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