nuttx/drivers/net/tun.c
zhanghongyu ba9ef06970 tun: add ioctl cmd TUNGETIFF implement
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
2022-12-20 21:15:50 +08:00

1271 lines
33 KiB
C

/****************************************************************************
* drivers/net/tun.c
*
* Copyright (C) 2015-2016 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>
#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <fcntl.h>
#include <debug.h>
#include <poll.h>
#include <arpa/inet.h>
#include <net/if.h>
#ifdef CONFIG_NET_PKT
# include <nuttx/net/pkt.h>
#endif
#include <nuttx/arch.h>
#include <nuttx/irq.h>
#include <nuttx/mutex.h>
#include <nuttx/wqueue.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ethernet.h>
#include <nuttx/net/tun.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_TUN)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* If processing is not done at the interrupt level, then high priority
* work queue support is required.
*/
#if !defined(CONFIG_SCHED_WORKQUEUE)
# error Work queue support is required in this configuration (CONFIG_SCHED_WORKQUEUE)
#endif
/* The low priority work queue is preferred. If it is not enabled, LPWORK
* will be the same as HPWORK.
*
* NOTE: However, the network should NEVER run on the high priority work
* queue! That queue is intended only to service short back end interrupt
* processing that never suspends. Suspending the high priority work queue
* may bring the system to its knees!
*/
#define TUNWORK LPWORK
/* CONFIG_TUN_NINTERFACES determines the number of physical interfaces
* that will be supported.
*/
#ifndef CONFIG_TUN_NINTERFACES
# define CONFIG_TUN_NINTERFACES 1
#endif
/* Make sure that packet buffers include in configured guard size and are an
* even multiple of 16-bits in length.
*/
#define NET_TUN_PKTSIZE ((CONFIG_NET_TUN_PKTSIZE + CONFIG_NET_GUARDSIZE + 1) & ~1)
/* This is a helper pointer for accessing the contents of the Ethernet
* header.
*/
#ifdef CONFIG_NET_ETHERNET
# define BUF ((FAR struct eth_hdr_s *)priv->dev.d_buf)
#endif
/****************************************************************************
* 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 */
bool read_wait;
bool write_wait;
struct work_s work; /* For deferring poll work to the work queue */
FAR struct pollfd *poll_fds;
mutex_t lock;
sem_t read_wait_sem;
sem_t write_wait_sem;
size_t read_d_len;
size_t write_d_len;
/* These packet buffer arrays required 16-bit alignment. That alignment
* is assured only by the preceding wide data types.
*/
uint8_t read_buf[NET_TUN_PKTSIZE];
uint8_t write_buf[NET_TUN_PKTSIZE];
/* This holds the information visible to the NuttX network */
struct net_driver_s dev; /* Interface understood by the network */
};
struct tun_driver_s
{
mutex_t lock;
uint8_t free_tuns;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Common TX logic */
static void tun_fd_transmit(FAR struct tun_device_s *priv);
static int tun_txpoll(FAR struct net_driver_s *dev);
#ifdef CONFIG_NET_ETHERNET
static int tun_txpoll_tap(FAR struct net_driver_s *dev);
#endif
static int tun_txpoll_tun(FAR struct net_driver_s *dev);
/* Interrupt handling */
static void tun_net_receive(FAR struct tun_device_s *priv);
#ifdef CONFIG_NET_ETHERNET
static void tun_net_receive_tap(FAR struct tun_device_s *priv);
#endif
static void tun_net_receive_tun(FAR struct tun_device_s *priv);
static void tun_txdone(FAR struct tun_device_s *priv);
/* 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);
#ifdef CONFIG_NET_MCASTGROUP
static int tun_addmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac);
static int tun_rmmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac);
#endif
static int tun_dev_init(FAR struct tun_device_s *priv,
FAR struct file *filep,
FAR const char *devfmt, bool tun);
static void tun_dev_uninit(FAR struct tun_device_s *priv);
/* File interface */
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);
static int tun_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup);
/****************************************************************************
* Private Data
****************************************************************************/
static struct tun_driver_s g_tun =
{
NXMUTEX_INITIALIZER,
};
static struct tun_device_s g_tun_devices[CONFIG_TUN_NINTERFACES];
static const struct file_operations g_tun_file_ops =
{
NULL, /* open */
tun_close, /* close */
tun_read, /* read */
tun_write, /* write */
NULL, /* seek */
tun_ioctl, /* ioctl */
tun_poll /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: tun_pollnotify
****************************************************************************/
static void tun_pollnotify(FAR struct tun_device_s *priv,
pollevent_t eventset)
{
FAR struct pollfd *fds = priv->poll_fds;
if (priv->read_wait && (eventset & POLLIN))
{
priv->read_wait = false;
nxsem_post(&priv->read_wait_sem);
}
if (priv->write_wait && (eventset & POLLOUT))
{
priv->write_wait = false;
nxsem_post(&priv->write_wait_sem);
}
if (fds == NULL)
{
return;
}
poll_notify(&fds, 1, eventset);
}
/****************************************************************************
* Name: tun_fd_transmit
*
* Description:
* Start hardware transmission. Called either from the txdone interrupt
* handling or from watchdog based polling.
*
* Input Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* None
*
* 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 void tun_fd_transmit(FAR struct tun_device_s *priv)
{
NETDEV_TXPACKETS(&priv->dev);
tun_pollnotify(priv, POLLIN);
}
/****************************************************************************
* Name: tun_txpoll
*
* Description:
* The transmitter is available, check if the network 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
*
* Input 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(FAR struct net_driver_s *dev)
{
int ret;
#ifdef CONFIG_NET_ETHERNET
if (dev->d_lltype == NET_LL_ETHERNET)
{
ret = tun_txpoll_tap(dev);
}
else
#endif
{
ret = tun_txpoll_tun(dev);
}
return ret;
}
/****************************************************************************
* Name: tun_txpoll_tap : for tap (ethernet bridge) mode
*
* Description:
* The transmitter is available, check if the network 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
*
* Input 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.
*
****************************************************************************/
#ifdef CONFIG_NET_ETHERNET
static int tun_txpoll_tap(FAR struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
/* Send the packet */
priv->read_d_len = priv->dev.d_len;
tun_fd_transmit(priv);
return 1;
}
#endif
/****************************************************************************
* Name: tun_txpoll_tun : for tun (IP tunneling) mode
*
* Description:
* The transmitter is available, check if the network 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
*
* Input 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_tun(FAR struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
priv->read_d_len = priv->dev.d_len;
tun_fd_transmit(priv);
return 1;
}
/****************************************************************************
* Name: tun_net_receive
*
* Description:
* An interrupt was received indicating the availability of a new RX
* packet
*
* Input Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Global interrupts are disabled by interrupt handling logic.
*
****************************************************************************/
static void tun_net_receive(FAR struct tun_device_s *priv)
{
#ifdef CONFIG_NET_ETHERNET
if (priv->dev.d_lltype == NET_LL_ETHERNET)
{
tun_net_receive_tap(priv);
}
else
#endif
{
tun_net_receive_tun(priv);
}
}
/****************************************************************************
* Name: tun_net_receive_tap : for tap (ethernet bridge) mode
*
* Description:
* An interrupt was received indicating the availability of a new RX packet
*
* Input Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Global interrupts are disabled by interrupt handling logic.
*
****************************************************************************/
#ifdef CONFIG_NET_ETHERNET
static void tun_net_receive_tap(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 tap */
pkt_input(&priv->dev);
#endif
/* We only accept IP packets of the configured type and ARP packets */
#if defined(CONFIG_NET_IPv4)
if (BUF->type == HTONS(ETHTYPE_IP))
{
ninfo("IPv4 frame\n");
NETDEV_RXIPV4(&priv->dev);
/* Receive an IPv4 packet from the network device */
ipv4_input(&priv->dev);
}
else
#endif
#ifdef CONFIG_NET_IPv6
if (BUF->type == HTONS(ETHTYPE_IP6))
{
ninfo("IPv6 frame\n");
NETDEV_RXIPV6(&priv->dev);
/* Give the IPv6 packet to the network layer. */
ipv6_input(&priv->dev);
}
else
#endif
#ifdef CONFIG_NET_ARP
if (BUF->type == HTONS(ETHTYPE_ARP))
{
arp_input(&priv->dev);
NETDEV_RXARP(&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_fd_transmit(priv);
priv->dev.d_len = 0;
}
}
else
#endif
{
NETDEV_RXDROPPED(&priv->dev);
priv->dev.d_len = 0;
}
/* 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)
{
/* And send the packet */
priv->write_d_len = priv->dev.d_len;
tun_fd_transmit(priv);
}
}
#endif
/****************************************************************************
* Name: tun_net_receive_tun : for tun (IP tunneling) mode
*
* Description:
* An interrupt was received indicating the availability of a new RX
* packet
*
* Input Parameters:
* priv - Reference to the driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Global interrupts are disabled by interrupt handling logic.
*
****************************************************************************/
static void tun_net_receive_tun(FAR struct tun_device_s *priv)
{
FAR struct net_driver_s *dev = &priv->dev;
/* Copy the data data from the hardware to dev->d_buf. Set amount of
* data in dev->d_len
*/
NETDEV_RXPACKETS(dev);
#ifdef CONFIG_NET_PKT
/* When packet sockets are enabled, feed the frame into the tap */
pkt_input(dev);
#endif
/* We only accept IP packets of the configured type */
#if defined(CONFIG_NET_IPv4)
if ((IPv4BUF->vhl & IP_VERSION_MASK) == IPv4_VERSION)
{
ninfo("IPv4 frame\n");
NETDEV_RXIPV4(dev);
/* Give the IPv4 packet to the network layer. */
ipv4_input(dev);
}
else
#endif
#if defined(CONFIG_NET_IPv6)
if ((IPv6BUF->vtc & IP_VERSION_MASK) == IPv6_VERSION)
{
ninfo("IPv6 frame\n");
NETDEV_RXIPV6(dev);
/* Give the IPv6 packet to the network layer. */
ipv6_input(dev);
}
else
#endif
{
NETDEV_RXDROPPED(dev);
dev->d_len = 0;
}
/* If the above function invocation resulted in data that should be
* sent out on the network, d_len field will set to a value > 0.
*/
if (dev->d_len > 0)
{
priv->write_d_len = dev->d_len;
tun_fd_transmit(priv);
}
}
/****************************************************************************
* Name: tun_txdone
*
* Description:
* An interrupt was received indicating that the last TX packet(s) is done
*
* Input 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 the network for new XMIT data */
priv->dev.d_buf = priv->read_buf;
devif_poll(&priv->dev, tun_txpoll);
}
/****************************************************************************
* Name: tun_ifup
*
* Description:
* NuttX Callback: Bring up the Ethernet interface when an IP address is
* provided
*
* Input Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static int tun_ifup(FAR struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
#ifdef CONFIG_NET_IPv4
ninfo("Bringing up: %d.%d.%d.%d\n",
(int)(dev->d_ipaddr & 0xff),
(int)((dev->d_ipaddr >> 8) & 0xff),
(int)((dev->d_ipaddr >> 16) & 0xff),
(int)(dev->d_ipaddr >> 24));
#endif
#ifdef CONFIG_NET_IPv6
ninfo("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
priv->bifup = true;
netdev_carrier_on(dev);
return OK;
}
/****************************************************************************
* Name: tun_ifdown
*
* Description:
* NuttX Callback: Stop the interface.
*
* Input Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static int tun_ifdown(FAR struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
irqstate_t flags;
netdev_carrier_off(dev);
flags = enter_critical_section();
/* Mark the device "down" */
priv->bifup = false;
leave_critical_section(flags);
return OK;
}
/****************************************************************************
* Name: tun_txavail_work
*
* 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.
*
* Input Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Called in normal user mode
*
****************************************************************************/
static void tun_txavail_work(FAR void *arg)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)arg;
int ret;
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
/* Thread has been canceled, skip poll-related work */
return;
}
/* Check if there is room to hold another network packet. */
if (priv->read_d_len != 0)
{
nxmutex_unlock(&priv->lock);
return;
}
net_lock();
if (priv->bifup)
{
/* Poll the network for new XMIT data */
priv->dev.d_buf = priv->read_buf;
devif_poll(&priv->dev, tun_txpoll);
}
net_unlock();
nxmutex_unlock(&priv->lock);
}
/****************************************************************************
* Name: 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.
*
* Input Parameters:
* dev - Reference to the NuttX driver state structure
*
* Returned Value:
* None
*
* Assumptions:
* Called from the network stack with the network locked.
*
****************************************************************************/
static int tun_txavail(FAR struct net_driver_s *dev)
{
FAR struct tun_device_s *priv = (FAR struct tun_device_s *)dev->d_private;
/* Schedule to perform the TX poll on the worker thread. */
if (work_available(&priv->work))
{
work_queue(TUNWORK, &priv->work, tun_txavail_work, priv, 0);
}
return OK;
}
/****************************************************************************
* Name: tun_addmac
*
* Description:
* NuttX Callback: Add the specified MAC address to the hardware multicast
* address filtering
*
* Input Parameters:
* dev - Reference to the NuttX driver state structure
* mac - The MAC address to be added
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_NET_MCASTGROUP
static int tun_addmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac)
{
/* Add the MAC address to the hardware multicast routing table */
return OK;
}
#endif
/****************************************************************************
* Name: tun_rmmac
*
* Description:
* NuttX Callback: Remove the specified MAC address from the hardware
* multicast address filtering
*
* Input Parameters:
* dev - Reference to the NuttX driver state structure
* mac - The MAC address to be removed
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_NET_MCASTGROUP
static int tun_rmmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac)
{
/* Add the MAC address to the hardware multicast routing table */
return OK;
}
#endif
/****************************************************************************
* Name: tun_dev_init
*
* Description:
* Initialize the TUN device
*
* Input 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, bool tun)
{
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_MCASTGROUP
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 = priv; /* Used to recover private state from dev */
/* Initialize the mutual exlcusion and wait semaphore */
nxmutex_init(&priv->lock);
nxsem_init(&priv->read_wait_sem, 0, 0);
nxsem_init(&priv->write_wait_sem, 0, 0);
/* Assign d_ifname if specified. */
if (devfmt)
{
strlcpy(priv->dev.d_ifname, devfmt, IFNAMSIZ);
}
/* Register the device with the OS so that socket IOCTLs can be performed */
ret = netdev_register(&priv->dev, tun ? NET_LL_TUN : NET_LL_ETHERNET);
if (ret != OK)
{
nxmutex_destroy(&priv->lock);
nxsem_destroy(&priv->read_wait_sem);
nxsem_destroy(&priv->write_wait_sem);
return ret;
}
filep->f_priv = priv; /* Set link to TUN device */
return ret;
}
/****************************************************************************
* Name: tun_dev_uninit
****************************************************************************/
static void 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 */
netdev_unregister(&priv->dev);
nxmutex_destroy(&priv->lock);
nxsem_destroy(&priv->read_wait_sem);
nxsem_destroy(&priv->write_wait_sem);
}
/****************************************************************************
* 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;
int ret;
if (priv == NULL)
{
return OK;
}
intf = priv - g_tun_devices;
ret = nxmutex_lock(&tun->lock);
if (ret >= 0)
{
tun->free_tuns |= (1 << intf);
tun_dev_uninit(priv);
nxmutex_unlock(&tun->lock);
}
return ret;
}
/****************************************************************************
* 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;
ssize_t nwritten = 0;
int ret;
if (priv == NULL || buflen > CONFIG_NET_TUN_PKTSIZE)
{
return -EINVAL;
}
for (; ; )
{
/* Write must return immediately if interrupted by a signal (or if the
* thread is canceled) and no data has yet been written.
*/
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return nwritten == 0 ? (ssize_t)ret : nwritten;
}
/* Check if there are free space to write */
if (priv->write_d_len == 0)
{
memcpy(priv->write_buf, buffer, buflen);
net_lock();
priv->dev.d_buf = priv->write_buf;
priv->dev.d_len = buflen;
tun_net_receive(priv);
net_unlock();
nwritten = buflen;
break;
}
/* Wait if there are no free space to write */
if ((filep->f_oflags & O_NONBLOCK) != 0)
{
nwritten = -EAGAIN;
break;
}
priv->write_wait = true;
nxmutex_unlock(&priv->lock);
nxsem_wait(&priv->write_wait_sem);
}
nxmutex_unlock(&priv->lock);
return nwritten;
}
/****************************************************************************
* 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;
ssize_t nread = 0;
int ret;
if (priv == NULL)
{
return -EINVAL;
}
for (; ; )
{
/* Read must return immediately if interrupted by a signal (or if the
* thread is canceled) and no data has yet been read.
*/
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return nread == 0 ? (ssize_t)ret : nread;
}
/* Check if there are data to read in write buffer */
if (priv->write_d_len > 0)
{
if (buflen < priv->write_d_len)
{
nread = -EINVAL;
break;
}
memcpy(buffer, priv->write_buf, priv->write_d_len);
nread = priv->write_d_len;
priv->write_d_len = 0;
NETDEV_TXDONE(&priv->dev);
tun_pollnotify(priv, POLLOUT);
break;
}
/* Check if there are data to read in read buffer */
if (priv->read_d_len > 0)
{
if (buflen < priv->read_d_len)
{
nread = -EINVAL;
break;
}
memcpy(buffer, priv->read_buf, priv->read_d_len);
nread = priv->read_d_len;
priv->read_d_len = 0;
net_lock();
tun_txdone(priv);
net_unlock();
break;
}
/* Wait if there are no data to read */
if ((filep->f_oflags & O_NONBLOCK) != 0)
{
nread = -EAGAIN;
break;
}
priv->read_wait = true;
nxmutex_unlock(&priv->lock);
nxsem_wait(&priv->read_wait_sem);
}
nxmutex_unlock(&priv->lock);
return nread;
}
/****************************************************************************
* Name: tun_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;
/* Some sanity checking */
if (priv == NULL || fds == NULL)
{
return -EINVAL;
}
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
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 |= 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 |= POLLIN;
}
tun_pollnotify(priv, eventset);
}
else
{
priv->poll_fds = 0;
}
errout:
nxmutex_unlock(&priv->lock);
return ret;
}
/****************************************************************************
* 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)
{
uint8_t free_tuns;
int intf;
FAR struct ifreq *ifr = (FAR struct ifreq *)arg;
if (priv != NULL || ifr == NULL ||
((ifr->ifr_flags & IFF_MASK) != IFF_TUN &&
(ifr->ifr_flags & IFF_MASK) != IFF_TAP))
{
return -EINVAL;
}
ret = nxmutex_lock(&tun->lock);
if (ret < 0)
{
return ret;
}
free_tuns = tun->free_tuns;
if (free_tuns == 0)
{
nxmutex_unlock(&tun->lock);
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,
(ifr->ifr_flags & IFF_MASK) == IFF_TUN);
if (ret != OK)
{
nxmutex_unlock(&tun->lock);
return ret;
}
tun->free_tuns &= ~(1 << intf);
priv = filep->f_priv;
strlcpy(ifr->ifr_name, priv->dev.d_ifname, IFNAMSIZ);
nxmutex_unlock(&tun->lock);
return OK;
}
else if (cmd == TUNGETIFF)
{
FAR struct ifreq *ifr = (FAR struct ifreq *)arg;
if (priv == NULL || ifr == NULL)
{
return -EINVAL;
}
strlcpy(ifr->ifr_name, priv->dev.d_ifname, IFNAMSIZ);
return OK;
}
return -ENOTTY;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tun_initialize
*
* Description:
* Instantiate a TUN network interface.
*
* Input Parameters:
*
* Returned Value:
* OK on success; Negated errno on failure.
*
* Assumptions:
*
****************************************************************************/
int tun_initialize(void)
{
g_tun.free_tuns = (1 << CONFIG_TUN_NINTERFACES) - 1;
register_driver("/dev/tun", &g_tun_file_ops, 0644, &g_tun);
return OK;
}
#endif /* CONFIG_NET && CONFIG_NET_TUN */