/****************************************************************************
* up_tapdev.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Based on code from uIP which also has a BSD-like license:
*
* Copyright (c) 2001, Adam Dunkels.
* All rights reserved.
*
* 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.
*
****************************************************************************/
#ifdef linux
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <linux/if.h>
#include <linux/if_tun.h>
extern int lib_rawprintf(const char *format, ...);
/****************************************************************************
* Private Definitions
****************************************************************************/
#define TAPDEV_DEBUG 1
#define DEVTAP "/dev/net/tun"
#define UIP_DRIPADDR0 192
#define UIP_DRIPADDR1 168
#define UIP_DRIPADDR2 0
#define UIP_DRIPADDR3 1
#define READ 3
#define WRITE 4
#define OPEN 5
#define IOCTL 54
#define SELECT 82
/****************************************************************************
* Private Types
****************************************************************************/
/* Warning: This is very much Linux version specific! */
struct sel_arg_struct
{
unsigned long n;
fd_set *inp;
fd_set *outp;
fd_set *exp;
struct timeval *tvp;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
#ifdef TAPDEV_DEBUG
static int gdrop = 0;
#endif
static int gtapdevfd;
/****************************************************************************
* Private Functions
****************************************************************************/
/* This is REALLY awkward.. we need to compile using the system header files,
* but we can't use any of the libc calls because all of the symbols are
* defined for NuttX (read, write, etc)! So we do hand rolled syscalls
* to get to the Linux functions.
*/
static inline int up_open(const char *filename, int flags, int mode)
{
int result;
__asm__ volatile ("int $0x80" \
: "=a" (result) \
: "0" (OPEN), "b" ((int)(filename)), "c" ((int)(flags)), "d" ((int)(mode)) \
: "memory");
return (int)result;
}
static inline int up_read(int fd, void* buf, size_t count)
{
ssize_t result;
__asm__ volatile ("int $0x80" \
: "=a" (result) \
: "0" (READ), "b" ((int)(fd)), "c" ((int)(buf)), "d" ((int)(count)) \
: "memory");
return (int)result;
}
static inline int up_write(int fd, const void* buf, size_t count)
{
ssize_t result;
__asm__ volatile ("int $0x80" \
: "=a" (result) \
: "0" (WRITE), "b" ((int)(fd)), "c" ((int)(buf)), "d" ((int)(count)) \
: "memory");
return (int)result;
}
static inline int up_ioctl(int fd, unsigned int cmd, unsigned long arg)
{
ssize_t result;
__asm__ volatile ("int $0x80" \
: "=a" (result) \
: "0" (IOCTL), "b" ((int)(fd)), "c" ((int)(cmd)), "d" ((long)(arg)) \
: "memory");
return (int)result;
}
static inline int up_select(struct sel_arg_struct *arg)
{
ssize_t result;
__asm__ volatile ("int $0x80" \
: "=a" (result) \
: "0" (SELECT),"b" ((struct sel_arg_struct *)(arg))
: "memory");
return (int)result;
}
#ifdef TAPDEV_DEBUG
static inline void dump_ethhdr(const char *msg, unsigned char *buf, int buflen)
{
lib_rawprintf("TAPDEV: %s %d bytes\n", msg, buflen);
lib_rawprintf(" %02x:%02x:%02x:%02x:%02x:%02x %02x:%02x:%02x:%02x:%02x:%02x %02x%02x\n",
buf[0], buf[1], buf[2], buf[3], buf[4], buf[5],
buf[6], buf[7], buf[8], buf[9], buf[10], buf[11],
#if UIP_BYTE_ORDER == UIP_LITTLE_ENDIAN
buf[12], buf[13]);
#else
buf[13], buf[12]);
#endif
}
#else
# define dump_ethhdr(m,b,l)
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
unsigned long up_getwalltime( void )
{
struct timeval tm;
(void)gettimeofday(&tm, NULL);
return tm.tv_sec*1000 + tm.tv_usec/1000;
}
void tapdev_init(void)
{
char buf[1024];
int ret;
gtapdevfd = up_open(DEVTAP, O_RDWR, 0644);
if (gtapdevfd < 0)
{
lib_rawprintf("TAPDEV: open failed: %d\n", -gtapdevfd );
return;
}
#ifdef linux
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
ret = up_ioctl(gtapdevfd, TUNSETIFF, (unsigned long) &ifr);
if (ret < 0)
{
lib_rawprintf("TAPDEV: ioctl failed: %d\n", -ret );
return;
}
}
#endif /* Linux */
snprintf(buf, sizeof(buf), "ifconfig tap0 inet %d.%d.%d.%d\n",
UIP_DRIPADDR0, UIP_DRIPADDR1, UIP_DRIPADDR2, UIP_DRIPADDR3);
system(buf);
}
unsigned int tapdev_read(unsigned char *buf, unsigned int buflen)
{
struct sel_arg_struct arg;
fd_set fdset;
struct timeval tv;
int ret;
/* We can't do anything if we failed to open the tap device */
if (gtapdevfd < 0)
{
return 0;
}
/* Wait for data on the tap device (or a timeout) */
tv.tv_sec = 0;
tv.tv_usec = 1000;
FD_ZERO(&fdset);
FD_SET(gtapdevfd, &fdset);
arg.n = gtapdevfd + 1;
arg.inp = &fdset;
arg.outp = NULL;
arg.exp = NULL;
arg.tvp = &tv;
ret = up_select(&arg);
if(ret == 0)
{
return 0;
}
ret = up_read(gtapdevfd, buf, buflen);
if (ret < 0)
{
lib_rawprintf("TAPDEV: read failed: %d\n", -ret);
return 0;
}
dump_ethhdr("read", buf, ret);
return ret;
}
void tapdev_send(unsigned char *buf, unsigned int buflen)
{
int ret;
#ifdef TAPDEV_DEBUG
lib_rawprintf("tapdev_send: sending %d bytes\n", buflen);
gdrop++;
if(gdrop % 8 == 7)
{
lib_rawprintf("Dropped a packet!\n");
return;
}
#endif
ret = up_write(gtapdevfd, buf, buflen);
if (ret < 0)
{
lib_rawprintf("TAPDEV: write failed: %d", -ret);
exit(1);
}
dump_ethhdr("write", buf, buflen);
}
#endif /* linux */
