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tapif.c
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tapif.c
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/*
* Copyright (c) 2001-2003 Swedish Institute of Computer Science.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#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 "lwip/opt.h"
#include "lwip/debug.h"
#include "lwip/def.h"
#include "lwip/ip.h"
#include "lwip/mem.h"
#include "lwip/stats.h"
#include "lwip/snmp.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#include "lwip/timeouts.h"
#include "netif/etharp.h"
#include "lwip/ethip6.h"
#include "tapif.h"
#define IFCONFIG_BIN "/sbin/ifconfig "
#if defined(LWIP_UNIX_LINUX)
#include <sys/ioctl.h>
#include <linux/if.h>
#include <linux/if_tun.h>
#include <netpacket/packet.h>
/*
* Creating a tap interface requires special privileges. If the interfaces
* is created in advance with `tunctl -u <user>` it can be opened as a regular
* user. The network must already be configured. If DEVTAP_IF is defined it
* will be opened instead of creating a new tap device.
*
* You can also use PRECONFIGURED_TAPIF environment variable to do so.
*/
#ifndef DEVTAP_DEFAULT_IF
#define DEVTAP_DEFAULT_IF "tap0"
#endif
#ifndef DEVTAP
#define DEVTAP "/dev/net/tun"
#endif
//use this
#define NETMASK_ARGS "netmask %d.%d.%d.%d"
#define IFCONFIG_ARGS " inet %d.%d.%d.%d " NETMASK_ARGS " up"
#elif defined(LWIP_UNIX_OPENBSD)
#define DEVTAP "/dev/tun0"
#define NETMASK_ARGS "netmask %d.%d.%d.%d"
#define IFCONFIG_ARGS "tun0 inet %d.%d.%d.%d " NETMASK_ARGS " link0"
#else /* others */
#define DEVTAP "/dev/tap0"
#define NETMASK_ARGS "netmask %d.%d.%d.%d"
#define IFCONFIG_ARGS "tap0 inet %d.%d.%d.%d " NETMASK_ARGS
#endif
/* Define those to better describe your network interface. */
#define IFNAME0 't'
#define IFNAME1 'p'
#ifndef TAPIF_DEBUG
#define TAPIF_DEBUG LWIP_DBG_OFF
#endif
#if 0
struct tapif {
/* Add whatever per-interface state that is needed here. */
int fd;
};
#endif
/* Forward declarations. */
static void tapif_input(struct netif *netif);
#if !NO_SYS
static void tapif_thread(void *arg);
#endif /* !NO_SYS */
static void print_hex(unsigned char *buf, int len)
{
int i = 0;
if (!buf)
{
return;
}
for (i=0; i<len; i++)
{
printf("0x%.2x ", buf[i]);
}
printf("\n");
}
static int do_tap(struct tapif *tap)
{
int err = 0;
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
if (!tap)
{
printf("tap is null\n");
err = -1;
return err;
}
tap->fd = open(DEVTAP, O_RDWR);
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_init: fd %d\n", tap->fd));
if (tap->fd == -1) {
perror("tapif_init: try running \"modprobe tun\" or rebuilding your kernel with CONFIG_TUN; cannot open "DEVTAP);
exit(1);
}
strncpy(ifr.ifr_name, tap->name, sizeof(ifr.ifr_name));
ifr.ifr_name[sizeof(ifr.ifr_name)-1] = 0; /* ensure \0 termination */
ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
if (ioctl(tap->fd, TUNSETIFF, (void *) &ifr) < 0) {
perror("tapif_init: "DEVTAP" ioctl TUNSETIFF");
exit(1);
}
return err;
}
static int do_socket(struct tapif *tap)
{
int err = 0;
int listenfd;
struct ifreq ifr;
int ifidx = 0;
struct sockaddr_ll fromaddr;
if (!tap)
{
printf("tap is null\n");
err = -1;
return err;
}
if ((listenfd = socket(
// AF_INET,
PF_PACKET,
// SOCK_STREAM,
SOCK_RAW,
// htons(ETH_P_IP)))
// htons(ETH_P_ARP)))
htons(ETH_P_ALL)))
// 0))
< 0)
{
perror("socket");
exit(1);
}
bzero(&fromaddr, sizeof(fromaddr));
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, tap->name, strlen(tap->name) + 1);
if (ioctl(listenfd, SIOCGIFINDEX, &ifr) != 0)
{
perror("ioctl SIOCGIFINDEX fail");
return -1;
}
ifidx = ifr.ifr_ifindex;
printf("interface Index:%d\n", ifidx);
fromaddr.sll_ifindex = ifidx;
fromaddr.sll_family = PF_PACKET;
fromaddr.sll_protocol=htons(ETH_P_ALL);//ETH_P_ALL);
err = bind(listenfd, (struct sockaddr*)&fromaddr, sizeof(fromaddr));
if (err < 0)
{
perror("bind err");
return err;
}
//set promisc
ifr.ifr_flags &= ~IFF_PROMISC;
printf("name %s\n", ifr.ifr_name);
if (ioctl(listenfd, SIOCSIFFLAGS, &ifr) < 0)
{
perror("set flag promisc");
err = -5;
return err;
}
tap->fd = listenfd;
return err;
}
/*-----------------------------------------------------------------------------------*/
static void low_level_init(struct netif *netif)
{
struct tapif *tapif;
#if LWIP_IPV4
int ret;
char buf[1024];
#endif /* LWIP_IPV4 */
char *preconfigured_tapif = getenv("PRECONFIGURED_TAPIF");
tapif = (struct tapif *)netif->state;
if (!tapif->name)
{
tapif->name ="tap0";
}
/* Obtain MAC address from network interface. */
/* (We just fake an address...) */
netif->hwaddr[0] = 0x02;
netif->hwaddr[1] = 0x12;
netif->hwaddr[2] = 0x34;
netif->hwaddr[3] = 0x56;
netif->hwaddr[4] = 0x78;
netif->hwaddr[5] = 0xab;
netif->hwaddr_len = 6;
/* device capabilities */
netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_IGMP;
#if 1
#if 0
do_tap(tapif);
// LWIP_DEBUGF(LWIP_DBG_ON, ("1111111111111111tapif_init: 1111111111111111111111fd %d\n", tapif->fd));
#else
if (do_socket(tapif) < 0)
{
exit(2);
}
#endif
#else
tapif->fd = open(DEVTAP, O_RDWR);
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_init: fd %d\n", tapif->fd));
if (tapif->fd == -1) {
#ifdef LWIP_UNIX_LINUX
perror("tapif_init: try running \"modprobe tun\" or rebuilding your kernel with CONFIG_TUN; cannot open "DEVTAP);
#else /* LWIP_UNIX_LINUX */
perror("tapif_init: cannot open "DEVTAP);
#endif /* LWIP_UNIX_LINUX */
exit(1);
}
#endif
#if 0
#ifdef LWIP_UNIX_LINUX
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
if (preconfigured_tapif) {
strncpy(ifr.ifr_name, preconfigured_tapif, sizeof(ifr.ifr_name));
} else {
strncpy(ifr.ifr_name, tapif->name, sizeof(ifr.ifr_name));
}
ifr.ifr_name[sizeof(ifr.ifr_name)-1] = 0; /* ensure \0 termination */
ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
if (ioctl(tapif->fd, TUNSETIFF, (void *) &ifr) < 0) {
perror("tapif_init: "DEVTAP" ioctl TUNSETIFF");
exit(1);
}
}
#endif /* LWIP_UNIX_LINUX */
#endif
netif_set_link_up(netif);
if (preconfigured_tapif == NULL) {
#if LWIP_IPV4
snprintf(buf, 1024, IFCONFIG_BIN "%s" IFCONFIG_ARGS, tapif->name,
ip4_addr1(netif_ip4_addr(netif)),
ip4_addr2(netif_ip4_addr(netif)),
ip4_addr3(netif_ip4_addr(netif)),
ip4_addr4(netif_ip4_addr(netif))
#ifdef NETMASK_ARGS
,
ip4_addr1(netif_ip4_netmask(netif)),
ip4_addr2(netif_ip4_netmask(netif)),
ip4_addr3(netif_ip4_netmask(netif)),
ip4_addr4(netif_ip4_netmask(netif))
#endif /* NETMASK_ARGS */
);
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_init: system(\"%s\");\n", buf));
ret = system(buf);
if (ret < 0) {
perror("ifconfig failed");
exit(1);
}
if (ret != 0) {
printf("ifconfig returned %d\n", ret);
}
#else /* LWIP_IPV4 */
perror("todo: support IPv6 support for non-preconfigured tapif");
exit(1);
#endif /* LWIP_IPV4 */
}
#if !NO_SYS
sys_thread_new("tapif_thread", tapif_thread, netif, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO);
#endif /* !NO_SYS */
}
/*-----------------------------------------------------------------------------------*/
/*
* low_level_output():
*
* Should do the actual transmission of the packet. The packet is
* contained in the pbuf that is passed to the function. This pbuf
* might be chained.
*
*/
/*-----------------------------------------------------------------------------------*/
static err_t low_level_output(struct netif *netif, struct pbuf *p)
{
struct tapif *tapif = (struct tapif *)netif->state;
char buf[1518]; /* max packet size including VLAN excluding CRC */
ssize_t written;
#if 0
if (((double)rand()/(double)RAND_MAX) < 0.2) {
printf("drop output\n");
return ERR_OK; /* ERR_OK because we simulate packet loss on cable */
}
#endif
if (p->tot_len > sizeof(buf)) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
perror("tapif: packet too large");
return ERR_IF;
}
/* initiate transfer(); */
pbuf_copy_partial(p, buf, p->tot_len, 0);
/* signal that packet should be sent(); */
written = write(tapif->fd, buf, p->tot_len);
printf("TX:\n");
print_hex(buf, p->tot_len);
if (written < p->tot_len) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
perror("tapif: write");
return ERR_IF;
} else {
MIB2_STATS_NETIF_ADD(netif, ifoutoctets, (u32_t)written);
return ERR_OK;
}
}
/*-----------------------------------------------------------------------------------*/
/*
* low_level_input():
*
* Should allocate a pbuf and transfer the bytes of the incoming
* packet from the interface into the pbuf.
*
*/
/*-----------------------------------------------------------------------------------*/
static struct pbuf *low_level_input(struct netif *netif)
{
struct pbuf *p;
u16_t len;
ssize_t readlen;
char buf[1518]; /* max packet size including VLAN excluding CRC */
struct tapif *tapif = (struct tapif *)netif->state;
int i = 0;
/* Obtain the size of the packet and put it into the "len"
variable. */
readlen = read(tapif->fd, buf, sizeof(buf));
if (readlen < 0) {
perror("read returned -1");
exit(1);
}
printf("RX:\n");
print_hex(buf, readlen);
len = (u16_t)readlen;
MIB2_STATS_NETIF_ADD(netif, ifinoctets, len);
#if 0
if (((double)rand()/(double)RAND_MAX) < 0.2) {
printf("drop\n");
return NULL;
}
#endif
/* We allocate a pbuf chain of pbufs from the pool. */
p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
if (p != NULL) {
pbuf_take(p, buf, len);
/* acknowledge that packet has been read(); */
} else {
/* drop packet(); */
MIB2_STATS_NETIF_INC(netif, ifindiscards);
LWIP_DEBUGF(NETIF_DEBUG, ("tapif_input: could not allocate pbuf\n"));
}
return p;
}
/*-----------------------------------------------------------------------------------*/
/*
* tapif_input():
*
* This function should be called when a packet is ready to be read
* from the interface. It uses the function low_level_input() that
* should handle the actual reception of bytes from the network
* interface.
*
*/
/*-----------------------------------------------------------------------------------*/
static void tapif_input(struct netif *netif)
{
struct pbuf *p = low_level_input(netif);
if (p == NULL) {
#if LINK_STATS
LINK_STATS_INC(link.recv);
#endif /* LINK_STATS */
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_input: low_level_input returned NULL\n"));
return;
}
if (netif->input(p, netif) != ERR_OK) {
LWIP_DEBUGF(NETIF_DEBUG, ("tapif_input: netif input error\n"));
pbuf_free(p);
}
}
static err_t low_level_probe(struct netif *netif,const char *name)
{
int len;
int s;
struct ifreq ifr;
len = strlen(name);
if (len > (IFNAMSIZ-1)) {
perror("tapif_init: name is too long");
return ERR_IF;
}
s = socket(AF_INET,SOCK_DGRAM,0);
if (s == -1) {
perror("tapif_init: socket");
return ERR_IF;
}
memset(&ifr,0,sizeof(ifr));
strncpy(ifr.ifr_name,name,len);
if (ioctl(s,SIOCGIFHWADDR,&ifr) == -1) {
perror("tapif_init: ioctl SIOCGIFHWADDR");
goto err;
}
u8_t* hwaddr = (u8_t*)&ifr.ifr_hwaddr.sa_data;
netif->hwaddr[0] = hwaddr[0];
netif->hwaddr[1] = hwaddr[1];
netif->hwaddr[2] = hwaddr[2];
netif->hwaddr[3] = hwaddr[3];
netif->hwaddr[4] = hwaddr[4];
netif->hwaddr[5] = hwaddr[5] ^ 1;
netif->hwaddr_len = 6;
if (ioctl(s,SIOCGIFMTU,&ifr) == -1) {
perror("tapif_init: ioctl SIOCGIFMTU");
goto err;
}
netif->mtu = ifr.ifr_mtu;
close(s);
return ERR_OK;
err:
close(s);
return ERR_IF;
}
/*-----------------------------------------------------------------------------------*/
/*
* tapif_init():
*
* Should be called at the beginning of the program to set up the
* network interface. It calls the function low_level_init() to do the
* actual setup of the hardware.
*
*/
/*-----------------------------------------------------------------------------------*/
err_t tapif_init(struct netif *netif)
{
struct tapif *tapif;
char *name = NULL;
err_t err=0;
if (!netif->state)
{
tapif = (struct tapif *)mem_malloc(sizeof(struct tapif));
if (tapif == NULL) {
LWIP_DEBUGF(NETIF_DEBUG, ("tapif_init: out of memory for tapif\n"));
return ERR_MEM;
}
netif->state = tapif;
}
else
{
tapif = (struct tapif *)netif->state;
name = tapif->name;
if (!name)
{
err = low_level_probe(netif, name);
if (err != ERR_OK)
{
return err;
}
}
}
MIB2_INIT_NETIF(netif, snmp_ifType_other, 100000000);
netif->name[0] = IFNAME0;
netif->name[1] = IFNAME1;
#if LWIP_IPV4
netif->output = etharp_output;
#endif /* LWIP_IPV4 */
#if LWIP_IPV6
netif->output_ip6 = ethip6_output;
#endif /* LWIP_IPV6 */
netif->linkoutput = low_level_output;
netif->mtu = 1500;
low_level_init(netif);
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
void tapif_poll(struct netif *netif)
{
tapif_input(netif);
}
#if NO_SYS
int tapif_select(struct netif *netif)
{
fd_set fdset;
int ret;
struct timeval tv;
struct tapif *tapif;
u32_t msecs = sys_timeouts_sleeptime();
tapif = (struct tapif *)netif->state;
tv.tv_sec = msecs / 1000;
tv.tv_usec = (msecs % 1000) * 1000;
FD_ZERO(&fdset);
FD_SET(tapif->fd, &fdset);
ret = select(tapif->fd + 1, &fdset, NULL, NULL, &tv);
if (ret > 0) {
tapif_input(netif);
}
return ret;
}
#else /* NO_SYS */
static void tapif_thread(void *arg)
{
struct netif *netif;
struct tapif *tapif;
fd_set fdset;
int ret;
netif = (struct netif *)arg;
tapif = (struct tapif *)netif->state;
while(1) {
FD_ZERO(&fdset);
FD_SET(tapif->fd, &fdset);
/* Wait for a packet to arrive. */
ret = select(tapif->fd + 1, &fdset, NULL, NULL, NULL);
if(ret == 1) {
/* Handle incoming packet. */
tapif_input(netif);
} else if(ret == -1) {
perror("tapif_thread: select");
}
}
}
#endif /* NO_SYS */