lwip-contrib-mac/ports/unix/netif/tunif.c

319 lines
8.6 KiB
C

/*
* 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 "netif/tunif.h"
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include "lwip/debug.h"
#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/ip.h"
#include "lwip/mem.h"
#include "lwip/netif.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#define IFNAME0 't'
#define IFNAME1 'n'
#ifndef TUNIF_DEBUG
#define TUNIF_DEBUG LWIP_DBG_OFF
#endif
#define IFCONFIG_CALL "/sbin/ifconfig tun0 inet %d.%d.%d.%d %d.%d.%d.%d"
struct tunif {
/* Add whatever per-interface state that is needed here. */
int fd;
};
/* Forward declarations. */
static void tunif_input(struct netif *netif);
static err_t tunif_output(struct netif *netif, struct pbuf *p,
ip_addr_t *ipaddr);
static void tunif_thread(void *data);
/*-----------------------------------------------------------------------------------*/
static void
low_level_init(struct netif *netif)
{
struct tunif *tunif;
char buf[sizeof(IFCONFIG_CALL) + 50];
tunif = (struct tunif *)netif->state;
/* Obtain MAC address from network interface. */
/* Do whatever else is needed to initialize interface. */
tunif->fd = open("/dev/tun0", O_RDWR);
LWIP_DEBUGF(TUNIF_DEBUG, ("tunif_init: fd %d\n", tunif->fd));
if (tunif->fd == -1) {
perror("tunif_init");
exit(1);
}
sprintf(buf, IFCONFIG_CALL,
ip4_addr1(&(netif->gw)),
ip4_addr2(&(netif->gw)),
ip4_addr3(&(netif->gw)),
ip4_addr4(&(netif->gw)),
ip4_addr1(&(netif->ip_addr)),
ip4_addr2(&(netif->ip_addr)),
ip4_addr3(&(netif->ip_addr)),
ip4_addr4(&(netif->ip_addr)));
LWIP_DEBUGF(TUNIF_DEBUG, ("tunif_init: system(\"%s\");\n", buf));
system(buf);
sys_thread_new("tunif_thread", tunif_thread, netif, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO);
}
/*-----------------------------------------------------------------------------------*/
/*
* 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 tunif *tunif, struct pbuf *p)
{
struct pbuf *q;
char buf[1500];
char *bufptr;
int rnd_val;
/* initiate transfer(); */
rnd_val = rand();
if (((double)rnd_val/(double)RAND_MAX) < 0.4) {
printf("drop\n");
return ERR_OK;
}
bufptr = &buf[0];
for(q = p; q != NULL; q = q->next) {
/* Send the data from the pbuf to the interface, one pbuf at a
time. The size of the data in each pbuf is kept in the ->len
variable. */
/* send data from(q->payload, q->len); */
memcpy(bufptr, q->payload, q->len);
bufptr += q->len;
}
/* signal that packet should be sent(); */
if (write(tunif->fd, buf, p->tot_len) == -1) {
perror("tunif: write");
}
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 tunif *tunif)
{
struct pbuf *p, *q;
u16_t len;
char buf[1500];
char *bufptr;
/* Obtain the size of the packet and put it into the "len"
variable. */
len = read(tunif->fd, buf, sizeof(buf));
/* if (((double)rand()/(double)RAND_MAX) < 0.1) {
printf("drop\n");
return NULL;
}*/
/* We allocate a pbuf chain of pbufs from the pool. */
p = pbuf_alloc(PBUF_LINK, len, PBUF_POOL);
if (p != NULL) {
/* We iterate over the pbuf chain until we have read the entire
packet into the pbuf. */
bufptr = &buf[0];
for(q = p; q != NULL; q = q->next) {
/* Read enough bytes to fill this pbuf in the chain. The
available data in the pbuf is given by the q->len
variable. */
/* read data into(q->payload, q->len); */
memcpy(q->payload, bufptr, q->len);
bufptr += q->len;
}
/* acknowledge that packet has been read(); */
} else {
/* drop packet(); */
}
return p;
}
/*-----------------------------------------------------------------------------------*/
static void
tunif_thread(void *arg)
{
struct netif *netif;
struct tunif *tunif;
fd_set fdset;
int ret;
netif = (struct netif *)arg;
tunif = (struct tunif *)netif->state;
while (1) {
FD_ZERO(&fdset);
FD_SET(tunif->fd, &fdset);
/* Wait for a packet to arrive. */
ret = select(tunif->fd + 1, &fdset, NULL, NULL, NULL);
if (ret == 1) {
/* Handle incoming packet. */
tunif_input(netif);
} else if (ret == -1) {
perror("tunif_thread: select");
}
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tunif_output():
*
* This function is called by the TCP/IP stack when an IP packet
* should be sent. It calls the function called low_level_output() to
* do the actuall transmission of the packet.
*
*/
/*-----------------------------------------------------------------------------------*/
static err_t
tunif_output(struct netif *netif, struct pbuf *p,
ip_addr_t *ipaddr)
{
struct tunif *tunif;
LWIP_UNUSED_ARG(ipaddr);
tunif = (struct tunif *)netif->state;
return low_level_output(tunif, p);
}
/*-----------------------------------------------------------------------------------*/
/*
* tunif_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
tunif_input(struct netif *netif)
{
struct tunif *tunif;
struct pbuf *p;
tunif = (struct tunif *)netif->state;
p = low_level_input(tunif);
if (p == NULL) {
LWIP_DEBUGF(TUNIF_DEBUG, ("tunif_input: low_level_input returned NULL\n"));
return;
}
#if 0
/* CS: ip_lookup() was removed */
if (ip_lookup(p->payload, netif)) {
#endif
netif->input(p, netif);
#if 0
}
#endif
}
/*-----------------------------------------------------------------------------------*/
/*
* tunif_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
tunif_init(struct netif *netif)
{
struct tunif *tunif;
tunif = (struct tunif *)mem_malloc(sizeof(struct tunif));
if (!tunif) {
return ERR_MEM;
}
netif->state = tunif;
netif->name[0] = IFNAME0;
netif->name[1] = IFNAME1;
netif->output = tunif_output;
low_level_init(netif);
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/