lwip/proj/minimal/mintapif.c

355 lines
9.5 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 <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>
#ifdef linux
#include <sys/ioctl.h>
#include <linux/if.h>
#include <linux/if_tun.h>
#define DEVTAP "/dev/net/tun"
#else /* linux */
#define DEVTAP "/dev/tap0"
#endif /* linux */
#include "lwip/stats.h"
#include "lwip/mem.h"
#include "netif/etharp.h"
#include "mintapif.h"
/* Define those to better describe your network interface. */
#define IFNAME0 'e'
#define IFNAME1 't'
struct mintapif {
struct eth_addr *ethaddr;
/* Add whatever per-interface state that is needed here. */
u32_t lasttime;
int fd;
};
static const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
/* Forward declarations. */
static void mintapif_input(struct netif *netif);
static err_t mintapif_output(struct netif *netif, struct pbuf *p,
struct ip_addr *ipaddr);
/*-----------------------------------------------------------------------------------*/
static void
low_level_init(struct netif *netif)
{
struct mintapif *mintapif;
char buf[1024];
mintapif = netif->state;
/* Obtain MAC address from network interface. */
mintapif->ethaddr->addr[0] = 1;
mintapif->ethaddr->addr[1] = 2;
mintapif->ethaddr->addr[2] = 3;
mintapif->ethaddr->addr[3] = 4;
mintapif->ethaddr->addr[4] = 5;
mintapif->ethaddr->addr[5] = 6;
/* Do whatever else is needed to initialize interface. */
mintapif->fd = open(DEVTAP, O_RDWR);
if(mintapif->fd == -1) {
perror("tapif: tapif_init: open");
exit(1);
}
#ifdef linux
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
if (ioctl(mintapif->fd, TUNSETIFF, (void *) &ifr) < 0) {
perror(buf);
exit(1);
}
}
#endif /* Linux */
snprintf(buf, sizeof(buf), "ifconfig tap0 inet %d.%d.%d.%d",
ip4_addr1(&(netif->gw)),
ip4_addr2(&(netif->gw)),
ip4_addr3(&(netif->gw)),
ip4_addr4(&(netif->gw)));
system(buf);
mintapif->lasttime = 0;
}
/*-----------------------------------------------------------------------------------*/
/*
* 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 mintapif *mintapif;
struct pbuf *q;
char buf[1500];
char *bufptr;
mintapif = netif->state;
/* initiate transfer(); */
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(mintapif->fd, buf, p->tot_len) == -1) {
perror("tapif: 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 mintapif *mintapif)
{
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(mintapif->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
avaliable 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(); */
printf("Could not allocate pbufs\n");
}
return p;
}
/*-----------------------------------------------------------------------------------*/
/*
* mintapif_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
mintapif_output(struct netif *netif, struct pbuf *p,
struct ip_addr *ipaddr)
{
p = etharp_output(netif, ipaddr, p);
if(p != NULL) {
return low_level_output(netif, p);
}
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
/*
* mintapif_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
mintapif_input(struct netif *netif)
{
struct mintapif *mintapif;
struct eth_hdr *ethhdr;
struct pbuf *p, *q;
mintapif = netif->state;
p = low_level_input(mintapif);
if(p != NULL) {
#ifdef LINK_STATS
lwip_stats.link.recv++;
#endif /* LINK_STATS */
ethhdr = p->payload;
q = NULL;
switch(htons(ethhdr->type)) {
case ETHTYPE_IP:
q = etharp_ip_input(netif, p);
pbuf_header(p, -14);
netif->input(p, netif);
break;
case ETHTYPE_ARP:
q = etharp_arp_input(netif, mintapif->ethaddr, p);
break;
default:
pbuf_free(p);
break;
}
if(q != NULL) {
low_level_output(netif, q);
pbuf_free(q);
}
}
}
/*-----------------------------------------------------------------------------------*/
/*
* mintapif_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.
*
*/
/*-----------------------------------------------------------------------------------*/
void
mintapif_init(struct netif *netif)
{
struct mintapif *mintapif;
mintapif = mem_malloc(sizeof(struct mintapif));
netif->state = mintapif;
netif->name[0] = IFNAME0;
netif->name[1] = IFNAME1;
netif->output = mintapif_output;
netif->linkoutput = low_level_output;
mintapif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
low_level_init(netif);
}
/*-----------------------------------------------------------------------------------*/
enum mintapif_signal
mintapif_wait(struct netif *netif, u16_t time)
{
fd_set fdset;
struct timeval tv, now;
struct timezone tz;
int ret;
struct mintapif *mintapif;
mintapif = netif->state;
while(1) {
if(mintapif->lasttime >= (u32_t)time * 1000) {
mintapif->lasttime = 0;
return MINTAPIF_TIMEOUT;
}
tv.tv_sec = 0;
tv.tv_usec = (u32_t)time * 1000 - mintapif->lasttime;
FD_ZERO(&fdset);
FD_SET(mintapif->fd, &fdset);
gettimeofday(&now, &tz);
ret = select(mintapif->fd + 1, &fdset, NULL, NULL, &tv);
if(ret == 0) {
mintapif->lasttime = 0;
return MINTAPIF_TIMEOUT;
}
gettimeofday(&tv, &tz);
mintapif->lasttime += (tv.tv_sec - now.tv_sec) * 1000000 + (tv.tv_usec - now.tv_usec);
mintapif_input(netif);
}
return MINTAPIF_PACKET;
}