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

378 lines
10 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 <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/pbuf.h"
#include "lwip/sys.h"
#include "netif/etharp.h"
#if defined(LWIP_DEBUG) && defined(LWIP_TCPDUMP)
#include "netif/tcpdump.h"
#endif /* LWIP_DEBUG && LWIP_TCPDUMP */
#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 */
#define IFNAME0 't'
#define IFNAME1 'p'
static const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
struct tapif {
struct eth_addr *ethaddr;
/* Add whatever per-interface state that is needed here. */
int fd;
};
/* Forward declarations. */
static void tapif_input(struct netif *netif);
static err_t tapif_output(struct netif *netif, struct pbuf *p,
struct ip_addr *ipaddr);
static void tapif_thread(void *data);
/*-----------------------------------------------------------------------------------*/
static void
low_level_init(struct netif *netif)
{
struct tapif *tapif;
char buf[100];
tapif = netif->state;
/* Obtain MAC address from network interface. */
/* (We just fake an address...) */
tapif->ethaddr->addr[0] = 0x1;
tapif->ethaddr->addr[1] = 0x2;
tapif->ethaddr->addr[2] = 0x3;
tapif->ethaddr->addr[3] = 0x4;
tapif->ethaddr->addr[4] = 0x5;
tapif->ethaddr->addr[5] = 0x6;
/* Do whatever else is needed to initialize interface. */
tapif->fd = open(DEVTAP, O_RDWR);
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_init: fd %d\n", tapif->fd));
if(tapif->fd == -1) {
#ifdef linux
perror("tapif_init: try running \"modprobe tun\" or rebuilding your kernel with CONFIG_TUN; cannot open "DEVTAP);
#else
perror("tapif_init: cannot open "DEVTAP);
#endif
exit(1);
}
#ifdef linux
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
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 /* 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)));
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_init: system(\"%s\");\n", buf));
system(buf);
sys_thread_new(tapif_thread, netif, 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 netif *netif, struct pbuf *p)
{
struct pbuf *q;
char buf[1514];
char *bufptr;
struct tapif *tapif;
tapif = netif->state;
#if 0
if(((double)rand()/(double)RAND_MAX) < 0.2) {
printf("drop output\n");
return ERR_OK;
}
#endif
/* 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(tapif->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 tapif *tapif)
{
struct pbuf *p, *q;
u16_t len;
char buf[1514];
char *bufptr;
/* Obtain the size of the packet and put it into the "len"
variable. */
len = read(tapif->fd, buf, sizeof(buf));
#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) {
/* 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
tapif_thread(void *arg)
{
struct netif *netif;
struct tapif *tapif;
fd_set fdset;
int ret;
netif = arg;
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");
}
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tapif_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
tapif_output(struct netif *netif, struct pbuf *p,
struct ip_addr *ipaddr)
{
p = etharp_output(netif, ipaddr, p);
if(p != NULL) {
low_level_output(netif, p);
p = NULL;
}
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
/*
* 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 tapif *tapif;
struct eth_hdr *ethhdr;
struct pbuf *p, *q;
tapif = netif->state;
p = low_level_input(tapif);
if(p == NULL) {
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_input: low_level_input returned NULL\n"));
return;
}
ethhdr = p->payload;
q = NULL;
switch(htons(ethhdr->type)) {
case ETHTYPE_IP:
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_input: IP packet\n"));
q = etharp_ip_input(netif, p);
pbuf_header(p, -14);
#if defined(LWIP_DEBUG) && defined(LWIP_TCPDUMP)
tcpdump(p);
#endif /* LWIP_DEBUG && LWIP_TCPDUMP */
netif->input(p, netif);
break;
case ETHTYPE_ARP:
LWIP_DEBUGF(TAPIF_DEBUG, ("tapif_input: ARP packet\n"));
q = etharp_arp_input(netif, tapif->ethaddr, p);
break;
default:
pbuf_free(p);
break;
}
if(q != NULL) {
low_level_output(netif, q);
pbuf_free(q);
}
}
/*-----------------------------------------------------------------------------------*/
static void
arp_timer(void *arg)
{
etharp_tmr();
sys_timeout(ARP_TMR_INTERVAL, (sys_timeout_handler)arp_timer, NULL);
}
/*-----------------------------------------------------------------------------------*/
/*
* 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;
tapif = mem_malloc(sizeof(struct tapif));
if (!tapif)
return ERR_MEM;
netif->state = tapif;
netif->name[0] = IFNAME0;
netif->name[1] = IFNAME1;
netif->output = tapif_output;
netif->linkoutput = low_level_output;
netif->mtu = 1500;
/* hardware address length */
netif->hwaddr_len = 6;
tapif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
low_level_init(netif);
etharp_init();
sys_timeout(ARP_TMR_INTERVAL, (sys_timeout_handler)arp_timer, NULL);
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/