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/**
* tap.h implementation
*
* Copyright (C) 2013 Ludwig Ortmann <ludwig.ortmann@fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*
* @ingroup native_cpu
* @{
* @file
* @author Ludwig Ortmann <ludwig.ortmann@fu-berlin.de>
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <err.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <inttypes.h>
#include <errno.h>
#ifdef __MACH__
#define _POSIX_C_SOURCE
#include <net/if.h>
#undef _POSIX_C_SOURCE
#include <ifaddrs.h>
#include <net/if_dl.h>
#elif defined(__FreeBSD__)
#include <sys/socket.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <net/if_dl.h>
#else
#include <net/if.h>
#include <linux/if_tun.h>
#include <linux/if_ether.h>
#endif
#define ENABLE_DEBUG (0)
#include "debug.h"
#include "cpu.h"
#include "cpu-conf.h"
#include "tap.h"
#include "nativenet.h"
#include "nativenet_internal.h"
#include "native_internal.h"
#include "hwtimer.h"
#include "timex.h"
#define TAP_BUFFER_LENGTH (ETHER_MAX_LEN)
int _native_marshall_ethernet(uint8_t *framebuf, radio_packet_t *packet);
int _native_tap_fd = -1;
unsigned char _native_tap_mac[ETHER_ADDR_LEN];
#ifdef __MACH__
pid_t sigio_child_pid;
#endif
void _native_handle_tap_input(void)
{
int nread;
union eth_frame frame;
radio_packet_t p;
DEBUG("_native_handle_tap_input\n");
/* TODO: check whether this is an input or an output event
TODO: refactor this into general io-signal multiplexer */
nread = real_read(_native_tap_fd, &frame, sizeof(union eth_frame));
DEBUG("_native_handle_tap_input - read %d bytes\n", nread);
if (nread > 0) {
if (ntohs(frame.field.header.ether_type) == NATIVE_ETH_PROTO) {
nread = nread - ETHER_HDR_LEN;
if ((nread - 1) <= 0) {
DEBUG("_native_handle_tap_input: no payload\n");
}
else {
unsigned long t = hwtimer_now();
p.processing = 0;
p.src = ntohs(frame.field.payload.nn_header.src);
p.dst = ntohs(frame.field.payload.nn_header.dst);
p.rssi = 0;
p.lqi = 0;
p.toa.seconds = HWTIMER_TICKS_TO_US(t)/1000000;
p.toa.microseconds = HWTIMER_TICKS_TO_US(t)%1000000;
/* XXX: check overflow */
p.length = ntohs(frame.field.payload.nn_header.length);
p.data = frame.field.payload.data;
if (p.length > (nread - sizeof(struct nativenet_header))) {
warnx("_native_handle_tap_input: packet with malicious length field received, discarding");
}
else {
DEBUG("_native_handle_tap_input: received packet of length %" PRIu16 " for %" PRIu16 " from %" PRIu16 "\n", p.length, p.dst, p.src);
_nativenet_handle_packet(&p);
}
}
}
else {
DEBUG("ignoring non-native frame\n");
}
/* work around lost signals */
fd_set rfds;
struct timeval t;
memset(&t, 0, sizeof(t));
FD_ZERO(&rfds);
FD_SET(_native_tap_fd, &rfds);
_native_in_syscall++; // no switching here
if (select(_native_tap_fd +1, &rfds, NULL, NULL, &t) == 1) {
int sig = SIGIO;
extern int _sig_pipefd[2];
extern ssize_t (*real_write)(int fd, const void *buf, size_t count);
real_write(_sig_pipefd[1], &sig, sizeof(int));
_native_sigpend++;
DEBUG("_native_handle_tap_input: sigpend++\n");
}
else {
DEBUG("_native_handle_tap_input: no more pending tap data\n");
#ifdef __MACH__
kill(sigio_child_pid, SIGCONT);
#endif
}
_native_in_syscall--;
}
else if (nread == -1) {
if ((errno == EAGAIN ) || (errno == EWOULDBLOCK)) {
//warn("read");
}
else {
err(EXIT_FAILURE, "_native_handle_tap_input: read");
}
}
else {
errx(EXIT_FAILURE, "internal error _native_handle_tap_input");
}
}
#ifdef __MACH__
void sigio_child(void)
{
pid_t parent = _native_pid;
if ((sigio_child_pid = real_fork()) == -1) {
err(EXIT_FAILURE, "sigio_child: fork");
}
if (sigio_child_pid > 0) {
/* return in parent process */
return;
}
/* watch tap interface and signal parent process if data is
* available */
fd_set rfds;
while (1) {
FD_ZERO(&rfds);
FD_SET(_native_tap_fd, &rfds);
if (select(_native_tap_fd +1, &rfds, NULL, NULL, NULL) == 1) {
kill(parent, SIGIO);
}
else {
kill(parent, SIGKILL);
err(EXIT_FAILURE, "osx_sigio_child: select");
}
pause();
}
}
#endif
int _native_marshall_ethernet(uint8_t *framebuf, radio_packet_t *packet)
{
int data_len;
union eth_frame *f;
unsigned char addr[ETHER_ADDR_LEN];
f = (union eth_frame*)framebuf;
addr[0] = addr[1] = addr[2] = addr[3] = addr[4] = addr[5] = 0xFF;
memcpy(f->field.header.ether_dhost, addr, ETHER_ADDR_LEN);
memcpy(f->field.header.ether_shost, _native_tap_mac, ETHER_ADDR_LEN);
f->field.header.ether_type = htons(NATIVE_ETH_PROTO);
/* XXX: check overflow */
memcpy(f->field.payload.data, packet->data, packet->length);
f->field.payload.nn_header.length = htons(packet->length);
f->field.payload.nn_header.dst = htons(packet->dst);
f->field.payload.nn_header.src = htons(packet->src);
data_len = packet->length + sizeof(struct nativenet_header);
/* Pad to minimum payload size.
* Linux does this on its own, but it doesn't hurt to do it here.
* As of now only tuntaposx needs this. */
if (data_len < ETHERMIN) {
DEBUG("padding data! (%d -> ", data_len);
data_len = ETHERMIN;
DEBUG("%d)\n", data_len);
}
return data_len + ETHER_HDR_LEN;
}
int8_t send_buf(radio_packet_t *packet)
{
uint8_t buf[TAP_BUFFER_LENGTH];
int nsent, to_send;
memset(buf, 0, sizeof(buf));
DEBUG("send_buf: Sending packet of length %" PRIu16 " from %" PRIu16 " to %" PRIu16 "\n", packet->length, packet->src, packet->dst);
to_send = _native_marshall_ethernet(buf, packet);
DEBUG("send_buf: trying to send %d bytes\n", to_send);
if ((nsent = _native_write(_native_tap_fd, buf, to_send)) == -1) {;
warn("write");
return -1;
}
return (nsent > INT8_MAX ? INT8_MAX : nsent);
}
int tap_init(char *name)
{
#ifdef __MACH__ /* OSX */
char clonedev[255] = "/dev/"; /* XXX bad size */
strncpy(clonedev+5, name, 250);
#elif defined(__FreeBSD__)
char clonedev[255] = "/dev/"; /* XXX bad size */
strncpy(clonedev+5, name, 250);
#else /* Linux */
struct ifreq ifr;
const char *clonedev = "/dev/net/tun";
#endif
/* implicitly create the tap interface */
if ((_native_tap_fd = open(clonedev , O_RDWR)) == -1) {
err(EXIT_FAILURE, "open(%s)", clonedev);
}
#if (defined(__MACH__) || defined(__FreeBSD__)) /* OSX/FreeBSD */
struct ifaddrs* iflist;
if (getifaddrs(&iflist) == 0) {
for (struct ifaddrs *cur = iflist; cur; cur = cur->ifa_next) {
if ((cur->ifa_addr->sa_family == AF_LINK) && (strcmp(cur->ifa_name, name) == 0) && cur->ifa_addr) {
struct sockaddr_dl* sdl = (struct sockaddr_dl*)cur->ifa_addr;
memcpy(_native_tap_mac, LLADDR(sdl), sdl->sdl_alen);
break;
}
}
freeifaddrs(iflist);
}
#else /* Linux */
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
strncpy(ifr.ifr_name, name, IFNAMSIZ);
if (ioctl(_native_tap_fd, TUNSETIFF, (void *)&ifr) == -1) {
_native_in_syscall++;
warn("ioctl TUNSETIFF");
warnx("probably the tap interface (%s) does not exist or is already in use", name);
exit(EXIT_FAILURE);
}
/* TODO: use strncpy */
strcpy(name, ifr.ifr_name);
/* get MAC address */
memset (&ifr, 0, sizeof (ifr));
snprintf (ifr.ifr_name, sizeof (ifr.ifr_name), "%s", name);
if (ioctl(_native_tap_fd, SIOCGIFHWADDR, &ifr) == -1) {
_native_in_syscall++;
warn("ioctl SIOCGIFHWADDR");
if (real_close(_native_tap_fd) == -1) {
warn("close");
}
exit(EXIT_FAILURE);
}
memcpy(_native_tap_mac, ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
#endif
DEBUG("_native_tap_mac: %02x:%02x:%02x:%02x:%02x:%02x\n", _native_tap_mac[0], _native_tap_mac[1], _native_tap_mac[2], _native_tap_mac[3], _native_tap_mac[4], _native_tap_mac[5]);
unsigned char *eui_64 = (unsigned char*)&_native_net_addr_long;
eui_64[0] = _native_tap_mac[0];
eui_64[1] = _native_tap_mac[1];
eui_64[2] = _native_tap_mac[2];
eui_64[3] = 0xff;
eui_64[4] = 0xfe;
eui_64[5] = _native_tap_mac[3];
eui_64[6] = _native_tap_mac[4];
eui_64[7] = _native_tap_mac[5];
/* configure signal handler for fds */
register_interrupt(SIGIO, _native_handle_tap_input);
#ifdef __MACH__
/* tuntap signalled IO is not working in OSX,
* check http://sourceforge.net/p/tuntaposx/bugs/17/ */
sigio_child();
#else
/* configure fds to send signals on io */
if (fcntl(_native_tap_fd, F_SETOWN, _native_pid) == -1) {
err(EXIT_FAILURE, "tap_init(): fcntl(F_SETOWN)");
}
/* set file access mode to nonblocking */
if (fcntl(_native_tap_fd, F_SETFL, O_NONBLOCK|O_ASYNC) == -1) {
err(EXIT_FAILURE, "tap_init(): fcntl(F_SETFL)");
}
#endif /* not OSX */
DEBUG("RIOT native tap initialized.\n");
return _native_tap_fd;
}
/** @} */