static int _recv(dev_eth_t *dev_eth, char *buf, int len) {
dev_eth_tap_t *dev = (dev_eth_tap_t*)dev_eth;
int nread = real_read(dev->tap_fd, buf, len);
DEBUG("ng_tapnet: read %d bytes\n", nread);
if (nread > 0) {
ethernet_hdr_t *hdr = (ethernet_hdr_t *)buf;
if (!(dev->promiscous) && !_is_addr_multicast(hdr->dst) &&
!_is_addr_broadcast(hdr->dst) &&
(memcmp(hdr->dst, dev->addr, ETHERNET_ADDR_LEN) != 0)) {
DEBUG("ng_eth_dev: received for %02x:%02x:%02x:%02x:%02x:%02x\n"
"That's not me => Dropped\n",
hdr->dst[0], hdr->dst[1], hdr->dst[2],
hdr->dst[3], hdr->dst[4], hdr->dst[5]);
#ifdef __MACH__
kill(_sigio_child_pid, SIGCONT);
#endif
return 0;
}
/* work around lost signals */
fd_set rfds;
struct timeval t;
memset(&t, 0, sizeof(t));
FD_ZERO(&rfds);
FD_SET(dev->tap_fd, &rfds);
_native_in_syscall++; /* no switching here */
if (real_select(dev->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("dev_eth_tap: sigpend++\n");
}
else {
#ifdef __MACH__
kill(_sigio_child_pid, SIGCONT);
#endif
}
_native_in_syscall--;
return nread;
}
else if (nread == -1) {
if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) {
}
else {
err(EXIT_FAILURE, "dev_eth_tap: read");
}
}
else if (nread == 0) {
DEBUG("_native_handle_tap_input: ignoring null-event");
}
else {
errx(EXIT_FAILURE, "internal error _rx_event");
}
return -1;
}
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");
}
}