int check_tun(const struct arguments *args,
const struct epoll_event *ev,
const int epoll_fd,
int sessions, int maxsessions) {
// Check tun error
if (ev->events & EPOLLERR) {
log_android(ANDROID_LOG_ERROR, "tun %d exception", args->tun);
if (fcntl(args->tun, F_GETFL) < 0) {
log_android(ANDROID_LOG_ERROR, "fcntl tun %d F_GETFL error %d: %s",
args->tun, errno, strerror(errno));
report_exit(args, "fcntl tun %d F_GETFL error %d: %s",
args->tun, errno, strerror(errno));
} else
report_exit(args, "tun %d exception", args->tun);
return -1;
}
// Check tun read
if (ev->events & EPOLLIN) {
uint8_t *buffer = malloc(get_mtu());
ssize_t length = read(args->tun, buffer, get_mtu());
if (length < 0) {
free(buffer);
log_android(ANDROID_LOG_ERROR, "tun %d read error %d: %s",
args->tun, errno, strerror(errno));
if (errno == EINTR || errno == EAGAIN)
// Retry later
return 0;
else {
report_exit(args, "tun %d read error %d: %s",
args->tun, errno, strerror(errno));
return -1;
}
}
else if (length > 0) {
// Write pcap record
if (pcap_file != NULL)
write_pcap_rec(buffer, (size_t) length);
if (length > max_tun_msg) {
max_tun_msg = length;
log_android(ANDROID_LOG_WARN, "Maximum tun msg length %d", max_tun_msg);
}
// Handle IP from tun
handle_ip(args, buffer, (size_t) length, epoll_fd, sessions, maxsessions);
free(buffer);
}
else {
// tun eof
free(buffer);
log_android(ANDROID_LOG_ERROR, "tun %d empty read", args->tun);
report_exit(args, "tun %d empty read", args->tun);
return -1;
}
}
return 0;
}
static void write_pcap_hdr(FILE *file)
{
struct pcap_file_header hdr = {
.magic = PCAP_FILE_MAGIC,
.version_major = 2,
.version_minor = 4,
.thiszone = 0,
.sigfigs = 0,
.snaplen = MAX_PSDU,
.linktype = DLT_IEEE802_15_4
};
if (fwrite(&hdr, sizeof(hdr), 1, file) != 1) {
perror("fwrite");
exit(1);
}
}
static void write_pcap_rec(FILE *file, const struct timeval *tv,
const void *buf, int n)
{
struct pcap_pkthdr hdr = {
.ts_sec = tv->tv_sec,
.ts_usec = tv->tv_usec,
.caplen = n,
.len = n
};
if (fwrite(&hdr, sizeof(hdr), 1, file) != 1) {
perror("fwrite");
exit(1);
}
if (fwrite(buf, n, 1, file) != 1) {
perror("fwrite");
exit(1);
}
}
static void receive_pcap(struct atrf_dsc *dsc, const char *name)
{
FILE *file;
uint8_t buf[MAX_PSDU+1]; /* PSDU+LQI */
struct timeval now;
int n;
int count = 0;
file = fopen(name, "w");
if (!file) {
perror(name);
exit(1);
}
write_pcap_hdr(file);
while (run) {
wait_for_interrupt(dsc,
IRQ_TRX_END,
quick ? 0xff : IRQ_TRX_END | IRQ_RX_START | IRQ_AMI,
quick ? -1 : 0);
if (!run)
break;
gettimeofday(&now, NULL);
n = atrf_buf_read(dsc, buf, sizeof(buf));
if (n < 0)
exit(1);
if (n < 2) {
fprintf(stderr, "%d bytes received\n", n);
continue;
}
write_pcap_rec(file, &now, buf, n-1);
if (!quick)
(void) write(2, ".", 1);
count++;
}
if (fclose(file) == EOF) {
perror(name);
exit(1);
}
fprintf(stderr, "%sreceived %d message%s\n", count ? "\n" : "",
count, count == 1 ? "" : "s");
}
static void receive(struct atrf_dsc *dsc, const char *name, int hex)
{
atrf_reg_write(dsc, REG_TRX_STATE, TRX_CMD_RX_ON);
/*
* 180 us, according to AVR2001 section 4.2. We time out after
* nominally 200 us.
*/
wait_for_interrupt(dsc, IRQ_PLL_LOCK, IRQ_PLL_LOCK, 1);
if (name)
receive_pcap(dsc, name);
else
receive_message(dsc, hex);
}
