/* return length of packet, 0 for bad FCS, -1 on error */
static int
parse_radiotap_header(unsigned char** buf, int len, struct packet_info* p)
{
struct ieee80211_radiotap_header* rh;
struct ieee80211_radiotap_iterator iter;
int err, rt_len;
rh = (struct ieee80211_radiotap_header*)*buf;
rt_len = le16toh(rh->it_len);
err = ieee80211_radiotap_iterator_init(&iter, rh, rt_len, NULL);
if (err) {
DEBUG("malformed radiotap header (init returns %d)\n", err);
return -1;
}
DEBUG("Radiotap: ");
while (!(err = ieee80211_radiotap_iterator_next(&iter))) {
if (iter.is_radiotap_ns) {
get_radiotap_info(&iter, p);
}
}
DEBUG("\nSIG %d", p->phy_signal);
/* sanitize */
if (p->phy_rate == 0 || p->phy_rate > 6000) {
/* assume min rate for mode */
DEBUG("*** fixing wrong rate\n");
if (p->phy_flags & PHY_FLAG_A)
p->phy_rate = 120; /* 6 * 2 */
else if (p->phy_flags & PHY_FLAG_B)
p->phy_rate = 20; /* 1 * 2 */
else if (p->phy_flags & PHY_FLAG_G)
p->phy_rate = 120; /* 6 * 2 */
else
p->phy_rate = 20;
}
DEBUG("\nrate: %.2f = idx %d\n", (float)p->phy_rate/10, p->phy_rate_idx);
DEBUG("signal: %d\n", p->phy_signal);
if (p->phy_flags & PHY_FLAG_BADFCS) {
/* we can't trust frames with a bad FCS - stop parsing */
DEBUG("=== bad FCS, stop ===\n");
return 0;
} else {
*buf = *buf + rt_len;
return len - rt_len;
}
}
static unsigned char *get_80211(struct priv_fbsd *pf, int *plen,
struct rx_info *ri)
{
struct bpf_hdr *bpfh;
struct ieee80211_radiotap_header *rth;
void *ptr;
unsigned char **data;
int *totlen;
data = &pf->pf_next;
totlen = &pf->pf_totlen;
assert(*totlen);
/* bpf hdr */
bpfh = (struct bpf_hdr*) (*data);
assert(bpfh->bh_caplen == bpfh->bh_datalen); /* XXX */
*totlen -= bpfh->bh_hdrlen;
/* check if more packets */
if ((int)bpfh->bh_caplen < *totlen) {
int tot = bpfh->bh_hdrlen + bpfh->bh_caplen;
int offset = BPF_WORDALIGN(tot);
*data = (unsigned char*)bpfh + offset;
*totlen -= offset - tot; /* take into account align bytes */
} else if ((int)bpfh->bh_caplen > *totlen)
abort();
*plen = bpfh->bh_caplen;
*totlen -= bpfh->bh_caplen;
assert(*totlen >= 0);
/* radiotap */
rth = (struct ieee80211_radiotap_header*)
((char*)bpfh + bpfh->bh_hdrlen);
get_radiotap_info(pf, rth, plen, ri);
*plen -= rth->it_len;
assert(*plen > 0);
/* data */
ptr = (char*)rth + rth->it_len;
return ptr;
}
/* return length of packet, 0 for bad FCS, -1 on error */
static int
parse_radiotap_header(unsigned char** buf, int len, struct packet_info* p)
{
struct ieee80211_radiotap_header* rh;
struct ieee80211_radiotap_iterator iter;
int err, rt_len;
rh = (struct ieee80211_radiotap_header*)*buf;
rt_len = le16toh(rh->it_len);
err = ieee80211_radiotap_iterator_init(&iter, rh, rt_len, NULL);
if (err) {
DEBUG("malformed radiotap header (init returns %d)\n", err);
return -1;
}
while (!(err = ieee80211_radiotap_iterator_next(&iter))) {
if (iter.is_radiotap_ns) {
get_radiotap_info(&iter, p);
}
}
DEBUG("\n");
DEBUG("SIG %d NOI %d SNR %d\n", p->phy_signal, p->phy_noise, p->phy_snr);
if (p->phy_signal > 0 || p->phy_signal < -95)
p->phy_signal = 0;
/* no SNR from radiotap, try to calculate, normal case nowadays */
if (p->phy_snr == 0 && p->phy_signal < 0) {
if (p->phy_noise < 0) {
p->phy_snr = p->phy_signal - p->phy_noise;
} else {
/* HACK: here we just assume noise to be -95dBm */
p->phy_snr = p->phy_signal + 95;
}
}
/* sanitize */
if (p->phy_snr > 99)
p->phy_snr = 99;
if (p->phy_rate == 0 || p->phy_rate > 6000) {
/* assume min rate for mode */
DEBUG("*** fixing wrong rate\n");
if (p->phy_flags & PHY_FLAG_A)
p->phy_rate = 120; /* 6 * 2 */
else if (p->phy_flags & PHY_FLAG_B)
p->phy_rate = 20; /* 1 * 2 */
else if (p->phy_flags & PHY_FLAG_G)
p->phy_rate = 120; /* 6 * 2 */
else
p->phy_rate = 20;
}
DEBUG("\nrate: %.2f\n", (float)p->phy_rate/10);
DEBUG("rate_idx: %d\n", p->phy_rate_idx);
DEBUG("signal: %d\n", p->phy_signal);
DEBUG("noise: %d\n", p->phy_noise);
DEBUG("snr: %d\n", p->phy_snr);
if (p->phy_flags & PHY_FLAG_BADFCS) {
/* we can't trust frames with a bad FCS - stop parsing */
DEBUG("=== bad FCS, stop ===\n");
return 0;
} else {
*buf = *buf + rt_len;
return len - rt_len;
}
}
