/* return packet length or -1 on error */
static int
parse_prism_header(unsigned char** buf, int len, struct packet_info* p)
{
wlan_ng_prism2_header* ph;
DEBUG("PRISM2 HEADER\n");
if (len > 0 && (size_t)len < sizeof(wlan_ng_prism2_header))
return -1;
ph = (wlan_ng_prism2_header*)*buf;
/*
* different drivers report S/N and rssi values differently
*/
if (((int)ph->noise.data) < 0) {
/* new madwifi */
p->phy_signal = ph->signal.data;
}
else if (((int)ph->rssi.data) < 0) {
/* broadcom hack */
p->phy_signal = ph->rssi.data;
}
else {
/* assume hostap */
p->phy_signal = ph->signal.data;
}
p->phy_rate = ph->rate.data * 10;
/* just in case...*/
if (p->phy_rate == 0 || p->phy_rate > 1080) {
/* assume min rate, guess mode from channel */
DEBUG("*** fixing wrong rate\n");
if (ph->channel.data > 14)
p->phy_rate = 120; /* 6 * 2 */
else
p->phy_rate = 20; /* 1 * 2 */
}
p->phy_rate_idx = rate_to_index(p->phy_rate);
/* guess phy mode */
if (ph->channel.data > 14)
p->phy_flags |= PHY_FLAG_A;
else
p->phy_flags |= PHY_FLAG_G;
/* always assume shortpre */
p->phy_flags |= PHY_FLAG_SHORTPRE;
DEBUG("devname: %s\n", ph->devname);
DEBUG("signal: %d -> %d\n", ph->signal.data, p->phy_signal);
DEBUG("rate: %d\n", ph->rate.data);
DEBUG("rssi: %d\n", ph->rssi.data);
*buf = *buf + sizeof(wlan_ng_prism2_header);
return len - sizeof(wlan_ng_prism2_header);
}
static void
get_radiotap_info(struct ieee80211_radiotap_iterator *iter, struct packet_info* p)
{
uint16_t x;
char c;
unsigned char known, flags, ht20, lgi;
switch (iter->this_arg_index) {
/* ignoring these */
case IEEE80211_RADIOTAP_TSFT:
case IEEE80211_RADIOTAP_FHSS:
case IEEE80211_RADIOTAP_LOCK_QUALITY:
case IEEE80211_RADIOTAP_TX_ATTENUATION:
case IEEE80211_RADIOTAP_DB_TX_ATTENUATION:
case IEEE80211_RADIOTAP_DBM_TX_POWER:
case IEEE80211_RADIOTAP_TX_FLAGS:
case IEEE80211_RADIOTAP_RX_FLAGS:
case IEEE80211_RADIOTAP_RTS_RETRIES:
case IEEE80211_RADIOTAP_DATA_RETRIES:
case IEEE80211_RADIOTAP_AMPDU_STATUS:
break;
case IEEE80211_RADIOTAP_FLAGS:
/* short preamble */
DEBUG("[flags %0x", *iter->this_arg);
if (*iter->this_arg & IEEE80211_RADIOTAP_F_SHORTPRE) {
p->phy_flags |= PHY_FLAG_SHORTPRE;
DEBUG(" shortpre");
}
if (*iter->this_arg & IEEE80211_RADIOTAP_F_BADFCS) {
p->phy_flags |= PHY_FLAG_BADFCS;
p->pkt_types |= PKT_TYPE_BADFCS;
DEBUG(" badfcs");
}
DEBUG("]");
break;
case IEEE80211_RADIOTAP_RATE:
//TODO check!
//printf("\trate: %lf\n", (double)*iter->this_arg/2);
DEBUG("[rate %0x]", *iter->this_arg);
p->phy_rate = (*iter->this_arg)*5; /* rate is in 500kbps */
p->phy_rate_idx = rate_to_index(p->phy_rate);
break;
#define IEEE80211_CHAN_A \
(IEEE80211_CHAN_5GHZ | IEEE80211_CHAN_OFDM)
#define IEEE80211_CHAN_B \
(IEEE80211_CHAN_2GHZ | IEEE80211_CHAN_CCK)
#define IEEE80211_CHAN_G \
(IEEE80211_CHAN_2GHZ | IEEE80211_CHAN_DYN)
case IEEE80211_RADIOTAP_CHANNEL:
/* channel & channel type */
p->phy_freq = le16toh(*(uint16_t*)iter->this_arg);
DEBUG("[freq %d", p->phy_freq);
iter->this_arg = iter->this_arg + 2;
x = le16toh(*(uint16_t*)iter->this_arg);
if (x & IEEE80211_CHAN_A) {
p->phy_flags |= PHY_FLAG_A;
DEBUG("A]");
}
else if (x & IEEE80211_CHAN_G) {
p->phy_flags |= PHY_FLAG_G;
DEBUG("G]");
}
else if (x & IEEE80211_CHAN_B) {
p->phy_flags |= PHY_FLAG_B;
DEBUG("B]");
}
break;
case IEEE80211_RADIOTAP_DBM_ANTSIGNAL:
c = *(char*)iter->this_arg;
DEBUG("[sig %0d]", c);
/* we get the signal per rx chain with newer drivers.
* save the highest value, but make sure we don't override
* with invalid values */
if (c < 0 && (p->phy_signal == 0 || c > p->phy_signal))
p->phy_signal = c;
break;
case IEEE80211_RADIOTAP_DBM_ANTNOISE:
DEBUG("[noi %0x]", *(char*)iter->this_arg);
p->phy_noise = *(char*)iter->this_arg;
break;
case IEEE80211_RADIOTAP_ANTENNA:
DEBUG("[ant %0x]", *iter->this_arg);
break;
case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
DEBUG("[snr %0x]", *iter->this_arg);
p->phy_snr = *iter->this_arg;
break;
case IEEE80211_RADIOTAP_DB_ANTNOISE:
//printf("\tantnoise: %02d\n", *iter->this_arg);
break;
case IEEE80211_RADIOTAP_MCS:
/* Ref http://www.radiotap.org/defined-fields/MCS */
known = *iter->this_arg++;
flags = *iter->this_arg++;
DEBUG("[MCS known %0x flags %0x index %0x]", known, flags, *iter->this_arg);
if (known & IEEE80211_RADIOTAP_MCS_HAVE_BW)
ht20 = (flags & IEEE80211_RADIOTAP_MCS_BW_MASK) == IEEE80211_RADIOTAP_MCS_BW_20;
else
ht20 = 1; /* assume HT20 if not present */
if (known & IEEE80211_RADIOTAP_MCS_HAVE_GI)
lgi = !(flags & IEEE80211_RADIOTAP_MCS_SGI);
else
lgi = 1; /* assume long GI if not present */
DEBUG(" %s %s", ht20 ? "HT20" : "HT40", lgi ? "LGI" : "SGI");
p->phy_rate_idx = 12 + *iter->this_arg;
p->phy_rate_flags = flags;
p->phy_rate = mcs_index_to_rate(*iter->this_arg, ht20, lgi);
DEBUG(" RATE %d ", p->phy_rate);
break;
default:
printlog("UNKNOWN RADIOTAP field %d", iter->this_arg_index);
break;
}
}