xref: /external/iw/scan.c

#include <net/if.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <stdbool.h>

#include <netlink/genl/genl.h>
#include <netlink/genl/family.h>
#include <netlink/genl/ctrl.h>
#include <netlink/msg.h>
#include <netlink/attr.h>

#include "nl80211.h"
#include "iw.h"

#define WLAN_CAPABILITY_ESS		(1<<0)
#define WLAN_CAPABILITY_IBSS		(1<<1)
#define WLAN_CAPABILITY_CF_POLLABLE	(1<<2)
#define WLAN_CAPABILITY_CF_POLL_REQUEST	(1<<3)
#define WLAN_CAPABILITY_PRIVACY		(1<<4)
#define WLAN_CAPABILITY_SHORT_PREAMBLE	(1<<5)
#define WLAN_CAPABILITY_PBCC		(1<<6)
#define WLAN_CAPABILITY_CHANNEL_AGILITY	(1<<7)
#define WLAN_CAPABILITY_SPECTRUM_MGMT	(1<<8)
#define WLAN_CAPABILITY_QOS		(1<<9)
#define WLAN_CAPABILITY_SHORT_SLOT_TIME	(1<<10)
#define WLAN_CAPABILITY_APSD		(1<<11)
#define WLAN_CAPABILITY_RADIO_MEASURE	(1<<12)
#define WLAN_CAPABILITY_DSSS_OFDM	(1<<13)
#define WLAN_CAPABILITY_DEL_BACK	(1<<14)
#define WLAN_CAPABILITY_IMM_BACK	(1<<15)
/* DMG (60gHz) 802.11ad */
/* type - bits 0..1 */
#define WLAN_CAPABILITY_DMG_TYPE_MASK		(3<<0)

#define WLAN_CAPABILITY_DMG_TYPE_IBSS		(1<<0) /* Tx by: STA */
#define WLAN_CAPABILITY_DMG_TYPE_PBSS		(2<<0) /* Tx by: PCP */
#define WLAN_CAPABILITY_DMG_TYPE_AP		(3<<0) /* Tx by: AP */

#define WLAN_CAPABILITY_DMG_CBAP_ONLY		(1<<2)
#define WLAN_CAPABILITY_DMG_CBAP_SOURCE		(1<<3)
#define WLAN_CAPABILITY_DMG_PRIVACY		(1<<4)
#define WLAN_CAPABILITY_DMG_ECPAC		(1<<5)

#define WLAN_CAPABILITY_DMG_SPECTRUM_MGMT	(1<<8)
#define WLAN_CAPABILITY_DMG_RADIO_MEASURE	(1<<12)

static unsigned char ms_oui[3]		= { 0x00, 0x50, 0xf2 };
static unsigned char ieee80211_oui[3]	= { 0x00, 0x0f, 0xac };
static unsigned char wfa_oui[3]		= { 0x50, 0x6f, 0x9a };

struct scan_params {
	bool unknown;
	enum print_ie_type type;
	bool show_both_ie_sets;
};

#define IEEE80211_COUNTRY_EXTENSION_ID 201

union ieee80211_country_ie_triplet {
	struct {
		__u8 first_channel;
		__u8 num_channels;
		__s8 max_power;
	} __attribute__ ((packed)) chans;
	struct {
		__u8 reg_extension_id;
		__u8 reg_class;
		__u8 coverage_class;
	} __attribute__ ((packed)) ext;
} __attribute__ ((packed));

static int handle_scan(struct nl80211_state *state,
		       struct nl_cb *cb,
		       struct nl_msg *msg,
		       int argc, char **argv,
		       enum id_input id)
{
	struct nl_msg *ssids = NULL, *freqs = NULL;
	char *eptr;
	int err = -ENOBUFS;
	int i;
	enum {
		NONE,
		FREQ,
		IES,
		SSID,
		DONE,
	} parse = NONE;
	int freq;
	bool passive = false, have_ssids = false, have_freqs = false;
	size_t tmp;
	unsigned char *ies;
	int flags = 0;

	ssids = nlmsg_alloc();
	if (!ssids)
		return -ENOMEM;

	freqs = nlmsg_alloc();
	if (!freqs) {
		nlmsg_free(ssids);
		return -ENOMEM;
	}

	for (i = 0; i < argc; i++) {
		switch (parse) {
		case NONE:
			if (strcmp(argv[i], "freq") == 0) {
				parse = FREQ;
				have_freqs = true;
				break;
			} else if (strcmp(argv[i], "ies") == 0) {
				parse = IES;
				break;
			} else if (strcmp(argv[i], "lowpri") == 0) {
				parse = NONE;
				flags |= NL80211_SCAN_FLAG_LOW_PRIORITY;
				break;
			} else if (strcmp(argv[i], "flush") == 0) {
				parse = NONE;
				flags |= NL80211_SCAN_FLAG_FLUSH;
				break;
			} else if (strcmp(argv[i], "ap-force") == 0) {
				parse = NONE;
				flags |= NL80211_SCAN_FLAG_AP;
				break;
			} else if (strcmp(argv[i], "ssid") == 0) {
				parse = SSID;
				have_ssids = true;
				break;
			} else if (strcmp(argv[i], "passive") == 0) {
				parse = DONE;
				passive = true;
				break;
			}
		case DONE:
			return 1;
		case FREQ:
			freq = strtoul(argv[i], &eptr, 10);
			if (eptr != argv[i] + strlen(argv[i])) {
				/* failed to parse as number -- maybe a tag? */
				i--;
				parse = NONE;
				continue;
			}
			NLA_PUT_U32(freqs, i, freq);
			break;
		case IES:
			ies = parse_hex(argv[i], &tmp);
			if (!ies)
				goto nla_put_failure;
			NLA_PUT(msg, NL80211_ATTR_IE, tmp, ies);
			free(ies);
			parse = NONE;
			break;
		case SSID:
			NLA_PUT(ssids, i, strlen(argv[i]), argv[i]);
			break;
		}
	}

	if (!have_ssids)
		NLA_PUT(ssids, 1, 0, "");
	if (!passive)
		nla_put_nested(msg, NL80211_ATTR_SCAN_SSIDS, ssids);

	if (have_freqs)
		nla_put_nested(msg, NL80211_ATTR_SCAN_FREQUENCIES, freqs);
	if (flags)
		NLA_PUT_U32(msg, NL80211_ATTR_SCAN_FLAGS, flags);

	err = 0;
 nla_put_failure:
	nlmsg_free(ssids);
	nlmsg_free(freqs);
	return err;
}

static void tab_on_first(bool *first)
{
	if (!*first)
		printf("\t");
	else
		*first = false;
}

static void print_ssid(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf(" ");
	print_ssid_escaped(len, data);
	printf("\n");
}

#define BSS_MEMBERSHIP_SELECTOR_VHT_PHY 126
#define BSS_MEMBERSHIP_SELECTOR_HT_PHY 127

static void print_supprates(const uint8_t type, uint8_t len, const uint8_t *data)
{
	int i;

	printf(" ");

	for (i = 0; i < len; i++) {
		int r = data[i] & 0x7f;

		if (r == BSS_MEMBERSHIP_SELECTOR_VHT_PHY && data[i] & 0x80)
			printf("VHT");
		else if (r == BSS_MEMBERSHIP_SELECTOR_HT_PHY && data[i] & 0x80)
			printf("HT");
		else
			printf("%d.%d", r/2, 5*(r&1));

		printf("%s ", data[i] & 0x80 ? "*" : "");
	}
	printf("\n");
}

static void print_ds(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf(" channel %d\n", data[0]);
}

static const char *country_env_str(char environment)
{
	switch (environment) {
	case 'I':
		return "Indoor only";
	case 'O':
		return "Outdoor only";
	case ' ':
		return "Indoor/Outdoor";
	default:
		return "bogus";
	}
}

static void print_country(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf(" %.*s", 2, data);

	printf("\tEnvironment: %s\n", country_env_str(data[2]));

	data += 3;
	len -= 3;

	if (len < 3) {
		printf("\t\tNo country IE triplets present\n");
		return;
	}

	while (len >= 3) {
		int end_channel;
		union ieee80211_country_ie_triplet *triplet = (void *) data;

		if (triplet->ext.reg_extension_id >= IEEE80211_COUNTRY_EXTENSION_ID) {
			printf("\t\tExtension ID: %d Regulatory Class: %d Coverage class: %d (up to %dm)\n",
			       triplet->ext.reg_extension_id,
			       triplet->ext.reg_class,
			       triplet->ext.coverage_class,
			       triplet->ext.coverage_class * 450);

			data += 3;
			len -= 3;
			continue;
		}

		/* 2 GHz */
		if (triplet->chans.first_channel <= 14)
			end_channel = triplet->chans.first_channel + (triplet->chans.num_channels - 1);
		else
			end_channel =  triplet->chans.first_channel + (4 * (triplet->chans.num_channels - 1));

		printf("\t\tChannels [%d - %d] @ %d dBm\n", triplet->chans.first_channel, end_channel, triplet->chans.max_power);

		data += 3;
		len -= 3;
	}

	return;
}

static void print_powerconstraint(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf(" %d dB\n", data[0]);
}

static void print_erp(const uint8_t type, uint8_t len, const uint8_t *data)
{
	if (data[0] == 0x00)
		printf(" <no flags>");
	if (data[0] & 0x01)
		printf(" NonERP_Present");
	if (data[0] & 0x02)
		printf(" Use_Protection");
	if (data[0] & 0x04)
		printf(" Barker_Preamble_Mode");
	printf("\n");
}

static void print_cipher(const uint8_t *data)
{
	if (memcmp(data, ms_oui, 3) == 0) {
		switch (data[3]) {
		case 0:
			printf("Use group cipher suite");
			break;
		case 1:
			printf("WEP-40");
			break;
		case 2:
			printf("TKIP");
			break;
		case 4:
			printf("CCMP");
			break;
		case 5:
			printf("WEP-104");
			break;
		default:
			printf("%.02x-%.02x-%.02x:%d",
				data[0], data[1] ,data[2], data[3]);
			break;
		}
	} else if (memcmp(data, ieee80211_oui, 3) == 0) {
		switch (data[3]) {
		case 0:
			printf("Use group cipher suite");
			break;
		case 1:
			printf("WEP-40");
			break;
		case 2:
			printf("TKIP");
			break;
		case 4:
			printf("CCMP");
			break;
		case 5:
			printf("WEP-104");
			break;
		case 6:
			printf("AES-128-CMAC");
			break;
		case 8:
			printf("GCMP");
			break;
		default:
			printf("%.02x-%.02x-%.02x:%d",
				data[0], data[1] ,data[2], data[3]);
			break;
		}
	} else
		printf("%.02x-%.02x-%.02x:%d",
			data[0], data[1] ,data[2], data[3]);
}

static void print_auth(const uint8_t *data)
{
	if (memcmp(data, ms_oui, 3) == 0) {
		switch (data[3]) {
		case 1:
			printf("IEEE 802.1X");
			break;
		case 2:
			printf("PSK");
			break;
		default:
			printf("%.02x-%.02x-%.02x:%d",
				data[0], data[1] ,data[2], data[3]);
			break;
		}
	} else if (memcmp(data, ieee80211_oui, 3) == 0) {
		switch (data[3]) {
		case 1:
			printf("IEEE 802.1X");
			break;
		case 2:
			printf("PSK");
			break;
		case 3:
			printf("FT/IEEE 802.1X");
			break;
		case 4:
			printf("FT/PSK");
			break;
		case 5:
			printf("IEEE 802.1X/SHA-256");
			break;
		case 6:
			printf("PSK/SHA-256");
			break;
		default:
			printf("%.02x-%.02x-%.02x:%d",
				data[0], data[1] ,data[2], data[3]);
			break;
		}
	} else
		printf("%.02x-%.02x-%.02x:%d",
			data[0], data[1] ,data[2], data[3]);
}

static void print_rsn_ie(const char *defcipher, const char *defauth,
			 uint8_t len, const uint8_t *data)
{
	bool first = true;
	__u16 version, count, capa;
	int i;

	version = data[0] + (data[1] << 8);
	tab_on_first(&first);
	printf("\t * Version: %d\n", version);

	data += 2;
	len -= 2;

	if (len < 4) {
		tab_on_first(&first);
		printf("\t * Group cipher: %s\n", defcipher);
		printf("\t * Pairwise ciphers: %s\n", defcipher);
		return;
	}

	tab_on_first(&first);
	printf("\t * Group cipher: ");
	print_cipher(data);
	printf("\n");

	data += 4;
	len -= 4;

	if (len < 2) {
		tab_on_first(&first);
		printf("\t * Pairwise ciphers: %s\n", defcipher);
		return;
	}

	count = data[0] | (data[1] << 8);
	if (2 + (count * 4) > len)
		goto invalid;

	tab_on_first(&first);
	printf("\t * Pairwise ciphers:");
	for (i = 0; i < count; i++) {
		printf(" ");
		print_cipher(data + 2 + (i * 4));
	}
	printf("\n");

	data += 2 + (count * 4);
	len -= 2 + (count * 4);

	if (len < 2) {
		tab_on_first(&first);
		printf("\t * Authentication suites: %s\n", defauth);
		return;
	}

	count = data[0] | (data[1] << 8);
	if (2 + (count * 4) > len)
		goto invalid;

	tab_on_first(&first);
	printf("\t * Authentication suites:");
	for (i = 0; i < count; i++) {
		printf(" ");
		print_auth(data + 2 + (i * 4));
	}
	printf("\n");

	data += 2 + (count * 4);
	len -= 2 + (count * 4);

	if (len >= 2) {
		capa = data[0] | (data[1] << 8);
		tab_on_first(&first);
		printf("\t * Capabilities:");
		if (capa & 0x0001)
			printf(" PreAuth");
		if (capa & 0x0002)
			printf(" NoPairwise");
		switch ((capa & 0x000c) >> 2) {
		case 0:
			break;
		case 1:
			printf(" 2-PTKSA-RC");
			break;
		case 2:
			printf(" 4-PTKSA-RC");
			break;
		case 3:
			printf(" 16-PTKSA-RC");
			break;
		}
		switch ((capa & 0x0030) >> 4) {
		case 0:
			break;
		case 1:
			printf(" 2-GTKSA-RC");
			break;
		case 2:
			printf(" 4-GTKSA-RC");
			break;
		case 3:
			printf(" 16-GTKSA-RC");
			break;
		}
		if (capa & 0x0040)
			printf(" MFP-required");
		if (capa & 0x0080)
			printf(" MFP-capable");
		if (capa & 0x0200)
			printf(" Peerkey-enabled");
		if (capa & 0x0400)
			printf(" SPP-AMSDU-capable");
		if (capa & 0x0800)
			printf(" SPP-AMSDU-required");
		printf(" (0x%.4x)\n", capa);
		data += 2;
		len -= 2;
	}

	if (len >= 2) {
		int pmkid_count = data[0] | (data[1] << 8);

		if (len >= 2 + 16 * pmkid_count) {
			tab_on_first(&first);
			printf("\t * %d PMKIDs\n", pmkid_count);
			/* not printing PMKID values */
			data += 2 + 16 * pmkid_count;
			len -= 2 + 16 * pmkid_count;
		} else
			goto invalid;
	}

	if (len >= 4) {
		tab_on_first(&first);
		printf("\t * Group mgmt cipher suite: ");
		print_cipher(data);
		printf("\n");
		data += 4;
		len -= 4;
	}

 invalid:
	if (len != 0) {
		printf("\t\t * bogus tail data (%d):", len);
		while (len) {
			printf(" %.2x", *data);
			data++;
			len--;
		}
		printf("\n");
	}
}

static void print_rsn(const uint8_t type, uint8_t len, const uint8_t *data)
{
	print_rsn_ie("CCMP", "IEEE 802.1X", len, data);
}

static void print_ht_capa(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf("\n");
	print_ht_capability(data[0] | (data[1] << 8));
	print_ampdu_length(data[2] & 3);
	print_ampdu_spacing((data[2] >> 2) & 7);
	print_ht_mcs(data + 3);
}

static const char *ht_secondary_offset[4] = {
	"no secondary",
	"above",
	"[reserved!]",
	"below",
};

static void print_ht_op(const uint8_t type, uint8_t len, const uint8_t *data)
{
	static const char *protection[4] = {
		"no",
		"nonmember",
		"20 MHz",
		"non-HT mixed",
	};
	static const char *sta_chan_width[2] = {
		"20 MHz",
		"any",
	};

	printf("\n");
	printf("\t\t * primary channel: %d\n", data[0]);
	printf("\t\t * secondary channel offset: %s\n",
		ht_secondary_offset[data[1] & 0x3]);
	printf("\t\t * STA channel width: %s\n", sta_chan_width[(data[1] & 0x4)>>2]);
	printf("\t\t * RIFS: %d\n", (data[1] & 0x8)>>3);
	printf("\t\t * HT protection: %s\n", protection[data[2] & 0x3]);
	printf("\t\t * non-GF present: %d\n", (data[2] & 0x4) >> 2);
	printf("\t\t * OBSS non-GF present: %d\n", (data[2] & 0x10) >> 4);
	printf("\t\t * dual beacon: %d\n", (data[4] & 0x40) >> 6);
	printf("\t\t * dual CTS protection: %d\n", (data[4] & 0x80) >> 7);
	printf("\t\t * STBC beacon: %d\n", data[5] & 0x1);
	printf("\t\t * L-SIG TXOP Prot: %d\n", (data[5] & 0x2) >> 1);
	printf("\t\t * PCO active: %d\n", (data[5] & 0x4) >> 2);
	printf("\t\t * PCO phase: %d\n", (data[5] & 0x8) >> 3);
}

static void print_capabilities(const uint8_t type, uint8_t len, const uint8_t *data)
{
	int i, base, bit;
	bool first = true;


	for (i = 0; i < len; i++) {
		base = i * 8;

		for (bit = 0; bit < 8; bit++) {
			if (!(data[i] & (1 << bit)))
				continue;

			if (!first)
				printf(",");
			else
				first = false;

#define CAPA(bit, name)		case bit: printf(" " name); break

			switch (bit + base) {
			CAPA(0, "HT Information Exchange Supported");
			CAPA(1, "reserved (On-demand Beacon)");
			CAPA(2, "Extended Channel Switching");
			CAPA(3, "reserved (Wave Indication)");
			CAPA(4, "PSMP Capability");
			CAPA(5, "reserved (Service Interval Granularity)");
			CAPA(6, "S-PSMP Capability");
			CAPA(7, "Event");
			CAPA(8, "Diagnostics");
			CAPA(9, "Multicast Diagnostics");
			CAPA(10, "Location Tracking");
			CAPA(11, "FMS");
			CAPA(12, "Proxy ARP Service");
			CAPA(13, "Collocated Interference Reporting");
			CAPA(14, "Civic Location");
			CAPA(15, "Geospatial Location");
			CAPA(16, "TFS");
			CAPA(17, "WNM-Sleep Mode");
			CAPA(18, "TIM Broadcast");
			CAPA(19, "BSS Transition");
			CAPA(20, "QoS Traffic Capability");
			CAPA(21, "AC Station Count");
			CAPA(22, "Multiple BSSID");
			CAPA(23, "Timing Measurement");
			CAPA(24, "Channel Usage");
			CAPA(25, "SSID List");
			CAPA(26, "DMS");
			CAPA(27, "UTC TSF Offset");
			CAPA(28, "TDLS Peer U-APSD Buffer STA Support");
			CAPA(29, "TDLS Peer PSM Support");
			CAPA(30, "TDLS channel switching");
			CAPA(31, "Interworking");
			CAPA(32, "QoS Map");
			CAPA(33, "EBR");
			CAPA(34, "SSPN Interface");
			CAPA(35, "Reserved");
			CAPA(36, "MSGCF Capability");
			CAPA(37, "TDLS Support");
			CAPA(38, "TDLS Prohibited");
			CAPA(39, "TDLS Channel Switching Prohibited");
			CAPA(40, "Reject Unadmitted Frame");
			CAPA(44, "Identifier Location");
			CAPA(45, "U-APSD Coexistence");
			CAPA(46, "WNM-Notification");
			CAPA(47, "Reserved");
			CAPA(48, "UTF-8 SSID");
			default:
				printf(" %d", bit);
				break;
			}
#undef CAPA
		}
	}

	printf("\n");
}

static void print_tim(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf(" DTIM Count %u DTIM Period %u Bitmap Control 0x%x "
	       "Bitmap[0] 0x%x",
	       data[0], data[1], data[2], data[3]);
	if (len - 4)
		printf(" (+ %u octet%s)", len - 4, len - 4 == 1 ? "" : "s");
	printf("\n");
}

static void print_vht_capa(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf("\n");
	print_vht_info(data[0] | (data[1] << 8) |
		       (data[2] << 16) | (data[3] << 24),
		       data + 4);
}

static void print_vht_oper(const uint8_t type, uint8_t len, const uint8_t *data)
{
	const char *chandwidths[] = {
		[0] = "20 or 40 MHz",
		[1] = "80 MHz",
		[3] = "80+80 MHz",
		[2] = "160 MHz",
	};

	printf("\n");
	printf("\t\t * channel width: %d (%s)\n", data[0],
		data[0] < ARRAY_SIZE(chandwidths) ? chandwidths[data[0]] : "unknown");
	printf("\t\t * center freq segment 1: %d\n", data[1]);
	printf("\t\t * center freq segment 2: %d\n", data[2]);
	printf("\t\t * VHT basic MCS set: 0x%.2x%.2x\n", data[4], data[3]);
}

static void print_obss_scan_params(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf("\n");
	printf("\t\t * passive dwell: %d TUs\n", (data[1] << 8) | data[0]);
	printf("\t\t * active dwell: %d TUs\n", (data[3] << 8) | data[2]);
	printf("\t\t * channel width trigger scan interval: %d s\n", (data[5] << 8) | data[4]);
	printf("\t\t * scan passive total per channel: %d TUs\n", (data[7] << 8) | data[6]);
	printf("\t\t * scan active total per channel: %d TUs\n", (data[9] << 8) | data[8]);
	printf("\t\t * BSS width channel transition delay factor: %d\n", (data[11] << 8) | data[10]);
	printf("\t\t * OBSS Scan Activity Threshold: %d.%02d %%\n",
		((data[13] << 8) | data[12]) / 100, ((data[13] << 8) | data[12]) % 100);
}

static void print_secchan_offs(const uint8_t type, uint8_t len, const uint8_t *data)
{
	if (data[0] < ARRAY_SIZE(ht_secondary_offset))
		printf(" %s (%d)\n", ht_secondary_offset[data[0]], data[0]);
	else
		printf(" %d\n", data[0]);
}

static void print_bss_load(const uint8_t type, uint8_t len, const uint8_t *data)
{
	printf("\n");
	printf("\t\t * station count: %d\n", (data[1] << 8) | data[0]);
	printf("\t\t * channel utilisation: %d/255\n", data[2]);
	printf("\t\t * available admission capacity: %d [*32us]\n", (data[4] << 8) | data[3]);
}

struct ie_print {
	const char *name;
	void (*print)(const uint8_t type, uint8_t len, const uint8_t *data);
	uint8_t minlen, maxlen;
	uint8_t flags;
};

static void print_ie(const struct ie_print *p, const uint8_t type,
		     uint8_t len, const uint8_t *data)
{
	int i;

	if (!p->print)
		return;

	printf("\t%s:", p->name);
	if (len < p->minlen || len > p->maxlen) {
		if (len > 1) {
			printf(" <invalid: %d bytes:", len);
			for (i = 0; i < len; i++)
				printf(" %.02x", data[i]);
			printf(">\n");
		} else if (len)
			printf(" <invalid: 1 byte: %.02x>\n", data[0]);
		else
			printf(" <invalid: no data>\n");
		return;
	}

	p->print(type, len, data);
}

#define PRINT_IGN {		\
	.name = "IGNORE",	\
	.print = NULL,		\
	.minlen = 0,		\
	.maxlen = 255,		\
}

static const struct ie_print ieprinters[] = {
	[0] = { "SSID", print_ssid, 0, 32, BIT(PRINT_SCAN) | BIT(PRINT_LINK), },
	[1] = { "Supported rates", print_supprates, 0, 255, BIT(PRINT_SCAN), },
	[3] = { "DS Parameter set", print_ds, 1, 1, BIT(PRINT_SCAN), },
	[5] = { "TIM", print_tim, 4, 255, BIT(PRINT_SCAN), },
	[7] = { "Country", print_country, 3, 255, BIT(PRINT_SCAN), },
	[11] = { "BSS Load", print_bss_load, 5, 5, BIT(PRINT_SCAN), },
	[32] = { "Power constraint", print_powerconstraint, 1, 1, BIT(PRINT_SCAN), },
	[42] = { "ERP", print_erp, 1, 255, BIT(PRINT_SCAN), },
	[45] = { "HT capabilities", print_ht_capa, 26, 26, BIT(PRINT_SCAN), },
	[74] = { "Overlapping BSS scan params", print_obss_scan_params, 14, 255, BIT(PRINT_SCAN), },
	[61] = { "HT operation", print_ht_op, 22, 22, BIT(PRINT_SCAN), },
	[62] = { "Secondary Channel Offset", print_secchan_offs, 1, 1, BIT(PRINT_SCAN), },
	[191] = { "VHT capabilities", print_vht_capa, 12, 255, BIT(PRINT_SCAN), },
	[192] = { "VHT operation", print_vht_oper, 5, 255, BIT(PRINT_SCAN), },
	[48] = { "RSN", print_rsn, 2, 255, BIT(PRINT_SCAN), },
	[50] = { "Extended supported rates", print_supprates, 0, 255, BIT(PRINT_SCAN), },
	[114] = { "MESH ID", print_ssid, 0, 32, BIT(PRINT_SCAN) | BIT(PRINT_LINK), },
	[127] = { "Extended capabilities", print_capabilities, 0, 255, BIT(PRINT_SCAN), },
};

static void print_wifi_wpa(const uint8_t type, uint8_t len, const uint8_t *data)
{
	print_rsn_ie("TKIP", "IEEE 802.1X", len, data);
}

static bool print_wifi_wmm_param(const uint8_t *data, uint8_t len)
{
	int i;
	static const char *aci_tbl[] = { "BE", "BK", "VI", "VO" };

	if (len < 19)
		goto invalid;

	if (data[0] != 1) {
		printf("Parameter: not version 1: ");
		return false;
	}

	printf("\t * Parameter version 1");

	data++;

	if (data[0] & 0x80)
		printf("\n\t\t * u-APSD");

	data += 2;

	for (i = 0; i < 4; i++) {
		printf("\n\t\t * %s:", aci_tbl[(data[0] >> 5) & 3]);
		if (data[0] & 0x10)
			printf(" acm");
		printf(" CW %d-%d", (1 << (data[1] & 0xf)) - 1,
				    (1 << (data[1] >> 4)) - 1);
		printf(", AIFSN %d", data[0] & 0xf);
		if (data[2] | data[3])
			printf(", TXOP %d usec", (data[2] + (data[3] << 8)) * 32);
		data += 4;
	}

	printf("\n");
	return true;

 invalid:
 	printf("invalid: ");
 	return false;
}

static void print_wifi_wmm(const uint8_t type, uint8_t len, const uint8_t *data)
{
	int i;

	switch (data[0]) {
	case 0x00:
		printf(" information:");
		break;
	case 0x01:
		if (print_wifi_wmm_param(data + 1, len - 1))
			return;
		break;
	default:
		printf(" type %d:", data[0]);
		break;
	}

	for(i = 1; i < len; i++)
		printf(" %.02x", data[i]);
	printf("\n");
}

static const char * wifi_wps_dev_passwd_id(uint16_t id)
{
	switch (id) {
	case 0:
		return "Default (PIN)";
	case 1:
		return "User-specified";
	case 2:
		return "Machine-specified";
	case 3:
		return "Rekey";
	case 4:
		return "PushButton";
	case 5:
		return "Registrar-specified";
	default:
		return "??";
	}
}

static void print_wifi_wps(const uint8_t type, uint8_t len, const uint8_t *data)
{
	bool first = true;
	__u16 subtype, sublen;

	while (len >= 4) {
		subtype = (data[0] << 8) + data[1];
		sublen = (data[2] << 8) + data[3];
		if (sublen > len)
			break;

		switch (subtype) {
		case 0x104a:
			tab_on_first(&first);
			printf("\t * Version: %d.%d\n", data[4] >> 4, data[4] & 0xF);
			break;
		case 0x1011:
			tab_on_first(&first);
			printf("\t * Device name: %.*s\n", sublen, data + 4);
			break;
		case 0x1012: {
			uint16_t id;
			tab_on_first(&first);
			if (sublen != 2) {
				printf("\t * Device Password ID: (invalid "
				       "length %d)\n", sublen);
				break;
			}
			id = data[4] << 8 | data[5];
			printf("\t * Device Password ID: %u (%s)\n",
			       id, wifi_wps_dev_passwd_id(id));
			break;
		}
		case 0x1021:
			tab_on_first(&first);
			printf("\t * Manufacturer: %.*s\n", sublen, data + 4);
			break;
		case 0x1023:
			tab_on_first(&first);
			printf("\t * Model: %.*s\n", sublen, data + 4);
			break;
		case 0x1024:
			tab_on_first(&first);
			printf("\t * Model Number: %.*s\n", sublen, data + 4);
			break;
		case 0x103b: {
			__u8 val = data[4];
			tab_on_first(&first);
			printf("\t * Response Type: %d%s\n",
			       val, val == 3 ? " (AP)" : "");
			break;
		}
		case 0x103c: {
			__u8 val = data[4];
			tab_on_first(&first);
			printf("\t * RF Bands: 0x%x\n", val);
			break;
		}
		case 0x1041: {
			__u8 val = data[4];
			tab_on_first(&first);
			printf("\t * Selected Registrar: 0x%x\n", val);
			break;
		}
		case 0x1042:
			tab_on_first(&first);
			printf("\t * Serial Number: %.*s\n", sublen, data + 4);
			break;
		case 0x1044: {
			__u8 val = data[4];
			tab_on_first(&first);
			printf("\t * Wi-Fi Protected Setup State: %d%s%s\n",
			       val,
			       val == 1 ? " (Unconfigured)" : "",
			       val == 2 ? " (Configured)" : "");
			break;
		}
		case 0x1047:
			tab_on_first(&first);
			printf("\t * UUID: ");
			if (sublen != 16) {
				printf("(invalid, length=%d)\n", sublen);
				break;
			}
			printf("%02x%02x%02x%02x-%02x%02x-%02x%02x-"
				"%02x%02x-%02x%02x%02x%02x%02x%02x\n",
				data[4], data[5], data[6], data[7],
				data[8], data[9], data[10], data[11],
				data[12], data[13], data[14], data[15],
				data[16], data[17], data[18], data[19]);
			break;
		case 0x1054: {
			tab_on_first(&first);
			if (sublen != 8) {
				printf("\t * Primary Device Type: (invalid "
				       "length %d)\n", sublen);
				break;
			}
			printf("\t * Primary Device Type: "
			       "%u-%02x%02x%02x%02x-%u\n",
			       data[4] << 8 | data[5],
			       data[6], data[7], data[8], data[9],
			       data[10] << 8 | data[11]);
			break;
		}
		case 0x1057: {
			__u8 val = data[4];
			tab_on_first(&first);
			printf("\t * AP setup locked: 0x%.2x\n", val);
			break;
		}
		case 0x1008:
		case 0x1053: {
			__u16 meth = (data[4] << 8) + data[5];
			bool comma = false;
			tab_on_first(&first);
			printf("\t * %sConfig methods:",
			       subtype == 0x1053 ? "Selected Registrar ": "");
#define T(bit, name) do {		\
	if (meth & (1<<bit)) {		\
		if (comma)		\
			printf(",");	\
		comma = true;		\
		printf(" " name);	\
	} } while (0)
			T(0, "USB");
			T(1, "Ethernet");
			T(2, "Label");
			T(3, "Display");
			T(4, "Ext. NFC");
			T(5, "Int. NFC");
			T(6, "NFC Intf.");
			T(7, "PBC");
			T(8, "Keypad");
			printf("\n");
			break;
#undef T
		}
		default: {
			const __u8 *subdata = data + 4;
			__u16 tmplen = sublen;

			tab_on_first(&first);
			printf("\t * Unknown TLV (%#.4x, %d bytes):",
			       subtype, tmplen);
			while (tmplen) {
				printf(" %.2x", *subdata);
				subdata++;
				tmplen--;
			}
			printf("\n");
			break;
		}
		}

		data += sublen + 4;
		len -= sublen + 4;
	}

	if (len != 0) {
		printf("\t\t * bogus tail data (%d):", len);
		while (len) {
			printf(" %.2x", *data);
			data++;
			len--;
		}
		printf("\n");
	}
}

static const struct ie_print wifiprinters[] = {
	[1] = { "WPA", print_wifi_wpa, 2, 255, BIT(PRINT_SCAN), },
	[2] = { "WMM", print_wifi_wmm, 1, 255, BIT(PRINT_SCAN), },
	[4] = { "WPS", print_wifi_wps, 0, 255, BIT(PRINT_SCAN), },
};

static inline void print_p2p(const uint8_t type, uint8_t len, const uint8_t *data)
{
	bool first = true;
	__u8 subtype;
	__u16 sublen;

	while (len >= 3) {
		subtype = data[0];
		sublen = (data[2] << 8) + data[1];

		if (sublen > len - 3)
			break;

		switch (subtype) {
		case 0x02: /* capability */
			tab_on_first(&first);
			if (sublen < 2) {
				printf("\t * malformed capability\n");
				break;
			}
			printf("\t * Group capa: 0x%.2x, Device capa: 0x%.2x\n",
				data[3], data[4]);
			break;
		case 0x0d: /* device info */
			if (sublen < 6 + 2 + 8 + 1) {
				printf("\t * malformed device info\n");
				break;
			}
			/* fall through for now */
		case 0x00: /* status */
		case 0x01: /* minor reason */
		case 0x03: /* device ID */
		case 0x04: /* GO intent */
		case 0x05: /* configuration timeout */
		case 0x06: /* listen channel */
		case 0x07: /* group BSSID */
		case 0x08: /* ext listen timing */
		case 0x09: /* intended interface address */
		case 0x0a: /* manageability */
		case 0x0b: /* channel list */
		case 0x0c: /* NoA */
		case 0x0e: /* group info */
		case 0x0f: /* group ID */
		case 0x10: /* interface */
		case 0x11: /* operating channel */
		case 0x12: /* invitation flags */
		case 0xdd: /* vendor specific */
		default: {
			const __u8 *subdata = data + 4;
			__u16 tmplen = sublen;

			tab_on_first(&first);
			printf("\t * Unknown TLV (%#.2x, %d bytes):",
			       subtype, tmplen);
			while (tmplen) {
				printf(" %.2x", *subdata);
				subdata++;
				tmplen--;
			}
			printf("\n");
			break;
		}
		}

		data += sublen + 3;
		len -= sublen + 3;
	}

	if (len != 0) {
		tab_on_first(&first);
		printf("\t * bogus tail data (%d):", len);
		while (len) {
			printf(" %.2x", *data);
			data++;
			len--;
		}
		printf("\n");
	}
}

static const struct ie_print wfa_printers[] = {
	[9] = { "P2P", print_p2p, 2, 255, BIT(PRINT_SCAN), },
};

static void print_vendor(unsigned char len, unsigned char *data,
			 bool unknown, enum print_ie_type ptype)
{
	int i;

	if (len < 3) {
		printf("\tVendor specific: <too short> data:");
		for(i = 0; i < len; i++)
			printf(" %.02x", data[i]);
		printf("\n");
		return;
	}

	if (len >= 4 && memcmp(data, ms_oui, 3) == 0) {
		if (data[3] < ARRAY_SIZE(wifiprinters) &&
		    wifiprinters[data[3]].name &&
		    wifiprinters[data[3]].flags & BIT(ptype)) {
			print_ie(&wifiprinters[data[3]], data[3], len - 4, data + 4);
			return;
		}
		if (!unknown)
			return;
		printf("\tMS/WiFi %#.2x, data:", data[3]);
		for(i = 0; i < len - 4; i++)
			printf(" %.02x", data[i + 4]);
		printf("\n");
		return;
	}

	if (len >= 4 && memcmp(data, wfa_oui, 3) == 0) {
		if (data[3] < ARRAY_SIZE(wfa_printers) &&
		    wfa_printers[data[3]].name &&
		    wfa_printers[data[3]].flags & BIT(ptype)) {
			print_ie(&wfa_printers[data[3]], data[3], len - 4, data + 4);
			return;
		}
		if (!unknown)
			return;
		printf("\tWFA %#.2x, data:", data[3]);
		for(i = 0; i < len - 4; i++)
			printf(" %.02x", data[i + 4]);
		printf("\n");
		return;
	}

	if (!unknown)
		return;

	printf("\tVendor specific: OUI %.2x:%.2x:%.2x, data:",
		data[0], data[1], data[2]);
	for (i = 3; i < len; i++)
		printf(" %.2x", data[i]);
	printf("\n");
}

void print_ies(unsigned char *ie, int ielen, bool unknown,
	       enum print_ie_type ptype)
{
	while (ielen >= 2 && ielen >= ie[1]) {
		if (ie[0] < ARRAY_SIZE(ieprinters) &&
		    ieprinters[ie[0]].name &&
		    ieprinters[ie[0]].flags & BIT(ptype)) {
			print_ie(&ieprinters[ie[0]], ie[0], ie[1], ie + 2);
		} else if (ie[0] == 221 /* vendor */) {
			print_vendor(ie[1], ie + 2, unknown, ptype);
		} else if (unknown) {
			int i;

			printf("\tUnknown IE (%d):", ie[0]);
			for (i=0; i<ie[1]; i++)
				printf(" %.2x", ie[2+i]);
			printf("\n");
		}
		ielen -= ie[1] + 2;
		ie += ie[1] + 2;
	}
}

static void print_capa_dmg(__u16 capa)
{
	switch (capa & WLAN_CAPABILITY_DMG_TYPE_MASK) {
	case WLAN_CAPABILITY_DMG_TYPE_AP:
		printf(" DMG_ESS");
		break;
	case WLAN_CAPABILITY_DMG_TYPE_PBSS:
		printf(" DMG_PCP");
		break;
	case WLAN_CAPABILITY_DMG_TYPE_IBSS:
		printf(" DMG_IBSS");
		break;
	}

	if (capa & WLAN_CAPABILITY_DMG_CBAP_ONLY)
		printf(" CBAP_Only");
	if (capa & WLAN_CAPABILITY_DMG_CBAP_SOURCE)
		printf(" CBAP_Src");
	if (capa & WLAN_CAPABILITY_DMG_PRIVACY)
		printf(" Privacy");
	if (capa & WLAN_CAPABILITY_DMG_ECPAC)
		printf(" ECPAC");
	if (capa & WLAN_CAPABILITY_DMG_SPECTRUM_MGMT)
		printf(" SpectrumMgmt");
	if (capa & WLAN_CAPABILITY_DMG_RADIO_MEASURE)
		printf(" RadioMeasure");
}

static void print_capa_non_dmg(__u16 capa)
{
	if (capa & WLAN_CAPABILITY_ESS)
		printf(" ESS");
	if (capa & WLAN_CAPABILITY_IBSS)
		printf(" IBSS");
	if (capa & WLAN_CAPABILITY_CF_POLLABLE)
		printf(" CfPollable");
	if (capa & WLAN_CAPABILITY_CF_POLL_REQUEST)
		printf(" CfPollReq");
	if (capa & WLAN_CAPABILITY_PRIVACY)
		printf(" Privacy");
	if (capa & WLAN_CAPABILITY_SHORT_PREAMBLE)
		printf(" ShortPreamble");
	if (capa & WLAN_CAPABILITY_PBCC)
		printf(" PBCC");
	if (capa & WLAN_CAPABILITY_CHANNEL_AGILITY)
		printf(" ChannelAgility");
	if (capa & WLAN_CAPABILITY_SPECTRUM_MGMT)
		printf(" SpectrumMgmt");
	if (capa & WLAN_CAPABILITY_QOS)
		printf(" QoS");
	if (capa & WLAN_CAPABILITY_SHORT_SLOT_TIME)
		printf(" ShortSlotTime");
	if (capa & WLAN_CAPABILITY_APSD)
		printf(" APSD");
	if (capa & WLAN_CAPABILITY_RADIO_MEASURE)
		printf(" RadioMeasure");
	if (capa & WLAN_CAPABILITY_DSSS_OFDM)
		printf(" DSSS-OFDM");
	if (capa & WLAN_CAPABILITY_DEL_BACK)
		printf(" DelayedBACK");
	if (capa & WLAN_CAPABILITY_IMM_BACK)
		printf(" ImmediateBACK");
}

static int print_bss_handler(struct nl_msg *msg, void *arg)
{
	struct nlattr *tb[NL80211_ATTR_MAX + 1];
	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
	struct nlattr *bss[NL80211_BSS_MAX + 1];
	char mac_addr[20], dev[20];
	static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
		[NL80211_BSS_TSF] = { .type = NLA_U64 },
		[NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
		[NL80211_BSS_BSSID] = { },
		[NL80211_BSS_BEACON_INTERVAL] = { .type = NLA_U16 },
		[NL80211_BSS_CAPABILITY] = { .type = NLA_U16 },
		[NL80211_BSS_INFORMATION_ELEMENTS] = { },
		[NL80211_BSS_SIGNAL_MBM] = { .type = NLA_U32 },
		[NL80211_BSS_SIGNAL_UNSPEC] = { .type = NLA_U8 },
		[NL80211_BSS_STATUS] = { .type = NLA_U32 },
		[NL80211_BSS_SEEN_MS_AGO] = { .type = NLA_U32 },
		[NL80211_BSS_BEACON_IES] = { },
	};
	struct scan_params *params = arg;
	int show = params->show_both_ie_sets ? 2 : 1;
	bool is_dmg = false;

	nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
		  genlmsg_attrlen(gnlh, 0), NULL);

	if (!tb[NL80211_ATTR_BSS]) {
		fprintf(stderr, "bss info missing!\n");
		return NL_SKIP;
	}
	if (nla_parse_nested(bss, NL80211_BSS_MAX,
			     tb[NL80211_ATTR_BSS],
			     bss_policy)) {
		fprintf(stderr, "failed to parse nested attributes!\n");
		return NL_SKIP;
	}

	if (!bss[NL80211_BSS_BSSID])
		return NL_SKIP;

	mac_addr_n2a(mac_addr, nla_data(bss[NL80211_BSS_BSSID]));
	printf("BSS %s", mac_addr);
	if (tb[NL80211_ATTR_IFINDEX]) {
		if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), dev);
		printf("(on %s)", dev);
	}

	if (bss[NL80211_BSS_STATUS]) {
		switch (nla_get_u32(bss[NL80211_BSS_STATUS])) {
		case NL80211_BSS_STATUS_AUTHENTICATED:
			printf(" -- authenticated");
			break;
		case NL80211_BSS_STATUS_ASSOCIATED:
			printf(" -- associated");
			break;
		case NL80211_BSS_STATUS_IBSS_JOINED:
			printf(" -- joined");
			break;
		default:
			printf(" -- unknown status: %d",
				nla_get_u32(bss[NL80211_BSS_STATUS]));
			break;
		}
	}
	printf("\n");

	if (bss[NL80211_BSS_TSF]) {
		unsigned long long tsf;
		tsf = (unsigned long long)nla_get_u64(bss[NL80211_BSS_TSF]);
		printf("\tTSF: %llu usec (%llud, %.2lld:%.2llu:%.2llu)\n",
			tsf, tsf/1000/1000/60/60/24, (tsf/1000/1000/60/60) % 24,
			(tsf/1000/1000/60) % 60, (tsf/1000/1000) % 60);
	}
	if (bss[NL80211_BSS_FREQUENCY]) {
		int freq = nla_get_u32(bss[NL80211_BSS_FREQUENCY]);
		printf("\tfreq: %d\n", freq);
		if (freq > 45000)
			is_dmg = true;
	}
	if (bss[NL80211_BSS_BEACON_INTERVAL])
		printf("\tbeacon interval: %d\n",
			nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]));
	if (bss[NL80211_BSS_CAPABILITY]) {
		__u16 capa = nla_get_u16(bss[NL80211_BSS_CAPABILITY]);
		printf("\tcapability:");
		if (is_dmg)
			print_capa_dmg(capa);
		else
			print_capa_non_dmg(capa);
		printf(" (0x%.4x)\n", capa);
	}
	if (bss[NL80211_BSS_SIGNAL_MBM]) {
		int s = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
		printf("\tsignal: %d.%.2d dBm\n", s/100, s%100);
	}
	if (bss[NL80211_BSS_SIGNAL_UNSPEC]) {
		unsigned char s = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
		printf("\tsignal: %d/100\n", s);
	}
	if (bss[NL80211_BSS_SEEN_MS_AGO]) {
		int age = nla_get_u32(bss[NL80211_BSS_SEEN_MS_AGO]);
		printf("\tlast seen: %d ms ago\n", age);
	}

	if (bss[NL80211_BSS_INFORMATION_ELEMENTS] && show--) {
		if (bss[NL80211_BSS_BEACON_IES])
			printf("\tInformation elements from Probe Response "
			       "frame:\n");
		print_ies(nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
			  nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
			  params->unknown, params->type);
	}
	if (bss[NL80211_BSS_BEACON_IES] && show--) {
		printf("\tInformation elements from Beacon frame:\n");
		print_ies(nla_data(bss[NL80211_BSS_BEACON_IES]),
			  nla_len(bss[NL80211_BSS_BEACON_IES]),
			  params->unknown, params->type);
	}

	return NL_SKIP;
}

static struct scan_params scan_params;

static int handle_scan_dump(struct nl80211_state *state,
			    struct nl_cb *cb,
			    struct nl_msg *msg,
			    int argc, char **argv,
			    enum id_input id)
{
	if (argc > 1)
		return 1;

	memset(&scan_params, 0, sizeof(scan_params));

	if (argc == 1 && !strcmp(argv[0], "-u"))
		scan_params.unknown = true;
	else if (argc == 1 && !strcmp(argv[0], "-b"))
		scan_params.show_both_ie_sets = true;

	scan_params.type = PRINT_SCAN;

	nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_bss_handler,
		  &scan_params);
	return 0;
}

static int handle_scan_combined(struct nl80211_state *state,
				struct nl_cb *cb,
				struct nl_msg *msg,
				int argc, char **argv,
				enum id_input id)
{
	char **trig_argv;
	static char *dump_argv[] = {
		NULL,
		"scan",
		"dump",
		NULL,
	};
	static const __u32 cmds[] = {
		NL80211_CMD_NEW_SCAN_RESULTS,
		NL80211_CMD_SCAN_ABORTED,
	};
	int trig_argc, dump_argc, err;

	if (argc >= 3 && !strcmp(argv[2], "-u")) {
		dump_argc = 4;
		dump_argv[3] = "-u";
	} else if (argc >= 3 && !strcmp(argv[2], "-b")) {
		dump_argc = 4;
		dump_argv[3] = "-b";
	} else
		dump_argc = 3;

	trig_argc = 3 + (argc - 2) + (3 - dump_argc);
	trig_argv = calloc(trig_argc, sizeof(*trig_argv));
	if (!trig_argv)
		return -ENOMEM;
	trig_argv[0] = argv[0];
	trig_argv[1] = "scan";
	trig_argv[2] = "trigger";
	int i;
	for (i = 0; i < argc - 2 - (dump_argc - 3); i++)
		trig_argv[i + 3] = argv[i + 2 + (dump_argc - 3)];
	err = handle_cmd(state, id, trig_argc, trig_argv);
	free(trig_argv);
	if (err)
		return err;

	/*
	 * WARNING: DO NOT COPY THIS CODE INTO YOUR APPLICATION
	 *
	 * This code has a bug, which requires creating a separate
	 * nl80211 socket to fix:
	 * It is possible for a NL80211_CMD_NEW_SCAN_RESULTS or
	 * NL80211_CMD_SCAN_ABORTED message to be sent by the kernel
	 * before (!) we listen to it, because we only start listening
	 * after we send our scan request.
	 *
	 * Doing it the other way around has a race condition as well,
	 * if you first open the events socket you may get a notification
	 * for a previous scan.
	 *
	 * The only proper way to fix this would be to listen to events
	 * before sending the command, and for the kernel to send the
	 * scan request along with the event, so that you can match up
	 * whether the scan you requested was finished or aborted (this
	 * may result in processing a scan that another application
	 * requested, but that doesn't seem to be a problem).
	 *
	 * Alas, the kernel doesn't do that (yet).
	 */

	if (listen_events(state, ARRAY_SIZE(cmds), cmds) ==
					NL80211_CMD_SCAN_ABORTED) {
		printf("scan aborted!\n");
		return 0;
	}

	dump_argv[0] = argv[0];
	return handle_cmd(state, id, dump_argc, dump_argv);
}
TOPLEVEL(scan, "[-u] [freq <freq>*] [ies <hex as 00:11:..>] [lowpri,flush,ap-force] [ssid <ssid>*|passive]", 0, 0,
	 CIB_NETDEV, handle_scan_combined,
	 "Scan on the given frequencies and probe for the given SSIDs\n"
	 "(or wildcard if not given) unless passive scanning is requested.\n"
	 "If -u is specified print unknown data in the scan results.\n"
	 "Specified (vendor) IEs must be well-formed.");
COMMAND(scan, dump, "[-u]",
	NL80211_CMD_GET_SCAN, NLM_F_DUMP, CIB_NETDEV, handle_scan_dump,
	"Dump the current scan results. If -u is specified, print unknown\n"
	"data in scan results.");
COMMAND(scan, trigger, "[freq <freq>*] [ies <hex as 00:11:..>] [lowpri,flush,ap-force] [ssid <ssid>*|passive]",
	NL80211_CMD_TRIGGER_SCAN, 0, CIB_NETDEV, handle_scan,
	 "Trigger a scan on the given frequencies with probing for the given\n"
	 "SSIDs (or wildcard if not given) unless passive scanning is requested.");