[thirdparty/iw.git] / 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"

struct scan_params {
	bool unknown;
};

static int handle_scan(struct nl80211_state *state,
		       struct nl_cb *cb,
		       struct nl_msg *msg,
		       int argc, char **argv)
{
	struct nl_msg *ssids = NULL;
	int err = -ENOBUFS;

	ssids = nlmsg_alloc();
	if (!ssids)
		return -ENOMEM;
	NLA_PUT(ssids, 1, 0, "");
	nla_put_nested(msg, NL80211_ATTR_SCAN_SSIDS, ssids);

	err = 0;
 nla_put_failure:
	nlmsg_free(ssids);
	return err;
}
COMMAND(scan, trigger, NULL,
	NL80211_CMD_TRIGGER_SCAN, 0, CIB_NETDEV, handle_scan);

typedef void (*printfn)(unsigned char type, unsigned char len, unsigned char *data);

static void print_ssid(unsigned char type, unsigned char len, unsigned char *data)
{
	int i;
	printf("\tSSID: ");
	for (i=0; i<len; i++) {
		if (isprint(data[i]))
			printf("%c", data[i]);
		else
			printf("\\x%.2x", data[i]);
	}
	printf("\n");
}

static void print_supprates(unsigned char type, unsigned char len, unsigned char *data)
{
	int i;

	if (type == 1)
		printf("\tSupported rates: ");
	else
		printf("\tExtended supported rates: ");

	for (i=0; i<len; i++) {
		int r = data[i] & 0x7f;
		printf("%d.%d%s ", r/2, 5*(r&1), data[i] & 0x80 ? "*":"");
	}
	printf("\n");
}

static void print_ds(unsigned char type, unsigned char len, unsigned char *data)
{
	printf("\tDS Parameter set: channel %d\n", data[0]);
}

static void print_ign(unsigned char type, unsigned char len, unsigned char *data)
{
	/* ignore for now, not too useful */
}

static const printfn ieprinters[] = {
	[0] = print_ssid,
	[1] = print_supprates,
	[3] = print_ds,
	[5] = print_ign,
	[50] = print_supprates,
};

static void print_vendor(unsigned char len, unsigned char *data,
			 struct scan_params *params)
{
	int i;

	/* currently _all_ vendor IEs are unknown (not parsed) */
	if (!params->unknown)
		return;

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

static void print_ies(unsigned char *ie, int ielen, struct scan_params *params)
{
	while (ielen >= 2 && ielen >= ie[1]) {
		if (ie[0] < ARRAY_SIZE(ieprinters) && ieprinters[ie[0]]) {
			ieprinters[ie[0]](ie[0], ie[1], ie + 2);
		} else if (ie[0] == 221 /* vendor */) {
			print_vendor(ie[1], ie + 2, params);
		} else if (params->unknown) {
			int i;

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

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 },
	};

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

	if (!bss[NL80211_BSS_BSSID])
		return NL_SKIP;

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

	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])
		printf("\tfreq: %d\n",
			nla_get_u32(bss[NL80211_BSS_FREQUENCY]));
	if (bss[NL80211_BSS_BEACON_INTERVAL])
		printf("\tbeacon interval: %d\n",
			nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]));
	if (bss[NL80211_BSS_CAPABILITY])
		printf("\tcapability: 0x%.4x\n",
			nla_get_u16(bss[NL80211_BSS_CAPABILITY]));
	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_INFORMATION_ELEMENTS])
		print_ies(nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
			  nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
			  arg);

	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)
{
	if (argc > 1)
		return 1;

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

	nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_bss_handler,
		  &scan_params);
	return 0;
}
COMMAND(scan, dump, "[-u]",
	NL80211_CMD_GET_SCAN, NLM_F_DUMP, CIB_NETDEV, handle_scan_dump);

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

	trig_argv[0] = argv[0];
	err = handle_cmd(state, II_NETDEV, ARRAY_SIZE(trig_argv), 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, II_NETDEV, ARRAY_SIZE(dump_argv), dump_argv);
}
TOPLEVEL(scan, NULL, 0, 0, CIB_NETDEV, handle_scan_combined);
Commit	Line	Data
3563f4c5 JB	1	#include <net/if.h>
	2	#include <errno.h>
	3	#include <string.h>
	4	#include <ctype.h>
764fe753	5	#include <stdbool.h>
3563f4c5 JB	6
	7	#include <netlink/genl/genl.h>
	8	#include <netlink/genl/family.h>
	9	#include <netlink/genl/ctrl.h>
	10	#include <netlink/msg.h>
	11	#include <netlink/attr.h>
	12
	13	#include "nl80211.h"
	14	#include "iw.h"
	15
764fe753 JB	16	struct scan_params {
	17	bool unknown;
	18	};
	19
7c37a24d JB	20	static int handle_scan(struct nl80211_state *state,
7c37a24d JB	21	struct nl_cb *cb,
3563f4c5 JB	22	struct nl_msg *msg,
	23	int argc, char **argv)
	24	{
	25	struct nl_msg *ssids = NULL;
	26	int err = -ENOBUFS;
	27
	28	ssids = nlmsg_alloc();
	29	if (!ssids)
	30	return -ENOMEM;
	31	NLA_PUT(ssids, 1, 0, "");
	32	nla_put_nested(msg, NL80211_ATTR_SCAN_SSIDS, ssids);
	33
	34	err = 0;
	35	nla_put_failure:
	36	nlmsg_free(ssids);
	37	return err;
	38	}
	39	COMMAND(scan, trigger, NULL,
	40	NL80211_CMD_TRIGGER_SCAN, 0, CIB_NETDEV, handle_scan);
	41
	42	typedef void (printfn)(unsigned char type, unsigned char len, unsigned char data);
	43
	44	static void print_ssid(unsigned char type, unsigned char len, unsigned char *data)
	45	{
	46	int i;
	47	printf("\tSSID: ");
	48	for (i=0; i<len; i++) {
	49	if (isprint(data[i]))
	50	printf("%c", data[i]);
	51	else
	52	printf("\\x%.2x", data[i]);
	53	}
	54	printf("\n");
	55	}
	56
	57	static void print_supprates(unsigned char type, unsigned char len, unsigned char *data)
	58	{
	59	int i;
	60
	61	if (type == 1)
	62	printf("\tSupported rates: ");
	63	else
	64	printf("\tExtended supported rates: ");
	65
	66	for (i=0; i<len; i++) {
	67	int r = data[i] & 0x7f;
	68	printf("%d.%d%s ", r/2, 5(r&1), data[i] & 0x80 ? "":"");
	69	}
	70	printf("\n");
	71	}
	72
	73	static void print_ds(unsigned char type, unsigned char len, unsigned char *data)
	74	{
	75	printf("\tDS Parameter set: channel %d\n", data[0]);
	76	}
	77
	78	static void print_ign(unsigned char type, unsigned char len, unsigned char *data)
	79	{
	80	/* ignore for now, not too useful */
	81	}
	82
764fe753 JB	83	static const printfn ieprinters[] = {
	84	[0] = print_ssid,
	85	[1] = print_supprates,
	86	[3] = print_ds,
	87	[5] = print_ign,
	88	[50] = print_supprates,
	89	};
	90
	91	static void print_vendor(unsigned char len, unsigned char *data,
	92	struct scan_params *params)
3563f4c5 JB	93	{
	94	int i;
	95
764fe753 JB	96	/* currently _all_ vendor IEs are unknown (not parsed) */
	97	if (!params->unknown)
	98	return;
	99
3563f4c5 JB	100	printf("\tVendor specific: OUI %.2x:%.2x:%.2x, data: ",
	101	data[0], data[1], data[2]);
	102	for (i=3; i<len; i++)
	103	printf("\\x%.2x", data[i]);
	104	printf("\n");
	105	}
	106
764fe753	107	static void print_ies(unsigned char ie, int ielen, struct scan_params params)
3563f4c5 JB	108	{
3563f4c5 JB	109	while (ielen >= 2 && ielen >= ie[1]) {
97ebbaf5	110	if (ie[0] < ARRAY_SIZE(ieprinters) && ieprinters[ie[0]]) {
3563f4c5	111	ieprinters[ie[0]](ie[0], ie[1], ie + 2);
764fe753 JB	112	} else if (ie[0] == 221 /* vendor */) {
	113	print_vendor(ie[1], ie + 2, params);
	114	} else if (params->unknown) {
3563f4c5 JB	115	int i;
	116
	117	printf("\tUnknown IE (%d): ", ie[0]);
	118	for (i=0; i<ie[1]; i++)
	119	printf("\\x%.2x", ie[2+i]);
	120	printf("\n");
	121	}
	122	ielen -= ie[1] + 2;
	123	ie += ie[1] + 2;
	124	}
	125	}
	126
	127	static int print_bss_handler(struct nl_msg msg, void arg)
	128	{
	129	struct nlattr *tb[NL80211_ATTR_MAX + 1];
	130	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
	131	struct nlattr *bss[NL80211_BSS_MAX + 1];
	132	char mac_addr[20], dev[20];
	133	static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
	134	[NL80211_BSS_TSF] = { .type = NLA_U64 },
	135	[NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
	136	[NL80211_BSS_BSSID] = { },
	137	[NL80211_BSS_BEACON_INTERVAL] = { .type = NLA_U16 },
	138	[NL80211_BSS_CAPABILITY] = { .type = NLA_U16 },
	139	[NL80211_BSS_INFORMATION_ELEMENTS] = { },
f2e17e1f JB	140	[NL80211_BSS_SIGNAL_MBM] = { .type = NLA_U32 },
f2e17e1f JB	141	[NL80211_BSS_SIGNAL_UNSPEC] = { .type = NLA_U8 },
3563f4c5 JB	142	};
	143
	144	nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
	145	genlmsg_attrlen(gnlh, 0), NULL);
	146
	147	if (!tb[NL80211_ATTR_BSS]) {
	148	fprintf(stderr, "bss info missing!");
	149	return NL_SKIP;
	150	}
	151	if (nla_parse_nested(bss, NL80211_BSS_MAX,
	152	tb[NL80211_ATTR_BSS],
	153	bss_policy)) {
	154	fprintf(stderr, "failed to parse nested attributes!");
	155	return NL_SKIP;
	156	}
	157
	158	if (!bss[NL80211_BSS_BSSID])
	159	return NL_SKIP;
	160
	161	mac_addr_n2a(mac_addr, nla_data(bss[NL80211_BSS_BSSID]));
	162	if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), dev);
	163	printf("BSS %s (on %s)\n", mac_addr, dev);
	164
e7109a8a JB	165	if (bss[NL80211_BSS_TSF]) {
	166	unsigned long long tsf;
	167	tsf = (unsigned long long)nla_get_u64(bss[NL80211_BSS_TSF]);
	168	printf("\tTSF: %llu usec (%llud, %.2lld:%.2llu:%.2llu)\n",
	169	tsf, tsf/1000/1000/60/60/24, (tsf/1000/1000/60/60) % 24,
	170	(tsf/1000/1000/60) % 60, (tsf/1000/1000) % 60);
	171	}
3563f4c5 JB	172	if (bss[NL80211_BSS_FREQUENCY])
	173	printf("\tfreq: %d\n",
	174	nla_get_u32(bss[NL80211_BSS_FREQUENCY]));
	175	if (bss[NL80211_BSS_BEACON_INTERVAL])
	176	printf("\tbeacon interval: %d\n",
	177	nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]));
	178	if (bss[NL80211_BSS_CAPABILITY])
	179	printf("\tcapability: 0x%.4x\n",
	180	nla_get_u16(bss[NL80211_BSS_CAPABILITY]));
f2e17e1f JB	181	if (bss[NL80211_BSS_SIGNAL_MBM]) {
	182	int s = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
	183	printf("\tsignal: %d.%.2d dBm\n", s/100, s%100);
	184	}
	185	if (bss[NL80211_BSS_SIGNAL_UNSPEC]) {
	186	unsigned char s = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
	187	printf("\tsignal: %d/100\n", s);
	188	}
3563f4c5 JB	189	if (bss[NL80211_BSS_INFORMATION_ELEMENTS])
3563f4c5 JB	190	print_ies(nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
764fe753 JB	191	nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
764fe753 JB	192	arg);
3563f4c5 JB	193
	194	return NL_SKIP;
	195	}
	196
764fe753	197	static struct scan_params scan_params;
3563f4c5	198
7c37a24d JB	199	static int handle_scan_dump(struct nl80211_state *state,
7c37a24d JB	200	struct nl_cb *cb,
3563f4c5 JB	201	struct nl_msg *msg,
	202	int argc, char **argv)
	203	{
764fe753 JB	204	if (argc > 1)
	205	return 1;
	206
	207	scan_params.unknown = false;
	208	if (argc == 1 && !strcmp(argv[0], "-u"))
	209	scan_params.unknown = true;
	210
	211	nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_bss_handler,
	212	&scan_params);
3563f4c5 JB	213	return 0;
3563f4c5 JB	214	}
764fe753	215	COMMAND(scan, dump, "[-u]",
3563f4c5	216	NL80211_CMD_GET_SCAN, NLM_F_DUMP, CIB_NETDEV, handle_scan_dump);
a5fe4ef2 JB	217
	218	static int handle_scan_combined(struct nl80211_state *state,
	219	struct nl_cb *cb,
	220	struct nl_msg *msg,
	221	int argc, char **argv)
	222	{
	223	static char *trig_argv[] = {
	224	NULL,
	225	"scan",
	226	"trigger",
	227	};
	228	static char *dump_argv[] = {
	229	NULL,
	230	"scan",
	231	"dump",
	232	};
	233	static const __u32 cmds[] = {
	234	NL80211_CMD_NEW_SCAN_RESULTS,
	235	NL80211_CMD_SCAN_ABORTED,
	236	};
	237	int err;
	238
	239	trig_argv[0] = argv[0];
	240	err = handle_cmd(state, II_NETDEV, ARRAY_SIZE(trig_argv), trig_argv);
	241	if (err)
	242	return err;
	243
61725dbe JB	244	/*
	245	* WARNING: DO NOT COPY THIS CODE INTO YOUR APPLICATION
	246	*
	247	* This code has a bug, which requires creating a separate
	248	* nl80211 socket to fix:
	249	* It is possible for a NL80211_CMD_NEW_SCAN_RESULTS or
	250	* NL80211_CMD_SCAN_ABORTED message to be sent by the kernel
	251	* before (!) we listen to it, because we only start listening
	252	* after we send our scan request.
	253	*
	254	* Doing it the other way around has a race condition as well,
	255	* if you first open the events socket you may get a notification
	256	* for a previous scan.
	257	*
	258	* The only proper way to fix this would be to listen to events
	259	* before sending the command, and for the kernel to send the
	260	* scan request along with the event, so that you can match up
	261	* whether the scan you requested was finished or aborted (this
	262	* may result in processing a scan that another application
	263	* requested, but that doesn't seem to be a problem).
	264	*
	265	* Alas, the kernel doesn't do that (yet).
	266	*/
	267
a5fe4ef2 JB	268	if (listen_events(state, ARRAY_SIZE(cmds), cmds) ==
	269	NL80211_CMD_SCAN_ABORTED) {
	270	printf("scan aborted!\n");
	271	return 0;
	272	}
	273
	274	dump_argv[0] = argv[0];
	275	return handle_cmd(state, II_NETDEV, ARRAY_SIZE(dump_argv), dump_argv);
	276	}
	277	TOPLEVEL(scan, NULL, 0, 0, CIB_NETDEV, handle_scan_combined);