iwinfo/iwinfo_nl80211.c

/*
 * iwinfo - Wireless Information Library - NL80211 Backend
 *
 *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
 *
 * The iwinfo library is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * The iwinfo library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with the iwinfo library. If not, see http://www.gnu.org/licenses/.
 *
 * The signal handling code is derived from the official madwifi tools,
 * wlanconfig.c in particular. The encryption property handling was
 * inspired by the hostapd madwifi driver.
 *
 * Parts of this code are derived from the Linux iw utility.
 */

#include <limits.h>
#include <glob.h>
#include <fnmatch.h>
#include <stdarg.h>

#include "iwinfo_nl80211.h"

#define min(x, y) ((x) < (y)) ? (x) : (y)

#define BIT(x) (1ULL<<(x))

static struct nl80211_state *nls = NULL;

static void nl80211_close(void)
{
	if (nls)
	{
		if (nls->nlctrl)
			genl_family_put(nls->nlctrl);

		if (nls->nl80211)
			genl_family_put(nls->nl80211);

		if (nls->nl_sock)
			nl_socket_free(nls->nl_sock);

		if (nls->nl_cache)
			nl_cache_free(nls->nl_cache);

		free(nls);
		nls = NULL;
	}
}

static int nl80211_init(void)
{
	int err, fd;

	if (!nls)
	{
		nls = malloc(sizeof(struct nl80211_state));
		if (!nls) {
			err = -ENOMEM;
			goto err;
		}

		memset(nls, 0, sizeof(*nls));

		nls->nl_sock = nl_socket_alloc();
		if (!nls->nl_sock) {
			err = -ENOMEM;
			goto err;
		}

		if (genl_connect(nls->nl_sock)) {
			err = -ENOLINK;
			goto err;
		}

		fd = nl_socket_get_fd(nls->nl_sock);
		if (fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC) < 0) {
			err = -EINVAL;
			goto err;
		}

		if (genl_ctrl_alloc_cache(nls->nl_sock, &nls->nl_cache)) {
			err = -ENOMEM;
			goto err;
		}

		nls->nl80211 = genl_ctrl_search_by_name(nls->nl_cache, "nl80211");
		if (!nls->nl80211) {
			err = -ENOENT;
			goto err;
		}

		nls->nlctrl = genl_ctrl_search_by_name(nls->nl_cache, "nlctrl");
		if (!nls->nlctrl) {
			err = -ENOENT;
			goto err;
		}
	}

	return 0;


err:
	nl80211_close();
	return err;
}

static int nl80211_readint(const char *path)
{
	int fd;
	int rv = -1;
	char buffer[16];

	if ((fd = open(path, O_RDONLY)) > -1)
	{
		if (read(fd, buffer, sizeof(buffer)) > 0)
			rv = atoi(buffer);

		close(fd);
	}

	return rv;
}

static int nl80211_readstr(const char *path, char *buffer, int length)
{
	int fd;
	int rv = -1;

	if ((fd = open(path, O_RDONLY)) > -1)
	{
		if ((rv = read(fd, buffer, length - 1)) > 0)
		{
			if (buffer[rv - 1] == '\n')
				rv--;

			buffer[rv] = 0;
		}

		close(fd);
	}

	return rv;
}


static int nl80211_msg_error(struct sockaddr_nl *nla,
	struct nlmsgerr *err, void *arg)
{
	int *ret = arg;
	*ret = err->error;
	return NL_STOP;
}

static int nl80211_msg_finish(struct nl_msg *msg, void *arg)
{
	int *ret = arg;
	*ret = 0;
	return NL_SKIP;
}

static int nl80211_msg_ack(struct nl_msg *msg, void *arg)
{
	int *ret = arg;
	*ret = 0;
	return NL_STOP;
}

static int nl80211_msg_response(struct nl_msg *msg, void *arg)
{
	return NL_SKIP;
}

static void nl80211_free(struct nl80211_msg_conveyor *cv)
{
	if (cv)
	{
		if (cv->cb)
			nl_cb_put(cv->cb);

		if (cv->msg)
			nlmsg_free(cv->msg);

		cv->cb  = NULL;
		cv->msg = NULL;
	}
}

static struct nl80211_msg_conveyor * nl80211_new(struct genl_family *family,
                                                 int cmd, int flags)
{
	static struct nl80211_msg_conveyor cv;

	struct nl_msg *req = NULL;
	struct nl_cb *cb = NULL;

	req = nlmsg_alloc();
	if (!req)
		goto err;

	cb = nl_cb_alloc(NL_CB_DEFAULT);
	if (!cb)
		goto err;

	genlmsg_put(req, 0, 0, genl_family_get_id(family), 0, flags, cmd, 0);

	cv.msg = req;
	cv.cb  = cb;

	return &cv;

err:
	if (cb)
		nl_cb_put(cb);

	if (req)
		nlmsg_free(req);

	return NULL;
}

static struct nl80211_msg_conveyor * nl80211_ctl(int cmd, int flags)
{
	if (nl80211_init() < 0)
		return NULL;

	return nl80211_new(nls->nlctrl, cmd, flags);
}

static int nl80211_phy_idx_from_uci_path(struct uci_section *s)
{
	const char *opt;
	char buf[128];
	int idx = -1;
	glob_t gl;

	opt = uci_lookup_option_string(uci_ctx, s, "path");
	if (!opt)
		return -1;

	snprintf(buf, sizeof(buf), "/sys/devices/%s/ieee80211/*/index", opt);  /**/
	if (glob(buf, 0, NULL, &gl))
		return -1;

	if (gl.gl_pathc > 0)
		idx = nl80211_readint(gl.gl_pathv[0]);

	globfree(&gl);

	return idx;
}

static int nl80211_phy_idx_from_uci_macaddr(struct uci_section *s)
{
	const char *opt;
	char buf[128];
	int i, idx = -1;
	glob_t gl;

	opt = uci_lookup_option_string(uci_ctx, s, "macaddr");
	if (!opt)
		return -1;

	snprintf(buf, sizeof(buf), "/sys/class/ieee80211/*");	/**/
	if (glob(buf, 0, NULL, &gl))
		return -1;

	for (i = 0; i < gl.gl_pathc; i++)
	{
		snprintf(buf, sizeof(buf), "%s/macaddress", gl.gl_pathv[i]);
		if (nl80211_readstr(buf, buf, sizeof(buf)) <= 0)
			continue;

		if (fnmatch(opt, buf, FNM_CASEFOLD))
			continue;

		snprintf(buf, sizeof(buf), "%s/index", gl.gl_pathv[i]);
		if ((idx = nl80211_readint(buf)) > -1)
			break;
	}

	globfree(&gl);

	return idx;
}

static int nl80211_phy_idx_from_uci_phy(struct uci_section *s)
{
	const char *opt;
	char buf[128];

	opt = uci_lookup_option_string(uci_ctx, s, "phy");
	if (!opt)
		return -1;

	snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", opt);
	return nl80211_readint(buf);
}

static int nl80211_phy_idx_from_uci(const char *name)
{
	struct uci_section *s;
	int idx = -1;

	s = iwinfo_uci_get_radio(name, "mac80211");
	if (!s)
		goto free;

	idx = nl80211_phy_idx_from_uci_path(s);

	if (idx < 0)
		idx = nl80211_phy_idx_from_uci_macaddr(s);

	if (idx < 0)
		idx = nl80211_phy_idx_from_uci_phy(s);

free:
	iwinfo_uci_free();
	return idx;
}

static struct nl80211_msg_conveyor * nl80211_msg(const char *ifname,
                                                 int cmd, int flags)
{
	int ifidx = -1, phyidx = -1;
	struct nl80211_msg_conveyor *cv;

	if (ifname == NULL)
		return NULL;

	if (nl80211_init() < 0)
		return NULL;

	if (!strncmp(ifname, "phy", 3))
		phyidx = atoi(&ifname[3]);
	else if (!strncmp(ifname, "radio", 5))
		phyidx = nl80211_phy_idx_from_uci(ifname);
	else if (!strncmp(ifname, "mon.", 4))
		ifidx = if_nametoindex(&ifname[4]);
	else
		ifidx = if_nametoindex(ifname);

	/* Valid ifidx must be greater than 0 */
	if ((ifidx <= 0) && (phyidx < 0))
		return NULL;

	cv = nl80211_new(nls->nl80211, cmd, flags);
	if (!cv)
		return NULL;

	if (ifidx > -1)
		NLA_PUT_U32(cv->msg, NL80211_ATTR_IFINDEX, ifidx);

	if (phyidx > -1)
		NLA_PUT_U32(cv->msg, NL80211_ATTR_WIPHY, phyidx);

	return cv;

nla_put_failure:
	nl80211_free(cv);
	return NULL;
}

static struct nl80211_msg_conveyor * nl80211_send(
	struct nl80211_msg_conveyor *cv,
	int (*cb_func)(struct nl_msg *, void *), void *cb_arg
) {
	static struct nl80211_msg_conveyor rcv;
	int err = 1;

	if (cb_func)
		nl_cb_set(cv->cb, NL_CB_VALID, NL_CB_CUSTOM, cb_func, cb_arg);
	else
		nl_cb_set(cv->cb, NL_CB_VALID, NL_CB_CUSTOM, nl80211_msg_response, &rcv);

	if (nl_send_auto_complete(nls->nl_sock, cv->msg) < 0)
		goto err;

	nl_cb_err(cv->cb,               NL_CB_CUSTOM, nl80211_msg_error,  &err);
	nl_cb_set(cv->cb, NL_CB_FINISH, NL_CB_CUSTOM, nl80211_msg_finish, &err);
	nl_cb_set(cv->cb, NL_CB_ACK,    NL_CB_CUSTOM, nl80211_msg_ack,    &err);

	while (err > 0)
		nl_recvmsgs(nls->nl_sock, cv->cb);

	return &rcv;

err:
	nl_cb_put(cv->cb);
	nlmsg_free(cv->msg);

	return NULL;
}

static struct nlattr ** nl80211_parse(struct nl_msg *msg)
{
	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
	static struct nlattr *attr[NL80211_ATTR_MAX + 1];

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

	return attr;
}


static int nl80211_subscribe_cb(struct nl_msg *msg, void *arg)
{
	struct nl80211_group_conveyor *cv = arg;

	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *mgrpinfo[CTRL_ATTR_MCAST_GRP_MAX + 1];
	struct nlattr *mgrp;
	int mgrpidx;

	if (!attr[CTRL_ATTR_MCAST_GROUPS])
		return NL_SKIP;

	nla_for_each_nested(mgrp, attr[CTRL_ATTR_MCAST_GROUPS], mgrpidx)
	{
		nla_parse(mgrpinfo, CTRL_ATTR_MCAST_GRP_MAX,
		          nla_data(mgrp), nla_len(mgrp), NULL);

		if (mgrpinfo[CTRL_ATTR_MCAST_GRP_ID] &&
		    mgrpinfo[CTRL_ATTR_MCAST_GRP_NAME] &&
		    !strncmp(nla_data(mgrpinfo[CTRL_ATTR_MCAST_GRP_NAME]),
		             cv->name, nla_len(mgrpinfo[CTRL_ATTR_MCAST_GRP_NAME])))
		{
			cv->id = nla_get_u32(mgrpinfo[CTRL_ATTR_MCAST_GRP_ID]);
			break;
		}
	}

	return NL_SKIP;
}

static int nl80211_subscribe(const char *family, const char *group)
{
	struct nl80211_group_conveyor cv = { .name = group, .id = -ENOENT };
	struct nl80211_msg_conveyor *req;

	req = nl80211_ctl(CTRL_CMD_GETFAMILY, 0);
	if (req)
	{
		NLA_PUT_STRING(req->msg, CTRL_ATTR_FAMILY_NAME, family);
		nl80211_send(req, nl80211_subscribe_cb, &cv);

nla_put_failure:
		nl80211_free(req);
	}

	return nl_socket_add_membership(nls->nl_sock, cv.id);
}


static int nl80211_wait_cb(struct nl_msg *msg, void *arg)
{
	struct nl80211_event_conveyor *cv = arg;
	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));

	if (gnlh->cmd == cv->wait)
		cv->recv = gnlh->cmd;

	return NL_SKIP;
}

static int nl80211_wait_seq_check(struct nl_msg *msg, void *arg)
{
	return NL_OK;
}

static int nl80211_wait(const char *family, const char *group, int cmd)
{
	struct nl80211_event_conveyor cv = { .wait = cmd };
	struct nl_cb *cb;

	if (nl80211_subscribe(family, group))
		return -ENOENT;

	cb = nl_cb_alloc(NL_CB_DEFAULT);

 	if (!cb)
		return -ENOMEM;

	nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, nl80211_wait_seq_check, NULL);
	nl_cb_set(cb, NL_CB_VALID,     NL_CB_CUSTOM, nl80211_wait_cb,        &cv );

	while (!cv.recv)
		nl_recvmsgs(nls->nl_sock, cb);

	nl_cb_put(cb);

	return 0;
}


static int nl80211_freq2channel(int freq)
{
	if (freq == 2484)
		return 14;
	else if (freq < 2484)
		return (freq - 2407) / 5;
	else if (freq >= 4910 && freq <= 4980)
		return (freq - 4000) / 5;
	else
		return (freq - 5000) / 5;
}

static int nl80211_channel2freq(int channel, const char *band)
{
	if (!band || band[0] != 'a')
	{
		if (channel == 14)
			return 2484;
		else if (channel < 14)
			return (channel * 5) + 2407;
	}
	else
	{
		if (channel >= 182 && channel <= 196)
			return (channel * 5) + 4000;
		else
			return (channel * 5) + 5000;
	}

	return 0;
}

static int nl80211_ifname2phy_cb(struct nl_msg *msg, void *arg)
{
	char *buf = arg;
	struct nlattr **attr = nl80211_parse(msg);

	if (attr[NL80211_ATTR_WIPHY_NAME])
		memcpy(buf, nla_data(attr[NL80211_ATTR_WIPHY_NAME]),
		       nla_len(attr[NL80211_ATTR_WIPHY_NAME]));
	else
		buf[0] = 0;

	return NL_SKIP;
}

static char * nl80211_ifname2phy(const char *ifname)
{
	static char phy[32] = { 0 };
	struct nl80211_msg_conveyor *req;

	memset(phy, 0, sizeof(phy));

	req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
	if (req)
	{
		nl80211_send(req, nl80211_ifname2phy_cb, phy);
		nl80211_free(req);
	}

	return phy[0] ? phy : NULL;
}

static char * nl80211_phy2ifname(const char *ifname)
{
	int ifidx = -1, cifidx = -1, phyidx = -1;
	char buffer[64];
	static char nif[IFNAMSIZ] = { 0 };

	DIR *d;
	struct dirent *e;

	/* Only accept phy name of the form phy%d or radio%d */
	if (!ifname)
		return NULL;
	else if (!strncmp(ifname, "phy", 3))
		phyidx = atoi(&ifname[3]);
	else if (!strncmp(ifname, "radio", 5))
		phyidx = nl80211_phy_idx_from_uci(ifname);
	else
		return NULL;

	memset(nif, 0, sizeof(nif));

	if (phyidx > -1)
	{
		if ((d = opendir("/sys/class/net")) != NULL)
		{
			while ((e = readdir(d)) != NULL)
			{
				snprintf(buffer, sizeof(buffer),
				         "/sys/class/net/%s/phy80211/index", e->d_name);

				if (nl80211_readint(buffer) == phyidx)
				{
					snprintf(buffer, sizeof(buffer),
					         "/sys/class/net/%s/ifindex", e->d_name);

					if ((cifidx = nl80211_readint(buffer)) >= 0 &&
					    ((ifidx < 0) || (cifidx < ifidx)))
					{
						ifidx = cifidx;
						strncpy(nif, e->d_name, sizeof(nif));
					}
				}
			}

			closedir(d);
		}
	}

	return nif[0] ? nif : NULL;
}

static int nl80211_get_mode_cb(struct nl_msg *msg, void *arg)
{
	int *mode = arg;
	struct nlattr **tb = nl80211_parse(msg);
	const int ifmodes[NL80211_IFTYPE_MAX + 1] = {
		IWINFO_OPMODE_UNKNOWN,		/* unspecified */
		IWINFO_OPMODE_ADHOC,		/* IBSS */
		IWINFO_OPMODE_CLIENT,		/* managed */
		IWINFO_OPMODE_MASTER,		/* AP */
		IWINFO_OPMODE_AP_VLAN,		/* AP/VLAN */
		IWINFO_OPMODE_WDS,			/* WDS */
		IWINFO_OPMODE_MONITOR,		/* monitor */
		IWINFO_OPMODE_MESHPOINT,	/* mesh point */
		IWINFO_OPMODE_P2P_CLIENT,	/* P2P-client */
		IWINFO_OPMODE_P2P_GO,		/* P2P-GO */
	};

	if (tb[NL80211_ATTR_IFTYPE])
		*mode = ifmodes[nla_get_u32(tb[NL80211_ATTR_IFTYPE])];

	return NL_SKIP;
}


static int nl80211_get_mode(const char *ifname, int *buf)
{
	char *res;
	struct nl80211_msg_conveyor *req;

	res = nl80211_phy2ifname(ifname);
	req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0);
	*buf = IWINFO_OPMODE_UNKNOWN;

	if (req)
	{
		nl80211_send(req, nl80211_get_mode_cb, buf);
		nl80211_free(req);
	}

	return (*buf == IWINFO_OPMODE_UNKNOWN) ? -1 : 0;
}

static int __nl80211_hostapd_query(const char *ifname, ...)
{
	va_list ap, ap_cur;
	char *phy, *search, *dest, *key, *val, buf[128];
	int len, mode, found = 0, match = 1;
	FILE *fp;

	if (nl80211_get_mode(ifname, &mode))
		return 0;

	if (mode != IWINFO_OPMODE_MASTER && mode != IWINFO_OPMODE_AP_VLAN)
		return 0;

	phy = nl80211_ifname2phy(ifname);

	if (!phy)
		return 0;

	snprintf(buf, sizeof(buf), "/var/run/hostapd-%s.conf", phy);
	fp = fopen(buf, "r");

	if (!fp)
		return 0;

	va_start(ap, ifname);

	/* clear all destination buffers */
	va_copy(ap_cur, ap);

	while ((search = va_arg(ap_cur, char *)) != NULL)
	{
		dest = va_arg(ap_cur, char *);
		len  = va_arg(ap_cur, int);

		memset(dest, 0, len);
	}

	va_end(ap_cur);

	/* iterate applicable lines and copy found values into dest buffers */
	while (fgets(buf, sizeof(buf), fp))
	{
		key = strtok(buf, " =\t\n");
		val = strtok(NULL, "\n");

		if (!key || !val || !*key || *key == '#')
			continue;

		if (!strcmp(key, "interface") || !strcmp(key, "bss"))
			match = !strcmp(ifname, val);

		if (!match)
			continue;

		va_copy(ap_cur, ap);

		while ((search = va_arg(ap_cur, char *)) != NULL)
		{
			dest = va_arg(ap_cur, char *);
			len  = va_arg(ap_cur, int);

			if (!strcmp(search, key))
			{
				strncpy(dest, val, len - 1);
				found++;
				break;
			}
		}

		va_end(ap_cur);
	}

	fclose(fp);

	va_end(ap);

	return found;
}

#define nl80211_hostapd_query(ifname, ...) \
	__nl80211_hostapd_query(ifname, ##__VA_ARGS__, NULL)


static inline int nl80211_wpactl_recv(int sock, char *buf, int blen)
{
	fd_set rfds;
	struct timeval tv = { 0, 256000 };

	FD_ZERO(&rfds);
	FD_SET(sock, &rfds);

	memset(buf, 0, blen);

	if (select(sock + 1, &rfds, NULL, NULL, &tv) < 0)
		return -1;

	if (!FD_ISSET(sock, &rfds))
		return -1;

	return recv(sock, buf, blen - 1, 0);
}

static int nl80211_wpactl_connect(const char *ifname, struct sockaddr_un *local)
{
	struct sockaddr_un remote = { 0 };
	size_t remote_length, local_length;

	int sock = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (sock < 0)
		return sock;

	remote.sun_family = AF_UNIX;
	remote_length = sizeof(remote.sun_family) +
		sprintf(remote.sun_path, "/var/run/wpa_supplicant-%s/%s",
		        ifname, ifname);

	if (fcntl(sock, F_SETFD, fcntl(sock, F_GETFD) | FD_CLOEXEC) < 0)
	{
		close(sock);
		return -1;
	}

	if (connect(sock, (struct sockaddr *)&remote, remote_length))
	{
		remote_length = sizeof(remote.sun_family) +
			sprintf(remote.sun_path, "/var/run/wpa_supplicant/%s", ifname);

		if (connect(sock, (struct sockaddr *)&remote, remote_length))
		{
			close(sock);
			return -1;
		}
	}

	local->sun_family = AF_UNIX;
	local_length = sizeof(local->sun_family) +
		sprintf(local->sun_path, "/var/run/iwinfo-%s-%d", ifname, getpid());

	if (bind(sock, (struct sockaddr *)local, local_length) < 0)
	{
		close(sock);
		return -1;
	}

	return sock;
}

static int __nl80211_wpactl_query(const char *ifname, ...)
{
	va_list ap, ap_cur;
	struct sockaddr_un local = { 0 };
	int len, mode, found = 0, sock = -1;
	char *search, *dest, *key, *val, *line, *pos, buf[512];

	if (nl80211_get_mode(ifname, &mode))
		return 0;

	if (mode != IWINFO_OPMODE_CLIENT && mode != IWINFO_OPMODE_ADHOC)
		return 0;

	sock = nl80211_wpactl_connect(ifname, &local);

	if (sock < 0)
		return 0;

	va_start(ap, ifname);

	/* clear all destination buffers */
	va_copy(ap_cur, ap);

	while ((search = va_arg(ap_cur, char *)) != NULL)
	{
		dest = va_arg(ap_cur, char *);
		len  = va_arg(ap_cur, int);

		memset(dest, 0, len);
	}

	va_end(ap_cur);

	send(sock, "STATUS", 6, 0);

	while (true)
	{
		if (nl80211_wpactl_recv(sock, buf, sizeof(buf)) <= 0)
			break;

		if (buf[0] == '<')
			continue;

		for (line = strtok_r(buf, "\n", &pos);
			 line != NULL;
			 line = strtok_r(NULL, "\n", &pos))
		{
			key = strtok(line, "=");
			val = strtok(NULL, "\n");

			if (!key || !val)
				continue;

			va_copy(ap_cur, ap);

			while ((search = va_arg(ap_cur, char *)) != NULL)
			{
				dest = va_arg(ap_cur, char *);
				len  = va_arg(ap_cur, int);

				if (!strcmp(search, key))
				{
					strncpy(dest, val, len - 1);
					found++;
					break;
				}
			}

			va_end(ap_cur);
		}

		break;
	}

	va_end(ap);

	close(sock);
	unlink(local.sun_path);

	return found;
}

#define nl80211_wpactl_query(ifname, ...) \
	__nl80211_wpactl_query(ifname, ##__VA_ARGS__, NULL)


static char * nl80211_ifadd(const char *ifname)
{
	char *rv = NULL, path[PATH_MAX];
	static char nif[IFNAMSIZ] = { 0 };
	struct nl80211_msg_conveyor *req;
	FILE *sysfs;

	req = nl80211_msg(ifname, NL80211_CMD_NEW_INTERFACE, 0);
	if (req)
	{
		snprintf(nif, sizeof(nif), "tmp.%s", ifname);

		NLA_PUT_STRING(req->msg, NL80211_ATTR_IFNAME, nif);
		NLA_PUT_U32(req->msg, NL80211_ATTR_IFTYPE, NL80211_IFTYPE_STATION);

		nl80211_send(req, NULL, NULL);

		snprintf(path, sizeof(path) - 1,
		         "/proc/sys/net/ipv6/conf/%s/disable_ipv6", nif);

		if ((sysfs = fopen(path, "w")) != NULL)
		{
			fwrite("0\n", 1, 2, sysfs);
			fclose(sysfs);
		}

		rv = nif;

	nla_put_failure:
		nl80211_free(req);
	}

	return rv;
}

static void nl80211_ifdel(const char *ifname)
{
	struct nl80211_msg_conveyor *req;

	req = nl80211_msg(ifname, NL80211_CMD_DEL_INTERFACE, 0);
	if (req)
	{
		NLA_PUT_STRING(req->msg, NL80211_ATTR_IFNAME, ifname);

		nl80211_send(req, NULL, NULL);

	nla_put_failure:
		nl80211_free(req);
	}
}

static void nl80211_hostapd_hup(const char *ifname)
{
	int fd, pid = 0;
	char buf[32];
	char *phy = nl80211_ifname2phy(ifname);

	if (phy)
	{
		snprintf(buf, sizeof(buf), "/var/run/wifi-%s.pid", phy);
		if ((fd = open(buf, O_RDONLY)) >= 0)
		{
			if (read(fd, buf, sizeof(buf)) > 0)
				pid = atoi(buf);

			close(fd);
		}

		if (pid > 0)
			kill(pid, 1);
	}
}


static int nl80211_probe(const char *ifname)
{
	return !!nl80211_ifname2phy(ifname);
}

struct nl80211_ssid_bssid {
	unsigned char *ssid;
	unsigned char bssid[7];
};

static int nl80211_get_ssid_bssid_cb(struct nl_msg *msg, void *arg)
{
	int ielen;
	unsigned char *ie;
	struct nl80211_ssid_bssid *sb = arg;
	struct nlattr **tb = nl80211_parse(msg);
	struct nlattr *bss[NL80211_BSS_MAX + 1];

	static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
		[NL80211_BSS_INFORMATION_ELEMENTS] = { 0 },
		[NL80211_BSS_STATUS]               = { .type = NLA_U32 },
	};

	if (!tb[NL80211_ATTR_BSS] ||
	    nla_parse_nested(bss, NL80211_BSS_MAX, tb[NL80211_ATTR_BSS],
	                     bss_policy) ||
	    !bss[NL80211_BSS_BSSID] ||
	    !bss[NL80211_BSS_STATUS] ||
	    !bss[NL80211_BSS_INFORMATION_ELEMENTS])
	{
		return NL_SKIP;
	}

	switch (nla_get_u32(bss[NL80211_BSS_STATUS]))
	{
	case NL80211_BSS_STATUS_ASSOCIATED:
	case NL80211_BSS_STATUS_AUTHENTICATED:
	case NL80211_BSS_STATUS_IBSS_JOINED:

		if (sb->ssid)
		{
			ie = nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
			ielen = nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]);

			while (ielen >= 2 && ielen >= ie[1])
			{
				if (ie[0] == 0)
				{
					memcpy(sb->ssid, ie + 2, min(ie[1], IWINFO_ESSID_MAX_SIZE));
					return NL_SKIP;
				}

				ielen -= ie[1] + 2;
				ie += ie[1] + 2;
			}
		}
		else
		{
			sb->bssid[0] = 1;
			memcpy(sb->bssid + 1, nla_data(bss[NL80211_BSS_BSSID]), 6);
			return NL_SKIP;
		}

	default:
		return NL_SKIP;
	}
}

static int nl80211_get_ssid(const char *ifname, char *buf)
{
	char *res;
	struct nl80211_msg_conveyor *req;
	struct nl80211_ssid_bssid sb;

	/* try to find ssid from scan dump results */
	res = nl80211_phy2ifname(ifname);
	req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);

	sb.ssid = (unsigned char *)buf;
	*buf = 0;

	if (req)
	{
		nl80211_send(req, nl80211_get_ssid_bssid_cb, &sb);
		nl80211_free(req);
	}

	/* failed, try to find from hostapd info */
	if (*buf == 0)
		nl80211_hostapd_query(ifname, "ssid", buf, IWINFO_ESSID_MAX_SIZE + 1);

	return (*buf == 0) ? -1 : 0;
}

static int nl80211_get_bssid(const char *ifname, char *buf)
{
	char *res, bssid[sizeof("FF:FF:FF:FF:FF:FF\0")];
	struct nl80211_msg_conveyor *req;
	struct nl80211_ssid_bssid sb;

	/* try to find bssid from scan dump results */
	res = nl80211_phy2ifname(ifname);
	req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);

	sb.ssid = NULL;
	sb.bssid[0] = 0;

	if (req)
	{
		nl80211_send(req, nl80211_get_ssid_bssid_cb, &sb);
		nl80211_free(req);
	}

	/* failed, try to find mac from hostapd info */
	if ((sb.bssid[0] == 0) &&
	    nl80211_hostapd_query(ifname, "bssid", bssid, sizeof(bssid)))
	{
		sb.bssid[0] = 1;
		sb.bssid[1] = strtol(&bssid[0],  NULL, 16);
		sb.bssid[2] = strtol(&bssid[3],  NULL, 16);
		sb.bssid[3] = strtol(&bssid[6],  NULL, 16);
		sb.bssid[4] = strtol(&bssid[9],  NULL, 16);
		sb.bssid[5] = strtol(&bssid[12], NULL, 16);
		sb.bssid[6] = strtol(&bssid[15], NULL, 16);
	}

	if (sb.bssid[0])
	{
		sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X",
		        sb.bssid[1], sb.bssid[2], sb.bssid[3],
		        sb.bssid[4], sb.bssid[5], sb.bssid[6]);

		return 0;
	}

	return -1;
}


static int nl80211_get_frequency_scan_cb(struct nl_msg *msg, void *arg)
{
	int *freq = arg;
	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *binfo[NL80211_BSS_MAX + 1];

	static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
		[NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
		[NL80211_BSS_STATUS]    = { .type = NLA_U32 },
	};

	if (attr[NL80211_ATTR_BSS] &&
	    !nla_parse_nested(binfo, NL80211_BSS_MAX,
	                      attr[NL80211_ATTR_BSS], bss_policy))
	{
		if (binfo[NL80211_BSS_STATUS] && binfo[NL80211_BSS_FREQUENCY])
			*freq = nla_get_u32(binfo[NL80211_BSS_FREQUENCY]);
	}

	return NL_SKIP;
}

static int nl80211_get_frequency_info_cb(struct nl_msg *msg, void *arg)
{
	int *freq = arg;
	struct nlattr **tb = nl80211_parse(msg);

	if (tb[NL80211_ATTR_WIPHY_FREQ])
		*freq = nla_get_u32(tb[NL80211_ATTR_WIPHY_FREQ]);

	return NL_SKIP;
}

static int nl80211_get_frequency(const char *ifname, int *buf)
{
	char *res, channel[4], hwmode[2];
	struct nl80211_msg_conveyor *req;

	/* try to find frequency from interface info */
	res = nl80211_phy2ifname(ifname);
	req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0);
	*buf = 0;

	if (req)
	{
		nl80211_send(req, nl80211_get_frequency_info_cb, buf);
		nl80211_free(req);
	}

	/* failed, try to find frequency from hostapd info */
	if ((*buf == 0) &&
	    nl80211_hostapd_query(ifname, "hw_mode", hwmode, sizeof(hwmode),
	                                  "channel", channel, sizeof(channel)) == 2)
	{
		*buf = nl80211_channel2freq(atoi(channel), hwmode);
	}

	/* failed, try to find frequency from scan results */
	if (*buf == 0)
	{
		res = nl80211_phy2ifname(ifname);
		req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);

		if (req)
		{
			nl80211_send(req, nl80211_get_frequency_scan_cb, buf);
			nl80211_free(req);
		}
	}

	return (*buf == 0) ? -1 : 0;
}

static int nl80211_get_channel(const char *ifname, int *buf)
{
	if (!nl80211_get_frequency(ifname, buf))
	{
		*buf = nl80211_freq2channel(*buf);
		return 0;
	}

	return -1;
}

static int nl80211_get_txpower_cb(struct nl_msg *msg, void *arg)
{
	int *buf = arg;
	struct nlattr **tb = nl80211_parse(msg);

	if (tb[NL80211_ATTR_WIPHY_TX_POWER_LEVEL])
		*buf = iwinfo_mbm2dbm(nla_get_u32(tb[NL80211_ATTR_WIPHY_TX_POWER_LEVEL]));

	return NL_SKIP;
}

static int nl80211_get_txpower(const char *ifname, int *buf)
{
	char *res;
	struct nl80211_msg_conveyor *req;

	res = nl80211_phy2ifname(ifname);
	req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0);

	if (req)
	{
		*buf = 0;
		nl80211_send(req, nl80211_get_txpower_cb, buf);
		nl80211_free(req);
		if (*buf)
			return 0;
	}

	return -1;
}


static int nl80211_fill_signal_cb(struct nl_msg *msg, void *arg)
{
	int8_t dbm;
	int16_t mbit;
	struct nl80211_rssi_rate *rr = arg;
	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *sinfo[NL80211_STA_INFO_MAX + 1];
	struct nlattr *rinfo[NL80211_RATE_INFO_MAX + 1];

	static struct nla_policy stats_policy[NL80211_STA_INFO_MAX + 1] = {
		[NL80211_STA_INFO_INACTIVE_TIME] = { .type = NLA_U32    },
		[NL80211_STA_INFO_RX_BYTES]      = { .type = NLA_U32    },
		[NL80211_STA_INFO_TX_BYTES]      = { .type = NLA_U32    },
		[NL80211_STA_INFO_RX_PACKETS]    = { .type = NLA_U32    },
		[NL80211_STA_INFO_TX_PACKETS]    = { .type = NLA_U32    },
		[NL80211_STA_INFO_SIGNAL]        = { .type = NLA_U8     },
		[NL80211_STA_INFO_TX_BITRATE]    = { .type = NLA_NESTED },
		[NL80211_STA_INFO_LLID]          = { .type = NLA_U16    },
		[NL80211_STA_INFO_PLID]          = { .type = NLA_U16    },
		[NL80211_STA_INFO_PLINK_STATE]   = { .type = NLA_U8     },
	};

	static struct nla_policy rate_policy[NL80211_RATE_INFO_MAX + 1] = {
		[NL80211_RATE_INFO_BITRATE]      = { .type = NLA_U16  },
		[NL80211_RATE_INFO_MCS]          = { .type = NLA_U8   },
		[NL80211_RATE_INFO_40_MHZ_WIDTH] = { .type = NLA_FLAG },
		[NL80211_RATE_INFO_SHORT_GI]     = { .type = NLA_FLAG },
	};

	if (attr[NL80211_ATTR_STA_INFO])
	{
		if (!nla_parse_nested(sinfo, NL80211_STA_INFO_MAX,
		                      attr[NL80211_ATTR_STA_INFO], stats_policy))
		{
			if (sinfo[NL80211_STA_INFO_SIGNAL])
			{
				dbm = nla_get_u8(sinfo[NL80211_STA_INFO_SIGNAL]);
				rr->rssi = rr->rssi ? (int8_t)((rr->rssi + dbm) / 2) : dbm;
			}

			if (sinfo[NL80211_STA_INFO_TX_BITRATE])
			{
				if (!nla_parse_nested(rinfo, NL80211_RATE_INFO_MAX,
				                      sinfo[NL80211_STA_INFO_TX_BITRATE],
				                      rate_policy))
				{
					if (rinfo[NL80211_RATE_INFO_BITRATE])
					{
						mbit = nla_get_u16(rinfo[NL80211_RATE_INFO_BITRATE]);
						rr->rate = rr->rate
							? (int16_t)((rr->rate + mbit) / 2) : mbit;
					}
				}
			}
		}
	}

	return NL_SKIP;
}

static void nl80211_fill_signal(const char *ifname, struct nl80211_rssi_rate *r)
{
	DIR *d;
	struct dirent *de;
	struct nl80211_msg_conveyor *req;

	r->rssi = 0;
	r->rate = 0;

	if ((d = opendir("/sys/class/net")) != NULL)
	{
		while ((de = readdir(d)) != NULL)
		{
			if (!strncmp(de->d_name, ifname, strlen(ifname)) &&
			    (!de->d_name[strlen(ifname)] ||
			     !strncmp(&de->d_name[strlen(ifname)], ".sta", 4)))
			{
				req = nl80211_msg(de->d_name, NL80211_CMD_GET_STATION,
				                  NLM_F_DUMP);

				if (req)
				{
					nl80211_send(req, nl80211_fill_signal_cb, r);
					nl80211_free(req);
				}
			}
		}

		closedir(d);
	}
}

static int nl80211_get_bitrate(const char *ifname, int *buf)
{
	struct nl80211_rssi_rate rr;

	nl80211_fill_signal(ifname, &rr);

	if (rr.rate)
	{
		*buf = (rr.rate * 100);
		return 0;
	}

	return -1;
}

static int nl80211_get_signal(const char *ifname, int *buf)
{
	struct nl80211_rssi_rate rr;

	nl80211_fill_signal(ifname, &rr);

	if (rr.rssi)
	{
		*buf = rr.rssi;
		return 0;
	}

	return -1;
}

static int nl80211_get_noise_cb(struct nl_msg *msg, void *arg)
{
	int8_t *noise = arg;
	struct nlattr **tb = nl80211_parse(msg);
	struct nlattr *si[NL80211_SURVEY_INFO_MAX + 1];

	static struct nla_policy sp[NL80211_SURVEY_INFO_MAX + 1] = {
		[NL80211_SURVEY_INFO_FREQUENCY] = { .type = NLA_U32 },
		[NL80211_SURVEY_INFO_NOISE]     = { .type = NLA_U8  },
	};

	if (!tb[NL80211_ATTR_SURVEY_INFO])
		return NL_SKIP;

	if (nla_parse_nested(si, NL80211_SURVEY_INFO_MAX,
	                     tb[NL80211_ATTR_SURVEY_INFO], sp))
		return NL_SKIP;

	if (!si[NL80211_SURVEY_INFO_NOISE])
		return NL_SKIP;

	if (!*noise || si[NL80211_SURVEY_INFO_IN_USE])
		*noise = (int8_t)nla_get_u8(si[NL80211_SURVEY_INFO_NOISE]);

	return NL_SKIP;
}


static int nl80211_get_noise(const char *ifname, int *buf)
{
	int8_t noise;
	struct nl80211_msg_conveyor *req;

	req = nl80211_msg(ifname, NL80211_CMD_GET_SURVEY, NLM_F_DUMP);
	if (req)
	{
		noise = 0;

		nl80211_send(req, nl80211_get_noise_cb, &noise);
		nl80211_free(req);

		if (noise)
		{
			*buf = noise;
			return 0;
		}
	}

	return -1;
}

static int nl80211_get_quality(const char *ifname, int *buf)
{
	int signal;

	if (!nl80211_get_signal(ifname, &signal))
	{
		/* A positive signal level is usually just a quality
		 * value, pass through as-is */
		if (signal >= 0)
		{
			*buf = signal;
		}

		/* The cfg80211 wext compat layer assumes a signal range
		 * of -110 dBm to -40 dBm, the quality value is derived
		 * by adding 110 to the signal level */
		else
		{
			if (signal < -110)
				signal = -110;
			else if (signal > -40)
				signal = -40;

			*buf = (signal + 110);
		}

		return 0;
	}

	return -1;
}

static int nl80211_get_quality_max(const char *ifname, int *buf)
{
	/* The cfg80211 wext compat layer assumes a maximum
	 * quality of 70 */
	*buf = 70;

	return 0;
}

static int nl80211_check_wepkey(const char *key)
{
	if (key && *key)
	{
		switch (strlen(key))
		{
		case 5:
		case 10:
			return IWINFO_CIPHER_WEP40;

		case 13:
		case 26:
			return IWINFO_CIPHER_WEP104;
		}
	}

	return 0;
}

static int nl80211_get_encryption(const char *ifname, char *buf)
{
	char wpa[2], wpa_key_mgmt[16], wpa_pairwise[16], wpa_groupwise[16];
	char auth_algs[2], wep_key0[27], wep_key1[27], wep_key2[27], wep_key3[27];

	struct iwinfo_crypto_entry *c = (struct iwinfo_crypto_entry *)buf;

	/* WPA supplicant */
	if (nl80211_wpactl_query(ifname,
			"pairwise_cipher", wpa_pairwise,  sizeof(wpa_pairwise),
			"group_cipher",    wpa_groupwise, sizeof(wpa_groupwise),
			"key_mgmt",        wpa_key_mgmt,  sizeof(wpa_key_mgmt)))
	{
		/* WEP */
		if (!strcmp(wpa_key_mgmt, "NONE"))
		{
			if (strstr(wpa_pairwise, "WEP-40"))
				c->pair_ciphers |= IWINFO_CIPHER_WEP40;
			else if (strstr(wpa_pairwise, "WEP-104"))
				c->pair_ciphers |= IWINFO_CIPHER_WEP104;

			if (strstr(wpa_groupwise, "WEP-40"))
				c->group_ciphers |= IWINFO_CIPHER_WEP40;
			else if (strstr(wpa_groupwise, "WEP-104"))
				c->group_ciphers |= IWINFO_CIPHER_WEP104;

			c->enabled      = !!(c->pair_ciphers | c->group_ciphers);
			c->auth_suites |= IWINFO_KMGMT_NONE;
			c->auth_algs   |= IWINFO_AUTH_OPEN; /* XXX: assumption */
		}

		/* WPA */
		else if (strstr(wpa_key_mgmt, "WPA"))
		{
			if (strstr(wpa_pairwise, "TKIP"))
				c->pair_ciphers |= IWINFO_CIPHER_TKIP;
			else if (strstr(wpa_pairwise, "CCMP"))
				c->pair_ciphers |= IWINFO_CIPHER_CCMP;
			else if (strstr(wpa_pairwise, "NONE"))
				c->pair_ciphers |= IWINFO_CIPHER_NONE;
			else if (strstr(wpa_pairwise, "WEP-40"))
				c->pair_ciphers |= IWINFO_CIPHER_WEP40;
			else if (strstr(wpa_pairwise, "WEP-104"))
				c->pair_ciphers |= IWINFO_CIPHER_WEP104;

			if (strstr(wpa_groupwise, "TKIP"))
				c->group_ciphers |= IWINFO_CIPHER_TKIP;
			else if (strstr(wpa_groupwise, "CCMP"))
				c->group_ciphers |= IWINFO_CIPHER_CCMP;
			else if (strstr(wpa_groupwise, "NONE"))
				c->group_ciphers |= IWINFO_CIPHER_NONE;
			else if (strstr(wpa_groupwise, "WEP-40"))
				c->group_ciphers |= IWINFO_CIPHER_WEP40;
			else if (strstr(wpa_groupwise, "WEP-104"))
				c->group_ciphers |= IWINFO_CIPHER_WEP104;

			if (strstr(wpa_key_mgmt, "WPA2"))
				c->wpa_version = 2;
			else if (strstr(wpa_key_mgmt, "WPA"))
				c->wpa_version = 1;

			if (strstr(wpa_key_mgmt, "PSK"))
				c->auth_suites |= IWINFO_KMGMT_PSK;
			else if (strstr(wpa_key_mgmt, "EAP") ||
			         strstr(wpa_key_mgmt, "802.1X"))
				c->auth_suites |= IWINFO_KMGMT_8021x;
			else if (strstr(wpa_key_mgmt, "NONE"))
				c->auth_suites |= IWINFO_KMGMT_NONE;

			c->enabled = !!(c->wpa_version && c->auth_suites);
		}

		return 0;
	}

	/* Hostapd */
	else if (nl80211_hostapd_query(ifname,
				"wpa",          wpa,          sizeof(wpa),
				"wpa_key_mgmt", wpa_key_mgmt, sizeof(wpa_key_mgmt),
				"wpa_pairwise", wpa_pairwise, sizeof(wpa_pairwise),
				"auth_algs",    auth_algs,    sizeof(auth_algs),
				"wep_key0",     wep_key0,     sizeof(wep_key0),
				"wep_key1",     wep_key1,     sizeof(wep_key1),
				"wep_key2",     wep_key2,     sizeof(wep_key2),
				"wep_key3",     wep_key3,     sizeof(wep_key3)))
	{
		c->wpa_version = wpa[0] ? atoi(wpa) : 0;

		if (wpa_key_mgmt[0])
		{
			if (strstr(wpa_key_mgmt, "PSK"))
				c->auth_suites |= IWINFO_KMGMT_PSK;

			if (strstr(wpa_key_mgmt, "EAP"))
				c->auth_suites |= IWINFO_KMGMT_8021x;

			if (strstr(wpa_key_mgmt, "NONE"))
				c->auth_suites |= IWINFO_KMGMT_NONE;
		}
		else
		{
			c->auth_suites |= IWINFO_KMGMT_PSK;
		}

		if (wpa_pairwise[0])
		{
			if (strstr(wpa_pairwise, "TKIP"))
				c->pair_ciphers |= IWINFO_CIPHER_TKIP;

			if (strstr(wpa_pairwise, "CCMP"))
				c->pair_ciphers |= IWINFO_CIPHER_CCMP;

			if (strstr(wpa_pairwise, "NONE"))
				c->pair_ciphers |= IWINFO_CIPHER_NONE;
		}

		if (auth_algs[0])
		{
			switch(atoi(auth_algs))
			{
			case 1:
				c->auth_algs |= IWINFO_AUTH_OPEN;
				break;

			case 2:
				c->auth_algs |= IWINFO_AUTH_SHARED;
				break;

			case 3:
				c->auth_algs |= IWINFO_AUTH_OPEN;
				c->auth_algs |= IWINFO_AUTH_SHARED;
				break;
			}

			c->pair_ciphers |= nl80211_check_wepkey(wep_key0);
			c->pair_ciphers |= nl80211_check_wepkey(wep_key1);
			c->pair_ciphers |= nl80211_check_wepkey(wep_key2);
			c->pair_ciphers |= nl80211_check_wepkey(wep_key3);
		}

		c->group_ciphers = c->pair_ciphers;
		c->enabled = (c->wpa_version || c->pair_ciphers) ? 1 : 0;

		return 0;
	}

	return -1;
}

static int nl80211_get_phyname(const char *ifname, char *buf)
{
	const char *name;

	name = nl80211_ifname2phy(ifname);

	if (name)
	{
		strcpy(buf, name);
		return 0;
	}
	else if ((name = nl80211_phy2ifname(ifname)) != NULL)
	{
		name = nl80211_ifname2phy(name);

		if (name)
		{
			strcpy(buf, ifname);
			return 0;
		}
	}

	return -1;
}


static int nl80211_get_assoclist_cb(struct nl_msg *msg, void *arg)
{
	struct nl80211_array_buf *arr = arg;
	struct iwinfo_assoclist_entry *e = arr->buf;
	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *sinfo[NL80211_STA_INFO_MAX + 1];
	struct nlattr *rinfo[NL80211_RATE_INFO_MAX + 1];
	struct nl80211_sta_flag_update *sta_flags;

	static struct nla_policy stats_policy[NL80211_STA_INFO_MAX + 1] = {
		[NL80211_STA_INFO_INACTIVE_TIME] = { .type = NLA_U32    },
		[NL80211_STA_INFO_RX_PACKETS]    = { .type = NLA_U32    },
		[NL80211_STA_INFO_TX_PACKETS]    = { .type = NLA_U32    },
		[NL80211_STA_INFO_RX_BITRATE]    = { .type = NLA_NESTED },
		[NL80211_STA_INFO_TX_BITRATE]    = { .type = NLA_NESTED },
		[NL80211_STA_INFO_SIGNAL]        = { .type = NLA_U8     },
		[NL80211_STA_INFO_RX_BYTES]      = { .type = NLA_U32    },
		[NL80211_STA_INFO_TX_BYTES]      = { .type = NLA_U32    },
		[NL80211_STA_INFO_TX_RETRIES]    = { .type = NLA_U32    },
		[NL80211_STA_INFO_TX_FAILED]     = { .type = NLA_U32    },
		[NL80211_STA_INFO_T_OFFSET]      = { .type = NLA_U64    },
		[NL80211_STA_INFO_STA_FLAGS] =
			{ .minlen = sizeof(struct nl80211_sta_flag_update) },
	};

	static struct nla_policy rate_policy[NL80211_RATE_INFO_MAX + 1] = {
		[NL80211_RATE_INFO_BITRATE]      = { .type = NLA_U16    },
		[NL80211_RATE_INFO_MCS]          = { .type = NLA_U8     },
		[NL80211_RATE_INFO_40_MHZ_WIDTH] = { .type = NLA_FLAG   },
		[NL80211_RATE_INFO_SHORT_GI]     = { .type = NLA_FLAG   },
	};

	/* advance to end of array */
	e += arr->count;
	memset(e, 0, sizeof(*e));

	if (attr[NL80211_ATTR_MAC])
		memcpy(e->mac, nla_data(attr[NL80211_ATTR_MAC]), 6);

	if (attr[NL80211_ATTR_STA_INFO] &&
	    !nla_parse_nested(sinfo, NL80211_STA_INFO_MAX,
	                      attr[NL80211_ATTR_STA_INFO], stats_policy))
	{
		if (sinfo[NL80211_STA_INFO_SIGNAL])
			e->signal = nla_get_u8(sinfo[NL80211_STA_INFO_SIGNAL]);

		if (sinfo[NL80211_STA_INFO_INACTIVE_TIME])
			e->inactive = nla_get_u32(sinfo[NL80211_STA_INFO_INACTIVE_TIME]);

		if (sinfo[NL80211_STA_INFO_RX_PACKETS])
			e->rx_packets = nla_get_u32(sinfo[NL80211_STA_INFO_RX_PACKETS]);

		if (sinfo[NL80211_STA_INFO_TX_PACKETS])
			e->tx_packets = nla_get_u32(sinfo[NL80211_STA_INFO_TX_PACKETS]);

		if (sinfo[NL80211_STA_INFO_RX_BITRATE] &&
		    !nla_parse_nested(rinfo, NL80211_RATE_INFO_MAX,
		                      sinfo[NL80211_STA_INFO_RX_BITRATE], rate_policy))
		{
			if (rinfo[NL80211_RATE_INFO_BITRATE])
				e->rx_rate.rate =
					nla_get_u16(rinfo[NL80211_RATE_INFO_BITRATE]) * 100;

			if (rinfo[NL80211_RATE_INFO_MCS])
				e->rx_rate.mcs = nla_get_u8(rinfo[NL80211_RATE_INFO_MCS]);

			if (rinfo[NL80211_RATE_INFO_40_MHZ_WIDTH])
				e->rx_rate.is_40mhz = 1;

			if (rinfo[NL80211_RATE_INFO_SHORT_GI])
				e->rx_rate.is_short_gi = 1;
		}

		if (sinfo[NL80211_STA_INFO_TX_BITRATE] &&
		    !nla_parse_nested(rinfo, NL80211_RATE_INFO_MAX,
		                      sinfo[NL80211_STA_INFO_TX_BITRATE], rate_policy))
		{
			if (rinfo[NL80211_RATE_INFO_BITRATE])
				e->tx_rate.rate =
					nla_get_u16(rinfo[NL80211_RATE_INFO_BITRATE]) * 100;

			if (rinfo[NL80211_RATE_INFO_MCS])
				e->tx_rate.mcs = nla_get_u8(rinfo[NL80211_RATE_INFO_MCS]);

			if (rinfo[NL80211_RATE_INFO_40_MHZ_WIDTH])
				e->tx_rate.is_40mhz = 1;

			if (rinfo[NL80211_RATE_INFO_SHORT_GI])
				e->tx_rate.is_short_gi = 1;
		}

		if (sinfo[NL80211_STA_INFO_RX_BYTES])
			e->rx_bytes = nla_get_u32(sinfo[NL80211_STA_INFO_RX_BYTES]);

		if (sinfo[NL80211_STA_INFO_TX_BYTES])
			e->tx_bytes = nla_get_u32(sinfo[NL80211_STA_INFO_TX_BYTES]);

		if (sinfo[NL80211_STA_INFO_TX_RETRIES])
			e->tx_retries = nla_get_u32(sinfo[NL80211_STA_INFO_TX_RETRIES]);

		if (sinfo[NL80211_STA_INFO_TX_FAILED])
			e->tx_failed = nla_get_u32(sinfo[NL80211_STA_INFO_TX_FAILED]);

		if (sinfo[NL80211_STA_INFO_T_OFFSET])
			e->t_offset = nla_get_u64(sinfo[NL80211_STA_INFO_T_OFFSET]);

		/* Station flags */
		if (sinfo[NL80211_STA_INFO_STA_FLAGS])
		{
			sta_flags = (struct nl80211_sta_flag_update *)
				nla_data(sinfo[NL80211_STA_INFO_STA_FLAGS]);

			if (sta_flags->mask & BIT(NL80211_STA_FLAG_AUTHORIZED) &&
			    sta_flags->set & BIT(NL80211_STA_FLAG_AUTHORIZED))
				e->is_authorized = 1;

			if (sta_flags->mask & BIT(NL80211_STA_FLAG_AUTHENTICATED) &&
			    sta_flags->set & BIT(NL80211_STA_FLAG_AUTHENTICATED))
				e->is_authenticated = 1;

			if (sta_flags->mask & BIT(NL80211_STA_FLAG_SHORT_PREAMBLE) &&
			    sta_flags->set & BIT(NL80211_STA_FLAG_SHORT_PREAMBLE))
				e->is_preamble_short = 1;

			if (sta_flags->mask & BIT(NL80211_STA_FLAG_WME) &&
			    sta_flags->set & BIT(NL80211_STA_FLAG_WME))
				e->is_wme = 1;

			if (sta_flags->mask & BIT(NL80211_STA_FLAG_MFP) &&
			    sta_flags->set & BIT(NL80211_STA_FLAG_MFP))
				e->is_mfp = 1;

			if (sta_flags->mask & BIT(NL80211_STA_FLAG_TDLS_PEER) &&
			    sta_flags->set & BIT(NL80211_STA_FLAG_TDLS_PEER))
				e->is_tdls = 1;
		}
	}

	e->noise = 0; /* filled in by caller */
	arr->count++;

	return NL_SKIP;
}

static int nl80211_get_assoclist(const char *ifname, char *buf, int *len)
{
	DIR *d;
	int i, noise = 0;
	struct dirent *de;
	struct nl80211_msg_conveyor *req;
	struct nl80211_array_buf arr = { .buf = buf, .count = 0 };
	struct iwinfo_assoclist_entry *e;

	if ((d = opendir("/sys/class/net")) != NULL)
	{
		while ((de = readdir(d)) != NULL)
		{
			if (!strncmp(de->d_name, ifname, strlen(ifname)) &&
			    (!de->d_name[strlen(ifname)] ||
			     !strncmp(&de->d_name[strlen(ifname)], ".sta", 4)))
			{
				req = nl80211_msg(de->d_name, NL80211_CMD_GET_STATION,
				                  NLM_F_DUMP);

				if (req)
				{
					nl80211_send(req, nl80211_get_assoclist_cb, &arr);
					nl80211_free(req);
				}
			}
		}

		closedir(d);

		if (!nl80211_get_noise(ifname, &noise))
			for (i = 0, e = arr.buf; i < arr.count; i++, e++)
				e->noise = noise;

		*len = (arr.count * sizeof(struct iwinfo_assoclist_entry));
		return 0;
	}

	return -1;
}

static int nl80211_get_txpwrlist_cb(struct nl_msg *msg, void *arg)
{
	int *dbm_max = arg;
	int ch_cur, ch_cmp, bands_remain, freqs_remain;

	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *bands[NL80211_BAND_ATTR_MAX + 1];
	struct nlattr *freqs[NL80211_FREQUENCY_ATTR_MAX + 1];
	struct nlattr *band, *freq;

	static struct nla_policy freq_policy[NL80211_FREQUENCY_ATTR_MAX + 1] = {
		[NL80211_FREQUENCY_ATTR_FREQ]         = { .type = NLA_U32  },
		[NL80211_FREQUENCY_ATTR_DISABLED]     = { .type = NLA_FLAG },
		[NL80211_FREQUENCY_ATTR_PASSIVE_SCAN] = { .type = NLA_FLAG },
		[NL80211_FREQUENCY_ATTR_NO_IBSS]      = { .type = NLA_FLAG },
		[NL80211_FREQUENCY_ATTR_RADAR]        = { .type = NLA_FLAG },
		[NL80211_FREQUENCY_ATTR_MAX_TX_POWER] = { .type = NLA_U32  },
	};

	ch_cur = *dbm_max; /* value int* is initialized with channel by caller */
	*dbm_max = -1;

	nla_for_each_nested(band, attr[NL80211_ATTR_WIPHY_BANDS], bands_remain)
	{
		nla_parse(bands, NL80211_BAND_ATTR_MAX, nla_data(band),
		          nla_len(band), NULL);

		nla_for_each_nested(freq, bands[NL80211_BAND_ATTR_FREQS], freqs_remain)
		{
			nla_parse(freqs, NL80211_FREQUENCY_ATTR_MAX,
			          nla_data(freq), nla_len(freq), freq_policy);

			ch_cmp = nl80211_freq2channel(nla_get_u32(
				freqs[NL80211_FREQUENCY_ATTR_FREQ]));

			if ((!ch_cur || (ch_cmp == ch_cur)) &&
			    freqs[NL80211_FREQUENCY_ATTR_MAX_TX_POWER])
			{
				*dbm_max = (int)(0.01 * nla_get_u32(
					freqs[NL80211_FREQUENCY_ATTR_MAX_TX_POWER]));

				break;
			}
		}
	}

	return NL_SKIP;
}

static int nl80211_get_txpwrlist(const char *ifname, char *buf, int *len)
{
	int ch_cur;
	int dbm_max = -1, dbm_cur, dbm_cnt;
	struct nl80211_msg_conveyor *req;
	struct iwinfo_txpwrlist_entry entry;

	if (nl80211_get_channel(ifname, &ch_cur))
		ch_cur = 0;

	req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
	if (req)
	{
		/* initialize the value pointer with channel for callback */
		dbm_max = ch_cur;

		nl80211_send(req, nl80211_get_txpwrlist_cb, &dbm_max);
		nl80211_free(req);
	}

	if (dbm_max > 0)
	{
		for (dbm_cur = 0, dbm_cnt = 0;
		     dbm_cur < dbm_max;
		     dbm_cur++, dbm_cnt++)
		{
			entry.dbm = dbm_cur;
			entry.mw  = iwinfo_dbm2mw(dbm_cur);

			memcpy(&buf[dbm_cnt * sizeof(entry)], &entry, sizeof(entry));
		}

		entry.dbm = dbm_max;
		entry.mw  = iwinfo_dbm2mw(dbm_max);

		memcpy(&buf[dbm_cnt * sizeof(entry)], &entry, sizeof(entry));
		dbm_cnt++;

		*len = dbm_cnt * sizeof(entry);
		return 0;
	}

	return -1;
}

static void nl80211_get_scancrypto(const char *spec,
	struct iwinfo_crypto_entry *c)
{
	if (strstr(spec, "WPA") || strstr(spec, "WEP"))
	{
		c->enabled = 1;

		if (strstr(spec, "WPA2-") && strstr(spec, "WPA-"))
			c->wpa_version = 3;

		else if (strstr(spec, "WPA2"))
			c->wpa_version = 2;

		else if (strstr(spec, "WPA"))
			c->wpa_version = 1;

		else if (strstr(spec, "WEP"))
			c->auth_algs = IWINFO_AUTH_OPEN | IWINFO_AUTH_SHARED;


		if (strstr(spec, "PSK"))
			c->auth_suites |= IWINFO_KMGMT_PSK;

		if (strstr(spec, "802.1X") || strstr(spec, "EAP"))
			c->auth_suites |= IWINFO_KMGMT_8021x;

		if (strstr(spec, "WPA-NONE"))
			c->auth_suites |= IWINFO_KMGMT_NONE;


		if (strstr(spec, "TKIP"))
			c->pair_ciphers |= IWINFO_CIPHER_TKIP;

		if (strstr(spec, "CCMP"))
			c->pair_ciphers |= IWINFO_CIPHER_CCMP;

		if (strstr(spec, "WEP-40"))
			c->pair_ciphers |= IWINFO_CIPHER_WEP40;

		if (strstr(spec, "WEP-104"))
			c->pair_ciphers |= IWINFO_CIPHER_WEP104;

		c->group_ciphers = c->pair_ciphers;
	}
	else
	{
		c->enabled = 0;
	}
}


struct nl80211_scanlist {
	struct iwinfo_scanlist_entry *e;
	int len;
};


static void nl80211_get_scanlist_ie(struct nlattr **bss,
                                    struct iwinfo_scanlist_entry *e)
{
	int ielen = nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
	unsigned char *ie = nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
	static unsigned char ms_oui[3] = { 0x00, 0x50, 0xf2 };
	int len;

	while (ielen >= 2 && ielen >= ie[1])
	{
		switch (ie[0])
		{
		case 0: /* SSID */
			len = min(ie[1], IWINFO_ESSID_MAX_SIZE);
			memcpy(e->ssid, ie + 2, len);
			e->ssid[len] = 0;
			break;

		case 48: /* RSN */
			iwinfo_parse_rsn(&e->crypto, ie + 2, ie[1],
			                 IWINFO_CIPHER_CCMP, IWINFO_KMGMT_8021x);
			break;

		case 221: /* Vendor */
			if (ie[1] >= 4 && !memcmp(ie + 2, ms_oui, 3) && ie[5] == 1)
				iwinfo_parse_rsn(&e->crypto, ie + 6, ie[1] - 4,
				                 IWINFO_CIPHER_TKIP, IWINFO_KMGMT_PSK);
			break;
		}

		ielen -= ie[1] + 2;
		ie += ie[1] + 2;
	}
}

static int nl80211_get_scanlist_cb(struct nl_msg *msg, void *arg)
{
	int8_t rssi;
	uint16_t caps;

	struct nl80211_scanlist *sl = arg;
	struct nlattr **tb = nl80211_parse(msg);
	struct nlattr *bss[NL80211_BSS_MAX + 1];

	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]                = { 0 },
		[NL80211_BSS_BEACON_INTERVAL]      = { .type = NLA_U16 },
		[NL80211_BSS_CAPABILITY]           = { .type = NLA_U16 },
		[NL80211_BSS_INFORMATION_ELEMENTS] = { 0 },
		[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]           = { 0 },
	};

	if (!tb[NL80211_ATTR_BSS] ||
		nla_parse_nested(bss, NL80211_BSS_MAX, tb[NL80211_ATTR_BSS],
		                 bss_policy) ||
		!bss[NL80211_BSS_BSSID])
	{
		return NL_SKIP;
	}

	if (bss[NL80211_BSS_CAPABILITY])
		caps = nla_get_u16(bss[NL80211_BSS_CAPABILITY]);
	else
		caps = 0;

	memset(sl->e, 0, sizeof(*sl->e));
	memcpy(sl->e->mac, nla_data(bss[NL80211_BSS_BSSID]), 6);

	if (caps & (1<<1))
		sl->e->mode = IWINFO_OPMODE_ADHOC;
	else if (caps & (1<<0))
		sl->e->mode = IWINFO_OPMODE_MASTER;
	else
		sl->e->mode = IWINFO_OPMODE_MESHPOINT;

	if (caps & (1<<4))
		sl->e->crypto.enabled = 1;

	if (bss[NL80211_BSS_FREQUENCY])
		sl->e->channel = nl80211_freq2channel(nla_get_u32(
			bss[NL80211_BSS_FREQUENCY]));

	if (bss[NL80211_BSS_INFORMATION_ELEMENTS])
		nl80211_get_scanlist_ie(bss, sl->e);

	if (bss[NL80211_BSS_SIGNAL_MBM])
	{
		sl->e->signal =
			(uint8_t)((int32_t)nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]) / 100);

		rssi = sl->e->signal - 0x100;

		if (rssi < -110)
			rssi = -110;
		else if (rssi > -40)
			rssi = -40;

		sl->e->quality = (rssi + 110);
		sl->e->quality_max = 70;
	}

	if (sl->e->crypto.enabled && !sl->e->crypto.wpa_version)
	{
		sl->e->crypto.auth_algs    = IWINFO_AUTH_OPEN | IWINFO_AUTH_SHARED;
		sl->e->crypto.pair_ciphers = IWINFO_CIPHER_WEP40 | IWINFO_CIPHER_WEP104;
	}

	sl->e++;
	sl->len++;

	return NL_SKIP;
}

static int nl80211_get_scanlist_nl(const char *ifname, char *buf, int *len)
{
	struct nl80211_msg_conveyor *req;
	struct nl80211_scanlist sl = { .e = (struct iwinfo_scanlist_entry *)buf };

	req = nl80211_msg(ifname, NL80211_CMD_TRIGGER_SCAN, 0);
	if (req)
	{
		nl80211_send(req, NULL, NULL);
		nl80211_free(req);
	}

	nl80211_wait("nl80211", "scan", NL80211_CMD_NEW_SCAN_RESULTS);

	req = nl80211_msg(ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);
	if (req)
	{
		nl80211_send(req, nl80211_get_scanlist_cb, &sl);
		nl80211_free(req);
	}

	*len = sl.len * sizeof(struct iwinfo_scanlist_entry);
	return *len ? 0 : -1;
}

static int wpasupp_ssid_decode(const char *in, char *out, int outlen)
{
#define hex(x) \
	(((x) >= 'a') ? ((x) - 'a' + 10) : \
		(((x) >= 'A') ? ((x) - 'A' + 10) : ((x) - '0')))

	int len = 0;

	while (*in)
	{
		if (len + 1 >= outlen)
			break;

		switch (*in)
		{
		case '\\':
			in++;
			switch (*in)
			{
			case 'n':
				out[len++] = '\n'; in++;
				break;

			case 'r':
				out[len++] = '\r'; in++;
				break;

			case 't':
				out[len++] = '\t'; in++;
				break;

			case 'e':
				out[len++] = '\033'; in++;
				break;

			case 'x':
				if (isxdigit(*(in+1)) && isxdigit(*(in+2)))
					out[len++] = hex(*(in+1)) * 16 + hex(*(in+2));
				in += 3;
				break;

			default:
				out[len++] = *in++;
				break;
			}
			break;

		default:
			out[len++] = *in++;
			break;
		}
	}

	if (outlen > len)
		out[len] = '\0';

	return len;
}

static int nl80211_get_scanlist_wpactl(const char *ifname, char *buf, int *len)
{
	int sock, qmax, rssi, tries, count = -1, ready = 0;
	char *pos, *line, *bssid, *freq, *signal, *flags, *ssid, reply[4096];
	struct sockaddr_un local = { 0 };
	struct iwinfo_scanlist_entry *e = (struct iwinfo_scanlist_entry *)buf;

	sock = nl80211_wpactl_connect(ifname, &local);

	if (sock < 0)
		return sock;

	send(sock, "ATTACH", 6, 0);
	send(sock, "SCAN", 4, 0);

	/*
	 * wait for scan results:
	 *   nl80211_wpactl_recv() will use a timeout of 256ms and we need to scan
	 *   72 channels at most. We'll also receive two "OK" messages acknowledging
	 *   the "ATTACH" and "SCAN" commands and the driver might need a bit extra
	 *   time to process the results, so try 72 + 2 + 1 times.
	 */
	for (tries = 0; tries < 75; tries++)
	{
		if (nl80211_wpactl_recv(sock, reply, sizeof(reply)) <= 0)
			continue;

		/* got an event notification */
		if (reply[0] == '<')
		{
			/* scan results are ready */
			if (strstr(reply, "CTRL-EVENT-SCAN-RESULTS"))
			{
				/* send "SCAN_RESULTS" command */
				ready = (send(sock, "SCAN_RESULTS", 12, 0) == 12);
				break;
			}

			/* is another unrelated event, retry */
			tries--;
		}
	}

	/* receive and parse scan results if the wait above didn't time out */
	if (ready && nl80211_wpactl_recv(sock, reply, sizeof(reply)) > 0)
	{
		nl80211_get_quality_max(ifname, &qmax);

		for (line = strtok_r(reply, "\n", &pos);
		     line != NULL;
		     line = strtok_r(NULL, "\n", &pos))
		{
			/* skip header line */
			if (count < 0)
			{
				count++;
				continue;
			}

			bssid  = strtok(line, "\t");
			freq   = strtok(NULL, "\t");
			signal = strtok(NULL, "\t");
			flags  = strtok(NULL, "\t");
			ssid   = strtok(NULL, "\n");

			if (!bssid || !freq || !signal || !flags || !ssid)
				continue;

			/* BSSID */
			e->mac[0] = strtol(&bssid[0],  NULL, 16);
			e->mac[1] = strtol(&bssid[3],  NULL, 16);
			e->mac[2] = strtol(&bssid[6],  NULL, 16);
			e->mac[3] = strtol(&bssid[9],  NULL, 16);
			e->mac[4] = strtol(&bssid[12], NULL, 16);
			e->mac[5] = strtol(&bssid[15], NULL, 16);

			/* SSID */
			wpasupp_ssid_decode(ssid, e->ssid, sizeof(e->ssid));

			/* Mode */
			if (strstr(flags, "[MESH]"))
				e->mode = IWINFO_OPMODE_MESHPOINT;
			else if (strstr(flags, "[IBSS]"))
				e->mode = IWINFO_OPMODE_ADHOC;
			else
				e->mode = IWINFO_OPMODE_MASTER;

			/* Channel */
			e->channel = nl80211_freq2channel(atoi(freq));

			/* Signal */
			rssi = atoi(signal);
			e->signal = rssi;

			/* Quality */
			if (rssi < 0)
			{
				/* The cfg80211 wext compat layer assumes a signal range
				 * of -110 dBm to -40 dBm, the quality value is derived
				 * by adding 110 to the signal level */
				if (rssi < -110)
					rssi = -110;
				else if (rssi > -40)
					rssi = -40;

				e->quality = (rssi + 110);
			}
			else
			{
				e->quality = rssi;
			}

			/* Max. Quality */
			e->quality_max = qmax;

			/* Crypto */
			nl80211_get_scancrypto(flags, &e->crypto);

			count++;
			e++;
		}

		*len = count * sizeof(struct iwinfo_scanlist_entry);
	}

	close(sock);
	unlink(local.sun_path);

	return (count >= 0) ? 0 : -1;
}

static int nl80211_get_scanlist(const char *ifname, char *buf, int *len)
{
	char *res;
	int rv, mode;

	*len = 0;

	/* Got a radioX pseudo interface, find some interface on it or create one */
	if (!strncmp(ifname, "radio", 5))
	{
		/* Reuse existing interface */
		if ((res = nl80211_phy2ifname(ifname)) != NULL)
		{
			return nl80211_get_scanlist(res, buf, len);
		}

		/* Need to spawn a temporary iface for scanning */
		else if ((res = nl80211_ifadd(ifname)) != NULL)
		{
			rv = nl80211_get_scanlist(res, buf, len);
			nl80211_ifdel(res);
			return rv;
		}
	}

	/* WPA supplicant */
	if (!nl80211_get_scanlist_wpactl(ifname, buf, len))
	{
		return 0;
	}

	/* station / ad-hoc / monitor scan */
	else if (!nl80211_get_mode(ifname, &mode) &&
	         (mode == IWINFO_OPMODE_ADHOC ||
	          mode == IWINFO_OPMODE_MASTER ||
	          mode == IWINFO_OPMODE_CLIENT ||
	          mode == IWINFO_OPMODE_MONITOR) &&
	         iwinfo_ifup(ifname))
	{
		return nl80211_get_scanlist_nl(ifname, buf, len);
	}

	/* AP scan */
	else
	{
		/* Got a temp interface, don't create yet another one */
		if (!strncmp(ifname, "tmp.", 4))
		{
			if (!iwinfo_ifup(ifname))
				return -1;

			rv = nl80211_get_scanlist_nl(ifname, buf, len);
			iwinfo_ifdown(ifname);
			return rv;
		}

		/* Spawn a new scan interface */
		else
		{
			if (!(res = nl80211_ifadd(ifname)))
				return -1;

			iwinfo_ifmac(res);

			/* if we can take the new interface up, the driver supports an
			 * additional interface and there's no need to tear down the ap */
			if (iwinfo_ifup(res))
			{
				rv = nl80211_get_scanlist_nl(res, buf, len);
				iwinfo_ifdown(res);
			}

			/* driver cannot create secondary interface, take down ap
			 * during scan */
			else if (iwinfo_ifdown(ifname) && iwinfo_ifup(res))
			{
				rv = nl80211_get_scanlist_nl(res, buf, len);
				iwinfo_ifdown(res);
				iwinfo_ifup(ifname);
				nl80211_hostapd_hup(ifname);
			}

			nl80211_ifdel(res);
			return rv;
		}
	}

	return -1;
}

static int nl80211_get_freqlist_cb(struct nl_msg *msg, void *arg)
{
	int bands_remain, freqs_remain;

	struct nl80211_array_buf *arr = arg;
	struct iwinfo_freqlist_entry *e = arr->buf;

	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *bands[NL80211_BAND_ATTR_MAX + 1];
	struct nlattr *freqs[NL80211_FREQUENCY_ATTR_MAX + 1];
	struct nlattr *band, *freq;

	nla_for_each_nested(band, attr[NL80211_ATTR_WIPHY_BANDS], bands_remain)
	{
		nla_parse(bands, NL80211_BAND_ATTR_MAX,
		          nla_data(band), nla_len(band), NULL);

		nla_for_each_nested(freq, bands[NL80211_BAND_ATTR_FREQS], freqs_remain)
		{
			nla_parse(freqs, NL80211_FREQUENCY_ATTR_MAX,
			          nla_data(freq), nla_len(freq), NULL);

			if (!freqs[NL80211_FREQUENCY_ATTR_FREQ] ||
			    freqs[NL80211_FREQUENCY_ATTR_DISABLED])
				continue;

			e->mhz = nla_get_u32(freqs[NL80211_FREQUENCY_ATTR_FREQ]);
			e->channel = nl80211_freq2channel(e->mhz);

			e->restricted = (
				freqs[NL80211_FREQUENCY_ATTR_NO_IR] &&
				!freqs[NL80211_FREQUENCY_ATTR_RADAR]
			) ? 1 : 0;

			e++;
			arr->count++;
		}
	}

	return NL_SKIP;
}

static int nl80211_get_freqlist(const char *ifname, char *buf, int *len)
{
	struct nl80211_msg_conveyor *req;
	struct nl80211_array_buf arr = { .buf = buf, .count = 0 };

	req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
	if (req)
	{
		nl80211_send(req, nl80211_get_freqlist_cb, &arr);
		nl80211_free(req);
	}

	if (arr.count > 0)
	{
		*len = arr.count * sizeof(struct iwinfo_freqlist_entry);
		return 0;
	}

	return -1;
}

static int nl80211_get_country_cb(struct nl_msg *msg, void *arg)
{
	char *buf = arg;
	struct nlattr **attr = nl80211_parse(msg);

	if (attr[NL80211_ATTR_REG_ALPHA2])
		memcpy(buf, nla_data(attr[NL80211_ATTR_REG_ALPHA2]), 2);
	else
		buf[0] = 0;

	return NL_SKIP;
}

static int nl80211_get_country(const char *ifname, char *buf)
{
	int rv = -1;
	struct nl80211_msg_conveyor *req;

	req = nl80211_msg(ifname, NL80211_CMD_GET_REG, 0);
	if (req)
	{
		nl80211_send(req, nl80211_get_country_cb, buf);
		nl80211_free(req);

		if (buf[0])
			rv = 0;
	}

	return rv;
}

static int nl80211_get_countrylist(const char *ifname, char *buf, int *len)
{
	int count;
	struct iwinfo_country_entry *e = (struct iwinfo_country_entry *)buf;
	const struct iwinfo_iso3166_label *l;

	for (l = IWINFO_ISO3166_NAMES, count = 0; l->iso3166; l++, e++, count++)
	{
		e->iso3166 = l->iso3166;
		e->ccode[0] = (l->iso3166 / 256);
		e->ccode[1] = (l->iso3166 % 256);
		e->ccode[2] = 0;
	}

	*len = (count * sizeof(struct iwinfo_country_entry));
	return 0;
}


struct nl80211_modes
{
	bool ok;
	uint32_t hw;
	uint32_t ht;
};

static int nl80211_get_modelist_cb(struct nl_msg *msg, void *arg)
{
	struct nl80211_modes *m = arg;
	int bands_remain, freqs_remain;
	uint16_t caps = 0;
	uint32_t vht_caps = 0;
	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *bands[NL80211_BAND_ATTR_MAX + 1];
	struct nlattr *freqs[NL80211_FREQUENCY_ATTR_MAX + 1];
	struct nlattr *band, *freq;

	if (attr[NL80211_ATTR_WIPHY_BANDS])
	{
		nla_for_each_nested(band, attr[NL80211_ATTR_WIPHY_BANDS], bands_remain)
		{
			nla_parse(bands, NL80211_BAND_ATTR_MAX,
			          nla_data(band), nla_len(band), NULL);

			if (bands[NL80211_BAND_ATTR_HT_CAPA])
				caps = nla_get_u16(bands[NL80211_BAND_ATTR_HT_CAPA]);

			/* Treat any nonzero capability as 11n */
			if (caps > 0)
			{
				m->hw |= IWINFO_80211_N;
				m->ht |= IWINFO_HTMODE_HT20;

				if (caps & (1 << 1))
					m->ht |= IWINFO_HTMODE_HT40;
			}

			nla_for_each_nested(freq, bands[NL80211_BAND_ATTR_FREQS],
			                    freqs_remain)
			{
				nla_parse(freqs, NL80211_FREQUENCY_ATTR_MAX,
				          nla_data(freq), nla_len(freq), NULL);

				if (!freqs[NL80211_FREQUENCY_ATTR_FREQ])
					continue;

				if (nla_get_u32(freqs[NL80211_FREQUENCY_ATTR_FREQ]) < 2485)
				{
					m->hw |= IWINFO_80211_B;
					m->hw |= IWINFO_80211_G;
				}
				else if (bands[NL80211_BAND_ATTR_VHT_CAPA])
				{
					vht_caps = nla_get_u32(bands[NL80211_BAND_ATTR_VHT_CAPA]);

					/* Treat any nonzero capability as 11ac */
					if (vht_caps > 0)
					{
						m->hw |= IWINFO_80211_AC;
						m->ht |= IWINFO_HTMODE_VHT20 | IWINFO_HTMODE_VHT40 | IWINFO_HTMODE_VHT80;

						switch ((vht_caps >> 2) & 3)
						{
						case 2:
							m->ht |= IWINFO_HTMODE_VHT80_80;
							/* fall through */

						case 1:
							m->ht |= IWINFO_HTMODE_VHT160;
						}
					}
				}
				else if (!(m->hw & IWINFO_80211_AC))
				{
					m->hw |= IWINFO_80211_A;
				}
			}
		}

		m->ok = 1;
	}

	return NL_SKIP;
}

static int nl80211_get_hwmodelist(const char *ifname, int *buf)
{
	struct nl80211_msg_conveyor *req;
	struct nl80211_modes m = { 0 };

	req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
	if (req)
	{
		nl80211_send(req, nl80211_get_modelist_cb, &m);
		nl80211_free(req);
	}

	if (m.ok)
	{
		*buf = m.hw;
		return 0;
	}

	return -1;
}

static int nl80211_get_htmodelist(const char *ifname, int *buf)
{
	struct nl80211_msg_conveyor *req;
	struct nl80211_modes m = { 0 };

	req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
	if (req)
	{
		nl80211_send(req, nl80211_get_modelist_cb, &m);
		nl80211_free(req);
	}

	if (m.ok)
	{
		*buf = m.ht;
		return 0;
	}

	return -1;
}


static int nl80211_get_ifcomb_cb(struct nl_msg *msg, void *arg)
{
	struct nlattr **attr = nl80211_parse(msg);
	struct nlattr *comb;
	int *ret = arg;
	int comb_rem, limit_rem, mode_rem;

	*ret = 0;
	if (!attr[NL80211_ATTR_INTERFACE_COMBINATIONS])
		return NL_SKIP;

	nla_for_each_nested(comb, attr[NL80211_ATTR_INTERFACE_COMBINATIONS], comb_rem)
	{
		static struct nla_policy iface_combination_policy[NUM_NL80211_IFACE_COMB] = {
			[NL80211_IFACE_COMB_LIMITS] = { .type = NLA_NESTED },
			[NL80211_IFACE_COMB_MAXNUM] = { .type = NLA_U32 },
		};
		struct nlattr *tb_comb[NUM_NL80211_IFACE_COMB+1];
		static struct nla_policy iface_limit_policy[NUM_NL80211_IFACE_LIMIT] = {
			[NL80211_IFACE_LIMIT_TYPES] = { .type = NLA_NESTED },
			[NL80211_IFACE_LIMIT_MAX] = { .type = NLA_U32 },
		};
		struct nlattr *tb_limit[NUM_NL80211_IFACE_LIMIT+1];
		struct nlattr *limit;

		nla_parse_nested(tb_comb, NUM_NL80211_IFACE_COMB, comb, iface_combination_policy);

		if (!tb_comb[NL80211_IFACE_COMB_LIMITS])
			continue;

		nla_for_each_nested(limit, tb_comb[NL80211_IFACE_COMB_LIMITS], limit_rem)
		{
			struct nlattr *mode;

			nla_parse_nested(tb_limit, NUM_NL80211_IFACE_LIMIT, limit, iface_limit_policy);

			if (!tb_limit[NL80211_IFACE_LIMIT_TYPES] ||
			    !tb_limit[NL80211_IFACE_LIMIT_MAX])
				continue;

			if (nla_get_u32(tb_limit[NL80211_IFACE_LIMIT_MAX]) < 2)
				continue;

			nla_for_each_nested(mode, tb_limit[NL80211_IFACE_LIMIT_TYPES], mode_rem) {
				if (nla_type(mode) == NL80211_IFTYPE_AP)
					*ret = 1;
			}
		}
	}

	return NL_SKIP;
}

static int nl80211_get_mbssid_support(const char *ifname, int *buf)
{
	struct nl80211_msg_conveyor *req;

	req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
	if (!req)
		return -1;

	nl80211_send(req, nl80211_get_ifcomb_cb, buf);
	nl80211_free(req);
	return 0;
}

static int nl80211_get_hardware_id(const char *ifname, char *buf)
{
	int rv = -1;
	char *res;

	/* Got a radioX pseudo interface, find some interface on it or create one */
	if (!strncmp(ifname, "radio", 5))
	{
		/* Reuse existing interface */
		if ((res = nl80211_phy2ifname(ifname)) != NULL)
		{
			rv = wext_ops.hardware_id(res, buf);
		}

		/* Need to spawn a temporary iface for finding IDs */
		else if ((res = nl80211_ifadd(ifname)) != NULL)
		{
			rv = wext_ops.hardware_id(res, buf);
			nl80211_ifdel(res);
		}
	}
	else
	{
		rv = wext_ops.hardware_id(ifname, buf);
	}

	/* Failed to obtain hardware IDs, search board config */
	if (rv)
	{
		rv = iwinfo_hardware_id_from_mtd((struct iwinfo_hardware_id *)buf);
	}

	return rv;
}

static const struct iwinfo_hardware_entry *
nl80211_get_hardware_entry(const char *ifname)
{
	struct iwinfo_hardware_id id;

	if (nl80211_get_hardware_id(ifname, (char *)&id))
		return NULL;

	return iwinfo_hardware(&id);
}

static int nl80211_get_hardware_name(const char *ifname, char *buf)
{
	const struct iwinfo_hardware_entry *hw;

	if (!(hw = nl80211_get_hardware_entry(ifname)))
		sprintf(buf, "Generic MAC80211");
	else
		sprintf(buf, "%s %s", hw->vendor_name, hw->device_name);

	return 0;
}

static int nl80211_get_txpower_offset(const char *ifname, int *buf)
{
	const struct iwinfo_hardware_entry *hw;

	if (!(hw = nl80211_get_hardware_entry(ifname)))
		return -1;

	*buf = hw->txpower_offset;
	return 0;
}

static int nl80211_get_frequency_offset(const char *ifname, int *buf)
{
	const struct iwinfo_hardware_entry *hw;

	if (!(hw = nl80211_get_hardware_entry(ifname)))
		return -1;

	*buf = hw->frequency_offset;
	return 0;
}

static int nl80211_lookup_phyname(const char *section, char *buf)
{
	int idx;

	if ((idx = nl80211_phy_idx_from_uci(section)) < 0)
		return -1;

	sprintf(buf, "phy%d", idx);
	return 0;
}

const struct iwinfo_ops nl80211_ops = {
	.name             = "nl80211",
	.probe            = nl80211_probe,
	.channel          = nl80211_get_channel,
	.frequency        = nl80211_get_frequency,
	.frequency_offset = nl80211_get_frequency_offset,
	.txpower          = nl80211_get_txpower,
	.txpower_offset   = nl80211_get_txpower_offset,
	.bitrate          = nl80211_get_bitrate,
	.signal           = nl80211_get_signal,
	.noise            = nl80211_get_noise,
	.quality          = nl80211_get_quality,
	.quality_max      = nl80211_get_quality_max,
	.mbssid_support   = nl80211_get_mbssid_support,
	.hwmodelist       = nl80211_get_hwmodelist,
	.htmodelist       = nl80211_get_htmodelist,
	.mode             = nl80211_get_mode,
	.ssid             = nl80211_get_ssid,
	.bssid            = nl80211_get_bssid,
	.country          = nl80211_get_country,
	.hardware_id      = nl80211_get_hardware_id,
	.hardware_name    = nl80211_get_hardware_name,
	.encryption       = nl80211_get_encryption,
	.phyname          = nl80211_get_phyname,
	.assoclist        = nl80211_get_assoclist,
	.txpwrlist        = nl80211_get_txpwrlist,
	.scanlist         = nl80211_get_scanlist,
	.freqlist         = nl80211_get_freqlist,
	.countrylist      = nl80211_get_countrylist,
	.lookup_phy       = nl80211_lookup_phyname,
	.close            = nl80211_close
};