path: root/net/wireless/nl80211.c

/*
 * This is the new netlink-based wireless configuration interface.
 *
 * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
 */

#include <linux/if.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/if_ether.h>
#include <linux/ieee80211.h>
#include <linux/nl80211.h>
#include <linux/rtnetlink.h>
#include <linux/netlink.h>
#include <linux/etherdevice.h>
#include <net/net_namespace.h>
#include <net/genetlink.h>
#include <net/cfg80211.h>
#include <net/sock.h>
#include "core.h"
#include "nl80211.h"
#include "reg.h"

static int nl80211_pre_doit(struct genl_ops *ops, struct sk_buff *skb,
			    struct genl_info *info);
static void nl80211_post_doit(struct genl_ops *ops, struct sk_buff *skb,
			      struct genl_info *info);

/* the netlink family */
static struct genl_family nl80211_fam = {
	.id = GENL_ID_GENERATE,	/* don't bother with a hardcoded ID */
	.name = "nl80211",	/* have users key off the name instead */
	.hdrsize = 0,		/* no private header */
	.version = 1,		/* no particular meaning now */
	.maxattr = NL80211_ATTR_MAX,
	.netnsok = true,
	.pre_doit = nl80211_pre_doit,
	.post_doit = nl80211_post_doit,
};

/* internal helper: get rdev and dev */
static int get_rdev_dev_by_info_ifindex(struct genl_info *info,
				       struct cfg80211_registered_device **rdev,
				       struct net_device **dev)
{
	struct nlattr **attrs = info->attrs;
	int ifindex;

	if (!attrs[NL80211_ATTR_IFINDEX])
		return -EINVAL;

	ifindex = nla_get_u32(attrs[NL80211_ATTR_IFINDEX]);
	*dev = dev_get_by_index(genl_info_net(info), ifindex);
	if (!*dev)
		return -ENODEV;

	*rdev = cfg80211_get_dev_from_ifindex(genl_info_net(info), ifindex);
	if (IS_ERR(*rdev)) {
		dev_put(*dev);
		return PTR_ERR(*rdev);
	}

	return 0;
}

/* policy for the attributes */
static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
	[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_NAME] = { .type = NLA_NUL_STRING,
				      .len = 20-1 },
	[NL80211_ATTR_WIPHY_TXQ_PARAMS] = { .type = NLA_NESTED },
	[NL80211_ATTR_WIPHY_FREQ] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_CHANNEL_TYPE] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_RETRY_SHORT] = { .type = NLA_U8 },
	[NL80211_ATTR_WIPHY_RETRY_LONG] = { .type = NLA_U8 },
	[NL80211_ATTR_WIPHY_FRAG_THRESHOLD] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_RTS_THRESHOLD] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_COVERAGE_CLASS] = { .type = NLA_U8 },

	[NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
	[NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
	[NL80211_ATTR_IFNAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ-1 },

	[NL80211_ATTR_MAC] = { .type = NLA_BINARY, .len = ETH_ALEN },
	[NL80211_ATTR_PREV_BSSID] = { .type = NLA_BINARY, .len = ETH_ALEN },

	[NL80211_ATTR_KEY] = { .type = NLA_NESTED, },
	[NL80211_ATTR_KEY_DATA] = { .type = NLA_BINARY,
				    .len = WLAN_MAX_KEY_LEN },
	[NL80211_ATTR_KEY_IDX] = { .type = NLA_U8 },
	[NL80211_ATTR_KEY_CIPHER] = { .type = NLA_U32 },
	[NL80211_ATTR_KEY_DEFAULT] = { .type = NLA_FLAG },
	[NL80211_ATTR_KEY_SEQ] = { .type = NLA_BINARY, .len = 8 },
	[NL80211_ATTR_KEY_TYPE] = { .type = NLA_U32 },

	[NL80211_ATTR_BEACON_INTERVAL] = { .type = NLA_U32 },
	[NL80211_ATTR_DTIM_PERIOD] = { .type = NLA_U32 },
	[NL80211_ATTR_BEACON_HEAD] = { .type = NLA_BINARY,
				       .len = IEEE80211_MAX_DATA_LEN },
	[NL80211_ATTR_BEACON_TAIL] = { .type = NLA_BINARY,
				       .len = IEEE80211_MAX_DATA_LEN },
	[NL80211_ATTR_STA_AID] = { .type = NLA_U16 },
	[NL80211_ATTR_STA_FLAGS] = { .type = NLA_NESTED },
	[NL80211_ATTR_STA_LISTEN_INTERVAL] = { .type = NLA_U16 },
	[NL80211_ATTR_STA_SUPPORTED_RATES] = { .type = NLA_BINARY,
					       .len = NL80211_MAX_SUPP_RATES },
	[NL80211_ATTR_STA_PLINK_ACTION] = { .type = NLA_U8 },
	[NL80211_ATTR_STA_VLAN] = { .type = NLA_U32 },
	[NL80211_ATTR_MNTR_FLAGS] = { /* NLA_NESTED can't be empty */ },
	[NL80211_ATTR_MESH_ID] = { .type = NLA_BINARY,
				.len = IEEE80211_MAX_MESH_ID_LEN },
	[NL80211_ATTR_MPATH_NEXT_HOP] = { .type = NLA_U32 },

	[NL80211_ATTR_REG_ALPHA2] = { .type = NLA_STRING, .len = 2 },
	[NL80211_ATTR_REG_RULES] = { .type = NLA_NESTED },

	[NL80211_ATTR_BSS_CTS_PROT] = { .type = NLA_U8 },
	[NL80211_ATTR_BSS_SHORT_PREAMBLE] = { .type = NLA_U8 },
	[NL80211_ATTR_BSS_SHORT_SLOT_TIME] = { .type = NLA_U8 },
	[NL80211_ATTR_BSS_BASIC_RATES] = { .type = NLA_BINARY,
					   .len = NL80211_MAX_SUPP_RATES },
	[NL80211_ATTR_BSS_HT_OPMODE] = { .type = NLA_U16 },

	[NL80211_ATTR_MESH_CONFIG] = { .type = NLA_NESTED },
	[NL80211_ATTR_SUPPORT_MESH_AUTH] = { .type = NLA_FLAG },

	[NL80211_ATTR_HT_CAPABILITY] = { .type = NLA_BINARY,
					 .len = NL80211_HT_CAPABILITY_LEN },

	[NL80211_ATTR_MGMT_SUBTYPE] = { .type = NLA_U8 },
	[NL80211_ATTR_IE] = { .type = NLA_BINARY,
			      .len = IEEE80211_MAX_DATA_LEN },
	[NL80211_ATTR_SCAN_FREQUENCIES] = { .type = NLA_NESTED },
	[NL80211_ATTR_SCAN_SSIDS] = { .type = NLA_NESTED },

	[NL80211_ATTR_SSID] = { .type = NLA_BINARY,
				.len = IEEE80211_MAX_SSID_LEN },
	[NL80211_ATTR_AUTH_TYPE] = { .type = NLA_U32 },
	[NL80211_ATTR_REASON_CODE] = { .type = NLA_U16 },
	[NL80211_ATTR_FREQ_FIXED] = { .type = NLA_FLAG },
	[NL80211_ATTR_TIMED_OUT] = { .type = NLA_FLAG },
	[NL80211_ATTR_USE_MFP] = { .type = NLA_U32 },
	[NL80211_ATTR_STA_FLAGS2] = {
		.len = sizeof(struct nl80211_sta_flag_update),
	},
	[NL80211_ATTR_CONTROL_PORT] = { .type = NLA_FLAG },
	[NL80211_ATTR_CONTROL_PORT_ETHERTYPE] = { .type = NLA_U16 },
	[NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT] = { .type = NLA_FLAG },
	[NL80211_ATTR_PRIVACY] = { .type = NLA_FLAG },
	[NL80211_ATTR_CIPHER_SUITE_GROUP] = { .type = NLA_U32 },
	[NL80211_ATTR_WPA_VERSIONS] = { .type = NLA_U32 },
	[NL80211_ATTR_PID] = { .type = NLA_U32 },
	[NL80211_ATTR_4ADDR] = { .type = NLA_U8 },
	[NL80211_ATTR_PMKID] = { .type = NLA_BINARY,
				 .len = WLAN_PMKID_LEN },
	[NL80211_ATTR_DURATION] = { .type = NLA_U32 },
	[NL80211_ATTR_COOKIE] = { .type = NLA_U64 },
	[NL80211_ATTR_TX_RATES] = { .type = NLA_NESTED },
	[NL80211_ATTR_FRAME] = { .type = NLA_BINARY,
				 .len = IEEE80211_MAX_DATA_LEN },
	[NL80211_ATTR_FRAME_MATCH] = { .type = NLA_BINARY, },
	[NL80211_ATTR_PS_STATE] = { .type = NLA_U32 },
	[NL80211_ATTR_CQM] = { .type = NLA_NESTED, },
	[NL80211_ATTR_LOCAL_STATE_CHANGE] = { .type = NLA_FLAG },
	[NL80211_ATTR_AP_ISOLATE] = { .type = NLA_U8 },
	[NL80211_ATTR_WIPHY_TX_POWER_SETTING] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_TX_POWER_LEVEL] = { .type = NLA_U32 },
	[NL80211_ATTR_FRAME_TYPE] = { .type = NLA_U16 },
	[NL80211_ATTR_WIPHY_ANTENNA_TX] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_ANTENNA_RX] = { .type = NLA_U32 },
	[NL80211_ATTR_MCAST_RATE] = { .type = NLA_U32 },
	[NL80211_ATTR_OFFCHANNEL_TX_OK] = { .type = NLA_FLAG },
	[NL80211_ATTR_KEY_DEFAULT_TYPES] = { .type = NLA_NESTED },
	[NL80211_ATTR_WOWLAN_TRIGGERS] = { .type = NLA_NESTED },
	[NL80211_ATTR_STA_PLINK_STATE] = { .type = NLA_U8 },
	[NL80211_ATTR_SCHED_SCAN_INTERVAL] = { .type = NLA_U32 },
};

/* policy for the key attributes */
static const struct nla_policy nl80211_key_policy[NL80211_KEY_MAX + 1] = {
	[NL80211_KEY_DATA] = { .type = NLA_BINARY, .len = WLAN_MAX_KEY_LEN },
	[NL80211_KEY_IDX] = { .type = NLA_U8 },
	[NL80211_KEY_CIPHER] = { .type = NLA_U32 },
	[NL80211_KEY_SEQ] = { .type = NLA_BINARY, .len = 8 },
	[NL80211_KEY_DEFAULT] = { .type = NLA_FLAG },
	[NL80211_KEY_DEFAULT_MGMT] = { .type = NLA_FLAG },
	[NL80211_KEY_TYPE] = { .type = NLA_U32 },
	[NL80211_KEY_DEFAULT_TYPES] = { .type = NLA_NESTED },
};

/* policy for the key default flags */
static const struct nla_policy
nl80211_key_default_policy[NUM_NL80211_KEY_DEFAULT_TYPES] = {
	[NL80211_KEY_DEFAULT_TYPE_UNICAST] = { .type = NLA_FLAG },
	[NL80211_KEY_DEFAULT_TYPE_MULTICAST] = { .type = NLA_FLAG },
};

/* policy for WoWLAN attributes */
static const struct nla_policy
nl80211_wowlan_policy[NUM_NL80211_WOWLAN_TRIG] = {
	[NL80211_WOWLAN_TRIG_ANY] = { .type = NLA_FLAG },
	[NL80211_WOWLAN_TRIG_DISCONNECT] = { .type = NLA_FLAG },
	[NL80211_WOWLAN_TRIG_MAGIC_PKT] = { .type = NLA_FLAG },
	[NL80211_WOWLAN_TRIG_PKT_PATTERN] = { .type = NLA_NESTED },
};

/* ifidx get helper */
static int nl80211_get_ifidx(struct netlink_callback *cb)
{
	int res;

	res = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
			  nl80211_fam.attrbuf, nl80211_fam.maxattr,
			  nl80211_policy);
	if (res)
		return res;

	if (!nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX])
		return -EINVAL;

	res = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX]);
	if (!res)
		return -EINVAL;
	return res;
}

static int nl80211_prepare_netdev_dump(struct sk_buff *skb,
				       struct netlink_callback *cb,
				       struct cfg80211_registered_device **rdev,
				       struct net_device **dev)
{
	int ifidx = cb->args[0];
	int err;

	if (!ifidx)
		ifidx = nl80211_get_ifidx(cb);
	if (ifidx < 0)
		return ifidx;

	cb->args[0] = ifidx;

	rtnl_lock();

	*dev = __dev_get_by_index(sock_net(skb->sk), ifidx);
	if (!*dev) {
		err = -ENODEV;
		goto out_rtnl;
	}

	*rdev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
	if (IS_ERR(*rdev)) {
		err = PTR_ERR(*rdev);
		goto out_rtnl;
	}

	return 0;
 out_rtnl:
	rtnl_unlock();
	return err;
}

static void nl80211_finish_netdev_dump(struct cfg80211_registered_device *rdev)
{
	cfg80211_unlock_rdev(rdev);
	rtnl_unlock();
}

/* IE validation */
static bool is_valid_ie_attr(const struct nlattr *attr)
{
	const u8 *pos;
	int len;

	if (!attr)
		return true;

	pos = nla_data(attr);
	len = nla_len(attr);

	while (len) {
		u8 elemlen;

		if (len < 2)
			return false;
		len -= 2;

		elemlen = pos[1];
		if (elemlen > len)
			return false;

		len -= elemlen;
		pos += 2 + elemlen;
	}

	return true;
}

/* message building helper */
static inline void *nl80211hdr_put(struct sk_buff *skb, u32 pid, u32 seq,
				   int flags, u8 cmd)
{
	/* since there is no private header just add the generic one */
	return genlmsg_put(skb, pid, seq, &nl80211_fam, flags, cmd);
}

static int nl80211_msg_put_channel(struct sk_buff *msg,
				   struct ieee80211_channel *chan)
{
	NLA_PUT_U32(msg, NL80211_FREQUENCY_ATTR_FREQ,
		    chan->center_freq);

	if (chan->flags & IEEE80211_CHAN_DISABLED)
		NLA_PUT_FLAG(msg, NL80211_FREQUENCY_ATTR_DISABLED);
	if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
		NLA_PUT_FLAG(msg, NL80211_FREQUENCY_ATTR_PASSIVE_SCAN);
	if (chan->flags & IEEE80211_CHAN_NO_IBSS)
		NLA_PUT_FLAG(msg, NL80211_FREQUENCY_ATTR_NO_IBSS);
	if (chan->flags & IEEE80211_CHAN_RADAR)
		NLA_PUT_FLAG(msg, NL80211_FREQUENCY_ATTR_RADAR);

	NLA_PUT_U32(msg, NL80211_FREQUENCY_ATTR_MAX_TX_POWER,
		    DBM_TO_MBM(chan->max_power));

	return 0;

 nla_put_failure:
	return -ENOBUFS;
}

/* netlink command implementations */

struct key_parse {
	struct key_params p;
	int idx;
	int type;
	bool def, defmgmt;
	bool def_uni, def_multi;
};

static int nl80211_parse_key_new(struct nlattr *key, struct key_parse *k)
{
	struct nlattr *tb[NL80211_KEY_MAX + 1];
	int err = nla_parse_nested(tb, NL80211_KEY_MAX, key,
				   nl80211_key_policy);
	if (err)
		return err;

	k->def = !!tb[NL80211_KEY_DEFAULT];
	k->defmgmt = !!tb[NL80211_KEY_DEFAULT_MGMT];

	if (k->def) {
		k->def_uni = true;
		k->def_multi = true;
	}
	if (k->defmgmt)
		k->def_multi = true;

	if (tb[NL80211_KEY_IDX])
		k->idx = nla_get_u8(tb[NL80211_KEY_IDX]);

	if (tb[NL80211_KEY_DATA]) {
		k->p.key = nla_data(tb[NL80211_KEY_DATA]);
		k->p.key_len = nla_len(tb[NL80211_KEY_DATA]);
	}

	if (tb[NL80211_KEY_SEQ]) {
		k->p.seq = nla_data(tb[NL80211_KEY_SEQ]);
		k->p.seq_len = nla_len(tb[NL80211_KEY_SEQ]);
	}

	if (tb[NL80211_KEY_CIPHER])
		k->p.cipher = nla_get_u32(tb[NL80211_KEY_CIPHER]);

	if (tb[NL80211_KEY_TYPE]) {
		k->type = nla_get_u32(tb[NL80211_KEY_TYPE]);
		if (k->type < 0 || k->type >= NUM_NL80211_KEYTYPES)
			return -EINVAL;
	}

	if (tb[NL80211_KEY_DEFAULT_TYPES]) {
		struct nlattr *kdt[NUM_NL80211_KEY_DEFAULT_TYPES];
		int err = nla_parse_nested(kdt,
					   NUM_NL80211_KEY_DEFAULT_TYPES - 1,
					   tb[NL80211_KEY_DEFAULT_TYPES],
					   nl80211_key_default_policy);
		if (err)
			return err;

		k->def_uni = kdt[NL80211_KEY_DEFAULT_TYPE_UNICAST];
		k->def_multi = kdt[NL80211_KEY_DEFAULT_TYPE_MULTICAST];
	}

	return 0;
}

static int nl80211_parse_key_old(struct genl_info *info, struct key_parse *k)
{
	if (info->attrs[NL80211_ATTR_KEY_DATA]) {
		k->p.key = nla_data(info->attrs[NL80211_ATTR_KEY_DATA]);
		k->p.key_len = nla_len(info->attrs[NL80211_ATTR_KEY_DATA]);
	}

	if (info->attrs[NL80211_ATTR_KEY_SEQ]) {
		k->p.seq = nla_data(info->attrs[NL80211_ATTR_KEY_SEQ]);
		k->p.seq_len = nla_len(info->attrs[NL80211_ATTR_KEY_SEQ]);
	}

	if (info->attrs[NL80211_ATTR_KEY_IDX])
		k->idx = nla_get_u8(info->attrs[NL80211_ATTR_KEY_IDX]);

	if (info->attrs[NL80211_ATTR_KEY_CIPHER])
		k->p.cipher = nla_get_u32(info->attrs[NL80211_ATTR_KEY_CIPHER]);

	k->def = !!info->attrs[NL80211_ATTR_KEY_DEFAULT];
	k->defmgmt = !!info->attrs[NL80211_ATTR_KEY_DEFAULT_MGMT];

	if (k->def) {
		k->def_uni = true;
		k->def_multi = true;
	}
	if (k->defmgmt)
		k->def_multi = true;

	if (info->attrs[NL80211_ATTR_KEY_TYPE]) {
		k->type = nla_get_u32(info->attrs[NL80211_ATTR_KEY_TYPE]);
		if (k->type < 0 || k->type >= NUM_NL80211_KEYTYPES)
			return -EINVAL;
	}

	if (info->attrs[NL80211_ATTR_KEY_DEFAULT_TYPES]) {
		struct nlattr *kdt[NUM_NL80211_KEY_DEFAULT_TYPES];
		int err = nla_parse_nested(
				kdt, NUM_NL80211_KEY_DEFAULT_TYPES - 1,
				info->attrs[NL80211_ATTR_KEY_DEFAULT_TYPES],
				nl80211_key_default_policy);
		if (err)
			return err;

		k->def_uni = kdt[NL80211_KEY_DEFAULT_TYPE_UNICAST];
		k->def_multi = kdt[NL80211_KEY_DEFAULT_TYPE_MULTICAST];
	}

	return 0;
}

static int nl80211_parse_key(struct genl_info *info, struct key_parse *k)
{
	int err;

	memset(k, 0, sizeof(*k));
	k->idx = -1;
	k->type = -1;

	if (info->attrs[NL80211_ATTR_KEY])
		err = nl80211_parse_key_new(info->attrs[NL80211_ATTR_KEY], k);
	else
		err = nl80211_parse_key_old(info, k);

	if (err)
		return err;

	if (k->def && k->defmgmt)
		return -EINVAL;

	if (k->defmgmt) {
		if (k->def_uni || !k->def_multi)
			return -EINVAL;
	}

	if (k->idx != -1) {
		if (k->defmgmt) {
			if (k->idx < 4 || k->idx > 5)
				return -EINVAL;
		} else if (k->def) {
			if (k->idx < 0 || k->idx > 3)
				return -EINVAL;
		} else {
			if (k->idx < 0 || k->idx > 5)
				return -EINVAL;
		}
	}

	return 0;
}

static struct cfg80211_cached_keys *
nl80211_parse_connkeys(struct cfg80211_registered_device *rdev,
		       struct nlattr *keys)
{
	struct key_parse parse;
	struct nlattr *key;
	struct cfg80211_cached_keys *result;
	int rem, err, def = 0;

	result = kzalloc(sizeof(*result), GFP_KERNEL);
	if (!result)
		return ERR_PTR(-ENOMEM);

	result->def = -1;
	result->defmgmt = -1;

	nla_for_each_nested(key, keys, rem) {
		memset(&parse, 0, sizeof(parse));
		parse.idx = -1;

		err = nl80211_parse_key_new(key, &parse);
		if (err)
			goto error;
		err = -EINVAL;
		if (!parse.p.key)
			goto error;
		if (parse.idx < 0 || parse.idx > 4)
			goto error;
		if (parse.def) {
			if (def)
				goto error;
			def = 1;
			result->def = parse.idx;
			if (!parse.def_uni || !parse.def_multi)
				goto error;
		} else if (parse.defmgmt)
			goto error;
		err = cfg80211_validate_key_settings(rdev, &parse.p,
						     parse.idx, false, NULL);
		if (err)
			goto error;
		result->params[parse.idx].cipher = parse.p.cipher;
		result->params[parse.idx].key_len = parse.p.key_len;
		result->params[parse.idx].key = result->data[parse.idx];
		memcpy(result->data[parse.idx], parse.p.key, parse.p.key_len);
	}

	return result;
 error:
	kfree(result);
	return ERR_PTR(err);
}

static int nl80211_key_allowed(struct wireless_dev *wdev)
{
	ASSERT_WDEV_LOCK(wdev);

	switch (wdev->iftype) {
	case NL80211_IFTYPE_AP:
	case NL80211_IFTYPE_AP_VLAN:
	case NL80211_IFTYPE_P2P_GO:
	case NL80211_IFTYPE_MESH_POINT:
		break;
	case NL80211_IFTYPE_ADHOC:
		if (!wdev->current_bss)
			return -ENOLINK;
		break;
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_P2P_CLIENT:
		if (wdev->sme_state != CFG80211_SME_CONNECTED)
			return -ENOLINK;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int nl80211_put_iftypes(struct sk_buff *msg, u32 attr, u16 ifmodes)
{
	struct nlattr *nl_modes = nla_nest_start(msg, attr);
	int i;

	if (!nl_modes)
		goto nla_put_failure;

	i = 0;
	while (ifmodes) {
		if (ifmodes & 1)
			NLA_PUT_FLAG(msg, i);
		ifmodes >>= 1;
		i++;
	}

	nla_nest_end(msg, nl_modes);
	return 0;

nla_put_failure:
	return -ENOBUFS;
}

static int nl80211_put_iface_combinations(struct wiphy *wiphy,
					  struct sk_buff *msg)
{
	struct nlattr *nl_combis;
	int i, j;

	nl_combis = nla_nest_start(msg,
				NL80211_ATTR_INTERFACE_COMBINATIONS);
	if (!nl_combis)
		goto nla_put_failure;

	for (i = 0; i < wiphy->n_iface_combinations; i++) {
		const struct ieee80211_iface_combination *c;
		struct nlattr *nl_combi, *nl_limits;

		c = &wiphy->iface_combinations[i];

		nl_combi = nla_nest_start(msg, i + 1);
		if (!nl_combi)
			goto nla_put_failure;

		nl_limits = nla_nest_start(msg, NL80211_IFACE_COMB_LIMITS);
		if (!nl_limits)
			goto nla_put_failure;

		for (j = 0; j < c->n_limits; j++) {
			struct nlattr *nl_limit;

			nl_limit = nla_nest_start(msg, j + 1);
			if (!nl_limit)
				goto nla_put_failure;
			NLA_PUT_U32(msg, NL80211_IFACE_LIMIT_MAX,
				    c->limits[j].max);
			if (nl80211_put_iftypes(msg, NL80211_IFACE_LIMIT_TYPES,
						c->limits[j].types))
				goto nla_put_failure;
			nla_nest_end(msg, nl_limit);
		}

		nla_nest_end(msg, nl_limits);

		if (c->beacon_int_infra_match)
			NLA_PUT_FLAG(msg,
				NL80211_IFACE_COMB_STA_AP_BI_MATCH);
		NLA_PUT_U32(msg, NL80211_IFACE_COMB_NUM_CHANNELS,
			    c->num_different_channels);
		NLA_PUT_U32(msg, NL80211_IFACE_COMB_MAXNUM,
			    c->max_interfaces);

		nla_nest_end(msg, nl_combi);
	}

	nla_nest_end(msg, nl_combis);