path: root/net/wireless/nl80211.c

/*
 * This is the new netlink-based wireless configuration interface.
 *
 * Copyright 2006, 2007	Johannes Berg <johannes@sipsolutions.net>
 */

#include <linux/if.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/mutex.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 <net/genetlink.h>
#include <net/cfg80211.h>
#include "core.h"
#include "nl80211.h"

/* 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,
};

/* internal helper: get drv and dev */
static int get_drv_dev_by_info_ifindex(struct genl_info *info,
				       struct cfg80211_registered_device **drv,
				       struct net_device **dev)
{
	int ifindex;

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

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

	*drv = cfg80211_get_dev_from_ifindex(ifindex);
	if (IS_ERR(*drv)) {
		dev_put(*dev);
		return PTR_ERR(*drv);
	}

	return 0;
}

/* policy for the attributes */
static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
	[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_NAME] = { .type = NLA_NUL_STRING,
				      .len = BUS_ID_SIZE-1 },

	[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_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_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 },
};

/* 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);
}

/* netlink command implementations */

static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
			      struct cfg80211_registered_device *dev)
{
	void *hdr;

	hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_WIPHY);
	if (!hdr)
		return -1;

	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->idx);
	NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
	return genlmsg_end(msg, hdr);

 nla_put_failure:
	return genlmsg_cancel(msg, hdr);
}

static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx = 0;
	int start = cb->args[0];
	struct cfg80211_registered_device *dev;

	mutex_lock(&cfg80211_drv_mutex);
	list_for_each_entry(dev, &cfg80211_drv_list, list) {
		if (++idx < start)
			continue;
		if (nl80211_send_wiphy(skb, NETLINK_CB(cb->skb).pid,
				       cb->nlh->nlmsg_seq, NLM_F_MULTI,
				       dev) < 0)
			break;
	}
	mutex_unlock(&cfg80211_drv_mutex);

	cb->args[0] = idx;

	return skb->len;
}

static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info)
{
	struct sk_buff *msg;
	struct cfg80211_registered_device *dev;

	dev = cfg80211_get_dev_from_info(info);
	if (IS_ERR(dev))
		return PTR_ERR(dev);

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
		goto out_err;

	if (nl80211_send_wiphy(msg, info->snd_pid, info->snd_seq, 0, dev) < 0)
		goto out_free;

	cfg80211_put_dev(dev);

	return genlmsg_unicast(msg, info->snd_pid);

 out_free