Commit 7bdbe400 authored by Johannes Berg's avatar Johannes Berg
Browse files

nl80211: support vendor dumpit commands 



In order to transfer many items in vendor commands, support the
dumpit netlink method for them.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent dd55ab59

include/net/cfg80211.h

+9 −0
Original line number Diff line number Diff line
@@ -2971,12 +2971,21 @@ enum wiphy_vendor_command_flags { 
 * @doit: callback for the operation, note that wdev is %NULL if the

 *	flags didn't ask for a wdev and non-%NULL otherwise; the data

 *	pointer may be %NULL if userspace provided no data at all

 * @dumpit: dump callback, for transferring bigger/multiple items. The

 *	@storage points to cb->args[5], ie. is preserved over the multiple

 *	dumpit calls.

 * It's recommended to not have the same sub command with both @doit and

 * @dumpit, so that userspace can assume certain ones are get and others

 * are used with dump requests.

 */

struct wiphy_vendor_command {

	struct nl80211_vendor_cmd_info info;

	u32 flags;

	int (*doit)(struct wiphy *wiphy, struct wireless_dev *wdev,

		    const void *data, int data_len);

	int (*dumpit)(struct wiphy *wiphy, struct wireless_dev *wdev,

		      struct sk_buff *skb, const void *data, int data_len,

		      unsigned long *storage);

};



/**

net/wireless/nl80211.c

+192 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 *

 * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>

 * Copyright 2013-2014  Intel Mobile Communications GmbH

 * Copyright 2015	Intel Deutschland GmbH

 */



#include <linux/if.h>
@@ -9938,6 +9939,9 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info) 
				if (!wdev->netdev && !wdev->p2p_started)

					return -ENETDOWN;

			}



			if (!vcmd->doit)

				return -EOPNOTSUPP;

		} else {

			wdev = NULL;

		}
@@ -9957,6 +9961,193 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info) 
	return -EOPNOTSUPP;

}



static int nl80211_prepare_vendor_dump(struct sk_buff *skb,

				       struct netlink_callback *cb,

				       struct cfg80211_registered_device **rdev,

				       struct wireless_dev **wdev)

{

	u32 vid, subcmd;

	unsigned int i;

	int vcmd_idx = -1;

	int err;

	void *data = NULL;

	unsigned int data_len = 0;



	rtnl_lock();



	if (cb->args[0]) {

		/* subtract the 1 again here */

		struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0] - 1);

		struct wireless_dev *tmp;



		if (!wiphy) {

			err = -ENODEV;

			goto out_unlock;

		}

		*rdev = wiphy_to_rdev(wiphy);

		*wdev = NULL;



		if (cb->args[1]) {

			list_for_each_entry(tmp, &(*rdev)->wdev_list, list) {

				if (tmp->identifier == cb->args[1] - 1) {

					*wdev = tmp;

					break;

				}

			}

		}



		/* keep rtnl locked in successful case */

		return 0;

	}



	err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,

			  nl80211_fam.attrbuf, nl80211_fam.maxattr,

			  nl80211_policy);

	if (err)

		goto out_unlock;



	if (!nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_ID] ||

	    !nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD]) {

		err = -EINVAL;

		goto out_unlock;

	}



	*wdev = __cfg80211_wdev_from_attrs(sock_net(skb->sk),

					   nl80211_fam.attrbuf);

	if (IS_ERR(*wdev))

		*wdev = NULL;



	*rdev = __cfg80211_rdev_from_attrs(sock_net(skb->sk),

					   nl80211_fam.attrbuf);

	if (IS_ERR(*rdev)) {

		err = PTR_ERR(*rdev);

		goto out_unlock;

	}



	vid = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_ID]);

	subcmd = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_SUBCMD]);



	for (i = 0; i < (*rdev)->wiphy.n_vendor_commands; i++) {

		const struct wiphy_vendor_command *vcmd;



		vcmd = &(*rdev)->wiphy.vendor_commands[i];



		if (vcmd->info.vendor_id != vid || vcmd->info.subcmd != subcmd)

			continue;



		if (!vcmd->dumpit) {

			err = -EOPNOTSUPP;

			goto out_unlock;

		}



		vcmd_idx = i;

		break;

	}



	if (vcmd_idx < 0) {

		err = -EOPNOTSUPP;

		goto out_unlock;

	}



	if (nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]) {

		data = nla_data(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]);

		data_len = nla_len(nl80211_fam.attrbuf[NL80211_ATTR_VENDOR_DATA]);

	}



	/* 0 is the first index - add 1 to parse only once */

	cb->args[0] = (*rdev)->wiphy_idx + 1;

	/* add 1 to know if it was NULL */

	cb->args[1] = *wdev ? (*wdev)->identifier + 1 : 0;

	cb->args[2] = vcmd_idx;

	cb->args[3] = (unsigned long)data;

	cb->args[4] = data_len;



	/* keep rtnl locked in successful case */

	return 0;

 out_unlock:

	rtnl_unlock();

	return err;

}



static int nl80211_vendor_cmd_dump(struct sk_buff *skb,

				   struct netlink_callback *cb)

{

	struct cfg80211_registered_device *rdev;

	struct wireless_dev *wdev;

	unsigned int vcmd_idx;

	const struct wiphy_vendor_command *vcmd;

	void *data;

	int data_len;

	int err;

	struct nlattr *vendor_data;



	err = nl80211_prepare_vendor_dump(skb, cb, &rdev, &wdev);

	if (err)

		return err;



	vcmd_idx = cb->args[2];

	data = (void *)cb->args[3];

	data_len = cb->args[4];

	vcmd = &rdev->wiphy.vendor_commands[vcmd_idx];



	if (vcmd->flags & (WIPHY_VENDOR_CMD_NEED_WDEV |

			   WIPHY_VENDOR_CMD_NEED_NETDEV)) {

		if (!wdev)

			return -EINVAL;

		if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_NETDEV &&

		    !wdev->netdev)

			return -EINVAL;



		if (vcmd->flags & WIPHY_VENDOR_CMD_NEED_RUNNING) {

			if (wdev->netdev &&

			    !netif_running(wdev->netdev))

				return -ENETDOWN;

			if (!wdev->netdev && !wdev->p2p_started)

				return -ENETDOWN;

		}

	}



	while (1) {

		void *hdr = nl80211hdr_put(skb, NETLINK_CB(cb->skb).portid,

					   cb->nlh->nlmsg_seq, NLM_F_MULTI,

					   NL80211_CMD_VENDOR);

		if (!hdr)

			break;



		if (nla_put_u32(skb, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||

		    (wdev && nla_put_u64(skb, NL80211_ATTR_WDEV,

					 wdev_id(wdev)))) {

			genlmsg_cancel(skb, hdr);

			break;

		}



		vendor_data = nla_nest_start(skb, NL80211_ATTR_VENDOR_DATA);

		if (!vendor_data) {

			genlmsg_cancel(skb, hdr);

			break;

		}



		err = vcmd->dumpit(&rdev->wiphy, wdev, skb, data, data_len,

				   (unsigned long *)&cb->args[5]);

		nla_nest_end(skb, vendor_data);



		if (err == -ENOBUFS || err == -ENOENT) {

			genlmsg_cancel(skb, hdr);

			break;

		} else if (err) {

			genlmsg_cancel(skb, hdr);

			goto out;

		}



		genlmsg_end(skb, hdr);

	}



	err = skb->len;

 out:

	rtnl_unlock();

	return err;

}



struct sk_buff *__cfg80211_alloc_reply_skb(struct wiphy *wiphy,

					   enum nl80211_commands cmd,

					   enum nl80211_attrs attr,
@@ -10994,6 +11185,7 @@ static const struct genl_ops nl80211_ops[] = { 
	{

		.cmd = NL80211_CMD_VENDOR,

		.doit = nl80211_vendor_cmd,

		.dumpit = nl80211_vendor_cmd_dump,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_WIPHY |