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Commit 4480f15c authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
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[PATCH] mac80211: clarify some mac80211 things 



The semantics of not having an add_interface callback are not well
defined, this callback is required because otherwise you cannot obtain
the requested MAC address of the device. Change the documentation to
reflect this, add a note about having no MAC address at all, add a
warning that mac_addr in struct ieee80211_if_init_conf can be NULL and
finally verify that a few callbacks are assigned by way of BUG_ON()

Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJiri Benc <jbenc@suse.cz>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 5558235c

include/net/mac80211.h

+12 −4
Original line number Diff line number Diff line
@@ -347,9 +347,16 @@ enum ieee80211_if_types { 
 * @mac_addr: pointer to MAC address of the interface. This pointer is valid

 *	until the interface is removed (i.e. it cannot be used after

 *	remove_interface() callback was called for this interface).

 *	This pointer will be %NULL for monitor interfaces, be careful.

 *

 * This structure is used in add_interface() and remove_interface()

 * callbacks of &struct ieee80211_hw.

 *

 * When you allow multiple interfaces to be added to your PHY, take care

 * that the hardware can actually handle multiple MAC addresses. However,

 * also take care that when there's no interface left with mac_addr != %NULL

 * you remove the MAC address from the device to avoid acknowledging packets

 * in pure monitor mode.

 */

struct ieee80211_if_init_conf {

	int if_id;
@@ -574,10 +581,11 @@ struct ieee80211_ops { 
	 * to returning zero. By returning non-zero addition of the interface

	 * is inhibited. Unless monitor_during_oper is set, it is guaranteed

	 * that monitor interfaces and normal interfaces are mutually

	 * exclusive. The open() handler is called after add_interface()

	 * if this is the first device added. At least one of the open()

	 * open() and add_interface() callbacks has to be assigned. If

	 * add_interface() is NULL, one STA interface is permitted only. */

	 * exclusive. If assigned, the open() handler is called after

	 * add_interface() if this is the first device added. The

	 * add_interface() callback has to be assigned because it is the only

	 * way to obtain the requested MAC address for any interface.

	 */

	int (*add_interface)(struct ieee80211_hw *hw,

			     struct ieee80211_if_init_conf *conf);

net/mac80211/ieee80211.c

+12 −17
Original line number Diff line number Diff line
@@ -2605,8 +2605,7 @@ static void ieee80211_start_hard_monitor(struct ieee80211_local *local) 
	struct ieee80211_if_init_conf conf;



	if (local->open_count && local->open_count == local->monitors &&

	    !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER) &&

	    local->ops->add_interface) {

	    !(local->hw.flags & IEEE80211_HW_MONITOR_DURING_OPER)) {

		conf.if_id = -1;

		conf.type = IEEE80211_IF_TYPE_MNTR;

		conf.mac_addr = NULL;
@@ -2649,7 +2648,6 @@ static int ieee80211_open(struct net_device *dev) 
	}

	ieee80211_start_soft_monitor(local);



	if (local->ops->add_interface) {

	conf.if_id = dev->ifindex;

	conf.type = sdata->type;

	conf.mac_addr = dev->dev_addr;
@@ -2659,12 +2657,6 @@ static int ieee80211_open(struct net_device *dev) 
			ieee80211_start_hard_monitor(local);

		return res;

	}

	} else {

		if (sdata->type != IEEE80211_IF_TYPE_STA)

			return -EOPNOTSUPP;

		if (local->open_count > 0)

			return -ENOBUFS;

	}



	if (local->open_count == 0) {

		res = 0;
@@ -4896,6 +4888,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len, 
			 ((sizeof(struct ieee80211_local) +

			   NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);



	BUG_ON(!ops->tx);

	BUG_ON(!ops->config);

	BUG_ON(!ops->add_interface);

	local->ops = ops;



	/* for now, mdev needs sub_if_data :/ */