Commit 4480f15c authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville

[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
......@@ -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);
......
......@@ -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;
......@@ -2649,21 +2648,14 @@ 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;
res = local->ops->add_interface(local_to_hw(local), &conf);
if (res) {
if (sdata->type == IEEE80211_IF_TYPE_MNTR)
ieee80211_start_hard_monitor(local);
return res;
}
} else {
if (sdata->type != IEEE80211_IF_TYPE_STA)
return -EOPNOTSUPP;
if (local->open_count > 0)
return -ENOBUFS;
conf.if_id = dev->ifindex;
conf.type = sdata->type;
conf.mac_addr = dev->dev_addr;
res = local->ops->add_interface(local_to_hw(local), &conf);
if (res) {
if (sdata->type == IEEE80211_IF_TYPE_MNTR)
ieee80211_start_hard_monitor(local);
return res;
}
if (local->open_count == 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 :/ */
......
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