[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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 6278857..c34fd9a 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -347,9 +347,16 @@
* @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 @@
* 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);
diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 773a103..fe32a2d 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -2605,8 +2605,7 @@
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 @@
}
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 @@
((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 :/ */