Originally by Johannes Berg. This patch adds support for devices that do not
report their MAC address until the firmware is loaded. While the address is not
known, a multicast on is used.
Signed-off-by: Luis Carlos Cobo <luisca@xxxxxxxxxxx>
Tested-by: Javier Cardona <javier@xxxxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/main.c | 61 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 62 insertions(+), 0 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c916c2f..8e8c0eb 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -551,6 +551,7 @@ struct ieee80211_local {
const struct ieee80211_ops *ops;
struct net_device *mdev; /* wmaster# - "master" 802.11 device */
+ unsigned int hwid;
int open_count;
int monitors, cooked_mntrs;
/* number of interfaces with corresponding FIF_ flags */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index cf477ad..2204aa5 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -178,6 +178,20 @@ static inline int identical_mac_addr_allowed(int type1, int type2)
type2 == IEEE80211_IF_TYPE_VLAN)));
}
+static void calculate_invalid_mac(u8 *addr, unsigned int hwid)
+{
+ /*
+ * Random multicast, private use address with hwid mixed in.
+ * Must be multicast to let is_valid_ether_addr() fail on it.
+ */
+ addr[0] = 0xe7;
+ addr[1] = 0xc4;
+ addr[2] = 0x2e ^ ((hwid >> 24) & 0xFF);
+ addr[3] = 0xdd ^ ((hwid >> 16) & 0xFF);
+ addr[4] = 0xcb ^ ((hwid >> 8) & 0xFF);
+ addr[5] = 0x8c ^ ((hwid >> 0) & 0xFF);
+}
+
static int ieee80211_open(struct net_device *dev)
{
struct ieee80211_sub_if_data *sdata, *nsdata;
@@ -187,9 +201,17 @@ static int ieee80211_open(struct net_device *dev)
u32 changed = 0;
int res;
bool need_hw_reconfig = 0;
+ u8 inval_addr[ETH_ALEN];
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ calculate_invalid_mac(inval_addr, local->hwid);
+
+ /* fail early if user set an invalid address */
+ if (compare_ether_addr(dev->dev_addr, inval_addr) &&
+ !is_valid_ether_addr(dev->dev_addr))
+ return -EADDRNOTAVAIL;
+
/* we hold the RTNL here so can safely walk the list */
list_for_each_entry(nsdata, &local->interfaces, list) {
struct net_device *ndev = nsdata->dev;
@@ -288,6 +310,32 @@ static int ieee80211_open(struct net_device *dev)
ieee80211_led_radio(local, local->hw.conf.radio_enabled);
}
+ /*
+ * Check all interfaces and copy the hopefully now-present
+ * MAC address to those that have the special invalid one.
+ */
+ list_for_each_entry(nsdata, &local->interfaces, list) {
+ struct net_device *ndev = nsdata->dev;
+
+ /*
+ * No need to check netif_running since we do not allow
+ * it to start up with this invalid address.
+ */
+ if (compare_ether_addr(inval_addr, ndev->dev_addr) == 0)
+ memcpy(ndev->dev_addr,
+ local->hw.wiphy->perm_addr,
+ ETH_ALEN);
+ }
+
+ /*
+ * Validate the MAC address for this device.
+ */
+ if (!is_valid_ether_addr(dev->dev_addr)) {
+ if (!local->open_count && local->ops->stop)
+ local->ops->stop(local_to_hw(local));
+ return -EADDRNOTAVAIL;
+ }
+
switch (sdata->vif.type) {
case IEEE80211_IF_TYPE_VLAN:
list_add(&sdata->u.vlan.list, &sdata->u.vlan.ap->u.ap.vlans);
@@ -995,6 +1043,8 @@ void ieee80211_if_setup(struct net_device *dev)
dev->open = ieee80211_open;
dev->stop = ieee80211_stop;
dev->destructor = ieee80211_if_free;
+ /* we will validate the address ourselves in ->open */
+ dev->validate_addr = NULL;
}
/* everything else */
@@ -1571,6 +1621,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
struct ieee80211_local *local;
int priv_size;
struct wiphy *wiphy;
+ static atomic_t hw_counter = ATOMIC_INIT(0);
+ u8 inval_addr[ETH_ALEN];
/* Ensure 32-byte alignment of our private data and hw private data.
* We use the wiphy priv data for both our ieee80211_local and for
@@ -1601,6 +1653,15 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
local = wiphy_priv(wiphy);
local->hw.wiphy = wiphy;
+ /*
+ * Hack for devices that cannot read the mac address until they are
+ * started... keep an invalid multicast address as the device MAC...
+ * Read on in ieee80211_open().
+ */
+ local->hwid = atomic_inc_return(&hw_counter);
+ calculate_invalid_mac(inval_addr, local->hwid);
+ memcpy(local->hw.wiphy->perm_addr, inval_addr, ETH_ALEN);
+
local->hw.priv = (char *)local +
((sizeof(struct ieee80211_local) +
NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
--
1.5.4.3
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