On Fri, Sep 06, 2024 at 04:40:36PM +0200, Francesco Dolcini wrote:
On Mon, Aug 26, 2024 at 01:01:23PM +0200, Sascha Hauer wrote:
The mwifiex driver tries to derive the MAC addresses of the virtual interfaces from the permanent address by adding the bss_num of the particular interface used. It does so each time the virtual interface is changed from AP to station or the other way round. This means that the devices MAC address changes during a change_virtual_intf call which is pretty unexpected by userspace.
Is this the only reason for this patch or there are other reasons? I'd like to understand the whole impact, to be sure the backport to stable is what we want.
Furthermore the driver doesn't use the permanent address to add the bss_num to, but instead the current MAC address increases each time we do a change_virtual_intf.
Fix this by initializing the MAC address once from the permanent MAC address during creation of the virtual interface and never touch it again. This also means that userspace can set a different MAC address which then stays like this forever and is not unexpectedly changed by the driver.
It is not clear how many (if any) MAC addresses after the permanent MAC address are reserved for a device, so set the locally admistered bit for all MAC addresses modified from the permanent address.
I wonder if we should not just use the same permanent mac address whatever the virtual interface is. Do we have something similar in other wireless drivers?
Yes, there are at least four driver that generate different MAC addresses for different vifs:
drivers/net/wireless/ath/ath6kl/cfg80211.c:3816 drivers/net/wireless/ath/wil6210/cfg80211.c:732 drivers/net/wireless/microchip/wilc1000/netdev.c:983 drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:606
(line numbers match 6.11-rc6):
For the mac80211 based drivers there are also tricks played to use unique MAC addresses in ieee80211_assign_perm_addr().
For reference in mwifiex setting different MAC addresses for different interfaces goes down to:
| commit 864164683678e27c931b5909c72a001b1b943f36 | Author: Xinming Hu huxm@marvell.com | Date: Tue Feb 13 14:10:15 2018 +0800 | | mwifiex: set different mac address for interfaces with same bss type | | Multiple interfaces with same bss type could affect each other if | they are sharing the same mac address. In this patch, different | mac address is assigned to new interface which have same bss type | with exist interfaces. | | Signed-off-by: Xinming Hu huxm@marvell.com | Signed-off-by: Kalle Valo kvalo@codeaurora.org
Signed-off-by: Sascha Hauer s.hauer@pengutronix.de Cc: stable@vger.kernel.org
drivers/net/wireless/marvell/mwifiex/cfg80211.c | 4 +- drivers/net/wireless/marvell/mwifiex/init.c | 1 - drivers/net/wireless/marvell/mwifiex/main.c | 54 ++++++++++++------------- drivers/net/wireless/marvell/mwifiex/main.h | 5 ++- 4 files changed, 30 insertions(+), 34 deletions(-)
...
diff --git a/drivers/net/wireless/marvell/mwifiex/main.c b/drivers/net/wireless/marvell/mwifiex/main.c index 96d1f6039fbca..46acddd03ffd1 100644 --- a/drivers/net/wireless/marvell/mwifiex/main.c +++ b/drivers/net/wireless/marvell/mwifiex/main.c @@ -971,34 +971,16 @@ mwifiex_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) } int mwifiex_set_mac_address(struct mwifiex_private *priv,
struct net_device *dev, bool external,u8 *new_mac)
struct net_device *dev, u8 *new_mac){ int ret;
- u64 mac_addr, old_mac_addr;
- u64 old_mac_addr;
- old_mac_addr = ether_addr_to_u64(priv->curr_addr);
- netdev_info(dev, "%s: old: %pM new: %pM\n", __func__, priv->curr_addr, new_mac);
- if (external) {
mac_addr = ether_addr_to_u64(new_mac);- } else {
/* Internal mac address change */if (priv->bss_type == MWIFIEX_BSS_TYPE_ANY)return -EOPNOTSUPP;this was the only usage of MWIFIEX_BSS_TYPE_ANY, correct? Did it had any reason before?
I haven't found a path to get here with priv->bss_type == MWIFIEX_BSS_TYPE_ANY. This function is called from mwifiex_init_new_priv_params() and mwifiex_add_virtual_intf(). Both functions set priv->bss_type to something else or bail out with an error before calling mwifiex_set_mac_address(). It's also called from the ndo_set_mac_address method, but for a registered net device the bss_type should also be set to something meaningful.
mac_addr = old_mac_addr;if (priv->bss_type == MWIFIEX_BSS_TYPE_P2P) {mac_addr |= BIT_ULL(MWIFIEX_MAC_LOCAL_ADMIN_BIT);mac_addr += priv->bss_num;} else if (priv->adapter->priv[0] != priv) {/* Set mac address based on bss_type/bss_num */mac_addr ^= BIT_ULL(priv->bss_type + 8);mac_addr += priv->bss_num;}- }
- old_mac_addr = ether_addr_to_u64(priv->curr_addr);
- u64_to_ether_addr(mac_addr, priv->curr_addr);
- ether_addr_copy(priv->curr_addr, new_mac);
/* Send request to firmware */ ret = mwifiex_send_cmd(priv, HostCmd_CMD_802_11_MAC_ADDRESS, @@ -1015,6 +997,26 @@ int mwifiex_set_mac_address(struct mwifiex_private *priv, return 0; } +int mwifiex_set_default_mac_address(struct mwifiex_private *priv,
struct net_device *dev)+{
- int priv_num;
- u8 mac[ETH_ALEN];
- ether_addr_copy(mac, priv->adapter->perm_addr);
- for (priv_num = 0; priv_num < priv->adapter->priv_num; priv_num++)
if (priv == priv->adapter->priv[priv_num])break;- if (priv_num) {
eth_addr_add(mac, priv_num);mac[0] |= 0x2;- }
Please see my concern on this in the beginning of the email.
@@ -1364,10 +1366,6 @@ void mwifiex_init_priv_params(struct mwifiex_private *priv, priv->assocresp_idx = MWIFIEX_AUTO_IDX_MASK; priv->gen_idx = MWIFIEX_AUTO_IDX_MASK; priv->num_tx_timeout = 0;
- if (is_valid_ether_addr(dev->dev_addr))
ether_addr_copy(priv->curr_addr, dev->dev_addr);- else
ether_addr_copy(priv->curr_addr, priv->adapter->perm_addr);With this change, when mfg_mode is true, priv->curr_addr will be not initialized. Wanted?
Not wanted, just me being ignorant. Let's have a look:
priv->adapter->perm_addr is initialized in the response handling of the HostCmd_CMD_GET_HW_SPEC command. This command is only issued when mfg_mode is false, so in mfg mode priv->adapter->perm_addr will be the zero address.
The only documentation we have for mfg_mode is:
manufacturing mode enable:1, disable:0
I don't know what this really is about, but I could imagine that this is for initial factory bringup when the chip is not parametrized and thus doesn't have a permanent MAC address yet.
Sascha