mac80211: allow drivers to control software crypto
Some drivers unfortunately cannot support software crypto, but
mac80211 currently assumes that they do.
This has the issue that if the hardware enabling fails for some
reason, the software fallback is used, which won't work. This
clearly isn't desirable, the error should be reported and the
key setting refused.
Support this in mac80211 by allowing drivers to set a new HW
flag IEEE80211_HW_SW_CRYPTO_CONTROL, in which case mac80211 will
only allow software fallback if the set_key() method returns 1.
The driver will also need to advertise supported cipher suites
so that mac80211 doesn't advertise any (future) software ciphers
that the driver can't actually do.
While at it, to make it easier to support this, refactor the
ieee80211_init_cipher_suites() code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index f8d9f0e..5167c53 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -90,7 +90,7 @@
{
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
- int ret;
+ int ret = -EOPNOTSUPP;
might_sleep();
@@ -150,7 +150,7 @@
return 0;
}
- if (ret != -ENOSPC && ret != -EOPNOTSUPP)
+ if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
sdata_err(sdata,
"failed to set key (%d, %pM) to hardware (%d)\n",
key->conf.keyidx,
@@ -163,7 +163,11 @@
case WLAN_CIPHER_SUITE_TKIP:
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_AES_CMAC:
- /* all of these we can do in software */
+ /* all of these we can do in software - if driver can */
+ if (ret == 1)
+ return 0;
+ if (key->local->hw.flags & IEEE80211_HW_SW_CRYPTO_CONTROL)
+ return -EINVAL;
return 0;
default:
return -EINVAL;