mac80211: make alignment warning optional
Driver authors should be aware of the alignment requirements, but
not everybody cares about the warning. This patch makes it depend
on a new Kconfig symbol MAC80211_DEBUG_PACKET_ALIGNMENT which can
be enabled regardless of MAC80211_DEBUG and is recommended for
driver authors (only). This also restricts the warning to data
packets so other packets need not be realigned to not trigger the
warning.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
index 09c2550..e77592d 100644
--- a/net/mac80211/Kconfig
+++ b/net/mac80211/Kconfig
@@ -98,6 +98,18 @@
Say N unless you know you need this.
+config MAC80211_DEBUG_PACKET_ALIGNMENT
+ bool "Enable packet alignment debugging"
+ depends on MAC80211
+ help
+ This option is recommended for driver authors and strongly
+ discouraged for everybody else, it will trigger a warning
+ when a driver hands mac80211 a buffer that is aligned in
+ a way that will cause problems with the IP stack on some
+ architectures.
+
+ Say N unless you're writing a mac80211 based driver.
+
config MAC80211_DEBUG
bool "Enable debugging output"
depends on MAC80211
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index d44c872..535407d 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -340,11 +340,15 @@
return load;
}
+#ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
static ieee80211_txrx_result
ieee80211_rx_h_verify_ip_alignment(struct ieee80211_txrx_data *rx)
{
int hdrlen;
+ if (!WLAN_FC_DATA_PRESENT(rx->fc))
+ return TXRX_CONTINUE;
+
/*
* Drivers are required to align the payload data in a way that
* guarantees that the contained IP header is aligned to a four-
@@ -371,11 +375,14 @@
return TXRX_CONTINUE;
}
+#endif
ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
{
ieee80211_rx_h_parse_qos,
+#ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
ieee80211_rx_h_verify_ip_alignment,
+#endif
NULL
};