mac80211: add helpers for frame control testing

A few general categories:

1) ieee80211_has_* tests if particular fctl bits are set, the helpers are de
in the same order as the fctl defines:

A combined _has_a4 was also added to test when both FROMDS and TODS are set.

2) ieee80211_is_* is meant to test whether the frame control is of a certain
ftype - data, mgmt, ctl, and two special helpers _is_data_qos, _is_data_pres
which also test a subset of the stype space.

When testing for a particular stype applicable only to one ftype, functions
like ieee80211_is_ack have been added.  Note that the ftype is also being
checked in these helpers.  They have been added for all mgmt and ctl stypes
in the same order as the STYPE defines.

3) ieee80211_get_* is meant to take a struct ieee80211_hdr * and returns a
pointer to somewhere in the struct, see get_SA, get_DA, get_qos_ctl.

The intel wireless drivers had helpers that used this namespace, convert the
all to use the new helpers and remove the byteshifting as they were defined
in cpu-order rather than little-endian.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 374 insertions, 18 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 8f2c20b4a15..371237b0d8b 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -98,6 +98,7 @@
 
 #define IEEE80211_MAX_SSID_LEN		32
 #define IEEE80211_MAX_MESH_ID_LEN	32
+#define IEEE80211_QOS_CTL_LEN		2
 
 struct ieee80211_hdr {
 	__le16 frame_control;
@@ -109,6 +110,355 @@ struct ieee80211_hdr {
 	u8 addr4[6];
 } __attribute__ ((packed));
 
+/**
+ * ieee80211_has_tods - check if IEEE80211_FCTL_TODS is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_tods(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_TODS)) != 0;
+}
+
+/**
+ * ieee80211_has_fromds - check if IEEE80211_FCTL_FROMDS is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_fromds(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FROMDS)) != 0;
+}
+
+/**
+ * ieee80211_has_a4 - check if IEEE80211_FCTL_TODS and IEEE80211_FCTL_FROMDS are set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_a4(__le16 fc)
+{
+	__le16 tmp = cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
+	return (fc & tmp) == tmp;
+}
+
+/**
+ * ieee80211_has_morefrags - check if IEEE80211_FCTL_MOREFRAGS is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_morefrags(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_MOREFRAGS)) != 0;
+}
+
+/**
+ * ieee80211_has_retry - check if IEEE80211_FCTL_RETRY is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_retry(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_RETRY)) != 0;
+}
+
+/**
+ * ieee80211_has_pm - check if IEEE80211_FCTL_PM is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_pm(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_PM)) != 0;
+}
+
+/**
+ * ieee80211_has_moredata - check if IEEE80211_FCTL_MOREDATA is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_moredata(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_MOREDATA)) != 0;
+}
+
+/**
+ * ieee80211_has_protected - check if IEEE80211_FCTL_PROTECTED is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_protected(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_PROTECTED)) != 0;
+}
+
+/**
+ * ieee80211_has_order - check if IEEE80211_FCTL_ORDER is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_has_order(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_ORDER)) != 0;
+}
+
+/**
+ * ieee80211_is_mgmt - check if type is IEEE80211_FTYPE_MGMT
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_mgmt(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT);
+}
+
+/**
+ * ieee80211_is_ctl - check if type is IEEE80211_FTYPE_CTL
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_ctl(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL);
+}
+
+/**
+ * ieee80211_is_data - check if type is IEEE80211_FTYPE_DATA
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_data(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_DATA);
+}
+
+/**
+ * ieee80211_is_data_qos - check if type is IEEE80211_FTYPE_DATA and IEEE80211_STYPE_QOS_DATA is set
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_data_qos(__le16 fc)
+{
+	/*
+	 * mask with QOS_DATA rather than IEEE80211_FCTL_STYPE as we just need
+	 * to check the one bit
+	 */
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_STYPE_QOS_DATA)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_DATA);
+}
+
+/**
+ * ieee80211_is_data_present - check if type is IEEE80211_FTYPE_DATA and has data
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_data_present(__le16 fc)
+{
+	/*
+	 * mask with 0x40 and test that that bit is clear to only return true
+	 * for the data-containing substypes.
+	 */
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | 0x40)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_DATA);
+}
+
+/**
+ * ieee80211_is_assoc_req - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_ASSOC_REQ
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_assoc_req(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ASSOC_REQ);
+}
+
+/**
+ * ieee80211_is_assoc_resp - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_ASSOC_RESP
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_assoc_resp(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ASSOC_RESP);
+}
+
+/**
+ * ieee80211_is_reassoc_req - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_REASSOC_REQ
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_reassoc_req(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_REASSOC_REQ);
+}
+
+/**
+ * ieee80211_is_reassoc_resp - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_REASSOC_RESP
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_reassoc_resp(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_REASSOC_RESP);
+}
+
+/**
+ * ieee80211_is_probe_req - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_PROBE_REQ
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_probe_req(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_PROBE_REQ);
+}
+
+/**
+ * ieee80211_is_probe_resp - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_PROBE_RESP
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_probe_resp(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_PROBE_RESP);
+}
+
+/**
+ * ieee80211_is_beacon - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_BEACON
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_beacon(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
+}
+
+/**
+ * ieee80211_is_atim - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_ATIM
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_atim(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ATIM);
+}
+
+/**
+ * ieee80211_is_disassoc - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_DISASSOC
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_disassoc(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_DISASSOC);
+}
+
+/**
+ * ieee80211_is_auth - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_AUTH
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_auth(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_AUTH);
+}
+
+/**
+ * ieee80211_is_deauth - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_DEAUTH
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_deauth(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_DEAUTH);
+}
+
+/**
+ * ieee80211_is_action - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_ACTION
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_action(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ACTION);
+}
+
+/**
+ * ieee80211_is_back_req - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_BACK_REQ
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_back_req(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK_REQ);
+}
+
+/**
+ * ieee80211_is_back - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_BACK
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_back(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK);
+}
+
+/**
+ * ieee80211_is_pspoll - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_PSPOLL
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_pspoll(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_PSPOLL);
+}
+
+/**
+ * ieee80211_is_rts - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_RTS
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_rts(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
+}
+
+/**
+ * ieee80211_is_cts - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_CTS
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_cts(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
+}
+
+/**
+ * ieee80211_is_ack - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_ACK
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_ack(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_ACK);
+}
+
+/**
+ * ieee80211_is_cfend - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_CFEND
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_cfend(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CFEND);
+}
+
+/**
+ * ieee80211_is_cfendack - check if IEEE80211_FTYPE_CTL && IEEE80211_STYPE_CFENDACK
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_cfendack(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CFENDACK);
+}
+
+/**
+ * ieee80211_is_nullfunc - check if FTYPE=IEEE80211_FTYPE_DATA and STYPE=IEEE80211_STYPE_NULLFUNC
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline int ieee80211_is_nullfunc(__le16 fc)
+{
+	return (fc & cpu_to_le16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
+	       cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC);
+}
 
 struct ieee80211s_hdr {
 	u8 flags;
@@ -553,48 +903,54 @@ enum ieee80211_back_parties {
 #define WLAN_MAX_KEY_LEN		32
 
 /**
+ * ieee80211_get_qos_ctl - get pointer to qos control bytes
+ * @hdr: the frame
+ *
+ * The qos ctrl bytes come after the frame_control, duration, seq_num
+ * and 3 or 4 addresses of length ETH_ALEN.
+ * 3 addr: 2 + 2 + 2 + 3*6 = 24
+ * 4 addr: 2 + 2 + 2 + 4*6 = 30
+ */
+static inline u8 *ieee80211_get_qos_ctl(struct ieee80211_hdr *hdr)
+{
+	if (ieee80211_has_a4(hdr->frame_control))
+		return (u8 *)hdr + 30;
+	else
+		return (u8 *)hdr + 24;
+}
+
+/**
  * ieee80211_get_SA - get pointer to SA
+ * @hdr: the frame
  *
  * Given an 802.11 frame, this function returns the offset
  * to the source address (SA). It does not verify that the
  * header is long enough to contain the address, and the
  * header must be long enough to contain the frame control
  * field.
- *
- * @hdr: the frame
  */
 static inline u8 *ieee80211_get_SA(struct ieee80211_hdr *hdr)
 {
-	__le16 fc = hdr->frame_control;
-	fc &= cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
-
-	switch (fc) {
-	case __constant_cpu_to_le16(IEEE80211_FCTL_FROMDS):
-		return hdr->addr3;
-	case __constant_cpu_to_le16(IEEE80211_FCTL_TODS|IEEE80211_FCTL_FROMDS):
+	if (ieee80211_has_a4(hdr->frame_control))
 		return hdr->addr4;
-	default:
-		return hdr->addr2;
-	}
+	if (ieee80211_has_fromds(hdr->frame_control))
+		return hdr->addr3;
+	return hdr->addr2;
 }
 
 /**
  * ieee80211_get_DA - get pointer to DA
+ * @hdr: the frame
  *
  * Given an 802.11 frame, this function returns the offset
  * to the destination address (DA). It does not verify that
  * the header is long enough to contain the address, and the
  * header must be long enough to contain the frame control
  * field.
- *
- * @hdr: the frame
  */
 static inline u8 *ieee80211_get_DA(struct ieee80211_hdr *hdr)
 {
-	__le16 fc = hdr->frame_control;
-	fc &= cpu_to_le16(IEEE80211_FCTL_TODS);
-
-	if (fc)
+	if (ieee80211_has_tods(hdr->frame_control))
 		return hdr->addr3;
 	else
 		return hdr->addr1;