[802.11] Add core support for detecting and using encrypted networks

Signed-off-by: Marty Connor <mdc@etherboot.org>

src/include/gpxe/errfile.h

@@ -158,6 +158,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_ib_mi			( ERRFILE_NET | 0x00200000 )
 #define ERRFILE_ib_cmrc			( ERRFILE_NET | 0x00210000 )
 #define ERRFILE_ib_srp			( ERRFILE_NET | 0x00220000 )
+#define ERRFILE_sec80211		( ERRFILE_NET | 0x00230000 )
 
 #define ERRFILE_image		      ( ERRFILE_IMAGE | 0x00000000 )
 #define ERRFILE_elf		      ( ERRFILE_IMAGE | 0x00010000 )

src/include/gpxe/ieee80211.h

@@ -2,6 +2,7 @@
 #define _GPXE_IEEE80211_H
 
 #include <gpxe/if_ether.h>	/* for ETH_ALEN */
+#include <endian.h>
 
 /** @file
  * Constants and data structures defined in IEEE 802.11, subsetted
@@ -779,10 +780,9 @@ struct ieee80211_ie_erp_info {
  *
  * Showing once again a striking clarity of design, the IEEE folks put
  * dynamically-sized data in the middle of this structure. As such,
- * the below structure definition is only a guideline; the
- * @c IEEE80211_RSN_FIELD, @c IEEE80211_RSN_CIPHER, and
- * @c IEEE80211_RSN_AUTHTYPE macros should be used to access any
- * data.
+ * the below structure definition only works for IEs we create
+ * ourselves, which always have one pairwise cipher and one AKM;
+ * received IEs should be parsed piecemeal.
  *
  * Also inspired was IEEE's choice of 16-bit fields to count the
  * number of 4-byte elements in a structure with a maximum length of
@@ -790,11 +790,9 @@ struct ieee80211_ie_erp_info {
  *
  * Many fields reference a cipher or authentication-type ID; this is a
  * three-byte OUI followed by one byte identifying the cipher with
- * respect to that OUI. For all standard ciphers the OUI is 00:0F:AC.
- *
- * The authentication types referenced in this structure have nothing
- * to do with 802.11 authentication frames or the @c algorithm field
- * within them.
+ * respect to that OUI. For all standard ciphers the OUI is 00:0F:AC,
+ * except in old-style WPA IEs encapsulated in vendor-specific IEs,
+ * where it's 00:50:F2.
  */
 struct ieee80211_ie_rsn {
 	/** Information element ID */
@@ -807,21 +805,21 @@ struct ieee80211_ie_rsn {
 	u16 version;
 
 	/** Cipher ID for the cipher used in multicast/broadcast frames */
-	u8 group_cipher[4];
+	u32 group_cipher;
 
 	/** Number of unicast ciphers supported */
 	u16 pairwise_count;
 
 	/** List of cipher IDs for supported unicast frame ciphers */
-	u8 pairwise_cipher[4];
+	u32 pairwise_cipher[1];
 
 	/** Number of authentication types supported */
 	u16 akm_count;
 
 	/** List of authentication type IDs for supported types */
-	u8 akm_list[4];
+	u32 akm_list[1];
 
-	/** Security capabilities field. */
+	/** Security capabilities field (RSN only) */
 	u16 rsn_capab;
 
 	/** Number of PMKIDs included (present only in association frames) */
@@ -834,140 +832,69 @@ struct ieee80211_ie_rsn {
 /** Information element ID for Robust Security Network information element */
 #define IEEE80211_IE_RSN	48
 
-/** OUI for standard ciphers in RSN information element */
-#define  IEEE80211_RSN_OUI	"\x00\x0F\xAC"
-
-/** Extract RSN IE version field */
-#define  IEEE80211_RSN_FIELD_version( rsnp ) ( (rsnp)->version )
-
-/** Extract RSN IE group_cipher field */
-#define  IEEE80211_RSN_FIELD_group_cipher( rsnp ) ( (rsnp)->group_cipher )
-
-/** Extract RSN IE pairwise_count field */
-#define  IEEE80211_RSN_FIELD_pairwise_count( rsnp ) ( (rsnp)->pairwise_count )
-
-/** Extract RSN IE akm_count field */
-#define  IEEE80211_RSN_FIELD_akm_count( rsnp )			\
-	( ( ( struct ieee80211_ie_rsn * ) ( ( void * ) ( rsnp ) + \
-		4*( ( rsnp )->pairwise_count - 1 ) ) )->akm_count )
-
-/** Extract RSN IE rsn_capab field */
-#define  IEEE80211_RSN_FIELD_rsn_capab( rsnp )			\
-	( ( ( struct ieee80211_ie_rsn * ) ( ( void * ) ( rsnp ) + \
-		4*( ( rsnp )->pairwise_count - 1 ) +		\
-		4*( ( rsnp )->akm_count - 1 ) ) )->rsn_capab )
-
-/** Extract RSN IE pmkid_count field */
-#define  IEEE80211_RSN_FIELD_pmkid_count( rsnp )		\
-	( ( ( struct ieee80211_ie_rsn * ) ( ( void * ) ( rsnp ) + \
-		4*( ( rsnp )->pairwise_count - 1 ) +		\
-		4*( ( rsnp )->akm_count - 1 ) ) )->pmkid_count )
-
-/** Extract field from RSN information element
- *
- * @v rsnp	Pointer to RSN information element
- * @v field	Name of field to extract
- * @ret val	Lvalue of the requested field
- *
- * You must fill the fields of the structure in order for this to work
- * properly.
- */
-#define  IEEE80211_RSN_FIELD( rsnp, field )	\
-	IEEE80211_RSN_FIELD_ ## field ( rsnp )
-
-/** Get pointer to pairwise cipher from RSN information element
- *
- * @v rsnp	Pointer to RSN information element
- * @v cipher	Index of pairwise cipher to extract
- * @ret ptr	Pointer to requested cipher
- */
-#define  IEEE80211_RSN_CIPHER( rsnp, cipher )	\
-	( ( rsnp )->pairwise_cipher + 4 * ( cipher ) )
-
-/** Get pointer to authentication type from RSN information element
- *
- * @v rsnp	Pointer to RSN information element
- * @v akm	Index of authentication type to extract
- * @ret ptr	Pointer to requested authentication type
- *
- * The @c pairwise_count field must be correct.
- */
-#define  IEEE80211_RSN_AUTHTYPE( rsnp, akm )	\
-    ( ( rsnp )->akm_list + 4 * ( ( rsnp )->pairwise_count - 1 ) + 4 * ( akm ) )
-
-/** Get pointer to PMKID from RSN information element
- *
- * @v rsnp	Pointer to RSN information element
- * @v idx	Index of PMKID to extract
- * @ret ptr	Pointer to requested PMKID
- *
- * The @c pairwise_count and @c akm_count fields must be correct.
- */
-#define  IEEE80211_RSN_PMKID( rsnp, idx )	\
-	( ( rsnp )->pmkid_list + 4 * ( ( rsnp )->pairwise_count - 1 ) +	\
-			4 * ( ( rsnp )->akm_count - 1 ) + 16 * ( idx ) )
-
-/** Verify size of RSN information element
- *
- * @v rsnp	Pointer to RSN information element
- * @ret ok	TRUE if count fields are consistent with length field
- *
- * It is important to drop any RSN IE that does not pass this function
- * before using the @c IEEE80211_RSN_FIELD, @c IEEE80211_RSN_CIPHER,
- * and @c IEEE80211_RSN_AUTHTYPE macros, to avoid potential security
- * compromise due to a malformed RSN IE.
- *
- * This function does not consider the possibility of some PMKIDs
- * included in the RSN IE, because PMKIDs are only included in RSN IEs
- * sent in association request frames, and we should never receive an
- * association request frame. An RSN IE that includes PMKIDs will
- * always fail this check.
- */
-static inline int ieee80211_rsn_check ( struct ieee80211_ie_rsn *rsnp ) {
-	if ( rsnp->len < 12 + 4 * rsnp->pairwise_count )
-		return 0;
-	return ( rsnp->len == 12 + 4 * ( rsnp->pairwise_count +
-				IEEE80211_RSN_FIELD ( rsnp, akm_count ) ) );
-}
-
 /** Calculate necessary size of RSN information element
  *
  * @v npair	Number of pairwise ciphers supported
  * @v nauth	Number of authentication types supported
  * @v npmkid	Number of PMKIDs to include
- * @ret size	Necessary size of RSN IE, including header bytes
+ * @v is_rsn	If TRUE, calculate RSN IE size; if FALSE, calculate WPA IE size
+ * @ret size	Necessary size of IE, including header bytes
  */
-static inline size_t ieee80211_rsn_size ( int npair, int nauth, int npmkid ) {
-	return 16 + 4 * ( npair + nauth ) + 16 * npmkid;
+static inline size_t ieee80211_rsn_size ( int npair, int nauth, int npmkid,
+					  int rsn_ie ) {
+	return 16 + 4 * ( npair + nauth ) + 16 * npmkid - 4 * ! rsn_ie;
 }
 
+/** Make OUI plus type byte into 32-bit integer for easy comparison */
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define _MKOUI( a, b, c, t )	\
+		( ( ( a ) << 24 ) | ( ( b ) << 16 ) | ( ( c ) << 8 ) | ( d ) )
+#define  OUI_ORG_MASK		0xFFFFFF00
+#define  OUI_TYPE_MASK		0x000000FF
+#else
+#define _MKOUI( a, b, c, t )	\
+		( ( ( t ) << 24 ) | ( ( c ) << 16 ) | ( ( b ) << 8 ) | ( a ) )
+#define  OUI_ORG_MASK		0x00FFFFFF
+#define  OUI_TYPE_MASK		0xFF000000
+#endif
+
+/** Organization part for OUIs in standard RSN IE */
+#define  IEEE80211_RSN_OUI	_MKOUI ( 0x00, 0x0F, 0xAC, 0 )
+
+/** Organization part for OUIs in old WPA IE */
+#define  IEEE80211_WPA_OUI	_MKOUI ( 0x00, 0x50, 0xF2, 0 )
+
+/** Old vendor-type WPA IE OUI type + subtype */
+#define  IEEE80211_WPA_OUI_VEN	_MKOUI ( 0x00, 0x50, 0xF2, 0x01 )
+
+
 /** 802.11 RSN IE: expected version number */
 #define  IEEE80211_RSN_VERSION		1
 
-/** 802.11 RSN IE: fourth byte of cipher type for 40-bit WEP */
-#define  IEEE80211_RSN_CTYPE_WEP40	1
+/** 802.11 RSN IE: cipher type for 40-bit WEP */
+#define  IEEE80211_RSN_CTYPE_WEP40	_MKOUI ( 0, 0, 0, 0x01 )
 
-/** 802.11 RSN IE: fourth byte of cipher type for 104-bit WEP */
-#define  IEEE80211_RSN_CTYPE_WEP104	5
+/** 802.11 RSN IE: cipher type for 104-bit WEP */
+#define  IEEE80211_RSN_CTYPE_WEP104	_MKOUI ( 0, 0, 0, 0x05 )
 
-/** 802.11 RSN IE: fourth byte of cipher type for TKIP ("WPA") */
-#define  IEEE80211_RSN_CTYPE_TKIP	2
+/** 802.11 RSN IE: cipher type for TKIP ("WPA") */
+#define  IEEE80211_RSN_CTYPE_TKIP	_MKOUI ( 0, 0, 0, 0x02 )
 
-/** 802.11 RSN IE: fourth byte of cipher type for CCMP ("WPA2") */
-#define  IEEE80211_RSN_CTYPE_CCMP	4
+/** 802.11 RSN IE: cipher type for CCMP ("WPA2") */
+#define  IEEE80211_RSN_CTYPE_CCMP	_MKOUI ( 0, 0, 0, 0x04 )
 
-/** 802.11 RSN IE: fourth byte of cipher type for "use group"
+/** 802.11 RSN IE: cipher type for "use group"
  *
  * This can only appear as a pairwise cipher, and means unicast frames
  * should be encrypted in the same way as broadcast/multicast frames.
  */
-#define  IEEE80211_RSN_CTYPE_USEGROUP	0
+#define  IEEE80211_RSN_CTYPE_USEGROUP	_MKOUI ( 0, 0, 0, 0x00 )
 
-/** 802.11 RSN IE: fourth byte of auth method type for using an 802.1X server */
-#define  IEEE80211_RSN_ATYPE_8021X	1
+/** 802.11 RSN IE: auth method type for using an 802.1X server */
+#define  IEEE80211_RSN_ATYPE_8021X	_MKOUI ( 0, 0, 0, 0x01 )
 
-/** 802.11 RSN IE: fourth byte of auth method type for using a pre-shared key */
-#define  IEEE80211_RSN_ATYPE_PSK	2
+/** 802.11 RSN IE: auth method type for using a pre-shared key */
+#define  IEEE80211_RSN_ATYPE_PSK	_MKOUI ( 0, 0, 0, 0x02 )
 
 /** 802.11 RSN IE capabilities: AP supports pre-authentication */
 #define  IEEE80211_RSN_CAPAB_PREAUTH	0x001
@@ -997,6 +924,42 @@ static inline size_t ieee80211_rsn_size ( int npair, int nauth, int npmkid ) {
 #define  IEEE80211_RSN_CAPAB_PEERKEY	0x200
 
 
+/** 802.11 RSN IE capabilities: One replay counter
+ *
+ * This should be AND'ed with @c IEEE80211_RSN_CAPAB_PTKSA_REPLAY or
+ * @c IEEE80211_RSN_CAPAB_GTKSA_REPLAY (or both) to produce a value
+ * which can be OR'ed into the capabilities field.
+ */
+#define IEEE80211_RSN_1_CTR		0x000
+
+/** 802.11 RSN IE capabilities: Two replay counters */
+#define IEEE80211_RSN_2_CTR		0x014
+
+/** 802.11 RSN IE capabilities: Four replay counters */
+#define IEEE80211_RSN_4_CTR		0x028
+
+/** 802.11 RSN IE capabilities: 16 replay counters */
+#define IEEE80211_RSN_16_CTR		0x03C
+
+
+/** 802.11 Vendor Specific information element
+ *
+ * One often sees the RSN IE masquerading as vendor-specific on
+ * devices that were produced prior to 802.11i (the WPA amendment)
+ * being finalized.
+ */
+struct ieee80211_ie_vendor {
+	u8 id;			/**< Vendor-specific ID: 221 */
+	u8 len;			/**< Vendor-specific length: variable */
+	u32 oui;		/**< OUI and vendor-specific type byte */
+	u8 data[0];		/**< Vendor-specific data */
+} __attribute__ ((packed));
+
+/** Information element ID for Vendor Specific information element */
+#define IEEE80211_IE_VENDOR	221
+
+
+
 
 /** Any 802.11 information element
  *
@@ -1034,8 +997,23 @@ union ieee80211_ie
 
 	/** Security information */
 	struct ieee80211_ie_rsn rsn;
+
+	/** Vendor-specific */
+	struct ieee80211_ie_vendor vendor;
 };
 
+/** Check that 802.11 information element is bounded by buffer
+ *
+ * @v ie	Information element
+ * @v end	End of buffer in which information element is stored
+ * @ret ok	TRUE if the IE is completely contained within the buffer
+ */
+static inline int ieee80211_ie_bound ( union ieee80211_ie *ie, void *end )
+{
+	void *iep = ie;
+	return ( iep + 2 <= end && iep + 2 + ie->len <= end );
+}
+
 /** Advance to next 802.11 information element
  *
  * @v ie	Current information element pointer
@@ -1055,7 +1033,7 @@ static inline union ieee80211_ie * ieee80211_next_ie ( union ieee80211_ie *ie,
 	if ( ! end )
 		return next_ie;
 
-	if ( next_ie_byte < end && next_ie_byte + next_ie->len <= end )
+	if ( ieee80211_ie_bound ( next_ie, end ) )
 		return next_ie;
 
 	return NULL;

src/include/gpxe/net80211.h

@@ -119,6 +119,9 @@ enum net80211_security_proto {
 	 * in the same 4-way handshake as the PSK method.
 	 */
 	NET80211_SECPROT_EAP = 2,
+
+	/** Dummy value used when the handshaking type can't be detected */
+	NET80211_SECPROT_UNKNOWN = 3,
 };
 
 
@@ -169,6 +172,9 @@ enum net80211_crypto_alg {
 	 * against WEP and minor success against TKIP fail.
 	 */
 	NET80211_CRYPT_CCMP = 3,
+
+	/** Dummy value used when the cryptosystem can't be detected */
+	NET80211_CRYPT_UNKNOWN = 4,
 };
 
 
@@ -539,37 +545,171 @@ struct net80211_frag_cache
 	struct io_buffer *iob[16];
 };
 
-/** Interface to an 802.11 cryptographic algorithm
+
+/** Interface to an 802.11 security handshaking protocol
+ *
+ * Security handshaking protocols handle parsing a user-specified key
+ * into a suitable input to the encryption algorithm, and for WPA and
+ * better systems, manage performing whatever authentication with the
+ * network is necessary.
  *
- * Cryptographic algorithms define a net80211_crypto structure
- * statically, using a gPXE linker table to make it available to the
- * 802.11 layer. When the algorithm needs to be used, the 802.11 code
- * will allocate a copy of the static definition plus whatever space
- * the algorithm has requested for private state, and point
- * net80211_device::crypto at it.
+ * At all times when any method in this structure is called with a
+ * net80211_device argument @a dev, a dynamically allocated copy of
+ * the handshaker structure itself with space for the requested amount
+ * of private data may be accessed as @c dev->handshaker. The
+ * structure will not be modified, and will only be freed during
+ * reassociation and device closing after the @a stop method has been
+ * called.
+ */
+struct net80211_handshaker
+{
+	/** The security handshaking protocol implemented */
+	enum net80211_security_proto protocol;
+
+	/** Initialize security handshaking protocol
+	 *
+	 * @v dev	802.11 device
+	 * @ret rc	Return status code
+	 *
+	 * This method is expected to access @c netX/key or other
+	 * applicable settings to determine the parameters for
+	 * handshaking. If no handshaking is required, it should call
+	 * sec80211_install() with the cryptosystem and key that are
+	 * to be used, and @c start and @c step should be set to @c
+	 * NULL.
+	 *
+	 * This is always called just before association is performed,
+	 * but after its parameters have been set; in particular, you
+	 * may rely on the contents of the @a essid field in @a dev.
+	 */
+	int ( * init ) ( struct net80211_device *dev );
+
+	/** Start handshaking
+	 *
+	 * @v dev	802.11 device
+	 * @ret rc	Return status code
+	 *
+	 * This method is expected to set up internal state so that
+	 * packets sent immediately after association, before @a step
+	 * can be called, will be handled appropriately.
+	 *
+	 * This is always called just before association is attempted.
+	 */
+	int ( * start ) ( struct net80211_device *dev );
+
+	/** Process handshaking state
+	 *
+	 * @v dev	802.11 device
+	 * @ret rc	Return status code, or positive if done
+	 *
+	 * This method is expected to perform as much progress on the
+	 * protocol it implements as is possible without blocking. It
+	 * should return 0 if it wishes to be called again, a negative
+	 * return status code on error, or a positive value if
+	 * handshaking is complete. In the case of a positive return,
+	 * net80211_crypto_install() must have been called.
+	 *
+	 * If handshaking may require further action (e.g. an AP that
+	 * might decide to rekey), handlers must be installed by this
+	 * function that will act without further calls to @a step.
+	 */
+	int ( * step ) ( struct net80211_device *dev );
+
+	/** Change cryptographic key based on setting
+	 *
+	 * @v dev	802.11 device
+	 * @ret rc	Return status code
+	 *
+	 * This method is called whenever the @c netX/key setting
+	 * @e may have been changed. It is expected to determine
+	 * whether it did in fact change, and if so, to install the
+	 * new key using net80211_crypto_install(). If it is not
+	 * possible to do this immediately, this method should return
+	 * an error; in that case the 802.11 stack will reassociate,
+	 * following the usual init/start/step sequence.
+	 *
+	 * This method is only relevant when it is possible to
+	 * associate successfully with an incorrect key. When it is
+	 * not, a failed association will be retried until the user
+	 * changes the key setting, and a successful association will
+	 * not be dropped due to such a change. When association with
+	 * an incorrect key is impossible, this function should return
+	 * 0 after performing no action.
+	 */
+	int ( * change_key ) ( struct net80211_device *dev );
+
+	/** Stop security handshaking handlers
+	 *
+	 * @v dev	802.11 device
+	 *
+	 * This method is called just before freeing a security
+	 * handshaker; it could, for example, delete a process that @a
+	 * start had created to manage the security of the connection.
+	 * If not needed it may be set to NULL.
+	 */
+	void ( * stop ) ( struct net80211_device *dev );
+
+	/** Amount of private data requested
+	 *
+	 * Before @c init is called for the first time, this structure's
+	 * @c priv pointer will point to this many bytes of allocated
+	 * data, where the allocation will be performed separately for
+	 * each net80211_device.
+	 */
+	int priv_len;
+
+	/** Whether @a start has been called
+	 *
+	 * Reset to 0 after @a stop is called.
+	 */
+	int started;
+
+	/** Pointer to private data
+	 *
+	 * In initializing this structure statically for a linker
+	 * table, set this to NULL.
+	 */
+	void *priv;
+};
+
+#define NET80211_HANDSHAKERS __table ( struct net80211_handshaker, \
+				       "net80211_handshakers" )
+#define __net80211_handshaker __table_entry ( NET80211_HANDSHAKERS, 01 )
+
+
+/** Interface to an 802.11 cryptosystem
+ *
+ * Cryptosystems define a net80211_crypto structure statically, using
+ * a gPXE linker table to make it available to the 802.11 layer. When
+ * the cryptosystem needs to be used, the 802.11 code will allocate a
+ * copy of the static definition plus whatever space the algorithm has
+ * requested for private state, and point net80211_device::crypto or
+ * net80211_device::gcrypto at it.
  */
 struct net80211_crypto
 {
 	/** The cryptographic algorithm implemented */
 	enum net80211_crypto_alg algorithm;
 
-	/** Initialize cryptographic algorithm using a given key
+	/** Initialize cryptosystem using a given key
 	 *
-	 * @v crypto	802.11 cryptographic algorithm
+	 * @v crypto	802.11 cryptosystem
 	 * @v key	Pointer to key bytes
 	 * @v keylen	Number of key bytes
+	 * @v rsc	Initial receive sequence counter, if applicable
 	 * @ret rc	Return status code
 	 *
 	 * This method is passed the communication key provided by the
 	 * security handshake handler, which will already be in the
-	 * low-level form required.
+	 * low-level form required. It may not store a pointer to the
+	 * key after returning; it must copy it to its private storage.
 	 */
-	int ( * initialize ) ( struct net80211_crypto *crypto, u8 *key,
-			       int keylen );
+	int ( * init ) ( struct net80211_crypto *crypto, const void *key,
+			 int keylen, const void *rsc );
 
-	/** Encrypt a frame using the cryptographic algorithm
+	/** Encrypt a frame using the cryptosystem
 	 *
-	 * @v crypto	802.11 cryptographic algorithm
+	 * @v crypto	802.11 cryptosystem
 	 * @v iob	I/O buffer
 	 * @ret eiob	Newly allocated I/O buffer with encrypted packet
 	 *
@@ -593,9 +733,9 @@ struct net80211_crypto
 	struct io_buffer * ( * encrypt ) ( struct net80211_crypto *crypto,
 					   struct io_buffer *iob );
 
-	/** Decrypt a frame using the cryptographic algorithm
+	/** Decrypt a frame using the cryptosystem
 	 *
-	 * @v crypto	802.11 cryptographic algorithm
+	 * @v crypto	802.11 cryptosystem
 	 * @v eiob	Encrypted I/O buffer
 	 * @ret iob	Newly allocated I/O buffer with decrypted packet
 	 *
@@ -626,6 +766,9 @@ struct net80211_crypto
 	void *priv;
 };
 
+#define NET80211_CRYPTOS __table ( struct net80211_crypto, "net80211_cryptos" )
+#define __net80211_crypto __table_entry ( NET80211_CRYPTOS, 01 )
+
 
 struct net80211_probe_ctx;
 struct net80211_assoc_ctx;
@@ -732,6 +875,9 @@ struct net80211_device
 		struct net80211_assoc_ctx *assoc;
 	} ctx;
 
+	/** Security handshaker being used */
+	struct net80211_handshaker *handshaker;
+
 	/** State of our association to the network
 	 *
 	 * Since the association process happens asynchronously, it's
@@ -777,14 +923,33 @@ struct net80211_device
 	/** Return status code associated with @c state */
 	int assoc_rc;
 
+	/** RSN or WPA information element to include with association
+	 *
+	 * If set to @c NULL, none will be included. It is expected
+	 * that this will be set by the @a init function of a security
+	 * handshaker if it is needed.
+	 */
+	union ieee80211_ie *rsn_ie;
+
 	/* ---------- Parameters of currently associated network ---------- */
 
-	/** 802.11 cryptographic algorithm for our current network
+	/** 802.11 cryptosystem for our current network
 	 *
 	 * For an open network, this will be set to NULL.
 	 */
 	struct net80211_crypto *crypto;
 
+	/** 802.11 cryptosystem for multicast and broadcast frames
+	 *
+	 * If this is NULL, the cryptosystem used for receiving
+	 * unicast frames will also be used for receiving multicast
+	 * and broadcast frames. Transmitted multicast and broadcast
+	 * frames are always sent unicast to the AP, who multicasts
+	 * them on our behalf; thus they always use the unicast
+	 * cryptosystem.
+	 */
+	struct net80211_crypto *gcrypto;
+
 	/** MAC address of the access point most recently associated */
 	u8 bssid[ETH_ALEN];
 
@@ -927,6 +1092,10 @@ struct net80211_wlan
 };
 
 
+/** 802.11 encryption key setting */
+extern struct setting net80211_key_setting __setting;
+
+
 /**
  * @defgroup net80211_probe 802.11 network location API
  * @{
@@ -974,6 +1143,7 @@ int net80211_send_auth ( struct net80211_device *dev,
 			 struct net80211_wlan *wlan, int method );
 int net80211_send_assoc ( struct net80211_device *dev,
 			  struct net80211_wlan *wlan );
+void net80211_deauthenticate ( struct net80211_device *dev, int rc );
 /** @} */
 
 

src/include/gpxe/sec80211.h

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _GPXE_SEC80211_H
+#define _GPXE_SEC80211_H
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <gpxe/net80211.h>
+#include <errno.h>
+
+/** @file
+ *
+ * Definitions for general secured-network routines.
+ *
+ * Any function in this file which may be referenced by code which is
+ * not exclusive to encryption-enabled builds (e.g. sec80211_detect(),
+ * which is called by net80211_probe_step() to fill the net80211_wlan
+ * structure's security fields) must be declared as a weak symbol,
+ * using an inline interface similar to that used for
+ * sec80211_detect() below. This prevents secure network support from
+ * bloating general builds by any more than a few tiny hooks to call
+ * crypto functions when crypto structures are non-NULL.
+ */
+
+int _sec80211_detect ( struct io_buffer *iob,
+		       enum net80211_security_proto *secprot,
+		       enum net80211_crypto_alg *crypt )
+	__attribute__ (( weak ));
+
+
+/**
+ * Inline safety wrapper for _sec80211_detect()
+ *
+ * @v iob	I/O buffer containing beacon frame
+ * @ret secprot	Security handshaking protocol used by network
+ * @ret crypt	Cryptosystem used by network
+ * @ret rc	Return status code
+ *
+ * This function transparently calls _sec80211_detect() if the file
+ * containing it was compiled in, or returns an error indication of
+ * @c -ENOTSUP if not.
+ */
+static inline int sec80211_detect ( struct io_buffer *iob,
+				    enum net80211_security_proto *secprot,
+				    enum net80211_crypto_alg *crypt ) {
+	if ( _sec80211_detect )
+		return _sec80211_detect ( iob, secprot, crypt );
+	return -ENOTSUP;
+}
+
+int sec80211_detect_ie ( int is_rsn, u8 *start, u8 *end,
+			 enum net80211_security_proto *secprot,
+			 enum net80211_crypto_alg *crypt );
+u8 * sec80211_find_rsn ( union ieee80211_ie *ie, void *ie_end,
+			 int *is_rsn, u8 **end );
+
+int sec80211_install ( struct net80211_crypto **which,
+		       enum net80211_crypto_alg crypt,
+		       const void *key, int len, const void *rsc );
+
+u32 sec80211_rsn_get_crypto_desc ( enum net80211_crypto_alg crypt, int rsnie );
+u32 sec80211_rsn_get_akm_desc ( enum net80211_security_proto secprot,
+				int rsnie );
+enum net80211_crypto_alg sec80211_rsn_get_net80211_crypt ( u32 desc );
+
+#endif /* _GPXE_SEC80211_H */
+

src/net/80211/net80211.c

@@ -29,6 +29,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <gpxe/ieee80211.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/net80211.h>
+#include <gpxe/sec80211.h>
 #include <gpxe/timer.h>
 #include <gpxe/nap.h>
 #include <unistd.h>
@@ -188,7 +189,8 @@ static void net80211_handle_auth ( struct net80211_device *dev,
 				   struct io_buffer *iob );
 static void net80211_handle_assoc_reply ( struct net80211_device *dev,
 					  struct io_buffer *iob );
-static int net80211_send_disassoc ( struct net80211_device *dev, int reason );
+static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
+				    int deauth );
 static void net80211_handle_mgmt ( struct net80211_device *dev,
 				   struct io_buffer *iob, int signal );
 /** @} */
@@ -208,15 +210,16 @@ static void net80211_rx_frag ( struct net80211_device *dev,
  * @defgroup net80211_settings 802.11 settings handlers
  * @{
  */
-static int net80211_check_ssid_update ( void );
+static int net80211_check_settings_update ( void );
 
 /** 802.11 settings applicator
  *
  * When the SSID is changed, this will cause any open devices to
- * re-associate.
+ * re-associate; when the encryption key is changed, we similarly
+ * update their state.
  */
-struct settings_applicator net80211_ssid_applicator __settings_applicator = {
-	.apply = net80211_check_ssid_update,
+struct settings_applicator net80211_applicator __settings_applicator = {
+	.apply = net80211_check_settings_update,
 };
 
 /** The network name to associate with
@@ -242,6 +245,18 @@ struct setting net80211_active_setting __setting = {
 	.type = &setting_type_int8,
 };
 
+/** The cryptographic key to use
+ *
+ * For hex WEP keys, as is common, this must be entered using the
+ * normal gPXE method for entering hex settings; an ASCII string of
+ * hex characters will not behave as expected.
+ */
+struct setting net80211_key_setting __setting = {
+	.name = "key",
+	.description = "Encryption key for protected 802.11 networks",
+	.type = &setting_type_string,
+};
+
 /** @} */
 
 
@@ -294,7 +309,16 @@ static void net80211_netdev_close ( struct net_device *netdev )
 
 	/* Send disassociation frame to AP, to be polite */
 	if ( dev->state & NET80211_ASSOCIATED )
-		net80211_send_disassoc ( dev, IEEE80211_REASON_LEAVING );
+		net80211_send_disassoc ( dev, IEEE80211_REASON_LEAVING, 0 );
+
+	if ( dev->handshaker && dev->handshaker->stop &&
+	     dev->handshaker->started )
+		dev->handshaker->stop ( dev );
+
+	free ( dev->crypto );
+	free ( dev->handshaker );
+	dev->crypto = NULL;
+	dev->handshaker = NULL;
 
 	netdev_link_down ( netdev );
 	dev->state = 0;
@@ -317,16 +341,25 @@ static int net80211_netdev_transmit ( struct net_device *netdev,
 				      struct io_buffer *iobuf )
 {
 	struct net80211_device *dev = netdev->priv;
+	struct ieee80211_frame *hdr = iobuf->data;
 	int rc = -ENOSYS;
 
-	if ( dev->crypto ) {
+	if ( dev->crypto && ! ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
+	     ( ( hdr->fc & IEEE80211_FC_TYPE ) == IEEE80211_TYPE_DATA ) ) {
 		struct io_buffer *niob = dev->crypto->encrypt ( dev->crypto,
 								iobuf );
 		if ( ! niob )
 			return -ENOMEM;	/* only reason encryption could fail */
 
-		free_iob ( iobuf );
-		iobuf = niob;
+		/* Free the non-encrypted iob */
+		netdev_tx_complete ( netdev, iobuf );
+
+		/* Transmit the encrypted iob; the Protected flag is
+		   set, so we won't recurse into here again */
+		netdev_tx ( netdev, niob );
+
+		/* Don't transmit the freed packet */
+		return 0;
 	}
 
 	if ( dev->op->transmit )
@@ -482,7 +515,7 @@ static int net80211_ll_push ( struct net_device *netdev,
 		( void * ) hdr + IEEE80211_TYP_FRAME_HEADER_LEN;
 
 	/* We can't send data packets if we're not associated. */
-	if ( ! netdev_link_ok ( netdev ) ) {
+	if ( ! ( dev->state & NET80211_ASSOCIATED ) ) {
 		if ( dev->assoc_rc )
 			return dev->assoc_rc;
 		return -ENETUNREACH;
@@ -1032,7 +1065,7 @@ static int net80211_process_ie ( struct net80211_device *dev,
 	int changed = 0;
 	int band = dev->channels[dev->channel].band;
 
-	if ( ( void * ) ie >= ie_end )
+	if ( ! ieee80211_ie_bound ( ie, ie_end ) )
 		return 0;
 
 	for ( ; ie; ie = ieee80211_next_ie ( ie, ie_end ) ) {
@@ -1103,10 +1136,6 @@ static int net80211_process_ie ( struct net80211_device *dev,
 			if ( ! ( ie->erp_info & IEEE80211_ERP_BARKER_LONG ) )
 				dev->phy_flags |= NET80211_PHY_USE_SHORT_PREAMBLE;
 			break;
-
-		case IEEE80211_IE_RSN:
-			/* XXX need to implement WPA stuff */
-			break;
 		}
 	}
 
@@ -1140,10 +1169,20 @@ static int net80211_process_ie ( struct net80211_device *dev,
 		   exist, so insertion sort works well. */
 		for ( i = 1; i < dev->nr_rates; i++ ) {
 			u16 rate = dev->rates[i];
+			u32 tmp, br, mask;
 
 			for ( j = i - 1; j >= 0 && dev->rates[j] >= rate; j-- )
 				dev->rates[j + 1] = dev->rates[j];
 			dev->rates[j + 1] = rate;
+
+			/* Adjust basic_rates to match by rotating the
+			   bits from bit j+1 to bit i left one position. */
+			mask = ( ( 1 << i ) - 1 ) & ~( ( 1 << ( j + 1 ) ) - 1 );
+			br = dev->basic_rates;
+			tmp = br & ( 1 << i );
+			br = ( br & ~( mask | tmp ) ) | ( ( br & mask ) << 1 );
+			br |= ( tmp >> ( i - j - 1 ) );
+			dev->basic_rates = br;
 		}
 
 		net80211_set_rtscts_rate ( dev );
@@ -1187,28 +1226,42 @@ net80211_marshal_request_info ( struct net80211_device *dev,
 
 	ie->id = IEEE80211_IE_RATES;
 	ie->len = dev->nr_rates;
+	if ( ie->len > 8 )
+		ie->len = 8;
+
 	for ( i = 0; i < ie->len; i++ ) {
 		ie->rates[i] = dev->rates[i] / 5;
 		if ( dev->basic_rates & ( 1 << i ) )
 			ie->rates[i] |= 0x80;
 	}
 
-	if ( ie->len > 8 ) {
+	ie = ieee80211_next_ie ( ie, NULL );
+
+	if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_RSN ) {
+		memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 );
+		ie = ieee80211_next_ie ( ie, NULL );
+	}
+
+	if ( dev->nr_rates > 8 ) {
 		/* 802.11 requires we use an Extended Basic Rates IE
 		   for the rates beyond the eighth. */
-		int rates = ie->len;
 
-		memmove ( ( void * ) ie + 2 + 8 + 2, ( void * ) ie + 2 + 8,
-			  rates - 8 );
-		ie->len = 8;
+		ie->id = IEEE80211_IE_EXT_RATES;
+		ie->len = dev->nr_rates - 8;
 
-		ie = ieee80211_next_ie ( ie, NULL );
+		for ( ; i < dev->nr_rates; i++ ) {
+			ie->rates[i - 8] = dev->rates[i] / 5;
+			if ( dev->basic_rates & ( 1 << i ) )
+				ie->rates[i - 8] |= 0x80;
+		}
 
-		ie->id = IEEE80211_IE_EXT_RATES;
-		ie->len = rates - 8;
+		ie = ieee80211_next_ie ( ie, NULL );
 	}
 
-	ie = ieee80211_next_ie ( ie, NULL );
+	if ( dev->rsn_ie && dev->rsn_ie->id == IEEE80211_IE_VENDOR ) {
+		memcpy ( ie, dev->rsn_ie, dev->rsn_ie->len + 2 );
+		ie = ieee80211_next_ie ( ie, NULL );
+	}
 
 	return ie;
 }
@@ -1275,13 +1328,6 @@ struct net80211_probe_ctx * net80211_probe_start ( struct net80211_device *dev,
 
 		ie = net80211_marshal_request_info ( dev,
 						     probe_req->info_element );
-		ie->id = IEEE80211_IE_REQUEST;
-		ie->len = 3;
-		ie->request[0] = IEEE80211_IE_COUNTRY;
-		ie->request[1] = IEEE80211_IE_ERP_INFO;
-		ie->request[2] = IEEE80211_IE_RSN;
-
-		ie = ieee80211_next_ie ( ie, NULL );
 
 		iob_put ( ctx->probe, ( void * ) ie - ctx->probe->data );
 	}
@@ -1404,6 +1450,10 @@ int net80211_probe_step ( struct net80211_probe_ctx *ctx )
 		}
 
 		ie = beacon->info_element;
+
+		if ( ! ieee80211_ie_bound ( ie, iob->tail ) )
+			ie = NULL;
+
 		while ( ie && ie->id != IEEE80211_IE_SSID )
 			ie = ieee80211_next_ie ( ie, iob->tail );
 
@@ -1459,10 +1509,27 @@ int net80211_probe_step ( struct net80211_probe_ctx *ctx )
 		memcpy ( iob_put ( wlan->beacon, iob_len ( iob ) ),
 			 iob->data, iob_len ( iob ) );
 
-		/* XXX actually check capab and RSN ie to
-		   figure this out */
-		wlan->handshaking = NET80211_SECPROT_NONE;
-		wlan->crypto = NET80211_CRYPT_NONE;
+		if ( ( rc = sec80211_detect ( wlan->beacon, &wlan->handshaking,
+					      &wlan->crypto ) ) == -ENOTSUP ) {
+			struct ieee80211_beacon *beacon =
+				( struct ieee80211_beacon * ) hdr->data;
+
+			if ( beacon->capability & IEEE80211_CAPAB_PRIVACY ) {
+				DBG ( "802.11 %p probe: secured network %s but "
+				      "encryption support not compiled in\n",
+				      dev, wlan->essid );
+				wlan->handshaking = NET80211_SECPROT_UNKNOWN;
+				wlan->crypto = NET80211_CRYPT_UNKNOWN;
+			} else {
+				wlan->handshaking = NET80211_SECPROT_NONE;
+				wlan->crypto = NET80211_CRYPT_NONE;
+			}
+		} else if ( rc != 0 ) {
+			DBGC ( dev, "802.11 %p probe warning: network "
+			       "%s with unidentifiable security "
+			       "settings: %s\n", dev, wlan->essid,
+			       strerror ( rc ) );
+		}
 
 		ctx->ticks_beacon = now;
 
@@ -1739,6 +1806,14 @@ static void net80211_step_associate ( struct process *proc )
 
 		DBGC ( dev, "802.11 %p associating\n", dev );
 
+		if ( dev->handshaker && dev->handshaker->start &&
+		     ! dev->handshaker->started ) {
+			rc = dev->handshaker->start ( dev );
+			if ( rc < 0 )
+				goto fail;
+			dev->handshaker->started = 1;
+		}
+
 		rc = net80211_send_assoc ( dev, dev->associating );
 		if ( rc )
 			goto fail;
@@ -1750,9 +1825,29 @@ static void net80211_step_associate ( struct process *proc )
 		/* state: crypto sync */
 		DBGC ( dev, "802.11 %p security handshaking\n", dev );
 
-		dev->state |= NET80211_CRYPTO_SYNCED;
-		/* XXX need to actually do something here once we
-		   support WPA */
+		if ( ! dev->handshaker || ! dev->handshaker->step ) {
+			dev->state |= NET80211_CRYPTO_SYNCED;
+			return;
+		}
+
+		rc = dev->handshaker->step ( dev );
+
+		if ( rc < 0 ) {
+			/* Only record the returned error if we're
+			   still marked as associated, because an
+			   asynchronous error will have already been
+			   reported to net80211_deauthenticate() and
+			   assoc_rc thereby set. */
+			if ( dev->state & NET80211_ASSOCIATED )
+				dev->assoc_rc = rc;
+			rc = 0;
+			goto fail;
+		}
+
+		if ( rc > 0 ) {
+			dev->assoc_rc = 0;
+			dev->state |= NET80211_CRYPTO_SYNCED;
+		}
 		return;
 	}
 
@@ -1804,27 +1899,36 @@ static void net80211_step_associate ( struct process *proc )
 }
 
 /**
- * Check for 802.11 SSID updates
+ * Check for 802.11 SSID or key updates
  *
  * This acts as a settings applicator; if the user changes netX/ssid,
  * and netX is currently open, the association task will be invoked
- * again.
+ * again. If the user changes the encryption key, the current security
+ * handshaker will be asked to update its state to match; if that is
+ * impossible without reassociation, we reassociate.
  */
-static int net80211_check_ssid_update ( void )
+static int net80211_check_settings_update ( void )
 {
 	struct net80211_device *dev;
 	char ssid[IEEE80211_MAX_SSID_LEN + 1];
+	int key_reassoc;
 
 	list_for_each_entry ( dev, &net80211_devices, list ) {
 		if ( ! ( dev->netdev->state & NETDEV_OPEN ) )
 			continue;
 
+		key_reassoc = 0;
+		if ( dev->handshaker && dev->handshaker->change_key &&
+		     dev->handshaker->change_key ( dev ) < 0 )
+			key_reassoc = 1;
+
 		fetch_string_setting ( netdev_settings ( dev->netdev ),
 				       &net80211_ssid_setting, ssid,
 				       IEEE80211_MAX_SSID_LEN + 1 );
 
-		if ( strcmp ( ssid, dev->essid ) != 0 &&
-		     ! ( ! ssid[0] && ( dev->state & NET80211_AUTO_SSID ) ) ) {
+		if ( key_reassoc ||
+		     ( ! ( ! ssid[0] && ( dev->state & NET80211_AUTO_SSID ) ) &&
+		       strcmp ( ssid, dev->essid ) != 0 ) ) {
 			DBGC ( dev, "802.11 %p updating association: "
 			       "%s -> %s\n", dev, dev->essid, ssid );
 			net80211_autoassociate ( dev );
@@ -1846,6 +1950,8 @@ void net80211_autoassociate ( struct net80211_device *dev )
 	if ( ! ( dev->state & NET80211_WORKING ) ) {
 		DBGC2 ( dev, "802.11 %p spawning association process\n", dev );
 		process_add ( &dev->proc_assoc );
+	} else {
+		DBGC2 ( dev, "802.11 %p restarting association\n", dev );
 	}
 
 	/* Clean up everything an earlier association process might
@@ -1865,6 +1971,7 @@ void net80211_autoassociate ( struct net80211_device *dev )
 			       IEEE80211_MAX_SSID_LEN + 1 );
 	dev->ctx.probe = NULL;
 	dev->associating = NULL;
+	dev->assoc_rc = 0;
 	net80211_set_state ( dev, NET80211_PROBED, NET80211_WORKING, 0 );
 }
 
@@ -2020,6 +2127,7 @@ int net80211_prepare_assoc ( struct net80211_device *dev,
 	struct ieee80211_frame *hdr = wlan->beacon->data;
 	struct ieee80211_beacon *beacon =
 		( struct ieee80211_beacon * ) hdr->data;
+	struct net80211_handshaker *handshaker;
 	int rc;
 
 	assert ( dev->netdev->state & NETDEV_OPEN );
@@ -2028,11 +2136,12 @@ int net80211_prepare_assoc ( struct net80211_device *dev,
 	memcpy ( dev->bssid, wlan->bssid, ETH_ALEN );
 	strcpy ( dev->essid, wlan->essid );
 
+	free ( dev->rsn_ie );
+	dev->rsn_ie = NULL;
+
 	dev->last_beacon_timestamp = beacon->timestamp;
 	dev->tx_beacon_interval = 1024 * beacon->beacon_interval;
 
-	/* XXX do crypto setup here */
-
 	/* Barring an IE that tells us the channel outright, assume
 	   the channel we heard this AP best on is the channel it's
 	   communicating on. */
@@ -2051,6 +2160,46 @@ int net80211_prepare_assoc ( struct net80211_device *dev,
 	dev->rate = 0;
 	dev->op->config ( dev, NET80211_CFG_RATE );
 
+	/* Free old handshaker and crypto, if they exist */
+	if ( dev->handshaker && dev->handshaker->stop &&
+	     dev->handshaker->started )
+		dev->handshaker->stop ( dev );
+	free ( dev->handshaker );
+	dev->handshaker = NULL;
+	free ( dev->crypto );
+	free ( dev->gcrypto );
+	dev->crypto = dev->gcrypto = NULL;
+
+	/* Find new security handshaker to use */
+	for_each_table_entry ( handshaker, NET80211_HANDSHAKERS ) {
+		if ( handshaker->protocol == wlan->handshaking ) {
+			dev->handshaker = zalloc ( sizeof ( *handshaker ) +
+						   handshaker->priv_len );
+			if ( ! dev->handshaker )
+				return -ENOMEM;
+
+			memcpy ( dev->handshaker, handshaker,
+				 sizeof ( *handshaker ) );
+			dev->handshaker->priv = ( ( void * ) dev->handshaker +
+						  sizeof ( *handshaker ) );
+			break;
+		}
+	}
+
+	if ( ( wlan->handshaking != NET80211_SECPROT_NONE ) &&
+	     ! dev->handshaker ) {
+		DBGC ( dev, "802.11 %p no support for handshaking scheme %d\n",
+		       dev, wlan->handshaking );
+		return -( ENOTSUP | ( wlan->handshaking << 8 ) );
+	}
+
+	/* Initialize security handshaker */
+	if ( dev->handshaker ) {
+		rc = dev->handshaker->init ( dev );
+		if ( rc < 0 )
+			return rc;
+	}
+
 	return 0;
 }
 
@@ -2091,8 +2240,8 @@ int net80211_send_auth ( struct net80211_device *dev,
  *
  * If the authentication method being used is Shared Key, and the
  * frame that was received included challenge text, the frame is
- * encrypted using the cryptographic algorithm currently in effect and
- * sent back to the AP to complete the authentication.
+ * encrypted using the cryptosystem currently in effect and sent back
+ * to the AP to complete the authentication.
  */
 static void net80211_handle_auth ( struct net80211_device *dev,
 				   struct io_buffer *iob )
@@ -2181,8 +2330,6 @@ int net80211_send_assoc ( struct net80211_device *dev,
 	DBGP ( "802.11 %p about to send association request:\n", dev );
 	DBGP_HD ( iob->data, ( void * ) ie - iob->data );
 
-	/* XXX add RSN ie for WPA support */
-
 	iob_put ( iob, ( void * ) ie - iob->data );
 
 	return net80211_tx_mgmt ( dev, IEEE80211_STYPE_ASSOC_REQ,
@@ -2227,9 +2374,11 @@ static void net80211_handle_assoc_reply ( struct net80211_device *dev,
  *
  * @v dev	802.11 device
  * @v reason	Reason for disassociation
+ * @v deauth	If TRUE, send deauthentication instead of disassociation
  * @ret rc	Return status code
  */
-static int net80211_send_disassoc ( struct net80211_device *dev, int reason )
+static int net80211_send_disassoc ( struct net80211_device *dev, int reason,
+				    int deauth )
 {
 	struct io_buffer *iob = alloc_iob ( 64 );
 	struct ieee80211_disassoc *disassoc;
@@ -2242,8 +2391,28 @@ static int net80211_send_disassoc ( struct net80211_device *dev, int reason )
 	disassoc = iob_put ( iob, sizeof ( *disassoc ) );
 	disassoc->reason = reason;
 
-	return net80211_tx_mgmt ( dev, IEEE80211_STYPE_DISASSOC, dev->bssid,
-				  iob );
+	return net80211_tx_mgmt ( dev, deauth ? IEEE80211_STYPE_DEAUTH :
+				  IEEE80211_STYPE_DISASSOC, dev->bssid, iob );
+}
+
+
+/**
+ * Deauthenticate from current network and try again
+ *
+ * @v dev	802.11 device
+ * @v rc	Return status code indicating reason
+ *
+ * The deauthentication will be sent using an 802.11 "unspecified
+ * reason", as is common, but @a rc will be set as a link-up
+ * error to aid the user in debugging.
+ */
+void net80211_deauthenticate ( struct net80211_device *dev, int rc )
+{
+	net80211_send_disassoc ( dev, IEEE80211_REASON_UNSPECIFIED, 1 );
+	dev->assoc_rc = rc;
+	netdev_link_err ( dev->netdev, rc );
+
+	net80211_autoassociate ( dev );
 }
 
 
@@ -2557,14 +2726,29 @@ void net80211_rx ( struct net80211_device *dev, struct io_buffer *iob,
 		iob_unput ( iob, 4 );
 	}
 
-	if ( hdr->fc & IEEE80211_FC_PROTECTED ) {
+	/* Only decrypt packets from our BSSID, to avoid spurious errors */
+	if ( ( hdr->fc & IEEE80211_FC_PROTECTED ) &&
+	     ! memcmp ( hdr->addr2, dev->bssid, ETH_ALEN ) ) {
+		/* Decrypt packet; record and drop if it fails */
 		struct io_buffer *niob;
-		if ( ! dev->crypto )
-			goto drop;	/* can't decrypt packets on an open network */
+		struct net80211_crypto *crypto = dev->crypto;
 
-		niob = dev->crypto->decrypt ( dev->crypto, iob );
-		if ( ! niob )
-			goto drop;	/* drop failed decryption */
+		if ( ! dev->crypto ) {
+			DBGC ( dev, "802.11 %p cannot decrypt packet "
+			       "without a cryptosystem\n", dev );
+			goto drop_crypt;
+		}
+
+		if ( ( hdr->addr1[0] & 1 ) && dev->gcrypto ) {
+			/* Use group decryption if needed */
+			crypto = dev->gcrypto;
+		}
+
+		niob = crypto->decrypt ( crypto, iob );
+		if ( ! niob ) {
+			DBGC ( dev, "802.11 %p decryption error\n", dev );
+			goto drop_crypt;
+		}
 		free_iob ( iob );
 		iob = niob;
 	}
@@ -2593,11 +2777,16 @@ void net80211_rx ( struct net80211_device *dev, struct io_buffer *iob,
 		rc80211_update_rx ( dev, hdr->fc & IEEE80211_FC_RETRY, rate );
 
 	/* Pass packet onward */
-	if ( netdev_link_ok ( dev->netdev ) ) {
+	if ( dev->state & NET80211_ASSOCIATED ) {
 		netdev_rx ( dev->netdev, iob );
 		return;
 	}
 
+	/* No association? Drop it. */
+	goto drop;
+
+ drop_crypt:
+	netdev_rx_err ( dev->netdev, NULL, EINVAL_CRYPTO_REQUEST );
  drop:
 	DBGC2 ( dev, "802.11 %p dropped packet fc=%04x seq=%04x\n", dev,
 		hdr->fc, hdr->seq );

src/net/80211/sec80211.c

@@ -0,0 +1,503 @@
+/*
+ * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <gpxe/ieee80211.h>
+#include <gpxe/net80211.h>
+#include <gpxe/sec80211.h>
+
+/** @file
+ *
+ * General secured-network routines required whenever any secure
+ * network support at all is compiled in. This involves things like
+ * installing keys, determining the type of security used by a probed
+ * network, and some small helper functions that take advantage of
+ * static data in this file.
+ */
+
+/** Mapping from net80211 crypto/secprot types to RSN OUI descriptors */
+struct descriptor_map {
+	/** Value of net80211_crypto_alg or net80211_security_proto */
+	u32 net80211_type;
+
+	/** OUI+type in appropriate byte order, masked to exclude vendor */
+	u32 oui_type;
+};
+
+/** Magic number in @a oui_type showing end of list */
+#define END_MAGIC	0xFFFFFFFF
+
+/** Mapping between net80211 cryptosystems and 802.11i cipher IDs */
+static struct descriptor_map rsn_cipher_map[] = {
+	{ .net80211_type = NET80211_CRYPT_WEP,
+	  .oui_type = IEEE80211_RSN_CTYPE_WEP40 },
+
+	{ .net80211_type = NET80211_CRYPT_WEP,
+	  .oui_type = IEEE80211_RSN_CTYPE_WEP104 },
+
+	{ .net80211_type = NET80211_CRYPT_TKIP,
+	  .oui_type = IEEE80211_RSN_CTYPE_TKIP },
+
+	{ .net80211_type = NET80211_CRYPT_CCMP,
+	  .oui_type = IEEE80211_RSN_CTYPE_CCMP },
+
+	{ .net80211_type = NET80211_CRYPT_UNKNOWN,
+	  .oui_type = END_MAGIC },
+};
+
+/** Mapping between net80211 handshakers and 802.11i AKM IDs */
+static struct descriptor_map rsn_akm_map[] = {
+	{ .net80211_type = NET80211_SECPROT_EAP,
+	  .oui_type = IEEE80211_RSN_ATYPE_8021X },
+
+	{ .net80211_type = NET80211_SECPROT_PSK,
+	  .oui_type = IEEE80211_RSN_ATYPE_PSK },
+
+	{ .net80211_type = NET80211_SECPROT_UNKNOWN,
+	  .oui_type = END_MAGIC },
+};
+
+
+/**
+ * Install 802.11 cryptosystem
+ *
+ * @v which	Pointer to the cryptosystem structure to install in
+ * @v crypt	Cryptosystem ID number
+ * @v key	Encryption key to use
+ * @v len	Length of encryption key
+ * @v rsc	Initial receive sequence counter, if applicable
+ * @ret rc	Return status code
+ *
+ * The encryption key will not be accessed via the provided pointer
+ * after this function returns, so you may keep it on the stack.
+ *
+ * @a which must point to either @c dev->crypto (for the normal case
+ * of installing a unicast cryptosystem) or @c dev->gcrypto (to
+ * install a cryptosystem that will be used only for decrypting
+ * group-source frames).
+ */
+int sec80211_install ( struct net80211_crypto **which,
+		       enum net80211_crypto_alg crypt,
+		       const void *key, int len, const void *rsc )
+{
+	struct net80211_crypto *crypto = *which;
+	struct net80211_crypto *tbl_crypto;
+
+	/* Remove old crypto if it exists */
+	free ( *which );
+	*which = NULL;
+
+	if ( crypt == NET80211_CRYPT_NONE ) {
+		DBG ( "802.11-Sec not installing null cryptography\n" );
+		return 0;
+	}
+
+	/* Find cryptosystem to use */
+	for_each_table_entry ( tbl_crypto, NET80211_CRYPTOS ) {
+		if ( tbl_crypto->algorithm == crypt ) {
+			crypto = zalloc ( sizeof ( *crypto ) +
+					  tbl_crypto->priv_len );
+			if ( ! crypto ) {
+				DBG ( "802.11-Sec out of memory\n" );
+				return -ENOMEM;
+			}
+
+			memcpy ( crypto, tbl_crypto, sizeof ( *crypto ) );
+			crypto->priv = ( ( void * ) crypto +
+					 sizeof ( *crypto ) );
+			break;
+		}
+	}
+
+	if ( ! crypto ) {
+		DBG ( "802.11-Sec no support for cryptosystem %d\n", crypt );
+		return -( ENOTSUP | EUNIQ_10 | ( crypt << 8 ) );
+	}
+
+	*which = crypto;
+
+	DBG ( "802.11-Sec installing cryptosystem %d as %p with key of "
+	      "length %d\n", crypt, crypto, len );
+
+	return crypto->init ( crypto, key, len, rsc );
+}
+
+
+/**
+ * Determine net80211 crypto or handshaking type value to return for RSN info
+ *
+ * @v rsnp		Pointer to next descriptor count field in RSN IE
+ * @v rsn_end		Pointer to end of RSN IE
+ * @v map		Descriptor map to use
+ * @v tbl_start		Start of linker table to examine for gPXE support
+ * @v tbl_end		End of linker table to examine for gPXE support
+ * @ret rsnp		Updated to point to first byte after descriptors
+ * @ret map_ent		Descriptor map entry of translation to use
+ *
+ * The entries in the linker table must be either net80211_crypto or
+ * net80211_handshaker structures, and @a tbl_stride must be set to
+ * sizeof() the appropriate one.
+ *
+ * This function expects @a rsnp to point at a two-byte descriptor
+ * count followed by a list of four-byte cipher or AKM descriptors; it
+ * will return @c NULL if the input packet is malformed, and otherwise
+ * set @a rsnp to the first byte it has not looked at. It will return
+ * the first cipher in the list that is supported by the current build
+ * of gPXE, or the first of all if none are supported.
+ *
+ * We play rather fast and loose with type checking, because this
+ * function is only called from two well-defined places in the
+ * RSN-checking code. Don't try to use it for anything else.
+ */
+static struct descriptor_map * rsn_pick_desc ( u8 **rsnp, u8 *rsn_end,
+					       struct descriptor_map *map,
+					       void *tbl_start, void *tbl_end )
+{
+	int ndesc;
+	int ok = 0;
+	struct descriptor_map *map_ent, *map_ret = NULL;
+	u8 *rsn = *rsnp;
+	void *tblp;
+	size_t tbl_stride = ( map == rsn_cipher_map ?
+			      sizeof ( struct net80211_crypto ) :
+			      sizeof ( struct net80211_handshaker ) );
+
+	if ( map != rsn_cipher_map && map != rsn_akm_map )
+		return NULL;
+
+	/* Determine which types we support */
+	for ( tblp = tbl_start; tblp < tbl_end; tblp += tbl_stride ) {
+		struct net80211_crypto *crypto = tblp;
+		struct net80211_handshaker *hs = tblp;
+
+		if ( map == rsn_cipher_map )
+			ok |= ( 1 << crypto->algorithm );
+		else
+			ok |= ( 1 << hs->protocol );
+	}
+
+	/* RSN sanity checks */
+	if ( rsn + 2 > rsn_end ) {
+		DBG ( "RSN detect: malformed descriptor count\n" );
+		return NULL;
+	}
+
+	ndesc = *( u16 * ) rsn;
+	rsn += 2;
+
+	if ( ! ndesc ) {
+		DBG ( "RSN detect: no descriptors\n" );
+		return NULL;
+	}
+
+	/* Determine which net80211 crypto types are listed */
+	while ( ndesc-- ) {
+		u32 desc;
+
+		if ( rsn + 4 > rsn_end ) {
+			DBG ( "RSN detect: malformed descriptor (%d left)\n",
+			      ndesc );
+			return NULL;
+		}
+
+		desc = *( u32 * ) rsn;
+		rsn += 4;
+
+		for ( map_ent = map; map_ent->oui_type != END_MAGIC; map_ent++ )
+			if ( map_ent->oui_type == ( desc & OUI_TYPE_MASK ) )
+				break;
+
+		/* Use first cipher as a fallback */
+		if ( ! map_ret )
+			map_ret = map_ent;
+
+		/* Once we find one we support, use it */
+		if ( ok & ( 1 << map_ent->net80211_type ) ) {
+			map_ret = map_ent;
+			break;
+		}
+	}
+
+	if ( ndesc > 0 )
+		rsn += 4 * ndesc;
+
+	*rsnp = rsn;
+	return map_ret;
+}
+
+
+/**
+ * Find the RSN or WPA information element in the provided beacon frame
+ *
+ * @v ie	Pointer to first information element to check
+ * @v ie_end	Pointer to end of information element space
+ * @ret is_rsn	TRUE if returned IE is RSN, FALSE if it's WPA
+ * @ret end	Pointer to byte immediately after last byte of data
+ * @ret data	Pointer to first byte of data (the `version' field)
+ *
+ * If both an RSN and a WPA information element are found, this
+ * function will return the first one seen, which by ordering rules
+ * should always prefer the newer RSN IE.
+ *
+ * If no RSN or WPA infomration element is found, returns @c NULL and
+ * leaves @a is_rsn and @a end in an undefined state.
+ *
+ * This function will not return a pointer to an information element
+ * that states it extends past the tail of the io_buffer, or whose @a
+ * version field is incorrect.
+ */
+u8 * sec80211_find_rsn ( union ieee80211_ie *ie, void *ie_end,
+			 int *is_rsn, u8 **end )
+{
+	u8 *rsn = NULL;
+
+	if ( ! ieee80211_ie_bound ( ie, ie_end ) )
+		return NULL;
+
+	while ( ie ) {
+		if ( ie->id == IEEE80211_IE_VENDOR &&
+		     ie->vendor.oui == IEEE80211_WPA_OUI_VEN ) {
+			DBG ( "RSN detect: old-style WPA IE found\n" );
+			rsn = &ie->vendor.data[0];
+			*end = rsn + ie->len - 4;
+			*is_rsn = 0;
+		} else if ( ie->id == IEEE80211_IE_RSN ) {
+			DBG ( "RSN detect: 802.11i RSN IE found\n" );
+			rsn = ( u8 * ) &ie->rsn.version;
+			*end = rsn + ie->len;
+			*is_rsn = 1;
+		}
+
+		if ( rsn && ( *end > ( u8 * ) ie_end || rsn >= *end ||
+			      *( u16 * ) rsn != IEEE80211_RSN_VERSION ) ) {
+			DBG ( "RSN detect: malformed RSN IE or unknown "
+			      "version, keep trying\n" );
+			rsn = NULL;
+		}
+
+		if ( rsn )
+			break;
+
+		ie = ieee80211_next_ie ( ie, ie_end );
+	}
+
+	if ( ! ie ) {
+		DBG ( "RSN detect: no RSN IE found\n" );
+		return NULL;
+	}
+
+	return rsn;
+}
+
+
+/**
+ * Detect crypto and AKM types from RSN information element
+ *
+ * @v is_rsn	If TRUE, IE is a new-style RSN information element
+ * @v start	Pointer to first byte of @a version field
+ * @v end	Pointer to first byte not in the RSN IE
+ * @ret secprot	Security handshaking protocol used by network
+ * @ret crypt	Cryptosystem used by network
+ * @ret rc	Return status code
+ *
+ * If the IE cannot be parsed, returns an error indication and leaves
+ * @a secprot and @a crypt unchanged.
+ */
+int sec80211_detect_ie ( int is_rsn, u8 *start, u8 *end,
+			 enum net80211_security_proto *secprot,
+			 enum net80211_crypto_alg *crypt )
+{
+	enum net80211_security_proto sp;
+	enum net80211_crypto_alg cr;
+	struct descriptor_map *map;
+	u8 *rsn = start;
+
+	/* Set some defaults */
+	cr = ( is_rsn ? NET80211_CRYPT_CCMP : NET80211_CRYPT_TKIP );
+	sp = NET80211_SECPROT_EAP;
+
+	rsn += 2;		/* version - already checked */
+	rsn += 4;		/* group cipher - we don't use it here */
+
+	if ( rsn >= end )
+		goto done;
+
+	/* Pick crypto algorithm */
+	map = rsn_pick_desc ( &rsn, end, rsn_cipher_map,
+			      table_start ( NET80211_CRYPTOS ),
+			      table_end ( NET80211_CRYPTOS ) );
+	if ( ! map )
+		goto invalid_rsn;
+
+	cr = map->net80211_type;
+
+	if ( rsn >= end )
+		goto done;
+
+	/* Pick handshaking algorithm */
+	map = rsn_pick_desc ( &rsn, end, rsn_akm_map,
+			      table_start ( NET80211_HANDSHAKERS ),
+			      table_end ( NET80211_HANDSHAKERS ) );
+	if ( ! map )
+		goto invalid_rsn;
+
+	sp = map->net80211_type;
+
+ done:
+	DBG ( "RSN detect: OK, crypto type %d, secprot type %d\n", cr, sp );
+	*secprot = sp;
+	*crypt = cr;
+	return 0;
+
+ invalid_rsn:
+	DBG ( "RSN detect: invalid RSN IE\n" );
+	return -EINVAL;
+}
+
+
+/**
+ * Detect the cryptosystem and handshaking protocol used by an 802.11 network
+ *
+ * @v iob	I/O buffer containing beacon frame
+ * @ret secprot	Security handshaking protocol used by network
+ * @ret crypt	Cryptosystem used by network
+ * @ret rc	Return status code
+ *
+ * This function uses weak linkage, as it must be called from generic
+ * contexts but should only be linked in if some encryption is
+ * supported; you must test its address against @c NULL before calling
+ * it. If it does not exist, any network with the PRIVACY bit set in
+ * beacon->capab should be considered unknown.
+ */
+int _sec80211_detect ( struct io_buffer *iob,
+		       enum net80211_security_proto *secprot,
+		       enum net80211_crypto_alg *crypt )
+{
+	struct ieee80211_frame *hdr = iob->data;
+	struct ieee80211_beacon *beacon =
+		( struct ieee80211_beacon * ) hdr->data;
+	u8 *rsn, *rsn_end;
+	int is_rsn, rc;
+
+	*crypt = NET80211_CRYPT_UNKNOWN;
+	*secprot = NET80211_SECPROT_UNKNOWN;
+
+	/* Find RSN or WPA IE */
+	if ( ! ( rsn = sec80211_find_rsn ( beacon->info_element, iob->tail,
+					   &is_rsn, &rsn_end ) ) ) {
+		/* No security IE at all; either WEP or no security. */
+		*secprot = NET80211_SECPROT_NONE;
+
+		if ( beacon->capability & IEEE80211_CAPAB_PRIVACY )
+			*crypt = NET80211_CRYPT_WEP;
+		else
+			*crypt = NET80211_CRYPT_NONE;
+
+		return 0;
+	}
+
+	/* Determine type of security */
+	if ( ( rc = sec80211_detect_ie ( is_rsn, rsn, rsn_end, secprot,
+					 crypt ) ) == 0 )
+		return 0;
+
+	/* If we get here, the RSN IE was invalid */
+
+	*crypt = NET80211_CRYPT_UNKNOWN;
+	*secprot = NET80211_SECPROT_UNKNOWN;
+	DBG ( "Failed to handle RSN IE:\n" );
+	DBG_HD ( rsn, rsn_end - rsn );
+	return rc;
+}
+
+
+/**
+ * Determine RSN descriptor for specified net80211 ID
+ *
+ * @v id	net80211 ID value
+ * @v rsnie	Whether to return a new-format (RSN IE) descriptor
+ * @v map	Map to use in translation
+ * @ret desc	RSN descriptor, or 0 on error
+ *
+ * If @a rsnie is false, returns an old-format (WPA vendor IE)
+ * descriptor.
+ */
+static u32 rsn_get_desc ( unsigned id, int rsnie, struct descriptor_map *map )
+{
+	u32 vendor = ( rsnie ? IEEE80211_RSN_OUI : IEEE80211_WPA_OUI );
+
+	for ( ; map->oui_type != END_MAGIC; map++ ) {
+		if ( map->net80211_type == id )
+			return map->oui_type | vendor;
+	}
+
+	return 0;
+}
+
+/**
+ * Determine RSN descriptor for specified net80211 cryptosystem number
+ *
+ * @v crypt	Cryptosystem number
+ * @v rsnie	Whether to return a new-format (RSN IE) descriptor
+ * @ret desc	RSN descriptor
+ *
+ * If @a rsnie is false, returns an old-format (WPA vendor IE)
+ * descriptor.
+ */
+u32 sec80211_rsn_get_crypto_desc ( enum net80211_crypto_alg crypt, int rsnie )
+{
+	return rsn_get_desc ( crypt, rsnie, rsn_cipher_map );
+}
+
+/**
+ * Determine RSN descriptor for specified net80211 handshaker number
+ *
+ * @v secprot	Handshaker number
+ * @v rsnie	Whether to return a new-format (RSN IE) descriptor
+ * @ret desc	RSN descriptor
+ *
+ * If @a rsnie is false, returns an old-format (WPA vendor IE)
+ * descriptor.
+ */
+u32 sec80211_rsn_get_akm_desc ( enum net80211_security_proto secprot,
+				int rsnie )
+{
+	return rsn_get_desc ( secprot, rsnie, rsn_akm_map );
+}
+
+/**
+ * Determine net80211 cryptosystem number from RSN descriptor
+ *
+ * @v desc	RSN descriptor
+ * @ret crypt	net80211 cryptosystem enumeration value
+ */
+enum net80211_crypto_alg sec80211_rsn_get_net80211_crypt ( u32 desc )
+{
+	struct descriptor_map *map = rsn_cipher_map;
+
+	for ( ; map->oui_type != END_MAGIC; map++ ) {
+		if ( map->oui_type == ( desc & OUI_TYPE_MASK ) )
+			break;
+	}
+
+	return map->net80211_type;
+}