[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both

Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve
answers to AFS clients.  KerberosIV security is fully supported.  The patches
and some example test programs can be found in:

	http://people.redhat.com/~dhowells/rxrpc/

This will eventually replace the old implementation of kernel-only RxRPC
currently resident in net/rxrpc/.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 83 insertions, 2 deletions

diff --git a/include/rxrpc/packet.h b/include/rxrpc/packet.h
index 1447f0aaa0eb..452a9bb02d48 100644
--- a/include/rxrpc/packet.h
+++ b/include/rxrpc/packet.h
@@ -33,7 +33,8 @@ struct rxrpc_header
 #define RXRPC_MAXCALLS		4			/* max active calls per conn */
 #define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
 #define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
-#define RXRPC_CIDSHIFT		2			/* shift for connection ID */
+#define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
+#define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */
 
 	__be32		callNumber;	/* call ID (0 for connection-level packets) */
 #define RXRPC_PROCESS_MAXCALLS	(1<<2)	/* maximum number of active calls per conn (power of 2) */
@@ -62,7 +63,10 @@ struct rxrpc_header
 
 	uint8_t		userStatus;	/* app-layer defined status */
 	uint8_t		securityIndex;	/* security protocol ID */
-	__be16		_rsvd;		/* reserved (used by kerberos security as cksum) */
+	union {
+		__be16	_rsvd;		/* reserved */
+		__be16	cksum;		/* kerberos security checksum */
+	};
 	__be16		serviceId;	/* service ID */
 
 } __attribute__((packed));
@@ -124,4 +128,81 @@ struct rxrpc_ackpacket
 
 } __attribute__((packed));
 
+/*
+ * ACK packets can have a further piece of information tagged on the end
+ */
+struct rxrpc_ackinfo {
+	__be32		rxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
+	__be32		maxMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
+	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
+	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
+};
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 challenge packet
+ */
+struct rxkad_challenge {
+	__be32		version;	/* version of this challenge type */
+	__be32		nonce;		/* encrypted random number */
+	__be32		min_level;	/* minimum security level */
+	__be32		__padding;	/* padding to 8-byte boundary */
+} __attribute__((packed));
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 response packet
+ */
+struct rxkad_response {
+	__be32		version;	/* version of this reponse type */
+	__be32		__pad;
+
+	/* encrypted bit of the response */
+	struct {
+		__be32		epoch;		/* current epoch */
+		__be32		cid;		/* parent connection ID */
+		__be32		checksum;	/* checksum */
+		__be32		securityIndex;	/* security type */
+		__be32		call_id[4];	/* encrypted call IDs */
+		__be32		inc_nonce;	/* challenge nonce + 1 */
+		__be32		level;		/* desired level */
+	} encrypted;
+
+	__be32		kvno;		/* Kerberos key version number */
+	__be32		ticket_len;	/* Kerberos ticket length  */
+} __attribute__((packed));
+
+/*****************************************************************************/
+/*
+ * RxRPC-level abort codes
+ */
+#define RX_CALL_DEAD		-1	/* call/conn has been inactive and is shut down */
+#define RX_INVALID_OPERATION	-2	/* invalid operation requested / attempted */
+#define RX_CALL_TIMEOUT		-3	/* call timeout exceeded */
+#define RX_EOF			-4	/* unexpected end of data on read op */
+#define RX_PROTOCOL_ERROR	-5	/* low-level protocol error */
+#define RX_USER_ABORT		-6	/* generic user abort */
+#define RX_ADDRINUSE		-7	/* UDP port in use */
+#define RX_DEBUGI_BADTYPE	-8	/* bad debugging packet type */
+
+/*
+ * Rx kerberos security abort codes
+ * - unfortunately we have no generalised security abort codes to say things
+ *   like "unsupported security", so we have to use these instead and hope the
+ *   other side understands
+ */
+#define RXKADINCONSISTENCY	19270400	/* security module structure inconsistent */
+#define RXKADPACKETSHORT	19270401	/* packet too short for security challenge */
+#define RXKADLEVELFAIL		19270402	/* security level negotiation failed */
+#define RXKADTICKETLEN		19270403	/* ticket length too short or too long */
+#define RXKADOUTOFSEQUENCE	19270404	/* packet had bad sequence number */
+#define RXKADNOAUTH		19270405	/* caller not authorised */
+#define RXKADBADKEY		19270406	/* illegal key: bad parity or weak */
+#define RXKADBADTICKET		19270407	/* security object was passed a bad ticket */
+#define RXKADUNKNOWNKEY		19270408	/* ticket contained unknown key version number */
+#define RXKADEXPIRED		19270409	/* authentication expired */
+#define RXKADSEALEDINCON	19270410	/* sealed data inconsistent */
+#define RXKADDATALEN		19270411	/* user data too long */
+#define RXKADILLEGALLEVEL	19270412	/* caller not authorised to use encrypted conns */
+
 #endif /* _LINUX_RXRPC_PACKET_H */