[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 */