Merge tag 'rxrpc-next-20170829' of git://git.kernel.org/pub/scm/linux…

…/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Miscellany

Here are a number of patches that make some changes/fixes and add a couple
of extensions to AF_RXRPC for kernel services to use.  The changes and
fixes are:

 (1) Use time64_t rather than u32 outside of protocol or
     UAPI-representative structures.

 (2) Use the correct time stamp when loading a key from an XDR-encoded
     Kerberos 5 key.

 (3) Fix IPv6 support.

 (4) Fix some places where the error code is being incorrectly made
     positive before returning.

 (5) Remove some white space.

And the extensions:

 (6) Add an end-of-Tx phase notification, thereby allowing kAFS to
     transition the state on its own call record at the correct point,
     rather than having to do it in advance and risk non-completion of the
     call in the wrong state.

 (7) Allow a kernel client call to be retried if it fails on a network
     error, thereby making it possible for kAFS to iterate over a number of
     IP addresses without having to reload the Tx queue and re-encrypt data
     each time.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/rxrpc.txt

@@ -818,10 +818,15 @@ The kernel interface functions are as follows:
 
  (*) Send data through a call.
 
+	typedef void (*rxrpc_notify_end_tx_t)(struct sock *sk,
+					      unsigned long user_call_ID,
+					      struct sk_buff *skb);
+
 	int rxrpc_kernel_send_data(struct socket *sock,
 				   struct rxrpc_call *call,
 				   struct msghdr *msg,
-				   size_t len);
+				   size_t len,
+				   rxrpc_notify_end_tx_t notify_end_rx);
 
      This is used to supply either the request part of a client call or the
      reply part of a server call.  msg.msg_iovlen and msg.msg_iov specify the
@@ -832,6 +837,11 @@ The kernel interface functions are as follows:
      The msg must not specify a destination address, control data or any flags
      other than MSG_MORE.  len is the total amount of data to transmit.
 
+     notify_end_rx can be NULL or it can be used to specify a function to be
+     called when the call changes state to end the Tx phase.  This function is
+     called with the call-state spinlock held to prevent any reply or final ACK
+     from being delivered first.
+
  (*) Receive data from a call.
 
 	int rxrpc_kernel_recv_data(struct socket *sock,
@@ -965,6 +975,51 @@ The kernel interface functions are as follows:
      size should be set when the call is begun.  tx_total_len may not be less
      than zero.
 
+ (*) Check to see the completion state of a call so that the caller can assess
+     whether it needs to be retried.
+
+	enum rxrpc_call_completion {
+		RXRPC_CALL_SUCCEEDED,
+		RXRPC_CALL_REMOTELY_ABORTED,
+		RXRPC_CALL_LOCALLY_ABORTED,
+		RXRPC_CALL_LOCAL_ERROR,
+		RXRPC_CALL_NETWORK_ERROR,
+	};
+
+	int rxrpc_kernel_check_call(struct socket *sock, struct rxrpc_call *call,
+				    enum rxrpc_call_completion *_compl,
+				    u32 *_abort_code);
+
+     On return, -EINPROGRESS will be returned if the call is still ongoing; if
+     it is finished, *_compl will be set to indicate the manner of completion,
+     *_abort_code will be set to any abort code that occurred.  0 will be
+     returned on a successful completion, -ECONNABORTED will be returned if the
+     client failed due to a remote abort and anything else will return an
+     appropriate error code.
+
+     The caller should look at this information to decide if it's worth
+     retrying the call.
+
+ (*) Retry a client call.
+
+	int rxrpc_kernel_retry_call(struct socket *sock,
+				    struct rxrpc_call *call,
+				    struct sockaddr_rxrpc *srx,
+				    struct key *key);
+
+     This attempts to partially reinitialise a call and submit it again whilst
+     reusing the original call's Tx queue to avoid the need to repackage and
+     re-encrypt the data to be sent.  call indicates the call to retry, srx the
+     new address to send it to and key the encryption key to use for signing or
+     encrypting the packets.
+
+     For this to work, the first Tx data packet must still be in the transmit
+     queue, and currently this is only permitted for local and network errors
+     and the call must not have been aborted.  Any partially constructed Tx
+     packet is left as is and can continue being filled afterwards.
+
+     It returns 0 if the call was requeued and an error otherwise.
+
 
 =======================
 CONFIGURABLE PARAMETERS

fs/afs/rxrpc.c

@@ -291,6 +291,19 @@ static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 	iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
 }
 
+/*
+ * Advance the AFS call state when the RxRPC call ends the transmit phase.
+ */
+static void afs_notify_end_request_tx(struct sock *sock,
+				      struct rxrpc_call *rxcall,
+				      unsigned long call_user_ID)
+{
+	struct afs_call *call = (struct afs_call *)call_user_ID;
+
+	if (call->state == AFS_CALL_REQUESTING)
+		call->state = AFS_CALL_AWAIT_REPLY;
+}
+
 /*
  * attach the data from a bunch of pages on an inode to a call
  */
@@ -310,14 +323,8 @@ static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
 		bytes = msg->msg_iter.count;
 		nr = msg->msg_iter.nr_segs;
 
-		/* Have to change the state *before* sending the last
-		 * packet as RxRPC might give us the reply before it
-		 * returns from sending the request.
-		 */
-		if (first + nr - 1 >= last)
-			call->state = AFS_CALL_AWAIT_REPLY;
-		ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
-					     msg, bytes);
+		ret = rxrpc_kernel_send_data(afs_socket, call->rxcall, msg,
+					     bytes, afs_notify_end_request_tx);
 		for (loop = 0; loop < nr; loop++)
 			put_page(bv[loop].bv_page);
 		if (ret < 0)
@@ -409,7 +416,8 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 	if (!call->send_pages)
 		call->state = AFS_CALL_AWAIT_REPLY;
 	ret = rxrpc_kernel_send_data(afs_socket, rxcall,
-				     &msg, call->request_size);
+				     &msg, call->request_size,
+				     afs_notify_end_request_tx);
 	if (ret < 0)
 		goto error_do_abort;
 
@@ -740,6 +748,20 @@ static int afs_deliver_cm_op_id(struct afs_call *call)
 	return call->type->deliver(call);
 }
 
+/*
+ * Advance the AFS call state when an RxRPC service call ends the transmit
+ * phase.
+ */
+static void afs_notify_end_reply_tx(struct sock *sock,
+				    struct rxrpc_call *rxcall,
+				    unsigned long call_user_ID)
+{
+	struct afs_call *call = (struct afs_call *)call_user_ID;
+
+	if (call->state == AFS_CALL_REPLYING)
+		call->state = AFS_CALL_AWAIT_ACK;
+}
+
 /*
  * send an empty reply
  */
@@ -759,7 +781,8 @@ void afs_send_empty_reply(struct afs_call *call)
 	msg.msg_flags		= 0;
 
 	call->state = AFS_CALL_AWAIT_ACK;
-	switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0)) {
+	switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0,
+				       afs_notify_end_reply_tx)) {
 	case 0:
 		_leave(" [replied]");
 		return;
@@ -797,7 +820,8 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 	msg.msg_flags		= 0;
 
 	call->state = AFS_CALL_AWAIT_ACK;
-	n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len);
+	n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len,
+				   afs_notify_end_reply_tx);
 	if (n >= 0) {
 		/* Success */
 		_leave(" [replied]");

include/keys/rxrpc-type.h

@@ -127,4 +127,27 @@ struct rxrpc_key_data_v1 {
 #define AFSTOKEN_K5_ADDRESSES_MAX	16	/* max K5 addresses */
 #define AFSTOKEN_K5_AUTHDATA_MAX	16	/* max K5 pieces of auth data */
 
+/*
+ * Truncate a time64_t to the range from 1970 to 2106 as in the network
+ * protocol.
+ */
+static inline u32 rxrpc_time64_to_u32(time64_t time)
+{
+	if (time < 0)
+		return 0;
+
+	if (time > UINT_MAX)
+		return UINT_MAX;
+
+	return (u32)time;
+}
+
+/*
+ * Extend u32 back to time64_t using the same 1970-2106 range.
+ */
+static inline time64_t rxrpc_u32_to_time64(u32 time)
+{
+	return (time64_t)time;
+}
+
 #endif /* _KEYS_RXRPC_TYPE_H */

include/net/af_rxrpc.h

@@ -19,8 +19,22 @@ struct sock;
 struct socket;
 struct rxrpc_call;
 
+/*
+ * Call completion condition (state == RXRPC_CALL_COMPLETE).
+ */
+enum rxrpc_call_completion {
+	RXRPC_CALL_SUCCEEDED,		/* - Normal termination */
+	RXRPC_CALL_REMOTELY_ABORTED,	/* - call aborted by peer */
+	RXRPC_CALL_LOCALLY_ABORTED,	/* - call aborted locally on error or close */
+	RXRPC_CALL_LOCAL_ERROR,		/* - call failed due to local error */
+	RXRPC_CALL_NETWORK_ERROR,	/* - call terminated by network error */
+	NR__RXRPC_CALL_COMPLETIONS
+};
+
 typedef void (*rxrpc_notify_rx_t)(struct sock *, struct rxrpc_call *,
 				  unsigned long);
+typedef void (*rxrpc_notify_end_tx_t)(struct sock *, struct rxrpc_call *,
+				      unsigned long);
 typedef void (*rxrpc_notify_new_call_t)(struct sock *, struct rxrpc_call *,
 					unsigned long);
 typedef void (*rxrpc_discard_new_call_t)(struct rxrpc_call *, unsigned long);
@@ -37,7 +51,8 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *,
 					   gfp_t,
 					   rxrpc_notify_rx_t);
 int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
-			   struct msghdr *, size_t);
+			   struct msghdr *, size_t,
+			   rxrpc_notify_end_tx_t);
 int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *,
 			   void *, size_t, size_t *, bool, u32 *);
 bool rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *,
@@ -48,5 +63,9 @@ void rxrpc_kernel_get_peer(struct socket *, struct rxrpc_call *,
 int rxrpc_kernel_charge_accept(struct socket *, rxrpc_notify_rx_t,
 			       rxrpc_user_attach_call_t, unsigned long, gfp_t);
 void rxrpc_kernel_set_tx_length(struct socket *, struct rxrpc_call *, s64);
+int rxrpc_kernel_retry_call(struct socket *, struct rxrpc_call *,
+			    struct sockaddr_rxrpc *, struct key *);
+int rxrpc_kernel_check_call(struct socket *, struct rxrpc_call *,
+			    enum rxrpc_call_completion *, u32 *);
 
 #endif /* _NET_RXRPC_H */

net/rxrpc/af_rxrpc.c

@@ -336,6 +336,75 @@ void rxrpc_kernel_end_call(struct socket *sock, struct rxrpc_call *call)
 }
 EXPORT_SYMBOL(rxrpc_kernel_end_call);
 
+/**
+ * rxrpc_kernel_check_call - Check a call's state
+ * @sock: The socket the call is on
+ * @call: The call to check
+ * @_compl: Where to store the completion state
+ * @_abort_code: Where to store any abort code
+ *
+ * Allow a kernel service to query the state of a call and find out the manner
+ * of its termination if it has completed.  Returns -EINPROGRESS if the call is
+ * still going, 0 if the call finished successfully, -ECONNABORTED if the call
+ * was aborted and an appropriate error if the call failed in some other way.
+ */
+int rxrpc_kernel_check_call(struct socket *sock, struct rxrpc_call *call,
+			    enum rxrpc_call_completion *_compl, u32 *_abort_code)
+{
+	if (call->state != RXRPC_CALL_COMPLETE)
+		return -EINPROGRESS;
+	smp_rmb();
+	*_compl = call->completion;
+	*_abort_code = call->abort_code;
+	return call->error;
+}
+EXPORT_SYMBOL(rxrpc_kernel_check_call);
+
+/**
+ * rxrpc_kernel_retry_call - Allow a kernel service to retry a call
+ * @sock: The socket the call is on
+ * @call: The call to retry
+ * @srx: The address of the peer to contact
+ * @key: The security context to use (defaults to socket setting)
+ *
+ * Allow a kernel service to try resending a client call that failed due to a
+ * network error to a new address.  The Tx queue is maintained intact, thereby
+ * relieving the need to re-encrypt any request data that has already been
+ * buffered.
+ */
+int rxrpc_kernel_retry_call(struct socket *sock, struct rxrpc_call *call,
+			    struct sockaddr_rxrpc *srx, struct key *key)
+{
+	struct rxrpc_conn_parameters cp;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	_enter("%d{%d}", call->debug_id, atomic_read(&call->usage));
+
+	if (!key)
+		key = rx->key;
+	if (key && !key->payload.data[0])
+		key = NULL; /* a no-security key */
+
+	memset(&cp, 0, sizeof(cp));
+	cp.local		= rx->local;
+	cp.key			= key;
+	cp.security_level	= 0;
+	cp.exclusive		= false;
+	cp.service_id		= srx->srx_service;
+
+	mutex_lock(&call->user_mutex);
+
+	ret = rxrpc_prepare_call_for_retry(rx, call);
+	if (ret == 0)
+		ret = rxrpc_retry_client_call(rx, call, &cp, srx, GFP_KERNEL);
+
+	mutex_unlock(&call->user_mutex);
+	_leave(" = %d", ret);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_kernel_retry_call);
+
 /**
  * rxrpc_kernel_new_call_notification - Get notifications of new calls
  * @sock: The socket to intercept received messages on
@@ -591,13 +660,13 @@ static int rxrpc_getsockopt(struct socket *sock, int level, int optname,
 			    char __user *optval, int __user *_optlen)
 {
 	int optlen;
-	
+
 	if (level != SOL_RXRPC)
 		return -EOPNOTSUPP;
 
 	if (get_user(optlen, _optlen))
 		return -EFAULT;
-	
+
 	switch (optname) {
 	case RXRPC_SUPPORTED_CMSG:
 		if (optlen < sizeof(int))
@@ -606,7 +675,7 @@ static int rxrpc_getsockopt(struct socket *sock, int level, int optname,
 		    put_user(sizeof(int), _optlen))
 			return -EFAULT;
 		return 0;
-		
+
 	default:
 		return -EOPNOTSUPP;
 	}