Merge tag 'rxrpc-rewrite-20160904-2' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Split output code from sendmsg code

Here's a set of small patches that split the packet transmission code from
the sendmsg code and simply rearrange the new file to make it more
logically laid out ready for being rewritten.  An enum is also moved out of
the header file to there as it's only used there.  This needs to be applied
on top of the just-posted fixes patch set.
====================

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

5 files changed, 660 insertions, 640 deletions

diff --git a/net/rxrpc/Makefile b/net/rxrpc/Makefile
index 10f3f48a16a8..8fc6ea347182 100644
--- a/net/rxrpc/Makefile
+++ b/net/rxrpc/Makefile
@@ -22,6 +22,7 @@ af-rxrpc-y := \
 	peer_object.o \
 	recvmsg.o \
 	security.o \
+	sendmsg.o \
 	skbuff.o \
 	utils.o
 
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 4e86d248dc5e..bb342f5fe7e4 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -131,13 +131,6 @@ struct rxrpc_skb_priv {
 
 #define rxrpc_skb(__skb) ((struct rxrpc_skb_priv *) &(__skb)->cb)
 
-enum rxrpc_command {
-	RXRPC_CMD_SEND_DATA,		/* send data message */
-	RXRPC_CMD_SEND_ABORT,		/* request abort generation */
-	RXRPC_CMD_ACCEPT,		/* [server] accept incoming call */
-	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */
-};
-
 /*
  * RxRPC security module interface
  */
@@ -814,6 +807,7 @@ extern unsigned int rxrpc_idle_ack_delay;
 extern unsigned int rxrpc_rx_window_size;
 extern unsigned int rxrpc_rx_mtu;
 extern unsigned int rxrpc_rx_jumbo_max;
+extern unsigned int rxrpc_resend_timeout;
 
 extern const char *const rxrpc_pkts[];
 extern const s8 rxrpc_ack_priority[];
@@ -823,10 +817,7 @@ extern const char *rxrpc_acks(u8 reason);
 /*
  * output.c
  */
-extern unsigned int rxrpc_resend_timeout;
-
 int rxrpc_send_data_packet(struct rxrpc_connection *, struct sk_buff *);
-int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
 
 /*
  * peer_event.c
@@ -888,6 +879,11 @@ int __init rxrpc_init_security(void);
 void rxrpc_exit_security(void);
 int rxrpc_init_client_conn_security(struct rxrpc_connection *);
 int rxrpc_init_server_conn_security(struct rxrpc_connection *);
+ 
+/*
+ * sendmsg.c
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
 
 /*
  * skbuff.c
diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
index bdc5e42fe600..39e7cc37c392 100644
--- a/net/rxrpc/misc.c
+++ b/net/rxrpc/misc.c
@@ -64,6 +64,11 @@ unsigned int rxrpc_rx_mtu = 5692;
  */
 unsigned int rxrpc_rx_jumbo_max = 4;
 
+/*
+ * Time till packet resend (in jiffies).
+ */
+unsigned int rxrpc_resend_timeout = 4 * HZ;
+
 const char *const rxrpc_pkts[] = {
 	"?00",
 	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 817ae801e769..5b5508f6fc2a 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -14,299 +14,12 @@
 #include <linux/net.h>
 #include <linux/gfp.h>
 #include <linux/skbuff.h>
-#include <linux/circ_buf.h>
 #include <linux/export.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
 #include "ar-internal.h"
 
 /*
- * Time till packet resend (in jiffies).
- */
-unsigned int rxrpc_resend_timeout = 4 * HZ;
-
-static int rxrpc_send_data(struct rxrpc_sock *rx,
-			   struct rxrpc_call *call,
-			   struct msghdr *msg, size_t len);
-
-/*
- * extract control messages from the sendmsg() control buffer
- */
-static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
-			      unsigned long *user_call_ID,
-			      enum rxrpc_command *command,
-			      u32 *abort_code,
-			      bool *_exclusive)
-{
-	struct cmsghdr *cmsg;
-	bool got_user_ID = false;
-	int len;
-
-	*command = RXRPC_CMD_SEND_DATA;
-
-	if (msg->msg_controllen == 0)
-		return -EINVAL;
-
-	for_each_cmsghdr(cmsg, msg) {
-		if (!CMSG_OK(msg, cmsg))
-			return -EINVAL;
-
-		len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
-		_debug("CMSG %d, %d, %d",
-		       cmsg->cmsg_level, cmsg->cmsg_type, len);
-
-		if (cmsg->cmsg_level != SOL_RXRPC)
-			continue;
-
-		switch (cmsg->cmsg_type) {
-		case RXRPC_USER_CALL_ID:
-			if (msg->msg_flags & MSG_CMSG_COMPAT) {
-				if (len != sizeof(u32))
-					return -EINVAL;
-				*user_call_ID = *(u32 *) CMSG_DATA(cmsg);
-			} else {
-				if (len != sizeof(unsigned long))
-					return -EINVAL;
-				*user_call_ID = *(unsigned long *)
-					CMSG_DATA(cmsg);
-			}
-			_debug("User Call ID %lx", *user_call_ID);
-			got_user_ID = true;
-			break;
-
-		case RXRPC_ABORT:
-			if (*command != RXRPC_CMD_SEND_DATA)
-				return -EINVAL;
-			*command = RXRPC_CMD_SEND_ABORT;
-			if (len != sizeof(*abort_code))
-				return -EINVAL;
-			*abort_code = *(unsigned int *) CMSG_DATA(cmsg);
-			_debug("Abort %x", *abort_code);
-			if (*abort_code == 0)
-				return -EINVAL;
-			break;
-
-		case RXRPC_ACCEPT:
-			if (*command != RXRPC_CMD_SEND_DATA)
-				return -EINVAL;
-			*command = RXRPC_CMD_ACCEPT;
-			if (len != 0)
-				return -EINVAL;
-			break;
-
-		case RXRPC_EXCLUSIVE_CALL:
-			*_exclusive = true;
-			if (len != 0)
-				return -EINVAL;
-			break;
-		default:
-			return -EINVAL;
-		}
-	}
-
-	if (!got_user_ID)
-		return -EINVAL;
-	_leave(" = 0");
-	return 0;
-}
-
-/*
- * abort a call, sending an ABORT packet to the peer
- */
-static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
-{
-	if (call->state >= RXRPC_CALL_COMPLETE)
-		return;
-
-	write_lock_bh(&call->state_lock);
-
-	if (__rxrpc_abort_call(call, abort_code, ECONNABORTED)) {
-		del_timer_sync(&call->resend_timer);
-		del_timer_sync(&call->ack_timer);
-		clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
-		clear_bit(RXRPC_CALL_EV_ACK, &call->events);
-		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
-		rxrpc_queue_call(call);
-	}
-
-	write_unlock_bh(&call->state_lock);
-}
-
-/*
- * Create a new client call for sendmsg().
- */
-static struct rxrpc_call *
-rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
-				  unsigned long user_call_ID, bool exclusive)
-{
-	struct rxrpc_conn_parameters cp;
-	struct rxrpc_call *call;
-	struct key *key;
-
-	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
-
-	_enter("");
-
-	if (!msg->msg_name)
-		return ERR_PTR(-EDESTADDRREQ);
-
-	key = rx->key;
-	if (key && !rx->key->payload.data[0])
-		key = NULL;
-
-	memset(&cp, 0, sizeof(cp));
-	cp.local		= rx->local;
-	cp.key			= rx->key;
-	cp.security_level	= rx->min_sec_level;
-	cp.exclusive		= rx->exclusive | exclusive;
-	cp.service_id		= srx->srx_service;
-	call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
-
-	_leave(" = %p\n", call);
-	return call;
-}
-
-/*
- * send a message forming part of a client call through an RxRPC socket
- * - caller holds the socket locked
- * - the socket may be either a client socket or a server socket
- */
-int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
-{
-	enum rxrpc_command cmd;
-	struct rxrpc_call *call;
-	unsigned long user_call_ID = 0;
-	bool exclusive = false;
-	u32 abort_code = 0;
-	int ret;
-
-	_enter("");
-
-	ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
-				 &exclusive);
-	if (ret < 0)
-		return ret;
-
-	if (cmd == RXRPC_CMD_ACCEPT) {
-		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
-			return -EINVAL;
-		call = rxrpc_accept_call(rx, user_call_ID, NULL);
-		if (IS_ERR(call))
-			return PTR_ERR(call);
-		rxrpc_put_call(call);
-		return 0;
-	}
-
-	call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
-	if (!call) {
-		if (cmd != RXRPC_CMD_SEND_DATA)
-			return -EBADSLT;
-		call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
-							 exclusive);
-		if (IS_ERR(call))
-			return PTR_ERR(call);
-	}
-
-	rxrpc_see_call(call);
-	_debug("CALL %d USR %lx ST %d on CONN %p",
-	       call->debug_id, call->user_call_ID, call->state, call->conn);
-
-	if (call->state >= RXRPC_CALL_COMPLETE) {
-		/* it's too late for this call */
-		ret = -ESHUTDOWN;
-	} else if (cmd == RXRPC_CMD_SEND_ABORT) {
-		rxrpc_send_abort(call, abort_code);
-		ret = 0;
-	} else if (cmd != RXRPC_CMD_SEND_DATA) {
-		ret = -EINVAL;
-	} else if (rxrpc_is_client_call(call) &&
-		   call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
-		/* request phase complete for this client call */
-		ret = -EPROTO;
-	} else if (rxrpc_is_service_call(call) &&
-		   call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
-		   call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
-		/* Reply phase not begun or not complete for service call. */
-		ret = -EPROTO;
-	} else {
-		ret = rxrpc_send_data(rx, call, msg, len);
-	}
-
-	rxrpc_put_call(call);
-	_leave(" = %d", ret);
-	return ret;
-}
-
-/**
- * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
- * @sock: The socket the call is on
- * @call: The call to send data through
- * @msg: The data to send
- * @len: The amount of data to send
- *
- * Allow a kernel service to send data on a call.  The call must be in an state
- * appropriate to sending data.  No control data should be supplied in @msg,
- * nor should an address be supplied.  MSG_MORE should be flagged if there's
- * more data to come, otherwise this data will end the transmission phase.
- */
-int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
-			   struct msghdr *msg, size_t len)
-{
-	int ret;
-
-	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
-
-	ASSERTCMP(msg->msg_name, ==, NULL);
-	ASSERTCMP(msg->msg_control, ==, NULL);
-
-	lock_sock(sock->sk);
-
-	_debug("CALL %d USR %lx ST %d on CONN %p",
-	       call->debug_id, call->user_call_ID, call->state, call->conn);
-
-	if (call->state >= RXRPC_CALL_COMPLETE) {
-		ret = -ESHUTDOWN; /* it's too late for this call */
-	} else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
-		   call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
-		   call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
-		ret = -EPROTO; /* request phase complete for this client call */
-	} else {
-		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
-	}
-
-	release_sock(sock->sk);
-	_leave(" = %d", ret);
-	return ret;
-}
-EXPORT_SYMBOL(rxrpc_kernel_send_data);
-
-/**
- * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
- * @sock: The socket the call is on
- * @call: The call to be aborted
- * @abort_code: The abort code to stick into the ABORT packet
- *
- * Allow a kernel service to abort a call, if it's still in an abortable state.
- */
-void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
-			     u32 abort_code)
-{
-	_enter("{%d},%d", call->debug_id, abort_code);
-
-	lock_sock(sock->sk);
-
-	_debug("CALL %d USR %lx ST %d on CONN %p",
-	       call->debug_id, call->user_call_ID, call->state, call->conn);
-
-	rxrpc_send_abort(call, abort_code);
-
-	release_sock(sock->sk);
-	_leave("");
-}
-
-EXPORT_SYMBOL(rxrpc_kernel_abort_call);
-
-/*
  * send a packet through the transport endpoint
  */
 int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
@@ -375,346 +88,3 @@ send_fragmentable:
 	_leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);
 	return ret;
 }
-
-/*
- * wait for space to appear in the transmit/ACK window
- * - caller holds the socket locked
- */
-static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
-				    struct rxrpc_call *call,
-				    long *timeo)
-{
-	DECLARE_WAITQUEUE(myself, current);
-	int ret;
-
-	_enter(",{%d},%ld",
-	       CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
-			  call->acks_winsz),
-	       *timeo);
-
-	add_wait_queue(&call->waitq, &myself);
-
-	for (;;) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		ret = 0;
-		if (CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
-			       call->acks_winsz) > 0)
-			break;
-		if (signal_pending(current)) {
-			ret = sock_intr_errno(*timeo);
-			break;
-		}
-
-		release_sock(&rx->sk);
-		*timeo = schedule_timeout(*timeo);
-		lock_sock(&rx->sk);
-	}
-
-	remove_wait_queue(&call->waitq, &myself);
-	set_current_state(TASK_RUNNING);
-	_leave(" = %d", ret);
-	return ret;
-}
-
-/*
- * attempt to schedule an instant Tx resend
- */
-static inline void rxrpc_instant_resend(struct rxrpc_call *call)
-{
-	read_lock_bh(&call->state_lock);
-	if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
-		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
-		if (call->state < RXRPC_CALL_COMPLETE &&
-		    !test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
-			rxrpc_queue_call(call);
-	}
-	read_unlock_bh(&call->state_lock);
-}
-
-/*
- * queue a packet for transmission, set the resend timer and attempt
- * to send the packet immediately
- */
-static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
-			       bool last)
-{
-	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	int ret;
-
-	_net("queue skb %p [%d]", skb, call->acks_head);
-
-	ASSERT(call->acks_window != NULL);
-	call->acks_window[call->acks_head] = (unsigned long) skb;
-	smp_wmb();
-	call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);
-
-	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
-		_debug("________awaiting reply/ACK__________");
-		write_lock_bh(&call->state_lock);
-		switch (call->state) {
-		case RXRPC_CALL_CLIENT_SEND_REQUEST:
-			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
-			break;
-		case RXRPC_CALL_SERVER_ACK_REQUEST:
-			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
-			if (!last)
-				break;
-		case RXRPC_CALL_SERVER_SEND_REPLY:
-			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
-			break;
-		default:
-			break;
-		}
-		write_unlock_bh(&call->state_lock);
-	}
-
-	_proto("Tx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
-
-	sp->need_resend = false;
-	sp->resend_at = jiffies + rxrpc_resend_timeout;
-	if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
-		_debug("run timer");
-		call->resend_timer.expires = sp->resend_at;
-		add_timer(&call->resend_timer);
-	}
-
-	/* attempt to cancel the rx-ACK timer, deferring reply transmission if
-	 * we're ACK'ing the request phase of an incoming call */
-	ret = -EAGAIN;
-	if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
-		/* the packet may be freed by rxrpc_process_call() before this
-		 * returns */
-		if (rxrpc_is_client_call(call))
-			rxrpc_expose_client_call(call);
-		ret = rxrpc_send_data_packet(call->conn, skb);
-		_net("sent skb %p", skb);
-	} else {
-		_debug("failed to delete ACK timer");
-	}
-
-	if (ret < 0) {
-		_debug("need instant resend %d", ret);
-		sp->need_resend = true;
-		rxrpc_instant_resend(call);
-	}
-
-	_leave("");
-}
-
-/*
- * Convert a host-endian header into a network-endian header.
- */
-static void rxrpc_insert_header(struct sk_buff *skb)
-{
-	struct rxrpc_wire_header whdr;
-	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-
-	whdr.epoch	= htonl(sp->hdr.epoch);
-	whdr.cid	= htonl(sp->hdr.cid);
-	whdr.callNumber	= htonl(sp->hdr.callNumber);
-	whdr.seq	= htonl(sp->hdr.seq);
-	whdr.serial	= htonl(sp->hdr.serial);
-	whdr.type	= sp->hdr.type;
-	whdr.flags	= sp->hdr.flags;
-	whdr.userStatus	= sp->hdr.userStatus;
-	whdr.securityIndex = sp->hdr.securityIndex;
-	whdr._rsvd	= htons(sp->hdr._rsvd);
-	whdr.serviceId	= htons(sp->hdr.serviceId);
-
-	memcpy(skb->head, &whdr, sizeof(whdr));
-}
-
-/*
- * send data through a socket
- * - must be called in process context
- * - caller holds the socket locked
- */
-static int rxrpc_send_data(struct rxrpc_sock *rx,
-			   struct rxrpc_call *call,
-			   struct msghdr *msg, size_t len)
-{
-	struct rxrpc_skb_priv *sp;
-	struct sk_buff *skb;
-	struct sock *sk = &rx->sk;
-	long timeo;
-	bool more;
-	int ret, copied;
-
-	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
-
-	/* this should be in poll */
-	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
-
-	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
-		return -EPIPE;
-
-	more = msg->msg_flags & MSG_MORE;
-
-	skb = call->tx_pending;
-	call->tx_pending = NULL;
-	rxrpc_see_skb(skb);
-
-	copied = 0;
-	do {
-		if (!skb) {
-			size_t size, chunk, max, space;
-
-			_debug("alloc");
-
-			if (CIRC_SPACE(call->acks_head,
-				       ACCESS_ONCE(call->acks_tail),
-				       call->acks_winsz) <= 0) {
-				ret = -EAGAIN;
-				if (msg->msg_flags & MSG_DONTWAIT)
-					goto maybe_error;
-				ret = rxrpc_wait_for_tx_window(rx, call,
-							       &timeo);
-				if (ret < 0)
-					goto maybe_error;
-			}
-
-			max = call->conn->params.peer->maxdata;
-			max -= call->conn->security_size;
-			max &= ~(call->conn->size_align - 1UL);
-
-			chunk = max;
-			if (chunk > msg_data_left(msg) && !more)
-				chunk = msg_data_left(msg);
-
-			space = chunk + call->conn->size_align;
-			space &= ~(call->conn->size_align - 1UL);
-
-			size = space + call->conn->header_size;
-
-			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
-
-			/* create a buffer that we can retain until it's ACK'd */
-			skb = sock_alloc_send_skb(
-				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
-			if (!skb)
-				goto maybe_error;
-
-			rxrpc_new_skb(skb);
-
-			_debug("ALLOC SEND %p", skb);
-
-			ASSERTCMP(skb->mark, ==, 0);
-
-			_debug("HS: %u", call->conn->header_size);
-			skb_reserve(skb, call->conn->header_size);
-			skb->len += call->conn->header_size;
-
-			sp = rxrpc_skb(skb);
-			sp->remain = chunk;
-			if (sp->remain > skb_tailroom(skb))
-				sp->remain = skb_tailroom(skb);
-
-			_net("skb: hr %d, tr %d, hl %d, rm %d",
-			       skb_headroom(skb),
-			       skb_tailroom(skb),
-			       skb_headlen(skb),
-			       sp->remain);
-
-			skb->ip_summed = CHECKSUM_UNNECESSARY;
-		}
-
-		_debug("append");
-		sp = rxrpc_skb(skb);
-
-		/* append next segment of data to the current buffer */
-		if (msg_data_left(msg) > 0) {
-			int copy = skb_tailroom(skb);
-			ASSERTCMP(copy, >, 0);
-			if (copy > msg_data_left(msg))
-				copy = msg_data_left(msg);
-			if (copy > sp->remain)
-				copy = sp->remain;
-
-			_debug("add");
-			ret = skb_add_data(skb, &msg->msg_iter, copy);
-			_debug("added");
-			if (ret < 0)
-				goto efault;
-			sp->remain -= copy;
-			skb->mark += copy;
-			copied += copy;
-		}
-
-		/* check for the far side aborting the call or a network error
-		 * occurring */
-		if (call->state == RXRPC_CALL_COMPLETE)
-			goto call_terminated;
-
-		/* add the packet to the send queue if it's now full */
-		if (sp->remain <= 0 ||
-		    (msg_data_left(msg) == 0 && !more)) {
-			struct rxrpc_connection *conn = call->conn;
-			uint32_t seq;
-			size_t pad;
-
-			/* pad out if we're using security */
-			if (conn->security_ix) {
-				pad = conn->security_size + skb->mark;
-				pad = conn->size_align - pad;
-				pad &= conn->size_align - 1;
-				_debug("pad %zu", pad);
-				if (pad)
-					memset(skb_put(skb, pad), 0, pad);
-			}
-
-			seq = atomic_inc_return(&call->sequence);
-
-			sp->hdr.epoch	= conn->proto.epoch;
-			sp->hdr.cid	= call->cid;
-			sp->hdr.callNumber = call->call_id;
-			sp->hdr.seq	= seq;
-			sp->hdr.serial	= atomic_inc_return(&conn->serial);
-			sp->hdr.type	= RXRPC_PACKET_TYPE_DATA;
-			sp->hdr.userStatus = 0;
-			sp->hdr.securityIndex = conn->security_ix;
-			sp->hdr._rsvd	= 0;
-			sp->hdr.serviceId = call->service_id;
-
-			sp->hdr.flags = conn->out_clientflag;
-			if (msg_data_left(msg) == 0 && !more)
-				sp->hdr.flags |= RXRPC_LAST_PACKET;
-			else if (CIRC_SPACE(call->acks_head,
-					    ACCESS_ONCE(call->acks_tail),
-					    call->acks_winsz) > 1)
-				sp->hdr.flags |= RXRPC_MORE_PACKETS;
-			if (more && seq & 1)
-				sp->hdr.flags |= RXRPC_REQUEST_ACK;
-
-			ret = conn->security->secure_packet(
-				call, skb, skb->mark,
-				skb->head + sizeof(struct rxrpc_wire_header));
-			if (ret < 0)
-				goto out;
-
-			rxrpc_insert_header(skb);
-			rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
-			skb = NULL;
-		}
-	} while (msg_data_left(msg) > 0);
-
-success:
-	ret = copied;
-out:
-	call->tx_pending = skb;
-	_leave(" = %d", ret);
-	return ret;
-
-call_terminated:
-	rxrpc_free_skb(skb);
-	_leave(" = %d", -call->error);
-	return ret;
-
-maybe_error:
-	if (copied)
-		goto success;
-	goto out;
-
-efault:
-	ret = -EFAULT;
-	goto out;
-}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
new file mode 100644
index 000000000000..7376794a0308
--- /dev/null
+++ b/net/rxrpc/sendmsg.c
@@ -0,0 +1,648 @@
+/* AF_RXRPC sendmsg() implementation.
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+enum rxrpc_command {
+	RXRPC_CMD_SEND_DATA,		/* send data message */
+	RXRPC_CMD_SEND_ABORT,		/* request abort generation */
+	RXRPC_CMD_ACCEPT,		/* [server] accept incoming call */
+	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */
+};
+
+/*
+ * wait for space to appear in the transmit/ACK window
+ * - caller holds the socket locked
+ */
+static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
+				    struct rxrpc_call *call,
+				    long *timeo)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret;
+
+	_enter(",{%d},%ld",
+	       CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
+			  call->acks_winsz),
+	       *timeo);
+
+	add_wait_queue(&call->waitq, &myself);
+
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		ret = 0;
+		if (CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),
+			       call->acks_winsz) > 0)
+			break;
+		if (signal_pending(current)) {
+			ret = sock_intr_errno(*timeo);
+			break;
+		}
+
+		release_sock(&rx->sk);
+		*timeo = schedule_timeout(*timeo);
+		lock_sock(&rx->sk);
+	}
+
+	remove_wait_queue(&call->waitq, &myself);
+	set_current_state(TASK_RUNNING);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * attempt to schedule an instant Tx resend
+ */
+static inline void rxrpc_instant_resend(struct rxrpc_call *call)
+{
+	read_lock_bh(&call->state_lock);
+	if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
+		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+		if (call->state < RXRPC_CALL_COMPLETE &&
+		    !test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
+			rxrpc_queue_call(call);
+	}
+	read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * queue a packet for transmission, set the resend timer and attempt
+ * to send the packet immediately
+ */
+static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
+			       bool last)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	int ret;
+
+	_net("queue skb %p [%d]", skb, call->acks_head);
+
+	ASSERT(call->acks_window != NULL);
+	call->acks_window[call->acks_head] = (unsigned long) skb;
+	smp_wmb();
+	call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);
+
+	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
+		_debug("________awaiting reply/ACK__________");
+		write_lock_bh(&call->state_lock);
+		switch (call->state) {
+		case RXRPC_CALL_CLIENT_SEND_REQUEST:
+			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+			break;
+		case RXRPC_CALL_SERVER_ACK_REQUEST:
+			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
+			if (!last)
+				break;
+		case RXRPC_CALL_SERVER_SEND_REPLY:
+			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
+			break;
+		default:
+			break;
+		}
+		write_unlock_bh(&call->state_lock);
+	}
+
+	_proto("Tx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
+
+	sp->need_resend = false;
+	sp->resend_at = jiffies + rxrpc_resend_timeout;
+	if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
+		_debug("run timer");
+		call->resend_timer.expires = sp->resend_at;
+		add_timer(&call->resend_timer);
+	}
+
+	/* attempt to cancel the rx-ACK timer, deferring reply transmission if
+	 * we're ACK'ing the request phase of an incoming call */
+	ret = -EAGAIN;
+	if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
+		/* the packet may be freed by rxrpc_process_call() before this
+		 * returns */
+		if (rxrpc_is_client_call(call))
+			rxrpc_expose_client_call(call);
+		ret = rxrpc_send_data_packet(call->conn, skb);
+		_net("sent skb %p", skb);
+	} else {
+		_debug("failed to delete ACK timer");
+	}
+
+	if (ret < 0) {
+		_debug("need instant resend %d", ret);
+		sp->need_resend = true;
+		rxrpc_instant_resend(call);
+	}
+
+	_leave("");
+}
+
+/*
+ * Convert a host-endian header into a network-endian header.
+ */
+static void rxrpc_insert_header(struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	whdr.epoch	= htonl(sp->hdr.epoch);
+	whdr.cid	= htonl(sp->hdr.cid);
+	whdr.callNumber	= htonl(sp->hdr.callNumber);
+	whdr.seq	= htonl(sp->hdr.seq);
+	whdr.serial	= htonl(sp->hdr.serial);
+	whdr.type	= sp->hdr.type;
+	whdr.flags	= sp->hdr.flags;
+	whdr.userStatus	= sp->hdr.userStatus;
+	whdr.securityIndex = sp->hdr.securityIndex;
+	whdr._rsvd	= htons(sp->hdr._rsvd);
+	whdr.serviceId	= htons(sp->hdr.serviceId);
+
+	memcpy(skb->head, &whdr, sizeof(whdr));
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - caller holds the socket locked
+ */
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+			   struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	struct sock *sk = &rx->sk;
+	long timeo;
+	bool more;
+	int ret, copied;
+
+	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+	/* this should be in poll */
+	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+		return -EPIPE;
+
+	more = msg->msg_flags & MSG_MORE;
+
+	skb = call->tx_pending;
+	call->tx_pending = NULL;
+	rxrpc_see_skb(skb);
+
+	copied = 0;
+	do {
+		if (!skb) {
+			size_t size, chunk, max, space;
+
+			_debug("alloc");
+
+			if (CIRC_SPACE(call->acks_head,
+				       ACCESS_ONCE(call->acks_tail),
+				       call->acks_winsz) <= 0) {
+				ret = -EAGAIN;
+				if (msg->msg_flags & MSG_DONTWAIT)
+					goto maybe_error;
+				ret = rxrpc_wait_for_tx_window(rx, call,
+							       &timeo);
+				if (ret < 0)
+					goto maybe_error;
+			}
+
+			max = call->conn->params.peer->maxdata;
+			max -= call->conn->security_size;
+			max &= ~(call->conn->size_align - 1UL);
+
+			chunk = max;
+			if (chunk > msg_data_left(msg) && !more)
+				chunk = msg_data_left(msg);
+
+			space = chunk + call->conn->size_align;
+			space &= ~(call->conn->size_align - 1UL);
+
+			size = space + call->conn->header_size;
+
+			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
+
+			/* create a buffer that we can retain until it's ACK'd */
+			skb = sock_alloc_send_skb(
+				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
+			if (!skb)
+				goto maybe_error;
+
+			rxrpc_new_skb(skb);
+
+			_debug("ALLOC SEND %p", skb);
+
+			ASSERTCMP(skb->mark, ==, 0);
+
+			_debug("HS: %u", call->conn->header_size);
+			skb_reserve(skb, call->conn->header_size);
+			skb->len += call->conn->header_size;
+
+			sp = rxrpc_skb(skb);
+			sp->remain = chunk;
+			if (sp->remain > skb_tailroom(skb))
+				sp->remain = skb_tailroom(skb);
+
+			_net("skb: hr %d, tr %d, hl %d, rm %d",
+			       skb_headroom(skb),
+			       skb_tailroom(skb),
+			       skb_headlen(skb),
+			       sp->remain);
+
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		}
+
+		_debug("append");
+		sp = rxrpc_skb(skb);
+
+		/* append next segment of data to the current buffer */
+		if (msg_data_left(msg) > 0) {
+			int copy = skb_tailroom(skb);
+			ASSERTCMP(copy, >, 0);
+			if (copy > msg_data_left(msg))
+				copy = msg_data_left(msg);
+			if (copy > sp->remain)
+				copy = sp->remain;
+
+			_debug("add");
+			ret = skb_add_data(skb, &msg->msg_iter, copy);
+			_debug("added");
+			if (ret < 0)
+				goto efault;
+			sp->remain -= copy;
+			skb->mark += copy;
+			copied += copy;
+		}
+
+		/* check for the far side aborting the call or a network error
+		 * occurring */
+		if (call->state == RXRPC_CALL_COMPLETE)
+			goto call_terminated;
+
+		/* add the packet to the send queue if it's now full */
+		if (sp->remain <= 0 ||
+		    (msg_data_left(msg) == 0 && !more)) {
+			struct rxrpc_connection *conn = call->conn;
+			uint32_t seq;
+			size_t pad;
+
+			/* pad out if we're using security */
+			if (conn->security_ix) {
+				pad = conn->security_size + skb->mark;
+				pad = conn->size_align - pad;
+				pad &= conn->size_align - 1;
+				_debug("pad %zu", pad);
+				if (pad)
+					memset(skb_put(skb, pad), 0, pad);
+			}
+
+			seq = atomic_inc_return(&call->sequence);
+
+			sp->hdr.epoch	= conn->proto.epoch;
+			sp->hdr.cid	= call->cid;
+			sp->hdr.callNumber = call->call_id;
+			sp->hdr.seq	= seq;
+			sp->hdr.serial	= atomic_inc_return(&conn->serial);
+			sp->hdr.type	= RXRPC_PACKET_TYPE_DATA;
+			sp->hdr.userStatus = 0;
+			sp->hdr.securityIndex = conn->security_ix;
+			sp->hdr._rsvd	= 0;
+			sp->hdr.serviceId = call->service_id;
+
+			sp->hdr.flags = conn->out_clientflag;
+			if (msg_data_left(msg) == 0 && !more)
+				sp->hdr.flags |= RXRPC_LAST_PACKET;
+			else if (CIRC_SPACE(call->acks_head,
+					    ACCESS_ONCE(call->acks_tail),
+					    call->acks_winsz) > 1)
+				sp->hdr.flags |= RXRPC_MORE_PACKETS;
+			if (more && seq & 1)
+				sp->hdr.flags |= RXRPC_REQUEST_ACK;
+
+			ret = conn->security->secure_packet(
+				call, skb, skb->mark,
+				skb->head + sizeof(struct rxrpc_wire_header));
+			if (ret < 0)
+				goto out;
+
+			rxrpc_insert_header(skb);
+			rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
+			skb = NULL;
+		}
+	} while (msg_data_left(msg) > 0);
+
+success:
+	ret = copied;
+out:
+	call->tx_pending = skb;
+	_leave(" = %d", ret);
+	return ret;
+
+call_terminated:
+	rxrpc_free_skb(skb);
+	_leave(" = %d", -call->error);
+	return ret;
+
+maybe_error:
+	if (copied)
+		goto success;
+	goto out;
+
+efault:
+	ret = -EFAULT;
+	goto out;
+}
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
+			      unsigned long *user_call_ID,
+			      enum rxrpc_command *command,
+			      u32 *abort_code,
+			      bool *_exclusive)
+{
+	struct cmsghdr *cmsg;
+	bool got_user_ID = false;
+	int len;
+
+	*command = RXRPC_CMD_SEND_DATA;
+
+	if (msg->msg_controllen == 0)
+		return -EINVAL;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+
+		len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+		_debug("CMSG %d, %d, %d",
+		       cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+		if (cmsg->cmsg_level != SOL_RXRPC)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case RXRPC_USER_CALL_ID:
+			if (msg->msg_flags & MSG_CMSG_COMPAT) {
+				if (len != sizeof(u32))
+					return -EINVAL;
+				*user_call_ID = *(u32 *) CMSG_DATA(cmsg);
+			} else {
+				if (len != sizeof(unsigned long))
+					return -EINVAL;
+				*user_call_ID = *(unsigned long *)
+					CMSG_DATA(cmsg);
+			}
+			_debug("User Call ID %lx", *user_call_ID);
+			got_user_ID = true;
+			break;
+
+		case RXRPC_ABORT:
+			if (*command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			*command = RXRPC_CMD_SEND_ABORT;
+			if (len != sizeof(*abort_code))
+				return -EINVAL;
+			*abort_code = *(unsigned int *) CMSG_DATA(cmsg);
+			_debug("Abort %x", *abort_code);
+			if (*abort_code == 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_ACCEPT:
+			if (*command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			*command = RXRPC_CMD_ACCEPT;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_EXCLUSIVE_CALL:
+			*_exclusive = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (!got_user_ID)
+		return -EINVAL;
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * abort a call, sending an ABORT packet to the peer
+ */
+static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
+{
+	if (call->state >= RXRPC_CALL_COMPLETE)
+		return;
+
+	write_lock_bh(&call->state_lock);
+
+	if (__rxrpc_abort_call(call, abort_code, ECONNABORTED)) {
+		del_timer_sync(&call->resend_timer);
+		del_timer_sync(&call->ack_timer);
+		clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
+		clear_bit(RXRPC_CALL_EV_ACK, &call->events);
+		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+		rxrpc_queue_call(call);
+	}
+
+	write_unlock_bh(&call->state_lock);
+}
+
+/*
+ * Create a new client call for sendmsg().
+ */
+static struct rxrpc_call *
+rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+				  unsigned long user_call_ID, bool exclusive)
+{
+	struct rxrpc_conn_parameters cp;
+	struct rxrpc_call *call;
+	struct key *key;
+
+	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
+
+	_enter("");
+
+	if (!msg->msg_name)
+		return ERR_PTR(-EDESTADDRREQ);
+
+	key = rx->key;
+	if (key && !rx->key->payload.data[0])
+		key = NULL;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.local		= rx->local;
+	cp.key			= rx->key;
+	cp.security_level	= rx->min_sec_level;
+	cp.exclusive		= rx->exclusive | exclusive;
+	cp.service_id		= srx->srx_service;
+	call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
+
+	_leave(" = %p\n", call);
+	return call;
+}
+
+/*
+ * send a message forming part of a client call through an RxRPC socket
+ * - caller holds the socket locked
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+{
+	enum rxrpc_command cmd;
+	struct rxrpc_call *call;
+	unsigned long user_call_ID = 0;
+	bool exclusive = false;
+	u32 abort_code = 0;
+	int ret;
+
+	_enter("");
+
+	ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
+				 &exclusive);
+	if (ret < 0)
+		return ret;
+
+	if (cmd == RXRPC_CMD_ACCEPT) {
+		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
+			return -EINVAL;
+		call = rxrpc_accept_call(rx, user_call_ID, NULL);
+		if (IS_ERR(call))
+			return PTR_ERR(call);
+		rxrpc_put_call(call);
+		return 0;
+	}
+
+	call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
+	if (!call) {
+		if (cmd != RXRPC_CMD_SEND_DATA)
+			return -EBADSLT;
+		call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
+							 exclusive);
+		if (IS_ERR(call))
+			return PTR_ERR(call);
+	}
+
+	rxrpc_see_call(call);
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, call->state, call->conn);
+
+	if (call->state >= RXRPC_CALL_COMPLETE) {
+		/* it's too late for this call */
+		ret = -ESHUTDOWN;
+	} else if (cmd == RXRPC_CMD_SEND_ABORT) {
+		rxrpc_send_abort(call, abort_code);
+		ret = 0;
+	} else if (cmd != RXRPC_CMD_SEND_DATA) {
+		ret = -EINVAL;
+	} else if (rxrpc_is_client_call(call) &&
+		   call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
+		/* request phase complete for this client call */
+		ret = -EPROTO;
+	} else if (rxrpc_is_service_call(call) &&
+		   call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+		   call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+		/* Reply phase not begun or not complete for service call. */
+		ret = -EPROTO;
+	} else {
+		ret = rxrpc_send_data(rx, call, msg, len);
+	}
+
+	rxrpc_put_call(call);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
+ * @sock: The socket the call is on
+ * @call: The call to send data through
+ * @msg: The data to send
+ * @len: The amount of data to send
+ *
+ * Allow a kernel service to send data on a call.  The call must be in an state
+ * appropriate to sending data.  No control data should be supplied in @msg,
+ * nor should an address be supplied.  MSG_MORE should be flagged if there's
+ * more data to come, otherwise this data will end the transmission phase.
+ */
+int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len)
+{
+	int ret;
+
+	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
+
+	ASSERTCMP(msg->msg_name, ==, NULL);
+	ASSERTCMP(msg->msg_control, ==, NULL);
+
+	lock_sock(sock->sk);
+
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, call->state, call->conn);
+
+	if (call->state >= RXRPC_CALL_COMPLETE) {
+		ret = -ESHUTDOWN; /* it's too late for this call */
+	} else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+		   call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+		   call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+		ret = -EPROTO; /* request phase complete for this client call */
+	} else {
+		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
+	}
+
+	release_sock(sock->sk);
+	_leave(" = %d", ret);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_kernel_send_data);
+
+/**
+ * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
+ * @sock: The socket the call is on
+ * @call: The call to be aborted
+ * @abort_code: The abort code to stick into the ABORT packet
+ *
+ * Allow a kernel service to abort a call, if it's still in an abortable state.
+ */
+void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
+			     u32 abort_code)
+{
+	_enter("{%d},%d", call->debug_id, abort_code);
+
+	lock_sock(sock->sk);
+
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, call->state, call->conn);
+
+	rxrpc_send_abort(call, abort_code);
+
+	release_sock(sock->sk);
+	_leave("");
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);