Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 882 insertions, 0 deletions

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
new file mode 100644
index 000000000..71e40f91d
--- /dev/null
+++ b/net/rxrpc/sendmsg.c
@@ -0,0 +1,882 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC sendmsg() implementation.
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#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/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Return true if there's sufficient Tx queue space.
+ */
+static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
+{
+	unsigned int win_size =
+		min_t(unsigned int, call->tx_winsize,
+		      call->cong_cwnd + call->cong_extra);
+	rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
+
+	if (_tx_win)
+		*_tx_win = tx_win;
+	return call->tx_top - tx_win < win_size;
+}
+
+/*
+ * Wait for space to appear in the Tx queue or a signal to occur.
+ */
+static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
+					 struct rxrpc_call *call,
+					 long *timeo)
+{
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (rxrpc_check_tx_space(call, NULL))
+			return 0;
+
+		if (call->state >= RXRPC_CALL_COMPLETE)
+			return call->error;
+
+		if (signal_pending(current))
+			return sock_intr_errno(*timeo);
+
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
+		*timeo = schedule_timeout(*timeo);
+	}
+}
+
+/*
+ * Wait for space to appear in the Tx queue uninterruptibly, but with
+ * a timeout of 2*RTT if no progress was made and a signal occurred.
+ */
+static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call)
+{
+	rxrpc_seq_t tx_start, tx_win;
+	signed long rtt, timeout;
+
+	rtt = READ_ONCE(call->peer->srtt_us) >> 3;
+	rtt = usecs_to_jiffies(rtt) * 2;
+	if (rtt < 2)
+		rtt = 2;
+
+	timeout = rtt;
+	tx_start = READ_ONCE(call->tx_hard_ack);
+
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+
+		tx_win = READ_ONCE(call->tx_hard_ack);
+		if (rxrpc_check_tx_space(call, &tx_win))
+			return 0;
+
+		if (call->state >= RXRPC_CALL_COMPLETE)
+			return call->error;
+
+		if (timeout == 0 &&
+		    tx_win == tx_start && signal_pending(current))
+			return -EINTR;
+
+		if (tx_win != tx_start) {
+			timeout = rtt;
+			tx_start = tx_win;
+		}
+
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
+		timeout = schedule_timeout(timeout);
+	}
+}
+
+/*
+ * Wait for space to appear in the Tx queue uninterruptibly.
+ */
+static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call,
+					    long *timeo)
+{
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (rxrpc_check_tx_space(call, NULL))
+			return 0;
+
+		if (call->state >= RXRPC_CALL_COMPLETE)
+			return call->error;
+
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
+		*timeo = schedule_timeout(*timeo);
+	}
+}
+
+/*
+ * 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,
+				    bool waitall)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret;
+
+	_enter(",{%u,%u,%u}",
+	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
+
+	add_wait_queue(&call->waitq, &myself);
+
+	switch (call->interruptibility) {
+	case RXRPC_INTERRUPTIBLE:
+		if (waitall)
+			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
+		else
+			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
+		break;
+	case RXRPC_PREINTERRUPTIBLE:
+	case RXRPC_UNINTERRUPTIBLE:
+	default:
+		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
+		break;
+	}
+
+	remove_wait_queue(&call->waitq, &myself);
+	set_current_state(TASK_RUNNING);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Schedule an instant Tx resend.
+ */
+static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
+{
+	spin_lock_bh(&call->lock);
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		call->rxtx_annotations[ix] =
+			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
+			RXRPC_TX_ANNO_RETRANS;
+		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
+			rxrpc_queue_call(call);
+	}
+
+	spin_unlock_bh(&call->lock);
+}
+
+/*
+ * Notify the owner of the call that the transmit phase is ended and the last
+ * packet has been queued.
+ */
+static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
+				rxrpc_notify_end_tx_t notify_end_tx)
+{
+	if (notify_end_tx)
+		notify_end_tx(&rx->sk, call, call->user_call_ID);
+}
+
+/*
+ * Queue a DATA packet for transmission, set the resend timeout and send
+ * the packet immediately.  Returns the error from rxrpc_send_data_packet()
+ * in case the caller wants to do something with it.
+ */
+static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
+			      struct sk_buff *skb, bool last,
+			      rxrpc_notify_end_tx_t notify_end_tx)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned long now;
+	rxrpc_seq_t seq = sp->hdr.seq;
+	int ret, ix;
+	u8 annotation = RXRPC_TX_ANNO_UNACK;
+
+	_net("queue skb %p [%d]", skb, seq);
+
+	ASSERTCMP(seq, ==, call->tx_top + 1);
+
+	if (last)
+		annotation |= RXRPC_TX_ANNO_LAST;
+
+	/* We have to set the timestamp before queueing as the retransmit
+	 * algorithm can see the packet as soon as we queue it.
+	 */
+	skb->tstamp = ktime_get_real();
+
+	ix = seq & RXRPC_RXTX_BUFF_MASK;
+	rxrpc_get_skb(skb, rxrpc_skb_got);
+	call->rxtx_annotations[ix] = annotation;
+	smp_wmb();
+	call->rxtx_buffer[ix] = skb;
+	call->tx_top = seq;
+	if (last)
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
+	else
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
+
+	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;
+			rxrpc_notify_end_tx(rx, call, notify_end_tx);
+			break;
+		case RXRPC_CALL_SERVER_ACK_REQUEST:
+			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
+			now = jiffies;
+			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
+			if (call->ackr_reason == RXRPC_ACK_DELAY)
+				call->ackr_reason = 0;
+			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
+			if (!last)
+				break;
+			fallthrough;
+		case RXRPC_CALL_SERVER_SEND_REPLY:
+			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
+			rxrpc_notify_end_tx(rx, call, notify_end_tx);
+			break;
+		default:
+			break;
+		}
+		write_unlock_bh(&call->state_lock);
+	}
+
+	if (seq == 1 && rxrpc_is_client_call(call))
+		rxrpc_expose_client_call(call);
+
+	ret = rxrpc_send_data_packet(call, skb, false);
+	if (ret < 0) {
+		switch (ret) {
+		case -ENETUNREACH:
+		case -EHOSTUNREACH:
+		case -ECONNREFUSED:
+			rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+						  0, ret);
+			goto out;
+		}
+		_debug("need instant resend %d", ret);
+		rxrpc_instant_resend(call, ix);
+	} else {
+		unsigned long now = jiffies;
+		unsigned long resend_at = now + call->peer->rto_j;
+
+		WRITE_ONCE(call->resend_at, resend_at);
+		rxrpc_reduce_call_timer(call, resend_at, now,
+					rxrpc_timer_set_for_send);
+	}
+
+out:
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - The caller holds the call user access mutex, but not the socket lock.
+ */
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+			   struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len,
+			   rxrpc_notify_end_tx_t notify_end_tx,
+			   bool *_dropped_lock)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	struct sock *sk = &rx->sk;
+	enum rxrpc_call_state state;
+	long timeo;
+	bool more = msg->msg_flags & MSG_MORE;
+	int ret, copied = 0;
+
+	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+	/* this should be in poll */
+	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+reload:
+	ret = -EPIPE;
+	if (sk->sk_shutdown & SEND_SHUTDOWN)
+		goto maybe_error;
+	state = READ_ONCE(call->state);
+	ret = -ESHUTDOWN;
+	if (state >= RXRPC_CALL_COMPLETE)
+		goto maybe_error;
+	ret = -EPROTO;
+	if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+	    state != RXRPC_CALL_SERVER_SEND_REPLY)
+		goto maybe_error;
+
+	ret = -EMSGSIZE;
+	if (call->tx_total_len != -1) {
+		if (len - copied > call->tx_total_len)
+			goto maybe_error;
+		if (!more && len - copied != call->tx_total_len)
+			goto maybe_error;
+	}
+
+	skb = call->tx_pending;
+	call->tx_pending = NULL;
+	rxrpc_see_skb(skb, rxrpc_skb_seen);
+
+	do {
+		/* Check to see if there's a ping ACK to reply to. */
+		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
+			rxrpc_send_ack_packet(call, false, NULL);
+
+		if (!skb) {
+			size_t remain, bufsize, chunk, offset;
+
+			_debug("alloc");
+
+			if (!rxrpc_check_tx_space(call, NULL))
+				goto wait_for_space;
+
+			/* Work out the maximum size of a packet.  Assume that
+			 * the security header is going to be in the padded
+			 * region (enc blocksize), but the trailer is not.
+			 */
+			remain = more ? INT_MAX : msg_data_left(msg);
+			ret = call->conn->security->how_much_data(call, remain,
+								  &bufsize, &chunk, &offset);
+			if (ret < 0)
+				goto maybe_error;
+
+			_debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
+
+			/* create a buffer that we can retain until it's ACK'd */
+			skb = sock_alloc_send_skb(
+				sk, bufsize, msg->msg_flags & MSG_DONTWAIT, &ret);
+			if (!skb)
+				goto maybe_error;
+
+			sp = rxrpc_skb(skb);
+			sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
+			rxrpc_new_skb(skb, rxrpc_skb_new);
+
+			_debug("ALLOC SEND %p", skb);
+
+			ASSERTCMP(skb->mark, ==, 0);
+
+			__skb_put(skb, offset);
+
+			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;
+			if (call->tx_total_len != -1)
+				call->tx_total_len -= 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;
+
+			seq = call->tx_top + 1;
+
+			sp->hdr.seq	= seq;
+			sp->hdr._rsvd	= 0;
+			sp->hdr.flags	= conn->out_clientflag;
+
+			if (msg_data_left(msg) == 0 && !more)
+				sp->hdr.flags |= RXRPC_LAST_PACKET;
+			else if (call->tx_top - call->tx_hard_ack <
+				 call->tx_winsize)
+				sp->hdr.flags |= RXRPC_MORE_PACKETS;
+
+			ret = call->security->secure_packet(call, skb, skb->mark);
+			if (ret < 0)
+				goto out;
+
+			ret = rxrpc_queue_packet(rx, call, skb,
+						 !msg_data_left(msg) && !more,
+						 notify_end_tx);
+			/* Should check for failure here */
+			skb = NULL;
+		}
+	} while (msg_data_left(msg) > 0);
+
+success:
+	ret = copied;
+	if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
+		read_lock_bh(&call->state_lock);
+		if (call->error < 0)
+			ret = call->error;
+		read_unlock_bh(&call->state_lock);
+	}
+out:
+	call->tx_pending = skb;
+	_leave(" = %d", ret);
+	return ret;
+
+call_terminated:
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	_leave(" = %d", call->error);
+	return call->error;
+
+maybe_error:
+	if (copied)
+		goto success;
+	goto out;
+
+efault:
+	ret = -EFAULT;
+	goto out;
+
+wait_for_space:
+	ret = -EAGAIN;
+	if (msg->msg_flags & MSG_DONTWAIT)
+		goto maybe_error;
+	mutex_unlock(&call->user_mutex);
+	*_dropped_lock = true;
+	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
+				       msg->msg_flags & MSG_WAITALL);
+	if (ret < 0)
+		goto maybe_error;
+	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
+		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
+			ret = sock_intr_errno(timeo);
+			goto maybe_error;
+		}
+	} else {
+		mutex_lock(&call->user_mutex);
+	}
+	*_dropped_lock = false;
+	goto reload;
+}
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
+{
+	struct cmsghdr *cmsg;
+	bool got_user_ID = false;
+	int len;
+
+	if (msg->msg_controllen == 0)
+		return -EINVAL;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+
+		len = cmsg->cmsg_len - 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;
+				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
+			} else {
+				if (len != sizeof(unsigned long))
+					return -EINVAL;
+				p->call.user_call_ID = *(unsigned long *)
+					CMSG_DATA(cmsg);
+			}
+			got_user_ID = true;
+			break;
+
+		case RXRPC_ABORT:
+			if (p->command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			p->command = RXRPC_CMD_SEND_ABORT;
+			if (len != sizeof(p->abort_code))
+				return -EINVAL;
+			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
+			if (p->abort_code == 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_CHARGE_ACCEPT:
+			if (p->command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			p->command = RXRPC_CMD_CHARGE_ACCEPT;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_EXCLUSIVE_CALL:
+			p->exclusive = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_UPGRADE_SERVICE:
+			p->upgrade = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_TX_LENGTH:
+			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
+				return -EINVAL;
+			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
+			if (p->call.tx_total_len < 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_SET_CALL_TIMEOUT:
+			if (len & 3 || len < 4 || len > 12)
+				return -EINVAL;
+			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
+			p->call.nr_timeouts = len / 4;
+			if (p->call.timeouts.hard > INT_MAX / HZ)
+				return -ERANGE;
+			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
+				return -ERANGE;
+			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
+				return -ERANGE;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (!got_user_ID)
+		return -EINVAL;
+	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
+		return -EINVAL;
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Create a new client call for sendmsg().
+ * - Called with the socket lock held, which it must release.
+ * - If it returns a call, the call's lock will need releasing by the caller.
+ */
+static struct rxrpc_call *
+rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+				  struct rxrpc_send_params *p)
+	__releases(&rx->sk.sk_lock.slock)
+	__acquires(&call->user_mutex)
+{
+	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) {
+		release_sock(&rx->sk);
+		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 | p->exclusive;
+	cp.upgrade		= p->upgrade;
+	cp.service_id		= srx->srx_service;
+	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
+				     atomic_inc_return(&rxrpc_debug_id));
+	/* The socket is now unlocked */
+
+	rxrpc_put_peer(cp.peer);
+	_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)
+	__releases(&rx->sk.sk_lock.slock)
+	__releases(&call->user_mutex)
+{
+	enum rxrpc_call_state state;
+	struct rxrpc_call *call;
+	unsigned long now, j;
+	bool dropped_lock = false;
+	int ret;
+
+	struct rxrpc_send_params p = {
+		.call.tx_total_len	= -1,
+		.call.user_call_ID	= 0,
+		.call.nr_timeouts	= 0,
+		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
+		.abort_code		= 0,
+		.command		= RXRPC_CMD_SEND_DATA,
+		.exclusive		= false,
+		.upgrade		= false,
+	};
+
+	_enter("");
+
+	ret = rxrpc_sendmsg_cmsg(msg, &p);
+	if (ret < 0)
+		goto error_release_sock;
+
+	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
+		ret = -EINVAL;
+		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
+			goto error_release_sock;
+		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
+		goto error_release_sock;
+	}
+
+	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
+	if (!call) {
+		ret = -EBADSLT;
+		if (p.command != RXRPC_CMD_SEND_DATA)
+			goto error_release_sock;
+		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
+		/* The socket is now unlocked... */
+		if (IS_ERR(call))
+			return PTR_ERR(call);
+		/* ... and we have the call lock. */
+		ret = 0;
+		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
+			goto out_put_unlock;
+	} else {
+		switch (READ_ONCE(call->state)) {
+		case RXRPC_CALL_UNINITIALISED:
+		case RXRPC_CALL_CLIENT_AWAIT_CONN:
+		case RXRPC_CALL_SERVER_PREALLOC:
+		case RXRPC_CALL_SERVER_SECURING:
+			rxrpc_put_call(call, rxrpc_call_put);
+			ret = -EBUSY;
+			goto error_release_sock;
+		default:
+			break;
+		}
+
+		ret = mutex_lock_interruptible(&call->user_mutex);
+		release_sock(&rx->sk);
+		if (ret < 0) {
+			ret = -ERESTARTSYS;
+			goto error_put;
+		}
+
+		if (p.call.tx_total_len != -1) {
+			ret = -EINVAL;
+			if (call->tx_total_len != -1 ||
+			    call->tx_pending ||
+			    call->tx_top != 0)
+				goto out_put_unlock;
+			call->tx_total_len = p.call.tx_total_len;
+		}
+	}
+
+	switch (p.call.nr_timeouts) {
+	case 3:
+		j = msecs_to_jiffies(p.call.timeouts.normal);
+		if (p.call.timeouts.normal > 0 && j == 0)
+			j = 1;
+		WRITE_ONCE(call->next_rx_timo, j);
+		fallthrough;
+	case 2:
+		j = msecs_to_jiffies(p.call.timeouts.idle);
+		if (p.call.timeouts.idle > 0 && j == 0)
+			j = 1;
+		WRITE_ONCE(call->next_req_timo, j);
+		fallthrough;
+	case 1:
+		if (p.call.timeouts.hard > 0) {
+			j = p.call.timeouts.hard * HZ;
+			now = jiffies;
+			j += now;
+			WRITE_ONCE(call->expect_term_by, j);
+			rxrpc_reduce_call_timer(call, j, now,
+						rxrpc_timer_set_for_hard);
+		}
+		break;
+	}
+
+	state = READ_ONCE(call->state);
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, state, call->conn);
+
+	if (state >= RXRPC_CALL_COMPLETE) {
+		/* it's too late for this call */
+		ret = -ESHUTDOWN;
+	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
+		ret = 0;
+		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
+			ret = rxrpc_send_abort_packet(call);
+	} else if (p.command != RXRPC_CMD_SEND_DATA) {
+		ret = -EINVAL;
+	} else {
+		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
+	}
+
+out_put_unlock:
+	if (!dropped_lock)
+		mutex_unlock(&call->user_mutex);
+error_put:
+	rxrpc_put_call(call, rxrpc_call_put);
+	_leave(" = %d", ret);
+	return ret;
+
+error_release_sock:
+	release_sock(&rx->sk);
+	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
+ * @notify_end_tx: Notification that the last packet is queued.
+ *
+ * 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,
+			   rxrpc_notify_end_tx_t notify_end_tx)
+{
+	bool dropped_lock = false;
+	int ret;
+
+	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
+
+	ASSERTCMP(msg->msg_name, ==, NULL);
+	ASSERTCMP(msg->msg_control, ==, NULL);
+
+	mutex_lock(&call->user_mutex);
+
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, call->state, call->conn);
+
+	switch (READ_ONCE(call->state)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_SERVER_ACK_REQUEST:
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
+				      notify_end_tx, &dropped_lock);
+		break;
+	case RXRPC_CALL_COMPLETE:
+		read_lock_bh(&call->state_lock);
+		ret = call->error;
+		read_unlock_bh(&call->state_lock);
+		break;
+	default:
+		/* Request phase complete for this client call */
+		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
+		ret = -EPROTO;
+		break;
+	}
+
+	if (!dropped_lock)
+		mutex_unlock(&call->user_mutex);
+	_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
+ * @error: Local error value
+ * @why: 3-char string indicating why.
+ *
+ * Allow a kernel service to abort a call, if it's still in an abortable state
+ * and return true if the call was aborted, false if it was already complete.
+ */
+bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
+			     u32 abort_code, int error, const char *why)
+{
+	bool aborted;
+
+	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
+
+	mutex_lock(&call->user_mutex);
+
+	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
+	if (aborted)
+		rxrpc_send_abort_packet(call);
+
+	mutex_unlock(&call->user_mutex);
+	return aborted;
+}
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);
+
+/**
+ * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
+ * @sock: The socket the call is on
+ * @call: The call to be informed
+ * @tx_total_len: The amount of data to be transmitted for this call
+ *
+ * Allow a kernel service to set the total transmit length on a call.  This
+ * allows buffer-to-packet encrypt-and-copy to be performed.
+ *
+ * This function is primarily for use for setting the reply length since the
+ * request length can be set when beginning the call.
+ */
+void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
+				s64 tx_total_len)
+{
+	WARN_ON(call->tx_total_len != -1);
+	call->tx_total_len = tx_total_len;
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);