// 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"

/*
 * Propose an abort to be made in the I/O thread.
 */
bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
                         enum rxrpc_abort_reason why)
{
        _enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);

        if (!call->send_abort && !rxrpc_call_is_complete(call)) {
                call->send_abort_why = why;
                call->send_abort_err = error;
                call->send_abort_seq = 0;
                trace_rxrpc_abort_call(call, abort_code);
                /* Request abort locklessly vs rxrpc_input_call_event(). */
                smp_store_release(&call->send_abort, abort_code);
                rxrpc_poke_call(call, rxrpc_call_poke_abort);
                return true;
        }

        return false;
}

/*
 * Wait for a call to become connected.  Interruption here doesn't cause the
 * call to be aborted.
 */
static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
{
        DECLARE_WAITQUEUE(myself, current);
        int ret = 0;

        _enter("%d", call->debug_id);

        if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
                goto no_wait;

        add_wait_queue_exclusive(&call->waitq, &myself);

        for (;;) {
                switch (call->interruptibility) {
                case RXRPC_INTERRUPTIBLE:
                case RXRPC_PREINTERRUPTIBLE:
                        set_current_state(TASK_INTERRUPTIBLE);
                        break;
                case RXRPC_UNINTERRUPTIBLE:
                default:
                        set_current_state(TASK_UNINTERRUPTIBLE);
                        break;
                }

                if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
                        break;
                if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
                     call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
                    signal_pending(current)) {
                        ret = sock_intr_errno(*timeo);
                        break;
                }
                *timeo = schedule_timeout(*timeo);
        }

        remove_wait_queue(&call->waitq, &myself);
        __set_current_state(TASK_RUNNING);

no_wait:
        if (ret == 0 && rxrpc_call_is_complete(call))
                ret = call->error;

        _leave(" = %d", ret);
        return ret;
}

/*
 * Return true if there's sufficient Tx queue space.
 */
static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
{
        rxrpc_seq_t tx_bottom = READ_ONCE(call->tx_bottom);

        if (_tx_win)
                *_tx_win = tx_bottom;
        return call->send_top - tx_bottom < 256;
}

/*
 * 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 (rxrpc_call_is_complete(call))
                        return call->error;

                if (signal_pending(current))
                        return sock_intr_errno(*timeo);

                trace_rxrpc_txqueue(call, rxrpc_txqueue_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->srtt_us) >> 3;
        rtt = usecs_to_jiffies(rtt) * 2;
        if (rtt < 2)
                rtt = 2;

        timeout = rtt;
        tx_start = READ_ONCE(call->tx_bottom);

        for (;;) {
                set_current_state(TASK_UNINTERRUPTIBLE);

                if (rxrpc_check_tx_space(call, &tx_win))
                        return 0;

                if (rxrpc_call_is_complete(call))
                        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_txqueue(call, rxrpc_txqueue_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 (rxrpc_call_is_complete(call))
                        return call->error;

                trace_rxrpc_txqueue(call, rxrpc_txqueue_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_bottom, 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;
}

/*
 * 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 void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
                               struct rxrpc_txbuf *txb,
                               rxrpc_notify_end_tx_t notify_end_tx)
{
        struct rxrpc_txqueue *sq = call->send_queue;
        rxrpc_seq_t seq = txb->seq;
        bool poke, last = txb->flags & RXRPC_LAST_PACKET;
        int ix = seq & RXRPC_TXQ_MASK;
        rxrpc_inc_stat(call->rxnet, stat_tx_data);

        ASSERTCMP(txb->seq, ==, call->send_top + 1);

        if (last)
                trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
        else
                trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);

        if (WARN_ON_ONCE(sq->bufs[ix]))
                trace_rxrpc_tq(call, sq, seq, rxrpc_tq_queue_dup);
        else
                trace_rxrpc_tq(call, sq, seq, rxrpc_tq_queue);

        /* Add the packet to the call's output buffer */
        poke = (READ_ONCE(call->tx_bottom) == call->send_top);
        sq->bufs[ix] = txb;
        /* Order send_top after the queue->next pointer and txb content. */
        smp_store_release(&call->send_top, seq);
        if (last) {
                set_bit(RXRPC_CALL_TX_NO_MORE, &call->flags);
                rxrpc_notify_end_tx(rx, call, notify_end_tx);
                call->send_queue = NULL;
        }

        if (poke)
                rxrpc_poke_call(call, rxrpc_call_poke_start);
}

/*
 * Allocate a new txqueue unit and add it to the transmission queue.
 */
static int rxrpc_alloc_txqueue(struct sock *sk, struct rxrpc_call *call)
{
        struct rxrpc_txqueue *tq;

        tq = kzalloc_obj(*tq, sk->sk_allocation);
        if (!tq)
                return -ENOMEM;

        tq->xmit_ts_base = KTIME_MIN;
        for (int i = 0; i < RXRPC_NR_TXQUEUE; i++)
                tq->segment_xmit_ts[i] = UINT_MAX;

        if (call->send_queue) {
                tq->qbase = call->send_top + 1;
                call->send_queue->next = tq;
                call->send_queue = tq;
        } else if (WARN_ON(call->tx_queue)) {
                kfree(tq);
                return -ENOMEM;
        } else {
                /* We start at seq 1, so pretend seq 0 is hard-acked. */
                tq->nr_reported_acks = 1;
                tq->segment_acked = 1UL;
                tq->qbase = 0;
                call->tx_qbase = 0;
                call->send_queue = tq;
                call->tx_qtail = tq;
                call->tx_queue = tq;
        }

        trace_rxrpc_tq(call, tq, call->send_top, rxrpc_tq_alloc);
        return 0;
}

/*
 * 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_txbuf *txb;
        struct sock *sk = &rx->sk;
        enum rxrpc_call_state state;
        long timeo;
        bool more = msg->msg_flags & MSG_MORE;
        int ret, copied = 0;

        if (test_bit(RXRPC_CALL_TX_NO_MORE, &call->flags)) {
                trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
                                  call->cid, call->call_id, call->rx_consumed,
                                  0, -EPROTO);
                return -EPROTO;
        }

        timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);

        ret = rxrpc_wait_to_be_connected(call, &timeo);
        if (ret < 0)
                return ret;

        if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
                ret = rxrpc_init_client_conn_security(call->conn);
                if (ret < 0)
                        return ret;
        }

        /* this should be in poll */
        sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);

reload:
        txb = call->tx_pending;
        call->tx_pending = NULL;
        if (txb)
                rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);

        ret = -EPIPE;
        if (sk->sk_shutdown & SEND_SHUTDOWN)
                goto maybe_error;
        state = rxrpc_call_state(call);
        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) {
                /* Request phase complete for this client call */
                trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
                                  call->cid, call->call_id, call->rx_consumed,
                                  0, -EPROTO);
                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;
        }

        do {
                if (!txb) {
                        size_t remain;

                        _debug("alloc");

                        if (!rxrpc_check_tx_space(call, NULL))
                                goto wait_for_space;

                        /* See if we need to begin/extend the Tx queue. */
                        if (!call->send_queue || !((call->send_top + 1) & RXRPC_TXQ_MASK)) {
                                ret = rxrpc_alloc_txqueue(sk, call);
                                if (ret < 0)
                                        goto maybe_error;
                        }

                        /* 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);
                        txb = call->conn->security->alloc_txbuf(call, remain, sk->sk_allocation);
                        if (!txb) {
                                ret = -ENOMEM;
                                goto maybe_error;
                        }
                }

                _debug("append");

                /* append next segment of data to the current buffer */
                if (msg_data_left(msg) > 0) {
                        size_t copy = umin(txb->space, msg_data_left(msg));

                        _debug("add %zu", copy);
                        if (!copy_from_iter_full(txb->data + txb->offset,
                                                 copy, &msg->msg_iter))
                                goto efault;
                        _debug("added");
                        txb->space -= copy;
                        txb->len += copy;
                        txb->offset += 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 (rxrpc_call_is_complete(call))
                        goto call_terminated;

                /* add the packet to the send queue if it's now full */
                if (!txb->space ||
                    (msg_data_left(msg) == 0 && !more)) {
                        if (msg_data_left(msg) == 0 && !more)
                                txb->flags |= RXRPC_LAST_PACKET;

                        ret = call->security->secure_packet(call, txb);
                        if (ret < 0)
                                goto out;
                        rxrpc_queue_packet(rx, call, txb, notify_end_tx);
                        txb = NULL;
                }
        } while (msg_data_left(msg) > 0);

success:
        ret = copied;
        if (rxrpc_call_is_complete(call) &&
            call->error < 0)
                ret = call->error;
out:
        call->tx_pending = txb;
        _leave(" = %d", ret);
        return ret;

call_terminated:
        rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
        _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)
        __acquires(&call->user_mutex)
{
        struct rxrpc_conn_parameters cp;
        struct rxrpc_peer *peer;
        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);
        }

        peer = rxrpc_lookup_peer(rx->local, srx, GFP_KERNEL);
        if (!peer) {
                release_sock(&rx->sk);
                return ERR_PTR(-ENOMEM);
        }

        key = rx->key;
        if (key && !rx->key->payload.data[0])
                key = NULL;

        memset(&cp, 0, sizeof(cp));
        cp.local                = rx->local;
        cp.peer                 = peer;
        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, &p->call, GFP_KERNEL,
                                     atomic_inc_return(&rxrpc_debug_id));
        /* The socket is now unlocked */

        rxrpc_put_peer(peer, rxrpc_peer_put_application);
        _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)
{
        struct rxrpc_call *call;
        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. */
                p.call.nr_timeouts = 0;
                ret = 0;
                if (rxrpc_call_is_complete(call))
                        goto out_put_unlock;
        } else {
                switch (rxrpc_call_state(call)) {
                case RXRPC_CALL_CLIENT_AWAIT_CONN:
                case RXRPC_CALL_SERVER_RECV_REQUEST:
                        if (p.command == RXRPC_CMD_SEND_ABORT)
                                break;
                        fallthrough;
                case RXRPC_CALL_UNINITIALISED:
                case RXRPC_CALL_SERVER_PREALLOC:
                        rxrpc_put_call(call, rxrpc_call_put_sendmsg);
                        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:
                WRITE_ONCE(call->next_rx_timo, p.call.timeouts.normal);
                fallthrough;
        case 2:
                WRITE_ONCE(call->next_req_timo, p.call.timeouts.idle);
                fallthrough;
        case 1:
                if (p.call.timeouts.hard > 0) {
                        ktime_t delay = ms_to_ktime(p.call.timeouts.hard * MSEC_PER_SEC);

                        WRITE_ONCE(call->expect_term_by,
                                   ktime_add(p.call.timeouts.hard,
                                             ktime_get_real()));
                        trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
                        rxrpc_poke_call(call, rxrpc_call_poke_set_timeout);

                }
                break;
        }

        if (rxrpc_call_is_complete(call)) {
                /* it's too late for this call */
                ret = -ESHUTDOWN;
                goto out_put_unlock;
        }

        switch (p.command) {
        case RXRPC_CMD_SEND_ABORT:
                rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
                                    rxrpc_abort_call_sendmsg);
                ret = 0;
                break;
        case RXRPC_CMD_SEND_DATA:
                ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
                break;
        default:
                ret = -EINVAL;
                break;
        }

out_put_unlock:
        if (!dropped_lock)
                mutex_unlock(&call->user_mutex);
error_put:
        rxrpc_put_call(call, rxrpc_call_put_sendmsg);
        _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.
 *
 * Return: %0 if successful and a negative error code otherwise.
 */
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},", call->debug_id);

        ASSERTCMP(msg->msg_name, ==, NULL);
        ASSERTCMP(msg->msg_control, ==, NULL);

        mutex_lock(&call->user_mutex);

        ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
                              notify_end_tx, &dropped_lock);
        if (ret == -ESHUTDOWN)
                ret = call->error;

        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: Indication as to why.
 *
 * Allow a kernel service to abort a call if it's still in an abortable state.
 *
 * 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, enum rxrpc_abort_reason why)
{
        bool aborted;

        _enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);

        mutex_lock(&call->user_mutex);
        aborted = rxrpc_propose_abort(call, abort_code, error, why);
        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);