b24d2891cf
Set the timestamp on sk_buffs holding packets to be transmitted before queueing them because the moment the packet is on the queue it can be seen by the retransmission algorithm - which may see a completely random timestamp. If the retransmission algorithm sees such a timestamp, it may retransmit the packet and, in future, tell the congestion management algorithm that the retransmit timer expired. Signed-off-by: David Howells <dhowells@redhat.com>
595 lines
15 KiB
C
595 lines
15 KiB
C
/* AF_RXRPC sendmsg() implementation.
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*
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* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/net.h>
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#include <linux/gfp.h>
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#include <linux/skbuff.h>
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#include <linux/export.h>
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#include <net/sock.h>
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#include <net/af_rxrpc.h>
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#include "ar-internal.h"
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enum rxrpc_command {
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RXRPC_CMD_SEND_DATA, /* send data message */
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RXRPC_CMD_SEND_ABORT, /* request abort generation */
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RXRPC_CMD_ACCEPT, /* [server] accept incoming call */
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RXRPC_CMD_REJECT_BUSY, /* [server] reject a call as busy */
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};
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/*
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* wait for space to appear in the transmit/ACK window
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* - caller holds the socket locked
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*/
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static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
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struct rxrpc_call *call,
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long *timeo)
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{
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DECLARE_WAITQUEUE(myself, current);
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int ret;
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_enter(",{%u,%u,%u}",
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call->tx_hard_ack, call->tx_top, call->tx_winsize);
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add_wait_queue(&call->waitq, &myself);
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for (;;) {
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set_current_state(TASK_INTERRUPTIBLE);
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ret = 0;
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if (call->tx_top - call->tx_hard_ack < call->tx_winsize)
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break;
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if (call->state >= RXRPC_CALL_COMPLETE) {
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ret = -call->error;
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break;
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}
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if (signal_pending(current)) {
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ret = sock_intr_errno(*timeo);
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break;
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}
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trace_rxrpc_transmit(call, rxrpc_transmit_wait);
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release_sock(&rx->sk);
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*timeo = schedule_timeout(*timeo);
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lock_sock(&rx->sk);
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}
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remove_wait_queue(&call->waitq, &myself);
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set_current_state(TASK_RUNNING);
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_leave(" = %d", ret);
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return ret;
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}
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/*
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* Schedule an instant Tx resend.
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*/
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static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
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{
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spin_lock_bh(&call->lock);
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if (call->state < RXRPC_CALL_COMPLETE) {
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call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
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if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
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rxrpc_queue_call(call);
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}
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spin_unlock_bh(&call->lock);
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}
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/*
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* Queue a DATA packet for transmission, set the resend timeout and send the
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* packet immediately
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*/
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static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
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bool last)
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{
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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rxrpc_seq_t seq = sp->hdr.seq;
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int ret, ix;
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_net("queue skb %p [%d]", skb, seq);
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ASSERTCMP(seq, ==, call->tx_top + 1);
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/* We have to set the timestamp before queueing as the retransmit
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* algorithm can see the packet as soon as we queue it.
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*/
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skb->tstamp = ktime_get_real();
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ix = seq & RXRPC_RXTX_BUFF_MASK;
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rxrpc_get_skb(skb, rxrpc_skb_tx_got);
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call->rxtx_annotations[ix] = RXRPC_TX_ANNO_UNACK;
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smp_wmb();
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call->rxtx_buffer[ix] = skb;
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call->tx_top = seq;
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if (last) {
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set_bit(RXRPC_CALL_TX_LAST, &call->flags);
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trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
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} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
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trace_rxrpc_transmit(call, rxrpc_transmit_queue_reqack);
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} else {
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trace_rxrpc_transmit(call, rxrpc_transmit_queue);
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}
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if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
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_debug("________awaiting reply/ACK__________");
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write_lock_bh(&call->state_lock);
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switch (call->state) {
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case RXRPC_CALL_CLIENT_SEND_REQUEST:
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call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
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break;
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case RXRPC_CALL_SERVER_ACK_REQUEST:
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call->state = RXRPC_CALL_SERVER_SEND_REPLY;
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if (!last)
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break;
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case RXRPC_CALL_SERVER_SEND_REPLY:
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call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
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break;
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default:
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break;
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}
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write_unlock_bh(&call->state_lock);
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}
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if (seq == 1 && rxrpc_is_client_call(call))
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rxrpc_expose_client_call(call);
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ret = rxrpc_send_data_packet(call, skb);
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if (ret < 0) {
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_debug("need instant resend %d", ret);
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rxrpc_instant_resend(call, ix);
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}
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rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
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_leave("");
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}
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/*
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* send data through a socket
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* - must be called in process context
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* - caller holds the socket locked
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*/
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static int rxrpc_send_data(struct rxrpc_sock *rx,
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struct rxrpc_call *call,
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struct msghdr *msg, size_t len)
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{
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struct rxrpc_skb_priv *sp;
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struct sk_buff *skb;
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struct sock *sk = &rx->sk;
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long timeo;
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bool more;
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int ret, copied;
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timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
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/* this should be in poll */
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sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
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if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
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return -EPIPE;
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more = msg->msg_flags & MSG_MORE;
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skb = call->tx_pending;
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call->tx_pending = NULL;
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rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
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copied = 0;
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do {
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/* Check to see if there's a ping ACK to reply to. */
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if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
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rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
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if (!skb) {
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size_t size, chunk, max, space;
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_debug("alloc");
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if (call->tx_top - call->tx_hard_ack >=
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call->tx_winsize) {
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ret = -EAGAIN;
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if (msg->msg_flags & MSG_DONTWAIT)
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goto maybe_error;
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ret = rxrpc_wait_for_tx_window(rx, call,
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&timeo);
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if (ret < 0)
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goto maybe_error;
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}
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max = RXRPC_JUMBO_DATALEN;
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max -= call->conn->security_size;
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max &= ~(call->conn->size_align - 1UL);
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chunk = max;
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if (chunk > msg_data_left(msg) && !more)
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chunk = msg_data_left(msg);
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space = chunk + call->conn->size_align;
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space &= ~(call->conn->size_align - 1UL);
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size = space + call->conn->security_size;
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_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
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/* create a buffer that we can retain until it's ACK'd */
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skb = sock_alloc_send_skb(
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sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
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if (!skb)
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goto maybe_error;
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rxrpc_new_skb(skb, rxrpc_skb_tx_new);
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_debug("ALLOC SEND %p", skb);
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ASSERTCMP(skb->mark, ==, 0);
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_debug("HS: %u", call->conn->security_size);
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skb_reserve(skb, call->conn->security_size);
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skb->len += call->conn->security_size;
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sp = rxrpc_skb(skb);
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sp->remain = chunk;
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if (sp->remain > skb_tailroom(skb))
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sp->remain = skb_tailroom(skb);
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_net("skb: hr %d, tr %d, hl %d, rm %d",
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skb_headroom(skb),
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skb_tailroom(skb),
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skb_headlen(skb),
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sp->remain);
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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}
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_debug("append");
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sp = rxrpc_skb(skb);
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/* append next segment of data to the current buffer */
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if (msg_data_left(msg) > 0) {
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int copy = skb_tailroom(skb);
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ASSERTCMP(copy, >, 0);
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if (copy > msg_data_left(msg))
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copy = msg_data_left(msg);
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if (copy > sp->remain)
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copy = sp->remain;
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_debug("add");
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ret = skb_add_data(skb, &msg->msg_iter, copy);
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_debug("added");
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if (ret < 0)
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goto efault;
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sp->remain -= copy;
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skb->mark += copy;
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copied += copy;
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}
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/* check for the far side aborting the call or a network error
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* occurring */
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if (call->state == RXRPC_CALL_COMPLETE)
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goto call_terminated;
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/* add the packet to the send queue if it's now full */
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if (sp->remain <= 0 ||
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(msg_data_left(msg) == 0 && !more)) {
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struct rxrpc_connection *conn = call->conn;
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uint32_t seq;
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size_t pad;
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/* pad out if we're using security */
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if (conn->security_ix) {
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pad = conn->security_size + skb->mark;
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pad = conn->size_align - pad;
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pad &= conn->size_align - 1;
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_debug("pad %zu", pad);
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if (pad)
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memset(skb_put(skb, pad), 0, pad);
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}
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seq = call->tx_top + 1;
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sp->hdr.seq = seq;
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sp->hdr._rsvd = 0;
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sp->hdr.flags = conn->out_clientflag;
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if (msg_data_left(msg) == 0 && !more)
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sp->hdr.flags |= RXRPC_LAST_PACKET;
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else if (call->tx_top - call->tx_hard_ack <
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call->tx_winsize)
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sp->hdr.flags |= RXRPC_MORE_PACKETS;
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ret = conn->security->secure_packet(
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call, skb, skb->mark, skb->head);
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if (ret < 0)
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goto out;
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rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
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skb = NULL;
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}
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} while (msg_data_left(msg) > 0);
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success:
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ret = copied;
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out:
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call->tx_pending = skb;
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_leave(" = %d", ret);
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return ret;
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call_terminated:
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rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
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_leave(" = %d", -call->error);
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return -call->error;
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maybe_error:
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if (copied)
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goto success;
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goto out;
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efault:
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ret = -EFAULT;
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goto out;
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}
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/*
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* extract control messages from the sendmsg() control buffer
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*/
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static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
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unsigned long *user_call_ID,
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enum rxrpc_command *command,
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u32 *abort_code,
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bool *_exclusive)
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{
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struct cmsghdr *cmsg;
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bool got_user_ID = false;
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int len;
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*command = RXRPC_CMD_SEND_DATA;
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if (msg->msg_controllen == 0)
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return -EINVAL;
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for_each_cmsghdr(cmsg, msg) {
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if (!CMSG_OK(msg, cmsg))
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return -EINVAL;
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len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
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_debug("CMSG %d, %d, %d",
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cmsg->cmsg_level, cmsg->cmsg_type, len);
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if (cmsg->cmsg_level != SOL_RXRPC)
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continue;
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switch (cmsg->cmsg_type) {
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case RXRPC_USER_CALL_ID:
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if (msg->msg_flags & MSG_CMSG_COMPAT) {
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if (len != sizeof(u32))
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return -EINVAL;
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*user_call_ID = *(u32 *) CMSG_DATA(cmsg);
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} else {
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if (len != sizeof(unsigned long))
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return -EINVAL;
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*user_call_ID = *(unsigned long *)
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CMSG_DATA(cmsg);
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}
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_debug("User Call ID %lx", *user_call_ID);
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got_user_ID = true;
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break;
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case RXRPC_ABORT:
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if (*command != RXRPC_CMD_SEND_DATA)
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return -EINVAL;
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*command = RXRPC_CMD_SEND_ABORT;
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if (len != sizeof(*abort_code))
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return -EINVAL;
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*abort_code = *(unsigned int *) CMSG_DATA(cmsg);
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_debug("Abort %x", *abort_code);
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if (*abort_code == 0)
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return -EINVAL;
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break;
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case RXRPC_ACCEPT:
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if (*command != RXRPC_CMD_SEND_DATA)
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return -EINVAL;
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*command = RXRPC_CMD_ACCEPT;
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if (len != 0)
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return -EINVAL;
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break;
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case RXRPC_EXCLUSIVE_CALL:
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*_exclusive = true;
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if (len != 0)
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return -EINVAL;
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break;
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default:
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return -EINVAL;
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}
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}
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if (!got_user_ID)
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return -EINVAL;
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_leave(" = 0");
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return 0;
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}
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/*
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* Create a new client call for sendmsg().
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*/
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static struct rxrpc_call *
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rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
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unsigned long user_call_ID, bool exclusive)
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{
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struct rxrpc_conn_parameters cp;
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struct rxrpc_call *call;
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struct key *key;
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DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
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_enter("");
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if (!msg->msg_name)
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return ERR_PTR(-EDESTADDRREQ);
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key = rx->key;
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if (key && !rx->key->payload.data[0])
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key = NULL;
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memset(&cp, 0, sizeof(cp));
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cp.local = rx->local;
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cp.key = rx->key;
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cp.security_level = rx->min_sec_level;
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cp.exclusive = rx->exclusive | exclusive;
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cp.service_id = srx->srx_service;
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call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
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_leave(" = %p\n", call);
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return call;
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}
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/*
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* send a message forming part of a client call through an RxRPC socket
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* - caller holds the socket locked
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* - the socket may be either a client socket or a server socket
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*/
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int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
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{
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enum rxrpc_command cmd;
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struct rxrpc_call *call;
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unsigned long user_call_ID = 0;
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bool exclusive = false;
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u32 abort_code = 0;
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int ret;
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_enter("");
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ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
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&exclusive);
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if (ret < 0)
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return ret;
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if (cmd == RXRPC_CMD_ACCEPT) {
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if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
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return -EINVAL;
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call = rxrpc_accept_call(rx, user_call_ID, NULL);
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if (IS_ERR(call))
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return PTR_ERR(call);
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rxrpc_put_call(call, rxrpc_call_put);
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return 0;
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}
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call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
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if (!call) {
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if (cmd != RXRPC_CMD_SEND_DATA)
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return -EBADSLT;
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call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
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exclusive);
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if (IS_ERR(call))
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return PTR_ERR(call);
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}
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_debug("CALL %d USR %lx ST %d on CONN %p",
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call->debug_id, call->user_call_ID, call->state, call->conn);
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if (call->state >= RXRPC_CALL_COMPLETE) {
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/* it's too late for this call */
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ret = -ESHUTDOWN;
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} else if (cmd == RXRPC_CMD_SEND_ABORT) {
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ret = 0;
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if (rxrpc_abort_call("CMD", call, 0, abort_code, ECONNABORTED))
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ret = rxrpc_send_call_packet(call,
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RXRPC_PACKET_TYPE_ABORT);
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} else if (cmd != RXRPC_CMD_SEND_DATA) {
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ret = -EINVAL;
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} else if (rxrpc_is_client_call(call) &&
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call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
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/* request phase complete for this client call */
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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, rxrpc_call_put);
|
|
_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
|
|
* @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.
|
|
*/
|
|
void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
|
|
u32 abort_code, int error, const char *why)
|
|
{
|
|
_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
|
|
|
|
lock_sock(sock->sk);
|
|
|
|
if (rxrpc_abort_call(why, call, 0, abort_code, error))
|
|
rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
|
|
|
|
release_sock(sock->sk);
|
|
_leave("");
|
|
}
|
|
|
|
EXPORT_SYMBOL(rxrpc_kernel_abort_call);
|