137 lines
3.6 KiB
C
137 lines
3.6 KiB
C
/* ar-skbuff.c: socket buffer destruction handling
|
|
*
|
|
* Copyright (C) 2007 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 License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/net.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/sock.h>
|
|
#include <net/af_rxrpc.h>
|
|
#include "ar-internal.h"
|
|
|
|
/*
|
|
* set up for the ACK at the end of the receive phase when we discard the final
|
|
* receive phase data packet
|
|
* - called with softirqs disabled
|
|
*/
|
|
static void rxrpc_request_final_ACK(struct rxrpc_call *call)
|
|
{
|
|
/* the call may be aborted before we have a chance to ACK it */
|
|
write_lock(&call->state_lock);
|
|
|
|
switch (call->state) {
|
|
case RXRPC_CALL_CLIENT_RECV_REPLY:
|
|
call->state = RXRPC_CALL_CLIENT_FINAL_ACK;
|
|
_debug("request final ACK");
|
|
|
|
/* get an extra ref on the call for the final-ACK generator to
|
|
* release */
|
|
rxrpc_get_call(call);
|
|
set_bit(RXRPC_CALL_EV_ACK_FINAL, &call->events);
|
|
if (try_to_del_timer_sync(&call->ack_timer) >= 0)
|
|
rxrpc_queue_call(call);
|
|
break;
|
|
|
|
case RXRPC_CALL_SERVER_RECV_REQUEST:
|
|
call->state = RXRPC_CALL_SERVER_ACK_REQUEST;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
write_unlock(&call->state_lock);
|
|
}
|
|
|
|
/*
|
|
* drop the bottom ACK off of the call ACK window and advance the window
|
|
*/
|
|
static void rxrpc_hard_ACK_data(struct rxrpc_call *call,
|
|
struct rxrpc_skb_priv *sp)
|
|
{
|
|
int loop;
|
|
u32 seq;
|
|
|
|
spin_lock_bh(&call->lock);
|
|
|
|
_debug("hard ACK #%u", sp->hdr.seq);
|
|
|
|
for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
|
|
call->ackr_window[loop] >>= 1;
|
|
call->ackr_window[loop] |=
|
|
call->ackr_window[loop + 1] << (BITS_PER_LONG - 1);
|
|
}
|
|
|
|
seq = sp->hdr.seq;
|
|
ASSERTCMP(seq, ==, call->rx_data_eaten + 1);
|
|
call->rx_data_eaten = seq;
|
|
|
|
if (call->ackr_win_top < UINT_MAX)
|
|
call->ackr_win_top++;
|
|
|
|
ASSERTIFCMP(call->state <= RXRPC_CALL_COMPLETE,
|
|
call->rx_data_post, >=, call->rx_data_recv);
|
|
ASSERTIFCMP(call->state <= RXRPC_CALL_COMPLETE,
|
|
call->rx_data_recv, >=, call->rx_data_eaten);
|
|
|
|
if (sp->hdr.flags & RXRPC_LAST_PACKET) {
|
|
rxrpc_request_final_ACK(call);
|
|
} else if (atomic_dec_and_test(&call->ackr_not_idle) &&
|
|
test_and_clear_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags)) {
|
|
/* We previously soft-ACK'd some received packets that have now
|
|
* been consumed, so send a hard-ACK if no more packets are
|
|
* immediately forthcoming to allow the transmitter to free up
|
|
* its Tx bufferage.
|
|
*/
|
|
_debug("send Rx idle ACK");
|
|
__rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, sp->hdr.serial,
|
|
false);
|
|
}
|
|
|
|
spin_unlock_bh(&call->lock);
|
|
}
|
|
|
|
/*
|
|
* destroy a packet that has an RxRPC control buffer
|
|
* - advance the hard-ACK state of the parent call (done here in case something
|
|
* in the kernel bypasses recvmsg() and steals the packet directly off of the
|
|
* socket receive queue)
|
|
*/
|
|
void rxrpc_packet_destructor(struct sk_buff *skb)
|
|
{
|
|
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
|
|
struct rxrpc_call *call = sp->call;
|
|
|
|
_enter("%p{%p}", skb, call);
|
|
|
|
if (call) {
|
|
/* send the final ACK on a client call */
|
|
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
|
|
rxrpc_hard_ACK_data(call, sp);
|
|
rxrpc_put_call(call);
|
|
sp->call = NULL;
|
|
}
|
|
|
|
if (skb->sk)
|
|
sock_rfree(skb);
|
|
_leave("");
|
|
}
|
|
|
|
/**
|
|
* rxrpc_kernel_free_skb - Free an RxRPC socket buffer
|
|
* @skb: The socket buffer to be freed
|
|
*
|
|
* Let RxRPC free its own socket buffer, permitting it to maintain debug
|
|
* accounting.
|
|
*/
|
|
void rxrpc_kernel_free_skb(struct sk_buff *skb)
|
|
{
|
|
rxrpc_free_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL(rxrpc_kernel_free_skb);
|