linux_dsm_epyc7002/net/rxrpc/recvmsg.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

758 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC recvmsg() implementation
*
* Copyright (C) 2007 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/skbuff.h>
#include <linux/export.h>
#include <linux/sched/signal.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Post a call for attention by the socket or kernel service. Further
* notifications are suppressed by putting recvmsg_link on a dummy queue.
*/
void rxrpc_notify_socket(struct rxrpc_call *call)
{
struct rxrpc_sock *rx;
struct sock *sk;
_enter("%d", call->debug_id);
if (!list_empty(&call->recvmsg_link))
return;
rcu_read_lock();
rx = rcu_dereference(call->socket);
sk = &rx->sk;
if (rx && sk->sk_state < RXRPC_CLOSE) {
if (call->notify_rx) {
spin_lock_bh(&call->notify_lock);
call->notify_rx(sk, call, call->user_call_ID);
spin_unlock_bh(&call->notify_lock);
} else {
write_lock_bh(&rx->recvmsg_lock);
if (list_empty(&call->recvmsg_link)) {
rxrpc_get_call(call, rxrpc_call_got);
list_add_tail(&call->recvmsg_link, &rx->recvmsg_q);
}
write_unlock_bh(&rx->recvmsg_lock);
if (!sock_flag(sk, SOCK_DEAD)) {
_debug("call %ps", sk->sk_data_ready);
sk->sk_data_ready(sk);
}
}
}
rcu_read_unlock();
_leave("");
}
/*
* Pass a call terminating message to userspace.
*/
static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg)
{
u32 tmp = 0;
int ret;
switch (call->completion) {
case RXRPC_CALL_SUCCEEDED:
ret = 0;
if (rxrpc_is_service_call(call))
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp);
break;
case RXRPC_CALL_REMOTELY_ABORTED:
tmp = call->abort_code;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
break;
case RXRPC_CALL_LOCALLY_ABORTED:
tmp = call->abort_code;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
break;
case RXRPC_CALL_NETWORK_ERROR:
tmp = -call->error;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp);
break;
case RXRPC_CALL_LOCAL_ERROR:
tmp = -call->error;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp);
break;
default:
pr_err("Invalid terminal call state %u\n", call->state);
BUG();
break;
}
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_terminal, call->rx_hard_ack,
call->rx_pkt_offset, call->rx_pkt_len, ret);
return ret;
}
/*
* Pass back notification of a new call. The call is added to the
* to-be-accepted list. This means that the next call to be accepted might not
* be the last call seen awaiting acceptance, but unless we leave this on the
* front of the queue and block all other messages until someone gives us a
* user_ID for it, there's not a lot we can do.
*/
static int rxrpc_recvmsg_new_call(struct rxrpc_sock *rx,
struct rxrpc_call *call,
struct msghdr *msg, int flags)
{
int tmp = 0, ret;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &tmp);
if (ret == 0 && !(flags & MSG_PEEK)) {
_debug("to be accepted");
write_lock_bh(&rx->recvmsg_lock);
list_del_init(&call->recvmsg_link);
write_unlock_bh(&rx->recvmsg_lock);
rxrpc_get_call(call, rxrpc_call_got);
write_lock(&rx->call_lock);
list_add_tail(&call->accept_link, &rx->to_be_accepted);
write_unlock(&rx->call_lock);
}
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_to_be_accepted, 1, 0, 0, ret);
return ret;
}
/*
* End the packet reception phase.
*/
static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
{
_enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]);
trace_rxrpc_receive(call, rxrpc_receive_end, 0, call->rx_top);
ASSERTCMP(call->rx_hard_ack, ==, call->rx_top);
if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) {
rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, false, true,
rxrpc_propose_ack_terminal_ack);
//rxrpc_send_ack_packet(call, false, NULL);
}
write_lock_bh(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_RECV_REPLY:
__rxrpc_call_completed(call);
write_unlock_bh(&call->state_lock);
break;
case RXRPC_CALL_SERVER_RECV_REQUEST:
call->tx_phase = true;
call->state = RXRPC_CALL_SERVER_ACK_REQUEST;
call->expect_req_by = jiffies + MAX_JIFFY_OFFSET;
write_unlock_bh(&call->state_lock);
rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial, false, true,
rxrpc_propose_ack_processing_op);
break;
default:
write_unlock_bh(&call->state_lock);
break;
}
}
/*
* Discard a packet we've used up and advance the Rx window by one.
*/
static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
{
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top;
u8 flags;
int ix;
_enter("%d", call->debug_id);
hard_ack = call->rx_hard_ack;
top = smp_load_acquire(&call->rx_top);
ASSERT(before(hard_ack, top));
hard_ack++;
ix = hard_ack & RXRPC_RXTX_BUFF_MASK;
skb = call->rxtx_buffer[ix];
rxrpc_see_skb(skb, rxrpc_skb_rx_rotated);
sp = rxrpc_skb(skb);
flags = sp->hdr.flags;
serial = sp->hdr.serial;
if (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO)
serial += (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO) - 1;
call->rxtx_buffer[ix] = NULL;
call->rxtx_annotations[ix] = 0;
/* Barrier against rxrpc_input_data(). */
smp_store_release(&call->rx_hard_ack, hard_ack);
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
_debug("%u,%u,%02x", hard_ack, top, flags);
trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack);
if (flags & RXRPC_LAST_PACKET) {
rxrpc_end_rx_phase(call, serial);
} else {
/* Check to see if there's an ACK that needs sending. */
if (after_eq(hard_ack, call->ackr_consumed + 2) ||
after_eq(top, call->ackr_seen + 2) ||
(hard_ack == top && after(hard_ack, call->ackr_consumed)))
rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial,
true, true,
rxrpc_propose_ack_rotate_rx);
if (call->ackr_reason && call->ackr_reason != RXRPC_ACK_DELAY)
rxrpc_send_ack_packet(call, false, NULL);
}
}
/*
* Decrypt and verify a (sub)packet. The packet's length may be changed due to
* padding, but if this is the case, the packet length will be resident in the
* socket buffer. Note that we can't modify the master skb info as the skb may
* be the home to multiple subpackets.
*/
static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
u8 annotation,
unsigned int offset, unsigned int len)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc_seq_t seq = sp->hdr.seq;
u16 cksum = sp->hdr.cksum;
_enter("");
/* For all but the head jumbo subpacket, the security checksum is in a
* jumbo header immediately prior to the data.
*/
if ((annotation & RXRPC_RX_ANNO_JUMBO) > 1) {
__be16 tmp;
if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0)
BUG();
cksum = ntohs(tmp);
seq += (annotation & RXRPC_RX_ANNO_JUMBO) - 1;
}
return call->conn->security->verify_packet(call, skb, offset, len,
seq, cksum);
}
/*
* Locate the data within a packet. This is complicated by:
*
* (1) An skb may contain a jumbo packet - so we have to find the appropriate
* subpacket.
*
* (2) The (sub)packets may be encrypted and, if so, the encrypted portion
* contains an extra header which includes the true length of the data,
* excluding any encrypted padding.
*/
static int rxrpc_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
u8 *_annotation,
unsigned int *_offset, unsigned int *_len)
{
unsigned int offset = sizeof(struct rxrpc_wire_header);
unsigned int len;
int ret;
u8 annotation = *_annotation;
/* Locate the subpacket */
len = skb->len - offset;
if ((annotation & RXRPC_RX_ANNO_JUMBO) > 0) {
offset += (((annotation & RXRPC_RX_ANNO_JUMBO) - 1) *
RXRPC_JUMBO_SUBPKTLEN);
len = (annotation & RXRPC_RX_ANNO_JLAST) ?
skb->len - offset : RXRPC_JUMBO_SUBPKTLEN;
}
if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) {
ret = rxrpc_verify_packet(call, skb, annotation, offset, len);
if (ret < 0)
return ret;
*_annotation |= RXRPC_RX_ANNO_VERIFIED;
}
*_offset = offset;
*_len = len;
call->conn->security->locate_data(call, skb, _offset, _len);
return 0;
}
/*
* Deliver messages to a call. This keeps processing packets until the buffer
* is filled and we find either more DATA (returns 0) or the end of the DATA
* (returns 1). If more packets are required, it returns -EAGAIN.
*/
static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
struct msghdr *msg, struct iov_iter *iter,
size_t len, int flags, size_t *_offset)
{
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
rxrpc_seq_t hard_ack, top, seq;
size_t remain;
bool last;
unsigned int rx_pkt_offset, rx_pkt_len;
int ix, copy, ret = -EAGAIN, ret2;
if (test_and_clear_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags) &&
call->ackr_reason)
rxrpc_send_ack_packet(call, false, NULL);
rx_pkt_offset = call->rx_pkt_offset;
rx_pkt_len = call->rx_pkt_len;
if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) {
seq = call->rx_hard_ack;
ret = 1;
goto done;
}
/* Barriers against rxrpc_input_data(). */
hard_ack = call->rx_hard_ack;
seq = hard_ack + 1;
while (top = smp_load_acquire(&call->rx_top),
before_eq(seq, top)
) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
skb = call->rxtx_buffer[ix];
if (!skb) {
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_hole, seq,
rx_pkt_offset, rx_pkt_len, 0);
break;
}
smp_rmb();
rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
sp = rxrpc_skb(skb);
if (!(flags & MSG_PEEK))
trace_rxrpc_receive(call, rxrpc_receive_front,
sp->hdr.serial, seq);
if (msg)
sock_recv_timestamp(msg, sock->sk, skb);
if (rx_pkt_offset == 0) {
ret2 = rxrpc_locate_data(call, skb,
&call->rxtx_annotations[ix],
&rx_pkt_offset, &rx_pkt_len);
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq,
rx_pkt_offset, rx_pkt_len, ret2);
if (ret2 < 0) {
ret = ret2;
goto out;
}
} else {
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq,
rx_pkt_offset, rx_pkt_len, 0);
}
/* We have to handle short, empty and used-up DATA packets. */
remain = len - *_offset;
copy = rx_pkt_len;
if (copy > remain)
copy = remain;
if (copy > 0) {
ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter,
copy);
if (ret2 < 0) {
ret = ret2;
goto out;
}
/* handle piecemeal consumption of data packets */
rx_pkt_offset += copy;
rx_pkt_len -= copy;
*_offset += copy;
}
if (rx_pkt_len > 0) {
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq,
rx_pkt_offset, rx_pkt_len, 0);
ASSERTCMP(*_offset, ==, len);
ret = 0;
break;
}
/* The whole packet has been transferred. */
last = sp->hdr.flags & RXRPC_LAST_PACKET;
if (!(flags & MSG_PEEK))
rxrpc_rotate_rx_window(call);
rx_pkt_offset = 0;
rx_pkt_len = 0;
if (last) {
ASSERTCMP(seq, ==, READ_ONCE(call->rx_top));
ret = 1;
goto out;
}
seq++;
}
out:
if (!(flags & MSG_PEEK)) {
call->rx_pkt_offset = rx_pkt_offset;
call->rx_pkt_len = rx_pkt_len;
}
done:
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_data_return, seq,
rx_pkt_offset, rx_pkt_len, ret);
if (ret == -EAGAIN)
set_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags);
return ret;
}
/*
* Receive a message from an RxRPC socket
* - we need to be careful about two or more threads calling recvmsg
* simultaneously
*/
int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
struct rxrpc_call *call;
struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
struct list_head *l;
size_t copied = 0;
long timeo;
int ret;
DEFINE_WAIT(wait);
trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0);
if (flags & (MSG_OOB | MSG_TRUNC))
return -EOPNOTSUPP;
timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
try_again:
lock_sock(&rx->sk);
/* Return immediately if a client socket has no outstanding calls */
if (RB_EMPTY_ROOT(&rx->calls) &&
list_empty(&rx->recvmsg_q) &&
rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
release_sock(&rx->sk);
return -ENODATA;
}
if (list_empty(&rx->recvmsg_q)) {
ret = -EWOULDBLOCK;
if (timeo == 0) {
call = NULL;
goto error_no_call;
}
release_sock(&rx->sk);
/* Wait for something to happen */
prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
TASK_INTERRUPTIBLE);
ret = sock_error(&rx->sk);
if (ret)
goto wait_error;
if (list_empty(&rx->recvmsg_q)) {
if (signal_pending(current))
goto wait_interrupted;
trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait,
0, 0, 0, 0);
timeo = schedule_timeout(timeo);
}
finish_wait(sk_sleep(&rx->sk), &wait);
goto try_again;
}
/* Find the next call and dequeue it if we're not just peeking. If we
* do dequeue it, that comes with a ref that we will need to release.
*/
write_lock_bh(&rx->recvmsg_lock);
l = rx->recvmsg_q.next;
call = list_entry(l, struct rxrpc_call, recvmsg_link);
if (!(flags & MSG_PEEK))
list_del_init(&call->recvmsg_link);
else
rxrpc_get_call(call, rxrpc_call_got);
write_unlock_bh(&rx->recvmsg_lock);
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0);
/* We're going to drop the socket lock, so we need to lock the call
* against interference by sendmsg.
*/
if (!mutex_trylock(&call->user_mutex)) {
ret = -EWOULDBLOCK;
if (flags & MSG_DONTWAIT)
goto error_requeue_call;
ret = -ERESTARTSYS;
if (mutex_lock_interruptible(&call->user_mutex) < 0)
goto error_requeue_call;
}
release_sock(&rx->sk);
if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
BUG();
if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
if (flags & MSG_CMSG_COMPAT) {
unsigned int id32 = call->user_call_ID;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
sizeof(unsigned int), &id32);
} else {
unsigned long idl = call->user_call_ID;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
sizeof(unsigned long), &idl);
}
if (ret < 0)
goto error_unlock_call;
}
if (msg->msg_name) {
struct sockaddr_rxrpc *srx = msg->msg_name;
size_t len = sizeof(call->peer->srx);
memcpy(msg->msg_name, &call->peer->srx, len);
srx->srx_service = call->service_id;
msg->msg_namelen = len;
}
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_SERVER_ACCEPTING:
ret = rxrpc_recvmsg_new_call(rx, call, msg, flags);
break;
case RXRPC_CALL_CLIENT_RECV_REPLY:
case RXRPC_CALL_SERVER_RECV_REQUEST:
case RXRPC_CALL_SERVER_ACK_REQUEST:
ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len,
flags, &copied);
if (ret == -EAGAIN)
ret = 0;
if (after(call->rx_top, call->rx_hard_ack) &&
call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK])
rxrpc_notify_socket(call);
break;
default:
ret = 0;
break;
}
if (ret < 0)
goto error_unlock_call;
if (call->state == RXRPC_CALL_COMPLETE) {
ret = rxrpc_recvmsg_term(call, msg);
if (ret < 0)
goto error_unlock_call;
if (!(flags & MSG_PEEK))
rxrpc_release_call(rx, call);
msg->msg_flags |= MSG_EOR;
ret = 1;
}
if (ret == 0)
msg->msg_flags |= MSG_MORE;
else
msg->msg_flags &= ~MSG_MORE;
ret = copied;
error_unlock_call:
mutex_unlock(&call->user_mutex);
rxrpc_put_call(call, rxrpc_call_put);
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret);
return ret;
error_requeue_call:
if (!(flags & MSG_PEEK)) {
write_lock_bh(&rx->recvmsg_lock);
list_add(&call->recvmsg_link, &rx->recvmsg_q);
write_unlock_bh(&rx->recvmsg_lock);
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0, 0, 0, 0);
} else {
rxrpc_put_call(call, rxrpc_call_put);
}
error_no_call:
release_sock(&rx->sk);
error_trace:
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret);
return ret;
wait_interrupted:
ret = sock_intr_errno(timeo);
wait_error:
finish_wait(sk_sleep(&rx->sk), &wait);
call = NULL;
goto error_trace;
}
/**
* rxrpc_kernel_recv_data - Allow a kernel service to receive data/info
* @sock: The socket that the call exists on
* @call: The call to send data through
* @iter: The buffer to receive into
* @want_more: True if more data is expected to be read
* @_abort: Where the abort code is stored if -ECONNABORTED is returned
* @_service: Where to store the actual service ID (may be upgraded)
*
* Allow a kernel service to receive data and pick up information about the
* state of a call. Returns 0 if got what was asked for and there's more
* available, 1 if we got what was asked for and we're at the end of the data
* and -EAGAIN if we need more data.
*
* Note that we may return -EAGAIN to drain empty packets at the end of the
* data, even if we've already copied over the requested data.
*
* *_abort should also be initialised to 0.
*/
int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
struct iov_iter *iter,
bool want_more, u32 *_abort, u16 *_service)
{
size_t offset = 0;
int ret;
_enter("{%d,%s},%zu,%d",
call->debug_id, rxrpc_call_states[call->state],
iov_iter_count(iter), want_more);
ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING);
mutex_lock(&call->user_mutex);
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_CLIENT_RECV_REPLY:
case RXRPC_CALL_SERVER_RECV_REQUEST:
case RXRPC_CALL_SERVER_ACK_REQUEST:
ret = rxrpc_recvmsg_data(sock, call, NULL, iter,
iov_iter_count(iter), 0,
&offset);
if (ret < 0)
goto out;
/* We can only reach here with a partially full buffer if we
* have reached the end of the data. We must otherwise have a
* full buffer or have been given -EAGAIN.
*/
if (ret == 1) {
if (iov_iter_count(iter) > 0)
goto short_data;
if (!want_more)
goto read_phase_complete;
ret = 0;
goto out;
}
if (!want_more)
goto excess_data;
goto out;
case RXRPC_CALL_COMPLETE:
goto call_complete;
default:
ret = -EINPROGRESS;
goto out;
}
read_phase_complete:
ret = 1;
out:
switch (call->ackr_reason) {
case RXRPC_ACK_IDLE:
break;
case RXRPC_ACK_DELAY:
if (ret != -EAGAIN)
break;
/* Fall through */
default:
rxrpc_send_ack_packet(call, false, NULL);
}
if (_service)
*_service = call->service_id;
mutex_unlock(&call->user_mutex);
_leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort);
return ret;
short_data:
trace_rxrpc_rx_eproto(call, 0, tracepoint_string("short_data"));
ret = -EBADMSG;
goto out;
excess_data:
trace_rxrpc_rx_eproto(call, 0, tracepoint_string("excess_data"));
ret = -EMSGSIZE;
goto out;
call_complete:
*_abort = call->abort_code;
ret = call->error;
if (call->completion == RXRPC_CALL_SUCCEEDED) {
ret = 1;
if (iov_iter_count(iter) > 0)
ret = -ECONNRESET;
}
goto out;
}
EXPORT_SYMBOL(rxrpc_kernel_recv_data);
/**
* rxrpc_kernel_get_reply_time - Get timestamp on first reply packet
* @sock: The socket that the call exists on
* @call: The call to query
* @_ts: Where to put the timestamp
*
* Retrieve the timestamp from the first DATA packet of the reply if it is
* in the ring. Returns true if successful, false if not.
*/
bool rxrpc_kernel_get_reply_time(struct socket *sock, struct rxrpc_call *call,
ktime_t *_ts)
{
struct sk_buff *skb;
rxrpc_seq_t hard_ack, top, seq;
bool success = false;
mutex_lock(&call->user_mutex);
if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_RECV_REPLY)
goto out;
hard_ack = call->rx_hard_ack;
if (hard_ack != 0)
goto out;
seq = hard_ack + 1;
top = smp_load_acquire(&call->rx_top);
if (after(seq, top))
goto out;
skb = call->rxtx_buffer[seq & RXRPC_RXTX_BUFF_MASK];
if (!skb)
goto out;
*_ts = skb_get_ktime(skb);
success = true;
out:
mutex_unlock(&call->user_mutex);
return success;
}
EXPORT_SYMBOL(rxrpc_kernel_get_reply_time);