tmp_suning_uos_patched/net/rxrpc/output.c
David Howells 4790963ef4 rxrpc: Fix decision on when to generate an IDLE ACK
[ Upstream commit 9a3dedcf18096e8f7f22b8777d78c4acfdea1651 ]

Fix the decision on when to generate an IDLE ACK by keeping a count of the
number of packets we've received, but not yet soft-ACK'd, and the number of
packets we've processed, but not yet hard-ACK'd, rather than trying to keep
track of which DATA sequence numbers correspond to those points.

We then generate an ACK when either counter exceeds 2.  The counters are
both cleared when we transcribe the information into any sort of ACK packet
for transmission.  IDLE and DELAY ACKs are skipped if both counters are 0
(ie. no change).

Fixes: 805b21b929 ("rxrpc: Send an ACK after every few DATA packets we receive")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:21:12 +02:00

680 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC packet transmission
*
* 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/gfp.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
struct rxrpc_ack_buffer {
struct rxrpc_wire_header whdr;
struct rxrpc_ackpacket ack;
u8 acks[255];
u8 pad[3];
struct rxrpc_ackinfo ackinfo;
};
struct rxrpc_abort_buffer {
struct rxrpc_wire_header whdr;
__be32 abort_code;
};
static const char rxrpc_keepalive_string[] = "";
/*
* Increase Tx backoff on transmission failure and clear it on success.
*/
static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
{
if (ret < 0) {
u16 tx_backoff = READ_ONCE(call->tx_backoff);
if (tx_backoff < HZ)
WRITE_ONCE(call->tx_backoff, tx_backoff + 1);
} else {
WRITE_ONCE(call->tx_backoff, 0);
}
}
/*
* Arrange for a keepalive ping a certain time after we last transmitted. This
* lets the far side know we're still interested in this call and helps keep
* the route through any intervening firewall open.
*
* Receiving a response to the ping will prevent the ->expect_rx_by timer from
* expiring.
*/
static void rxrpc_set_keepalive(struct rxrpc_call *call)
{
unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
keepalive_at += now;
WRITE_ONCE(call->keepalive_at, keepalive_at);
rxrpc_reduce_call_timer(call, keepalive_at, now,
rxrpc_timer_set_for_keepalive);
}
/*
* Fill out an ACK packet.
*/
static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
struct rxrpc_call *call,
struct rxrpc_ack_buffer *pkt,
rxrpc_seq_t *_hard_ack,
rxrpc_seq_t *_top,
u8 reason)
{
rxrpc_serial_t serial;
unsigned int tmp;
rxrpc_seq_t hard_ack, top, seq;
int ix;
u32 mtu, jmax;
u8 *ackp = pkt->acks;
tmp = atomic_xchg(&call->ackr_nr_unacked, 0);
tmp |= atomic_xchg(&call->ackr_nr_consumed, 0);
if (!tmp && (reason == RXRPC_ACK_DELAY ||
reason == RXRPC_ACK_IDLE))
return 0;
/* Barrier against rxrpc_input_data(). */
serial = call->ackr_serial;
hard_ack = READ_ONCE(call->rx_hard_ack);
top = smp_load_acquire(&call->rx_top);
*_hard_ack = hard_ack;
*_top = top;
pkt->ack.bufferSpace = htons(8);
pkt->ack.maxSkew = htons(0);
pkt->ack.firstPacket = htonl(hard_ack + 1);
pkt->ack.previousPacket = htonl(call->ackr_highest_seq);
pkt->ack.serial = htonl(serial);
pkt->ack.reason = reason;
pkt->ack.nAcks = top - hard_ack;
if (reason == RXRPC_ACK_PING)
pkt->whdr.flags |= RXRPC_REQUEST_ACK;
if (after(top, hard_ack)) {
seq = hard_ack + 1;
do {
ix = seq & RXRPC_RXTX_BUFF_MASK;
if (call->rxtx_buffer[ix])
*ackp++ = RXRPC_ACK_TYPE_ACK;
else
*ackp++ = RXRPC_ACK_TYPE_NACK;
seq++;
} while (before_eq(seq, top));
}
mtu = conn->params.peer->if_mtu;
mtu -= conn->params.peer->hdrsize;
jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
pkt->ackinfo.maxMTU = htonl(mtu);
pkt->ackinfo.rwind = htonl(call->rx_winsize);
pkt->ackinfo.jumbo_max = htonl(jmax);
*ackp++ = 0;
*ackp++ = 0;
*ackp++ = 0;
return top - hard_ack + 3;
}
/*
* Record the beginning of an RTT probe.
*/
static int rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
enum rxrpc_rtt_tx_trace why)
{
unsigned long avail = call->rtt_avail;
int rtt_slot = 9;
if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
goto no_slot;
rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
goto no_slot;
call->rtt_serial[rtt_slot] = serial;
call->rtt_sent_at[rtt_slot] = ktime_get_real();
smp_wmb(); /* Write data before avail bit */
set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
return rtt_slot;
no_slot:
trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
return -1;
}
/*
* Cancel an RTT probe.
*/
static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call,
rxrpc_serial_t serial, int rtt_slot)
{
if (rtt_slot != -1) {
clear_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
smp_wmb(); /* Clear pending bit before setting slot */
set_bit(rtt_slot, &call->rtt_avail);
trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_cancel, rtt_slot, serial);
}
}
/*
* Send an ACK call packet.
*/
int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
rxrpc_serial_t *_serial)
{
struct rxrpc_connection *conn;
struct rxrpc_ack_buffer *pkt;
struct msghdr msg;
struct kvec iov[2];
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top;
size_t len, n;
int ret, rtt_slot = -1;
u8 reason;
if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
return -ECONNRESET;
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
conn = call->conn;
msg.msg_name = &call->peer->srx.transport;
msg.msg_namelen = call->peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
pkt->whdr.epoch = htonl(conn->proto.epoch);
pkt->whdr.cid = htonl(call->cid);
pkt->whdr.callNumber = htonl(call->call_id);
pkt->whdr.seq = 0;
pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
pkt->whdr.userStatus = 0;
pkt->whdr.securityIndex = call->security_ix;
pkt->whdr._rsvd = 0;
pkt->whdr.serviceId = htons(call->service_id);
spin_lock_bh(&call->lock);
if (ping) {
reason = RXRPC_ACK_PING;
} else {
reason = call->ackr_reason;
if (!call->ackr_reason) {
spin_unlock_bh(&call->lock);
ret = 0;
goto out;
}
call->ackr_reason = 0;
}
n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
spin_unlock_bh(&call->lock);
if (n == 0) {
kfree(pkt);
return 0;
}
iov[0].iov_base = pkt;
iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
iov[1].iov_base = &pkt->ackinfo;
iov[1].iov_len = sizeof(pkt->ackinfo);
len = iov[0].iov_len + iov[1].iov_len;
serial = atomic_inc_return(&conn->serial);
pkt->whdr.serial = htonl(serial);
trace_rxrpc_tx_ack(call->debug_id, serial,
ntohl(pkt->ack.firstPacket),
ntohl(pkt->ack.serial),
pkt->ack.reason, pkt->ack.nAcks);
if (_serial)
*_serial = serial;
if (ping)
rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping);
ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
conn->params.peer->last_tx_at = ktime_get_seconds();
if (ret < 0)
trace_rxrpc_tx_fail(call->debug_id, serial, ret,
rxrpc_tx_point_call_ack);
else
trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
rxrpc_tx_point_call_ack);
rxrpc_tx_backoff(call, ret);
if (call->state < RXRPC_CALL_COMPLETE) {
if (ret < 0) {
rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
rxrpc_propose_ACK(call, pkt->ack.reason,
ntohl(pkt->ack.serial),
false, true,
rxrpc_propose_ack_retry_tx);
}
rxrpc_set_keepalive(call);
}
out:
kfree(pkt);
return ret;
}
/*
* Send an ABORT call packet.
*/
int rxrpc_send_abort_packet(struct rxrpc_call *call)
{
struct rxrpc_connection *conn;
struct rxrpc_abort_buffer pkt;
struct msghdr msg;
struct kvec iov[1];
rxrpc_serial_t serial;
int ret;
/* Don't bother sending aborts for a client call once the server has
* hard-ACK'd all of its request data. After that point, we're not
* going to stop the operation proceeding, and whilst we might limit
* the reply, it's not worth it if we can send a new call on the same
* channel instead, thereby closing off this call.
*/
if (rxrpc_is_client_call(call) &&
test_bit(RXRPC_CALL_TX_LAST, &call->flags))
return 0;
if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
return -ECONNRESET;
conn = call->conn;
msg.msg_name = &call->peer->srx.transport;
msg.msg_namelen = call->peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
pkt.whdr.epoch = htonl(conn->proto.epoch);
pkt.whdr.cid = htonl(call->cid);
pkt.whdr.callNumber = htonl(call->call_id);
pkt.whdr.seq = 0;
pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
pkt.whdr.flags = conn->out_clientflag;
pkt.whdr.userStatus = 0;
pkt.whdr.securityIndex = call->security_ix;
pkt.whdr._rsvd = 0;
pkt.whdr.serviceId = htons(call->service_id);
pkt.abort_code = htonl(call->abort_code);
iov[0].iov_base = &pkt;
iov[0].iov_len = sizeof(pkt);
serial = atomic_inc_return(&conn->serial);
pkt.whdr.serial = htonl(serial);
ret = kernel_sendmsg(conn->params.local->socket,
&msg, iov, 1, sizeof(pkt));
conn->params.peer->last_tx_at = ktime_get_seconds();
if (ret < 0)
trace_rxrpc_tx_fail(call->debug_id, serial, ret,
rxrpc_tx_point_call_abort);
else
trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
rxrpc_tx_point_call_abort);
rxrpc_tx_backoff(call, ret);
return ret;
}
/*
* send a packet through the transport endpoint
*/
int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
bool retrans)
{
struct rxrpc_connection *conn = call->conn;
struct rxrpc_wire_header whdr;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct msghdr msg;
struct kvec iov[2];
rxrpc_serial_t serial;
size_t len;
int ret, rtt_slot = -1;
_enter(",{%d}", skb->len);
if (hlist_unhashed(&call->error_link)) {
spin_lock_bh(&call->peer->lock);
hlist_add_head_rcu(&call->error_link, &call->peer->error_targets);
spin_unlock_bh(&call->peer->lock);
}
/* Each transmission of a Tx packet needs a new serial number */
serial = atomic_inc_return(&conn->serial);
whdr.epoch = htonl(conn->proto.epoch);
whdr.cid = htonl(call->cid);
whdr.callNumber = htonl(call->call_id);
whdr.seq = htonl(sp->hdr.seq);
whdr.serial = htonl(serial);
whdr.type = RXRPC_PACKET_TYPE_DATA;
whdr.flags = sp->hdr.flags;
whdr.userStatus = 0;
whdr.securityIndex = call->security_ix;
whdr._rsvd = htons(sp->hdr._rsvd);
whdr.serviceId = htons(call->service_id);
if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
sp->hdr.seq == 1)
whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
iov[0].iov_base = &whdr;
iov[0].iov_len = sizeof(whdr);
iov[1].iov_base = skb->head;
iov[1].iov_len = skb->len;
len = iov[0].iov_len + iov[1].iov_len;
msg.msg_name = &call->peer->srx.transport;
msg.msg_namelen = call->peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
/* If our RTT cache needs working on, request an ACK. Also request
* ACKs if a DATA packet appears to have been lost.
*
* However, we mustn't request an ACK on the last reply packet of a
* service call, lest OpenAFS incorrectly send us an ACK with some
* soft-ACKs in it and then never follow up with a proper hard ACK.
*/
if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) ||
rxrpc_to_server(sp)
) &&
(test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
retrans ||
call->cong_mode == RXRPC_CALL_SLOW_START ||
(call->peer->rtt_count < 3 && sp->hdr.seq & 1) ||
ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
ktime_get_real())))
whdr.flags |= RXRPC_REQUEST_ACK;
if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
static int lose;
if ((lose++ & 7) == 7) {
ret = 0;
trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
whdr.flags, retrans, true);
goto done;
}
}
trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans,
false);
/* send the packet with the don't fragment bit set if we currently
* think it's small enough */
if (iov[1].iov_len >= call->peer->maxdata)
goto send_fragmentable;
down_read(&conn->params.local->defrag_sem);
sp->hdr.serial = serial;
smp_wmb(); /* Set serial before timestamp */
skb->tstamp = ktime_get_real();
if (whdr.flags & RXRPC_REQUEST_ACK)
rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
/* send the packet by UDP
* - returns -EMSGSIZE if UDP would have to fragment the packet
* to go out of the interface
* - in which case, we'll have processed the ICMP error
* message and update the peer record
*/
ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
conn->params.peer->last_tx_at = ktime_get_seconds();
up_read(&conn->params.local->defrag_sem);
if (ret < 0) {
rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
trace_rxrpc_tx_fail(call->debug_id, serial, ret,
rxrpc_tx_point_call_data_nofrag);
} else {
trace_rxrpc_tx_packet(call->debug_id, &whdr,
rxrpc_tx_point_call_data_nofrag);
}
rxrpc_tx_backoff(call, ret);
if (ret == -EMSGSIZE)
goto send_fragmentable;
done:
if (ret >= 0) {
if (whdr.flags & RXRPC_REQUEST_ACK) {
call->peer->rtt_last_req = skb->tstamp;
if (call->peer->rtt_count > 1) {
unsigned long nowj = jiffies, ack_lost_at;
ack_lost_at = rxrpc_get_rto_backoff(call->peer, false);
ack_lost_at += nowj;
WRITE_ONCE(call->ack_lost_at, ack_lost_at);
rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
rxrpc_timer_set_for_lost_ack);
}
}
if (sp->hdr.seq == 1 &&
!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
&call->flags)) {
unsigned long nowj = jiffies, expect_rx_by;
expect_rx_by = nowj + call->next_rx_timo;
WRITE_ONCE(call->expect_rx_by, expect_rx_by);
rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
rxrpc_timer_set_for_normal);
}
rxrpc_set_keepalive(call);
} else {
/* Cancel the call if the initial transmission fails,
* particularly if that's due to network routing issues that
* aren't going away anytime soon. The layer above can arrange
* the retransmission.
*/
if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
RX_USER_ABORT, ret);
}
_leave(" = %d [%u]", ret, call->peer->maxdata);
return ret;
send_fragmentable:
/* attempt to send this message with fragmentation enabled */
_debug("send fragment");
down_write(&conn->params.local->defrag_sem);
sp->hdr.serial = serial;
smp_wmb(); /* Set serial before timestamp */
skb->tstamp = ktime_get_real();
if (whdr.flags & RXRPC_REQUEST_ACK)
rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
switch (conn->params.local->srx.transport.family) {
case AF_INET6:
case AF_INET:
ip_sock_set_mtu_discover(conn->params.local->socket->sk,
IP_PMTUDISC_DONT);
ret = kernel_sendmsg(conn->params.local->socket, &msg,
iov, 2, len);
conn->params.peer->last_tx_at = ktime_get_seconds();
ip_sock_set_mtu_discover(conn->params.local->socket->sk,
IP_PMTUDISC_DO);
break;
default:
BUG();
}
if (ret < 0) {
rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
trace_rxrpc_tx_fail(call->debug_id, serial, ret,
rxrpc_tx_point_call_data_frag);
} else {
trace_rxrpc_tx_packet(call->debug_id, &whdr,
rxrpc_tx_point_call_data_frag);
}
rxrpc_tx_backoff(call, ret);
up_write(&conn->params.local->defrag_sem);
goto done;
}
/*
* reject packets through the local endpoint
*/
void rxrpc_reject_packets(struct rxrpc_local *local)
{
struct sockaddr_rxrpc srx;
struct rxrpc_skb_priv *sp;
struct rxrpc_wire_header whdr;
struct sk_buff *skb;
struct msghdr msg;
struct kvec iov[2];
size_t size;
__be32 code;
int ret, ioc;
_enter("%d", local->debug_id);
iov[0].iov_base = &whdr;
iov[0].iov_len = sizeof(whdr);
iov[1].iov_base = &code;
iov[1].iov_len = sizeof(code);
msg.msg_name = &srx.transport;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
memset(&whdr, 0, sizeof(whdr));
while ((skb = skb_dequeue(&local->reject_queue))) {
rxrpc_see_skb(skb, rxrpc_skb_seen);
sp = rxrpc_skb(skb);
switch (skb->mark) {
case RXRPC_SKB_MARK_REJECT_BUSY:
whdr.type = RXRPC_PACKET_TYPE_BUSY;
size = sizeof(whdr);
ioc = 1;
break;
case RXRPC_SKB_MARK_REJECT_ABORT:
whdr.type = RXRPC_PACKET_TYPE_ABORT;
code = htonl(skb->priority);
size = sizeof(whdr) + sizeof(code);
ioc = 2;
break;
default:
rxrpc_free_skb(skb, rxrpc_skb_freed);
continue;
}
if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
msg.msg_namelen = srx.transport_len;
whdr.epoch = htonl(sp->hdr.epoch);
whdr.cid = htonl(sp->hdr.cid);
whdr.callNumber = htonl(sp->hdr.callNumber);
whdr.serviceId = htons(sp->hdr.serviceId);
whdr.flags = sp->hdr.flags;
whdr.flags ^= RXRPC_CLIENT_INITIATED;
whdr.flags &= RXRPC_CLIENT_INITIATED;
ret = kernel_sendmsg(local->socket, &msg,
iov, ioc, size);
if (ret < 0)
trace_rxrpc_tx_fail(local->debug_id, 0, ret,
rxrpc_tx_point_reject);
else
trace_rxrpc_tx_packet(local->debug_id, &whdr,
rxrpc_tx_point_reject);
}
rxrpc_free_skb(skb, rxrpc_skb_freed);
}
_leave("");
}
/*
* Send a VERSION reply to a peer as a keepalive.
*/
void rxrpc_send_keepalive(struct rxrpc_peer *peer)
{
struct rxrpc_wire_header whdr;
struct msghdr msg;
struct kvec iov[2];
size_t len;
int ret;
_enter("");
msg.msg_name = &peer->srx.transport;
msg.msg_namelen = peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
whdr.epoch = htonl(peer->local->rxnet->epoch);
whdr.cid = 0;
whdr.callNumber = 0;
whdr.seq = 0;
whdr.serial = 0;
whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
whdr.flags = RXRPC_LAST_PACKET;
whdr.userStatus = 0;
whdr.securityIndex = 0;
whdr._rsvd = 0;
whdr.serviceId = 0;
iov[0].iov_base = &whdr;
iov[0].iov_len = sizeof(whdr);
iov[1].iov_base = (char *)rxrpc_keepalive_string;
iov[1].iov_len = sizeof(rxrpc_keepalive_string);
len = iov[0].iov_len + iov[1].iov_len;
_proto("Tx VERSION (keepalive)");
ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
if (ret < 0)
trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
rxrpc_tx_point_version_keepalive);
else
trace_rxrpc_tx_packet(peer->debug_id, &whdr,
rxrpc_tx_point_version_keepalive);
peer->last_tx_at = ktime_get_seconds();
_leave("");
}