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af_rxrpc: Add sysctls for configuring RxRPC parameters

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Add sysctls for configuring RxRPC protocol handling, specifically controls on
delays before ack generation, the delay before resending a packet, the maximum
lifetime of a call and the expiration times of calls, connections and
transports that haven't been recently used.

More info added in Documentation/networking/rxrpc.txt.

Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Howells 2014-02-07 18:58:44 +00:00
parent 6c9a2d3202
commit 5873c0834f
12 changed files with 273 additions and 27 deletions
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62
Documentation/networking/rxrpc.txt
View File

@ -27,6 +27,8 @@ Contents of this document:
(*) AF_RXRPC kernel interface.
(*) Configurable parameters.
========
OVERVIEW
@ -864,3 +866,63 @@ The kernel interface functions are as follows:
This is used to allocate a null RxRPC key that can be used to indicate
anonymous security for a particular domain.
=======================
CONFIGURABLE PARAMETERS
=======================
The RxRPC protocol driver has a number of configurable parameters that can be
adjusted through sysctls in /proc/net/rxrpc/:
(*) req_ack_delay
The amount of time in milliseconds after receiving a packet with the
request-ack flag set before we honour the flag and actually send the
requested ack.
Usually the other side won't stop sending packets until the advertised
reception window is full (to a maximum of 255 packets), so delaying the
ACK permits several packets to be ACK'd in one go.
(*) soft_ack_delay
The amount of time in milliseconds after receiving a new packet before we
generate a soft-ACK to tell the sender that it doesn't need to resend.
(*) idle_ack_delay
The amount of time in milliseconds after all the packets currently in the
received queue have been consumed before we generate a hard-ACK to tell
the sender it can free its buffers, assuming no other reason occurs that
we would send an ACK.
(*) resend_timeout
The amount of time in milliseconds after transmitting a packet before we
transmit it again, assuming no ACK is received from the receiver telling
us they got it.
(*) max_call_lifetime
The maximum amount of time in seconds that a call may be in progress
before we preemptively kill it.
(*) dead_call_expiry
The amount of time in seconds before we remove a dead call from the call
list. Dead calls are kept around for a little while for the purpose of
repeating ACK and ABORT packets.
(*) connection_expiry
The amount of time in seconds after a connection was last used before we
remove it from the connection list. Whilst a connection is in existence,
it serves as a placeholder for negotiated security; when it is deleted,
the security must be renegotiated.
(*) transport_expiry
The amount of time in seconds after a transport was last used before we
remove it from the transport list. Whilst a transport is in existence, it
serves to anchor the peer data and keeps the connection ID counter.

5
net/rxrpc/Makefile
View File

@ -20,9 +20,8 @@ af-rxrpc-y := \
ar-skbuff.o \
ar-transport.o
ifeq ($(CONFIG_PROC_FS),y)
af-rxrpc-y += ar-proc.o
endif
af-rxrpc-$(CONFIG_PROC_FS) += ar-proc.o
af-rxrpc-$(CONFIG_SYSCTL) += sysctl.o
obj-$(CONFIG_AF_RXRPC) += af-rxrpc.o

9
net/rxrpc/af_rxrpc.c
View File

@ -838,6 +838,12 @@ static int __init af_rxrpc_init(void)
goto error_key_type_s;
}
ret = rxrpc_sysctl_init();
if (ret < 0) {
printk(KERN_CRIT "RxRPC: Cannot register sysctls\n");
goto error_sysctls;
}
#ifdef CONFIG_PROC_FS
proc_create("rxrpc_calls", 0, init_net.proc_net, &rxrpc_call_seq_fops);
proc_create("rxrpc_conns", 0, init_net.proc_net,
@ -845,6 +851,8 @@ static int __init af_rxrpc_init(void)
#endif
return 0;
error_sysctls:
unregister_key_type(&key_type_rxrpc_s);
error_key_type_s:
unregister_key_type(&key_type_rxrpc);
error_key_type:
@ -865,6 +873,7 @@ error_call_jar:
static void __exit af_rxrpc_exit(void)
{
_enter("");
rxrpc_sysctl_exit();
unregister_key_type(&key_type_rxrpc_s);
unregister_key_type(&key_type_rxrpc);
sock_unregister(PF_RXRPC);

35
net/rxrpc/ar-ack.c
View File

@ -19,7 +19,29 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"
static unsigned int rxrpc_ack_defer = 1;
/*
* How long to wait before scheduling ACK generation after seeing a
* packet with RXRPC_REQUEST_ACK set (in jiffies).
*/
unsigned rxrpc_requested_ack_delay = 1;
/*
* How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
*
* We use this when we've received new data packets. If those packets aren't
* all consumed within this time we will send a DELAY ACK if an ACK was not
* requested to let the sender know it doesn't need to resend.
*/
unsigned rxrpc_soft_ack_delay = 1 * HZ;
/*
* How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
*
* We use this when we've consumed some previously soft-ACK'd packets when
* further packets aren't immediately received to decide when to send an IDLE
* ACK let the other end know that it can free up its Tx buffer space.
*/
unsigned rxrpc_idle_ack_delay = 1;
static const char *rxrpc_acks(u8 reason)
{
@ -82,24 +104,23 @@ void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
switch (ack_reason) {
case RXRPC_ACK_DELAY:
_debug("run delay timer");
call->ack_timer.expires = jiffies + rxrpc_ack_timeout * HZ;
add_timer(&call->ack_timer);
return;
expiry = rxrpc_soft_ack_delay;
goto run_timer;
case RXRPC_ACK_IDLE:
if (!immediate) {
_debug("run defer timer");
expiry = 1;
expiry = rxrpc_idle_ack_delay;
goto run_timer;
}
goto cancel_timer;
case RXRPC_ACK_REQUESTED:
if (!rxrpc_ack_defer)
expiry = rxrpc_requested_ack_delay;
if (!expiry)
goto cancel_timer;
if (!immediate || serial == cpu_to_be32(1)) {
_debug("run defer timer");
expiry = rxrpc_ack_defer;
goto run_timer;
}

18
net/rxrpc/ar-call.c
View File

@ -16,6 +16,16 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Maximum lifetime of a call (in jiffies).
*/
unsigned rxrpc_max_call_lifetime = 60 * HZ;
/*
* Time till dead call expires after last use (in jiffies).
*/
unsigned rxrpc_dead_call_expiry = 2 * HZ;
const char *const rxrpc_call_states[] = {
[RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq",
[RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl",
@ -38,8 +48,6 @@ const char *const rxrpc_call_states[] = {
struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);
static unsigned int rxrpc_call_max_lifetime = 60;
static unsigned int rxrpc_dead_call_timeout = 2;
static void rxrpc_destroy_call(struct work_struct *work);
static void rxrpc_call_life_expired(unsigned long _call);
@ -132,7 +140,7 @@ static struct rxrpc_call *rxrpc_alloc_client_call(
list_add(&call->error_link, &call->conn->trans->peer->error_targets);
spin_unlock(&call->conn->trans->peer->lock);
call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
add_timer(&call->lifetimer);
_leave(" = %p", call);
@ -349,7 +357,7 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
add_timer(&call->lifetimer);
_leave(" = %p {%d} [new]", call, call->debug_id);
return call;
@ -533,7 +541,7 @@ void rxrpc_release_call(struct rxrpc_call *call)
del_timer_sync(&call->resend_timer);
del_timer_sync(&call->ack_timer);
del_timer_sync(&call->lifetimer);
call->deadspan.expires = jiffies + rxrpc_dead_call_timeout * HZ;
call->deadspan.expires = jiffies + rxrpc_dead_call_expiry;
add_timer(&call->deadspan);
_leave("");

10
net/rxrpc/ar-connection.c
View File

@ -18,11 +18,15 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Time till a connection expires after last use (in seconds).
*/
unsigned rxrpc_connection_expiry = 10 * 60;
static void rxrpc_connection_reaper(struct work_struct *work);
LIST_HEAD(rxrpc_connections);
DEFINE_RWLOCK(rxrpc_connection_lock);
static unsigned long rxrpc_connection_timeout = 10 * 60;
static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
/*
@ -862,7 +866,7 @@ static void rxrpc_connection_reaper(struct work_struct *work)
spin_lock(&conn->trans->client_lock);
write_lock(&conn->trans->conn_lock);
reap_time = conn->put_time + rxrpc_connection_timeout;
reap_time = conn->put_time + rxrpc_connection_expiry;
if (atomic_read(&conn->usage) > 0) {
;
@ -916,7 +920,7 @@ void __exit rxrpc_destroy_all_connections(void)
{
_enter("");
rxrpc_connection_timeout = 0;
rxrpc_connection_expiry = 0;
cancel_delayed_work(&rxrpc_connection_reap);
rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);

2
net/rxrpc/ar-input.c
View File

@ -25,8 +25,6 @@
#include <net/net_namespace.h>
#include "ar-internal.h"
unsigned long rxrpc_ack_timeout = 1;
const char *rxrpc_pkts[] = {
"?00",
"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",

24
net/rxrpc/ar-internal.h
View File

@ -433,6 +433,10 @@ int rxrpc_reject_call(struct rxrpc_sock *);
/*
* ar-ack.c
*/
extern unsigned rxrpc_requested_ack_delay;
extern unsigned rxrpc_soft_ack_delay;
extern unsigned rxrpc_idle_ack_delay;
void __rxrpc_propose_ACK(struct rxrpc_call *, u8, __be32, bool);
void rxrpc_propose_ACK(struct rxrpc_call *, u8, __be32, bool);
void rxrpc_process_call(struct work_struct *);
@ -440,6 +444,8 @@ void rxrpc_process_call(struct work_struct *);
/*
* ar-call.c
*/
extern unsigned rxrpc_max_call_lifetime;
extern unsigned rxrpc_dead_call_expiry;
extern struct kmem_cache *rxrpc_call_jar;
extern struct list_head rxrpc_calls;
extern rwlock_t rxrpc_call_lock;
@ -460,6 +466,7 @@ void __exit rxrpc_destroy_all_calls(void);
/*
* ar-connection.c
*/
extern unsigned rxrpc_connection_expiry;
extern struct list_head rxrpc_connections;
extern rwlock_t rxrpc_connection_lock;
@ -493,7 +500,6 @@ void rxrpc_UDP_error_handler(struct work_struct *);
/*
* ar-input.c
*/
extern unsigned long rxrpc_ack_timeout;
extern const char *rxrpc_pkts[];
void rxrpc_data_ready(struct sock *, int);
@ -504,6 +510,7 @@ void rxrpc_fast_process_packet(struct rxrpc_call *, struct sk_buff *);
* ar-local.c
*/
extern rwlock_t rxrpc_local_lock;
struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *);
void rxrpc_put_local(struct rxrpc_local *);
void __exit rxrpc_destroy_all_locals(void);
@ -522,7 +529,7 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *, const void *, time_t,
/*
* ar-output.c
*/
extern int rxrpc_resend_timeout;
extern unsigned rxrpc_resend_timeout;
int rxrpc_send_packet(struct rxrpc_transport *, struct sk_buff *);
int rxrpc_client_sendmsg(struct kiocb *, struct rxrpc_sock *,
@ -572,6 +579,8 @@ void rxrpc_packet_destructor(struct sk_buff *);
/*
* ar-transport.c
*/
extern unsigned rxrpc_transport_expiry;
struct rxrpc_transport *rxrpc_get_transport(struct rxrpc_local *,
struct rxrpc_peer *, gfp_t);
void rxrpc_put_transport(struct rxrpc_transport *);
@ -579,6 +588,17 @@ void __exit rxrpc_destroy_all_transports(void);
struct rxrpc_transport *rxrpc_find_transport(struct rxrpc_local *,
struct rxrpc_peer *);
/*
* sysctl.c
*/
#ifdef CONFIG_SYSCTL
extern int __init rxrpc_sysctl_init(void);
extern void rxrpc_sysctl_exit(void);
#else
static inline int __init rxrpc_sysctl_init(void) { return 0; }
static inline void rxrpc_sysctl_exit(void) {}
#endif
/*
* debug tracing
*/

7
net/rxrpc/ar-output.c
View File

@ -18,7 +18,10 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"
int rxrpc_resend_timeout = 4;
/*
* Time till packet resend (in jiffies).
*/
unsigned rxrpc_resend_timeout = 4 * HZ;
static int rxrpc_send_data(struct kiocb *iocb,
struct rxrpc_sock *rx,
@ -487,7 +490,7 @@ static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
sp->need_resend = false;
sp->resend_at = jiffies + rxrpc_resend_timeout * HZ;
sp->resend_at = jiffies + rxrpc_resend_timeout;
if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
_debug("run timer");
call->resend_timer.expires = sp->resend_at;

5
net/rxrpc/ar-skbuff.c
View File

@ -83,6 +83,11 @@ static void rxrpc_hard_ACK_data(struct rxrpc_call *call,
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,
true);

10
net/rxrpc/ar-transport.c
View File

@ -17,11 +17,15 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Time after last use at which transport record is cleaned up.
*/
unsigned rxrpc_transport_expiry = 3600 * 24;
static void rxrpc_transport_reaper(struct work_struct *work);
static LIST_HEAD(rxrpc_transports);
static DEFINE_RWLOCK(rxrpc_transport_lock);
static unsigned long rxrpc_transport_timeout = 3600 * 24;
static DECLARE_DELAYED_WORK(rxrpc_transport_reap, rxrpc_transport_reaper);
/*
@ -235,7 +239,7 @@ static void rxrpc_transport_reaper(struct work_struct *work)
if (likely(atomic_read(&trans->usage) > 0))
continue;
reap_time = trans->put_time + rxrpc_transport_timeout;
reap_time = trans->put_time + rxrpc_transport_expiry;
if (reap_time <= now)
list_move_tail(&trans->link, &graveyard);
else if (reap_time < earliest)
@ -271,7 +275,7 @@ void __exit rxrpc_destroy_all_transports(void)
{
_enter("");
rxrpc_transport_timeout = 0;
rxrpc_transport_expiry = 0;
cancel_delayed_work(&rxrpc_transport_reap);
rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0);

113
net/rxrpc/sysctl.c Normal file
View File

@ -0,0 +1,113 @@
/* sysctls for configuring RxRPC operating parameters
*
* Copyright (C) 2014 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 Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/sysctl.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
static struct ctl_table_header *rxrpc_sysctl_reg_table;
static const unsigned zero = 0;
static const unsigned one = 1;
/*
* RxRPC operating parameters.
*
* See Documentation/networking/rxrpc.txt and the variable definitions for more
* information on the individual parameters.
*/
static struct ctl_table rxrpc_sysctl_table[] = {
/* Values measured in milliseconds */
{
.procname = "req_ack_delay",
.data = &rxrpc_requested_ack_delay,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
.extra1 = (void *)&zero,
},
{
.procname = "soft_ack_delay",
.data = &rxrpc_soft_ack_delay,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
.extra1 = (void *)&one,
},
{
.procname = "idle_ack_delay",
.data = &rxrpc_idle_ack_delay,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
.extra1 = (void *)&one,
},
{
.procname = "resend_timeout",
.data = &rxrpc_resend_timeout,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
.extra1 = (void *)&one,
},
/* Values measured in seconds but used in jiffies */
{
.procname = "max_call_lifetime",
.data = &rxrpc_max_call_lifetime,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
.extra1 = (void *)&one,
},
{
.procname = "dead_call_expiry",
.data = &rxrpc_dead_call_expiry,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
.extra1 = (void *)&one,
},
/* Values measured in seconds */
{
.procname = "connection_expiry",
.data = &rxrpc_connection_expiry,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = (void *)&one,
},
{
.procname = "transport_expiry",
.data = &rxrpc_transport_expiry,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = (void *)&one,
},
{ }
};
int __init rxrpc_sysctl_init(void)
{
rxrpc_sysctl_reg_table = register_net_sysctl(&init_net, "net/rxrpc",
rxrpc_sysctl_table);
if (!rxrpc_sysctl_reg_table)
return -ENOMEM;
return 0;
}
void rxrpc_sysctl_exit(void)
{
if (rxrpc_sysctl_reg_table)
unregister_net_sysctl_table(rxrpc_sysctl_reg_table);
}