From 5873c0834f8896aa9da338b941035a2f8b29e99b Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 7 Feb 2014 18:58:44 +0000 Subject: [PATCH] af_rxrpc: Add sysctls for configuring RxRPC parameters 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 --- Documentation/networking/rxrpc.txt | 62 ++++++++++++++++ net/rxrpc/Makefile | 5 +- net/rxrpc/af_rxrpc.c | 9 +++ net/rxrpc/ar-ack.c | 35 +++++++-- net/rxrpc/ar-call.c | 18 +++-- net/rxrpc/ar-connection.c | 10 ++- net/rxrpc/ar-input.c | 2 - net/rxrpc/ar-internal.h | 24 +++++- net/rxrpc/ar-output.c | 7 +- net/rxrpc/ar-skbuff.c | 5 ++ net/rxrpc/ar-transport.c | 10 ++- net/rxrpc/sysctl.c | 113 +++++++++++++++++++++++++++++ 12 files changed, 273 insertions(+), 27 deletions(-) create mode 100644 net/rxrpc/sysctl.c diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt index b89bc82eed46..aa08d2625f05 100644 --- a/Documentation/networking/rxrpc.txt +++ b/Documentation/networking/rxrpc.txt @@ -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. diff --git a/net/rxrpc/Makefile b/net/rxrpc/Makefile index d1c3429b69ed..ec126f91276b 100644 --- a/net/rxrpc/Makefile +++ b/net/rxrpc/Makefile @@ -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 diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index e61aa6001c65..7b1670489638 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -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); diff --git a/net/rxrpc/ar-ack.c b/net/rxrpc/ar-ack.c index cd97a0ce48d8..732b82f540c5 100644 --- a/net/rxrpc/ar-ack.c +++ b/net/rxrpc/ar-ack.c @@ -19,7 +19,29 @@ #include #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; } diff --git a/net/rxrpc/ar-call.c b/net/rxrpc/ar-call.c index a3bbb360a3f9..1e0903a2a0db 100644 --- a/net/rxrpc/ar-call.c +++ b/net/rxrpc/ar-call.c @@ -16,6 +16,16 @@ #include #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(""); diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c index 7bf5b5b9e8b9..6631f4f1e39b 100644 --- a/net/rxrpc/ar-connection.c +++ b/net/rxrpc/ar-connection.c @@ -18,11 +18,15 @@ #include #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); diff --git a/net/rxrpc/ar-input.c b/net/rxrpc/ar-input.c index eb7e16276cc1..540c03d338c9 100644 --- a/net/rxrpc/ar-input.c +++ b/net/rxrpc/ar-input.c @@ -25,8 +25,6 @@ #include #include "ar-internal.h" -unsigned long rxrpc_ack_timeout = 1; - const char *rxrpc_pkts[] = { "?00", "DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG", diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 5f43675ee1df..036e1dd84223 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -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 */ diff --git a/net/rxrpc/ar-output.c b/net/rxrpc/ar-output.c index d0e8f1c1898a..4814d882bcb4 100644 --- a/net/rxrpc/ar-output.c +++ b/net/rxrpc/ar-output.c @@ -18,7 +18,10 @@ #include #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; diff --git a/net/rxrpc/ar-skbuff.c b/net/rxrpc/ar-skbuff.c index de755e04d29c..af9f4fd2a365 100644 --- a/net/rxrpc/ar-skbuff.c +++ b/net/rxrpc/ar-skbuff.c @@ -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); diff --git a/net/rxrpc/ar-transport.c b/net/rxrpc/ar-transport.c index 92df566930b9..1976dec84f29 100644 --- a/net/rxrpc/ar-transport.c +++ b/net/rxrpc/ar-transport.c @@ -17,11 +17,15 @@ #include #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); diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c new file mode 100644 index 000000000000..cdc85e72af5d --- /dev/null +++ b/net/rxrpc/sysctl.c @@ -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 +#include +#include +#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); +} -- 2.30.2