linux-brain/net/tipc/sysctl.c

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/*
* net/tipc/sysctl.c: sysctl interface to TIPC subsystem
*
* Copyright (c) 2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
tipc: add trace_events for tipc socket The commit adds the new trace_events for TIPC socket object: trace_tipc_sk_create() trace_tipc_sk_poll() trace_tipc_sk_sendmsg() trace_tipc_sk_sendmcast() trace_tipc_sk_sendstream() trace_tipc_sk_filter_rcv() trace_tipc_sk_advance_rx() trace_tipc_sk_rej_msg() trace_tipc_sk_drop_msg() trace_tipc_sk_release() trace_tipc_sk_shutdown() trace_tipc_sk_overlimit1() trace_tipc_sk_overlimit2() Also, enables the traces for the following cases: - When user creates a TIPC socket; - When user calls poll() on TIPC socket; - When user sends a dgram/mcast/stream message. - When a message is put into the socket 'sk_receive_queue'; - When a message is released from the socket 'sk_receive_queue'; - When a message is rejected (e.g. due to no port, invalid, etc.); - When a message is dropped (e.g. due to wrong message type); - When socket is released; - When socket is shutdown; - When socket rcvq's allocation is overlimit (> 90%); - When socket rcvq + bklq's allocation is overlimit (> 90%); - When the 'TIPC_ERR_OVERLOAD/2' issue happens; Note: a) All the socket traces are designed to be able to trace on a specific socket by either using the 'event filtering' feature on a known socket 'portid' value or the sysctl file: /proc/sys/net/tipc/sk_filter The file determines a 'tuple' for what socket should be traced: (portid, sock type, name type, name lower, name upper) where: + 'portid' is the socket portid generated at socket creating, can be found in the trace outputs or the 'tipc socket list' command printouts; + 'sock type' is the socket type (1 = SOCK_TREAM, ...); + 'name type', 'name lower' and 'name upper' are the service name being connected to or published by the socket. Value '0' means 'ANY', the default tuple value is (0, 0, 0, 0, 0) i.e. the traces happen for every sockets with no filter. b) The 'tipc_sk_overlimit1/2' event is also a conditional trace_event which happens when the socket receive queue (and backlog queue) is about to be overloaded, when the queue allocation is > 90%. Then, when the trace is enabled, the last skbs leading to the TIPC_ERR_OVERLOAD/2 issue can be traced. The trace event is designed as an 'upper watermark' notification that the other traces (e.g. 'tipc_sk_advance_rx' vs 'tipc_sk_filter_rcv') or actions can be triggerred in the meanwhile to see what is going on with the socket queue. In addition, the 'trace_tipc_sk_dump()' is also placed at the 'TIPC_ERR_OVERLOAD/2' case, so the socket and last skb can be dumped for post-analysis. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:17:58 +09:00
#include "trace.h"
#include <linux/sysctl.h>
static struct ctl_table_header *tipc_ctl_hdr;
static struct ctl_table tipc_table[] = {
{
.procname = "tipc_rmem",
.data = &sysctl_tipc_rmem,
.maxlen = sizeof(sysctl_tipc_rmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
proc/sysctl: add shared variables for range check In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-19 07:58:50 +09:00
.extra1 = SYSCTL_ONE,
},
tipc: add name distributor resiliency queue TIPC name table updates are distributed asynchronously in a cluster, entailing a risk of certain race conditions. E.g., if two nodes simultaneously issue conflicting (overlapping) publications, this may not be detected until both publications have reached a third node, in which case one of the publications will be silently dropped on that node. Hence, we end up with an inconsistent name table. In most cases this conflict is just a temporary race, e.g., one node is issuing a publication under the assumption that a previous, conflicting, publication has already been withdrawn by the other node. However, because of the (rtt related) distributed update delay, this may not yet hold true on all nodes. The symptom of this failure is a syslog message: "tipc: Cannot publish {%u,%u,%u}, overlap error". In this commit we add a resiliency queue at the receiving end of the name table distributor. When insertion of an arriving publication fails, we retain it in this queue for a short amount of time, assuming that another update will arrive very soon and clear the conflict. If so happens, we insert the publication, otherwise we drop it. The (configurable) retention value defaults to 2000 ms. Knowing from experience that the situation described above is extremely rare, there is no risk that the queue will accumulate any large number of items. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-28 16:08:47 +09:00
{
.procname = "named_timeout",
.data = &sysctl_tipc_named_timeout,
.maxlen = sizeof(sysctl_tipc_named_timeout),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
proc/sysctl: add shared variables for range check In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-19 07:58:50 +09:00
.extra1 = SYSCTL_ZERO,
tipc: add name distributor resiliency queue TIPC name table updates are distributed asynchronously in a cluster, entailing a risk of certain race conditions. E.g., if two nodes simultaneously issue conflicting (overlapping) publications, this may not be detected until both publications have reached a third node, in which case one of the publications will be silently dropped on that node. Hence, we end up with an inconsistent name table. In most cases this conflict is just a temporary race, e.g., one node is issuing a publication under the assumption that a previous, conflicting, publication has already been withdrawn by the other node. However, because of the (rtt related) distributed update delay, this may not yet hold true on all nodes. The symptom of this failure is a syslog message: "tipc: Cannot publish {%u,%u,%u}, overlap error". In this commit we add a resiliency queue at the receiving end of the name table distributor. When insertion of an arriving publication fails, we retain it in this queue for a short amount of time, assuming that another update will arrive very soon and clear the conflict. If so happens, we insert the publication, otherwise we drop it. The (configurable) retention value defaults to 2000 ms. Knowing from experience that the situation described above is extremely rare, there is no risk that the queue will accumulate any large number of items. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-28 16:08:47 +09:00
},
tipc: add trace_events for tipc socket The commit adds the new trace_events for TIPC socket object: trace_tipc_sk_create() trace_tipc_sk_poll() trace_tipc_sk_sendmsg() trace_tipc_sk_sendmcast() trace_tipc_sk_sendstream() trace_tipc_sk_filter_rcv() trace_tipc_sk_advance_rx() trace_tipc_sk_rej_msg() trace_tipc_sk_drop_msg() trace_tipc_sk_release() trace_tipc_sk_shutdown() trace_tipc_sk_overlimit1() trace_tipc_sk_overlimit2() Also, enables the traces for the following cases: - When user creates a TIPC socket; - When user calls poll() on TIPC socket; - When user sends a dgram/mcast/stream message. - When a message is put into the socket 'sk_receive_queue'; - When a message is released from the socket 'sk_receive_queue'; - When a message is rejected (e.g. due to no port, invalid, etc.); - When a message is dropped (e.g. due to wrong message type); - When socket is released; - When socket is shutdown; - When socket rcvq's allocation is overlimit (> 90%); - When socket rcvq + bklq's allocation is overlimit (> 90%); - When the 'TIPC_ERR_OVERLOAD/2' issue happens; Note: a) All the socket traces are designed to be able to trace on a specific socket by either using the 'event filtering' feature on a known socket 'portid' value or the sysctl file: /proc/sys/net/tipc/sk_filter The file determines a 'tuple' for what socket should be traced: (portid, sock type, name type, name lower, name upper) where: + 'portid' is the socket portid generated at socket creating, can be found in the trace outputs or the 'tipc socket list' command printouts; + 'sock type' is the socket type (1 = SOCK_TREAM, ...); + 'name type', 'name lower' and 'name upper' are the service name being connected to or published by the socket. Value '0' means 'ANY', the default tuple value is (0, 0, 0, 0, 0) i.e. the traces happen for every sockets with no filter. b) The 'tipc_sk_overlimit1/2' event is also a conditional trace_event which happens when the socket receive queue (and backlog queue) is about to be overloaded, when the queue allocation is > 90%. Then, when the trace is enabled, the last skbs leading to the TIPC_ERR_OVERLOAD/2 issue can be traced. The trace event is designed as an 'upper watermark' notification that the other traces (e.g. 'tipc_sk_advance_rx' vs 'tipc_sk_filter_rcv') or actions can be triggerred in the meanwhile to see what is going on with the socket queue. In addition, the 'trace_tipc_sk_dump()' is also placed at the 'TIPC_ERR_OVERLOAD/2' case, so the socket and last skb can be dumped for post-analysis. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:17:58 +09:00
{
.procname = "sk_filter",
.data = &sysctl_tipc_sk_filter,
.maxlen = sizeof(sysctl_tipc_sk_filter),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{}
};
int tipc_register_sysctl(void)
{
tipc_ctl_hdr = register_net_sysctl(&init_net, "net/tipc", tipc_table);
if (tipc_ctl_hdr == NULL)
return -ENOMEM;
return 0;
}
void tipc_unregister_sysctl(void)
{
unregister_net_sysctl_table(tipc_ctl_hdr);
}