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809fa972fd
linux/drivers/net/bonding/bond_netlink.c
Hannes Frederic Sowa 809fa972fd reciprocal_divide: update/correction of the algorithm 
Jakub Zawadzki noticed that some divisions by reciprocal_divide()
were not correct [1][2], which he could also show with BPF code
after divisions are transformed into reciprocal_value() for runtime
invariance which can be passed to reciprocal_divide() later on;
reverse in BPF dump ended up with a different, off-by-one K in
some situations.

This has been fixed by Eric Dumazet in commit aee636c480
("bpf: do not use reciprocal divide"). This follow-up patch
improves reciprocal_value() and reciprocal_divide() to work in
all cases by using Granlund and Montgomery method, so that also
future use is safe and without any non-obvious side-effects.
Known problems with the old implementation were that division by 1
always returned 0 and some off-by-ones when the dividend and divisor
where very large. This seemed to not be problematic with its
current users, as far as we can tell. Eric Dumazet checked for
the slab usage, we cannot surely say so in the case of flex_array.
Still, in order to fix that, we propose an extension from the
original implementation from commit 6a2d7a955d resp. [3][4],
by using the algorithm proposed in "Division by Invariant Integers
Using Multiplication" [5], Torbjörn Granlund and Peter L.
Montgomery, that is, pseudocode for q = n/d where q, n, d is in
u32 universe:

1) Initialization:

  int l = ceil(log_2 d)
  uword m' = floor((1<<32)*((1<<l)-d)/d)+1
  int sh_1 = min(l,1)
  int sh_2 = max(l-1,0)

2) For q = n/d, all uword:

  uword t = (n*m')>>32
  q = (t+((n-t)>>sh_1))>>sh_2

The assembler implementation from Agner Fog [6] also helped a lot
while implementing. We have tested the implementation on x86_64,
ppc64, i686, s390x; on x86_64/haswell we're still half the latency
compared to normal divide.

Joint work with Daniel Borkmann.

  [1] http://www.wireshark.org/~darkjames/reciprocal-buggy.c
  [2] http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c
  [3] https://gmplib.org/~tege/division-paper.pdf
  [4] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html
  [5] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1.2556
  [6] http://www.agner.org/optimize/asmlib.zip

Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Jesse Gross <jesse@nicira.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21 23:17:20 -08:00

530 lines
14 KiB
C
Raw Blame History

/*
* drivers/net/bond/bond_netlink.c - Netlink interface for bonding
* Copyright (c) 2013 Jiri Pirko <jiri@resnulli.us>
* Copyright (c) 2013 Scott Feldman <sfeldma@cumulusnetworks.com>
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_link.h>
#include <linux/if_ether.h>
#include <net/netlink.h>
#include <net/rtnetlink.h>
#include "bonding.h"
int bond_get_slave(struct net_device *slave_dev, struct sk_buff *skb)
{
struct slave *slave = bond_slave_get_rtnl(slave_dev);
const struct aggregator *agg;
if (nla_put_u8(skb, IFLA_SLAVE_STATE, bond_slave_state(slave)))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_SLAVE_MII_STATUS, slave->link))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_SLAVE_LINK_FAILURE_COUNT,
slave->link_failure_count))
goto nla_put_failure;
if (nla_put(skb, IFLA_SLAVE_PERM_HWADDR,
slave_dev->addr_len, slave->perm_hwaddr))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_SLAVE_QUEUE_ID, slave->queue_id))
goto nla_put_failure;
if (slave->bond->params.mode == BOND_MODE_8023AD) {
agg = SLAVE_AD_INFO(slave).port.aggregator;
if (agg)
if (nla_put_u16(skb, IFLA_SLAVE_AD_AGGREGATOR_ID,
agg->aggregator_identifier))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static const struct nla_policy bond_policy[IFLA_BOND_MAX + 1] = {
[IFLA_BOND_MODE] = { .type = NLA_U8 },
[IFLA_BOND_ACTIVE_SLAVE] = { .type = NLA_U32 },
[IFLA_BOND_MIIMON] = { .type = NLA_U32 },
[IFLA_BOND_UPDELAY] = { .type = NLA_U32 },
[IFLA_BOND_DOWNDELAY] = { .type = NLA_U32 },
[IFLA_BOND_USE_CARRIER] = { .type = NLA_U8 },
[IFLA_BOND_ARP_INTERVAL] = { .type = NLA_U32 },
[IFLA_BOND_ARP_IP_TARGET] = { .type = NLA_NESTED },
[IFLA_BOND_ARP_VALIDATE] = { .type = NLA_U32 },
[IFLA_BOND_ARP_ALL_TARGETS] = { .type = NLA_U32 },
[IFLA_BOND_PRIMARY] = { .type = NLA_U32 },
[IFLA_BOND_PRIMARY_RESELECT] = { .type = NLA_U8 },
[IFLA_BOND_FAIL_OVER_MAC] = { .type = NLA_U8 },
[IFLA_BOND_XMIT_HASH_POLICY] = { .type = NLA_U8 },
[IFLA_BOND_RESEND_IGMP] = { .type = NLA_U32 },
[IFLA_BOND_NUM_PEER_NOTIF] = { .type = NLA_U8 },
[IFLA_BOND_ALL_SLAVES_ACTIVE] = { .type = NLA_U8 },
[IFLA_BOND_MIN_LINKS] = { .type = NLA_U32 },
[IFLA_BOND_LP_INTERVAL] = { .type = NLA_U32 },
[IFLA_BOND_PACKETS_PER_SLAVE] = { .type = NLA_U32 },
[IFLA_BOND_AD_LACP_RATE] = { .type = NLA_U8 },
[IFLA_BOND_AD_SELECT] = { .type = NLA_U8 },
[IFLA_BOND_AD_INFO] = { .type = NLA_NESTED },
};
static int bond_validate(struct nlattr *tb[], struct nlattr *data[])
{
if (tb[IFLA_ADDRESS]) {
if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
return -EINVAL;
if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
return -EADDRNOTAVAIL;
}
return 0;
}
static int bond_changelink(struct net_device *bond_dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct bonding *bond = netdev_priv(bond_dev);
int miimon = 0;
int err;
if (!data)
return 0;
if (data[IFLA_BOND_MODE]) {
int mode = nla_get_u8(data[IFLA_BOND_MODE]);
err = bond_option_mode_set(bond, mode);
if (err)
return err;
}
if (data[IFLA_BOND_ACTIVE_SLAVE]) {
int ifindex = nla_get_u32(data[IFLA_BOND_ACTIVE_SLAVE]);
struct net_device *slave_dev;
if (ifindex == 0) {
slave_dev = NULL;
} else {
slave_dev = __dev_get_by_index(dev_net(bond_dev),
ifindex);
if (!slave_dev)
return -ENODEV;
}
err = bond_option_active_slave_set(bond, slave_dev);
if (err)
return err;
}
if (data[IFLA_BOND_MIIMON]) {
miimon = nla_get_u32(data[IFLA_BOND_MIIMON]);
err = bond_option_miimon_set(bond, miimon);
if (err)
return err;
}
if (data[IFLA_BOND_UPDELAY]) {
int updelay = nla_get_u32(data[IFLA_BOND_UPDELAY]);
err = bond_option_updelay_set(bond, updelay);
if (err)
return err;
}
if (data[IFLA_BOND_DOWNDELAY]) {
int downdelay = nla_get_u32(data[IFLA_BOND_DOWNDELAY]);
err = bond_option_downdelay_set(bond, downdelay);
if (err)
return err;
}
if (data[IFLA_BOND_USE_CARRIER]) {
int use_carrier = nla_get_u8(data[IFLA_BOND_USE_CARRIER]);
err = bond_option_use_carrier_set(bond, use_carrier);
if (err)
return err;
}
if (data[IFLA_BOND_ARP_INTERVAL]) {
int arp_interval = nla_get_u32(data[IFLA_BOND_ARP_INTERVAL]);
if (arp_interval && miimon) {
pr_err("%s: ARP monitoring cannot be used with MII monitoring.\n",
bond->dev->name);
return -EINVAL;
}
err = bond_option_arp_interval_set(bond, arp_interval);
if (err)
return err;
}
if (data[IFLA_BOND_ARP_IP_TARGET]) {
__be32 targets[BOND_MAX_ARP_TARGETS] = { 0, };
struct nlattr *attr;
int i = 0, rem;
nla_for_each_nested(attr, data[IFLA_BOND_ARP_IP_TARGET], rem) {
__be32 target = nla_get_be32(attr);
targets[i++] = target;
}
err = bond_option_arp_ip_targets_set(bond, targets, i);
if (err)
return err;
}
if (data[IFLA_BOND_ARP_VALIDATE]) {
int arp_validate = nla_get_u32(data[IFLA_BOND_ARP_VALIDATE]);
if (arp_validate && miimon) {
pr_err("%s: ARP validating cannot be used with MII monitoring.\n",
bond->dev->name);
return -EINVAL;
}
err = bond_option_arp_validate_set(bond, arp_validate);
if (err)
return err;
}
if (data[IFLA_BOND_ARP_ALL_TARGETS]) {
int arp_all_targets =
nla_get_u32(data[IFLA_BOND_ARP_ALL_TARGETS]);
err = bond_option_arp_all_targets_set(bond, arp_all_targets);
if (err)
return err;
}
if (data[IFLA_BOND_PRIMARY]) {
int ifindex = nla_get_u32(data[IFLA_BOND_PRIMARY]);
struct net_device *dev;
char *primary = "";
dev = __dev_get_by_index(dev_net(bond_dev), ifindex);
if (dev)
primary = dev->name;
err = bond_option_primary_set(bond, primary);
if (err)
return err;
}
if (data[IFLA_BOND_PRIMARY_RESELECT]) {
int primary_reselect =
nla_get_u8(data[IFLA_BOND_PRIMARY_RESELECT]);
err = bond_option_primary_reselect_set(bond, primary_reselect);
if (err)
return err;
}
if (data[IFLA_BOND_FAIL_OVER_MAC]) {
int fail_over_mac =
nla_get_u8(data[IFLA_BOND_FAIL_OVER_MAC]);
err = bond_option_fail_over_mac_set(bond, fail_over_mac);
if (err)
return err;
}
if (data[IFLA_BOND_XMIT_HASH_POLICY]) {
int xmit_hash_policy =
nla_get_u8(data[IFLA_BOND_XMIT_HASH_POLICY]);
err = bond_option_xmit_hash_policy_set(bond, xmit_hash_policy);
if (err)
return err;
}
if (data[IFLA_BOND_RESEND_IGMP]) {
int resend_igmp =
nla_get_u32(data[IFLA_BOND_RESEND_IGMP]);
err = bond_option_resend_igmp_set(bond, resend_igmp);
if (err)
return err;
}
if (data[IFLA_BOND_NUM_PEER_NOTIF]) {
int num_peer_notif =
nla_get_u8(data[IFLA_BOND_NUM_PEER_NOTIF]);
err = bond_option_num_peer_notif_set(bond, num_peer_notif);
if (err)
return err;
}
if (data[IFLA_BOND_ALL_SLAVES_ACTIVE]) {
int all_slaves_active =
nla_get_u8(data[IFLA_BOND_ALL_SLAVES_ACTIVE]);
err = bond_option_all_slaves_active_set(bond,
all_slaves_active);
if (err)
return err;
}
if (data[IFLA_BOND_MIN_LINKS]) {
int min_links =
nla_get_u32(data[IFLA_BOND_MIN_LINKS]);
err = bond_option_min_links_set(bond, min_links);
if (err)
return err;
}
if (data[IFLA_BOND_LP_INTERVAL]) {
int lp_interval =
nla_get_u32(data[IFLA_BOND_LP_INTERVAL]);
err = bond_option_lp_interval_set(bond, lp_interval);
if (err)
return err;
}
if (data[IFLA_BOND_PACKETS_PER_SLAVE]) {
int packets_per_slave =
nla_get_u32(data[IFLA_BOND_PACKETS_PER_SLAVE]);
err = bond_option_packets_per_slave_set(bond,
packets_per_slave);
if (err)
return err;
}
if (data[IFLA_BOND_AD_LACP_RATE]) {
int lacp_rate =
nla_get_u8(data[IFLA_BOND_AD_LACP_RATE]);
err = bond_option_lacp_rate_set(bond, lacp_rate);
if (err)
return err;
}
if (data[IFLA_BOND_AD_SELECT]) {
int ad_select =
nla_get_u8(data[IFLA_BOND_AD_SELECT]);
err = bond_option_ad_select_set(bond, ad_select);
if (err)
return err;
}
return 0;
}
static int bond_newlink(struct net *src_net, struct net_device *bond_dev,
struct nlattr *tb[], struct nlattr *data[])
{
int err;
err = bond_changelink(bond_dev, tb, data);
if (err < 0)
return err;
return register_netdevice(bond_dev);
}
static size_t bond_get_size(const struct net_device *bond_dev)
{
return nla_total_size(sizeof(u8)) + /* IFLA_BOND_MODE */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_ACTIVE_SLAVE */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_MIIMON */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_UPDELAY */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_DOWNDELAY */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_USE_CARRIER */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_ARP_INTERVAL */
/* IFLA_BOND_ARP_IP_TARGET */
nla_total_size(sizeof(struct nlattr)) +
nla_total_size(sizeof(u32)) * BOND_MAX_ARP_TARGETS +
nla_total_size(sizeof(u32)) + /* IFLA_BOND_ARP_VALIDATE */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_ARP_ALL_TARGETS */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_PRIMARY */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_PRIMARY_RESELECT */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_FAIL_OVER_MAC */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_XMIT_HASH_POLICY */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_RESEND_IGMP */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_NUM_PEER_NOTIF */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_ALL_SLAVES_ACTIVE */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_MIN_LINKS */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_LP_INTERVAL */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_PACKETS_PER_SLAVE */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_AD_LACP_RATE */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_AD_SELECT */
nla_total_size(sizeof(struct nlattr)) + /* IFLA_BOND_AD_INFO */
nla_total_size(sizeof(u16)) + /* IFLA_BOND_AD_INFO_AGGREGATOR */
nla_total_size(sizeof(u16)) + /* IFLA_BOND_AD_INFO_NUM_PORTS */
nla_total_size(sizeof(u16)) + /* IFLA_BOND_AD_INFO_ACTOR_KEY */
nla_total_size(sizeof(u16)) + /* IFLA_BOND_AD_INFO_PARTNER_KEY*/
nla_total_size(ETH_ALEN) + /* IFLA_BOND_AD_INFO_PARTNER_MAC*/
0;
}
static int bond_fill_info(struct sk_buff *skb,
const struct net_device *bond_dev)
{
struct bonding *bond = netdev_priv(bond_dev);
struct net_device *slave_dev = bond_option_active_slave_get(bond);
struct nlattr *targets;
unsigned int packets_per_slave;
int i, targets_added;
if (nla_put_u8(skb, IFLA_BOND_MODE, bond->params.mode))
goto nla_put_failure;
if (slave_dev &&
nla_put_u32(skb, IFLA_BOND_ACTIVE_SLAVE, slave_dev->ifindex))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_MIIMON, bond->params.miimon))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_UPDELAY,
bond->params.updelay * bond->params.miimon))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_DOWNDELAY,
bond->params.downdelay * bond->params.miimon))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_USE_CARRIER, bond->params.use_carrier))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_ARP_INTERVAL, bond->params.arp_interval))
goto nla_put_failure;
targets = nla_nest_start(skb, IFLA_BOND_ARP_IP_TARGET);
if (!targets)
goto nla_put_failure;
targets_added = 0;
for (i = 0; i < BOND_MAX_ARP_TARGETS; i++) {
if (bond->params.arp_targets[i]) {
nla_put_be32(skb, i, bond->params.arp_targets[i]);
targets_added = 1;
}
}
if (targets_added)
nla_nest_end(skb, targets);
else
nla_nest_cancel(skb, targets);
if (nla_put_u32(skb, IFLA_BOND_ARP_VALIDATE, bond->params.arp_validate))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_ARP_ALL_TARGETS,
bond->params.arp_all_targets))
goto nla_put_failure;
if (bond->primary_slave &&
nla_put_u32(skb, IFLA_BOND_PRIMARY,
bond->primary_slave->dev->ifindex))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_PRIMARY_RESELECT,
bond->params.primary_reselect))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_FAIL_OVER_MAC,
bond->params.fail_over_mac))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_XMIT_HASH_POLICY,
bond->params.xmit_policy))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_RESEND_IGMP,
bond->params.resend_igmp))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_NUM_PEER_NOTIF,
bond->params.num_peer_notif))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_ALL_SLAVES_ACTIVE,
bond->params.all_slaves_active))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_MIN_LINKS,
bond->params.min_links))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_LP_INTERVAL,
bond->params.lp_interval))
goto nla_put_failure;
packets_per_slave = bond->params.packets_per_slave;
if (nla_put_u32(skb, IFLA_BOND_PACKETS_PER_SLAVE,
packets_per_slave))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_AD_LACP_RATE,
bond->params.lacp_fast))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_AD_SELECT,
bond->params.ad_select))
goto nla_put_failure;
if (bond->params.mode == BOND_MODE_8023AD) {
struct ad_info info;
if (!bond_3ad_get_active_agg_info(bond, &info)) {
struct nlattr *nest;
nest = nla_nest_start(skb, IFLA_BOND_AD_INFO);
if (!nest)
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BOND_AD_INFO_AGGREGATOR,
info.aggregator_id))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BOND_AD_INFO_NUM_PORTS,
info.ports))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BOND_AD_INFO_ACTOR_KEY,
info.actor_key))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BOND_AD_INFO_PARTNER_KEY,
info.partner_key))
goto nla_put_failure;
if (nla_put(skb, IFLA_BOND_AD_INFO_PARTNER_MAC,
sizeof(info.partner_system),
&info.partner_system))
goto nla_put_failure;
nla_nest_end(skb, nest);
}
}
return 0;
nla_put_failure:
return -EMSGSIZE;
}
struct rtnl_link_ops bond_link_ops __read_mostly = {
.kind = "bond",
.priv_size = sizeof(struct bonding),
.setup = bond_setup,
.maxtype = IFLA_BOND_MAX,
.policy = bond_policy,
.validate = bond_validate,
.newlink = bond_newlink,
.changelink = bond_changelink,
.get_size = bond_get_size,
.fill_info = bond_fill_info,
.get_num_tx_queues = bond_get_num_tx_queues,
.get_num_rx_queues = bond_get_num_tx_queues, /* Use the same number
as for TX queues */
};
int __init bond_netlink_init(void)
{
return rtnl_link_register(&bond_link_ops);
}
void bond_netlink_fini(void)
{
rtnl_link_unregister(&bond_link_ops);
}
MODULE_ALIAS_RTNL_LINK("bond");
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