kernel-fxtec-pro1x/drivers/net/bonding/bond_netlink.c
Nikolay Aleksandrov 059b47e8aa bonding: convert primary_slave to use RCU
This is necessary mainly for two bonding call sites: procfs and
sysfs as it was dereferenced without any real protection.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 17:31:35 -07:00

614 lines
18 KiB
C

/*
* 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.
*/
#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"
static size_t bond_get_slave_size(const struct net_device *bond_dev,
const struct net_device *slave_dev)
{
return nla_total_size(sizeof(u8)) + /* IFLA_BOND_SLAVE_STATE */
nla_total_size(sizeof(u8)) + /* IFLA_BOND_SLAVE_MII_STATUS */
nla_total_size(sizeof(u32)) + /* IFLA_BOND_SLAVE_LINK_FAILURE_COUNT */
nla_total_size(MAX_ADDR_LEN) + /* IFLA_BOND_SLAVE_PERM_HWADDR */
nla_total_size(sizeof(u16)) + /* IFLA_BOND_SLAVE_QUEUE_ID */
nla_total_size(sizeof(u16)) + /* IFLA_BOND_SLAVE_AD_AGGREGATOR_ID */
0;
}
static int bond_fill_slave_info(struct sk_buff *skb,
const struct net_device *bond_dev,
const struct net_device *slave_dev)
{
struct slave *slave = bond_slave_get_rtnl(slave_dev);
if (nla_put_u8(skb, IFLA_BOND_SLAVE_STATE, bond_slave_state(slave)))
goto nla_put_failure;
if (nla_put_u8(skb, IFLA_BOND_SLAVE_MII_STATUS, slave->link))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_SLAVE_LINK_FAILURE_COUNT,
slave->link_failure_count))
goto nla_put_failure;
if (nla_put(skb, IFLA_BOND_SLAVE_PERM_HWADDR,
slave_dev->addr_len, slave->perm_hwaddr))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BOND_SLAVE_QUEUE_ID, slave->queue_id))
goto nla_put_failure;
if (BOND_MODE(slave->bond) == BOND_MODE_8023AD) {
const struct aggregator *agg;
agg = SLAVE_AD_INFO(slave)->port.aggregator;
if (agg)
if (nla_put_u16(skb, IFLA_BOND_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 const struct nla_policy bond_slave_policy[IFLA_BOND_SLAVE_MAX + 1] = {
[IFLA_BOND_SLAVE_QUEUE_ID] = { .type = NLA_U16 },
};
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_slave_changelink(struct net_device *bond_dev,
struct net_device *slave_dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct bonding *bond = netdev_priv(bond_dev);
struct bond_opt_value newval;
int err;
if (!data)
return 0;
if (data[IFLA_BOND_SLAVE_QUEUE_ID]) {
u16 queue_id = nla_get_u16(data[IFLA_BOND_SLAVE_QUEUE_ID]);
char queue_id_str[IFNAMSIZ + 7];
/* queue_id option setting expects slave_name:queue_id */
snprintf(queue_id_str, sizeof(queue_id_str), "%s:%u\n",
slave_dev->name, queue_id);
bond_opt_initstr(&newval, queue_id_str);
err = __bond_opt_set(bond, BOND_OPT_QUEUE_ID, &newval);
if (err)
return err;
}
return 0;
}
static int bond_changelink(struct net_device *bond_dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct bonding *bond = netdev_priv(bond_dev);
struct bond_opt_value newval;
int miimon = 0;
int err;
if (!data)
return 0;
if (data[IFLA_BOND_MODE]) {
int mode = nla_get_u8(data[IFLA_BOND_MODE]);
bond_opt_initval(&newval, mode);
err = __bond_opt_set(bond, BOND_OPT_MODE, &newval);
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;
char *active_slave = "";
if (ifindex != 0) {
slave_dev = __dev_get_by_index(dev_net(bond_dev),
ifindex);
if (!slave_dev)
return -ENODEV;
active_slave = slave_dev->name;
}
bond_opt_initstr(&newval, active_slave);
err = __bond_opt_set(bond, BOND_OPT_ACTIVE_SLAVE, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_MIIMON]) {
miimon = nla_get_u32(data[IFLA_BOND_MIIMON]);
bond_opt_initval(&newval, miimon);
err = __bond_opt_set(bond, BOND_OPT_MIIMON, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_UPDELAY]) {
int updelay = nla_get_u32(data[IFLA_BOND_UPDELAY]);
bond_opt_initval(&newval, updelay);
err = __bond_opt_set(bond, BOND_OPT_UPDELAY, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_DOWNDELAY]) {
int downdelay = nla_get_u32(data[IFLA_BOND_DOWNDELAY]);
bond_opt_initval(&newval, downdelay);
err = __bond_opt_set(bond, BOND_OPT_DOWNDELAY, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_USE_CARRIER]) {
int use_carrier = nla_get_u8(data[IFLA_BOND_USE_CARRIER]);
bond_opt_initval(&newval, use_carrier);
err = __bond_opt_set(bond, BOND_OPT_USE_CARRIER, &newval);
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) {
netdev_err(bond->dev, "ARP monitoring cannot be used with MII monitoring\n");
return -EINVAL;
}
bond_opt_initval(&newval, arp_interval);
err = __bond_opt_set(bond, BOND_OPT_ARP_INTERVAL, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_ARP_IP_TARGET]) {
struct nlattr *attr;
int i = 0, rem;
bond_option_arp_ip_targets_clear(bond);
nla_for_each_nested(attr, data[IFLA_BOND_ARP_IP_TARGET], rem) {
__be32 target = nla_get_be32(attr);
bond_opt_initval(&newval, (__force u64)target);
err = __bond_opt_set(bond, BOND_OPT_ARP_TARGETS,
&newval);
if (err)
break;
i++;
}
if (i == 0 && bond->params.arp_interval)
netdev_warn(bond->dev, "Removing last arp target with arp_interval on\n");
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) {
netdev_err(bond->dev, "ARP validating cannot be used with MII monitoring\n");
return -EINVAL;
}
bond_opt_initval(&newval, arp_validate);
err = __bond_opt_set(bond, BOND_OPT_ARP_VALIDATE, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_ARP_ALL_TARGETS]) {
int arp_all_targets =
nla_get_u32(data[IFLA_BOND_ARP_ALL_TARGETS]);
bond_opt_initval(&newval, arp_all_targets);
err = __bond_opt_set(bond, BOND_OPT_ARP_ALL_TARGETS, &newval);
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;
bond_opt_initstr(&newval, primary);
err = __bond_opt_set(bond, BOND_OPT_PRIMARY, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_PRIMARY_RESELECT]) {
int primary_reselect =
nla_get_u8(data[IFLA_BOND_PRIMARY_RESELECT]);
bond_opt_initval(&newval, primary_reselect);
err = __bond_opt_set(bond, BOND_OPT_PRIMARY_RESELECT, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_FAIL_OVER_MAC]) {
int fail_over_mac =
nla_get_u8(data[IFLA_BOND_FAIL_OVER_MAC]);
bond_opt_initval(&newval, fail_over_mac);
err = __bond_opt_set(bond, BOND_OPT_FAIL_OVER_MAC, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_XMIT_HASH_POLICY]) {
int xmit_hash_policy =
nla_get_u8(data[IFLA_BOND_XMIT_HASH_POLICY]);
bond_opt_initval(&newval, xmit_hash_policy);
err = __bond_opt_set(bond, BOND_OPT_XMIT_HASH, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_RESEND_IGMP]) {
int resend_igmp =
nla_get_u32(data[IFLA_BOND_RESEND_IGMP]);
bond_opt_initval(&newval, resend_igmp);
err = __bond_opt_set(bond, BOND_OPT_RESEND_IGMP, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_NUM_PEER_NOTIF]) {
int num_peer_notif =
nla_get_u8(data[IFLA_BOND_NUM_PEER_NOTIF]);
bond_opt_initval(&newval, num_peer_notif);
err = __bond_opt_set(bond, BOND_OPT_NUM_PEER_NOTIF, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_ALL_SLAVES_ACTIVE]) {
int all_slaves_active =
nla_get_u8(data[IFLA_BOND_ALL_SLAVES_ACTIVE]);
bond_opt_initval(&newval, all_slaves_active);
err = __bond_opt_set(bond, BOND_OPT_ALL_SLAVES_ACTIVE, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_MIN_LINKS]) {
int min_links =
nla_get_u32(data[IFLA_BOND_MIN_LINKS]);
bond_opt_initval(&newval, min_links);
err = __bond_opt_set(bond, BOND_OPT_MINLINKS, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_LP_INTERVAL]) {
int lp_interval =
nla_get_u32(data[IFLA_BOND_LP_INTERVAL]);
bond_opt_initval(&newval, lp_interval);
err = __bond_opt_set(bond, BOND_OPT_LP_INTERVAL, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_PACKETS_PER_SLAVE]) {
int packets_per_slave =
nla_get_u32(data[IFLA_BOND_PACKETS_PER_SLAVE]);
bond_opt_initval(&newval, packets_per_slave);
err = __bond_opt_set(bond, BOND_OPT_PACKETS_PER_SLAVE, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_AD_LACP_RATE]) {
int lacp_rate =
nla_get_u8(data[IFLA_BOND_AD_LACP_RATE]);
bond_opt_initval(&newval, lacp_rate);
err = __bond_opt_set(bond, BOND_OPT_LACP_RATE, &newval);
if (err)
return err;
}
if (data[IFLA_BOND_AD_SELECT]) {
int ad_select =
nla_get_u8(data[IFLA_BOND_AD_SELECT]);
bond_opt_initval(&newval, ad_select);
err = __bond_opt_set(bond, BOND_OPT_AD_SELECT, &newval);
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_option_active_slave_get_ifindex(struct bonding *bond)
{
const struct net_device *slave;
int ifindex;
rcu_read_lock();
slave = bond_option_active_slave_get_rcu(bond);
ifindex = slave ? slave->ifindex : 0;
rcu_read_unlock();
return ifindex;
}
static int bond_fill_info(struct sk_buff *skb,
const struct net_device *bond_dev)
{
struct bonding *bond = netdev_priv(bond_dev);
unsigned int packets_per_slave;
int ifindex, i, targets_added;
struct nlattr *targets;
struct slave *primary;
if (nla_put_u8(skb, IFLA_BOND_MODE, BOND_MODE(bond)))
goto nla_put_failure;
ifindex = bond_option_active_slave_get_ifindex(bond);
if (ifindex && nla_put_u32(skb, IFLA_BOND_ACTIVE_SLAVE, 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;
primary = rtnl_dereference(bond->primary_slave);
if (primary &&
nla_put_u32(skb, IFLA_BOND_PRIMARY, primary->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_MODE(bond) == 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 */
.slave_maxtype = IFLA_BOND_SLAVE_MAX,
.slave_policy = bond_slave_policy,
.slave_changelink = bond_slave_changelink,
.get_slave_size = bond_get_slave_size,
.fill_slave_info = bond_fill_slave_info,
};
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");