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linux/net/ipv4/nexthop.c
Eric Dumazet 09eed1192c neighbour: switch to standard rcu, instead of rcu_bh 
rcu_bh is no longer a win, especially for objects freed
with standard call_rcu().

Switch neighbour code to no longer disable BH when not necessary.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-21 21:32:18 -07:00

3790 lines
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// SPDX-License-Identifier: GPL-2.0
/* Generic nexthop implementation
*
* Copyright (c) 2017-19 Cumulus Networks
* Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
*/
#include <linux/nexthop.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <net/arp.h>
#include <net/ipv6_stubs.h>
#include <net/lwtunnel.h>
#include <net/ndisc.h>
#include <net/nexthop.h>
#include <net/route.h>
#include <net/sock.h>
#define NH_RES_DEFAULT_IDLE_TIMER (120 * HZ)
#define NH_RES_DEFAULT_UNBALANCED_TIMER 0 /* No forced rebalancing. */
static void remove_nexthop(struct net *net, struct nexthop *nh,
struct nl_info *nlinfo);
#define NH_DEV_HASHBITS 8
#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
static const struct nla_policy rtm_nh_policy_new[] = {
[NHA_ID] = { .type = NLA_U32 },
[NHA_GROUP] = { .type = NLA_BINARY },
[NHA_GROUP_TYPE] = { .type = NLA_U16 },
[NHA_BLACKHOLE] = { .type = NLA_FLAG },
[NHA_OIF] = { .type = NLA_U32 },
[NHA_GATEWAY] = { .type = NLA_BINARY },
[NHA_ENCAP_TYPE] = { .type = NLA_U16 },
[NHA_ENCAP] = { .type = NLA_NESTED },
[NHA_FDB] = { .type = NLA_FLAG },
[NHA_RES_GROUP] = { .type = NLA_NESTED },
};
static const struct nla_policy rtm_nh_policy_get[] = {
[NHA_ID] = { .type = NLA_U32 },
};
static const struct nla_policy rtm_nh_policy_dump[] = {
[NHA_OIF] = { .type = NLA_U32 },
[NHA_GROUPS] = { .type = NLA_FLAG },
[NHA_MASTER] = { .type = NLA_U32 },
[NHA_FDB] = { .type = NLA_FLAG },
};
static const struct nla_policy rtm_nh_res_policy_new[] = {
[NHA_RES_GROUP_BUCKETS] = { .type = NLA_U16 },
[NHA_RES_GROUP_IDLE_TIMER] = { .type = NLA_U32 },
[NHA_RES_GROUP_UNBALANCED_TIMER] = { .type = NLA_U32 },
};
static const struct nla_policy rtm_nh_policy_dump_bucket[] = {
[NHA_ID] = { .type = NLA_U32 },
[NHA_OIF] = { .type = NLA_U32 },
[NHA_MASTER] = { .type = NLA_U32 },
[NHA_RES_BUCKET] = { .type = NLA_NESTED },
};
static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = {
[NHA_RES_BUCKET_NH_ID] = { .type = NLA_U32 },
};
static const struct nla_policy rtm_nh_policy_get_bucket[] = {
[NHA_ID] = { .type = NLA_U32 },
[NHA_RES_BUCKET] = { .type = NLA_NESTED },
};
static const struct nla_policy rtm_nh_res_bucket_policy_get[] = {
[NHA_RES_BUCKET_INDEX] = { .type = NLA_U16 },
};
static bool nexthop_notifiers_is_empty(struct net *net)
{
return !net->nexthop.notifier_chain.head;
}
static void
__nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info,
const struct nh_info *nhi)
{
nh_info->dev = nhi->fib_nhc.nhc_dev;
nh_info->gw_family = nhi->fib_nhc.nhc_gw_family;
if (nh_info->gw_family == AF_INET)
nh_info->ipv4 = nhi->fib_nhc.nhc_gw.ipv4;
else if (nh_info->gw_family == AF_INET6)
nh_info->ipv6 = nhi->fib_nhc.nhc_gw.ipv6;
nh_info->is_reject = nhi->reject_nh;
nh_info->is_fdb = nhi->fdb_nh;
nh_info->has_encap = !!nhi->fib_nhc.nhc_lwtstate;
}
static int nh_notifier_single_info_init(struct nh_notifier_info *info,
const struct nexthop *nh)
{
struct nh_info *nhi = rtnl_dereference(nh->nh_info);
info->type = NH_NOTIFIER_INFO_TYPE_SINGLE;
info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL);
if (!info->nh)
return -ENOMEM;
__nh_notifier_single_info_init(info->nh, nhi);
return 0;
}
static void nh_notifier_single_info_fini(struct nh_notifier_info *info)
{
kfree(info->nh);
}
static int nh_notifier_mpath_info_init(struct nh_notifier_info *info,
struct nh_group *nhg)
{
u16 num_nh = nhg->num_nh;
int i;
info->type = NH_NOTIFIER_INFO_TYPE_GRP;
info->nh_grp = kzalloc(struct_size(info->nh_grp, nh_entries, num_nh),
GFP_KERNEL);
if (!info->nh_grp)
return -ENOMEM;
info->nh_grp->num_nh = num_nh;
info->nh_grp->is_fdb = nhg->fdb_nh;
for (i = 0; i < num_nh; i++) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
struct nh_info *nhi;
nhi = rtnl_dereference(nhge->nh->nh_info);
info->nh_grp->nh_entries[i].id = nhge->nh->id;
info->nh_grp->nh_entries[i].weight = nhge->weight;
__nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh,
nhi);
}
return 0;
}
static int nh_notifier_res_table_info_init(struct nh_notifier_info *info,
struct nh_group *nhg)
{
struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
u16 num_nh_buckets = res_table->num_nh_buckets;
unsigned long size;
u16 i;
info->type = NH_NOTIFIER_INFO_TYPE_RES_TABLE;
size = struct_size(info->nh_res_table, nhs, num_nh_buckets);
info->nh_res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO |
__GFP_NOWARN);
if (!info->nh_res_table)
return -ENOMEM;
info->nh_res_table->num_nh_buckets = num_nh_buckets;
for (i = 0; i < num_nh_buckets; i++) {
struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
struct nh_grp_entry *nhge;
struct nh_info *nhi;
nhge = rtnl_dereference(bucket->nh_entry);
nhi = rtnl_dereference(nhge->nh->nh_info);
__nh_notifier_single_info_init(&info->nh_res_table->nhs[i],
nhi);
}
return 0;
}
static int nh_notifier_grp_info_init(struct nh_notifier_info *info,
const struct nexthop *nh)
{
struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
if (nhg->hash_threshold)
return nh_notifier_mpath_info_init(info, nhg);
else if (nhg->resilient)
return nh_notifier_res_table_info_init(info, nhg);
return -EINVAL;
}
static void nh_notifier_grp_info_fini(struct nh_notifier_info *info,
const struct nexthop *nh)
{
struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
if (nhg->hash_threshold)
kfree(info->nh_grp);
else if (nhg->resilient)
vfree(info->nh_res_table);
}
static int nh_notifier_info_init(struct nh_notifier_info *info,
const struct nexthop *nh)
{
info->id = nh->id;
if (nh->is_group)
return nh_notifier_grp_info_init(info, nh);
else
return nh_notifier_single_info_init(info, nh);
}
static void nh_notifier_info_fini(struct nh_notifier_info *info,
const struct nexthop *nh)
{
if (nh->is_group)
nh_notifier_grp_info_fini(info, nh);
else
nh_notifier_single_info_fini(info);
}
static int call_nexthop_notifiers(struct net *net,
enum nexthop_event_type event_type,
struct nexthop *nh,
struct netlink_ext_ack *extack)
{
struct nh_notifier_info info = {
.net = net,
.extack = extack,
};
int err;
ASSERT_RTNL();
if (nexthop_notifiers_is_empty(net))
return 0;
err = nh_notifier_info_init(&info, nh);
if (err) {
NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
return err;
}
err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
event_type, &info);
nh_notifier_info_fini(&info, nh);
return notifier_to_errno(err);
}
static int
nh_notifier_res_bucket_idle_timer_get(const struct nh_notifier_info *info,
bool force, unsigned int *p_idle_timer_ms)
{
struct nh_res_table *res_table;
struct nh_group *nhg;
struct nexthop *nh;
int err = 0;
/* When 'force' is false, nexthop bucket replacement is performed
* because the bucket was deemed to be idle. In this case, capable
* listeners can choose to perform an atomic replacement: The bucket is
* only replaced if it is inactive. However, if the idle timer interval
* is smaller than the interval in which a listener is querying
* buckets' activity from the device, then atomic replacement should
* not be tried. Pass the idle timer value to listeners, so that they
* could determine which type of replacement to perform.
*/
if (force) {
*p_idle_timer_ms = 0;
return 0;
}
rcu_read_lock();
nh = nexthop_find_by_id(info->net, info->id);
if (!nh) {
err = -EINVAL;
goto out;
}
nhg = rcu_dereference(nh->nh_grp);
res_table = rcu_dereference(nhg->res_table);
*p_idle_timer_ms = jiffies_to_msecs(res_table->idle_timer);
out:
rcu_read_unlock();
return err;
}
static int nh_notifier_res_bucket_info_init(struct nh_notifier_info *info,
u16 bucket_index, bool force,
struct nh_info *oldi,
struct nh_info *newi)
{
unsigned int idle_timer_ms;
int err;
err = nh_notifier_res_bucket_idle_timer_get(info, force,
&idle_timer_ms);
if (err)
return err;
info->type = NH_NOTIFIER_INFO_TYPE_RES_BUCKET;
info->nh_res_bucket = kzalloc(sizeof(*info->nh_res_bucket),
GFP_KERNEL);
if (!info->nh_res_bucket)
return -ENOMEM;
info->nh_res_bucket->bucket_index = bucket_index;
info->nh_res_bucket->idle_timer_ms = idle_timer_ms;
info->nh_res_bucket->force = force;
__nh_notifier_single_info_init(&info->nh_res_bucket->old_nh, oldi);
__nh_notifier_single_info_init(&info->nh_res_bucket->new_nh, newi);
return 0;
}
static void nh_notifier_res_bucket_info_fini(struct nh_notifier_info *info)
{
kfree(info->nh_res_bucket);
}
static int __call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
u16 bucket_index, bool force,
struct nh_info *oldi,
struct nh_info *newi,
struct netlink_ext_ack *extack)
{
struct nh_notifier_info info = {
.net = net,
.extack = extack,
.id = nhg_id,
};
int err;
if (nexthop_notifiers_is_empty(net))
return 0;
err = nh_notifier_res_bucket_info_init(&info, bucket_index, force,
oldi, newi);
if (err)
return err;
err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
NEXTHOP_EVENT_BUCKET_REPLACE, &info);
nh_notifier_res_bucket_info_fini(&info);
return notifier_to_errno(err);
}
/* There are three users of RES_TABLE, and NHs etc. referenced from there:
*
* 1) a collection of callbacks for NH maintenance. This operates under
* RTNL,
* 2) the delayed work that gradually balances the resilient table,
* 3) and nexthop_select_path(), operating under RCU.
*
* Both the delayed work and the RTNL block are writers, and need to
* maintain mutual exclusion. Since there are only two and well-known
* writers for each table, the RTNL code can make sure it has exclusive
* access thus:
*
* - Have the DW operate without locking;
* - synchronously cancel the DW;
* - do the writing;
* - if the write was not actually a delete, call upkeep, which schedules
* DW again if necessary.
*
* The functions that are always called from the RTNL context use
* rtnl_dereference(). The functions that can also be called from the DW do
* a raw dereference and rely on the above mutual exclusion scheme.
*/
#define nh_res_dereference(p) (rcu_dereference_raw(p))
static int call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
u16 bucket_index, bool force,
struct nexthop *old_nh,
struct nexthop *new_nh,
struct netlink_ext_ack *extack)
{
struct nh_info *oldi = nh_res_dereference(old_nh->nh_info);
struct nh_info *newi = nh_res_dereference(new_nh->nh_info);
return __call_nexthop_res_bucket_notifiers(net, nhg_id, bucket_index,
force, oldi, newi, extack);
}
static int call_nexthop_res_table_notifiers(struct net *net, struct nexthop *nh,
struct netlink_ext_ack *extack)
{
struct nh_notifier_info info = {
.net = net,
.extack = extack,
};
struct nh_group *nhg;
int err;
ASSERT_RTNL();
if (nexthop_notifiers_is_empty(net))
return 0;
/* At this point, the nexthop buckets are still not populated. Only
* emit a notification with the logical nexthops, so that a listener
* could potentially veto it in case of unsupported configuration.
*/
nhg = rtnl_dereference(nh->nh_grp);
err = nh_notifier_mpath_info_init(&info, nhg);
if (err) {
NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
return err;
}
err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE,
&info);
kfree(info.nh_grp);
return notifier_to_errno(err);
}
static int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
enum nexthop_event_type event_type,
struct nexthop *nh,
struct netlink_ext_ack *extack)
{
struct nh_notifier_info info = {
.net = net,
.extack = extack,
};
int err;
err = nh_notifier_info_init(&info, nh);
if (err)
return err;
err = nb->notifier_call(nb, event_type, &info);
nh_notifier_info_fini(&info, nh);
return notifier_to_errno(err);
}
static unsigned int nh_dev_hashfn(unsigned int val)
{
unsigned int mask = NH_DEV_HASHSIZE - 1;
return (val ^
(val >> NH_DEV_HASHBITS) ^
(val >> (NH_DEV_HASHBITS * 2))) & mask;
}
static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
{
struct net_device *dev = nhi->fib_nhc.nhc_dev;
struct hlist_head *head;
unsigned int hash;
WARN_ON(!dev);
hash = nh_dev_hashfn(dev->ifindex);
head = &net->nexthop.devhash[hash];
hlist_add_head(&nhi->dev_hash, head);
}
static void nexthop_free_group(struct nexthop *nh)
{
struct nh_group *nhg;
int i;
nhg = rcu_dereference_raw(nh->nh_grp);
for (i = 0; i < nhg->num_nh; ++i) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
WARN_ON(!list_empty(&nhge->nh_list));
nexthop_put(nhge->nh);
}
WARN_ON(nhg->spare == nhg);
if (nhg->resilient)
vfree(rcu_dereference_raw(nhg->res_table));
kfree(nhg->spare);
kfree(nhg);
}
static void nexthop_free_single(struct nexthop *nh)
{
struct nh_info *nhi;
nhi = rcu_dereference_raw(nh->nh_info);
switch (nhi->family) {
case AF_INET:
fib_nh_release(nh->net, &nhi->fib_nh);
break;
case AF_INET6:
ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
break;
}
kfree(nhi);
}
void nexthop_free_rcu(struct rcu_head *head)
{
struct nexthop *nh = container_of(head, struct nexthop, rcu);
if (nh->is_group)
nexthop_free_group(nh);
else
nexthop_free_single(nh);
kfree(nh);
}
EXPORT_SYMBOL_GPL(nexthop_free_rcu);
static struct nexthop *nexthop_alloc(void)
{
struct nexthop *nh;
nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
if (nh) {
INIT_LIST_HEAD(&nh->fi_list);
INIT_LIST_HEAD(&nh->f6i_list);
INIT_LIST_HEAD(&nh->grp_list);
INIT_LIST_HEAD(&nh->fdb_list);
}
return nh;
}
static struct nh_group *nexthop_grp_alloc(u16 num_nh)
{
struct nh_group *nhg;
nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
if (nhg)
nhg->num_nh = num_nh;
return nhg;
}
static void nh_res_table_upkeep_dw(struct work_struct *work);
static struct nh_res_table *
nexthop_res_table_alloc(struct net *net, u32 nhg_id, struct nh_config *cfg)
{
const u16 num_nh_buckets = cfg->nh_grp_res_num_buckets;
struct nh_res_table *res_table;
unsigned long size;
size = struct_size(res_table, nh_buckets, num_nh_buckets);
res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
if (!res_table)
return NULL;
res_table->net = net;
res_table->nhg_id = nhg_id;
INIT_DELAYED_WORK(&res_table->upkeep_dw, &nh_res_table_upkeep_dw);
INIT_LIST_HEAD(&res_table->uw_nh_entries);
res_table->idle_timer = cfg->nh_grp_res_idle_timer;
res_table->unbalanced_timer = cfg->nh_grp_res_unbalanced_timer;
res_table->num_nh_buckets = num_nh_buckets;
return res_table;
}
static void nh_base_seq_inc(struct net *net)
{
while (++net->nexthop.seq == 0)
;
}
/* no reference taken; rcu lock or rtnl must be held */
struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
{
struct rb_node **pp, *parent = NULL, *next;
pp = &net->nexthop.rb_root.rb_node;
while (1) {
struct nexthop *nh;
next = rcu_dereference_raw(*pp);
if (!next)
break;
parent = next;
nh = rb_entry(parent, struct nexthop, rb_node);
if (id < nh->id)
pp = &next->rb_left;
else if (id > nh->id)
pp = &next->rb_right;
else
return nh;
}
return NULL;
}
EXPORT_SYMBOL_GPL(nexthop_find_by_id);
/* used for auto id allocation; called with rtnl held */
static u32 nh_find_unused_id(struct net *net)
{
u32 id_start = net->nexthop.last_id_allocated;
while (1) {
net->nexthop.last_id_allocated++;
if (net->nexthop.last_id_allocated == id_start)
break;
if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
return net->nexthop.last_id_allocated;
}
return 0;
}
static void nh_res_time_set_deadline(unsigned long next_time,
unsigned long *deadline)
{
if (time_before(next_time, *deadline))
*deadline = next_time;
}
static clock_t nh_res_table_unbalanced_time(struct nh_res_table *res_table)
{
if (list_empty(&res_table->uw_nh_entries))
return 0;
return jiffies_delta_to_clock_t(jiffies - res_table->unbalanced_since);
}
static int nla_put_nh_group_res(struct sk_buff *skb, struct nh_group *nhg)
{
struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
struct nlattr *nest;
nest = nla_nest_start(skb, NHA_RES_GROUP);
if (!nest)
return -EMSGSIZE;
if (nla_put_u16(skb, NHA_RES_GROUP_BUCKETS,
res_table->num_nh_buckets) ||
nla_put_u32(skb, NHA_RES_GROUP_IDLE_TIMER,
jiffies_to_clock_t(res_table->idle_timer)) ||
nla_put_u32(skb, NHA_RES_GROUP_UNBALANCED_TIMER,
jiffies_to_clock_t(res_table->unbalanced_timer)) ||
nla_put_u64_64bit(skb, NHA_RES_GROUP_UNBALANCED_TIME,
nh_res_table_unbalanced_time(res_table),
NHA_RES_GROUP_PAD))
goto nla_put_failure;
nla_nest_end(skb, nest);
return 0;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
{
struct nexthop_grp *p;
size_t len = nhg->num_nh * sizeof(*p);
struct nlattr *nla;
u16 group_type = 0;
int i;
if (nhg->hash_threshold)
group_type = NEXTHOP_GRP_TYPE_MPATH;
else if (nhg->resilient)
group_type = NEXTHOP_GRP_TYPE_RES;
if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
goto nla_put_failure;
nla = nla_reserve(skb, NHA_GROUP, len);
if (!nla)
goto nla_put_failure;
p = nla_data(nla);
for (i = 0; i < nhg->num_nh; ++i) {
p->id = nhg->nh_entries[i].nh->id;
p->weight = nhg->nh_entries[i].weight - 1;
p += 1;
}
if (nhg->resilient && nla_put_nh_group_res(skb, nhg))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
int event, u32 portid, u32 seq, unsigned int nlflags)
{
struct fib6_nh *fib6_nh;
struct fib_nh *fib_nh;
struct nlmsghdr *nlh;
struct nh_info *nhi;
struct nhmsg *nhm;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
if (!nlh)
return -EMSGSIZE;
nhm = nlmsg_data(nlh);
nhm->nh_family = AF_UNSPEC;
nhm->nh_flags = nh->nh_flags;
nhm->nh_protocol = nh->protocol;
nhm->nh_scope = 0;
nhm->resvd = 0;
if (nla_put_u32(skb, NHA_ID, nh->id))
goto nla_put_failure;
if (nh->is_group) {
struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
goto nla_put_failure;
if (nla_put_nh_group(skb, nhg))
goto nla_put_failure;
goto out;
}
nhi = rtnl_dereference(nh->nh_info);
nhm->nh_family = nhi->family;
if (nhi->reject_nh) {
if (nla_put_flag(skb, NHA_BLACKHOLE))
goto nla_put_failure;
goto out;
} else if (nhi->fdb_nh) {
if (nla_put_flag(skb, NHA_FDB))
goto nla_put_failure;
} else {
const struct net_device *dev;
dev = nhi->fib_nhc.nhc_dev;
if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
goto nla_put_failure;
}
nhm->nh_scope = nhi->fib_nhc.nhc_scope;
switch (nhi->family) {
case AF_INET:
fib_nh = &nhi->fib_nh;
if (fib_nh->fib_nh_gw_family &&
nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
goto nla_put_failure;
break;
case AF_INET6:
fib6_nh = &nhi->fib6_nh;
if (fib6_nh->fib_nh_gw_family &&
nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
goto nla_put_failure;
break;
}
if (nhi->fib_nhc.nhc_lwtstate &&
lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
goto nla_put_failure;
out:
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static size_t nh_nlmsg_size_grp_res(struct nh_group *nhg)
{
return nla_total_size(0) + /* NHA_RES_GROUP */
nla_total_size(2) + /* NHA_RES_GROUP_BUCKETS */
nla_total_size(4) + /* NHA_RES_GROUP_IDLE_TIMER */
nla_total_size(4) + /* NHA_RES_GROUP_UNBALANCED_TIMER */
nla_total_size_64bit(8);/* NHA_RES_GROUP_UNBALANCED_TIME */
}
static size_t nh_nlmsg_size_grp(struct nexthop *nh)
{
struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
size_t tot = nla_total_size(sz) +
nla_total_size(2); /* NHA_GROUP_TYPE */
if (nhg->resilient)
tot += nh_nlmsg_size_grp_res(nhg);
return tot;
}
static size_t nh_nlmsg_size_single(struct nexthop *nh)
{
struct nh_info *nhi = rtnl_dereference(nh->nh_info);
size_t sz;
/* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
* are mutually exclusive
*/
sz = nla_total_size(4); /* NHA_OIF */
switch (nhi->family) {
case AF_INET:
if (nhi->fib_nh.fib_nh_gw_family)
sz += nla_total_size(4); /* NHA_GATEWAY */
break;
case AF_INET6:
/* NHA_GATEWAY */
if (nhi->fib6_nh.fib_nh_gw_family)
sz += nla_total_size(sizeof(const struct in6_addr));
break;
}
if (nhi->fib_nhc.nhc_lwtstate) {
sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
}
return sz;
}
static size_t nh_nlmsg_size(struct nexthop *nh)
{
size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
sz += nla_total_size(4); /* NHA_ID */
if (nh->is_group)
sz += nh_nlmsg_size_grp(nh);
else
sz += nh_nlmsg_size_single(nh);
return sz;
}
static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
{
unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
struct sk_buff *skb;
int err = -ENOBUFS;
skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
if (!skb)
goto errout;
err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
if (err < 0) {
/* -EMSGSIZE implies BUG in nh_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
info->nlh, gfp_any());
return;
errout:
if (err < 0)
rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
}
static unsigned long nh_res_bucket_used_time(const struct nh_res_bucket *bucket)
{
return (unsigned long)atomic_long_read(&bucket->used_time);
}
static unsigned long
nh_res_bucket_idle_point(const struct nh_res_table *res_table,
const struct nh_res_bucket *bucket,
unsigned long now)
{
unsigned long time = nh_res_bucket_used_time(bucket);
/* Bucket was not used since it was migrated. The idle time is now. */
if (time == bucket->migrated_time)
return now;
return time + res_table->idle_timer;
}
static unsigned long
nh_res_table_unb_point(const struct nh_res_table *res_table)
{
return res_table->unbalanced_since + res_table->unbalanced_timer;
}
static void nh_res_bucket_set_idle(const struct nh_res_table *res_table,
struct nh_res_bucket *bucket)
{
unsigned long now = jiffies;
atomic_long_set(&bucket->used_time, (long)now);
bucket->migrated_time = now;
}
static void nh_res_bucket_set_busy(struct nh_res_bucket *bucket)
{
atomic_long_set(&bucket->used_time, (long)jiffies);
}
static clock_t nh_res_bucket_idle_time(const struct nh_res_bucket *bucket)
{
unsigned long used_time = nh_res_bucket_used_time(bucket);
return jiffies_delta_to_clock_t(jiffies - used_time);
}
static int nh_fill_res_bucket(struct sk_buff *skb, struct nexthop *nh,
struct nh_res_bucket *bucket, u16 bucket_index,
int event, u32 portid, u32 seq,
unsigned int nlflags,
struct netlink_ext_ack *extack)
{
struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
struct nlmsghdr *nlh;
struct nlattr *nest;
struct nhmsg *nhm;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
if (!nlh)
return -EMSGSIZE;
nhm = nlmsg_data(nlh);
nhm->nh_family = AF_UNSPEC;
nhm->nh_flags = bucket->nh_flags;
nhm->nh_protocol = nh->protocol;
nhm->nh_scope = 0;
nhm->resvd = 0;
if (nla_put_u32(skb, NHA_ID, nh->id))
goto nla_put_failure;
nest = nla_nest_start(skb, NHA_RES_BUCKET);
if (!nest)
goto nla_put_failure;
if (nla_put_u16(skb, NHA_RES_BUCKET_INDEX, bucket_index) ||
nla_put_u32(skb, NHA_RES_BUCKET_NH_ID, nhge->nh->id) ||
nla_put_u64_64bit(skb, NHA_RES_BUCKET_IDLE_TIME,
nh_res_bucket_idle_time(bucket),
NHA_RES_BUCKET_PAD))
goto nla_put_failure_nest;
nla_nest_end(skb, nest);
nlmsg_end(skb, nlh);
return 0;
nla_put_failure_nest:
nla_nest_cancel(skb, nest);
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static void nexthop_bucket_notify(struct nh_res_table *res_table,
u16 bucket_index)
{
struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
struct nexthop *nh = nhge->nh_parent;
struct sk_buff *skb;
int err = -ENOBUFS;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
goto errout;
err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
RTM_NEWNEXTHOPBUCKET, 0, 0, NLM_F_REPLACE,
NULL);
if (err < 0) {
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, nh->net, 0, RTNLGRP_NEXTHOP, NULL, GFP_KERNEL);
return;
errout:
if (err < 0)
rtnl_set_sk_err(nh->net, RTNLGRP_NEXTHOP, err);
}
static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
bool *is_fdb, struct netlink_ext_ack *extack)
{
if (nh->is_group) {
struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
/* Nesting groups within groups is not supported. */
if (nhg->hash_threshold) {
NL_SET_ERR_MSG(extack,
"Hash-threshold group can not be a nexthop within a group");
return false;
}
if (nhg->resilient) {
NL_SET_ERR_MSG(extack,
"Resilient group can not be a nexthop within a group");
return false;
}
*is_fdb = nhg->fdb_nh;
} else {
struct nh_info *nhi = rtnl_dereference(nh->nh_info);
if (nhi->reject_nh && npaths > 1) {
NL_SET_ERR_MSG(extack,
"Blackhole nexthop can not be used in a group with more than 1 path");
return false;
}
*is_fdb = nhi->fdb_nh;
}
return true;
}
static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
struct netlink_ext_ack *extack)
{
struct nh_info *nhi;
nhi = rtnl_dereference(nh->nh_info);
if (!nhi->fdb_nh) {
NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
return -EINVAL;
}
if (*nh_family == AF_UNSPEC) {
*nh_family = nhi->family;
} else if (*nh_family != nhi->family) {
NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
return -EINVAL;
}
return 0;
}
static int nh_check_attr_group(struct net *net,
struct nlattr *tb[], size_t tb_size,
u16 nh_grp_type, struct netlink_ext_ack *extack)
{
unsigned int len = nla_len(tb[NHA_GROUP]);
u8 nh_family = AF_UNSPEC;
struct nexthop_grp *nhg;
unsigned int i, j;
u8 nhg_fdb = 0;
if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
NL_SET_ERR_MSG(extack,
"Invalid length for nexthop group attribute");
return -EINVAL;
}
/* convert len to number of nexthop ids */
len /= sizeof(*nhg);
nhg = nla_data(tb[NHA_GROUP]);
for (i = 0; i < len; ++i) {
if (nhg[i].resvd1 || nhg[i].resvd2) {
NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
return -EINVAL;
}
if (nhg[i].weight > 254) {
NL_SET_ERR_MSG(extack, "Invalid value for weight");
return -EINVAL;
}
for (j = i + 1; j < len; ++j) {
if (nhg[i].id == nhg[j].id) {
NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
return -EINVAL;
}
}
}
if (tb[NHA_FDB])
nhg_fdb = 1;
nhg = nla_data(tb[NHA_GROUP]);
for (i = 0; i < len; ++i) {
struct nexthop *nh;
bool is_fdb_nh;
nh = nexthop_find_by_id(net, nhg[i].id);
if (!nh) {
NL_SET_ERR_MSG(extack, "Invalid nexthop id");
return -EINVAL;
}
if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
return -EINVAL;
if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
return -EINVAL;
if (!nhg_fdb && is_fdb_nh) {
NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
return -EINVAL;
}
}
for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) {
if (!tb[i])
continue;
switch (i) {
case NHA_FDB:
continue;
case NHA_RES_GROUP:
if (nh_grp_type == NEXTHOP_GRP_TYPE_RES)
continue;
break;
}
NL_SET_ERR_MSG(extack,
"No other attributes can be set in nexthop groups");
return -EINVAL;
}
return 0;
}
static bool ipv6_good_nh(const struct fib6_nh *nh)
{
int state = NUD_REACHABLE;
struct neighbour *n;
rcu_read_lock();
n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
if (n)
state = READ_ONCE(n->nud_state);
rcu_read_unlock();
return !!(state & NUD_VALID);
}
static bool ipv4_good_nh(const struct fib_nh *nh)
{
int state = NUD_REACHABLE;
struct neighbour *n;
rcu_read_lock();
n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
(__force u32)nh->fib_nh_gw4);
if (n)
state = READ_ONCE(n->nud_state);
rcu_read_unlock();
return !!(state & NUD_VALID);
}
static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
{
struct nexthop *rc = NULL;
int i;
for (i = 0; i < nhg->num_nh; ++i) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
struct nh_info *nhi;
if (hash > atomic_read(&nhge->hthr.upper_bound))
continue;
nhi = rcu_dereference(nhge->nh->nh_info);
if (nhi->fdb_nh)
return nhge->nh;
/* nexthops always check if it is good and does
* not rely on a sysctl for this behavior
*/
switch (nhi->family) {
case AF_INET:
if (ipv4_good_nh(&nhi->fib_nh))
return nhge->nh;
break;
case AF_INET6:
if (ipv6_good_nh(&nhi->fib6_nh))
return nhge->nh;
break;
}
if (!rc)
rc = nhge->nh;
}
return rc;
}
static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash)
{
struct nh_res_table *res_table = rcu_dereference(nhg->res_table);
u16 bucket_index = hash % res_table->num_nh_buckets;
struct nh_res_bucket *bucket;
struct nh_grp_entry *nhge;
/* nexthop_select_path() is expected to return a non-NULL value, so
* skip protocol validation and just hand out whatever there is.
*/
bucket = &res_table->nh_buckets[bucket_index];
nh_res_bucket_set_busy(bucket);
nhge = rcu_dereference(bucket->nh_entry);
return nhge->nh;
}
struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
{
struct nh_group *nhg;
if (!nh->is_group)
return nh;
nhg = rcu_dereference(nh->nh_grp);
if (nhg->hash_threshold)
return nexthop_select_path_hthr(nhg, hash);
else if (nhg->resilient)
return nexthop_select_path_res(nhg, hash);
/* Unreachable. */
return NULL;
}
EXPORT_SYMBOL_GPL(nexthop_select_path);
int nexthop_for_each_fib6_nh(struct nexthop *nh,
int (*cb)(struct fib6_nh *nh, void *arg),
void *arg)
{
struct nh_info *nhi;
int err;
if (nh->is_group) {
struct nh_group *nhg;
int i;
nhg = rcu_dereference_rtnl(nh->nh_grp);
for (i = 0; i < nhg->num_nh; i++) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
err = cb(&nhi->fib6_nh, arg);
if (err)
return err;
}
} else {
nhi = rcu_dereference_rtnl(nh->nh_info);
err = cb(&nhi->fib6_nh, arg);
if (err)
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
static int check_src_addr(const struct in6_addr *saddr,
struct netlink_ext_ack *extack)
{
if (!ipv6_addr_any(saddr)) {
NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
return -EINVAL;
}
return 0;
}
int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
struct nh_info *nhi;
bool is_fdb_nh;
/* fib6_src is unique to a fib6_info and limits the ability to cache
* routes in fib6_nh within a nexthop that is potentially shared
* across multiple fib entries. If the config wants to use source
* routing it can not use nexthop objects. mlxsw also does not allow
* fib6_src on routes.
*/
if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
return -EINVAL;
if (nh->is_group) {
struct nh_group *nhg;
nhg = rtnl_dereference(nh->nh_grp);
if (nhg->has_v4)
goto no_v4_nh;
is_fdb_nh = nhg->fdb_nh;
} else {
nhi = rtnl_dereference(nh->nh_info);
if (nhi->family == AF_INET)
goto no_v4_nh;
is_fdb_nh = nhi->fdb_nh;
}
if (is_fdb_nh) {
NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
return -EINVAL;
}
return 0;
no_v4_nh:
NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
return -EINVAL;
}
EXPORT_SYMBOL_GPL(fib6_check_nexthop);
/* if existing nexthop has ipv6 routes linked to it, need
* to verify this new spec works with ipv6
*/
static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
struct netlink_ext_ack *extack)
{
struct fib6_info *f6i;
if (list_empty(&old->f6i_list))
return 0;
list_for_each_entry(f6i, &old->f6i_list, nh_list) {
if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
return -EINVAL;
}
return fib6_check_nexthop(new, NULL, extack);
}
static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
struct netlink_ext_ack *extack)
{
if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
NL_SET_ERR_MSG(extack,
"Route with host scope can not have a gateway");
return -EINVAL;
}
if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
return -EINVAL;
}
return 0;
}
/* Invoked by fib add code to verify nexthop by id is ok with
* config for prefix; parts of fib_check_nh not done when nexthop
* object is used.
*/
int fib_check_nexthop(struct nexthop *nh, u8 scope,
struct netlink_ext_ack *extack)
{
struct nh_info *nhi;
int err = 0;
if (nh->is_group) {
struct nh_group *nhg;
nhg = rtnl_dereference(nh->nh_grp);
if (nhg->fdb_nh) {
NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
err = -EINVAL;
goto out;
}
if (scope == RT_SCOPE_HOST) {
NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
err = -EINVAL;
goto out;
}
/* all nexthops in a group have the same scope */
nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
err = nexthop_check_scope(nhi, scope, extack);
} else {
nhi = rtnl_dereference(nh->nh_info);
if (nhi->fdb_nh) {
NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
err = -EINVAL;
goto out;
}
err = nexthop_check_scope(nhi, scope, extack);
}
out:
return err;
}
static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
struct netlink_ext_ack *extack)
{
struct fib_info *fi;
list_for_each_entry(fi, &old->fi_list, nh_list) {
int err;
err = fib_check_nexthop(new, fi->fib_scope, extack);
if (err)
return err;
}
return 0;
}
static bool nh_res_nhge_is_balanced(const struct nh_grp_entry *nhge)
{
return nhge->res.count_buckets == nhge->res.wants_buckets;
}
static bool nh_res_nhge_is_ow(const struct nh_grp_entry *nhge)
{
return nhge->res.count_buckets > nhge->res.wants_buckets;
}
static bool nh_res_nhge_is_uw(const struct nh_grp_entry *nhge)
{
return nhge->res.count_buckets < nhge->res.wants_buckets;
}
static bool nh_res_table_is_balanced(const struct nh_res_table *res_table)
{
return list_empty(&res_table->uw_nh_entries);
}
static void nh_res_bucket_unset_nh(struct nh_res_bucket *bucket)
{
struct nh_grp_entry *nhge;
if (bucket->occupied) {
nhge = nh_res_dereference(bucket->nh_entry);
nhge->res.count_buckets--;
bucket->occupied = false;
}
}
static void nh_res_bucket_set_nh(struct nh_res_bucket *bucket,
struct nh_grp_entry *nhge)
{
nh_res_bucket_unset_nh(bucket);
bucket->occupied = true;
rcu_assign_pointer(bucket->nh_entry, nhge);
nhge->res.count_buckets++;
}
static bool nh_res_bucket_should_migrate(struct nh_res_table *res_table,
struct nh_res_bucket *bucket,
unsigned long *deadline, bool *force)
{
unsigned long now = jiffies;
struct nh_grp_entry *nhge;
unsigned long idle_point;
if (!bucket->occupied) {
/* The bucket is not occupied, its NHGE pointer is either
* NULL or obsolete. We _have to_ migrate: set force.
*/
*force = true;
return true;
}
nhge = nh_res_dereference(bucket->nh_entry);
/* If the bucket is populated by an underweight or balanced
* nexthop, do not migrate.
*/
if (!nh_res_nhge_is_ow(nhge))
return false;
/* At this point we know that the bucket is populated with an
* overweight nexthop. It needs to be migrated to a new nexthop if
* the idle timer of unbalanced timer expired.
*/
idle_point = nh_res_bucket_idle_point(res_table, bucket, now);
if (time_after_eq(now, idle_point)) {
/* The bucket is idle. We _can_ migrate: unset force. */
*force = false;
return true;
}
/* Unbalanced timer of 0 means "never force". */
if (res_table->unbalanced_timer) {
unsigned long unb_point;
unb_point = nh_res_table_unb_point(res_table);
if (time_after(now, unb_point)) {
/* The bucket is not idle, but the unbalanced timer
* expired. We _can_ migrate, but set force anyway,
* so that drivers know to ignore activity reports
* from the HW.
*/
*force = true;
return true;
}
nh_res_time_set_deadline(unb_point, deadline);
}
nh_res_time_set_deadline(idle_point, deadline);
return false;
}
static bool nh_res_bucket_migrate(struct nh_res_table *res_table,
u16 bucket_index, bool notify,
bool notify_nl, bool force)
{
struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
struct nh_grp_entry *new_nhge;
struct netlink_ext_ack extack;
int err;
new_nhge = list_first_entry_or_null(&res_table->uw_nh_entries,
struct nh_grp_entry,
res.uw_nh_entry);
if (WARN_ON_ONCE(!new_nhge))
/* If this function is called, "bucket" is either not
* occupied, or it belongs to a next hop that is
* overweight. In either case, there ought to be a
* corresponding underweight next hop.
*/
return false;
if (notify) {
struct nh_grp_entry *old_nhge;
old_nhge = nh_res_dereference(bucket->nh_entry);
err = call_nexthop_res_bucket_notifiers(res_table->net,
res_table->nhg_id,
bucket_index, force,
old_nhge->nh,
new_nhge->nh, &extack);
if (err) {
pr_err_ratelimited("%s\n", extack._msg);
if (!force)
return false;
/* It is not possible to veto a forced replacement, so
* just clear the hardware flags from the nexthop
* bucket to indicate to user space that this bucket is
* not correctly populated in hardware.
*/
bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
}
}
nh_res_bucket_set_nh(bucket, new_nhge);
nh_res_bucket_set_idle(res_table, bucket);
if (notify_nl)
nexthop_bucket_notify(res_table, bucket_index);
if (nh_res_nhge_is_balanced(new_nhge))
list_del(&new_nhge->res.uw_nh_entry);
return true;
}
#define NH_RES_UPKEEP_DW_MINIMUM_INTERVAL (HZ / 2)
static void nh_res_table_upkeep(struct nh_res_table *res_table,
bool notify, bool notify_nl)
{
unsigned long now = jiffies;
unsigned long deadline;
u16 i;
/* Deadline is the next time that upkeep should be run. It is the
* earliest time at which one of the buckets might be migrated.
* Start at the most pessimistic estimate: either unbalanced_timer
* from now, or if there is none, idle_timer from now. For each
* encountered time point, call nh_res_time_set_deadline() to
* refine the estimate.
*/
if (res_table->unbalanced_timer)
deadline = now + res_table->unbalanced_timer;
else
deadline = now + res_table->idle_timer;
for (i = 0; i < res_table->num_nh_buckets; i++) {
struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
bool force;
if (nh_res_bucket_should_migrate(res_table, bucket,
&deadline, &force)) {
if (!nh_res_bucket_migrate(res_table, i, notify,
notify_nl, force)) {
unsigned long idle_point;
/* A driver can override the migration
* decision if the HW reports that the
* bucket is actually not idle. Therefore
* remark the bucket as busy again and
* update the deadline.
*/
nh_res_bucket_set_busy(bucket);
idle_point = nh_res_bucket_idle_point(res_table,
bucket,
now);
nh_res_time_set_deadline(idle_point, &deadline);
}
}
}
/* If the group is still unbalanced, schedule the next upkeep to
* either the deadline computed above, or the minimum deadline,
* whichever comes later.
*/
if (!nh_res_table_is_balanced(res_table)) {
unsigned long now = jiffies;
unsigned long min_deadline;
min_deadline = now + NH_RES_UPKEEP_DW_MINIMUM_INTERVAL;
if (time_before(deadline, min_deadline))
deadline = min_deadline;
queue_delayed_work(system_power_efficient_wq,
&res_table->upkeep_dw, deadline - now);
}
}
static void nh_res_table_upkeep_dw(struct work_struct *work)
{
struct delayed_work *dw = to_delayed_work(work);
struct nh_res_table *res_table;
res_table = container_of(dw, struct nh_res_table, upkeep_dw);
nh_res_table_upkeep(res_table, true, true);
}
static void nh_res_table_cancel_upkeep(struct nh_res_table *res_table)
{
cancel_delayed_work_sync(&res_table->upkeep_dw);
}
static void nh_res_group_rebalance(struct nh_group *nhg,
struct nh_res_table *res_table)
{
int prev_upper_bound = 0;
int total = 0;
int w = 0;
int i;
INIT_LIST_HEAD(&res_table->uw_nh_entries);
for (i = 0; i < nhg->num_nh; ++i)
total += nhg->nh_entries[i].weight;
for (i = 0; i < nhg->num_nh; ++i) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
int upper_bound;
w += nhge->weight;
upper_bound = DIV_ROUND_CLOSEST(res_table->num_nh_buckets * w,
total);
nhge->res.wants_buckets = upper_bound - prev_upper_bound;
prev_upper_bound = upper_bound;
if (nh_res_nhge_is_uw(nhge)) {
if (list_empty(&res_table->uw_nh_entries))
res_table->unbalanced_since = jiffies;
list_add(&nhge->res.uw_nh_entry,
&res_table->uw_nh_entries);
}
}
}
/* Migrate buckets in res_table so that they reference NHGE's from NHG with
* the right NH ID. Set those buckets that do not have a corresponding NHGE
* entry in NHG as not occupied.
*/
static void nh_res_table_migrate_buckets(struct nh_res_table *res_table,
struct nh_group *nhg)
{
u16 i;
for (i = 0; i < res_table->num_nh_buckets; i++) {
struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
u32 id = rtnl_dereference(bucket->nh_entry)->nh->id;
bool found = false;
int j;
for (j = 0; j < nhg->num_nh; j++) {
struct nh_grp_entry *nhge = &nhg->nh_entries[j];
if (nhge->nh->id == id) {
nh_res_bucket_set_nh(bucket, nhge);
found = true;
break;
}
}
if (!found)
nh_res_bucket_unset_nh(bucket);
}
}
static void replace_nexthop_grp_res(struct nh_group *oldg,
struct nh_group *newg)
{
/* For NH group replacement, the new NHG might only have a stub
* hash table with 0 buckets, because the number of buckets was not
* specified. For NH removal, oldg and newg both reference the same
* res_table. So in any case, in the following, we want to work
* with oldg->res_table.
*/
struct nh_res_table *old_res_table = rtnl_dereference(oldg->res_table);
unsigned long prev_unbalanced_since = old_res_table->unbalanced_since;
bool prev_has_uw = !list_empty(&old_res_table->uw_nh_entries);
nh_res_table_cancel_upkeep(old_res_table);
nh_res_table_migrate_buckets(old_res_table, newg);
nh_res_group_rebalance(newg, old_res_table);
if (prev_has_uw && !list_empty(&old_res_table->uw_nh_entries))
old_res_table->unbalanced_since = prev_unbalanced_since;
nh_res_table_upkeep(old_res_table, true, false);
}
static void nh_hthr_group_rebalance(struct nh_group *nhg)
{
int total = 0;
int w = 0;
int i;
for (i = 0; i < nhg->num_nh; ++i)
total += nhg->nh_entries[i].weight;
for (i = 0; i < nhg->num_nh; ++i) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
int upper_bound;
w += nhge->weight;
upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
atomic_set(&nhge->hthr.upper_bound, upper_bound);
}
}
static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
struct nl_info *nlinfo)
{
struct nh_grp_entry *nhges, *new_nhges;
struct nexthop *nhp = nhge->nh_parent;
struct netlink_ext_ack extack;
struct nexthop *nh = nhge->nh;
struct nh_group *nhg, *newg;
int i, j, err;
WARN_ON(!nh);
nhg = rtnl_dereference(nhp->nh_grp);
newg = nhg->spare;
/* last entry, keep it visible and remove the parent */
if (nhg->num_nh == 1) {
remove_nexthop(net, nhp, nlinfo);
return;
}
newg->has_v4 = false;
newg->is_multipath = nhg->is_multipath;
newg->hash_threshold = nhg->hash_threshold;
newg->resilient = nhg->resilient;
newg->fdb_nh = nhg->fdb_nh;
newg->num_nh = nhg->num_nh;
/* copy old entries to new except the one getting removed */
nhges = nhg->nh_entries;
new_nhges = newg->nh_entries;
for (i = 0, j = 0; i < nhg->num_nh; ++i) {
struct nh_info *nhi;
/* current nexthop getting removed */
if (nhg->nh_entries[i].nh == nh) {
newg->num_nh--;
continue;
}
nhi = rtnl_dereference(nhges[i].nh->nh_info);
if (nhi->family == AF_INET)
newg->has_v4 = true;
list_del(&nhges[i].nh_list);
new_nhges[j].nh_parent = nhges[i].nh_parent;
new_nhges[j].nh = nhges[i].nh;
new_nhges[j].weight = nhges[i].weight;
list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
j++;
}
if (newg->hash_threshold)
nh_hthr_group_rebalance(newg);
else if (newg->resilient)
replace_nexthop_grp_res(nhg, newg);
rcu_assign_pointer(nhp->nh_grp, newg);
list_del(&nhge->nh_list);
nexthop_put(nhge->nh);
/* Removal of a NH from a resilient group is notified through
* bucket notifications.
*/
if (newg->hash_threshold) {
err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp,
&extack);
if (err)
pr_err("%s\n", extack._msg);
}
if (nlinfo)
nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
}
static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
struct nl_info *nlinfo)
{
struct nh_grp_entry *nhge, *tmp;
list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
remove_nh_grp_entry(net, nhge, nlinfo);
/* make sure all see the newly published array before releasing rtnl */
synchronize_net();
}
static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
{
struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
struct nh_res_table *res_table;
int i, num_nh = nhg->num_nh;
for (i = 0; i < num_nh; ++i) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
if (WARN_ON(!nhge->nh))
continue;
list_del_init(&nhge->nh_list);
}
if (nhg->resilient) {
res_table = rtnl_dereference(nhg->res_table);
nh_res_table_cancel_upkeep(res_table);
}
}
/* not called for nexthop replace */
static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
{
struct fib6_info *f6i, *tmp;
bool do_flush = false;
struct fib_info *fi;
list_for_each_entry(fi, &nh->fi_list, nh_list) {
fi->fib_flags |= RTNH_F_DEAD;
do_flush = true;
}
if (do_flush)
fib_flush(net);
/* ip6_del_rt removes the entry from this list hence the _safe */
list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
/* __ip6_del_rt does a release, so do a hold here */
fib6_info_hold(f6i);
ipv6_stub->ip6_del_rt(net, f6i,
!READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode));
}
}
static void __remove_nexthop(struct net *net, struct nexthop *nh,
struct nl_info *nlinfo)
{
__remove_nexthop_fib(net, nh);
if (nh->is_group) {
remove_nexthop_group(nh, nlinfo);
} else {
struct nh_info *nhi;
nhi = rtnl_dereference(nh->nh_info);
if (nhi->fib_nhc.nhc_dev)
hlist_del(&nhi->dev_hash);
remove_nexthop_from_groups(net, nh, nlinfo);
}
}
static void remove_nexthop(struct net *net, struct nexthop *nh,
struct nl_info *nlinfo)
{
call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh, NULL);
/* remove from the tree */
rb_erase(&nh->rb_node, &net->nexthop.rb_root);
if (nlinfo)
nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
__remove_nexthop(net, nh, nlinfo);
nh_base_seq_inc(net);
nexthop_put(nh);
}
/* if any FIB entries reference this nexthop, any dst entries
* need to be regenerated
*/
static void nh_rt_cache_flush(struct net *net, struct nexthop *nh,
struct nexthop *replaced_nh)
{
struct fib6_info *f6i;
struct nh_group *nhg;
int i;
if (!list_empty(&nh->fi_list))
rt_cache_flush(net);
list_for_each_entry(f6i, &nh->f6i_list, nh_list)
ipv6_stub->fib6_update_sernum(net, f6i);
/* if an IPv6 group was replaced, we have to release all old
* dsts to make sure all refcounts are released
*/
if (!replaced_nh->is_group)
return;
nhg = rtnl_dereference(replaced_nh->nh_grp);
for (i = 0; i < nhg->num_nh; i++) {
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
struct nh_info *nhi = rtnl_dereference(nhge->nh->nh_info);
if (nhi->family == AF_INET6)
ipv6_stub->fib6_nh_release_dsts(&nhi->fib6_nh);
}
}
static int replace_nexthop_grp(struct net *net, struct nexthop *old,
struct nexthop *new, const struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct nh_res_table *tmp_table = NULL;
struct nh_res_table *new_res_table;
struct nh_res_table *old_res_table;
struct nh_group *oldg, *newg;
int i, err;
if (!new->is_group) {
NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
return -EINVAL;
}
oldg = rtnl_dereference(old->nh_grp);
newg = rtnl_dereference(new->nh_grp);
if (newg->hash_threshold != oldg->hash_threshold) {
NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with one of a different type.");
return -EINVAL;
}
if (newg->hash_threshold) {
err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new,
extack);
if (err)
return err;
} else if (newg->resilient) {
new_res_table = rtnl_dereference(newg->res_table);
old_res_table = rtnl_dereference(oldg->res_table);
/* Accept if num_nh_buckets was not given, but if it was
* given, demand that the value be correct.
*/
if (cfg->nh_grp_res_has_num_buckets &&
cfg->nh_grp_res_num_buckets !=
old_res_table->num_nh_buckets) {
NL_SET_ERR_MSG(extack, "Can not change number of buckets of a resilient nexthop group.");
return -EINVAL;
}
/* Emit a pre-replace notification so that listeners could veto
* a potentially unsupported configuration. Otherwise,
* individual bucket replacement notifications would need to be
* vetoed, which is something that should only happen if the
* bucket is currently active.
*/
err = call_nexthop_res_table_notifiers(net, new, extack);
if (err)
return err;
if (cfg->nh_grp_res_has_idle_timer)
old_res_table->idle_timer = cfg->nh_grp_res_idle_timer;
if (cfg->nh_grp_res_has_unbalanced_timer)
old_res_table->unbalanced_timer =
cfg->nh_grp_res_unbalanced_timer;
replace_nexthop_grp_res(oldg, newg);
tmp_table = new_res_table;
rcu_assign_pointer(newg->res_table, old_res_table);
rcu_assign_pointer(newg->spare->res_table, old_res_table);
}
/* update parents - used by nexthop code for cleanup */
for (i = 0; i < newg->num_nh; i++)
newg->nh_entries[i].nh_parent = old;
rcu_assign_pointer(old->nh_grp, newg);
/* Make sure concurrent readers are not using 'oldg' anymore. */
synchronize_net();
if (newg->resilient) {
rcu_assign_pointer(oldg->res_table, tmp_table);
rcu_assign_pointer(oldg->spare->res_table, tmp_table);
}
for (i = 0; i < oldg->num_nh; i++)
oldg->nh_entries[i].nh_parent = new;
rcu_assign_pointer(new->nh_grp, oldg);
return 0;
}
static void nh_group_v4_update(struct nh_group *nhg)
{
struct nh_grp_entry *nhges;
bool has_v4 = false;
int i;
nhges = nhg->nh_entries;
for (i = 0; i < nhg->num_nh; i++) {
struct nh_info *nhi;
nhi = rtnl_dereference(nhges[i].nh->nh_info);
if (nhi->family == AF_INET)
has_v4 = true;
}
nhg->has_v4 = has_v4;
}
static int replace_nexthop_single_notify_res(struct net *net,
struct nh_res_table *res_table,
struct nexthop *old,
struct nh_info *oldi,
struct nh_info *newi,
struct netlink_ext_ack *extack)
{
u32 nhg_id = res_table->nhg_id;
int err;
u16 i;
for (i = 0; i < res_table->num_nh_buckets; i++) {
struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
struct nh_grp_entry *nhge;
nhge = rtnl_dereference(bucket->nh_entry);
if (nhge->nh == old) {
err = __call_nexthop_res_bucket_notifiers(net, nhg_id,
i, true,
oldi, newi,
extack);
if (err)
goto err_notify;
}
}
return 0;
err_notify:
while (i-- > 0) {
struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
struct nh_grp_entry *nhge;
nhge = rtnl_dereference(bucket->nh_entry);
if (nhge->nh == old)
__call_nexthop_res_bucket_notifiers(net, nhg_id, i,
true, newi, oldi,
extack);
}
return err;
}
static int replace_nexthop_single_notify(struct net *net,
struct nexthop *group_nh,
struct nexthop *old,
struct nh_info *oldi,
struct nh_info *newi,
struct netlink_ext_ack *extack)
{
struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp);
struct nh_res_table *res_table;
if (nhg->hash_threshold) {
return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE,
group_nh, extack);
} else if (nhg->resilient) {
res_table = rtnl_dereference(nhg->res_table);
return replace_nexthop_single_notify_res(net, res_table,
old, oldi, newi,
extack);
}
return -EINVAL;
}
static int replace_nexthop_single(struct net *net, struct nexthop *old,
struct nexthop *new,
struct netlink_ext_ack *extack)
{
u8 old_protocol, old_nh_flags;
struct nh_info *oldi, *newi;
struct nh_grp_entry *nhge;
int err;
if (new->is_group) {
NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
return -EINVAL;
}
err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack);
if (err)
return err;
/* Hardware flags were set on 'old' as 'new' is not in the red-black
* tree. Therefore, inherit the flags from 'old' to 'new'.
*/
new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP);
oldi = rtnl_dereference(old->nh_info);
newi = rtnl_dereference(new->nh_info);
newi->nh_parent = old;
oldi->nh_parent = new;
old_protocol = old->protocol;
old_nh_flags = old->nh_flags;
old->protocol = new->protocol;
old->nh_flags = new->nh_flags;
rcu_assign_pointer(old->nh_info, newi);
rcu_assign_pointer(new->nh_info, oldi);
/* Send a replace notification for all the groups using the nexthop. */
list_for_each_entry(nhge, &old->grp_list, nh_list) {
struct nexthop *nhp = nhge->nh_parent;
err = replace_nexthop_single_notify(net, nhp, old, oldi, newi,
extack);
if (err)
goto err_notify;
}
/* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
* update IPv4 indication in all the groups using the nexthop.
*/
if (oldi->family == AF_INET && newi->family == AF_INET6) {
list_for_each_entry(nhge, &old->grp_list, nh_list) {
struct nexthop *nhp = nhge->nh_parent;
struct nh_group *nhg;
nhg = rtnl_dereference(nhp->nh_grp);
nh_group_v4_update(nhg);
}
}
return 0;
err_notify:
rcu_assign_pointer(new->nh_info, newi);
rcu_assign_pointer(old->nh_info, oldi);
old->nh_flags = old_nh_flags;
old->protocol = old_protocol;
oldi->nh_parent = old;
newi->nh_parent = new;
list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) {
struct nexthop *nhp = nhge->nh_parent;
replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL);
}
call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack);
return err;
}
static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
struct nl_info *info)
{
struct fib6_info *f6i;
if (!list_empty(&nh->fi_list)) {
struct fib_info *fi;
/* expectation is a few fib_info per nexthop and then
* a lot of routes per fib_info. So mark the fib_info
* and then walk the fib tables once
*/
list_for_each_entry(fi, &nh->fi_list, nh_list)
fi->nh_updated = true;
fib_info_notify_update(net, info);
list_for_each_entry(fi, &nh->fi_list, nh_list)
fi->nh_updated = false;
}
list_for_each_entry(f6i, &nh->f6i_list, nh_list)
ipv6_stub->fib6_rt_update(net, f6i, info);
}
/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
* linked to this nexthop and for all groups that the nexthop
* is a member of
*/
static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
struct nl_info *info)
{
struct nh_grp_entry *nhge;
__nexthop_replace_notify(net, nh, info);
list_for_each_entry(nhge, &nh->grp_list, nh_list)
__nexthop_replace_notify(net, nhge->nh_parent, info);
}
static int replace_nexthop(struct net *net, struct nexthop *old,
struct nexthop *new, const struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
bool new_is_reject = false;
struct nh_grp_entry *nhge;
int err;
/* check that existing FIB entries are ok with the
* new nexthop definition
*/
err = fib_check_nh_list(old, new, extack);
if (err)
return err;
err = fib6_check_nh_list(old, new, extack);
if (err)
return err;
if (!new->is_group) {
struct nh_info *nhi = rtnl_dereference(new->nh_info);
new_is_reject = nhi->reject_nh;
}
list_for_each_entry(nhge, &old->grp_list, nh_list) {
/* if new nexthop is a blackhole, any groups using this
* nexthop cannot have more than 1 path
*/
if (new_is_reject &&
nexthop_num_path(nhge->nh_parent) > 1) {
NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
return -EINVAL;
}
err = fib_check_nh_list(nhge->nh_parent, new, extack);
if (err)
return err;
err = fib6_check_nh_list(nhge->nh_parent, new, extack);
if (err)
return err;
}
if (old->is_group)
err = replace_nexthop_grp(net, old, new, cfg, extack);
else
err = replace_nexthop_single(net, old, new, extack);
if (!err) {
nh_rt_cache_flush(net, old, new);
__remove_nexthop(net, new, NULL);
nexthop_put(new);
}
return err;
}
/* called with rtnl_lock held */
static int insert_nexthop(struct net *net, struct nexthop *new_nh,
struct nh_config *cfg, struct netlink_ext_ack *extack)
{
struct rb_node **pp, *parent = NULL, *next;
struct rb_root *root = &net->nexthop.rb_root;
bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
bool create = !!(cfg->nlflags & NLM_F_CREATE);
u32 new_id = new_nh->id;
int replace_notify = 0;
int rc = -EEXIST;
pp = &root->rb_node;
while (1) {
struct nexthop *nh;
next = *pp;
if (!next)
break;
parent = next;
nh = rb_entry(parent, struct nexthop, rb_node);
if (new_id < nh->id) {
pp = &next->rb_left;
} else if (new_id > nh->id) {
pp = &next->rb_right;
} else if (replace) {
rc = replace_nexthop(net, nh, new_nh, cfg, extack);
if (!rc) {
new_nh = nh; /* send notification with old nh */
replace_notify = 1;
}
goto out;
} else {
/* id already exists and not a replace */
goto out;
}
}
if (replace && !create) {
NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
rc = -ENOENT;
goto out;
}
if (new_nh->is_group) {
struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp);
struct nh_res_table *res_table;
if (nhg->resilient) {
res_table = rtnl_dereference(nhg->res_table);
/* Not passing the number of buckets is OK when
* replacing, but not when creating a new group.
*/
if (!cfg->nh_grp_res_has_num_buckets) {
NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion");
rc = -EINVAL;
goto out;
}
nh_res_group_rebalance(nhg, res_table);
/* Do not send bucket notifications, we do full
* notification below.
*/
nh_res_table_upkeep(res_table, false, false);
}
}
rb_link_node_rcu(&new_nh->rb_node, parent, pp);
rb_insert_color(&new_nh->rb_node, root);
/* The initial insertion is a full notification for hash-threshold as
* well as resilient groups.
*/
rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack);
if (rc)
rb_erase(&new_nh->rb_node, &net->nexthop.rb_root);
out:
if (!rc) {
nh_base_seq_inc(net);
nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
if (replace_notify &&
READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode))
nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
}
return rc;
}
/* rtnl */
/* remove all nexthops tied to a device being deleted */
static void nexthop_flush_dev(struct net_device *dev, unsigned long event)
{
unsigned int hash = nh_dev_hashfn(dev->ifindex);
struct net *net = dev_net(dev);
struct hlist_head *head = &net->nexthop.devhash[hash];
struct hlist_node *n;
struct nh_info *nhi;
hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
if (nhi->fib_nhc.nhc_dev != dev)
continue;
if (nhi->reject_nh &&
(event == NETDEV_DOWN || event == NETDEV_CHANGE))
continue;
remove_nexthop(net, nhi->nh_parent, NULL);
}
}
/* rtnl; called when net namespace is deleted */
static void flush_all_nexthops(struct net *net)
{
struct rb_root *root = &net->nexthop.rb_root;
struct rb_node *node;
struct nexthop *nh;
while ((node = rb_first(root))) {
nh = rb_entry(node, struct nexthop, rb_node);
remove_nexthop(net, nh, NULL);
cond_resched();
}
}
static struct nexthop *nexthop_create_group(struct net *net,
struct nh_config *cfg)
{
struct nlattr *grps_attr = cfg->nh_grp;
struct nexthop_grp *entry = nla_data(grps_attr);
u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
struct nh_group *nhg;
struct nexthop *nh;
int err;
int i;
if (WARN_ON(!num_nh))
return ERR_PTR(-EINVAL);
nh = nexthop_alloc();
if (!nh)
return ERR_PTR(-ENOMEM);
nh->is_group = 1;
nhg = nexthop_grp_alloc(num_nh);
if (!nhg) {
kfree(nh);
return ERR_PTR(-ENOMEM);
}
/* spare group used for removals */
nhg->spare = nexthop_grp_alloc(num_nh);
if (!nhg->spare) {
kfree(nhg);
kfree(nh);
return ERR_PTR(-ENOMEM);
}
nhg->spare->spare = nhg;
for (i = 0; i < nhg->num_nh; ++i) {
struct nexthop *nhe;
struct nh_info *nhi;
nhe = nexthop_find_by_id(net, entry[i].id);
if (!nexthop_get(nhe)) {
err = -ENOENT;
goto out_no_nh;
}
nhi = rtnl_dereference(nhe->nh_info);
if (nhi->family == AF_INET)
nhg->has_v4 = true;
nhg->nh_entries[i].nh = nhe;
nhg->nh_entries[i].weight = entry[i].weight + 1;
list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
nhg->nh_entries[i].nh_parent = nh;
}
if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
nhg->hash_threshold = 1;
nhg->is_multipath = true;
} else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) {
struct nh_res_table *res_table;
res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg);
if (!res_table) {
err = -ENOMEM;
goto out_no_nh;
}
rcu_assign_pointer(nhg->spare->res_table, res_table);
rcu_assign_pointer(nhg->res_table, res_table);
nhg->resilient = true;
nhg->is_multipath = true;
}
WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1);
if (nhg->hash_threshold)
nh_hthr_group_rebalance(nhg);
if (cfg->nh_fdb)
nhg->fdb_nh = 1;
rcu_assign_pointer(nh->nh_grp, nhg);
return nh;
out_no_nh:
for (i--; i >= 0; --i) {
list_del(&nhg->nh_entries[i].nh_list);
nexthop_put(nhg->nh_entries[i].nh);
}
kfree(nhg->spare);
kfree(nhg);
kfree(nh);
return ERR_PTR(err);
}
static int nh_create_ipv4(struct net *net, struct nexthop *nh,
struct nh_info *nhi, struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct fib_nh *fib_nh = &nhi->fib_nh;
struct fib_config fib_cfg = {
.fc_oif = cfg->nh_ifindex,
.fc_gw4 = cfg->gw.ipv4,
.fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
.fc_flags = cfg->nh_flags,
.fc_nlinfo = cfg->nlinfo,
.fc_encap = cfg->nh_encap,
.fc_encap_type = cfg->nh_encap_type,
};
u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
int err;
err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
if (err) {
fib_nh_release(net, fib_nh);
goto out;
}
if (nhi->fdb_nh)
goto out;
/* sets nh_dev if successful */
err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
if (!err) {
nh->nh_flags = fib_nh->fib_nh_flags;
fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
!fib_nh->fib_nh_scope ? 0 : fib_nh->fib_nh_scope - 1);
} else {
fib_nh_release(net, fib_nh);
}
out:
return err;
}
static int nh_create_ipv6(struct net *net, struct nexthop *nh,
struct nh_info *nhi, struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct fib6_nh *fib6_nh = &nhi->fib6_nh;
struct fib6_config fib6_cfg = {
.fc_table = l3mdev_fib_table(cfg->dev),
.fc_ifindex = cfg->nh_ifindex,
.fc_gateway = cfg->gw.ipv6,
.fc_flags = cfg->nh_flags,
.fc_nlinfo = cfg->nlinfo,
.fc_encap = cfg->nh_encap,
.fc_encap_type = cfg->nh_encap_type,
.fc_is_fdb = cfg->nh_fdb,
};
int err;
if (!ipv6_addr_any(&cfg->gw.ipv6))
fib6_cfg.fc_flags |= RTF_GATEWAY;
/* sets nh_dev if successful */
err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
extack);
if (err) {
/* IPv6 is not enabled, don't call fib6_nh_release */
if (err == -EAFNOSUPPORT)
goto out;
ipv6_stub->fib6_nh_release(fib6_nh);
} else {
nh->nh_flags = fib6_nh->fib_nh_flags;
}
out:
return err;
}
static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct nh_info *nhi;
struct nexthop *nh;
int err = 0;
nh = nexthop_alloc();
if (!nh)
return ERR_PTR(-ENOMEM);
nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
if (!nhi) {
kfree(nh);
return ERR_PTR(-ENOMEM);
}
nh->nh_flags = cfg->nh_flags;
nh->net = net;
nhi->nh_parent = nh;
nhi->family = cfg->nh_family;
nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
if (cfg->nh_fdb)
nhi->fdb_nh = 1;
if (cfg->nh_blackhole) {
nhi->reject_nh = 1;
cfg->nh_ifindex = net->loopback_dev->ifindex;
}
switch (cfg->nh_family) {
case AF_INET:
err = nh_create_ipv4(net, nh, nhi, cfg, extack);
break;
case AF_INET6:
err = nh_create_ipv6(net, nh, nhi, cfg, extack);
break;
}
if (err) {
kfree(nhi);
kfree(nh);
return ERR_PTR(err);
}
/* add the entry to the device based hash */
if (!nhi->fdb_nh)
nexthop_devhash_add(net, nhi);
rcu_assign_pointer(nh->nh_info, nhi);
return nh;
}
/* called with rtnl lock held */
static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct nexthop *nh;
int err;
if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
return ERR_PTR(-EINVAL);
}
if (!cfg->nh_id) {
cfg->nh_id = nh_find_unused_id(net);
if (!cfg->nh_id) {
NL_SET_ERR_MSG(extack, "No unused id");
return ERR_PTR(-EINVAL);
}
}
if (cfg->nh_grp)
nh = nexthop_create_group(net, cfg);
else
nh = nexthop_create(net, cfg, extack);
if (IS_ERR(nh))
return nh;
refcount_set(&nh->refcnt, 1);
nh->id = cfg->nh_id;
nh->protocol = cfg->nh_protocol;
nh->net = net;
err = insert_nexthop(net, nh, cfg, extack);
if (err) {
__remove_nexthop(net, nh, NULL);
nexthop_put(nh);
nh = ERR_PTR(err);
}
return nh;
}
static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback,
unsigned long *timer_p, bool *has_p,
struct netlink_ext_ack *extack)
{
unsigned long timer;
u32 value;
if (!attr) {
*timer_p = fallback;
*has_p = false;
return 0;
}
value = nla_get_u32(attr);
timer = clock_t_to_jiffies(value);
if (timer == ~0UL) {
NL_SET_ERR_MSG(extack, "Timer value too large");
return -EINVAL;
}
*timer_p = timer;
*has_p = true;
return 0;
}
static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {};
int err;
if (res) {
err = nla_parse_nested(tb,
ARRAY_SIZE(rtm_nh_res_policy_new) - 1,
res, rtm_nh_res_policy_new, extack);
if (err < 0)
return err;
}
if (tb[NHA_RES_GROUP_BUCKETS]) {
cfg->nh_grp_res_num_buckets =
nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]);
cfg->nh_grp_res_has_num_buckets = true;
if (!cfg->nh_grp_res_num_buckets) {
NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0");
return -EINVAL;
}
}
err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER],
NH_RES_DEFAULT_IDLE_TIMER,
&cfg->nh_grp_res_idle_timer,
&cfg->nh_grp_res_has_idle_timer,
extack);
if (err)
return err;
return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER],
NH_RES_DEFAULT_UNBALANCED_TIMER,
&cfg->nh_grp_res_unbalanced_timer,
&cfg->nh_grp_res_has_unbalanced_timer,
extack);
}
static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
struct nlmsghdr *nlh, struct nh_config *cfg,
struct netlink_ext_ack *extack)
{
struct nhmsg *nhm = nlmsg_data(nlh);
struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)];
int err;
err = nlmsg_parse(nlh, sizeof(*nhm), tb,
ARRAY_SIZE(rtm_nh_policy_new) - 1,
rtm_nh_policy_new, extack);
if (err < 0)
return err;
err = -EINVAL;
if (nhm->resvd || nhm->nh_scope) {
NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
goto out;
}
if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
goto out;
}
switch (nhm->nh_family) {
case AF_INET:
case AF_INET6:
break;
case AF_UNSPEC:
if (tb[NHA_GROUP])
break;
fallthrough;
default:
NL_SET_ERR_MSG(extack, "Invalid address family");
goto out;
}
memset(cfg, 0, sizeof(*cfg));
cfg->nlflags = nlh->nlmsg_flags;
cfg->nlinfo.portid = NETLINK_CB(skb).portid;
cfg->nlinfo.nlh = nlh;
cfg->nlinfo.nl_net = net;
cfg->nh_family = nhm->nh_family;
cfg->nh_protocol = nhm->nh_protocol;
cfg->nh_flags = nhm->nh_flags;
if (tb[NHA_ID])
cfg->nh_id = nla_get_u32(tb[NHA_ID]);
if (tb[NHA_FDB]) {
if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
goto out;
}
if (nhm->nh_flags) {
NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
goto out;
}
cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
}
if (tb[NHA_GROUP]) {
if (nhm->nh_family != AF_UNSPEC) {
NL_SET_ERR_MSG(extack, "Invalid family for group");
goto out;
}
cfg->nh_grp = tb[NHA_GROUP];
cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
if (tb[NHA_GROUP_TYPE])
cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
NL_SET_ERR_MSG(extack, "Invalid group type");
goto out;
}
err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb),
cfg->nh_grp_type, extack);
if (err)
goto out;
if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES)
err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP],
cfg, extack);
/* no other attributes should be set */
goto out;
}
if (tb[NHA_BLACKHOLE]) {
if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
goto out;
}
cfg->nh_blackhole = 1;
err = 0;
goto out;
}
if (!cfg->nh_fdb && !tb[NHA_OIF]) {
NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
goto out;
}
if (!cfg->nh_fdb && tb[NHA_OIF]) {
cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
if (cfg->nh_ifindex)
cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
if (!cfg->dev) {
NL_SET_ERR_MSG(extack, "Invalid device index");
goto out;
} else if (!(cfg->dev->flags & IFF_UP)) {
NL_SET_ERR_MSG(extack, "Nexthop device is not up");
err = -ENETDOWN;
goto out;
} else if (!netif_carrier_ok(cfg->dev)) {
NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
err = -ENETDOWN;
goto out;
}
}
err = -EINVAL;
if (tb[NHA_GATEWAY]) {
struct nlattr *gwa = tb[NHA_GATEWAY];
switch (cfg->nh_family) {
case AF_INET:
if (nla_len(gwa) != sizeof(u32)) {
NL_SET_ERR_MSG(extack, "Invalid gateway");
goto out;
}
cfg->gw.ipv4 = nla_get_be32(gwa);
break;
case AF_INET6:
if (nla_len(gwa) != sizeof(struct in6_addr)) {
NL_SET_ERR_MSG(extack, "Invalid gateway");
goto out;
}
cfg->gw.ipv6 = nla_get_in6_addr(gwa);
break;
default:
NL_SET_ERR_MSG(extack,
"Unknown address family for gateway");
goto out;
}
} else {
/* device only nexthop (no gateway) */
if (cfg->nh_flags & RTNH_F_ONLINK) {
NL_SET_ERR_MSG(extack,
"ONLINK flag can not be set for nexthop without a gateway");
goto out;
}
}
if (tb[NHA_ENCAP]) {
cfg->nh_encap = tb[NHA_ENCAP];
if (!tb[NHA_ENCAP_TYPE]) {
NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
goto out;
}
cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
if (err < 0)
goto out;
} else if (tb[NHA_ENCAP_TYPE]) {
NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
goto out;
}
err = 0;
out:
return err;
}
/* rtnl */
static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nh_config cfg;
struct nexthop *nh;
int err;
err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
if (!err) {
nh = nexthop_add(net, &cfg, extack);
if (IS_ERR(nh))
err = PTR_ERR(nh);
}
return err;
}
static int __nh_valid_get_del_req(const struct nlmsghdr *nlh,
struct nlattr **tb, u32 *id,
struct netlink_ext_ack *extack)
{
struct nhmsg *nhm = nlmsg_data(nlh);
if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
NL_SET_ERR_MSG(extack, "Invalid values in header");
return -EINVAL;
}
if (!tb[NHA_ID]) {
NL_SET_ERR_MSG(extack, "Nexthop id is missing");
return -EINVAL;
}
*id = nla_get_u32(tb[NHA_ID]);
if (!(*id)) {
NL_SET_ERR_MSG(extack, "Invalid nexthop id");
return -EINVAL;
}
return 0;
}
static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)];
int err;
err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
ARRAY_SIZE(rtm_nh_policy_get) - 1,
rtm_nh_policy_get, extack);
if (err < 0)
return err;
return __nh_valid_get_del_req(nlh, tb, id, extack);
}
/* rtnl */
static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nl_info nlinfo = {
.nlh = nlh,
.nl_net = net,
.portid = NETLINK_CB(skb).portid,
};
struct nexthop *nh;
int err;
u32 id;
err = nh_valid_get_del_req(nlh, &id, extack);
if (err)
return err;
nh = nexthop_find_by_id(net, id);
if (!nh)
return -ENOENT;
remove_nexthop(net, nh, &nlinfo);
return 0;
}
/* rtnl */
static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(in_skb->sk);
struct sk_buff *skb = NULL;
struct nexthop *nh;
int err;
u32 id;
err = nh_valid_get_del_req(nlh, &id, extack);
if (err)
return err;
err = -ENOBUFS;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
goto out;
err = -ENOENT;
nh = nexthop_find_by_id(net, id);
if (!nh)
goto errout_free;
err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, 0);
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
goto errout_free;
}
err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
out:
return err;
errout_free:
kfree_skb(skb);
goto out;
}
struct nh_dump_filter {
u32 nh_id;
int dev_idx;
int master_idx;
bool group_filter;
bool fdb_filter;
u32 res_bucket_nh_id;
};
static bool nh_dump_filtered(struct nexthop *nh,
struct nh_dump_filter *filter, u8 family)
{
const struct net_device *dev;
const struct nh_info *nhi;
if (filter->group_filter && !nh->is_group)
return true;
if (!filter->dev_idx && !filter->master_idx && !family)
return false;
if (nh->is_group)
return true;
nhi = rtnl_dereference(nh->nh_info);
if (family && nhi->family != family)
return true;
dev = nhi->fib_nhc.nhc_dev;
if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx))
return true;
if (filter->master_idx) {
struct net_device *master;
if (!dev)
return true;
master = netdev_master_upper_dev_get((struct net_device *)dev);
if (!master || master->ifindex != filter->master_idx)
return true;
}
return false;
}
static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb,
struct nh_dump_filter *filter,
struct netlink_ext_ack *extack)
{
struct nhmsg *nhm;
u32 idx;
if (tb[NHA_OIF]) {
idx = nla_get_u32(tb[NHA_OIF]);
if (idx > INT_MAX) {
NL_SET_ERR_MSG(extack, "Invalid device index");
return -EINVAL;
}
filter->dev_idx = idx;
}
if (tb[NHA_MASTER]) {
idx = nla_get_u32(tb[NHA_MASTER]);
if (idx > INT_MAX) {
NL_SET_ERR_MSG(extack, "Invalid master device index");
return -EINVAL;
}
filter->master_idx = idx;
}
filter->group_filter = nla_get_flag(tb[NHA_GROUPS]);
filter->fdb_filter = nla_get_flag(tb[NHA_FDB]);
nhm = nlmsg_data(nlh);
if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
return -EINVAL;
}
return 0;
}
static int nh_valid_dump_req(const struct nlmsghdr *nlh,
struct nh_dump_filter *filter,
struct netlink_callback *cb)
{
struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)];
int err;
err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
ARRAY_SIZE(rtm_nh_policy_dump) - 1,
rtm_nh_policy_dump, cb->extack);
if (err < 0)
return err;
return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
}
struct rtm_dump_nh_ctx {
u32 idx;
};
static struct rtm_dump_nh_ctx *
rtm_dump_nh_ctx(struct netlink_callback *cb)
{
struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx;
BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
return ctx;
}
static int rtm_dump_walk_nexthops(struct sk_buff *skb,
struct netlink_callback *cb,
struct rb_root *root,
struct rtm_dump_nh_ctx *ctx,
int (*nh_cb)(struct sk_buff *skb,
struct netlink_callback *cb,
struct nexthop *nh, void *data),
void *data)
{
struct rb_node *node;
int s_idx;
int err;
s_idx = ctx->idx;
for (node = rb_first(root); node; node = rb_next(node)) {
struct nexthop *nh;
nh = rb_entry(node, struct nexthop, rb_node);
if (nh->id < s_idx)
continue;
ctx->idx = nh->id;
err = nh_cb(skb, cb, nh, data);
if (err)
return err;
}
ctx->idx++;
return 0;
}
static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb,
struct nexthop *nh, void *data)
{
struct nhmsg *nhm = nlmsg_data(cb->nlh);
struct nh_dump_filter *filter = data;
if (nh_dump_filtered(nh, filter, nhm->nh_family))
return 0;
return nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI);
}
/* rtnl */
static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
{
struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb);
struct net *net = sock_net(skb->sk);
struct rb_root *root = &net->nexthop.rb_root;
struct nh_dump_filter filter = {};
int err;
err = nh_valid_dump_req(cb->nlh, &filter, cb);
if (err < 0)
return err;
err = rtm_dump_walk_nexthops(skb, cb, root, ctx,
&rtm_dump_nexthop_cb, &filter);
if (err < 0) {
if (likely(skb->len))
goto out;
goto out_err;
}
out:
err = skb->len;
out_err:
cb->seq = net->nexthop.seq;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
return err;
}
static struct nexthop *
nexthop_find_group_resilient(struct net *net, u32 id,
struct netlink_ext_ack *extack)
{
struct nh_group *nhg;
struct nexthop *nh;
nh = nexthop_find_by_id(net, id);
if (!nh)
return ERR_PTR(-ENOENT);
if (!nh->is_group) {
NL_SET_ERR_MSG(extack, "Not a nexthop group");
return ERR_PTR(-EINVAL);
}
nhg = rtnl_dereference(nh->nh_grp);
if (!nhg->resilient) {
NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient");
return ERR_PTR(-EINVAL);
}
return nh;
}
static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p,
struct netlink_ext_ack *extack)
{
u32 idx;
if (attr) {
idx = nla_get_u32(attr);
if (!idx) {
NL_SET_ERR_MSG(extack, "Invalid nexthop id");
return -EINVAL;
}
*nh_id_p = idx;
} else {
*nh_id_p = 0;
}
return 0;
}
static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh,
struct nh_dump_filter *filter,
struct netlink_callback *cb)
{
struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)];
struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)];
int err;
err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1,
rtm_nh_policy_dump_bucket, NULL);
if (err < 0)
return err;
err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack);
if (err)
return err;
if (tb[NHA_RES_BUCKET]) {
size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1;
err = nla_parse_nested(res_tb, max,
tb[NHA_RES_BUCKET],
rtm_nh_res_bucket_policy_dump,
cb->extack);
if (err < 0)
return err;
err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID],
&filter->res_bucket_nh_id,
cb->extack);
if (err)
return err;
}
return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
}
struct rtm_dump_res_bucket_ctx {
struct rtm_dump_nh_ctx nh;
u16 bucket_index;
u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */
};
static struct rtm_dump_res_bucket_ctx *
rtm_dump_res_bucket_ctx(struct netlink_callback *cb)
{
struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx;
BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
return ctx;
}
struct rtm_dump_nexthop_bucket_data {
struct rtm_dump_res_bucket_ctx *ctx;
struct nh_dump_filter filter;
};
static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb,
struct netlink_callback *cb,
struct nexthop *nh,
struct rtm_dump_nexthop_bucket_data *dd)
{
u32 portid = NETLINK_CB(cb->skb).portid;
struct nhmsg *nhm = nlmsg_data(cb->nlh);
struct nh_res_table *res_table;
struct nh_group *nhg;
u16 bucket_index;
int err;
if (dd->ctx->nh.idx < dd->ctx->done_nh_idx)
return 0;
nhg = rtnl_dereference(nh->nh_grp);
res_table = rtnl_dereference(nhg->res_table);
for (bucket_index = dd->ctx->bucket_index;
bucket_index < res_table->num_nh_buckets;
bucket_index++) {
struct nh_res_bucket *bucket;
struct nh_grp_entry *nhge;
bucket = &res_table->nh_buckets[bucket_index];
nhge = rtnl_dereference(bucket->nh_entry);
if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family))
continue;
if (dd->filter.res_bucket_nh_id &&
dd->filter.res_bucket_nh_id != nhge->nh->id)
continue;
err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
RTM_NEWNEXTHOPBUCKET, portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
cb->extack);
if (err < 0) {
if (likely(skb->len))
goto out;
goto out_err;
}
}
dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1;
bucket_index = 0;
out:
err = skb->len;
out_err:
dd->ctx->bucket_index = bucket_index;
return err;
}
static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb,
struct netlink_callback *cb,
struct nexthop *nh, void *data)
{
struct rtm_dump_nexthop_bucket_data *dd = data;
struct nh_group *nhg;
if (!nh->is_group)
return 0;
nhg = rtnl_dereference(nh->nh_grp);
if (!nhg->resilient)
return 0;
return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd);
}
/* rtnl */
static int rtm_dump_nexthop_bucket(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb);
struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx };
struct net *net = sock_net(skb->sk);
struct nexthop *nh;
int err;
err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb);
if (err)
return err;
if (dd.filter.nh_id) {
nh = nexthop_find_group_resilient(net, dd.filter.nh_id,
cb->extack);
if (IS_ERR(nh))
return PTR_ERR(nh);
err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd);
} else {
struct rb_root *root = &net->nexthop.rb_root;
err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh,
&rtm_dump_nexthop_bucket_cb, &dd);
}
if (err < 0) {
if (likely(skb->len))
goto out;
goto out_err;
}
out:
err = skb->len;
out_err:
cb->seq = net->nexthop.seq;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
return err;
}
static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res,
u16 *bucket_index,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)];
int err;
err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1,
res, rtm_nh_res_bucket_policy_get, extack);
if (err < 0)
return err;
if (!tb[NHA_RES_BUCKET_INDEX]) {
NL_SET_ERR_MSG(extack, "Bucket index is missing");
return -EINVAL;
}
*bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]);
return 0;
}
static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,
u32 *id, u16 *bucket_index,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)];
int err;
err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1,
rtm_nh_policy_get_bucket, extack);
if (err < 0)
return err;
err = __nh_valid_get_del_req(nlh, tb, id, extack);
if (err)
return err;
if (!tb[NHA_RES_BUCKET]) {
NL_SET_ERR_MSG(extack, "Bucket information is missing");
return -EINVAL;
}
err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET],
bucket_index, extack);
if (err)
return err;
return 0;
}
/* rtnl */
static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(in_skb->sk);
struct nh_res_table *res_table;
struct sk_buff *skb = NULL;
struct nh_group *nhg;
struct nexthop *nh;
u16 bucket_index;
int err;
u32 id;
err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack);
if (err)
return err;
nh = nexthop_find_group_resilient(net, id, extack);
if (IS_ERR(nh))
return PTR_ERR(nh);
nhg = rtnl_dereference(nh->nh_grp);
res_table = rtnl_dereference(nhg->res_table);
if (bucket_index >= res_table->num_nh_buckets) {
NL_SET_ERR_MSG(extack, "Bucket index out of bounds");
return -ENOENT;
}
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return -ENOBUFS;
err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index],
bucket_index, RTM_NEWNEXTHOPBUCKET,
NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
0, extack);
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
goto errout_free;
}
return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
errout_free:
kfree_skb(skb);
return err;
}
static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
{
unsigned int hash = nh_dev_hashfn(dev->ifindex);
struct net *net = dev_net(dev);
struct hlist_head *head = &net->nexthop.devhash[hash];
struct hlist_node *n;
struct nh_info *nhi;
hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
if (nhi->fib_nhc.nhc_dev == dev) {
if (nhi->family == AF_INET)
fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
orig_mtu);
}
}
}
/* rtnl */
static int nh_netdev_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct netdev_notifier_info_ext *info_ext;
switch (event) {
case NETDEV_DOWN:
case NETDEV_UNREGISTER:
nexthop_flush_dev(dev, event);
break;
case NETDEV_CHANGE:
if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
nexthop_flush_dev(dev, event);
break;
case NETDEV_CHANGEMTU:
info_ext = ptr;
nexthop_sync_mtu(dev, info_ext->ext.mtu);
rt_cache_flush(dev_net(dev));
break;
}
return NOTIFY_DONE;
}
static struct notifier_block nh_netdev_notifier = {
.notifier_call = nh_netdev_event,
};
static int nexthops_dump(struct net *net, struct notifier_block *nb,
enum nexthop_event_type event_type,
struct netlink_ext_ack *extack)
{
struct rb_root *root = &net->nexthop.rb_root;
struct rb_node *node;
int err = 0;
for (node = rb_first(root); node; node = rb_next(node)) {
struct nexthop *nh;
nh = rb_entry(node, struct nexthop, rb_node);
err = call_nexthop_notifier(nb, net, event_type, nh, extack);
if (err)
break;
}
return err;
}
int register_nexthop_notifier(struct net *net, struct notifier_block *nb,
struct netlink_ext_ack *extack)
{
int err;
rtnl_lock();
err = nexthops_dump(net, nb, NEXTHOP_EVENT_REPLACE, extack);
if (err)
goto unlock;
err = blocking_notifier_chain_register(&net->nexthop.notifier_chain,
nb);
unlock:
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(register_nexthop_notifier);
int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
{
int err;
rtnl_lock();
err = blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
nb);
if (err)
goto unlock;
nexthops_dump(net, nb, NEXTHOP_EVENT_DEL, NULL);
unlock:
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(unregister_nexthop_notifier);
void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap)
{
struct nexthop *nexthop;
rcu_read_lock();
nexthop = nexthop_find_by_id(net, id);
if (!nexthop)
goto out;
nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
if (offload)
nexthop->nh_flags |= RTNH_F_OFFLOAD;
if (trap)
nexthop->nh_flags |= RTNH_F_TRAP;
out:
rcu_read_unlock();
}
EXPORT_SYMBOL(nexthop_set_hw_flags);
void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index,
bool offload, bool trap)
{
struct nh_res_table *res_table;
struct nh_res_bucket *bucket;
struct nexthop *nexthop;
struct nh_group *nhg;
rcu_read_lock();
nexthop = nexthop_find_by_id(net, id);
if (!nexthop || !nexthop->is_group)
goto out;
nhg = rcu_dereference(nexthop->nh_grp);
if (!nhg->resilient)
goto out;
if (bucket_index >= nhg->res_table->num_nh_buckets)
goto out;
res_table = rcu_dereference(nhg->res_table);
bucket = &res_table->nh_buckets[bucket_index];
bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
if (offload)
bucket->nh_flags |= RTNH_F_OFFLOAD;
if (trap)
bucket->nh_flags |= RTNH_F_TRAP;
out:
rcu_read_unlock();
}
EXPORT_SYMBOL(nexthop_bucket_set_hw_flags);
void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets,
unsigned long *activity)
{
struct nh_res_table *res_table;
struct nexthop *nexthop;
struct nh_group *nhg;
u16 i;
rcu_read_lock();
nexthop = nexthop_find_by_id(net, id);
if (!nexthop || !nexthop->is_group)
goto out;
nhg = rcu_dereference(nexthop->nh_grp);
if (!nhg->resilient)
goto out;
/* Instead of silently ignoring some buckets, demand that the sizes
* be the same.
*/
res_table = rcu_dereference(nhg->res_table);
if (num_buckets != res_table->num_nh_buckets)
goto out;
for (i = 0; i < num_buckets; i++) {
if (test_bit(i, activity))
nh_res_bucket_set_busy(&res_table->nh_buckets[i]);
}
out:
rcu_read_unlock();
}
EXPORT_SYMBOL(nexthop_res_grp_activity_update);
static void __net_exit nexthop_net_exit_batch(struct list_head *net_list)
{
struct net *net;
rtnl_lock();
list_for_each_entry(net, net_list, exit_list) {
flush_all_nexthops(net);
kfree(net->nexthop.devhash);
}
rtnl_unlock();
}
static int __net_init nexthop_net_init(struct net *net)
{
size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
net->nexthop.rb_root = RB_ROOT;
net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
if (!net->nexthop.devhash)
return -ENOMEM;
BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
return 0;
}
static struct pernet_operations nexthop_net_ops = {
.init = nexthop_net_init,
.exit_batch = nexthop_net_exit_batch,
};
static int __init nexthop_init(void)
{
register_pernet_subsys(&nexthop_net_ops);
register_netdevice_notifier(&nh_netdev_notifier);
rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
rtm_dump_nexthop, 0);
rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket,
rtm_dump_nexthop_bucket, 0);
return 0;
}
subsys_initcall(nexthop_init);
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