netfilter: nf_tables: fix flowtable free

Every flow_offload entry is added into the table twice. Because of this,
rhashtable_free_and_destroy can't be used, since it would call kfree for
each flow_offload object twice.

This patch cleans up the flowtable via nf_flow_table_iterate() to
schedule removal of entries by setting on the dying bit, then there is
an explicitly invocation of the garbage collector to release resources.

Based on patch from Felix Fietkau.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2018-02-06 13:22:47 +01:00
parent c0ea1bcb39
commit b408c5b04f
6 changed files with 26 additions and 13 deletions

View File

@ -14,6 +14,7 @@ struct nf_flowtable_type {
struct list_head list;
int family;
void (*gc)(struct work_struct *work);
void (*free)(struct nf_flowtable *ft);
const struct rhashtable_params *params;
nf_hookfn *hook;
struct module *owner;
@ -98,6 +99,7 @@ int nf_flow_table_iterate(struct nf_flowtable *flow_table,
void nf_flow_table_cleanup(struct net *net, struct net_device *dev);
void nf_flow_table_free(struct nf_flowtable *flow_table);
void nf_flow_offload_work_gc(struct work_struct *work);
extern const struct rhashtable_params nf_flow_offload_rhash_params;

View File

@ -260,6 +260,7 @@ static struct nf_flowtable_type flowtable_ipv4 = {
.family = NFPROTO_IPV4,
.params = &nf_flow_offload_rhash_params,
.gc = nf_flow_offload_work_gc,
.free = nf_flow_table_free,
.hook = nf_flow_offload_ip_hook,
.owner = THIS_MODULE,
};

View File

@ -253,6 +253,7 @@ static struct nf_flowtable_type flowtable_ipv6 = {
.family = NFPROTO_IPV6,
.params = &nf_flow_offload_rhash_params,
.gc = nf_flow_offload_work_gc,
.free = nf_flow_table_free,
.hook = nf_flow_offload_ipv6_hook,
.owner = THIS_MODULE,
};

View File

@ -232,19 +232,16 @@ static inline bool nf_flow_is_dying(const struct flow_offload *flow)
return flow->flags & FLOW_OFFLOAD_DYING;
}
void nf_flow_offload_work_gc(struct work_struct *work)
static int nf_flow_offload_gc_step(struct nf_flowtable *flow_table)
{
struct flow_offload_tuple_rhash *tuplehash;
struct nf_flowtable *flow_table;
struct rhashtable_iter hti;
struct flow_offload *flow;
int err;
flow_table = container_of(work, struct nf_flowtable, gc_work.work);
err = rhashtable_walk_init(&flow_table->rhashtable, &hti, GFP_KERNEL);
if (err)
goto schedule;
return 0;
rhashtable_walk_start(&hti);
@ -270,7 +267,16 @@ void nf_flow_offload_work_gc(struct work_struct *work)
out:
rhashtable_walk_stop(&hti);
rhashtable_walk_exit(&hti);
schedule:
return 1;
}
void nf_flow_offload_work_gc(struct work_struct *work)
{
struct nf_flowtable *flow_table;
flow_table = container_of(work, struct nf_flowtable, gc_work.work);
nf_flow_offload_gc_step(flow_table);
queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
}
EXPORT_SYMBOL_GPL(nf_flow_offload_work_gc);
@ -449,5 +455,12 @@ void nf_flow_table_cleanup(struct net *net, struct net_device *dev)
}
EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
void nf_flow_table_free(struct nf_flowtable *flow_table)
{
nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
WARN_ON(!nf_flow_offload_gc_step(flow_table));
}
EXPORT_SYMBOL_GPL(nf_flow_table_free);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");

View File

@ -24,6 +24,7 @@ static struct nf_flowtable_type flowtable_inet = {
.family = NFPROTO_INET,
.params = &nf_flow_offload_rhash_params,
.gc = nf_flow_offload_work_gc,
.free = nf_flow_table_free,
.hook = nf_flow_offload_inet_hook,
.owner = THIS_MODULE,
};

View File

@ -5399,17 +5399,12 @@ err:
nfnetlink_set_err(ctx->net, ctx->portid, NFNLGRP_NFTABLES, -ENOBUFS);
}
static void nft_flowtable_destroy(void *ptr, void *arg)
{
kfree(ptr);
}
static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable)
{
cancel_delayed_work_sync(&flowtable->data.gc_work);
kfree(flowtable->name);
rhashtable_free_and_destroy(&flowtable->data.rhashtable,
nft_flowtable_destroy, NULL);
flowtable->data.type->free(&flowtable->data);
rhashtable_destroy(&flowtable->data.rhashtable);
module_put(flowtable->data.type->owner);
}