mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![wenxu](/assets/img/avatar_default.png)
The .deactivate and .activate interfaces already deal with the reference
counter. Otherwise, this results in spurious "Device is busy" errors.
Fixes: a3c90f7a23
("netfilter: nf_tables: flow offload expression")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
288 lines
6.9 KiB
C
288 lines
6.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/netlink.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/netfilter/nf_conntrack_common.h>
|
|
#include <linux/netfilter/nf_tables.h>
|
|
#include <net/ip.h> /* for ipv4 options. */
|
|
#include <net/netfilter/nf_tables.h>
|
|
#include <net/netfilter/nf_tables_core.h>
|
|
#include <net/netfilter/nf_conntrack_core.h>
|
|
#include <net/netfilter/nf_conntrack_extend.h>
|
|
#include <net/netfilter/nf_flow_table.h>
|
|
|
|
struct nft_flow_offload {
|
|
struct nft_flowtable *flowtable;
|
|
};
|
|
|
|
static int nft_flow_route(const struct nft_pktinfo *pkt,
|
|
const struct nf_conn *ct,
|
|
struct nf_flow_route *route,
|
|
enum ip_conntrack_dir dir)
|
|
{
|
|
struct dst_entry *this_dst = skb_dst(pkt->skb);
|
|
struct dst_entry *other_dst = NULL;
|
|
struct flowi fl;
|
|
|
|
memset(&fl, 0, sizeof(fl));
|
|
switch (nft_pf(pkt)) {
|
|
case NFPROTO_IPV4:
|
|
fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
|
|
fl.u.ip4.flowi4_oif = nft_in(pkt)->ifindex;
|
|
break;
|
|
case NFPROTO_IPV6:
|
|
fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
|
|
fl.u.ip6.flowi6_oif = nft_in(pkt)->ifindex;
|
|
break;
|
|
}
|
|
|
|
nf_route(nft_net(pkt), &other_dst, &fl, false, nft_pf(pkt));
|
|
if (!other_dst)
|
|
return -ENOENT;
|
|
|
|
route->tuple[dir].dst = this_dst;
|
|
route->tuple[!dir].dst = other_dst;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool nft_flow_offload_skip(struct sk_buff *skb, int family)
|
|
{
|
|
if (skb_sec_path(skb))
|
|
return true;
|
|
|
|
if (family == NFPROTO_IPV4) {
|
|
const struct ip_options *opt;
|
|
|
|
opt = &(IPCB(skb)->opt);
|
|
|
|
if (unlikely(opt->optlen))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void nft_flow_offload_eval(const struct nft_expr *expr,
|
|
struct nft_regs *regs,
|
|
const struct nft_pktinfo *pkt)
|
|
{
|
|
struct nft_flow_offload *priv = nft_expr_priv(expr);
|
|
struct nf_flowtable *flowtable = &priv->flowtable->data;
|
|
struct tcphdr _tcph, *tcph = NULL;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_flow_route route;
|
|
struct flow_offload *flow;
|
|
enum ip_conntrack_dir dir;
|
|
struct nf_conn *ct;
|
|
int ret;
|
|
|
|
if (nft_flow_offload_skip(pkt->skb, nft_pf(pkt)))
|
|
goto out;
|
|
|
|
ct = nf_ct_get(pkt->skb, &ctinfo);
|
|
if (!ct)
|
|
goto out;
|
|
|
|
switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
|
|
case IPPROTO_TCP:
|
|
tcph = skb_header_pointer(pkt->skb, pkt->xt.thoff,
|
|
sizeof(_tcph), &_tcph);
|
|
if (unlikely(!tcph || tcph->fin || tcph->rst))
|
|
goto out;
|
|
break;
|
|
case IPPROTO_UDP:
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
|
|
ct->status & IPS_SEQ_ADJUST)
|
|
goto out;
|
|
|
|
if (!nf_ct_is_confirmed(ct))
|
|
goto out;
|
|
|
|
if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
|
|
goto out;
|
|
|
|
dir = CTINFO2DIR(ctinfo);
|
|
if (nft_flow_route(pkt, ct, &route, dir) < 0)
|
|
goto err_flow_route;
|
|
|
|
flow = flow_offload_alloc(ct);
|
|
if (!flow)
|
|
goto err_flow_alloc;
|
|
|
|
if (flow_offload_route_init(flow, &route) < 0)
|
|
goto err_flow_add;
|
|
|
|
if (tcph) {
|
|
ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
|
|
ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
|
|
}
|
|
|
|
ret = flow_offload_add(flowtable, flow);
|
|
if (ret < 0)
|
|
goto err_flow_add;
|
|
|
|
dst_release(route.tuple[!dir].dst);
|
|
return;
|
|
|
|
err_flow_add:
|
|
flow_offload_free(flow);
|
|
err_flow_alloc:
|
|
dst_release(route.tuple[!dir].dst);
|
|
err_flow_route:
|
|
clear_bit(IPS_OFFLOAD_BIT, &ct->status);
|
|
out:
|
|
regs->verdict.code = NFT_BREAK;
|
|
}
|
|
|
|
static int nft_flow_offload_validate(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
const struct nft_data **data)
|
|
{
|
|
unsigned int hook_mask = (1 << NF_INET_FORWARD);
|
|
|
|
return nft_chain_validate_hooks(ctx->chain, hook_mask);
|
|
}
|
|
|
|
static const struct nla_policy nft_flow_offload_policy[NFTA_FLOW_MAX + 1] = {
|
|
[NFTA_FLOW_TABLE_NAME] = { .type = NLA_STRING,
|
|
.len = NFT_NAME_MAXLEN - 1 },
|
|
};
|
|
|
|
static int nft_flow_offload_init(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
const struct nlattr * const tb[])
|
|
{
|
|
struct nft_flow_offload *priv = nft_expr_priv(expr);
|
|
u8 genmask = nft_genmask_next(ctx->net);
|
|
struct nft_flowtable *flowtable;
|
|
|
|
if (!tb[NFTA_FLOW_TABLE_NAME])
|
|
return -EINVAL;
|
|
|
|
flowtable = nft_flowtable_lookup(ctx->table, tb[NFTA_FLOW_TABLE_NAME],
|
|
genmask);
|
|
if (IS_ERR(flowtable))
|
|
return PTR_ERR(flowtable);
|
|
|
|
priv->flowtable = flowtable;
|
|
flowtable->use++;
|
|
|
|
return nf_ct_netns_get(ctx->net, ctx->family);
|
|
}
|
|
|
|
static void nft_flow_offload_deactivate(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
enum nft_trans_phase phase)
|
|
{
|
|
struct nft_flow_offload *priv = nft_expr_priv(expr);
|
|
|
|
nf_tables_deactivate_flowtable(ctx, priv->flowtable, phase);
|
|
}
|
|
|
|
static void nft_flow_offload_activate(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr)
|
|
{
|
|
struct nft_flow_offload *priv = nft_expr_priv(expr);
|
|
|
|
priv->flowtable->use++;
|
|
}
|
|
|
|
static void nft_flow_offload_destroy(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr)
|
|
{
|
|
nf_ct_netns_put(ctx->net, ctx->family);
|
|
}
|
|
|
|
static int nft_flow_offload_dump(struct sk_buff *skb, const struct nft_expr *expr)
|
|
{
|
|
struct nft_flow_offload *priv = nft_expr_priv(expr);
|
|
|
|
if (nla_put_string(skb, NFTA_FLOW_TABLE_NAME, priv->flowtable->name))
|
|
goto nla_put_failure;
|
|
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
return -1;
|
|
}
|
|
|
|
static struct nft_expr_type nft_flow_offload_type;
|
|
static const struct nft_expr_ops nft_flow_offload_ops = {
|
|
.type = &nft_flow_offload_type,
|
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_flow_offload)),
|
|
.eval = nft_flow_offload_eval,
|
|
.init = nft_flow_offload_init,
|
|
.activate = nft_flow_offload_activate,
|
|
.deactivate = nft_flow_offload_deactivate,
|
|
.destroy = nft_flow_offload_destroy,
|
|
.validate = nft_flow_offload_validate,
|
|
.dump = nft_flow_offload_dump,
|
|
};
|
|
|
|
static struct nft_expr_type nft_flow_offload_type __read_mostly = {
|
|
.name = "flow_offload",
|
|
.ops = &nft_flow_offload_ops,
|
|
.policy = nft_flow_offload_policy,
|
|
.maxattr = NFTA_FLOW_MAX,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int flow_offload_netdev_event(struct notifier_block *this,
|
|
unsigned long event, void *ptr)
|
|
{
|
|
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
|
|
|
|
if (event != NETDEV_DOWN)
|
|
return NOTIFY_DONE;
|
|
|
|
nf_flow_table_cleanup(dev);
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block flow_offload_netdev_notifier = {
|
|
.notifier_call = flow_offload_netdev_event,
|
|
};
|
|
|
|
static int __init nft_flow_offload_module_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = register_netdevice_notifier(&flow_offload_netdev_notifier);
|
|
if (err)
|
|
goto err;
|
|
|
|
err = nft_register_expr(&nft_flow_offload_type);
|
|
if (err < 0)
|
|
goto register_expr;
|
|
|
|
return 0;
|
|
|
|
register_expr:
|
|
unregister_netdevice_notifier(&flow_offload_netdev_notifier);
|
|
err:
|
|
return err;
|
|
}
|
|
|
|
static void __exit nft_flow_offload_module_exit(void)
|
|
{
|
|
nft_unregister_expr(&nft_flow_offload_type);
|
|
unregister_netdevice_notifier(&flow_offload_netdev_notifier);
|
|
}
|
|
|
|
module_init(nft_flow_offload_module_init);
|
|
module_exit(nft_flow_offload_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
|
|
MODULE_ALIAS_NFT_EXPR("flow_offload");
|