kernel: check dst of flow offloading table

Flow offload dst can become invalid after the route cache is created.
dst_check() in packet path is necessary to prevent packet drop.

Signed-off-by: Ritaro Takenaka <ritarot634@gmail.com>
This commit is contained in:
Ritaro Takenaka 2022-05-25 15:55:48 +09:00 committed by Hauke Mehrtens
parent 78b7515c2e
commit 6d891adf39
8 changed files with 119 additions and 22 deletions

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@ -0,0 +1,97 @@
From 94936600fce68845edea66ae6d06ad12d6469e0b Mon Sep 17 00:00:00 2001
From: Ritaro Takenaka <ritarot634@gmail.com>
Date: Tue, 31 May 2022 00:25:08 +0900
Subject: [PATCH] netfilter: flowtable: add check_dst in packet path
Flow offload dst can become invalid after the route cache is created.
dst_check() in packet path is necessary to prevent packet drop.
[ Upstream commit 2738d9d963bd1f06d5114c2b4fa5771a95703991
8b9229d15877ec77775633f058d14145f6eb98fa
e5075c0badaaac245a6fa0b4625b5cd714d8ade3 ]
Signed-off-by: Ritaro Takenaka <ritarot634@gmail.com>
---
include/net/netfilter/nf_flow_table.h | 5 ++++-
net/netfilter/nf_flow_table_core.c | 13 +++++++++++++
net/netfilter/nf_flow_table_ip.c | 12 ++----------
3 files changed, 19 insertions(+), 11 deletions(-)
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -56,7 +56,10 @@ struct flow_offload_tuple {
u16 mtu;
- struct dst_entry *dst_cache;
+ struct {
+ struct dst_entry *dst_cache;
+ u32 dst_cookie;
+ };
};
struct flow_offload_tuple_rhash {
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -23,6 +23,18 @@ struct flow_offload_entry {
static DEFINE_MUTEX(flowtable_lock);
static LIST_HEAD(flowtables);
+static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
+{
+ const struct rt6_info *rt;
+
+ if (flow_tuple->l3proto == NFPROTO_IPV6) {
+ rt = (const struct rt6_info *)flow_tuple->dst_cache;
+ return rt6_get_cookie(rt);
+ }
+
+ return 0;
+}
+
static void
flow_offload_fill_dir(struct flow_offload *flow, struct nf_conn *ct,
struct nf_flow_route *route,
@@ -55,6 +67,7 @@ flow_offload_fill_dir(struct flow_offloa
ft->iifidx = other_dst->dev->ifindex;
ft->dst_cache = dst;
+ ft->dst_cookie = flow_offload_dst_cookie(ft);
}
struct flow_offload *
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -215,14 +215,6 @@ static bool nf_flow_exceeds_mtu(const st
return true;
}
-static int nf_flow_offload_dst_check(struct dst_entry *dst)
-{
- if (unlikely(dst_xfrm(dst)))
- return dst_check(dst, 0) ? 0 : -1;
-
- return 0;
-}
-
static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb,
const struct nf_hook_state *state,
struct dst_entry *dst)
@@ -273,7 +265,7 @@ nf_flow_offload_ip_hook(void *priv, stru
if (nf_flow_state_check(flow, ip_hdr(skb)->protocol, skb, thoff))
return NF_ACCEPT;
- if (nf_flow_offload_dst_check(&rt->dst)) {
+ if (!dst_check(&rt->dst, 0)) {
flow_offload_teardown(flow);
return NF_ACCEPT;
}
@@ -500,7 +492,7 @@ nf_flow_offload_ipv6_hook(void *priv, st
sizeof(*ip6h)))
return NF_ACCEPT;
- if (nf_flow_offload_dst_check(&rt->dst)) {
+ if (!dst_check(&rt->dst, tuplehash->tuple.dst_cookie)) {
flow_offload_teardown(flow);
return NF_ACCEPT;
}

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@ -1,6 +1,6 @@
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -160,6 +160,8 @@ struct nf_flow_table_hw {
@@ -163,6 +163,8 @@ struct nf_flow_table_hw {
int nf_flow_table_hw_register(const struct nf_flow_table_hw *offload);
void nf_flow_table_hw_unregister(const struct nf_flow_table_hw *offload);
@ -19,7 +19,7 @@
struct flow_offload_entry {
struct flow_offload flow;
@@ -164,6 +165,22 @@ void flow_offload_free(struct flow_offlo
@@ -177,6 +178,22 @@ void flow_offload_free(struct flow_offlo
}
EXPORT_SYMBOL_GPL(flow_offload_free);
@ -52,7 +52,7 @@
/* For layer 4 checksum field offset. */
#include <linux/tcp.h>
#include <linux/udp.h>
@@ -296,6 +297,7 @@ nf_flow_offload_ip_hook(void *priv, stru
@@ -288,6 +289,7 @@ nf_flow_offload_ip_hook(void *priv, stru
skb->dev = outdev;
nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
skb_dst_set_noref(skb, &rt->dst);
@ -60,7 +60,7 @@
neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
return NF_STOLEN;
@@ -526,6 +528,7 @@ nf_flow_offload_ipv6_hook(void *priv, st
@@ -518,6 +520,7 @@ nf_flow_offload_ipv6_hook(void *priv, st
skb->dev = outdev;
nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
skb_dst_set_noref(skb, &rt->dst);

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@ -536,7 +536,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
#include <net/netfilter/nf_flow_table.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
@@ -338,8 +337,7 @@ flow_offload_lookup(struct nf_flowtable
@@ -351,8 +350,7 @@ flow_offload_lookup(struct nf_flowtable
}
EXPORT_SYMBOL_GPL(flow_offload_lookup);
@ -546,7 +546,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
void (*iter)(struct flow_offload *flow, void *data),
void *data)
{
@@ -372,6 +370,7 @@ nf_flow_table_iterate(struct nf_flowtabl
@@ -385,6 +383,7 @@ nf_flow_table_iterate(struct nf_flowtabl
return err;
}
@ -576,7 +576,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
+#endif /* _XT_FLOWOFFLOAD_H */
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -130,6 +130,10 @@ static inline void flow_offload_dead(str
@@ -133,6 +133,10 @@ static inline void flow_offload_dead(str
flow->flags |= FLOW_OFFLOAD_DYING;
}

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@ -77,7 +77,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
};
enum flow_offload_tuple_dir {
@@ -68,6 +74,7 @@ struct flow_offload_tuple_rhash {
@@ -71,6 +77,7 @@ struct flow_offload_tuple_rhash {
#define FLOW_OFFLOAD_DNAT 0x2
#define FLOW_OFFLOAD_DYING 0x4
#define FLOW_OFFLOAD_TEARDOWN 0x8
@ -85,7 +85,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
struct flow_offload {
struct flow_offload_tuple_rhash tuplehash[FLOW_OFFLOAD_DIR_MAX];
@@ -120,6 +127,22 @@ unsigned int nf_flow_offload_ip_hook(voi
@@ -123,6 +130,22 @@ unsigned int nf_flow_offload_ip_hook(voi
unsigned int nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state);
@ -156,7 +156,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -248,10 +248,16 @@ static inline bool nf_flow_has_expired(c
@@ -261,10 +261,16 @@ static inline bool nf_flow_has_expired(c
return nf_flow_timeout_delta(flow->timeout) <= 0;
}
@ -173,7 +173,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
rhashtable_remove_fast(&flow_table->rhashtable,
&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
@@ -271,6 +277,9 @@ static void flow_offload_del(struct nf_f
@@ -284,6 +290,9 @@ static void flow_offload_del(struct nf_f
if (!(flow->flags & FLOW_OFFLOAD_TEARDOWN))
flow_offload_fixup_ct_state(e->ct);
@ -183,7 +183,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
flow_offload_free(flow);
}
@@ -361,6 +370,9 @@ static void nf_flow_offload_gc_step(stru
@@ -374,6 +383,9 @@ static void nf_flow_offload_gc_step(stru
if (!teardown)
nf_ct_offload_timeout(flow);
@ -193,7 +193,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
if (nf_flow_has_expired(flow) || teardown)
flow_offload_del(flow_table, flow);
}
@@ -490,10 +502,43 @@ int nf_flow_dnat_port(const struct flow_
@@ -503,10 +515,43 @@ int nf_flow_dnat_port(const struct flow_
}
EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
@ -237,7 +237,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
INIT_DEFERRABLE_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
err = rhashtable_init(&flowtable->rhashtable,
@@ -534,6 +579,8 @@ static void nf_flow_table_iterate_cleanu
@@ -547,6 +592,8 @@ static void nf_flow_table_iterate_cleanu
{
nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
flush_delayed_work(&flowtable->gc_work);
@ -246,7 +246,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
}
void nf_flow_table_cleanup(struct net_device *dev)
@@ -547,6 +594,26 @@ void nf_flow_table_cleanup(struct net_de
@@ -560,6 +607,26 @@ void nf_flow_table_cleanup(struct net_de
}
EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
@ -273,7 +273,7 @@ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
void nf_flow_table_free(struct nf_flowtable *flow_table)
{
mutex_lock(&flowtable_lock);
@@ -556,9 +623,58 @@ void nf_flow_table_free(struct nf_flowta
@@ -569,9 +636,58 @@ void nf_flow_table_free(struct nf_flowta
nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
rhashtable_destroy(&flow_table->rhashtable);

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@ -55,7 +55,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
int (*ndo_get_phys_port_id)(struct net_device *dev,
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -85,6 +85,21 @@ struct flow_offload {
@@ -88,6 +88,21 @@ struct flow_offload {
};
};

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@ -16,7 +16,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -75,6 +75,7 @@ struct flow_offload_tuple_rhash {
@@ -78,6 +78,7 @@ struct flow_offload_tuple_rhash {
#define FLOW_OFFLOAD_DYING 0x4
#define FLOW_OFFLOAD_TEARDOWN 0x8
#define FLOW_OFFLOAD_HW 0x10
@ -26,7 +26,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
struct flow_offload_tuple_rhash tuplehash[FLOW_OFFLOAD_DIR_MAX];
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -370,7 +370,7 @@ static void nf_flow_offload_gc_step(stru
@@ -383,7 +383,7 @@ static void nf_flow_offload_gc_step(stru
if (!teardown)
nf_ct_offload_timeout(flow);

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@ -11,7 +11,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -80,9 +80,10 @@ struct flow_offload_tuple_rhash {
@@ -83,9 +83,10 @@ struct flow_offload_tuple_rhash {
struct flow_offload {
struct flow_offload_tuple_rhash tuplehash[FLOW_OFFLOAD_DIR_MAX];
u32 flags;

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@ -9,7 +9,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -90,6 +90,7 @@ struct flow_offload {
@@ -93,6 +93,7 @@ struct flow_offload {
#define FLOW_OFFLOAD_PATH_ETHERNET BIT(0)
#define FLOW_OFFLOAD_PATH_VLAN BIT(1)
#define FLOW_OFFLOAD_PATH_PPPOE BIT(2)
@ -17,7 +17,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
struct flow_offload_hw_path {
struct net_device *dev;
@@ -100,6 +101,7 @@ struct flow_offload_hw_path {
@@ -103,6 +104,7 @@ struct flow_offload_hw_path {
u16 vlan_proto;
u16 vlan_id;
u16 pppoe_sid;