[PATCH 5.15 232/245] netfilter: flowtable: simplify route logic

Greg Kroah-Hartman
2024-02-27T14:11:36Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit fa502c86566680ac62bc28ec883a069bf7a2aa5e ]

Grab reference to dst from skbuff earlier to simplify route caching.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 9e0f0430389b ("netfilter: nft_flow_offload: reset dst in route object after setting up flow")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/netfilter/nf_flow_table.h | 4 ++--
net/netfilter/nf_flow_table_core.c | 24 +++---------------------
net/netfilter/nft_flow_offload.c | 12 ++++++++----
3 files changed, 13 insertions(+), 27 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index aaa518e777e9e..7677aacf72002 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -257,8 +257,8 @@ nf_flow_table_offload_del_cb(struct nf_flowtable *flow_table,
up_write(&flow_table->flow_block_lock);
}

-int flow_offload_route_init(struct flow_offload *flow,
- const struct nf_flow_route *route);
+void flow_offload_route_init(struct flow_offload *flow,
+ const struct nf_flow_route *route);

int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow);
void flow_offload_refresh(struct nf_flowtable *flow_table,
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 4f61eb1282834..4e0a2d47f6a6b 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -124,9 +124,6 @@ static int flow_offload_fill_route(struct flow_offload *flow,
break;
case FLOW_OFFLOAD_XMIT_XFRM:
case FLOW_OFFLOAD_XMIT_NEIGH:
- if (!dst_hold_safe(route->tuple[dir].dst))
- return -1;
-
flow_tuple->dst_cache = dst;
flow_tuple->dst_cookie = flow_offload_dst_cookie(flow_tuple);
break;
@@ -147,27 +144,12 @@ static void nft_flow_dst_release(struct flow_offload *flow,
dst_release(flow->tuplehash[dir].tuple.dst_cache);
}

-int flow_offload_route_init(struct flow_offload *flow,
+void flow_offload_route_init(struct flow_offload *flow,
const struct nf_flow_route *route)
{
- int err;
-
- err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
- if (err < 0)
- return err;
-
- err = flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
- if (err < 0)
- goto err_route_reply;
-
+ flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
+ flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);
flow->type = NF_FLOW_OFFLOAD_ROUTE;
-
- return 0;
-
-err_route_reply:
- nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
-
- return err;
}
EXPORT_SYMBOL_GPL(flow_offload_route_init);

diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index f8346497c9b49..fbb9f3a6c8444 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -240,9 +240,14 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
break;
}

+ if (!dst_hold_safe(this_dst))
+ return -ENOENT;
+
nf_route(nft_net(pkt), &other_dst, &fl, false, nft_pf(pkt));
- if (!other_dst)
+ if (!other_dst) {
+ dst_release(this_dst);
return -ENOENT;
+ }

nft_default_forward_path(route, this_dst, dir);
nft_default_forward_path(route, other_dst, !dir);
@@ -326,8 +331,7 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
if (!flow)
goto err_flow_alloc;

- if (flow_offload_route_init(flow, &route) < 0)
- goto err_flow_add;
+ flow_offload_route_init(flow, &route);

if (tcph) {
ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
@@ -338,12 +342,12 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
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);
dst_release(route.tuple[!dir].dst);
err_flow_route:
clear_bit(IPS_OFFLOAD_BIT, &ct->status);
--
2.43.0