From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/net/bridge/br_input.c | 136 +++++++++++++++++++++++++++++++++++----------
1 files changed, 105 insertions(+), 31 deletions(-)
diff --git a/kernel/net/bridge/br_input.c b/kernel/net/bridge/br_input.c
index 2532c1a..bf5bf14 100644
--- a/kernel/net/bridge/br_input.c
+++ b/kernel/net/bridge/br_input.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Handle incoming frames
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
*/
#include <linux/slab.h>
@@ -16,16 +12,16 @@
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netfilter_bridge.h>
+#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
+#include <net/netfilter/nf_queue.h>
+#endif
#include <linux/neighbour.h>
#include <net/arp.h>
+#include <net/dsa.h>
#include <linux/export.h>
#include <linux/rculist.h>
#include "br_private.h"
#include "br_private_tunnel.h"
-
-/* Hook for brouter */
-br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
-EXPORT_SYMBOL(br_should_route_hook);
static int
br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb)
@@ -47,6 +43,13 @@
u64_stats_update_end(&brstats->syncp);
vg = br_vlan_group_rcu(br);
+
+ /* Reset the offload_fwd_mark because there could be a stacked
+ * bridge above, and it should not think this bridge it doing
+ * that bridge's work forwarding out its ports.
+ */
+ br_switchdev_frame_unmark(skb);
+
/* Bridge is just like any other port. Make sure the
* packet is allowed except in promisc modue when someone
* may be running packet capture.
@@ -81,11 +84,14 @@
bool local_rcv, mcast_hit = false;
struct net_bridge *br;
u16 vid = 0;
+ u8 state;
if (!p || p->state == BR_STATE_DISABLED)
goto drop;
- if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid))
+ state = p->state;
+ if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid,
+ &state))
goto out;
nbp_switchdev_frame_mark(p, skb);
@@ -93,7 +99,7 @@
/* insert into forwarding database after filtering to avoid spoofing */
br = p->br;
if (p->flags & BR_LEARNING)
- br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false);
+ br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, 0);
local_rcv = !!(br->dev->flags & IFF_PROMISC);
if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) {
@@ -108,7 +114,7 @@
}
}
- if (p->state == BR_STATE_LEARNING)
+ if (state == BR_STATE_LEARNING)
goto drop;
BR_INPUT_SKB_CB(skb)->brdev = br->dev;
@@ -120,7 +126,7 @@
br_do_proxy_suppress_arp(skb, br, vid, p);
} else if (IS_ENABLED(CONFIG_IPV6) &&
skb->protocol == htons(ETH_P_IPV6) &&
- br->neigh_suppress_enabled &&
+ br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
pskb_may_pull(skb, sizeof(struct ipv6hdr) +
sizeof(struct nd_msg)) &&
ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
@@ -156,7 +162,7 @@
if (dst) {
unsigned long now = jiffies;
- if (dst->is_local)
+ if (test_bit(BR_FDB_LOCAL, &dst->flags))
return br_pass_frame_up(skb);
if (now != dst->used)
@@ -186,8 +192,11 @@
u16 vid = 0;
/* check if vlan is allowed, to avoid spoofing */
- if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid))
- br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
+ if ((p->flags & BR_LEARNING) &&
+ nbp_state_should_learn(p) &&
+ !br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
+ br_should_learn(p, skb, &vid))
+ br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, 0);
}
/* note: already called with rcu_read_lock */
@@ -199,16 +208,68 @@
return 1;
}
+static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
+{
+#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
+ struct nf_hook_entries *e = NULL;
+ struct nf_hook_state state;
+ unsigned int verdict, i;
+ struct net *net;
+ int ret;
+
+ net = dev_net(skb->dev);
+#ifdef HAVE_JUMP_LABEL
+ if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))
+ goto frame_finish;
+#endif
+
+ e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]);
+ if (!e)
+ goto frame_finish;
+
+ nf_hook_state_init(&state, NF_BR_PRE_ROUTING,
+ NFPROTO_BRIDGE, skb->dev, NULL, NULL,
+ net, br_handle_frame_finish);
+
+ for (i = 0; i < e->num_hook_entries; i++) {
+ verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state);
+ switch (verdict & NF_VERDICT_MASK) {
+ case NF_ACCEPT:
+ if (BR_INPUT_SKB_CB(skb)->br_netfilter_broute) {
+ *pskb = skb;
+ return RX_HANDLER_PASS;
+ }
+ break;
+ case NF_DROP:
+ kfree_skb(skb);
+ return RX_HANDLER_CONSUMED;
+ case NF_QUEUE:
+ ret = nf_queue(skb, &state, i, verdict);
+ if (ret == 1)
+ continue;
+ return RX_HANDLER_CONSUMED;
+ default: /* STOLEN */
+ return RX_HANDLER_CONSUMED;
+ }
+ }
+frame_finish:
+ net = dev_net(skb->dev);
+ br_handle_frame_finish(net, NULL, skb);
+#else
+ br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
+#endif
+ return RX_HANDLER_CONSUMED;
+}
+
/*
* Return NULL if skb is handled
* note: already called with rcu_read_lock
*/
-rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
+static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
{
struct net_bridge_port *p;
struct sk_buff *skb = *pskb;
const unsigned char *dest = eth_hdr(skb)->h_dest;
- br_should_route_hook_t *rhook;
if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
return RX_HANDLER_PASS;
@@ -219,6 +280,8 @@
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
return RX_HANDLER_CONSUMED;
+
+ memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
p = br_port_get_rcu(skb->dev);
if (p->flags & BR_VLAN_TUNNEL) {
@@ -287,29 +350,40 @@
}
}
+ if (unlikely(br_mrp_process(p, skb)))
+ return RX_HANDLER_PASS;
+
forward:
switch (p->state) {
case BR_STATE_FORWARDING:
- rhook = rcu_dereference(br_should_route_hook);
- if (rhook) {
- if ((*rhook)(skb)) {
- *pskb = skb;
- return RX_HANDLER_PASS;
- }
- dest = eth_hdr(skb)->h_dest;
- }
- /* fall through */
case BR_STATE_LEARNING:
if (ether_addr_equal(p->br->dev->dev_addr, dest))
skb->pkt_type = PACKET_HOST;
- NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
- dev_net(skb->dev), NULL, skb, skb->dev, NULL,
- br_handle_frame_finish);
- break;
+ return nf_hook_bridge_pre(skb, pskb);
default:
drop:
kfree_skb(skb);
}
return RX_HANDLER_CONSUMED;
}
+
+/* This function has no purpose other than to appease the br_port_get_rcu/rtnl
+ * helpers which identify bridged ports according to the rx_handler installed
+ * on them (so there _needs_ to be a bridge rx_handler even if we don't need it
+ * to do anything useful). This bridge won't support traffic to/from the stack,
+ * but only hardware bridging. So return RX_HANDLER_PASS so we don't steal
+ * frames from the ETH_P_XDSA packet_type handler.
+ */
+static rx_handler_result_t br_handle_frame_dummy(struct sk_buff **pskb)
+{
+ return RX_HANDLER_PASS;
+}
+
+rx_handler_func_t *br_get_rx_handler(const struct net_device *dev)
+{
+ if (netdev_uses_dsa(dev))
+ return br_handle_frame_dummy;
+
+ return br_handle_frame;
+}
--
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