[PATCH net v2] Net:cache didn't flush when ipv6 rule changed

["Lena Wang (王娜)" <Lena.Wang@mediatek.com>]

From bf53859b379a653eec8a14fbb3f29286f9f888fb Mon Sep 17 00:00:00 2001
From: shiming cheng <shiming.cheng@mediatek.com>
Date: Mon, 26 Feb 2024 20:17:58 +0800
Subject: [PATCH net v2] Net:cache didn't flush when ipv6 rule changed

When changed from old rule&route configure to new one as below,
ipv6 cache dst_entry did not change to new route table as no
cache flush callback function, then forward to wrong out interface.
When fib6_check dst_entry, the fib6_node version[fn_sernm] is
always the same with socket dst_cookie, old cache dst_entry is
always used and no chance to update.

So we need to update fib6_node version when rule changed and
flush cache to avoid dispatching a wrong interface.

Signed-off-by: shiming cheng <shiming.cheng@mediatek.com>
---
v2: 
    1. Add the fix tag.
    2. Changes according to David Ahern's suggestions, modify flush
functions same way as ipv4 flush cache and use tabs to aligh with
existing code.
---
---
 net/ipv6/fib6_rules.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 7523c4baef35..52c04f0ac498 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -449,6 +449,11 @@ static size_t fib6_rule_nlmsg_payload(struct
fib_rule *rule)
 	       + nla_total_size(16); /* src */
 }
 
+static void fib6_rule_flush_cache(struct fib_rules_ops *ops)
+{
+	rt_genid_bump_ipv6(ops->fro_net);
+}
+
 static const struct fib_rules_ops __net_initconst
fib6_rules_ops_template = {
 	.family			= AF_INET6,
 	.rule_size		= sizeof(struct fib6_rule),
@@ -461,6 +466,7 @@ static const struct fib_rules_ops __net_initconst
fib6_rules_ops_template = {
 	.compare		= fib6_rule_compare,
 	.fill			= fib6_rule_fill,
 	.nlmsg_payload		= fib6_rule_nlmsg_payload,
+	.flush_cache		= fib6_rule_flush_cache,
 	.nlgroup		= RTNLGRP_IPV6_RULE,
 	.owner			= THIS_MODULE,
 	.fro_net		= &init_net,
-- 
2.18.0