diff mbox series

[net-next,v4,2/5] ipv6: keep track of routes using src

Message ID 8e2c5bdc1b81e411da76df89cd9c13be2869ea2d.1574252982.git.pabeni@redhat.com
State Accepted
Delegated to: David Miller
Headers show
Series net: introduce and use route hint | expand

Commit Message

Paolo Abeni Nov. 20, 2019, 12:47 p.m. UTC 
Use a per namespace counter, increment it on successful creation
of any route using the source address, decrement it on deletion
of such routes.

This allows us to check easily if the routing decision in the
current namespace depends on the packet source. Will be used
by the next patch.

Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 include/net/ip6_fib.h    | 30 ++++++++++++++++++++++++++++++
 include/net/netns/ipv6.h |  3 +++
 net/ipv6/ip6_fib.c       |  4 ++++
 net/ipv6/route.c         |  3 +++
 4 files changed, 40 insertions(+)

Comments

David Ahern Nov. 21, 2019, 8:09 p.m. UTC | #1 
On 11/20/19 5:47 AM, Paolo Abeni wrote:
> Use a per namespace counter, increment it on successful creation
> of any route using the source address, decrement it on deletion
> of such routes.
> 
> This allows us to check easily if the routing decision in the
> current namespace depends on the packet source. Will be used
> by the next patch.
> 
> Suggested-by: David Ahern <dsahern@gmail.com>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>  include/net/ip6_fib.h    | 30 ++++++++++++++++++++++++++++++
>  include/net/netns/ipv6.h |  3 +++
>  net/ipv6/ip6_fib.c       |  4 ++++
>  net/ipv6/route.c         |  3 +++
>  4 files changed, 40 insertions(+)
> 

Reviewed-by: David Ahern <dsahern@gmail.com>
diff mbox series

Patch

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 8ac3a59e5126..f1535f172935 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -90,7 +90,32 @@  struct fib6_gc_args {
 
 #ifndef CONFIG_IPV6_SUBTREES
 #define FIB6_SUBTREE(fn)	NULL
+
+static inline bool fib6_routes_require_src(const struct net *net)
+{
+	return false;
+}
+
+static inline void fib6_routes_require_src_inc(struct net *net) {}
+static inline void fib6_routes_require_src_dec(struct net *net) {}
+
 #else
+
+static inline bool fib6_routes_require_src(const struct net *net)
+{
+	return net->ipv6.fib6_routes_require_src > 0;
+}
+
+static inline void fib6_routes_require_src_inc(struct net *net)
+{
+	net->ipv6.fib6_routes_require_src++;
+}
+
+static inline void fib6_routes_require_src_dec(struct net *net)
+{
+	net->ipv6.fib6_routes_require_src--;
+}
+
 #define FIB6_SUBTREE(fn)	(rcu_dereference_protected((fn)->subtree, 1))
 #endif
 
@@ -212,6 +237,11 @@  static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
 	return ((struct rt6_info *)dst)->rt6i_idev;
 }
 
+static inline bool fib6_requires_src(const struct fib6_info *rt)
+{
+	return rt->fib6_src.plen > 0;
+}
+
 static inline void fib6_clean_expires(struct fib6_info *f6i)
 {
 	f6i->fib6_flags &= ~RTF_EXPIRES;
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 022a0fd1a5a4..5ec054473d81 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -83,6 +83,9 @@  struct netns_ipv6 {
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 	unsigned int		fib6_rules_require_fldissect;
 	bool			fib6_has_custom_rules;
+#ifdef CONFIG_IPV6_SUBTREES
+	unsigned int		fib6_routes_require_src;
+#endif
 	struct rt6_info         *ip6_prohibit_entry;
 	struct rt6_info         *ip6_blk_hole_entry;
 	struct fib6_table       *fib6_local_tbl;
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index f66bc2af4e9d..7bae6a91b487 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1461,6 +1461,8 @@  int fib6_add(struct fib6_node *root, struct fib6_info *rt,
 		}
 #endif
 		goto failure;
+	} else if (fib6_requires_src(rt)) {
+		fib6_routes_require_src_inc(info->nl_net);
 	}
 	return err;
 
@@ -1933,6 +1935,8 @@  int fib6_del(struct fib6_info *rt, struct nl_info *info)
 		struct fib6_info *cur = rcu_dereference_protected(*rtp,
 					lockdep_is_held(&table->tb6_lock));
 		if (rt == cur) {
+			if (fib6_requires_src(cur))
+				fib6_routes_require_src_dec(info->nl_net);
 			fib6_del_route(table, fn, rtp, info);
 			return 0;
 		}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index edcb52543518..c92b367e058d 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -6199,6 +6199,9 @@  static int __net_init ip6_route_net_init(struct net *net)
 	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
 			 ip6_template_metrics, true);
 	INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
+#ifdef CONFIG_IPV6_SUBTREES
+	net->ipv6.fib6_routes_require_src = 0;
+#endif
 #endif
 
 	net->ipv6.sysctl.flush_delay = 0;