[net-next,3/9] ipv4: Notify route if replacing currently offloaded one
diff mbox series

Message ID 20191210172402.463397-4-idosch@idosch.org
State Changes Requested
Delegated to: David Miller
Headers show
Series
  • Simplify IPv4 route offload API
Related show

Commit Message

Ido Schimmel Dec. 10, 2019, 5:23 p.m. UTC
From: Ido Schimmel <idosch@mellanox.com>

When replacing a route, its replacement should only be notified in case
the replaced route is of any interest to listeners. In other words, if
the replaced route is currently used in the data path, which means it is
the first route in the FIB alias list with the given {prefix, prefix
length, table ID}.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
---
 net/ipv4/fib_trie.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

Comments

David Ahern Dec. 11, 2019, 5:40 p.m. UTC | #1
On 12/10/19 10:23 AM, Ido Schimmel wrote:
> From: Ido Schimmel <idosch@mellanox.com>
> 
> When replacing a route, its replacement should only be notified in case
> the replaced route is of any interest to listeners. In other words, if
> the replaced route is currently used in the data path, which means it is
> the first route in the FIB alias list with the given {prefix, prefix
> length, table ID}.
> 
> Signed-off-by: Ido Schimmel <idosch@mellanox.com>
> ---
>  net/ipv4/fib_trie.c | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> 
> diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
> index 9264d6628e9f..6822aa90657a 100644
> --- a/net/ipv4/fib_trie.c
> +++ b/net/ipv4/fib_trie.c
> @@ -978,6 +978,27 @@ static struct key_vector *fib_find_node(struct trie *t,
>  	return n;
>  }
>  
> +/* Return the first fib alias matching prefix length and table ID. */
> +static struct fib_alias *fib_find_first_alias(struct hlist_head *fah, u8 slen,
> +					      u32 tb_id)
> +{
> +	struct fib_alias *fa;
> +
> +	hlist_for_each_entry(fa, fah, fa_list) {
> +		if (fa->fa_slen < slen)
> +			continue;
> +		if (fa->fa_slen != slen)
> +			break;
> +		if (fa->tb_id > tb_id)
> +			continue;
> +		if (fa->tb_id != tb_id)
> +			break;
> +		return fa;

Rather than duplicating fib_find_alias, how about adding a 'bool
find_first' argument and bail on it:

		if (find_first)
			return fa;

		continue to tos and priority compares.

> +	}
> +
> +	return NULL;
> +}
> +
>  /* Return the first fib alias matching TOS with
>   * priority less than or equal to PRIO.
>   */
> @@ -1217,6 +1238,17 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
>  			new_fa->tb_id = tb->tb_id;
>  			new_fa->fa_default = -1;
>  
> +			if (fib_find_first_alias(&l->leaf, fa->fa_slen,
> +						 tb->tb_id) == fa) {
> +				enum fib_event_type fib_event;
> +
> +				fib_event = FIB_EVENT_ENTRY_REPLACE_TMP;
> +				err = call_fib_entry_notifiers(net, fib_event,
> +							       key, plen,
> +							       new_fa, extack);
> +				if (err)
> +					goto out_free_new_fa;
> +			}
>  			err = call_fib_entry_notifiers(net,
>  						       FIB_EVENT_ENTRY_REPLACE,
>  						       key, plen, new_fa,
>
Ido Schimmel Dec. 11, 2019, 7:47 p.m. UTC | #2
On Wed, Dec 11, 2019 at 10:40:09AM -0700, David Ahern wrote:
> On 12/10/19 10:23 AM, Ido Schimmel wrote:
> > +/* Return the first fib alias matching prefix length and table ID. */
> > +static struct fib_alias *fib_find_first_alias(struct hlist_head *fah, u8 slen,
> > +					      u32 tb_id)
> > +{
> > +	struct fib_alias *fa;
> > +
> > +	hlist_for_each_entry(fa, fah, fa_list) {
> > +		if (fa->fa_slen < slen)
> > +			continue;
> > +		if (fa->fa_slen != slen)
> > +			break;
> > +		if (fa->tb_id > tb_id)
> > +			continue;
> > +		if (fa->tb_id != tb_id)
> > +			break;
> > +		return fa;
> 
> Rather than duplicating fib_find_alias, how about adding a 'bool
> find_first' argument and bail on it:
> 
> 		if (find_first)
> 			return fa;
> 
> 		continue to tos and priority compares.

Sure, I'll change this tomorrow morning.

Thanks, David!

> 
> > +	}
> > +
> > +	return NULL;
> > +}

Patch
diff mbox series

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 9264d6628e9f..6822aa90657a 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -978,6 +978,27 @@  static struct key_vector *fib_find_node(struct trie *t,
 	return n;
 }
 
+/* Return the first fib alias matching prefix length and table ID. */
+static struct fib_alias *fib_find_first_alias(struct hlist_head *fah, u8 slen,
+					      u32 tb_id)
+{
+	struct fib_alias *fa;
+
+	hlist_for_each_entry(fa, fah, fa_list) {
+		if (fa->fa_slen < slen)
+			continue;
+		if (fa->fa_slen != slen)
+			break;
+		if (fa->tb_id > tb_id)
+			continue;
+		if (fa->tb_id != tb_id)
+			break;
+		return fa;
+	}
+
+	return NULL;
+}
+
 /* Return the first fib alias matching TOS with
  * priority less than or equal to PRIO.
  */
@@ -1217,6 +1238,17 @@  int fib_table_insert(struct net *net, struct fib_table *tb,
 			new_fa->tb_id = tb->tb_id;
 			new_fa->fa_default = -1;
 
+			if (fib_find_first_alias(&l->leaf, fa->fa_slen,
+						 tb->tb_id) == fa) {
+				enum fib_event_type fib_event;
+
+				fib_event = FIB_EVENT_ENTRY_REPLACE_TMP;
+				err = call_fib_entry_notifiers(net, fib_event,
+							       key, plen,
+							       new_fa, extack);
+				if (err)
+					goto out_free_new_fa;
+			}
 			err = call_fib_entry_notifiers(net,
 						       FIB_EVENT_ENTRY_REPLACE,
 						       key, plen, new_fa,