[v2] batman-adv: Remove orig_node reference handling from send_skb_unicast
Commit Message
The function batadv_send_skb_unicast is not acquiring a reference for an
orig_node nor removing it from any datastructure. It still reduces the
reference counter for an object which is still in the hands of the caller.
This is confusing and can lead to problems in the reference handling in the
caller function.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
v2:
- remove bogus multicast example
- remove Fixes:
net/batman-adv/send.c | 22 ++++++++++++++++------
net/batman-adv/soft-interface.c | 3 +++
2 files changed, 19 insertions(+), 6 deletions(-)
Comments
On Mon, Jun 27, 2016 at 01:02:01AM +0200, Sven Eckelmann wrote:
> The function batadv_send_skb_unicast is not acquiring a reference for an
> orig_node nor removing it from any datastructure. It still reduces the
> reference counter for an object which is still in the hands of the caller.
>
> This is confusing and can lead to problems in the reference handling in the
> caller function.
>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
I like it, indeed easier to read, especially for the multicast
part.
Maybe make it a "This is confusing and could lead to ... in the future." to
avoid people misreading it as a fix?
> diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
> index 729deec..44be408 100644
> --- a/net/batman-adv/send.c
> +++ b/net/batman-adv/send.c
> @@ -362,8 +362,6 @@ int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
The kernel doc of batadv_send_skb_unicast seems to need an update,
too ("s/ and release a reference to this orig_node//").
@@ -362,8 +362,6 @@ int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
ret = NET_XMIT_SUCCESS;
out:
- if (orig_node)
- batadv_orig_node_put(orig_node);
if (ret == NET_XMIT_DROP)
kfree_skb(skb);
return ret;
@@ -395,6 +393,7 @@ int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
struct batadv_orig_node *orig_node;
u8 *src, *dst;
+ int ret;
src = ethhdr->h_source;
dst = ethhdr->h_dest;
@@ -406,8 +405,13 @@ int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
}
orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
- return batadv_send_skb_unicast(bat_priv, skb, packet_type,
- packet_subtype, orig_node, vid);
+ ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
+ packet_subtype, orig_node, vid);
+
+ if (orig_node)
+ batadv_orig_node_put(orig_node);
+
+ return ret;
}
/**
@@ -425,10 +429,16 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid)
{
struct batadv_orig_node *orig_node;
+ int ret;
orig_node = batadv_gw_get_selected_orig(bat_priv);
- return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
- orig_node, vid);
+ ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
+ orig_node, vid);
+
+ if (orig_node)
+ batadv_orig_node_put(orig_node);
+
+ return ret;
}
void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
@@ -57,6 +57,7 @@
#include "hard-interface.h"
#include "multicast.h"
#include "network-coding.h"
+#include "originator.h"
#include "packet.h"
#include "send.h"
#include "sysfs.h"
@@ -377,6 +378,8 @@ dropped:
dropped_freed:
batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
end:
+ if (mcast_single_orig)
+ batadv_orig_node_put(mcast_single_orig);
if (primary_if)
batadv_hardif_put(primary_if);
return NETDEV_TX_OK;