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authorEric W. Biederman <ebiederm@xmission.com>2010-05-04 17:36:46 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-21 09:37:32 -0700
commit910a7e905f36e51a17d6e8bb4ad6dcd5ac5f1d53 (patch)
tree63587b03de37a6b9a6b58c203719a24d57edf850
parentd6523ddf2376f39eaa89a4d68a33052d20c138b9 (diff)
netlink: Implment netlink_broadcast_filtered
When netlink sockets are used to convey data that is in a namespace we need a way to select a subset of the listening sockets to deliver the packet to. For the network namespace we have been doing this by only transmitting packets in the correct network namespace. For data belonging to other namespaces netlink_bradcast_filtered provides a mechanism that allows us to examine the destination socket and to decide if we should transmit the specified packet to it. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--include/linux/netlink.h4
-rw-r--r--net/netlink/af_netlink.c21
2 files changed, 23 insertions, 2 deletions
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 6eaca5e1e8c..59d066936ab 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -188,6 +188,10 @@ extern int netlink_has_listeners(struct sock *sk, unsigned int group);
extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
__u32 group, gfp_t allocation);
+extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
+ __u32 pid, __u32 group, gfp_t allocation,
+ int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
+ void *filter_data);
extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
extern int netlink_register_notifier(struct notifier_block *nb);
extern int netlink_unregister_notifier(struct notifier_block *nb);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 6464a1972a6..a2eb965207d 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -978,6 +978,8 @@ struct netlink_broadcast_data {
int delivered;
gfp_t allocation;
struct sk_buff *skb, *skb2;
+ int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
+ void *tx_data;
};
static inline int do_one_broadcast(struct sock *sk,
@@ -1020,6 +1022,9 @@ static inline int do_one_broadcast(struct sock *sk,
p->failure = 1;
if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
p->delivery_failure = 1;
+ } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
+ kfree_skb(p->skb2);
+ p->skb2 = NULL;
} else if (sk_filter(sk, p->skb2)) {
kfree_skb(p->skb2);
p->skb2 = NULL;
@@ -1038,8 +1043,10 @@ out:
return 0;
}
-int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
- u32 group, gfp_t allocation)
+int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid,
+ u32 group, gfp_t allocation,
+ int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
+ void *filter_data)
{
struct net *net = sock_net(ssk);
struct netlink_broadcast_data info;
@@ -1059,6 +1066,8 @@ int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
info.allocation = allocation;
info.skb = skb;
info.skb2 = NULL;
+ info.tx_filter = filter;
+ info.tx_data = filter_data;
/* While we sleep in clone, do not allow to change socket list */
@@ -1083,6 +1092,14 @@ int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
}
return -ESRCH;
}
+EXPORT_SYMBOL(netlink_broadcast_filtered);
+
+int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
+ u32 group, gfp_t allocation)
+{
+ return netlink_broadcast_filtered(ssk, skb, pid, group, allocation,
+ NULL, NULL);
+}
EXPORT_SYMBOL(netlink_broadcast);
struct netlink_set_err_data {