netlink: allow to pass data pointer to netlink_dump_start() callback

This patch allows you to pass a data pointer that can be
accessed from the dump callback.

Netfilter is going to use this patch to provide filtered dumps
to user-space. This is specifically interesting in ctnetlink that
may handle lots of conntrack entries. We can save precious
cycles by skipping the conversion to TLV format of conntrack
entries that are not interesting for user-space.

More specifically, ctnetlink will include one operation to allow
to filter the dumping of conntrack entries by ctmark values.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pablo Neira Ayuso 2012-02-24 14:30:16 +00:00 committed by David S. Miller
parent 80d326fab5
commit 7175c88307
2 changed files with 3 additions and 0 deletions

View file

@ -225,6 +225,7 @@ struct netlink_callback {
int (*dump)(struct sk_buff * skb,
struct netlink_callback *cb);
int (*done)(struct netlink_callback *cb);
void *data;
u16 family;
u16 min_dump_alloc;
unsigned int prev_seq, seq;
@ -251,6 +252,7 @@ __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
struct netlink_dump_control {
int (*dump)(struct sk_buff *skb, struct netlink_callback *);
int (*done)(struct netlink_callback*);
void *data;
u16 min_dump_alloc;
};

View file

@ -1750,6 +1750,7 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
cb->dump = control->dump;
cb->done = control->done;
cb->nlh = nlh;
cb->data = control->data;
cb->min_dump_alloc = control->min_dump_alloc;
atomic_inc(&skb->users);
cb->skb = skb;