This is a note to let you know that I've just added the patch titled
netlink: add a start callback for starting a netlink dump
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netlink-add-a-start-callback-for-starting-a-netlink-dump.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fc9e50f5a5a4e1fa9ba2756f745a13e693cf6a06 Mon Sep 17 00:00:00 2001
From: Tom Herbert <tom@xxxxxxxxxxxxxxx>
Date: Tue, 15 Dec 2015 15:41:37 -0800
Subject: netlink: add a start callback for starting a netlink dump
From: Tom Herbert <tom@xxxxxxxxxxxxxxx>
commit fc9e50f5a5a4e1fa9ba2756f745a13e693cf6a06 upstream.
The start callback allows the caller to set up a context for the
dump callbacks. Presumably, the context can then be destroyed in
the done callback.
Signed-off-by: Tom Herbert <tom@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/netlink.h | 2 ++
include/net/genetlink.h | 2 ++
net/netlink/af_netlink.c | 4 ++++
net/netlink/genetlink.c | 16 ++++++++++++++++
4 files changed, 24 insertions(+)
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -131,6 +131,7 @@ netlink_skb_clone(struct sk_buff *skb, g
struct netlink_callback {
struct sk_buff *skb;
const struct nlmsghdr *nlh;
+ int (*start)(struct netlink_callback *);
int (*dump)(struct sk_buff * skb,
struct netlink_callback *cb);
int (*done)(struct netlink_callback *cb);
@@ -153,6 +154,7 @@ struct nlmsghdr *
__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
struct netlink_dump_control {
+ int (*start)(struct netlink_callback *);
int (*dump)(struct sk_buff *skb, struct netlink_callback *);
int (*done)(struct netlink_callback *);
void *data;
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h
@@ -114,6 +114,7 @@ static inline void genl_info_net_set(str
* @flags: flags
* @policy: attribute validation policy
* @doit: standard command callback
+ * @start: start callback for dumps
* @dumpit: callback for dumpers
* @done: completion callback for dumps
* @ops_list: operations list
@@ -122,6 +123,7 @@ struct genl_ops {
const struct nla_policy *policy;
int (*doit)(struct sk_buff *skb,
struct genl_info *info);
+ int (*start)(struct netlink_callback *cb);
int (*dumpit)(struct sk_buff *skb,
struct netlink_callback *cb);
int (*done)(struct netlink_callback *cb);
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2203,6 +2203,7 @@ int __netlink_dump_start(struct sock *ss
cb = &nlk->cb;
memset(cb, 0, sizeof(*cb));
+ cb->start = control->start;
cb->dump = control->dump;
cb->done = control->done;
cb->nlh = nlh;
@@ -2216,6 +2217,9 @@ int __netlink_dump_start(struct sock *ss
mutex_unlock(nlk->cb_mutex);
+ if (cb->start)
+ cb->start(cb);
+
ret = netlink_dump(sk);
sock_put(sk);
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -513,6 +513,20 @@ void *genlmsg_put(struct sk_buff *skb, u
}
EXPORT_SYMBOL(genlmsg_put);
+static int genl_lock_start(struct netlink_callback *cb)
+{
+ /* our ops are always const - netlink API doesn't propagate that */
+ const struct genl_ops *ops = cb->data;
+ int rc = 0;
+
+ if (ops->start) {
+ genl_lock();
+ rc = ops->start(cb);
+ genl_unlock();
+ }
+ return rc;
+}
+
static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
/* our ops are always const - netlink API doesn't propagate that */
@@ -577,6 +591,7 @@ static int genl_family_rcv_msg(struct ge
.module = family->module,
/* we have const, but the netlink API doesn't */
.data = (void *)ops,
+ .start = genl_lock_start,
.dump = genl_lock_dumpit,
.done = genl_lock_done,
};
@@ -588,6 +603,7 @@ static int genl_family_rcv_msg(struct ge
} else {
struct netlink_dump_control c = {
.module = family->module,
+ .start = ops->start,
.dump = ops->dumpit,
.done = ops->done,
};
Patches currently in stable-queue which might be from tom@xxxxxxxxxxxxxxx are
queue-4.4/netlink-add-a-start-callback-for-starting-a-netlink-dump.patch