[PATCH 0/2] net: Use nlmsg_{multicast, unicast} that contain if statement

[PATCH 0/2] net: Use nlmsg_{multicast, unicast} that contain if statement

[Yajun Deng]

Patch1: use nlmsg_{multicast, unicast} instead of netlink_
{broadcast,unicast} in rtnetlink.
Patch2: The caller no need deal with the if statements and use
the rename function.

Yajun Deng (2):
  rtnetlink: use nlmsg_{multicast, unicast} instead of
    netlink_{broadcast,unicast}
  net/sched: Remove unnecessary judgment statements

 include/linux/rtnetlink.h |  2 +-
 net/core/rtnetlink.c      | 13 +++++++------
 net/sched/act_api.c       | 20 ++++++--------------
 net/sched/cls_api.c       | 28 +++++++++++-----------------
 net/sched/sch_api.c       | 18 ++++++------------
 5 files changed, 31 insertions(+), 50 deletions(-)

-- 
2.32.0

[PATCH 1/2] rtnetlink: use nlmsg_{multicast, unicast} instead of netlink_{broadcast,unicast}

[Yajun Deng]

It has a 'NETLINK_CB(' statement in nlmsg_multicast() and has 'if (err'
in nlmsg_{multicast, unicast}, use nlmsg_{multicast, unicast} instead
of netlink_{broadcast,unicast}. so the caller would not deal with the
'if (err >0 )' statement. Add the return value for nlmsg_multicast.
As also, rename rtnetlink_send() to rtnl_send(), this makes style
uniform.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
 include/linux/rtnetlink.h |  2 +-
 net/core/rtnetlink.c      | 13 +++++++------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index bb9cb84114c1..60bef82e42ab 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -9,7 +9,7 @@
 #include <linux/refcount.h>
 #include <uapi/linux/rtnetlink.h>
 
-extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
+extern int rtnl_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
 extern int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
 extern void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
 			u32 group, struct nlmsghdr *nlh, gfp_t flags);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f6af3e74fc44..c081d607bb69 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -707,17 +707,18 @@ static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
 	return err;
 }
 
-int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned int group, int echo)
+int rtnl_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned int group, int echo)
 {
 	struct sock *rtnl = net->rtnl;
 	int err = 0;
 
-	NETLINK_CB(skb).dst_group = group;
-	if (echo)
+	err = nlmsg_multicast(rtnl, skb, pid, group, GFP_KERNEL);
+
+	if (echo) {
 		refcount_inc(&skb->users);
-	netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
-	if (echo)
-		err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
+		err = nlmsg_unicast(rtnl, skb, pid);
+	}
+
 	return err;
 }
 
-- 
2.32.0

Re: [PATCH 1/2] rtnetlink: use nlmsg_{multicast, unicast} instead of netlink_{broadcast,unicast}

[Cong Wang]

On Tue, Jul 13, 2021 at 5:37 AM Yajun Deng <yajun.deng@linux.dev> wrote:
>
> It has a 'NETLINK_CB(' statement in nlmsg_multicast() and has 'if (err'
> in nlmsg_{multicast, unicast}, use nlmsg_{multicast, unicast} instead
> of netlink_{broadcast,unicast}. so the caller would not deal with the
> 'if (err >0 )' statement. Add the return value for nlmsg_multicast.
> As also, rename rtnetlink_send() to rtnl_send(), this makes style
> uniform.
>
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
> ---
>  include/linux/rtnetlink.h |  2 +-
>  net/core/rtnetlink.c      | 13 +++++++------
>  2 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
> index bb9cb84114c1..60bef82e42ab 100644
> --- a/include/linux/rtnetlink.h
> +++ b/include/linux/rtnetlink.h
> @@ -9,7 +9,7 @@
>  #include <linux/refcount.h>
>  #include <uapi/linux/rtnetlink.h>
>
> -extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
> +extern int rtnl_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
>  extern int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
>  extern void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
>                         u32 group, struct nlmsghdr *nlh, gfp_t flags);
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index f6af3e74fc44..c081d607bb69 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -707,17 +707,18 @@ static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
>         return err;
>  }
>
> -int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned int group, int echo)
> +int rtnl_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned int group, int echo)
>  {
>         struct sock *rtnl = net->rtnl;
>         int err = 0;
>
> -       NETLINK_CB(skb).dst_group = group;
> -       if (echo)
> +       err = nlmsg_multicast(rtnl, skb, pid, group, GFP_KERNEL);
> +
> +       if (echo) {
>                 refcount_inc(&skb->users);

You also moved this refcount_inc() down after nlmsg_multicast().
Are you sure it is safe?

And the name rtnl_send() is bad given that rtnl_unicast() follows it...

Thanks.