[PATCH 1/1] netfilter: Use IS_ERR_OR_NULL instead of IS_ERR and NULl check to simplify the codes in ip_vs_genl_dump_dests and resolve_normal_ct

[PATCH 1/1] netfilter: Use IS_ERR_OR_NULL instead of IS_ERR and NULl check to simplify the codes in ip_vs_genl_dump_dests and resolve_normal_ct

[fgao]

From: Gao Feng <fgao@ikuai8.com>

Signed-off-by: Gao Feng <fgao@ikuai8.com>
---
 v1: Initial Version

 net/netfilter/ipvs/ip_vs_ctl.c    | 2 +-
 net/netfilter/nf_conntrack_core.c | 6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index c3c809b..6dc86cc 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3267,7 +3267,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
 
 
 	svc = ip_vs_genl_find_service(ipvs, attrs[IPVS_CMD_ATTR_SERVICE]);
-	if (IS_ERR(svc) || svc == NULL)
+	if (IS_ERR_OR_NULL(svc))
 		goto out_err;
 
 	/* Dump the destinations */
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 153e33f..634d592 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1108,10 +1108,8 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
 	if (!h) {
 		h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
 				   skb, dataoff, hash);
-		if (!h)
-			return NULL;
-		if (IS_ERR(h))
-			return (void *)h;
+		if (IS_ERR_OR_NULL(h))
+			return ERR_CAST(h);
 	}
 	ct = nf_ct_tuplehash_to_ctrack(h);
 
-- 
1.9.1

Re: [PATCH 1/1] netfilter: Use IS_ERR_OR_NULL instead of IS_ERR and NULl check to simplify the codes in ip_vs_genl_dump_dests and resolve_normal_ct

[Pablo Neira Ayuso]

This patch title is too long, no more than 80 chars please, when it
goes over that boundary it becomes a description ;)

More comments below.

On Thu, Jul 21, 2016 at 10:09:19PM +0800, fgao@ikuai8.com wrote:
> From: Gao Feng <fgao@ikuai8.com>
> 
> Signed-off-by: Gao Feng <fgao@ikuai8.com>
> ---
>  v1: Initial Version
> 
>  net/netfilter/ipvs/ip_vs_ctl.c    | 2 +-
>  net/netfilter/nf_conntrack_core.c | 6 ++----
>  2 files changed, 3 insertions(+), 5 deletions(-)
> 
[...]
> diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
> index 153e33f..634d592 100644
> --- a/net/netfilter/nf_conntrack_core.c
> +++ b/net/netfilter/nf_conntrack_core.c
> @@ -1108,10 +1108,8 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
>  	if (!h) {
>  		h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
>  				   skb, dataoff, hash);
> -		if (!h)
> -			return NULL;
> -		if (IS_ERR(h))
> -			return (void *)h;
> +		if (IS_ERR_OR_NULL(h))
> +			return ERR_CAST(h);

Interesting.

I think we can actually simplify this patch, I'm sending a patch for
this now.

Re: [PATCH 1/1] netfilter: Use IS_ERR_OR_NULL instead of IS_ERR and NULl check to simplify the codes in ip_vs_genl_dump_dests and resolve_normal_ct

[Pablo Neira Ayuso]

This patch title is too long, no more than 80 chars.

On Thu, Jul 21, 2016 at 10:09:19PM +0800, fgao@ikuai8.com wrote:
> From: Gao Feng <fgao@ikuai8.com>

Please, include a description here.

> Signed-off-by: Gao Feng <fgao@ikuai8.com>

More comments below.
> ---
>  v1: Initial Version
> 
>  net/netfilter/ipvs/ip_vs_ctl.c    | 2 +-
>  net/netfilter/nf_conntrack_core.c | 6 ++----
>  2 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index c3c809b..6dc86cc 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> @@ -3267,7 +3267,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
>  
>  
>  	svc = ip_vs_genl_find_service(ipvs, attrs[IPVS_CMD_ATTR_SERVICE]);
> -	if (IS_ERR(svc) || svc == NULL)
> +	if (IS_ERR_OR_NULL(svc))
>  		goto out_err;
>  
>  	/* Dump the destinations */

You have to send this chunk through ipvs-devel mailing list to request
and Acked-by on this.

> diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
> index 153e33f..634d592 100644
> --- a/net/netfilter/nf_conntrack_core.c
> +++ b/net/netfilter/nf_conntrack_core.c
> @@ -1108,10 +1108,8 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
>  	if (!h) {
>  		h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
>  				   skb, dataoff, hash);
> -		if (!h)
> -			return NULL;
> -		if (IS_ERR(h))
> -			return (void *)h;
> +		if (IS_ERR_OR_NULL(h))
> +			return ERR_CAST(h);
>  	}
>  	ct = nf_ct_tuplehash_to_ctrack(h);
>  
> -- 
> 1.9.1
> 
> 

Re: [PATCH 1/1] netfilter: Use IS_ERR_OR_NULL instead of IS_ERR and NULl check to simplify the codes in ip_vs_genl_dump_dests and resolve_normal_ct

[Pablo Neira Ayuso]

On Thu, Jul 21, 2016 at 06:45:53PM +0200, Pablo Neira Ayuso wrote:
> > diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
> > index 153e33f..634d592 100644
> > --- a/net/netfilter/nf_conntrack_core.c
> > +++ b/net/netfilter/nf_conntrack_core.c
> > @@ -1108,10 +1108,8 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
> >  	if (!h) {
> >  		h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
> >  				   skb, dataoff, hash);
> > -		if (!h)
> > -			return NULL;
> > -		if (IS_ERR(h))
> > -			return (void *)h;
> > +		if (IS_ERR_OR_NULL(h))
> > +			return ERR_CAST(h);
> 
> Interesting.
> 
> I think we can actually simplify this patch, I'm sending a patch for
> this now.

Forget this, I cannot actually achieve the simplification, we need the
ENOMEM to drop packets when we're under stress.