Re: [PATCH v2 3/3] Make use of pr_fmt where applicable

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Fri, Oct 24, 2014 at 04:46:32PM -0200, Marcelo Ricardo Leitner wrote:
> And also remove PRINTR macro in favor of net_*_ratelimited().
> 
> Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
> ---
> 
> Notes:
>     v1-v2:
>       make use of net_err_ratelimited()
> 
>  net/netfilter/nfnetlink_log.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
> index b1e3a05794169283ed50d1c0fb4f44d9e7753eeb..0eb10bf295e92ad29541f58ca1de67e3380157c0 100644
> --- a/net/netfilter/nfnetlink_log.c
> +++ b/net/netfilter/nfnetlink_log.c
> @@ -12,6 +12,8 @@
>   * it under the terms of the GNU General Public License version 2 as
>   * published by the Free Software Foundation.
>   */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>  #include <linux/module.h>
>  #include <linux/skbuff.h>
>  #include <linux/if_arp.h>
> @@ -45,9 +47,6 @@
>  #define NFULNL_QTHRESH_DEFAULT 	100	/* 100 packets */
>  #define NFULNL_COPY_RANGE_MAX	0xFFFF	/* max packet size is limited by 16-bit struct nfattr nfa_len field */
>  
> -#define PRINTR(x, args...)	do { if (net_ratelimit()) \
> -				     printk(x, ## args); } while (0);
> -
>  struct nfulnl_instance {
>  	struct hlist_node hlist;	/* global list of instances */
>  	spinlock_t lock;
> @@ -335,8 +334,7 @@ nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
>  			skb = nfnetlink_alloc_skb(net, pkt_size,
>  						  peer_portid, GFP_ATOMIC);
>  			if (!skb)
> -				pr_err("nfnetlink_log: can't even alloc %u bytes\n",
> -				       pkt_size);
> +				pr_err("can't even alloc %u bytes\n", pkt_size);
>  		}
>  	}
>  
> @@ -569,7 +567,7 @@ __build_packet_message(struct nfnl_log_net *log,
>  		int size = nla_attr_size(data_len);
>  
>  		if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
> -			printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
> +			pr_warn("no tailroom!\n");
>  			return -1;

I think we can just goto nla_put_failure and remove this warning.

>  		}
>  
> @@ -585,7 +583,7 @@ __build_packet_message(struct nfnl_log_net *log,
>  	return 0;
>  
>  nla_put_failure:
> -	PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
> +	net_err_ratelimited("error creating log nlmsg\n");

I'd remove this one too.

But before doing any error message cleanup, we should also call
nlmsg_cancel() here to leave the nflog netlink batch message in
consistent state in case of errors. And we don't check for errors
after __build_packet_message() which may result in sending an
incomplete message to userspace.

Would you send us patches to address this? Thanks.