[PATCH v4 3/4] nfnetlink: introduce generic netfilter subsystem decoder

[Chen Jingpiao]

On 03/10 03:55, Dmitry V. Levin wrote:
> On Thu, Mar 08, 2018 at 10:53:46PM +0800, Chen Jingpiao wrote:
> > * netlink_netfilter.c: Include "nlattr.h".
> > (decode_netlink_netfilter): Call decode_nlattr.
> > ---
> >  netlink_netfilter.c | 12 ++++++++++--
> >  1 file changed, 10 insertions(+), 2 deletions(-)
> > 
> > diff --git a/netlink_netfilter.c b/netlink_netfilter.c
> > index a6028a1e5..b6c68120c 100644
> > --- a/netlink_netfilter.c
> > +++ b/netlink_netfilter.c
> > @@ -31,6 +31,7 @@
> >  #ifdef HAVE_LINUX_NETFILTER_NFNETLINK_H
> >  
> >  # include "print_fields.h"
> > +# include "nlattr.h"
> >  
> >  # include <netinet/in.h>
> >  # include <arpa/inet.h>
> > @@ -79,8 +80,15 @@ decode_netlink_netfilter(struct tcb *const tcp,
> >  		const size_t offset = NLMSG_ALIGN(sizeof(nfmsg));
> >  		if (len > offset) {
> >  			tprints(", ");
> > -			printstr_ex(tcp, addr + offset,
> > -				    len - offset, QUOTE_FORCE_HEX);
> > +			if ((nlmsghdr->nlmsg_type >= NFNL_MSG_BATCH_BEGIN
> > +			     && nlmsghdr->nlmsg_type <= NFNL_MSG_BATCH_END)
> 
> NFNL_MSG_BATCH_BEGIN and NFNL_MSG_BATCH_END were introduced in linux kernel
> commit v3.13-rc1~105^2~186^2~2, what if strace is being built with older
> kernel headers?
> 
> We have fallback definitions for these constants in
> xlat/nl_netfilter_msg_types.in, but currently they are not available
> in this file.

Now I want to send a patch like v4.18-173-g4c437e185
and v4.17-33-gc826fa0f7 to solve this problem.
And apply it after this patch instead of solve this problem in this patch.
Do you think this solution is okay?

--
Chen Jingpiao