Re: [bug] FWMARKs and persistence in IPVS: The Use of Unions

[Simon Horman <horms@verge.net.au>]

On Tue, Apr 28, 2009 at 01:30:26PM +0200, Fabien Duchêne wrote:
> Simon Horman a écrit :
> > On Tue, Apr 28, 2009 at 07:23:55PM +1000, Simon Horman wrote:
> >> On Tue, Apr 28, 2009 at 11:07:40AM +0200, Jan Engelhardt wrote:
> >>> On Tuesday 2009-04-28 10:15, Simon Horman wrote:
> >>>> It seems to me that it should be easy enough to fix by changing
> >>>> fwmark in ip_vs_sched_persist() from:
> >>>>
> >>>> union nf_inet_addr fwmark = {
> >>>> 	.all = { 0, 0, 0, htonl(svc->fwmark) }
> >>>> };
> >>>>
> >>>> to:
> >>>>
> >>>> union nf_inet_addr fwmark = {
> >>>> 	.all = { htonl(svc->fwmark), 0, 0, 0 }
> >>>> };
> >>>>
> >>>> Assuming that this would result in fwmark->ip being set to
> >>>> htonl(svc->fwmark), which is relevant if svc->af is AF_INET - that is,
> >>>> for IPv4.[...]
> >>>> An alternate idea would be to change the af value used for fwmarks,
> >>>> but this seems to be even less clean than the current (slightly broken)
> >>>> technique of using nf_inet_addr for IPv4 or IPv6 addresses, or fwmarks.
> >>> If you use ->all, then using NFPROTO_UNSPEC as af
> >>> seems to me like a good match.
> > 
> > I am guessing that AF_UNSPEC is more appropriate than NFPROTO_UNSPEC.
> > Please correct me if I am wrong.
> > 
> >> That seems reasonable, though ip_vs_ct_in_get() would still
> >> need to use the real af for the cp->af == af and
> >> ip_vs_addr_equal(af, s_addr, &cp->caddr) portinos of the check.
> > 
> > It looks like checking for proto == IPPROTO_IP can tell us if
> > the destination is a fwmark. This is based on the assumption that
> > iph.protocol can never be IPPROTO_IP in ip_vs_sched_persist().
> > 
> > The following patch expresses these ideas as they crrently stand.
> > Fabien, is it possible for you to test this?
> > 
> Yep!
> 
> I'll do it right now.

Hi Fabien,

did you get a chance to test this?

> > Index: net-next-2.6/net/netfilter/ipvs/ip_vs_conn.c
> > ===================================================================
> > --- net-next-2.6.orig/net/netfilter/ipvs/ip_vs_conn.c	2009-04-28 20:37:48.000000000 +1000
> > +++ net-next-2.6/net/netfilter/ipvs/ip_vs_conn.c	2009-04-28 20:37:51.000000000 +1000
> > @@ -260,7 +260,10 @@ struct ip_vs_conn *ip_vs_ct_in_get
> >  	list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
> >  		if (cp->af == af &&
> >  		    ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
> > -		    ip_vs_addr_equal(af, d_addr, &cp->vaddr) &&
> > +		    /* protocol should only be IPPROTO_IP if
> > +		     * d_addr is a fwmark */
> > +		    ip_vs_addr_equal(protocol == IPPROTO_IP ? AF_UNSPEC : af,
> > +		                     d_addr, &cp->vaddr) &&
> >  		    s_port == cp->cport && d_port == cp->vport &&
> >  		    cp->flags & IP_VS_CONN_F_TEMPLATE &&
> >  		    protocol == cp->protocol) {
> > @@ -698,7 +701,9 @@ ip_vs_conn_new(int af, int proto, const 
> >  	cp->cport	   = cport;
> >  	ip_vs_addr_copy(af, &cp->vaddr, vaddr);
> >  	cp->vport	   = vport;
> > -	ip_vs_addr_copy(af, &cp->daddr, daddr);
> > +	/* proto should only be IPPROTO_IP if d_addr is a fwmark */
> > +	ip_vs_addr_copy(proto == IPPROTO_IP ? AF_UNSPEC : af,
> > +			&cp->daddr, daddr);
> >  	cp->dport          = dport;
> >  	cp->flags	   = flags;
> >  	spin_lock_init(&cp->lock);
> > Index: net-next-2.6/net/netfilter/ipvs/ip_vs_core.c
> > ===================================================================
> > --- net-next-2.6.orig/net/netfilter/ipvs/ip_vs_core.c	2009-04-28 20:37:48.000000000 +1000
> > +++ net-next-2.6/net/netfilter/ipvs/ip_vs_core.c	2009-04-28 20:37:51.000000000 +1000
> > @@ -278,7 +278,7 @@ ip_vs_sched_persist(struct ip_vs_service
> >  		 */
> >  		if (svc->fwmark) {
> >  			union nf_inet_addr fwmark = {
> > -				.all = { 0, 0, 0, htonl(svc->fwmark) }
> > +				.ip = htonl(svc->fwmark)
> >  			};
> >  
> >  			ct = ip_vs_ct_in_get(svc->af, IPPROTO_IP, &snet, 0,
> > @@ -306,7 +306,7 @@ ip_vs_sched_persist(struct ip_vs_service
> >  			 */
> >  			if (svc->fwmark) {
> >  				union nf_inet_addr fwmark = {
> > -					.all = { 0, 0, 0, htonl(svc->fwmark) }
> > +					.ip = htonl(svc->fwmark)
> >  				};
> >  
> >  				ct = ip_vs_conn_new(svc->af, IPPROTO_IP,
> > 
> > 

-- 
Simon Horman
  VA Linux Systems Japan K.K. Satellite Lab in Sydney, Australia
  H: www.vergenet.net/~horms/            W: www.valinux.co.jp/en

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