On Monday, November 08, 2010 22:43:46 Simon Horman wrote:
> On Mon, Nov 08, 2010 at 03:51:56PM +0100, Hans Schillstrom wrote:
> > Hello
> > I have been struggling with SIP for a while ....
> > L7 helpers like sip needs skb defrag
> > ex virtio only copies the first 128 byte into the skb (incl mac hdr)
> > in that case Call-Id will never be found.
> >
> > There is a skb_find_text() that might be used insead of this, but it requires some changes in ip_vs_pe_sip.c
>
> Thanks for tracking that down!
>
> > Signed-off-by: Hans Schillstrom <hans.schillstrom@xxxxxxxxxxxx>
> >
> > diff --git a/net/netfilter/ipvs/ip_vs_pe.c b/net/netfilter/ipvs/ip_vs_pe.c
> > index e99f920..c0ac69a 100644
> > --- a/net/netfilter/ipvs/ip_vs_pe.c
> > +++ b/net/netfilter/ipvs/ip_vs_pe.c
> > @@ -76,6 +72,24 @@ struct ip_vs_pe *ip_vs_pe_getbyname(const char *name)
> > return pe;
> > }
> >
> > +/* skb defrag for L7 helpers */
> > +char *ip_vs_skb_defrag(struct sk_buff *skb, int offset, int len)
> > +{
> > + char *p = kmalloc(skb->len, GFP_ATOMIC);
> > + if (!p)
> > + goto err;
> > + if (skb_copy_bits(skb, offset, p, len))
> > + goto err;
> > + IP_VS_DBG(10, "IPVS defrag: offs:%d len:%d\n", offset, len);
> > + return p;
> > +
> > +err:
> > + if (p)
> > + kfree(p);
> > + return NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(ip_vs_skb_defrag);
> > +
> > /* Register a pe in the pe list */
> > int register_ip_vs_pe(struct ip_vs_pe *pe)
> > {
> > diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c
> > index b8b4e96..78caa83 100644
> > --- a/net/netfilter/ipvs/ip_vs_pe_sip.c
> > +++ b/net/netfilter/ipvs/ip_vs_pe_sip.c
> > @@ -71,6 +71,7 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
> > struct ip_vs_iphdr iph;
> > unsigned int dataoff, datalen, matchoff, matchlen;
> > const char *dptr;
> > + int fr;
> >
> > ip_vs_fill_iphdr(p->af, skb_network_header(skb), &iph);
> >
> > @@ -85,21 +86,30 @@ ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
> >
> > dptr = skb->data + dataoff;
> > datalen = skb->len - dataoff;
> > -
> > + fr = 0;
> > + if( skb_shinfo(skb)->nr_frags ) {
>
> >From a style point of view the line above should probably be:
>
> if (skb_shinfo(skb)->nr_frags) {
I have to remind my self all time about that, but some times ...
>
> > + dptr = ip_vs_skb_defrag(skb, dataoff, datalen);
> > + if (!dptr)
> > + return -EINVAL;
> > + fr = 1;
> > + }
>
> But I wonder if this logic can be rolld into ip_vs_skb_defrag(),
> perhaps using ERR_PTR() and friends. Then again, what you have
> may already be at least as clean as that idea.
I will have another look at it.
>
> > if (get_callid(dptr, dataoff, datalen, &matchoff, &matchlen))
> > - return -EINVAL;
> > + goto err;
> >
> > p->pe_data = kmalloc(matchlen, GFP_ATOMIC);
> > if (!p->pe_data)
> > - return -ENOMEM;
> > + goto err;
> >
> > /* N.B: pe_data is only set on success,
> > * this allows fallback to the default persistence logic on failure
> > */
> > memcpy(p->pe_data, dptr + matchoff, matchlen);
> > p->pe_data_len = matchlen;
> > -
> > return 0;
> > +err:
> > + if (fr)
> > + kfree(dptr);
> > + return -EINVAL;
> > }
> >
> > static bool ip_vs_sip_ct_match(const struct ip_vs_conn_param *p,
> > diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
> > index a6421e6..08bd547 100644
> > --- a/include/net/ip_vs.h
> > +++ b/include/net/ip_vs.h
> > @@ -817,6 +817,7 @@ void ip_vs_unbind_pe(struct ip_vs_service *svc);
> > int register_ip_vs_pe(struct ip_vs_pe *pe);
> > int unregister_ip_vs_pe(struct ip_vs_pe *pe);
> > struct ip_vs_pe *ip_vs_pe_getbyname(const char *name);
> > +extern char *ip_vs_skb_defrag(struct sk_buff *skb, int offset, int len);
>
> Personally I'm not a fan of the extern keyword.
I am :-)
I'll remove it
>
> > static inline void ip_vs_pe_get(const struct ip_vs_pe *pe)
> > {
> >
> > --
> > Regards
> > Hans Schillstrom <hans.schillstrom@xxxxxxxxxxxx>
> >
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