| Message ID | 1448496501-109561-4-git-send-email-jarno@ovn.org |
|---|---|
| State | Not Applicable |
| Headers | show |
On Wed, Nov 25, 2015 at 04:08:16PM -0800, Jarno Rajahalme wrote: > NAT checksum recalculation code assumes existence of skb_dst, which > becomes a problem for a later patch in the series ("openvswitch: > Interface with NAT."). Simplify this by removing the check on > skb_dst, as the checksum will be dealt with later in the stack. > > Suggested-by: Pravin Shelar <pshelar@nicira.com> > Signed-off-by: Jarno Rajahalme <jarno@ovn.org> > --- > net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 29 ++++++++--------------------- > net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 29 ++++++++--------------------- > 2 files changed, 16 insertions(+), 42 deletions(-) > > diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c > index 5075b7e..f8aad03 100644 > --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c > +++ b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c > @@ -127,28 +127,15 @@ static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, > u8 proto, void *data, __sum16 *check, > int datalen, int oldlen) > { > - const struct iphdr *iph = ip_hdr(skb); > - struct rtable *rt = skb_rtable(skb); > - > if (skb->ip_summed != CHECKSUM_PARTIAL) { > - if (!(rt->rt_flags & RTCF_LOCAL) && > - (!skb->dev || skb->dev->features & NETIF_F_V4_CSUM)) { > - skb->ip_summed = CHECKSUM_PARTIAL; > - skb->csum_start = skb_headroom(skb) + > - skb_network_offset(skb) + > - ip_hdrlen(skb); > - skb->csum_offset = (void *)check - data; > - *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, > - datalen, proto, 0); > - } else { > - *check = 0; > - *check = csum_tcpudp_magic(iph->saddr, iph->daddr, > - datalen, proto, > - csum_partial(data, datalen, > - 0)); > - if (proto == IPPROTO_UDP && !*check) > - *check = CSUM_MANGLED_0; > - } > + const struct iphdr *iph = ip_hdr(skb); > + > + skb->ip_summed = CHECKSUM_PARTIAL; > + skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + > + ip_hdrlen(skb); > + skb->csum_offset = (void *)check - data; > + *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, > + proto, 0); Is this change going to work with traffic that is redirected to the localhost?
On Tue, Dec 1, 2015 at 12:51 PM, Pablo Neira Ayuso <pablo@netfilter.org> wrote: > On Wed, Nov 25, 2015 at 04:08:16PM -0800, Jarno Rajahalme wrote: >> NAT checksum recalculation code assumes existence of skb_dst, which >> becomes a problem for a later patch in the series ("openvswitch: >> Interface with NAT."). Simplify this by removing the check on >> skb_dst, as the checksum will be dealt with later in the stack. >> >> Suggested-by: Pravin Shelar <pshelar@nicira.com> >> Signed-off-by: Jarno Rajahalme <jarno@ovn.org> >> --- >> net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 29 ++++++++--------------------- >> net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 29 ++++++++--------------------- >> 2 files changed, 16 insertions(+), 42 deletions(-) >> >> diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c >> index 5075b7e..f8aad03 100644 >> --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c >> +++ b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c >> @@ -127,28 +127,15 @@ static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, >> u8 proto, void *data, __sum16 *check, >> int datalen, int oldlen) >> { >> - const struct iphdr *iph = ip_hdr(skb); >> - struct rtable *rt = skb_rtable(skb); >> - >> if (skb->ip_summed != CHECKSUM_PARTIAL) { >> - if (!(rt->rt_flags & RTCF_LOCAL) && >> - (!skb->dev || skb->dev->features & NETIF_F_V4_CSUM)) { >> - skb->ip_summed = CHECKSUM_PARTIAL; >> - skb->csum_start = skb_headroom(skb) + >> - skb_network_offset(skb) + >> - ip_hdrlen(skb); >> - skb->csum_offset = (void *)check - data; >> - *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, >> - datalen, proto, 0); >> - } else { >> - *check = 0; >> - *check = csum_tcpudp_magic(iph->saddr, iph->daddr, >> - datalen, proto, >> - csum_partial(data, datalen, >> - 0)); >> - if (proto == IPPROTO_UDP && !*check) >> - *check = CSUM_MANGLED_0; >> - } >> + const struct iphdr *iph = ip_hdr(skb); >> + >> + skb->ip_summed = CHECKSUM_PARTIAL; >> + skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + >> + ip_hdrlen(skb); >> + skb->csum_offset = (void *)check - data; >> + *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, >> + proto, 0); > > Is this change going to work with traffic that is redirected to the > localhost? localhost should handle CHECKSUM_PARTIAL just fine. So I do not see problem with always converting skb to CHECKSUM_PARTIAL skb.
diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c index 5075b7e..f8aad03 100644 --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c @@ -127,28 +127,15 @@ static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, u8 proto, void *data, __sum16 *check, int datalen, int oldlen) { - const struct iphdr *iph = ip_hdr(skb); - struct rtable *rt = skb_rtable(skb); - if (skb->ip_summed != CHECKSUM_PARTIAL) { - if (!(rt->rt_flags & RTCF_LOCAL) && - (!skb->dev || skb->dev->features & NETIF_F_V4_CSUM)) { - skb->ip_summed = CHECKSUM_PARTIAL; - skb->csum_start = skb_headroom(skb) + - skb_network_offset(skb) + - ip_hdrlen(skb); - skb->csum_offset = (void *)check - data; - *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, - datalen, proto, 0); - } else { - *check = 0; - *check = csum_tcpudp_magic(iph->saddr, iph->daddr, - datalen, proto, - csum_partial(data, datalen, - 0)); - if (proto == IPPROTO_UDP && !*check) - *check = CSUM_MANGLED_0; - } + const struct iphdr *iph = ip_hdr(skb); + + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + + ip_hdrlen(skb); + skb->csum_offset = (void *)check - data; + *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, + proto, 0); } else inet_proto_csum_replace2(check, skb, htons(oldlen), htons(datalen), true); diff --git a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c index 238e70c..e0be97e 100644 --- a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c @@ -131,28 +131,15 @@ static void nf_nat_ipv6_csum_recalc(struct sk_buff *skb, u8 proto, void *data, __sum16 *check, int datalen, int oldlen) { - const struct ipv6hdr *ipv6h = ipv6_hdr(skb); - struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); - if (skb->ip_summed != CHECKSUM_PARTIAL) { - if (!(rt->rt6i_flags & RTF_LOCAL) && - (!skb->dev || skb->dev->features & NETIF_F_V6_CSUM)) { - skb->ip_summed = CHECKSUM_PARTIAL; - skb->csum_start = skb_headroom(skb) + - skb_network_offset(skb) + - (data - (void *)skb->data); - skb->csum_offset = (void *)check - data; - *check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, - datalen, proto, 0); - } else { - *check = 0; - *check = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, - datalen, proto, - csum_partial(data, datalen, - 0)); - if (proto == IPPROTO_UDP && !*check) - *check = CSUM_MANGLED_0; - } + const struct ipv6hdr *ipv6h = ipv6_hdr(skb); + + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + + (data - (void *)skb->data); + skb->csum_offset = (void *)check - data; + *check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, + datalen, proto, 0); } else inet_proto_csum_replace2(check, skb, htons(oldlen), htons(datalen), true);
NAT checksum recalculation code assumes existence of skb_dst, which becomes a problem for a later patch in the series ("openvswitch: Interface with NAT."). Simplify this by removing the check on skb_dst, as the checksum will be dealt with later in the stack. Suggested-by: Pravin Shelar <pshelar@nicira.com> Signed-off-by: Jarno Rajahalme <jarno@ovn.org> --- net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 29 ++++++++--------------------- net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 29 ++++++++--------------------- 2 files changed, 16 insertions(+), 42 deletions(-)