From: Changli Gao <xiaosuo@xxxxxxxxx>
Add a static function nf_nat_csum() to replace the duplicate code in
nf_nat_mangle_udp_packet() and __nf_nat_mangle_tcp_packet().
Signed-off-by: Changli Gao <xiaosuo@xxxxxxxxx>
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
---
net/ipv4/netfilter/nf_nat_helper.c | 76 +++++++++++++++---------------------
1 files changed, 31 insertions(+), 45 deletions(-)
diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
index 4a0c6b5..31427fb 100644
--- a/net/ipv4/netfilter/nf_nat_helper.c
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -153,6 +153,35 @@ void nf_nat_set_seq_adjust(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
}
EXPORT_SYMBOL_GPL(nf_nat_set_seq_adjust);
+static void nf_nat_csum(struct sk_buff *skb, struct iphdr *iph, void *data,
+ int datalen, __sum16 *check, int oldlen)
+{
+ struct rtable *rt = skb_rtable(skb);
+
+ if (skb->ip_summed != CHECKSUM_PARTIAL) {
+ if (!(rt->rt_flags & RTCF_LOCAL) &&
+ skb->dev->features & NETIF_F_V4_CSUM) {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_headroom(skb) +
+ skb_network_offset(skb) +
+ iph->ihl * 4;
+ skb->csum_offset = (void *)check - data;
+ *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+ datalen, iph->protocol, 0);
+ } else {
+ *check = 0;
+ *check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+ datalen, iph->protocol,
+ csum_partial(data, datalen,
+ 0));
+ if (iph->protocol == IPPROTO_UDP && !*check)
+ *check = CSUM_MANGLED_0;
+ }
+ } else
+ inet_proto_csum_replace2(check, skb,
+ htons(oldlen), htons(datalen), 1);
+}
+
/* Generic function for mangling variable-length address changes inside
* NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
* command in FTP).
@@ -169,7 +198,6 @@ int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
const char *rep_buffer,
unsigned int rep_len, bool adjust)
{
- struct rtable *rt = skb_rtable(skb);
struct iphdr *iph;
struct tcphdr *tcph;
int oldlen, datalen;
@@ -192,26 +220,7 @@ int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
match_offset, match_len, rep_buffer, rep_len);
datalen = skb->len - iph->ihl*4;
- if (skb->ip_summed != CHECKSUM_PARTIAL) {
- if (!(rt->rt_flags & RTCF_LOCAL) &&
- skb->dev->features & NETIF_F_V4_CSUM) {
- skb->ip_summed = CHECKSUM_PARTIAL;
- skb->csum_start = skb_headroom(skb) +
- skb_network_offset(skb) +
- iph->ihl * 4;
- skb->csum_offset = offsetof(struct tcphdr, check);
- tcph->check = ~tcp_v4_check(datalen,
- iph->saddr, iph->daddr, 0);
- } else {
- tcph->check = 0;
- tcph->check = tcp_v4_check(datalen,
- iph->saddr, iph->daddr,
- csum_partial(tcph,
- datalen, 0));
- }
- } else
- inet_proto_csum_replace2(&tcph->check, skb,
- htons(oldlen), htons(datalen), 1);
+ nf_nat_csum(skb, iph, tcph, datalen, &tcph->check, oldlen);
if (adjust && rep_len != match_len)
nf_nat_set_seq_adjust(ct, ctinfo, tcph->seq,
@@ -240,7 +249,6 @@ nf_nat_mangle_udp_packet(struct sk_buff *skb,
const char *rep_buffer,
unsigned int rep_len)
{
- struct rtable *rt = skb_rtable(skb);
struct iphdr *iph;
struct udphdr *udph;
int datalen, oldlen;
@@ -274,29 +282,7 @@ nf_nat_mangle_udp_packet(struct sk_buff *skb,
if (!udph->check && skb->ip_summed != CHECKSUM_PARTIAL)
return 1;
- if (skb->ip_summed != CHECKSUM_PARTIAL) {
- if (!(rt->rt_flags & RTCF_LOCAL) &&
- skb->dev->features & NETIF_F_V4_CSUM) {
- skb->ip_summed = CHECKSUM_PARTIAL;
- skb->csum_start = skb_headroom(skb) +
- skb_network_offset(skb) +
- iph->ihl * 4;
- skb->csum_offset = offsetof(struct udphdr, check);
- udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
- datalen, IPPROTO_UDP,
- 0);
- } else {
- udph->check = 0;
- udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
- datalen, IPPROTO_UDP,
- csum_partial(udph,
- datalen, 0));
- if (!udph->check)
- udph->check = CSUM_MANGLED_0;
- }
- } else
- inet_proto_csum_replace2(&udph->check, skb,
- htons(oldlen), htons(datalen), 1);
+ nf_nat_csum(skb, iph, udph, datalen, &udph->check, oldlen);
return 1;
}
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
