netfilter: xt_TCPMSS: collapse tcpmss_reverse_mtu{4,6} into one function

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jan Engelhardt 2008-07-21 10:02:59 -07:00 committed by David S. Miller
parent 72961ecf84
commit db1a75bdcc
1 changed files with 13 additions and 29 deletions

View File

@ -147,17 +147,21 @@ tcpmss_mangle_packet(struct sk_buff *skb,
return TCPOLEN_MSS;
}
static u_int32_t tcpmss_reverse_mtu4(const struct iphdr *iph)
static u_int32_t tcpmss_reverse_mtu(const struct sk_buff *skb,
unsigned int family)
{
struct flowi fl = {
.fl4_dst = iph->saddr,
};
struct flowi fl = {};
const struct nf_afinfo *ai;
struct rtable *rt = NULL;
u_int32_t mtu = ~0U;
if (family == PF_INET)
fl.fl4_dst = ip_hdr(skb)->saddr;
else
fl.fl6_dst = ipv6_hdr(skb)->saddr;
rcu_read_lock();
ai = nf_get_afinfo(AF_INET);
ai = nf_get_afinfo(family);
if (ai != NULL)
ai->route((struct dst_entry **)&rt, &fl);
rcu_read_unlock();
@ -178,7 +182,8 @@ tcpmss_tg4(struct sk_buff *skb, const struct net_device *in,
__be16 newlen;
int ret;
ret = tcpmss_mangle_packet(skb, targinfo, tcpmss_reverse_mtu4(iph),
ret = tcpmss_mangle_packet(skb, targinfo,
tcpmss_reverse_mtu(skb, PF_INET),
iph->ihl * 4,
sizeof(*iph) + sizeof(struct tcphdr));
if (ret < 0)
@ -193,28 +198,6 @@ tcpmss_tg4(struct sk_buff *skb, const struct net_device *in,
}
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
static u_int32_t tcpmss_reverse_mtu6(const struct ipv6hdr *iph)
{
struct flowi fl = {
.fl6_dst = iph->saddr,
};
const struct nf_afinfo *ai;
struct rtable *rt = NULL;
u_int32_t mtu = ~0U;
rcu_read_lock();
ai = nf_get_afinfo(AF_INET6);
if (ai != NULL)
ai->route((struct dst_entry **)&rt, &fl);
rcu_read_unlock();
if (rt != NULL) {
mtu = dst_mtu(&rt->u.dst);
dst_release(&rt->u.dst);
}
return mtu;
}
static unsigned int
tcpmss_tg6(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
@ -229,7 +212,8 @@ tcpmss_tg6(struct sk_buff *skb, const struct net_device *in,
tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr);
if (tcphoff < 0)
return NF_DROP;
ret = tcpmss_mangle_packet(skb, targinfo, tcpmss_reverse_mtu6(ipv6h),
ret = tcpmss_mangle_packet(skb, targinfo,
tcpmss_reverse_mtu(skb, PF_INET6),
tcphoff,
sizeof(*ipv6h) + sizeof(struct tcphdr));
if (ret < 0)