diff options
| -rw-r--r-- | net/netfilter/xt_TCPMSS.c | 42 |
1 files changed, 13 insertions, 29 deletions
diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c index 217e2b68632..beb5094703c 100644 --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -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) |