diff options
| -rw-r--r-- | 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 4a0c6b548ee..31427fb57aa 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; } |