diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 1998-09-19 19:15:08 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 1998-09-19 19:15:08 +0000 |
| commit | 03ba4131783cc9e872f8bb26a03f15bc11f27564 (patch) | |
| tree | 88db8dba75ae06ba3bad08e42c5e52efc162535c /net/ipv4/ip_nat_dumb.c | |
| parent | 257730f99381dd26e10b832fce4c94cae7ac1176 (diff) | |
- Merge with Linux 2.1.121.
- Bugfixes.
Diffstat (limited to 'net/ipv4/ip_nat_dumb.c')
| -rw-r--r-- | net/ipv4/ip_nat_dumb.c | 40 |
1 files changed, 33 insertions, 7 deletions
diff --git a/net/ipv4/ip_nat_dumb.c b/net/ipv4/ip_nat_dumb.c index 07a7afc23..c48ea9263 100644 --- a/net/ipv4/ip_nat_dumb.c +++ b/net/ipv4/ip_nat_dumb.c @@ -5,7 +5,7 @@ * * Dumb Network Address Translation. * - * Version: $Id: ip_nat_dumb.c,v 1.3 1998/03/15 03:31:44 davem Exp $ + * Version: $Id: ip_nat_dumb.c,v 1.4 1998/08/26 12:03:49 davem Exp $ * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> * @@ -17,11 +17,12 @@ * Fixes: * Rani Assaf : A zero checksum is a special case * only in UDP + * Rani Assaf : Added ICMP messages rewriting + * * * NOTE: It is just working model of real NAT. */ -#include <linux/config.h> #include <linux/types.h> #include <linux/mm.h> #include <linux/sched.h> @@ -36,9 +37,6 @@ #include <linux/udp.h> #include <linux/firewall.h> #include <linux/ip_fw.h> -#ifdef CONFIG_IP_MASQUERADE -#include <net/ip_masq.h> -#endif #include <net/checksum.h> #include <linux/route.h> #include <net/route.h> @@ -68,20 +66,48 @@ ip_do_nat(struct sk_buff *skb) switch(iph->protocol) { case IPPROTO_TCP: - cksum = (u16*)&((struct tcphdr*)(((char*)iph) + iph->ihl*4))->check; + cksum = (u16*)&((struct tcphdr*)(((char*)iph) + (iph->ihl<<2)))->check; + if ((u8*)(cksum+1) > skb->tail) + goto truncated; check = csum_tcpudp_magic(iph->saddr, iph->daddr, 0, 0, ~(*cksum)); *cksum = csum_tcpudp_magic(~osaddr, ~odaddr, 0, 0, ~check); break; case IPPROTO_UDP: - cksum = (u16*)&((struct udphdr*)(((char*)iph) + iph->ihl*4))->check; + cksum = (u16*)&((struct udphdr*)(((char*)iph) + (iph->ihl<<2)))->check; + if ((u8*)(cksum+1) > skb->tail) + goto truncated; if ((check = *cksum) != 0) { check = csum_tcpudp_magic(iph->saddr, iph->daddr, 0, 0, ~check); check = csum_tcpudp_magic(~osaddr, ~odaddr, 0, 0, ~check); *cksum = check ? : 0xFFFF; } + break; + case IPPROTO_ICMP: + { + struct icmphdr *icmph = (struct icmphdr*)((char*)iph + (iph->ihl<<2)); + struct iphdr *ciph; + + if ((icmph->type != ICMP_DEST_UNREACH) && + (icmph->type != ICMP_TIME_EXCEEDED) && + (icmph->type != ICMP_PARAMETERPROB)) break; + + ciph = (struct iphdr *) (icmph + 1); + + if ((u8*)(ciph+1) > skb->tail) + goto truncated; + + if (rt->rt_flags&RTCF_DNAT && ciph->saddr == odaddr) + ciph->saddr = iph->daddr; + if (rt->rt_flags&RTCF_SNAT && ciph->daddr == osaddr) + ciph->daddr = iph->saddr; + break; + } default: break; } } return 0; + +truncated: + return -EINVAL; } |