static inline unsigned __inet_dev_addr_type(struct net *net,
const struct net_device *dev,
__be32 addr)
{
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
struct fib_result res;
unsigned ret = RTN_BROADCAST;
struct fib_table *local_table;
if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
return RTN_BROADCAST;
if (ipv4_is_multicast(addr))
return RTN_MULTICAST;
#ifdef CONFIG_IP_MULTIPLE_TABLES
res.r = NULL;
#endif
local_table = fib_get_table(net, RT_TABLE_LOCAL);
if (local_table) {
ret = RTN_UNICAST;
if (!local_table->tb_lookup(local_table, &fl, &res)) {
if (!dev || dev == res.fi->fib_dev)
ret = res.type;
fib_res_put(&res);
}
}
return ret;
}
unsigned inet_addr_type(u32 addr)
{
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
struct fib_result res;
unsigned ret = RTN_BROADCAST;
if (ZERONET(addr) || BADCLASS(addr))
return RTN_BROADCAST;
if (MULTICAST(addr))
return RTN_MULTICAST;
#ifdef CONFIG_IP_MULTIPLE_TABLES
res.r = NULL;
#endif
if (ip_fib_local_table) {
ret = RTN_UNICAST;
if (!ip_fib_local_table->tb_lookup(ip_fib_local_table,
&fl, &res)) {
ret = res.type;
fib_res_put(&res);
}
}
return ret;
}
struct net_device * ip_dev_find(u32 addr)
{
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
struct fib_result res;
struct net_device *dev = NULL;
#ifdef CONFIG_IP_MULTIPLE_TABLES
res.r = NULL;
#endif
if (!local_table || local_table->tb_lookup(local_table, &fl, &res)) {
return NULL;
}
if (res.type != RTN_LOCAL)
goto out;
dev = FIB_RES_DEV(res);
if (dev)
atomic_inc(&dev->refcnt);
out:
fib_res_put(&res);
return dev;
}
struct net_device * ip_dev_find(struct net *net, __be32 addr)
{
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
struct fib_result res;
struct net_device *dev = NULL;
struct fib_table *local_table;
#ifdef CONFIG_IP_MULTIPLE_TABLES
res.r = NULL;
#endif
local_table = fib_get_table(net, RT_TABLE_LOCAL);
if (!local_table || local_table->tb_lookup(local_table, &fl, &res))
return NULL;
if (res.type != RTN_LOCAL)
goto out;
dev = FIB_RES_DEV(res);
if (dev)
dev_hold(dev);
out:
fib_res_put(&res);
return dev;
}
int
ip_do_nat(struct sk_buff *skb)
{
struct rtable *rt = (struct rtable*)skb->dst;
struct iphdr *iph = skb->nh.iph;
u32 odaddr = iph->daddr;
u32 osaddr = iph->saddr;
u16 check;
IPCB(skb)->flags |= IPSKB_TRANSLATED;
/* Rewrite IP header */
iph->daddr = rt->rt_dst_map;
iph->saddr = rt->rt_src_map;
iph->check = 0;
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
/* If it is the first fragment, rewrite protocol headers */
if (!(iph->frag_off & htons(IP_OFFSET))) {
u16 *cksum;
switch(iph->protocol) {
case IPPROTO_TCP:
cksum = (u16*)&((struct tcphdr*)(((char*)iph) + (iph->ihl<<2)))->check;
if ((u8*)(cksum+1) > skb->tail)
goto truncated;
check = *cksum;
if (skb->ip_summed != CHECKSUM_HW)
check = ~check;
check = csum_tcpudp_magic(iph->saddr, iph->daddr, 0, 0, check);
check = csum_tcpudp_magic(~osaddr, ~odaddr, 0, 0, ~check);
if (skb->ip_summed == CHECKSUM_HW)
check = ~check;
*cksum = check;
break;
case IPPROTO_UDP:
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;
u32 idaddr, isaddr;
int updated;
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;
isaddr = ciph->saddr;
idaddr = ciph->daddr;
updated = 0;
if (rt->rt_flags&RTCF_DNAT && ciph->saddr == odaddr) {
ciph->saddr = iph->daddr;
updated = 1;
}
if (rt->rt_flags&RTCF_SNAT) {
if (ciph->daddr != osaddr) {
struct fib_result res;
struct rt_key key;
unsigned flags = 0;
key.src = ciph->daddr;
key.dst = ciph->saddr;
key.iif = skb->dev->ifindex;
key.oif = 0;
#ifdef CONFIG_IP_ROUTE_TOS
key.tos = RT_TOS(ciph->tos);
#endif
#ifdef CONFIG_IP_ROUTE_FWMARK
key.fwmark = 0;
#endif
/* Use fib_lookup() until we get our own
* hash table of NATed hosts -- Rani
*/
if (fib_lookup(&key, &res) == 0) {
if (res.r) {
ciph->daddr = fib_rules_policy(ciph->daddr, &res, &flags);
if (ciph->daddr != idaddr)
updated = 1;
}
fib_res_put(&res);
}
} else {
ciph->daddr = iph->saddr;
updated = 1;
}
}
if (updated) {
cksum = &icmph->checksum;
/* Using tcpudp primitive. Why not? */
check = csum_tcpudp_magic(ciph->saddr, ciph->daddr, 0, 0, ~(*cksum));
*cksum = csum_tcpudp_magic(~isaddr, ~idaddr, 0, 0, ~check);
}
break;
}
default:
break;
}