__sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, u_int8_t protocol)
{
const struct iphdr *iph = ip_hdr(skb);
__sum16 csum = 0;
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
break;
if ((protocol == 0 && !csum_fold(skb->csum)) ||
!csum_tcpudp_magic(iph->saddr, iph->daddr,
skb->len - dataoff, protocol,
skb->csum)) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
}
/* fall through */
case CHECKSUM_NONE:
if (protocol == 0)
skb->csum = 0;
else
skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
skb->len - dataoff,
protocol, 0);
csum = __skb_checksum_complete(skb);
}
return csum;
}
struct rtsocket *rt_udp_dest_socket(struct rtskb *skb)
{
struct udphdr *uh = skb->h.uh;
unsigned short ulen = ntohs(uh->len);
u32 saddr = skb->nh.iph->saddr;
u32 daddr = skb->nh.iph->daddr;
struct rtnet_device* rtdev = skb->rtdev;
if (uh->check == 0)
skb->ip_summed = CHECKSUM_UNNECESSARY;
/* ip_summed (yet) never equals CHECKSUM_HW
else
if (skb->ip_summed == CHECKSUM_HW) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
if ( !rt_udp_check(uh, ulen, saddr, daddr, skb->csum) )
return NULL;
skb->ip_summed = CHECKSUM_NONE;
}*/
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
/* patch broadcast daddr */
if (daddr == rtdev->broadcast_ip)
daddr = rtdev->local_ip;
/* find the destination socket */
skb->sk = rt_udp_v4_lookup(daddr, uh->dest);
return skb->sk;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
unsigned long daddr,
unsigned short len,
unsigned short proto,
unsigned int sum)
{
return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
}
static __wsum lro_tcp_data_csum(struct iphdr *iph, struct tcphdr *tcph, int len)
{
__wsum tcp_csum;
__wsum tcp_hdr_csum;
__wsum tcp_ps_hdr_csum;
tcp_csum = ~csum_unfold(tcph->check);
tcp_hdr_csum = csum_partial((u8 *)tcph, TCP_HDR_LEN(tcph), tcp_csum);
tcp_ps_hdr_csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
len + TCP_HDR_LEN(tcph),
IPPROTO_TCP, 0);
return csum_sub(csum_sub(tcp_csum, tcp_hdr_csum),
tcp_ps_hdr_csum);
}
static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, __be32 saddr, __be32 daddr)
{
__wsum psum;
if (uh->check == 0 || skb_csum_unnecessary(skb))
return 0;
psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
if (skb->ip_summed == CHECKSUM_COMPLETE &&
!csum_fold(csum_add(psum, skb->csum)))
return 0;
skb->csum = psum;
return __skb_checksum_complete(skb);
}
static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, u32 saddr, u32 daddr)
{
unsigned int psum;
if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY)
return 0;
psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
if (skb->ip_summed == CHECKSUM_HW &&
!(u16)csum_fold(csum_add(psum, skb->csum)))
return 0;
skb->csum = psum;
return __skb_checksum_complete(skb);
}
static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, unsigned int len,
u_int8_t protocol)
{
const struct iphdr *iph = ip_hdr(skb);
__sum16 csum = 0;
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
if (len == skb->len - dataoff)
return nf_ip_checksum(skb, hook, dataoff, protocol);
/* fall through */
case CHECKSUM_NONE:
skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
skb->len - dataoff, 0);
skb->ip_summed = CHECKSUM_NONE;
return __skb_checksum_complete_head(skb, dataoff + len);
}
return csum;
}
struct rtsocket *rt_udp_dest_socket(struct rtskb *skb)
{
struct udphdr *uh;
unsigned short ulen;
struct rtsocket *rtsk;
u32 saddr = skb->nh.iph->saddr;
u32 daddr = skb->nh.iph->daddr;
uh = skb->h.uh;
ulen = ntohs(uh->len);
if (uh->check == 0)
skb->ip_summed = CHECKSUM_UNNECESSARY;
/* ip_summed (yet) never equals CHECKSUM_HW
else
if (skb->ip_summed == CHECKSUM_HW) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
if ( !rt_udp_check(uh, ulen, saddr, daddr, skb->csum) )
return NULL;
skb->ip_summed = CHECKSUM_NONE;
}*/
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
/* find a socket */
if ((rtsk = rt_udp_v4_lookup(saddr, uh->source, daddr, uh->dest)) == NULL)
return NULL;
skb->sk = rtsk;
return rtsk;
}