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kernel/linux-imx6_3.14.28/net/ipv6/ip6_checksum.c 2.27 KB
6b13f685e   김민수   BSP 최초 추가
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  #include <net/ip.h>
  #include <net/udp.h>
  #include <net/udplite.h>
  #include <asm/checksum.h>
  
  #ifndef _HAVE_ARCH_IPV6_CSUM
  __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  			const struct in6_addr *daddr,
  			__u32 len, unsigned short proto,
  			__wsum csum)
  {
  
  	int carry;
  	__u32 ulen;
  	__u32 uproto;
  	__u32 sum = (__force u32)csum;
  
  	sum += (__force u32)saddr->s6_addr32[0];
  	carry = (sum < (__force u32)saddr->s6_addr32[0]);
  	sum += carry;
  
  	sum += (__force u32)saddr->s6_addr32[1];
  	carry = (sum < (__force u32)saddr->s6_addr32[1]);
  	sum += carry;
  
  	sum += (__force u32)saddr->s6_addr32[2];
  	carry = (sum < (__force u32)saddr->s6_addr32[2]);
  	sum += carry;
  
  	sum += (__force u32)saddr->s6_addr32[3];
  	carry = (sum < (__force u32)saddr->s6_addr32[3]);
  	sum += carry;
  
  	sum += (__force u32)daddr->s6_addr32[0];
  	carry = (sum < (__force u32)daddr->s6_addr32[0]);
  	sum += carry;
  
  	sum += (__force u32)daddr->s6_addr32[1];
  	carry = (sum < (__force u32)daddr->s6_addr32[1]);
  	sum += carry;
  
  	sum += (__force u32)daddr->s6_addr32[2];
  	carry = (sum < (__force u32)daddr->s6_addr32[2]);
  	sum += carry;
  
  	sum += (__force u32)daddr->s6_addr32[3];
  	carry = (sum < (__force u32)daddr->s6_addr32[3]);
  	sum += carry;
  
  	ulen = (__force u32)htonl((__u32) len);
  	sum += ulen;
  	carry = (sum < ulen);
  	sum += carry;
  
  	uproto = (__force u32)htonl(proto);
  	sum += uproto;
  	carry = (sum < uproto);
  	sum += carry;
  
  	return csum_fold((__force __wsum)sum);
  }
  EXPORT_SYMBOL(csum_ipv6_magic);
  #endif
  
  int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
  {
  	int err;
  
  	UDP_SKB_CB(skb)->partial_cov = 0;
  	UDP_SKB_CB(skb)->cscov = skb->len;
  
  	if (proto == IPPROTO_UDPLITE) {
  		err = udplite_checksum_init(skb, uh);
  		if (err)
  			return err;
  	}
  
  	if (uh->check == 0) {
  		/* RFC 2460 section 8.1 says that we SHOULD log
  		   this error. Well, it is reasonable.
  		 */
  		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0
  ");
  		return 1;
  	}
  	if (skb->ip_summed == CHECKSUM_COMPLETE &&
  	    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
  			     skb->len, proto, skb->csum))
  		skb->ip_summed = CHECKSUM_UNNECESSARY;
  
  	if (!skb_csum_unnecessary(skb))
  		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
  							 &ipv6_hdr(skb)->daddr,
  							 skb->len, proto, 0));
  
  	return 0;
  }
  EXPORT_SYMBOL(udp6_csum_init);