Eric Lee / smarc-fsl-linux-kernel

Blame view

net/ipv6/ip6_checksum.c 2.27 KB
edit raw normal view history
acb3e0411   Cong Wang   ipv6: move csum_i... 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
 
  #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);