138 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			138 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| #include <net/ip.h>
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| #include <net/udp.h>
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| #include <net/udplite.h>
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| #include <asm/checksum.h>
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| 
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| #ifndef _HAVE_ARCH_IPV6_CSUM
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| __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
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| 			const struct in6_addr *daddr,
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| 			__u32 len, __u8 proto, __wsum csum)
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| {
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| 
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| 	int carry;
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| 	__u32 ulen;
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| 	__u32 uproto;
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| 	__u32 sum = (__force u32)csum;
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| 
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| 	sum += (__force u32)saddr->s6_addr32[0];
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| 	carry = (sum < (__force u32)saddr->s6_addr32[0]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)saddr->s6_addr32[1];
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| 	carry = (sum < (__force u32)saddr->s6_addr32[1]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)saddr->s6_addr32[2];
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| 	carry = (sum < (__force u32)saddr->s6_addr32[2]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)saddr->s6_addr32[3];
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| 	carry = (sum < (__force u32)saddr->s6_addr32[3]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)daddr->s6_addr32[0];
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| 	carry = (sum < (__force u32)daddr->s6_addr32[0]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)daddr->s6_addr32[1];
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| 	carry = (sum < (__force u32)daddr->s6_addr32[1]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)daddr->s6_addr32[2];
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| 	carry = (sum < (__force u32)daddr->s6_addr32[2]);
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| 	sum += carry;
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| 
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| 	sum += (__force u32)daddr->s6_addr32[3];
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| 	carry = (sum < (__force u32)daddr->s6_addr32[3]);
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| 	sum += carry;
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| 
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| 	ulen = (__force u32)htonl((__u32) len);
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| 	sum += ulen;
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| 	carry = (sum < ulen);
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| 	sum += carry;
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| 
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| 	uproto = (__force u32)htonl(proto);
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| 	sum += uproto;
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| 	carry = (sum < uproto);
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| 	sum += carry;
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| 
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| 	return csum_fold((__force __wsum)sum);
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| }
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| EXPORT_SYMBOL(csum_ipv6_magic);
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| #endif
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| 
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| int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
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| {
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| 	int err;
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| 
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| 	UDP_SKB_CB(skb)->partial_cov = 0;
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| 	UDP_SKB_CB(skb)->cscov = skb->len;
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| 
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| 	if (proto == IPPROTO_UDPLITE) {
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| 		err = udplite_checksum_init(skb, uh);
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| 		if (err)
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| 			return err;
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| 
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| 		if (UDP_SKB_CB(skb)->partial_cov) {
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| 			skb->csum = ip6_compute_pseudo(skb, proto);
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| 			return 0;
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| 		}
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| 	}
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| 
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| 	/* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
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| 	 * we accept a checksum of zero here. When we find the socket
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| 	 * for the UDP packet we'll check if that socket allows zero checksum
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| 	 * for IPv6 (set by socket option).
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| 	 *
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| 	 * Note, we are only interested in != 0 or == 0, thus the
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| 	 * force to int.
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| 	 */
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| 	err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
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| 							ip6_compute_pseudo);
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| 	if (err)
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| 		return err;
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| 
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| 	if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
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| 		/* If SW calculated the value, we know it's bad */
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| 		if (skb->csum_complete_sw)
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| 			return 1;
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| 
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| 		/* HW says the value is bad. Let's validate that.
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| 		 * skb->csum is no longer the full packet checksum,
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| 		 * so don't treat is as such.
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| 		 */
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| 		skb_checksum_complete_unset(skb);
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| 	}
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL(udp6_csum_init);
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| 
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| /* Function to set UDP checksum for an IPv6 UDP packet. This is intended
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|  * for the simple case like when setting the checksum for a UDP tunnel.
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|  */
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| void udp6_set_csum(bool nocheck, struct sk_buff *skb,
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| 		   const struct in6_addr *saddr,
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| 		   const struct in6_addr *daddr, int len)
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| {
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| 	struct udphdr *uh = udp_hdr(skb);
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| 
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| 	if (nocheck)
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| 		uh->check = 0;
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| 	else if (skb_is_gso(skb))
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| 		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
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| 	else if (skb->ip_summed == CHECKSUM_PARTIAL) {
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| 		uh->check = 0;
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| 		uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
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| 		if (uh->check == 0)
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| 			uh->check = CSUM_MANGLED_0;
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| 	} else {
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| 		skb->ip_summed = CHECKSUM_PARTIAL;
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| 		skb->csum_start = skb_transport_header(skb) - skb->head;
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| 		skb->csum_offset = offsetof(struct udphdr, check);
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| 		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
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| 	}
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| }
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| EXPORT_SYMBOL(udp6_set_csum);
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