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v5.9
  1// SPDX-License-Identifier: GPL-2.0
  2#include <net/ip.h>
  3#include <net/udp.h>
  4#include <net/udplite.h>
  5#include <asm/checksum.h>
  6
  7#ifndef _HAVE_ARCH_IPV6_CSUM
  8__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  9			const struct in6_addr *daddr,
 10			__u32 len, __u8 proto, __wsum csum)
 11{
 12
 13	int carry;
 14	__u32 ulen;
 15	__u32 uproto;
 16	__u32 sum = (__force u32)csum;
 17
 18	sum += (__force u32)saddr->s6_addr32[0];
 19	carry = (sum < (__force u32)saddr->s6_addr32[0]);
 20	sum += carry;
 21
 22	sum += (__force u32)saddr->s6_addr32[1];
 23	carry = (sum < (__force u32)saddr->s6_addr32[1]);
 24	sum += carry;
 25
 26	sum += (__force u32)saddr->s6_addr32[2];
 27	carry = (sum < (__force u32)saddr->s6_addr32[2]);
 28	sum += carry;
 29
 30	sum += (__force u32)saddr->s6_addr32[3];
 31	carry = (sum < (__force u32)saddr->s6_addr32[3]);
 32	sum += carry;
 33
 34	sum += (__force u32)daddr->s6_addr32[0];
 35	carry = (sum < (__force u32)daddr->s6_addr32[0]);
 36	sum += carry;
 37
 38	sum += (__force u32)daddr->s6_addr32[1];
 39	carry = (sum < (__force u32)daddr->s6_addr32[1]);
 40	sum += carry;
 41
 42	sum += (__force u32)daddr->s6_addr32[2];
 43	carry = (sum < (__force u32)daddr->s6_addr32[2]);
 44	sum += carry;
 45
 46	sum += (__force u32)daddr->s6_addr32[3];
 47	carry = (sum < (__force u32)daddr->s6_addr32[3]);
 48	sum += carry;
 49
 50	ulen = (__force u32)htonl((__u32) len);
 51	sum += ulen;
 52	carry = (sum < ulen);
 53	sum += carry;
 54
 55	uproto = (__force u32)htonl(proto);
 56	sum += uproto;
 57	carry = (sum < uproto);
 58	sum += carry;
 59
 60	return csum_fold((__force __wsum)sum);
 61}
 62EXPORT_SYMBOL(csum_ipv6_magic);
 63#endif
 64
 65int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
 66{
 67	int err;
 68
 69	UDP_SKB_CB(skb)->partial_cov = 0;
 70	UDP_SKB_CB(skb)->cscov = skb->len;
 71
 72	if (proto == IPPROTO_UDPLITE) {
 73		err = udplite_checksum_init(skb, uh);
 74		if (err)
 75			return err;
 76
 77		if (UDP_SKB_CB(skb)->partial_cov) {
 78			skb->csum = ip6_compute_pseudo(skb, proto);
 79			return 0;
 80		}
 81	}
 82
 83	/* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
 84	 * we accept a checksum of zero here. When we find the socket
 85	 * for the UDP packet we'll check if that socket allows zero checksum
 86	 * for IPv6 (set by socket option).
 87	 *
 88	 * Note, we are only interested in != 0 or == 0, thus the
 89	 * force to int.
 90	 */
 91	err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
 92							ip6_compute_pseudo);
 93	if (err)
 94		return err;
 95
 96	if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
 97		/* If SW calculated the value, we know it's bad */
 98		if (skb->csum_complete_sw)
 99			return 1;
100
101		/* HW says the value is bad. Let's validate that.
102		 * skb->csum is no longer the full packet checksum,
103		 * so don't treat is as such.
104		 */
105		skb_checksum_complete_unset(skb);
106	}
107
108	return 0;
109}
110EXPORT_SYMBOL(udp6_csum_init);
111
112/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
113 * for the simple case like when setting the checksum for a UDP tunnel.
114 */
115void udp6_set_csum(bool nocheck, struct sk_buff *skb,
116		   const struct in6_addr *saddr,
117		   const struct in6_addr *daddr, int len)
118{
119	struct udphdr *uh = udp_hdr(skb);
120
121	if (nocheck)
122		uh->check = 0;
123	else if (skb_is_gso(skb))
124		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
125	else if (skb->ip_summed == CHECKSUM_PARTIAL) {
126		uh->check = 0;
127		uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
128		if (uh->check == 0)
129			uh->check = CSUM_MANGLED_0;
130	} else {
131		skb->ip_summed = CHECKSUM_PARTIAL;
132		skb->csum_start = skb_transport_header(skb) - skb->head;
133		skb->csum_offset = offsetof(struct udphdr, check);
134		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
135	}
136}
137EXPORT_SYMBOL(udp6_set_csum);
v4.6
 
  1#include <net/ip.h>
  2#include <net/udp.h>
  3#include <net/udplite.h>
  4#include <asm/checksum.h>
  5
  6#ifndef _HAVE_ARCH_IPV6_CSUM
  7__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  8			const struct in6_addr *daddr,
  9			__u32 len, __u8 proto, __wsum csum)
 10{
 11
 12	int carry;
 13	__u32 ulen;
 14	__u32 uproto;
 15	__u32 sum = (__force u32)csum;
 16
 17	sum += (__force u32)saddr->s6_addr32[0];
 18	carry = (sum < (__force u32)saddr->s6_addr32[0]);
 19	sum += carry;
 20
 21	sum += (__force u32)saddr->s6_addr32[1];
 22	carry = (sum < (__force u32)saddr->s6_addr32[1]);
 23	sum += carry;
 24
 25	sum += (__force u32)saddr->s6_addr32[2];
 26	carry = (sum < (__force u32)saddr->s6_addr32[2]);
 27	sum += carry;
 28
 29	sum += (__force u32)saddr->s6_addr32[3];
 30	carry = (sum < (__force u32)saddr->s6_addr32[3]);
 31	sum += carry;
 32
 33	sum += (__force u32)daddr->s6_addr32[0];
 34	carry = (sum < (__force u32)daddr->s6_addr32[0]);
 35	sum += carry;
 36
 37	sum += (__force u32)daddr->s6_addr32[1];
 38	carry = (sum < (__force u32)daddr->s6_addr32[1]);
 39	sum += carry;
 40
 41	sum += (__force u32)daddr->s6_addr32[2];
 42	carry = (sum < (__force u32)daddr->s6_addr32[2]);
 43	sum += carry;
 44
 45	sum += (__force u32)daddr->s6_addr32[3];
 46	carry = (sum < (__force u32)daddr->s6_addr32[3]);
 47	sum += carry;
 48
 49	ulen = (__force u32)htonl((__u32) len);
 50	sum += ulen;
 51	carry = (sum < ulen);
 52	sum += carry;
 53
 54	uproto = (__force u32)htonl(proto);
 55	sum += uproto;
 56	carry = (sum < uproto);
 57	sum += carry;
 58
 59	return csum_fold((__force __wsum)sum);
 60}
 61EXPORT_SYMBOL(csum_ipv6_magic);
 62#endif
 63
 64int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
 65{
 66	int err;
 67
 68	UDP_SKB_CB(skb)->partial_cov = 0;
 69	UDP_SKB_CB(skb)->cscov = skb->len;
 70
 71	if (proto == IPPROTO_UDPLITE) {
 72		err = udplite_checksum_init(skb, uh);
 73		if (err)
 74			return err;
 
 
 
 
 
 75	}
 76
 77	/* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
 78	 * we accept a checksum of zero here. When we find the socket
 79	 * for the UDP packet we'll check if that socket allows zero checksum
 80	 * for IPv6 (set by socket option).
 
 
 
 81	 */
 82	return skb_checksum_init_zero_check(skb, proto, uh->check,
 83					   ip6_compute_pseudo);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 84}
 85EXPORT_SYMBOL(udp6_csum_init);
 86
 87/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
 88 * for the simple case like when setting the checksum for a UDP tunnel.
 89 */
 90void udp6_set_csum(bool nocheck, struct sk_buff *skb,
 91		   const struct in6_addr *saddr,
 92		   const struct in6_addr *daddr, int len)
 93{
 94	struct udphdr *uh = udp_hdr(skb);
 95
 96	if (nocheck)
 97		uh->check = 0;
 98	else if (skb_is_gso(skb))
 99		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
100	else if (skb->ip_summed == CHECKSUM_PARTIAL) {
101		uh->check = 0;
102		uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
103		if (uh->check == 0)
104			uh->check = CSUM_MANGLED_0;
105	} else {
106		skb->ip_summed = CHECKSUM_PARTIAL;
107		skb->csum_start = skb_transport_header(skb) - skb->head;
108		skb->csum_offset = offsetof(struct udphdr, check);
109		uh->check = ~udp_v6_check(len, saddr, daddr, 0);
110	}
111}
112EXPORT_SYMBOL(udp6_set_csum);