include/net/ip6_checksum.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4  *              operating system.  INET is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              Checksumming functions for IPv6
   8  *
   9  * Authors:     Jorge Cwik, <jorge@laser.satlink.net>
  10  *              Arnt Gulbrandsen, <agulbra@nvg.unit.no>
  11  *              Borrows very liberally from tcp.c and ip.c, see those
  12  *              files for more names.
  13  */
  14
  15 /*
  16  *      Fixes:
  17  *
  18  *      Ralf Baechle                    :       generic ipv6 checksum
  19  *      <ralf@waldorf-gmbh.de>
  20  */
  21
  22 #ifndef _CHECKSUM_IPV6_H
  23 #define _CHECKSUM_IPV6_H
  24
  25 #include <asm/types.h>
  26 #include <asm/byteorder.h>
  27 #include <net/ip.h>
  28 #include <asm/checksum.h>
  29 #include <linux/in6.h>
  30 #include <linux/tcp.h>
  31 #include <linux/ipv6.h>
  32
  33 #ifndef _HAVE_ARCH_IPV6_CSUM
  34 __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  35                         const struct in6_addr *daddr,
  36                         __u32 len, __u8 proto, __wsum csum);
  37 #endif
  38
  39 static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto)
  40 {
  41         return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
  42                                             &ipv6_hdr(skb)->daddr,
  43                                             skb->len, proto, 0));
  44 }
  45
  46 static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
  47 {
  48         const struct ipv6hdr *iph = skb_gro_network_header(skb);
  49
  50         return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
  51                                             skb_gro_len(skb), proto, 0));
  52 }
  53
  54 static __inline__ __sum16 tcp_v6_check(int len,
  55                                    const struct in6_addr *saddr,
  56                                    const struct in6_addr *daddr,
  57                                    __wsum base)
  58 {
  59         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
  60 }
  61
  62 static inline void __tcp_v6_send_check(struct sk_buff *skb,
  63                                        const struct in6_addr *saddr,
  64                                        const struct in6_addr *daddr)
  65 {
  66         struct tcphdr *th = tcp_hdr(skb);
  67
  68         if (skb->ip_summed == CHECKSUM_PARTIAL) {
  69                 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
  70                 skb->csum_start = skb_transport_header(skb) - skb->head;
  71                 skb->csum_offset = offsetof(struct tcphdr, check);
  72         } else {
  73                 th->check = tcp_v6_check(skb->len, saddr, daddr,
  74                                          csum_partial(th, th->doff << 2,
  75                                                       skb->csum));
  76         }
  77 }
  78
  79 static inline void tcp_v6_gso_csum_prep(struct sk_buff *skb)
  80 {
  81         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
  82         struct tcphdr *th = tcp_hdr(skb);
  83
  84         ipv6h->payload_len = 0;
  85         th->check = ~tcp_v6_check(0, &ipv6h->saddr, &ipv6h->daddr, 0);
  86 }
  87
  88 #if IS_ENABLED(CONFIG_IPV6)
  89 static inline void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
  90 {
  91         struct ipv6_pinfo *np = inet6_sk(sk);
  92
  93         __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
  94 }
  95 #endif
  96
  97 static inline __sum16 udp_v6_check(int len,
  98                                    const struct in6_addr *saddr,
  99                                    const struct in6_addr *daddr,
 100                                    __wsum base)
 101 {
 102         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, base);
 103 }
 104
 105 void udp6_set_csum(bool nocheck, struct sk_buff *skb,
 106                    const struct in6_addr *saddr,
 107                    const struct in6_addr *daddr, int len);
 108
 109 int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
 110 #endif