include/net/ip6_checksum.h

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