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, unsigned short proto,
  41                         __wsum csum);
  42 #endif
  43
  44 static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto)
  45 {
  46         return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
  47                                             &ipv6_hdr(skb)->daddr,
  48                                             skb->len, proto, 0));
  49 }
  50
  51 static __inline__ __sum16 tcp_v6_check(int len,
  52                                    const struct in6_addr *saddr,
  53                                    const struct in6_addr *daddr,
  54                                    __wsum base)
  55 {
  56         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
  57 }
  58
  59 static inline void __tcp_v6_send_check(struct sk_buff *skb,
  60                                        const struct in6_addr *saddr,
  61                                        const struct in6_addr *daddr)
  62 {
  63         struct tcphdr *th = tcp_hdr(skb);
  64
  65         if (skb->ip_summed == CHECKSUM_PARTIAL) {
  66                 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
  67                 skb->csum_start = skb_transport_header(skb) - skb->head;
  68                 skb->csum_offset = offsetof(struct tcphdr, check);
  69         } else {
  70                 th->check = tcp_v6_check(skb->len, saddr, daddr,
  71                                          csum_partial(th, th->doff << 2,
  72                                                       skb->csum));
  73         }
  74 }
  75
  76 #if IS_ENABLED(CONFIG_IPV6)
  77 static inline void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
  78 {
  79         struct ipv6_pinfo *np = inet6_sk(sk);
  80
  81         __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
  82 }
  83 #endif
  84
  85 int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
  86 #endif