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__ __sum16 tcp_v6_check(int len,
  47                                    const struct in6_addr *saddr,
  48                                    const struct in6_addr *daddr,
  49                                    __wsum base)
  50 {
  51         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
  52 }
  53
  54 static inline void __tcp_v6_send_check(struct sk_buff *skb,
  55                                        const struct in6_addr *saddr,
  56                                        const struct in6_addr *daddr)
  57 {
  58         struct tcphdr *th = tcp_hdr(skb);
  59
  60         th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
  61         skb->csum_start = skb_transport_header(skb) - skb->head;
  62         skb->csum_offset = offsetof(struct tcphdr, check);
  63 }
  64
  65 static inline void tcp_v6_gso_csum_prep(struct sk_buff *skb)
  66 {
  67         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
  68         struct tcphdr *th = tcp_hdr(skb);
  69
  70         ipv6h->payload_len = 0;
  71         th->check = ~tcp_v6_check(0, &ipv6h->saddr, &ipv6h->daddr, 0);
  72 }
  73
  74 static inline __sum16 udp_v6_check(int len,
  75                                    const struct in6_addr *saddr,
  76                                    const struct in6_addr *daddr,
  77                                    __wsum base)
  78 {
  79         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, base);
  80 }
  81
  82 void udp6_set_csum(bool nocheck, struct sk_buff *skb,
  83                    const struct in6_addr *saddr,
  84                    const struct in6_addr *daddr, int len);
  85
  86 int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
  87 #endif