LXR linux/include/net/inet

   1#ifndef _INET_ECN_H_
   2#define _INET_ECN_H_
   3
   4#include <linux/ip.h>
   5#include <linux/skbuff.h>
   6
   7#include <net/inet_sock.h>
   8#include <net/dsfield.h>
   9
  10enum {
  11        INET_ECN_NOT_ECT = 0,
  12        INET_ECN_ECT_1 = 1,
  13        INET_ECN_ECT_0 = 2,
  14        INET_ECN_CE = 3,
  15        INET_ECN_MASK = 3,
  16};
  17
  18static inline int INET_ECN_is_ce(__u8 dsfield)
  19{
  20        return (dsfield & INET_ECN_MASK) == INET_ECN_CE;
  21}
  22
  23static inline int INET_ECN_is_not_ect(__u8 dsfield)
  24{
  25        return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT;
  26}
  27
  28static inline int INET_ECN_is_capable(__u8 dsfield)
  29{
  30        return (dsfield & INET_ECN_ECT_0);
  31}
  32
  33static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
  34{
  35        outer &= ~INET_ECN_MASK;
  36        outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) :
  37                                          INET_ECN_ECT_0;
  38        return outer;
  39}
  40
  41#define INET_ECN_xmit(sk) do { inet_sk(sk)->tos |= INET_ECN_ECT_0; } while (0)
  42#define INET_ECN_dontxmit(sk) \
  43        do { inet_sk(sk)->tos &= ~INET_ECN_MASK; } while (0)
  44
  45#define IP6_ECN_flow_init(label) do {           \
  46      (label) &= ~htonl(INET_ECN_MASK << 20);   \
  47    } while (0)
  48
  49#define IP6_ECN_flow_xmit(sk, label) do {                               \
  50        if (INET_ECN_is_capable(inet6_sk(sk)->tclass))                  \
  51                (label) |= htonl(INET_ECN_ECT_0 << 20);                 \
  52    } while (0)
  53
  54static inline int IP_ECN_set_ce(struct iphdr *iph)
  55{
  56        u32 check = (__force u32)iph->check;
  57        u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
  58
  59        /*
  60         * After the last operation we have (in binary):
  61         * INET_ECN_NOT_ECT => 01
  62         * INET_ECN_ECT_1   => 10
  63         * INET_ECN_ECT_0   => 11
  64         * INET_ECN_CE      => 00
  65         */
  66        if (!(ecn & 2))
  67                return !ecn;
  68
  69        /*
  70         * The following gives us:
  71         * INET_ECN_ECT_1 => check += htons(0xFFFD)
  72         * INET_ECN_ECT_0 => check += htons(0xFFFE)
  73         */
  74        check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn);
  75
  76        iph->check = (__force __sum16)(check + (check>=0xFFFF));
  77        iph->tos |= INET_ECN_CE;
  78        return 1;
  79}
  80
  81static inline void IP_ECN_clear(struct iphdr *iph)
  82{
  83        iph->tos &= ~INET_ECN_MASK;
  84}
  85
  86static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner)
  87{
  88        dscp &= ~INET_ECN_MASK;
  89        ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
  90}
  91
  92struct ipv6hdr;
  93
  94static inline int IP6_ECN_set_ce(struct ipv6hdr *iph)
  95{
  96        if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
  97                return 0;
  98        *(__be32*)iph |= htonl(INET_ECN_CE << 20);
  99        return 1;
 100}
 101
 102static inline void IP6_ECN_clear(struct ipv6hdr *iph)
 103{
 104        *(__be32*)iph &= ~htonl(INET_ECN_MASK << 20);
 105}
 106
 107static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
 108{
 109        dscp &= ~INET_ECN_MASK;
 110        ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
 111}
 112
 113static inline int INET_ECN_set_ce(struct sk_buff *skb)
 114{
 115        switch (skb->protocol) {
 116        case cpu_to_be16(ETH_P_IP):
 117                if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
 118                        return IP_ECN_set_ce(ip_hdr(skb));
 119                break;
 120
 121        case cpu_to_be16(ETH_P_IPV6):
 122                if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
 123                        return IP6_ECN_set_ce(ipv6_hdr(skb));
 124                break;
 125        }
 126
 127        return 0;
 128}
 129
 130#endif
 131