5 #include <linux/skbuff.h>
6 #include <net/dsfield.h>
16 static inline int INET_ECN_is_ce(__u8 dsfield)
18 return (dsfield & INET_ECN_MASK) == INET_ECN_CE;
21 static inline int INET_ECN_is_not_ect(__u8 dsfield)
23 return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT;
26 static inline int INET_ECN_is_capable(__u8 dsfield)
28 return (dsfield & INET_ECN_ECT_0);
31 static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
33 outer &= ~INET_ECN_MASK;
34 outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) :
39 #define INET_ECN_xmit(sk) do { inet_sk(sk)->tos |= INET_ECN_ECT_0; } while (0)
40 #define INET_ECN_dontxmit(sk) \
41 do { inet_sk(sk)->tos &= ~INET_ECN_MASK; } while (0)
43 #define IP6_ECN_flow_init(label) do { \
44 (label) &= ~htonl(INET_ECN_MASK << 20); \
47 #define IP6_ECN_flow_xmit(sk, label) do { \
48 if (INET_ECN_is_capable(inet_sk(sk)->tos)) \
49 (label) |= __constant_htons(INET_ECN_ECT_0 << 4); \
52 static inline int IP_ECN_set_ce(struct iphdr *iph)
54 u32 check = iph->check;
55 u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
58 * After the last operation we have (in binary):
59 * INET_ECN_NOT_ECT => 01
60 * INET_ECN_ECT_1 => 10
61 * INET_ECN_ECT_0 => 11
68 * The following gives us:
69 * INET_ECN_ECT_1 => check += htons(0xFFFD)
70 * INET_ECN_ECT_0 => check += htons(0xFFFE)
72 check += htons(0xFFFB) + htons(ecn);
74 iph->check = check + (check>=0xFFFF);
75 iph->tos |= INET_ECN_CE;
79 static inline void IP_ECN_clear(struct iphdr *iph)
81 iph->tos &= ~INET_ECN_MASK;
84 static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner)
86 u32 dscp = ipv4_get_dsfield(outer) & ~INET_ECN_MASK;
87 ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
92 static inline int IP6_ECN_set_ce(struct ipv6hdr *iph)
94 if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
96 *(u32*)iph |= htonl(INET_ECN_CE << 20);
100 static inline void IP6_ECN_clear(struct ipv6hdr *iph)
102 *(u32*)iph &= ~htonl(INET_ECN_MASK << 20);
105 static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner)
107 u32 dscp = ipv6_get_dsfield(outer) & ~INET_ECN_MASK;
108 ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
111 static inline int INET_ECN_set_ce(struct sk_buff *skb)
113 switch (skb->protocol) {
114 case __constant_htons(ETH_P_IP):
115 if (skb->nh.raw + sizeof(struct iphdr) <= skb->tail)
116 return IP_ECN_set_ce(skb->nh.iph);
119 case __constant_htons(ETH_P_IPV6):
120 if (skb->nh.raw + sizeof(struct ipv6hdr) <= skb->tail)
121 return IP6_ECN_set_ce(skb->nh.ipv6h);