1 #ifndef _INET_ECN_H_ 2 #define _INET_ECN_H_ 3 4 #include <linux/ip.h> 5 #include <linux/skbuff.h> 6 #include <net/dsfield.h> 7 8 enum { 9 INET_ECN_NOT_ECT = 0, 10 INET_ECN_ECT_1 = 1, 11 INET_ECN_ECT_0 = 2, 12 INET_ECN_CE = 3, 13 INET_ECN_MASK = 3, 14 }; 15 16 static inline int INET_ECN_is_ce(__u8 dsfield) 17 { 18 return (dsfield & INET_ECN_MASK) == INET_ECN_CE; 19 } 20 21 static inline int INET_ECN_is_not_ect(__u8 dsfield) 22 { 23 return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT; 24 } 25 26 static inline int INET_ECN_is_capable(__u8 dsfield) 27 { 28 return (dsfield & INET_ECN_ECT_0); 29 } 30 31 static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner) 32 { 33 outer &= ~INET_ECN_MASK; 34 outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) : 35 INET_ECN_ECT_0; 36 return outer; 37 } 38 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) 42 43 #define IP6_ECN_flow_init(label) do { \ 44 (label) &= ~htonl(INET_ECN_MASK << 20); \ 45 } while (0) 46 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); \ 50 } while (0) 51 52 static inline int IP_ECN_set_ce(struct iphdr *iph) 53 { 54 u32 check = iph->check; 55 u32 ecn = (iph->tos + 1) & INET_ECN_MASK; 56 57 /* 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 62 * INET_ECN_CE => 00 63 */ 64 if (!(ecn & 2)) 65 return !ecn; 66 67 /* 68 * The following gives us: 69 * INET_ECN_ECT_1 => check += htons(0xFFFD) 70 * INET_ECN_ECT_0 => check += htons(0xFFFE) 71 */ 72 check += htons(0xFFFB) + htons(ecn); 73 74 iph->check = check + (check>=0xFFFF); 75 iph->tos |= INET_ECN_CE; 76 return 1; 77 } 78 79 static inline void IP_ECN_clear(struct iphdr *iph) 80 { 81 iph->tos &= ~INET_ECN_MASK; 82 } 83 84 static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner) 85 { 86 u32 dscp = ipv4_get_dsfield(outer) & ~INET_ECN_MASK; 87 ipv4_change_dsfield(inner, INET_ECN_MASK, dscp); 88 } 89 90 struct ipv6hdr; 91 92 static inline int IP6_ECN_set_ce(struct ipv6hdr *iph) 93 { 94 if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph))) 95 return 0; 96 *(u32*)iph |= htonl(INET_ECN_CE << 20); 97 return 1; 98 } 99 100 static inline void IP6_ECN_clear(struct ipv6hdr *iph) 101 { 102 *(u32*)iph &= ~htonl(INET_ECN_MASK << 20); 103 } 104 105 static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner) 106 { 107 u32 dscp = ipv6_get_dsfield(outer) & ~INET_ECN_MASK; 108 ipv6_change_dsfield(inner, INET_ECN_MASK, dscp); 109 } 110 111 static inline int INET_ECN_set_ce(struct sk_buff *skb) 112 { 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); 117 break; 118 119 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); 122 break; 123 } 124 125 return 0; 126 } 127 128 #endif 129