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 10 enum { 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 18 static inline int INET_ECN_is_ce(__u8 dsfield) 19 { 20 return (dsfield & INET_ECN_MASK) == INET_ECN_CE; 21 } 22 23 static inline int INET_ECN_is_not_ect(__u8 dsfield) 24 { 25 return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT; 26 } 27 28 static inline int INET_ECN_is_capable(__u8 dsfield) 29 { 30 return dsfield & INET_ECN_ECT_0; 31 } 32 33 static 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 static inline void INET_ECN_xmit(struct sock *sk) 42 { 43 inet_sk(sk)->tos |= INET_ECN_ECT_0; 44 if (inet6_sk(sk) != NULL) 45 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 46 } 47 48 static inline void INET_ECN_dontxmit(struct sock *sk) 49 { 50 inet_sk(sk)->tos &= ~INET_ECN_MASK; 51 if (inet6_sk(sk) != NULL) 52 inet6_sk(sk)->tclass &= ~INET_ECN_MASK; 53 } 54 55 #define IP6_ECN_flow_init(label) do { \ 56 (label) &= ~htonl(INET_ECN_MASK << 20); \ 57 } while (0) 58 59 #define IP6_ECN_flow_xmit(sk, label) do { \ 60 if (INET_ECN_is_capable(inet6_sk(sk)->tclass)) \ 61 (label) |= htonl(INET_ECN_ECT_0 << 20); \ 62 } while (0) 63 64 static inline int IP_ECN_set_ce(struct iphdr *iph) 65 { 66 u32 check = (__force u32)iph->check; 67 u32 ecn = (iph->tos + 1) & INET_ECN_MASK; 68 69 /* 70 * After the last operation we have (in binary): 71 * INET_ECN_NOT_ECT => 01 72 * INET_ECN_ECT_1 => 10 73 * INET_ECN_ECT_0 => 11 74 * INET_ECN_CE => 00 75 */ 76 if (!(ecn & 2)) 77 return !ecn; 78 79 /* 80 * The following gives us: 81 * INET_ECN_ECT_1 => check += htons(0xFFFD) 82 * INET_ECN_ECT_0 => check += htons(0xFFFE) 83 */ 84 check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn); 85 86 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 87 iph->tos |= INET_ECN_CE; 88 return 1; 89 } 90 91 static inline void IP_ECN_clear(struct iphdr *iph) 92 { 93 iph->tos &= ~INET_ECN_MASK; 94 } 95 96 static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner) 97 { 98 dscp &= ~INET_ECN_MASK; 99 ipv4_change_dsfield(inner, INET_ECN_MASK, dscp); 100 } 101 102 struct ipv6hdr; 103 104 static inline int IP6_ECN_set_ce(struct ipv6hdr *iph) 105 { 106 if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph))) 107 return 0; 108 *(__be32*)iph |= htonl(INET_ECN_CE << 20); 109 return 1; 110 } 111 112 static inline void IP6_ECN_clear(struct ipv6hdr *iph) 113 { 114 *(__be32*)iph &= ~htonl(INET_ECN_MASK << 20); 115 } 116 117 static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner) 118 { 119 dscp &= ~INET_ECN_MASK; 120 ipv6_change_dsfield(inner, INET_ECN_MASK, dscp); 121 } 122 123 static inline int INET_ECN_set_ce(struct sk_buff *skb) 124 { 125 switch (skb->protocol) { 126 case cpu_to_be16(ETH_P_IP): 127 if (skb->network_header + sizeof(struct iphdr) <= skb->tail) 128 return IP_ECN_set_ce(ip_hdr(skb)); 129 break; 130 131 case cpu_to_be16(ETH_P_IPV6): 132 if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail) 133 return IP6_ECN_set_ce(ipv6_hdr(skb)); 134 break; 135 } 136 137 return 0; 138 } 139 140 #endif 141