1 #ifndef _INET_ECN_H_ 2 #define _INET_ECN_H_ 3 4 #include <linux/ip.h> 5 #include <net/dsfield.h> 6 7 enum { 8 INET_ECN_NOT_ECT = 0, 9 INET_ECN_ECT_1 = 1, 10 INET_ECN_ECT_0 = 2, 11 INET_ECN_CE = 3, 12 INET_ECN_MASK = 3, 13 }; 14 15 static inline int INET_ECN_is_ce(__u8 dsfield) 16 { 17 return (dsfield & INET_ECN_MASK) == INET_ECN_CE; 18 } 19 20 static inline int INET_ECN_is_not_ect(__u8 dsfield) 21 { 22 return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT; 23 } 24 25 static inline int INET_ECN_is_capable(__u8 dsfield) 26 { 27 return (dsfield & INET_ECN_ECT_0); 28 } 29 30 static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner) 31 { 32 outer &= ~INET_ECN_MASK; 33 outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) : 34 INET_ECN_ECT_0; 35 return outer; 36 } 37 38 #define INET_ECN_xmit(sk) do { inet_sk(sk)->tos |= INET_ECN_ECT_0; } while (0) 39 #define INET_ECN_dontxmit(sk) \ 40 do { inet_sk(sk)->tos &= ~INET_ECN_MASK; } while (0) 41 42 #define IP6_ECN_flow_init(label) do { \ 43 (label) &= ~htonl(INET_ECN_MASK << 20); \ 44 } while (0) 45 46 #define IP6_ECN_flow_xmit(sk, label) do { \ 47 if (INET_ECN_is_capable(inet_sk(sk)->tos)) \ 48 (label) |= __constant_htons(INET_ECN_ECT_0 << 4); \ 49 } while (0) 50 51 static inline void IP_ECN_set_ce(struct iphdr *iph) 52 { 53 u32 check = iph->check; 54 u32 ecn = (iph->tos + 1) & INET_ECN_MASK; 55 56 /* 57 * After the last operation we have (in binary): 58 * INET_ECN_NOT_ECT => 01 59 * INET_ECN_ECT_1 => 10 60 * INET_ECN_ECT_0 => 11 61 * INET_ECN_CE => 00 62 */ 63 if (!(ecn & 2)) 64 return; 65 66 /* 67 * The following gives us: 68 * INET_ECN_ECT_1 => check += htons(0xFFFD) 69 * INET_ECN_ECT_0 => check += htons(0xFFFE) 70 */ 71 check += htons(0xFFFB) + htons(ecn); 72 73 iph->check = check + (check>=0xFFFF); 74 iph->tos |= INET_ECN_CE; 75 } 76 77 static inline void IP_ECN_clear(struct iphdr *iph) 78 { 79 iph->tos &= ~INET_ECN_MASK; 80 } 81 82 static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner) 83 { 84 u32 dscp = ipv4_get_dsfield(outer) & ~INET_ECN_MASK; 85 ipv4_change_dsfield(inner, INET_ECN_MASK, dscp); 86 } 87 88 struct ipv6hdr; 89 90 static inline void IP6_ECN_set_ce(struct ipv6hdr *iph) 91 { 92 if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph))) 93 return; 94 *(u32*)iph |= htonl(INET_ECN_CE << 20); 95 } 96 97 static inline void IP6_ECN_clear(struct ipv6hdr *iph) 98 { 99 *(u32*)iph &= ~htonl(INET_ECN_MASK << 20); 100 } 101 102 static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner) 103 { 104 u32 dscp = ipv6_get_dsfield(outer) & ~INET_ECN_MASK; 105 ipv6_change_dsfield(inner, INET_ECN_MASK, dscp); 106 } 107 108 #endif 109