#ifndef _INET_ECN_H_ #define _INET_ECN_H_ #include <linux/ip.h> #include <linux/skbuff.h> #include <net/inet_sock.h> #include <net/dsfield.h> enum { INET_ECN_NOT_ECT = 0, INET_ECN_ECT_1 = 1, INET_ECN_ECT_0 = 2, INET_ECN_CE = 3, INET_ECN_MASK = 3, }; static inline int INET_ECN_is_ce(__u8 dsfield) { return (dsfield & INET_ECN_MASK) == INET_ECN_CE; } static inline int INET_ECN_is_not_ect(__u8 dsfield) { return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT; } static inline int INET_ECN_is_capable(__u8 dsfield) { return (dsfield & INET_ECN_ECT_0); } static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner) { outer &= ~INET_ECN_MASK; outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) : INET_ECN_ECT_0; return outer; } #define INET_ECN_xmit(sk) do { inet_sk(sk)->tos |= INET_ECN_ECT_0; } while (0) #define INET_ECN_dontxmit(sk) \ do { inet_sk(sk)->tos &= ~INET_ECN_MASK; } while (0) #define IP6_ECN_flow_init(label) do { \ (label) &= ~htonl(INET_ECN_MASK << 20); \ } while (0) #define IP6_ECN_flow_xmit(sk, label) do { \ if (INET_ECN_is_capable(inet_sk(sk)->tos)) \ (label) |= __constant_htons(INET_ECN_ECT_0 << 4); \ } while (0) static inline int IP_ECN_set_ce(struct iphdr *iph) { u32 check = iph->check; u32 ecn = (iph->tos + 1) & INET_ECN_MASK; /* * After the last operation we have (in binary): * INET_ECN_NOT_ECT => 01 * INET_ECN_ECT_1 => 10 * INET_ECN_ECT_0 => 11 * INET_ECN_CE => 00 */ if (!(ecn & 2)) return !ecn; /* * The following gives us: * INET_ECN_ECT_1 => check += htons(0xFFFD) * INET_ECN_ECT_0 => check += htons(0xFFFE) */ check += htons(0xFFFB) + htons(ecn); iph->check = check + (check>=0xFFFF); iph->tos |= INET_ECN_CE; return 1; } static inline void IP_ECN_clear(struct iphdr *iph) { iph->tos &= ~INET_ECN_MASK; } static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner) { u32 dscp = ipv4_get_dsfield(outer) & ~INET_ECN_MASK; ipv4_change_dsfield(inner, INET_ECN_MASK, dscp); } struct ipv6hdr; static inline int IP6_ECN_set_ce(struct ipv6hdr *iph) { if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph))) return 0; *(u32*)iph |= htonl(INET_ECN_CE << 20); return 1; } static inline void IP6_ECN_clear(struct ipv6hdr *iph) { *(u32*)iph &= ~htonl(INET_ECN_MASK << 20); } static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner) { u32 dscp = ipv6_get_dsfield(outer) & ~INET_ECN_MASK; ipv6_change_dsfield(inner, INET_ECN_MASK, dscp); } static inline int INET_ECN_set_ce(struct sk_buff *skb) { switch (skb->protocol) { case __constant_htons(ETH_P_IP): if (skb->nh.raw + sizeof(struct iphdr) <= skb->tail) return IP_ECN_set_ce(skb->nh.iph); break; case __constant_htons(ETH_P_IPV6): if (skb->nh.raw + sizeof(struct ipv6hdr) <= skb->tail) return IP6_ECN_set_ce(skb->nh.ipv6h); break; } return 0; } #endif