#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