[mirror_ubuntu-zesty-kernel.git] / include / net / inet_ecn.h

#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;
}

/*
 * RFC 3168 9.1.1
 *  The full-functionality option for ECN encapsulation is to copy the
 *  ECN codepoint of the inside header to the outside header on
 *  encapsulation if the inside header is not-ECT or ECT, and to set the
 *  ECN codepoint of the outside header to ECT(0) if the ECN codepoint of
 *  the inside header is CE.
 */
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;
}

static inline void INET_ECN_xmit(struct sock *sk)
{
	inet_sk(sk)->tos |= INET_ECN_ECT_0;
	if (inet6_sk(sk) != NULL)
		inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
}

static inline void INET_ECN_dontxmit(struct sock *sk)
{
	inet_sk(sk)->tos &= ~INET_ECN_MASK;
	if (inet6_sk(sk) != NULL)
		inet6_sk(sk)->tclass &= ~INET_ECN_MASK;
}

#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(inet6_sk(sk)->tclass))			\
		(label) |= htonl(INET_ECN_ECT_0 << 20);			\
    } while (0)

static inline int IP_ECN_set_ce(struct iphdr *iph)
{
	u32 check = (__force u32)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 += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn);

	iph->check = (__force __sum16)(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(unsigned int dscp, struct iphdr *inner)
{
	dscp &= ~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;
	*(__be32*)iph |= htonl(INET_ECN_CE << 20);
	return 1;
}

static inline void IP6_ECN_clear(struct ipv6hdr *iph)
{
	*(__be32*)iph &= ~htonl(INET_ECN_MASK << 20);
}

static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
{
	dscp &= ~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 cpu_to_be16(ETH_P_IP):
		if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
			return IP_ECN_set_ce(ip_hdr(skb));
		break;

	case cpu_to_be16(ETH_P_IPV6):
		if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
			return IP6_ECN_set_ce(ipv6_hdr(skb));
		break;
	}

	return 0;
}

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _INET_ECN_H_
	2	#define _INET_ECN_H_
	3
	4	#include <linux/ip.h>
2566a509	5	#include <linux/skbuff.h>
14c85021 ACM	6
14c85021 ACM	7	#include <net/inet_sock.h>
1da177e4 LT	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	{
a02cec21	30	return dsfield & INET_ECN_ECT_0;
1da177e4 LT	31	}
1da177e4 LT	32
b5d9c9c2 ED	33	/*
	34	* RFC 3168 9.1.1
	35	* The full-functionality option for ECN encapsulation is to copy the
	36	* ECN codepoint of the inside header to the outside header on
	37	* encapsulation if the inside header is not-ECT or ECT, and to set the
	38	* ECN codepoint of the outside header to ECT(0) if the ECN codepoint of
	39	* the inside header is CE.
	40	*/
1da177e4 LT	41	static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
	42	{
	43	outer &= ~INET_ECN_MASK;
	44	outer \|= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) :
	45	INET_ECN_ECT_0;
	46	return outer;
	47	}
	48
ca067070 SG	49	static inline void INET_ECN_xmit(struct sock *sk)
	50	{
	51	inet_sk(sk)->tos \|= INET_ECN_ECT_0;
	52	if (inet6_sk(sk) != NULL)
	53	inet6_sk(sk)->tclass \|= INET_ECN_ECT_0;
	54	}
	55
	56	static inline void INET_ECN_dontxmit(struct sock *sk)
	57	{
	58	inet_sk(sk)->tos &= ~INET_ECN_MASK;
	59	if (inet6_sk(sk) != NULL)
	60	inet6_sk(sk)->tclass &= ~INET_ECN_MASK;
	61	}
1da177e4 LT	62
	63	#define IP6_ECN_flow_init(label) do { \
	64	(label) &= ~htonl(INET_ECN_MASK << 20); \
	65	} while (0)
	66
	67	#define IP6_ECN_flow_xmit(sk, label) do { \
e9df2e8f	68	if (INET_ECN_is_capable(inet6_sk(sk)->tclass)) \
95026cd2	69	(label) \|= htonl(INET_ECN_ECT_0 << 20); \
1da177e4 LT	70	} while (0)
1da177e4 LT	71
2566a509	72	static inline int IP_ECN_set_ce(struct iphdr *iph)
1da177e4	73	{
5c78f275	74	u32 check = (__force u32)iph->check;
1da177e4 LT	75	u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
	76
	77	/*
	78	* After the last operation we have (in binary):
	79	* INET_ECN_NOT_ECT => 01
	80	* INET_ECN_ECT_1 => 10
	81	* INET_ECN_ECT_0 => 11
	82	* INET_ECN_CE => 00
	83	*/
	84	if (!(ecn & 2))
2566a509	85	return !ecn;
1da177e4 LT	86
	87	/*
	88	* The following gives us:
	89	* INET_ECN_ECT_1 => check += htons(0xFFFD)
	90	* INET_ECN_ECT_0 => check += htons(0xFFFE)
	91	*/
5c78f275	92	check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn);
1da177e4	93
5c78f275	94	iph->check = (__force __sum16)(check + (check>=0xFFFF));
1da177e4	95	iph->tos \|= INET_ECN_CE;
2566a509	96	return 1;
1da177e4 LT	97	}
	98
	99	static inline void IP_ECN_clear(struct iphdr *iph)
	100	{
	101	iph->tos &= ~INET_ECN_MASK;
	102	}
	103
29bb43b4	104	static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner)
1da177e4	105	{
29bb43b4	106	dscp &= ~INET_ECN_MASK;
1da177e4 LT	107	ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
	108	}
	109
	110	struct ipv6hdr;
	111
2566a509	112	static inline int IP6_ECN_set_ce(struct ipv6hdr *iph)
1da177e4 LT	113	{
1da177e4 LT	114	if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
2566a509	115	return 0;
92d9ece7	116	(__be32)iph \|= htonl(INET_ECN_CE << 20);
2566a509	117	return 1;
1da177e4 LT	118	}
	119
	120	static inline void IP6_ECN_clear(struct ipv6hdr *iph)
	121	{
92d9ece7	122	(__be32)iph &= ~htonl(INET_ECN_MASK << 20);
1da177e4 LT	123	}
1da177e4 LT	124
29bb43b4	125	static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
1da177e4	126	{
29bb43b4	127	dscp &= ~INET_ECN_MASK;
1da177e4 LT	128	ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
	129	}
	130
2566a509 TG	131	static inline int INET_ECN_set_ce(struct sk_buff *skb)
	132	{
	133	switch (skb->protocol) {
f3a7c66b	134	case cpu_to_be16(ETH_P_IP):
27a884dc	135	if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
eddc9ec5	136	return IP_ECN_set_ce(ip_hdr(skb));
2566a509 TG	137	break;
2566a509 TG	138
f3a7c66b	139	case cpu_to_be16(ETH_P_IPV6):
27a884dc	140	if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
0660e03f	141	return IP6_ECN_set_ce(ipv6_hdr(skb));
2566a509 TG	142	break;
	143	}
	144
	145	return 0;
	146	}
	147
1da177e4	148	#endif