mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Eric Dumazet](/assets/img/avatar_default.png)
INET_ECN_encapsulate() is better understood if we can read the official statement. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
148 lines
3.3 KiB
C
148 lines
3.3 KiB
C
#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
|