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add ECN support in layer-3.

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- implement the tunnel egress rule in ip_ecn_egress() in ip_ecn.c.
   make ip{,6}_ecn_egress() return integer to tell the caller that
   this packet should be dropped.
 - handle ECN at fragment reassembly in ip_input.c and frag6.c.

Obtained from:	KAME
This commit is contained in:
Hajimu UMEMOTO 2003-10-29 15:07:04 +00:00
parent 3c0173a666
commit 59dfcba4aa
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=121684
10 changed files with 186 additions and 54 deletions
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37
sys/netinet/in_gif.c
View File

@ -161,10 +161,8 @@ in_gif_output(ifp, family, m)
/* version will be set in ip_output() */
iphdr.ip_ttl = ip_gif_ttl;
iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
if (ifp->if_flags & IFF_LINK1)
ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
else
ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
&iphdr.ip_tos, &tos);
/* prepend new IP header */
M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
@ -250,10 +248,12 @@ in_gif_input(m, off)
return;
}
ip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
else
ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos, &ip->ip_tos) == 0) {
m_freem(m);
return;
}
break;
}
#endif
@ -261,7 +261,8 @@ in_gif_input(m, off)
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6;
u_int8_t itos;
u_int8_t itos, oitos;
af = AF_INET6;
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
@ -269,13 +270,17 @@ in_gif_input(m, off)
return;
}
ip6 = mtod(m, struct ip6_hdr *);
itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
else
ip_ecn_egress(ECN_NOCARE, &otos, &itos);
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos, &itos) == 0) {
m_freem(m);
return;
}
if (itos != oitos) {
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
}
break;
}
#endif /* INET6 */

19
sys/netinet/ip.h
View File

@ -84,10 +84,11 @@ CTASSERT(sizeof (struct ip) == 20);
#define IPTOS_THROUGHPUT 0x08
#define IPTOS_RELIABILITY 0x04
#define IPTOS_MINCOST 0x02
/* ECN bits proposed by Sally Floyd */
#define IPTOS_CE 0x01 /* congestion experienced */
#define IPTOS_ECT 0x02 /* ECN-capable transport */
#if 1
/* ECN RFC3168 obsoletes RFC2481, and these will be deprecated soon. */
#define IPTOS_CE 0x01
#define IPTOS_ECT 0x02
#endif
/*
* Definitions for IP precedence (also in ip_tos) (hopefully unused)
@ -101,6 +102,16 @@ CTASSERT(sizeof (struct ip) == 20);
#define IPTOS_PREC_PRIORITY 0x20
#define IPTOS_PREC_ROUTINE 0x00
/*
* ECN (Explicit Congestion Notification) codepoints in RFC3168
* mapped to the lower 2 bits of the TOS field.
*/
#define IPTOS_ECN_NOTECT 0x00 /* not-ECT */
#define IPTOS_ECN_ECT1 0x01 /* ECN-capable transport (1) */
#define IPTOS_ECN_ECT0 0x02 /* ECN-capable transport (0) */
#define IPTOS_ECN_CE 0x03 /* congestion experienced */
#define IPTOS_ECN_MASK 0x03 /* ECN field mask */
/*
* Definitions for options.
*/

84
sys/netinet/ip_ecn.c
View File

@ -1,5 +1,5 @@
/* $FreeBSD$ */
/* $KAME: ip_ecn.c,v 1.11 2001/05/03 16:09:29 itojun Exp $ */
/* $KAME: ip_ecn.c,v 1.12 2002/01/07 11:34:47 kjc Exp $ */
/*
* Copyright (C) 1999 WIDE Project.
@ -55,6 +55,37 @@
#include <netinet6/ip6_ecn.h>
#endif
/*
* ECN and TOS (or TCLASS) processing rules at tunnel encapsulation and
* decapsulation from RFC3168:
*
* Outer Hdr at Inner Hdr at
* Encapsulator Decapsulator
* Header fields: -------------------- ------------
* DS Field copied from inner hdr no change
* ECN Field constructed by (I) constructed by (E)
*
* ECN_ALLOWED (full functionality):
* (I) if the ECN field in the inner header is set to CE, then set the
* ECN field in the outer header to ECT(0).
* otherwise, copy the ECN field to the outer header.
*
* (E) if the ECN field in the outer header is set to CE and the ECN
* field of the inner header is not-ECT, drop the packet.
* if the ECN field in the inner header is set to ECT(0) or ECT(1)
* and the ECN field in the outer header is set to CE, then copy CE to
* the inner header. otherwise, make no change to the inner header.
*
* ECN_FORBIDDEN (limited functionality):
* (I) set the ECN field to not-ECT in the outer header.
*
* (E) if the ECN field in the outer header is set to CE, drop the packet.
* otherwise, make no change to the ECN field in the inner header.
*
* the drop rule is for backward compatibility and protection against
* erasure of CE.
*/
/*
* modify outer ECN (TOS) field on ingress operation (tunnel encapsulation).
*/
@ -70,10 +101,18 @@ ip_ecn_ingress(mode, outer, inner)
*outer = *inner;
switch (mode) {
case ECN_ALLOWED: /* ECN allowed */
*outer &= ~IPTOS_CE;
/*
* full-functionality: if the inner is CE, set ECT(0)
* to the outer. otherwise, copy the ECN field.
*/
if ((*inner & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
*outer &= ~IPTOS_ECN_ECT1;
break;
case ECN_FORBIDDEN: /* ECN forbidden */
*outer &= ~(IPTOS_ECT | IPTOS_CE);
/*
* limited-functionality: set not-ECT to the outer
*/
*outer &= ~IPTOS_ECN_MASK;
break;
case ECN_NOCARE: /* no consideration to ECN */
break;
@ -82,8 +121,9 @@ ip_ecn_ingress(mode, outer, inner)
/*
* modify inner ECN (TOS) field on egress operation (tunnel decapsulation).
* the caller should drop the packet if the return value is 0.
*/
void
int
ip_ecn_egress(mode, outer, inner)
int mode;
const u_int8_t *outer;
@ -94,13 +134,28 @@ ip_ecn_egress(mode, outer, inner)
switch (mode) {
case ECN_ALLOWED:
if (*outer & IPTOS_CE)
*inner |= IPTOS_CE;
/*
* full-functionality: if the outer is CE and the inner is
* not-ECT, should drop it. otherwise, copy CE.
*/
if ((*outer & IPTOS_ECN_MASK) == IPTOS_ECN_CE) {
if ((*inner & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT)
return (0);
*inner |= IPTOS_ECN_CE;
}
break;
case ECN_FORBIDDEN: /* ECN forbidden */
/*
* limited-functionality: if the outer is CE, should drop it.
* otherwise, leave the inner.
*/
if ((*outer & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
return (0);
break;
case ECN_NOCARE: /* no consideration to ECN */
break;
}
return (1);
}
#ifdef INET6
@ -115,28 +170,31 @@ ip6_ecn_ingress(mode, outer, inner)
if (!outer || !inner)
panic("NULL pointer passed to ip6_ecn_ingress");
outer8 = (ntohl(*outer) >> 20) & 0xff;
inner8 = (ntohl(*inner) >> 20) & 0xff;
ip_ecn_ingress(mode, &outer8, &inner8);
*outer &= ~htonl(0xff << 20);
*outer |= htonl((u_int32_t)outer8 << 20);
}
void
int
ip6_ecn_egress(mode, outer, inner)
int mode;
const u_int32_t *outer;
u_int32_t *inner;
{
u_int8_t outer8, inner8;
u_int8_t outer8, inner8, oinner8;
if (!outer || !inner)
panic("NULL pointer passed to ip6_ecn_egress");
outer8 = (ntohl(*outer) >> 20) & 0xff;
inner8 = (ntohl(*inner) >> 20) & 0xff;
ip_ecn_egress(mode, &outer8, &inner8);
*inner &= ~htonl(0xff << 20);
*inner |= htonl((u_int32_t)inner8 << 20);
inner8 = oinner8 = (ntohl(*inner) >> 20) & 0xff;
if (ip_ecn_egress(mode, &outer8, &inner8) == 0)
return (0);
if (inner8 != oinner8) {
*inner &= ~htonl(0xff << 20);
*inner |= htonl((u_int32_t)inner8 << 20);
}
return (1);
}
#endif

8
sys/netinet/ip_ecn.h
View File

@ -1,5 +1,5 @@
/* $FreeBSD$ */
/* $KAME: ip_ecn.h,v 1.6 2001/05/03 14:51:48 itojun Exp $ */
/* $KAME: ip_ecn.h,v 1.8 2002/01/07 11:34:47 kjc Exp $ */
/*
* Copyright (C) 1999 WIDE Project.
@ -35,6 +35,9 @@
* http://www.aciri.org/floyd/papers/draft-ipsec-ecn-00.txt
*/
#ifndef _NETINET_IP_ECN_H_
#define _NETINET_IP_ECN_H_
#if defined(_KERNEL) && !defined(_LKM)
#include "opt_inet.h"
#endif
@ -45,5 +48,6 @@
#ifdef _KERNEL
extern void ip_ecn_ingress(int, u_int8_t *, const u_int8_t *);
extern void ip_ecn_egress(int, const u_int8_t *, u_int8_t *);
extern int ip_ecn_egress(int, const u_int8_t *, u_int8_t *);
#endif
#endif

17
sys/netinet/ip_input.c
View File

@ -1037,6 +1037,7 @@ ip_reass(struct mbuf *m, struct ipqhead *head, struct ipq *fp,
struct mbuf *t;
int hlen = ip->ip_hl << 2;
int i, next;
u_int8_t ecn, ecn0;
IPQ_LOCK_ASSERT();
@ -1085,6 +1086,22 @@ ip_reass(struct mbuf *m, struct ipqhead *head, struct ipq *fp,
#define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
/*
* Handle ECN by comparing this segment with the first one;
* if CE is set, do not lose CE.
* drop if CE and not-ECT are mixed for the same packet.
*/
ecn = ip->ip_tos & IPTOS_ECN_MASK;
ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
if (ecn == IPTOS_ECN_CE) {
if (ecn0 == IPTOS_ECN_NOTECT)
goto dropfrag;
if (ecn0 != IPTOS_ECN_CE)
GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
}
if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
goto dropfrag;
/*
* Find a segment which begins after this one does.
*/

10
sys/netinet6/ah_input.c
View File

@ -405,7 +405,10 @@ ah4_input(m, off)
}
ip = mtod(m, struct ip *);
/* ECN consideration. */
ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
if (!ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos)) {
ipsecstat.in_inval++;
goto fail;
}
if (!key_checktunnelsanity(sav, AF_INET,
(caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
@ -812,7 +815,10 @@ ah6_input(mp, offp, proto)
}
ip6 = mtod(m, struct ip6_hdr *);
/* ECN consideration. */
ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
if (!ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow)) {
ipsec6stat.in_inval++;
goto fail;
}
if (!key_checktunnelsanity(sav, AF_INET6,
(caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "

10
sys/netinet6/esp_input.c
View File

@ -371,7 +371,10 @@ esp4_input(m, off)
}
ip = mtod(m, struct ip *);
/* ECN consideration. */
ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
if (!ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos)) {
ipsecstat.in_inval++;
goto bad;
}
if (!key_checktunnelsanity(sav, AF_INET,
(caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
@ -723,7 +726,10 @@ esp6_input(mp, offp, proto)
}
ip6 = mtod(m, struct ip6_hdr *);
/* ECN consideration. */
ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
if (!ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow)) {
ipsec6stat.in_inval++;
goto bad;
}
if (!key_checktunnelsanity(sav, AF_INET6,
(caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
ipseclog((LOG_ERR, "ipsec tunnel address mismatch "

23
sys/netinet6/frag6.c
View File

@ -52,6 +52,8 @@
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet/in_systm.h> /* for ECN definitions */
#include <netinet/ip.h> /* for ECN definitions */
#include <net/net_osdep.h>
@ -151,6 +153,7 @@ frag6_input(mp, offp, proto)
int first_frag = 0;
int fragoff, frgpartlen; /* must be larger than u_int16_t */
struct ifnet *dstifp;
u_int8_t ecn, ecn0;
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
@ -349,6 +352,26 @@ frag6_input(mp, offp, proto)
goto insert;
}
/*
* Handle ECN by comparing this segment with the first one;
* if CE is set, do not lose CE.
* drop if CE and not-ECT are mixed for the same packet.
*/
ecn = (ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK;
ecn0 = (ntohl(q6->ip6q_down->ip6af_head) >> 20) & IPTOS_ECN_MASK;
if (ecn == IPTOS_ECN_CE) {
if (ecn0 == IPTOS_ECN_NOTECT) {
free(ip6af, M_FTABLE);
goto dropfrag;
}
if (ecn0 != IPTOS_ECN_CE)
q6->ip6q_down->ip6af_head |= htonl(IPTOS_ECN_CE << 20);
}
if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) {
free(ip6af, M_FTABLE);
goto dropfrag;
}
/*
* Find a segment which begins after this one does.
*/

28
sys/netinet6/in6_gif.c
View File

@ -168,11 +168,9 @@ in6_gif_output(ifp, family, m)
m_freem(m);
return ENETUNREACH;
}
if (ifp->if_flags & IFF_LINK1)
ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
else
ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
ip6->ip6_flow &= ~ntohl(0xff00000);
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
&otos, &itos);
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
if (dst->sin6_family != sin6_dst->sin6_family ||
@ -259,10 +257,12 @@ in6_gif_input(mp, offp, proto)
return IPPROTO_DONE;
}
ip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
else
ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos8, &ip->ip_tos) == 0) {
m_freem(m);
return IPPROTO_DONE;
}
break;
}
#endif /* INET */
@ -277,10 +277,12 @@ in6_gif_input(mp, offp, proto)
return IPPROTO_DONE;
}
ip6 = mtod(m, struct ip6_hdr *);
if (gifp->if_flags & IFF_LINK1)
ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
else
ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
ECN_ALLOWED : ECN_NOCARE,
&otos, &ip6->ip6_flow) == 0) {
m_freem(m);
return IPPROTO_DONE;
}
break;
}
#endif

4
sys/netinet6/ip6_ecn.h
View File

@ -36,6 +36,6 @@
*/
#ifdef _KERNEL
extern void ip6_ecn_ingress __P((int, u_int32_t *, const u_int32_t *));
extern void ip6_ecn_egress __P((int, const u_int32_t *, u_int32_t *));
extern void ip6_ecn_ingress(int, u_int32_t *, const u_int32_t *);
extern int ip6_ecn_egress(int, const u_int32_t *, u_int32_t *);
#endif