diff options
Diffstat (limited to 'freebsd/sys/netinet/ip_ecn.c')
| -rw-r--r-- | freebsd/sys/netinet/ip_ecn.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/freebsd/sys/netinet/ip_ecn.c b/freebsd/sys/netinet/ip_ecn.c new file mode 100644 index 00000000..97b32b2c --- /dev/null +++ b/freebsd/sys/netinet/ip_ecn.c @@ -0,0 +1,194 @@ +#include <freebsd/machine/rtems-bsd-config.h> + +/* $KAME: ip_ecn.c,v 1.12 2002/01/07 11:34:47 kjc Exp $ */ + +/*- + * Copyright (C) 1999 WIDE Project. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ +/* + * ECN consideration on tunnel ingress/egress operation. + * http://www.aciri.org/floyd/papers/draft-ipsec-ecn-00.txt + */ + +#include <freebsd/sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <freebsd/local/opt_inet.h> +#include <freebsd/local/opt_inet6.h> + +#include <freebsd/sys/param.h> +#include <freebsd/sys/systm.h> +#include <freebsd/sys/mbuf.h> +#include <freebsd/sys/errno.h> + +#include <freebsd/netinet/in.h> +#include <freebsd/netinet/in_systm.h> +#include <freebsd/netinet/ip.h> +#ifdef INET6 +#include <freebsd/netinet/ip6.h> +#endif + +#include <freebsd/netinet/ip_ecn.h> +#ifdef INET6 +#include <freebsd/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). + */ +void +ip_ecn_ingress(int mode, u_int8_t *outer, const u_int8_t *inner) +{ + + if (!outer || !inner) + panic("NULL pointer passed to ip_ecn_ingress"); + + *outer = *inner; + switch (mode) { + case ECN_ALLOWED: /* ECN allowed */ + /* + * 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 */ + /* + * limited-functionality: set not-ECT to the outer + */ + *outer &= ~IPTOS_ECN_MASK; + break; + case ECN_NOCARE: /* no consideration to ECN */ + break; + } +} + +/* + * modify inner ECN (TOS) field on egress operation (tunnel decapsulation). + * the caller should drop the packet if the return value is 0. + */ +int +ip_ecn_egress(int mode, const u_int8_t *outer, u_int8_t *inner) +{ + + if (!outer || !inner) + panic("NULL pointer passed to ip_ecn_egress"); + + switch (mode) { + case ECN_ALLOWED: + /* + * 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 +void +ip6_ecn_ingress(int mode, u_int32_t *outer, const u_int32_t *inner) +{ + u_int8_t outer8, inner8; + + if (!outer || !inner) + panic("NULL pointer passed to ip6_ecn_ingress"); + + inner8 = (ntohl(*inner) >> 20) & 0xff; + ip_ecn_ingress(mode, &outer8, &inner8); + *outer &= ~htonl(0xff << 20); + *outer |= htonl((u_int32_t)outer8 << 20); +} + +int +ip6_ecn_egress(int mode, const u_int32_t *outer, u_int32_t *inner) +{ + u_int8_t outer8, inner8, oinner8; + + if (!outer || !inner) + panic("NULL pointer passed to ip6_ecn_egress"); + + outer8 = (ntohl(*outer) >> 20) & 0xff; + 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 |